Process of preparing nonfibrous, piezoelectric polymer sheet of improved activity

US4692285A · kind A · utility

Assignee

• Pennwalt Corporation · US

Inventors

• Philip E. Bloomfield · Yeadon, US
• Seymour Preis · Allentown, US

Key dates

• Filing date: Jul 1, 1985
• Grant date: Sep 8, 1987
• Expiry date: Jul 1, 2005

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N30/857

Abstract

A nonfibrous, unoriented sheet of a copolymer resin of about 65 to 85 mol percent of vinylidene fluoride and from 15 to about 35 mol percent of at least one other copolymerizable substituted monoolefinic monomer, said sheet having improved and uniform piezoelectric properties for hydrophonic use, and the process for preparing said sheet with improved piezoelectric and dielectric breakdown strength properties wherein it is heated for at least about 20 minutes within the temperature range of above the crystalline melting temperature and below a defined temperature, cooled to below the Curie temperature and then electrically poled, are disclosed herein.