Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/56—Electroplating: Baths therefor from solutions of alloys
  • C25D3/60—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of tin

Definitions

• the present invention is directed to improved baths and process for electroplating tin-nickel alloys and to bright tin-nickel electrodeposits.
• Electrodeposits for electrodepositing tin-nickel have excellent throwing power. Although the electrodeposits obtained from commercial baths are fairly attractive, the deposits are not as clear and bright as required for most decorative applications. Only those deposits plated over a bright undercoat in thicknesses less than 6 microns appear bright. Essentially here the deposit is transparent. In thicknesses greater than 6 microns, there is a slight white clouding-over of the deposit resulting in a hazy deposit, which increases with increased thickness. It is desirable to have a clear, lustrous deposit and even more desirable to have a clear, bright deposit. We have now discovered a process utilizing special baths from which we are able to electrodeposit bright tin-nickel.
• the invention also contemplates improved baths electrodepositing lustrous, clear and bright tin-nickel alloys in thicknesses greater than 6 microns.
• the invention further contemplates a process for electrodepositing lustrous, clear, and bright tin-nickel electrodeposits in thicknesses greater than 6 microns.
• lustrous and bright tin-nickel electrodeposits may be obtained from acidic baths which contain an effective amount of a brightener.
• specific compounds and combinations of specific compounds are effective brightene-rs for tin-nickel alloy electrodeposition.
• the electrodeposit may be made on dull basis metals, although this is not preferred. As deposited initially, the tin-nickel is fairly bright and as electrodeposition continues, the deposit becomes increasingly bright resulting in a lustrous deposit. Tin-nickel as electrodeposited from standard baths may be described as cloudy-bright. The deposit has a slight white clouded appearance. It is not lustrous. We have been able to increase brightness to (i) hazy-bright, a slight background haze in an essentially clear deposit, and (ii) clear-bright, brightness approaching that normally associated with a mirror. By using the various additives specified hereinafter, it is possible to obtain hazy-bright and/or clear-bright deposits. These deposits are lustrous.
• Lustrous and bright deposits are obtained from acid baths containing, as a brightener, phenylpropiolic acid; phenylpropiolic amide; triaminotriphenyl methane; l-(p-aminophenyl)-3-methylpyrazole; steanamidopropyldimethyl-(fl hydroxyethyhammoniurn dihydrogen phosphate; or 1,S-diphenyloarbohydrazide.
• phenylpropiolic acid phenylpropiolic amide
• triaminotriphenyl methane l-(p-aminophenyl)-3-methylpyrazole
• steanamidopropyldimethyl-(fl hydroxyethyhammoniurn dihydrogen phosphate or 1,S-diphenyloarbohydrazide.
• Phenylpropiolic acid, phenylpropiolic amide, and triaminotriphenyl methane are useful brighteners when added to the baths in amounts between 0.01 g./l. and 0.3 g./ 1.; preferably baths containing 0.05 g./l. and 0.2 g./l. are used.
• l-(p-aminophenyl)-3-methylpyrazole is a useful brightener when added to the bath in amounts between 0.05 g./l. and l g./l.; preferably baths containing 0.2 g./l. and 0.5 g./l. are used.
• Stearamidopropyldimethyl- (fi-hydroxyethyl-ammonium dihydrogen phosphate is a useful brightener when added to the bath in amounts between 0.001 g./l. and 0.2 vg./l.; preferably baths com 1,5-diphenylcarbohydrazide is a useful brightener when added to the bath in amounts between 0.05 g./l. and 0.5 g./l.; preferably baths containing 0.2 g./l. and 0.3 g./l. are used.
• the bath contains less than the minimum concentration specified for each brightener. Smaller concentrations may be extremely effective when more than one brightener is used in combination.
• the maximum preferred concentration specified for each brightener is that concentration at which acceptable brightness will be achieved with the variation of conditions to be found in commercial practice. Above the preferred maximum concentration specified, the deposit tends to become brittle at high current densities (above about 7.5 amp./ sq. dm.). Above the maximum concentration specified, the brittleness becomes severe enough to cause cracking and some exfoliation so that the current density range is substantially reduced.
• Phosphoric acid and its salts have also been discovered to be brighteners.
• Phosphoric acid when added to the bath in amounts between 0.1 g./l. and 15 g./l., and preferably between 0.5 g./l. and 7 g./l., results in lustrous, hazybright deposits.
• the brightness activity is most significant in the 0.5-7.0 g./l. range. Although amounts in excess of 7.0 g./l. up to 15 g./l. do not appear to produce an increase in the brightness of the deposit, this presence does not give detrimental effects. Above about 15 g./l., the deposit possesses a grainy appearance. Concentrations of less than 0.5 g./l.
• Phosphoric acid as used herein includes the ortho, pyro, metaand hypo-phosphoric acid as well as the equivalent series of salts.
• the potassium, sodium, and ammonium salts are preferred.
• Combinations of the various brighteners give unusually good deposits; in particular, deposits approaching mirrorbrightness have been obtained by using phosphoric acid in combination with one of the other brighteners.
• the ranges in which the individual brighteners are effective are also the same general ranges in which they are effective in combination, it is possible to use amounts smaller than the minimum specified concentration of one brightener, in combination with another brightener in relatively higher concentrations.
• the combinations of brighteners are particularly preferred in that the brightest deposits are obtained with combinations of brighteners.
• the use of phosphoric acid in combination with one of the other brighteners has been particularly useful in that it tends to broaden the limits of the range of concentrations of brightener permitted in the bath.
• a preferred method of incorporating the brightener in the bath is to add a water solution containing g./l. to 200 g./l. of phosphoric acid and 5 g./l. to 50 g./l. of at least one of the other brighteners specified herein.
• Tin-nickel is deposited from acid baths, primarily from chloride and/ or fluoride baths.
• the preferred baths contain both chloride and fluoride anions; stannous tin in the amounts of 26 g./l. to 37.5 g./l.; and nickel in amounts between 60 g./l. and 82.5 g./l.
• the total fluorine for new baths is between 34 g./l. and 45 g./l. in the mixed baths.
• the stannic tin concentration increases in baths which are in operation. As this occurs, the fluorine should be increased so that it at least equals the total tin in the bath.
• the chloride content is not critical.
• the pH is maintained between 2 and 3.5, generally by the addition of ammonium hydroxide or hydrofluoric acid.
• the baths should also contain a suitable agent.
• a class of agents which has been found to be satisfactory includes a sulfonated cyclic fluorocarbon such as perfluoro-4-methyl cyclohexyl sulfonic acid; perfluorocyclohexyl sulfonic acid; perfluoro-Z-methyl cyclohexyl sulfonic acid; perfluoro-1-rnethyl cyclohexyl sulfonic acid; perfluoro-2,5-dimethyl cyclohexyl sulfonic acid; perfluoro-4- ethyl cyclohexyl sulfonic acid; perfluoro-4-isopropyl cyclohexyl sulfonic acid; and the salts of these acids.
• the bath is operated at high temperatures, preferably between 65
• All-chloride baths are generally operated at lower pHs, i.e., not greater than about 1, by the addition of hydrochloric acid.
• the tin is added in the form of stannous chloride, and the nickel in the form of nickel chloride. All of the baths are initially made up by adding the noted chemicals to water. However, equivalent chemicals may be added, e.g., stannous tin may be added in the form of the oxide or the fluoride, as well as the chloride.
• the tin and nickel may be replaced either chemically or by anodic corrosion of metallic anodes or a combination of both.
• tin-nickel approximately 65% tin and 35% nickel
• the physical appearance of the deposit obtained in each example is described. As noted they are lustrous and bright and in some cases they are a clear-bright.
• Triaminotriphenyl methane was added to the standard bath in the amount of 0.25 g./l.
• a small copper plated zinc die cast handle was plated at an average current density of approximately 2.3 amperes per square decimeter (amp/sq. dm.) for 25 minutes to an average thickness of approximately 20 microns.
• the deposit was clear-bright over the decorative area of the handle to give a lustrous, attractive article.
• EXAMPLE 2 Triaminotriphenyl methane in the amount of 0.05 g./l. was added to the standard bath which was placed in a Hull Cell. In this plating cell, a smooth brass panel was plated as cathode for 10 minutes with the current adjusted so that the current density ranged from a low of approximately 0.0'5 amp/sq. dm. at one end of the panel to about 8 amp./ sq. dm. at the other end of the panel. The average thickness of the tin-nickel was approximately 9 microns and the thickness at the high current density end of the panel was approximately 27 microns. The deposit was hazy-bright in appearance over the entire panel.
• Phenylpropiolic acid in the amount of 0.2 g./l. was added to the standard bath in a small plating tank.
• Tinnickel was plated directly on a steel cathode at an average current density of 2.3 amp/sq. dm. for 45 minutes to give an average thickness of approximately 40 microns. At this thickness 2.
• hazy-bright deposit was obtained over the surface of the cathode.
• Phenylpropiolic acid in the amount of 0.04 g./l. was added to the standard bath formulation in a Hull Cell. With a smooth brass panel as cathode plated at 2.7 amp/sq. dm. for minutes, the deposit was hazybright.
• Phenylpropiolic amide in the amount of 0.25 g./l. was added to the standard tin-nickel bath in a Hull Cell.
• a smooth brass panel was plated at an average current density of 2.7 amp/sq. dm. for ten minutes. At the end of this time the plate was clear-bright and lustrous over all but the high current density edge of the current density range.
• Phenylpropiolic amide in the amount of 0.2 g./l. was added to the standard tin-nickel bath in a small laboratory tank.
• a copper-plated zinc die cast handle was plated at approximately 2.3 amp./ sq. dm. for 30 minutes.
• An average tin-nickel thickness of approximately 23 microns was obtained. The deposit was clear-bright and lustrous.
• Phenylpropiolic amide in the amount of 0.1 g./l. was added to the standard tin-nickel bath formulation in a Hull Cell.
• a smooth brass panel was plated for 10 minutes at an average current density of 2.7 amp/sq. dm., the deposit obtained was clear-bright over the entire current density range.
• EXAMPLE 9 The compound l-(p-aminophenyl)-3-methylpyrazole in the amount of 0.5 g./l. was added to the standard tinnickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp./ sq. dm. for 10 minutes. The tin-nickel deposit was clearbright over the entire panel.
• EXAMPLE 10 The compound 1-(p-aminophenyl)-3-methylpyrazole in the amount of 0.1 g./l. was added to the standard tinnickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp/sq. dm. for 10 minutes. The tin-nickel deposit was clearbright over the entire panel.
• EXAMPLE 11 The compound, stearamidopropyldimethyl-(/3-hydroxyethyl)-ammonium dihydrogen phosphate in the amount of 0.12 g./1. was added to the standard tin-nickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp/sq. dm. for 10 minutes. The tin-nickel deposit was clear-bright over the entire panel.
• EXAMPLE 13 The compound 1,S-diphenylcarbohydrazide in the amount of 0.4 g./l. was added to the standard tin-nickel 0 formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp/sq. dm. for 10 minutes. The tin-nickel deposit was hazy-bright over the entire panel.
• EXAMPLE 14 The compound 1,S-diphenylcarbohydrazide in the amount of 0.10 g./l. was added to the standard tin-nickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp./ sq. dm. for 10 minutes. The tin-nickel deposit was hazy-bright over the entire panel.
• EXAMPLE 15 The compound, phosphoric acid (H PO in the amount of 11 g./l. was added to the standard tin-nickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp./ sq. dm. for 10 minutes. The tin-nickel deposit was clear-bright over the area of the panel below about 3 amp/sq. dm. and hazy-bright on areas above about 3 amp/sq. dm.
• H PO phosphoric acid
• EXAMPLE 16 The compound, phosphoric acid (H PO in the amount of 6 g./l. was added to the standard tin-nickel formulation ina Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp/sq. dm. for 10 minutes. The tin-nickel deposit was hazy-bright over the entire panel.
• H PO phosphoric acid
• EXAMPLE 17 The compound, phosphoric acid (H PO in the amount of 0.6 g./l. was added to the standard tin-nickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp./ sq. dm. for 1-0 minutes. The tin-nickel deposit was hazy-bright over the entire panel.
• H PO phosphoric acid
• EXAMPLE 18 A combination of phenylpropiolic acid, 0.08 g./l., and stearamidopropyldimethyl (fl-hydroxyethyDammonium hydrogen phosphate, 0.003 g./l., was added to the standard tin-nickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp./ sq. dm. for 10 minutes. The tin-nickel deposit was clear-bright over the entire panel.
• EXAMPLE 19 A combination of stearamidopropyldimethyl-(ti-hydroxyethyl)ammonium dihydrogen phosphate, 0.12 g./l. and phosphoric acid, 1.8 g./l. was added to the standard tin-nickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp/sq. dm. for 10 minutes. The tin-nickel deposit was clear-bright over the entire panel.
• EXAMPLE 20 A combination of phenylpropiolic acid, 0.04 g./l. and phosphoric acid, 0.6 g./l., was added to the standard tinnickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp/sq. dm. for 10 minutes. The tin-nickel deposit was clearbright over the entire panel.
• EXAMPLE 21 A combination of phenylpropiolic amide, 0.06 g./l. and phosphoric acid, 1 g./l., was added to the standard tinnickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp/sq. dm. for 10 minutes. The tin-nickel deposit was clearbright over the entire panel.
• EXAMPLE 22 A combination of triaminotriphenyl methane, 0.02 g./l., and phosphoric acid, 0.5 g./l., was added to the standard tin-nickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp./ sq. dm. for 10 minutes. The tin-nickel deposit was clear-bright over the entire panel.
• EXAMPLE 23 A combination of l-(p-aminophenyl)-3-methy1pyrazole, 0.1 g./l., and phosphoric acid, 0.8 g./l., was added to the standard tin-nickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 an1p./ sq. dm. for 10 minutes. The tin-nickel deposit was clear-bright over the entire panel.
• EXAMPLE 24 A combination of 1,S-diphenylcarbohydrazide, 0.1 g./l., and phosphoric acid, 2.0 g./l. was added to the standard tin-nickel formulation in a Hull Cell. A smooth brass panel was plated at an average current density of 2.7 amp/sq. dm. for 10 minutes. The tin-nickel deposit was hazy-bright over the entire panel.
• An acidic aqueous electrolyte for bright tin-nickel plating containing Sn++ ions, Ni++ ions and an effective amount of at least one brightener selected from the class consisting of phenylpropiolic acid, phenylpropiolic amide, triaminotriphenyl methane, 1-(p-aminophenyl)-3-methylpyrazole, stearamidopropyldimethyl-(p-hydroxyethyl)ammonium dihydrogen phosphate, 1,5-diphenylcarbohydrazide and phosphoric acid, to cause the tin-nickel electrodeposit to be lustrous and bright.
• at least one brightener selected from the class consisting of phenylpropiolic acid, phenylpropiolic amide, triaminotriphenyl methane, 1-(p-aminophenyl)-3-methylpyrazole, stearamidopropyldimethyl-(p-hydroxy
• An acidic aqueous electrolyte for the electrodeposition of bright tin-nickel containing Sn++ ions, Ni ions and as a brightener between 0.01 g./l. and 0.3 g./l. of phenylpropiolic acid.
• An acidic aqueous electrolyte for the electrodeposition of bright tin-nickel containing Sn++ ions, Ni++ ions and as a brightener between :05 g./l. and 0.2 g./l. of phenylpropiolic acid.
• An acidic aqueous electroyte for the electrodeposition of bright tin-nickel containing Sn++ ions, Ni++ ions and as a brightener between 0.01 g./l. and 0.3 g./l. of phenylpropiolic amide.
• An acidic aqueous electrolyte for the electrodeposition of bright tin-nickel containing Sn++ ions, Ni++ ions and as a brightener between 0.05 and 0.2 g./l. of phenylpropiolic amide.
• An acidic aqueous electrolyte for the electrodeposition of bright tin-nickel containing Sn++ ions, Ni++ ions and as a brightener between 0.01 g./l. and 0.3 g./l. of triaminotriphenyl methane.
• An acidic aqueous electrolyte for the electrodeposition of bright tin-nickel containing Sn++ ions, Ni++ ions and as a brightener between 0.05 g./l. and 0.2 g./l. of triaminotriphenyl methane.
• An acidic aqueous electrolyte for the electrodeposition of bright tin-nickel containing Sn++ ions, Ni++ ions and as a brightener between 0.05 g./l. and 1 g./l. of l-(paminophenyl) -3-methy1pyrazole.
• An acidic aqueous electrolyte for the electrodeposition of bright tin-nickel containing Sn ions, Ni++ ions and as a brightener between 0.001 g./l. and 0.2 g./l. of stearamidopropyldimethyl (5 hydroxyethyl)ammoniurn dihydrogen phosphate.
• An acidic aqueous electrolyte for the electrodeposition of bright tin-nickel containing Sn++ ions, Ni++ ions and as a brightener between 0.05 g./l. and 0.5 g./l. of l,5-diphenylcarbohydrazide.
• a composition of matter capable of brightening activity when incorporated in an acidic tin-nickel electroplating bath said composition containing water and 5 g./l. to 200 g./l. of phosphoric acid and 5 g./l. to 50 g./l. of at least one compound selected from the class consisting of phenylpropiolic acid, phenylpropiolic amide, triaminotriphenyl methane, l-(p-aminophenyl)-3-methylpyrazole, stearamidopropyldimethyl (B hydroxyethyl)- ammonium dihydrogen phosphate, and 1,5-diphenylcarbohydrazide.
• the improvement comprising adding to said electrolyte an amount of at least one brightener selected from the class consisting of phenylpropiolic acid, phenylpropiolic amide, triaminotriphenyl methane, l-(p-aminophenyl)-3-methylpyrazole, stearamidopropyldimethyl (,8 hydroxyethyD- ammonium dihydrogen phosphate, 1,5-diphenylcarbohydrazide and phosphoric acid, sufficient to cause the tinnickel electrodeposit to be lustrous and bright.
• at least one brightener selected from the class consisting of phenylpropiolic acid, phenylpropiolic amide, triaminotriphenyl methane, l-(p-aminophenyl)-3-methylpyrazole, stearamidopropyldimethyl (,8 hydroxyethyD- ammonium dihydrogen phosphate, 1,5-dipheny
• a chlorine and fluorine containing acidic bath for tin-nickel electroplating having a pH between about 2 and 2.5, and containing between 26 g./l. and 37.5 g./l. of Sn++ ions, between 60 g./l. and 82.5 g./l. of Ni++ ions, between 34 g./1. and 45 g./l.
• tin-nickel electrodeposit containing an effective amount of at least one brightener selected from the class consisting of phenylpropiolic acid, phenylpropiolic amide, triaminotriphenyl methane l-(p-aminophenyl) 3 methylpyrazole, stearamidopropyldimethyl (flhydroxyethyhammonium dihydrogen phosphate, 1,5-diphenylcarbohydrazide and phosphoric acid, to cause the tin-nickel electrodeposit to be lustrous and bright.
• at least one brightener selected from the class consisting of phenylpropiolic acid, phenylpropiolic amide, triaminotriphenyl methane l-(p-aminophenyl) 3 methylpyrazole, stearamidopropyldimethyl (flhydroxyethyhammonium dihydrogen phosphate, 1,5-diphenylcarbohydrazi
• the bath of claim 19 containing about 49 g./l. of stannous chloride, about 300 g./l. of hydrated nickel chloride, about 56 g./l. of ammonium bifluoride, and sufficient ammonium hydroxide to adjust the pH to between 2 and 2.5.
• a chlorine and fluorine containing acidic bath for tin-nickel electroplating having a pH between about 2 and 2.5, and containing between 26 g./l. and 37.5 g./l. of Sn++ ions, between 60 g./l. and 82.5 g./1. of Ni++ ions, between 34 g./l. and 45 g./l. of F ions, and containing between 0.01 g./l. and 0.3 g./l. of phenylpropiolic acid.
• the bath of claim 21 containing about 49 g./l. of stannous chloride, about 300 g./l. of hydrated nickel chloride, about 5 6 g./l. of ammonium bifiuoride, and sufficient ammonium hydroxide to adjust the pH to between 2 and 2.5.

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Citations (9)

• 0
  • NL NL266076D patent/NL266076A/xx unknown
• 1960
  • 1960-06-17 US US36750A patent/US3141836A/en not_active Expired - Lifetime
• 1961
  • 1961-05-31 GB GB19714/61A patent/GB983365A/en not_active Expired
  • 1961-06-16 DE DEM73346A patent/DE1260914B/de active Pending
  • 1961-06-16 DE DEM73350A patent/DE1260918B/de active Pending
  • 1961-06-16 DE DEM73348A patent/DE1260916B/de active Pending
  • 1961-06-16 DE DEM73347A patent/DE1260915B/de active Pending
  • 1961-06-16 DE DEM73349A patent/DE1260917B/de active Pending
  • 1961-06-16 BE BE605099A patent/BE605099A/fr unknown
  • 1961-06-16 DE DEM49376A patent/DE1247802B/de active Pending

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