Published May 1975
Polybutylene terephthalate (sometimes called polytetramethylene terephthalate), an engineering thermoplastic, is a relatively new com- mercial product (marketing was begun in 1970). In this report, a preliminary process design is presented for the manufacture of four grades of polybutylene terephthalate (PBT): "plain"; self-extinguishing; glass- filled; and self-extinguishing, glass-filled." Estimated capital and production costs are given for each of the four grades.
PBT is made commercially by reacting dimethyl terephthalate with 1,4-butanediol. The manufacture of dimethyl terephthalate has been treated in Process Economics Program Report s 9, 9A, and 9B, Dimethyl Terephthalate and Terephthalic Acid. However, none of our previous re- ports has covered the manufacture of 1,4-butanediol. Accordingly, preliminary process designs as well as estimated capital and production costs are presented in this report for the manufacture of 1,4-butanediol by two routes. The first route uses acetylene and formaldehyde as the raw materials and the second route uses 1,4-dichloro-2-butene as the starting material.
Patents on PBT, 1,4-butanediol, and related subjects are reviewed in the report.
