Method for the continuous production of polybutylene terephthalate from terephthal acid and butane diole

Patent 6657040 Issued on December 2, 2003. Estimated Expiration Date:

December 19, 2021. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Process for the manufacture of linear high molecular weight polyesters
Patent #: 4214072
Issued on: 07/22/1980
Inventor: Sterzel , et al.

Process and apparatus for the manufacture of linear high molecular weight polyesters
Patent #: 4235844
Issued on: 11/25/1980
Inventor: Sterzel , et al.

Process for the continuous production of polybutylene terephthalate of high molecular weight
Patent #: 4499261
Issued on: 02/12/1985
Inventor: Heinze , et al.

Process for the continuous production of high-molecular polybutyleneterephthalate
Patent #: 4680376
Issued on: 07/14/1987
Inventor: Heinze , et al.

Process for preparing residues containing dihydroxy compounds
Patent #: 5789500
Issued on: 08/04/1998
Inventor: Braune

Continuous preparation of thermoplastic polyesters
Patent #: 5854377
Issued on: 12/29/1998
Inventor: Braune

Method of reprocessing residues containing dihydroxy compounds
Patent #: 6174970
Issued on: 01/16/2001
Inventor: Braune

Polyalkylene arylates containing a high proportion of carboxyl end groups
Patent #: 6232435
Issued on: 05/15/2001
Inventor: Heitz, et al.

Use of high-molecular polyester moulding materials Patent #: 6262185
Issued on: 07/17/2001
Inventor: Heitz, et al.

Inventors

Assignee

BASF Aktiengesellschaft

Application

No. 10/018337 filed on 12/19/2001

US Classes:

528/279, Material contains a Group IVB metal atom (Ti, Zr, Hf)526/65, POLYMERIZING IN TWO OR MORE PHYSICALLY DISTINCT ZONES526/71, REMOVING ONLY NONPOLYMERIZED OR NONPOLYMERIZABLE MATERIAL DURING POLYMERIZATION PROCESS528/308.6, Contains terephthalic acid or substituted forms thereof528/481, Treating at O Deg C (32 Deg F) or below, or at 200 Deg C (392 Deg F) or above528/503Temperature maintaining, heating or cooling

Examiners

Primary: Acquah, Samuel A.

Attorney, Agent or Firm

Keil & Weinkauf

International Classes

C08G 63/00 (20060101)
C08G 63/78 (20060101)
C08G 63/85 (20060101)

Foreign Application Priority Data

1999-06-29 DE

Abstract

The invention relates to a method for the continuous production of polybutylene terephthalate from terephthal acid and 1,4-butane diole, comprising the following stages: a) direct esterification of terephthal acid with 1,4-butane diole in a reactor cascade of at least two reactors b) pre-condensation of the esterification product obtained in stage a), c) polycondensation of the pre-condensate obtained in stage b), whereby the temperature of the reactor cascade in stage a) is progressively decreased during its operation.