JPS5921649A - Novel nematic liquid crystal compound - Google Patents

Abstract

NEW MATERIAL:A compound of formula I [R and R' are 1-7C straight chain alkyl; the cyclohexane ring is in the trans(equatorial-equatorial configuration)]. USE:An electrooptical display material, capable of increasing the transition temperature between the nematic phase and the isotropic liquid phase remarkably by mixing a small amount thereof with the well-known liquid crystal mixture, having a weakly negative dielectric anisotropy, and usable as a material for dynamic light scattering type display cells in the state of a mixture with another nematic liquid crystal compound having a negative or weakly positive dielectric anisotropy and as a material for electric field type dispaly cells in the state of a mixture with another nematic liquid crystal compound having a strongly positive dielectric anisotropy. PROCESS:A compound of formula II is reacted with a comound of formula III in an inert organic solvent, e.g. benzene or toluene, in the presence of a basic compound, e.g. pyridine, as a catalyst to afford the aimed compound of formula I .

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel nematic liquid crystalline compounds of cyclohexanecarboxylic acid derivatives useful as electrodynamic display materials.

The novel nematic liquid crystal compound provided by the present invention is a compound represented by the general formula Rzentml (Kasha-R', (I)).

A typical liquid crystal display cell is M-shut (M-hayashi 5).
chadt) etc. [APPL, IED PHY] C8LE
TTER818127-128 (1971)] or the field effect mode cell proposed by GsHHe41meier and others [PROCEED
ING C) F THEI, g, □E, E, 5'6
1167-1171 (j968): ] or the dynamic scattering mode cell proposed by G.H. Beilmeier (
GsHH Heilmeier) etc. [APPLIED PH
YSIC8LF:TTER813,9l- (1968)] or DL-White (DL
Wht=) #δougNf OF APPI
, IE() PHYS"IC8'45,' 471
There is a guest-host type cell proposed by E3 <19'74'). □ Various percentage notes are required for the liquid crystal additive used in these liquid crystal display cells, but each Yuzu display cell VC-1 is required to have a nematic phase in a wide temperature range including room temperature. This is an important percentage point. Many of the materials that can be used in practical use with such a % name are usually obtained by mixing several or more components consisting of a compound that has a nematic phase near room temperature and a compound that has a nematic phase in a temperature range above room temperature. Prepared by. Most of the above-mentioned mixed liquid crystals currently in practical use are at least -30°C to +65°C.
is required to have a nematic phase over the entire temperature range. In order to meet such requirements, 4,4'-substituted terf-nyl, 4'r'4'-Wt-substituted biphenylcyclohexane, 4 , 4'-substituted benzoyloxybenzoic acid phenyl ester, having a crystalline phase-nematic phase transition temperature (C-N point) of about 100'C and a nematic phase-isotropic liquid phase transition temperature of about 200'C. (N-N points) are often used.

In recent years, as liquid crystal display cells have been used for multiple purposes such as outdoors, there has been a need for liquid crystal display cells with a nematic temperature range higher than +65°C. For this purpose, a compound is required that has a nematic phase-isotropic liquid phase transition temperature (N-1 point) higher than that of conventional compounds. The compound of formula (r) according to the present invention meets this requirement, and by mixing a small amount into a known liquid crystal mixture, it can significantly raise the western matic phase-isotropic liquid phase transition temperature (N-N point). be able to. Historically, the compound I of formula ([)
This is because it has extremely good compatibility with 4,4-substituted cyclohexylcarboxylic acid phenyl ester, which the present applicant reported as a nematic liquid crystal H material with excellent time-division driving characteristics in JP-A No. 45-83694. , an even better mixed liquid crystal can be obtained by mixing with these compounds.

The compound of formula ([) according to the present invention can be produced according to the following □ production method.

x%coca (n) Rsha coo-4 or 9) R' ([).

The compound of formula (II) is reacted with the compound of formula (II) in a kinetically active organic solvent such as ether, benzene, or toluene using a basic compound such as pyridine as a catalyst to form the formula ([) according to the present invention. Manufacture hardware.

Transition temperature of the compound of formula (I) prepared in this way
Listed in the table.

Table 1 1 n C5ILt CtH51B6 (CH3)
189 (SgN) 308 (1'L'4) 2 n
C5H1' nCJ "194 (C=+8) 214 (S
EN)319(N-tI)3nC5Hr
n-QHo 190(C→S)2[13(S茗1N
)313(N-tI)4 n -C3H7n CsH
o 191 (C-+8) 225 (8 dN) 309 (Ng
I) 5 n C3H1l n CsL
189 (C-+5) 215 (8jN) 51'1 (N-
tI) In the table, C represents a crystalline phase, S represents a smectic phase, N represents a nematic phase, and ■ represents an isotropic liquid phase.

The compound of formula (I) according to the invention is a nematic liquid crystal compound with weak negative dielectric anisotropy, and therefore, for example:
It can be conveniently used as a material for dynamic light scattering type display cells in a mixture with other nematic liquid crystal compounds having negative or weakly positive dielectric constant anisotropy, and it can also be used as a material for dynamic light scattering type display cells.
*Can be used as a material for field-effect display cells in the form of a mixture with other anisotropic liquid crystal compounds.

Thus, preferred representative examples which can be used in admixture with compounds of formula (D) include, for example, 4,4'-substituted benzoic acid phenyl esters, 4,4'-+i1
mcyclohexane-7carpoY
Acid biphenyl ester, 4(4-substituted cyclohexanecarbonyloxy)benzoic acid 4'-substituted phenyl ester 4(4K-substituted cyclohexyl)benzoic acid 4'-substituted phenylestenope 4(4-substituted cyclohexyl)benzoic acid [
4'-f-substituted cyclohegysyl ester, 4,4'-biphenyl, 4,4'-phenylcyclohexane, 4,4'
Examples include -M-substituted terphenyl, 4,4'-biphenylcyclohexane, 2 (4'-fff-substituted phenyl)5-substituted pyrimidine, and the like.

Table 2 shows the matrix liquid A (90% by weight of Al) which is currently widely used as an excellent nematic liquid crystal material for time division and drive customization.
and the formula shown in Table 1 (compound D, /161, fake 2, /
For each mixed liquid crystal consisting of 10% of each of 166, 4, 5, and 6, 4 (11) determined N-I points are posted, and for comparison, the parent liquid crystal (A) [1 About the body d1
11 determined N-I points are posted. In addition, the parent liquid crystal 仄) consists of and.

Table 2 N-I point (”C) (A) 54.0(A)+
(Consideration 1) 78.2 (A) + (Scrap 2
) 79.4(A) +(43)
78.8(A)+(A4) 7
8.3(A)+(/l65) 78.
6(A)+(46) 76.6 From the data listed in Table 2, the compound of formula ([) increases the N-I point of mixed liquid crystal (A) by 20°C or more when added at 10% by weight. I can understand what I'm getting. The fact that the upper limit of the operating temperature range can be raised by adding a small amount of the compound has a high practical value.

The effects of the present invention are also clarified by the following comparative experiments. The formula n7CsH7sha COO+n-C,H,: HH(al
These known compounds were mixed in various proportions with the above-mentioned base liquid crystal (A).

Similarly, one of the formulas @J4 according to the present invention, i.e. the formula % formula % (
The compounds of 2) were mixed into the base liquid crystal (A) in various proportions.

Regarding the mixed liquid crystal of the two yuzu species obtained in this way, each N
- Point I was measured. Based on these measurement results, the relationship between the N-1 point and the added violet is shown in FIG. 1 of the attached drawings.

Among these 41 compounds, the compound of formula (r) according to the present invention is a typical known similar compound! It should be obvious that the increase in N-1 points for the addition foot is much larger than for Ig1.

Example 1 Compound of formula HO(φX(possible 8G)-C7[I, 28.
[[(0,100 mol), formula n-c, H7(EXC
OCJ compound 18.9!1. (,,9,1,flOm
ol≧f) #1. 2D 01JVcm,
While stirring in a room, add piribin at 15.8F, (0,
Did you drop 20, Dm・1)? 2Fi after finishing dripping! It was an intermission. After the reaction was completed, the reaction product was extracted with toluene. After washing the extract with water and drying, the ene from this liquid was distilled off, and the resulting reaction product was recrystallized from acetone to obtain 32.8 g (0,0759 mol) of the following compound. Ta.

n　C3H? 8Coo? C2H5 Yield: 759% Transition temperature 186℃ (Ca2) 189℃ (SgN) 308℃ (N4 engineering) Example 2 The following compound was obtained in the same manner as in Example 1.

n-C,H→)COO+ n-CmH7319℃(Nd
■) Example 6 The following compound was obtained in the same manner as in Example 1.

Yield 73B% Transition temperature 190℃ (c-+'5) 206℃ (SdN) 313’C (NRI) Example 4 The following compound was obtained using the same packaging as in Example 1.

Yield: 754% Transition temperature 191℃ (Ca2) 225℃ (SFN) 309℃ (N=I) Example 5 The following compound was obtained in the same manner as in Example 1.

Yield: 761% Transition temperature: 189°C (C-)S)
215°C (S!N) 611°C (Ngl) Example 6 The following compound was obtained in the same manner as in Example 1.
,,COO$”tL Yield 74.2% Transition temperature 182℃ (c-+5) 241℃ (sgN) 289℃ (Ngl)

[Brief explanation of drawings]

Figure 1 shows each of the mixed liquid crystals obtained by adding the compound of Example 2, which is one of the compounds according to the present invention, and the known compound (a) to a commonly used base liquid crystal (A). N-1
It is a chart showing the relationship between points and additions.

Claims (1)

[Claims] general formula It is expressed by .