Aq. paper-coating material with high solids content - contains pigment mixt. of coarse calcium carbonate and non-film-forming polymer dispersion, and synthetic polymer binder dispersion

摘要

An aq. paper-coating material contg. at least 75 wt.% solids (I) is claimed; the aq. slurry of (I) contains, as essential components, (a) a pigment mixt. contg. 60-95 wt.% coarse CaCO3 with mean particle size at least 2 microns and 5-40 wt.% non-film-forming synthetic organic pigment (II) in the form of an aq. dispersion of a synthetic polymer binder (III) (2-20 pts.wt. to 100 pts.wt. component (a), w.r.t. solids). Specifically (II) is an aq. dispersion of a non-film-forming styrene polymer and (III) is a film-forming copolymer of (b1) 45-75 wt.% styrene, (b2) 54-15 wt.% butadiene and/or acrylate ester and (b3) 1-10 wt.% mono-unsatd. 3-5C carboxylic acid, or of acrylate esters and/or vinyl acetate and mono-unsatd. 3-5C carboxylic acid. USE/ADVANTAGE - The invention provides a paper coating material with a very high solids content, which enables the prodn. of paper with higher gloss (w.r.t. prior-art materials).