Kabushiki Kaisha Ueno Seiyaku Oyo Kenkyujo

Kabushiki Kaisha Ueno Seiyaku Oyo Kenkyusho

Kabushiki Kaisha Ueno Seiyaku Oyo Kenkujo

Ueno Fine Chemicals Industry, Ltd.

Kabushiki Kaisha Ueno Seiyako Oyo Kenkyujo

Kabushiki Kaisha Veno Seiyaku Oyo Kenkyujo

Lef Technology, Inc.

Kabushiki Kaisha Ueno Seiyaku Oyo K.

Masaya Kitayama

Ryuzo Ueno

Kenji Minami

Hiroyuki Wakamori

Hiroyuki Kato

Kiichi Kometani

Masaharu Kittaka

Nobuhiro Yonetani

Nobutaka Izumichi

Shigeru Ito

Yoshiro Uchiyama

Motoki Asahara

Kazunori Ueda

Kuniyo Yanagawase

Shigeji Mori

Katsunori Tanikawa

Syungo Nara

Naoshi Saito

Kazuyuki Hirao

Ryoichi Otsuka

Taihei Hamasaki

Masamitsu Kubotsu

Naoko Mori

Hikari Hirai

Shingo Kanehira

Mariko Tanigawa

Kunikazu Asaka

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 10seconds 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.

Method of modifying liquid crystal polymers

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).

Naphthol derivative and charge control agent comprising the same

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.

Method for preparing 2,6-naphthalene dicarboxylic acid

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.

Crystalline parahydroxybenzoic acid anhydride and process for preparing the same

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&#xb0; 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.

Method for joining liquid-crystalline polyester resin composition parts and jointed article made of liquid-crystalline polyester resin composition

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.

Thermotropic liquid-crystalline polymer

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.

Charge controllers

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.

Alkylenebisnaphtol derivative and charge control agent which consists of the same

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&#x2013;200&#xb0; C. According to the present invention, 2-hydroxy-6-ureidocarbonyl naphthalene derivative can easily be obtained within relatively short time and high yield.

Method for preparing 2-hydroxy-6-ureidocarbonyl naphthalene derivative

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.

Liquid-crystal polyester resin

The present invention provides a method for preparing dimer of a monohydroxy aromatic compound. In the method of the present invention, oxidative coupling reaction of a monohydroxy aromatic compound represented by formula [I]:Ar&#x2014;OH&#x2003;&#x2003;[I]

Process for production of dimers or aromatic monohydroxyl compounds

The present invention provides a binaphthol compound represented by formula [1]:and a salt thereof. The binaphthol compound of the present invention is useful for manufacturing antiseptic compounds or chiral catalysts. According to the method of the present invention, binaphthol compounds can be prepared in high yield with low cost.

Binaphthol derivative and process for producing the same

A liquid crystal polyester resin comprising 1 to 500 mmol % of a recurring unit derived from 4-hydroxyisophthalic acid and/or salicylic acid as a comonomer and 10 to 5,000 ppm in terms of an alkali metal of an alkali metal compound. This resin has excellent colorability, improved heat resistance and high mechanical properties.

Liquid crystal polyester resin

Granular product of parahydroxybenzoic acid or its ester which exhibits well suppressed dusting and caking tendency and a process for preparing the product are provided. The granular product of parahydroxybenzoic acid or its ester according to the instant invention has an average particle size of equal to or more than 150 &mgr;m and a hardness of 10-3000 g. The granular product of the invention can be prepared by dry compressing powdery parahydroxybenzoic acid or its ester to give compressed material, pulverizing and classifying the material.

Granule of parahydroxybenzoic acid or parahydroxybenzoic ester and process for producing the same

A liquid crystal polyester resin composition which suppresses the formation of a blister caused by a heat treatment at a high temperature and has excellent moldability. This composition comprises (A) a liquid crystal polyester comprising at least two aromatic oxycarbonyl recurring units and (B) a liquid crystal polyester comprising at least two aromatic oxycarbonyl recurring units, at least one aromatic dioxy recurring unit and at least one aromatic dicarbonyl recurring unit. The weight ratio of the liquid crystal polyester (A) to the liquid crystal polyester (B) is 90/10 to 30/70.

Growing community of inventors

Takarazuka, Japan

Masaya Kitayama