Polytetrafluoroethylene resin

• US 6,177,533 B1
• Filed: 09/29/1999
• Issued: 01/23/2001
• Est. Priority Date: 11/13/1998
• Status: Expired due to Term

• Current Assignee: The Chemours Company FC, LLC (The Chemours Company)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Woodward, Jones Clay
• Primary Examiner(s): PEZZUTO, HELEN LEE
• Application Number:
  US09/408,827
• Time in Patent Office: 482 Days
• Field of Search: 526/206, 526/250, 526/255
• US Class Current: 526/255
• CPC Class Codes: C08F 14/26 Tetrafluoroethene
• CPC Class Codes: C08F 2/38 Polymerisation using regulators, e.g. chain terminating agents , e.g. telomerisation

Abstract

Stretchable polytetrafluoroethylene resin has high break strength and/or low creep rate.

Claims

1. A stretchable, fibrillatable, non-melt-fabricable polytetrafluoroethylene resin having standard specific gravity of no more than 2.160, rheometer pressure of at least 25 MPa, stress relaxation time of at least 650 seconds, and break strength of at least 3.0 kilogram force.

2. The polytetrafluoroethylene resin of claim 1, wherein said resin has creep rate at 365°

C. of no more than 0.1 min<sup>−

1</sup>.

3. The polytetrafluoroethylene resin of claim 1, wherein said break strength is at least 3.1 kgf.

4. The polytetrafluoroethylene resin of claim 1, wherein said creep rate is no more than 0.08 min⁻

1.

5. The polytetrafluoroethylene resin of claim 1, wherein said creep rate is no more than 0.07 min⁻

1.

6. The polytetrafluoroethylene resin of claim 1, wherein said standard specific gravity is no more than 2.157.

7. The polytetrafluoroethylene resin of claim 1, wherein said rheometer pressure is at least 30 MPa.

8. The polytetrafluoroethylene resin of claim 1, wherein said resin is fine powder.

9. The polytetrafluoroethylene resin of claim 1, wherein said resin is the dispersed solid component of an aqueous dispersion.