Patent · US Expired

Polytetramethyleneadipamide film

US4699973A · kind A · utility

3Cited by
6References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 2, 1986
Grant dateOct 13, 1987
Priority date
Expiry dateMay 2, 2006

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08J2377/00
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A polyamide film prepared from a polyamide composition comprised of at least 60% by weight of polytetramethyleneadipamide or a copolymer polyamide containing at least 60% by weight of a polytetramethyleneadipamide component, said film being at least monoaxially stretched at a stretching ratio of at least 1.5, said film having a characteristic value .DELTA.T of from 30.degree. to 60.degree. C. as determined from the relationship: EQU .DELTA.T=Tm-Tc, wherein Tm (melting point) is the peak melting temperature (.degree.C.) when the temperature is increased at a rate of 20.degree. C./min by means of a differential scanning calorimeter (DSC) and Tc (crystallization temperature) is the peak crystallization temperature (.degree.C.) when the temperature, 20.degree. C. above the melting point, is decreased at a rate of 80.degree. C./min by means of a DSC, and said film having a retention rate of its breaking strength after a hydrothermal treatment at 135.degree. C. for 30 minutes of at least 60%.

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