Forming catalytic sites from reducible silver-heterocyclic complexes
View Patent ↗A non-aqueous metal catalytic composition includes (a) a complex of silver and a hindered aromatic N-heterocycle 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, 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 complex of silver and a hindered aromatic N-heterocycle comprising reducible silver ions, in an amount of at least 2 weight % and up to and including 25 weight %, wherein the silver complex of a hindered aromatic N-heterocycle is represented by the following structure:
wherein n is 1 to 4; m is 1 to 4; p is 1 to 4; q is 1 to 4;
X is a coordinating or non-coordinating anion;
R b and R c are independently H, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group; and
R a and R d are independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group,
(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, a 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 amounts of components (a) through (c) in the non-aqueous metal catalytic composition,
to provide a precursor article comprising the metal catalytic layer or the metal catalytic pattern composed of the non-aqueous metal catalytic composition,
photoreducing the reducible silver ions to silver particles in the metal catalytic layer or the metal 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, and
electrolessly plating a metal other than silver onto the silver particles in the metal catalytic layer or metal catalytic pattern.
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 , 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.
4. The method of claim 1 , wherein the non-aqueous metal catalytic composition further comprises an inert organic solvent.
5. The method of claim 1 , wherein the photocurable component or non-curable polymer acts as an organic solvent medium and no additional inert organic solvents are purposely added to the non-aqueous metal catalytic composition.
6. The method of claim 1 , wherein the non-aqueous metal catalytic composition further comprises an inert organic solvent.
7. The method of claim 1 , wherein the substrate is a continuous transparent polymeric web.
8. The method of claim 7 , comprising:
providing two or more metal catalytic patterns on two or more portions of the continuous transparent polymeric web using ink jetting or flexographic printing,
exposing the two or more metal catalytic patterns to radiation for photoreducing the silver ions to silver particles in each of the two or more metal catalytic patterns in the two or more portions of the continuous transparent polymeric web, and
electrolessly plating the silver particles in the two or more portions of the continuous transparent polymeric web with an electrically conductive metal, to provide two or more electrically-conductive patterns of electrically-conductive metal on the continuous transparent polymeric web.
9. The method of claim 8 , comprising forming electrically-conductive patterns on both supporting sides of the continuous transparent polymeric web to provide the same or different two or more electrically-conductive patterns of an electrically-conductive metal on both supporting sides of the continuous transparent polymeric web.
10. The method of claim 8 , comprising forming two or more electrically-conductive product articles from the two or more electrically-conductive patterns on the continuous transparent polymeric web.
11. The method of claim 10 , further comprising assembling the two or more electrically-conductive product articles into the same or different devices.
12. 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 complex of silver and a hindered aromatic N-heterocycle comprising reducible silver ions, in an amount of at least 2 weight % and up to and including 25 weight %,
(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, a 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 amounts 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,
photoreducing the reducible silver ions to silver particles in the metal 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, and
electrolessly plating a metal other than silver onto the silver particles in the metal catalytic pattern,
wherein the complex of silver and the hindered aromatic N-heterocycle is one or more of the following AgPy-1 through AgPy-9:
13. 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 complex of silver and a hindered aromatic N-heterocycle comprising reducible silver ions, in an amount of at least 2 weight % and up to and including 25 weight %,
(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, a 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 amounts 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,
photoreducing the reducible silver ions to silver particles in the metal 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, and
electrolessly plating a metal other than silver onto the silver particles in the metal catalytic pattern,
wherein the complex of silver and a hindered aromatic N-heterocycle is a silver-benzthiazole complex, silver-pyrimidine complex, silver-pyrazine complex, silver benzoxazole complex, or a combination thereof.