MODIFIED POLYTETRAFLUOROETHYLENE FINE POWDER AND UNIAXIALLY STRETCHED POROUS BODY

• US 20160289361A1
• Filed: 12/01/2014
• Published: 10/06/2016
• Est. Priority Date: 11/29/2013
• Status: Active Grant

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: YAMANAKA, Taku, ONO, Makoto, YASUDA, Kohei, YAMADA, Masahiko, CHAEN, Shinichi, SAWADA, Yasuhiko, TAIRA, Takahiro, YOSHIDA, Hirotoshi, KATO, Taketo
• Granted Patent: US 11,084,895 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B29C 55/04 uniaxial, e.g. oblique
• CPC Class Codes: C08F 214/262 with fluorinated vinyl ethers
• CPC Class Codes: C08F 2500/11 Melt tension or melt strength
• CPC Class Codes: C08F 2500/24 Polymer with special particle form or size
• CPC Class Codes: C08F 2500/26 Use as polymer for film forming
• CPC Class Codes: C08F 2800/10 as molar percentages
• CPC Class Codes: C08J 2327/18 Homopolymers or copolymers of tetrafluoroethylene
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets

Abstract

The present invention aims to provide a modified polytetrafluoroethylene fine powder capable of providing a stretched body having high strength, a small pore size, and excellent homogeneity. The modified polytetrafluoroethylene fine powder of the present invention has non-melt-processability, has a standard specific gravity of 2.155 or lower, includes 0.015 mol % or more of a polymer unit derived from perfluoro(methyl vinyl ether) in all the monomer units, is obtained by emulsion polymerizing tetrafluoroethylene and at least the perfluoro(methyl vinyl ether) in the presence of a fluorosurfactant having a LogPOW value of 3.4 or lower, and has an extrusion pressure of 20.0 MPa or lower.

Claims

1. A modified polytetrafluoroethylene fine powder,

having non-melt-processability,

having a standard specific gravity of 2.155 or lower,

comprising 0.015 mol % or more of a polymer unit derived from perfluoro(methyl vinyl ether) in all the monomer units,

being obtained by emulsion copolymerizing tetrafluoroethylene and at least the perfluoro(methyl vinyl ether) in the presence of a fluorosurfactant having a LogPOW value of 3.4 or lower, and

having an extrusion pressure of 20.0 MPa or lower.

2. The modified polytetrafluoroethylene fine powder according to claim 1,

wherein the amount of the polymer unit derived from the perfluoro(methyl vinyl ether) is 0.025 mol % or more in all the monomer units.

3. The modified polytetrafluoroethylene fine powder according to claim 1, having a breaking strength of 28 N or higher.

4. The modified polytetrafluoroethylene fine powder according to claim 1, having a breaking strength of 30 N or higher.

5. The modified polytetrafluoroethylene fine powder according to claim 1, having a breaking strength of 32 N or higher.

6. The modified polytetrafluoroethylene fine powder according to claim 1, having a breaking strength of 34 N or higher.

7. The modified polytetrafluoroethylene fine powder according to claim 1, having a breaking strength of 36 N or higher.

8. The modified polytetrafluoroethylene fine powder according to claim 1, having an average primary particle size of 210 nm or greater and 300 nm or smaller.

9. A uniaxially stretched porous body, which is formed from the modified polytetrafluoroethylene fine powder according to claim 1.

10. The uniaxially stretched porous body according to claim 9, which is a film.

11. The uniaxially stretched porous body according to claim 9, which is a tube.

12. The uniaxially stretched porous body according to claim 9, which is a fiber.