No rerack metal plating of electrically nonconductive articles

Claim 2

The process of claim 2 wherein the selected material is N, N-dimethylformamide.

Claim 3

The process of claim 2 wherein the selected material is N-methyl-2-pyrrolidone.

Claim 4

The process of claim 1 wherein the lower alkyl formamide is of the formula: wherein the R''s each represent a 1-4C alkyl group or a hydrogen atom with at least one R being a 1-4C alkyl group.

Claim 5

The process of claim 3 wherein the N,N-dimethylformamide is an aqueous solution of about 58-95 weight percent N,N-dimethylformamide concentration.

Claim 6

The process of claim 4 wherein the N-methyl-2-pyrrolidone is in an aqueous solution of at least about 80 weight percent N-methyl-2-pyrrolidone concentration.

Claim 7

A no rerack process for the metal plating of plastic articles on vinyl plastisol-coated racks, which comprises: a. contacting the vinyl plastisol-coated rack characterized by being susceptible to electroless metal plating, prior to racking the plastic articles destined to be plated, with a liquid material selected from the group consisting of a lower alkyl formamide, N-methyl-2-pyrrolidone, and mixtures thereof, for a period sufficient to render the rack substantially nonsusceptible to electroless plating of metal thereon during a subsequent chemical reduction metal plating step; b. racking plastic articles destined to be metal plated on the thus-treated rack; c. converting hydrophobic surfaces of the racked plastic articles to hydrophilic surfaces receptive to chemical reduction metal plating process aqueous solutions; d. activating the hydrophilic surfaces of the racked plastic articles; e. electrolessly metal plating the racked activated plastic article surfaces by contacting the articles with a chemical reduction metal plating solution until the article surfaces are rendered electrically conductive; and f. without reracking the electrolessly metal plated article, electroplating a metal layer onto the conductive surface of the articles while still on the same rack; g. the electroless metal plating of step (e) and hence the electroplating of step (f) occurring without any substantial metal plating of the rack.

Claim 8

The process of claim 8 wherein the racked plastic articles are sensitized prior to being activated.

Claim 9

The process of claim 9 wherein the selected material is N,N-dimethylformamide.

Claim 10

The process of claim 9 wherein the selected material is N-methyl-2-pyrrolidone.

Claim 11

The process of claim 8 wherein the lower alkyl formamide is of the formula wherein the R''s represent a 1-4C alkyl group or a hydrogen atom with at least one R being a 1-4C alkyl group.

Claim 12

The process of claim 9 wherein the electroless metal plating is electroless copper plating and the chemical reduction metal plating solution is a chemical reduction copper plating solution.

Claim 13

The process of claim 9 wherein the electroless metal plating is electroless nickel plating and the chemical reduction metal plating solution is a chemical reduction nickel plating solution.

Claim 14

The process of claim 9 wherein the contacting of the rack with the selected liquid material is effected by immersing the rack in a liquid bath thereof.

Claim 15

The process of claim 10 wherein the N,N-dimethylformamide is in an aqueous solution of about 58-95 weight N,N-dimethylformamide concentration.

Claim 16

The process of claim 11 wherein the N-methyl-2-pyrrolidone is in an aqueous solution of at least about 80 weight percent N-methyl-2-pyrrolidone concentration.

Claim 17

The process of claim 8 wherein the hydrophobic surfaces of the racked plastic articles are converted to the hydrophilic surfaces by immersing the racked articles in a conditioning solution comprising an aqueous acid solution containing concentrated sulfuric acid and chromic acid for a period sufficient to effect such conversion.

Claim 18

The process of claim 8 wherein the electroplating of the racked articles is of a copper electroplate layer onto the conductive surfaces thereof.

Claim 19

The process of claim 19 further characterized by electroplating one or more final metal electroplate layers over the copper electroplate layer while the articles are still on the same rack.

Claim 20

A preconditioned vinyl plastisol-coated rack for holding articles destined to be metal plated and characterized by being substantially nonsusceptible to electroless plating deposition of metal thereon while immersed in a chemical reduction metal plating solution, the rack having been conditioned by contacting the same with a liquid material selected from the group consisting of N,N-dimethylformamide, N-methyl-2-pyrrolidone, and mixtures thereof for a time sufficient to render the rack substantially nonsusceptible to electroless plating deposition of metal thereon while in contact with the chemical reduction metal plating solution.

Claim 21

The rack of claim 21 wherein the selected material is N,N-dimethylformamide.

Claim 22

The rack of claim 21 wherein the selected material is N-methyl-2-pyrrolidone.