Kureha Corporation

Hisaaki Terashima

Yusuke Sato

Keiko Aita

Kazuyuki Kanno

Nobufumi Sato

Hiroyuki Sato

Masahiro Yamazaki

Shunsuke Abe

Kotaku Saigusa

To provide a piezoelectric body film that can suppress decrease in the piezoelectric constant d, a method of producing a piezoelectric body film, and a piezoelectric body device. A piezoelectric body film comprising a fluororesin as a piezoelectric material, the fluororesin containing, as a main constituent unit, a repeating unit derived from vinylidene fluoride, a piezoelectric constant dof the piezoelectric body film being 20 pC/N or greater, and an extrapolated onset temperature at start of shrinkage determined by TMA measurement being not lower than 90° C. and not higher than 115° C. The difference between piezoelectric constants dmeasured before and after heating the piezoelectric body film at 100° C. for 24 hours relative to the piezoelectric constant dbefore the heating for 24 hours is 20% or less.

Piezoelectric body film, piezoelectric body film production method, and piezoelectric body device

To provide a piezoelectric body film that can suppress decrease in the piezoelectric constant d31, a method of producing a piezoelectric body film, and a piezoelectric body device. A piezoelectric body film comprising a fluororesin as a piezoelectric material, the fluororesin containing, as a main constituent unit, a repeating unit derived from vinylidene fluoride, a piezoelectric constant d31 of the piezoelectric body film being 20 pC/N or greater, and an extrapolated onset temperature at start of shrinkage determined by TMA measurement being not lower than 90° C. and not higher than 115° C. The difference between piezoelectric constants d31 measured before and after heating the piezoelectric body film at 100° C. for 24 hours relative to the piezoelectric constant d31 before the heating for 24 hours is 20% or less.

A vinylidene fluoride resin film is produced by using a film composition containing at least a vinylidene fluoride resin and organic particles. The vinylidene fluoride resin film includes a plurality of protrusions on at least one surface thereof. Among the plurality of protrusions, the number of protrusions greater than 0.10 &#x3bc;m in height from a flat surface at which the protrusions are not present is from 40 to 400, per 0.10 mmof the vinylidene fluoride resin film.

Vinylidene fluoride resin film

Provided is a vinylidene fluoride resin film that is produced using a film composition including at least a vinylidene fluoride resin and inorganic particles; and that includes a plurality of protrusions on at least one surface thereof. Among the plurality of protrusions, the number of protrusions greater than 0.10 &#x3bc;m in height from a flat surface at which the protrusions are not present is from 7.0 to 50 per 0.10 mmof the vinylidene fluoride resin film.

A method for producing an undrawn polyglycolic acid-based resin yarn, including: a discharge step of discharging a molten polyglycolic acid-based resin through a spinneret, to thereby form a fibrous polyglycolic acid-based resin; a keeping step of keeping the fibrous polyglycolic acid-based resin for 0.0012 seconds or more after the discharge in an atmosphere having a temperature of not lower than 110.5&#xb0; C. but not higher than a melting point of the polyglycolic acid-based resin; and a cooling step of cooling the fibrous polyglycolic acid-based resin obtained in the keeping step, to thereby obtain an undrawn polyglycolic acid-based resin yarn.

Growing community of inventors

Tokyo, Japan

Hisaaki Terashima