Abstract: The present invention relates to a process for producing a resin useful in plastic lenses, to plastic lenses containing the resin and to a process for producing the lenses.

Abstract: The present invention relates to resin useful in preparing plastic lenses having a high refractive index comprising reacting an aliphatic polyisocyanate compounds having at least one sulfur atom with one or more of active hydrogen compounds selected from the group consisting of a polyol, a polythiol having sulfur atoms only in a mercapto groups, and a polythiol having at least one sulfur atom other than in the mercapto groups; lenses containing the above-mentioned resin; and a method for the preparation thereof characterized by adding an internal release agent to the mixture of the above-mentioned raw materials in casting lenses from the resin; and lenses obtained by this method.

Abstract: A process for producing a plastic lens having a high refractive index and profile regularity which includes forming a mixture of one or more of sulfur-containing aromatic polyisocyanate compounds, one or more of active hydrogen compounds selected from the group consisting of polyol compounds and polythiol compounds, and at least one internal mold releasing agent. Then subjecting the resulting mixture to casting polymerization, to form the plastic lens.

Abstract: Disclosed herein are a novel and highly refractive S-alkyl thiocarbamate base resin useful in preparing lenses and a process for producing the resin comprising reacting one or more of polyisocyanate compounds and one or more of mercapto compound having at least one hydroxyl group, a plastic lens made of the resin, and a process for making a plastic lens of high profile regularity from the resin by using internal mold releasing agents in the casting polymerization process.

Abstract: A novel compound, 4-(4-hydroxyphenyl)-3-cyclohexene-1-ol, and a novel preparation process of 4,4'-biphenol by using the novel compound as the raw material.4-(4-Hydroxyphenyl)-3-cyclohexene-1-ol can be obtained by conducting a thermal decomposition reaction of 4,4-bis(4-hydroxyphenyl)cyclohexanol. 4,4'-Biphenol can be industrially manufactured by conducting a dehydrogenation reaction of 4-(4-hydroxyphenyl)-3-cyclohexene-1-ol.

Abstract: Polyurethane base lens resins obtained by reacting one or more of sulfur-containing polyisocyanates compound with one or more of sulfur-containing polyols, and polyurethane base lenses comprising these resins are disclosed.A method for preparing polyurethane base lenses which comprises adding internal mold releasing agents to the mixture of the above polyisocyanates and polyols prior to casting polymerization is also disclosed.

Abstract: This invention relates to a novel preparation process of 4-(4-hydroxyphenyl)-cyclohexanol, which comprises subjecting 4-(4-hydroxphenyl)-3-cyclohexen-1-ol to reduction. 4-(4-Hydroxyphenyl)-cyclohexanol is a compound useful as a monomer for liquid crystalline polyesters and the like.

Abstract: A novel compound, 4-(4-hydroxyphenyl)-3-cyclohexene-1-ol, and a novel preparation process of 4,4'-biphenol by using the novel compound as the raw material.4-(4-Hydroxyphenyl)-3-cyclohexene-1-ol can be obtained by conducting a thermal decomposition reaction of 4,4-bis(4-hydroxyphenyl)cyclohexanol. 4,4'-Biphenol can be industrially manufactured by conducting a dehydrogenation reaction of 4-(4-hydroxyphenyl)-3-cyclohexene-1-ol.

Abstract: A novel compound, 4-(4-hydroxyphenyl)-3-cyclohexene-1-ol, and a novel preparation process of 4,4'-biphenol by using the novel compound as the raw material.4-(4-Hydroxyphenyl)-3-cyclohexene-1-ol can be obtained by conducting a thermal decomposition reaction of 4,4-bis(4-hydroxyphenyl)cyclohexanol. 4,4'-Biphenol can be industrially manufactured by conducting a dehydrogenation reaction of 4-(4-hydroxyphenyl)-3-cyclohexene-1-ol.

Abstract: 2,4-Xylenol can be obtained in high yield and high purity from a crude 2,4-xylenol isomer mixture containing 2,5-xylenol by selectively reacting the 2,5-xylenol with an aldehyde in the presence of an aromatic sulfonic acid, thereby converting the 2,5-xylenol into a xylenol-aldehyde condensate and, subsequently, separating the 2,4-xylenol, e.g., by distillation.

Abstract: Novel 4,4-bis(4-hydroxyphenyl)cyclohexanecarboxylic acid derivatives. These compounds can be prepared by reacting a cyclohexanone-4-carboxylic acid with a phenol.

Abstract: A process for preparing cyclohexanonecarboxylic acid compounds by catalytically hydrogenating the corresponding hydroxybenzoic acid compounds in a secondary alcohol or tertiary alcohol solvent.

Abstract: A process for the preparation of 4'-hydroxybiphenyl-4-carboxylic acid by reacting a cyclohexanone-4-carboxylic acid compound with phenol in the presence of an acid catalyst, and then subjecting the resulting 4,4-bis(4-hydroxyphenyl)cyclohexanecarboxylic acid compound to decomposition and dehydrogenation reactions in the presence of a base and a dehydrogenation catalyst. The aforesaid cyclohexanone-4-carboxylic acid compound is obtained by catalytically hydrogenating a 4-hydroxybenzoic acid compound in a secondary alcohol or tertiary alcohol solvent, and the reaction mixture thus obtained is directly used for the reaction with phenol.

Abstract: Novel 4,4-bis(4-hydroxyphenyl)cyclohexanecarboxylic acid derivatives. These compounds can be prepared by reacting a cyclohexanone-4-carboxylic acid with a phenol.

Abstract: A process for preparing 4,4'-biphenol comprising subjecting 4,4-bis(4-hydroxyphenyl)cyclohexanol to decomposition and dehydrogenation in the presence of a dehydrogenation catalyst.4,4-Bis(4-hydroxyphenyl)cyclohexanol is a novel compound which can be prepared by reacting 4-hydroxycyclohexanone with phenol.