Abstract: A liquid crystal composition suitable for a guest-host liquid crystal device and the composition comprises a solution of a liquid crystal substance and a pleochroic dye which comprises at least one azo type compound having the formula (I), ##STR1## wherein R.sup.1 represents a hydrogen atom, an alkyl group or an alkoxy group each of which may be substituted by an alkoxy or an aryl group; a cyclohexyl group which may be substituted by an alkyl group; or --COOR.sup.3 (wherein R.sup.3 represents an alkyl group which may be substituted by an alkoxy group, a cyclohexyl group which may be substituted by an alkyl group, or an aryl group which may be substituted by an alkoxy or an alkyl group);R.sub.2 represents ##STR2## where R.sup.4 and R.sup.5 each represents an alkyl group which may be substituted by an alkoxy or an aryl group; or R.sup.4 and R.sup.5 may be connected to each other to form a ring;Z.sup.1 and Z.sup.2 each represents a hydrogen atom, a halogen atom, and alkyl group or an alkoxy group, or Z.sup.

Abstract: An anthraquinone compound represented by formula: ##STR1## wherein R and X are as defined in the specification, and a polarizing film containing the same. The anthraquinone compound exhibits satisfactory compatibility with organic polymers and high dichroism, and the polarizing films have excellent performance characteristics.

Abstract: A polarizing film which comprises a film base having thereon an anthraquinone dye of general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 each represents a hydrogen atom, an alkyl group, an alkoxy group, an aralkyloxy group, an aryl group, a cyclohexyl group, a 4-alkylcyclohexyl group, a carboxylic acid ester group, a carboxylic acid amide group, a halogen atom, ##STR2## X represents an oxygen atom, a sulfur atom or an amino group.

Abstract: An anthraquinone compound represented by formula: ##STR1## wherein R and X are as defined in the specification, and a polarizing film containing the same. The anthraquinone compound exhibits satisfactory compatibility with organic polymers and high dichroism, and the polarizing films have excellent performance characteristics.

Abstract: An optical recording member for performing recording and reproduction of information by causing changes in the state thereof with a laser beam, which optical recording member comprises a base plate and a recording layer provided on the base plate and containing therein a phthalocyanine type compound and/or naphthalocyanine type compound represented by the following general formula: ##STR1## (where: R.sup.1 to R.sup.4 represent substituted and/or unsubstituted alkyl group, alkoxyalkyl group, aryl group, and so forth; and A denotes Pb, Sn, Cu, Ni, VO, and so on).

Abstract: An optical recording medium is disclosed, comprising a support having provided thereon a recording layer containing a naphtholactam dye represented by formula: ##STR1## wherein K represents a substituted or unsubstituted aromatic amine residue; R represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted allyl group; Z.sup.- represents an anion; ring A represents a substituted or unsubstituted naphthalene ring; and m represents 1 or 2. The recording layer can be formed by coating easily, has a high reflectance to provide a satisfactory contrast of recording, and exhibits excellent resistance to light.

Abstract: An optical recording medium in which recording and/or reproducing is made by the state changes of material owing to laser beams, comprising an indophenol-group dye supported on a substrate.

Abstract: A liquid crystal composition comprising a host liquid crystal material and at least one guest novel anthraquine dye dissolved in said host liquid crystal material has a high order parameter, sufficient solubility in the host liquid crystal and high stability.

Abstract: An anthraquinone dye and a liquid crystal composition containing the dye are disclosed.The liquid crystal composition is preferably used in an electro-optic cell which enables a good color display utilizing the guest-host effect of the liquid crystal.

Abstract: An anthraquinone dye and a liquid crystal composition containing the same are disclosed. The anthraquinone dye shows a cyan color and has excellent order parameter, solubility and stability. The liquid crystal composition is particularly used in an electro-optic cell, which is interposed between two facing electrode plates and permits the realization of good color displays utilizing the guest-host effect of a liquid crystal.

Abstract: Pleochroic azo dyes represented by the formula (I): ##STR1## wherein X represents group --OCOR.sup.1 or --COOR.sup.1 (wherein R.sup.1 represents an alkyl group, an alkoxyalkyl group, an alkoxyphenyl group, an alkylcyclohexyl group, an alkoxyalkylcyclohexyl group, a cycloalkylcyclohexyl group, an alkoxycyclohexyl group, or a phenyl group substituted by a substituent selected from among an alkyl group containing 3 to 18 carbon atoms, an alkoxyalkyl group, a cycloalkyl group, an aryl group, a cyano group, a halogen atom, an acyloxy group, a carboxylic acid ester group, and an arylazo group); Y represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, a cycloalkyl group, an alkoxy group, a nitro group, a cyano group, a carboxylic acid ester group, an acyloxy group, an alkylsulfonyl group, an aryl group, a halogen atom, or group ##STR2## wherein R.sup.2 and R.sup.3 each represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, or R.sup.2 and R.sup.

Abstract: The present liquid crystal composition is characterized by containing a dye of anthraquinone series represented by the following general formula (1) dissolved as a guest in a host liquid crystal: ##STR1## wherein R represents an alkyl group or a cycloalkyl group. The alkyl group or the cycloalkyl group of the dye of anthraquinone series includes those substituted by alkyl, hydroxyl, alkoxy, cycloalkyl, aryl, aryloxy, dialkylamino, or heterocyclic residue. Furthermore, the liquid crystal composition can contain two or more other kinds of the dye of anthraquinone series, or can be used in combination with other dyes. In the dye of anthraquinone series, the group --COOR at the 2-position and the group --CN at the 3-position are particularly important for realization of cyan color and a high S value.The dye of anthraquinone series is particularly effective for preparation of a black dye.

Abstract: Phthalonitrile derivatives represented by the formula (I): ##STR1## (wherein X and Y each represents an alkyl group having 1 to 9 carbon atoms, an alkoxy group havng 1 to 9 carbon atoms, ##STR2## (wherein R.sup.1 represents a hydrogen atom, --C.sub.m H.sub.2m+1, --O--(CH.sub.2 CH.sub.2 O).sub.n --C.sub.m H.sub.2m+1, ##STR3## or a halogen atom, wherein m represents an integer of 1 to 9 and n represents 0, 1 or 2), but at least one of X and Y does not represent a methyl group, and Y does not not represent an alkyl group having 1 to 9 carbon atoms or an alkoxy group having 1 to 9 carbon atoms in the case that X represents R.sup.1 H and R.sup.1 represents an alkyl group having 1 to 9 carbon atoms).

Abstract: A liquid crystal composition comprising a host liquid crystal and at least one perylene dye dissolved therein represented by the formula: ##STR1## wherein X represents an oxygen atom or a sulfur atom, R.sup.1 and R.sup.2 each represents an aryl group when X represents an oxygen atom; or an aryl group or an alkyl group containing 1 to 18 carbon atoms when X represents a sulfur atom.

Abstract: A liquid crystal composition comprising a host liquid crystal And a pleochroic dye dissolved therein as a guest material is described, which is characterized in that the pleochroic dye contains an anthraquinone-based dye yielding a Magenta color and/or an orange color.

Abstract: A portable reflectance spectrometer is disclosed. The spectrometer essentially includes an optical unit and an electronic recording unit. The optical unit includes a pair of thermoelectrically-cooled detectors, for detecting total radiance and selected radiance projected through a circular variable filter wheel, and is capable of operating to provide spectral data in the range 0.4 .mu.m to 2.5 .mu.m without requiring conventional substitution of filter elements. The electronic recording unit essentially includes power supplies, amplifiers, and digital recording electronics designed to permit recordation of data on tape casettes. Both the optical unit and electronic recording unit are packaged to permit carriage as backpack items and thereby be manually portable.