Substrates seeded with precious metal salts, process for producing the same and their use
AssigneeRobert Bosch GmbH
InventorsLothar Weber, Thomas Brinz, Ulrich Eisele, Dorothee Kling
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Abstract
To provide a substrate enclosed in a uniform nucleation layer, a substrate is nucleated with a noble metal salt where the noble metal salt is chemically bound to the substrate, and a method is described for binding a noble metal salt chemically to a substrate. To provide a metal plated powder, a powder is nucleated with a noble metal salt and the nucleation is coated with a metal layer. A method is also provided for nucleating the powder surface with a noble metal salt in such a manner that it is chemically bound to the substrate and then metal plated by a conventional electroless method.
Claims30
A substrate nucleated with a noble metal salt, comprising:
- a portion having a substrate surface, the noble metal salt being chemically bonded to the substrate surface by a first group X—(K)m and a second group X, the first and second groups being capable of bonding to the substrate surface via at least one oxygen bridge,
- wherein K is a group capable of complexing the noble metal salt,
- wherein m is an integer between 1 and 3,
- wherein X is selected from a group consisting of a hydrocarbon moiety, a zirconyl moiety, a titanyl moiety, and a further moiety which includes aluminum, and
- wherein K is a π function.
A method for a nucleation of substrates using a noble metal salt, the substrate having a substrate surface which is one of an oxidic surface and a surface coated with an oxide film, the method comprising the steps of:
- chemically bonding the noble metal salt on the substrate surface via a chemical reaction by mediating an at least bifunctional compound having a formula (A)n—X—(K)m, the bifunctional compound being capable of entering into a further compound via the substrate surface and the noble metal salt, wherein A is a first group which is reactable with a hydrate shell on an oxide for forming an oxygen bridge to a second group X, wherein X is selected from a group consisting of a hydrocarbon moiety, a zirconyl moiety, a titanyl moiety, and a further moiety which includes aluminum, wherein K is a π function and is a group which is capable of complexing the noble metal salt, and wherein n and m are integers having values between 1 and 3;
- and
- reacting the first group with a soluble complex noble metal compound which is capable of a ligand exchange with the π function.
A powder nucleated with a noble metal salt, comprising:
- a nucleation portion which is coated with a metal layer, the nucleation portion including a nucleation surface, the noble metal salt being chemically bonded to the nucleation surface by a first group X—(K)m and a second group X, the first and second groups being capable of bonding to the nucleation surface via at least one oxygen bridge,
- wherein K is a group capable of complexing the noble metal salt,
- wherein m is an integer between 1 and 3,
- wherein X is selected from a group consisting of a hydrocarbon moiety, a zirconyl moiety, a titanyl moiety, and a further moiety which includes aluminum, and
- wherein K is a π function.
A method for metal plating a powder having a powder surface, comprising the steps of:
- (a) chemically bonding a noble metal salt to the powder surface;
- (b) nucleating the powder surface with the chemically bound noble metal salt via a chemical reaction by mediating an at least bifunctional compound having a formula (A)n—X—(K)m, the bifunctional compound being capable of entering into a further compound via the powder surface and the noble metal salt, wherein A is a first group which is reactable with a hydrate shell on an oxide for forming an oxygen bridge to a second group X, wherein X is selected from a group consisting of a hydrocarbon moiety, a zirconyl moiety, a titanyl moiety, and a further moiety which includes aluminum, wherein K is a π function and is a group which is capable of complexing the noble metal salt, and wherein n and m are integers having values between 1 and 3;
- (c) reacting the first group with a soluble complex noble metal compound which is capable of a ligand exchange with the π function;
- (d) after step (c), electroless metal plating the powder surface;
- and
- (e) after step (c), electroless metal plating the powder in a bath containing at least one salt of at least one metal to be applied and a reducing agent having a reduction potential, the reduction potential being coordinated with the at least one salt.
Dependencies are inferred from the claim text.