COLOUR-DEVELOPER COMPOSITIONS FOR RECORDING MATERIALS

1429069 Phenolic compositions FUJI PHOTO FILM CO Ltd 21 Nov 1973 [21 Nov 1972] 53953/73 Headings C3R C3P and C3U [Also in Division D2] An aqueous colour-developer composition for use in the preparation of a recording material and which is capable of reaction with a colourformer to form a coloured image comprises both an alkali metal salt of a phenolic resin and a water soluble metal compound. The phenolic resin may be a phenol-aldehyde novolak resin or a phenol-acetylene polymer. Many examples of para-substituted phenol-HCHO resins are listed particularly p-(C 1 -C 12 ) alkyl phenol- HCHO resins. Suitable metal compounds are the water-soluble compounds of the Group IB, Group IIA, Group IIB, Group IIIA, Group IVA, Group VIB, Group VIIB or Group VIII metals of the Periodic Table, preferably the sulphates, chlorides, nitrates or acetates of Zn, Sn, Mg, Al or Ni. The amount of metal compound is preferably greater than 0À1 gram equivalent per gram equivalent of the phenolic resin. The composition may be prepared in the presence of a water-soluble polymeric substance such as a protein, e.g. gelatine, albumin or casein; a cellulose, e.g. carboxymethyl- or hydroxyethylcellulose; a polysaccharide, e.g. gum arabic, agar, sodium alginate, starch or carboxymethyl starch; or a synthetic polymer such as polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid or polyacrylamide. The composition may also comprise a binder such as styrenebutadiene copolymer latex, polyvinyl alcohol, maleic anhydride-styrene copolymer, starch, casein, gum arabic, and carboxymethyl cellulose; additional colour developers such as acidic or activated terra alba and/or inorganic pigments such as zinc oxide or magnesium carbonate. Aqueous colour developer compositions are prepared in Examples 1 and 2 from the sodium salt of p-phenyl-phenol/HCHO resin and a metal compound selected from ZnSO 4 .7H 2 O, ZnCl 2 , MgSO 4 .7H 2 O, SnSO 4 , Al 2 (SO 4 ) 3 .17H 2 O, PbSO 4 , COSO 4 .7H 2 O, FeSO 4 .7H 2 O, SnCl 2 .2H 2 O or NiSO 4 .7H 2 O, and either (1) polyvinyl alcohol; or (2) activated terra alba and styrene-butadiene rubber; and in Example (3) from the sodium salt of p-tert-butylphenol/HCHO resin and various metal salts as listed in Examples 1, 2, kaolin and gum arabic; and in Example 4 from the sodium salt of p-chlorophenol/HCHO resin and various metal salts as listed in Examples 1, 2, zinc oxide and the ammonium salt of a styrene-maleic anhydride copolymer. Each composition is used in making a recording material by coating it on to a paper sheet and superimposing thereon a microcapsule sheet containing " Crystal " Violet Lactone or 3,N,N- dibenzyl - amino - 7 - N,N - diethylaminofluoran and applying a compressive pressure to develop a colour.