PL175622B1 - Liquid-crystalline chlorine compounds, mixes containing them and lc display employing such mixes - Google Patents

Abstract

1.New liquid crystal chloro compounds of the general formula I, in which Ri and R2 are the same or different and represent the group Y- (CH2) n- (O] m- (CH2) k- (O) 1- (CH2) p-, where Y is H, F, Cl, n, p and k take values from 0 to 7, m and l are 0 or 1; Zi and Z2 are the same or different and represent a single bond or the group CH = CH, Ai is one of the fragments marked by formulas 2, 4, 5, 6 and A2 represents a single bond or one of fragments marked with the formulas 2 65, where X ,, Χ2, Χ3 and surround independently hydrogen or fluorine or chlorine, and B, B, and B2 are independently a single bond or a bridging group such as CH2CH2, OCH2 CH2O; s and that represent a number independently 0 or 1 and satisfy the condition s + t # 0. 2. The method of obtaining liquid crystal chloro compounds of general formula I, in which R 1 and R 2 are the same or different 1 represent the group Y- (CH2) n- (O) m- (CH2) k- (O) and- (CH2) p-, where Y is the H, F, Cl, n, p and k atom take the values from 0 to 7, m and l are 0 or 1: Zi and Z2 are the same or different and are a single bond or a CH = CH group; Ai means one of fragments marked with formulas 2, 4, 5, 6 and A2 represent a bond single or one of the fragments marked with formulas 2-6, where Xi, Χ2, Χ3 and X4 are independently hydrogen or fluorine, or chlorine, and B, B and B2 are independently a single bond or a bridging group such as CH2CH2, OCH2, CH2O; s and t independently denote the number 0 or i and satisfy the condition s + t # 0, characterized in that it is heating the compound of formula Is the same or different and represent a group terminal selected from the set: Y- (CH2) n- (O) m- (CH2) k- (O) i- (CH2) p-, where Y is H, F, Cl, n, p and k are 0 to 7, m and l are 0 or 1; Zi and Z2 are the same or different and represent a single bond or a CH = CH group; Ai means one of the fragments with the formulas 2, 4, 5, 6 and A2 is single bond or one of the fragments marked with the formulas 2 - 10, where Xi, X2, X3 and Χ4 are independently ...

Description

The subject of the invention is a compound of general formula I in which Rj and R2 are the same or different and represent the group Y- (CH2) n- (O) _m - (CH2) k- (O) and- (CH2) p-, where Y is H, F, Cl; n, peak ranges from 0 to 7, m and l are 0 or 1; Z and Z2 are the same or different and represent a single bond or a CH = CH group, Ai is one of the fragments marked with formulas 2, 4, 5, 6 and A2 is a single bond or one of the fragments marked with formulas 2 - 6, where Xi, Χ2 , Χ3 and Χ4 are independently hydrogen or fluoro or chloro, and B, B and B2 are independently a single bond or a bridging group such as CH2CH2, OCH2, CH2O; s and t are independently 0 or 1 and satisfy the condition s + t I 0.

The compounds of the invention are obtained by heating a compound of formula 7 in which R 1 and R 2 are the same or different and represent a group selected from the group: Y (CH2) n- (O) _m - (CH2) k- (O) i- (CH2) p-, where Y is H, F, Cl; n, peak ranges from 0 to 7, m and l are 0 or 1; Zi and Z2 are the same or different and represent a single bond; or a group CH = CH; Ai is one of the fragments marked with the formulas 2,4, 5, 6 and A2 is a single bond or one of the fragments marked with the formulas 2 - 6, where Xi, ,2, Χ3 and Χ4 are independently hydrogen or fluorine or chlorine, and B, B and B 2 are independently a single bond or a bridging group such as CH2CH2, OCH2, CH2O; s and t are independently 0 or 1 and satisfy the condition s + t I 0; with an excess, preferably two molar, of PCty in aromatic or chlorinated hydrocarbons, preferably in benzene, at a temperature above 50 ° C.

The liquid crystal compounds of the present invention are used as components of liquid crystal mixtures. They enable to obtain mixtures with high values of optical anisotropy (An) and different Δε / ε_ ratio. Compared to the known compounds not laterally substituted with chlorine, they have lower melting points and the stability of the smectic phases is strongly reduced. This allows to obtain nematic mixtures having a nematic phase at low temperatures.

These mixtures contain in their composition only compounds and or compounds and other known liquid crystalline compounds and / or non-liquid crystalline compounds such as solvents and / or optically active compounds and / or dichroic dyes and / or polymers. Compounds of formulas 8-16 have advantageous properties as components of mixtures.

Mixtures containing two and three rings have moderately high refining temperatures. The presence of the tetracyclic compounds of the invention in the mixture, preferably the compounds of formulas 12-16, causes the mesotase range of the nematic mixture to be greater than 150 ° C.

The described mixtures are used in the liquid crystal indicator. It consists of two parallel plates with glued polarizers, at least one of which is made of transparent material, which are the substrate for electrodes, orienting layers, and / or insulating layers, and / or color filters, between which there is a liquid crystal mixture.

The following examples illustrate the spirit of the invention without limiting its scope.

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Example 1. Preparation of 3,4-difluoro-3'-chloro-4 '- (trans-4-pentylcyclohexylethyl-2) biphenyl

A mixture of 0.1 mol of 3- (3,4-difluorophenyl) -6- (trans-4-pentylocykloheksyloetylo-2) cyclohex-2-enone l, 0.2 mol PCl5, 100 cm ³ of benzene was heated at reflux for 8 hours It was then cooled, poured onto water, the layers were separated, the organic layer was washed neutral with K2CO3 solution, dried over K2CO3 and filtered. Benzene was distilled off and the residue was dissolved in hexane, filtered through a pad of silica gel, the solvent was evaporated and the oil was crystallized from ethanol. The compound was obtained with temperature, phase transitions K 13 N 45 I, yield 40%. This compound has at the temperature of 20 ° C n ₀ = 1.513 and n _e = 1.620, Δη = 0.107; dielectric constants, ε «= 5.4, ε ± = 3.8, and the viscosity at 40 °, 30 ° and 20 ° is 48, 76 and 142 mPa s respectively.

By comparison, 3,4-difluoro-4 '- (trans-4-pentylcyclohexyl-2) biphenyl has a melting point of 31.5 °, lit. Goto Y., Ogawa T., Sawada S., Sugimori S., Mol. Cryst. Liq. Cryst. 209.1 (1991).

The following compounds were prepared analogously:

4- (trans-4-pentylcyclohexylethyl-2) -3-chloro-4 '- (trans-4-propylcyclohexyl) biphenyl

K 81.5 ° C N 220.5 ° C I

For comparison, 4- (trans-4-pentylcyclohexylethyl-2) -4 '- (trans-4-propylcyclohexyl) -biphenyl has a phase transition K 208.1 S 234 N 263.1 I, lit. Petrzilka M., Schadt M., (Hoffmann-La Roche): DE 3,237,367 (October 8, 1982).

4- (trans-4-pentylcyclohexylethyl) -2) -3-chloro-2'-fluoro-4'-methoxybiphenyl

K 45.2 ° CN 97 ° C; An = 0.14; n ₀ = 1.517, ne = 1.657, Δε = -0.25, ειι = 4.32, ε ± = 4.57

4- (trans-4-propylcyclohexylethyl-2) -3'-chloro-4 "-methoxyterphenyl K 92.6 ° CN 232 ° Cl 4- (trans-4-pentyIcyclohexyl) -3-chloro-4" -methoxyterphenyl) 4- (trans-4-pentylcyclohexyl) -3-chloro-4 "-ethoxyterphenyls 1 4- (trans-4-pentylcyclohexyl) -3-chloro-4" -fluoroterphenyl

For comparison, 4- (trans-4-propylcyclohexy 1 o) -4 "-fluoroterphenyl has phase transitions: K 140 S 147 N 3011, lit. Poetsch E., Meyer V., Bartmann E., Hittich R., Rieger B., Reiffenrath V., Coates D. Greenfield S., (Merck) EP 439.089 (01/21/1991).

4-pentyl-3 "" - chloro-4 "" - methoxyquaterphenyl K 115 ° C Sa 141 ° C N 298 ° C I

K 90.3 ° C N 273 ° C I K 102 ° C N 275 ° C I K 105 ° CN 210 ° CI

Example 2

Mixture A was prepared with the following composition:

% 4- (trans-4-propylcyclohexyl) benzeneisothiocyanate 40 wt

% 4- (trans-4-hexylcyclohexyl) benzeneisothiocyanate 42 wt

4- (trans-4- _{octylcyclohexyl} ) benzeneisothiocyanate was _weighed .

Mixture A has the following parameters:

T _N -i 42 ° C

V ₁₀ 20 ° C 1.69

V ₅ o.20 ° C 1.95

V ₉ o. 20 ° C 2.38

An, 20 ° C 0.1680 η, 20 ° C 12.9 mPa s

10 wt% of 4- (4-trans-pentylcyclohexylethyl-2) -3-chloro-3 ', 4'-difluorobiphenes] was introduced into mixture A to obtain mixture B.

10 wt.% Of 4- (4-trans-pentyl cyclohexylethyl-2) -3-chloro-4 '- (trans-4-propylcyclohexyl) biphenyl was introduced into mixture A and the mixture was obtained.

10 wt% of 4- (4-trans-pentylcyclohexyl) -3'-chloro-4 "methoxyterphenyl was introduced into mixture A to give mixture D.

10% 4- (4-trans-pentylcyclohexyl) -3'-chloro-4'-fluoroterphenyl) was introduced into mixture A and the mixture E was obtained.

10 wt% of 4- (4-trans-butylcyclohexylethyl-2) -3-chloro-2'-fluoro-4'-methoxybiphenyl was introduced into mixture A to obtain mixture F.

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Mixtures B, C, D, E and F have the following parameters:

B C. D E. F. Temp. clear 41.5 61.5 61 54 45 η, 20 ° C 15.2 15.5 16.5 17.9 16.5 An, 20 ° C 0.1567 0.1769 0.1783 0.1648 0.166

Example 3.

Mixture G was prepared with the following composition:

4- (trans-4-propylcyclohexyl) benzeneisothiocyanate 35.0 wt.%

4- (trans-4-pentylcyclohexyl) benzeneisothiocyanate 9.0 wt.%

4- (trans-4-heptylcyclohexyl) benzeneisothiocyanate 16.0 wt.%

4-methoxyphenyl 4- (trans-4-pentylcyclohexanecarboxylate 10.0 wt.%

4- (trans-4-ethylcyclohexyl) -1-nonylbenzene 5.0 wt.%

4- (trans-4-ethylcyclohexyl) phenyl-2- (trans-4-propylcyclohexyl) ethane 25.0 wt.%

The G mixture has the following parameters:

Tn-i 42 ^o C η, 20 ° C 14.5 mPa-s

An, 20 ° C 0.1408

10 wt.% Of 4- (trans-4-pentylcyclohexylethyl-2) -3-chloro-4 '- (trans-4-propylcyclohexyl) biphenyl was introduced into mixture G to obtain mixture H.

The H mixture has the following parameters:

Tn-i 72 ° C η, 20 ° C 17.8 nP ^ ass

An, 20 ° C 0.1445

Example 4.

10 wt% of 4- (trans-4-butylcyclohexylethyl-2) -3-chloro-2'-fluoro-4'-methoxybiphenyl was introduced into mixture H to give mixture I.

Mixture I has the following parameters:

Tn-i 56 ° C η, 20 ° C 18.2 mPa-s

An, 20 ° C 0.1435

175 622 a

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175 622

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Publishing Department of the UP RP. Circulation of 90 copies

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Claims (2)

Patent claims 1. New liquid crystal chloro compounds of the general formula I, in which Ri and R2 are the same or different and represent the group Y- (CH2) n- (O) _m - (CH2) k- (O) i- (CH2) p-, where Y is H, F, Cl, n, peak ranges from 0 to 7, m and l are 0 or 1; Zi and Z2 are the same or different and represent a single bond or CH = cH; Ai is one of the fragments represented by the formulas 2, 4, 5, 6 and A2 is a single bond or one of the fragments represented by the formulas 2-6, where Xi, X 2, X 3 and X 4 are independently hydrogen or fluorine or chlorine, and B, Bi and B2 are independently a single bond or a bridging group such as CH2CH2, OCH2 CH2O; s and t independently represent the number 0 or ii satisfy the condition s + t Ψ 0. 2. The method of obtaining liquid crystal chloro compounds of general formula I, in which Ri and R2 are the same or different and represent the group Y- (CH2) _n - (O) m- (CH2) k- (O) 1- (CH2) p- where Y is H, F, Cl, n, peak ranges from 0 to 7, m and l are 0 or i; Zi and Z2 are the same or different and represent a single bond or CH = CH; Ai is one of the fragments represented by the formulas 2, 4, 5, 6 and A2 is a single bond or one of the fragments represented by the formulas 2-6, where Xi, X2, X3 and Χ4 are independently hydrogen or fluorine or chlorine, and B, B and B2 are independently a single bond or a bridging group such as CH2CH2, OCH2, CH2O; s and t are independently the number 0 or ii satisfy the condition s + 1Ψ 0, characterized in that it consists in heating the compound of formula 7 in which Ri and R2 are the same or different and represent a terminal group selected from the set: Y- (CH2 ) n- (O) m (CH2) k- (O) 1- (CH2) p-, where Y is H, F, Cl, n, peak ranges from 0 to 7, m and l are 0 or and ; Zi and Z2 are the same or different and represent a single bond or CH = CH; Ai is one of the fragments represented by the formulas 2, 4, 5, 6 and A2 is a single bond or one of the fragments represented by the formulas 2 - 10, where Xi, X2, X 3 and X4 are independently hydrogen or fluorine or chlorine, and B , B and B 2 are independently a single bond or a bridging group such as CH 2 CH 2, OCH 2, CH 2 O; s and t are independently 0 or - and satisfy the condition s + t Ψ 0, with an excess of preferably two molar, PCl in aromatic or chlorinated hydrocarbons, preferably in benzene, at a temperature above 50 ° C. The invention relates to novel liquid crystal chloro compounds which are laterally substituted benzene derivatives for use as components of liquid crystal mixtures. Liquid crystal compounds containing a fluorine atom in the lateral position of the benzene ring have gained practical significance as components of mixtures due to their low viscosity and high chemical stability for various types of liquid crystal indicators. This is confirmed by the following patents: DE 4032579, DE 4030392, EP 460436, JP 92: 255793, DE 4i06345, DE 40273i5, DE 4034508, DE 4i00288, DE 40i0447, DE 4ii00i8, DE 40i6i30, DE 40i3297, DE 4i08705, DE 40i08705, , DE 4i07i20, DE 4i08398, DE 40i3083, DE 40i2403, DE 4i07389, DE 40i20i4, DE 4iii0i5, DE 40375i9, DE 4ii3053, DE 4i23539, DE 4iii99i, DE 4i04i83, DE 4ii2024, GB 92: 05230, WO 92: 05230, WO 92: 05230, WO 92: 05230 : 05209, WO 92: 06748, WO 9i: i2233, WO 9i: i5555, JP 9i: 203987, JP 92: 54i38, JP 93: 58928, JP 92: 91056, EP 492668, EP 502407, EP 507094. 175 622 The liquid-crystal fluoro compounds are characterized by low viscosity, low value of optical anisotropy, An, and high chemical stability. For some applications, especially in nonlinear optics or indicators working with the use of the supercoiled nematics effect, compounds having a higher value of optical anisotropy, the ordinary refractive index no and the perpendicular component of electric permittivity ε_ are needed. Such properties can be obtained by exchanging the Cl atom for the F atom. The known methods of preparing compounds containing a Cl or F atom laterally are complicated and multi-step. These are the lithiation or coupling reactions of arylboronic acids and Grignard compounds catalyzed by palladium compounds. They usually require low temperatures and the use of an inert atmosphere. The present invention overcomes these difficulties by providing a simple and effective method for the preparation of laterally substituted chlorinated derivatives.