Vinylidene cyanide copolymer
AssigneeMitsubishi Petrochemical Co., Ltd.
InventorsManabu Kishimoto, Iwao Seo, Yukiko Fujimoto
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Abstract
Disclosed is a vinylidene cyanide copolymer obtained by copolymerization of vinylidene cyanide and two kind of vinyl compounds. By formation of a ternary copolymer, a monomer difficultly copolymerizabke with vinylidene cyanide can be incorporated into the polymer, and high piezoelectric performance can be obtained when polarized.
Claims7
In a piezoelectric material or element which is obtained by effecting polarization of a copolymer by applying a high potential after stretching the copolymer to 1.5 to 6-fold, the improvement wherein said copolymer comprises the structural unit represented by (I) and either one of the structural units represented by (II) and (III) being alternately polymerized with (I) with a ratio of the structural unit (II) to that of (III) being within the range of from 0.2/1 to 5/1, and has a weight average molecular weight of 200,000 to 1,500,000;
- wherein the structural units (I), (II), and (III) have the formulae ##STR3## wherein R.sub.1 and R.sub.2 are different, and each represents a hydrogen atom, a straight chain alkyl group having 1 to 15 carbon atoms, di- or trichloromethyl, di- or trifluoromethyl, t-butyl, phenyl, 4-nitrophenyl, 4-cyanophenyl, 4-trifluoromethylphenyl or naphthyl.
Dependencies are inferred from the claim text.