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公开(公告)号:US20200283625A1
公开(公告)日:2020-09-10
申请号:US16496823
申请日:2018-03-26
Applicant: I.S.T CORPORATION
Inventor: Yuki SHIRAI , Koji MORIUCHI
Abstract: The present invention provides a colorless and transparent polyimide film which exhibits excellent heat resistance, transparency and strength equivalent to those of the conventional colorless and transparent polyimide film, can be produced at a lower cost than the conventional polyimide film, and is more resistant to methyl ethyl ketone than the conventional polyimide film. The colorless and transparent polyimide film of the present invention is made from a specific polyimide resin. The specific polyimide resins comprise a site derived from BPDA, at least one site selected from the group comprising a site derived from BPADA and a site derived from ODPA, a site derived from TFMB, and at least one site selected from the group comprising a site derived from 3,3′-DDS and a site derived from 4,4′-DDS. The haze value of the polyimide film is in the range of 0.1 or more and 2.0 or less.
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公开(公告)号:US20170283990A1
公开(公告)日:2017-10-05
申请号:US15425249
申请日:2017-02-06
Applicant: I.S.T Corporation
Inventor: Ryuta NAKAGAKI , Katsuki MORISHIMA , Koji MORIUCHI
Abstract: The method for producing a polyimide fiber includes a coagulation step of forming a polyimide precursor fiber by extruding a polyimide precursor solution containing a polyimide precursor and a compound having an acid dissociation constant (pKa) of a conjugate acid in water at 25° C. of 6.0 to 10 inclusive and an octanol-water partition coefficient (Log P) at 25° C. of −0.75 to 0.75 inclusive into a poor solvent or nonsolvent for the polyimide precursor; and a heat drawing step of forming the polyimide fiber by drawing the polyimide precursor fiber while heating same. The polyimide fiber of the present disclosure has a physical property such that the coefficient of thermal expansion thereof is in the range of −15 ppm/K to 0 ppm/K inclusive.
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