Polymerisate und Mischpolymerisate von Polyvinylaethern und Verfahren zu deren Herstellung

摘要

The invention comprises compounds of formula XCF2-CF2-O(-CFX-CF2-O-)n-CF=CF2 (I), where X is fluorine, chlorine, hydrogen, difluoromethyl, chlorodifluoromethyl or perfluoromethyl, and n is at least 1, preferably 1-5. They are prepared by pyrolysis of compounds of formula XCF2-CF2-O(CFX-CF2-O)n-CF(CF3)Y (II), where Y is COF or COOMe, Me being a monovalent metal. The pyrolysis of acid fluorides is generally effected in the gaseous phase at 300-600 DEG C., or lower if a catalyst such as Na2SO4 or ZnO is used, and that of metal salts at 170-250 DEG C., or as low as 100 DEG C. if a polar solvent is used. The products may be polymerized (see Division C3). Compounds of Formula II in which Y is COF may be obtained by polymerization of hexafluoropropylene oxide alone or with an epoxide of formula as appropriate. The polymerization may be effected in bulk using active carbon as catalyst or in a polar solvent using a fluoride or tertiary amine catalyst. The acid fluoride may be converted to the corresponding acids and salts thereof by hydrolysis. Specifications 781,532 and 899,227 are referred to. Reference has been directed to the Comptroller to Specification 928,315.ALSO:The invention comprises polymers of perfluorovinyl ethers of formula XCF2-CF2-O(CFX-CF2-O)n-CF=CF2 (I), where X is fluorine, chlorine, hydrogen, difluoromethyl, chlorodifluoromethyl or perfluoromethyl, and n is at least 1, preferably 1-5 (for preparation see Division C2). The polymers include homopolymers and copolymers with one or more fluorinated vinyl monomers such as tetrafluoroethylene, chlorotrifluoroethylene and vinylidene fluoride, e.g. copolymers containing 1 or 2 weight per cent of monomer of formula I. Polymerisation may be effected in bulk or in solution (e.g. in water or a fluorocarbon solvent) using a free radical initiator (e.g. a perfluorinated peroxide or azo compound), or using actinic light. Specifications 781,532 and 899,227 are referred to. Reference has been directed by the Comptroller to Specification 928,315.