Abstract: A borate phosphor represented by the formula a(M.sup.II.sub.1-x, M.sup.IV.sub.x/2)O.bM.sup.V.sub.2 O.sub.5.cM.sup.I.sub.2 O.(B.sub.1-y-z,M.sup.III.sub.y, M.sup.VI.sub.z/2).sub.2 O.sub.3 :dCe,eTb wherein M.sup.II is at least one divalent metal selected from the group consisting of Mg, Be, Zn, Cd, Ca, Sr and Ba; M.sup.IV is at least one tetravalent element selected from the group consisting of Si, Ti, Ge, Zr, Sn, Th and Pb; M.sup.V is at least one pentavalent element selected from the group consisting of P, V, Nb, Sb, Ta and As; M.sup.I is at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs; M.sup.III is at least one trivalent metal selected from the group consisting of Al, Sc, Ga, Y, In, La, Lu, Gd, Bi and Tl; M.sup.VI is at least one hexavalent meteal selected from the group consisting of Mo, Te and W; and a, b, c, d, e, x, y and z are numbers satisfying the conditions of 0<a.ltoreq.2.0; 0.ltoreq.b.ltoreq.0.3; 0.ltoreq.c.ltoreq.0.3, 0<d.ltoreq.0.6, 0.ltoreq.e.ltoreq.0.

Abstract: Liquid crystalline p-cyanocinnamic acid p'-n-alkoxyphenyl esters, and nematic liquid crystal compositions containing the same, useful for electro-optical devices, are described.

Abstract: When a 4,4'-substituted benzylideneaniline compound having specific substituents is compounded in a nematic liquid crystal material, a liquid crystal composition having a positive dielectric anisotropy and a broad mesomorphic range extending above and below room temperature can be obtained. An electro-optical element comprising a thin layer of this liquid crystal composition filled and supported between two substrates can be used for light modulation and display.

Abstract: A liquid crystal electro-optical element which comprises a nematic liquid crystal composition having a positive dielectric anisotropy which is composed of p-n-alkylbenzylidene-p'-cyanoaniline and an improver selected from the group consisting of p-n-alkyl cyanobenzene, p-alkylbenzylidene-p'-alkoxyaniline, and p-alkoxybenzylidene-p'-n-alkylaniline.

Abstract: Nematic liquid crystal compositions having positive dielectric anisotropy are obtained by mixing at least one of p-n-alkylphenyl-p'-cyanobenzoates represented by the formula, ##STR1## wherein R.sub.2 is n-alkyl group of 3 to 8 carbon atoms with at least one of p-cyanophenyl-p'-n-alkylbenzoates represented by the formula, ##STR2## wherein R.sub.1 is n-alkyl group of 4 to 8 carbon atoms. Said compositions exhibit nematic liquid crystal phase over a broad temperature range and therefore, are useful for the torsion effect-type display device.

Abstract: When a 4,4'-substituted benzylideneaniline compound having specific substituents is compounded in a nematic liquid crystal material, a liquid crystal composition having a positive dielectric anisotropy and a broad mesomorphic range extending above and below room temperature can be obtained. An electro-optical element comprising a thin layer of this liquid crystal composition filled and supported between two substrates can be used for light modulation and display.

Abstract: By incorporating at least one of p-n-alkylcyanobenzene, p-cyanobenzylideneaniline and p-cyanophenyl p'-n-octyloxybenzoate into a Schiff base type nematic liquid crystal composition having negative dielectric anisotropy, a nematic liquid crystal composition having positive dielectric anisotropy is obtained. The nematic liquid crystal composition of the latter exhibits a liquid crystal state in a broad temperature range including room temperature and is useful for a torsion effect type electrooptical display device which can operate at low voltages.

Abstract: In an electro-optical element comprising a pair of electrode plates and a layer of nematic liquid crystal material having a positive dielectric anisotropy positioned between the two plates, at least one of the electrode plates is coated on its inner face with organic high molecular materials. Molecular axes of the liquid crystal are oriented uniformly on the electrode face by rubbing the coated electrode along one direction.