Polyplastics Co., Ltd.

Keiichi Kanaka

Kenji Hijikata

Yukihiko Kageyama

Noriyuki Hayashi

Toshihiro Kobashi

Kaoru Yamamoto

Shinya Yamada

Toshio Shiwaku

Mineo Ohtake

Toshiro Murao

Tatsuya Saito

Katsutoshi Sakamoto

Mitsuharu Kusagaya

It is an object of the present invention to manufacture high quality thermotropic liquid-crystalline polymer generating no low boiling gas and inducing no discoloration resulted from thermal degradation at high yield. To manufacture a liquid-crystalline polymer having 50 mol % or larger ratio of constitutive unit introduced from 4-hydroxybenzoic acid, the reaction is conducted under the presence of an acylating agent and of a catalyst quantity of aromatic sulfonic acid.

Method for manufacturing thermotropic liquid-crystalline polymer

To provide a resin composition, in which a liquid crystal polymer is made into fiber in a molded article to exhibit an extremely high reinforcing effect which has not been available yet, and from which a molded article having an excellent mechanical strength can be manufactured in a stable manner. That is, a thermoplastic resin composition, wherein 100 parts by weight in total consisting of 99-50 parts by weight of a thermoplastic polyester resin (A) not forming an anisotropic molten phase and 1-50 parts by weight of a liquid crystal polymer (B) capable of forming an anisotropic molten phase is blended with 0.001-2.0 parts by weight of one or more kinds of compounds (C) selected from phosphorus oxoacid monoester and diester represented by the following formulae (I) and (II):(X)P(&#x2550;O) (OR)&#x2003;&#x2003;(I)(X)P(OR)&#x2003;&#x2003;(II)wherein n is 1 or 2; X is a hydrogen atom, a hydroxyl group or a monovalent organic group and, when there are plural X's, they may be the same or different; and R is a monovalent organic group and, when there are plural R's, they may be the same or different.

Thermoplastic resin composition and molded object thereof

A process for producing a liquid crystalline polymer with increased polymerization rate and reduced deposition of monomer-derived substances to the reaction vessel during production is provided. A liquid crystalline polymer having a constituent unit derived from 4-hydroxybenzoic acid in an amount 8 mol % or less is produced by conducting reaction at the presence of a catalytic amount of a catalyst comprising a potassium compound and a trivalent cobalt compound in combination.

Process for producing liquid crystalline polymer

A novel wholly aromatic polyester capable of forming an anisotropic melt phase is provided. Such polyester has been demonstrated to be capable of forming quality molded articles having a combination of excellent heat resistance and mechanical properties. The resulting polyester further is capable of readily being melt processed while using conventional equipment. Four essential recurring units are present in the polyester of the present invention wherein (I) is derived from 2,6-napthalenedicarboxylic acid and/or 4,4'-biphenyldicarboxylicacid; (II) is derived from another dicarboxylic acid (as defined) such as terephthalic acid; and (III) is derived from aromatic diols (as defined) such as 1,4-dihydroxybenzene and 4,4'-dihydroxybiphenyl; and (IV) is derived from another aromatic diol (as defined), such as 4,4'-dihydroxydiphenyl ether. In a preferred embodiment, an inorganic filler is dispersed therein. Molded articles exhibiting highly satisfactory tensile strengths, tensile elongations, and tensile moduli are made possible when melt processing the wholly aromatic polyester.

Aromatic polyester and polyester resin composition

Normally solid, melt-stable copolyester molding resins are formed of the polycondensation reaction product of(a) an aromatic dicarboxylic acid or an ester-forming derivative thereof, (b) an aliphatic dihydroxy compound which includes at least 35 mole % of of units derived from 1,4-cyclohexanedimethanol, and (c) a melt-stable effective amount between 0.1 to 35 mole %, based on the amount of the aromatic dicarboxylic acid, of an ester-forming diol compound of the following formula I:

Melt-stable copolyester molding resins, process for making same, and

Novel moldable, highly stable, normally solid polyoxymethylene resin compositions and molded articles formed of the same include a stabilizing effective amount of an alkoxy-substituted phenoxy-containing compound having the formula (I) or (II):

Stabilized polyoxymethylene molding compositions and molded articles

A polyester exhibiting melt anisotropy and improved thermal stability is provided which consists essentially of structural units represented by the formulas (i) to (iii), wherein: ##STR1## wherein Ar.sub.1 is 1,4-phenylene and/or 2,6-naphthalene, Ar.sub.2 is 2,6-naphthalene and/or 2,7-naphthalene, and X.sub.3 is an aliphatic hydrocarbon containing 2 to 8 carbon atoms.

Polyester which exhibits melt anisotropy

An improved easily processable wholly aromatic polyester exhibiting melt anisotropy and excellent thermal stability is provided which consists essentially of the structural units (i) to (iii) wherein: ##STR1## and wherein Ar.sub.1 is 1,4-phenylene, Ar.sub.2 is 2,6-naphthalene and 2,7-naphthalene, and Ar.sub.3 is 1,4-phenylene and/or 4,4'-biphenylene.

Easily processable, wholly aromatic polyester

Moldable polyester resins having high melt-phase stability and which form substantially no thermal decomposition products during melt-phase processing have a carboxyl end group concentration of no greater than 40 milliequivalent/kg, and are the reaction product of (a) an aromatic dicarboxylic acid or its ester-forming derivative, (b) an aliphatic dihydroxy compound having 2 to 8 carbon atoms, and (c) an ester-forming comonomer having the general formula (I):

Melt-stable polyester resins and molded articles thereof

An improved polyester exhibiting melt anisotropy and excellent thermal stability is provided which consists essentially of the structural units (I) to (III) wherein: ##STR1## wherein Ar.sub.1 is 1,4-phenylene, Ar.sub.2 is a mixed system of 2,6-naphthalene and 2,7-naphthalene, and Ar.sub.3 is an aromatic ring containing 6 or more carbon atoms, the unit (I) accounting for 15 to 90 mole percent and the unit (II) for 20 to 70 mole percent of the total amount of the structural units, and the percentage of 2,7-naphthalene to the total amount of Ar.sub.2 in the unit (II) being between 10 and 90 mole percent.

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Shizuoka, Japan

Keiichi Kanaka