The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 28, 2013
Filed:
Dec. 17, 2009
Takayuki Araki, Settsu, JP;
Tetsuhiro Kodani, Settsu, JP;
Takayuki Araki, Settsu, JP;
Tetsuhiro Kodani, Settsu, JP;
Daikin Industries, Ltd., Osaka, JP;
Abstract
There is provided a method of forming a thin film of vinylidene fluoride homopolymer having crystal form I which is applicable to various substrates in relatively easy way (coating conditions, application method, etc.), a process for preparing a vinylidene fluoride homopolymer having crystal form I efficiently at high purity, and novel vinylidene fluoride homopolymers which can give a thin film being excellent in ferroelectricity. The method of forming a thin film of vinylidene fluoride homopolymer comprises (i) a step for preparing a green powder product of vinylidene fluoride homopolymer comprising crystal form I alone or as main component by subjecting vinylidene fluoride to radical polymerization in the presence of a bromine compound or iodine compound having 1 to 20 carbon atoms which contains at least one moiety represented by —CRfRfX, wherein X. is iodine atom or bromine atom; Rf. and Rf. are the same or different and each is selected from fluorine atom or perfluoroalkyl groups having 1 to 5 carbon atoms and (ii) a step for forming a thin film on a substrate surface by using vinylidene fluoride homopolymer which comprises crystal form I alone or as main component and is obtained from the green powder product of vinylidene fluoride homopolymer comprising crystal form I alone or as main component.