Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
  • C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
  • C07D307/34—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
  • C07D307/38—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with substituted hydrocarbon radicals attached to ring carbon atoms
  • C07D307/40—Radicals substituted by oxygen atoms
  • C07D307/46—Doubly bound oxygen atoms, or two oxygen atoms singly bound to the same carbon atom
• • 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
  • C25D3/30—Electroplating: Baths therefor from solutions of tin
  • C25D3/32—Electroplating: Baths therefor from solutions of tin characterised by the organic bath constituents used

Definitions

• ABSTRACT excreted aromatic aldehydes and 5-membered ring hetero cyclic aldehydes, wherein the aldehyde group is bonded directly to thearomatic ring, conjugated aromatic ring or 5-membered ring heterocyclic group, said ring or group being otherwise inertly substituted or unsubstituted; to said novel brighteners; and a method of producing said novel brighteners.
• This invention relates to the electrodeposition of tin in acid tin plating compositions, acid tin plating baths, and to processes for the electrodeposition of bright tin in the presence of specific novel brighteners.
• this invention provides an acid solution for electrodepositing bright tin containing stannous ions; sulfate ions; glacial acrylic acid; at least one non-ionic alkoxylated wetting agent; and as a brightener, the reaction product of hexan-2,5-dione and a compound selected from the group consisting 'of homocyclic aromatic aldehydes and S-membe'red ring heterocyclic aldehydes, wherein the aldehyde group is bonded directly to the aromatic ring, conjugated aromatic ring or 5-membered ring heterocyclic group, said ring or group being otherwise inertly substituted or unsubstituted.
• This invention is an acid solution for electrodepositing bright, well-leveled tin comprising:
• this invention relates to a process of producing bright, highly leveled, tin electrodeposits which comprises passing current from an anodeto a metal cathode through an aqueous acidic bath composition containing at least one stannous compound providing bivalent tin ions for electroplating tin; glacial acrylic acid; at least one non-ionic water soluble alkoxylated wetting agent; and the reaction product of hexan-2,5-dione and a member selected from the group consisting of S-membered heterocyclic ring aldehydes, 6-membered homocyclic ring aldehydes and condensed aromatic rings bearing aldehyde .groups.
• This invention has been found applicable to a wide variety of conventional acid tin baths such as, for example, baths containing a bivalent tin salt, such as stannous sulfate and an acid, such as sulfuric acid; Furthermore, thecompositions and methods herein are applicable to both barrel andrack electroplating processes.
• concentrations of tin and free acid may be varied generally within the limits conventional in this art. For example, baths with a tin content of 10 to 100 grams per liter and a free acidconcentration of 20 to 200 grams per liter may be utilized with the additives of the invention herein.
• the preparation of the reaction'product of hexan- 2,5-dione and an aldehyde selected from the group consisting of 5-membered ring heterocyclic aldehydes, 6-membered homocyclic ring or condensed aromatic ring is effected by reacting hexan-2,5-dione in a mole ratio of 1:1 or 2:] of aldehyde to hexan-2,5-dio ne.
• reaction is catalyzed by a-catalytic amount of alkali.
• the reaction temperature should be maintained within the range between 5 C and 50 C, preferably between 0 C and 25 C.
• this invention resides in a method for producing a primary brightener for acid tin plating baths, the steps which comprise reacting as reactants hexan-2,5-dione and an aldehyde selected from the group consisting of 5-membered ring heterocyclic aldehydes, 6-membered ring homocyclic aldehydes, and condensed aromatic ring aldehydes, in
• a molar ratio of about 1:1 to about 1:2 in the presence of a catalytic amount of alkali, at a temperature between 5 C and 50 C, subsequently adding an acid to the reaction mixture and separating the reaction product.
• reaction product When a typical aldehyde, furfuraldehyde, is reacted in a unimolar ratio with hexan-2,5-dione, the reaction product is predominantly a single chemical entity with but two major peaks in the vapor phase chromatogram representing the cis' and trans forms of the product.
• the cooperating additives employed in cooperation with the primary brightener are non-ionic alkoxylated wetting agents and glacial acrylic acid.
• the wetting agent serves to transform the loosely adherent, spotty, sometimes dendritically crystalline tin deposit from an additive-free bath into a dense, continuous, adherent, microcrystalline deposit.
• the acrylic acid seems to function by increasing the hydrogen overvoltage at the cathode and thereby favoring the increase of cathode current efficiency for the deposition of tin.
• Non-ionic alkoxylated wetting agents operable in the practice of this invention include aromatic polyethers and aliphatic polyethers.
• the wetting agent is a polyalkoxylated alkyl phenol.
• Typical polyalkoxylated alkyl phenols include polyethoxylated alkyl phenols having the formula:
• R represents hydrogen or methyl and p is an integer of from about 7 to 50 (preferably from about 20 to 40).
• polyethers which may be employed in amounts of L to 50 grams per liter (preferably about 2 10 grams per liter) include nitrogen-containing aliphatic polyethers characterized by the following general. formula:
• R represents a mixture of isomers having I2 22 carbon atoms, with 12 l preferred, and having a tertiary alkyl structure and n 15.
• the preferred operating conditions such as pH, temperature, and current density may vary depending upon the particular bath composition and the nature of the article receiving the layer of bright acid in tin electrodeposit. In general, good, bright acid tin electrodeposits may be obtained within a specific range of operating conditions.
• the bright acid tin electroplating processes using the compositions of the invention may be carried out at temperatures of about 10 C 60 C (preferably 15 C 20 C) either with or without agitation.
• the temperature of the plating solution is usually the ambient temperature, say 35 C or below, with lower temperatures giving optimum results, such as 15 20 C.
• suitable cooling must be provided such as by circulating cool water through immersed cooling coils, by means of refrigeration machines, etc.
• average current densities of 0.5 5.0 amperes per square decimeter (ASD) bright tin electrodeposits having average thicknesses of 0.25 25 microns may be obtained using plating times which may average 0.1 minutes.
• vigorous and uniform agitation of the plating bath composition may be provided either by mechanical movement of the article being plated or by solution agitation during the electrodeposition. Such agitation may permit the use of high plating current densities on the article being plated.
• the parts may be plated on racks, i.e. on fixtures holding single or multiple parts which may all be the same or which may be different in size, geometrical configuration, etc.
• Parts may also be plated in bulk in rotating barrels and in this type of plating, usually used for plating of smaller parts which lend themselves to tumbling action, the barrel loads usually consist of the same part although mixed loads are sometimes plated. Because of the number, size, and shape complexity of parts it is important that the plating bath be so formulated as to provide the widest possible bright plate current density range.
• the limiting currents density i.e., the current density at which the deposit ceases to be sound in structure and appearances, be as high as possible to allow for the wide variations in cathode current density which may be encountered due to the size and shape complexity of parts.
• the primary brightener additive may be used in the form of a stock solution in an organic solvent such as Cellosolv'e (ethylene glycol mono-ethyl ether), i.e., for example, 25 grams per liter in which form it would then be added at a concentration of 20 ml/l or 2 percent by
• an organic solvent such as Cellosolv'e (ethylene glycol mono-ethyl ether), i.e., for example, 25 grams per liter in which form it would then be added at a concentration of 20 ml/l or 2 percent by
• Cellosolv'e ethylene glycol mono-ethyl ether
• EXAMPLE- 1 Synthesis of Acid Tin Brightener To a 500 milliliter Erlenmeyer flask containing 75 milliliters of water was added 20 milliliters (0.25 mole) of furfuraldehyde and 30 milliliters (0.25 mole) of hexan-2,5-dione. While the mixture was stirred magnetically, a solution of grams (0.25 mole) of sodium hydroxide in 30 milliliters of water was slowly added through an addition funnel. The addition of the sodium hydroxide solution was controlled to maintain a temperature within the range of 22 C to 29 C. The stirring was continued for 2 hours.
• EXAMPLE 2 An acidic bright tin electroplating bath composition containing the following components was prepared and evaluated during four weeks of electrolysis:
• Solutionvolume Anode Cathode 4 liters slab tin (99.99% pure) brass strip polished on one side (facing anode) and having at bottom a 2.54 cm horizontal length and 2.54 cm X 2.54 cm 45 internal angle bend facing cathode.
• ambient room movin cathode rod parallel to an e and at about 10 cm from anode
• EXAMPLE 4 Synthesis of Acid Tin Brightener with Cooling 20 milliliters of furfural (0.25 mole) and 30 milliliters of hexan-2,5-dione (0.25 mole) were added to milliliters of water. The suspension obtained was cooled with an ice-salt bath to a temperature of 0 C. 10 grams of sodium hydroxide (0.25 mole).were dissolved in 30 tract was then dried over anhydrous magnesium sulfate and filtered. Thereafter, the low boiling components were removed under aspirator vacuum, keeping the bath at a temperature of between about 7080 C. 45 grams of reaction product were obtained. The product was a yellow brown liquid, appearing slightly viscous.
• R represents a mixture of isomers having 12-14 carbon atoms with a tertiary alkyl structure and n is equal to 15.
• the deposits from this system were somewhat less brilliant than those of Example 2 and showed a somewhat lower degree of leveling but were still excellent deposits.
• Priminox R-15 the system responded to a periodic current interruption cycle, typically plating for 10 seconds and not plating for 2 seconds, to substantially increase deposit luster and increase the limiting current density
• periodic replenishment of the furfural-hexan-2,5-dione reaction product and of acrylic acid was made to maintain optimum deposit luster.
• a process of producing bright highly leveled tin electrodeposits which comprises passing current from an anode to a metal cathode through an acidic bath composition containing:
• a non-ionic water soluble alkoxylated wetting agent selected from the group consisting of:
• R is an alkyl group of 8-16 carbon atoms and K is an integer 2-50;
• RNH ma wherein R is a mixture of isomers exhibiting 12 to 22 carbon atoms and having a tertiary alkyl structure and n is 15;
• R is hydrogen or a methyl group and p is an integer of about 7-60;
• non-ionic water soluble alkoxylated wetting agent is of the formula:
• R is an alkyl group of 8-16 carbon atoms and k is an integer 2-50.
• R is a mixture of isomers exhibiting 12 to 22 carbon atoms and having a tertiary alkyl structure and n is 15.
• non-ionic water soluble alkoxylated wetting agent is of the formula:
• a composition for providing bright highly leveled tin electrode'posits which comprises a bath composition containing:
• R is an alkyl group of 8-16 carbon atoms and K is an integer 2-50;
• R is a mixture of isomers exhibiting 12 to 22 carbon atoms and having a tertiary alkyl structure and n is 15;
• R is an alkyl group of 8-16 carbon atoms and k is an integer 2-50.
• composition as claimed in claim 11 whereinthe non-ionic water soluble alkoxylated wetting agent is of the formula:
• R is a mixture of isomers exhibiting 12 to 22 carbon atoms and having a tertiary alkyl structure and n is 15.
• composition of claim 11 wherein the brightener is the reaction product of hexan-2,5-dione and furfuraldehyde.
• composition of claim 11 wherein the brightener is the reaction product of hexan-2,5-dione and 1.0 gramper liter.

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

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• 1971
  • 1971-07-01 US US00159035A patent/US3755096A/en not_active Expired - Lifetime
• 1972
  • 1972-05-29 ZA ZA723658A patent/ZA723658B/xx unknown
  • 1972-06-20 GB GB2884972A patent/GB1373293A/en not_active Expired
  • 1972-06-21 AU AU43661/72A patent/AU472304B2/en not_active Expired
  • 1972-06-26 SE SE7208364A patent/SE385920B/xx unknown
  • 1972-06-28 ES ES404332A patent/ES404332A1/es not_active Expired
  • 1972-06-29 DE DE2231988A patent/DE2231988C2/de not_active Expired
  • 1972-06-30 FR FR7223710A patent/FR2143922B1/fr not_active Expired
  • 1972-06-30 NL NL7209231A patent/NL7209231A/xx not_active Application Discontinuation
  • 1972-06-30 IT IT9569/72A patent/IT959485B/it active
  • 1972-06-30 CA CA146,105A patent/CA1035315A/en not_active Expired
  • 1972-07-01 JP JP6618972A patent/JPS5632397B1/ja active Pending

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