Printing pastes for producing printed paper laminates impregnated with condensable resins

摘要

Printing pastes comprise a vinyl chloride copolymer, an organic solvent therefor and a pigment. Specified copolymers are copolymers of vinyl chloride with vinyl acetate, vinyl propionate or vinyl butyrate. Other resins, e.g. ketone resins, may also be present. Specified pigments are organic pigments and lampblack. White pigments, e.g. titanium dioxide, zinc white and antimony white; and fillers, e.g. silica gel; may also be present. Preferred solvents are aliphatic and cycloaliphatic ketones, e.g. methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, mesityl oxide and diacetone alcohol; optionally together with aromatic hydrocarbons, e.g. benzene, toluene and xylene; halogenated hydrocarbons, e.g. trichlorethylene and chlorobenzene; nitroalkanes, e.g. nitropropane; esters, e.g. ethyl acetate, butyl acetate and ethylglycol acetate; and amides, e.g. dimethylformamide. Examples describe pastes comprising (1) a vinyl chloride/vinyl acetate copolymer, red dye and methyl ethyl ketone; a mixture of vinyl chloride/vinyl acetate copolymers, a ketone resin, a yellow dye, toluene, methyl ethyl ketone and ethylglycol acetate; and mixture of vinyl chloride/vinyl acetate copolymers, b -copper phthalocyanine, toluene, ethylglycol acetate, methyl ethyl ketone and methyl isobutyl ketone; and (2) a mixture of vinyl chloride/vinyl acetate copolymers, lampblack, silica gel, xylene and cyclohexanone. The pastes may be used for printing paper webs which may be impregnated with urea/formaldehyde or melamine/formaldehyde resins and pressed to form laminates.