Method for electroplating high-impact plastics

A method electroplating an impact resistance plastic article comprising the following steps:

• providing a substrate of a polycarbonate which has been modified with between about 15 percent and about 50 percent by weight of acrylonitrile-butadiene-styrene;
• conditioning a surface of said substrate with a halogenated organic solvent conditioner at a temperature no higher than 120.degree. F. and for a duration sufficient to increase the amount of exposed acrylonitrile-butadiene-styrene at said conditioned surface, said organic solvent conditioner consisting of between about 5 and about 25 volume percent of a halogenated hydrocarbon in an aqueous medium, said halogenated hydrocarbon chosen from the group consisting of alcohols, ketones, and ethers;
• rinsing said conditioned surface of said substrate in water;
• etching said conditioned surface of said substrate with an acidic solution at a temperature of approximately 140.degree. F. to 180.degree. F. and for a duration of up to ten (10) minutes sufficient to roughen said conditioned surface;
• wherein said acidic solution is made by providing an aqueous sulfuric acid solution having a normality of about 10.5 to about 11.0 and then adding to each gallon of solution about 3.5 to about 4.0 pounds of chromic acid;
• rinsing said conditioned and etched surface of said substrate in water;
• neutralizing said conditioned and etched surface of said substrate in a neutralizing bath maintained at about 100.degree.-120.degree. F. for a time of about 0.5 to about 2.0 minutes;
• rinsing said conditioned and etched surface of said substrate in water;
• catalyzing said conditioned and etched surface of said substrate in a solution comprising between 20 to about 50 PPM palladium at between 80.degree. F. to 90.degree. F. for about 2 to 4 minutes;
• accelerating said catalyzed surface of said substrate in a solution comprising sulfuric acid and complexers to neutralize the effect of contaminates, at a temperature of between 110.degree. F. to 140.degree. F. for approximately one-half (1/2) to 3 minutes;
• electrolessly depositing a layer of a metal strike on said catalyzed and accelerated surface of said substrate;
• and
• electrochemically plating a metal onto said layer of said metal strike.