Printing ink

A method of printing on a surface which comprises:

• a. applying on the surface an ink comprising (a) a resin mixture consisting essentially of an epoxy resin combined with a second resin comprising a substantially anhydrous water-soluble thermosetting stable methylated urea-formaldehyde resin wherein the weight of the methoxyl subtituents therein is between 28 and 40% of the weight of the resin and the molar ratio of the reacted formaldehyde in said resin to said methoxyl substituents is such that in the absence of organic solvent the resin at 25.degree. C is soluble to the extent of at least 50% by weight in water and dissolves at least 50% of its weight of toluene, the polymeric form of said resin being not substantially in excess of tetrameric, the molar ratio of reacted urea to reacted formaldehyde in said resin and the molar ratio of reacted formaldehyde to reacted methanol therein being within the ranges:
• ______________________________________ Molar ratio Ranges Urea :CH.sub.2 O :CH.sub.3 OH CH.sub.2 O :CH.sub.3 OH ______________________________________ Lower 1 2.2 1.3 1 1.10 Upper 1 2.8 2.0 1 2.15 ______________________________________
• and said resin comprising essentially of ##STR11## units, --CH.sub.2 bridges between said units, and --H, --CH.sub.2 OH and --CH.sub.2 OCH.sub.3 substituents;
• and (b) a pigment, to form an inked surface.

A method of forming a solvent-free printing ink, which comprises:

• a. forming a liquid resin mixture consisting essentially of an epoxy resin and a second resin, comprising a substantially anhydrous water-soluble thermosetting stable methylated urea-formaldehyde resin wherein the weight of the methoxyl substituents therein is between 28 and 40% of the weight of the resin and the molar ratio of the reacted formaldehyde in said resin to said methoxyl substituents is such that in the absence of organic solvent the resin at 25.degree. C. is soluble to the extent of at least 50% by weight in water and dissolves at least 50% of its weight of toluene, the polymeric form of said resin being not substantially in excess of tetrameric, the molar ratio of reacted urea to reacted formaldehyde in said resin and the molar ratio of reacted formaldehyde to reacted methanol therein being within the ranges:
• ______________________________________ Molar ratio Ranges Urea :CH.sub.2 O :CH.sub.3 OH CH.sub.2 O :CH.sub.3 OH ______________________________________ Lower 1 2.2 1.3 1 1.10 Upper 1 2.8 2.0 1 2.15 ______________________________________
• and said resin consisting essentially of ##STR12## units, --CH.sub.2 bridges between said units, and --H, --CH.sub.2 OH and --CH.sub.2 OCH.sub.3 substituents;
• and
• b. combining said liquid resin mixture with a pigment to form the ink.

A method of selectively depositing a metal on a surface, which comprises:

• a. sensitizing the surface with a sensitizing species capable of catalyzing a metal deposition from an electroless metal deposition solution;
• b. selectively coating said sensitized surface with at least a resin coat comprising a reactive resin combined with a second resin comprising a substantially anhydrous water-soluble thermosetting stable methylated urea-formaldehyde resin wherein the weight of the methoxyl substituents therein is between 28 and 40% of the weight of the resin and the molar ratio of the reacted formaldehyde in said resin to said methoxyl substituents is such that in the absence of organic solvent the resin at 25.degree. C. is soluble to the extent of at least 50% by weight in water and dissolves at least 50% of its weight of toluene, the polymeric form of said resin being not substantially in excess of tetrameric, the molar ratio of reacted urea to reacted formaldehyde in said resin and the molar ratio of reacted formaldehyde to reacted methanol therein being within the ranges:
• ______________________________________ Molar ratio Ranges Urea :CH.sub.2 O :CH.sub.3 OH CH.sub.2 O :CH.sub.3 OH ______________________________________ Lower 1 2.2 1.3 1 1.10 Upper 1 2.8 2.0 1 2.15 ______________________________________
• and said resin consisting essentially of ##STR13## units, --CH.sub.2 bridges between said units, and --H, --CH.sub.2 OH and --CH.sub.2 OCH.sub.3 substituents to delineate an exposed sensitized surface pattern;
• and
• c. treating said selectively coated surface with a desensitizing agent to desensitize said exposed pattern and sensitize said resin coat.