Reducing agent and method for the electroless deposition of silver
First Claim
1. In a method for the electroless deposition of metallic silver wherein a substrate is contacted with an aqueous alkaline medium containing a water soluble ionic silver composition capable of reduction to metallic silver and a reducer for said composition, the improvement which comprises providing as said reducer an effective amount of a compound represented by the general formula,
where n is two (2) to seven (7), R2 is represented by the formula COOH or CH2 R1, each R1 group is independently selected from the class consisting of OH, NH2, NHCH3, NHC2 H5 and NHC3 H7 and at least one of the R1 groups is NH2, NHCH3, NHC2 H5 or NHC3 H7.
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Accused Products
Abstract
A brighter, more uniform deposit of electroless silver is achieved over a wider temperature range by employing as a reducer a compound represented by the general formula:
R.sup.2 --(CHR.sup.1).sub.n --CH.sub.2 OH
where n is two (2) to seven (7), R2 is represented by the formula COOH or CH2 R1, each R1 group is independently selected from the class consisting of OH, NH2, NHCH3, NHC2 H5 or NHC3 H7 and at least one of the R1 groups is NH2, NHCH3, NHC2 H5 or NHC3 H7.
Preferred reducers are N-methylglucamine, d-glucamine and glucosaminic acid.
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Citations
33 Claims
- 1. In a method for the electroless deposition of metallic silver wherein a substrate is contacted with an aqueous alkaline medium containing a water soluble ionic silver composition capable of reduction to metallic silver and a reducer for said composition, the improvement which comprises providing as said reducer an effective amount of a compound represented by the general formula,
- space="preserve" listing-type="equation">R.sup.2 --(CHR.sup.1).sub.n --CH.sub.2 OH
where n is two (2) to seven (7), R2 is represented by the formula COOH or CH2 R1, each R1 group is independently selected from the class consisting of OH, NH2, NHCH3, NHC2 H5 and NHC3 H7 and at least one of the R1 groups is NH2, NHCH3, NHC2 H5 or NHC3 H7. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
- 24. In a silvering solution comprising an aqueous alkaline medium containing a water soluble ionic silver composition capable of reduction to metallic silver and a reducer for said composition, the improvement which comprises providing as said reducer an effective amount of a compound represented by the general formula,
- space="preserve" listing-type="equation">R.sup.2 --(CHR.sup.1).sub.n --CH.sub.2 OH
where n is two (2) to seven (7), R2 is represented by the formula COOH or CH2 R1, each R1 group is independently selected from the class consisting of OH, NH2, NHCH3, NCHC2 H5 and NHC3 H7 and at least one of the R1 groups is NH2, NHCH3, NHC2 H5 or NHC3 H7. - View Dependent Claims (25, 26, 27, 28)
- 29. In a reducer solution for silvering comprising an aqueous alkaline medium containing a strong base and a reducer capable of reducing an ionic silver composition to metallic silver, the improvement which comprises providing as said reducer an effective amount of a compound represented by the general formula.
- space="preserve" listing-type="equation">R.sup.2 --(CHR.sup.1).sub.n --CH.sub.2 OH
where n is two (2) to seven (7), R2 is represented by the formula COOH or CH2 R1, each R1 group is independently selected from the class consisting of OH, NH2, NHCH3, NHC2 H5 and NHC3 H7 and at least one of the R1 groups is NH2, NHCH3, NHC2 H5 or NHC3 H7. - View Dependent Claims (30, 31, 32, 33)
Specification