JPS5982382A - M-dioxane ester containing halogen - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (R is H or 1-10C alkyl; X is F or Cl; n is 1 or 2). EXAMPLE:4-(4'-Fluoro)biphenylyl 4-(5-butyl-1,3-dioxan-2-yl)benzoate. USE:A component in liquid crystal compositions, capable of exhibiting the liquid crystal phase within a wide temperature range, increasing the clear point of the liquid crystal compositions while increasing scarcely the viscosity thereof by adding to the liquid crystal compositions due to the low viscosity thereof through a high clear point, and having improved stability to moisture, heat and light without changing the threshold voltage and saturation voltage of the compositions so much. PROCESS:A 4-(5-alkyl-1,3-dioxan-2-yl)benzoyl chloride of formula II is reacted with a 4-halogenophenol or 4-hydroxy-4'-halogenobiphenyl of formula III in the presence of pyridine to give the aimed compound of formula I .

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a novel liquid crystal "P" (and a liquid crystal composition containing the same) that exhibits a liquid crystal phase over a wide temperature range and has positive dielectric anisotropy.

Display elements 11 using liquid crystals have come to be widely used in watches, iTs, cameras, etc. This single-crystal display element has an optical i6 direction of liquid crystal material: 11. U dielectric j J
, which takes advantage of the property of j-tropism, but the 1-1 crystal phase includes a nematic liquid crystal phase, a smectic/1 (crystalline phase), a cholesteric liquid crystal phase, and a nematic liquid crystal phase. TN (twisted nematic) type, DE
Type I (dynamic scattering type), guest-host type, 1) A P
There are different types of liquid crystals, and the characteristics 71 required for each type of liquid crystal material used in the world are different. However, in any case, it is desirable that the liquid crystal materials used in these display elements exhibit a liquid crystal phase in as wide a range as possible in nature, but at present there is no single material that satisfies such conditions. Instead, the current situation is to mix several types of liquid crystal materials or non-liquid crystal materials to fit a material that can withstand practical use. or,
These substances need to be stable against moisture, light, heat, air, etc. It is desirable for the viscosity to be as low as possible, as well as to increase the response speed.By the way, in order to widen the liquid crystal temperature range toward high temperatures, it is necessary to use a liquid crystal substance with a high melting point as a component. However, liquid crystal substances with high melting points generally have high viscosity, and therefore liquid crystal compositions containing them also have high viscosity, so they can be used at high temperatures, for example, up to 80°C.
The response speed of liquid crystal display elements, especially at low temperatures, tends to become significantly slower. However, the present inventors have developed a liquid crystal material that exhibits a liquid crystal phase over a wide m degree range, has a high clearing point, and has a low viscosity.

That is, the present invention is represented by the general formula (in the above formula, R represents hydrogen or an alkyl group having 1 to 10 carbon atoms; 4-(5-alkyl-1,

The present invention is an ester of a phenyl fatty conductor and a liquid crystal composition containing the same.

Compounds of the present invention rJ-+'t#I t:A'c,
and f'l is one of the compounds of the present invention, 4-(5
-butyl-1,3-dioxan-2-yl)benzoic II
zo-4-(4'-furj lorahifueni/l ester C
-N point is 133.5 to 135.0 (:, N-I point is 2
'i' Wide temperature of 4.5℃: 1i 1ahir: t
By adding it as a component of the composition, it is possible to increase the viscosity of the liquid crystal composition and raise the clearing point. Moreover, the +τ city of the compound of the present invention? Although the anisotropy value is about +2, it does not change the threshold voltage and saturation voltage of the composition so much. It also has good stability against moisture, heat, light, etc.

Next, the method for producing the compound of the present invention will be shown by the known method θ;
(Keriba) Manufactured by Japanese Patent Application Publication No. 5'Y-126486);
'c! (5-alkyl-1,3-dioxane-2
-yl)benzoic acid chloride and 4-logenophenol or 4-hydroquine-4'-logenobiphenyl are reacted in the presence of pyridine to form a large amount of 4-(5-alkyl-1, 3-diokypn-2-yl) 4- of benzoic acid
Esters of phenyl derivatives substituted with nitrogen are obtained.

This is expressed as a chemical formula: (R,

Example 1 (4=(5-butyl-1,3-dimexan-2-yl)benzoic acid-4(4/-fur:An) 11! ! A:]]4-hydroxy/-4-fluorobiphenyl 19f in pyridine i
Qrl! nimkasu. 4-(5-butyl-
], :] 5-dimekylin-2ylbenzoic acid chloride 2.
Remove 7f and set aside overnight. Toluene 2 I)
(1) Separate the toluene layer using 1'Xit to remove the toluene layer, first with 6NJ and t'P, then wash with 2N caustic soda solution, and then with water until it becomes neutral. do. After drying with anhydrous sulfur and acid, the toluene layer is removed under reduced pressure.

The precipitated crystals were completely crystallized with ethanol (+1 crystals and -L'th '4-(5-butyl-1,3-dime xan-2-yl)benzene-rrI' -4-,-(4,J- Full 8 mouths) 4urc of biphenylyl ester. Yield: 1.5 f, I
ll<rate 32chi, the O-N point of this is] 33. ! b
~135.0°C, N-■ point 1.274 @ J°C.

Rumored Group F Example Layer Book Cα Example 2 to 7 Actually, in place of 4-(5-butyl-1,3-cyogitun-2-yl)benzoic acid chloride in Rule 1 of 11, other alkyl groups are substituted. using 4-(5-alkyl-1,3-dioxan-2-yl)benz'fjrl chloride with 4-hydroxy-4'-furA robiphenyl
-Hydroxy-4'-chlorobiphenyl or this-fluj
Using lophenol or H4-10 lophenol, a compound of formula (1) was produced in the same manner.

The physical property values are shown in the first section along with the results of Example 1.

1st Clothing Example Date (Usage Example) Trans-4-propyl (4'-cyanophenyl) cyclohexane 28 Thi-trans-4-benzene (ih'-cyanophenyl) cyclohexane
The N-, T-point & J of the liquid crystal composition having a composition of 42% 2% trans-4-butyl-(4'-cyanophenyl)cyclohexane 30%: 52°C. When this liquid crystal composition '$J is inserted into a TN cell (twisted nematic cell) with a cell thickness of 0 μm, the operating threshold and pressure are 1.5
3V %Pi: full K4. The pressure is 2. l2V
Met. Also, the viscous melon had a temperature of 23 CTl at 20°C.

4-(5-
Benzoic acid-4,-(4”-fluoro)biphenyl ester 3 t
The N-I point of the l inner product composition with ut set to jJI+ is 57C, and when this is made into a TN cell similar to that described in 1jil, the threshold voltage is 1.55V, and the saturation voltage is 2.14.
It was V. Meo 'Zanlkura, Jin 1: 20 D and 25
It was cp.

L11ni A4

Claims (2)

[Claims] (1) General formula (in the above formula, B represents hydrogen or an alkyl group having 1 to 1 carbon atoms, X represents either F or C/, and is 1 or 2) Esters of 4-halogen-substituted phenyl derivatives of 4-(5-alkyl-1,3-diokylin-2-yl)benzoic acid as shown. (2) General formula (in the above formula, R number - 7 hydrogen or alkyl groups having 1 to 10 carbon atoms, X represents either F or l'icl, n
+: l: 1 or 2), −(5
-alkyl-1,3-dioxan-2-yl) 7r(
An i+ crystal composition characterized in that it contains at least one ester f of a 4-)-rogen-substituted phenolic acid/I-derivative of breath acid.