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

• R is a straight-chain or cyclic organic radical comprising at least two carbon atoms linked exclusively to oxygen, sulfur and/or nitrogen atoms, each of said carbon atoms being linked to a S-R SO H group,
• R is a bivalent lower aliphatic radical
• n is an integer equal to the number of said carbon atoms in the radical R, or water-soluble salts of such compounds.
• triazine derivatives having the structural formula Lia-Sean wherein R, has the meaning above indicated, or their water-soluble salts, such as the alkali metal or ammonium salts, are suitable as brightening additives for electroplating baths in accordance with the present invention.
• the bivalent radical R may, for instance, be a methylene, ethylene, propylene, hydroxypropylene, chloropropylene or similarradical.
• Such triazine compounds may, for example, be obtained by transforming tricyanogen chloride into trimercaptocyanuric acid, and thereafter reacting an alkali metal salt of the acid with an organic halogensulfonic acid, such as 2bromoethane-1'-sulfonic acid, 3-bromopropane-l-sulfonic acid, 3-chloro 2 hydroxypropane-l-sulfonic acid or their alkali metal salts, or with a sultonc, such as propanesultone or butanesult'one, to form the corresponding mercapto-alkanesulfonic acid triazine derivatives or their salts.
• an organic halogensulfonic acid such as 2bromoethane-1'-sulfonic acid, 3-bromopropane-l-sulfonic acid, 3-chloro 2 hydroxypropane-l-sulfonic acid or their alkali metal salts
• a sultonc such as propanesultone
• Suitable compounds havingthe above general Formula I are those wherein the radical R is a 5- or 6- membered heterocyclic radical with at least two nitrogen atoms.
• Compounds of this type are, for example, 1,3,4- thiodiazole-2,5-bis(mercaptopropane-l-sulfonic acid) Patented Aug. 26, 1958 ice , 2 1,3,4-thiodiazole-2,5-bis(mercapto 2 hydroxypropanel-sulfonic acid) or 1,3,4 oxdiazole 2,5 bis(mercaptopropane-Lsulfoiric acid) and the like, or their water-soluble salts, such as alkali metal and ammonium salts.
• the radical R in Formula I need not necessarily be a cyclic radical.
• acyclic compounds such as dithiobiuret-S,S'-dipropanesulfonic acid wherein R, has the meaning defined in Formula I and R is an aliphatic of aromatic radical, and their watersoluble salts.
• the dibas'ic S-alkanesulfonic acids may be obtained, for example, by reacting methylene, ethylene, hexamethyleneor phenylene-dithiourea with propanesultone, butanesultone or halogen-alkanesulfonic acids or alkali metal salts thereof,
• tribasic and higher polybasic S- alkanesulfonic acids and their water-soluble salts are effective as brightening agent's according to the present invention.
• the b'righteners disclosed herein may advantageously be employed in conjunction with all types of electroplating baths, and especially with electroplating solutions for the production of copper, nickel, silver, zinc, cadmium, bronze and brass electrodep'osits.
• the brightening additives in accordance with the present invention will produce bright and lustrous metal electrodeposits when used as the sole additives in electroplating baths, they may also be employed in combination with known brightening additives, smoothing agents, sequestering agents, inhibitors, anionic, cationic or electroneut'ral surface-active agents, salts which increase the conductivity of the bath and similar additives customarily used to improve the metal electrodeposits.
• suitable additional brightcners are those which are disclosed in copending application Serial No. 442,199, filed July 8, 1954.
• sequestering agents are compounds disclosed in copending applications Serial No. 458,984, filed September 28, 1954, and Serial No. 544,586, filed November 2, 1955, and in German Patent No. 934,508; in other words, the term sequestering agents is intended to designate those additives which prevent the mineral salts in hard water and impurities in the inorganic metal salt from interfering with the brightening effect of the brightening additive.
• the quantity of the S-alkanesulfonic acid compounds added to electroplating baths according to the present invention may range from 0.01 to 20 gm. per liter of bath.
• the effective current density range of such electroplating baths lies between 0.5 and 12 amp./dm. and the temperature of the solution may reach as high as 60 C.
• the current density range at which the optimum brightening effect is achieved will vary from one particular brightener to the other, but in general the range is of considerable breadth for the entire group of brighteners herein disclosed.
• the optimum current density range may, however, be broadened by employing a mixture of two or more members of the group.
• Electroplating baths modified in accordance with our invention may be employed to deposit metal electrodeposits on any desired customary base metal, such as iron, steel, zinc and similar non-precious metals or alloys thereof.
• the base metal may first be provided with a thin copper coating in a separate cyanide bath in customary fashion, or the base metal may be provided directly with the final copper plate without a preliminary thin copper base coat in accordance with the process disclosed in copending application Serial No. 458,983, filed September 28, 1954.
• electroplating baths modified in accordance with the present invention produce full-bright electrodeposits of extraordinary high quality which do not require subsequent bufling or polishing.
• Example I were dissolved in an acid aqueous copper sulfate bath -composed of water, 220 gm. per liter crystalline copper sulfate and 60 gm. per liter sulfuric acid. Sheet metal objects copper-plated in this electroplating solution at room temperature and at elevated temperatures up to 60 C. with a current density from 0.5 to 8 amp./dm.
• Example II The same full-bright copper electrodeposits were obtained when 0.2 to- 1.5 gm. per liter of the trisodium salt -(CHzh-BOaNB.
• Example I were added to the acid copper sulfate solution described in Example I instead of the trisodium salt of 1,3,5-triazine-2,4,6-tri-(mercaptopropane 1 sulfonic acid), and brass and iron objects were copper-plated therein under the conditions of temperature and current density described in Example I.
• Example III 0.5 to 1.0 gm. per liter of the disodium salt of 1,8,4- thiodiazole-Z,S-bis-(mercaptopropane 1 sulfonic acid) having the structural formula was added to an acid copper sulfate solution composed of water, 200 gm. per liter crystalline copper sulfate and 60 gm. per liter sulfuric acid. Brass and iron objects electroplated in this solution at current densities from 2 to 10 amp./dm. and at temperatures between room temperature and C. were provided with a full-bright, high-quality copper plate which required no buifing or polishing subsequent to rinsing.
• Example IV 0.2 to 1.0 gm. per liter of the dipotassium salt of N,N-methylene-di-(isothiourea-S-propane 1 sulfonic acid) having the structural formula was added to the acid copper sulfate solution of Example III instead of the disodium salt of l,3,4-thiodiazole-2,5-
• Brass and iron objects electroplated in this modified copper sulfate bath at current densities from 1 to 11 amp./dm. and at temperatures between room temperature and about C. were provided with full-bright, high-quality copper plates which required no bufiing or polishing.
• Example V 1.2 gm. per liter of the trisodium salt of 1,3,5-triazine- 2,4,6-tri-(mercaptopropane-Z-hydroxy 1 sulfonic acid) having the structural formula shown in Example II and 0.8 to 1.2 gm. per liter 1,3-bis-(dibutylamino)-propanol-2, described in said copending application Serial No. 458,984,
• Example VI From 1 to gm. per liter of the ammonium salt of 1,3,5-triazine-2,4,6-tri-(mercaptopropane 2 hydroxy-lsulfonic acid) having the structural formula
• Example VII From 0.5 to 1.5 gm. per liter of the disodium salt of 1,3,4 thiodiazole-2,5-di-(mercaptopropane 1 sulfonic acid) having the structural formula were dissolved in a zinc cyanide bath composed of water, 57 gm. per liter zinc cyanide, 72 gm. per liter sodium hydroxide and 40 gm. per liter sodium cyanide. Sheet steel electroplated in this solution at current densities from 1 to amp./dm. and at temperatures between room temperature and about 40 C. were provided with full-brigl1t zinc electrodeposits of extremely high quality which re quired no additional bufling or polishing.
• Example VIII From 1 to 2 gm. per liter of the disodium salt of N,N- methylene-di-(isothiourea S-propane 1 sulfonic acid) having the structural formula were dissolved in a cadmium cyanide bath composed of water, 125 gm. per liter cadmium sulfate, 140 gm. per liter sodium cyanide and 72 gm. per liter sodium hydroxide. Steel and iron objects electroplated in this solution at current densities from 3 to 8 amp./dm. and at temperatures between room temperature and about 35 C. were provided with full-bright cadmium electroplates of extremely high quality which required no further bufiing or polishing.
• Example IX 1.0 gm. per liter of the trisodium salt of 1,3,5-triazine- 2,4,6-tri-(mercaptopropane 1 sulfonic acid) having the structural formula shown in Example II, 0.05 gm. per liter N,N-diethyl-dithiocarbamic acid-ethylester-w-sodium sulfonate and 1.2 gm. per liter 1,3-bis-(diethylamino)- propanol-2, as well as 0.5 gm.
• Example X The disodium salt of the 1,3,4-thiazole-2,5-bis-mercapto-2'-oxypropane-1'-sulfonic acid was substituted for 6 the thiadiazole derivative in Example HI. A fullabright copper plate was obtained.
• Example XI The disodium salt of the 1,3,4-triazole-2,5-bis-mercaptopropane-1-sulfonic acid was used instead of the triazin derivatives according to Example II. An excellent copper plate was obtained.
• Example XII The dipotassium salt of N,N'-m'ethylene-di-(isothiourea-S-prop-ane-l-sulfonic acid) according to Examples IV and VIII is substituted by an equal amount of the salts of the corresponding ethylene, hexamethylene or phenylene derivatives. Full-bright copper electroplates were obtained.
• Example XIV The disodium salt of the dithiobiuret-S,S'-dipropane sulfonic acid was substituted for the N,N'-methylene-di- (isothiourea-S-propane-l-sulfonic acid) in Example VIII. A good bright copper plate was formed.
• An electroplating bath for producing bright electrodeposits of metals selected from the group consisting of copper, zinc, cadmium, nickel, silver, bronze and brass comprising an aqueous solution of an inorganic salt of the metal to be electrodeposited and, as a brightener, an organic sulfonic acid compound having the general formula wherein R is selected from the group consisting of straightchain and cyclic organic radicals comprising at least two carbon atoms linked exclusively to atoms selected from the group consisting of oxygen, nitrogen and sulfur, each of said carbon atoms being linked to an SR --SO X group, R is a bivalent lower aliphatic radical, X is selected from the group consisting of hydrogen, alkali metal and ammonium, and n is an integer equal to the number of said carbon atoms in the radical R, said brightening agent being present in suflicient amount to effect the brightening action.
• R is a N,N-methylene-di-isothiourea radical.
• the process of producing bright and lustrous deposits of metal selected from the group consisting of copper, zinc, cadmium, nickel, silver, bronze and brass, which comprises electrodepositing said metal from a bath containing said metal in the form of an aqueous solution of an inorganic salt of the metal in the presence of a brightening agent having the general formula wherein R is selected from the group consisting of straight chain and cyclic organic radicals comprising at least two carbon atoms linked exclusively to atoms selected from the group consisting of oxygen, nitrogen and sulfur, each of said carbon atoms being linked to an SR SO X group, R is a bivalent lower aliphatic radical, X is selected from the group consisting of hydro- 7 gen, alkali metal and ammonium, and n is an integer equal 9.
• the electroplating bath v.of claim 1 wherein the to the number of said carbon atoms in the radical R, said quantity of brightener in said bath is between about 0.01 brightening agent being present in sufficient amount to to20 gin/liter. efiect the brightening action. 10.
• the quantity of 6. The process according to claim 5, wherein R is a 5 brightener used is between about 0.01 to 20 gm./liter. 1,3,5-triazine radical.
• R is a s mn Cited in the file of this Patent 1, h 1 radical- UNITED STATES PATENTS 8.
• R is a N,N-methylene-di-isothiourea radical. 10 2647866 Brown 1953 UNITED STATES PATENT OFFICE U CERTIFICATE OF CORRECTION Patent No 2,849,352 August 26, 1958 Alfred Kirstahler et al,

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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)
• Nitrogen- Or Sulfur-Containing Heterocyclic Ring Compounds With Rings Of Six Or More Members (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)
• Plural Heterocyclic Compounds (AREA)

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Cited By (30)

Citations (1)

Family Cites Families (1)

• 0
  • NL NL110592D patent/NL110592C/xx active
  • BE BE556462D patent/BE556462A/xx unknown
  • NL NL217034D patent/NL217034A/xx unknown
• 1956
  • 1956-06-15 DE DED23152A patent/DE1053274B/de active Pending
  • 1956-10-25 US US618183A patent/US2849352A/en not_active Expired - Lifetime
• 1957
  • 1957-03-21 CH CH4410257A patent/CH373243A/de unknown
  • 1957-04-25 GB GB13149/57A patent/GB847841A/en not_active Expired
  • 1957-05-21 FR FR1175604D patent/FR1175604A/fr not_active Expired
• 1964
  • 1964-04-20 NL NL6404306A patent/NL6404306A/xx unknown

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