Patent ID: 8420744

Claim:
A method for producing a modified polysiloxane compound represented by formula (IV): X′(Y) n (IV) [wherein X′ represents a polymer block having a repeating unit represented by formula (V): (wherein R 1 represents a hydrogen atom or a methyl group), Y represents a polymer block having a repeating unit represented by formula (III): (wherein R 3 and R 4 each represent a linear or branched alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, or an arylalkyl group, and R 3 and R 4 may be the same as or different from each other), and n represents 1 or 2], the method comprising subjecting a modified polysiloxane compound represented by formula (I): X(Y) n (I) [wherein X represents a polymer block having a repeating unit represented by formula (II): (wherein R 1 is defined as above, and R 2 represents a linear or branched alkyl group having 1 to 6 carbon atoms), and Y and n are each defined as above], and having an X to Y weight ratio of 1/99≦X/Y≦90/10 and a number-average molecular weight of 1,000 to 100,000, to treat for elimination of a protecting group for a hydroxyl group by adding a non-aqueous solution containing hydrogen chloride in the presence of a non-aqueous solvent and the amount of the hydrogen chloride is 0.9 to 1.3 equivalents with respect to 1 equivalent of the repeating unit represented by formula (II).