Toray Industries, Inc.

Director-general of the Agency of Industrial Science and Technology

Masaru Okamoto

Toshihide Inoue

Toru Yamanaka

Yasunori Ichikawa

Toshimasa Hirai

Norio Kitajima

Shiro Kataoka

The present invention relates to polyesters capable to give moldings having excellent flow characteristics, heat resistance and mechanical properties. These polyesters are prepared by copolymerizing specified amounts of specific dioxycompounds such as t-butylhydroquinone, phenylhydroquinone and so on with polyesters comprising specified amounts of p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, hydroquinone and terephthalic acid or terephthalic acid and isophthalic acid.

Aromatic polyesters having good heat resistance

A flame-retardant thermotropic polyester composition comprising 100 parts by weight of thermotropic polyester (A) and 0.5 to 60 parts by weight of poly(bromostyrene)(B) having the following structural unit produced from bromostyrene monomer, as the principal structural component thereof, and having a number average molecular weight of 1.times.10.sup.3 to 30.times.10.sup.4 ; ##STR1## has excellent flame retardancy, mechanical properties and heat resistance, and the shaped articles molded from the composition has also superior appearance.

Flame-retardant thermotropic polyester composition and its shaped article

Disclosed is a flame-retardant liquid crystal polyester composition, which comprises (A) 100 wt. parts of a liquid crystal polyester comprising structural units of the following formulae (I), (II), (III) and (IV), in which the amount of units (I) and (II) is 77 to 95 mole% based on the sum of units (I), (II) and (III), the amount of units (III) is 23 to 5 mole% based on the sum of units (I), (II) and (III), and the units (I)/units (II) molar ratio is 75/25-95/5 and (B) 0.5 to 30 wt. parts of a polymeric flame retardant having an average dispersed particle diameter not larger than 2.5 .mu.m: ##STR1## wherein R.sub.1 and R.sub.2 are specific aromatic residues. This composition gives a molded article having a superior flame retardancy, heat resistance, mechanical properties, and appearance.

Flame-retardant liquid crystal polyester composition, process for

A multi-layer molded article having good interlayer adhesion and exhibiting igh modulus even when its thickness is large, which comprises at least one layer formed by an anisotropic melt-forming polyester having structural units selected from the following structural units (I) to (III), the molar ratio of (I)/[(I)+(II)+(III)] being in the range of 20 to 100 mol %: ##STR1## wherein X represents at least one group selected from ##STR2## Y represents at least one group selected from ##STR3## and Z represents at least one group selected from ##STR4##

Multi-layer molded article and process for producing same

An aromatic polyester comprising the following structural units [(I)+(II)], (I)+(II)+(III)], [(I)+(II)+(IV)], [(I)+(III)+(IV)], or [(I)+(II)+(III)+(IV)], the unit (I) occupying 20-85 mol % of all structural units, and a shaped article of a high elastic modulus obtained from the polyester: ##STR1## wherein R.sub.1 represents one or more groups selected from ##STR2## and R.sub.2 represents one or more groups selected from ##STR3##

Aromatic polyesters and their shaped articles

A high modulus polyester comprising the following structural units (I) anr (II) and (III), the structural units (I) and (II) occupying 51-99 mol % of the whole and the structural unit (III) occupying 49-1 mol % of the whole, and a high modulus shaped article obtained from the polyester: ##STR1## wherein R represents one or more divalent radicals selected from ##STR2## and X represents chlorine or bromine atom.

Growing community of inventors

Tokai, Japan

Masaru Okamoto