초록 ▼

The present invention provides a method of preparing an aqueous dispersion of poly(perfluorovinyl ether)homopolymers. The present invention further relates to a method of making an aqueous fluoropolymer dispersion comprising bicomponent particles of poly(perfluorovinyl ether)homopolymers and a secon

The present invention provides a method of preparing an aqueous dispersion of poly(perfluorovinyl ether)homopolymers. The present invention further relates to a method of making an aqueous fluoropolymer dispersion comprising bicomponent particles of poly(perfluorovinyl ether)homopolymers and a second fluoropolymer. The dispersions of the present invention may be used for rendering fibrous substrates oil repellent, water repellent and/or stain repellent.

대표청구항 ▼

1. A method of making a poly(perfluorovinyl ether) homopolymer dispersion comprising the steps of:a. pre-emulsifying an aqueous mixture of a perfluorovinyl ether in the presence of a fluorochemical emulsifier to an average emulsion droplet size of one micron or less, andb. polymerizing said perfluor

1. A method of making a poly(perfluorovinyl ether) homopolymer dispersion comprising the steps of:a. pre-emulsifying an aqueous mixture of a perfluorovinyl ether in the presence of a fluorochemical emulsifier to an average emulsion droplet size of one micron or less, andb. polymerizing said perfluorovinyl ether in the presence of an initiator at temperature and for a time sufficient to produce particles of poly(perfluorovinyl ether). 2. The method of claim 1 wherein said perfluorovinyl ethers are of the formula: 2 ═CF—R f wherein R f represents a perfluorinated organic group having a chain length of at least 2 atoms and having at least one carbon atom and at least one oxygen atom. 3. The method of claim 2 wherein said R f group is a perfluoroalkoxy group, a perfluoroether group or a perfluoropolyether group. 4. The method of claim 2 wherein said R f group is of the formula: 1 f O) n (R 2 f O) m R 3 f wherein R 1 f , R 2 f each independently represents a linear or branched perfluoroalkylene group having 1 or 6 carbon atoms, R 3 f represents a linear, branched or cyclic perfluoroalkyl group having 1 to 6 carbon atoms and n and m each independently represents an integer of 0 to 10. 5. The method of claim 4 wherein at least one of n and m is different from 0. 6. The method of claim 4 wherein m is 0, n is 1, R t f is —CF 2 CF 2 —, —CF 2 CF(CF 3 )— or —CF 2 CF 2 CF 2 — and R 3 f represents a linear, branched or cyclic perfluoroalkyl group having 1 to 6 carbon atoms. 7. The method of claim 1 wherein the concentration of perfluorovinyl ether monomer is from 1 to 70 wt % of said emulsion. 8. The method of claim 1 wherein the concentration of perfluorovinyl ether monomer is from 20 to 40 wt. % of said emulsion. 9. The method of claim 1 wherein the concentration of said fluorinated emulsifier is from 0.1 to 4 wt % of said emulsion. 10. The method of claim 1 wherein the concentration of said initiator is from 0.01 to 2 wt % of said pre-emulsion. 11. The method of claim 1 wherein the temperature is from 40 to 80° C. and the time from 6 to 48 hours. 12. The method of claim 1 wherein the degree of conversion of said polymerization is at least 1 percent. 13. The method of claim 1 wherein said fluoropolymer comprise particles having an average size of 50 to 200 nanometers. 14. The method of claim 1 wherein said emulsifier comprises repeating units derivable from a monomer of the formula:wherein a is 0, 1 or 2, and t is an integer of 2 to 4, and G is a moiety containing one or more nonionic, anionic or cationic hydrophilic groups. 15. The method of claim 1 wherein said emulsifier is selected from f a —O—(CF 2 O) k (CF 2 CF 2 O) p (CF(CF 3 )CF 2 O) q —Q 1 —COOM or 1 —O—(CF 2 O) k (CF 2 CF 2 O) p (CF(CF 3 )CF 2 O) q —Q 2 —COOZwherein k, p and q each represent a value of 0 to 15, and the sum of k, p and q being such that the number average molecular weight is at least 200 g/mol, R f a represents a perfluoroalkyl group of 2 to 4 carbon atoms, M and Z each independently represent hydrogen or a cation and Q 1 and Q 2 each independently represents —CF 2 — or —CF(CF 3 )—. 16. The method of claim 14 further comprising an emulsifier of the formula: 1 —O—(CF 2 O) k (CF 2 CF 2 O) p (CF(CF 3 )CF 2 O) q —Q 2 —COOZwherein k, p and q each represent a value of 0 to 15, and the sum of k, p and q being such that the number average molecular weight is at least 200 g/mol, R f a represents a perfluoroalkyl group of 2 to 4 carbon atoms, M and Z each independently represent hydrogen or a cation and Q 1 and Q 2 each independently represents —CF 2 — or —CF(CF 3 ). 17. The method of claim 1 wherein said initiator comprises a water-soluble initiator. 18. The method of claim 17 wherein said water-so luble initiator is present in amounts from 0.01 to 2 weight percent, based on the total weight of the monomers. 19. The method of claim 1 wherein the temperature of said polymerization step is between 50 and 80° C. 20. The method of claim 1 wherein the amount of emulsifier is from 0.01 to 15 weight percent, relative to the total weight of the monomers. 21. The method of claim 1 further comprising the step of isolating said particles of poly(perfluorovinyl ether) from said dispersion.