GB1222418A - Record material for producing copies of graphic information - Google Patents

Abstract

1,222,418. Colour-reactive record sheets. NATIONAL CASH REGISTER CO. 23 July, 1968 [25 Aug., 1967], No. 35014/68. Heading D2B. A record material compries a support sheet carrying two or more colour-reative dye precursors, separately micro-encapsulated, and capable of assuming different colours when reacted with a reactant material interspersed with the capsules or on the surface of a separate receiving sheet, so that close intermingled small dots of different colours cause the marks to appear grey or black to the eye. In Example I, 3,3-bis-(p-dimethylaminophenyl)-6-dimethylaminophthalide is dissolved in chlozinated biphenyl and emulsified in a solution of pigskin gelatine in water. A solution of gum arabic and vinyl methyl ether-maleic anhydride copolymer is added, the pH lowered by dropwise addition of acetic acid, and the mixture cooled with agitation. The capsules are hardened by adding glutaraldehyde and dried. Agglomeration of the capsules can be prevented by the addition of a copolymer of maleic anhydride with vinyl methyl ether or ethylene, 3,3-bis-(1,2-dimethylindol-3-yl)phthalide and 4,4#-(bis-(dimethylamino)-benzophenone are each separately encapsulated in a generally similar fashion. The three types of capsules are mixed and applied as a coating to paper. In Example II, 3,3-bis-(p-dimethylaminophenyl)-6- dimethylaminophthalide, 3,3-bis-(1-ethyl,2- methylindol-3-yl)phthalide, and 4,4#-bis-(diethylamino)benzophenone are each separately dissolved in a mixture of chlorinated biphenyl and petroleum oil, and separately encapsulated; the capsules are mixed and coated on to a substrate. In Example III, 4,4'-bis-(diethylamino)- benzophenone; 9-diethylaminospiro-[12-H-[a]- xanthene-12,1#-phthalide]; and 3,3-bis-(p-dimethylaminophenyl)-6-dimethylaminophthalide are separately encapsulated as in Example 1 and coated on to a substrate. In Example IV, a mixture of 3,3-bis-(p-dimethylaminophenyl)-6- dimethylaminophthalide and 3,7-bis-(dimethylamino)-10-benzoylphenothiazine; 9-diethylaminospiro-[12-H-benzo[a]xanthene-12,1'- phthalide] and 4,4'-bis-(diethylamino)-benzophenone are separately encapsulated as in Example 1 and coated on to a substrate. In Example V, the same mixture of dyes as in Example IV, and separately 3,3-bis-(1-ethyl-2- methylindol-3-yl)-phthalide and 4,4'-bis-(diethy- ]amino)-benzophenone are encapsulated and the capsules mixed and coated on to a substrate.