Patent ID: 8778865

Claim:
A method for softening a fiber product, said fiber product being selected from the group consisting of clothes and bedclothes, comprising treating the fiber product with a composition comprising a quaternary ammonium salt (I) represented by formula (I) and a quaternary ammonium salt (II) represented by formula (II) at a weight ratio of the quaternary ammonium salts (I) to (II), (I):(II), of 50.1:49.9 to 99.99:0.01: wherein, R 1 and R 2 , which may be the same as or different from each other, represent a hydrocarbon group having 11 to 23 carbon atoms; R 3 and R 4 , which may be the same as or different from each other, represent a hydrocarbon group having 1 to 4 carbon atoms that may have a hydroxy group; k and 1, which may be the same as or different from each other, represent an integer showing the mole number of added oxyethylene group ranging from 1 to 4; and X − represents an anion; wherein, R 5 and R 6 , which may be the same as or different from each other, represent a hydrocarbon group having 11 to 23 carbon atoms; R 7 and R 8 , which may be the same as or different from each other, represent a hydrocarbon group having 1 to 4 carbon atoms that may have a hydroxy group; m and n, which may be the same as or different from each other, represent an integer showing the mole number of added oxyethylene group ranging from 5 to 10; and X′ − represents an anion, wherein the composition further comprises an inorganic or organic salt other than the quaternary ammonium salt (I) or (II).