Catalytic compositions for the preparation of poly(butylene terephthalate)
US5516879A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1995 |
| Grant date | May 14, 1996 |
| Priority date | — |
| Expiry date | Mar 28, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/82
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.