PHOTOSENSITIVE REDUCIBLE SILVER ION-CONTAINING COMPOSITIONS
A photosensitive reducible silver ion-containing composition can be used to provide electrically-conductive silver metal in thin films or patterns. This composition comprises: a) a non-hydroxylic-solvent soluble silver complex represented by formula (I): wherein P represents a 5- or 6-membered N-heteroaromatic compound; a is 1 or 2; b is 1 or 2; and c is 1, 2, 3, or 4, but when a is 1, b is 1, and when a is 2, b is 2; b) optionally, a photosensitizer; and c) a solvent medium having a non-hydroxylic solvent. Electrically-conductive silver can be provided by photochemical conversion of the reducible silver ions in the complex. L is represented by formula (III): wherein R 4 is a branched or linear alkyl group having 1 to 8 carbon atoms and any of hydrogen atoms of the R 4 branched or linear alkyl group optionally can be replaced with a fluorine atom.
1 . A photosensitive reducible silver ion-containing composition comprising:
a) a non-hydroxylic-solvent soluble silver complex comprising a reducible silver ion complexed with an α-oxy carboxylate and a 5- or 6-membered N-heteroaromatic compound,
the non-hydroxylic-solvent soluble silver complex being represented by the following formula (I):
wherein L represents the α-oxy carboxylate represented by the following formula (III):
wherein R 4 is a branched or linear alkyl group having 1 to 8 carbon atoms and any of hydrogen atoms of the R 4 branched or linear alkyl group optionally can be replaced with a fluorine atom; P represents the 5- or 6-membered N-heteroaromatic compound; a is 1 or 2; b is 1 or 2; and c is 1, 2, 3, or 4, provided that when a is 1, b is 1, and when a is 2, b is 2;
b) optionally, a photosensitizer that can either reduce the reducible silver ion or oxidize the α-oxy carboxylate; and
c) a solvent medium comprising at least one non-hydroxylic solvent.
2 . The photosensitive reducible silver ion-containing composition of claim 1 , wherein the photosensitizer is present as an electron-accepting photosensitizer.
3 . The photosensitive reducible silver ion-containing composition of claim 1 , wherein the photosensitizer is present as an electron-donating photosensitizer.
4 . The photosensitive reducible silver ion-containing composition of claim 1 , wherein P is a 6-membered N-heteroaromatic compound.
5 . The photosensitive reducible silver ion-containing composition of claim 1 , wherein P is a 5- or 6-membered N-heteroaromatic compound that is selected from the group consisting of pyridine, 2-methylpyridine, 4-methylpyridine, 2,6-dimethylpyridine, 2,3-dimethylpyridine, 3,4-dimethylpyridine, 4-pyridylacetone, 3-chloropyridine, 3-fluoropyridine, oxazole, 4-methyloxazole, isoxazole, 3-methylisoxazole, pyrimidine, pyrazine, pyridazine, and thiazole.
6 . The photosensitive reducible silver ion-containing composition of claim 1 , wherein one or more non-hydroxylic-solvent soluble silver complexes are present in an amount of at least 5 weight % and up to and including 90 weight %, based on the total weight of the photosensitive reducible silver ion-containing composition.
7 . The photosensitive reducible silver ion-containing composition of claim 1 , wherein the solvent medium comprises one or more non-hydroxylic solvents selected from the group consisting of acetonitrile, benzonitrile, acetone, methyl ethyl ketone, butyronitrile, propylene carbonate, propionitrile, isovaleronitrile, valeronitrile, and a mixture of two or more of these organic solvents.
8 . The photosensitive reducible silver ion-containing composition of claim 1 that meets a silver ion stability test such that when the photosensitive reducible silver ion-containing composition is held for 24 hours at ambient temperature and in yellow safelight, less than 0.1 mol % of its original silver ion content is reduced to silver metal.
9 . The photosensitive reducible silver ion-containing composition of claim 1 , wherein the 5- or 6-membered N-heteroaromatic compound has an oxidation potential of at least 1.0 V vs. saturated calomel electrode (SCE); the α-oxy carboxylate has a first oxidation potential of at least 1.2 V vs. saturated calomel electrode (SCE); and upon decarboxylation of the α-oxy carboxylate, a second radical is generated that has an oxidation potential of less than 1.0 V vs. saturated calomel electrode (SCE).
10 . The photosensitive reducible silver ion-containing composition of claim 1 , wherein the 5- or 6-membered N-heteroaromatic compound has an oxidation potential of at least 1.5 V vs. saturated calomel electrode (SCE).
11 . The photosensitive reducible silver ion-containing composition of claim 1 , wherein:
a and b are both 1 and c is 1 or 2;
(ii) a and b are both 2 and c is 2; or
(iii) a and b are both 2 and c is 4.