POLYTETRAFLUOROETHYLENE MIXTURE

• US 20130267621A1
• Filed: 12/21/2011
• Published: 10/10/2013
• Est. Priority Date: 12/21/2010
• Status: Active Grant

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: Sawada, Yasuhiko, Kasai, Shunji, Yamanaka, Taku, Shibuya, Yoshiyuki, Inui, Kunihiko, Chaen, Shinichi
• Granted Patent: US 8,937,132 B2
• Time in Patent Office: Days
• US Class Current: 521/134
• CPC Class Codes: B01D 2323/42 Details of membrane preparation apparatus
• CPC Class Codes: B01D 67/0027 by stretching
• CPC Class Codes: B01D 71/36 Polytetrafluoroethene
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2205/16 Fibres; Fibrils
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene

Abstract

Provided is a material that can be easily biaxially oriented, homogeneously stretched even with a high draw ratio, and formed into a PTFE porous membrane with low pressure loss. The present invention relates to a polytetrafluoroethylene mixture comprising: a fibrillable modified polytetrafluoroethylene; and a fibrillable polytetrafluoroethylene homopolymer, the polytetrafluoroethylene homopolymer having strength at break of 25 N or higher.

Claims

1. A polytetrafluoroethylene mixture comprising:

a fibrillable modified polytetrafluoroethylene; and

a polytetrafluoroethylene homopolymer,

the polytetrafluoroethylene homopolymer having strength at break of 25 N or higher.

2. The polytetrafluoroethylene mixture according to claim 1,

wherein the mass ratio of the modified polytetrafluoroethylene to the polytetrafluoroethylene homopolymer, that is, modified polytetrafluoroethylene/polytetrafluoroethylene homopolymer, is 5 to 99/95 to 1.

3. The polytetrafluoroethylene mixture according to claim 1,

wherein the modified polytetrafluoroethylene includes a modified monomer unit in an amount of 0.005 to 0.500 wt % of the weight of all monomer units.

4. The polytetrafluoroethylene mixture according to claim 1,

wherein the modified polytetrafluoroethylene has a cylinder extrusion pressure, at a reduction ratio of 1600, of 70 MPa or higher.

5. The polytetrafluoroethylene mixture according to claim 1

wherein the modified polytetrafluoroethylene and the polytetrafluoroethylene homopolymer are obtainable by emulsion polymerization.

6. The polytetrafluoroethylene mixture according to claim 1, comprising:

mixed powder obtainable by coagulation of an aqueous dispersion containing the modified polytetrafluoroethylene and the polytetrafluoroethylene homopolymer.

7. A polytetrafluoroethylene porous membrane obtainable by stretching the polytetrafluoroethylene mixture according to claim 1.