JPS5910533A - Novel nematic halogenide - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (R is 1-7C alkyl; n is 1 or 2, X is F, when n is 1, or F or Cl, when n is 2). USE:A material for cells of dynamic scattering type displays or field effect type displays: it is a nematic liquid crystal with weak dielectric anistropy. When a compound where n is 1 is mixed, it increases dielectric anisotropy or reduces it little, when another compound where n is 2 is mixed, it lowers the viscosity of mixed liquid crystal or increases little. PREPARATION:The reaction between p-halobenzene of formula II or a p-halobiphenyl and a compound of formula III is effected in carbon disulfide or nitrobenzene in the presence of anhydrous aluminum chloride to give a compound of formula IV, which is made to react with hydrazine and potassium hydroxide in diethylene or triethylene glycol to give the compound of formula I .

Description

[Detailed Description of the Invention] The present invention! The present invention relates to novel nematic metal halides of 1-cyclohexyl-2-phenylethane and 1-cyclohexyl-2-biphenylethane derivatives that are useful as pneumatic display compounds. The novel nematic liquid crystal provided by the present invention is a trans(equatorial)-4-n-alkynohycyclohexylethane derivative represented by the general formula.

M-Shut (M@5) is a typical liquid crystal display cell.
chadt) etc. [APPLIED PHYSIC8L
ETTER 81, 127-128 (1971)) or the field effect mode cell proposed by G@RHsilmeier et al. [: PROCEED
ING OFT)IE 1. E, E, E, 56 11
<S2-1171 (1968)] or the dynamic scattering mode cell proposed by G.H. Beilmeier (G@HH
ellmeier) etc. [APPLIEDpllysr
cs tETTERs 13-191 (196B))
Or D a L * Ho 7 () (D L Wh
ite) etc. [JOURNAL OF APPLIED
There is a guest-host type Cernato proposed by PI Y81C845, 4718 (1974).

Among the compounds of formula (I), the 1-cyclohexyl-2-phenylethane derivative with n=1 has a low viscosity, so that by mixing it with various nematic liquid crystal materials, the viscosity of the material can be effectively reduced.

Compounds conventionally used as viscosity reducing agents include 4-
Alkyl-4'-alkylphenylcyclohexane lohexyl-4'-alkylcyclohexane carboxylate Many have negative dielectric constant anisotropy. Therefore, when these compounds are mixed into various nematic liquid crystal materials for the purpose of reducing the viscosity, they have the disadvantage of reducing the dielectric anisotropy of the material. This makes it difficult to drive field effect cells at low voltages, which is one of the important issues in this technical field. Among the compounds of formula (I), the 1-cyclohexyl-2-phenylethane derivative with n = 1 has weak positive attraction and is anisotropic? This is a new compound that overcomes these drawbacks. That is, when preparing a mixed liquid crystal having a desired viscosity by mixing it with one or more other nematic liquid crystal compounds, the known viscosity reducing agent reduces the dielectric anisotropy of the mixed liquid crystal. On the other hand, the compound of formula (I) where n = 1 can either increase its dielectric anisotropy or suppress its decrease to a small extent.

Among the compounds of formula (I), n=2 1-cyclohexyl-
Does the 2-piphenylethane derivative have a high nematic phase 4 isotropic liquid phase transition temperature (N-I point)? It is a low viscosity liquid crystal compound with Having a nematic phase over a wide temperature range including room temperature is an important characteristic commonly required for various display cells. Most of the materials that can be used for practical purposes with such properties are usually produced by mixing several or more components, which consist of a compound that has a nematic phase near room temperature and a compound that has a nematic phase above room temperature. Therefore, it is prepared.

Most of the above-mentioned mixed liquid crystals currently in practical use are
It is required to have a nematic phase over the entire hot water temperature range of at least 150C to +65C. In order to meet these requirements, compounds having a nematic phase in a temperature range higher than room temperature (,4,4'-substituted terphenyl,
4.4'-substituted piphenylcyclohexane-4+ 4'
fm:tl! Such as benzoyloxybenzoic acid phenyl ester, which has a crystalline phase to nematic phase transition temperature (C-N point) of about 1 Of]c and a nematic phase to isotropic liquid phase transition temperature (N-I point) of about 2000. Compounds having the following are often used. However, when these compounds are mixed in sufficient amounts to bring the mixed liquid crystal to a temperature of 65C or higher, which is the N-I point, they increase the viscosity of the resulting mixed liquid crystal, thereby causing a slow response speed. It has the undesirable property of

Among the compounds of formula (1) according to this publication, the 1-cyclohexyl-2-piphenylethane derivative in which n=2 is a novel compound with improved properties. That is, when this compound is mixed with one or more other nematic liquid crystal compounds to produce a practical mixed liquid crystal wFA having an N-I point of 65C or more, the above-mentioned known liquid crystal compound is mixed with the mixed liquid crystal. In contrast to increasing the viscosity to a wide range, the viscosity of the mixed liquid crystal can be lowered or the increase V can be suppressed to a much smaller range.

The compound of formula (I) according to the present invention can be produced according to the following manufacturing method. The definitions of R%X and n in the following formula are the same as the above definitions.

Step m1 - P-halobenzene or P-halobiphenyl is reacted with a compound of formula (II) and anhydrous aluminum chloride in carbon disulfide or nitrobenzene to produce a compound of formula (1).

Step 2-1 The compound of formula (lu) produced in step 1 is reacted with hydrazine and potassium hydroxide in diethylene glycol or triethylene glycol to react the compound of formula (I) with potassium hydroxide.
).

The transition temperature of the compound of formula (I) thus prepared is
Listed in the table.

In Table 1, C represents a crystalline phase, N represents a nematic phase, and ■ represents an isotropic liquid phase.

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

Thus, preferred representatives which can be used in admixture with compounds of formula (I) include, for example, 4,4'-substituted benzoic acid phenyl ester, 4,4'-substituted cyclohexanecarboxylic acid phenylnisder, 4.4'-substituted cyclohexanecarboxylic acid biphenylnisder, 4(4-
[mcyclohexanecarbonyloxy)benzoic acid 4'-
Substituted phenyl ester, 4 (4-@substituted cyclohexyl)
Benzoic acid 4'-substituted phenyl ester, 4 (4-substituted cyclo-scythyl) benzoic acid! Acid 4'-fi1m cyclohexyl ester, 4,4'-biphenyl, 4,4'-phenyl dichloroxine, 4,4'-substituted terphenyl,
4.4'-hyphenylcyclohexane, 2(4'-ft
5-substituted phenyl), 5-substituted pyrimidine, and the like.

Table 2 shows 5 of the compounds of formula (1) shown in Table 1, which are 80 compounds of the currently widely used mixed liquid crystal (A), n = 1.
The viscosity, dielectric, and coefficient field universality measured for each mixed liquid crystal containing 203 IC % of /161, MU2, and MURO are also displayed, and for comparison, the measured viscosity and dielectric constant of the mixed liquid crystal (A) itself are also displayed. The resulting viscosity and dielectric anisotropy are displayed. Incidentally, the mixed liquid crystal (A) consists of and.

From the data posted in Table 2, Table 2, 5 of the compound of formula (I)
In the case of n==1, the dielectric constant anisotropy of the mixed liquid crystal is not significantly reduced. It can be understood that this reduces the viscosity of the mixed liquid crystal.

This effect of the present invention is also clarified by the following comparative experiment. Known compounds of the formula (%), which are widely used for the purpose of reducing the viscosity of mixed liquid crystals, were mixed in various proportions into the above-mentioned mixed liquid crystal (A). Similarly, one of the compounds according to the invention, namely
The material of the formula (A) was mixed in various proportions with the mixed liquid crystal (A).The viscosity and dielectric anisotropy of each of the 3ffjT type mixed liquid crystals thus obtained were added. Based on the measurement results, Figure 1 of the attached drawings shows the relationship between viscosity and the amount of addition, and Figure 2 shows the relationship between
Figure 3 shows the relationship between dielectric anisotropy and viscosity as a function of I and the amount added. From these facts, the formula (1
) of the compound with n = -1, the decrease in the externality of the dielectric constant due to the decrease in viscosity is much smaller than in the known compounds used for the purpose of decreasing viscosity. 5 Table 6 shows 80% by weight of the parent liquid crystal (B) which is currently widely used as a nematic liquid crystal preparation material, and n=2 /I64, /%5 of the compound of formula CI) shown in Table 1.
The N-1 point and viscosity measured for each mixed liquid crystal: C consisting of 20 weight 70 of each of scrap 6, shoulder 7, rot 8, and rot 9 are posted, and for comparison, the base liquid crystal (B) itself The measured N-T, 4 and viscosity are displayed. In addition, the base liquid crystal (B) is: From the data listed in Table 3 and Table 6, compounds of formula (1) with n=2 either reduce or significantly increase the viscosity of the mixed liquid crystal. -Meeting 1. C, mixed liquid crystal N-I
It will be understood that the points can be raised to a point high enough for practical use.

The viscosity value of about 25 centivoices 720C is considerably lower than the viscosity value of a volume of mixed liquid crystal having an N-I point of 65C or more, which is at the current average practical level. The low effect of the present invention is also clarified by the following comparative experiment. The chemical structure is similar to that of the compound of formula (I) according to the present invention with n = 2, and one of the compounds of formula (I) according to the present invention is N
Known compounds of formulas used for the purpose of increasing the -I point were mixed in various proportions with the above-mentioned base liquid crystal (B). Similarly, one of the compounds according to the present invention, ie, a compound having the formula % (7), was mixed into the base liquid crystal (B) in various proportions. Regarding the two types of mixed liquid crystals obtained in this way, each N-
Point I and viscosity were measured. Based on these measurement results, Figure 4 of the attached drawings shows the relationship between the KN-I point and the amount added, Figure 5 shows the relationship between the viscosity and the amount added, and Figure 7.6 shows the relationship between the NI point and the viscosity. From these relevant facts, the formula (I
It will be understood that the compound (5) in which n=2 exhibits a much smaller increase in viscosity as the N-I point increases compared to typical known similar compounds.

Next, the present invention will be specifically explained using examples.

Example: 16.0 g of anhydrous aluminum chloride in 100 d of carbon sulfide
(0,120 mol) was added thereto, and 20.1 (0,100 mol) of trans-4-n-propylcyclohexyl acetic acid chloride was added dropwise while stirring at room temperature. io this
Cool to 9.6°C, stir and add p-fluorobenzene to 1K.
11 (0,100 mol)k gradually dropped at 10C
After reacting for 5 hours at room temperature, the mixture was returned to room temperature and reacted for 2 hours. After the reaction, carbon disulfide was distilled off, and the mixture was added to ice water and stirred at 60C for 1 hour. After cooling, extract with ether, wash with water, dry, distill off the ether, and vacuum distillate to obtain the following compound 1.
8.1 g (0,0691 mol) was obtained.

This compound contains triethylene glycol 100IIl! ,
80% hydrazine hydride 12.1&(0,193
mol), 85% potassium hydroxide 22.8g (0,34
6 mol)' and gradually raise the temperature while stirring.
The reaction was carried out at 50C for 3 hours.

After cooling, water 1501 was added and extracted with n-hexane.

After washing with water and drying with anhydrous sodium sulfate, n-hexane was distilled off and purified by vacuum distillation to obtain the following compound 13.2.
9 (0,0532 mol) was obtained.

Yield 5!1.2% Transition temperature 5ccc→I)
-2sc (IHN) Example 2 The following compound was obtained in the same manner as in Example 1.

Yield 57.1'Pa Transition temperature 9C(C
-4I)-8C(xpN) The following compound was obtained in the same manner as in Example 1.

Yield 53.8% Transition temperature 7tll” (C→
I)-28C(IaN) Example 4 The following compound was obtained in the same manner as in Example 1.

Yield 56.4% Transition temperature 12r; (C-+I
)-11C(IdN) Example 5 The following compound was obtained in the same manner as in Example 1.

Yield 55.9% Transition temperature 15C(C→I)-
1U (IdN) Example 6 Carbon disulfide 10011/anhydrous aluminum chloride 16 in
．． 0 g (0.12 Omol) of trans-4-n-propylcyclohexyl acetate chloride (20.3.9 (0.10 t) mol) was added dropwise with stirring at room temperature. A solution of 18.911 (0.10 Omol) of P-chlorobiphenyl dissolved in 30 g of divalent carbon was added dropwise to the solution, and the mixture was heated at 10C for 5
After reacting for an hour, the mixture was returned to room temperature and reacted for 2 hours.

After the reaction, the binary carbon was distilled off, and then added to ice water and stirred at 60C for 1 hour. After cooling, extract with ether,
After washing with water, drying, and distilling off the ether, the following compound 26.4I was purified by recrystallization with ethanol. (0,0660 mol) was obtained.

Transition temperature 143C (C-+I) 137C (I4N) Triethylene glycol 20011/, 8
0% hydrazine hydride 11.6J' (0,185
mol), 85% potassium hydroxide 21.7II (0,3
Add Omol) and gradually raise the temperature while stirring.
The reaction was carried out at 160C for 3 hours.

After cooling, 300 d of water was added and extracted with benzene. After washing with water and drying over anhydrous sodium sulfate, benzene was distilled off and recrystallization was performed with n-hexane-ethanol to obtain 16.6 g (0,0488 mol) of the following compound.

Yield 4B, 8% Transition temperature 10CI'(C4N)
tssc (NII) Example 7 Anhydrous aluminum chloride in 10Omt carbon disulfide 16.
1 (0,120 mol)' and 20.3 g (0,100 mol) of trans-4-n-propylcyclohexyl acetic acid chloride was added dropwise while stirring at room temperature. This was cooled to 1 DC, and without stirring, 17.2/l (0,100 mol) of p-7oo biphenyl was filtered through a binary carbon filter.
A solution in which m1K was dissolved was added dropwise and reacted at 10G for 5 hours, then returned to room temperature and reacted for 2 hours. After the reaction was completed and carbon disulfide was distilled off, the mixture was added to ice water and stirred at 60C for 1 hour. After cooling, it was extracted with ether, washed with water, dried, and after distilling off the ether, it was recrystallized and purified with ethanol to obtain the following compound 21.610.0<9 mol).

Transition temperature 1o8c (c-+I) 104C (INN) Triethylene glycol 15Qd, 80%
Hydrazine hydride 11.2. ! 1J (0,179
mol), 85% potassium hydroxide 21.011 (,0,
520 mol) was added thereto, the temperature was gradually raised while stirring, and the reaction was carried out at 150 C for 5 hours.

After cooling, water 7[]QmA! was added and extracted with n-hexane. After washing with water and drying with anhydrous sodium chloride, n
- Hexane was distilled off, recrystallization was carried out with n-hexane-ethanol, and the following compound 16.8.17 (0,0520 m
ol) was obtained.

Yield 52.0% Transition temperature 76 c(C,2N
)125C(N#I) Example 8 The following compound was obtained in the same manner as in Example 7.

Yield 495% Transition temperature 68 C (CdN)
961,'(Nix) Example 9 The following compound was obtained in the same manner as in Example 7.

Yield 50.8% Transition temperature 69C(CiN
)113C(N-I) Example 1゜The following compound was obtained in the same manner as in Example 7.

Yield: 552% Transition temperature: 82 C (CiN)
121C(NdI) Example The following compound was obtained in the same manner as in Example 7.

Yield 52.2% Transition temperature 75c(CiN)1
09C(NrI) Example 12 The following compound was obtained in the same manner as in Example 7.

Yield 55.7'76 Transition temperature 87 U
(CHN)119C(Nax) Example 16 In the same manner as in Example 6, the following compound was obtained.

Collection 54.2% Transition temperature 110 C (CdN
)152t? (NμI) Example 14 The following compound was obtained in the same manner as in Example 6.

Yield 52.9% Transition temperature 114C(CHN)1
7c (NHI)

[Brief explanation of drawings]

Figures 1, 2 and 3 show compounds of the present invention (/%1)
, known compound (7g615) and known compound (/#61
6) is a chart showing the additive relationship in each mixed liquid crystal obtained by adding each of 6) to the base liquid crystal (A).

Claims (1)

[Claims] A compound represented by