Patent · US Expired

Biaxially stretched polyester films

US4454312A · kind A · utility

20Cited by
5References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 10, 1982
Grant dateJun 12, 1984
Priority date
Expiry dateDec 10, 2002

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08J2367/02
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

Abstract

A biaxially stretched polyester film comprising a polyester and zirconium as an internal particle material, produced by polycondensation of terephthalic acid or its esterified derivative and alkylene glycol as the major essential monomeric components in the presence of a polycondensation catalyst, during which zirconium in the form of any compound thereof in an amount of 80 to 2500 ppm in terms of zirconium atom to the polyester as produced being introduced into the reaction system at a stage after the initiation of the reaction and before the intrinsic viscosity of the reaction mixture reaching 0.2, and subjecting the produced polyester to film forming.

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