DD297257A5 - POLYMER MATERIALS AND ITS USE - Google Patents

Abstract

Polymeric materials containing nonlinear optically active chromophores with electron donor / acceptor substituted conjugated p-systems and additional photocrosslinking groups, characterized in that the photocrosslinking groups absorb in the UV region of the wavelength l300 nm, are outstandingly suitable for the production of non-linear optical arrangements. which can be used in optical components.

Description

Merck Patent Limited Company

6100 Darmstadt

Polymen materials and their use Field of application of the invention

The invention relates to polymer materials containing nonlinear optically active chromophores with electron donor.-acceptor-substituted conjugated π systems and additionally photocrosslinking groups, characterized in that the photocrosslinking groups in the UV range of wavelength λ έ absorb 300 nm.

Materials exhibiting nonlinear optical behavior are characterized by field strength dependent dielectric susceptibility. This nonlinearity of dielectric susceptibility results in a number of effects which are of great technical interest.

The second harmonic generation (SHG) is the generation of light that is half the wavelength compared to the incident light. The electro-optical effect (Pockels effect) is the change in the refractive index of a material with an applied electric field; Methods of sum and difference frequency mixing as well as frequency division - * allow continuous tuning of laser light.

Nonlinear optical materials are suitable for the production of optical components. These include, for example, electro-optical modulators, electro-optical switches, electro-optical directional couplers and frequency doublers.

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These devices find application e.g. in optical communications engineering, for modulating and controlling optical signals, as spatial light modulators in optical signal processing, for frequency doubling of semiconductor lasers, for optical data storage, sensor technology and xerography.

Characteristic of the known technical solutions

Polymers have proven to be non-linear optical materials. They are characterized by high mechanical resistance and good chemical stability. For this reason many polymers developed with dissolved or covalently bonded NLO chromophores (NLO = nonlinear optical) have been developed to date. Polymers provided with dissolved or covalently bonded NLO chromophores typically undergo a second-order nonlinear susceptibility (χ ¹ ') by the application of an electrical field in the fluid state, with the NLO chromophores dipolarly oriented. The dipolar orientation is achieved by cooling

( 2 ) frozen below the glass transition temperature. As a result, χ ^ν ' is, to a first approximation, proportional to the concentration of NLO chromophores, E field strength, hyperpolarizability β, and dipole moment μ. Therefore, compounds with large dipole moments and simultaneously high B values are of considerable interest. For this reason, NLO chromophores have already been investigated, which consist of a conjugated π-system, at the ends of which an electron acceptor or an electron donor are bound. Polymeric materials containing such donor / acceptor-substituted π-systems in side chains are known, for example polymethacrylates (EP 0231770, EP 0230898), polystyrenes (JP 63041831, JP 61148433) or polyester (EP 0297530).

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However, the known NLO-r polymers have the disadvantage that the dipolar orientation also relaxes below the Glaeübergangstemperatur to varying degrees.

Object of the invention

The aim of the invention was to find Polymermateriälien, suitable for use in nonlinear optics, in which this relaxation is no longer observed or only to a small extent.

Explanation of the essence of the invention

This object is achieved by providing the polymer materials according to the invention. It has surprisingly been found that the relaxation of the dipolar orientation in the glassy state can be considerably reduced if the polymer materials thus oriented are photocrosslinked. JP 61167930 describes NLO side-chain polymers which are photochemically treated. However, reactive radicals are generated by means of hard UV radiation (λ <200 nm), x-ray or ion current from halogen-containing side chains.

The invention thus relates to polymer materials containing non-linear optically active chromophores with electron donor / acceptor-substituted conjugated n-systems and additionally photocrosslinking groups, characterized in that the photocrosslinking groups in the UV range of wavelength λ έ absorb 300 nm.

The invention relates in particular to said polymer materials based on homo- and copolymers in which the non-linear optical chromophores and photocrosslinkable groups, covalently bound, are contained in side chains.

The invention further photocrosslinked polymer materials containing nonlinear optical chromophores with electron donor / acceptor-substituted conjugated π systems, characterized in that the photocrosslinking was carried out by means of UV light of wavelength λ έ 300 mn.

The invention also relates to nonlinear optical arrangements containing the photocrosslinked polymer materials according to the invention.

Finally, the invention relates to a process for the preparation of the nonlinear optical arrangements according to the invention by photocrosslinking and dipolarizing the photocrosslinkable polymer materials in any order or simultaneously with UV light of wavelength λ 2 300, and by using the nonlinear optical arrangements in US Pat optical components and optical components containing the non-linear optical devices according to the invention.

The polymer materials of the present invention consist mainly of homopolymers or copolymers in which non-linear optical chromophores and photocrosslinkable groups are covalently bonded. By "homopolymers" is meant polymers in which the nonlinear optical chromophore and photocrosslinking group are covalently linked within a monomer unit, for example in a polymerizable unsaturated dicarboxylic acid ester such as itaconic acid diester, where one alkoxy component contains the chromophore, the other the photoinitiator. By "copolymers" is meant accordingly polymers that can be prepared from various monomers, wherein

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Chromophore and initiator are each bound in a different monomer unit. Preferably, the NLO chromophores as well as the photocrosslinking groups are linked in side chains.

The structure of the polymer backbone is largely uncritical. The polymeric materials of this invention may, for example, possess polyacrylates of polymethacrylate, polymethacrylamide, polyacrylamide, polyurethane, polystyrene, polycarbonate, polyester, polyvinylester or polyimide structure. Preferably, both units, the NLO-chromophore and the photocrosslinking group, are polymer-polymerizable Bonded groups, for example as Alkoholkoroponenten in acrylates, methacrylates or common homologues such as chloro or cyanoacrylates or Etliylacrylaten. However, they can also be bound as corresponding Arain components in acrylamides, methacrylamides or common homologues, as mentioned above.

A preferred group of monomers having photocrosslinking groups attached in side chains are monomers of formula I.

I CH ₂ = C (X) ₀₁ -In

wherein

R is -H, -Cl, -CN, C _1-6 -alkyl or phenyl,

X is -CO-, -COO-, -O-C0-, - (CH ₂ ) J ₁ Y-, -COO (CH ₂ ) _n Y-, -CO (OCH ₂ CH ₂ ) _n Y- where η = 1 -10,

Y is a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -NH-, -N (C _1-6 alkyl) - and

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In a photin. · ¹ , ti a torgr ands tr cture

'2

ir

wherein

R ¹ -CR ³ R ⁴ R ⁵ or -P (R ⁶ ) ₂ ),

2 R -H / halogen, C,... Alkyl or C ₁ , _2- alkoxy,

R, R are each independently H, C _1-12 "alkyl, C _1-12 alkenyl, C _1-12 alkoxy or together C _2-6 alkylene,

R is -OH, C _1-6 -alkoxy, C 1-3 -alkanoyloxy, -N (C _1-6 -alkyl) ₂ ),

"O '" O' O * '

-NO, -SO ₂ R ⁷ , -OSO ₂ R ⁷ ,

R Cj ^ alkyl, C _1-6 -AlkBnOyI, phenyl or

j ₁₆ <benzoyl, each optionally with halo *

substituted, C _1-6 ~ alkyl or C _1-6 ~ alkoxy

R ^{7 is} C _1-6 alkyl, phenyl.

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The monomers of the formula I thus contain a polymerizable ethylenically unsaturated structural part in which the radical R can be hydrogen, chlorine, cyano, a C 1 -C 4 -alkyl or a phenyl group. Preferably, R is hydrogen and thus the unsaturated moiety is a vinylic group. This unsaturated structural part is linked either directly via a single bond or via a bridging group X with an arbitrary photoinitiator basic structure In, as in principle also exists in conventional photoinitiators.

The bridging group X may be a carbonyl, a carboxyl or an alkylene group having 1-10 C atoms, it may also be a carbonyloxyalkylene or a carbonylpolyoxyethylene group each having 1-10 methylene or oxy-ethylene units. The linkage with the photoinitiator basic structure In can be effected by a single bond, by an oxygen, sulfur, carbonyl, carboxyl or amino group. Preferred linkages of unsaturated moiety with photoinitiator base In are the single bond, the carbonyl, the carbonyloxymethyleneoxy and the carbonyloxyethoxy groups. In the case of linking by single bond, vinyl-substituted derivatives of conventional photoinitiators result. In the other cases of preferred linkages, acrylated photoinitiator derivatives result.

In stands essentially for the aromatic ketone moiety

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however, as present in most of the classical photoinitiators, they can also mean any other structures with photoinitiator properties.

If R stands for the grouping -CR ³ RR ⁵ , then, according to the abovementioned definitions for R ³ , R ⁴ and R, the photoinitiator bases of the acyloin ethers, the dialkoxyacetophenones, the hydroxyalkylphenones and aminoalkylphenones and also the cr-sulfonyl ketones.

Copolymerizable hydroxyalkylphenone derivatives are particularly preferred monomer units of the formula I.

l ^U 6

When R is the group -P (R) ₂ , the resulting photoinitiators belong to the class of acyl phosphine oxides.

Numerous unsaturated derivatives of various photoinitiator groups, as represented by formula I, are known and in part also commercially available. This applies in particular to the hydroxyalkylphenone derivatives described in DE-OS 35 34 and EP-OS 161463 and the corresponding unsaturated functionally-synthesized photoinitiators of German Patent Applications P 37 07 891 and P 37 38 567. They are in principle producible by standard methods of organic chemistry.

The reaction conditions in this case can be taken from the standard works of preparative organic chemistry, e.g. HOUBEN-WEYL, Methods of Organic Chemistry, Georg-Thieme Verlag, Stuttgart, or ORGANIC SYNTHESIS. J. Wiley, New York London Sydney.

In general, it is favorable to use the comonomers of the formula I or corresponding precursors according to the established synthesis methods as described for the underlying photoinitiators.

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ren are common to produce. It is advantageous, starting from the known Fot.oinitiatoren as starting substances and ar. to link these with common reactions, such as substitution reactions, in one or more steps, the unsaturated structural unit. However, it is also possible to use already suitably substituted precursors of the known photoinitiators and to generate the actual photoinitiator structure of action in them only when the unsaturated structural part is already present.

Particularly suitable as precursors for unsaturated functionalized photoinitiators are numerous of the photoinitiator derivatives described in German Patent Applications P 37 07 891 and P 37 38 567, which carry reactive substituents having functional groups.

Of these, preference is given to the hydroxyethoxy- and hydroxyethylthio-substituted photoinitiator derivatives, since these can be easily converted into the corresponding (meth) acrylic esters. Typical unsaturated functionalized photoinitiator derivatives which can serve as monomer building blocks of the formula I for the polymer materials according to the invention are, for example

(4-Vinylphenyl) -2-hydroxy-2-propyl ketone (Ia)

(4-Allyloxyphenyl) -2-hydroxy-2-propyl ketone (Ib)

(4- (2-Allyloxyethoxy) phenyl] -2-hydroxy-2-propyl ketone (Ic) 4- (2-hydroxy-2-methylpropionyl) phenoxyacetic acid

vinyl ester (id)

(4-Acryloyloxyphenyl) -2-hydroxy-2-propyl ketone (Ie)

(4-Methacryloyloxyphenyl) -2-hydroxy-2-propyl ketone (If)

[4- (2-acryloyloxyethoxy) phenyl] -2-hydroxy-2-

propy! ketone (Ig)

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[ 4- (2-methacryloyloxyethoxy) phenyl] -2-hydroxy-2-propyl ketone (Ih)

I4- (2-Acryloyloxy-diethoxy) -phenyl] -2-hydroxy-2-propyl ketone (Ii)

(4- (2-acryloyloxyethyl) thiophenyl] -2-hydroxy-2-

propyl ketone (Ij)

ί4- (2-acryloyloxyethylthio) phenyl] -2- (N-raorpholino) -

2-propyl ketone (Ik)

A preferred group of monomers containing the NLO chromohore pore covalently bound in side chains are monomers of formula II

R O

I II CH ₂ = CCZ- (Sp) ₀ yA II

wherein

R is -H, -Cl, -CN, -C _1-6 -alkyl or phenyl,

Z -NR ^X - or -O-,

Sp a spacer

R ^x -H or C _1-6 alkyl and

A is a non-linear optical chromophore, AH being a compound of formula III,

III

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wherein

D -NR 2> "* ^0R or -SR,

Each independently of one another is -H, -NR ¹ J, -OR ¹ or -SR ¹ ,

B -NO ₂ , -CN, ^ <j, ~ <g; _0R 2or

^ ⁼ > -CN

1 2 B and B are each independently -H, -NO ₂ ,

-CN, halogen, -CF ,,, -COOR ¹ , -CONR ¹ ,

1 11 1

-SO-R, -SO ₉ R, -SOR, or -SO ₀ NRi,

1 2

G and G are each independently a single bond, -fC (R ² ) = C (R ² ) - * _m -, -N = N-, -C = N-, -N = C- or -C = C-,

ra 1 or 2,

L is a carbo- or heterocyclic system with 5-18 ring atoms containing up to

three hetero ring atoms selected from the group N, O and S,

η O, 1, 2 or 3,

ρ 0 or 1,

Each R is independently H or C 1 -C 4 alkyl and

Each R is independently H or C 1 -C 8 alkyl

with the proviso that B is hydrogen if ρ is 1.

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The NLO chromophores A can in principle be bound to any C atom of the formula III which is linked to the linkage. Preferably, the NLO chromophore according to formula III is linked within the donor part (D, D ¹ ) to the radical of the formula II. Particularly preferred is the link via D.

In the formula III, D is preferably -NR ₂ or -OR B is preferably -NO ₀ and -CN.

Each independently of one another preferably denotes -H, -NR ₂ or -OR ¹ .

1 2 B and B are each independently H or an electron acceptor group such as -NO ₂ , -CN or halogen, such as. B. -F, -Cl or -Br, -CF ₃ , -COOR ¹ , -CONR ₂ and SuIfoxid-, sulfonate and sulfonamide groups, preferably -NO ₂ , -CN, -F, -Cl, -CF ₃ and - COOR ¹ . In the case of ρ equal to 1, however, both radicals B are H.

1 2 The bridge elements G and G are each independent

2 2 each other is a single bond, fC (R) = C (R)} _ with m equals 1 or 2, -GsC-, -C = N, -N = C-, -N = N- or -CsC-.

2 2 Particularly preferred are single bond, -C (R) - = C (R) - and -ChC-. <

L is a carbocyclic or heterocyclic π system having b to 18 ring atoms, in particular 1,4-phenylene, 2,6- and 2,7-naphthylene or anthracene, 2,5-pyrrolediyl, -furanyl and However, other heteroaromatics may also be L, but not more than three hetero ring atoms Preferred polymers according to the invention contain not more than two heteroaromatics in a side chain.

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R (in the formula III) denotes H or a branched or straight-chain alkyl radical having up to 24 C atoms. Preferably R is H or a straight-chain radical and is preferably methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, octadecyl, eicosyl and docosyl.

R (in formula III) is preferably H, methyl, ethyl, propyl, butyl, pentyl or hexyl.

Particularly preferred nonlinear optical chromophores of the formula III correspond to the partial HIa to IIIu. For the sake of simplicity, here and in the following Phe means 1,4-phenylene,

15 phe

-, Phe,

and

Het one of the preferred heteroareas, selected from the group 2,5-Pyrroldiyl, -Franandiyl and -Thiophendiyl, Pyridindiyl, Pyrimidindiyl, triazinediyl and indolediyl.

D-Phe ₃ -B

D-Plite ₁ -G ² -Phe ₂ -B

D-Phe-Phe ₁ -Het ₂ -B ₁ D-Phe -Phe-G ² -Phe-Phe D ₂ -B ₁ -G ¹ -Phe-Phe D-Phe ₂ -B ₁ -G ¹ -Het-Phe ₂ -B

IHa IHb IHc HIe HIf HIh HI IHj

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D-Phe ₁ -G ¹ -Phe-G ² -Phe-Phe D ₂ -B ₁ -G ¹ -Het-G ² -Phe ₂ -B-D-Phe-Phe-plié ₁ G ² -Phe ₂ -B D-Phe ₁ -Phe-Het-G ² -Phe ₂ -B D-Phe-Phe--Het ₁ G ² -Phe-Phe D ₂ -B ₁ -G ¹ -Phe-Phe-Phe G ² ₂ - B D-plié ₁ -G ¹ -Phe-Het-G ² -Phe-Phe D ₂ -B ₁ -G ¹ -Het-Phe-Phe G ² B ₂ D-PhO ₁ -G ¹ -Phe-Phe -Phe ₂ -B D-Phe ₁ -G ¹ -Phe-Het-Phe ₂ -B D-Phe ₁ -G ¹ -Het-Phe-Phe ₂ -B IHk Him Him Him Hip IHq Your Hit Him

Of the polymers according to the invention with the non-linear optical chromophores according to the sub-formulas HIa to IHu are particularly preferred those which the

15 given preferred meanings for D, D

B, B ¹ ,

B ² ,

_r l _r 2 G / G,

1 2 L, R and R have.

D-Phe, - means preferably

OR

R ¹ O

NO,

«Veh»

B ¹ O

-Phe, -B means preferably -

-NO

2 '

CN,

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Hal NO ₀ COOR ¹

Hal Hal CN Hal Hal

where Hal is F or Cl.

Of the NLO-Chroraophoren according to formula III are particularly preferred those in which all radicals D, B and

B 'is H or one of these radicals is different from H.

Very particularly preferred NLO chromophores are ρ, ρ ¹ -aminitrostilbene and chromophores derivable therefrom. They are, for example, by shortening or by extension of the π system with aromatic or heteroaromatic radicals, double bonds, triple bonds or additional substitution, preferably at the ends of the conjugated π system, adjacent and, seen electronically, in the same direction to the existing electron donor or acceptor, structurally derivable from the ρ, ρ'-aminonitrostilbene skeleton. Furthermore, NLO-Chroraophore are preferred in which instead of the amino or nitro group of the stilbene derivatives mentioned other electron donor or acceptor groups are bound.

The linkage of the NLO chromophores A according to formula II can, for example, within D or D, an alk rest of an amino or ether group, either directly

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₀ I or via a spacer, for example by an -0- and / or -N (C _1-6 -AIlCyI) - interrupted alkylene chain, carried out.

The compounds of formula III can be prepared by standard methods of organic chemistry.

The reaction conditions may be taken from the standard works of the preparation of Organic Chemistry, e.g. HOUBEN-WEYL, Methods of Organic Chemistry, Georg Thieme Verlag, Stuttgart, ORGANIC SYNTHESES, J. Wiley, New York-London-Sydney, or HETEROCYCLIC COMPOUNDS, Vol. 14, J. Wiley, New York-London-Sydney.

Thus, for example, compounds having -C = C double bonds can be prepared by condensing alkyl compounds with corresponding aldehydes or ketones in a conventional manner. The condensation is advantageously carried out with the addition of a dehydrating agent such as acetic anhydride, a base such as ammonia, ethylamine, piperidine, pyridine or a salt such as ammonium acetate or piperidinium acetate.

Also useful is the addition of an inert solvent such as hydrocarbons such as hexane, cyclohexane, benzene, toluene or xylene. The reaction temperature is usually between 0 ° and 250 ° C, preferably terminates between + 20 ° and 150 ⁰ C. At these temperatures, the reactions are usually 15 minutes to 48 hours. Stilbene derivatives can be prepared, for example, by Wittig reaction or also by Wittig-Horner reaction from corresponding aromatic aldehydes and corresponding Arylmethylphosphoniumsalzen or phosphonates.

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C = N or N = N double bonds are obtainable by analogous condensation reactions of aldehydes and primary aroins, or nitroso compounds and primary amines in a manner known to those skilled in the art.

In a further process for the preparation of said compounds, a (hetero) aryl halide is reacted with an olefin in the presence of a tertiary amine and a palladium catalyst (see RF Heck, Acc. Chem. Res., (1979) 146). Suitable (hetero) aryl halides are, for example, chlorides, bromides and iodides, in particular bromides. The tertiary amines required for the success of the coupling reaction, such as triethylamine, are also suitable as solvents. Suitable palladium catalysts are, for example, its salts, in particular Pd (II) acetate, together with organic phosphorus (IH) compounds such as, for example, triarylphosphines. It can be in the presence or absence of an inert solvent at temperatures between about 0 ° and 150 ⁰ C, preferably between about 20 ° and 100 ⁰ C, work; Suitable solvents are, for example, nitriles such as acetonitrile or hydrocarbons such as benzene or toluene. The (hetero) -aryl halides used as starting materials and olefins are widely available commercially or can be prepared by literature methods! be, for example by halogenation of corresponding parent compounds or by elimination reactions of corresponding alcohols or halides.

Furthermore, for the coupling of (hetero) aromatic compounds (hetero) aryl halides with (hetero) aryl tin compounds or (hetero) arylboronic acids can be implemented. Preferably, these reactions are carried out with the addition of a catalyst, e.g. a palladium (O) complex in inert solvents such as hydrocarbons at high temperatures, e.g. in boiling xylene, under protective gas.

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The vicinal position of electron donors and electron acceptors in multiple substitution may already be present at the level of the outgoing compounds. First, a number of vicinally substituted starting compounds are already commercially available, e.g. Phthalonitrile, o-dinitrobenzene, 3,4-dinitrotoluene, 3,4-dinitrobenzyl alcohol, 3-fluoro-4-nitrotoluene, o-phenylenediamine and o-dihaloaromatic and other unspecified vicinal by electron donors or acceptors substituted aromatics (Fa. Merck, Darmstadt). On the other hand, they can be prepared by suitable substitution reactions from lower-substituted precursors, for example by nitration of 3-cyanotoluene, the 3-cyano-4-nitrotoluene, optionally conversion of the nitro group via the amine with subsequent diazotization in the nitrile. O-phenylenediamine can be alkylated and converted into the benzaldehyde derivative by Vilsmeier's formylation. The reactions described are but a small selection of a wide variety of possible variations. The preparation methods are known in the art and in common textbooks, as well as in standard works of Preparative Organic Chemistry, z. In HOUBEN-ViEYL, Methods of Organic Chemistry, Georg Thieme-Verlag Stuttgart. The starting compounds themselves are known or can be prepared analogously to known methods.

The preparation of the polymer materials according to the invention is carried out in a conventional manner. Preferred polymer materials according to the invention are copolymers, preferably from monomer units according to formula I and II and optionally one further monomer unit III. As comonomers III are preferably considered:

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C ₁ - to C ₂₀ -, preferably C ₁ - to C ₈ -alkyl esters of acrylic acid and / or methacrylic acid, mixtures of these esters and mixtures of said esters with acrylonitrile, methacrylonitrile, styrene, 4-methylstyrene, acrylic and / or methacrylamide.

Examples of acrylic acid esters are:

Methylacrylate, ethylacrylate, propylacrylate, n-butylacrylate, isobutylacrylate, hexylacrylate, n-octylacrylate, 2-ethylhexylacrylate, nonylacrylate, decylacrylate, dodecylacrylate, hexadecylacrylate, octadecylacrylate and the corresponding methacrylates.

The acrylates and methacrylates mentioned are preferably alkanols having up to 8 carbon atoms.

The monomer ratio (molar ratio) of the monomers I, II and III for preparing the preferred polymer materials of the invention is preferably as follows: 10-80%, preferably 40-80% monomer I, 20-90%, preferably 20-60% monomer II and 0 -80%, preferably 0-50% monomer III. The sum of the percentages is naturally 100 for each monomer mixture to be copolymerized

The copolymerization is carried out in a manner known and customary to the person skilled in the art, namely in solution with the aid of customary thermally activatable free-radical initiators, such as, for example, benzoyl peroxide or azobisisobutyronitrile, with the exclusion of exposure to light.

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Typical solvents for the polymerization are about tetrahydrofuran and toluene. The reaction is usually carried out at the reflux temperature of the solvent or below, for example at about 60 ⁰ C in the case of toluene. The isolation is carried out by precipitation with a non-solvent, for example η-hexane. By optionally reprecipitated the copolymers can be purified.

The nonlinear optical arrangements according to the invention can be produced in various ways. For example, they can be prepared by applying a polymer material according to the invention, for example e.in copolymer by spin coating, brushing, printing or dipping on a substrate surface, such as glass applied, dipolar and irradiated with UV light of wavelength λ > 300 nm. Dipolar alignment and ordering may be performed simultaneously or in any order.

The orientation is suitably carried out at a temperature which is close to the glass transition temperature of the polymer, preferably by means of an electric field. The temperature can be both above and below the glass transition temperature. Subsequently, it is cooled in the electric field.

The required for the dipolar alignment by means of an electric field electrodes are usually mounted so that first the glass surface with an electrode, for. As indium-tin-oxide (ITO) or aluminum is coated, and after applying the polymer material of the invention, the second electrode, usually consisting of gold or chromium, is vapor-deposited.

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The exposure is usually carried out with corresponding UV lamps, for example mercury vapor lamps at room temperature.

Preferably, exposure is made simultaneously with an electric field applied.

The photocrosslinked polymer materials according to the invention are thus distinguished by their ease of preparation under mild conditions. They also have advantageous properties over conventional polymer materials such as in particular reduced relaxation of the dipolar orientation in the glass state, increased glass transition tempera door, greater mechanical stability and increased resistance to solvents.

The nonlinear optical arrangements according to the invention are thus suitable, for example, for use in optical components. They can thus be used by utilizing the electro-optical effect or frequency doubling and frequency mixing on the one hand in bulk materials and on the other hand in waveguide structures. The arrangements according to the invention may optionally themselves function as waveguides.

They are thus suitable for example in components in the field of integrated optics, sensor and telecommunications technology, for frequency doubling of laser light, for the production of directional couplers, switching elements, modulators, parametric amplifiers, waveguide structures, light valves and other, known in the art, optical components. Optical components are described for example in EP 0 218 938.

The following examples serve to illustrate the invention.

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Exemplary embodiments " *

example 1

Monomer with NLO chromophore

N-hexyl-N- (4-methacryloyloxybutyl) -4-amino-4'-nitrostilbene

a) N-hexyl-4-amino-4'-nitrostilbene

A solution of 47.9 g (0.20 mol) of 4-amino-4'-nitrostilbene (obtainable from 4-acetamidobenzaldehyde and 4-nitrophenylacetic acid by heating in pyridine / piperidine and subsequent deacetylation in ethanol / hydrochloric acid) and 33.0 g (0.20 mol) of 1-bromohexane in 170 ml of l, 3-dimethyl-2-imidazolinone (DMEU) is mixed with 16.8 g (0.20 mol) of sodium bicarbonate and heated to 100 ⁰ C for 3 h. The mixture is allowed to cool, poured into water and extracted with dichloromethane. The organic phase is dried over sodium sulfate, evaporated and the residue on a silica gel column with petroleum ether / ethyl acetate 1: 1 as the medium is chromatographed. You get red crystals.

b) N-Hexyl-N- (4-methacryloyloxybutyl) -4-amino-4'-nitrostilbene

A solution of 20.8 g (64.1 mmol) of N-hexyl-4-amino-4'-nitrostilbene, 20.6 g (76.9 mmol) of 4-iodobutyl methacrylate and 5 mg of 2,6-di-tert. butyl-4-methylphenol in 100 ml of DMEU is combined with 6.5 g (76.9 mmol) of sodium bicarbonate and heated to 100 ⁰ C for 16 h. Then, as described in Example la, worked up and chromatographed with toluene as the eluent.

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Example 2

Copolymer of the monomer of Example 1 b) and the monomer of the formula Ig

A solution of 4.64 g (10 mmol) of N-hexyl-N- (4-methacryloyloxybutyl) -4-amino-4'-nitrostilbene, 9.03 g (32.4 mmol) of the photoinitiator-containing monomer Ig, 0.101 g (1.12 mmol) Butanthiol and 0.558 g (3.4 mmol) of azobisisobutyronitrile in 50 ml of toluene is heated to 60 ⁰ C for 48 h. It is allowed to cool to room temperature, filtered off and the residue is washed with dichloromethane. The filtrate is concentrated and the polymer is precipitated from ethanol. A red solid is obtained.

Example 3

A solution of the copolymer of Example 2 (0.6 g in 1.6 g of N-methylpyrrolidin-2-one (NMP) and 1.6 g of ethoxyethyl acetate) is prepared.

The solution is filtered (filter with pore diameter 2 μ) to remove dust particles. A glass plate coated with ITO (indium tin oxide) (4 cm × 4 cm, thickness: 1.1 mm) is cleaned in neutral soap solution (Extran, Merck) by ultrasound for 10 minutes, then rinsed in double distilled water and rinsed with isopropanol. The polymer solution is spun onto this glass plate (1000 U / min), then dried in vacuo at 60 ⁰ C for 4 hours. The film thickness is about 1.3 pm. On this film, a semitransparent gold electrode is evaporated.

The film is heated in a vacuum oven to 60 ⁰ C, then a DC voltage of 100 V at a temperature of 80 ⁰ C is applied. At the same time, an Hg medium

PAT LOG 19-A 200789

- 24 -

exposed to pressure lamp. After 30 minutes, the exposure is stopped and the sample cooled to room temperature at 1 ° C / min. Thereafter, the E-FeId is turned off. To determine the relaxation behavior of the dipolar orientation, the film is measured at intervals as follows. The first measurement is carried out immediately after cooling the dipolar oriented and exposed film to room temperature. The film is placed in the beam path of an Nd: YAG laser (λ = 1.06 μΐη, pulse duration 7 nsec, pulse energy 0.5 mJ, 50 ° angle to the film surface). The intensity of the frequency-doubled light, which is a measure of the frequency doubling efficiency of the sample, is measured by detecting a photomultiplier signal.

Renewed measurements on the same sample are made every 24 hours. After 1 week, the intensity of the frequency-doubled radiation decreased to 90% of the initial value. Re-measurement after 1 month showed a decrease to 85% of the initial value. This corresponds to a relaxation of the dipolar orientation to 92 % of the initial value.

In order to investigate whether the irradiation with UV light photochemically damages the NLO chromophore, the adsorption spectrum of the polymer film (without evaporated gold electrode) was measured before and after the UV irradiation. A change in the spectrum after the UV irradiation was not observed.

PAT LOG 19-A 200789

- 25 comparative experiment

A copolymer of the monomers N-hexyl-N- (4-methacryloyloxybutyl) -4-amino-4'-nitrostilbene and methyl methacrylate (1: 9) was prepared. The polymer solution (0.5 g in 1.6 g NMP and 1.6 g ethoxyethyl acetate) was dried after spin coating (analogously to Example 3) in vacuo at 100 ⁰ C for 4 hours. The resulting film thickness was 1.9 μm. After vapor deposition of a gold electrode, the film was heated in vacuo to 100 ⁰ C and applied for 25 minutes, a DC voltage of 100 V, then cooled to RT at a rate of 1 ° C / min and turned off the E-FeId. The investigation of the relaxation behavior was carried out analogously to the methods described above.

Within one week, a significant decrease in the frequency doubling intensity to 65% of the initial value was already observed.

Example 4

It becomes an optical device as described by R. Lytel et al. in proc. SPIE, Vol. 824 , p. 152 (1988), with the copolymer of Example 2. The material shows excellent waveguiding properties.

PAT LOG 19-A 200789

Claims (7)

Merck Patent Company
with limited liability Darmstadt claims 1. Polymer materials containing non-linear optically active chromophores with electron donor / -acceptor ¬ substituted conjugated η systems and additionally photocrosslinking groups, characterized in that the photocrosslinking Gruppen'im UV range of wavelength λ έ 300 run absorb. 2. Homopolymer and copolymer based polymer materials according to claim 1, characterized in that the nonlinear optical chromophores and photocrosslinkable groups are covalently bound in side chains. 3. Photovoltaic polymer materials containing nonlinear optical chromophores with electron donor / acceptor-substituted conjugated n-Sys- men, characterized in that the photocrosslinking was carried out by means of UV light of wavelength λ έ 300 nm. 4. Nonlinear optical arrangements containing polymer materials according to claim 3. 5. A process for the preparation of nonlinear optical arrangements according to claim 4, characterized in that polymer materials according to claim 1 PAT LOG 19-Λ 300189 or 2 photocrosslinked and dipolar aligned in any order or concurrently with ultraviolet light of wavelength λ £ 300. 6. Use of the non-linear optical arrangements according to claim 4 in optical components. 7. Optical component containing nonlinear optical arrangements according to claim 4. PAT LOG 19-A 300189