Patent · US Expired

Method of producing polymeric electret element

US4591465A · kind A · utility

10Cited by
9References
17Claims
0Family size

Assignees

Inventors

Key dates

Filing dateSep 18, 1984
Grant dateMay 27, 1986
Priority date
Expiry dateSep 18, 2004

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08J2339/00
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

In producing an electret element having piezoelectric properties by subjecting a vinylidene cyanide copolymer to a polarization treatment, the copolymer is heat-treated at a temperature below the glass transition temperature thereof prior to or simultaneously with the polarization treatment to thereby increase the longitudinal piezoelectric effect (Kt).

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