Forming silver catalytic sites from silver phosphite carboxylates
View Patent ↗A non-aqueous metal catalytic composition includes (a) a silver carboxylate-trialkyl(triaryl)phosphite complex comprising reducible silver ions in an amount of at least 2 weight %, (b) a silver ion photoreducing composition in an amount of at least 1 weight %, and (c) a photocurable component or a non-curable polymer or a combination of a photocurable component and a non-curable polymer. This non-aqueous metal catalytic composition can be used to form silver metal particles in situ during suitable reducing conditions. The silver metal can be provided in a suitable layer or pattern on a substrate, which can then be subsequently subjected to electroless plating to form electrically-conductive layers or patterns for use in various articles or as touch screen displays in electronic devices.
1. A method for providing an article, comprising:
providing a metal catalytic pattern composed of a non-aqueous metal catalytic composition on a substrate, the non-aqueous metal catalytic composition comprising, in admixture:
(a) a silver complex comprising reducible silver ions, in an amount of at least 2 weight % and up to and including 25 weight %, which silver complex comprising reducible silver ions is represented by
L n AgX
wherein L n is trimethyl phosphite, triethyl phosphite, tri-iso-propyl phosphite, tri n-butyl phosphite, tri-iso-propyl phosphite, tri-iso-butyl phosphite, triamyl phosphite, tri-n-hexyl phosphite, tri-n-octyl phosphite, tri-n-nonyl phosphite, tri(ethylene glycol) phosphite, tri(propylene glycol) phosphite, tri(iso-propylene glycol) phosphite, tri(n-butylene glycol) phosphite, tri(iso-butylene glycol) phosphite, tri(n-pentylene glycol) phosphite, tri(n-hexylene glycol) phosphite, tri(n-nonylene glycol) phosphite, tri(diethylene glycol) phosphite, tri(triethylene glycol) phosphite, tri(polyethylene glycol) phosphite, tri(polypropylene glycol) phosphite, or tri(polybutylene glycol) phosphite, triphenyl phosphite, or a mixture thereof,
X is a carboxylate, and
n is 1, 2, or 3,
(b) a silver ion photoreducing composition in an amount of at least 1 weight % and up to and including 10 weight %, and
(c) a photocurable component, non-curable polymer, or a combination of a photocurable component and a non-curable polymer in an amount of at least 10 weight % and up to and including 97 weight %,
all amounts being based on the total amount of components (a) through (c) in the non-aqueous metal catalytic composition,
to provide a precursor article comprising the metal catalytic pattern composed of the non-aqueous metal catalytic composition, and
photoreducing the reducible silver ions to silver particles in the method catalytic pattern by imagewise exposure of the precursor article to radiation having a wavelength of at least 250 nm and up to and including 700 nm.
2. The method of claim 1 , comprising:
photoreducing the reducible silver ions to silver particles in the metal catalytic pattern in the presence of oxygen.
3. The method of claim 1 , wherein the silver complex containing reducible silver ions is silver acetate-triethylphosphite complex, silver acetate-tri-n-butylphosphite complex, silver benzoate-triethylphosphite complex, or silver acetate-triphenylphosphite complex.
4. The method of claim 1 , wherein the silver ion photoreducing composition comprises a free radical photoinitiator.
5. The method of claim 1 , comprising:
photoreducing the reducible silver ions to silver particles having an average particle size of at least 10 nm and up to and including 1000 nm and at least 80% of the number of the silver particles have a particle size of at least 10 nm and up to and including 100 nm.
6. The method of claim 1 , further comprising, after photoreducing the reducible silver ions to silver particles:
electrolessly plating a metal onto the silver particles in the metal catalytic pattern.
7. The method of claim 1 , further comprising, after photoreducing the reducible silver ions to silver particles:
removing silver complex containing reducible silver ions from the metal catalytic pattern, and
electrolessly plating a metal other than silver onto the silver particles in the metal catalytic pattern.
8. The method of claim 1 , wherein the non-aqueous metal catalytic composition further comprises an inert organic solvent.
9. The method of claim 1 , wherein the photocurable component or non-curable polymer acts as an organic solvent and no inert organic solvents are purposely added to the non-aqueous metal catalytic composition.
10. The method of claim 1 , wherein the silver complex comprising reducible silver ions, is one or more of the following compounds AgC-1 through AgC-7 wherein “iPr” is an isopropyl group:
11. The method of claim 1 , wherein the non-aqueous metal catalytic composition further comprises an inert organic solvent.