Method of producing polymeric phenazonium compounds
View Patent ↗A process of making a polymeric phenazonium compound having the general formula: wherein R 1 , R 2 , R 4 , R 5 , R 6 , R 8 and R 9 are the same or different, and represent hydrogen, a low alkyl or a substituted aryl, R 3 starts as NH 2 and is diazotized followed by polymerization, R 5 and R 8 may alternatively represent monomeric or polymeric phenazonium radicals, R 7 is a carbon in the aromatic ring, and wherein R X —N—R Y represents a substituted amine, and R X and R Y represent any combination of CH 3 , C 2 H 5 , and hydrogen, except that R X and R Y cannot both be hydrogen, A is an acid radical, and n is an integer from 2 to 100. The polymeric phenazonium compound is usable in as an additive in a metal plating bath. The method includes the steps of: a) dissolving an effective amount of an amino compound in a formic acid solution; b) adding a nitrite salt to diazotize the amino compound; and c) adding sulfamic acid to neutralize any excess nitrous acid that may be formed in step b), whereby a polymeric phenazonium compound is produced.
1. A process of making a polymeric phenazonium compound having the general formula:
wherein R 1 , R 2 , R 4 , R 5 , R 6 , R 8 and R 9 are the same or different, and represent hydrogen, a low alkyl or a substituted aryl, R 3 starts as NH 2 and is diazotized followed by polymerization, R 5 and R 8 may alternatively represent monomeric or polymeric phenazonium radicals, R 7 is a carbon in the aromatic ring, and wherein R X —N—R Y represents a substituted amine, and R X and R Y represent any combination of CH 3 , C 2 H 5 ,
and hydrogen, except that R X and R Y cannot both be hydrogen, A is an acid radical, and n is an integer from 2 to 100, the method comprising the steps of:
a) dissolving an effective amount of an amino compound in a formic acid solution;
b) adding a nitrite salt to diazotize the amino compound; and
c) adding sulfamic acid to neutralize any excess nitrous acid that may be formed in step b), and produce a polymeric phenazonium compound.
2. The method according to claim 1 , wherein n is an integer from 2 to 20.
3. The method according to claim 1 , wherein the amino compound is selected from the group consisting of 2-methyl-3-amino-7-dimethylamino-5-phenyl-phenazonium sulfate, 3-amino-6-methyl-7-dimethylamino-5-phenyl-phenazonium hydrogen sulfate, 2-methyl-3-amino-7-diethylamino-5-phenyl-phenazonium chloride, 3-amino-7-dimethylamino-5-methyl phenazonium acetate, 2-methyl-3-amino-7-phenylamino-5-phenyl-phenazonium hydrogen sulfate, 2-methyl-3-amino-7-dimethylamino-phenazonium hydrogen sulfate, 3-amino-7-methylamino-5-phenylphenazonium acetate, 2-phenyl-3-amino-7-ethylamino-5-phenyl-phenazonium chloride, 1,2,6,9-tetramethyl-3-amino-7-diethylamino-5-phenyl-phenazonium hydrogen sulfate, 2,8-dimethyl-3-amino-7-diethylamino-5-tolyl-phenazonium chloride, and 2,9-diphenyl-3-amino-6-methyl-7-dimethylamino-5-phenyl-phenazonium hydrogen sulfate.
4. The method of claim 1 , wherein the nitrite salt is sodium nitrite.
5. The method according to claim 1 , wherein the amino compound is dissolved in the formic acid at a temperature of between about −10 about 0° C.
6. The process according to claim 1 , wherein after step b) the reaction is warmed to at least 20° C.
7. The process according to claim 1 , further comprising the step of adding the polymeric phenazonium compound to an acid copper electrolyte bath.
8. The process according to claim 1 , wherein the concentration of the amino compound in the formic acid solution is between about 100 g/l and about 200 g/l.
9. The process according to claim 8 , wherein the concentration of the amino compound in the formic acid solution is between about 120 g/l and about 185 g/1.
10. The process according to claim 1 , wherein the process of producing the polymeric phenazonium compound does not include a step of neutralizing the polymeric phenazonium compound with a base.
11. The process according to claim 1 , wherein substantially no outgassing of nitrogen occurs.
12. The process according to claim 1 , wherein the concentration of polymerized phenazonium in the polymeric phenazonium compound is between about 30 g/l about 34 g/l.
13. A process of making a polymeric phenazonium compound having the general formula:
wherein R 1 , R 2 , R 4 , R 5 , R 6 , R 8 and R 9 are the same or different, and represent hydrogen, a low alkyl or a substituted aryl, R 3 starts as NH 2 and is diazotized followed by polymerization, R 5 and R 8 may alternatively represent monomeric or polymeric phenazonium radicals, R 7 is a carbon in the aromatic ring, and wherein R X —N—R Y represents a substituted amine, and R X and R Y represent any combination of CH 3 , C 2 H 5 ,
and hydrogen, except that R X and R Y cannot both be hydrogen, A is an acid radical, and n is an integer from 2 to 100, the method consisting essentially of the steps of:
a) dissolving an effective amount of an amino compound in a formic acid solution;
b) adding a nitrite salt to diazotize the amino compound; and
c) adding sulfamic acid to neutralize any excess nitrous acid that may be formed in step b), and produce a polymeric phenazonium compound.