Title:
【発明の名称】弗化ビニリデンとトリフルオロエチレンとの圧電性コポリマー
Document Type and Number:
Japanese Patent JP3048579
Kind Code:
B2
Abstract:
Copolymer of vinylidene fluoride and of trifluoroethylene having at the same time piezoelectric properties and a maximum use temperature which are both high, in which the overall molar content of trifluoroethylene is lower than 30%, characterised in that it has a heterogeneous structure, its cumulative molar composition distribution curve being included between two straight lines:
Y = -3.18 X + 140
and Y = 3.12 X + 109
X being the molar percentage of trifluoroethylene in the macromolecular chains and Y being the weight percentage of all the macromolecular chains whose trifluoroethylene content is higher than or equal to X. This copolymer is obtained by copolymerisation in aqueous suspension by reaction, in a first step, of a mixture of vinylidene fluoride and of trifluoroethylene in molar proportions of vinylidene fluoride of between 67 and 54% to 33 to 46% of trifluoroethylene and, in a second step, by progressive addition of vinylidene fluoride to the reaction mixture in proportions such that the molar quantity of added vinylidene fluoride represents 145 to 180% of the number of moles of initial vinylidene fluoride.
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Inventors:
Patrick couple
Application Number:
JP30870288A
Publication Date:
June 05, 2000
Filing Date:
December 06, 1988
Export Citation:
Assignee:
Elf Atochem Society Anonymous
International Classes:
C08F2/00; C08F2/18; C08F14/22; C08F214/22; C08F259/08; H01L41/18; H01L41/193; (IPC1-7): C08F214/22; C08F2/00; C08F2/18; H01L41/193
Domestic Patent References:
| JP5262391A |
Attorney, Agent or Firm:
Takashi Koshiba