Process for producing film and fiber-forming polyalkylene terephthalate

Claim 1

A method for producing high molecular weight, substantially colorless film and fiber-forming polyalkylene terephthalate whereby an alkylene glycol containing from 2 to 10 carbon atoms is reacted under ester interchange conditions with a lower dialkyl terephthalate wherein the alkyl portions of the dialkyl terephthalate each contain from 1 to 4 carbon atoms, and the resultant bis-hydroxyalkyl terephthalate is polycondensed at a temperature from 200 to 300° C. under reduced pressure and with the evolution of free glycol, said method being characterized in that the only catalyst present during the transesterification and polycondensation is from about 0.01 to about 0.3%, based on the weight of the lower dialkyl terephthalate, of a bimetallic compound obtained by reacting 1) a first compound selected from the group consisting of antimony (III) salts of monocarboxylic and dicarboxylic acids, zirconium (IV) salts of monocarboxylic and dicarboxylic acids, antimony (III) and zirconium (IV) alkoxides wherein each alkyl residue of said glycoxides contains from 1 to 12 carbon atoms, and antimony trioxide, 2) a second compound selected from the group consisting of zinc, calcium and manganese salts of monocarboxylic acids and zinc, calcium and manganese salts of dicarboxylic acids, the molar ratio of said first to said second compound being from 1:1 to 1:6, respectively, and 3) at least a stoichiometric amount of a third compound selected from the group consisting of anhydrides of monocarboxylic and dicarboxylic acids, alcohols containing from 1 to 20 carbon atoms and glycols containing from 2 to 20 carbon atoms, wherein the hydrocarbon residue of each of said monocarboxylic acids and dicarboxylic acids contains from 1 to 20 carbon atoms and is present as an aliphatic or aromatic group.

Claim 2

A method for producing high molecular weight, substantially colorless film and fiber-forming polyalkylene terephthalate whereby an alkylene glycol containing from 2 to 10 carbon atoms is reacted under ester interchange conditions with a lower dialkyl terephthalate wherein the alkyl portions of the dialkyl terephthalate each contain from 1 to 4 carbon atoms, and the resultant bis-hydroxyalkyl terephthalate is polycondensed at a temperature from 200 to 300° C. under reduced pressure and with the evolution of free glycol, said method being characterized in that the only catalyst present during the transesterification and polycondensation is from about 0.01 to about 0.3%, based on the weight of the lower dialkyl terephthalate, of a bimetallic compound obtained by reacting 1) a first compound selected from the group consisting of antimony (III) salts of monocarboxylic and dicarboxylic acids, zirconium (IV) salts of monocarboxylic and dicarboxylic acids, antimony (III) and zirconium (IV) alkoxides wherein each alkyl residue of said glycoxides contains from 1 to 12 carbon atoms, and antimony trioxide, 2) a second compound selected from the group consisting of zinc, calcium and manganese salts of monocarboxylic acids and zinc, calcium and manganese salts of dicarboxylic acids, the molar ratio of said first to said second compound being from 1:1 to 1:6, respectively, and 3) at least a stoichiometric amount of a third compound selected from the group consisting of anhydrides of monocarboxylic and dicarboxylic acids, alcohols containing from 1 to 20 carbon atoms and glycols containing from 2 to 20 carbon atoms, wherein the hydrocarbon residue of each of said monocarboxylic acids and dicarboxylic acids contains from 1 to 20 carbon atoms and is present as an aliphatic or aromatic group.

Claim 13

A method for producing high molecular weight, substantially colorless film and fiber-forming polyalkylene terephthalate whereby an alkylene glycol containing from 2 to 10 carbon atoms is reacted with terephthalic acid and the resultant bis-hydroxyalkyl terephthalate is polymerized at a temperature from 200° to 300° C. under reduced pressure and with the evolution of free glycol, said method being characterized in that the only catalyst present during the preparation of the polyalkylene terephthalate is from about 0.1 to about 0.3%, based on the weight of bis-hydroxyalkyl terephthalate, of a bimetallic compound obtained by reacting (1) a first compound selected from the group consisting of antimony (III) and zirconium (IV) salts of monocarboxylic and dicarboxylic acids, antimony (III) and zirconium (IV) alkoxides wherein each alkyl residue contains from 1 to 12 carbon atoms, and antimony trioxide, (2) a second compound selected from the group consisting of zinc, calcium and manganese salts of monocarboxylic and dicarboxylic acids, the molar ratio of said first to said second compound being from 1:1 to 1:6, respective respectively, and (3) at least a stoichiometric amount of a third compound selected from the group consisting of anhydrides of monocarboxylic and dicarboxylic acids, alcohols containing from 1 to 20 carbon atoms and glycols containing from 2 to 20 carbon atoms, wherein the hydrocarbon residue of each of said monocarboxylic acids and dicarboxylic acids contains from 2 to 20 carbon atoms and is present as an aliphatic or aromatic group.

Claim 14

A method for producing high molecular weight, substantially colorless film and fiber-forming polyalkylene terephthalate whereby an alkylene glycol containing from 2 to 10 carbon atoms is reacted with terephthalic acid and the resultant bis-hydroxyalkyl terephthalate is polymerized at a temperature from 200° to 300° C. under reduced pressure and with the evolution of free glycol, said method being characterized in that the only catalyst present during the preparation of the polyalkylene terephthalate is from about 0.1 to about 0.3%, based on the weight of bis-hydroxyalkyl terephthalate, of a bimetallic compound obtained by reacting (1) a first compound selected from the group consisting of antimony (III) and zirconium (IV) salts of monocarboxylic and dicarboxylic acids, antimony (III) and zirconium (IV) alkoxides wherein each alkyl residue contains from 1 to 12 carbon atoms, and antimony trioxide, (2) a second compound selected from the group consisting of zinc, calcium and manganese salts of monocarboxylic and dicarboxylic acids, the molar ratio of said first to said second compound being from 1:1 to 1:6, respective respectively, and (3) at least a stoichiometric amount of a third compound selected from the group consisting of anhydrides of monocarboxylic and dicarboxylic acids, alcohols containing from 1 to 20 carbon atoms and glycols containing from 2 to 20 carbon atoms, wherein the hydrocarbon residue of each of said monocarboxylic acids and dicarboxylic acids contains from 2 to 20 carbon atoms and is present as an aliphatic or aromatic group.