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

Definitions

• This invention relates to a method and bath for obtaining bright metal electrodeposits. It more particularly relates to the use of sulfonic acid derivatives of thioamides or isothioamides for obtaining bright metal electrodeposits.
• Another object of this invention is to provide electroplating bath brightener compounds which have high stability and long life.
• the compounds. used as brighteningragents in accordance with the invention have the general. structural for .wherein R, R and R", represent hydrocarbon radicals,
• R and/or R may also be hydrogen atoms.
• R and R may further form a polymethylene chain, so that the -thioamide group is a member ofa heterocyclic ring.
• Thehydrocarbon radicals are R and R"
• Brightening agents of this type are, for example,
• am-ide-N'-(propane w-sulfonic acid) betain am-ide-N'-(propane w-sulfonic acid) betain.
• the production of these compounds takes place, for example by reaction of the thioamides or isothioamide-S- esters with' organic amino sulfo-nic acids'or their salts.
• the isothioami'de S s'ters may also be reacted with haloalkanesulfonic acids or sultones.
• Suitable sulfonic .acids are. primarily those of the. aliphatic or aromatic series which react with the "thioamides or isothioamides in aqueous or non-aqueous, for example in' alcoholic solution or suspension.
• the reaction with the sultones may also take place in the -molten state. The reactions proceed readily and smoothly and as a rule produce high yields,
• thioamides or isothioamides which generally contain no sulfonic acid groups may be simultaneously used. In this manner'the working temperature may be increased up to .55" C. and
• wetting agents and ductility improving agents such as amino compounds free from carboxyl groups.
• ductility improving agents such as amino compounds free from carboxyl groups.
• the addition of the last-mentioned agents has the effect that inorganic impurities, such as those which are present in the hardness components of water and in technical grade metal salts, will not have a detrimental eifect upon the brightening effect.
• Amino compounds free from carboxyl groups of this type are, for example, N,N,N',N-tetraethyl-l,3-diamino propanol-2; N,N,N',N'-tetrahydroxyethyl-ethylene diamine-Z diethylamino-ethylchloride l; N,N dimethyl 4- bromoanilin-3-diethylamino-l-chloropropanol-Z; as well as halogen salts of quartenary ammonium compounds which have been formed from the last-mentioned substituents by internal rearrangement, as well as sulfuric acid derivatives which are derived from the first-mentioned amino compounds, such as N,N,N',N'-tetra-n-butyl-l,3- diaminopropanol-Z-monosulfuric acid ester and piperazine-N,N'-bis-(2-hydroxypropane-sulfonic
• the brightening agents according to the invention may also be advantageously used in an acid direct copper plating process, that is a process in which the, metal ob jects are treated prior to electroplating in an acid pickling bath containing inhibitors with a high inhibiting effect, and subsequently directly electroplated in said copper baths containing the agents accordinging to the invention, without intermediate rinsing.
• the brightening agents according to the invention may he used in acid, cyanide and alkaline electroplating baths for the production of copper, zinc, cadmium, tin, brass, bronze, silver and gold electroplates.
• the brightening agents are added to the baths in quantities from 0.001 gm./liter to 5 gm./liter, preferably from 0.05 to 0.03 gin/liter, and the electroplating process is carried out at bath temperatures from room temperature to 60? C., in alkaline baths up to 90 C., and'in current density ranges from 0.5 a'mp/dm. to 16 amp/dink, in'alkaline baths up to 40 am'pJdmP.
• Example I A customary acid copper electroplating 'bath which contained 210 gin/liter CuSO .5H O, 60 gm./ liter H 80, and as' brightening agent 2 gmJliter of a condensation product of dodecylalcohol and mols ethylene oxid Which had been 25% transformed into. the sulfuric acid ester, was modified with 0.3 gun/liter of the sodium saltof"caprothiolactam-N-(propane-w-sulfonic acid) having the structural formula Ii QHs-CHa-C mom nt usom A; brightening agent for the acid copper hath illustrated in Example I:
• Example IV Uniform brass electroplates. on iron and steel objects were. obtained when these materials were electroplated in a bath which contained 30 gm./liter copper cyanide, 9.4 gm./liter zinc cyanide, 56 gm./liter sodium cyanide,
• Example VII A tin electroplating bath which contained 420 gm./ liter potassium stannate and 22.5 gm./liter potassium hydroxide was modified with 3.5 gm./liter of potassium salt of caprothiolactam Ns(propane-w-sultonic acid). At current densitiesfofZ to 40 amp/din. and attemperatures
• Example VIII Thioacetamide N (propane w sulfonic acid) sodium salt having the following structural formula:
• CHa-(f-NH-CHI CHICHZ-S O N8 may be prepared by the following method. 16.1 gm./ liter (0.1 mol) w-aminopropanesodium sulfonate and 7.5 gm. (0.1 mol) thioacetamide were dissolved in 50 cc. water and the solution was heated for some time to 80 C., whereby ammonia escaped. After the evolution of ammonia had ceased the solution was evaporated in a vacuum. 20.7 gm. of a greenish-yellow product remained as a residue, which was purified by dissolving it in a small amount of water and reprecipitating it by adding an ether-acetone mixture. The use of this compound as a brightening agent is illustrated in Example II.
• CHr-(fi-SCHr- N-CHzCHgCHz-SOsNB may be prepared by the following method. 20.1 gm. of
• a method for producing bright metal electrodeposits on a base metal which comprises adding as a brightening compound to the electroplating bath solution containing a compound of the metal to be electrodeposited, a sulfonic acid compound having a structural formula, selected from the group consisting of:
• R and R are selected from the group consisting of hydrogen, hydrocarbon radicals, and taken together a polymethylene chain of a heterocyclic ring, and R" is a hydrocarbon radical, said brightening agent being added in sufiicient amount to obtain said bright electrodeposits.
• R and R are selected from the group consisting of hydrogen, hydrocarbon radicals, and taken together a polymethylene chain of heterocyclic ring, and R" is a hydrocarbon radical, and
• a method for producing bright copper electrodeposits on a base metal which comprises adding as a brightening compound to an acid copper electroplating bath solution a sulfonic acid "compound having a structural formula, selected from the'group consisting of:
• R and R' are selected from the group consisting of hydrogen, hydrocarbon radicals, and taken together a polymethylene chain of a heterocyclic ring, and R is a hydrocarbon radical, said brightening agent being added in sufficient amount to obtain said bright electrodeposits.
• An electroplating bath for producing bright metal electrodeposits on base metals which comprises an aqueous solution of a compound of the metal to be deposited and a brightening compound which is a sulfonic ama s acid compound having a structural formula, selected from the group consisting of: i i r R R"SO;H
• R and R are selected from the group consisting of hydrogen, hydrocarbon radicals, and taken together a polymethylene chain of a heterocyclic ring, and R" is a hydrocarbon radical, said brightening agent being added in sufficient amount to obtain said bright electrodeposits.
• An electroplating bath as defined in claim 7 selected from the group consisting of acid, cyanide and alkaline baths.
• An electroplating bath for producing bright metal elec'trodepositson base metals which comprises an aqueous solution of a compound of the metal to be deposited, a brightening compound which is a 'sulfonic acid compound having a structural formula, selected from the group consisting of:
• R and R are selected from the group consisting of hydrogen, hydrocarbon radicals, and taken together a'polyrnethylene chain of a heterocyclic ring, and R is a hydrocarbon radical, and in addition compounds having a structural formula selected from the group consisting of ,S RI wherein R, R and R" represent groups as above defined, said brightening agent being added in sufficient amount to obtain said bright electrodeposits.
• An acid copper electroplating bath for directly producing bright copper electrodeposits on base metals which comprises an aqueous acid solution of a copper salt and a brightening compound which is a sulfonic acid compound having a structural formula, selected from the group consisting of:
• N.-- R"-s0,rr R-G SR and their alkali metal salts wherein R and R are s e lected from the group consisting of hydrogen, hydrocarbon radicals, and taken together a polymethylene chain of a heterocyclic ring, and R is a hydrocarbon radical, said brightening agent being added in sufficient amount to obtain said bright electrodeposits.

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• 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)

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Cited By (8)

Citations (12)

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  • NL NL238490D patent/NL238490A/xx unknown
• 1958
  • 1958-04-26 DE DED27981A patent/DE1204044B/de active Pending
• 1959
  • 1959-03-02 BE BE576264A patent/BE576264A/fr unknown
  • 1959-03-16 CH CH7083259A patent/CH405863A/de unknown
  • 1959-04-14 GB GB12562/59A patent/GB875846A/en not_active Expired
  • 1959-04-20 US US807290A patent/US3075899A/en not_active Expired - Lifetime
  • 1959-04-24 FR FR793038A patent/FR1235348A/fr not_active Expired

Patent Citations (13)

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