Patent ID: 7371272

Claim:
A modifier for hydrophilicity which comprises a modified polyvinyl alcohol, with the degree of saponification of not less than 90%, containing a group represented by the formula (I) on a side chain thereof; in the formula, n represents an integer of 1 to 500, R 1 represents a hydrogen atom or an alkyl group containing 1 to 4 carbon atoms, and R 2 represents a hydrogen atom or a methyl group, said group represented by the above formula (I) accounting for 0.1 to 10 mole percent of the sum of hydroxyl groups and acetoxy groups in said modified polyvinyl alcohol, and said modified polyvinyl alcohol accounting for 0.1 to 30% by mass relative to said modifier for hydrophilicity, and said modifier for hydrophilicity further comprises a polyvinyl alcohol not containing any group represented by the formula (I) in an amount of 0.1 to 30% by mass relative to said modifier for hydrophilicity.