DD247227A1 - GLASSY NEMATIC LIQUID CRYSTALS - Google Patents

Abstract

The invention relates to vitreous liquid crystals which can be used as anisotropic solid optical media for the production of optical components as well as for thermo-electro-optical memory displays. The aim of the invention is anisotropic solid optical media. It has been found that novel crystalline liquid 2-substituted-1,4-bis (4-substituted-benzoyloxy) benzene of the general formula I alone, in mixtures with each other or with other crystalline liquid or non-crystalline liquids as glassy nematic liquid crystals, are suitable as anisotropic solid optical media as well as for thermoelectro-optical memory displays. Formula I

Description

Explanation of the essence of the invention

The object of the invention is the use of glassy nematic liquid crystals whose glass transition temperature is above room temperature, as anisotropic solid optical media.

It has been found that novel crystalline liquid 2-substituted-1,4-bis (4-substituted-benzoyloxy) benzene of the general formula

R ¹ -

\ / Y-c

R ¹ = C _n H _{2n + 1} ; -OC _n H _{2n + 1} ; .... n = 1-1

R ² = R ¹ , (CH ₂ I ₁₁₁ -CN with m = 0-4, NO ₂ ,

OOC - / "ÖVr ¹ H, Br

R ³ , R ⁴ = H, C _n H _{2n + 1} ; OC _n + 2n + 1; NO ₂ , CN R ² + R ³ = -O-CH ₂ -O-

X = CO; C = N-OOC; R ⁵ = C _n H _2n +, with η = 0-4;

CO-Y with Y = Z ¹ - (CH ₂ ) _n -Z ² (Z ¹ , Z ² = O, S, NR ⁵ , CHR ⁵ , CO, CH = CH, -N = CR ⁵ -) η = 0 Also Z ² = single bond, -OOC mean,

alone, in mixtures with each other or with other crystalline-liquid or non-crystalline liquid substances as glassy nematic liquid crystals with glass transition temperatures above room temperature as anisotropic solid optical media for the production of optical components such as compensators, prisms, optical rotation plates, polarizers and for thermoelectrooptical ^ Memory displays are suitable.

By producing correspondingly oriented layers, optical compensators, prisms and dichroic dye polarizers can be produced from this optical medium with homogeneous orientation, optical rotation plates can be produced with twisted orientation, and thermoelectro-optical memory displays can be produced using appropriate cells.

The synthesis of substances of the formula I is carried out by acylation of suitable intermediates. The molecule segments with the ring systems A and B can be introduced one after the other in different order, but also simultaneously. A variety of compounds are prepared by esterification of derivatives of the formula II (where Z ¹ = O, S, NR ⁵ )

H-Y

obtained with the acid chlorides III.

R ¹ - / Ä \ -C ΟΟ- / θ \ -00C

COCI

Acylation of Hydroquinone Derivatives IV

1 /\

- ^ Ay-COGl V

with the acid chlorides H - ^ Ay-COGl V succeeds by known methods.

The acylation of a trifunctional derivative VI leads to compounds of the general formula I.

HO- / O) -OH

(Z ² in Y = O, S, NR ⁵ ) Vl

- Y - H

embodiments Example 1:

0.01 mol of a derivative of formula II are in 100 ml of abs. Toluen added. 0.01 mol of the acid chloride III are added, dissolved in 50 ml of toluene, at room temperature. It is then added with stirring with 0.015 mol of triethylamine, allowed to stand for 20 h and then heated for 30 min to 8O ⁰ C. After cooling, the precipitated hydrochloride is filtered off with suction, the toluene withdrawn IV and the remaining residue was recrystallized. Suitable solvents are, for example, ethanol, n-amyl alcohol, dioxane, DMF. Yields: 43-68%.

Example 2:

0.01 mol of hydroquinone of the formula IV are reacted with 0.02 mol of an acid chloride V in the presence of 0.03 mol of triethylamine and, as described in Example 1, worked up

 Yields: 51-74%.

Example 3:

0.01 mol of a trifunctional derivative of the formula VI are reacted with 0.03 mol of an acid chloride V in the presence of 0.045 mol of triethylamine and worked up analogously to Example 1.

Yields: 39-57%

Table 1 shows the transformation temperatures (° C) of some of the substances according to the invention. Where:

K = crystalline-solid S = smectic N = nematic is = isotropic-liquid Numbers in parentheses indicate monotrophic transformations.

Table 1

-OC

-COO- (O) - (GH) -ClT

1 98 2 73 3 68 4 80 0 • 107 1 91 2 • 112 1 85 2 92 3 82 4 79 5 75 6 84 7 80 8th 84 9 93 10 93

(65)

98 80 96 (76)

(50)

(47) (39)

120

  117

  111

  109

• 105

• 105

• 105-104

• 104

• 104

Continuation Table 1

CH

-C 00 -H = CH-ZΟ) -OC £ -C 00-M ^- = CH-Zo) - ° ^Ή

HO

-COO-CH ₂ -

ΊΓΟ,

-COO-CH ₂ -CH = CH-Zo)

-C00-CH ₂ -CH ₂ -0- -C 00-CH ₂ -CH ₂ -0- (δ

121

5 120 6 110 7 108 8th 99 9 99 10 103

74

58

75

87

110

77

108

80

164

107

88

75

76

121

.96

.195

(.80)

.164

152

153 153 152 151 149 148

(.22)

(.17)

(.70)

.92

(.65)

.99

(.80)

.112

.130

.91

.109

.112)

.80

Continuation Table 1

j-COO-CH-ZO / CH ₃

-COO-CH ₂ -CH ₂ -II- (O)

t N /

-COO-CH ₂ -Zo) -O _V

OCH

-C00-CH ₂ - (H

134

78

85

151

(· 61)

•

121

113

95

112

80

86

58)

Table 2

IS

CH ₃ O

C ₂ H ₅ O

C ₃ H ₇ O

C ₄ H ₉ O

C ₅ H ₁₁ O

C ₆ H ₁₃ O

C ₇ H ₁₅ O

C ₈ H ₁₇ O

C ₉ H ₁₉ O

C10H21O

C ₇ H ₁₅

(· 151) (· 166) • 148 (108) • 155 • 136 • 149.5 • 151.5 • 154 • 158.5 · • 163 , • 166 , • 168 , • 130 ,

Table 3

is

C ₄ H ₉ OC ₈ H ₁₇ O

133 96

(122) • 103

Example 4

The substance of the formula

₈ H ₁₇ 0- <b) -C00

CH,

has a melting point of 7O ⁰ C and a clearing point of 94 ° C. It is heated to about 10O ⁰ C, until in the isotropic liquid inside. Thereafter, slow cooling to temperatures around 8O ⁰ C. In this nematic state, the molecular structure is orientable by wall effects and electrical or magnetic fields. Rapid cooling to temperatures of 0 to 5 ⁰ C causes the nematic phase solidify glassy. By re-heating and cooling in the manner already described a change in orientation is possible. The structure of the nematic phase fixed in the glass state is stable for several months.

Example 5

The substance of Example 4 is mixed with the substance

COO

(Conversion temperatures of this substance: K95 N187 Is, supercooling to about 65 ⁰ C) mixed. The mixing ratio was chosen so that the substance of Example 4 has a mole fraction of 0.72 in this binary mixture. The mixture melts in the temperature range between 50 ⁰ C and 72 ° C to a nematic phase. The clearing point is located at 111 ⁰ C. Subsequent rapid cooling with the cooling table leads to the formation of a turbid, vitreous body, showing the typical texture image of a nematic phase in the polarization microscope. This glassy body softens at increasing temperatures in a temperature range between 2O ⁰ C and 35 ⁰ C. A crystallization was observed after about 2-3 days.

Example 6

By adding 1% of the dichroic dye

/ C ₂ H ₅

CH ₂ -CH ₂ -OH

To the substances according to Example 1 and 2 and homogeneous orientation between two glass panes or other transparent material are formed colored polarizers that produce linearly polarized red light or absorb in vertical position linearly polarized red light.

Example 7

By filling the substances according to Example 1, 2, 3 into an electro-optical cell, which consists of two glass panes provided with an electrically conductive transparent and suitably structured layer at a distance of 5 to 30 / .mu.m, a thermo-electro-optical memory display is produced individual dots or larger areas are heated and switched from a glassy state to a normal nematic state by a laser or an electric heater, and then cooled back into the glass state while keeping the switched state, so that the inputted information is stored.

Claims (1)

Invention claim: Glassy nematic liquid crystals as anisotropic solid optical media and thermo-electro-optical memory displays, characterized in that new crystalline liquid 2-substituted-1,4-bis (4-substituted-benzoyloxy) benzene of the general formula -coo-Zc?) -ooc- / iT) -R ¹ R ² = R \ (CH ₂ ) _m CN with m = 0 to 4, NO ₂ , 00C- <O} - ^R -H, Br R ³ , R ⁴ = H, C _n H _{2n +} ! OC _n H _{2n +} ,; NO ₂ , CN
R2 + R3 = = (θ) s (h X = CO; C = N-OOC; R ⁴ = C _n H _2n +, with η = 0 to 4; R ⁵ CO-Y with Y = Z ¹ - (CH ₂ ) _n -Z ² (Z ¹ , Z ² = O, S, NR ⁵ , CHR ⁵ , CO, CH = CH, -N = CR ⁵ -) η = 0 -10
also Z ² = single bond, OOC mean, alone, in mixtures with each other or with other crystalline liquid or non-crystalline liquid substances. Field of application of the invention The invention relates to vitreous liquid crystals useful as anisotropic solid optical media for the production of optical components, e.g. Compensators, prisms, plates with optical rotation, polarizers and thermo-electro-optical memory displays can be used. Characteristic of the known technical solutions Glassy liquid crystals have already been described (H.Kelker, R. Hatz: Handbook of Liquid Crystals, Verlag Chemie, Weinheim 1980, N. Kirov, MP Fontana, N. Afanasieva: Mol. Cryst. Liq. Cryst., 89, 93 [1982]). The glass transition temperatures are very low and are typically well below 0 ° C, e.g. For example, N- (o-hydroxy-p-methoxybenzylidene) -p-butylaniline (M.Sorai, S. Seki: Bull. Chem. Soc., Japan, 44, 2887 [1971]; GPJohari: Phil , 549 [1982]) at -65 ° C. Substances with such low glass transition temperatures are in the usual crystalline-liquid (eg nematic) state at room temperature or are crystalline-solid because they can not be subcooled below the melting temperature for a sufficiently long time. As a result, they can not be used as anisotropic fixed media or for memory displays. It has already been proposed (WP C07C / 282 706/6; C 09 K / 282 705/8; C 09 K / 282 704/1; C09 K / 282 703/3) to use glassy liquid crystals at room temperature for the above-mentioned field of application. To further improve the properties of the mixtures to be used, however, new additional components are urgently needed. Object of the invention The aim of the invention are anisotropic solid optical media for the production of optical components or thermo-electro-optical memory displays.