Abstract: A method of modifying liquid crystal polymers, which involves a step of irradiating a liquid crystal polymer with the laser beam having a pulse width of 10?12 seconds or less. Using the invention method, the physical strength of the liquid crystal polymers can be improved as compared with the conventional liquid crystal polymers.

Abstract: A method of modifying liquid crystal polymers, which involves a step of irradiating a liquid crystal polymer with the laser beam having a pulse width of 10?12 seconds or less. Using the invention method, the physical strength of the liquid crystal polymers can be improved as compared with the conventional liquid crystal polymers.

Abstract: The present invention provides a novel naphthol derivative represented by the following general formula (I). The novel naphthol derivative of the present invention is useful as a positively electrifiable charge control agent. The present invention further provides an electrophotographic toner comprising a charge control agent comprising the novel naphthol derivative represented by formula (I).

Abstract: Disclosed is an improved method for preparing 2,6-naphthalene dicarboxylic acid from di-lower alkyl 2,6-naphthalene dicarboxylate, which is characterized in that hydrolyzing di-lower alkyl 2,6-naphthalene dicarboxylate in a specified amount of water in the presence of specified amount of hydrophobic organic solvent and an additive; that hydrolyzing di-lower alkyl 2,6-naphthalene dicarboxylate in a specific amount of a mixed solvent of non-water miscible alcohol and water; or in that di-lower alkyl 2,6-naphthalene dicarboxylate is hydrolyzed in two steps wherein the 1st step comprises hydrolyzing said ester in a water miscible organic solvent in the presence of a small amount of water, and the 2nd step comprises further hydrolyzing the reaction.

Abstract: The present invention provides a process for preparing crystalline parahydroxybenzoic acid anhydride, comprising the step of precipitating and isolating parahydroxybenzoic acid in an aqueous solvent at a temperature equal to or above the transition temperature of parahydroxybenzoic acid.

Abstract: The present invention provides a method for joining liquid-crystalline polyester resin composition parts, characterized in that the melting point of the liquid crystalline polyester resin measured by differential scanning calorimeter is 190-250° C. and that the parts are jointed by means of welding. By using the method of the present invention, jointed articles with sufficient joint strength are provided with accuracy.

Abstract: The present invention provides a process for preparing 3-nitro-4-alkoxybenzoic acid, which comprises the step of subjecting a mixture comprising 4-alkoxybenzoic acid and 40-80% nitric acid, wherein the amount of the 40-80% nitric acid is equal to or more than 8 times that of 4-alkoxybenzoic acid by weight, to a reaction at a temperature of 30-100° C.

Abstract: A thermotropic liquid crystalline polymer, which is obtainable by copolymerizing a trifunctional hydroxynaphthalene carboxylic acid represented by the general formula (I) and/or reactive derivative thereof with other polymerizing monomer(s) wherein one of m and n is 1 and the other is 2, and a composition including the polymer are provided. The molded article obtained from the thermotropic liquid crystalline polymer or the composition has less anisotropy in mechanical strength and improved weld strength.

Abstract: The present invention provides a safe charge control agent which exhibits an excellent negative chargeability and excellent dispersibility in and compatibility with binder resins, and is even applicable for col or toners. Specifically, the charge control agent consists of a naphthol derivative of formula [I]: and a salt thereof, and an electrophotographic toner comprising the agent are provided.

Abstract: The present invention provides a liquid-crystalline polyester resin, essentially consisting of the repeating units represented by formulae [I]-[IV]: wherein p, q, r and s satisfy the following formulae: 0.4?p/q?2.0, 2?r?15, 2?s?15, and p+q+r+s=100, provided that the liquid-crystalline polyester resin has a melting point of 190-250° C. determined by differential scanning calorimetry. The liquid-crystalline polyester resin of the present invention exhibits a good molding processability at low temperatures and excellent mechanical properties.

Abstract: The present invention provides a process for preparing crystalline parahydroxybenzoic acid anhydride, comprising the step of precipitating and isolating parahydroxybenzoic acid in an aqueous solvent at a temperature equal to or above the transition temperature of parahydroxybenzoic acid.

Abstract: The present invention provides an aminocarbonylnaphthol derivative represented by formula (1) and process for preparing the same: wherein each Y1 and Y2 is selected from the group consisting of aminocarbonyl group, carboxyl group and groups represented by formulae (2), (3) and (4), provided that at least one of Y1 and Y2 is aminocarbonyl group. The present invention also provides a novel cyanonaphthol derivative represented by formula (7) and a salt thereof as well as process for preparing them: wherein each Y7 and Y8 is independently selected from the group consisting of cyano group, groups represented by formulae (2), (3) and (4), carboxyl group and aminocarbonyl group, provided that at least one of Y7 and Y8 is cyano group.

Abstract: The present invention provides A method for producing a hydroxybenzoic acid compound comprising, preparing an alkali metal salt of a phenol compound from the phenol compound, and reacting the alkali metal salt of the phenol compound with carbon dioxide, wherein the step of preparing the alkali metal salt of the phenol compound from the phenol compound comprises the steps of: a) reacting an alkali metal alkoxide with an excess amount of the phenol compound, which is in excess of the alkali metal alkoxide, to give the alkali metal salt of the phenol compound, and b) distilling away the generated alcohol from the reaction simultaneously with carrying out step a). The method of the present invention makes it possible to produce hydroxybenzoic acid compound in high yield without using aprotic polar organic solvent.

Abstract: The present invention provides an alkylenebisnaphthol derivative represented by formula [I]: and a salt thereof. The compound of the present invention has an excellent triboelectric charge property and useful as charge control agent for electrophotographic toners.

Abstract: Disclosed is a method for preparing a 2-hydroxy-6-ureidocarbonyl naphthalene derivative. The method comprises the step of reacting 2-hydroxy-6-aminocarbonyl naphthalene and a isocyanate in an organic solvent at a temperature of 90–200° C. According to the present invention, 2-hydroxy-6-ureidocarbonyl naphthalene derivative can easily be obtained within relatively short time and high yield.

Abstract: The present invention provides a method for producing a hydroxybenzoic acid compound comprising, dehydrating a phenol compound and an alkaline metal compound to form the alkaline metal salt of the phenol compound and reacting the alkaline metal salt and carbon dioxide, wherein the dehydrating step is conducted by reacting the alkaline metal compound with an excess amount of the phenol compound at a temperature of 160° C. or above. According to the method of the present invention, the hydroxybenzoic acid compound can be obtained by simple steps with low cost without using an expensive aprotic polar organic solvent. The provided method can produce highly pure hydroxybenzoic acid compound comprising little by-products in high yield.

Abstract: The present invention provides a liquid-crystalline polyester resin which comprises monomer units derived from 2-hydroxy-3-naphthoic acid and/or 2-hydroxynaphthalene-3,6-dicarboxylic acid in an amount of 1-5000 mmol % based on the total monomer components of the resin and an alkaline metal compound in an amount of 10-3000 ppm as alkaline metal based on the total monomer components of the resin. The liquid-crystalline polyester resin of the present invention has good colorability, improved heat resistance and good mechanical properties.

Abstract: The present invention provides a method for joining liquid-crystalline polyester resin composition parts, characterized in that the melting point of the liquid crystalline polyester resin measured by differential scanning calorimeter is 190-250° C. and that the parts are jointed by means of welding. By using the method of the present invention, jointed articles with sufficient joint strength are provided with accuracy.

Abstract: Disclosed is an improved method for preparing 2,6-naphthalene dicarboxylic acid from di-lower alkyl 2,6-naphthalene dicarboxylate, which is characterized in that hydrolyzing di-lower alkyl 2,6-naphthalene dicarboxylate in a specified amount of water in the presence of specified amount of hydrophobic organic solvent and an additive; that hydrolyzing di-lower alkyl 2,6-naphthalene dicarboxylate in a specific amount of a mixed solvent of non-water miscible alcohol and water; or in that di-lower alkyl 2,6-naphthalene dicarboxylate is hydrolyzed in two steps wherein the 1st step comprises hydrolyzing said ester in a water miscible organic solvent in the presence of a small amount of water, and the 2nd step comprises further hydrolyzing the reaction.

Abstract: Disclosed is a method for preparing a 2-hydroxy-6-ureidocarbonyl naphthalene derivative. The method comprises the step of reacting 2-hydroxy-6-aminocarbonyl naphthalene and a isocyanate in an organic solvent at a temperature of 90-200° C. According to the present invention, 2-hydroxy-6-ureidocarbonyl naphthalene derivative can easily be obtained within relatively short time and high yield.