JPS59110700A - Liquid crystal compound - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to liquid crystals, and more particularly to monomeric liquid crystals useful in the preparation of polymeric liquid crystal materials.

The existence of liquid crystal materials has been recognized since the late 1800s. The term [liquid crystal 1 or "methodiene]" refers to a state of matter that lies between a solid crystal and an isotropic liquid, the latter being randomly arranged. It has a viscosity of 1 and is a completely fluid liquid.

The different degrees of order that liquid crystals have give rise to different types of structures called mesophases. Liquid crystals in the crystalline state have a dimensionally uniform pattern that is directionally and positionally ordered. When a crystal is heated, it initially loses one dimension of its positional order. This is called a smectic mesophase, and the liquid crystal in this phase maintains the directional order and two-dimensional positional order of the crystalline state.

Upon further heating, the liquid crystal can transform into a nematic mesophase. In this phase, the remaining positional order is lost and the liquid crystal maintains only unidirectional order of the crystalline state. The molecular arrangement (order) of the nematic mesophase is characterized by an orientation of the molecules along an axis that coincides with the long axis of the molecules.

Since the centers of gravity of molecules are arranged on the irregular side, there is no long-range order of position.

The molecular order in the cholesteric mesophase is such that the molecules are oriented along an axis that coincides with the long axis of the molecules as in the nematic phase, but that axis is continuously oriented along a second axis perpendicular to the first axis. It is characterized by changing. For this reason, the nillesteric mesophase is often called the twisted nematic mesophase. id optical activity is required for mengenic materials to form cholesteric mesophases.

The term "cholesteric" is historical in origin since the first discovered liquid crystal material exhibiting a cholesteric mesophase was cholesteryl benzoate. However, it has been recognized that the presence of a cholesterol moiety is not required and that non-cholesterol derivatives also exhibit cholesteric mesophases.

Liquid crystal materials have been of considerable interest because they exhibit unique optical properties such as selectively reflecting visible light and exhibiting iridescence and circular dichroism.

For example, U.S. Pat. No. 3,720.625 discloses mixtures of cholesteric and nematic liquid crystals useful in temperature-sensitive visual displays: U.S. Pat. No. 3,766.0.
No. 61 discloses a decorative film consisting of a proportion of solid materials whose composition exhibits cholesteric properties, and U.S. Pat.
No. 5.923.685 discloses cholesteric materials that transition to a nematic state upon exposure to an electric field, and U.S. Pat. Discloses a mixture of materials.

Although colored images obtained using cholesteric materials are useful, most such images are not permanent. Therefore, there has been substantial interest in the preparation of cholesteric materials capable of fixing color. No. 5,766,061 discloses a decorative film in which color is fixed by cooling. Additionally, U.S. Pat. is disclosed. - However, it is not always practical to employ temperature changes to fix the color, and the color can be fixed by other means, e.g. photopolymerization, and the resulting fixed color is temperature-insensitive to cholesteric materials. You may be interested in developing this. Applicant is aware of only one such polymer. This was reported by a group of Japanese researchers, who reported that poly(gammabuti/L, L7/
'Lutamate) has disclosed that it can be photopolymerized and fixed in various ways so that it is not sensitive to temperature.

Accordingly, one object of the present invention is to provide a four-monomer polymeric cholesterlink liquid crystal material useful in the preparation of polymeric films with fixed color that is essentially moisture-insensitive.

Furthermore, another object of the invention is to provide a composition that exhibits different optical responses over different temperature ranges;
The purpose of the present invention is to provide monomeric compounds that can be used in combination with mesogenic materials.

These and other objects of the invention will become apparent from the detailed description of the preferred embodiments set forth below.

The present invention relates to new cholesteric liquid crystal monomers useful in producing polymeric materials with unique optical properties.

In one embodiment, the present invention is useful for preparing polymeric films and consists of a photomerizable monomer having the following structure.

~ (However, R1 is H or CH3, R2 is an alkylene chain having ~14 methylene groups or lower alkyl-substituted methylene groups, and Y is O or 1. However, when R1 is CH3, Y is 1 ).

The invention in a second embodiment is useful in the preparation of polymeric films and consists of photopolymerizable monomers having the following structure.

~ (where R, is H or CH3, A is -R30- or -R,O-, R3 is an alkylene chain having 2 to 14 methylene groups or lower alkyl-substituted methylene groups, R4
is an alkylene or lower alkyl substituted alkylene ether, diether or triether having from 5 to 111 total carbon atoms in the alkylene chain, provided that the terminal alkylene chain adjacent to the carbonate moiety consists of 2 or more carbon atoms. And y (4o-6 is only 1).

The present invention in the third embodiment is useful as an intermediate for the preparation of photopolymerizable monomers and comprises a compound having the following structure: F'y (where X+ is Br, ,
R2 is an alkylene chain having 5 to 1 methylene groups or lower alkyl-substituted methylene groups, and Y is O or 1; ).

A derivative of cholesterol that can be used in the practice of this invention is hacholestyrol (Y=O), 1:5,6-dihydrocholesterol (y=1). Additionally, there are many choices for the side chains at the J positions. Therefore, the polymerizability of the side chain is determined by the presence of an ester chain consisting of an acrylate or methacrylate moiety cross-linked to an ester chain or a carbonate chain. consists of an alkyl chain consisting of lower alkyl-substituted methylene groups. As used herein, lower argyl means an alkyl group consisting of 1 to 4 carbon atoms. Methacrylate ester (R1=CH3, n=5.10 and 111
) have been reported in Soviet literature, but these esters were prepared for solution polymerization reactions and are not covered by the present invention.
It was not recognized that it could be used in the photopolymerized film disclosed in the FA document.

On the other hand, if carbonate chains are present, the bridge becomes even more complex. That is, it consists of 2 to ill methylene groups or lower alkyl-substituted methylene groups, or alkylene or alkyl-substituted alkylene ethers and diethers having a total number of carbon atoms of 3 to 111 in the alkylene chain (with the exception of triethers). , the terminal alkylene chain adjacent to the carbonate moiety consists of two or more carbon atoms). Examples of ether moieties utilized in the practice of this invention include ethylene glycol, diethylene glycol, triethylene glycol, tetramethylene glycol,
It is similar to oxybis-1-propatol, 11'-oxybis-1-butanol, 1-1-oxybis-2-glopanol, and the like.

The compounds of the invention in their pure state tend to crystallize out at inopportune times and are therefore somewhat difficult to process. Furthermore, since the majority exhibit no colored cholesteric mesophase or a very narrow colored cholesteric mesophase,
It is difficult to obtain colored polymers from pure monomers. Therefore, a pure compound of the present invention is limited in its ability to produce polymeric films with the desired optical/sponse properties.

Surprisingly, these limitations have been overcome and the compounds of the present invention, as well as other compounds of the present invention, are suitable for forming films exhibiting cholesteric liquid crystal properties. It has been discovered that they can be prepared and photopolymerized in the presence of photoinitiators, thereby giving films with certain optical properties. When the film is colored, it is desirable that the fixed color be substantially identical to the color of the unpolymerized film; however, in some cases (to obtain a polymerized film with a fixed color that is different from the color of the unpolymerized film) This is desirable.

Cholesteryl ester derivatives of the present invention can be prepared by reacting a W-substituted alkyl acid halide (preferably W~dibromolkyl acid chloride) with a desired cholesterol derivative f[) to obtain cholesteryl W-substituted alkyl ester (II).
[) in surprisingly good yields. By reacting this compound with an alkali metal acrylate or methacrylate (■) in the presence of a radical inhibitor and a suitable catalyst, the desired acrylic acid methacrylate ester (V) can be obtained. . This reaction order can be seen by reference to the general reaction of the absence.

~ R,0 11 ~ In these and other reactions shown here, R+ is CHa (or CHa + R2 is 3-111 methine (1
3) Y is 0 or 1; xl is Br, ■ or sulfonic acid ester; X2 is Brt; Th1dca; and M
is Na or K. Suitable sulfonic acid esters include, for example, CH3sOs ip CH3C6H4S
O3; C6H55O3ip BrC6H45O3-, etc. 5x is preferably Br and X2 is preferably C4. Furthermore, for intermediates of type (1), it is desirable for R2 to have 11-111 carbon atoms in the alkylene chain.

The tyryl carbonate derivatives shown here are prepared in good yields by a slightly different route. In this reaction sequence, W-haloalkyl carbonate derivatives (for example, This compound then reacts with an alkali metal acrylate or methacrylate (1'/) as described above to yield a carbonate monomer (■).

Alternatively, a compound of type (■) may be of type ■
and hydroxyalkyl acrylate or methacrylate (X). General reaction sequences illustrating these alternative methods are shown below.

(However, R,, x, , X2 and Y are omitted) The above, A is approximately 0- or -R40-1 where R3 is an alkylene group chain having 2 to 14 methylene or lower alkyl substituted methylene groups , and R are in the alkylene chain ~1) An alkylene group having a total carbon number of 1 is a lower alkyl-substituted alkylene ether, diether, or triether. However, the terminal alkylene chain adjacent to the carbonate moiety consists of two or more carbon atoms). Examples of suitable ether moieties have been given above, but one limitation must be placed on the length of one terminal chain. The terminal chain in question is the alkylene group adjacent to the carbonate moiety in product (1). The synthetic route described here cannot use ethers with a single carbon atom next to this reaction site. That is, compounds of type ■ and type X contain a 10-CH2-OH moiety -! do not have. Therefore, the terminal alkylene chain adjacent to the carbonate moiety must contain at least two carbon atoms.

The advantages and contributions of the invention will become more apparent from the following examples, which are intended to be illustrative and not intended to limit the scope of the invention.

Example 1 This example illustrates the preparation of cholesteryl w-Fl substituted alkyl esters of type 1. 01 mole of cholesteryl: 5,6-hydrocholesterol, 0.12
200 molar of pyridine and 0.12 molar W-bromoalkanol chloride in a suitable solvent such as ethanol-free chloroform or ether/dichloromethane.
'Dissolve in 500ml. The mixture is stirred for 2 hours at 0° C. and for 16 hours at ambient temperature and diluted with 300 ml of solvent.

The organic phase is washed twice with 200 ml portions of hydrochloric acid and with water, after which it is dried over magnesium sulfate. Drying/concentration of the liquid yields the ester (I[[)5, which is purified by recrystallization from a suitable solvent such as 1:1 ether-ethanol. Representative compounds are shown in the table below.

I engineering Ia 100 g9
99-100IIIb 5 0
g6 120-121 Engineering IIcu08
6g? -90 IrId U 1 91
92-9 IZIe 10 1
87 Examples 65-67 This example shows the preparation of cholesteryl ester mitogen of type (1). Potassium acrylate or potassium methacrylate 0.15 mol, ester III O, 05 mol/l/,
0.01 mol of N,N,N,N-tetra-n-bunal ammonium bromide and 2.6-di-t-butylcunzur.
A two-phase solution consisting of 0.00311 mol of radical inhibitor is prepared in a mixture of 30 ml of ice and 15 ml of chloroform. The two-phase solution was maintained at 110-115°C/1l
Heat and stir in 1A for 100 hours. After cooling, the mixture contains 11+1 ether and dichloromethane.
After drying over magnesium sulfate, the organic phase is concentrated and reconstituted from a suitable solvent such as ethanol-ether or acetone-ethanol. Crystallized acrylate or methacrylate is obtained. Representative monomers are shown below; Va Hio 0 8*51
15-71.5vb CH3100l *5g-
64Vc H50g7 *) 15.5-f
J, 5Vd CH35090*118-57.5V
e H30g filter 6g, 5-70.5 (67
, 5) Vf CH3 O7573-711 (56
,0)Vg H3158111-1,13(U55)■h CH3U 1 71 113-
115 (below room temperature) Vi H1017062,5-
64,5 (5g, 0)Vj CH3,10156
*Uuuryo-490 The temperature range used in this example and thereafter is as follows:
The melting range is unless otherwise noted with an asterisk or parentheses.

An asterisk indicates that the range is in the mesophase range, while parentheses indicate that the range is in the monodropink mesophase range, and the latter was measured as the temperature was decreased. For materials with a measurable melting point, the monotropic mesophase range is often below the melting range.

EXAMPLE This example demonstrates the preparation of cholesteryl ester monomers of type 1 using a (rather than phase transfer catalytic conditions as shown in Example 2) neutral, aprotic solvent system. Brominated ester ■005 mol, potassium acrylate 010 mol, and 2,6-di-t-butylkunzulu radical inhibitor 0
．． A mixture consisting of 0.005 ume is prepared in 50 ml of dimethylformamide. The mixture is heated at 70-80° C. in a tank with stirring for an incubation period. After cooling, the mixture is diluted with 2.50 ml of water and extracted with ether (150 ml). The organic phase was washed with brine and dried over magnesium iift (i,ff
1a J, i L, acrylic acid monomer (■) was obtained by recrystallization from ether-ethanol. Iodine-substituted esters of type 1 also gave suitable results under these conditions.

Example 1 This example shows the preparation of type 1 cholesteryl W-haloargyl carbonate. 0.075 mol of 6-promohegisanol and 0.055 pyridine in 50 ml of dichloromethane
A commercially available solution of 0.05 mol of cholesteryl chloroformate in 50 ml of dichloromethane is added to the solution of ml. The addition takes place at room temperature.

The resulting mixture was stirred for 18 hours, then diluted with 20'Oml of dichloromethane and diluted with 75ml of IN hydrochloric acid.
Wash once twice and on ice. The organic phase is dried over magnesium sulfate and concentrated to give a solid -VJ-bromoalkyl carbonate of type 1, which is purified by recrystallization from ether-ethanol. Compound (■a) obtained with a yield of 7 g% has a melting point of 87 to 885°C.

Example 5 This Example 1 shows the preparation of cholesteryl acryloyl- or methacryloyl-oxyalkyl carbonates from carbonates of type 1. A solution of 0.02 mol of the product of Example U (■a) and 0.06 mol of potassium methacrylate is heated as described in Example 2 for 40 hours.

Recrystallization of the solid product from a 1=15 solution of acetone-ethanol gives a 68% yield of methacrylic acid monomer, which melts at 585-60°C.

EXAMPLE 6 This example demonstrates an alternative method for preparing a Type 1 compound by reacting a Type X hydroxyalkyl acrylate or methacrylate with a Type 2 cholesteryl haloformate.

Hydroxyargyl acrylate or hydroxyalkyl methacrylate 0,06 in dichloromethane 140ml
Cholesteryl haloforme 0O1 dissolved in 0ml dichloromethane in a solution of 4mol and pyridine 004mol
1 mol solution is added dropwise. The addition is carried out at 0° C., after which the mixture is allowed to reach room temperature and stir for 6 hours. The resulting mixture was diluted with 2” rOml dichloromethane and diluted with I
Washed with 60 N of hydrochloric acid followed by water, the organic phase is dried over magnesium sulfate and condensed to a solid which is recrystallized from a suitable solvent such as acetone-ethanol.

A typical product is as follows: IXa CH3(CH2)60 0 68 58.
5 60(51,0)IXb CH3(CH2)20
0 82 80-gBuo, 1) IXc H(
CH2)2Q 0 81. 85.5-87 (5[1
i, 0) IXd H(CH2)60 0 1111
+***52 -62 Example 7 In this example, A is -(CH2CH20)2- and -(CH
,.

Figure 2 shows the preparation of alkylene ethers and alkylene diethers of type 1, which are CH20)3-.

Starting compounds of type X were prepared by methods described in the chemical literature. The following product was then obtained by reacting as described in Example 6: IXe CH3
(CH2CH20) 2 0 60 1
[,5-529(U31) Engineering xf CH3(CH2CH
20) 3 0 62 without melting point 65) Example 8 This example shows the color range of various monomeric esters of the present invention measured with a line optical microscope using light transmitted through a crosspolar at 250x magnification. shows. viettl to mettler
er)'s FP5 temperature controller and Mettler's F
Control the temperature using a P52 high temperature stage. Cooling is achieved by passing a stream of nitrogen gas through a dry ice cooled copper coil followed by a P52 high temperature stage. The results are shown in the table below.

Va 57.8-59.2 Vb (55,8-55u) V C (
11g, 5-33.0”

Claims (1)

[Claims] 1. A liquid crystal compound having the following structure. y (in the formula, R1 is H and CH3, R2 is a lower alkyl-substituted methylene group, and Y is O
Or 1. However, when R1 is CH3, Y is 1) 2 A liquid crystal compound having the following structure. (In the formula, R1 is H or CH3, A is -R30- or 1'R40-5R3 is an alkylene chain having 2 to 1 methylene or lower alkyl substituted methylene groups, R4 is the total number of carbon atoms in the alkylene chain. An alkylene ether, diether group or triether having ~111, where the terminal alkylene chain adjacent to the carbonate moiety consists of two carbon atoms above each other, and Y is O or 1) with the following structure: A liquid crystal compound with 1(y (in the formula, Xl is Br, ■ is still a sulfonic acid ester, R
2 to 14 methylene or lower alkyl substituted methylene groups, and Y is o4 or 1)