GB998830A - Decorating compositions and method of decorating therewith - Google Patents

Abstract

Silver mercaptides are prepared by the reaction between a silver salt or oxide and a mercaptan. The term mercaptan includes tertiary alkyl mercaptans containing 7 or more carbon atoms in the tertiary alkyl radical, primary and secondary alkyl mercaptans and other mercaptans which may be aliphatic, alicyclic, heterocyclic, aryl, alkaryl, aralkyl or terpenyl, and other compounds named in a list, e.g. p-chlorophenyl and 2-hydroxyethyl mercaptans, thioglycolic acid and esters thereof, and isooctyl 3mercaptopropionate. The mercaptides may be made by stirring an aqueous solution of a silver salt with a mercaptan. In Example 1, to a mixture of 8 mole tertiary nonyl mercaptan, chloroform, 4 mole Na2CO3, and water, was added 8.4 mole AgNO3 with stirring during 20 minutes. After stirring the mixture was allowed to settle. The chloroform layer was washed with water, filtered, stirred with activated charcoal, and filtered. The filtrate was kept for 4 hrs. in an open dish on a steam bath, with occasional stirring. A deep ruby, moderately viscous oil resulted. In Example 2, 2-naphthalenethiol, AgNo3 and sodium acetate were used.ALSO:A metallic coating is formed by use of a decorating composition comprising a silver mercaptide, a flux and a vehicle. The composition may be applied to an article and fired to a metallic film, lustre colour or stain. The mercaptide may be aliphatic, alicyclic, heterocyclic, aryl, alkaryl, aralkyl or terpenyl, and is preferably tertiary alkyl, e.g. with 7-30 carbon atoms per molecule. A long list of suitable mercaptides is given. The flux may be a salt or resinate of Rh, Ir, Bi, Cr, Pb, Cd, Sn, Cu, Co, Sb or U. The salt may be, e.g., borate, nitrate, silicate. The vehicle may be a mixture of essential oil, terpenes, resins, methyl ethyl ketone, cyclohexanone, ethyl acetate, amyl acetate, "Cellosolve" (Registered Trade Mark), butanol, nitrobenzene, toluene, xylene, petroleum ether, chloroform, carbon tetrachloride, Assyrian asphalt, balsams, or artificial resins, or may be lacquer or wax. The composition may also contain Au, Pt and/or Pd, e.g. as sulphoresinates, organic complexes or powder; Ag powder, amorphous, flakes or spherules, may also be employed. The composition may contain, e.g., 0.1-40.0% or more of silver. The composition may be applied by brushing, spraying, stippling, stamping, printing, or decalcomania transfer. The material may be fired at 250-900 DEG C. by kiln, flash, lehr or infra-red firing. Substrates include laminated artificial resins, glass, glass-ceramic, ceramic, quartz, mica, alumina, aluminium, stainless steel. Specific compositions and method of use are disclosed in the examples. Specification 926,979 is referred to.