LU85102A1 - POLYMER LIQUID CRYSTALS - Google Patents

Description

- 1 - * *

Polymeric liquid crystals

The invention relates to liquid crystals, in particular polymeric liquid crystals with very specific optical properties.

The existence of liquid crystalline substances has been known 5 since the 1990s. The terms "liquid crystals" or "mesophases" refer to a number of material states that move between liquid crystals and randomly oriented isotropic liquids. Liquid-crystalline substances have structural features of crystals on the one hand, but can also be viscous to slightly fluid on the other hand.

; In the case of liquid crystals, one can differentiate between three different structures (mesophases) due to their different degrees of order. In the crystalline state, the liquid crystals have a uniform three-dimensional structure with an orientation and positioning order. If the crystals are then heated, they can initially lose a dimension in their positioning order. In this state, the so-called smectic state, the liquid crystals keep the orientation order of the crystalline state as well as the two-dimensional positioning order.

With further heating, the liquid crystals can change into the nematic state. In this phase the last order of positioning is also lost and the liquid crystalline substance only has the one-dimensional order of orientation of the crystalline state.

2_ ~% *! _ 2 -

The molecular arrangement of nematic states is characterized in that the molecules are arranged along an axis that coincides with the longitudinal axis of the molecules. The centers of gravity of the molecules show a random arrangement, so that there is no longitudinal positioning arrangement.

In the fcholesteric mesophase, the molecular arrangement is characterized in that the molecules are arranged along an axis which, as in the nematic phase 10, coincides with the longitudinal axis of the molecules. However, this axis continuously changes its direction along a second axis which is perpendicular to the first. The cholesteric mesophases are therefore often referred to as helically rotated nematic mesophases (twist structure) 15 net. The prerequisite for the cholesteric mesophase is the optical activity of the liquid crystals in question.

; The term "cholesteric" is primarily historical. The first discovered cholesteric structure; The liquid-crystalline substance exhibiting was namely 20 cholesteryl benzoate. However, it has long been known that the presence of the cholesterol fragment j | is not required and that noncholesterol can also show a derivative cholesteric structure.

Of particular interest are liquid-crystalline substances 25 with a cholesteric structure, since such substances are a! unique optical properties, such as selective reflection of visible light to produce iridescent color! ben as well as circular dichroism. So e.g. in US Pat. No. 3,720,623 mixtures of cholesteric and .1! 30 nematic liquid crystals are described, which are suitable for temperature-sensitive visual displays. In US Pat. No. 3,766,061, films for decorative purposes are described which contain solids in such a ratio that the composition exhibits cholesteric properties. US Pat. No. 3,923,685 relates to cholesteric substances which, under the action of an electric Fel-5, change into the nematic state. U.S. Patent 3,931,041 describes combinations of nematic and given cholesteric substances suitable for imaging and display devices.

i Ï I Although colored images produced in this way using cholesteric substances are not useful, they are usually not permanent.

I There is therefore a lively interest in the production of cholesteric substances whose color can be fixed. For example, described in the above-mentioned US Pat. No. 1,576,661 films for decorative purposes, in which 'ti §j' color is fixed by cooling. In addition, US Pat. No. 4,293,435 also describes polymeric liquid crystals in which the color is reduced by lowering the polymer temperature is fixed below the glass transition temperature, where- | 20 is itself fixed by the polymer in the solid state.

L.

The use of temperature changes to fix the dye is not always appropriate. There was therefore an interest in the development of cholesteric substances; 25 their color in other ways, e.g. can be fixed by photopolymerization, the resulting t; fixed color is insensitive to temperature. However, only one such polymer is known to the applicant. A group reports on such a polymer; 30pe by Japanese researchers. It's about ! V '

Ii poly (gamma-butyl-L-glutamate), which can be photopolymerized to triethylene glycol | ’dimethacrylate, which fixes the color so that it is insensitive to temperature fl y 4 Jllieh will.

»JS

i j ....

• · - 4 -

One object of the invention is therefore to provide polymeric cholesteric liquid-crystalline substances with fixed, essentially temperature-insensitive colors.

5 Another object of the invention is to provide combinations of monomeric compounds that different optical reactions within one! show wide temperature range.

Another object of the invention is also the provision of polymer films with fixed colors, as can be used in a large number of optical devices.

: j These and other objects of the invention are derived from the! following detailed description of preferred 15 implementation variants clearly.

The invention relates to new cholesteric liquid crystalline monomers and combinations thereof with substances which support the formation of a mixture which; Show cholesteric liquid crystalline properties.

| 20 These substances can be shaped as films, heated to the desired temperature or cooled down to; this way a cholesteric film with the desired:! * to produce the optical response. Finally, these substances are photopolymerized in order to permanently fix the optical properties of the polymer obtained.

| - An embodiment of the invention relates to a for the preparation of a polymer film with fixed optical! Properties suitable composition, characterized f. 30. ·, That this is a photopolymerizable monomer î a: · Ol___ i s n »« '- 5 - of the structure. χτ

* R.O ο I

L1 «Y

CH ^ C-C-O-A-C-O-A ^^ VB \

H

yH

. y I wherein R ^ H or CH3, A -R2 ~, ~ ^ 3 ° ~ 0 (3er “R40-, R2 a (alkylene chain with 3 to 14 methylene or lower alkyl-substituted methylene groups, R ^ an alkylene chain with | 5 2 up to 14 methylene or lower alkyl-substituted methyl groups, R 1 is an alkylene or lower alkyl-substituted alkylene ether, diether or triether with a total of I 3 to 14 carbon atoms in the alkylene, units with I: I of Provided that the terminal alkyl unit adjacent to the carbonate unit 10 has at least 2 carbon atoms,% 'and Y is 0 or 1, and contains a suitable photoinitiator.

i! • 4 I relates to a second variant of the invention. a polymer film with a fixed optical reaction, which! & - 15 was obtained by photopolymerization of an assembly. setting, which is a photopolymerizable monomer of the structure I for l! ts

! * X

Ί T

si /! l! î ί - 6 - ». \,, -

" H

y ^ y 'fi? ? (T \

CH ^ C-C-O-A-C-CM ^^^ I

IH

yH

y wherein R1 is H or CH3, A -R2 ~, -R3O or -R ^ O-, R2 is a 1 alkylene chain with 3 to 14 methylene or lower alkyl-substituted methylene groups, R3 is an alkylene chain with | 2 to 14 methylene- or lower alkyl-substituted methyl- I 5lengruppan, R4 an alkylene or lower alkyl-substituted | 'ten · alkylene ethers, diethers or triethers with a total of I 3 to 14 C-atoxen in the alkylene units, with | with the proviso that the terminal alkylene unit adjacent to the carbonate unit I has at least 2 carbon atoms, Λ | '! 10 and Y is 0 or 1, and contains a suitable photoinitiator.

I 'A third embodiment variant of the invention relates to 1 a process for the production of polymer liquid crystal! line substances with a fixed optical reaction- I ’15 contain the film, characterized by the stages in the production i’ of a film containing a photooolerizable monomer ft "jj | 3 structure il [fi il ί ϊ ί ί:

R-0 Q

| 1II I

C ^ C-C-O-A-C-G-A, ^^, ^

H

IyH

.y where H or CH ^, A -R ^ O- 0 <3 -R ^ O- »R2 e * ne

Alkylene chain with 3 to 14 methylene or lower alkyl substituted methylene groups, R7 is an alkylene chain with E | . ό il is 2 to 14 methylene or lower alkyl-substituted methylene groups, an alkylene or lower alkyl-substituted alkylene ether, diether or triether with a total of 3 to 14 carbon atoms in the alkylene units, with the proviso that the terminal i to the Carbonate unit adjacent alkylene unit has at least 10 carbon atoms, and Y represents 0 or 1, and {; contains a suitable .. photoinitiator, ti * (| the orientation of this film; ;; the setting of the temperature of the film to achieve the desired optical reaction i; and Ï'1 1 <3 photopolymerization of the film.

V.

Cholesterol derivatives which can be used according to the invention are cho * j j-iester (with y = 0) and 5,6-dihydrochol ester in (y = l).

There are also a number of substitution options in the side chain of the 3 ~ position. So e.g. The polymerizable portion of the side chain can contain an acrylate or j methacrylate fragment, which is connected via a bridge to fine ester or carbonate bond. Is a !

If an ester bond is present, the bridge can contain an alkyl chain of 3 to 14 methylene or lower alkyl-substituted methylene groups, here lower alkyl being understood as having 1 to 4 carbon atoms. 5 of the Soviet literature describes methacrylate esters with = CH ^ and n - 5, 10 and 14. However, these were made for the purpose of their use in solvent polymerization reactions. However, there is no question of their usability for producing photopolymerized films.

On the other hand, if there is a carbonate bond, the bridge can be more complex. So e.g. it can contain 2 to 14 methylene or lower alkyl substituted methylene groups or an alkylene or lower alkyl substituted alkylene ether,! ^ S-aiether or -trie ther with a total of 3 to 14 carbon atoms S. contained in the alkylene fragments, the terminal alkylene fragment I adjacent to the carbonate fragment having at least 2 carbon atoms. Examples of ether residues as can be used in the practice of the invention are analogs of ethylene glycol, diethylene glycol, triethylene glycol, tetramethylene glycol, 2,21-oxybis-1-i-propanol, 4,4'-oxybis-1-butanol, 1,1 1'-Oxybis-2-propanol and others

i fl 'In the pure state, the compounds according to the invention are somewhat | r 25 difficult to treat as they tend to be in to crystallize in moments. In addition, it is difficult to obtain colored polymers from the pure polymers, since most of them either I show no colored cholesteric mesophase at all or only! 30 a very narrow. The pure compounds according to the invention

; -V

I gen are therefore in their ability to manufacture poly! limited films with desired properties.

’| Surprisingly, it has now been found that these restrictions are eliminated and colored and uncolored films which contain a compound according to the invention and either a second compound according to the invention or a second substance which is suitable for forming a film with cholesteric liquid-crystalline properties , and can be photopolymerized in the presence of a suitable photoinitiator, whereby films with fixed optical properties are obtained. If the film is colored, the fixed color can preferably be

Actually the same as the color of the unpolymerized film. In some cases, however, it may be desirable to obtain a polymerized film with a fixed color different from that of the unpolymerized film. All of these options will become ff | contemplated by the invention.

A preferred method of practicing the invention involves making a film that exhibits a desired I1 * optical property at a particular temperature. In the case of colored films, this is usually e.g. by preparing a mixture of substances that create a cholesteric film! possible, a photoinitiator and optionally one

Jj crosslinker, heating the mixture to achieve an I 25 viscous liquid, distribution and alignment of the 'liquid between glass plates, immersing the plates T' in a thermostatic water bath and setting the ί | Temperature to achieve the desired color. In the case of uncolored films, the optical properties must be determined spectrophotometrically. The film is then exposed to a suitable radiation source, e.g. a mercury lamp, illuminated. The | Polymer films obtained in this way remain depending on the length of time. - 10 -

Type of the second component, which is explained in more detail below, remains essentially unchanged even when it is above. 'are exposed to high temperatures for several weeks.

Examples of suitable photoinitiators for carrying out 5 the invention are benzophenone, 2,2-dimethoxy-2-phenyl-acetophenone, 2,2-diethoxy-acetophenone, 2-benzoyloxyaceto-phenone, 2-chlorodioxanthone and 2-hydroxycyclohexylphenyl-ketone, all these compounds are illustrative but not restrictive.

10 Examples of suitable optical crosslinkers which may be used for carrying out the invention are trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, di- and triethylene glycol triacrylate and dimethacrylate, 15 1,6-hexanediol butyl acrylate and 1,4-dimethyl acrylate and 1,4-dimethyl acrylate and dimethacrylate, similarly substituted acrylamides and methacrylamides, and many others, the compounds listed being merely illustrative and not restrictive.

20 A large number of combinations can be selected within a wide range to produce films with different optical properties. Nevertheless, with regard to the combinations of the new monomeric compounds, several general fixed positions can be made.

First, combinations of similar monomers give films that show cholesteric mesophases within a wide temperature range that are comparable to those of the single monomers. E.g. prepares an acrylate / 30 methacrylate / pair of cholesterol derivatives, where Y is O and A - (CH0) .n-, shows methacrylate {R.

«C Ί U 1 = H) a color range (only monotropic) at 57.8 to! ; ci._ - 11 - 59.2 ° C shows. A mixture of the two (1: 1) shows a colored measuring phase range from 56.5 to 55.9 ° C.

Second, combinations of similar monomers with very different alkyl chain lengths result in mixtures 5 with considerably broadened mesophase ranges compared to the individual components. So e.g. shows in the case of the production of a pair of acrylate monomers (R ^ = H and Y = O), where in one monomer A - ((^ 2) ^ 0 means and in the other monomer - (<^ 2) 3- means , 10 the first monomer has a color range from 57.8 to 59.2, whereas the second monomer has no color, an I 1: 1 mixture of the two monomers shows a considerably wider color range from 68 to -15 ° C, the Value -15 ° C represents the lower limit still detectable by the test instrument, 15. With careful mixing of the two monomers mesophases can be prepared, which shows a complete optical reaction over a wide temperature range.

i

Third, the addition of small amounts of non-20 mesogenic substances to a mixture of mesogenic substances can lead to significant changes in the optical reaction area. So e.g. the addition of 2% of t | 'Photoinitiators or a crosslinker a decrease by j. Effect 10 degrees or above in the color range shown by the mixture of the pure mesogenic substances.

\

As indicated above, an alternative method for preparing photopolymerized films with fi-fixed optical properties is to combine an 'i - ~ Ί compound of the invention with a second substance il 30, which is suitable for the formation of a film, the cholesteric f3üssjgkrista] line properties j ,, shows. It is not necessary that this second Cor— 1 j! component is polymerizable or mesogenic. Nevertheless ψ · - 12 - it should preferably be photopolymerizable in order to achieve stable polymer films in this way. A large number of substances are possible for the preparation of typical films. Examples of substances which are only 5 illustrative but not restrictive are cholesteryl oleyl carbonate and 2-methyl-1,4-phenylene-bis (4'-hexyloxybenzoate), which are mesogenic, however. . are not polymerizable, p-methoxyphenyl p- (6-meth-acryloyloxyhexyloxy) benzoate, which is not mesogenic, but 10 is polymerizable, and cholesteryl 11- (methylacrylamido) undecanoate, which is both mesogenic and polymerizable. The usability of certain compounds from the. is illustrated in Example 9.

The color intensity and uniformity exhibited by various combinations according to the invention are also achieved by the alignment. So e.g. certain forms of mechanical shear must be used to obtain colored films, as is known from the prior art. Such alignment is satisfactorily achieved by layering the monomers between glass plates or polyester films.

Although the polymerization of the films can be carried out in almost all cases by radical or thermal initiation, either in solution or in bulk, a fixed color or optical reaction cannot be determined. Instead, the polymers prepared in solution or in bulk form rather colorless smectic mesophases or amorphous polymers. Photo-30 polymerisation is therefore necessary to achieve the objects according to the invention. The way of

Carrying out the photopolymerization has a certain effect on the optical parameters of the polymer obtained. Is e.g. if the reaction is to be doubled, it is advisable to use a high-power light source which induces rapid polymerization. Reverse ί * "* '*'.

- 13 - • can be produced by slow polymerization, induced 1 'by a low-power light source, polymer films in which the reaction is shifted towards the red end of the spectrum.

5 According to the invention, photopolymerization cannot! polymerized films also films with multiple reactions i 1 ", are produced. S. e.g. a colored film can be covered with a mask, after which the uncovered areas are irradiated to fix the color. A color change can be achieved in the unpolymerized portion of the film by removing the mask and changing the temperature of the partially cured film. The second color can then be fixed by subsequent irradiation, resulting in a two-color film.

15 If desired, this technique can also be applied to films with multiple optical reactions.

Because of their unique ability to reflect very specific wavelengths of light from the UV near range to the infrared range, the films according to the invention are extremely useful. So e.g. makes their insensitivity | sensitivity to temperature fluctuations i- suitable for use as a filter in optical l »

Devices such as as a band, notch and circular \ cular polymerization filter. They are also well suited for reflective displays and so-called "Scheffer j cells". If the films also reflect in the visible spectrum and show vivid iridescent colors; ^ they are also used to replace dyes and pigments | suitable. So e.g. they come as floor and wall coverings; "30 textiles, mats, paper products and unconventional \ inks in the graphics in question.

| The advantages and features of the invention are illustrated in more detail by the examples below, the invention> 7i \ - 14 -.

However, this does not limit the scope of the application. Examples

The structures of the connections denoted below with Roman numerals and the details of their manufacture. 5 positions are disclosed in the associated parallel application j, to which reference is made here. In the following, the temperature ranges mean temperature ranges if there is no information j by an asterisk (*) or brackets. An asterisk means that the area j 10 is a mesophase area, whereas the brackets on! indicate that the range is a monotropic mesophase range, the latter being measured at reduced temperature i. In the case of compounds with precisely determinable i j: melting ranges, the monotropic mesophase range 15 is frequently below the melting range.

". Ο o

! 'M

H

| y where A = R2 = ^ CH2 ^ n ’

l · I

: ß>: "t! Λ" i. * - 15 -

Melting or mesophase

Compound n y rich (° C) IVa H 10 0 * 54.5 - 71.5 5 Vb CH3 10 0 * 58 - 64

Vc H 5 0 * 45.5 - 68.5

Vd CH3 5 0 * 4 8 - 57.5

Ve H 3 0 68.5 - 70.5 (67.5)

Vf CH3 3 0 73 74 (56.0) i 10 Vg B 3 1 41 - 43 (35.5) I Vh CH3 3 1 43 - 45 (below the I room temperature)

Vi H 10 1 62.5 - 64.5 (5B.0)

Vh CH3 10 1 * 33.7 - 49.0 1 -

Y ^ Y

m ΛΚΎ

i R ·, Ο O

I 11 H H

’L CH2 = C-C-0-A-C-0-Vn ^ nW IX

il H

y

H

y P where A = r30 = (CH2) n0, or 15 R40 =. (CH2CR20) n .. p q Schirelz or —3 - * - pesophase

Connection Κη (CH? L_n0 y reich (cC) _ | ^ IXa CH3 6 0 58.5-60 (51.0) | IXb CH3 2 0 80 81 (40.1) 20 ^ 3Xc H 2 0 85.5 - 87 (56.0)

Li il IXd H 6 0 * 52 - 62 1? ......

* »- 16 -

Compound Rj A y From enamel or prey mesophase range ___________ (%) range (° C) __ IXe CH3 tCH2CH20) 2 0 60 48.5-52.9 (33.1) 5lXf CH3 (CH2CH20) 3 0 62 none Sp (6.5)

example 1

This example illustrates the color ranges of the various monomeric esters V according to the invention, measured with the aid of a Leitz light microscope with light passing through cross polarizers at 250-fold magnification.

A temperature controller of the | Type Mettler FP5 and a heating table of the type Mettler FP52 are used, the cooling taking place by passing a nitrogen flow through a copper coil cooler cooled with dry ice and then through the heating table.

j 'connection______________ color range (° C) _

Va 57.8 - 59.2 *

Vb (55.8-55.3) 20 Vc ’(48.5 - 33.0) ί Vd (51.0-26.5) i’ Ve no color 1 Vf no color

Example 2 '! .. ........

25 This example describes the colored mesophase regions as obtained for mixtures of the above-described paired monomers with identical ii alkyl chain rings. The measurements were carried out using the 4 apparatus described in Example 1 with heating! 30 performed a monomer mixture up to the melting temperature and subsequent cooling. The individual! | 1 / Components are mixtures in a weight ratio of 1: 1.

VN.

>> 'i ψ ·

- 17 - • R2 or R ^ O

- More optical

Reaction

Component n color range xC) 5 Va - Vb 10 violet-red (56.5 - 55, 9)

Vc - Vd 5 Violet-Orange (50.2 - 29.5)

Ve - Vf 3 No staining 61.5 Mesophase I Vg - Vh 3 No staining not measured IXa -IXd 6 Violet-Blue- (51-1) IQ violet IXb -IXc 2 No staining 47 Mesophase

Example 3 j ^ This example describes the colored mesophase ranges 1 obtained with two-component mixtures from above! 15 described monomers with different alkyl chain length. The color measurements are carried out as described in Example 1, j. The individual components are mixtures in a weight ratio of 1: 1.

Rn or Ro0 _. . , il _2_3_ Optical! 20 reaction * component n color range (C) **

Va 10 violet-orange- (68 - -15) red] Ve 3 | j 25vb 10 green-orange (47.5 - -15) IXC 2 ü ** - 15 ° is the lower temperature limit of the thermostatic i '£ « ii | tables water bath.

L · ri / /! * »- 18 -

Example 4

This example describes the colored mesophase regions obtained with mixtures of the above-described monomers with different alkyl chain lengths. The 5 mixtures contain Irgacure 651 as a photoinitiator and possibly other specified components. Irgacure 651 is 2,2-dimethoxy-2-phenylacetophenone. The color measurements are made using a thermostatic water bath.

10 Optical

Reaction

Crane components weight (g) color range (° C) || Vb 1.0 ί Ve 1.0 Violet-Red (50 - -5) I 15 Photoinitiator 0.04

Vb 0.25 \ Vh 0.25 teal-red (40 - -5)! -I 1 photoinitiator 0.01 i Vd 0.50 I 20 Vf 0.50 green-red (45 - 30) | i

Photoinitiator 0.02 j jj Vb 0.50 fj _ IXb 0.50 | Photoinitiator 0.02 Orange-Green-Red (32 - 0) pi - 25 Methylmethacry- I lat 0.05 it S Vd 0.40 f Vc 0.40 | Va 0.20 violet-orange (16 - 6) | _ 30 photoinitiator 0.02 I '! | Trimethylolpro- ij pantriacrylate 0.06: rj Vb 0.5 I ft ixe 0.5 green-red (37 - 0) £ «* <-! £. 35 photoinitiator 0.01 4 \ -v Ί 7 ·; Ψ * - 19 -

Example 5

This example illustrates a colored polymer film obtained from a film containing a single monomer of the invention and 1% Irgacure 651. In the table below, the maxima Umax) of the "apparent absorption", the degree of permeability in percent (% T) and half the width of the film at half height (HB-HH) and that after photopolymerization of the film at the specified temperature obtained polymer indicated. The polymerization takes place in these and in the other examples by exposing the film to a 450 watt mercury lamp for 30 seconds.

Film monomer film polymer_

temp. } max HB-HH Λ max HB-HH

Component (° C) (nm)% T (nm) (nm)% T (nm) | 15 Vg 25 738 53 45 738 55 50 IXd 25 438 49 27 441 46 33]! Example 6 | | This example illustrates several of those listed; Polymer films obtained from monomer compositions. Velvet films contain 1% Irgacure 651 photoinitiator.

Four of these films also contain 3% trimethylol- | propane triacrylate, the pair Vb: IXb ,. the 3% trimethylol. 'Propane trimethacrylate contains, except.

Film monomer film polymer

| 25 assembly temp. λ max HB-HH Ti max HB-HH

j tongue (weight ratio) _ (° C) (nm)% T (nm) _ (nm)% T (nn) * Va; Ve (1: 1) 23 505 49 18 505 51 20 j VbrIXb (1: 1) 25.5 585 42 21 585 42 21 I * 30 Vc: IXc (3: 1) 25.5 563 46 25 568 45 26

VcrIXc * (1: 1) 24.5 950 53 50 950 53 50 IXc: IXd * (1: 1) 25.5 1260 59 112 1260 59 112 | /) * colorless mixture j St

Example 7 if «*

This example illustrates the differently colored polymer films that can be obtained by exposing the monomer mixture to different temperatures and then exposing the colored film to UV radiation. The mono used in this example

Is a mixture of the compounds Vb and

Vf (1: 1 weight ratio). The maxima of apparent absorption and color are given for each film.

10 film temperature (° C) ^ max (nm) color 45 485 - 470 blue-green I 35 515 green * 25 542 lime green I 11 605 orange 115 A comparable experiment is carried out with a mixture of

Connections Va and Ve (1: 1) carried out, whereby the following results are achieved: <1 film temperature- permeable- I rature> max keit! 20 (C) _ (nm) _ (%) (nm) color_ | 32 480 47 32 20 Blue 23 505 51 0 Blue-Green 4j I 18 530 48 42 Linden Green V, I 10 574 48 40 Orange! *> *: Ί 25 Example 8 | This example illustrates the effect of non-mesogenic substances on a monomer mixture. A mixture - from the compounds Vc and Vd (weight ratio 1: 1)

ff results in a colored mesophase range of 50.2-29.5 ° C

1 | f 1 30 as in Example 2. When adding 2 Oew.% of a photo ’: A.

• · * - .21-

Initiator, the colored mesogenic area shifts towards the temperature range of 43-20 ° C.

4th

Example 9

This example illustrates polymer films that can be produced from a compound according to the invention and from the unrelated substances mentioned below:

CH

I 3 A

I · CHjO 0 i «V * - c-c (ch2) 6-o ^ O> -Ü-o ^ 5> -och3 Ÿ1

I B

1 pp

li ο if, .CH3- (ffl2) 7-CB.ra- (CHp8-CHic> APvP c.

4> Ky h '2¼ —-— Ey! · / Y i "y.

i; \\ - 22 - • 1

Compound A is a nematic liquid crystalline substance that cannot participate in photopolymerization. Compound B is a non-mesogenic substance that may participate in photopolymerization. Compound C is a cholesteric liquid crystalline substance that is unable to participate in the photopolymerization. All three substances are suitable for the formation of a film with cholesteric liquid-crystalline properties. To illustrate this fact, films are prepared and photopolymerized using 1% Irgacure 651 photoinitiator and 3% trimethylolpropane trimethacrylate.

? Composite * film monomer film _ polymer

'haïïnÎ (e? U'Ver ~ J MX BB-HH X max HB HH

jj 15 haltnlS> t c> ltm)% T (nm> <nm)% T ln.)! * * l '

Vd: A (2: 1) 24 355 43 30 350 41 35

Vb: B (1: 1) 25 388 52 15 400 42 40 j Vg: C (4: 1) 25 700 51 33 730 55 52 ij!, Although the film made from the pair Vd: A shows suitable f, 20 optical properties , it is still not as durable as other films in which both links of the!] v 'pair are polymerizable. If such a polymer film, e.g. Heated at 60 ° C for a day, p - crystallizes and an opaque color is obtained 251ose film.

I- 'f. The invention is not limited to the above description illustrations, but also relates to all modifications unsubstantiated by the claims.

r> - ;; / ¥ '\

Claims (18)

1. Composition for the preparation of a polymer film with (fixed optical reaction, characterized in that it is a photopolym ^ risierbciras monomer of the structure II> il R-0 or a IIll II CH2 = CC-0-AC-0-kN ^ / | sNI ^ J * hy 11, η s wherein R1 is H or CH3, A - & 2 ~ '_R3 ° "° âer -P ^ O-, R2 is an alkylene chain with 3 to 14 methylene- or nie-alkyl-substituted methylene groups, an alkylene chain with 2 to 14 methylene or lower alkyl] substituted methyl en groups, R ^ an alkylene ether, diethyl or ~ triether J ^ 0 with a total of 3 to 14 carbon atoms in the alkyl 1 eneinhel ten £, with the measure that the end position, which is adjacent to the ~ carbonate unit, contains at least; * 2 C atoms, and Y o rv> r 1 means t unc] Pjnf, n tK »- | suitable photoinitiate contains *.:! / - V. - - 24 - 2. Composition according to claim 1, thereby g e k e η n - | "indicates that it contains a second substance which is suitable for forming a film having the properties of cholesteric * liquid crystals. 3. Composition according to claim 2, characterized in that the second substance is a compound of the structure according to claim 1. 4. Composition according to claim 2, thereby g e k e η n -! ' is characterized in that the second substance is a photopolymerizable substance with a different structure from claim 1. 5. Composition according to claim 2, characterized in that the second substance is a meso-3 "! that substance with a structure different from claim 1. 5 Removal of the mask after completion of the photopolymerization, adjustment of the temperature of the film to obtain a different optical property of the unpolymerized sections and 10 photopolymerization of the film to obtain a polymer film with numerous optical properties. 6. The composition according to claim 2, characterized in that it contains a crosslinking agent. <*. '! 7. The composition according to claim 2, thereby g e k e η n - | records that lower alkyl is substituted. r: * η 8. Polymer film with a fixed optical reaction, characterized in 3 that the film was obtained by photopotl tj lymerisation of a composition according to one of claims r -p 1 to 7. 9. Polymer film according to claim 8, characterized g e k e η n - I. indicates that the film is colored. | | 10. Polymer film according to opposition 9, thereby g e k e η n - | indicates that the film has multiple colors. ! ^ «Si— ^ j • a -25 - t - - 11. Polymer film according to claim 8, characterized in that the film reflects UV light. , 12. Polymer film according to claim 8, characterized in that the film reflects IR light. ! 5 13. Process for the preparation of polymeric liquid crystals stalline substances with fixed optical reaction i * containing films according to claim 8, characterized g e- j that it comprises the steps of producing a film containing a photopolymerizable monomer of the structure T ^ Y Λκν fl? ? I; cHj ^ -c-o-a-c-ck ^ ij! H YH y l! * in which H or CH ^ »A -R2 ~ i -R ^ O- or -R ^ O-, R2 an! '' alkylene chain with 3 to 14 methylene or lower alkyl-substituted methylene groups, an alkylene chain with 2 j: 10 to 14 Methylene or lower alkyl substituted methy! len groups, an alkylene ether, -diether or -tri-,: ether with a total of 3 to 14 carbon atoms in the alkylene units, with the proviso that the terminal, 1st alkylene unit adjacent to the carbonate unit is at least j 15 has at least 2 carbon atoms and Y represents 0 or 1, l ·. I and a suitable photoinitiator; the direction of this film; j · \ ι setting the temperature of the film to achieve * · - 26- the desired optical response; and the photopolymerization of the film. 14. The method according to claim 13, characterized in that there are also the additional steps of masking at least part of the film against the photopolymerizing radiation, 15. The method according to claim 13, characterized in that the temperature is set so that the film is colored. 16. The method according to claim 14, characterized in that polymer films are produced with several colors by the temperature setting. 17. The method according to claim 13, characterized in that the temperature is set so that the film reflects UV light. 18. The method according to claim 13, characterized in that the temperature is set so that the film reflects IR ~ light. /