Stock material or miscellaneous articles – Liquid crystal optical display having layer of specified...
Reexamination Certificate
2000-08-24
2003-06-10
Wu, Shean C. (Department: 1756)
Stock material or miscellaneous articles
Liquid crystal optical display having layer of specified...
C252S299610, C252S299630, C252S299660, C544S298000, C544S334000, C544S335000, C549S369000, C546S193000, C546S194000, C546S236000, C568S588000, C568S647000, C570S127000, C570S129000, C570S130000
Reexamination Certificate
active
06576303
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a liquid crystalline compound and a liquid crystal composition. More specifically, it relates to a novel liquid crystalline compound having a negative dielectric anisotropy value (&Dgr;∈), a liquid crystal composition comprising this compound as one of components and a liquid crystal display device comprising this liquid crystal composition.
BACKGROUND ART
In recent years, liquid crystal display devices of various modes have been developed in order to obtain a liquid crystal display having a high quality. In particular, an in-plane switching (IPS) mode and a vertical aligning (VA) mode are paid attentions in developing a liquid crystal display having a wide viewing angle. Liquid crystal compositions used for these liquid crystal display devices are expected to have a negative and absolutely large value of &Dgr;∈, and hence many developments have been actively made on liquid crystal materials to meet the expectation as above.
Known as such liquid crystal materials having a negative and absolutely large value of &Dgr;∈ are, for example, 2,3-dicyanophenylene expressed by a formula (13) (Japanese Patent Application Laid-Open No. 10557/1984) and liquid crystalline compounds having a 2,3-difluorophenylene skeleton expressed by formulas (14) or (15) (Japanese Patent Application Laid-Open No. 1725/1990 or Japanese Patent Application WO Laid-Open No. 503441/1990, respectively):
wherein R and R′ represent an alkyl group and the like.
However, among these known compounds, 2,3-dicyanophenylene expressed by the formula (13) has a negative and absolutely large value of &Dgr;∈, but has a problem that it is not only inferior in a compatibility but also lacking in a chemical and physical stability. Accordingly, it is not necessarily satisfactory.
The compound expressed by the formula (14) is simply shown as a component for a ferroelectric liquid crystal composition, and therefore applicability thereof as a nematic liquid crystal composition is not clear. Further, the compound expressed by the formula (15) is shown without any electro-optical characteristics thereof, and therefore it's applicability as a component for a nematic liquid crystal composition is not clear as well.
DISCLOSURE OF THE INVENTION
An object of the present invention is to solve the defects in conventional technology described above. Another object of the present invention is to provide a novel liquid crystalline compound having a negative and absolutely large &Dgr;∈ value, being excellent in a compatibility with other liquid crystalline compounds, having a low viscosity, and being stable chemically and physically; to provide a liquid crystal composition comprising the compound as one of components, and to provide a liquid crystal display device comprising the liquid crystal composition.
For achieving the object described above, the present invention is summarized as follows:
(1) A liquid crystalline compound expressed by the general formula (1):
R
1
—A
1
—B
1
—A
2
—B
2
—A
3
—B
3
—Z—B
4
—A
4
—R
2
(1)
wherein A
1
, A
2
, A
3
and A
4
each independently represent a single bond, 1,4-cyclohexylene, 1,4-phenylene which may be substituted with a fluorine atom(s), dioxane-2,5-diyl, pyrimidine-2,5-diyl, piperidine-1,4-diyl, pyridine-2,5-diyl which may be substituted with a fluorine atom(s) or 1-sila-1,4-cyclohexylene; Z represents a group selected from divalent groups expressed by partial structural formulas (I) to (VI):
wherein X represents a hydrogen atom or a fluorine atom, and Y represents difluoromethyl group, difluoromethoxy group, formyl group or carboxyl group; B
1
, B
2
, B
3
and B
4
each independently represent a single bond, 1,2-ethylene, 1,2-ethenylene, 1,2-ethynylene, oxymethylene, methyleneoxy, carbonyloxy, oxycarbonyl or 1,4-butylene group, provided that when Z is a group represented by the partial structural formula (III), then B
4
is neither oxymethylene nor oxycarbonyl group, and that when Z is a group represented by the partial structural formula (IV), then B
3
is neither methyleneoxy nor carbonyloxy group; R
1
and R
2
each independently represent an alkyl group or a fluoroalkyl group substituted with at least one fluorine atom having 1 to 10 carbon atoms in which alkyl group or fluoroalkyl group one or not adjacent two or more methylene groups may be replaced by an oxygen atom, a sulfur atom or —CH═CH—.
(2) The liquid crystalline compound as recited in paragraph 1 wherein Z is a group represented by the partial structural formula (I).
(3) The liquid crystalline compound as recited in paragraph 1 wherein Z is a group represented by the partial structural formula (II).
(4) The liquid crystalline compound as recited in paragraph 1 wherein Z is a group represented by the partial structural formula (V).
(5) The liquid crystalline compound as recited in paragraph 1 wherein Z is a group represented by the partial structural formula (VI).
(6) A liquid crystal composition comprising two or more components at least one of which is a liquid crystalline compound recited in any of paragraphs 1 to 5 above.
(7) A liquid crystal composition comprising, as a first component, at least one liquid crystalline compound recited in any one of paragraphs 1 to 5 above, and, as a second component, at least one compound selected from the group consisting of the compounds expressed by any one of the formulas (2), (3) and (4):
wherein R
3
represents an alkyl group having 1 to 10 carbon atoms in which alkyl group one or not adjacent two or more methylene groups may be replaced by an oxygen atom or —CH═CH—, and any hydrogen atom thereof may be replaced by a fluorine atom; Y
1
represents a fluorine atom, a chlorine atom, OCF
3
, OCF
2
H, CF
3
, CF
2
H, CFH
2
, OCF
2
CF
2
H or OCF
2
CFHCF
3
; L
1
and L
2
each independently represent a hydrogen atom or a fluorine atom; Z
1
and Z
2
each independently represent a 1,2-ethylene group, a 1,4-butylene group, —COO—, —CF
2
O—, —OCF
2
—, —CH═CH— or a single bond; ring B represents trans-1,4-cyclohexylene, 1,3-dioxane-2,5-diyl or 1,4-phenylene in which any hydrogen atom on the ring may be replaced by a fluorine atom; and ring C represents trans-1,4-cyclohexylene, or 1,4-phenylene in which any hydrogen atom on the ring may be replaced by a fluorine atom.
(8) A liquid crystal composition comprising, as a first component, at least one liquid crystalline compound recited in any one of paragraphs 1 to 5 above, and, as a second component, at least one compound selected from the group consisting of compounds expressed by the formulas (5) and (6):
wherein R
4
and R
5
each independently represent an alkyl group having 1 to 10 carbon atoms in which alkyl group one or not adjacent two or more methylene groups may be replaced by an oxygen atom or —CH═CH—, and any hydrogen atom thereof may be replaced by a fluorine atom; Y
2
represents a —CN group or —C≡C—CN; ring E represents trans-1,4-cyclohexylene, 1,4-phenylene, 1,3-dioxane-2,5-diyl or pyrimidine-2,5-diyl; ring G represents trans-1,4-cyclohexylene, 1,4-phenylene 4-phenylene in which any hydrogen atom on the ring may be replaced by a fluorine atom or pyrimidine-2,5-diyl; ring H represents trans-1,4-cyclohexylene or 1,4-phenylene; Z
3
represents a 1,2-ethylene group, —COO— or a single bond; L
3
, L
4
and L
5
each independently represent a hydrogen atom or a fluorine atom; and b, c and d each independently represent 0 or 1.
(9) A liquid crystal composition comprising, as a first component, at least one liquid crystalline compound recited in any one of paragraphs 1 to 5 above, and as a second component, at least one compound selected from the group consisting of the compounds expressed by any one of the formulas (7), (8) and (9):
wherein R
6
and R
7
each independently represent an alkyl group having 1 to 10 carbon atoms in which alkyl group one or not adjacent two or more methylene groups may be replaced by an oxygen atom or —CH═CH—, and any hydrogen atom thereof may be replaced by a fluorine atom; rings I, J and K ea
Fujita Atsuko
Nakagawa Etsuo
Takeshita Fusayuki
Tamura Norio
Tekeuchi Hiroyuki
Chisso Corporation
Wenderoth , Lind & Ponack, L.L.P.
Wu Shean C.
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