公开(公告)号：US20210388126A1

公开(公告)日：2021-12-16

申请号：US16957288

申请日：2018-12-25

Applicant: DAIKIN INDUSTRIES, LTD.

Inventor： Kazuhiro MISHIMA ,  Takahiro TAIRA ,  Chiaki OKUI ,  Takayuki TANAKA ,  Masayoshi MIYAMOTO ,  Taku YAMANAKA

IPC: C08F14/26 ,  C08J3/16 ,  C08J3/28

Abstract: A method for producing a polytetrafluoroethylene powder, which includes applying an ultrasonic wave to a polytetrafluoroethylene aqueous dispersion containing polytetrafluoroethylene particles to coagulate the polytetrafluoroethylene particles.

公开(公告)号：US20210347953A1

公开(公告)日：2021-11-11

申请号：US17259859

申请日：2019-07-12

Applicant: OSAKA UNIVERSITY ,  DAIKIN INDUSTRIES, LTD.

Inventor： Akihiro OSHIMA ,  Takayuki TANAKA ,  Hideki NAKAYA ,  Kazuyuki SATOH ,  Ryosuke SENBA

IPC: C08J3/28 ,  C08F8/50 ,  C08F114/26

Abstract: Provided is a method for producing low-molecular-weight polytetrafluoroethylene which is less likely to generate C6-C14 perfluorocarboxylic acids and salts thereof. The disclosure relates to a method for producing low-molecular-weight polytetrafluoroethylene having a melt viscosity at 380° C. of 1.0×102 to 7.0×105 Pa·s. The method includes (1) irradiating high-molecular-weight polytetrafluoroethylene with radiation in a substantially oxygen-free state and decomposing the high-molecular-weight polytetrafluoroethylene into a low-molecular-weight component and (2) deactivating, in a substantially oxygen-free state, at least part of main-chain radicals and end radicals generated by the irradiation and providing the low-molecular-weight polytetrafluoroethylene.

公开(公告)号：US20240150533A1

公开(公告)日：2024-05-09

申请号：US18400039

申请日：2023-12-29

Applicant: DAIKIN INDUSTRIES, LTD.

Inventor： Takayuki TANAKA ,  Masayoshi Miyamoto ,  Tomoki Minamiyama ,  Takeki Kusunoki ,  Tokahiro Taira ,  Takuya Yamabe ,  Hirotoshi Yoshida ,  Taketo Kato ,  Taku Yamanaka ,  Mitsuo Tsukamoto

IPC: B29C71/02 ,  C08F114/26

CPC classification number: C08J7/08 ,  C08F114/26 ,  C08J2327/18

Abstract: A method for producing a polytetrafluoroethylene particle, which includes subjecting tetrafluoroethylene to suspension polymerization in an aqueous medium to prepare a suspension-polymerized particle of polytetrafluoroethylene, washing and then crushing the suspension-polymerized particle or crushing the suspension-polymerized particle with washing to prepare a crushed particle, dehydrating the crushed particle to prepare a crushed particle having a water content of 40% by mass or less, and subjecting the dehydrated crushed particle to heat treatment to produce a polytetrafluoroethylene particle.