| 摘要 |
<p>660,502. Pressure - sensitive recording materials. NATIONAL CASH REGISTER CO. June 13, 1949 [July 13, 1948 ; July 13, 1948], Nos. 15633/49 and 15634/49. Drawings to Specification. Classes 96 and 140. [Also in Group XV] Paper, cardboard, glass, metal, or wood is coated with a solid film, e.g. of methyl cellulose, polyvinyl alcohol, casein, synthetic latex, starch, or a mixture of starch, 'casein, and a butadiene copolymer containing, insulated from each other, particles of solid, and droplets of liquid which produce a colour effect when they contact each other e.g. under pressure, e.g. on typing, which ruptures the binder. The liquid reactant may be crystal violet lactone,malachite green lactone, tetrachloro malachite green lactone, 3,3 - bis - (p - diethylaminophenyl) - 6 - di - methylaminophthalide, or 2,4-bis-[p-(dimethylamino - phenylazo) - anilino] - 6 - hydroxy sym.- triazine, in a non-evaporating, oily solvent, e.g. chlorinated diphenyl. The solid reactant may be attapulgite, halloysite, magnesium trisilicate, or a sodium aluminium silicate zeolite, or a synthetic zeolite in which a cation of a naturallyoccurring compound has been replaced by nickel, copper, iron, zinc, mercury, barium, lead, cadmium, or potassium. In an example, paper is coated with the liquid colour-reactant in gelatin, wetted with water containing formaldehyde and a wetting agent, dried and a top coating of starch and attapulgite clay applied. Specification 628,960 is referred to.</p> |
