Photosensitive reducible silver ion-containing compositions
A photosensitive reducible silver ion-containing composition can be used to provide electrically-conductive silver metal in thin film or patterns on a substrate after irradiation with UV-visible light. The composition comprises: a) a non-hydroxylic-solvent soluble silver complex represented by the following formula (I): wherein L represents an α-oxy carboxylate; P represents a primary alkylamine; a is 1 or 2; b is 1 or 2; and c is 1, 2, 3, or 4, provided that when a is b, 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.
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 primary alkylamine,
the non-hydroxylic-solvent soluble silver complex being represented by the following formula (I):
(Ag + ) a (L) b (P) c (I)
wherein L represents the α-oxy carboxylate; P represents the primary alkylamine; 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) a photosensitizer that is either: an electron-accepting photosensitizer that upon absorption of incident electromagnetic radiation, is capable of oxidizing the α-oxy carboxylate; or an electron-donating photosensitizer that has an oxidation potential that is greater than the oxidation potential of the α-oxy carboxylate; and
c) a solvent medium comprising at least one non-hydroxylic solvent and less than 10 weight % of water based on the total weight of all solvents in the solvent medium,
wherein the non-hydroxylic-solvent soluble silver complex is present in an amount of at least 10 weight % and up to and including 90 weight %, based on the total weight of the photosensitive reducible silver ion-containing composition; and the photosensitizer is present in an amount of at least 0.5 weight % and up to and including 4 weight %, based on the total weight of the non-hydroxylic-solvent soluble silver complex.
2. The photosensitive reducible silver ion-containing composition of claim 1 , wherein the non-hydroxylic solvent is 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.
3. 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.
4. The photosensitive reducible silver ion-containing composition of claim 1 , wherein L is represented by the following formula (II):
wherein R 1 , R 2 , and R 3 are independently hydrogen or branched or linear alkyl groups.
5. The photosensitive reducible silver ion-containing composition of claim 1 , wherein P is a primary alkylamine having a boiling point of less than or equal to 175° C.
6. The photosensitive reducible silver ion-containing composition of claim 1 , wherein P is a primary alkylamine selected from the group consisting of propylamine, n-butylamine, t-butylamine, isopropylamine, 2,2,2-trifluoroethylamine, 2,2,3,3,3-pentafluoropropylamine, 3,3,3-trifluoropropylamine, 1,2-dimethylpropylamine, t-amyl amine, isopentylamine, 2-amino-3-methylbutane, 3,3-dimethyl-2-butylamine, 2-aminohexane, and sec-butylamine.