Coated paper product suitable for the preparation of planographic printing plates

摘要

739,847. Coated paper. WARREN CO., S. D. March 8, 1954 [May 22, 1953], No. 6675/54. Class 96. [Also in Group XVI] Coated paper for making planographic printing plates comprises a paper base coated with a barrier layer substantially impervious to water, a first layer of mineral pigment and protein, e.g. insolubilized casein, and a second layer of mineral-coating comprising titanium dioxide and an insolubilized cellulose derivative, both layers of mineral-coating being free from hydrous mineral pigment such as clay. The cellulose derivative may be methyl, methylethyl, hydroxy-ethyl, sodium-carboxy-methylhydroxy - ethyl, sodium - sulpho - ethyl, sodiumcarboxy-methyl cellulose, or sodium cellulose sulphate. In an example, a paper base is coated on its back with clay, casein and dimethyl urea, and with a barrier coating of clay, polymerized styrene and butadiene. The first mineral coating comprises precipitated barium sulphate, casein and dimethyl urea. The second mineral coating comprises titanium dioxide, hydroxy ethyl cellulose, melaminoformaldehyde or urea-formaldehyde &c., a wetting agent, e.g. the double sulphate of sodium and 7-ethyl-2-methyl undecanol-4, tributyl phosphate, and hydrochloric acid.