公开(公告)号：US20220235156A1

公开(公告)日：2022-07-28

申请号：US17659182

申请日：2022-04-14

Applicant: AGC INC.

Inventor： Shinya HIGUCHI ,  Masahiro TAKAZAWA ,  Yingwei LAI ,  Shiro EBATA ,  Takehiro KOSE

IPC: C08F114/26

Abstract: To provide a method for producing an aqueous dispersion of polytetrafluoroethylene, whereby formation of fluorinated oligomers as byproducts is little and CFT of a coating film to be formed is large.
A method for producing an aqueous dispersion of polytetrafluoroethylene, which comprises step A1 of polymerizing a non-fluorinated monomer in an aqueous medium to obtain a solution 1 containing a polymer comprising units based on said non-fluorinated monomer, step A2 of conducting polymerization of tetrafluoroethylene in said solution 1 without substantially adding a surfactant to said solution 1, to obtain an aqueous emulsion containing polytetrafluoroethylene particles, and step A3 of adding a nonionic surfactant to said aqueous emulsion, and then concentrating said aqueous emulsion to obtain an aqueous dispersion of polytetrafluoroethylene, wherein the amount of said non-fluorinated monomer used is at most 200 mass ppm to the amount of said tetrafluoroethylene supplied to the polymerization system.

公开(公告)号：US20200216591A1

公开(公告)日：2020-07-09

申请号：US16820839

申请日：2020-03-17

Applicant: AGC Inc.

Inventor： Shinya HIGUCHI ,  Shiro Ebata ,  Takehiro Kose

IPC: C08F214/26 ,  C08J9/22 ,  B29C48/00

Abstract: To provide a modified PTFE excellent in heat resistance. The modified polytetrafluoroethylene comprises a polymer having units based on tetrafluoroethylene and a polymer having units based on a fluorine-free monomer, wherein the endothermic amount ratio R calculated by a prescribed method is at least 0.65.

公开(公告)号：US20230357515A1

公开(公告)日：2023-11-09

申请号：US18352379

申请日：2023-07-14

Applicant: AGC Inc.

Inventor： Shinya HIGUCHI ,  Kaori ABE ,  Takehiro KOSE

IPC: C08J3/05 ,  C08F114/26

CPC classification number: C08J3/05 ,  C08F114/26 ,  C08J2327/18

Abstract: To provide a method for producing an aqueous polytetrafluoroethylene dispersion, whereby the formation of fluorinated oligomers as byproducts is minimized, CFT of the formed coating film is large, and a highly concentrated aqueous polytetrafluoroethylene dispersion is easily obtainable. The method for producing an aqueous polytetrafluoroethylene dispersion, which comprises step A1 of polymerizing a non-fluorinated monomer in an aqueous medium to obtain a solution 1 containing a polymer containing units based on the non-fluorinated monomer, step A2 of conducting polymerization of tetrafluoroethylene in the solution 1 without substantially adding a surfactant to the solution 1, to obtain an aqueous emulsion containing polytetrafluoroethylene particles, and step A3 of adding a nonionic surfactant to the aqueous emulsion at a rate of from 10 to 150 mass % to the mass of PTFE contained in the aqueous emulsion, and subsequently concentrating the aqueous emulsion to obtain an aqueous polytetrafluoroethylene dispersion, wherein the amount of the non-fluorinated monomer used, to the amount of the tetrafluoroethylene supplied to the polymerization system, is at most 200 mass ppm.

公开(公告)号：US20210403623A1

公开(公告)日：2021-12-30

申请号：US17470469

申请日：2021-09-09

Applicant: AGC Inc.

Inventor： Kosuke SHIBASAKI ,  Yukiko HATTORI ,  Shinya HIGUCHI ,  Junko ANZAI

IPC: C08F214/26

Abstract: To provide a method for producing a fluorinated polymer which does not require an emulsifier as an essential component while an aqueous medium with little environmental burden is used.
A method for producing a fluorinated polymer, which comprises polymerizing at least one fluorinated monomer selected from tetrafluoroethylene, chlorotrifluoroethylene and vinylidene fluoride, in an aqueous medium in the presence of a first polymer having units based on a compound represented by the following formula (1): CXY═CR1-L-R2  (1) wherein X and Y are each independently a hydrogen atom, a halogen atom or a methyl group, R1 is a hydrogen atom, a halogen atom or a C1-3 alkyl group, L is —CO—O—*, —O—CO—* or —O—, provided that * represents the binding position to R2, and R2 is a cyclic alkyl group, a monovalent aromatic hydrocarbon group or a C1-6 linear alkyl group, provided that the C1-6 linear alkyl group as R2 may have an etheric oxygen atom in a carbon-carbon bond, and the hydrogen atom in the cyclic alkyl group, the monovalent aromatic hydrocarbon group or the C1-6 linear alkyl group as R2 may be replaced with a halogen atom.

公开(公告)号：US20200216583A1

公开(公告)日：2020-07-09

申请号：US16819749

申请日：2020-03-16

Applicant: AGC Inc.

Inventor： Shinya HIGUCHI ,  Shiro Ebata ,  Takehiro Kose

IPC: C08F14/26 ,  B29C48/00

Abstract: To provide a modified polytetrafluoroethylene excellent in breaking strength. The modified polytetrafluoroethylene comprises a polymer having units based on tetrafluoroethylene and a polymer having units based on a monomer represented by formula (1), wherein the content of the units based on a monomer represented by formula (1) is from 10 to 500 mass ppm, to all units in the modified polytetrafluoroethylene, and the standard specific gravity is from 2.155 to 2.175, CH2═CR1-L-R2  Formula (1) wherein R1 represents a hydrogen atom or an alkyl group, L represents a single bond, —CO—O—*, —O—CO—*, or —O—, * represents a bonding position to R2, and R2 represents a hydrogen atom, an alkyl group, or a nitrile group.

公开(公告)号：US20200207880A1

公开(公告)日：2020-07-02

申请号：US16814106

申请日：2020-03-10

Applicant: AGC Inc.

Inventor： Shinya HIGUCHI ,  Shiro EBATA ,  Takehiro KOSE

IPC: C08F2/16 ,  C08F214/26 ,  C08J3/16

Abstract: To provide a novel method for producing a modified PTFE.The method for producing a modified polytetrafluoroethylene comprises polymerizing tetrafluoroethylene in an aqueous medium in which a polymer comprising units based on a fluorine-free monomer is present.