CA2005984A1

CA2005984A1 - Laminated polarizers

Info

Publication number: CA2005984A1
Application number: CA 2005984
Authority: CA
Inventors: Karl Heinz Aleksander Ostoja Starzewski; Hanns Peter Muller; Tillmann Hassel
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1988-12-21
Filing date: 1989-12-19
Publication date: 1990-06-21
Also published as: FI95968C; JPH02223901A; JP2839163B2; EP0374626A2; DE3842968A1; DE58909061D1; FI95968B; FI896090A0; EP0374626A3; EP0374626B1; US5049427A

Abstract

Laminated polarizers A b s t r a c t Laminated polarizers are described comprising a polarizing core layer and adhesive layers on one or both sides, each of which can accept a transparent outer layer, the polarizer being a polymer product containing polyacetylene, whose matrix is a polymer having polar groups, and as adhesive layers, in addition to conventional adhesives, such as epoxy resins or acrylic polymers, thermoplastic polyurethane-polyureas are used in particular, having a predominantly linear molecular structure with urethane segments and urea segments bonded exlusively aliphatically or cycloaliphatically.

Le A 26 413 - US

Description

2Q~ 4 The invention relates to laminated polarizerq which comprisQ a polarizing core layer made fro~ a polymer containing polyacetylene (PAC) and adhesive layers on one or both sides made from a particular polyurethane-polyurea, each of the said adhesive layers being able to accept a transparent outer layer.
The production of laminates made from different substrates with adhesive (sticking) layers located between them is known. BE 617,286 discloses a laminate made from an optical element and glass using a cross-linked epoxy resin as adhesive layer. In order to cross-link the said epoxy resin, it has to be reacted at 95C
for 48 hours. Examples of other known adhesive layers are: epoxy resins which cure with amine , acid anhydrides or polyamides (DE-OS 1,594,044; US 4,416,946); acrylate systems, which may be monomeric or oligomeric systems with vinyl groups, which can be cured by thermal, free radical or photochemical means after application of the outer layer tJP 56/33,610 (1981), JP 59/58,410 (1984), JP
59/48,714 (1984), JP 58/171,008 (1983)]; mixtures of polyacrylates with phenolic re~ins, which are applied in solution [JP 55/155,307 (1980)]; isocyanate adhesives [JP
53/47,696 (1978)] and polyurethanes [JP 60/159,704 (1985)]-While with many laminates, mechanical properties such as strength, energy absorption characteristics (safety glasses) and an adequate adhesion of the laminate components generally are of paramount importance, there Le A 26 413-Foreiqn countries Z00~98'~

are other additional requirements in the case of the highly effective laminated polarizers according to the invention; namely:
l) high transparency, all clouding phenomena having to be excluded, 2) a high degree of light fastness 3) protection of the polarizing core layer from chemical environmental influences 4) compatibility of the adhesive layer~ and if appropriate of the outer layers with the polarizing core layer without impairment of the optical proper-ties.
In principle, it is also po~sible to use the adhesive layers mentioned above for the lamination of polymers containing polyacetylene, whose matrix is a polymer with polar groups. The polyurethane-polyureas described in more detail below are, however, advan-tageously suitable for this purpo~e.
Laminated polarizers have been found made from a polarizing core layer and Adhe~ive layers on one or both sides, each of which can accept a transparent outer layer, the polarizer being a polymer product containing polyacetylene the matrix of the polymer product being a polymer having polar groups. Suitable adhesive layers must be transparent and are in principle known to those skilled in the art. Epoxy resins and acrylic polymers may for example be mentioned. In particular, for the adhesive layers, thermopla3tic polyurethane-polyureas having a predominantly linear molecular structure with urethane segments and urea segments bonded exclusively Le A 26 413 - 2 -aliphatically or cycloaliphatically, are used which are distinguished by having ,a) a content of urea groups -NH-CO-NH- of 1-20% by weight and b) a content of carboxyl groups -COOH bonded directly to the main chain of the molecule in lateral posi-tions, of 0.001-10% by weight, all relative to the total weight of the polyurethane-polyureas.
The polyurethane-polyureas mentioned are adhesive materials with high light fastness and high transparency.
Furthermore, they impart excellent adhesion between the outer layers mentioned and the polarizing core layer.
They moreover impart high edge stability to the whole laminate, as can be seen from the boiling test with whole laminates produced using this adhesive. This boiling test simultaneously reveal~ the high barrier effect against water. This high edge stability and the barrier effect against water are extraordinarily important in order effectively to prevent the penetration of water to the polarizing core layer, ~ince the matrix of the polarizing core layer, containing polar groups, i~ in many cases sensitive to water. Thermoplastic polyurethane-polyureas of this type have been dLsclosed in DE-OS 2,644,434 and by the equivalent thereto, US 4,166,149, US 4,174,240 and US 4,254,176.
The polyurethane-polyureas which are to be used as adhesive layer~ may, for example, be applied by pouring a ~olution of ~his adhesive material onto the polarizing core layer and evaporating the solvent. The polarizing core layer thu~ provided with adhesive layers Le A 26 413 - 3 -~005'384 on one or both sides may then be bonded to the outer layers. It is likewise possible in the case of outer layers which are to be used to operate the other way around and to initially apply adhesive material to the outer layer(s), after which ~oining of the outer layers provided with adhesive layers with ~he polarizing core layer is again underta~en. Still further production methods comprise, for example, coextrusion of the three layers in a manner known in principle to those skilled in the art.
The polyurethane-polyureas used according to the invention for the production of the adhesive layers are particularly effective as hot melt adhesives and thus bond the core layer to the outer layers under the influence of relatively high temperature and pressure, for example at 100-200C and at 5-50 bar. In addition to pressure bonding at elevated temperature swelling of the adhesive layers with a suitable solvent, for example methylene chloride or tetrahydrofuran i5 also possible, the bond being produced likewise under pressure but without the application of elevated temperature, after applying the other layers of the laminate.
Under normal conditions, adhesive layers made from the polyurethane-polyurea~ used according to the invention are tack-free. The laminated polarizers accord-ing to the invention therefore comprise the polarizing core layer and the adhesive layers on both sides. The adhesive layers may bear outer layers.
It is thereby possible to initially apply only adhesive layers made from polyurethane-polyureas of this Le ~ 26 413 - 4 -X00598~

type to both sides of the polarizing core layer and in~tead of directly applying outer layer4, for example in ~uccessive production steps, to apply both outer layers, for example under the influence of elevated temperature and pressure only durinq a much later procedure (occasioned by intermediate ~torage and/or transport).
This can give considerable advan~age~ when delivering, for example by saving weight or by avoiding damaqe in transport, for example when the outer layers are to be of glass.
Laminated polarizer~ of this type may for example be protected against contamination and damage by lamina-tion with a poorly adhering, removable outer film, made for example from polyethylene or silicone-treated paper.
The preparation of the polyurethane-polyureas which are to be used according to the invention i5 carried out for example according to the prepolymer principle, i.e. by reacting an excess of a suitable diisocyanate with dihydroxy compounds to form the cor-responding prepolymers having isocyanate groups in terminal positions and subsequently extending the chain of these prepolymers with diamine chain extension agents.
The co-application in small amounts of monofunctional reactants as chain terminators is possible here if appropriate in order to control the molecular weight and thereby to ad~ust the physical properties of the polymer.
In general, the type and relative proportions of the ~tructural components are selected in such a way that a calculated molecular weight between 10,000 and 500,000, preferably between 20,000 and 200,000, results. In the Le A 26 41~ - 5 -~00598~

preparation of the polyurethane-polyureas which are to be u~ed according to the invention, the bifunctional st;ructura~ components are generally used in amounts such that 1.1 to 4, preferably 1.2 to 3, isocyanate groups and S 0~1 to 3, preferably 0.2 to 2, amino groups of the chain extension agents are utilized per hydroxyl group of the alcohol structural component.
Diisocyanates suitable for the preparation are those of the formula Q (NC0)2 having aliphatically and/or cycloaliphatically bonded isocyanate groups in which Q is an aliphatic hydrocarbon radical having 2 to 12 C atoms or a cycloaliphatic or mixed aliphatic-~ycloaliphatic hydrocarbon radical having 4 to 15 C atoms. Examples of diisocyanates of this type are ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocy~nate, dodecamethylene diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate, 4,4'-diisocyanato-dicyclohexylmethane or l-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane ( i80-phorone diisocyanate) or any de~ired mixtures of diiso-cyanates of this type. Cycloaliphatic or mixed aliphatic-cycloaliphatic diisocyanates are preferably used, particularly preferably isophorone diisocyanate.
The alcoholic structural components are: S i) the relati~ely high molecular weight diols known per ~e from polyurethane chemistry, in the molecular weight range 300 to 6,000, preferably 800 to 3,000, ii) dihydroxycarboxylic acids of the formula ~e A 26 413 - 6 -ZOOS~84 Ho:CH2-C-CH2-OH
COOH
in which R repre~ents hydrogen or a C~-c4 alkyl radical and optionally iii) low molecular weight aliphatic or cycloaliphatic diol~, preferably in the molecular weight range 62 to 300.
The relative proportions of the individual components i), ii) and iii), which may be reacted simul-taneously or successively with the isocyanate component, are preferably selected here in such a way that 0.01 to 12 hydroxyl groups of the component ii) and O to 10 hydroxyl groups of the component iii) are present per hydroxyl group of the component i). Component i) may comprise the polyester diol~, polyether diol~, polythio-ether diol~, polyacetal diols or polye~ter amide diols known per ~e. The polyester diols or polyether diols known p~r ~e from polyurathane chemistry are preferably used. Their preparation ~nd composition is known to those skilled in the art.
Component ii) of the formula mentioned may for example comprise dimethylol acetic acid, 3,~-dimethylol propionic acid or ~ dimethylol-n-valeric acid. ~
Dimethylol propionic acid is preferred. The component iii) too may compri~e glycols of the type known to those skilled in the art.

~e A 26 413 - 7 -Suitable diamine chain extension agen~s are preferably aliphatic, cycloaliphatic or mixed aliphatic-cycloaliphatic diamines having primary amino groups, in the molecular weight range 60 to 300.
Example~ of these are: ethylene diamine, tetra-methylene diamine, hexamethylene diamine, 4,4'-diamino-dicyclohexyl methane, 1,4-diaminocyclohexane, 4,4'-diamino-3,3'-dimethyl-dicyclohexylmethane or l-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (isophorone-diamine). 4,4'-diamino-dicyclohexylmethane or isophorone-diamine are preferably used.
Monofunctional reactants for ad~usting to the desired molecular weight (chain terminators) are generally concomitantly used in amounts from 0.05 to 3, preferably 0.1 to 1% by weight, relative to the total amount of the structural components. The following monofunctional reactants may be mentioned by way of example: monoisocyanates, such as methyl isocyanate;
monoalcohols, such as methanol, ethanol, butanol, tert-butanol, oc~anol, isopropanol, cyclohexanol; monoamines, such as methylamine, bu~ylamine, dibutylamine.

The preparation of these polyurethane-polyureas which are to be used as adhesive layers in the laminated polarizers according to the invention is preferably carried out at the prepolymer stage, generally at about 80 to 150C. The end point of the reaction is determined by NC0 ti~ration. After the formation of the prepolymer, the chain extension reaction then occurs with the diamine chain extension agent either in the melt or in solution, the solvents which are suitable for the latter being Le A 26 413 ~ . .. .

;~005984 known to those skilled in the art. The chain extension reaction can be carried out particularly advantageously in heated-reaction extruders. In order to carry out ths chain extension reaction, ad~ustment i8 made to a temper-ature of 120 to 300C, preferably 150 to 250C.
The adhesive layers in the laminated polarizers according to the invention have, for example, a layer thickness of 0.5-50 ~m, preferably 0.5-20 ~m. In the case of the production of adhesive layers of this type by the casting technique, multiple casting i8 possible in order to obtain thicker layers. The outer layers have thicknesses of 5 ~m to 1 mm, preferably 5-100 ~m. The polarizing core layer has a thicknes~ of 1-100 ~m, preferably 5-50 ~m. Such outer layers may be even thicker in the case where optical lenses and/or prisms come into consideration for the outer layer.
Examples of suitable outer layer~ are aromatic polyesters, polyacrylonitriles, poly(meth)acrylates, polysulphones, aromatic polycarbonates, cellulose aceta es, cellulose acetate butyrates, polyamides, polyhydantoins, polyimides, polyamide-imides, polypara-phenylenebenzo-bis-imidazoles and -oxazoles, polyether ketones and mineral gla~ses, particular mention being made of the polyester~, poly(meth)acrylates, poly-carbonates, cellulose esters and mineral glasses. The transparency of these materials is their most important feature. They are generally used as thin sheets or as films.
The polarizing core layer is a polarizer made from polymer product~ containing polyacetylene (PAC), Le A 26 413 - 9 -Z O O S 98~

whose matrix is a polymer wi~h polar groups, and which has a maximum degree of polarization P of at least 90~, p:referably at least 95%, particularly preferably at least 93~, and a maximum dichroic ratio QE of S or more, prefer-ably 10 or more, both relative to the visible light range. These polarizers are used as films, in which a preferred direction is produced by stretching. Here, the stretch ratio t iS more than 200%, preferably at least 500%, particularly preferably at least 600~.
The degree of polarization P, the dichroic ratio QE and the stretch ratio ~ are defined as follows:
Transmission in the transmitting position minus Transmission in the blocking position p = . x 100 Transmission in the transmi~ting position plus Transmission in the blocking position Extinction in the blocking position QE =
Extinction in ~he transmi~;ng posi~ion (both q~antities apply ~o linearly polarized ligh~).
1--lo = x 100 lo (1 = length after stretching; lo = length before stretching) Polarizers of the type which may be used accord-ing to the invention may for example be produced by polymerization of acetylene in the solution of a polymer having polar groups in the presence of a nickel catalyst, which i8 obtained by reacting a nickel (0) compound or a Le A 26 413 compound which can be converted in situ into a nickel (o) compound, with phosphoru~ compounds, such as are dis-c.losed in-EP 0,249,019 A 1, preferably with pho3phorus compounds of the formulae R~ R6~
R1~P X (I) and R5;P~C-C;o (II), R

in which Rl, R2 and R3 independently of each other denote straight-chain or branched C1-C20-alkyl, C,-C20-alkoxy, C3-C3-cycloalkyl, C2-C~-alkenyl, C6-Cl2-aryl, C6-Cl2-aryloxy, C,-Cl5-aralkyl or di(Cl-C4-alkyl)-amino, R4, R5, R6, R7 and R~ independently of each other denote straight-chain or branched C~-C20-alkyl, C2-C30-alkenyl, C1-C20-alkoxy, C3-C~-cycloalkyl, C~-C12-aryl, C6-C12-aryloxy or C7-C1~-aralkyl, and R' may additionally denote hydrogen and R6 may additionally denote hydrogen and acyl and X denotes double-bonded oxygen, the group NR~or the group ,R10 C 9 and Ra and R10 independently of each other denote hydrogen, silyl, acyl, phenyl, cyano or Rl.
Phosphorus compounds of the formul~e (I) and (II) in which X denotes CR~R10 and R4 represents C6-C~2-aryl are Le A 26 413 XQ 0~9 preferably used.
It is particularly preferable to carry out the acetylene-polymerization in the presence of a nickel c:ompound, which can be prepared by reacting a nickel (0) compound or a compound which can be converted in situ into a nickel (0) compound with compounds of the formulae R12~ 19 (III) and R16 ~ I (IV) R ~ Phenyl ~
Phenyl in which R11, Rl2, and Rl3 independently of each other denote Ci-CB-alkyl, phenyl or benzyl, Rl5, Rl6 and R18 independently of each other denote C1-Ca-alkyl and phenyl, and Rl8 may additionally denote hydrogen or acyl, and Rl9 represents hydrogen, Cl-C8-alkyl or phenyl.
Most particularly preferred phosphoru~ compounds are those of the formulae R13~ I
R12~ P=CH-Phenyl (V) and (Phanyl)3P~C-C=O (VI) Ph~nyl in which R11, R12, R13 and R1~ have the meaning given above.
In order to prepare the catalyst, 1-4 mol of the compound of the formula (I) or (III) or (V) and 1-4 mol of the compound of the formula (II) or (IV) or (VI), are u~ed per mol of nickel (0) compound, and preferably about 1 mol of the compound of the formula (I) or (III) or (v) L~ A 26 413 - 12 -Z0059~34 and about 1 mol of the compound of the formula (II~ or ~IV) or (VI) are used per mol of the nickel (0) compound.
The catalyst i prepared at a temperature of 0 to 100C, preferably 20 to 70C. The preparation is carried out with the exclusion of oxygen, preferably in a 801-vent, which must be inert towards the reactants, such as benzene, toluene, cyclohexane or n-hexane. After it has been prepared, the catalyst is normally isolated as a solid by filtration, the solution being concentrated and/or cooled beforehand as required. However, the catalyst may also be used directly for the polymerization of acetylene without being isolated, i.e. as a solution.
Examples of nickel (O) compoundc which may be mentioned are Ni(cyclooctadiene)2 and Ni(allyl)2. The following may be mentioned as example~ of nickel com-pounds, which can be converted in situ into nickel (0) compounds: Ni acetylacetonate, Ni octanoate and Ni stearate, which can be reduced with the aid of conven-tional reducing agents, such as borohydride, aluminium hydride, aluminium alkyls or organolithium compounds.
The following may be mentioned as examples of straight-chain or branched C1-C20-alkyl: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and the - isomeric amy1s, hexyls, octyls, decyls, dodecyls, and eicosyls. A preferred alkyl has 1-8 carbon atom~.
The following may be mentioned as examples of straight-chain or branched C1-C20-alkoxy: methoxy, ethoxy, propoxy, i~opropoxy, butoxy, isobutoxy, tert-butoxy and the isomeric amyloxy, hexyloxy, octyloxy, decyloxy, dodecyloxy and eicosyloxy. A pre~erred alkoxy has 1-8 Le A 26 413 - 13 -;~0059~4 carbon atoms.
The following may be mentioned a~ examplQs of C3-C8-cycloal~yl: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, methylcyclohexyl, S cycloheptyl, cyclooctyl~
The following may be mentioned as examples of C8-C12-aryl 5 phenyl, naphthyl, biphenylyl. A preferred aryl i8 phenyl.
Examples of C2-C6-alkenyl which may be mentioned are: vinyl, propenyl, allyl, butenyl, pentenyl, hexenyl and branched isomers thereof. Further examples of alkenyl are octenyl, decenyl, eicosenyl or triacontenyl.
The following may be mentioned as examples of C6-Cl2-aryloxy: phenoxy, naphthyloxy, biphenyloxy. Phenoxy is preferred.
The following may be mentioned as examples of di~ Cl-C4-al~yl )-amino: dimethylamino, diethylamino, dipropylamino, methylbutylamino, ethylbutylamino and 80 on.
Example~ of silyl which may be mentioned are tri-Cl-C4-alkylsilyl, triphenylsilyl or mixed trisubstituted alkylphenylsilyls, preferably tri-Cl-C4-alkylsilyls, such as trimethylsilyl, triethylsilyl and 80 on.
Acyls which may be mentioned are C~-C8-alkylcar-bonyl or C6-Cl2-arylcarbonyl, which may be substituted in the manner mentioned below, such as acetyl, propionyl, butyryl, C~-alkyl-carbonyl, C8-alkyl-carbonyl, benzoyl t substituted benzoyl or naphthyl-carbonyl. A preferred acyl i3 a substituted or unsubstituted C1-C4-alkyl-carbonyl or benozyl. Acetyl or benzoyl are particularly Le A 26 413 - 14 -preferred.
The above substituents may be singly to triply, preferably singly or doubly, particularly preferably ~singly, substituted by Cl-C4-alkoxy, by phenyl or phenoxy, and in the case of multiple substitution the substituents may be variously selected from those li~ted above.
The amount of nickel catalyst used for the acetylene polymerization is no~ critical. Typical cata-lyst concentration~ are 10-1-10-5, preferably 10-2-10-4 mol of nickel catalyst per litre of polymerization mixture.
The polymerization of the acetylene may be carried out both continuously and discontinuously. During this, a temperature of 20-120C, preferably 40-110C, particularly preferably 60 to 100C, is maintained.
lS The polymerization may be carried out at normal pressure but polymerization is also possible at increased pressure, for example at 1.01-20 bar, employing if appropriate a mixture containing a protective gas (such a8 N2).
The acetylene can be taken from a pressure bottle and used without further purification. With catalyst~
which are sensitive to acetone it may be necessary to freeze out in a cold trap beforehand, any acetone which i8 contained in the acetylene.
The pol~merization of the acetylene is carried out in a polymer solution of a polymer bearing polar groups. Here, polar groups are halogen atoms, nitrile groups, hydroxyl groups, e~ter groups and the like.
Examples of suitable polymers of this type bearing polar groups are polyvinyl chloride, polyvinyl alcohol (PVA) Le A 26 413 - 15 -~ 0 05 9~ ~

made from partially saponified polyvinyl acetate (PVAC) and other (co)polymers containing vinyl alcohol, poly-acrylonitrile, copolymers containing acrylonitrile, polyvinylpyrrolidone, methylcellulo~e and other cellulose derivatives, polycarbonate and 80 on; solutions of polyvinyl chloride, polyvinyl alcohol (PVA) made from partially saponified PVAC and other (co)polymer~ contain-ing vinyl alcohol, polyacrylonitrile, copolymers c~ntain-ing acrylonitrile, and polyvinylpyrrolidone are prefer-ably used.
The polyvinyl alcohol made from partially saponi-fied PVAC which is particularly preferably to be used as a solution, is in this case a polymer which has a degree of saponification of 70-90%, for example, preferably 80-15 90~.
These polymers containing polar groups arepresent in the form of a 301ution. Solvent~ for this purpose are for example dimethylformamide (DMF), dimethyl ~ulphoxide (DMS0) and 80 on. The concentration of the polymer in the solvent is 1-20% by weight, preferably 2-10~ by weight.
In order to produce the highly effective polar-izers which can be used according to the invention, the polymerization of the acetylene is carried out in the solution of a polymer bearing polar groups in the pre-sence of the nickel catalyst described, during a time interval of 5-1000 sec, preferably 5-600 sec.
The polarizers for the core layer which are obtained by short-duration polymerization (5-600 sec) and using the preferred catalysts are highly effective. They ~e A 26 413 - 16 -~ O ~ ~ 8 ~

have a maximum degree of polari~ation which iq even higher ~han de~cribed above, namely at least 95%, prefer-ably at l~ast 98%, particularly preferably at leaYt 99~.
Highly effective polarizers of this type further-more have a dichroic ratio QE f 10 or more over almostt;he whole wavelength range of visible light, namely in the range 400-800 nm. This ratio Q~ applie~ to a certain wavelength and in the case of suitable dichroic dyes is limited to a narrow wavelength range of visible light.
0 ThiB i8 discernible from the inherent colour of polar-izers produced with the aid of dichroic dyes; the said materials are moreover difficult to distribute uniformly over a relatively large surface of a film which iq to be coloured with the said dyes.
In contrastt the highly effective polarizers ~ust described exhibit a high Q~ value over almost the whole range of vi~ible light and are therefore colour-neutral, which is discernible from their inherent grey colour.
Films are produced from the polymer products containing polyacetylene (PAC), which can be carried out by casting from the solutions which arise during poly-merization. The films are ~tretched in the manner dis-cussed above.
The polymerization solution dsscribed above may be used directly for casting; however, stabilizers and/or plasticizers may also be added before proces~ing in a manner familiar to those skilled in the art. ~tabilizers of this type (for example W-stabilizer~) may, however, be incorporated additionally or alternatively into the adhesive layers or the outer layers. It i8 preferable to Le A 26 413 - 17 -~O~)S9~4 incorporate the stabilizer~ in the adhesive layer~ or the outer layers.
If the matrix of the polymer product containing polyacetylene tPAC) i8 a PVA, the polymer product con-taining polyacetylene may also be precipitated from the polymerization solution and freed from solvent, for example dimethy~formamide. The polymer product can then be taken up in water and cast therefrom. In this case it is advisable to add a plasticizer to this polymer solu-tion. Precipitating agents are, for example, toluene, cyclohexane, acetone, methanol, ethanol and others in which PVA is not soluble.
The lamination impart~ mechanical stability to the polarizer and protect~ it from being swollen by solvent~ or water. Chemical stability is moreover achi-eved, for exa~ple by protection from atmospheric sub-stances. The ease of handling is significantly increased by virtue of adequate stability and the possibility of cleaning the surface.
The degree of order in a stretched core layer is not reduced by the formation of the laminate and by the addition of plasticizers and/or stabilizers. This is also true of lamination by hot melt adhesion.
Example l Preparation of catalyst S mmol of bis-cyclooctadiene-nickel (0) in 100 ml sf dry toluene saturated with nitrogen were mixed under nitrogen with 5 mmol of benzoyl-methylene-triphenyl-phosphorane and 5 mmol of methylene-trimethylphosphorane.
The mixture was heated with vigorous stirring for about Le A 26 41~ - 18 -~005~84 1 hour at 40 to 60C~ The dark yellowi~h-brown solution was filtered and concentrated in vacuo to dryne6s. The yellow ca~alyst was dissolved in 25 ml of dry dimethyl-formamide saturated with nitrogen. This solution or a S part thereof was used in the subsequent polymerization of acetylane.
Exam~le 2 5 g of polyvinyl alcohol (degree of saponifica-tion 88%) were dissolved in 245 g of dry DMF (degassed, saturated with N2) at 120C in a 250 ml reaction flask (gas inlet, dropping funnel without pre sure compensation with N2 feed, ~tirrer, internal thermometer, reflux conden3er with bubble gauge) and then ad~usted to a temperature of 80C. Then 1.0 mmol of the cataly~t described in Example 1 in 5.0 ml of DMF were stirred in under N2 and a uniform stream of acetylene gas (dry ice/acetone) was fed in for 15 sec. The reaction solution was then filtered through a polyamide cloth having a mesh width of 200 ~m.
The clear blue PVA-PAC solution ~absorption maximum 633 nm) was spread hot on a PET film with a doctor blade to form a 400 ~m layer. After evaporation of the ~olvent a clear, blue film was obtained, which was pulled off the base and stretched at about 130C to 760%.
The optometric data of the polarizer formed in this manner, with light of wavelength 600 nm, were:
Dichroic ratio QE: 2 1 . 4 Degree of polarization P: 99.4%
The optometric data (including those from the following examples) were measured with the aid of a Le A ?5 413 - 19 -~005984 spectrophotometer of the type Uvikon 810 P supplied by Kontron.
Examples 3-6 Other polarizers containing polyacetylene (PAC) were produced analogously to Examples 1 and 2. Their properties are listed in the following table.

Le A 26 413 - 20 -0~ O ~ d~ I` ' ~O ~ Cr.
~ 1~ N P~ O~ O~ ~n ~

.~ .. _ _........... __ _ D N I~ I~ C
~o ~ ~ dP ~0 U~ ~0 O
--_ _ ~ U~ _l ~ ~ ~ O--~ D ~ æ _ - ~ D a ~ ~ O

7 ~ O. ~. ~
O~u~ O ~ O O .
~ ~^ ~ ~
~ ~ D ~ D ~ D ~

L~ A 26 413 - 21 -X013~98~

Example 7 A polyvinyl alcohol-polyacetylene film produced analogously to Example 2-6 and stretched at 145C, which contained 2~ of glycerol as plasticizer, relative to the matrix, which plasticizer has been added to the ca~ting solution after polymerization was complete, had the following optometric data for light of wavelength 600 nm:
Dichroic ratio QE: 19 . S, Degree of polarization P: 99.7%
and was laminated as follows:
2 mm thick glass sheets were coated on one side using a doctor blade to a layer thickness of 400 ~ with a poly-urethane polyurea (PU) in accordance with DE 2,644,434, as a 5% strength ~olution in methylene chloride (the solution con~ained lOY. UV-absorber of the formula HC ~ ~CN

(Bayer W 340-) relative to PU), and dried. The approxi-mately 12 ~ thick polarizing film described above was laîd between the PU- coated sides of two such glass sheets and sub~ected to a pressure of 20 bar at 150C for ~ 5 min. A polarizer resulted which had the following properties with light of wavelength 600 nms Dichroic ratio QE: 19.4 Degree of polarization P: 99.6%
Corresponding results were obtained, when the ~5 Le A 26 413 Z005g~4 core layer was provided with adhesive layers and subse-quently the outer layers were applied.
L-ikewise comparable results were obtained when this polarizing core layer provided with a PU- adhesi~e S layers was covered with silicone treated paper, placed in intermediate storage for 1 week and only then bonded with the outer layers.
Example 8 A 1000 hour stability test was carried out in each case in relation to heat resistance at 100C and to W resistance, using 2 PU-bonded PVA-PAC polarizing films laminated to glass.
Afterwards the polarizing properties with light of wavelength 600 nm were afterwards as follows:
lS Heat test Xenon lamp (1000 h, 100C) test (1000 h, W) Dichroic ratio Qes 18.7 19.6 Degree of polarization P: 99.6% 99.2 La A 26 413 - 23 -

Claims

1. Laminated polarizers made from a polarizing core layer and adhesive layers on one or both sides, each of which can accept a transparent outer layer, the polarizer comprising a polymer product containing polyacetylene as core layer, the matrix of the polymer product being a polymer having polar groups.

2. Laminated polarizers according to Claim 1, produced by applying the adhesive layers to the polariz-ing core layer and applying the transparent outer layers by hot melt adhesion after an intervening period of time (occasioned by intermediate storage and/or transport).

3. Laminated polarizers according to Claim 2, characterized in that until an outer layer is applied the adhesive layers are provided with an easily removable protective layer.

4. Laminated polarizers according to Claim 1, characterized in that as adhesive layers, thermoplastic polyurethane-polyureas are used having a predominantly linear molecular structure with urethane segments and urea segments bonded exclusively aliphatically or cyclo-aliphatically, and which are distinguished by having a) a content of urea groups -NH-CO-NH- of 1-20% by weight and b) a content of carboxyl groups -COOH bonded directly to the main chain of the molecule in lateral posi-tions, of 0.001-10% by weight, all relative to the total weight of the polyurethane-polyureas.

5. Laminated polarizers according to Claim l, characterized by outer layers applied on one or both Le A 26 413 - 24 -sides, made from mineral glasses, an aromatic polyester, polyacrylonitrile, poly(meth)acrylate, polysulphone, aromatic polycarbonate, cellulose acetate, cellulose acetate butyrate, polyamide, polyhydantoin, polyimide, polyamide-imide, polyparaphenylenebenzo-bis-imidazole and -oxazoles, polyether ketones, and preferably from an aromatic polyester, polyacrylate, polycarbonate, cel-lulose ester and mineral glasses.

6. Laminated polarizers according to Claim 1, characterized by a polarizing core layer in the form of a stretched film, with a stretch ratio c of more than 200%, preferably at least 500%, particularly preferably at least 600%.

7. Laminated polarizers according to Claim 1, whose polarizing core layer can be produced by polymerizing acetylene in the solution of a polymer having polar groups in the presence of a nickel catalyst, which is obtained by reacting a nickel (0) compound or a compound which can be converted in situ into a nickel (0) com-pound, with phosphorus compounds of the formulae and in which R1, R2 and R3 independently of each other denote straight-chain or branched C1-C20-alkyl, C1-C20-alkoxy, C3-C8-cycloalkyl, C2-C8-alkenyl, C6-C12-aryl, C6-Cl2-aryloxy, C7-C15-aralkyl or Le A 26 413 - 25 -di(c1-C4alkyl)-amino, R4, R5, R6, R7 and R8 independently of each other denote straight-chain or branched C1-C20-alkyl, C2-C30-alkenyl, C1-C20-alkoxy, C3-C8-cycloalkyl, C6-C12-aryl, C5-Cl2-aryloxy or C5-Cl1-aralkyl, and R7 may additionally denote hydrogen and R8 may additionally denote hydrogen or acyl and X denotes double-bonded oxygen, the group NR9 or the group , and R9 and R10 independently of each other denote hydrogen, silyl, acyl, phenyl, cyano or R1.

8. Laminated polarizers according to Claim 7, characterized in that the nickel catalyst for producing the polarizing core layer is obtained by reaction with phosphorus compounds of the formulae and in which R1, R2, and R3 independently of each other denote straight-chain or branched C1-C20-alkyl, C1-C20-alkoxy, C3-C8-cycloalkyl, C2-C6-alkenyl, C6-C12-aryl, C6 C12-aryloxy- C7-C15-aralkyl or di (C1-C4-alkyl)-amino, R4 represents C6-C12-aryl, Le A 26 413 R5, R6, R7 and R8 independently of each other denote straight-chain or branched C1-C20-alkyl, C2-C30-alkenyl, C1-C20-alkoxy, C3-C8-cycloalkyl, C6-C12-aryl, C8-C12-aryloxy or C7-C15-aralkyl, in which R7 may additionally denote hydrogen and R8 may additionally denote hydrogen or acyl, and R9 and R10 independently of each other denote hydrogen, silyl, acyl, phenyl, cyano or R1, and is preferably obtained by reaction with phosphorus compounds of the formulae and in which R11, R12 and R13 independently of each other denote C1-C8-alkyl, phenyl or benzyl and R15, R16 and R18 independently of each other denote C1-C8 alkyl or phenyl, and R18 may additionally denote hydrogen or acyl, and R19 represents hydrogen, C1-C8-alkyl or phenyl, and is particularly preferably obtained by reaction with phosphorus compounds of the formulae and Le A 26 413 - 27 -in which R11, R12, R13 and R18 have the meaning above.

9. Laminated polarizers according to Claim 8, in which the polarizing core layer is obtained by short-duration polymerization.

10. Laminated polarizers according to Claim 9, characterized in that the matrix of the polymer product containing polyacetylene is a polyvinyl acetate saponi-fied to 70-90%.

11. Laminated polarizers according to Claim 1, characterized by a content of stabilizers in the polariz-ing core layer, in the adhesive layer or in the outer layer.

Le A 26 413 - 28 -