Abstract: A thermotropic liquid crystal polyester consisting essentially of ethylene glycol residue, terephthalic acid residue and parahydroxybenzoic acid residue wherein the mol ratio of ethylene glycol residue to terephthalic acid residue is substantially about 1:1 and the mol ratio of terephthalic acid residue to parahydroxybenzoic acid residue is in the range of about 5:95 to about 25:75, the polyester having an intrinsic viscosity of at least about 0.5 dl/g measured in a 50:50 by weight solvent mixture of phenol and 1,1,2,2-tetrachlorethane at 20.degree. C., and a transmittance of at least about 80% to 530 nm light at a light path length of said solvent mixture. A method for forming the thermotropic liquid crystal polyester is also disclosed.

Abstract: A thermotropic liquid crystal polyester consisting essentially of ethylene glycol residue, terephthalic acid residue and parahydroxybenzoic acid residue wherein the mol ratio of ethylene glycol residue to terephthalic acid residue is substantially about 1:1 and the mol ratio of terephthalic acid residue to parahydroxybenzoic acid residue is in the range of about 5:95 to about 25:75, the polyester having an intrinsic viscosity of at least about 0.5 dl/g measured in a 50:50 by weight solvent mixture of phenol and 1,1,2,2-tetrachlorethane at 20.degree. C., and a transmittance of at least about 80% to 530 nm light at a light path length of 10 mm measured using a 0.4 wt. % solution of the polyester in said solvent mixture. A method for forming the thermotropic liquid crystal polyester is also disclosed. The liquid crystal polyester of the present invention is useful for injection molding applications and various extrusion molding purposes, such as the manufacture of films, sheets, fibers, pipes, etc.

Abstract: A heat-curable resin composition obtained by mixing (A) a polyester resulting from the depolymerization of a polyester of a high degree of polymerization comprising an aromatic dicarboxylic acid and an aliphatic dialcohol using a compound containing about 2 to about 12 carboxyl groups per molecule with (B) a polyoxirane compound containing about 2 to about 100 oxirane groups per molecule. A heat-curable resin composition obtained by adding to the above resin composition a salt formed between an aliphatic monocarboxylic acid containing 2 to 20 carbon atoms and an element of Group II of the Periodic Table as a curing accelerator is an especially superior material for powder paints. Powder paints prepared from these heat-curable resin compositions provide coatings having superior appearance and properties upon baking after coating by a method such as an electrostatic spray coating method or a fluidized dip coating method.

Abstract: A polyester resin composition obtained by mixing a molten polyester having an average degree of polymerization ranging from about 5 to 50 mainly comprising a terephthalic acid unit, a p-hydroxybenzoic acid unit and an ethylene glycol unit, and one hardener selected from the group consisting of a diglycidyl compound, hexaalkoxymethylmelamine or the condensate thereof, and a blocked isocyanate, with the composition being suitable for the preparation of a powder paint. The thus produced polyester resin composition can be finely pulverized with ease, shows no blocking property, facilitates pigmentation and provides beautiful coatings excellent in weather resistance, solvent resistance, humidity resistance, antifouling property, and with intimate adhesiveness to metal.