CA1074805A

CA1074805A - Low viscosity poly(epoxide-caprolactone) polyols

Info

Publication number: CA1074805A
Application number: CA262153A
Authority: CA
Inventors: Robert A. Taller; Decker K. Elder
Original assignee: Union Carbide Corp
Current assignee: Union Carbide Corp
Priority date: 1975-10-07
Filing date: 1976-09-27
Publication date: 1980-04-01
Also published as: JPS6328922B2; SE432600B; FR2327270A1; DE2645039B2; DE2645039A1; DE2645039C3; JPS5247095A; JPS6017792B2; US4045474A; SE7611110L; FR2327270B1; IT1068411B; JPS6335617A; GB1531046A

Abstract

ABSTRACT OF THE DISCLOSURE

High funotionality polyol compositons that have a low viscosity of less than 5,000 cks. at 130°F. and an equivalent weight of at least 150 are useful for the forma-tion of high performance coatings. These are produced by reacting a mixture of at least two polycaprolactone polyols having a hydroxyl number from about 180 to 500 and a diepoxide.

Description

~ ~ 9882 ~ACKGROUND OF TXE INVENTION
, It i3 known that caprolactone polyols are suitably employed irl forming urethane coatlng~ and that they o~er a number o~ advantages over conventlonal pol~ester polyols.
One o~ theee advantages i~ that reaction o~ caprolactone polyols with pol~isocyanates generally provides urethane coatings having better weatherir~g charactPristics~ Clear coatings ~or exterior application are obtai~ed ~rom caprolac-tone pol~ol~ ar3d a~omatic polyisocyar~ate~ ~uch as tolylene diisocyanates but ~uch coatings tend to yellow du~ to the known light instability as~ociated with aromatic dlisoc~anate~. :
It i3 also known that li~ht stable urethane coating~
are provided by reaction o~ caprolactone polyols w~th al~phat-lc dii~oc~anates~ :
It is dlsclo~ed in U~ SO 3,896,303 to ~erki~ and Com~tock that adducts o~ polyepoxides and polycaprolactone pol~ols havlng runctional hydroxyl groups, produced by react-ing polycaprolactone polyols and polyepoxides, can be reacted wlth aliphatic polyi~ocyarlates to produce polyurethane coat- :
lngs use~ul ln high per~ormance appllcations. Su~h coati~gs . .
exhibit the characteristlcs o~ high hardness, good impact resi~tance, low temperature flexibiliky, and chemical re31~
anoe. One o~ the di~advantage~ associated with khe products obtained in thi~ patent 1~ their high viscos~ties~ which pre-~ent problems ln th~ir manu~acture and useO Thls rlece~sltate~
the addîtion o~ solventsg resulting in a lower total solids content~, Consequenkly, cure requires more ener~y and the volatllization o~ the solven~s causes atmospheric pollution.
It is an ob~ec~ o~ this irlventlon ~.~ pro~ide cer-'.

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~ 0 7 ~ ~ 5 tain improved low viscosity polycaprolactone-ba3ed polyols which are especially use~ul ln the formation o~ high per~orm-ance coating~. These products have higher equivalent welght and substantially lower viscosity khan the compositions dis-closed in the prior art.
Another ob~ect i~ to provide polycaprolactone based polyols which are used with particular advantage in forming light stable polyurethane coatings h~ving a good balance o~
hardness, flexibilit~ and abrasion resistance a~ well as woatherability, chemical resistance and high total solid~
content.
Variou~ other ob~ect~ and advantages o~ this inven~
tion will become apparent to those skilled i~ the art ~rom the accompanying descripkion and disclosure.

SUMM~RY OF THE INVENTION

It has no~ bee~ discovered that low vlsco~ity, high ~unct~onality adduct~ o~ polycaprolactone polyQls and polyepoxide~ use~ul in producing urethane coat~ngs can be produced by reacting a diepox~de with an ~xcess o~ a mixture o~ certain polycaprolactone polyols. Partlcularly desirable propertie~ are obtained when the ratio o~ the mixture u~
polycaprolactone polyol~ to diepoxide is ~rom abouk 2.5:1 to about 4:1. Under these conditions the adducts o~ poly-caprolactone polyol~ and diepoxides produced ha~e low vlscos-ities o~ less than 5,000 cks. at 130F. which were hereto~ore unobtalnable. By uslng a mixture o~ polycaprolactone polyols having diX~erent hydroxyl numbers, as hereina~ter described, these low visco~ities can be obkained in combination wlth 3~

? . 9882 4~305 equ~valent weights above 150, DESCRIPTION OF THE INVENTIGN

Production o~ the adducts o~ polycaprolactone pol~-ols and diepoxldes o~ the present invention involve~ the reaction o~ a mixture o~ at least two polycaprolacton~ polyols with a diepoxide ln cr~tical ratios. The pol~caprolactone ~:
polyols which may be u~ed in this reaction and their means of ~-pr~paration are known ln the art and are de~cribed in U. S.
3,169,945 to Hostettler and Young. They are produced by the polymerization o~ epsilon-caprolactone ln the presence o~ a polyhydric initiator~
The pre~erred polycaprolactone polyols are the trifunctlonal compounds having hydroxyl numbers o~ ~rom about 180 to about 60o and average molecular weight~ o~ ~rom about 300 to 1,000. Illustrative o~ suitable polycaprolactone polyol~ one can mention the reaction product obtalned by reacting epsilon caprolactone and trimethylolpropane to an average molecular weight of ~rom 300 to 1,000; other suitable inltiators can be u~ed ~uoh as gl~cerol, 1,2,4-butanetriol, 1~2,6-hexanetriol, pentaerythrltol, dipentaer~thritol, the o~yethylated or oxgpropylated a~ducts of such compoundsJ -~
such as, ~or example, the ethylene oxide adducts o~ trimethyl~
olpropane, and m1xtures o~ any o~ the aforesaid in~tiators.
One can-also use a d1~unctlonal inlkiakor ~uch as ethylene glyool, propylene glycol, diethylPne glyco~, dlpropylene gl~col, the butanediolsg the hexanediols and the llke~ Any ::
~ .
o~ the known polycaprolactone polyo?s having the above h~
droxyl number~ and molecular wei~h-ts can be used.

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~ ~ 7 4~ S

The diepoxides which are reacted with the above-described polycaprolactone polyols to produce the novel adducts of the present lnvention comprise organic molecule~
~ree o~ non-benzoid unsaturation which contain oxirane groups.
The carbon atoms o~ the oxlrane group may or may not be part o~ a saturated cyclic ring. The oxirane group may be present as ~n end capping unlt o~ the molecule or it may be contained on internal carbon atoms. Generally, no atom~ other than carbon3 hydrogen and oxygen are pre~ent with the exception that aromatic rings, when present ln the compo~md, may be brom~nated or chlorlnated.
It iB pre~erred to employ cycloaliphat~c diepoxides.
From a ~tandpolnt o~ providing polyols usef'ul in producing high ~olids urethane coatings with good hardness and weather-ability, particularly pre~erred compounds are those havin~
the general ~ormula:

C~12 - O - C - ~ RC - O CE

2 R

where R is hgdrogen or an alkyl group having ~rom 1 to 4 carbon atoms, R~ is a valence bond or a hydrocarbon radical having ~rom 1 to 5 carbon atoms and "a" is zero or one. ~t is to be under~tood khat the R groups may be the same as or ai~erent ~rom ea~h okher. ~It is preferred that R be hydro-gen or methyl and that no more than two o~ the R groups bond- -ed to a ring be mekhyl.
Diepoxide~ such as tho~e des~ribed in the ~ormula above are known ln the art. Speci~ic examples o~ :luoh com-.

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. ~ ~ 9882 ~74~5 pound~ are de~cribed in U0 S. 2~890~194 and U. S. 2,750,395 both issued to B. Phillips et al. Illustrative thereo~ one can mention 3,4-epoxyc~clohexylmethyl--3,4-epo~ycyclohexane-carboxylate, 3,4~epoxy-l-methylcyclohexylmethyl~394-epoxy-l-methylcyclohexanecarboxylate, 3,4-epo~y-6-methylcyclohexyl-methyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 394-epo~y-

3-methylcyclohexylmethyl-3,4-epoxy 3-methylcyclohexanecar boxylate, bis(3,4-epoxycyclohexylmethyl)oxalate, bi~(3,4-epoxy-6-methylcyclohexylmethyl)succlnate, bi~(3,4-epoxycyclo-hexylmethyl)adipate and bis(3,4-epo~y-6-methylcyclohexylmethyl~
adipate. Al~o one can mentlon as suitable 2~2-bi.~(3,4-epoxy-cyclohexyl)propane and bis(2,3-epoxycyclopent~l)ether.
When a single polycaprolactone polyol as de~crlbed above is rea¢ted with a diepoxide aa described above in a poly¢aprolactone.polyol to dlepoxide ratio o~ ~rom 2~5:1 ~o

4:1 an adduct is obtained which has a de~irably low ~lscosity~
However, the equivalent weight of the adduct i~ undesirably low. Con~equently, a larger proportion o~ higher co~t i~o-cyanate i~ re~uired to produce a polyurethane coating. In :
- 20 some ln~tance~, hlgher isocyanate content can result in in~erior weathering characteristics. The presenk invention employs a mixture o~ polycaprolactone polyol~ w~th hydroxyl numbers ~uch that the dl~erence between the hydroxyl ~umbers is ~rom about 300 to 400, pre~erably ~rom 250 and 3509 the molecular weight~ o~ the polycaprolactone polyols being from .
300 to 1,000. The mole ratio o~ polycaprolactone polyols to dlepoxide~ is ~rom 2.5:1 to 4:1. The adducts thu~ obtai~ed have low vi~Go~itie~ o~ le~s than 5,000 cks. at 130F. and equivalent we1ghts abovP 150; polyurethane coating co~posi-tion~ produced there~rom have a ~ood balance o~ phy~ical ~ .. ..

.. ~ . .

~ 7 ~ 5 properties. Such low viscosity, high equivalent weight adducts have not heretofore been disclosed and it was an unexpected and unobvious ~inding that they could be obtained when a mixture o~ at lea~t two polycaprolactone polyols having di~ferent hydroxyl numbers wa,s reacted with a diepox-ide. Polyurethane coatings produced by reacting thçse adducts with a polyisocyanate have a combination o~ hlgh hardne~s, rlexlbllit~ and abrasion resistance~ Particularly deslrable propertie~ are obtained when a polycaprolactone polyol hav-lng a hydroxyl number of not more than 310 and a polycapro-lactone polyol having a hydroxyl number o~ not less than 560 are employed. The mixture o~ polycaprolactone polyols may be used in any combination ~uch that the ratio o~ the sum o~ the moles o~ the polycaprolactone polyol~ used to the . number of mole~ o~ dlepoxide u~ed i~ ~rom 205-1 to ~ llustrativelyt a polycaprolactone ~riol having a hydroxyl number o~ 560, a polycaprolactone trlol having a hydroxyl number o~ 310 and a cycloaliphatic diepo~ide can be reacted in a mole ratlo o~ 2:2:1, respectively~ to yield an adduct of pol~caprolactone polyols and diepoxide having an equivalent welght o~ about 163. This adduct3 when co~-bined with a polyisocyanate, wlll ~orm a polgurethane coating exh~bitlng hlgh hardness, flexibil~ty, abrasion resistance -~
and good weatherabllity. The low v~scosity o~ such a coat- :~
in~-~about 1,013 cks. at 130F.~-allows the use o~ l~ss sol-vent when ~ormulatlng a polyurethane coatlng. Co~se~uently high ~olids content in the fina~ coating ca~ be achieved.
O~e can al~o var~ the mol~ ratios ~ro~ 2:2:1 ~peci~ied above to 2:1.5:1, or 2:101~ or 3:1:1, or 1:3:1, or 2~5:1:1, or 1.5:2:1, or 1.5:1:1 or any other pos~-lble combi-.: :

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~; 9882 ~(3 748~5 nation in which the sum o~ the moles of polycaprolactone polyols is ~rom 2.5 to 4 per mole of diepoxide.
When compared with an adduct produced by reacting 2 moles o~ a polycaprolactone polyol having a hydroxyl num-ber Or 560 with 1 mole o~ 3,4-epoxycytlohexylmethyl-3,4-epo~ycyclohexanecarboxylate, which has an equivalent weight o~ 140 and a visc09ity 0~ 22, 000 cks . at 130F., the lower viscosltles and-higher equivalent weights of the adducts o~
this invention are clearly evident. Similar results were observed when the adducts o~ the present inventlon were compared to those obtained by reacting 2.5 or 3 moles o~ a single polycaprolactone polyol having a hydroxyl number o~
560 and 3,4-epoxycyclohexylmethyl-3,4-epox~cyclohexanecarboxy-late. In the latter instances viscosities were ~rom about 8, ooo ck~. to about 10,000 cks. at 130F. and the equivalent weights were *rom about 125 to about 135. It can be seen that when using a single polycaprolactone polyol one does not obtain the desired low viscosity and high equivalent ., weight.
The adduct~ o~ this inventlon are prepared by reacting the polycaprolactone polyols and diepoxides at a temperature *rom about 212~. to 3~4F., pre~erably between about ~96F. and 3~7F. and mo~t pre~erably at about 3QQF~
: The reaction proceeds ~atis~a¢torily at substan~ially atmos-.... . .
pheric pressure under ~n inert atmosphere. However~ elevated pres~ures may be used.
The reaction is pre~erably carried out in the presence o~ a catalyst. Metal catalysts, particularly organic derivatives o~ tin including stannous and stannic compounds are especially suitable. Illustrative o~ this type of cata~

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~ ~ 7 ~ 9882 ly~t are ~he following, which may be employed lndividually or in combination stannous salts of carboxylic acid 6uch as stannous ~ctoate, stannous oleate, 6tannous ~ce~ate and stannous laurate; dialkyltin dicarboxylates such as dibutyl-tin dilaurate, dibutyltin diacetate, dibutyltin dit2-ethyl-hexanoate) and other~ ~uch as, for exa~)le, di-n-octyl tin mercaptide, and the like. The catalyst is used in an amDunt usually between about 0.001 and about 0.1 weight percent of the combined total weight of the polycaprolactone polyols and dlepoxide reactants.
It is believed that during the reaction of the mixture of polycaprolactone polyols and diepoxide at least a major portion of the polycaprolactone groups are mono-functional when reacted with the diepoxide such that the equivalent o~ one hydroxyl group of the polyol react6 with a single epoxy group to open the oxirane ri~g to form a hy-droxyl group on one of the oxirane carbon atoms, and an e~her linkage with the second oxirane carbon atom and a carbon atom of the polyol~ The following equation ill~strates the reaction of two moles ~f a polycaprolactone triol with one .
mole of a cyclohexene diepoxide:

CH2 [O - C(~) - (GH2)~a 1 ~

~H3C~2- C -~H2 ~ - C(O) - ~CH2)~ b- ~ ~ l ~ ~2 -CH2 L - ~(o) - (CH2~5~ c OH
~ 7H~ [O - C(O) -i~(CH2)~ ~ - o~ ~ - X -:~H3~H2~ccH2 ~ ~ ~ (C~2)5~ b ~
~_ CH~ E c (o) (CH2)5~ c OH _ 2 In the above equation, X i~ any of the bivalent groups tha~ links the t~o 3,4~epoxycyclohexy1 nuclei such as ' 9 .

.

" ~'~ 9882 ~'7~8~5 -CH200C~, -CH200CRCOOCH2- or -C(CH3)2-. The values o~
a, b and c ~ay be any integers, including zeroJ such that the average molecular weight o~ the polycaprolactone polyol reactant 3hown is ~rom about 300 to 1,000. It is to be understood that the structure of the product shown ln the above equation is lllustrative only and that any of the three hydrox~l groups o~ the caprolactone triol may react to open the oxirane groups o~ the diepoxide reactant.
The above equation represents a theoretlcal norm.
However, additional species o~ longer chain length can be present in the reaction product as a result o~ reactions o~
the hydroxyl groups of the product shown with unreactecl oxirane group~ during the inltial phase o~ the reaction.
Moreover, additonal reaction mechanisms~ such as the reaction o~ hydroxyl groups o~ unreacted pol~caprolactone polyo~s with the ester llnkage o~ the dlepoxide, may account for other long chain components in the reaction product. The presence o~ these long chain components can result in an increase in product viscosit~.
Wikh an excess o~ polycaprolactone polyol above that needed for a stoichiometrically complete react~on with the diepoxide in the reaction mixture9 shorther chain length products such as those illustrated in the above e~uation are ~avored. Th~s is believed to be due to the greater availa-bility of hydroxyl ~unctional groups in the polyols to react with the oxirane groups in the init~al phase of ~he reaction.
The novel adducts o~ the present invention are useful in the production o~ polyurethane compositions, par-ticularly high solids cQ~ings having high hardness, ~lexi-billty, abrasion resistance and good weatherabllity. To .' . .

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~ ~ 7 ~ 8~ S

produce such coatings~ the novel ad~ct~ are reacted with polyisocyanates containing reactive isocyanato groups.
Polyisocyanates suitable for reacting with the adducts o~ the present invention are any o~ those which are well }cnown in the art of polyurethane chemistry, including aliphatic, cycloaliphatic, araliphatic and aromatic polyiso-cyanates and biuret-containing polyisocyanates. To produce light-stable coatings, the aliphatic poly~soc~anates are pre~erred~
The polyisocyanates used are so well known in the art that they do not need any further description to enable one skilled in the art to know what they are.
The polyisocyanate and the novel adducts o~ thi~
invention are reacted ln proportions su~icient to allow reaction o~ all the hydroxyl groups with an isocyanato group.
Tho~e skilled in the art are fully aware that generally a slight excess o~ isocyanato groups is employed.
Normally~ both the adduct and the polyisocyanate are in a liquid state. Solvents well known in the art may be used with the isocyanate i~ desired, but such solvents have the e~ect of reducing the ~olids content o~ the coating.
Usually, the adduct and polyisocyanate are kept separate until a short period prior to the time o~ appllca tion o~ the coating to the substrate. The two components are then miæed and applied to the substrate. Any application technique known to the art such as spraylng, b~ushing or rolllng onto the substrate may be employed.
Conventlonal additives, such as pigments, colorants, leveling agents and dispersing agents may be present in the usual known concentrations.

~` 9882 ~ ~ 7 ~ ~ 5 Normally, coatings produced from the adducts o~
the present invention cure at room temperature~ but heating at temperatures up to about 302~F. may be used to accelerate curing and facilitate solvent removal. Preferred tempera-tures are between room temperature and 200F.
The polyurethane coatings produced by the novel :
adducts of polycaprolactone polyols and diepoxides described herein are suitable ~or application to metal, wood, plastic, fabric and leather substrates, although this list ~s not intended to be exclus~veO
The examples that follow are meant to be illus-trative only and not to limit the invention.

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For ~he sake of brevity in the Examples thatfollow, the deslgnations indicated ~n column 1 of Table I
will ke used in lieu of the complete description given in the second column.
. TABLE I
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Polyol A A polycaprolactone triol having a Hydroxyl No. o~ 560 and an average molecular weight of 300 (equiva-lent weight = 100~. It is pre pared by the reaction o~ trim-ethylolpropane as initiator with epsilon caprolactone monomer in the presence of stannous octoate catalyst ~0.002 weigh~ percent, based on weight of total charge), at a temperature of approxi~ately 374F, and a mole ratio of monomer ~o initiator of about 1.45:1.
,~ . .
Polyol B A polycaprolactone triol having a Hydroxyl No. of 310 and an - average molecular weight of 540 (equivalent welght = 180)~ It is prepared by the reaction of trimethylolpropane with 3.6 moles of epsilon-caprolactone.
Polyepoxide A 3,4-Epoxycyclohexylmethyl-3,4-epoxy-cyclohexanecarboxylate, Polyol C A polycaprolactone polyol which is prepared by the reaction of Polyol A and Polyepoxide A above in a mole ratio of ~:1 respectively.
Polyisocyanate A A biuret ~f 1,6-hexamethylene - diisocyanate having a free-NCO
con~ent of about 17012 weight per-cent and an equivalen~ weight of --- about 245.3.
Levellng Agent A r 31 ~ 3 .
(~H3)3S~o- lliot~ SlO ~ _~3 ~ ~H3~ l C3H~Oc3H~ C4H~

13.

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~ 5 Except where indicated otherwise in the ~ollowing Examples~ Table II indicates the ~tandard procedures or instrument~ u~ed to determine the phy3ical and chemical prop-ertie3 of the polyols and coatings ln the example~.

TABL~ II
Property Te~t Procedure Vi~co~ity Cannon-Fenske caplllary type visco-meter Hardness~ Sward Sward hardness te~ter -~
Hardnessg Pencil ~he "leads" o~ pencil~ containing "lead" o~ di~erent hardne~e~ are ground ~lat, perpendicular ~o the axi3. The coating i~ then scratched with the ed~e o~ the "lead." The hardest pencil (e7g. H~ 2H~ whiah does not penetrate the coating is de-signated as the pencil hardne~ o~ .
the coating.
Abra~ion Re~i~tance Taber abra~ion (lO00 gram weight~
lO00 cyc~es CS-lO wheel); indicates welght (mg.~ lost during te~t~
}mpact . Gardne~ impact tester 20~ ~lo~ Gardner glo~meter (scale o~ 0 to 1009 100 = mirror flni~h) Hydroxyl No. Number o~ milligram~ o~ KOH re~uired to completely neutralize the hydro~
ly8i product of the ~ully a¢etylated derivatlve prepared ~rom one gram o~
olyol.

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r ~ 9882 ~L07~8~

CONTROL Ar) UCTS

A serie~ of reactlon~ was carried out to produce adducts u~ing a singl~ polycaprolactone polyol and a dlepoxide ~or comparlson wlth the no~Jel adducts o~ Examples 1 and 2, which u~ed mixture~ o~ polycaprolactone pol~ols.
In run~ n~ambered through 4 the reackants were chaxged to a

5-l~ter kettle that wa~ equipped with a ~tirrer, the~no~
couple and inlet tube ~or nitrogen. The amount~ charged were 3,256 g. o~ Polyol A and 744 g. o~ Polyepoxlde A (a 10 polyol to epoxide ratio o~ 4:1). The temperature o~ the mlxture was raised to 100C. and ~tannous octoate was add~d ~n the amount shown in the table below. After catalyst addltion, the temperature wa~ increa~e~ to 150~C. and main-tained ak 150-155~C. Periodically sample~ were removed and analyzed ~or unreacted oxirane. Wh.en analy~ indl¢ated an unreacted oxirane conkent below 0.55 wel~ht percent, the reactior~ was 3toppedO The p~ lcal propertie~ o~ th adduct~
obtaîned are given in the table below. In r~ ber 5 an adduct wa~ prepared in which the msle ratlo oX Pol~ol A to Poly~poxide A was 2:1, u~lng essentiall~ the ~ame reactlon condition~ as runs 1 to 4.

Run Nos . 1 2 3 4* 5 Cataly~t, ppm 14 30 150 170 148 E~ulvalent wt. 121 ~,^120 I21 124 141 Wat~r, % by wt~ 0.06 0.03 0,.02 0003 --Oxlrane3 ~ by w~q o.44 o.3o o~o6 o.o3 0051 Color~ Gardner 2.5 ~ 1.5 2,,0 1.0 Vl~eo~it~r, at 130~F. 1,736 13750 1,949 2~,893 21,850 *In this run ~he cakaly~t wa~ added in two equal portions, ;;

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~ 5 the first at 100C. and the second p~rtion after the temperature reached 150-C.

A 5-liter kettle that wa equipped wlth .
thermometer~ ~tirrer and nitrogen inlet tube was charged with 1,200 g. of Polyol A~ 2,172 g. of Polyol B and 548 g.
of Polyepoxide ~ (a mole ratlo of 2:2:1, respectively~.
The temperature of the reaction mass was raised to 100C.
and 0.723 g. (185 ppm) of ~tannous octoate ca~alyst was addedO The temperature was increased to 150C. and the reaction was allowed to proceed until the unreacted oxirane ln the kettle was 0.31 weight per,cent. The adduct of the polycaprolactone triols and diepoxide ~as . :.
a yellow liquid ha~ing a hydroxyl number of 345, a water content of 0.03 weight percent, a Gardner color of 3OS
and ~ ~iscosity of 1,013 cks~ at 13~F. The noYel adduct produced in this example, by reacting ~wo poly~aprolactone triols of m~xed hydroxyl numbex and a diepoxide in a mole ratio of 2:2:1, yieided a lower viscosity and higher equivalent weight of 163 than any of the con~rol adducts produced by rea~ting a single polycaprolac~one ~riol and a diepoxide ~n mole rat~os of 4:1 and 2:1. Thi~ us- -trates tha~ ~he u~e of a ~ix~ure of polyois wi:Ll produce : ~ adduct of eve~ lower visoosity and of higher de~ir~d .
equivalent weight than adduets obtained by empL~ying 8~m1l8r ov~ra~l polycaprolac~one pol~ol ~o diepoxide :. - ' , .

.. .

7 ~

ratios using only a single polycaprolactone polyol.

To a 2-liter, 4-necked flask equipped with stirrer, thermometer and nitrogen inlet tube were charged 450 g. of Polyol A, 540 g. of Polyol B and 274 g. of Poly-epoxide A (a mole ratio of 1.5:1.1, respectively). The temperature of the reaction mass was raised to 100C. and 0.19 g. (150 ppm) of stannous octoate catalyst was added.
The temperature was increased to 150C. and the reaction was allowed to proceed until the unreacted oxirane was 0.106 weight percent. The adduct of the polycaprolactone triols and diepoxide was a yellow liquid having a hydroxyl number of 333, a Gardner color o about 3.5 and a viscosLty of 3,790 cks.
of 130F. The novel adducts produced in this example had a equivalent weight of 168, which was even higher than that of the 2:2:1 adduct of Example 1. While the viscosity was some-what higher than the 4:1 mole ratio control adducts, the adducts of this Example have both the desired equivalent wei~ about 150 and viscosity below 5,000 cks. at 130F., whereas none of the control adducts achieve this combination of properties.

A white-pigmented two-package polyurethane coating ~;
was prepared from the adduct of Example 1 and Polyioscyanate A.
,. ',:

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:",, .. . ... .. ~ . .. ., , . ., , ., . .. . . ~ ... . . ,., . :.
- : . .
: , ; . . ..

~7~
9~82 There were charged to a pebble mill 243.92 g.
of the adduct of Example 1, 292.74 g. of titanium dioxide, 7.32 g. of soya lecithin as grinding aid and 120.14 g.
of ethoxyethyl acetate. The composition was ground and a pigment grind of less than 7 Hegman was produced.
There were charged to a quart con~ainer 145.83 g~.
o the pi~inent grind produced above, 100 g. of Polyiso-eyanate A, 0.013 g. of dibutyltin dilaurate, 0.13 g. of Leveling 170a .

7 ~ ~ 5 9~82 Agent A and 50 g. of ethoxyethyl acetate. This produced a pigmented coating composition having a No 2 Zahn cup spray viscosity of between 20 to 25 seconds and a total solids contents of 65%. It was sprayed onto unprimed steel panels and cured for 1~ mînutes at a temperature of 302F. The cured coatings were allowed to stand for seven days at room temperature and physical tests were run. The physical data is summarized in Table III wherein it is compared to the white-pigmented coating of Example 4 and a Control Coating as hereinafter set forth.

,_ .
Using a procedure slmilar to that of Example 3, a white-pigmented coating composition was prod-uced substituting the novel adduct of Example 2 as the polyol adduct component.
The following components in the indicated amo~nts comprised the coating:
Pi~ment Grind Wei~ht, g.
Adduct for Example 2 83.
TiO~ 94 95 Soya lecithin 1.9 E~hoxyethyl acetate 68. ;
Coating Formulation Polyisocyanate A 50.
Pigment grind 86.93 Dibutyltin dilaurate 0.0133 Leveling Agent A 1 0.067 Ethoxyethyl acetate 31.
The coating was applied to the same metal substrate and in the same manner described in Example 3. Physical prope~ties of the cured coating are given in Table III.
CONTROL COATING A
Table III includes physical data on a control coat-18.
.. ~.'.'.

- , ~ . ' 9~82 .
74~

~ng prepared iErom Polyvl C. The ~ methods of pro~uotion and application ~7ere used ~s deQcr~bed ln Examples 3 and 4 w~th ~e foll~wirlg iEormulat:Lon. In producing the coating form~lation, ~l~hoxyethyl acetate was added in an amount sufficient to g~re afNo. 2 Zahn Cup Viscosity of 25 ~econds.

We~:

Polyol C l,S00 Tio~ 1" 546 . 5 Soya leeithin 7 . 5 Ethoxyethyl acetate 450.
~ .
Polyisocyanate A 155.6 Pigment gr~ nd . 6 Dibutyltin dilaurate 0~ 065 Leveling Agent A 0.1 The physical proper'cies of the control coa~ing, measured a:Eter a 7-day cure at roc~m teinperature, are compared to the compositions o this ~n~ren~cion in Table III .

.

r -.' - 19.

7 ~ ~ S

TABLE III

Coating Con 20 Glo~ 60 7 78 Hardne~s, Sward* 64 50 48 Hardness, Pencil 7H 4H 3H
Abrasion Resistance~
mg. lo~s 46.1 24.9 ~3.6 Gardner Impa¢t~ ln.-lb.
Face 120 160 ~160 Rever~e 130 160 ~160 Spray Solid~, ~** 5~ 65 60 :

*An average o~ two value~ measured in perpend~cular directions on the sample~
**At No. 2 Zahn vi~cosity o~ 25 second~. :

The daka shows that the ~oatlng composition~
conta~ning adducts o~ thi~ inventloYl had higher ~pra~ solid~ : -content than did the control coatin~. The coatlng compo~i tion~ of khe novel adduct~ of thi3 i~vention have ~enerally superior ~mpact re~l~tance and abrasion re~ista~ce and satls-~actor~ hardness and glos~ value~ when compared to the con-trol coating.

20, .. . ~ . .
-: , . ~- . , - . .

` 9882 ~74~5 ~:XAMPIE ~

Using a procedure ~imllar to tha~ o~ ~xample 3, a green metallic coating wa~ prepared ~rom the adduct of Example 1 using the ~ollowing compo3ition:
Pi~ment Grind Adduct from Example 1 325.22 Phthalocyanlne green 32.56 Carbon black 1.88 Etho~yethyl acetate 160~8 ~ Z~
Pigment grlnd 85061 Polyl~ocyanate A 100. .:
Dibu~yltin dilaurate 00013 .
Rluminum powder 3.07 Leveling Agent A 0.13 Ethoxyethyl acetate 61.
The coating wa~ ~prayed onto the same metal sub~
strate and in th~ ~ame manner a~ ~he coatlng o~ Example 3.
Physlcal propertie~ o~ the cured coating appear in T~ble IV.
.:
~0 EXAMPLE 6 U~ing a procedure ~imilar to that o~ Example 3, a green metalllc coating was prepared ~rom the adduct o~
Example 2 u~ing the ~ollowing compo~ition: `:
Pigment C~rind ~e~:
Adduct ~rom E~ample 2 166, Phthal~cyanlne green 15~8 Carbon black Oo91 Soya lecithln Q,33 Ethoxyethyl ac~tate 71.1 ~D~ .
Pl~m~nt grind 65~,86 Polyi~ocyanate A 75,, Dlbu~rltin dilaurate ~ 0 .02 Alumirlum powder 1,04 ~eveling Agent A 0, 099 :Etho}~ethyl acetate 46.
The coatlng wa~ ~prayed onto the ~ame m~tal sub-21.

~ I g 8 8 2 strate and in the ~æme ~nner as the coa~ng of Example 3. Physical propert~es o~ the cured coating appear ~n Table IV. ~ -55~3b5 _~0~-rNG B
A green metallic coa~ing was prepared using Polyol C by a procedure ~milar to that of Example 3.
In produeing ~he coating formulation, etho~yethyl acetate was added in ~n amount sufficient ~o give a : :
No..2 Zahn Cup visc09ity of 25 seconds.
p~,~= ~ , Phthalocyanine green 131.25 Carbon ~lack 7.58 Ethoxyethyl acetate 125.

Pigment grind 117~6 ~olyisocyanate A 155.6 Dibutyltin dilaura~e 0.065 Aluminum powder Leveling Agent A 0 1 The coating w~s sprayed ont~ the same metal substrate and in the 6ame manner as the coating of Example 3. Physical properties o the coating are given in T~ble IV.

~ ' " , 22. ~:

G

~74~0$

TABLE IV

~5~ Contr~ _ _ 20 Gloss ^ 73 ~1 83 Hardness, Sward* 56 68 56 Hardness, Pencil 2H H 3H

- A~r~siorl Resist~ce, 26.8 9.5 14.9 ~Ig. 106s Gardner Impact, in. lb.
I~ace 40 100 160 Re~reræe 10 100 125 Spray Sol~ds, %** 50 55 56 *An average of two ~ralues taken iII perpendirular direc tions on the ~ample.
*~t No. 2 Zahn cup viscosity of 25 secorlds.
~ e dzta ~rther lllustrates t~a~ the novel adducts of the pre~en'c inventi~n . re suitable for use in pro~ucing meta71ic coatin~s having a good balance of phys~cal properties. When compared to the control coating, they exhibite~d superior impact resis~ance, 20: higher glQSS, higher total solids content and comparabl2 hardnes~ .

,.,- . ; , , .

23.
.

~ . .

Claims

WHAT IS CLAIMED IS:

1. An adduct of a polycaprolactone polyol and a cycloaliphatic diepoxide comprising the reaction product of (a) at least two polycaprolactone polyols having average hydroxyl numbers from about 180 to about 600 and (b) a cycloaliphatic diepoxide, said adduct having a viscosity of less than 5,000 cks. at 130°F. and an equivalent weight of at least 150.

2. An adduct as claimed in claim 1, wherein the mole ratio of polycaprolactone polyols to cycloaliphatic diepoxide is from 2.5:1 to 4:1.

3. An adduct as claimed in claim 1 wherein the mole ratio of the two polycaprolactone polyols to the cyclo-aliphatic diepoxide is 2:2:1, respectively.

4. An adduct as claimed in claim 1 wherein the mole ratio of the two polycaprolactone polyols to the cyclo-aliphatic diepoxide is 1.5:1:1, respectively.

24.