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
  • C25D3/12—Electroplating: Baths therefor from solutions of nickel or cobalt
  • C25D3/14—Electroplating: Baths therefor from solutions of nickel or cobalt from baths containing acetylenic or heterocyclic compounds
• • 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
  • C25D3/12—Electroplating: Baths therefor from solutions of nickel or cobalt
  • C25D3/14—Electroplating: Baths therefor from solutions of nickel or cobalt from baths containing acetylenic or heterocyclic compounds
  • C25D3/16—Acetylenic compounds

Definitions

• ABSTRACT A process for the production of semi-bright electrodeposits of nickel and nickel alloys containing at least 80 percent nickel wherein the electroplating bath used is an aqueous solution containing at least one nickel salt and brightening and/or leveling amounts of a propylene oxide adduct of propargyl alcohol and a coumarin material.
• the electroplating bath also contains butyne diol.
• This invention relates to an improved composition and process for the electrodeposition of metal and more particularly it relates to improved composition and process for the formation of semi-bright electrodeposits of nickel and nickel alloys.
• coumarin as an additive in Watts type nickel electroplating baths, to produce soft, ductile, lustrous deposits with excellent leveling is well known. It is further known that the degree of leveling obtained is, in general, proportional to the concentration of coumarin in the plating bath, at least within concentration ranges of about 0.05 to 0.3 grams per liter.
• an object of the present invention to provide an improved process for the production of bright electrodeposits of nickel and nickel-cobalt alloys containing at least 80 percent nickel.
• a further object of the present invention is to provide an improved electroplating bath in which bright nickel and nickel-cobalt alloy electroplates may be deposited.
• Another object of the present invention is to provide an improved additive composition for use in electroplating baths for the deposition of nickel and nickelcobalt alloy electroplates.
• the present invention includes a plating bath for the electrodeposition of nickel which comprises an aqueous solution of at least one nickel salt and brightening and/or leveling amounts of a propylene oxide adduct of propargyl alcohol and a coumarin material, as additives. Additionally, in a most preferred embodiment, the bath will also contain butyne diol. From this bath, there is electrodeposited a semi-bright, ductile nickel plate having excellent leveling properties.
• the electroplating baths used are aqueous solutions containing one or more nickel salts.
• such baths may be prepared by dissolving nickel chloride and/or nickel sulfate and boric acid in water.
• nickel electroplating baths based on nickel sulfate, nickel chloride, nickel formate, nickel sulfamate, nickel fluoroborate, or the like, as the nickel salt dissolved in the aqueous acidic solvent, may also be used. Additionally, the electroplating baths of the present invention may also contain one or more cobalt salts, of the same or similar type as the nickel salts have been indicated above. Where the electroplating baths used contain cobalt salts in addition to the nickel salts, the relative amount ofthese should be such that the resulting nickel-cobalt alloy electroplate produced contains at least about percent nickel.
• nickel electroplating baths will contain brightening and/or leveling amounts of a propylene oxide adduct of propargyl alcohol and a coumarin compound and, in a preferred embodiment, also butyne diol.
• brightening and leveling amounts, it is intended that each of these materials, when used, will be present in the electroplating bath in amounts such that the combination will be sufficient to promote the formation of a semi-bright, ductile and self-leveling nickel electrodeposit.
• the propylene oxide adducts of propargyl alcohol which are used have the formula:
• n is a number from 1 to 3.
• these adducts will be present in the electroplating bath in amounts within the range of about 1 to 20 milligrams per liter, with amounts within the range of about 2 to 10 milligrams per liter being preferred.
• coumarin compound or material in addition to coumarin itself, which is the most preferred, various substituted coumarins may also be used, such as 3-chlorocoumarin, 6-chlorocoumarin, 3-bromocoumarin, 3-acetyl coumarin, 7-hydroxy ethyl coumarin, S-methoxy coumarin, 7-ethoxycoumarin, 4,8-dimethyl coumarin, coumarin, 7 oxypropanesulfonic acid and the like.
• the coumarin or substituted coumarin compounds are present in the electroplating baths in I amounts within the range of about 0.025 to 0.5 grams per liter, with amounts within the range of about 0.05 to 0.3 grams per liter being preferred.
• the combination of the propylene oxide adduct of propargyl alcohol with the coumarin compound overcomes the adverse effects of the coumarin degradation products and results in a consistantly semibright deposit, it has been found that as the electroplating bath is used over an extended period of time, there is a gradual decrease in the leveling properties, for a given concentration of coumarin. This decrease in leveling is minimized by also including butyne diol in the bath, as an additional additive. In this manner, without increasing the coumarin concentration, a semibright nickel electrodeposit, having excellent leveling, is consistently produced. Accordingly, in its most preferred embodiment, the electroplating bath of the present invention will typically contain from about 3 to 60 milligrams/liter butyne diol, with amounts of from about 10 to 40 milligrams/liter being preferred.
• an aqueous acidic solution is formed containing the desired nickel or nickel and cobalt salts.
• these electroplating baths will have a pH within the range of about 3 to 4.5 and, depending upon the particular nickel salts used, will contain the nickel salts in amounts within the range of about 200 to 400 grams per liter.
• cobalt salts are also present in the electroplating baths, these will typically be present in amounts within the range of about 10 to 30 grams per liter, depending upon the particular salts used as well as the amount of the nickel salt which is present.
• this material is desirably present in amounts within the range of about 30 to 60 grams per liter. Additionally, the additive components are included in the electroplating bath in the amounts which have been indicated hereinabove.
• the electroplating solutions will typically be used at a temperature within the range of about 45 to 63 degrees centigrade.
• agitation of the solution either by air agitation, cathode rod agitation, mechanical agitation or the like, is preferred.
• semi-bright nickel electrodeposits are obtained over a wide current density range, e.g., 5 to 150 amps per square foot the typical average current densities used in the operation of the process are within the range of about 25 to 50 amps per square foot, with plating times of from about to 60 minutes.
• the coumarin degrada tion products will decrease the brightness and leveling obtained from a given concentration of coumarin, in a proportion to the melilotic acid concentration, thus requiring the use of greater amounts of coumarin to maintain the leveling
• the concentration of coumarin may be maintained at a consistent level even when appreciable amounts of melilotic acid are present, while still obtaining excellent brightness and leveling results.
• the propylene oxide adduct rather than the ethylene oxide material, there is an appreciable reduction in the health and safety hazards encountered in the preparation of this adduct, as well as a simplification of the preparation process.
• the safe inhalation level of propylene oxide is at least twice that of ethylene oxide while the range of concentrations of mixtures in air which are explosive is less than one third that of ethylene oxide. Additionally, unlike ethylene oxide, the preparation of the adduct can be carried out at atmospheric pressure.
• Example 2 The electroplating bath of Example I was electrolyzed for the equivalent of ampere hours per gallon to produce an appreciable concentration of degradation products, primarily melilotic acid.
• the coumarin concentration was adjusted to 0.15 grams/liter and upon electroplating for 20 minutes at an average current density of 40 amps/ft as in Example I, there was obtained a non-uniformly semi-bright nickel electro-deposit which had some darkness in the low current density areas. Additionally, the leveling of the deposit had declined, from that obtained in the previous Example, to only a moderate level.
• Example 3 To the electroplating bath of Example 2 there was added, in addition to the propargyl alcohol adduct, 25 milligrams/liter of butyne diol. Upon electroplating a steel panel under the same conditions of time and current density, there was obtained a nickel electrodeposit which was not only uniformly semi-bright with a bright low current density area but in which the leveling was restored to a high level which was equal to that obtained in Example 1.
• a plating bath for the electrodeposition of nickel which comprises an aqueous acidic solution of at least one nickel salt and, as additives, a coumarin compound and a propylene oxide adduct of propargyl alcohol, containing one to three moles of oxide per mole of alcohol, said adduct present in an amount ranging from about 2 to mg/l, said additives being present in the plating bath in amounts such that the combination thereof produces a semi-bright ductile, self-leveling nickel deposit.
• the plating bath as claimed in claim 2 in which the coumarin compound is present in an amount of from about .025 to 0.5 grams per liter, the propylene oxide propargyl alcohol adduct is present in an amount of from about 2 to 10 milligrams per liter and the butyne diol is present in an amount of from about 3 to 60 milligrams per liter.
• n is a number from 1 to 3.
• the plating bath as claimed in clalm 4 1n Wl'llCh the coumarin is present in an amount of from about 0.05 to 0.3 grams per liter, the propylene oxide-propargyl alcohol adduct is present in an amount of from about 2 to 10 milligrams per liter and the butyne diol is present in an amount of from about 10 to 40 milligrams per liter.
• a process for producing semi-bright nickel deposits which comprises electrodepositing nickel on a base from the electroplating bath as claimed in claim 1.
• n is a number from 1 to 3.
• the plating bath contains the coumarin compound in an amount of from about 0.025 to 0.5 grams per liter, the propylene oxide adduct of propargyl alcohol in an amount of from about 2 to 10 milligrams per liter and the butyne diol in an amount of from about 3 to 60 milligrams per liter.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electroplating And Plating Baths Therefor (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=26793147

Family Applications (2)

Family Applications After (1)

Country Status (7)

Cited By (4)

Families Citing this family (3)

Citations (2)

Family Cites Families (3)

• 1970
  • 1970-12-11 US US00097346A patent/US3719568A/en not_active Expired - Lifetime
• 1971
  • 1971-09-22 DE DE2147257A patent/DE2147257C3/de not_active Expired
  • 1971-09-27 CA CA123,811A patent/CA993832A/en not_active Expired
  • 1971-09-29 AU AU34014/71A patent/AU454350B2/en not_active Expired
  • 1971-11-02 GB GB5091671A patent/GB1338688A/en not_active Expired
  • 1971-11-23 FR FR7141897A patent/FR2117877B1/fr not_active Expired
  • 1971-12-09 NL NL7116879A patent/NL7116879A/xx unknown
• 1973
  • 1973-02-28 US US00336588A patent/US3795592A/en not_active Expired - Lifetime
• 1974
  • 1974-01-23 NL NL7400921A patent/NL7400921A/xx unknown
  • 1974-01-31 DE DE2404614A patent/DE2404614A1/de active Pending
  • 1974-02-28 GB GB910774A patent/GB1456583A/en not_active Expired
  • 1974-02-28 FR FR7406858A patent/FR2219241B1/fr not_active Expired

Patent Citations (2)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events