Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
  • C07D233/04—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member
  • C07D233/06—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, directly attached to ring carbon atoms
• • 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
  • C25D3/18—Heterocyclic compounds

Definitions

• the invention relates to a bath for electrolytic deposition of nickel coatings having high brightness and good ductility, and to a process of nickel plating by using this bath.
• a great number of brightening organic additives employed in nickel plating contain C N groups, among which imidazol compounds are found.
• the imidazol compounds normally may be referred to brighteners of the second class or levellers, and are in such case used together with brighteners of the first class or carriers.
• the said new bri teners of imidazol type have, thus, in the 2-position a substituent with one or several double or triple bonds, one of these bonds preferably being in conjugated position to the double bond in the 2-position of the imidazol nucleus.
• the said substituents in the 2-position are preferably alkenyl or alkynyl groups containing up to 6 carbon atoms.
• the cyclic hydrocarbon radical contemplated as R is preferably aromatic, as for example a phenyl group.
• the substituent in the 2-position is an unsaturated, aliphatic radical with more than one unsaturated bond, it probably includes more than 6 carbon atoms, for example in the case of two double bonds up to 12 carbon atoms or more.
• the substituent in the 2-position is an unsaturated aliphatic bridge having an aromatic radical attached thereto
• the aliphatic bridge preferably is a radical containing at maximum 6 carbon atoms
• the aromatic radical consists preferably of a phenyl group.
• the said substituents in the 2-position may contain groups rendering the compound more water soluble, for example sulphonic or carboxylic groups.
• the substituents in the 4- and S-position of the imidazol ring are preferably hydrogen atoms or methyl ice groups, but may also be other unsaturated or saturated hydrocarbon radicals, such as alkyl groups containing, for example, up to 4 carbon atoms.
• the substituent groups in the 4- and S-position may be of same or different type.
• the substituent in the 3-position of the imidazol ring is preferably hydrogen, but may also be a saturated or unsaturated hydrocarbon radical, such as an alkyl, alkenyl, alkynyl or alkoxy group, above all such groups having at maximum 6 carbon atoms, or an amino containing group, for example an amino alkyl group, such as an amino ethyl or amino propyl group.
• amino containing groups may be amino alkyl-amino alkyl groups wherein alkyl preferably consists of methyl or ethyl, a piperazinyl group or groups containing 3 or 4 amino groups attached to each other by means of methylene or ethylene groups.
• a cyclic radical as substituent in 3-position is normally heterocyclic or flomatic.
• the new brighteners are active in very low concentrations and may, for example, be applied in a concentration as low as 0.001 g./litre. They are preferably applied in a concentration not exceeding 0.1 g./ litre.
• the process according to the invention is carried out. in a manner known for nickel plating metal objects, but with a bath containing a brightener described above.
• the new brighteners are highly superior to the simple imidazol compounds.
• the nickel deposits obtained show improved ductility.
• the new brighteners are combined with brighteners of the first class, usually aromatic sulphur compounds, such as sodium benzene disulphonate, sodium naphthalene trisulphonate, sulphonamides, sulphonirnides, and the like.
• the new brighteners are excellently to incorporate in most of the bright nickel plating baths known per se, for example acid aqueous baths containing at least one nickel salt.
• the nickel plating bath may, for example, be of sulphate, chloride, fluoborate or sulphamate type.
• the said new brighteners are new chemical compounds which are preferably synthetized in a manner analogous with that used for unsubstituted imidazol. If desired, an unsubstituted or partially imidazol may be substituted in a manner known per se.
• Example 1 A nickel plating bath of the following composition is prepared and applied at the current densities and temperatures as indicated in the table below:
• Example 2 In this experiment a nickel plating bath of the below composition is used at the current densities and temperatures as indicated in the following table.
• Nickel sulphate g./l 300 Nickel chloride g./l 60 Boric acid g./l 40 Sodium naphthalene trisulphonate g./l 15 Z-ethynyl-imidazol g./l 0.01 pH 3.5 .0 Current density a./drn. 2-8 Temperature C 45-60 Even in this example stirring of the nickel plating bath during the deposition of nickel proved desirable. The nickel coating obtained is even in this case of uniform and good brightness as well as of good ductility.
• Example 3 the nickel plating bath had the composition and was used at the current densities and tem- Even in this case it proved desirable to stir the nickel plating bath while the nickel deposition was going on. The brightness obtained was uniform and good over the entire plate and the nickel deposit showed good ductility.
• Example 4 In this experiment a nickel plating bath was used which had the composition as follows:
• the imidazol brightener applied in this example was 2-propenyl-3-diethylenediamin-imidazol having the forv mula:
• Example 4 The experiment as carried out in Example 4 was repeated under the conditions indicated, with the exception, however, that as imidazol brightener was used 2- (fi-phenylethenyl)-3-(,B-hydroxyethyl) -imidazol in an amount of 0.02 g./l.
• the nickel deposit resulting from this experiment showed uniform and good brightness over the entire plate.
• Example 6-12 The experiment as carried out in Example 4 was repeated under the conditions indicated, the nickel plating bath having the composition as defined in Example 4, with the exception, however, that as imidazol brightener 0.01 g./l. of the imidazols as listed in the table below 4 was used. In some examples, the structural formula of the imidazol used is shown.
• Example Imidazol brightener Formula 6 3-propynyl-imidazol. 7 2-propenyl-3-(flhydroxyethyD- imidazol. 8 3-propeny1-imidazo1... lfiI("3H HC ⁇ /GH I
• l' CH2 OHtOHg 9 t. 2-propeny1-3- aminoethylimidazol. 10 2-pr0penyl-3-butylimidazol. 11 2-propenyl-4,5- N--CCH dimethyl-imidazol. I! ll CH;-CH OHC ⁇ /OOH3 12 3-propynylamino- N CH ethyl-imidazol. II II HG CH 1? NO H4.NH.CH .CECH
• the nickel deposits obtained by these experiments showed good ductility and uniform as well as good brightness.
• Nickel plating bath containing at least one nickel salt as a source of nickel and as a brightener, an imidazol compound having the formula wherein R is selected from the group consisting of hydrogen and AR A being an aliphatic bridge and R being selected from the group consisting of unsaturated and saturated, aliphatic and cyclic radicals, and aromatic radicals; wherein R and R are selected from the group consisting of hydrogen, aliphatic and cyclic, saturated and unsaturated hydrocarbon radicals; and wherein R is selected from the group consisting of hydrogen and -A-R A being an aliphatic bridge and R being selected from the group consisting of aliphatic and cyclic, saturated and unsaturated hydrocarbon radicals and aliphatic radicals bearing at least one amino group, and alkoxy groups; at least one of R and R being present and at least one of R and R being an unsaturated radical; said brightener being provided in an amount of 0.001 to 0.1 gram/liter.
• Process for nickel plating comprising electrodepositing nickel from a bath containing at least one nickel salt as a source of nickel and as a brightener, an imidazol compound having the formula wherein R is selected from the group consisting of hydrogen and A-R A being an aliphatic bridge and R being selected from the group consisting of unsaturated and saturated, aliphatic and cyclic radicals and aromatic radicals; wherein R and R are selected from the group consisting of hydrogen, aliphatic and cyclic, saturated and unsaturated hydrocarbon radicals; and wherein R is selected from the group consisting of hydrogen and AR A being an aliphatic bridge and R being selected from the group consisting of aliphatic and cyclic, saturated and unsaturated hydrocarbon radicals and aliphatic radicals bearing at least one amino group, and alkoxy groups; at least one of R and R being present and at least one of R and R being an unsaturated radical; said brightener being provided in an amount of 0.001 to 0.1 gram/liter.

Landscapes

• 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)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20294231

Family Applications (1)

Country Status (4)

Cited By (4)

Families Citing this family (1)

Citations (6)

• 0
  • NL NL285768D patent/NL285768A/xx unknown
• 1962
  • 1962-11-20 GB GB43916/62A patent/GB962873A/en not_active Expired
  • 1962-11-21 DE DEK48273A patent/DE1233690B/de active Pending
  • 1962-11-21 US US239329A patent/US3130135A/en not_active Expired - Lifetime

Patent Citations (6)

Also Published As

Similar Documents