Catalytic compositions containing tetrabutyl titanate and a mixture of cocatalysts for the preparation of poly(butylene terephthalate)
US5519108A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1995 |
| Grant date | May 21, 1996 |
| Priority date | — |
| Expiry date | Jun 7, 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 0.0005 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. The alkali metal hypophosphite can be a hypophosphite salt containing any number of alkali metal groups. The alkali metal polyphosphate can be a polyphosphate salt containing one, two, three, four, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.