Nippon Petrochemicals Company, Limited

Nippon Oil Corporation

Yoshikuni Yamada

Satoshi Murouchi

Toshitaka Kobayashi

Toshio Nakayama

An optical pickup lens holder which comprises a wholly aromatic liquid crystalline polyester resin composition comprising 97 to 45 mass percent of a wholly aromatic liquid crystalline polyester having a melting point of 320&#xb0; C. or higher, 3 to 50 mass percent of an inorganic spherical hollow material having an aspect ratio of 2 or less and 0 to 30 mass percent of an inorganic filler having as aspect ratio of 4 or more, wherein the percentages are made to 100 mass percent in total, and having a specific gravity in the range of 1.00 to 1.35. The lens holder exhibits excellent characteristics, while retaining good heat resistance in soldering and good processability inherent in a liquid crystalline polyester, exhibits high injection processability and high adaptability to a soldering process even in a sheet form lens holder having a thin part and an opening port.

Wholly aromatic liquid crystal polyester resin composition and optical pickup lens holder

A molded product of a wholly aromatic liquid crystal polyester resin composition having a dielectric constant of 3.0 or less and a dielectric dissipation factor of 0.04 or less and is obtained by an injection molding of a composition comprising 90 to 45 percent by weight of the wholly aromatic liquid crystal polyester having a melting point of 320C or more, 10 to 40 percent by weight of an inorganic spherical hollow material having an aspect ratio of 2 or less, and 0 to 15 percent by weight of an inorganic filler having an aspect ratio of 4 or more. The molded product has dielectric properties suitable for information and telecommunications equipment, and is excellent in solder heat resistance, processability, and dimensional stability. The molded product is advantageous as a substrate material for use in information and telecommunications equipment such as a cellular mobile phone and as a fixing/holding member of a transmitter-receiver element.

Wholly aromatic liquid crystal polyester resin molded product

A method of producing a thermotropic liquid crystalline copolyester having an extremely small amount of out-gases comprising the steps of: (1) charging in a reactor 5-100 mol % of aromatic hydroxycarboxylic acid, 0-47.5 mol % of aromatic dicarboxylic acid and 0-47.5 mol % of aromatic diol, so that the sum of mol % of each material is 100 mol % and the molt of aromatic dicarboxylic acid and that of aromatic diol are substantially equal; (2) adding acetic anhydride of an amount which satisfies the formula, (B-C)/A&gE;1.04, &ldquo;A&rdquo; representing the total molar number of the hydroxy group in a reaction system, &ldquo;B&rdquo; representing the molar number of acetic anhydride to be added, and &ldquo;C&rdquo; representing the molar number of water present in the reaction system prior to addition of acetic anhydride; (3) acetylation; (4) melt polymerization; and (5) solid-phase polymerization.

Method of producing thermotropic liquid crystalline copolyester, thermotropic liquid crystalline copolyester composition obtained by the same method, and molding made of the same composition

A method of producing a thermotropic liquid crystalline copolyester having an extremely small amount of out-gases comprising the steps of: (1) charging in a reactor 5-100 mol % of aromatic hydroxycarboxylic acid, 0-47.5 mol % of aromatic dicarboxylic acid and 0-47.5 mol % of aromatic diol, so that the sum of mol % of each material is 100 mol % and the mol % of aromatic dicarboxylic acid and that of aromatic diol are substantially equal; (2) adding acetic anhydride of an amount which satisfies the formula, (B&minus;C)/A&gE;1.04, &ldquo;A&rdquo; representing the total molar number of the hydroxy group in a reaction system, &ldquo;B&rdquo; representing the molar number of acetic anhydride to be added, and &ldquo;C&rdquo; representing the molar number of water present in the reaction system prior to addition of acetic anhydride; (3) acetylation; (4) melt polymerization; and (5) solid-phase polymerization.

A thermotropic liquid crystal polyester and a sealing material used for electric and electronic parts prepared from the thermotropic liquid crystal polyester, which polyester can be molded at low temperatures, while which polyester has heat resistance capable of well withstanding the process such as soldering. The thermotropic liquid crystal polyester is characterized in that it contains five kinds of specified repeating structural units in the respective ratios and it meets specific conditions of an intrinsic viscosity or the temperature of complete melting and storage elastic modulus.

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Kawasaki, Japan

Yoshikuni Yamada