Coated pressure sensitive copying paper

Claim 1

A pressure sensitive copying paper comprising a support having coated thereon a layer of a color-forming composition consisting essentially of leuco dye color former, an aromatic secondary amine selected from the group consisting of N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-cyclohexyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N,N'-disec-butyl-p-phenylenediamine, N,N'-di-beta-naphthyl-p-phenylenediamine, N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N-(1-methylpropyl)-N'-phenyl-p-phenylenediamine, N,N'-diphenylamine, p-isopropoxy-di-phenyl-amine, phenylalpha-naphthylamine, phenyl-beta-naphthylamine, a reaction product of acetone with phenyl-beta-naphthylamine, N,N'-diphenylbenzidine, p-methoxy-acetoanilide, hydrazobenzene and N-phenyl-m-anisidine, or derivative thereof, to improve fastness and discoloration resistance of said leuco dye, and an organic solvent, said leuco dye being capable of forming a color when contacted with a color developer selected from the group consisting of a clay, an organic acid and a phenol resin, and a layer of said color developer on the same or a different support.