摘要 |
Disclosed is a color-developing composition for pressure-sensitive recording sheet material of the self-contained type comprising (A) 100 parts by weight of a copolymer obtained by reacting a p-alkylphenol having an alkyl moiety of from 1 to 12 carbon atoms and phenol with formaldehyde and (B) from 1 to 20 parts by weight of a hindered phenolic compound selected from phenols having an alkyl, alkylene or hydroxyl substituent radical in at least the 2- or 6-position, or both, of the benzene ring and derivatives thereof, the copolymer and the hindered phenolic compound being homogeneously dissolved in mutual solution. The hindered phenolic compound is either added to the starting materials for the preparation of the copolymer or, at the end of the copolymerization reaction, added to the resulting copolymer and dissolved homogeneously in mutual solution. |