Reinforced thermoplastic molding compositions are provided comprising a high molecular weight linear polyester, such as poly(1,4-butylene terephthalate) and another high molecular weight polyester, such as poly(ethylene terephthalate), in combination with talc and one or more reinforcing agents or fillers.
Polyester molding composition containing polybutylene terephthalate, nucleated polyethylene terephthalate or mixtures thereof as well as thermally stable reinforcing fibers and polyphenylene sulfide having a melt flow rate of less than about 1,000.
Resin compositions comprising (A) a polyester, (B) a flame retardant, (C) an antimony compound, and (D) a filler selected from the group comprising magnesium silicate and mixtures of magnesium silicate with calcium metasilicate are disclosed. The disclosed compositions exhibit superior heat resistance, flame retardance, arc resistance and tracking resistance.
A polybutylene terephthalate is manufactured by the steps of polycondensating in the liquid phase terephthalic acid or a lower alcohol ester thereof as the acid component and 1,4-butanediol as the diol component to obtain a prepolymer of polybutylene terephthalate, solidifying the prepolymer and further polymerizing the prepolymer in the solid phase to obtain a polybutylene terephthalate of a higher polymerization degree, 0.001 to 5 percent by weight, based on the prepolymer, of a nucleator being added to the polymerization mixture at any time during a period of from the monomer-mixing stage before the starting of the solid phase polymerization, the solid phase polymerization being conducted in the presence of the nucleator uniformly dispersed in the polymerization mixture. The solid polymerization can be treated subsequently to the liquid polymerization and can proceed in a short time.
The invention relates to polymer mixtures which comprise a polyester, glass fibres, a brominated polystyrene and talcum. By using milled glass fibres a polymer mixture is obtained having a high tracking index, good flame-retarding properties and a great rigidity. The invention also relates to articles formed from such polymer mixtures and to a method of preparing the polymer mixtures according to the invention.
A novel molding composition is disclosed which comprises polybutylene terephthalate, polyethylene terephthalate, and 20-85% of zinc oxide by total weight of said molding composition.
