Compositions for and methods of improving adhesion of plated metal on plastic substrates

Claim 1

The process of increasing the adhesion of plated metal on polypropylene substrates, which comprises immersing the substrate in aqueous emulsion of an organic latent adhesion promoter consisting essentially of: a. linseed oil 3 grams b. turpentine 3 grams c. linoleic acid 1.5 grams d. surfactant 2 % by volume e. deionized water to make 300 mls. total solution f. potassium hydroxide to give a pH of about 8.0 then oxidizing the resulting substrate to develop said adhesion promoter, and thereafter plating the oxidized substrate.

Claim 8

The method of plating a polystyrene substrate with a metal film by chemical deposition from an aqueous solution containing a soluble salt of the metal to be deposited, which comprises the steps of a. cleaning the surface of the resin substrate by immersing it in a hot aqueous alkaline solution; b. withdrawing the substrate from said cleaning solution and immersing it in the aqueous adhesion promoting emulsion consisting essentially of: a. linseed oil 3 grams b. turpentine 3 grams c. linoleic acid 1.5 grams d. surfactant 2% by volume e. water to make 300 mls. total solution f. potassium hydroxide to give a pH of about 8, for a period of about 10 minutes at a temperature of approximately 170* F; c. rinsing the substrate and immersing it in a chromic-sulfuric acid oxidizing solution consisting essentially of about 30 percent (weight) chromic acid, 25 percent (weight) sulfuric acid (66* Be), the balance being water, maintaining said substrate in said oxidizing solution while at a temperature of about 170* F for 5 minutes; d. removing and thoroughly rinsing said substrate in water, then immersing it in an aqueous solution of phosphoric acid containing 10-20 ppm of a surface active agent for about 5 minutes; e. removing and rinsing the substrate in water and then immersing it in a colloidal activating solution comprising about 20 percent (volume) of concentrated hydrochloric acid, 60-70 percent (volume) water and from 10-20 percent (volume) of the following composition: Wt. % PdCl2 0.16 HCl (37%) 58.0 Water (deionized) 33.9 SnCl2 (anhydrous) 6.82 Na2SnO3 .3H2O 1.13 and maintaining said substrate in said activating solution for about 5 minutes at 80* F; f. removing said substrate, rinsing in water and then immersing it in an aqueous accelerating solution containing approximAtely 2 pounds of fluoroboric acid per gallon for 1 minute at 110* F; g. removing and rinsing the substrate and immersing it in an aqueous electroless copper or nickel plating solution to deposit an adherent film of the metal on said substrate.

Claim 9

The method of plating a polystyrene substrate with a metal film by chemical deposition from an aqueous solution containing a soluble salt of the metal to be deposited, which comprises the steps of a. cleaning the surface of the resin substrate by immersing it in a hot aqueous alkaline solution; b. withdrawing the substrate from said cleaning solution and immersing it in the aqueous adhesion promoting emulsion consisting essentially of: a. linseed oil 3 grams b. turpentine 3 grams c. linoleic acid 1.5 grams d. surfactant 2% by volume e. water to make 300 mls. total solution f. potassium hydroxide to give a pH of about 8, for a period of about 10 minutes at a temperature of approximately 170* F; c. rinsing the substrate and immersing it in a chromic-sulfuric acid oxidizing solution consisting essentially of about 30 percent (weight) chromic acid, 25 percent (weight) sulfuric acid (66* Be), the balance being water, maintaining said substrate in said oxidizing solution while at a temperature of about 170* F for 5 minutes; d. removing and thoroughly rinsing said substrate in water, then immersing it in an aqueous solution of phosphoric acid containing 10-20 ppm of a surface active agent for about 5 minutes; e. removing and rinsing the substrate in water and then immersing it in a colloidal activating solution comprising about 20 percent (volume) of concentrated hydrochloric acid, 60-70 percent (volume) water and from 10-20 percent (volume) of the following composition: Wt. % PdCl2 0.16 HCl (37%) 58.0 Water (deionized) 33.9 SnCl2 (anhydrous) 6.82 Na2SnO3 .3H2O 1.13 and maintaining said substrate in said activating solution for about 5 minutes at 80* F; f. removing said substrate, rinsing in water and then immersing it in an aqueous accelerating solution containing approximAtely 2 pounds of fluoroboric acid per gallon for 1 minute at 110* F; g. removing and rinsing the substrate and immersing it in an aqueous electroless copper or nickel plating solution to deposit an adherent film of the metal on said substrate.