4-hydroxy-4'-isopropoxydiphenyl sulfone developer composition, wet pulverizing method, and dispersion

摘要

A method of preventing hydration of 4-hydroxy-4'-isopropoxydiphenyl sulfone characterized by wet pulverizing the sulfone in water in the presence of a diphenyl sulfone derivative represented by general formula (I): (wherein R<1> represents hydrogen or lower alkyl; R<2> and R<3> represent each independently lower alkyl; and n and m represent each an integer of 0, 1 to 4, provided when R<1> is hydrogen, not both of m and n are 0 at the same time). A highly sensitive recording paper free from scumming can be produced by using a dispersion of a developer comprising the above sulfone.