GB1095900A - Fluorocarbon esters and polymers thereof - Google Patents

Abstract

Aerosols for conferring oil- or water-repellency comprise a propellant and an organic solvent solution of a homopolymer or copolymer of a fluorinated ester of the formula <FORM:1095900/C4-C5/1> where Rf is a C3- 21 perfluoroalkyl group, R is hydrogen or a methyl group, m is 1-10, and n is 0 or 1-10. Specified propellants are dichlorodifluoromethane monofluorotrichloromethane and dichlorotetrafluoromethane. Examples 7, 8 and 10 describe the preparation of aerosol compositions.ALSO:The invention comprises homopolymers and copolymers of fluorinated esters of the formula <FORM:1095900/C3/1> where Rf is a C3- 21 perfluoroalkyl group, R is hydrogen or a methyl group, m is 1-10 and n is 0 or 1-10. The polymers are prepared by conventional techniques using heat, free-radical catalysts or U.V. or ionizing radiation to initiate polymerization. Emulsion polymerization in an aqueous medium in the presence of a surfactant and a peroxide- or azo-type free-radical catalyst is preferred. Specified comonomers are acrylic and methacrylic acids and derivatives thereof, vinyl and allyl esters of aliphatic acids, styrene and derivatives thereof, halogenated vinyl and vinylidene compounds, vinyl alkyl ketones, dienes and fluorinated unsaturated esters of the formulae Rf(CH2)qOOC.CR=CH2 and RfCH=CH(CH2)qOOC.CR=CH2, where q is 1-10. The polymers can be modified by reaction of the side-chain hydroxyl groups therein with mono- or poly-functional compounds, e.g. monoisocyanates, ureas, alkyl-pyridinium chlorides, stearic chloride or anhydride, or polyisocyanates such as toluene diisocyanate, hexamethylene diisocyanate, hexahydrobiphenyl-4,41-diisocyanate and 3,5-diisocyanates and benzotrifluorides, triazines such as cyanuric chloride, methylolmelamine or polyethylene imide derivatives. The homopolymers, copolymers and modified polymers are used in oil- and water-proofing compositions (see Divisions B2, C4 and D1). Numerous examples of polymers are provided.ALSO:The invention comprises fluorinated esters of the formula <FORM:1095900/C2/1> wherein Rf is a straight or branched chain C3- 21 perfluoroalkyl group, R is hydrogen or a methyl group, m is 1-10 and n is 0 or 1-10. The compounds are prepared by reacting a haloalkanol RfCH2CHX(CH2)mOH with a carboxylate CH2 = CR(CH2)nCOOM where X is halogen, other than fluorine, and X is an alkali metal or silver. The reaction is preferably effected at 80-200 DEG C. in the presence of an inert organic liquid in the presence of a polymerization inhibitor. Preferred compounds are those in which Rf is a straight chain radical, m is 1 and n is 0. The compounds can be polymerized to give products which are used as oiland water-proofing agents (see Divisions B2, C3, C4 and D1). Numerous compounds are specified. The haloalkanol reactants RfCH2CHX(CH2)mOH are prepared by reacting an unsaturated alcohol CH2 = CH(CH2)mOH with either a perfluoroalkylhalide RfX or a perfluorosulphonyl halide RfSO2X, preferably in the presence of a free-radical catalyst. Examples 1 and 11 describe the preparation of <FORM:1095900/C2/2> and F(CH2)8CH2CHBr(CH2)2OH.ALSO:Porous materials are treated with a composition comprising a homopolymer or copolymer of a fluorinated ester of the formula <FORM:1095900/D1-D2/1> where Rf is a C3-21 perfluoroalkyl group, R is hydrogen or a methyl group, m is 1-0 and n is 0 or 1-10, said copolymer containing at least 25% by wt. of the above fluorinated ester. The oil-repellent compositions may take the form of aqueous emulsions, organic solvent solutions or self-pressurised sprays and can be applied to the substrate by painting, dipping or spraying at room or elevated temperatures. The treated materials are dried and may be cured at elevated temperatures. During or after curing a soaping process may be applied. Water-repellent and organic-solvent-repellent compositions are obtained by modification of the fluorenated polymer by reaction of the hydroxyl groups thereof with mono- or poly-functional compounds. Modification with a hydrophobic monofunctional compound, e.g. an alkyl pyridinium salt, yields a polymer which can impart water- and oil-repellency. Modification with a polyfunctional compound, e.g. a polyisocyanate, triazine or methylolmelamine or polyethylene imide, yields a cross-linked polymer which is also insoluble in organic solvents. This modification of the polymer may be effected by treatment of the proofing composition or of the proofed substrate. Suitable substrates are woven and knitted fabrics, fibre boards, felts and papers. All the Examples describe the treatment of fabrics. Example 2 includes the treatment of paper.ALSO:Rigid and flexible substrates are rendered oil- or water-repellent by coating with a composition comprising a homopolymer or copolymer of a fluorinated ester of the formula: <FORM:1095900/B1-B2/1> where Rf is a C3-21 perfluoroalkyl group, R is hydrogen or a methyl group, m is 1-10 and n is 0 or 1-10, said copolymer containing at least 25% by wt. of said fluorinated ester. The compositions may take the form of aqueous emulsions, organic solvent solutions or aerosols and can be applied by painting, dipping or spraying. The coated materials may be dried and cured at elevated temperatures. Water-repellent compositions are obtained by modification of the polymers by reaction of the hydroxyl groups therein in with mono- and poly-functional compounds. This modification may be effected after the coating has been applied to the substrate. Specified substrates include fabrics, fibre board, felts, leather, glass and wood. Examples relate to the treatment of fabrics. Examples 6 and 7 also describe the coating glass bottles and ceilingboards with an oil-repellent composition.