Catalytic production of polyesters

Claim 1

In a process for the manufacture of solid fiber-forming polyesters and copolyesters of dicarboxylic acid compounds and aliphatic glycols in the presence of catalysts, the improvement of using as polycondensation catalyst a silicon compound selected from the group consisting of: ##STR5## (IV) QCH 2 CH 2 SiR 3 ** wherein W is CH 2 ═CX-- or ##STR6## X is hydrogen or methyl and is methyl only when m is one; R* is alkyl or haloalkyl having from 1 to 4 carbon atoms; R** is methyl, ethyl, butyl, acetoxy methoxy, ethoxy or butoxy; R is methyl, ethyl, butyl or trimethylsiloxy; R' is methyl, methoxy, ethoxy, butoxy or trimethylsiloxy; R" is methoxy, ethoxy, butoxy, trimethylsiloxy or vinyldimethylsiloxy; R'" is methyl, ethyl, butyl or trimethylsilyl; Me is methyl; Z is methyl or W; Q is an NH 2 CH 2 --, NH 2 CH 2 CH 2 NHCH 2 --, NC--, HS-- or HSCH 2 CH 2 S-- group; n is an integer having a value of from 2 to 5; m is an integer having a value of zero or one; x is an integer having a value of from 1 to 100; and y is an integer having a value of from 1 to 100.