CA2106304A1

CA2106304A1 - Radiation curable vinyl/silicone release coating

Info

Publication number: CA2106304A1
Application number: CA002106304A
Authority: CA
Inventors: Mieczyslaw H. Mazurek; Steven S. Kantner; Albert I. Everaerts
Original assignee: Individual
Current assignee: 3M Co
Priority date: 1991-03-20
Filing date: 1992-03-13
Publication date: 1992-09-21
Also published as: JPH06506014A; DE69208085T2; EP0583259B1; US5527578A; WO1992016590A1; DE69208085D1; EP0583259A1

Abstract

The invention relates to a radiation curable release coating composition comprising: a) from about 0.05 to about 25 percent by weight of polymer selected from the group consisting of polymers falling within general formula (I) and mixtures thereof, wherein: X
are monovalent moieties having ethylenic unsaturation which can be the same or different; Y are divalent linking groups which can be the same or different; D are monovalent moieties which can be the same or different selected from the group consisting of hydrogen, an alkyl group of 1 to about 10 carbon atoms, aryl, and substituted aryl; R are divalent hydrocarbon groups which can be the same or different; R1 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl; R2 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl.

Description

WO 92/16590 PCI'/US92/02021 3 0 ~

Ri~DIATION CIJR2~BLE VINYL/8ILICONE RELE:A~E COATING

Field of the Invention This invention relates to a radiation curable vinyl-silicone release coating composition, to a vinyl-silicone release coating, and to substrates coated with the release coating.

10 Backqround of the Invention Polymeric coatings having specific release properties toward adhesives are widely used. Silicones such as polydimethylsiloxanes, polymers containing predominantly dimethylsiloxane units, are frequently 15 employed as release coatings for products such as labels or large adhesive-coated sheets sold in other than roll form. Notwithstanding a relatively high cost, such polymers are used for these applications because of their capability of providing coatings of 20 very low release values, e.g., in the range 0.4-1.6 N/lOo mm width. The term "release value" refers to the amount of force required to peel a strip of pressure-sensitive adhesive tape from a surface.
Polydimethylsiloxanes are less useful, 25 however, as release coatings on the back surface of adhesive tape, because their low release force can cause roll instability and handling problems. Such a coating on the back surface of a tape is often referred to as a low adhesion backsize or LAB. LABs for tapes 30 in roll form ideally exhibit release values toward the adhesive in the range of about 6-35 N/100 mm width.
Polymers with higher release values make it increasingly difficult to use the tape, and delamination of the adhesive from the substrate often 35 can result. Many non-silicone polymers, e.g., certain types of polyurethanes, find use as low adhesion backsizes for pressure sensitive adhesive tapes because WO92/16590 PCT/US92~02021 3 ~ 2 of their much higher release value than that of the polydimethysiloxanes, typically greater than 20 N/lOo mm width.
For products such as tapes and liners, ;5 coatings having specific release properties toward adhesives, which are intermediate between thase of the polydimethysiloxanes and conventionally used non-silicone LAB coatings have been highly desired.
U.S. Patent No. 4,728,571 (Clemens et al.) (assigned to lO the assignee of the present case) provides such coatings through use of polysiloxane-grafted vinyl ;copolymers. Controlled release is provided over a broad range of values via variation in the molecular weight and the number of polysiloxane grafts. Since 15 the polysiloxane is chemically anchored to the backbone of the copolymers, such coatings avoid the migration problems common in prior art systems, which result in unstable release properties or in adhesive contamination. Also, since the polysiloxane 20 constitutes only a minor weight fraction of the coating teven at low release values suitable for release liner applications), these copolymer compositions provide a potential cost savings over conventional 100% silicone release compositions and numerous blends. However, 25 these coatings are solvent-borne.
Rising energy costs and concern over both environmental pollution and hazards to worker health have contributed to a need for development o~
solvent-free (or at least high solids), 30 radiation-curable release coatings. Thus, a solventless, radiation-curable release coating composition capable of providing controlled release throughout the intermediate region suitable for LABs is highly desired. Ideally, from a cost perspective, such ~A~
35 a composition should be low in silicone content. Most systems which have been developed, however, contain fairly high levels of silicone.

- , , W092/16590 P~T/USg2/0202~
- 3 - ~ 9 ~ 3 ~ ~
U.S. Patent No. 4,678,846 (Weitemeyer et al.) describes acrylate or methacrylate ester modified organopolysiloxane mixtures, which can be used by themselves or in admixture with other unsaturated 5 compounds as radiation-curable coating compositions to obtain "good abhesive properties towards adhesives."
EP 58909 (Herberts GMBH), Published September 1, 1982, discloses a radiation-curable composition containing liquid polyorganosiloxane having 10 unsaturated groups, photosensitizer, and, optionally, vinyl monomer. The composition is used for the production of release coatings and is especially useful for coating paper.
U.S. Patent No. 4,558,082 (Eckberg) describes 15 photocurable acrylated silicone polymers prepared by reacting limoneneoxide-functional silicones with acrylic acid or a substituted acrylic acid in the presence of a catalyst. A preferred use of the compositions is as release coatings for paper, and it 20 is disclosed that the compositions exhibit improved anchorage to substrates, such as superc~lendered kraft paper, when up to 20% by weight of N-vinylpyrrolidone is included.
U.S. Patent No. 4,606,933 (Griswold et alO) 25 describes radiation-polymerizable acrylate-functional organopolysiloxanes and their use as release coatings.
It is stated that it may be desirable to add a diluent to the compositions to aid in their application to a substrate. The diluent, preferably a reactive diluent, 30 such as an acrylate ester, can be employed at levels up to about 30% by weight of the radiation-curable composition.
U.S. Pat nt No. 4,783,490 tEckberg et al.
;- discloses W -curable compositions comprising 35 mercapto-substituted silicon compounds, reactive co-compounds such as multifunctional acrylates, and photoinitiator. Reactive diluents, such as WO92~16590 PCT/US9~02021 ~io~30i~ .

monofunctional acrylates, may optionally be added to control viscosity, although generally it is not desirable to add more than about 25~ by weight. The compositions may be formulated for application to paper 5 substrates as a release coating.
EP 159683 (DeSoto Inc.), Published October 30, 1985, describes an electron beam-cur2lble liquid release coating composition comprising from 60 to 95 parts functionalized organopolysiloxane, e.g., acrylated 10 organopolysiloxane, from 3 to 25 parts of a polyester, e.g., a multifunctional acrylate, and from 1 to 10 parts acid, e.g., acrylic acid. The composition can optionally further include from 1 to 15 parts of a monoacrylate or monomethacrylate monomer to adjust the 15 hardness.
U.S. Patent No. 4,608,270 (Varaprath) discloses coating compositions comprising polydiorganosiloxanes which contain one or more acryloylamino-substituted hydrocarbon radicals.
These compositions are radiation-polymerizable to form release coatings and may optionally include polymerizable vinyl monomers.
U.S. Patent Nos. 4,576,999 and 4,640,967 (Eckberg) describe epoxy- and/or acrylic-functional 25 polysiloxanes which, when combined with appropriate catalysts, form ultraviolet radiation-curable release coating compositions. It is stated that cure performance and substrate adhesion may be enhanced by the addition of up to 10 parts of an aliphatic epoxy 30 monomer for every 10 parts epoxysilicone fluid.
U.S. Patent No~ 4J070l526 (Colquhoun et al.) discloses radiation-curable compositions comprising .
mercaptoalkyl-substituted polydiorganosiloxane fluid, from about 1 to 50 parts by weight vinyl monomer (per 100 parts of the fluid), and, optionally, a methylvinylpolysiloxane. Upon curing, controllably variable release of adhesives is said to be provided.

WO92/16~90 PCT/US92/02021 2~ ~30~

Release data for compositions containing greater than 50 parts of vinyl monomer (see Ta~le I of U.S.
4,070,526) indicates that release is not reliably obtained at these higher levels, i.e., at lower levels 5 of silicone.
A few systems have been developed which reliably provide relaase at low silicone levels.
However, these systems suffer from the disadvantage of being inhomogeneous mixtures which, although acceptable 10 for paper substrates, are unsuitable for use on polymeric films due to pxoblems with dewetting. In addition, such inhomogeneous mixtures are unsuitable for use in an electrospray coating process due to problems with phase separation.
U.S. Patent No. 4,016,333 (Gaske et al.) describes radiation-polymerizable release coating compositions (typically for paper substrates) in the form of nonaqueous emulsions of from 2 to about 50 weight percent o~ a liquid alkyl hydrogen polysiloxane 20 in a radiation-polymerizable polyethylenically unsaturated liquid, preferably a polyacrylate. It is stated that an emulsi~ying agPnt can be used to promote long-term emulsion stability and that the emulsion can also be ayitated as it is applied.
U.S. Patent No. 4,201,808 (Cully et al.) discloses radiation-curab}e release coating compositions, most commonly for paper substrates, comprising from about 10 to 90 weight percent (based on the total weight of the composition) of an 30 organopolysiloxane containing ~n average of at }east one acryloxy and/or methacryloxy group per molecule, from about 90 to 10 weight percent of a low molecular weight acrylated polyol crosslinking agent, and from 0 to about 10 weight percent of a photosensitizer. To 35 adjust viscosity, the compositions can also contain .f.rom o. 01 to ahout 30 weight percent of a reactive . ~ such as a liquid organic monoacrylate ester.

W092/16~90 PCT/US92/02021 2~a~
It is stated that the composition components may undergo a degree of separation during storage, making mild agitation or mixing necessary just prior to use.
WO 88/07931 (Avery), Published October 20, 1988, describes tailorable, radiation--curable release surfaces formed by curing a composition which is a dispersion of a reactive silicone (reactive group-containing dimethyl siloxane polymers present in an amount of from 1 to 30% by weight of the 10 composition) as a discontinuous phase in a continuous phase of a reactive resin (comprising from about 50 to 100~ by weight reactive oligomer and from ahout 50 to o% by weight reactive monomer based on the total weight of resin). The reactive monomer, preferably a 15 multifunctional acrylate, is used to control viscosity.
The release coatings are said to achieve preferential concentration of the silicone at the surface by the partial or total incompatibility of the silicone and the resin. The quality of release is initially poorer 20 and is stated to increase or improve with time.
A need exists for a solventless, radiation-curable release coating composition of substantially reduced silicone content which upon curing provides controllable, reproducible levels of 25 release in the intermediate region suitable for LABs, which wets both paper and polymeric films well and cures to firmly anchored coatinys, which has utility for a broad range of PSA types, and which does not adversely affect the tack and peel properties of PSAs 30 with which they come in contact.
A need also exists ~or a coating which possesses the desired level of release immediately upon curing, thus being suitable for integrated manufacture of PSA-coated labels and tapes, e.g., wherein both the 35 PSA and release coating are coated during the same manufacturing process.

W092/~6590 PCT/US92/02021 2~ a~3~
A need also exists for a radlation-curable release coating composition which is suitable for application via an electrospray coa~ing process.

5 Summary of the Invention It has been discovered that these needs can be met through use of a homogeneous composition comprising small amounts of telechelic organopolysiloxanes in combination with both multifunctional and 10 monofunctional vinyl, preferably acrylatP, monomers.
The organopolysiloxanes contain terminal groups which, in addition to being reactive, are also capable of intermolecular hydrogen bonding.
More specifically, this invention provides a 15 radiation-curable release coating composition comprising (a) from about 0.05 to about 25 percent by weight of polymer selected from the group consisting of polymers falling within the general formula:
D Rl R3 Rl D
X--Y--N--R--S i ~0--( S i ~ ) n--~ S i--R--N Y X
R2 ~ 1 2 and mixtures thereof, wherein X are monovalent moieties having ethylenic unsaturation which can be the same or 30 different;
Y are divalent linking groups which can be the same or different;
D are monovalent moieties which can be the same or different selected from the group 35 consisting of hydrogen, an alkyl group of 1 to about 10 carbon atoms, aryl, and substituted aryl;
R are divalent hydrocarbon groups which can be the same or different;

WO92/16590 PCT/US~2/02021 2 ~

Rl are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;
R2 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;
R3 are monovalent moieties which can be 10 the same or different selected from the group consisting of alkyl, substituted alkyl, vinyl, aryl, and substituted aryl;
R4 are monovalent moieties which can be the same or different selected from the group 15 consisting of alkyl, substituted alkyl, vinyl, aryl, and substituted aryl; and n is an integer of about 25 to about 750;
(b) from about 5 to about 60 percent by weight of one or more multifunctional free radically : 20 polymerizable vinyl monomers copolymerizable with said polymer; and (c) from about 25 to about 95 percent by weight of one or more monofunctional ~ree radically polymerizable vinyl monomers copolymerizable with said 25 polymer;
wherein said weight percentages are based upon the total weight of said radiation-curable release coating composition.
: The release coating composition can further 30 comprise an amount of free radical initiator sufficient to initiate polymerization of the compositi,on.
This invention also provides a sheet coated on -;
at least a portion of at least one major surface with the above-described release coatiny composition, as -.
35 well as a cured version thereof.

WO92/16590 PCT/~S92/02021 - 9 - ~ t ~
Detalled Description_of the Invention Telechelic silicones suitable for use in the release coating composition of the invention are similar to those represented by Formula I above and 5 disclosed in U.S. Serial No. 07/411,410, assigned to the assignse of the present case. The telechelic silicones can be prepared by reaction of an organopolysiloxane diamine, represented by the general formula D Rl R3 Rl D
H-N-R-Si - (O--Si -)n--o-si-R-N-H II

where n, R, Rl, R2, R3, R~, and D are as defined above, with an electrophile having ethylenic unsaturation, X, 20 and such other functionality that, upon reaction with the organopolysiloxane diamine, not only a terminal X
group but also an amide, substituted amine, urea, or urethane moiety is provided. Examples of the types of functionality required in such electrophilic compounds 25 include acid halide, acid anhydride, cyclic anhydride, and azlactone, each of which provides an amide moiety upon reaction with the diamine, epoxy or acrylate, each of which provides a substituted amine moiety, and isocyanate, which provides a urea moiety.

Preferably, X comprises CH=C-, wherein Rs is selected from the group consisting of hydrogen and 35 -COOH and R5 is selected from the group consisting of hydrogen, methyl, and -CH~COOH. Most preferably, R5 : comprises hydrogPn and R6 is selected from the group consisting of hydrogen and methyl. The reaction can be carried out at a temperature of about -10C to about 50C and under atmospheric pressure by combining the W092J16~90 PCT/US92tO2021 diamine and the electrophile while providing - appropriate mixing. A nonreactive organic solvent can be used as a diluent but is not necessary, and the two reactants can be charged into the reaction vessel in 5 any order. Alternatively, an organopolysiloxane diamine according to Formula II above can be reacted first with a compound containing two electrophilic groups, e.g., a diisocyanate, (or with a compound such as phosgene) and the resultant product reacted in a 10 second step with a nucleophile, e.g., an amine or an alcohol, to provide terminally difunctional silicone according to Formula I. When an alcohol such as hydroxyethyl acrylate, hydroxyethyl methacrylate, or hydroxypropyl methacrylate is utilized, the product 15 organopolysiloxane contains urethane moieties.
The divalent linking group Y is generated upon reaction of the electrophile with the diamine and is chosen so as to activate the ethylenically unsaturated monovalent X groups towards free radical 20 polymerization, particularly free ra~ical copolymerization with the vinyl monomer(s) of element (b). The Y group accomplishes this by changing the electron density of X. Y is selected from, for example, the group of structures containing aromatic 25 moieties which when bound to X yield vinyl pyridinyl or - styrenic-type functionalities; structures containing carboxyl moieties which when bound to X at the oxygen side yie}d vinyl ester and isopropenyl ester-type functionalities; structures containing carboxamide 30 moieties which when bound to X at the nitrogen side yield N-vinyl amide and N-isopropenyl amide-type functionalities; and structures containing carboxamide -~
moieties which when bound to X at the carbonyl side yield acrylamide, methacrylamide, and maleimide-type functionalities. A special example of this final structure is when Y comprises a carbonyl group which depending on the nature of X can result in acrylamide, methacrylamide, beta-carboxy acrylamicle, or maleimide functionality.
Organopolysiloxane diamines useful in the 5 preparation of the telechelic silicones can be prepared in various ways. In a first method, an organopolysiloxane terminated at both chain ends with hydroxy groups, as represented by the general formula Rl3 HO--( Sl~) n--H III

where R3, R4, and n are as defin~d above, can be subjected to a condensation reaction with a compound represented by the general formula D Rl H-N-R-Si-Q IV
l2 where D, R, Rl, and R2 are as defined above and Q is a hydroxy group or a hydrolyzable group. A second method involves the reaction of a cyclic organosiloxane, represented by the general formula - (--si~) V
tl where R3 and R4 are as defined above and k is a positive integer of 3 to 8, with an amine functional endblocker, 40 represented by the general formula ~3 ~ - 12 - ~~

D Rl Rl D
H-N-R-Si-o-Si-R-N-H VI
l2 l2 where D, R, Rl, and R2 are as defined above, in the presence of a ~asic catalyst, such as 10 tetramethylammonium hydroxide or triorganosilanolate.
A third method, a modification of the second, is preferred and involves running the reaction in two stages utilizing a minimum amount of an essentially anhydrous amino alkyl functional silanolate catalyst 15 represented by the general formula D R
H-l-R-Si-o M* VII

where D, R, R~, and R2 are as defined above and M+ is a cation selected from the group consisting of K~, Na~, 25 and tetraorganoammonium ion, with N(CH3)4~ being preferred. In the first stage of the reaction, a low molecular weight organopolysiloxane diamine, represented by the general formula D Rl R3 Rl D
I I l l I
H-N-R-Si ~ o-Si -)X--o-Si-R-N-H VIII
l2 l4 l2 where D, R, Rl, R2, R3, and R4 are as defined above and x is an integer of about 4 to about 40, is prepared by reacting an amine functional disiloxane endblocker represented by Formula VI above with a cyclic 40 organosiloxane represented by Formula V in the presence of a catalytic amount of essentially anhydrous amino W092/16~90 PCT/US92/02021 21 ~30;1 alkyl functional silanolate represented by Formula VII
in an inert atmosphere, such as nitrogen or argon. The preferred catalyst for use in this reaction is 3-aminopropyl dimethyl tetramethylammonium silanolate, 5 which can be obtained as a crystalline solid from the reaction of one molar equivalent of 1,3-bis(3-aminopropyl) tetramethyldisiloxane with two molar equivalents of tetramethylammonium hydroxide pentahydrate in tetrahydrofuran under reflux, followed 10 by drying under vacuum (0.1/mmHg) for five hours at 60OC. The amount of catalyst employed should be less than about 0.05 percent, preferably about 0.005 to about 0.03 percent, by weight, of the resultant organopolysiloxane diamine of Formula II. The reaction 15 can be carried out in bulk at a temperature of 80-90C, ; and under these conditions is usually complete in about 0.5-2 hours, as judged by substantially complete disappearance of the endblocker in the reaction mixture as determined by vapor phase chromatography. The 20 second stage oE the reaction involves the slow addition of the remainder of the cyclic organosiloxane required to achieve the desired molecular weight. This addition is preferably carried out dropwise at such a rate that the cyclic organosiloxane is incorporated into the 25 polymer about as fast as it is added, usually in about five to seven hours at the reaction temperature of 80-90C. By utilizing this two-stage method with a minimum amount of essentially anhydrous catalyst, organopolysiloxane diamines represented by Formula II
30 above can be consistently prepared having excellent difunctionality with little contamination from monofunctional and nonfunctional polysiloxane impurities.
Preferred organopolysiloxane diamines for use 35 in preparing the telechelic silicones of this invention are those for which n is an integer of about 50 to about 270, R is selected from the group consisting of W092J~6590 PCT/VS92tO2021 ~ 14 -alkylene of one to about twelve carbon atoms, alkylarylene, and arylene, Rl and R2 are independently selected from the group consisting of alkyl of one to about twelve carbon atoms, substituted alkyl of one to 5 about twelve carbon atoms, aryl, and substituted aryl, R3 and R4 are at least 50% methyl wherein any remaining R3 and R4 groups are independently selected from the group consisting of alkyl of about two to about twelve carbon atoms, substituted alkyl of about two to about lO twelve carbon atoms, vinyl, aryl, and substituted aryl, and D is hydrogen. Such a range of molecular weights provides good release performance yet good compatibility with the vinyl monomers. Most preferably, n is an integer of about 50 to about 200, R
is alkylene of one to about twelve carbon atoms and Rt, R2, R3, and R4 are methyl, as polydimethylsiloxanes are the most readily available, the most inert, and provide the lowest release value for a given weight percentage of silicone.
Examples of electrophiles suitable for reaction with organopolysiloxane diamines to produce the telechelic silicones of the invention include but are not limited to isocyanatoethyl methacrylate, alkenyl azlactones such as vinyl dimethyl azlactone and isopropenyl dimethyl azlactone, m-isopropenyl-~, ~-dimethyl benzyl isocyanate, glycidyl methacrylate, acryloyl ethyl carbonic anhydride, and maleic anhydride, multifunctional acrylates such as hexanediol diacrylate and trimethylolpropane triacrylate. Some 30 electrophiles, e.g., isocyanatoethyl methacrylate, are commercially available, and others can be prepared via literature methods. Alkenyl azlactones and their -_ preparation are described in U.S. Patent No. 4,777,276 (Rasmussen et al.). According to Rasmussen, the ~.
35 synthesis of the azlactones has been fully discussed in the literature by (a) Y. Iwakura, F. Toda, and Y. Torii, Tetrahedron, 23, 3363 (1967); (b) K. Hubner, WO92/16590 P~T/US92/02021 ~ 9~3~

F. Kollinsky, G. Mardert, and H. Pennewiss, Angew, Makromol. Chem. 11, 109 (1970); (c) L. D. Taylor and T. E. Platt, J. Polym. Sci. Polym. Letters Edit., 7, 597 (1969j; partisularly with regard to the 5-membered 5 rings, the 2-aklenyl-1,3-oxazolin-5-ones. Typically, an amino acid such as 2-aminobutyric acid is reacted with the acylateing agent (e.g., (meth)acryloylchloride or (meth)acrylic anhydride) in the presence of a base (e.g., aqueous sodium hydroxide) to produce the lo acylated amino acid. Cyclization to the azlactone is then accomplished in the presence of a dehydrating agent (e.g., acetic anhydride, ethyl chloroformate, or dicyclohexylcarbodiimide). Acryloyl ethyl carbonic anhydride can be prepared from ethyl chloroformate and 15 acrylic acid by the method of R. Hatada and H. Kondo given in Bull. Chem. Soc. Japan. 41 (10), 2521 (1968).
The preparation of acryloyl ethyl carbonic anhydride according to Hatada is set forth in the Examples.
Conditions for reaction of amines with multifunctional 20 acrylates in a Michael addition reaction are described in U.S. Patent No. 4,603,086 and involve slow addition of the amine to at least an equimolar amount of the multifunctional acrylate at temperatures between room temperature and 100C, optionally adding a solvent to 2s form a uniform solution. Preferred electrophiles are those which react under relatively mild conditions with the organopolysiloxane diamine and include those selected from the group consisting of isocyanatoethyl methacrylate, m-isopropenyl-~,~-dimethylbenzyl 30 isocyanate, vinyl dimethyl azlactone, and acryloyl ethyl carbonic anhydride.
A preferred telechelic silicone for use in the composition of the invention comprises the organopolysiloxane of Formula I wherein ~ 3~ - 16 -X comprises CH2=C-; Y comprises -COCH2CH2N-C- ; D=H; R comprises -CH2CH2CH2-; and R1, R2, R3 and R4 each comprise -CH3.
Another preferred organopol~ysiloxane comprises lO the organopolysiloxane of Formula I wherein X comprises CH2=CH-; Y comprises -C - N - C - C-; D=H; R comprises ` 15 -CH2CH2CH2-; and Rl, R2, R3 and R4 each comprise -CH3.
Another preferred organopolysiloxane comprises the organopolysiloxane of Formula I wherein X comprises O
CHt=CH-, Y comprises -C-, D=H, R comprises -CH2CH2CH2-;
and R~, R2, R3 and R4 each comprise -CH3.
Another preferrPd organopolysiloxane comprises 25 the organopolysiloxane of Formula I wherein X comprises CH3 o ~ CH3 0 CH2=C - ; Y comprises -C - N - C- C- ; D=H; R comprises -CH2CH2CH2-; and R1, R2, R3 and R4 each comprise -CH3.
. Another preferred organopolysiloxane comprises the organopolysiloxane of Formula I wherein X comprises CH2=C- ; Y comprises ~C--N--C--; D=H ; R comprises CH3 .
-CH2CH2CH2-; and Rl, R2, R3, and R4 each comprise -CH3.
Monofunctional free radically polymerizable vinyl monomers suitable for use in the release coating composition o~ this invention are those which can serve as reactive diluents for the telechelic silicones, thus WO92~16~0 P~T/US92/~20~1 - 17 - 2~3~
providing homogeneous compositions which ensure good silicone co-cure. Representative examples of such monomers include, but are not limited to those selected from the group consisting of styrene, butyl acrylate, 5 hexyl acrylate, benzyl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-ethoxyethyl acrylate, isooctyl acrylate, isononyl acrylate, isodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, octaclecyl acrylate, butyl methacrylate, isobornyl methacrylate, isooctyl 10 methacrylate, tetrahydrofurfuryl acrylate, and mixtures thereof. Such monomers are known in the art, and many are commercially available. Preferred monofunctional vinyl monomers are acrylic monomers ox mixtures containing predominantly (i.e., about 50 to about 100 15 mole percent) acrylic monomer due to their rapid cure rate. Most preferred monomers comprise monomers selected from the group consisting of acrylates of non-tertiary alcohols comprising from about four to about twelve carbon atoms, such as those selected from 20 the group consisting of cyclohexyl acrylate, iFobornyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and mixtures thereof, due to their good solvating ability, high reactivity, and low volatiiity.
Polar monomers including but not limited to those selected from the group consisting of acrylic acid, N-vinyl pyrrolidone, hydroxyethyl acrylate, methacrylic acid, and mixtures thereof, may be included in the composition to promote adhesion of the release 30 coating to various substrates. Such monomers are best utilized at low levels, e.g., at levels up to about 15%
by weight, typically about 1 to about 15~ by weight, preferably about 5 to about 10% by weight, based upon the weight of the monofunctional free radically 35 polymerizable vinyl monomer in order to avoid reducing the homogeneity of the composition.

- ~8 -Representative examples of multifunctional vinyl monomers useful in the release coating composition include, but are not limit:ed to, divinyl benzene, and acrylates, methacrylates, and 5 beta-acryloxypropionates of 1,6-hexanediol, trimethylolpropane, 1,4-butanediol, t~ and tetraethylene glycol, pentaerythritol, their ethoxylated and propoxylated analogs, and mixtures thereof. Such ~onomers are included :in the composition 10 to ensure rapid cure rates and a tightly crosslinked coating. Preferred multifunctional monomers include acrylates of 1,6-hexanediol, trimethylolpropane, their ethoxylated and propoxylated analogs, and mixtures thereof, due to low cost, good reactivity, and lower 15 silicone incompatibility.
The radiation curable release coating composition of the invention can be prepared by combining from about 0.05 to about 25 percent, preferably from about 0.1 to about 15 percent, and most 20 preferably from about 0.2 to about 10 percent by weight, of one or more telechelic silicones represented by Formula I above, from about 5 to about 60 percent, preferably from about 5 to about 35 percent, and most preferably from about 10 to about 30 percent by weight 25 of one or more multifunctional vinyl monomers, and from about 25 to about 95 percent, preferably about 55 to about 95 percent by weight of one or more monofunctional vinyl monomers; wherein the weight percentages are based upon the total weight of the 30 radiation curable release coating composition.
Preferred multifunctional vinyl monomers have 2 to 6 functional groups. Most preferred multifunctional monomers have 2 to 3 functional groups. Flatting agent(s), pigment(s), small amounts of solvent(s), or 35 other additives can be included in the composition as needed for a particular application.

.

WO92/16590 PCT/US92/~2021 L~

The composition can be coated or sprayed on a substrate and then cured by exposure to electron beam, visible, or ultraviolet radiation.
The release coating composition can be applied 5 to suitable substrates by any conventional means such as by brushing, dipping, spraying, or by coating techniques such as offset gravure or transfer roll coating. The composition can also be applied in an electrospray coating process, as described in U.S.
lo Patent No. 4,748,043. The release coating composition is particularly well-suited for electrospray coating because it possesses a low surface tension and very low viscosity, which allows not only for generation of the f ine droplets which characterize the electrospray 15 process, but also ensures that once deposited on the substrate the droplets will rapidly and completely spread to form a continuous coating prior to cure. In most cases, it is desirable when electrospray coating to include in the composition a small amount of 20 conductivity enhancing additive, such as methanol, (i.e., about 0.1 to about 5 percent by weight based upon the total weight of the release coating composition, preferably about 0.05 to about 2 percent by weight) in order to obtain a wide ~low rate window 25 which will enable the deposition of useful coating thicknesses (500 to 3000 Angstroms) at industrially viable line speeds (50 to 1000 m/min). When coating by methods other than electrospray, or when coating porous substrates such as paper, the viscosity of the 30 composition is preferably increased prior to coating by addition of viscosity enhancer such as a copolymer comprising polar and nonpolar monomers or by a degree of prepolymerization of the monofunctional vinyl monomer(s) before addition of the multifunctional 35 monomer(s) and telechelic silicones(s).

W092/15590 PCT/US92tO2~2 ;2,~ & ~ 20 The release coating composition of this invention can be used as a coating on a substrate, which can be a sheet, a fiber, or a shaped object.
However, the preferred substrates are lhose used for 5 pressure-sensitive adhesive products. The composition can be applied to at least a portion of at least one major surface of suitable flexible or inflexible backing materials and then cured. Use~Eul flexible backing materials include paper, plastic films such as 10 poly(propylene), poly(ethylene), poly(vinyl chloride), poly(tetrafluoroethylene), polyester Ce.g., poly(ethylene terephthalate)], polyimide film such as DuPont's Kapton~, cellulose acetate, and ethyl cellulose, although any surface requiring release 15 toward adhesives can be used. Backings can thus also be of woven fabric formed of threads of synthetic or natural materials such as cotton, nylo~, rayon, glass, or ceramic material, or they can be o~ nonwoven ~abric such as air-laid webs of natural or synthetic fibers or 20 blends of these. In addition, sultable backings can be formed of metal, metallized polymeric film, or ceramic sheet material. Primers can be utilized, but they are not always necessary.
Curing of the hybrid release coating should be 25 carried out in as oxygen-free an environment as possible, e.g., in an inert atmosphere such as nitrogen gas. When visible or ultraviolet radiation is used for curing, the composition also contains photoinitiator.
Suitable photoinitiators include but are not limited to 30 those selected from the group consisting of benzoin ethers, benzophenone and derivatives thereof, acetophenone derivatives, camphorquinone, and mixtures thereof. Photoinitiator is generally used at a concentration of from about 0.1 percent to about 5 - 35 percent by weight of the total weight of the release coating composition.

W~92/16590 PCT/~S92/02021 7~ a~a~

The release coating composition of this invention provides coatings which possess the desired level of release immediately upon curing. Thus, the composition is suitable for use in the integrated manufacture of PSA-coated labels and tapes. The composition is of relatively low silicone content, yet reliably and reproducibly provides thle intermediate levels of release needed for L~B performance. The specific level of release provided upon curing can bP
lo controllably varied through variation in the weight percentage and molecular weight of telechelic silicones(s) included in the composition. The composition wets both paper and polymeric films well due to its homoqeneity, which apparently derives from 15 the use of only small amounts of silicone, the use of telechelic silicone(s) having polar endgroups compatible with the vinyl components, and the use of only small amounts of the highly polar multifunctional vinyl monomer(s). The use of difunctional, rather than 20 monofunctional, silicone(s) ensures a high degree of co-cure of the silicone and vinyl components, and, thus, release coatings obtained via cure of the composition of the invention contain little or no free silicone to adversely affect the tack and peel 25 properties of PSAs which come in contact with them.
The release coating composition of the invention cures rapidly to firmly anchored, highly crosslinked! solvent resistant, tack-free coatings which have utility for a broad range of PSA types such as natural rubber-based, 30 acrylic, and other synthetic, film-forming elastomeric materials.

- Exam~les : The following description includes exemplary 35 preparations of copolymerizable telechelic silicones and numerous radiation-curable release coating compositions prepared with them in combination with WO92/16~90 PCT/US92/02021 ? 1 ~

monofunctional and multifunctional vinyl monomers. The description also includes the exemplary preparation of flexible substrates coated with the above described release coating composition, radiation curing of said 5 coating, and evaluation of immediate release properties and aged release properties of the cu:red coating. The monofunctional and multifunctional monomers used in these examples are set forth hereinafter in Table I.
The pressure sensitive adhesive (PSA) coated tapes used in testing the release performance of these coatings are characterized in Table II. All parts and percentages in the examples and the rest o~ the specification are by weight unless otherwise specified.

TABLE I - REACTANT ABBREVIATIONS

Abbreviation Reactant Photoinitiator 20 BP benzophenone Monofunctional Reactants IOA isooctyl acrylate NVP N-vinyl pyrrolidone 25 HEA 2-hydroxyethyl acrylate AA acrylic acid LA lauryl acrylate ODA octadecyl acrylate EHA 2-ethylhexyl acrylate 30 Sty styrene BMA butyl methacrylate ChxA cyclohexyl acrylate IBOA isobornyl acrylate WO92/16~90 ~ 5~ PCT/~S92/02021 Multifunctional Reactants HDDA 1,6-hexanediol diacrylate TMPTA trimethylolpropane triacrylate DVB divinyl benzene 5 TMPTMA trimethylolpropane trimethacrylate EOTMPTA triacrylate of ethoxylated trimethylolpropane HDDA Aopate 1,6-hexane diol di(beta-acryloxypropionate) TMPTA Aopate trimethylolpropane tri(beta-acryloxypropionate) Terms Used In SPecifi cation 15 visc. viscosity Imm. immediate RT room temperature Lamin. lamination Sil silicone Functional Si.licones MAUS methacryloxyurea siloxane ACk~S acrylamidoamido siloxane MACMAS methacrylamidoamido siloxane 25 MeStUS ~-methylstyrylurea siloxane ACMS acrylamido siloxane CACMS ~-carboxyacrylamido siloxane MAHAS methacryloxyhydroxyamino siloxane TABLE II - TEST TAPE OEL~RACTERIZATION

Tape Characterization A an aggressive latex acrylic PSA coated on a cellulose-acetate backing B a latex ruhber-resin PSA coated on a creped paper backing C a latex acrylic PSA coated on a non-woven rayon backing W~92/165~0 PCT/US92/02021 ~ 24 -D a tackified block polymer PSA coated on a cast polypropylene backing E an aggressive solventborne acrylic PSA
coated on a foamed acrylic rubber backing 5 F a solventborne rubber-resin PSA coated on a creped paper backing G a solventborne acrylic PSA coated on biaxially oriented polypropylene backing H a removable acrylic PSA coated on a cellulose acetate backing I a tackified block copolymer PSA coated on biaxially oriented polypropylene backing Test Methods The test method used to evaluate the xelease coated flexible sheet materials of the Examples is a modification of the industry standard peel adhesion test used to evaluate PSA coated materials. The standard test is described in detail in various 20 publications of the American Society for Testing and Materials (A5TM), Philadelphia, PA, and the Pressure Sensitive Tape Council (PSTC), Glenview, Ill. The modified standard method is described in detail below.
The reference source of the standard test method is 25 ASTM D3330 78 PSTC-l (ll/75).

Immediate Release Value This test measures the effectiveness of the LAB as a release agent. The immediate release value is 30 a quantitative measure of the force required to remove a flexible adhesive tape from a substrate coated with the test composition at a specific angle and rate of removal. In the following examples this force is expressed in Newtons per decimeter (N/dm).
Immediate release testing was conducted by laminating a 2.54 cm by 20.32 cm strip of the coated substrate prepared in the examples coated side up to the stage of an Instrumentors, Inc. slip/peel tester (model 3M90) with double coated tape. A l.9 cm by WO92/16590 PCT/USg2/02021 s~ c) ~ ~

15.24 cm strip of a PSA coated test tape (characterized in Table II) was rolled down onto the laminate thus formed with a 1.82 kg rubber roller. The force required to remove this tape at 180 and 228.6 5 cm/minute was then measured. The results of these tests are reported below.

Aqed Release Value Aged release testing was conducted in a 10 similar manner to immediate release testing, with the exception of allowing the test tape to dwell in contact with the coated substrate for two days at either room temperature or 65C, prior to removal. For these aged test tapes, readhesions were also measured by adhering 15 the freshly peeled tape to a clean glass plate and measuring the peel adhesion in normal fashion using the same Instrumentors slip/peel tester indicated above, again peeling at 228.6 cm/min and at a 180 peel angle.
The average value obtained is reported in Newtons per 20 decimeter. These measurements were taken to determine whether a drop in the adhesion value occurred due to undesirable contamination of the adhesive surface by the release coating. The results of these tests are reported below.
Preparation of Functional Silicones Difunctional polysiloxanes terminated on both ends with ethylenically unsaturated groups were prepared as described below. These are identified in 30 the examples and in the tables as 4K AC~AS, 5K ACMAS, lOK ACMAS,5K ACMS, 4K MACMAS, 20K MAHAS, 2.6K MAUS, 5K
MAUS, lOK MAUS, 12K MAUS, 20K MAUS, 54K MAUS, and 5K
MeStUS, wherein the number denotes molecular weight : (MW) in thousands and the letters indicate the type of functionality as defined below. Synthesis of WO92/16590 PCT/US92/02~1 ~ .L ~ ' 26 -difunctional precursors for all free-radically polymerizable siloxanes described in this application was performed in the following way:

PreParation of ~ ~-bisr3-aminopropyl~
~olydimethylsiloxane (PDMS) A mixture of 14.9 g (0.06 mole) bis(3-aminopropyl) tetramethyldisiloxane endblocker and 103.0 g octamethylcyclotetrasiloxane (D4) (previously lO purged for lO minutes with argon, less than 20 ppm H2O
by Karl-Fischer Titration) was stirred and heated to 80-850c under argon in an oil bath. A small amount (0.03-0.05 g) of catalyst, anhydrous 3-aminopropyl dimethyl tetramethylammonium silanolate, was added and 15 the reaction followed by vapor phase chromatography (VPC). In 30-45 minutes, the viscosity had increased and the end blocker had completely disappeared.
Additional D~ ~250.0 g) was added dropwise at such a rate that the ratio of integrated areas of D4 to D5 20 peaks in the VPC of the reaction mixture did not exceed about 6 or 7:1 (5-6 hours~. A~ter addition was complete, heating was continued until eguilibrium was achieved as judged by a return of the D4:D5 ratio to about l.5:l (2-3 hours~. The reaction mixture was then 25 heated to 150C for 30 minutes to decompose the catalyst and then stripped of residual cyclics under high vacuum (O.l-l.0 mm Hg). After cooling to 25C, the diamino PDMS was obtained as a clear, colorless oil. The yield was 307.l g (87%). The molecular 30 weight of the product was determined by titration of a sample in THF/IPA with O.OS N HCl to a bromophenol blue end point, and, in this case, was found to be 5,lO0 g/mol (theoretical M~ = 5,000 g/mol).

- 27 - 2~ S~

4K, 5K, lOK ACMAS
Polydimethylsiloxane terminated on both ends with acrylamidoamido groups and having an average 5 molecular weight of about 5,000 (5K AC~S) was prepared by thoroughly mixing 50 g (0.0l mole) of aminopropyl-terminated polydimethylsiloxane prepared according to the above description with 2.8 g (0.02 mole) of vinyldimethylazlactone (VDM), prepared as l0 previously described in U.S. Patent NoO 4,777,276 (Rasmussen et al.) at room temperature.
The viscosity of the reaction mixture increased as the reaction progressed. The number average molecular weight of the difunctional 15 polysiloxane was determined by acid titration of the precursor and was confirmed by gel permeation chromatography (GPC) analysis before and after capping with VDM. 4K ~CMAS and lOX ACMAS, were prepared by using aminopropyl-terminated polydimethylsiloxane 20 precursors with molecular weights of 4,000 and l0,000 respectively, prepared according to the above-described procedure.

; 2.6K, 5K, l0R, 12K, 20K, 54K MAUS
4K MACMAS/5K MeStUS/5K ACMS
Other free-radically polymeri~able siloxanes were prepared by reacting aminopropyl-terminated polydimethylsiloxanes with varying molecular weights prepared accordîng to the above-described method with 30 other capping agents, such as with isocyanatoethyl methacrylate, commercially available from Showa Rhodia, isopropenyl dimethyl azlactone, prepared as previously described in U.S. Patent No. 4,777,276 (Rasmussen et al.), and with m-isopropenyl-~ dimethyl benzyl isocyanate av~ilable from American Cyanamid under the trade name m-TMI~, at room temperature to form polysiloxanes with methacryloxyurea (MAUS), W092/16590 PCT/US~2/02021 ~ & ~ 28 -methacrylamidoamido (MACMAS), and ~-methylstyryl urea (MeStUS) groups on both ends, respectively. 5,000 MW
acrylamido functional siloxane (SK ACMS) was prepared by adding a solution of 3.79 g (26.3 mmol) acryloyl 5 ethyl carbonic anhydride (prepared from ethyl chloroformate and acrylic acid according to the method of R. Hatada and H. Kondo, Bull. Chem. Soc. JaPan, 41 (10), 2521 (1968)) in 9 g CH2Cl2 to 59.1 g (11.8 mmol) 5,000 MW degassed aminopropyl-terminated 10 polydimethylsiloxane (prepared according to the above-described method) in a 100 mL round bottom flask, stirring one hour at room temperature under nitrogen, and distilling off solvent on a rotary evaporator.
The preparation of acryloyl ethyl carbonic 15 anhydride according to Hatada et al., Bull. Chem. Soc.
Japan 41 (10), 2521 (1968), is set forth below.
Into a 500 mL 2-neck round bottomed flask equipped with a mechanical stirrer and addition funnel equipped with a pressure equilibrating side-arm and 20 attached nitrogen inlet was placed lO0 g dichloromethane, 30 g (0.28 mole) ethyl chloroformate, and 10.7 g (0.27 mole) NaH as a 60% mineral oil dispersion. The head space was purged with nitrogen and resulting suspension cooled in an ice bath. 1 g of 25 pyridine was added followed by dropwise addition of 19.2 g (0.27 mole) acrylic acid over 30 minutes to the well stirred cooled solution. The cooling bath was removed and the solution was agitated an additional 2 hours, then quenched by addition of 49 mL 5~ a~ueous 30 HCl (i.e., 7 mL concentrated HCl diluted with 42 mL
deionized water). The mixture was transferred to a separatory funnel, and the organic layer separated, -.
washed one time with 20 mL deionized water, and dried over MgSO4. After filtration, a small amount of 35 phenothiazine (ca. 0.05 g) was added as inhibitor, and the solvent was stripped using a rot~ry evaporator at aspirator vacuum and room temperature. The resulting W092/16S90 PCT~US9~/02021 - 29 ~ 2~ 4 two phase material (product and mineral oil) was transferred to a distillation apparatus and distilled under reduced pressure (bp 60C at 0.05 m~g) to yield product.

A polysiloxane with methacryloxyhydroxypropyl-amino (2OK MAHAS) groups on both ends was prepared utilizing the procedure described in Example 4 of U.S.
10 Patent No. 4,293,397. 40.34 g (2 mmol) degassed 20,171 MW amine terminated polydimethylsiloxane synthesized as described above was placed in a 250 mL 2-neck flask containing 1.47 g (10.3 mmol) glycidyl methacrylate and 9.4 mg methoxyhydroquinone. A mechanical stirrer and a 15 nitrogen inlet were attached, the headspace was flushed with nitrogen, and the reaction mixture was st:irred for 65 hours at 60C.
Example 4 of U~S. Patent No. 4,293,397 reads as follows:
Into a flask of 2 liter capacity were introduced 740 g of octamethylcyclotetrasiloxane and 24.8 g of 1,1,3,3-tetramethyl-1,3-diaminopropyldisiloxane and further 7.6 g of a 1~ by weight solution of 25 tetramethylammonium hydroxide in dimethylpolysiloxanolate was added thereinto in an atmosphere o~ dry nitrogen gas ~ollowed by further agitation at 90C for 3 hours to effect the reaction between the siloxane components. The temperature of 30 the reaction mixture was then increased to 150C where nitrogen gas was bubbled into the reaction mixture for :~ , 2 hours to distil off the low volatile matter produced by the reaction. After cooling of the reaction mixture down to 60C, a mixture of 73.3 g of glycidyl 35 methacrylate and 0.47 g of methoxyhydro~uinone was added thereto in an atmosphere of dry nitrogen and the reaction was carried out at the same temperature ~or 24 WO92/16590 PCT/USg2/02~21 2~ ~ 30 -hours to give a milky white liquid product having a viscosity of 6690 centipoise at 25~C. The content of non-volatile material in this liquid product as measured by heating at 105C for 3 hours was 93.5%. In 5 the next place, 100 parts by weight of the above obtained liquid product was admixed with 8 parts by weight of finely divided silica aerogel having a specific surface area of 180 m2g with its surface having been treated with hexamekhyldisilazane and 1.0 parts by 10 weight of 4-methoxybenzophenone followed by kneading in a three-roller mill to give a uniform composition having a viscosity of 450 poise. The thus obtained photocurable composition was spread into a layer of 1 mm thick which was subjected to irradiation with 15 ultraviolet light for 10 seconds under air cooling with a high pressure mercury lamp of 2 kilowatts placed 15 cm from the coated surface to give a cured product having no tackiness on the sur~ace.

20Examples l throuqh 10 and Comparative Example 1 These exampies show variation in silicone MW
and functionality.
A master batch was prepared by mixing 135 g isooctyl acrylate ~IOA), 15 g ethoxylated trimethylol 25 propane triacrylate (EOTMPTA, available from Arco Chemical Company under the tradename Sartomer~ 454), and 6 g benzophenone (BP). 10 g aliquots of the resulting solution were combined with 50 mg o~ 2.6K, 5K, 10K, 20K, and 54K MAUS, 5K ACMAS, 5K MeStUS, 5K
30 ACMS, 4K MACMAS, and 20K MAHAS ~Examples 1 through 10 respectively). These clear solutions were thinly coated by hand onto 61 micron biaxially oriented polypropylene (BOPP) by pouring a small amount onto one end of a 15.2 cm by 91 cm sheet of film and spreading 35 down its length with a paper tissue. The coatings were passed through a PPG lndustries W processor three passes at 22.9 meters per minute with two medium WO92/16590 PCT/U~92/02~21 . 3 ~ l~

pressure mercury lamps on at 78.7 W/cm (total dose 300 mJ/cm2) under a nitrogen atmosphere. The starting master batch solution tcontaining no silicone) was coated and cured in similar fashion as Comparative 5 Example 1. The resulting cured coatings were conditioned overnight under constant temperature and humidity conditions (22C and 50% relative humidity) and testsd for immediate and aged release performance using test methodology described above. Results are 10 presented in Table III and show that the presence of a low level of difunctional silicone imparts significantly lower levels of release than a similar coating with no silicone and that a wide range of molecular weights and functionalities for the silicone 15 are useful in practicing this invention.

Examples 11 throuqh 14 These examples show variation in the nature of the polar monomer.
A master batch was prepared by mixing 40 g IOA, 10 g EOTMPTAr 2 g BP, and 1 g 5K MAUS. 6 g aliguots of the resulting solution were combined with 1 g of N-vinyl pyrrolidone (NVP) or 2-hydroxyethyl acrylate (HEA) (Examples 11 and 12 respectively, both 25 hazy) or 2 g of acrylic acid (AA) or IOA (Examples 13 and 14, respectively, both clear). These solutions were coated, cured, and tested using the procedure described in Example 1 above, with the exception that the coatings were cured with Pour passes at 22.9 meters 30 per minute (total dose 400 mJ/cm2) rather than three.
Results of the release testing are presented in Table IV and show that the presence of polar monomers to, for example, promote adhesion to substrate, in g~neral does not influence the release performance of these 35 coatings. In the case of Example 11, the basic nature WO92/16~90 PCT/US92/02021 ~ t~ a ~ 32 of the NVP in the coating leads to specific interaction with the AA present in the PSA, giving a build in release on aging.

Examples 15 throuqh 22 and Com~arative Examples 2 throuqh 4 These examples show use of high levels of silicone and solution casting of PSA onto the resulting coated release sheets. The examples compare these l0 materials to similar coatings made using a commercially available methacrylated silicone and to a paper release liner coated with a commercial silicone.
A master batch was prepared by mixing l08 g IOA, 12 g EOTMPTA, and 4.8 g BP. 6 g aliquots of the 15 resulting solution were combined with 0.3, 0.6, 0.9, and l.5 g of 5K MAUS ~Examples 15 through 18, respectively); 0.3, 0.6, 0.9, and 1.5 g l0K MAUS
(Examples l9 through 22, respectively); and 0.3 and 0.6 ~ of a methacrylate functional silicone fluid t30 20 centistokes viscosity) available from SWS Silicones under the tradename F~815~ ~Comparative ~xamples 2 and 3). These clear solutions were coated, cured, and ~-onditioned using the procedure described in Example ll above. They were tested ~or release performance by 25 overcoating them using a knife coater with a tackified block polymer PSA solution of l0 g of a styrene-isoprene block polymer (obtained from Shell under the tradename Kraton~ l}07), lO g of a aliphatic tackifying resin (obtained from Goodyear ~ire under the 30 tradename Wingtack Plus~), and 30 g toluene, and drying (30 min at 65DC~ to yield a 25 micron thick dry adhesive coating. An acrylate PSA consisting of a 94/6 IOA/AA solution copolymer at 35% solids in ethyl acetate prepared according to methods described by 35 Ulrich in U.S. Patent No. ReO 24,906 was similarly coated and dried l0 min at 65C. These same adhesives were also solvent cast and dried onto a paper liner _ 33 _ 2~ &~
coated with a condensation cured solventborne silicone release coating available from Dow Corniny under the tradename Syl-off (Comparative Example 4). The resulting adhesive films were conditioned for two days under constant temperature and humidity conditions (22C and 50~ relative humidity) and a 35 micron thick polyester terephthalate (PET) film was laminated to them. 1.3 cm x 15.2 cm strips of these laminates were cut and release and readhesion measured as described 10 above. The laminates were also dwelled in a 65C oven for 2 days and tested for release and readhesion.
Results of the release testing are presented in Table V
and show somewhat higher levels of release than the standard siliconized paper liner and improved 15 readhesion values, particularly ~or the tackified block polymer PSA, relative to similar coatings prepared with F-815.

Exameles 23 throuqh 32 These examples show variation in the amount of acrylic acid (AA) present in either an IOA or lauryl acrylate (LA) based release coating at constant silicone content ~2% 5R MAUS).
A master batch was prepared by mixing 41.25 g 25 IOA, 11.25 g EOTMPTA, 1.5 g 5K MAUS, and 3 g BP. 7.6 g aliquots of the resulting solution were combined with 3 g IOA, 2.5 g IOA and 0.5 g AA, 2 g IOA and 1 g AA, 1 g IOA and 2 g AA, and 3 g AA (Examples 23 through 27, respectively). All were clear solutions except for 27, 30 which was very slightly hazy. A similar series of formulations were made up by substituting lauryl acrylate (LA) for IOA in both the master batch and dilutions (Examples 28 through 32, respectively).
Formulations 28 and 29 were clear solutions, 30 very 35 slightly hazy, 31 slightly ha~y, and 32 was hazy.
These solutions were coated, cured, and tested using the procedure described in Example 1 above with the i: ~

WO9~/16590 P~T/US92/02021 7~ 3 l5 - 34 -exception that the coatings were cured with four passes at 22.9 mpm (total dose 400 mJ/cm~) rather than three, and immediate release testing was not: done. Results of the release testing are presented in Table VI. These 5 results show that the presence and level of AA does not have a significant effect on the release per~ormance and that the use of LA gives somewhat: lower release than IOA.

ExamPles 33 throu~h 38 and Comparative Exam~les 5 and 6 These examples show an LA/EOTMPTA/AA system with varying low levels of silicone and a similar series prepared with slightly prepolymerized LA to enhance the coating viscosity.
A master batch was prepared by mixing 34 g LA, 4 g EOTMPTA, 2 g AA, and 1.6 g BP. This had a Brookfield viscosity of 8 cenkipoise (spindle 2, 60 rpm). lO g aliquots of the resulting solution were combined with 20.8, 52.2, and 98.5 mg 5K MAUS (Examples 20 33 through 35, respectively). A second master batch was prepared by combining 34 g LA, 2 g AA, and 114.7 mg Irgacure~ 651 photoinitiator, a benzoin ether type ~ree radical initiator available ~rom Ciba-Geigy, purging the resulting solution five minutes with nitrogen at 1 25 L/min, and inducing polymerization by shaking the sealed glass bottle under low intensity W lights until an exotherm and increase in viscosity was noted. To the resulting syrup was added 4 g EOTMPTA and 1.6 g BP
to yield a master batch with a Brookfield viscosity of 30 487 centipoise (spindle 2, 30 rpm). lO g ali~uots of this were combined with 22.2, 47.9, and 97.7 mg 5K MAUS
(Examples 36 through 38, respectively). The resulting clear solutions as well as the starting non-silicone containing low and high viscosity master batches (Comparative Examples 5 and 6, respectively) were coated, cured, and tested using the procedure described in Example 1 above with the exception that the coatings , :

W092/165g0 PCT/US92/02021 2 ~

were cured with four passes at 22.9 meters per minute (total dose 400 mJ/cm2) rather than three. Results of the release testing are presented in Table VII and show that raising the viscosity of the coating solution (desirable for coating by, for example, differential gravure methods) does not significantly alter release performance and again demonstrates that the presence of a low level of difunctional silicone significantly lowers release relative to the same coating composition 10 with no silicone.

ExamPles 39 throuqh 46 These examples show the use of mixtures of IOA
and LA for the monofunctional monomer adding two 15 different molecular weight silicones at two different levels.
A master batch was prepared by mixing 26.3 g LA, 8.8 g IOA, 3 g EOTMPTA, 2 g AA, and 2 g BP. 5 g aliquots of the resulting solution were combined with ~O O.1 g and 0.2 g 5X MAUS (Examples 39 and 40) and 0.1 g and 0.2 g lOK MAUS (Examples 41 and 42). A second master batch was prepared by mixing 17.5 g LA, 17.5 g IOA, 3 g EOTMPTA, 2 g AA, and 2 g BP. 5 g aliquots of the resulting solution were combined with 0.1 g and 0.2 25 g 5K MAUS (Examples 43 and 44) and 0.1 g and 0.2 g 10X
MAUS (Examples 45 and 46). The resulting clear solutions were coated, cured, and tested using the procedure described in Example 1 above with the exception that the coatings were done on 35 micron PET
30 rather than 61 micron BOPP and readhesion testing was not done. Results of the release testing are presented in Table VIII and show that mixtures of monofunctional monomers are useful in the practice of this invention.

WO~2/16590 PCT/US~2/02021 Examples 4? throuqh 50_ and Comparative Exam~les 7 and 8 These examples show the use of mixtures of IOA
or LA with octadecyl acrylate (ODA) for the monofunctional monomer adding silicone at two different levels. They also demonstrate coating as a high solids solution in cyclohexane rather than t}le 100% solids materials described above, this being done in order to keep the crystalline ODA in solution i.^or coating.
A master batch was prepared by mixing 42 g of 10 a 50% solids solution of ODA in cyclohexane, 2.8 g EOTMPTA, 1.4 g AA, and 1.1 g BP. 6.8 g aliquots of the resulting solution were combined with 1.3 g IOA
(Comparative Example 7), 1.3 g IOA and 0.1 g 12K MAUS
(Example 47), 1.3 g IOA and 0.2 g 12K MAUS (Example 15 48), 1.3 g LA (Comparative Example 8), 1.3 g LA and 0.1 g 12K MAUS (Example 49), and 1.3 g LA and 0.2 g 12K
MAUS (Example 50). These solutions were coated, cured, and tested using the procedure described in Example 1 above with the exception that the coatings were cured 20 with five passes at 22.9 meters per minute (kotal dose 500 mJ/c*) rather than three, the coatings were dried 40 minutes at 65C after curing to remove residual cyclohexane, and readhesion testing was not done.
Results of the release testing are presented in Table 25 IX and show that mixtures of monofunctional monomers including ODA are useful in the practice of this invention and that coating can be done with added solvent without unduly influencing release.

ExamPles 51 throu~h 56 These examples show the use of 2-ethylhexyl acrylate (EHA) as the monofunctional acrylate and the .
use of high levels of 1,6-hexanediol diacrylate (HDDA) or mixtures of HDDA and trimethylol propane triacrylate (TMPTA) as the multifunctional acrylate.

WO92/1~590 PCT/US92/02021 A master batch was prepared by mixing 35 g EHA, 15 g HDDA, and 1.5 g BP. 10.3 g aliquots of the resulting solution were combined with 60.7 mg, 0.2 g, and 0.5 g 10K ACMAS (Examples 51 through 53, 5 respectively). A second master batch was prepared by mixing 35 g EHA, }0 g TMPTA, 5 g HDDA, and 1.5 g BP.
10.3 g aliquots of the resulting solution were combined with 60.5 mg, 0.2 g, and 0.5 g 5K AC~AS (Examples 54 through 56, respectively). These solutions were 10 coated, cured, and tested using the procedure described in Example 1 above with the exception that the coatings were cured with four passes at 18.3 meters per minute (total dose 500 mJ/cm2) rather than three at 22.9 meters per minute. Results of the release testing are 15 presented in Table X and show that high levels of multifunctional monomers and mixtures of them are useful in the practice of this invention.

Examples 57 throuqh 66 These examples show the use of high levels of mixtures of multifunctional acrylates as well as the use of beta acryloxypropionates of 1,6-hexane diol and trimethylol propane.
A solution of 0.5 g 10K ACMAS in 49.5 g EHA
25 was prepared and 5 g aliquots were combined with 1 g EHA, 1 g TMPTA, 3 g HDDA, and 0.3 g BP tExample 57 -slightly hazy) or with 1 g EHA, 1.5 g TMPTA, 2 g HDDA, 0.5 g AA, and 0.3 g BP (Example 5~ - slightly hazy);
3 y aliquots were combined with 3 g EHA, 1 g TMPTA, 3 g 30 HDDA, and 0.3 g BP (Example 59 - very slightly hazy) or with 3 g EHA, 1.5 g TMPTA, 2 g HDDA, 0.5 g AA, and 0.3 g BP (Example 60 - very slightly hazy); and 1 g aliquots were combined with 5 g EHA, 1 g TMPTA, 3 g HDDA, and 0.3 g BP (Example 61 - clear) or with 5 g 35 EHA, 1.5 g TMPTA, 2 g HDDA, 0.5 g AA, and 0.3 g BP
(Example 62 - clear). Similarly a solution of 2.0 g 10K ACMAS in 48 g IOA ~as prepared and 5 g aliquots W092/16590 PCT/USg2/02~21 2 ~ Q ~

were combined with 3 g IOA, 2 g of the di(beta-acryloxypropionate) ester of 1,6-hexanediol ("HDDA Aopate") available ~rom Rohm and Haas under the trade name QM926~, and 0.3 g BP (Example 63 - hazy);
5 with 2.5 g IOA, 1.5 g of the tri(beta-acryloxypropionate) aster of trimethylolpropane ("TMPTA Aopate") available from Rohm and Haas under the trade name QM920~, 1 g AA, and O.3 g BP (Example 64 - hazy); with 3.5 g IOA, 1.5 g ~MPTA
10 Aopate, and 0.3 g BP (Example 65 - slightly hazy); or with 3 g IOA, 1.5 g HDDA Aopate, O.5 g AA, and O.3 g BP
(Example 66 - clear). ~hese solutions were coated, cured, and tested using the procedure described in Example 1 above with the exception that the coatings 15 were cured with three passes at 18.3 meters per min-lte (total dose 375 mJ/cm2) rather than three at 22.9 meters per minute onto a cast polypropylene backing, release testing for Examples 57 through 62 was done at 30.5 cm/min rather than 228.6 cm/min, and readhesion testing 20 was not done. Results of the release testing are presented in Table XI and also show that high levels of multifunctional monomers and mixtures of them are useful in the practice of this invention and that the l'Aopates" are useful multi~unctional monomers.
Exam~les 67 throuqh 72 These examples show the use o~ partially prepolymerized EHA or EHA/AA mixtures to impart higher viscosity to the coating solution.
70 g EHA and 0.3 g Irgacure~ 651 photoinitiator available from Ciba-Geigy were combined, purged five minutes with`nitrogen at 1 L/min, and polymerization induced by shaking the sealed glass bottle under low intensity W lights until an exotherm 35 and increase in viscosity was noted. To the resulting syrup was added 20 g TMPTA, 10 g HDDA, and 3 g BP to yield a master batch with a Brookfield viscosity o~ 545 .

WO92/165gO PCT/~92/02021 2 ~

centipoise (spindle 2, 30 rpm). 20.6 g aliquots of this were combined with 0.1 g and 0.4 g 5K ACMAS
(Examples 67 - clear and 68 - hazy, respectively).
Similarly a mixture of 65 g EHA, 5 g AA, and 0.3 g 5 Irgacure~ 651 was prepared, purged, polymerized, and combined with 20 g TMPTA, 10 g HDDA, a~d 3 g BP tc yield a master batch with a Brookfield viscosity of 475 centipoise (spindle 2, 30 rpm). 20.6 g aliquots of this were combined with 0.1 g and 0.4 g 5K ACMAS
(Examples 69 - slightly hazy and 70 - hazy, respectively) or with 0.1 g and 0.4 g 5K MeStUS
(Examples 71 - slightly hazy and 72 - hazy, respectively). These solutions were coated, cured, and tested using the procedure described in Example 1 15 above, with the exception that the coatings were cured with three passes at 18.3 meters per minute (total dose 375 mJ/cm2) rather than three at 22.9 meters per minute onto a cast polypropylene backing and release te~ting was done at 30.5 cm/min rather than 228.6 cm/min.
20 Results of the release testing are presented in Table XII and also show that the use of viscosity enhanced coating solutions does not substantially influence release performance.

Example 73 and ComParatiVe Exam~les 9 throuqh 11 These examples contrast release results ~or a coating made following the teachings o~ this invention (containing 10% multifunctional monomer and a low level of silicone (5%)) with coatings prepared from the same 30 silicone at a high level combined with monofunctional monomer but no multifunctional monomer.
A mixture of 9 g IOA, 1 g TMPTA Aopate, 0.5 g 10K MAUS, and 0.3 g BP was prepared (Example 73 -: clear). Similarly prepared were mixtures of 2 g IOA, 35 8 g 5K MAVS, and 0.3 g BP (Comparative Example 9 -clear), 3 g isobornyl acrylate (IBOA~, 7 g lOK MAUS, and 0.3 g BP (Comparative Example 10 clear), and 2 g :

W092/l6590 PCT/~S92/02021 7 ~ ,~ ! .3 ~ ~
L~, 8 g lOK MAUS, and 0.3 g BP (Comparative Example 11 - hazy). These solutions were coated, cured, and tested using the procedure described in Example 1 above with the exception that the coatings were cured with 5 three passes at 18.3 meters per minute (total dose 375 mJ/cm2) rather than three at 22.9 meters per minute.
Results of the release testing are presented in Table XIII and show that even at high levels of silicone the release value builds much higher on heat aging in the 10 absence of a multifunctional monomer.

Examples 74 throuqh 77 and Comparative Example 12 These examples show the use of elsctron beam irradiation to cure the coatings, demonstrate curing 15 onto a high density polyethylene substrate (HDPE), and contrast release results for these coated sheets with those obtained from uncoated HDPE.
Mixtures of 7 g EHA, 3 g HDDA, and 44.5 mg lOK
MAUS tExample 74); 7 g EHA, 3 g HDDA, and 0.2 g lOK
20 MAUS (Example 75); 7 g EHA, 1 g HDDA, 1 g TMPTA, 1 g AA, and 40.4 mg 5R MAUS (Example 76); and 7 g EHA, 1 g HDDA, 1 g TMPTA, 1 g AA, and 0.2 g 5K MAUS (Example 77) were prepared and the resulting clear solutions wipe coated onto 102 micron thick HDPE film as described in 25 Example 1 above. The resulting coatings were passed through an ESI Electrocurtain~ CB-150 electron beam processor at 6.1 meters per minute, given a dose oE 4 Mrad at 175 KeV accelerating voltage. The resulting cured coatings along with a sheet of uncoated HDPE
30 (Comparative Example 12) were conditioned overni~ht under constant temperature and humidity conditions (22C and 50% relative humidity). A 2.5 cm x lS.2 cm t piece of the acrylic foam tape construction, test tape E, was laminated to these sheets with a 1.82 kg rubber 35 roller and the resulting laminate dwelled two days at room temperature or 65~C. Release testing in this case was done by attaching the foam tape construction to the WO92/16590 ~ a ~ PCT/US92/02021 stage of the slip/peel tester with double stick tape and peeling the HDPE sheet from it at 180 and 30.5 cm/min. Neither immediate release nor readhesion testing was done in this case. Results are shown in 5 Table XIV and demonstrate that electron beam curing is an effective means of imparting cure, that HDPE can successfully be used as a substrate for these coatings, and that release performance for these coatings is significantly lower than the re~atively low energy lo uncoated HDPE.

Exam~les 78 throuqh 83 These examples show the use of up to 70%
multifunctional reactant and also compare release 15 results for tapes laminated to coatings immediately after cure to tests of the same coatings after a 24 hour conditioning period. This comparison serves as an illustration of per~ormance in an integrated manufacturing situation where adhesive would be 20 contacted with the release coating shortly after cure.
A master batch o~ 0.5 g 4K ACMAS in 9.5 g IOA
was prepared. 1 g aliquots of this were combined with 6 g IOA, 3 y HDDA, and 0.2 g Darocur~ 1173 acetophenone type free radical initiator available from EM
Industries Inc. (Example 78 - clear); with 5 g IOA, 4 g HDDA and 0.2 g Darocur~ 1173 (Example 79 - clear); with 4 g IOh, 5 g HDDA, and 0.2 g Darocur~ 1173 (Example 80 - very slightly hazy); with 3 g IOA, 6 g HDDA, and 0.2 g Darocur~ 1173 photoinitiator, (Example 81 -30 hazy); with 2.5 g IOA, 6.5 g HDDA, and 0.2 g Darocur~1173 (Example 82 - hazy); and with 2 g IOA, 7 g HDDA, and 0.2 g Darocur~ 1173 (Example 83 - hazy). These solutions were coated, cured, and tested using the procedure described in Example 1 above. Test tapes were 35 also laminated to coatings from Examples 78 and 79 immediately after curing (within one minute), and aged release and readhesion testing was conducted as WO92~16590 PCT/US92/02021 ~ ~it3&~ 42 -described above. Results are shown in Table XV and demonstrate the utility of very high levels of multifunctional monomer as well as the fact that these coatings attain their release performance immediately 5 after cure.

Examples 84 throuqh E~8 These examples show the use of non-acrylate (e.g., methacrylate or styrenic) mono-- and 10 multifunctional reactants and the use of cyclohexyl acrylate.
A master batch of 0.5 g 4K ACMAS in 9.5 g IOA
was prepared. 1 g aliquots of this were combined with 5 g IOA, 3 g HDDA, 1 g divinyl benzene (DVB), and 0.2 g 15 Darocur~ 1173 (Example 84); with 5 g IOA, 3 g HDDA, 1 g trimethylol propane trimethacrylate ~TMPTMA), and 0.2 g Darocur~ 1173 ~Example 85); with 4 g IOA, 2 g styrene (Sty), 3 g HDDA, and 0.2 g Darocur~ 1173 (Example 86);
and with 4 g IOA, 2 g butyl methacrylate (BMA), 3 g 20 HDDA, and 0.2 g Darocur~ 1173 (Example 87). A mixture ~; of 8 g cyclohexyl acrylate (ChxA), 2 g HDDA, 1 g 4K
ACMAS, and 0.2 g Darocur~ 1173 was prepared as Example 88. These clear solutions were coated, cured, and tested using the procedure described in Example 1 25 above with the exception that the coatings were cured with four passes at 22.9 meters per minute (total dose 400 mJ/cm2) rather than three. Results are shown in Table XVI and demonstrate that methacrylate or styrenic mono- and multifunctional reactants as well as 30 cyclohexyl acrylate are useful in the practice of this invention.

Exam~les 89 throuqh 93 and Comparative Example 13 These examples show the application of the 35 release coatings using the electrospray process onto both polyester (PET) and biaxially oriented WO92/16590 PCT~US92/02021 ~ 43 ~
polypropylene (BOPP) film and give release results for different types of adhesives at varying silicone levels compared to a similar coating with no silicone.
A mixture of 225 g IOA, 75 g HDDA, 6 g 5 Darocur~ ~173, and 30 g methanol was prepared (Comparative Example 13) giving a solution with conductivity 8 microsiemens/m, Brookfield viscosity 6 centipoise, and surface tension 22.5 dlynes/cm.
Identical formulations were prepared containing in 10 addition 0.3 g (Example 89), 0.6 g (Example 90), 1.5 g (Example 91), 3.0 g (Example 92), and 15.0 g (Example 93) 10K ACMAS which had similar viscosities, surface tensions, and conductivities in the range of 8 to 12 microsiemens per meter. These clear solutions were 15 introduced into a coating head which contained 21 capillary needles using a Sage Model 355 syrin~e pump.
The design of this electrospray coating head, which coats a width of 25.4 cm, and specifics about the line used are disclosed in US 4~748,043. A voltage 20 differential of 5.4 to 5.5 RV dc was applied between the capillary needles and the extractor plate, which was held at 4 KV dc aboYe ground potential (i.e., the capillary needles were 9.4 to 9.5 XV dc above ground).
The extractor plate was spaced 9 cm from the film 25 surface. The film passed under a Corona charger and the surface was charged to a potential of -2.4 to -3.3 KV/cm2. At a constant syringe pump speed deliverincJ
1474 microliters per hour per orifice, samples of BOPP
were coated at 2000 angstroms (based on first 30 principles) at 9.1 meters per minute web transport speed, and PET at 1000 and 2000 angstroms at 18.3 and 9.1 meters per minute, respectively. Curing was done in an inert nitrogen atmosphere with one 78.7 Watt/cm medium pressure mercury ultraviolet light (corresponding to a dose of 100 mJ/cm2 at 9.1 meters per minute and 51 mJ/cm2 at 18.3 meter5 per minute), then conditioned and tested as described in Example 1 above.

WO~/16590 PCT/U~9~/0202 ~ q~ 44 -Results are shown in Table XVII and demonstrate the ability to tailor release level by varying the amount of silicone present, as well as the utility of this coating process for the release coating compositions of 5 this invention.

Examples 94 throuah 98 and Comparative Example 14 These examples show the use o~ the electrospray process to coat ~ormulations with various 10 types and levels of monofunctional reactant and multifunctional reactant. The use of a level of multifunctional reactant outside the useful region is also shown as a comparative example.
Solutions were prepared and coated onto BOPP
15 at 2000 angstroms using the process and conditions described in Example 89 above except that web speed was held at 18.3 meters per minute, sy~inge pump speed delivery was increased to 2793 microliters per hour per orifice, and curing was done with two medium pressure 20 mercury lamps at 78.7 Watt/cm (total dose 101 mJ/cm2).
Conditioning and testing was conducted as described in Example 1 above. Specifics of the solutions, including formulation, conductivity, surface tension, and viscosity were as follows. Example 94: a mixture of 25 435 g IOA, 60 g HDDA, 45 c3 TMPTA, 30 g AA, 12 g 5K
ACMAS, 12 g Darocur~ 1173, and 30 g methanol; 1.5 microsiemens per meter, 24.5 dynes/cm, 5 centipoise.
Example 95: a mixture of 240 g IOA, 15 g AA, 45 g HDDA, 7.5 g 5K ACMAS, 15 g methanol, and 6 g Darocur~
30 1173; 2.0 microsiemens per meter, 23.4 dynes/cm, 5 centipoise. Example 96: a mixture of 210 g IOA, 90 g HDDA, 45 g 4K ACMAS, 15 g methanol, and 6 g Darocur~
1173; 4.5 microsiemens per meter, 22.9 dynes/cm, 8 centipoise. Example 97: a mixture of 120 g isobornyl 35 acrylate (IBOA), 90 g IOA, 90 g HDDA, 45 g 4K ACMAS, 15 g methanol, and 6 g Darocur~ 1173; 4 microsiemens per meter, 23 dynes/cm, 11 centipoise. Example 98: a WO92tl6590 PCT/US92/02021 mixture of 210 g IBOA, 90 g HDDA, 45 g 4K ACMAS, 15 g methanol, and 6 g Darocur~ 1173; 2.5 microsiemens per meter, 23.5 dynes/cm, 14 centipoise. Comparative Example 14: a mixture of 255 g IOA, 45 g AA, 18 g 5 HDDA, 45 g 10K ACMAS, 15 g methanol, and 6 g Darocur~
1173; 1.2 microsiemens per meter, 24.5 dynes/cm, 5 centipoise. Results are presented in Table XVIII and demonstrate that a wide variety of formulations can be successfully electrosprayed. The comparative example 10 shows that at multifunctional reactant contents lower than 5~, release value increases significantly on aging relative to similar coatings with higher crosslink density, and readhesion values are lower.

Examples 99 and 100 and Com~arative Example 15 These examples show electrospray coating of the release coating compositions of this invention onto a paper substrate and compare the release obtained to that obtained from the uncoated paper for a 20 repositionable adhesive.
The formulations from Examples 94 and 95 described above were electrosprayed onto a sub 20 bond paper (Examples 99 and 100 respectively) at 1000, 1500, and 2000 angstroms by varying the syringe pump speed 25 delivery between 1396, 2095, and 2793 microliters per hour per orifice at constant web speed (18.3 meters per minute~. Curing, conditioning, and testing was conducted as described in Example 94 above. The results are shown in Table XIX and are compared to 30 release testing done from uncoated paper (Comparative Example 15), demonstrating utility for paper substrates.

W092/16590 PCT/US92/020~1 ~ ~,. t~ q ~

Exam~les 101 and 102 -These examples show the use of the release coating compositions of this invention in an indirect transfer roll coating technique coupled with electron 5 beam curing.
Partially prepolymerized syrups of isooctyl acrylate (IOA) and 2-~thylhexyl acrylate (EHA) were prepared using techniques described in Examples 33 and 67 above. Example 101: 250 g of the IOA syrup (Brookfield viscosity 13,000 centipoise) was combined with 245 g IOA monomer, 0.6 g 10K MAUS, 60 g HDDA, and 45 g TMPTA to yield a clear solution with Broo~field viscosity 712 centipoise (spindle 2, 30 rpm). Example 102: 175 g of the EHA syrup (Brookfield viscosity 11,500 centipoise) was combined with 275 g EHA monomer, 45 g 10K MAUS, 120 g HDDA, and 30 g TMPTMA. The resulting solution was somewhat hazy, so an adclitional 43 g EHA monomer was added to clear it up. The resulting solution had a Brookfield viscosity of 141 20 centipoise (spindle 2, 60 rpm). Coating was done onto either 25 micron PET (Example 101) or 41 micron PET
(Example 102) using a Polytype S.A. Fribourg Labcoat~
five roll coater run in an indirect transfer roll coating mode with a smooth steel pick up roll (without 25 doctor blade) running at one-tenth the speed of the rubber transfer roll which was run at a fifty percent higher speed than the web line (running at 4.6 meters per minute) to smooth the coating. Curing was done with an ESI Electrocurtain~ model CB 300/30/380 30 electron beam processor at 3 Mrad and 175 XeV in a nitrogen atmosphere. Samples were conditioned and tested as described in Example 1 above. Results are --shown in Table XX and demonstrate that the release coating compositions of this invention can be coated 35 with traditional roll coating methods.

Example 103 This example demonstrates the use of the release coating compositions of this invention in a differential gravure coating technique.
175 g of the partially prepolymerized syrup of EHA described in Example 101 above was combined with 245 g EHA monomer, 180 g HDDA, 24 g BP, and 18 g 5K
MAUS to yield a clear solution with a ]3rookfield viscosity of 150 cen~ipoise (spindle 3, 12 rpm).
10 Coating was done onto 41 micron PET using a Worldwide brand four roll coater run in a differential gravure mode (200 line pyramidal gravure cylinder as pick up roll, smooth rubber roll as transfer roll, and steel back up roll). At a line speed of 10.4 meters per 15 minute, the ratio of transfer roll speed (run at the same speed as the web) to pick up roll speed was varied from 8:1 to 10:1 to 13:1 to 15:1 to obtain descending coating weights. Curing was done with three 78.7 Watts/cm medium pressure mercury lamps ~total dose 200 20 mJ/cm2) under a nitrogen atmosphere. Tape I was laminated to these coatings within 5 minutes of cure with a 1.82 kg rubber roller, and immediate release testing was done as described above. Readhesion testing of this tape was also conducted on a clean 25 glass plate. Aged release and readhesion testing was not performed in this instance. Results are shown in Table XXI and demonstrate that the release coating compositions of this invention can be coated by differential gravure techniques with higher release 30 values being obtained at lower coating weights.

~t W092/16590 PCT/USg2/02021 vu~ ~ 48 -TABLE III

Variation in Silicone MW & Functionality in a 90/10 5 IOA/EOTMPTA ~ 4% Benæophenone Formulation Releasle Readhesion (N/dm) (Nldm~

0.5% Imm. day day day day No. Silicone Tape RT RT 65C RT 65C
1 2.6K MAUS A 4.4 12.5 19.634.4 33.3 - B16.230.0 34.4 47.749.9 15 2 5X MAUS A1.9 6.7 7.4 35.636.3 10.1 18.4 24.1 47.751.0 3 10K MAUS A1.2 10.2 5.8 38.434.6 B9.0 18.8 20.1 48.650.8 4 20K MAUS A0.9 3.4 5.5 35.537.6 B3.7 11.2 -- 47.1 --54K MAUS A0.6 2.3 5.1 35.929.0 B2.0 4.6 11.2 52.552.8 6 5X MAUS A0.6 3.6 6.6 33.726.0 B4.4 8.5 16.8 54.350.3 25 7 5K MAUS A0.6 3.6 6.6 33.726.0 B10.114.7 27.6 49.351.7 8 5K ACMS A0.6 1.9 3.8 32.437.1 B1.4 8.2 14.5 44.643.1 9 4K MACMAS A 1.0 4.7 6.735.2 32.5 B3.1 12.8 19.6 41.941.5 10K MAHAS A 0.7 5.5 5.133.3 32.1 B7.8 10.3 21.7 42.740.6 Comp. no A9.829.3 25.7 34.931.4 1 silicone B38.124.145.5 47.750.1 ~-WO92/16S90 PCT~V~92/0~021 2 ~

TABLE IV

Variation in Polar Monomer Nature Using 6 g Aliquot of 5 40/10/2/l IOA/EOTMPTA/BP/5K MAUS

Release Readhesion (N/dm) _ (N/dm~
Added Imm. 2 day 2 day 2 day 2 day No. Monomer Tape RT RT 65C _ RT 65C
11 lg NVP A 2.233.7 32.1 31.0 28.7 B 2.612.0 17.5 39.4 39.8 12 lg HEA A 0.42.9 6.0 43.3 35.0 B 2.211.4 17.7 44.0 47.7 13 2g AA A 0.6 -- 4.4 30.3 33.1 B 3.79.9 17.9 42.9 42.2 14 2g IOA A 0.63.5 6.4 36.5 31.2 B 3.511.6 -- 44.0 45.8 ., .

W092/16~9~ PCT/U~92/0 ~ 50 -TABLE V

Variation in Amount of 5K & 10K MAUS in 90/10 IOA/EOTMPTA + 4% BP Formulation Release Readhesion _ ~N!dm)_ tNLdm) -day day day day No. Additive Adhesive RT 65C RT 65C
5% 5K Xraton* 2.0 3.3 89.5 76 . 0 MAUS Acrylate 5.3 12.0 61. 7 43.8 16 10% 5K Kraton1.1 1.8 77.9 76.4 MAUS Acrylate 3.1 11. 8 70 . 7 58. 7 17 15% 5K Kraton2O0 2.4 81.0 80. 6 MAUS Acrylate 2.4 9. 6 62.6 55.2 18 25% 5K Kraton1.8 1.8 76.2 79.0 MAUS Acrylate 2.6 11.8 61.9 50.1 20 19 5% 10K Kraton1.8 2.4 91.1 84.3 MAUS Acrylate 3.9 12. 7 60.0 50.1 20 10% 10K Kraton2.8 2.6 77 . 5 75 . 3 MAUS Acrylate 5.5 11. 6 60 . 9 49 .5 21 15% 10K Kraton2.0 4.6 70 . 5 61. 5 MAUS Acrylate3.1 9.4 56.7 49.9 2225g610K Kraton 0.4 2. 6 65.5 60 .6 MAUS Acrylate2.8 8.3 56.9 47 . 3 Comp.2 5%F-815 Kraton 2.6 2.2 64.4 52. 3 Acrylate 2.2 2.4 53.4 49. 7 30 Comp.3 10~ F-815 Kraton 33.9 1.8 19.7 15.3 Acrylate 9.0 15.8 47.1 49.7 Comp.4 Paper w/ Kraton2.0 0.9 59.1 45.1 Sil-Off Acrylate0.2 0.4 60.2 59.5 35 * Kraton~ 1107 (Shell) W 0 92tl6590 P ~ tUS92tO2021 TABLE VI
, .
Variation in AA Content in IOA or LA Systems with 2% 5K
5 MAUS & BP

Release Readhesion _ tN/dm) (N/dm~ ~
2 day 2 day 2 day 2 day 10 No. SYStem Tape RT 65C _ RT 65C

23 IOA/EOTMPTA A5.1 8.3 32.2 26.4 85/15 - B12.917.7 45.8 46.2 15 24 IOA/EOTMPTA/AA A4.2 6.4 34.9 35.5 80/15/5 B14.919.7 45.8 48.4 IOA/EOTMPTA/AA A3.9 6.7 38.8 32.4 75/15jlO B14.919.3 46.6 47.9 26 IOA/EOTMPTA/AA A2.6 4.8 32.8 35.0 65/15/20 B12.918.8 51.9 49.3 27 IOA/EOTMPTA/AA A -- 5.3 34.0 35.0 55/15/30 B9.611.2 50.6 --28 LA/EOTMPTA A2.5 3.8 34.3 30.6 85/15 B15.317.1 46.0 45.5 25 29 LA/EOTMPTA/AA A2.3 4.1 32.0 28.S
80/15/5 B11.616.4 45.5 45.1 LA/EOTNPTA/AA A2.5 3.6 36.9 35.3 75/15/10 B12.515.8 43.6 45.3 31 LA/EOTMPTA/AA A2.0 3.4 33.9 32.4 65/15/20 B9.914.7 44.0 43.6 32 LA/EOTMPTA/AA A2.5 4.1 31.7 35.6 55/15/30 B10.716.4 44.2 --. .

WO92/16590 PCT/US92/~2021 TABLE VII

Comparison of Low Viscosity and Viscosity-Enhanced Formulations: 85/10/5 LA/EOTMPTA/AA + 4~ BP

Release Readhesion (Nldm) _ (N/dm) Imm. 2 day 2 day 2 day 2 day ; 10 No. Sam~le Tape RT_ RT65C RT 65C
Comp. Low visc A 8.5 20.3 18.7 -- 29.0 no Sil B22.833.1 28.9 43.1 49.5 33 Low visc A 1.6 ~ 33.4 30.3 0.2% Sil B 9.0 -- 20.8 49.5 50.1 34 Low visc A 1.0 3.4 3.6 35.7 28.3 0.5% Sil B 2.8 11.6 17.5 44.4 51.7 Low visc A 0.7 3.4 4.8 29.3 29.0 1.0~ 5il B 6.3 15.3 21.2 50.6 51.4 20 Comp. High visc A 7.4 16.9 22.5 25.8 31.4 6 no Sil B28.737.4>44.0 43.1 --36 High visc A 1.5 4.5 6.7 36.2 30.8 0.2% Sil B 6.8 17.5 21.5 47.5 53.6 37 High visc A 1.0 3.1 7.0 29.9 28.7 0.5% Sil B 9.6 14.4 21.5 45.5 50.3 38 High visc A 0.9 2.9 5.7 31.8 27.7 1.0~ Sil B 2.4 13.8 19.5 45.5 50.8 WO92/16~90 PCT/VS92/02021 3 ~ ~
TABLE VIII

Mixtures of IOA/L~

Release Silicone (N/dm) L,A/IOA % Imm. 2 day 2 day No. ratioMW MAUS Tape R1` RT 65C

39 3110.20% A0.9 2.95.3 5X B2.4 13.621.2 3/10.40% A0.6 2.63.5 5K B1.1 9.416.2 15 41 3/10.20% A0.6 1.52.8 SK B0.7 6.811.8 42 3/10.40% A0.4 1.62.9 lOK B0.7 8.315.5 43 1/10.20% A0.7 1.85.8 5K B3.5 9.923.9 44 1/10.40% A0.6 3.16.6 5K B0.4 9.4 -17.5 1/10.20% ~0.4 1.83.1 lOK B1.1 5.714.4 25 46 1/10.40% A0.4 1.62.8 10K B0.6 3.58.3 ., ; , . - , , .. : , . , : .. ' :
.. . . . . . . ..
.. .

WO92/16590 PCT/US92/020~1 ' s~ t~ It~ ~
TABLE IX
ODA/LA/EOTMPTA (A) or ODA/IOA/TMPTA (B) Formulations Rel~ase Silicone ~N/dm!
12K MAUS Imm. 2 day 2 day No. Form. wt % Ta~e _RT RT 65C_ Comp. 7 ` (B) none A 2.211.2 17.9 47 (B) 2% A 0.4 1.5 4.4 48 (B) 4% A 0.4 2.6 2.9 Comp. 8 (A) none A 2.0 7.6 11.2 1549 (A) 2% A 0.4 2.5 2.6 (A) 4% A 0.4 1.8 2.6 TABLE X
EHA/HDDA (A) or EHA/TMPI'A/HDDA ~B) Formulations Release Readhesion Silicone (N~dm~ lNLdm) 25 wt ~ Imm. 2 day 2 day 2 day 2 day No. Form. MW ACMAS Tape RT RT 65C RT 65C

51 (A)0.60% C 1.3 4.0 8.4 19.4 17.2 52 (A)2.00% C 0.9 3.9 8.3 21.0 16.4 53 ~A)5.00% C 0.8 3.8 8.9 18.4 16.7 35 54 (B)0.60% C 2.7 8.610.0 19.2 18.5 (B)Z.00% C 1.8 5.1 8.9 21.0 17.2 56 (B)5.00% C 1.8 5.6 9.5 21.2 16.5 : .

~ 55 ~ 2~&~

TABLE XI

Release * (Ntdm) Imm. 2 day 2 day No. TaPe RT RT _ 65~C

57 D7.7 29.8 33.4 sh 10 58 D14.3 19.6 slsh9.3 sh 59 D25.3 28.1 slsh13.5 sh D5.5 15.3 12.6 sh 61 D16.8 sh 40.3 38.8 sh 62 D18.4 sh 21.8 sh25.2 sh 15 63 C1.3 3.8 9.1 6~ C0.9 3.6 11.2 C0.9 4.1 10.8 66 C0.9 4.1 10.5 * sh = shocky; slsh = slightly shocky TABLE XII

Readhesion Release fN/dm~ fN/dm ~
Imm. 2 day 2 day 2 day 2 day No. Tape RT RT RT 65C 65C
30 67 D 21.5 28.9 ~ 144.3 68 D 12.5 19.123.1 130.0 151.1 69 D 20.6 14.0 9.5 137.4 147.7 D 12.3 18~118.3 131.9 --71 D 9.5 11.516.0 140.6 141.7 35 72 D 24.2 23.3 9.6 128.7 150.6 '~ .
,:
, WO 92/16590 PCI'/USg2/02021 TABLE XIII

Readhesion Release (N~dm~ ~N/dm) Imm. 2 day 2 day 2 day 2 day No. TaDe RT RT 65C RT 65C
73 C 2.4 6.6 1~.3 15.9 15.2 10 Comp. 9 C 1.2 4.6 15.8 15.7 15.2 Comp. 10 C 1.0 7.8 lB~5 14.6 14.5 Comp. 11 C 1.0 4~4 14~3 16~4 14.3 1~ TABLE XIV

Release (N/dm) 2 day 2 day No. Tape RT 65C
74 E 4.6 6.7 E 4.1 7.2 76 E 6.0 8.0 77 E 5.4 7.8 Comp. 12 E 42.7 40.6 .

.

WO92/16590 PCT/U~92/02~21 2 1 ~
TABLE XV
High Levels of HDDA - 0.5% 4K ACMAS
ReadhPsion Release (N/dm) (Ntdm) IOA/Imm. 2 day 2 day 2 day 2 day No. HDDA Tape RT _ RT 65C RT 65C
78 70/30 A 0.9 3.4 3.9 34.7 37.8 F 5.5 14.3 20.9 43.8 42.5 10 78 Immed. A 4.2 5.7 35.0 33.0 Lamin. F 16.6 22.2 42.6 45.2 79 60/40 A 0.6 2.8 4.5 38.5 35.9 F 4.7 19.1 18.5 46.3 46.4 79 Immed. A 4.5 6.1 37.4 38.2 Lamin. F 13.1 17.9 44.9 44.4 50/50 A 0.7 2.5 4.2 35.7 38.8 F 3.4 10.8 15.0 48.3 47.7 81 40/60 A 0.7 2.9 4.5 40.6 29.6 F 2.8 9.8 16.2 46.8 48.7 20 82 35/65 A 0.7 4.7 7.0 39.1 40.0 F 6.9 18.2 22.2 44.5 46.0 83 30/70 A 0.7 5.4 8.9 36.3 43.3 F 6.6 11.8 20.7 46.8 49.5 Readhesion Release (N~dm~ (Nldm~
Imm.2 day 2 day 2 day 2 day No. Tape RT RT 65C RT 65C
84 A 0.6 2.5 2.3 32.0 31.8 F 1.214.7 19.7 45.4 47.4 A 1.0 3.8 9.0 36.3 38.2 F 7.123.3 24.1 44.6 46.0 35 86 ~ 1.3 8.6 14.3 42.3 42.3 F 2.315.6 13.7 45.4 48.3 87 A 0.7 4.4 5.4 39.0 37.6 F 3.212.3 16.5 4603 48.6 88 A 0.9 2.3 6.4 32.4 37.1 F 1.2 9.3 13.9 46.7 45.5 ., ,'~ ' .

.

WO92/16590 P~T/US92/0202 2 ~ ;J ~ 58 Release Readhesion Coating (N/dm) fNldm) 5Thickness Imm. 2 day 2 day 2 day 2 day No. Sub. fAL Tape RT RT 65c RT 65C
Comp. BOPP 2000 F 57.5 58.4 59.4 48.1 46.7 13 BOPP 2000 A 14.2 29.9 33.4 33.6 35.0 PET 1000 F 55.963.3 65.7 5}.1 51.0 PET 1000 A 20.335.0 33.0 35.0 32.0 PET 1000 G 32.137.9 40.3 42.7 42.7 PET 2000 F 55.963.9 64.3 51.1 51.1 PET 2000 A 16.033.0 29.6 30.6 35.0 PET 2000 G 34.242.0 42.2 42.7 41.6 89 BOPP 2000 F 44.4 50.6 53.7 46.7 46.7 BOPP 2000 A 10.2 26.1 27.3 32.1 35.0 PET 1000 F 52.158.4 62.4 51.1 49.6 PET 1000 A 15.825.5 26.4 30.6 27.7 PET 1000 G 29.936.2 36.8 43.8 41.6 PET 2000 F 43.355.4 59.2 49.6 51.1 PET 2000 A 12.525.5 25.2 27.7 26.3 PET 2000 G 27.434.6 37.7 43.8 39.4 BOPP 2000 F 38.2 48.3 49.9 48.1 49.6 BOPP 2000 A 7.6 20.7 25.4 32.1 33.6 PET 1000 F 40.655.7 61.7 49.6 49.6 PET 1000 A 10.126.8 23.8 32.1 33.6 PET 1000 G 26.334.5 35.6 41.6 41.6 PET 2000 F 38.249.3 56.8 48.2 49.6 PET 2000 A 7.419.7 20.7 33.6 35.0 PET 2000 G 21.626.7 26.4 49.3 46.0 91 BOPP 2000 F 28.6 29.8 37.4 45.3 48.1 BOPP 2000 A 2.9 8.3 11.5 33.6 35.0 PET 1000 F 39.549.2 54.0 49.6 49.6 PET 1000 A 7.418.8 21.4 29.2 36.5 PET 1000 G18 . 924.523.8 47.1 46.0 PET 2000 F 27.335.3 42.3 46.7 49.6 PET 2000 A 2.3 7.6 9.5 36.~ 37.9 PET 2000 G 7.711.7 11.7 55.8 52.6 W092/l6590 PCT/U~92tO2021 _ 59 _ 2~a~3~
TABLE XVII (cont.) ReleaseReadhesion Coating(Nldm) _ ~NIdm~
ThicknessImm. 2 day 2 day 2 day 2 day No. Sub. f~) Ta~e RT RT 65C _ RT 65C

92 BOPP 2000 F 6.6 8.3 18.5 52.5 49.6 BOPP 2000 A 1.0 1.9 7.3 39.4 33.6 PET 1000 F 4.79.2 15.6 49.6 51.1 PET 1000 A 1.01.5 3.6 35.0 26.3 PET 1000 G 0.82.0 3.4 53.7 42.7 PET 2000 F 6.112.0 18.5 55.4 51.1 PET 2000 A 0.71.3 2.2 39.4 30.6 PET 2000 G 1.82.3 3.6 56.9 53.7 93 BOPP 2000 F 2.0 3.8 8.2 52.5 51.1 BOPP 2000 A 0.7 1.5 2.9 35.0 33.6 PET 1000 F 4.811.1 16.2 54.0 51.1 PET 1000 A 1.01.5 3.4 26.3 30.6 PET 1000 G 1.82.4 3.8 54.8 49.3 PET 2000 F 1.83.6 7.4 54.0 54.0 PET 2000 A 0.81.5 2.8 26.3 27.7 PET 2000 G 1.1206 6.6 55.8 49.3 -~ 25 .

~:

W092/16~0 PCT/US92/02021 TABLE XVIII

Release Results for BOPP Electrosprayed at 2000 ~

Readhesion Release (NldmL ~ IL~L~
Imm. 2 day 2 day 2 day2 day No. TapeRT RT 65C RT65C

94 A 3.1 16.0 16.8 42.3 39.4 G10.5 20.9 20.8 50.4 48.2 F23.1 37.4 39.8 45.2 45.2 I 1.5 s 7.4 s 6.1 s 96.4 21.9 s A 1.2 4.7 6.3 35.0 37.9 G 2.7 6.4 72.0 54.8 50.4 F12.0 19.7 24.5 45.2 46.7 I 1.4 s 2.8 s 3.2 s 79.9 3.4 s 2096 A 0.7 4.7 4.5 42.3 43.8 G 1.9 8.5 9.4 59.1 50.4 F 5.3 10.5 15.0 46.7 48.1 I 1.5 s 2.5 s 1.2 s 70.1 s5.5 s 97 A 0.9 3.5 6.6 45.2 43.8 G 2.6 9.3 12.3 55.8 52.6 F 4.2 14.7 16.8 46.7 49.6 I 1.3 s 2.5 s 3.2 s 89.8 9.9 s 98 A 1.2 5.3 8.9 45.2 45.2 G 2.9 10.8 13.2 58.0 52.6 F 8.0 16.5 22.0 45.2 46.7 I 1.4 s 3.5 s 3.9 s 88.7 13.1 s Comp. A 1.9 16.5 19.1 21.9 23.3 14 G 5.0 16.1 14.6 35.0 31.8 ~11.1 24.9 28.6 35.0 35.0 I l.9 s 4.5 s 3.7 s 28.5 s6.6 s , .
s = shocky .

WOg /1659~ P~T/~S92/02021 - 6~ Q~C,~

TABLE XIX

Release results for electrosprayed samples Readhesion Coating Release ~N~m~ ~N/dmL
Thickness Imm. 2 day 2 day 2 day 2 day No. (A)_ _ Tape ~ RT 65C RT 65C
Comp. 15 H 8.912.1 9.2 7.6 6.6 99 1000 H l.94.2 6.3 7.4 606 1500 H 1.84.1 5.7 8.8 7.6 2000 H 3.46.7 7.6 7.9 6.7 15100 1000 H 3.15.0 7.1 8.3 6.3 1500 H 2.35.0 5.7 8.3 7.0 2000 ~ 2~67.4 8.9 7.7 7.4 TABI.E XX

Readhesion _ Release (Nldm~ ~NIdm) Imm. 2 day 2 day 2 day 2 day No. TapeRT RT 65C RT 65C
101 I6.5 9.7 10.6 65.8 --G18.2 18.7 18.4 49.2 46.1 102 I3.3 7.8 9.0 63.7 70.5 G7.8 5.8 7.1 52.0 53.7 TABLE XXI

Release Readhesion Transfer to (N/dm) (Ntdm) Pickup Speed Imm. Imm.
No. Ratio_ _ Tape RT RT

103 8/1 I 2.2 81.0 10/1 I 3.3 82.1 13/1 I 5.5 86.5 15/1 I 10.1 89.8 . .

WO92~16590 PCT/VSg~/0~21 ~ 0~ 62 -While this invention has been described in connection with specific embodiments, it should be understood that it is capable of further modification. The claims herein are intended to cover those variations which one 5 skilled in the art would recognize as the chemical equivalent of what has been described here.

Claims

1. A substrate coated on at least a portion of at least one major surface with a radiation curable release coating composition, said composition comprising:
(a) from - 0.05 to - 25 percent by weight of polymer selected from the group consisting of polymers falling within the general formula:
I
and mixtures thereof, wherein:
X are monovalent moieties having ethylenic unsaturation which can be the same or different;
Y are divalent linking groups which can be the same or different;
D are monovalent moieties which can be the same or different selected from the group consisting of hydrogen, an alkyl group of 1 to about 10 carbon atoms, aryl, and substituted aryl;
R are divalent hydrocarbon groups which can be the same or different;
R1 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;
R2 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;
R3 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, vinyl, aryl, and substituted aryl;

R4 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, vinyl, aryl, and substituted aryl; and n is an integer of - 25 to - 750;
(b) from - 5 to - 60 percent by weight of one or more multifunctional free radically polymerizable vinyl monomers copolymerizable with said polymer; and (c) from - 25 to - 95 percent by weight of one or more monofunctional free radically polymerizable vinyl monomers copolymerizable with said polymer;
wherein said weight percentages are based upon the total weight of said radiation curable release coating composition.

2. A radiation curable release coating composition comprising:
(a) from - 0.05 to - 5 percent by weight of polymer selected from the group consisting of polymers falling within the general formula:
I
and mixtures thereof, wherein:
X are monovalent moieties having ethylenic unsaturation which can be the same or different;
Y are divalent linking groups which can be the same or different;
D are monovalent moieties which can be the same or different selected from the group consisting of hydrogen, an alkyl group of 1 to about 10 carbon atoms, aryl, and substituted aryl;

R are divalent hydrocarbon groups which can be the same or different;
R1 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;
R2 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;
R3 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, vinyl, aryl, and substituted aryl;
R4 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, vinyl, aryl, and substituted aryl; and n is an integer of - 25 to - 750;
(b) from - 5 to - 60 percent by weight of one or more multifunctional free radically polymerizable vinyl monomers copolymerizable with said polymer; and (c) from - 25 to - 95 percent by weight of one or more monofunctional free radically polymerizable vinyl monomers copolymerizable with said polymer;
wherein said weight percentages are based upon the total weight of said radiation curable release coating composition.

3. The composition of Claim 2 wherein X comprises , wherein R3 is selected from the group consisting of hydrogen and -COOH and R6 is selected from the group consisting of hydrogen, methyl, and -CH2COOH, n is an integer of - 50 to - 270, R is selected from the group consisting of alkylene of one to - 12 carbon atoms, alkylarylene, and arylene, R1 and R2 are independently selected from the group consisting of alkyl of one to - 12 carbon atoms, substituted alkyl of one to - 12 carbon atoms, aryl, and substituted aryl, R3 and R4 are at least 50% methyl wherein any remaining R3 and R4 groups are independently selected from the group consisting of alkyl of - 2 to - 12 carbon atoms, substituted alkyl of - 2 to - 12 carbon atoms, vinyl, aryl, and substituted aryl, and D is hydrogen.

4 . The composition of Claim 2 which further comprises - 0.1 to - 5 weight percent of a free radical initiator based upon the total weight of said release coating composition, wherein said free radical initiator is selected from the group consisting of benzoin ethers, benzophenone, derivatives of benzophenone, acetophenone derivatives, camphorquinone, and mixtures thereof.

5 . The composition of Claim 2 wherein X comprises CH2=CH-, Y comprises -?-, D=H, R comprises -CH2CH2CH2-;
and R1, R2, R3 and R4 each comprise -CH3.

6 . The composition of Claim 2 wherein said monofunctional free radically polymerizable vinyl monomer comprises - 50 to - 100 mole percent acrylic monomer.

7. The composition of Claim 2 wherein said monofunctional free radically polymerizable vinyl monomer is selected from the group consisting of cyclohexyl acrylate, isobornyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and mixtures thereof.

8. The composition of Claim 2 wherein - 5 to - 15 percent of said monofunctional free radically polymerizable vinyl monomer comprises polar monomer.

9. The composition of Claim 8 wherein said polar monomer is selected from the group consisting of acrylic acid, N-vinyl pyrrolidone, hydroxyethyl acrylate, methacrylic acid, and mixtures thereof.

10. The composition of Claim 2 wherein said multifunctional free radically polymerizable monomer is selected from the group consisting of acrylates of 1,6-hexanediol, trimethylolpropane, their ethoxylated and propoxylated analogs, and mixtures thereof.

11 . The composition of Claim 2 which comprises - 0.2 to - 5 weight percent of said polymer, - 55 to - 95 percent by weight of said monofunctional free radically polymerizable vinyl monomer, and - 10 to - 30 weight percent of said free radically polymerizable multifunctional vinyl monomer.

12. A substrate coated on at least a portion of at least one major surface with a composition according to claims 2-11.