Abstract: A copolyamide composition prepared from hexamethylene diamine and either mixtures of adipic acid and terephthalic acid, or mixtures of adipic acid, terephthalic acid and isophthalic acid, has a melting point below 320.degree. C., a glass transition temperature between 100.degree. C. and 120.degree. C. and physical properties similar to nylon 66.

Abstract: A copolyamide composition prepared from hexamethylene diamine and mixtures of adipic acid, terephthalic acid and isophthalic acid, has a melting point below 300.degree. C., a glass transition temperature between 100.degree. C. and 130.degree. C. and physical properties similar to nylon 66.

Abstract: A catalyst composition for use in a polycondensation reaction for making poly(ethylene terephthalate) from terephthalic acid comprising: (a) an antimony salt catalyst present in a range from about 10 to about 1,000 ppm; (b) a metal salt catalyst of at least one of cobalt, magnesium, zinc, manganese, calcium, and lead, present in a range from about 10 to about 500 ppm; and (c) an alkali metal acetate, present in a range from about 10 to about 500 ppm; all amounts are based on the metallic elements relative to the theoretical yield of the poly(ethylene terephthalate), by weight, to be made from the terephthalic acid. The catalyst composition was found to have increased the reaction rate in the production of poly(ethylene terephthalate), as well as improved the color of the produced product, by reducing the degree of yellowness in the final poly(ethylene terephthalate) product. Attenuation of the yellowish color indicates a reduction in the amount of undesired side reaction product.

Abstract: A catalyst composition for use in a polycondensation reaction for making poly(ethylene terephthalate) from terephthalic acid comprising: (a) an antimony salt catalyst present in a range from about 10 to about 1,000 ppm; (b) a metal salt catalyst of at least one of cobalt, magnesium, zinc, manganese, calcium, and lead, present in a range from about 10 to about 500 ppm; and (c) a phosphorus salt co-catalyst selected from the group consisting of alkali metal phosphates, alkali metal phosphites, alkali metal hypophosphites and alkali metal polyphosphates, present in a range from about 10 to about 500 ppm; all amounts are based on the metallic or phosphorus element relative to the theoretical yield of the poly(ethylene terephthalate), by weight, to be made from the terephthalic acid.

Abstract: A catalyst composition for use in the preparation of poly(butylene terephthalate) from dimethyl terephthalate, comprising: (a) a titanium compound primary catalyst, from about 0.0005 PHR to about 5 PHR; (b) a first co-catalyst containing at least one of Zn, Co, Mn, Mg, Ca, or Pb series compounds, between about 0.0001 PHR and 5 PHR; and (c) a second co-catalyst containing an alkali metal phosphate, an alkali metal phosphite, an alkali hypophosphite, or an alkali metal polyphosphate between about 0.0001 PHR and 5 PHR; wherein PHR represents parts of the primary catalyst or the co-catalyst per one hundred parts, by weight, of dimethyl terephthalate. Preferred titanium compounds include tetrabutyl titanate or tetra(isopropyl)titanate. Preferred metal compounds for use as first co-catalyst are metal acetates. The alkali metal phosphate can be a phosphate salt containing one, two, or three metal groups; and the alkali metal phosphite can be a phosphite salt containing one or two metal groups.

Abstract: A catalyst composition for use in the preparation of poly(butylene terephthalate) from dimethyl terephthalate, comprising: (a) a titanium compound primary catalyst, from about 0.01 PHR to about 1 PHR; and (b) an alkali metal phosphate or alkali metal phosphite co-catalyst, from about 0.001 PHR to about 1 PHR; wherein PHR represents parts of the primary catalyst or the co-catalyst per one hundred parts, by weight, of dimethyl terephthalate. Preferred titanium compounds include tetrabutyl titanate or tetra(isopropyl) titanate; the alkali metal phosphate can be a phosphate salt containing one, two, or three metal groups; and the alkali metal phosphite can be a phosphite salt containing one or two metal groups. With this catalyst composition, the transesterification rate was increased by 10 percent or more. Furthermore, the reaction product poly(butylene terephthalate) shows an increased intrinsic viscosity over those without the co-catalyst, indicating a greater degree of polymerization.

Abstract: A catalyst composition for the polymerization of polyamide/copolyamide comprising a primary catalyst which comprises an alkali metal hypophosphite or an alkali-earth metal hypophosphite, and an organic phosphite cocatalyst. The catalyst composition of this invention is most useful when used in conjunction with the reactive extrusion technology which requires a very fast polymerization rate to take full advantage of this evolving technology.

Abstract: A polyamide/copolyamide catalyst composition comprising a primary catalyst which comprises an alkali metal hypophosphite or an alkali-earth metal hypophosphite, and a cocatalyst which comprises an organic salt or an inorganic salt. The catalyst composition of this invention is most useful when used in conjunction with the reactive extrusion technology which requires a very fast polymerization rate to take full advantage of this evolving technology.

Abstract: A method for the polymerization of Nylon 6 from caprolactam and water using a catalyst composition comprising a primary catalyst, which can be an alkali metal hypophosphite or an alkali-earth metal hypophosphite, and an organic phosphite as cocatalyst. The catalyst composition used in this invention is most useful when used in conjunction with the reactive extrusion technology which requires a very fast polymerization rate to take full advantage of this evolving technology.

Abstract: A catalyst composition for the polymerization of Nylon 6 from caprolactam comprising a primary catalyst which comprises an alkali metal hypophosphite or an alkaliearth metal hypophosphite, and an organic phosphite cocatalyst. The catalyst composition of this invention is most useful when used in conjunction with the reactive extrusion technology which requires a very fast polymerization rate to take full advantage of this evolving technology.

Abstract: A catalyst composition for the polymerization of polyamide/copolyamide comprising a primary catalyst which comprises an alkali metal hypophosphite or an alkali-earth metal hypophosphite, and a cocatalyst which comprises an amine compound. The cocatalyst amine compound is selected from the group consisting of phenylene diamines, hindered amines, poly(hindered amines), and benzotriazoles. The catalyst composition of this invention is most useful when used in conjunction with the reactive extrusion technology which requires a very fast polymerization rate to take full advantage of this evolving technology.

Abstract: A method for the polymerization of Nylon 6 from caprolactam and water using a catalyst composition comprising a primary catalyst, which can be an alkali metal hypophosphite or an alkali-earth metal hypophosphite, and an amine cocatalyst. The amine cocatalyst can be selected from the group consisting of phenylene diamines, hindered amines, poly(hindered amines), Group I benzotriazoles, and Group II benzotriazoles. The catalyst composition used in this invention is most useful when used in conjunction with the reactive extrusion technology which requires a very fast polymerization rate to take full advantage of this evolving technology.

Abstract: A catalyst composition for the polymerization of Nylon 6 from caprolactam comprising a primary catalyst which comprises an alkali metal hypophosphite or an alkaliearth metal hypophosphite, and an amine cocatalyst. The amine cocatalyst can be selected from the group consisting of phenylene diamines, hindered amines, poly(hindered amines), Group I benzotriazoles, and Group I benzotriazoles. The catalyst composition of this invention is most useful when used in conjunction with the reactive extrusion technology which requires a very fast polymerization rate to take full advantage of this evolving technology.

Abstract: Poly(butylene terephthalate) is prepared in a two-stage process wherein terephthalic acid and 1,4-butanediol are esterified in the presence of a catalytic amount of a catalyst having an organo-metallic component which is an organo-titanate compound, an organo-tin compound or a combination thereof and a salt component which is an organic acid salt or an inorganic salt. In a second step, the esterification product is subject to polycondensation. By following the foregoing procedure, the formation of tetrahydrofuran is significantly suppressed and the percent conversion of esterification products increased.