WO1994000797A1

WO1994000797A1 - Optical non-linear polymers

Info

Publication number: WO1994000797A1
Application number: PCT/EP1993/001476
Authority: WO
Inventors: Rolf-Peter Herr; Martin Schadt; Klaus Schmitt
Original assignee: F. Hoffmann-La Roche Ag
Priority date: 1992-06-19
Filing date: 1993-06-11
Publication date: 1994-01-06
Also published as: JPH06509889A; EP0600064A1

Abstract

The invention is concerned with nlo polymers of general formula (I) for the production of polymer layers having optical non-linear properties in selectively defined and optionally shaped areas, which areas are separate from those areas having a centro-symmetrical structure or areas having other optical non-linear properties. In formula (I) Ma, Mb, Mc signify monomer units for homo- or copolymers; x, y, z indicate mole fractions of the copolymers, whereby in each case 0 < x « 1; 0 « y < 1 and 0 « z < 1; Sa, Sb, Sc represent spacer units; F denotes an nlo-active chromophore having an adsorption in the region of 300 nm to 700 nm; Za, Zb represent molecule units which are photochemically dimerizable; n is a magnitude of 4-1000000; and s is 1, 2 or 3. The polymers in accordance with the invention are characterized in that the nlo-active (nlo = non-linear optic) chromophores (F) are bonded via a spacer (Sa) to the monomer unit (Ma) and themselves carry, likewise via a spacer, one or more photochemically dimerizable groups (Za) which serve for the photochemical cross-linkage of the polymer.

Description

Optical non-linear polymers

The invention is concerned with polymers for the production of polymer layers having optical non-linear properties in selectively defined and optionally shaped areas, which areas are separate from those areas having a centro-symmetrical structure or areas having other optical non-linear properties.

It is known that organic and polymeric materials having large delocalized π-electron systems can have non-linear optical coefficients which are larger than in inorganic materials.

Further, the properties of organic and polymeric materials can be varied readily and, accordingly, desirable secondary properties such as mechanical and chemical stability, optical absorption etc. can be adjusted without negatively influencing the non-linearity.

Thin films of organic or polymeric materials having a large non- linearity of the second order have a great application potential in the field of optical communication, laser technology, electrooptics etc.

It is of particular significance that the reason for the non-linearity of these materials is based on the polarizability of the π-electron system and not on the displacement or re-orientation of atoms or molecules. Consequently, building elements having ultrashort response times can be realized with these materials.

The production of materials suitable for the aforementioned field has been the subject of intensive research for many years and is documented, for example, in the following publications:

Materials for NonLinear Optics; Chemical Perspectives: ACS

Symp. Ser. No. 455 (1991).

Proceedings of SPIE Vol. 1147 (1989), Nonlinear Optical Properties of Organic Materials 2. Side-chain polymers which are doped with nlo-active chromo¬ phores (nlo = non-linear optic) or which have nlo molecules as side- chains are of particular significance for these applications. For the purpose of the present description copolymers and homopolymers are also to be understood under side-chain polymers. It is known that appropriately selected representatives of this class of material can be dipolarly orientated by heating above the glass temperature in a high electric field and that the thus-obtained non-centrosymmetrical arrangement is retained by cooling in an electric field below the glass temperature Tg. Such frozen polarized glasses are nlo materials having a large χ(2)-susceptibility. (KD. Singer et al., Appl. Phys. Lett. 49, 1986).

A fundamental obstacle to the industrial use of these materials is on the one hand the limited miscibility of nlo chromphores in the polymer and on the other hand the insufficient long-term stability of the dipolar arrangement. It has been found that even below the glass temperature of the polymer system relaxation occurs, which destroys the imported non-centrosymmetrical structure.

Different strategies are available to increase the stability of the dipolar arrangement by modification of the polymer. For example, as the relaxation process slows down with the glass temperature interval, there exist a course of choosing polymers which have a glass temperature which is as high as possible. Another course comprises using polymer networks in place of linear polymers.

Substantially better long term-stable and temperature-stable nlo polymers have been achieved using nlo chromophores having several (2- 4) reactive substituents, which function as cross-linkers of an epoxide system (M. Eich, J. Appl. Phys. ££, 3241, 1989). In these epoxides the cross-linking reaction takes place under the influence of an electric field and leads to a partial dipolar-orientated network which remains after disconnecting the field, since the dipolar arrangement is chemically fixed.

For the industrial use of nlo-active polymer networks in complex building elements, their simple and precise structural nature is of fundamental significance. Because in the hitherto known processes the cross-linkage is brought about thermally, it embraces the entire layer and can therefore not be limited to desired areas.

Structuring is only possible by introducing structured polarizing electrodes. However, this is associated with a series of disadvantages. The limits of the polarized region become diffuse by virtue of unavoidably occurring electrical stray fields on the periphery of the electrodes. This is not acceptable for many applications, e.g. strip wave guides, of periodic structures from polarized and non-polarized regions. More¬ over, for most applications the electrode layers must again be removed laboriously in further process steps.

On the other hand, selective structuring is possible in the case of polymers in which not only the monomers but also the nlo chromo- phores carry photo-cross linkable groups, whereby, however, also in this case the limited miscibility of the nlo chromophores with the monomers determines the concentration of these chromophores.

The invention now provides stable nlo-active polymers, as well as materials for the manufacture of such polymers, which no longer have the aforementioned disadvantages or which only have these to a lesser extent.

The invention is concerned with nlo-active polymers of the general formula

wherein

M_a, M , Mc signify monomer units for homo- or copolymers; x, y, z indicate mole fractions of the copolymers, whereby in each case 0 < x < l; 0 < y < l and 0 < z < 1; Sa, Sb, Sc represent spacer units; F denotes a nlo-active chromophore having an adsorption in the region of 300 nm to 700 nm; Z_a, Zb represent molecule units which are photochemically dimerizable; n is a magnitude of 4-1000000; and s is 1, 2 or 3,

which are characterized in that the nlo-active chromophores (F) are bonded via a spacer (Sa) to the monomer unit (Ma) and themselves, again via a spacer, carry one or more photochemically dimerizable groups (Z_a) which serve for the photochemical cross-linkage of the polymer.

Thus, the bonding of the nlo-active chromophores on the one hand via the monomer unit to the polymer chain and on the other hand via the dimerizing unit into the network provides several advantages. The concentration of the nlo-active chromophore can be varied in the polymer in a practically unlimited manner and the bonding of the chromophore at both ends of the molecule in the network provides for an effective restraint of the mobility, which guarantees long-term the stability of the nlo-active polymer layer.

The monomer units M_a, Mb and M_c for the formation of homo¬ polymers or copolymers have, in the scope of the present invention, the structures which are usual in polymer chemistry. Such monomer units are, for example, acrylate, methacrylate, chloroacrylate, phenylacryl- ate, acryloxyphenyl, acrylamide, methacrylamide, chloroacrylamide, phenylacrylamide, vinyl ethers, styrene derivatives, vinyl esters, maleic acid derivatives, fumaric acid derivatives, siloxanes, epoxides and the like. Acrylate, methacrylate, chloroacrylate, acrylamide, methacryl¬ amide, chloroacrylamide, styrene derivatives, siloxanes and the like are preferred monomer units.

Under the term "copolymers" there are to be understood not only statistical but also alternating copolymers. Statistical copolymers are preferably used. Homopolymers embrace linear and cyclic polymers such as, for example, cyclic polysiloxanes. The spacer units S_a and S bind the nlo-active chromophore (F) with the monomer unit (M_a), and, respectively, the dimerization unit (Zb) with the monomer unit (Mb). The spacer S_c links the nlo-active chromophore (F) with the dimerization unit (Z_a), whereby the nlo-active chromophore (F) can carry one or more dimerization units (Z_a) and correspondingly one or more spacers (Sc).

Such spacer units are known per se. In the present instance the term "spacer units" Sa, Sb and Sc signifies, for example, a n-alkylene chain with 1 to 10, preferably with 1 to 4, carbon atoms, a cyclo-alkylene group with 3 to 8 carbon atoms or phenylene, which can be substituted with -CN, -NO2 or halogen, or carbonate, an ester group, an ether group and the like, or a combination of such groups. The spacer units Sa or S_c can also be integrated into the nlo-active chromophore (F).

Examples of preferred spacer units (Sa, Sb and S_c) are methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, cyclo-butane-l,3-diyl, cyclo-pen- tane-l,2-diyl, cyclo-pentane-l,3-diyl, cyclo-hexane-l,3-diyl, cyclo-hexane- 1,4-diyl, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, ethyleneoxycar- bonyl, ethylenecarboxyl and the like.

Examples of spacer units which are integrated into the nlo-active chromophore (F) - i.e. form a part of the compound (F) - are e.g. piperidine, pyrrolidine or indole.

The nlo-active chromophore denoted by (F) can be any compound which absorbs in the visible region of light and which is stable under the photo-chemical cross-linkage conditions, nlo-active chromophores (F) having an absorption in the region of 300 nm to 700 nm of general formula II are preferred in the scope of the present invention:

In formula II

Ca denotes an electron acceptor Cd denotes an electron donor

Ar_a, Arb denote phenylene, pyrimidine, pyridine, naphthyl, imidazole, oxazole, thiazole, benzoxazole or benzothiazole; 5 Arc denotes phenylene, pyrimidine, pyridine, naphthyl, 1-benzazine, 2-benzazine, 1,2-benzodiazine, 2,3-benzodiazine, 1,3-benzodiazine, 1,4-benzodiazine, 1,2,3,4-tetrahydro-l-benzazine, indole or dihydroindole; 0 m, r denote 1, 2 or 3 p, q denote 0 or 1.

The compounds of formula II are aniline derivatives of general formula II-A, diazo derivatives of general formula II-B or bis-diazo 15 derivatives of general formula II-C:

\ cA Ar_a— N=N-Ar_b N=N Ar_c— fc_dl

^{1 a c L dJ}r II-C

20

The compounds of formula II always contain at least one electron acceptor (Ca) and at least one electron donor (Cd), which in each case are separated from one another by the conjugated aromatic system.

-Ε> In the compounds of formulae II electron acceptors (Ca) can be groups such as -NO2, -Cl, -Br, -CN, -CHO, -COCH3, alkylsulphonate, alkylsulphone, arylsulphonate, arylsulphone, N-diarylsulphonamide, N-dialkylsulphonamide, N-alkylarylsulphonamide, -CH=C(CN)2, -C(CN)=C(CN)2 or -C(CH3)=C(CN)2 and the like.

30

Electron donors (Cd) signify in the scope of the present invention dialkylamines, cyclic alkylamines, arylalkylamines, diarylamines, alkoxy groups or thioalkyl groups and the like. Examples of preferred electron donor groups are dimethylamine, diethylamine, dipropyl-

35 amine, methylethylamine, methylphenylamine, methoxy, ethoxy, propyloxy, piperidine or pyrrolidine. The electron donor (Cd) can also be fused to the conjugated aromatic system; this is the case, for example, when Ar_c signifies indole, dihydroindole or 1,2,3,4-tetrahydro-l-benzazine.

As mentioned earlier, the compounds of formula II are in each case linked via a spacer Sa with the monomer unit (M_a) and via one or more spacers (Sc) with one or more dimerizable units (Z_a). These spacers (S_a or S_c) can be bonded either to one of the rings Ar_a,b or _c or to a donor or to an acceptor group. However, they can also form part of the donor or the acceptor group. Combined donor-spacer groups can be, for example, piperidine, pyrrolidine, alkoxy groups and the like. Examples of combined acceptor-spacer groups are alkylsulphonate, N-diphenyl- sulphonamide, N-dialkylsulphonamide and the like.

The compounds set forth hereinafter are intended to illustrate the aforementioned nlo-active chromphores of general formula II-A to II-C in more detail and to emphasize preferred aspects, but are not in any manner a limitation.

Examples of aniline derivatives of general formula II-A are

wherein

R¹ represents -Nθ2, -Cl, -Br, -CN, -CHO, -COCH3, alkylsulphonate, alkylsulphone, aryl¬ sulphonate, arylsulphone, N-diarylsulphonamide, N- dialkylsulphonamide, N-alkylarylsulphonamide, -CH=C(CN)2, -C(CN)=C(CN)2 or -C(CH3)=C(CN)2;

R2 signifies alkyl with 1 to 4 carbon atoms, aryl or a further Sc group;

R^^a represents dialkylamine, cycloamine, alkylaryl- amine or diarylamine; and

Sa, Sc signifies alkylene or -COOalkylene.

The spacer groups Sa and Sc can be optionally interchanged in formulae II-l to II-4, i.e. the nlo-active chromophore (F) can be bonded at the donor site or at the acceptor site with the monomer M_a. In the compounds II-2 and II-3 the spacer group (Sa or Sc) forms part of the donor group which is bonded directly to the monomer (M_a) or to the dimerization unit (Z_a).

The compounds of formula II-5 to 11-19 are examples of preferred diazo compounds of general formula II-B.

wherein Rl, R2, Sa and Sc are as defined above; R^ represents alkoxy, thioalkyl, dialkylamine, cycloamine, alkylarylamine or diarylamine; R^ signifies hydrogen, halogen -Nθ2, -CN or alkyl; R5 and ^ represent hydrogen, halogen, -Nθ2 or -CN; and ------ signifies a single bond or a double bond. Compounds of the general formulae are examples of preferred bis-diazo compounds of formula II-C:

wherein the symbols R¹, R², R³, R⁴, R5, R^β, S_a, S_c, and ---=.- are as defined above.

Also in the compounds of formulae II-5 to 11-32 the spacer groups (Sa and Sc) can be optionally interchanged and therefore the nlo-active chromophore (F) can be linked either at the donor site or at the acceptor site with the monomer (M_a).

As will be evident from formulae II-l to 11-32, the electron donors or the electron acceptors can be free functional groups or can be linked with one of the spacers Sa or Sc. Examples of nlo-active chromophores (F) having free donor groups are compounds of the formulae II-4, II-8, 11-13, 11-16 to 11-19, II-23, π-26 and 11-29 to 11-32.

Examples of nlo-active chromophores having donor groups linked with one of the spacers are the aforementioned compounds of general formulae II-l, II-5, II-9 to 11-12, 11-15, 11-20, 11-24, 11-25 and 11-28.

Examples of nlo-active chromophores having fused cyclic donor groups on ring Ar_c are compounds of the general formulae II-9, 11-10; 11-15, 11-24, 11-25 and 11-28. Examples of nlo-active chromophores having free acceptor groups are compounds of general formulae II-l to 11-10 and 11-13 to 11-32.

Compounds of general formulae 11-11 and 11-12 illustrate compounds in which the spacer is bonded to the acceptor group.

Compounds of general formulae II-2, II-3, II-6, II-7, 11-14, 11-21, 11-22 and 11-27 are examples of compounds in which the spacer forms part of the donor group.

The dimerization units Z_a and Zb are molecule units which can undergo a photochemical [2 + 2] cycloaddition, which leads to the cross- linkage of the polymer and accordingly to its stabilization. The dimerizable units are, however, not, or only to a very small extent, incorporated into the chain under the polymerization conditions. Such dimerizable units are in the scope of the present invention, for example, compounds of general formulae III and IV:

In formulae III and IV

ring A signifies benzene, pyridine, pyrimidine or furan R7,R8,R9 signifies H, alkyl, alkoxy, dialkylamine, cyclo- alkylamine, alkoxycarbonyl, alkyl-COO, carboxyl, -CN, halogen, -Nθ2, whereby R⁷ and R⁸ or R⁸ and R⁹ together can also signify -O(CH2)lO-; 1 signifies 1 or 2; RlO signifies hydroxy, alkoxy, aryl, aryloxy, aryloxy- alkyl, aryloxycarbonyl, phenyl-COO-alkoxy; 0 signifies 1 or 2, whereby the bonding to the spacer units Sb and, respectively, S_c can be effected via the residues R⁷, R⁸, R⁹, R¹⁰.

In compounds having formulae III and IV the term "alkyl" signifies a straight-chain or branched alkyl group with 1 to 10 carbon atoms, preferably a straight-chain alkyl group with 1 to 4 carbon atoms, such as, for example, methyl, ethyl, propyl or butyl.

In formulae III and IV the terms "alkoxy" and "alkoxycarbonyl" denote an ether and, respectively, an ester in which the alkyl residue is as defined above. Such residues are methoxy, ethoxy, propyloxy, butyl- oxy, methoxycarbonyl, ethoxycarbonyl, propyloxycarbonyl or butyloxycarbonyl.

In compounds having formulae III and IV the term "aryl" denotes phenyl or naphthyl which is unsubstituted or substituted with halogen, -Nθ2, -CN, alkyl or alkoxy.

Cinnamic acid and chalcone derivatives of general formula III as well as coumarin derivatives of formula IV are particularly suitable for the photochemical cross-linkage of the polymer. Such preferred dimerization units are, for example:

^IΠ-⁴

wherein R⁷, R⁸, R⁹ and RlO are as defined above; and H signifies -OH, alkoxy or halogen.

The polymers of formula I are distinguished by the fact that they are accessible in a simple manner. The monomers are constructed from the individual components, i.e. from the dimerizable unit of formula III or IV, the spacers (S_a, Sb and, respectively, S_c), the nlo- active chromophores II and the polymerizable units (M_a or Mb). The formation of the polymers is then effected in a manner known per se. The polymerization can be effected, for example, in the melt or in solution with the exclusion of oxygen in the presence of a radical initiator which can generate radicals thermally, photochemically or by a redox-reaction. The reaction can be effected in a temperature range of -10°C to 120°C, preferably in a range of 20°C to 100°C.

For the production of polymer layers having selectively defined areas, a solution of the polymer material obtained can be prepared, which is centrifuged in a spin-coating apparatus on to a carrier coated with an electrode so that homogeneous layers of 0.5-5 μm thickness result, nlo-active chromophores can subsequently be adjusted dipolarly e.g. using a so-called Corona-Poling apparatus under a high electric field strength. At the same time, the region to be cross-linked can be exposed to e.g. a mercury-high pressure lamp, a xenon lamp or a pulsed UV-laser. The exposure duration depends on the capacity of the individual lamps and can vary from a few minutes to several hours. The cross-linkage can, however, also be effected by irradiating the homogeneous layer using filters which e.g. let through only the radiation which is suitable for the cross-linkage reaction.

Examples of particularly preferred monomers (M_a-Sa-F-Sb-Za) for the manufacture of polymers of formula I are set for the hereinafter:

Preferred monomers are:

2

4

1 a

10 11 12

13

Examples of preferred polymers of formula I are:

IS

1-6 12

IS IS

21

The following Examples are intended to illustrate the invention in further detail.

Procedures for nlo chromophores (F) and nlo copolymers

Example 1

A) Comonomer 1 (M_a-Sa-F-Sc-Z_a)

3.5 g of 5-(4-(N-[E]-(2-(3-(4-chlorophenyl)acryloyloxy)ethyl)-N-methyl- amino)-[E]-phenylazo)-2-nitrobenzoic acid, 0.92 ml of 2-hydroxyethyl methacrylate, 0.066 g of 4-toluenesulphonic acid monohydrate and 0.193 g of 4-dimethylaminopyridine were dissolved in 100 ml of tetra- hydrofuran. A solution of 1.7 g of dicyclohexylcarbodiimide in 10 ml of tetrahydrofuran was added dropwise to this solution at room temper¬ ature while stirring within 10 min. The mixture was stirred at room temperature for 3.5 hours, filtered, concentrated and diluted with 200 ml of dichloromethane. The solution was washed with 100 ml of 5% acetic acid and subsequently 3 times with 100 ml of water each time, dried over sodium sulphate, filtered and concentrated. Chromatography of the residue on silica gel with diethyl ether gave 3.8 g of 5-(4-(N-[E]-(2-(3-(4- chlorophenyl)acryloyloxy)ethyl)-N-methylamino)-[E]-phenylazo)-2-nitro- benzoic acid 2-methacryloyloxyethyl ester as dark red crystals with a melting point of 90.8 - 92.8°C. λ_max. (0.772 mg/100 ml in CH2CI2, d = 1 cm): 284 nm (e = 33500), 472 nm (ε = 28000).

The 5-(4-(N-[E]-(2-(3-(4-chlorophenyl)acryloyloxy)ethyl)-N-methyl- amino)-[E]-phenylazo)-2-nitrobenzoic acid used as the starting material was prepared as follows:

a) 26.75 g of N-(2-hydroxyethyl)-N-methyl-aniline, 33.92 g of trans-4- chlorocinnamic acid and 0.227 g of 4-dimethylaminopyridine were placed in 150 ml of dichloromethane. A solution of 37.95 g of dicyclohexylcarbodiimide in 100 ml of dichloromethane was added dropwise while stirring at room temperature within 30 min. The mixture was stirred at room temperature for 20 hours, filtered, washed with 100 ml of 5% acetic acid and subsequently three times with 150 ml of water each time, dried over sodium sulphate, filtered and concentrated. Recrystallization from ethanol gave 49.8 g of [E]-N-(2-(3-(4-chloro- phenyl)acryloyloxy)ethyl)-N-methyl-aniline as white crystals with a melting point of 58.3-58.5°C.

b) 9.1 g of 5-amino-2-nitro-benzoic acid were treated with 120 ml of 3.5N hydrochloric acid and stirred at room temperature for 30 min. Thereafter, the mixture was cooled to -5 to -8°C and a solution of 4.02 g of sodium nitrite in 15 ml of water was added dropwise in such a manner that the temperature of the reaction mixture did not exceed +2°C. The mixture was stirred at 0°C for a further 30 min. and subsequently treated in 2 portions with 9 ml of a 75% aqueous hexafluorophosphoric acid solution. After stirring at -5 to 0°C for 30 min. the resulting precipi¬ tate was filtered off, washed with 60 ml of an ice-cold 5% aqueous hexa- fluorophosphoric acid solution and subsequently with 120 ml of ice-cold diethyl ether. After drying in a vacuum at room temperature there were obtained 11.9 g of 5-diazonium-hexafluorophosphato-2-nitrobenzoic acid as yellowish-white crystals.

c) 4.7 g of 5-diazonium-hexafluorophosphato-2-nitro-benzoic acid were dissolved at 0°C in 400 ml of a mixture of methanol and water (vol. 5:3). A solution of 3.7 g of [E]-N-(2-(3-(4-chlorophenyl)acryloyloxy)ethyD- N-methyl-aniline in 25 ml of tetrahydrofuran was added dropwise at 0 to 5°C within 30 min. The mixture was stirred at 0 to 5°C for a further 2.5 hours. The precipitated product was filtered off and washed with 30 ml of ice-cold methanol. After recrystallization from 300 ml of i-propanol and drying in a vacuum there were obtained 4.67 g of 5-(4-(N-[E]-(2-(3-(4- chlorophenyl)acryloyloxy)ethyl)-N-methylamino)-[E]-phenylazo)-2- nitrobenzoic acid as dark red crystals with a melting point of 172.2- 173.2°C.

B) Comonomer 2 (Mb-Sb-Zb)

49.95 g of trans-4-methoxycinnamic acid, 32.5 g of 2-hydroxyethyl methacrylate and 0.34 g of 4-dimethylaminopyridine were placed in 250 ml of dichloromethane. A solution of 57.9 g of dicyclohexylcarbo- diimide in 150 ml of dichloromethane was added dropwise at room temperature within 15 min. The mixture was stirred at room temper¬ ature for a further 28 hours. Subsequently, the precipitated N,N'- dicyclohexylurea was filtered off and washed with 50 ml of dichloro¬ methεme. The combined dichloromethane solutions were washed with 200 ml of 5% acetic acid and subsequently three times with 250 ml of water and dried over sodium sulphate. After removal of the solvent the residue was recrystallized from ethanol at -60°C. This gave 65.1 g of 2- methacryloyloxyethyl [E]-(3-(4-methoxyphenyl)acrylate as white crystals with a melting point of 35-36°C.

C) Copolymer from comonomer 1 and comonomer 2

1 g of 5-(4-(N-[E]-(2-(3-(4-chlorophenyl)acryloyloxy)ethyl)-N-methyl- amino)-[E]-phenylazo)-2-nitrobenzoic acid 2-methacryloyloxyethyl ester, 4.21 g of 2-methacryloyloxyethyl [E]-(3-(4-methoxyphenyl)acrylate and 0.0132 g of azobisisobutyronitrile were dissolved in 32 ml of tetrahydro- furan. A weak stream of argon was passed through the solution for 10 min. and the reaction vessel was subsequently sealed airtight. The solution was heated to 60°C for 24 hours. Thereafter, the reaction vessel was opened and the solution was diluted with 10 ml of tetrahydrofuran while stirring. Subsequently, the diluted solution was added dropwise to 800 ml of diethyl ether while stirring at room temperature. The separated polymer was filtered off, dried, dissolved in 40 ml of dichloro- methane and this solution was added dropwise to 800 ml of diethyl ether. This procedure was repeated twice. After filtration and drying at 50°C in a vacuum there were obtained 3.65 g of poly [l-[2-[5-[(E)-4-[2-[(E)-3-(4- chloro-phenyl)-acryloyloxy]-ethyl-methyl-amino]-phenylazo]-2-nitro- benzoyloxy]-ethoxycarbonyl]-l-methyl-ethylene-co-l-[2-[(E)-3-(4-methoxy- phenyl)-acryloyloxy]-ethoxycarbonyl]-l-methyl-ethylene] (1:9). The polymer has a glass stage at Tg = 77°C. λ_max. (0.653 mg/100 ml in CH2CI2, d = 1 cm ): 307.7 nm, (log I„/I = 0.418), 475 nm, Gog I l = 0.05).

The following copolymers were manufactured analogously:

D) Poly [l-[2-[5-[(E)-4-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethyl- methyl-ειmino]-phenylazo]-2-nitro-benzoyloxy]-ethoxycarbonyl]-l-methyl- ethylene-co-l-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethoxycarbonyl]-l- methyl-ethylene] ( 1 :9); glass stage at Tg = 84 °C; λ_max. (1.137 mg/100 ml in CH₂C1₂): 283.4 nm, (log I l = 0,713), 472.2 nm, (log I₀/I = 0.057).

E) Poly[l-[2-[5-[(E)-4-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethyl-methyl- amino]-phenylazo]-2-chloro-benzoyloxy]-ethoxycarbonyl]-l-methyl- ethylene-co-l-[2-[(E)-3-(4-methoxy-phenyl)-acryloyloxy]-ethoxycarbonyl]- 1-methyl-ethylene] (1:4): glass stage at T_g = 79 °C; λ_max. (0.760 mg 100 ml in CH₂C1₂): 295.3 nm, (log I₀/I = 0,451) 425.6 nm, (log I₀/I = 0.130).

F) Poly[l-[2-[5-[(E)-4-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethyl-methyl- amino]-phenylazo]-2-bromo-benzoyloxy]-ethoxycarbonyl]-l-methyl-ethyl- ene-co-l-[2-[(E)-3-(4-methoxy-phenyl)-acryloyloxy]-ethoxycarbonyl]-l- methyl-ethylene] (1:4): glass stage at T_g = 79 °C; λ_max. (0.613 mg/100 ml in CH₂C1₂): 295.5 nm , (log 1,11 = 0.335), 427.3 nm , (log I₀/I = 0.103).

G) Poly[l-[2-[5-[(E)-4-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethyl-methyl- amino]-phenylazo]-2-nitro-benzoyloxy]-ethoxycarbonyl]-l-methyl-ethyl- ene-co-l-[2-[(E)-3-(4-methoxy-phenyl)-acryloyloxy]-ethoxycarbonyl]-l- methyl-ethylene-co-l-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethoxycar- bonyl]-l-methyl-ethylene] (1:5:4): glass stage at Tg = 79 °C; λ_max. (0.733 mg/100 ml in CH₂C1₂): 286.7 nm , (log I₀/I = 0.465), 477.2 nm , (log I₀/I =

0.055).

Example 2

A) Comonomer 3 (M_a-Sa-F-S_c-Za)

1.04 g of dicyclohexylcarbodiimide were added at room temperature while stirring to a solution of 2.25 g of 4-(2-(N-ethyl-N-4-(3-hydroxy- carbonyl-4-nitro-[E]-phenylazo)-phenyl-amino)-acetoxy)-[E]-cinnamic acid methyl ester and 0.7 g of 2-hydroxyethyl methacrylate in 10 ml of pyridine. The mixture was stirred at room temperature for a further 6 hours and subsequently diluted with 50 ml of dichloromethane. Precipitated, N,N'-dicyclohexylurea was filtered off, the filtrate was diluted with a further 100 ml of dichloromethane, washed with 50 ml of 5% acetic acid and subsequently three times with 100 ml of water each time. After drying the solution over sod um sulphate and evaporation of the solvent the residue was recrystallized from a mixture of 80 ml of ethanol and 2 ml of tetrahydrofuran. After drying in a vacuum there were obtained 1.54 g of 4-(2-(N-ethyl-N-4-(3-(2-methacryloyoxyethyloxy- carbonyl)-4-nitro-[E]-phenylazo)-phenyl-amino)-acetoxy)-[E]-cinnamic acid methyl ester as dark red crystals with a melting point of 117- 126.5°C. λ_max. (CH2CI2): 278.5 nm (ε = 35000), 455 nm (ε = 29600).

The 4-(2-(N-ethyl-N-4-(3-hydroxycarbonyl-4-nitro-[E]-phenylazo)- phenyl-amino)-acetoxy)-[E]-cinnamic acid methyl ester used as the starting material was prepared as follows:

a) 10 g of 2-N-ethyl-N-phenyl-aminoacetic acid, 9.47 g of [E]-4- hydroxycinnamic acid methyl ester and 0.07 g of 4-dimethylamino- pyridine were dissolved in 90 ml of a mixture of dichloromethane and tetrahydrofuran (vol. 7:2). A solution of 11.51 g of dicyclohexylcarbodi- imide in 50 ml of dichloromethane was added dropwise while stirring at room temperature within 10 min. The mixture was stirred at room temperature for a further 18 hours and the precipitated N,N'-dicyclo- hexylurea was subsequently filtered off. The solution was diluted with 150 ml of dichloromethane, washed with 100 ml of 5% acetic acid and thereafter three times with 100 ml of water each time. After drying over sodium sulphate and concentration of the solvent the residue was recrystallized from a mixture of 100 ml of n-hexane and 20 ml of toluene. This gave 13.1 g of [E]-4-(2-N-ethyl-N-phenyl-aminoacetoxy)cinnamic acid methyl ester as colourless crystals with a melting point of 58.5- 59.5°C

b) 3.39 g of 5-diazonium-hexafluorophosphato-2-nitro-benzoic acid were dissolved at 0°C in 300 ml of a mixture of methanol and water (vol. 5:3). A solution of 2.87 g of [E]-4-(2-N-ethyl-N-phenyl-aminoacetoxy)- cinnamic acid methyl ester in 25 ml of tetrahydrofuran was added dropwise at 0 to 5°C within 30 min. The mixture was stirred at 0 to 5°C for a further 3 hours. The precipitated product was filtered off and washed with 30 ml of ice-cold methanol. After recyrstallization from 240 ml of i-propanol there were obtained 3.9 g of 4-(2-(N-ethyl-N-4-(3- hydroxycarbonyl-4-nitro-[E]-phenylazo)-phenyl-amino)-acetoxy)-[E]- cinnamic acid methyl ester as red crystals with a melting point of 165- 169.5°C .

B) Comonomer 4 ((Mb-Zb)

5.3 g of methacrylic acid, 10.5 g of [E]-4-hydroxycinnamic acid methyl ester and 0.08 g of 4-dimethylaminopyridine were dissolved in 170 ml of a mixture of dichloromethane and tetrahydrofuran (vol. 7.5:1). 12.43 g of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride were introduced in 10 portions into the solution at room temperature. The mixture was stirred at room temperature for a further 6 hours and subsequently diluted with 150 ml of dichloromethane. The solution was washed three times with 200 ml of water each time and thereafter dried over sodium sulphate. After evaporation of the solvent the residue was recrystallized from 200 ml of ethanol. This gave, after drying in a vacuum, 10.34 g of [E]-4-methacryloyloxycinnamic acid methyl ester with a melting point of 78-80°C.

C) Copolymer from comonomer 3 and comonomer 4

2.78 g of [E]-4-methacryloyloxycinnamic acid methyl ester and 0.807g of 4-(2-(N-ethyl-N-4-(3-((2-methacryloyoxyethyl)oxycarbonyl)-4-nitro-[E]- phenylazo)-phenyl-amino)-acetoxy)-[E]-cinnamic acid methyl ester were polymerized and worked-up analogously to Example 1C). This gave 2.26 g of poly[l-[2-[5-[(E)-[4-ethyl-[4-[(E)-2-methoxycarbonyl-vinyl]- phenoxycarbonyl-methyl]-amino]-phenylazo]-2-nitro-benzoyloxy]- ethoxycarbonyl]-l-methyl-ethylene-co-l-[4-[(E)-2-methoxycarbonyl-vinyl]- phenoxycarbonyl]-l-methyl-ethylene] (1:9). The polymer has a glass stage at T_g = 140°C. λ_max. (0.639 mg/100 ml CH₂C1₂): 276.9 nm , (log I₀/I = 0.527), 461 nm , (log I_o I = 0.054).

The following copolymers were manufactred analogously:

D) Poly[l-[2-[5-[(E)-[4-ethyl-[4-[(E)-2-methoxycarbonyl-vinyl]-phenoxycar- bonylmethyl]-amino]-phenylazo]-2-nitro-benzoyloxy]-ethoxycarbonyl]-l- methyl-ethylene-co-l-[2-[4-[(E)-2-methoxycarbonyl-vinyl]-phenoxy]- ethoxycarbonyl]-l-methyl-ethylene] (1:9): glass stage at Tg = 93 °C; λ_maχ. (0.647 mg/100 ml CH₂C1₂): 291.2 nm, (log l = 0.438), 463.6 nm, (log I₀/I = 0.049).

n

E) Poly[l-[2-[5-[(E)-[4-ethyl-[4-[(E)-2-methoxycarbonyl-vinyl]-phenoxy- carbonylmethyl]-amino]-phenylazo]-2-nitro-benzoyloxy]-ethoxycarbonyl]- l-methyl-ethylene-co-l-[2-[4-[(E)-2-methoxycarbonyl-vinyl]-phenoxy]- ethoxycarbonyl]-l-methyl-ethylene] (1:4): glass stage at Tg = 92 °C; λ_max. (0.628 mg/100 ml CH₂C1₂): 290.4 nm , (log I l = 0.359), 456.5 nm , (log I₀/I = 0.088).

Example 3

A) Comonomer 5 (M_a-Sa-F(-Sc-Z_a)2)

2.74 g of 5-(4-(N,N-bis-[E]-(2-(3-phenylacryloyloxy)ethyl))-[E]-phenylazo)- 2-nitrobenzoic acid, 1.12 g of 2-hydroxyethyl methacrylate and 0.04 g of 4- dimethylaminopyridine were dissolved in 90 ml of dichloromethane. A solution of 0.98 g of dicyclohexylcarbodiimide in 40 ml of dichloro¬ methane was added dropwise to this solution at room temperature while stirring. The mixture was stirred at room temperature for 14 hours and filtered. The solution was washed with 50 ml of 5% acetic acid and subsequently 3 times with 50 ml of water each time, dried over sodium sulphate, filtered and concentrated. Chromotography of the residue on silica gel with diethyl ether gave 2.04 g of 5-(4-(N,N-Bis-[E]-(2-(3-phenyl- acryloyloxy)ethyl))-[E]-phenylazo)-2-nitrobenzoic acid 2-methacryloyl- oxyethyl ester as dark red crystals with a melting point of 104-106°C. λmax. (0.975 mg/100 ml ethanol): 276 nm, (58460), 463 nm, (29600).

The 5-(4-(N,N-bis-[E]-(2-(3-phenylacryloyloxy)ethyl))-[E]- phenylazo)-2-nitrobenzoic acid used as the starting material was prepared as follows:

a) 18.12 g of N,N-bis-(2-hydroxyethyl)-aniline, 31.11 g of trans- cinnamic acid and 0.31 g of 4-dimethylaminopyτidine were placed in 250 ml of diethyl ether. A solution of 47.66 g of dicyclohexylcarbodiimide in 250 ml of diethyl ether was added dropwise while stirring at room temperature within 30 min. The mixture was stirred at room temperature for 3 hours, filtered, washed with 150 ml of 5% acetic acid and subsequently three times with 200 ml of water each time, dried over sodium sulphate, filtered and concentrated. After drying in a vacuum there were obtained 31.9 g of N,N-bis-[E]-(2-(3-phenylacryloyloxy)ethyl)- aniline as a colourless viscous liquid.

b) 4.88 g of 5-diazonium-hexafluorophosphato-2-nitro-benzoic acid were dissolved in 40 ml of diethyl ether at 0°C. A solution of 6.36 g of N,N-bis-[E]-(2-(3-phenylacryloyloxy)ethyl)-aniline in 60 ml of diethyl ether was added dropwise at 0 to 5°C within 30 min. The mixture was stirred at 0 to 5°C for one hour and at room temperature for a further hour and subsequently cooled to 0°C. The precipitated product was filtered off and washed with 30 ml of ice-cold methanol. After recrystallization from 300 ml of i-propanol and drying in a vacuum there were obtained 3.75 g of 5-(4-(N,N-bis-[E]-(2-(3-phenylacryloyloxy)ethyl))- [E]-phenylazo)-2-nitrobenzoic acid as dark red crystals with a melting point of 150- 156°C.

B) Comonomer 6 (Mb-Sb-Zb)

29.17 g of trans-cinnamic acid, 25 g of 2-hydroxyethyl methacrylate and 0.24 g of 4-dimethylaminopyridine were placed in 230 ml of dichloro¬ methane. A solution of 42.7 g of dicyclohexylcarbodiimide in 200 ml of dichloromethane was added dropwise at room temperature within 30 min. The mixture was stirred at room temperature for a further 20 hours. Subsequently, the precipitated N,N'-dicyclohexylurea was filtered off and washed with 50 ml of dichloromethane. The combined dichloromethane solutions were washed with 200 ml of 5% acetic acid and subsequently three times with 250 ml of water each time, dried over sodium sulphate, filtered and concentrated. After drying in a vacuum there were obtained 31.5 g of 2-methacryloyloxyethyl [E]-3-phenylacrylate as a colourless liquid.

C) Copolymer from comonomer 5 and comonomer 6

1.725 g of 5-(4-(N,N-Bis-[E]-(2-(3-phenylacryloyloxy)ethyl))-[E]-phenylazo)- 2-nitrobenzoic acid 2-methacryloyloxyethyl ester, 5.41 g of 2-methacryl- oyloxyethyl [E]-3-phenylacrylate and 0.0379 g of azobisisobutyronitrile were dissolved in 46 ml of tetrahydrofuran. A weak stream of argon was passed through the solution for 10 min. and the reaction vessel was subsequently sealed airtight. The solution was heated to 60°C for 24 hours. Thereafter, the reaction vessel was opened and the solution was diluted with 15 ml of tetrahydrofuran while stirring. Subsequently, the diluted solution was added dropwise to 800 ml of diethyl ether while stirring at room temperature. The separated polymer was filtered off, dried, dissolved in 50 ml of dichloromethane and this solution was added dropwise to 800 ml of diethyl ether. This procedure was repeated twice. After filtration and drying at 50°C in a vacuum there were obtained 5.7 g ofpoly[l-[2-[5-[(E)-4-[bis-[2-[(E)-3-phenyl-acryloyloxy]-ethyl]-amino]- phenylazo]-2-nitro-benzoyloxy]-ethoxycarbonyl]-l-methyl-ethylene-co-l- [2-[(E)-3-phenyl-acryloyloxy]-ethoxycarbonyl]-l-methyl-ethylene] (1:9) The polymer has a glass stage at Tg = 64°C.

The following copolymers were manufactured analogously:

D) Poly[l-[2-[5-[(E)-4-[bis-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethyl]- amino]-phenylazo]-2-nitro-benzoyloxy]-ethoxycarbonyl]-l-methyl- ethylene-co-l-[2-[(E)-3-(4-methoxy-phenyl)-acryloyloxy]-ethoxycarbonyl]- 1-methyl-ethylene] (1:9): λ_max. (0.560 mg/100 ml CH₂C1₂): 297.2 nm, (log I₀/I = 0.370), 465.3 nm, (log I₀/I = 0.042).

E) Poly[l-[2-[5-[(E)-4-[bis-[2-[(E)-3-(4-methoxy-phenyl)-acryloyloxy]-ethyl]- amino]-phenylazo]-2-nitro-benzoyloxy]-ethoxycarbonyl]-l-methyl- ethylene-co-l-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethoxycarbonyl]-l- methyl-ethylene] (1:9): glass stage at Tg -= 83 °C; λ_max. (0.585 mg/100 ml CH₂C1₂): 284.6 nm, Gog I„/I = 0.409), 476.6 nm, (log I₀/I = 0.044).

Example 4

A) Comonomer 7 (M_a-S_a-F-Sc-Za)

0.506 g of 5-[(E)-4-[N-[(E)-2-(2-methyl-acryloyloxy)-ethyl]-N-methyl- amino]-phenylazo]-2-nitro-benzoeic acid, 0.263 g of (E)-3-(4-hydroxy- phenyD-acrylic acid methyl ester and 0.015 g of p-toluenesulphonic acid were dissolved in 7 ml of dry pyridine and cooled to 0°C. 0.303 g of dicyclohexylcarbodiimide dissolved in 5 ml of pyridine was slowly added dropwise to this mixture over 3 hours. The mixture was stirred at 0°C for a further 24 hours. After warming to room temperature the precipitated dicyclohexylurea was filtered off and washed several times with dichloromethane. The combined filtrates were evaporated to dryness and the residue was chromatographed on silica gel with a mixture of ether and hexane (19:1). After removing the eluent and drying in a vacuum there was obtained 0.521 g of 5-[(E)-4-[N-[(E)-2-(2- methyl-acryloyloxy)-ethyl]-N-methyl-amino]-phenylazo]-2-nitro-benzoic acid (E)-4-(2-methoxycarbonyl-vinyl)-phenyl ester as a brown powder, λmax. (in CH₂C1₂): 280.8 nm, (ε = 36020), 483.4 nm, (ε = 32184).

The 5-[(E)-4-[N-[(E)-2-(2-methyl-acryloyloxy)-ethyl]-N-methyl- amino]-phenylazo]-2-nitro-benzoic acid used as the starting material was prepared as follows:

a) 28 g of N-2-hydroxyethyl-N-methyl-aniline, 0.24 g of 4-dimethyl- aminopyridine and 17 g of methacrylic acid were dissolved in 200 ml of dichloromethane. A solution of 41 g of dicyclohexylcarbodimide in 40 ml of dichloromethane was added dropwise while stirring at 0°C within 4 hours. The mixture was stirred at room temperature for a further 18 hours. The mixture was subsequently concentrated to dryness and the residue was chromatographed on silica gel with hexane/ether (7/3). 39.4 g of N-[2-(E)-(2-methyl-acryloyloxy)-ethyl]-N-methyl-aniline were isolated as a yellow oil. Mass spectrometric analysis: M⁺=219.

b) 9 g of 5-diazonium-hexafluorophosphato-2-nitro-benzoic acid were dissolved at 0°C in 400 ml of a mixture of methanol and water (vol. 5:3). A solution of 10 g of N-[2-(E)-(2-methyl-acryloyloxy)-ethyl]-N-methyl- aniline in 30 ml of methanol was added dropwise at 0 to 5°C within

30 min. The precipitated product was filtered off and washed with 30 ml of ice-cold methanol. After chromatography on silica gel with ether/ ethyl acetate (99:1) and drying in a vacuum there were obtained 9.4 g of 5-[(E)-4-[N-[(E)-2-(2-methyl-acryloyloxy)-ethyll-N-methyl-amino]- phenylazo]-2-nitro-benzoic acid as red crystals with a melting point of 151 - 152.9 °C. λ_max. (in CH₂C1₂): 280.4 nm, (ε = 11414), 472.2 nm, (ε = 29342).

B) Comonomer 8 (Mb-Sb-Zb)

6 g of 3-[4-(2-hydroxyethoxy)-phenyl3-acrylic acid methyl ester, 5.95 g of dicyclohexylcarbodiimide and 0.37 g of 4-dimethylaminopyridine in 80 ml of absolute tetrahydrofuran were placed in a 200 ml sulphonation flask. 2.56 g of methacrylic acid in 10 ml of tetrahydrofuran were slowly added dropwise to this solution. The reaction mixture was stirred at room temperature overnight. Subsequently, the precipitated dicyclohexylurea was filtered off. The solution remaining was evaporated to dryness, the residue was taken up in ether and extracted 3 times with 200 ml of 5% acetic acid and 3 times with 200 ml of water. The ether was removed in a vacuum and the product was recrystallized from cyclohexane. Subsequent filtration over silica gel with a mixture of ether and petroleum ether (1:1) as the eluent gave 4.3 g of (E)-3-[4-[2-(2- methyl-acryloyloxy)-ethoxy3-phenyl3-acrylic acid methyl ester as white crystals with a melting point of 81 - 81.7°C. λ_max. (in CH₂C1₂): 306.5 nm, (ε = 23674).

The 3-[4-(2-hydroxyethoxy)-phenyl3-acrylic acid methyl ester used as the starting material was prepared as follows:

30 g of (E)-4-hydroxycinnamic acid methyl ester, 29 g of potassium carbonate and a spatula tip of potassium iodide were placed in 200 ml of dimethylformamide and heated to 80-85°C. 14.91 g of 2-chloroethanol were added dropwise to this mixture within 5 minutes. The reaction mixture was stirred at 80-85°C for 3 days. After evaporating the solvent the residue was recrystallized from i-propanol. After drying in a vacuum there were obtained 16.05 g of 3-[4-(2-hydroxyethoxy)-phenyl]- acrylic acid methyl ester as light yellowish crystals.

C) Copolymer aus Comonomer 7 und Comonomer 8

0.480 g of 5-[(E)-4-[N-[(E)-2-(2-methyl-acryloyloxy)-ethyl]-N-methyl- amino]-phenylazo]-2-nitro-benzoic acid (E)-4-(2-methoxycarbonyl-vinyl)- phenyl ester and 2.19 g of (E)-3-[4-[2-(2-methyl-acryloyloxy)-ethoxy]- phenyll-acrylic acid methyl ester were polymerized and worked-up analogously to Example 1C). This gave 2.11 g of red poly[l-[2-[methyl-4- [(E)-3-[4-[(E)-2-methoxycarbonyl-vinyl]-phenoxycarbonyl]-4-nitro- phenylazo]-phenyl-amino]-ethoxycarbonyl]-l-methyl-ethylene-co-l-[2-[4- [(E)-2-methoxycarbonyl-vinyl]-phenoxy]-ethoxycarbonyl]-l-methyl- ethylene] (1:9). The polymer has a glass stage at Tg = 94 °C; λ_max. (0.697 mg/100 ml in CH₂C1₂): 290.9 nm, (log I₀/I = 0.485), 481.8 nm, (log I₀/I = 0.060).

The following copolymers can be manufactured analogously: D) Poly[l-[2-[methyl-4-[(E)-3-[2-[4-[(E)-2-methoxycarbonyl-vinyl]- phenoxy]-ethoxy-carbonyl]-4-nitro-phenylazo]-phenyl-amino]-ethoxy- carbonyl]-l-methyl-ethylene-co-l-[2-[4-[(E)-2-methoxycarbonyl-vinyl]- phenoxy]-ethoxycarbonyl]-l-methyl-ethylene] (1:9)

E) Poly[l-[l-[4-[(E)-3-[2-[4-[(E)-2-methoxycarbonyl-vinyl]-phenoxy]-ethoxy- carbonyl]-4-nitro-phenylazo]-phenyl]-piperidin-4-yl-oxycarbonyl]-l- methyl-ethylene-co-l-[2-[4-[(E)-2-methoxycarbonyl-vinyl]-phenoxy]- ethoxycarbonyl]- 1-methyl-ethylene] (1:9)

F) Poly[l-[2-[methyl-4-[(E)-3-[2-[4-[(E)-2-methoxycarbonyl-vinyl]- phenoxy]-ethoxy-carbonyl]-4-nitro-phenylazo]-phenyl-amino]-ethoxy- carbonyl]-l-methyl-ethylene-co-l-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]- ethoxycarbonyl]-l-methyl-ethylene] (1:9); λ_max. (0.710 mg/100 ml in CH₂C1₂): 284.4 nm, Gog I₀/I = 0.485), 474.5 nm, (log I₀/I = 0.059).

G) Poly[l-[2-[methyl-4-[(E)-3-[2-[4-[(E)-2-methoxycarbonyl-vinyl]- phenoxy]-ethoxy-carbonyl]-4-nitro-phenylazo]-phenyl-amino]- ethoxycarbonyl]-l-methyl-ethylene-co-l-[2-[(E)-3-(4-nitro-phenyl)- acryloyloxy]-ethoxycarbonyl]-l-methyl-ethylene] (1:9); λ_ma . (0.676 mg/100 ml in CH₂C1₂): 300.0 nm, Gog yi = 0.397), 475.3 nm, (log I₀/I = 0.052).

Example 5

A) Comonomer 9 (M_a-S_a-F-Sc-Za)

A solution of 0.76 g of 4-N-methyl-aminobenzoic acid (2-methyl-acryloyl- oxy)-ethyl ester, 1.5 g of 4-[(E)-4-[N-[2-[(E)-3-(4-chloro-phenyl)-acryloyl- oxy]-ethyl]-N-methyl-amino]-phenylazo]-phenylsulphonyl chloride and 9.5 ml of pyridine in 50 ml of acetone was boiled under reflux for 16 hours. The reaction mixture was subsequently concentrated to dryness. Chromatography of the residue on silica gel with ethyl acetate/hexane (3/7) gave 0.96 g of 4-[(E)-4-[N-[2-[(E)-3-(4-chloro-phenyl)- acryloyloxy]-ethyl]-N-methylamino]-phenylazo]-phenyl-N-methyl- sulphonamidobenzoic acid (2-methyl-acryloyloxy)-ethyl ester as orange- red crystals. λ_max. (0.685 g/100 ml in CH₂C1₂): 278 nm (ε = 32965), 438 nm (ε = 20562).

The 4-N-methyl-aminobenzoic acid (2-methyl-acryloyloxy)-ethyl ester used as the starting material was prepared as follows:

5 g of 4-N-methyl-aminobenzoic acid, 4.3 g of 2-hydroxyethylmeth- acrylate, 6.8 g of dicyclohexylcarbodiimide and 0.05 g of 4-dimethyl- aminopyridine were dissolved in 50 ml of dichloromethane at 0°C and slowly warmed to room temperautre overnight while stirring. Subsequently, the precipitated N,N'-dicyclohexylurea was filtered off and washed with dichloromethane. The combined dichloromethane solutions were dried over sodium sulphate. After removing the solvent in a vacuum the residue was chromatographed on silica gel with toluene/acetone (95/5). This gave 5 g of 4-N-methyl-aminobenzoic acid (2- methyl-acryloyloxy)-ethyl ester as white crystals.

The 4-[(E)-4-[N-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethyl]-N- methyl-amino]-phenylazo]-phenylsulphonyl chloride used as the starting material was prepared as follows:

a) A solution of 5.6 g of N-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]- ethyl]-N-methyl-aniline in 10 ml of methylene chloride was added dropwise to a solution, cooled to 0°C, of 5 g of 4-diazobenzenesulphonic acid in a mixture of 300 ml of methanol and 70 ml of water. The reaction mixture was stirred overnight. After the addition of 2 g of sodium hydroxide in 10 ml of distilled water the mixture was stirred for a further hour. The precipitated product was filtered off under suction. After drying in a vacuum 6.3 g of the orange coloured sodium salt of 4- [(E)-4-[N-[2-[(E)-3-(4-chloro-phenyl)-acryloyloxy]-ethyl]-N-methyl-amino]- phenylazol-phenylsulfonic acid were obtained. b) A mixture of 2 g of sodium 4-[(E)-4-[N-[2-[(E)-3-(4-chloro-phenyl)- acryloyloxy]-ethyl]-N-methyl-amino]-phenylazo]-phenylsulphonate, 2.2 g of phosphorus pentachloride and 10 ml of acetyl chloride was boiled under reflux for 12 hours. The solution was subseqently concentrated to dryness in a vacuum. The residue remaining was extracted with ethyl acetate. The extraction solution was dried over sodium sulphate. After removing the solvent 1.3 g of the orange coloured 4-[(E)-4-[N-[2-[(E)-3-(4- chloro-phenyl)-acryloyloxy]-ethyl]-N-methyl-amino]-phenylazo]-phenyl- sulphonyl chloride remained behind.

B) Copolymer from comonomer 9 and comonomer 2 (from Example IB)

0.652 g of [E]-3-(4-methoxy-phenyl)-acrylic acid (2-methyl-acryloyloxy)- ethyl ester and 0.558 g of 4-[(E)-4-[N-[2-[(E)-3-(4-chloro-phenyl)- acryloyloxy]-ethyl]-N-methyl-amino]-phenylazo]-phenyl-N-methyl- sulphonamidobenzoic acid (2-methyl-acryloyloxy)-ethyl ester were polymerized and worked-up analogously to Example IC). This gave 0.74 g of orange-red poly[l-[2-[4-[4-[(E)-4-[N-[2-[(E)-3-(4-chloro-phenyl)- acryloyloxy]-ethyl]-N-methyl-amino]-phenylazo]-phenyl-N-methyl- sulphonamido]-benzoyloxy]-ethoxycarbonyl]-l-methyl-ethylene-co-l-[2- [(E)-3-(4-methoxy-phenyl)-acryloyloxy]-ethoxycarbonyl]-l-methyl- ethylene] (1:4). The polymer has a glass stage at Tg = 88 °C. λmax. (0.685 mg 100 ml in CH₂C1₂): 295.5 nm, (log I₀/I = 0.408), 439.5 nm, (log I_o I = 0.103).

Claims

1. Polymers of the general formula

wherein

M_a, Mb, M_c signify monomer units for homo- or copolymers; x, y, z indicate mole fractions of the copolymers, whereby in each case 0 < x < l; 0 < y < l and 0 < z < 1; Sa» Sb, S_c represent spacer units; F denotes a nlo-active chromophore having an adsorbtion in the region of 300 nm to 700 nm; Z_a, Zb represent molecule units which are photochemically dimerizable; n is a magnitude of 4-1000000; and s is 1, 2 or 3,

which are characterized in that the nlo-active chromophores (F) are bonded via a spacer (Sa) to the monomer unit (M_a) and themselves, again via a spacer, carry one or more photochemically dimerizable groups (Z_a) which serve for the photochemical cross-linkage of the polymer.

2. Polymers in accordance with claim 1, wherein the nlo- active chromophore is a compound of the general formula:

wherein Ca denotes an electron acceptor

Cd denotes an electron donor

Ara, Arb denote phenylene, pyrimidine, pyridine, naphthyl, imidazole, oxazole, thiazole, benzoxazole or benzothiazole;

Ar_c denotes phenylene, pyrimidine, pyridine, naphthyl, 1-benzazine, 2-benzazine, 1,2-benzodiazine, 2,3-benzodiazine, 1,3-benzodiazine, 1,4-benzodiazine, 1,2,3,4-tetrahydro-l-benzazine, indole or dihydroindole; m, r denote 1, 2 or 3; p, q denote 0 or 1.

3. Polymers in accordance with claim 1, wherein the dimerizable units (Z_a and Zb) are compounds of the general formulae

wherein

ring A signifies benzene, pyridine, pyrimidine or furan

R?,R8,R9 signifies H, alkyl, alkoxy, dialkylamine, cyclo- alkylamine, alkoxycarbonyl, alkyl-COO, carboxyl,

-CN, halogen, -Nθ2, whereby R? and R⁸ or R⁸ and R⁹ together can also signify -O(CH2)lO-; 1 signifies 1 or 2;

RlO signifies hydroxy, alkoxy, aryl, aryloxy, aryloxy- alkyl, aryloxycarbonyl, phenyl-COO-alkoxy; o signifies 1 or 2.

4. Polymers in accordance with claim 3, wherein o is 1.

5. The use of polymers in accordance with any one of claims 1 to 4 for the manufacture of polymer layers having optical non-linear properties in selectively defined and optionally shaped areas, which areas are separate from those areas having a centro-symmetrical structure or areas having other optical non-linear properties.

6. A process for the manufacture of nlo polymers of formula I as defined in claim 1, characterized by firstly reacting the monomer units (M_a and, respectively, M ) with the spacer units (S_a, Sb and, respectivley, S_c), optionally the nlo active chromophore (F) and the dimerizable units (Z_a and, respectively Zb) and polymerizing the thus- obtained monomers to the polymers of general formula I.

***