| 摘要 |
PROBLEM TO BE SOLVED: To obtain a coupling sheet excellent in developed color density and color forming properties in pressure-sensitive copy paper by laminating a layer containing a coupler consisting of a polyvalent metal salt of a specific nucleus substituted hydroxycarboxylic acid compd. and a polyvalent metal salt of specific monocarboxylic acid on a sheet like support. SOLUTION: A coupler is prepared by compounding a multivalent metal salt of a nuclear substituted hydroxycarboxylic acid represented by formula I (wherein R<1> , R<2> , R<3> and R<4> are a hydrogen atom, an alkyl group, an aralkyl group or a phenyl group) and a polyvalent metal salt of monocarboxylic acid represented by formula II (wherein R<5> is a hydrogen atom, an alkyl group, an alkenyl group or a cycloalkyl group) in a predetermined ratio. A dispersion prepared by dispersing a predetermined amt. of this coupler in water is applied to a sheet like support and dried to laminate a coupler-containing layer to form a coupling sheet. The content of the compd. represented by the formula II is pref. 0.1-30% by wt. of the compd. represented by formula I. |
