Method for treating polymeric substrates prior to plating employing accelerating composition containing an alkyl amine

Claim 1

In a process for treating a polymeric plastic substrate to render it receptive to electroless plating including the steps of etching the substrate with an aqueous acid solution containing hexavalent chromium ions, rinsing and activating the etched substrate with an acidic tin-palladium complex, rinsing and accelerating the activated substrate, the improvement comprising contacting the activated substrate during the accelerating step with an aqueous acidic accelerating solution having a pH of about 0 to about 7 and containing an aqueous soluble compatible substituted alkyl amine present in an amount effective to complex substantially all of any contaminating cupric and ferric ions present and to extract any residual tin constituents present on the surface of the activated substrate, an anion of a mineral acid or alkali metal salts thereof present in an amount up to about 120 g/l, said substituted alkyl amine corresponding to the following structural formula: ##STR3## Wherein: R 1 is an organic radical ##STR4## in which x and y=1 to 4; R, R 2 and R 3 is H or --CH 2 ] z X in which z=1 to 6 and X is --OH, --SO 3 H, --COOH, --NH 2 , halide, --CH 3 , or --OCH 3 , as well as the alkali metal salts of the foregoing.