Patent ID: 7758656

Claim:
A method of preparing a treated textile, comprising steps of: (1) preparing a treatment liquid comprising a water- and oil-repellent agent, (2) adjusting pH of the treatment liquid to at most 7, (3) applying the treatment liquid to a textile, (4) subsequent to applying the treatment liquid, treating the textile with steam, and (5) washing the textile with water and dehydrating the textile, wherein the water- and oil-repellent agent comprises at least one fluorine-containing compound which is a fluorine-containing polymer, and the water- and oil-repellent agent or the treatment liquid contains an organic salt which is a monovalent metal salt of an organic acid, provided that the organic acid is at least one selected from the group consisting of formic acid, acetic acid, oxalic acid and phthalic acid when the monovalent metal is potassium, and that the organic acid is at least one selected from the group consisting of formic acid, oxalic acid and phthalic acid when the monovalent metal is sodium, and the fluorine-containing polymer consists of: (I) a repeat unit derived from a monomer having a fluoroalkyl group, which is a (meth)acrylate ester of the formula: Rf-A-OCOCR 11 ═CH 2 wherein Rf is a fluoroalkyl group having 3 to 21 carbon atoms, R 11 is a hydrogen atom or a methyl group, and A is a linear or branched alkylene group having 1 to 20 carbon atoms, a —SO 2 N(R 21 )R 22 — group or a —CH 2 CH(OR 23 )CH 2 — group where R 21 is an alkyl group having 1 to 10 carbon atoms, R 22 is a linear or branched alkylene group having 1 to 10 carbon atoms, and R 23 is a hydrogen atom or a acyl group having 1 to 10 carbon atoms, (II) a repeat unit derived from a fluorine-free monomer, and (III) optionally present, a repeat unit derived from a crosslinkable monomer which is a fluorine-free vinyl monomer having at least two reactive groups.