US 9,809,899 B2
Treatment for electroplating racks to avoid rack metallization
Roderick D. Herdman, Staffordshire (GB); Trevor Pearson, West Midlands (GB); Roshan V. Chapaneri, West Midlands (GB); and Alison Hyslop, Birmingham (GB)
Filed by MacDermid Acumen, Inc., Waterbury, CT (US)
Filed on Aug. 7, 2014, as Appl. No. 14/454,131.
Prior Publication US 2016/0040315 A1, Feb. 11, 2016
Int. Cl. C25D 5/54 (2006.01); C25D 5/56 (2006.01); C25D 17/08 (2006.01); C09D 181/00 (2006.01); C25D 5/34 (2006.01); C23C 18/16 (2006.01); C23C 18/20 (2006.01); C23C 18/22 (2006.01); C23C 18/30 (2006.01)
CPC C25D 17/08 (2013.01) [C09D 181/00 (2013.01); C23C 18/1653 (2013.01); C23C 18/2086 (2013.01); C23C 18/22 (2013.01); C23C 18/30 (2013.01); C25D 5/34 (2013.01)] 6 Claims
 
1. A method of metallizing non-conductive substrates, the method comprising the steps of:
a) mounting a non-conductive substrate to be metallized on one or more electroplating racks, wherein the one or more electroplating racks are coated with a plastisol composition to form a solid insulating coating on at least a portion of the one or more electroplating racks, the plastisol composition having dispersed therein an effective amount of an additive having the structure:

OG Complex Work Unit Drawing
 wherein R, R′, R″ and R′″ are either the same or are independently selected from C1-C10 alkyl, benzyl, substituted benzyl, phenyl, or substituted phenyl and M is a divalent metal cation, selected from the group consisting of nickel, copper and zinc;
b) etching the non-conductive substrate mounted on the one or more electroplating racks with an etchant that does not contain chromic acid;
c) activating the surface of the non-conductive substrate by immersing the one or more electroplating racks with the non-conductive substrate mounted thereon into a solution comprising palladium;
d) immersing the one or more electroplating racks containing the non-conductive substrate mounted thereon in an electroless metallization bath to electrolessly deposit metal thereon; and
e) electroplating the non-conductive substrate to plate metal thereon,
wherein the one or more electroplating racks coated with the plastisol composition remain free of the electrolessly deposited metal.