Linear and cyclic polymers or oligomers having a photoreactive ethene group

a technology of photoreactive ethene and linear cyclic polymers, which is applied in the field of linear and cyclic polymers or oligomers having a photoreactive ethene group, can solve the problems of incomplete conversion, insufficient stability with time, and inoptimal methods

Inactive Publication Date: 2000-03-21
ROLIC AG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These methods are, however, not optimal, since on the one hand the solubility of such orientatable molecules in the polymer is limited and on the other hand the stability with time can not be guaranteed to a sufficient extent.
A disadvantage of this method is, however, the fact that the esterification of the free hydroxy groups on the polymer with photochemically dimerizable units usually leads to a non-reproducible and, above all, to an incomplete conversion.
The free hydroxy groups still present in the orientating layer lead to an undesired ion solubility.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

1 g of methacryloyloxyethyl 3-(E)-[4-pentyl-4'-biphenyl]acrylate and 0.002 g of azobisisobutyronitrile were dissolved in 4 ml of tetrahydrofuran. The solution was flushed for 10 minutes with a weak nitrogen stream and the reaction vessel was subsequently closed air-tight. The solution was heated to 60.degree. C. for 24 hours. Thereafter, the reaction vessel was opened and the solution was diluted with 5 ml of tetrahydrofuran while stirring. Subsequently, the diluted solution was added dropwise to 450 ml of diethyl ether while stirring at room temperature. The separated polymer was filtered off, dried, dissolved in 30 ml of dichlormethane and this solution was added dropwise to 450 ml of diethyl ether. This procedure was repeated twice. Filtration and drying at 50.degree. C. in a vacuum gave 0.4 g of poly(methacryloyloxyethyl 3-(E)-[4-pentyl-4'-biphenyl]acrylate), Tg. 123.degree. C., cl.p. (S-I) 160.degree. C.;

The methacryloyloxyethyl 3-(E)-[4-pentyl-4'-biphenyl]acrylate used as the ...

example 2

1.5 g of 4-methacryloyloxybutyl (E)-3-[4-(4-methoxyphenyl carbonyloxy)phenyl]acrylate and 0.003 g of azobisisobutyronitrile were dissolved in 6.8 ml of tetrahydrofuran. The solution was flushed for 10 minutes with a weak argon stream and subsequently the reaction vessel was closed air-tight. The solution was heated to 60.degree. C. for 20 hours. Thereafter, the reaction vessel was opened and the solution was diluted with 3.5 ml of tetrahydrofuran while stirring. Subsequently, the diluted solution was added dropwise to 300 ml of diethyl ether at room temperature while stirring. The separated polymer was filtered off, dried, dissolved in 10 ml of dichlormethane and this solution was added dropwise to 300 ml of diethyl ether. This procedure was repeated twice. Filtration and drying at 50.degree. C. in a vacuum gave 1.15 g of poly(4-methacryloyloxybutyl (E)-3-[4-(4-methoxyphenylcarbonyloxy)phenyl]acrylate). The polymer has a glass stage at Tg=38.degree. C. (.DELTA.c.sub.p =0.17 J / gK) an...

example 3

2.5 g of methacryloyloxyethyl (E)-3-(4-methoxyphenyl)-acrylate) and 2.5 g of 2-methacryloyloxyethyl (E)-3-(4-chlorophenyl)acrylate as well as 0.014 g of azobisisobutyronitrile were dissolved in 35 ml of tetrahydrofuran. The solution was flushed for 10 minutes with a weak argon stream and the reaction vessel was subsequently closed air-tight. The solution was heated to 60.degree. C. for 24 hours. Thereafter, the reaction vessel was opened and the solution was diluted with 7.5 ml of tetrahydrofuran while stirring. Subsequently, the diluted solution was added dropwise to 500 ml of diethyl ether while stirring at room temperature. The separated polymer was filtered off, dried, dissolved in 40 ml of dichloromethane and this solution was added dropwise to 500 ml of diethyl ether. This procedure was repeated twice. Filtration and drying at 50.degree. C. in a vacuum gave 3.8 g of poly(2-methacryloyloxyethyl (E)-3-(4-methoxyphenyl)acrylate-co-2-methacryloyloxyethyl (E)-3-(4-chlorophenyl)acry...

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PUM

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Abstract

The invention is concerned with linear and cyclic polymers or oligomers having a photoreactive ethene group. The polymers are of the formula wherein Ma, Mb, Mc are monomer units for homo- or copolymers; x, y, z are mole fractions of the copolymers, whereby in each case 0<x< / =1; 0< / =y< / =1 and 0< / =z<1; Sa, Sb are spacer units; Za, Zb are molecular units which can undergo photochemical isomerization / dimerization; n is a magnitude of 4-100 000 and m is 0 or 1, The compounds are used as an orienting layer for liquid cyrstals.

Description

FIELD OF THE INVENTIONThe invention is concerned with novel linear and cyclic polymers or oligomers having a photoreactive ethene group for use as orientating layers for liquid crystals.BACKGROUND OF THE ARTThe alignment of liquid crystal phases in cells can be brought about in various ways and is usually effected by rubbing a glass plate coated with a polymer layer or by the inclined vapour deposition of a SiO.sub.x layer on a glass plate. Generally uniformly aligned layers are produced in this manner.It is, however, also possible to obtain a structured orientation of the liquid crystal phase. This can be achieved, for example, by coating a glass plate with a polymer with which are admixed, for example, photochemically orientatable dyestuff molecules or photochemically dimerizable molecules, as described, for example, in EP-A-0445629. These methods are, however, not optimal, since on the one hand the solubility of such orientatable molecules in the polymer is limited and on the oth...

Claims

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Application Information

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IPC IPC(8): C08F246/00C08G77/00C08G77/38G02F1/1337G02F1/13C08F220/22C08F2/04C08F12/00C08F20/00C08F20/22C08F20/26C08F220/28C08G77/04C08G83/00C08L101/00C09K19/56
CPCC08F246/00C08G77/38G02F1/133711C08F2220/365G02F1/133788G02F2001/133765C08F2220/305G02F1/133753C08F220/305C08F220/365G02F1/133765
InventorHERR, ROLF-PETERKELLY, STEPHENSCHADT, MARTINSCHMITT, KLAUSSSCHUSTER, ANDREAS
OwnerROLIC AG