| 摘要 |
PURPOSE:A color-developing ink for pressure-sensitive copying paper that is composed of a color-developing agent of a reaction product from a specific condensate and a polyvalent metal compound, pigments and organic solvents, thus showing improved color-developing performance and giving bright images with increased light resistance. CONSTITUTION:The reaction between a mixture of p-hydroxybenzoic acid with a p-substituted alkylphenol bearing 1-12C alkyl at a molar ratio of (0.1-5):1 and formaldehyde is carried out in the presence of an acidic catalyst such as phosphoric acid to give a condensate. The resultant condensate is allowed to react with a polyvalent metal compound such as zinc oxide, preferably at a weight ratio of (95:5)-(20:80), preferably at 80-180 deg.C to give an electron-accepting color developer. Then, the color developer is mixed with pigments such as titanium oxide, binders such as acrylic resin and organic solvents such as methyl ethyl ketone to give the objective color-developing ink for pressure-sensitive ink for pressure-sensitive copying paper. USE:For flexographic printing. |
