Electrically inscribable recording blanks suitable for use as lithographic masters

摘要

884,504. Paper for electric recording &c. WARREN CO., S. D. Nov. 25, 1959 [Feb. 11, 1959], No. 40012/59. Class 96. Paper for electric recording and suitable for use, after receiving the inscribed matter, as a lithographic printing master on off-set duplicating machines, and having a reduced tendency for the electric, inscribing spark to wander, is formed from a paper base or a coated paper base which is electrically conductive and oleophilic with at least one intermediate layer of hydrophilic, but water-insoluble material of substantially lower conductivity than the base, and a top layer containing a minor proportion of a substance of high electrical conductivity, e.g. carbon black, the intermediate and top layers being pigmented and opaque. The carbon black may be 1 to 10% of the pigment portion. The hydrophilic coating may comprise, e.g. cuprous thiocyanate, or lead thiosulphate, dimethylol urea, and casein or soya protein. The oleophilic coating material may include a plasticized vinyl acetate copolymer latex. The paper base may include a wetstrength resin and a clay filler.