SU890982A3 - Electrooptical material - Google Patents

Abstract

PURPOSE:To provide a liquid crystal compsn. with positive dielectric anisotropy, low threshold voltage, wide liquid crystal temp. range and high reliability by mixing Ptype biphenyl liquid crystal substances with N-type ester liquid crystal substances having sufficient compatibility with the P-type substances and wide liquid crystal temp. range.

Description

The invention relates to an electro-optical material consisting of nematic liquid crystals with positive dielectric anisotropy, cyanobiphenyls and cyanotherphenyls, and phenyl benzoates, which can be used in indicator devices. An electro-optical material containing phenyl benzoates is known, which have good mutual solubility with other components of tU. However, they are relatively viscous and are unsatisfactory in terms of performance times. An electro-optical material is known, including Cy-Cd-alkyl cyanobifenes and alkyl substituted cyanothermal 2J, However, this material has unsatisfactory electrical characteristics, in particular, in terms of the magnitude and stability of threshold voltages (see Table 2). The purpose of the invention is to improve the electro-optical characteristics of the proposed material. This goal is achieved by the fact that in electro-optical material, there is a mixture of pn-alkyl-substituted cyanobiphenyls and terphenyls (mixture A) containing, in wt. pn-Pentyl cyanothermal, 8 and additionally containing from one to three compounds of general formula D (C)

where R is alkyl or alkoxy

890982

Continued table. one

The number of components B is given for the expansion of the region of the mesomorphic state.

The dependence of the electro-optical characteristics on the content of the mixture A in the electro-optical material is given in Table 1.

Table I

66

1.3

78

Neither display can be blurred in the inoperative state when the composition of the electro-optical material changes.

Example 2. Mixture A is used in combination with other components D:

Ci "flig

diiHg

520

6.00

CsH-ji 190 5 (Joo 9, - / - .. CJN 11.4

Measurements are carried out under conditions of 1/3 displacement, 1/3 of the load, setting the voltage of the 3 V power source, the supply voltage in the idle state of the display is 1.03 V, in the operating state - 1.97 V. 90982 e, n o dN 16.2 I (JK-10.0 The dependence of the electro-optical characteristics of the material on the qualitative and quantitative composition of the components is given in Table 2. Table 2

The characteristics of the material obtained are as follows: the area of the nematic state from -20 to, does not freeze 8 for five days at, threshold potential difference i, 25 V, response time, mS: GlOOCaS c), 500 () and - 70С25 ° С ), 180 (. Example A. Material components,: area of nematic state from -20 ° C to + 58 ° C, threshold potential difference 1.25 V, response time, ms: -70 (25 ° C), 500 ( 0 ° С) and п -75 (2FC), 230 СО ° С). Example 5. Components of the material,%:

The area of the nematic state is from -20 ° C to +60 ° C, the threshold potential difference is 1.4 V, the response time, ms: H - 110 (25 ° C), 700 () iGp - 90 ° 25 ° C, 290 (° C).

Claims (2)

1. For the UK fP SHOZEZ, cl.-C 2C, published 1975. 2.G.Gray et al. Some new mesogenes -J.Phys. (Paris) 36. CL. C1 (3), 1975, p. 399-3 7 (prototype).