Patent · US Expired

Polyester resins having improved rheological properties

US6447711B1 · kind B1 · utility

10Cited by

9References

3Claims

0Family size

Assignee

Sinco Engineering, S.p.A. · IT

Inventors

Hussain Al Ghatta · Anagni, IT
Arianna Giovannini · Bologna, IT
Sandro Cobror · Pozzilli, IT

Key dates

Filing date	Jul 3, 1996
Grant date	Sep 10, 2002
Priority date	—
Expiry date	Jul 3, 2016

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB29C2049/023
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

Polyester resins particularly suitable for extrusion and injection blow-molding contain from 20 to 1000 ppm of a dianhydride of an aromatic tetracarboxylic acid and show values of die swell less than 45%.The resins are obtained by solid state polycondensation of resin having intrinsic viscosity less than 0.7 dl/g, added with a dianhydride of an aromatic tetracarboxylic acid in amount between 0.02 and less than 0.05% by weight.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.