Liquid-crystal composition
AssigneesSharp Kabushiki Kaisha, Merck Patent Gesellschaft met beschrankter haftung
InventorsYutaka Ishii, Fumiaki Funada, Masataka Matsuura
Life of this patent
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Abstract
A liquid-crystal composition to be used in a multiplex-driving system in a twisted nematic (TN) type liquid-crystal display devices is extremely superior in its display characteristics, and is able to meet sufficiently the demands to increase the information content of various liquid-crystal display devices of high-level multiplexing operation. The liquid-crystal composition is more considerable in its usefulness than the validity thereof in half-tone display especially when it is used in a liquid-crystal television. The liquid crystal composition having a positive dielectric anisotropy in the nematic phase, comprises each 3 wt % or more of 2-(4-alkoxyphenyl)-5-alkylpyrimidine compound and of a cyanobiphenyl compound.
Claims20
In a liquid crystal display device of the matrix display type having a high contrast ratio and a broad effective viewing-angle range, which contains a liquid crystal composition having a positive dielectric anisotropy in the nematic phase, said composition comprising 3 wt.% or more of 2-(4-alkoxyphenyl)-5-alkylpyrimidine compounds and a p-type component comprising cyanobiphenyl compounds selected from the group consisting of a 4-alkyl-4'-cyanobiphenyl, a 4-alkoxy-4'-cyanobiphenyl, a 4-alkoxy-ethyleneoxy-4'-cyanobiphenyl, and a 4-cyano-4'-(4-alkyl)-cyclohexylbiphenyl, the improvement comprising said composition further including a low-viscosity material having a viscosity (.eta.) at 20.degree. of 20 mm.sup.2.s.sup.-1 or lower and a high clearing-point material having a clearing point (T.sub.cp) of 100.degree. C. or higher, each of said materials being present in an effective amount so that the clearing point of the composition is 60.degree. C. or higher and the viscosity at 20.degree. C. is 35 mm.sup.2.s.sup.-1 or lower.
A liquid crystal composition having a positive dielectric anisotropy in the nematic phase, a p-type component consisting essentially of cyanobiphenyl compounds sselected from the group consisting of a 4-alkyl-4'-cyanobiphenyl, a 4-alkoxy-4'-cyanobiphenyl, a 4-alkoxy-ethyleneoxy-4'-cyanobiphenyl, and a 4-cyano-4'(4-alkyl)-cyclohexyl biphenyl, comprising 3 wt.% or more of a 2-(4-alkoxyphenyl)-4-alkylpyrimidine compound, a low-viscosity material having a viscosity (.eta.) at 20.degree. C. of 20 mm.sup.2.s.sup.-1 or lower and a high clearing-point material having a clearing point (T.sub.cp) of 100.degree. C. or higher.
Dependencies are inferred from the claim text.