Process for preparing tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer

• US 4,499,249 A
• Filed: 04/28/1983
• Issued: 02/12/1985
• Est. Priority Date: 04/30/1982
• Status: Expired due to Fees

• Current Assignee: Daikin Kogyo Co., Ltd.
• Original Assignee: Daikin Kogyo Co., Ltd.
• Inventors: Nakagawa, Shinichi, Omori, Mitsugu, Nakagawa, Tsuneo, Amano, Toshihiko, Ihara, Kiyohiko, Yamaguchi, Sadaatsu, Asano, Kohzoh
• Primary Examiner(s): Wong, Jr., Harry
• Application Number:
  US06/489,289
• Time in Patent Office: 656 Days
• Field of Search: 526/247, 526/206, 526/231
• US Class Current: 526/206
• CPC Class Codes: C08F 214/262 with fluorinated vinyl ethers

Abstract

A process for preparing a tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer comprising polymerizing tetrafluoroethylene and fluoro(alkyl vinyl ether) in an aqueous suspension system which comprises a mixed medium of water and a fluorohydrocarbon or a chlorofluorohydrocarbon in a volume ratio of from 1:1 to 10:1 at a temperature of from 0° to 25° C. in the presence of a polymerization initiator of the formula:

[Cl(CF.sub.2).sub.n --COO].sub.2                           (I)

wherein n is an integer of 1 to 10, the copolymer obtained by the process having a small number of unstable terminal groups and excellent flex life.

Claims

1. A process for preparing a tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer, comprising:

polymerizing tetrafluoroethylene and fluoro(alkyl vinyl ether) selected from the group consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), ##STR3## in an aqueous suspension system which comprises a mixed medium of water and a fluorohydrocarbon or a chlorofluorohydrocarbon in a volume ratio of from 1;

1 to 10;

1 at a temperature of from 0°

to 25°

C. in the presence of a polymerization initiator of the formula;

space="preserve" listing-type="equation">[Cl(CF.sub.2).sub.n --COO].sub.2

wherein n is an integer of 1 to 10.

2. The process according to claim 1, wherein the polymerization initiator is a compound of the formula (I) wherein n is an integer of 1 to 4.

3. The process according to claim 1, wherein the polymerization initiator is a compound of the formula:

space="preserve" listing-type="equation">[ClCF.sub.2 CF.sub.2 COO].sub.2.

4. The process according to claim 1, wherein the weight ratio of tetrafluoroethylene and fluoro(alkyl vinyl ehter) is from 1:

1 to 10;

1.

5. The process according to claim 1, wherein the volume ratio of water and fluorohydrocarbon or chlorofluorohydrocarbon is from 1.5:

1 to 5;

1.

6. The process according to claim 1, wherein the fluorohydrocarbon or the chlorofluorohydrocarbon is selected from the group consisting of 1,1,2,-trichloro-1,2,2-trifluoroethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, trichlorofluoromethane, dichlorodifluoromethane and perfluorocyclobutane.

7. The process according to claim 1, wherein the reaction temperature is from 5°

to 15°

C.

8. The process according to claim 1, wherein the reaction pressure is from 0.5 to 15 kg/cm² G.

9. The process according to claim 8, wherein the polymerization initiator is a compound of the formula (I) wherein n is an integer of 1 to 4.

10. The process according to claim 1, wherein the weight ratio of the produced copolymer to the solvent is 0.4 or more.