Electroplating bath for depositing chromium or chromium alloy and process for depositing chromium or chromium alloy
AssigneeMacDermid, Incorporated
InventorYoann Coll
Life of this patent
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Abstract
An electroplating bath for depositing chromium or chromium alloys from a trivalent chromium bath that includes: (1) at least one trivalent chromium ion, (2) at least one complexing agent, (3) at least one halogen salt, and (4) at least one stabilizing agent which is different from the complexing agent, wherein the electroplating bath has a pH from 4 to 7 and is substantially free of divalent sulphur compounds and boric acid, its salts and/or derivatives and wherein the molar ratio of the complexing agent to the trivalent chromium ion is from 8:1 to 15:1. A process for depositing chromium or chromium alloys onto a substrate is also included.
Claims22
An electroplating bath for depositing chromium or chromium alloys from a trivalent chromium bath comprising:
- a) 0.2 to 1 mol/L of at least one trivalent chromium ion,
- b) 2 to 10 mol/L of at least one complexing agent, wherein the at least one complexing agent is selected from the group consisting of formic acid, acetic acid, propionic acid, lactic acid, malic acid, citric acid, succinic acid, gluconic acid, glycine, aspartic acid, glutamic acid, and mixtures thereof, or their salts and mixtures thereof,
- c) 0.01 to 0.5 mol/L of at least one halogen salt,
- d) 0.01 to 1 mol/L of at least one stabilizing agent, wherein the at least one stabilizing agent is selected from the group consisting of glycolic acid, tartaric acid, pyruvic acid, and mixtures thereof, or their salts and mixtures thereof,
- e) 0 to 10 g/L of at least one additive, wherein the at least one additive is selected from the group consisting of:
- brighteners,
- wetting agents, and
- combinations thereof,
- wherein the electroplating bath has a pH from 4 to 7 and is substantially free of divalent sulphur compounds and boric acid, its salts and/or derivatives and wherein the molar ratio of the complexing agent to the trivalent chromium ion is from 8:1 to 15:1,
- wherein the electroplating bath is substantially free of chloride ions.
An electroplating bath for depositing chromium or chromium alloys from a trivalent chromium bath consisting essentially of:
- a) 0.2 to 1 mol/L of at least one trivalent chromium ion,
- b) 2 to 10 mol/L of at least one complexing agent, wherein the at least one complexing agent is selected from the group consisting of formic acid, acetic acid, propionic acid, lactic acid, malic acid, citric acid, succinic acid, gluconic acid, glycine, aspartic acid, glutamic acid, and mixtures thereof, or their salts and mixtures thereof,
- c) 0.01 to 0.5 mol/L of at least one halogen salt,
- d) 0.01 to 1 mol/L of at least one stabilizing agent, wherein the at least one stabilizing agent is selected from the group consisting of glycolic acid, tartaric acid, pyruvic acid, and mixtures thereof, or their salts and mixtures thereof,
- e) 0 to 10 g/L of at least one additive, wherein the at least one additive is selected from the group consisting of:
- brighteners,
- wetting agents, and
- combinations thereof,
- wherein the electroplating bath has a pH from 4 to 7 and is substantially free of divalent sulphur compounds and boric acid, its salts and/or derivatives and wherein the molar ratio of the complexing agent to the trivalent chromium ion is from 8:1 to 15:1.
An electroplating bath for depositing chromium or chromium alloys from a trivalent chromium bath consisting of:
- a) 0.2 to 1 mol/L of at least one trivalent chromium ion,
- b) 2 to 10 mol/L of at least one complexing agent, wherein the at least one complexing agent is selected from the group consisting of formic acid, acetic acid, propionic acid, lactic acid, malic acid, citric acid, succinic acid, gluconic acid, glycine, aspartic acid, glutamic acid, and mixtures thereof, or their salts and mixtures thereof,
- c) 0.01 to 0.5 mol/L of at least one halogen salt,
- d) 0.01 to 1 mol/L of at least one stabilizing agent, wherein the at least one stabilizing agent is selected from the group consisting of glycolic acid, tartaric acid, pyruvic acid, and mixtures thereof, or their salts and mixtures thereof,
- e) 0 to 10 g/L of at least one additive, wherein the at least one additive is selected from the group consisting of:
- brighteners,
- wetting agents, and
- combinations thereof,
- wherein the electroplating bath has a pH from 4 to 7 and is substantially free of divalent sulphur compounds and boric acid, its salts and/or derivatives and wherein the molar ratio of the complexing agent to the trivalent chromium ion is from 8:1 to 15:1,
- wherein the electroplating bath is substantially free of chloride ions.
Dependencies are inferred from the claim text.