EP0048929A1 - Rhodium-plated article with black or blue color, process for making the same and bath therefor - Google Patents
Rhodium-plated article with black or blue color, process for making the same and bath therefor Download PDFInfo
- Publication number
- EP0048929A1 EP0048929A1 EP19810107517 EP81107517A EP0048929A1 EP 0048929 A1 EP0048929 A1 EP 0048929A1 EP 19810107517 EP19810107517 EP 19810107517 EP 81107517 A EP81107517 A EP 81107517A EP 0048929 A1 EP0048929 A1 EP 0048929A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- acid
- rhodium
- plating bath
- bath
- rhodium plating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims description 32
- 230000008569 process Effects 0.000 title claims description 28
- 238000007747 plating Methods 0.000 claims abstract description 85
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 48
- 239000010948 rhodium Substances 0.000 claims abstract description 48
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 48
- 239000002253 acid Substances 0.000 claims abstract description 41
- 239000000654 additive Substances 0.000 claims abstract description 24
- 150000003839 salts Chemical class 0.000 claims abstract description 20
- 230000000996 additive effect Effects 0.000 claims abstract description 16
- 125000003118 aryl group Chemical group 0.000 claims abstract description 14
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 claims abstract description 13
- ACVYVLVWPXVTIT-UHFFFAOYSA-M phosphinate Chemical compound [O-][PH2]=O ACVYVLVWPXVTIT-UHFFFAOYSA-M 0.000 claims abstract description 13
- 150000001412 amines Chemical class 0.000 claims abstract description 12
- 239000001828 Gelatine Substances 0.000 claims abstract description 7
- 229920000159 gelatin Polymers 0.000 claims abstract description 7
- 235000019322 gelatine Nutrition 0.000 claims abstract description 7
- 239000000203 mixture Substances 0.000 claims abstract description 7
- 238000009713 electroplating Methods 0.000 claims abstract description 5
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 12
- WPYMKLBDIGXBTP-UHFFFAOYSA-N benzoic acid Chemical compound OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 claims description 9
- 150000003283 rhodium Chemical class 0.000 claims description 9
- -1 alkali metal salt Chemical class 0.000 claims description 8
- XNGIFLGASWRNHJ-UHFFFAOYSA-N phthalic acid Chemical compound OC(=O)C1=CC=CC=C1C(O)=O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 claims description 8
- 239000003792 electrolyte Substances 0.000 claims description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 6
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 6
- 239000005711 Benzoic acid Substances 0.000 claims description 4
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 4
- 235000011054 acetic acid Nutrition 0.000 claims description 4
- 235000010233 benzoic acid Nutrition 0.000 claims description 4
- XLJMAIOERFSOGZ-UHFFFAOYSA-N cyanic acid Chemical compound OC#N XLJMAIOERFSOGZ-UHFFFAOYSA-N 0.000 claims description 4
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical compound CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 claims description 4
- 150000007522 mineralic acids Chemical class 0.000 claims description 4
- LNOPIUAQISRISI-UHFFFAOYSA-N n'-hydroxy-2-propan-2-ylsulfonylethanimidamide Chemical compound CC(C)S(=O)(=O)CC(N)=NO LNOPIUAQISRISI-UHFFFAOYSA-N 0.000 claims description 4
- 229910052708 sodium Inorganic materials 0.000 claims description 4
- 239000011734 sodium Substances 0.000 claims description 4
- 239000000758 substrate Substances 0.000 claims description 4
- ZAJAQTYSTDTMCU-UHFFFAOYSA-N 3-aminobenzenesulfonic acid Chemical compound NC1=CC=CC(S(O)(=O)=O)=C1 ZAJAQTYSTDTMCU-UHFFFAOYSA-N 0.000 claims description 3
- HWTDMFJYBAURQR-UHFFFAOYSA-N 80-82-0 Chemical compound OS(=O)(=O)C1=CC=CC=C1[N+]([O-])=O HWTDMFJYBAURQR-UHFFFAOYSA-N 0.000 claims description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 3
- 229910052783 alkali metal Inorganic materials 0.000 claims description 3
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 3
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 3
- 150000007524 organic acids Chemical class 0.000 claims description 3
- GFEPEQYRZIPEIX-UHFFFAOYSA-N 1-(2-aminophenyl)-2-phenylethane-1,2-dione Chemical compound NC1=CC=CC=C1C(=O)C(=O)C1=CC=CC=C1 GFEPEQYRZIPEIX-UHFFFAOYSA-N 0.000 claims description 2
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 claims description 2
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 claims description 2
- WHUUTDBJXJRKMK-UHFFFAOYSA-N Glutamic acid Natural products OC(=O)C(N)CCC(O)=O WHUUTDBJXJRKMK-UHFFFAOYSA-N 0.000 claims description 2
- AVXURJPOCDRRFD-UHFFFAOYSA-N Hydroxylamine Chemical compound ON AVXURJPOCDRRFD-UHFFFAOYSA-N 0.000 claims description 2
- WHUUTDBJXJRKMK-VKHMYHEASA-N L-glutamic acid Chemical compound OC(=O)[C@@H](N)CCC(O)=O WHUUTDBJXJRKMK-VKHMYHEASA-N 0.000 claims description 2
- 229920002873 Polyethylenimine Polymers 0.000 claims description 2
- 235000021355 Stearic acid Nutrition 0.000 claims description 2
- KDYFGRWQOYBRFD-UHFFFAOYSA-N Succinic acid Natural products OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 claims description 2
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 claims description 2
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 claims description 2
- SRSXLGNVWSONIS-UHFFFAOYSA-N benzenesulfonic acid Chemical compound OS(=O)(=O)C1=CC=CC=C1 SRSXLGNVWSONIS-UHFFFAOYSA-N 0.000 claims description 2
- 229940092714 benzenesulfonic acid Drugs 0.000 claims description 2
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims description 2
- 239000004327 boric acid Substances 0.000 claims description 2
- KDYFGRWQOYBRFD-NUQCWPJISA-N butanedioic acid Chemical compound O[14C](=O)CC[14C](O)=O KDYFGRWQOYBRFD-NUQCWPJISA-N 0.000 claims description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 claims description 2
- 235000015165 citric acid Nutrition 0.000 claims description 2
- XPPKVPWEQAFLFU-UHFFFAOYSA-N diphosphoric acid Chemical compound OP(O)(=O)OP(O)(O)=O XPPKVPWEQAFLFU-UHFFFAOYSA-N 0.000 claims description 2
- 125000003916 ethylene diamine group Chemical group 0.000 claims description 2
- 239000004220 glutamic acid Substances 0.000 claims description 2
- 235000013922 glutamic acid Nutrition 0.000 claims description 2
- 239000004310 lactic acid Substances 0.000 claims description 2
- 235000014655 lactic acid Nutrition 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 claims description 2
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 claims description 2
- 229920002401 polyacrylamide Polymers 0.000 claims description 2
- 229940005657 pyrophosphoric acid Drugs 0.000 claims description 2
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 claims description 2
- 235000012239 silicon dioxide Nutrition 0.000 claims description 2
- 239000008117 stearic acid Substances 0.000 claims description 2
- 239000011975 tartaric acid Substances 0.000 claims description 2
- 235000002906 tartaric acid Nutrition 0.000 claims description 2
- NJRXVEJTAYWCQJ-UHFFFAOYSA-N thiomalic acid Chemical compound OC(=O)CC(S)C(O)=O NJRXVEJTAYWCQJ-UHFFFAOYSA-N 0.000 claims description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims 2
- 125000000542 sulfonic acid group Chemical group 0.000 claims 2
- WHOZNOZYMBRCBL-OUKQBFOZSA-N (2E)-2-Tetradecenal Chemical compound CCCCCCCCCCC\C=C\C=O WHOZNOZYMBRCBL-OUKQBFOZSA-N 0.000 claims 1
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 claims 1
- 102100021587 Embryonic testis differentiation protein homolog A Human genes 0.000 claims 1
- 101000898120 Homo sapiens Embryonic testis differentiation protein homolog A Proteins 0.000 claims 1
- 125000003277 amino group Chemical group 0.000 claims 1
- 150000001555 benzenes Chemical class 0.000 claims 1
- 235000019441 ethanol Nutrition 0.000 claims 1
- 229940044654 phenolsulfonic acid Drugs 0.000 claims 1
- 238000005260 corrosion Methods 0.000 description 10
- 230000007797 corrosion Effects 0.000 description 10
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 8
- 239000011248 coating agent Substances 0.000 description 8
- 238000000576 coating method Methods 0.000 description 8
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 8
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 6
- 229910052759 nickel Inorganic materials 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 229910001369 Brass Inorganic materials 0.000 description 4
- 239000010951 brass Substances 0.000 description 4
- 229910052697 platinum Inorganic materials 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 229910021529 ammonia Inorganic materials 0.000 description 3
- 239000012298 atmosphere Substances 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 238000005868 electrolysis reaction Methods 0.000 description 3
- 230000003628 erosive effect Effects 0.000 description 3
- 239000004615 ingredient Substances 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000010406 cathode material Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000003086 colorant Substances 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004070 electrodeposition Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000010956 nickel silver Substances 0.000 description 2
- 239000002736 nonionic surfactant Substances 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 2
- 239000010452 phosphate Substances 0.000 description 2
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- YWFDDXXMOPZFFM-UHFFFAOYSA-H rhodium(3+);trisulfate Chemical compound [Rh+3].[Rh+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O YWFDDXXMOPZFFM-UHFFFAOYSA-H 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 229910001260 Pt alloy Inorganic materials 0.000 description 1
- 229910000629 Rh alloy Inorganic materials 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 229940116318 copper carbonate Drugs 0.000 description 1
- GEZOTWYUIKXWOA-UHFFFAOYSA-L copper;carbonate Chemical compound [Cu+2].[O-]C([O-])=O GEZOTWYUIKXWOA-UHFFFAOYSA-L 0.000 description 1
- 239000002537 cosmetic Substances 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000010985 leather Substances 0.000 description 1
- 159000000003 magnesium salts Chemical class 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- MOFOBJHOKRNACT-UHFFFAOYSA-N nickel silver Chemical compound [Ni].[Ag] MOFOBJHOKRNACT-UHFFFAOYSA-N 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- PXXKQOPKNFECSZ-UHFFFAOYSA-N platinum rhodium Chemical compound [Rh].[Pt] PXXKQOPKNFECSZ-UHFFFAOYSA-N 0.000 description 1
- UUWCBFKLGFQDME-UHFFFAOYSA-N platinum titanium Chemical compound [Ti].[Pt] UUWCBFKLGFQDME-UHFFFAOYSA-N 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- KHZALYIIDCJNTD-UHFFFAOYSA-N rhodium titanium Chemical compound [Ti].[Rh] KHZALYIIDCJNTD-UHFFFAOYSA-N 0.000 description 1
- CVHZOJJKTDOEJC-UHFFFAOYSA-N saccharin Chemical compound C1=CC=C2C(=O)NS(=O)(=O)C2=C1 CVHZOJJKTDOEJC-UHFFFAOYSA-N 0.000 description 1
- 239000000901 saccharin and its Na,K and Ca salt Substances 0.000 description 1
- 239000001509 sodium citrate Substances 0.000 description 1
- NLJMYIDDQXHKNR-UHFFFAOYSA-K sodium citrate Chemical compound O.O.[Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O NLJMYIDDQXHKNR-UHFFFAOYSA-K 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
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
- C25D3/50—Electroplating: Baths therefor from solutions of platinum group metals
- C25D3/52—Electroplating: Baths therefor from solutions of platinum group metals characterised by the organic bath constituents used
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
- C25D11/02—Anodisation
- C25D11/34—Anodisation of metals or alloys not provided for in groups C25D11/04 - C25D11/32
Definitions
- the present invention relates to a novel article which is plated with rhodium developing black or blue color, a process for making the same and a novel bath for rhodium-plating.
- Rhodium-plating has been generally employed for use in electric contacts, lead frames and ornamental articles due to its good hardness, wear resistance, corrosion or erosion resistance and stability in the contact resistance. Furthermore, it has been desired to develop rhodium plating with different colors besides white, as it will enhance the practical value of the rhodium plating.
- an object of the present invention is to provide a noble rhodium-plated article with black or blue color as well as mirror-like gloss.
- Another object of the present invention is to provide a process and a plating bath for making such rhodium-plated article with black or blue color.
- a further object of the present invention is to provide a process for improving the wear resistance of the rhodium plating with the black color.
- plating bath or “bath” hereinafter
- bath composition for plating which provides a plating suitable for ornamental articles, particularly glasses, watches, accessories, cosmetics or dinner wares; rhodium-plating with black or blue color and mirror-like gloss is obtainable through a normal plating manner in an acid rhodium-plating bath comprising an additive consisting of at least one selected from the group consisting of organocarboxylic acid, aromatic sulfonic acid or salts of these, amine, gelatine, butynediol and hypophosphite, the resultant rhodium-plating providing good adhesion and good corrosion or erosion resistance. Based on such finding, the inventors have completed the present invention.
- the rhodium-plated articles of the present invention are suitable for, e.g., frames or glasses, cases, faces and bands of watches, necktie pins, lighters, necklaces, rings, compacts, caps for lipsticks and the like.
- the articles of the present invention may be utilized not only in the ornamental purpose but in various fields which require such a good plated. coating.
- the plating bath of the present invention comprises a normal acid rhodium plating bath comprising rhodium salt and free acid (known per se), and an additive consisting of at least one selected from the group consisting of organocarboxylic acid, aromatic sulfonic acid or salts of these, amine, gelatine, butynediol and hypophosphite (referred to "additive" hereinafter).
- This plating bath is used for placing treatment of the articles resulting in rhodium-plated articles with desired properties.
- the plating bath comprising three ingredients of rhodium salt, free acid and the additive such as organocarboxylic acid hereinabove mentioned will be sufficient for accomplishing the purpose of the present invention.
- Rhodium salts which are normally used in the conventional rhodium plating, e.g., sulfate, phosphate, sulfamic acid and the like are employed as the rhodium salt for the plating bath.
- the rhodium salt concentration in the bath ranges within a conventional, normal concentration, i.e., from 0.1 g/I to 20 g/I. At a concentration below 0.1 g/l - the speed of electrodesposition will be undesirably reduced. At a concentration exceeding 20 g/I the expensive rhodium would be used without effective utilization.
- the free acid encompasses acids which are normally used in the acid plating bath, such as sulfuric acid, phosphoric acid, sulfamic acid and the like.
- organocarboxylic acid and aromatic sulfonic acid are used in either a free acid form or a salt form, only one of these being sufficient, however, two or more being applicable.
- organocarboxylic acid or aromatic sulfonic acid denote also their salts hereinafter. Such salts encompass sodium or potassium salt.
- the concentration of organocarboxylic acid and/or aromatic sulfonic acid should be determined relating to the concentration of rhodium, and, however, be not less than 0.01 g/I, a lower concentration of which would deteriorat- ingly affect upon color development.
- These additives may be added to the bath up to a solubility limit in the bath, however, used at a concentration which is practically sufficient.
- Organocarboxylic acid of the invention encompasses acetic acid and benzoic acid which have only one carboxylic group and no other functional group, phthalic acid and thiomalic acid which have two carboxylic groups, and salts of each.
- Aromatic suifonic acid encompasses benzenesulfonic acid, nitrobenzenesulfonic acid, phenosulfonic acid, metanilic acid or the like and salts of these acids.
- the additives to the bath in the present invention further encompasses amine, gelatine and butynediol.
- Amine encompasses ethylenediamine, triethanolamine, sulfuric hydroxylamine, diethylenetriamine or the like.
- One amine among those as the additive is sufficient, however two or more amines or amine(s) with other additives may be used.
- the concentration of amine, gelatine and butynediol in the bath approximates to that of organocarboxylic acid.
- Hypophosphite as the additive encompasses alkali metal salts (sodium or potassium salt), alkaline earth metal salts (calcium or magnesium salt), other divalent metal salts (Co-, Ni-, Fe-, or Mn- salt) and the like. Among those salts alkali metal salts or alkaline earth metal salts are preferred.
- the concentration of hypophosphite as the additive in the bath approximately ranges from 0.5 to 10 g/I. A lower concentration less than 0.5 g/I does not develop sufficient effect, and that exceeding 10 g/I would cause to get cloudy, i.e., to loose the gloss.
- This additive of hypophosphite requires slightly different conditions of plating with respect to pH, bath temperature or the like from the other additives aforementioned.
- the pH should be below 2.5 as a higher pH would cause cracks or precipitation in the bath.
- An optimum temperature for hypophosphite approximately ranges from 20 to 45 C. A higher temperature exceeding 45°C is not preferred as it enhances the possibility of the partial clouding.
- the current density at a conventional, normal range e.g., approximately 0.5 - 5 A/dm 2 ) may be adopted.
- the additives as hereinabove mentioned belong to essential ingredients of the bath according to the present .
- a further agent as a brightener may be added to the bath, i.e., 0.1- - 10 mg./I or nonionic surfactant may be used.
- nonionic surfactant encompasses that of the ether type, e.g. polyoxyethylene- alkylether, polyoxyethylenealkylphenylether or the like, which are generally used as the brightener in the prior art, however, further serve to inhibit the plating from forming microcracks, partial clouding and to produce a uniform color tone.
- the pH value of the bath should not exceed 6. At a higher pH value than 6, rhodium in t.he bath will form hydroxide to form precipitation to disadvantage.
- the color of the rhodium-plated coating or film relates to the thickness thereof, wherein a thinner coating will produce blue color while a thicker coating black color.
- benzoic acid is used as organocarboxylic acid
- the plating of the thickness less than 0.05 micron produces the blue color
- the thickness of 0.1 micron or more produces the black color
- the thickness between 0.05 and 0.1 micron will produce bluish black color.
- the thickness of 5 microns shows still the black color.
- Other organocarboxylic acid develops also the similar results in the color as well as the other additives aforementioned.
- the control or choice of the color is preferably made mainly by changing the plating time under a predetermined bath condition.
- the bath temperature and current density for plating procedure are adopted within the values as adopted in the conventional manner.
- a bath temperature of 10 - 80°C should be adopted.
- the current density will not sufficiently rise resulting in the low electrodeposition efficiency.
- the disadvantage of violent vaporization of the bath will overcome the advantage of enhancement in the electrodeposition efficiency.
- the current density having close relation with the color tone should be 0.1 - 10 A/dm 2 .
- a higher current density than 10 A/dm 2 will cause violent evaporation of gas at a cathode in the bath accompanied by a deteriorated color tone.
- the cathode may be selected from known material having a metallic surface such as brass, German silver (nickel silver), stainless steel or the like (however, iron, aluminium and zinc cannot be plated directly thereon).
- the cathode material further encompasses articles coated with strike (substrate coating), e.g., nickel strike or paradium-nickel strike.
- strike substrate coating
- the cathode material encompasses also non-metallic articles coated with such substrate coating.
- insoluble electrodes is sufficient for the anode, e.g., platinum electrode, titanium electrode coated , with platinum or platinum-rhodium plating.
- the article thus obtainable according to the present invention has the mirror-like gloss with its surface, the black or blue color, good adhesion, good corrosion or erosion resistance, and the hardness. compatible with the conventional rhodium plated articles without applying other conventional agents for various purposes.
- the rhodium-plated article with the black or blue color is obtainable through applying a bath essentially consisting of three ingredients, i.e., rhodium salt, free acid and the additive of the invention, the additive being organocarboxylic acid, aromatic sulfonic acid or one of other members aforementioned.
- anodic electrolysis treatment or so-called anodic treatment
- anodic electrolysis treatment or so-called anodic treatment
- Plated articles with the black color to be treated through the anodic treatment are those which were rhodium-plated on the surface and have the black color as aforementioned.
- a bath for this treatment is such that accompanies a reaction generating oxygen, provided that the plated coating or substrate of plating should not be corroded or eroded upon dipping the articles for treatment or during the treatment.
- strong acid such as sulfuric acid, hydrochloric acid, nitric acid or the like, and strong alkali such as sodium hydroxide and potassium hydroxide are not preferred.
- Electrolyte applicable to the anodic treatment encompasses organic and inorganic substances either alone or in combination.
- the pH value and the temperature of the bath for anodic treatment may be adopted according to such conditions that are applicable in the conventional plating or electrolytic treatment.
- organic acid such as citric acid, glutamic acid, tartaric acid, acetic acid, stearic acid, lactic acid, succinic acid, sulfamic acid,. or salts thereof with sodium, potassium or ammonium
- inorganic acid such as pyrophosphoric acid, phosphoric acid, carbonic acid, cyanic acid, boric acid, silicic acid, or salts of _ these inorganic acids
- methyl alcohol, ehtyl alcohol, ethyleneglycohol, benzilamine, cycrohexane, EDTA sodium saccharinate, polyacrylamide, or polyethylene imine.
- an insoluble cathode of known nature, e.g., platinum, titanium-rhodium alloy, titanium-platinum alloy, stainless steel, carbon or the like may be employed.
- the anodic treatment of the present invention is successfully effected, e.g., under the following conditions: a bath temperature at 30 - 60°C, a concentration of the electrolyte at 10 - .100 g/I, a current density of 0.1 - 20 A/dm 2 and a treating period of 3- 60 minutes.
- a bath temperature at 30 - 60°C a concentration of the electrolyte at 10 - .100 g/I
- a current density of 0.1 - 20 A/dm 2 e.g., a current density of 0.1 - 20 A/dm 2
- a treating period of 3- 60 minutes e.g., under the following conditions: a bath temperature at 30 - 60°C, a concentration of the electrolyte at 10 - .100 g/I, a current density of 0.1 - 20 A/dm 2 and a treating period of 3- 60 minutes.
- deviation from these conditions may be done optionally.
- composition of the bath generally affects upon the bath potential, anode current density and treating time, which makes it necessary to choose each optimal condition for each treating bath, thus such treatment conditions cannot be unconditionally or generally determined without specifying the bath composition. This reason is understood by that the oxygen overvoltage for each electrolyte is different.
- the. anode current density of not less than 0.1 A/dm 2 is sufficient at a treatment time of three minutes, whereas a shorter treatment time suffices at a higher. current density, or a longer treatment time is applied if the current density is small.
- the concentration of the electrolyte in the bath is so adopted that oxygen can be released at the anode, which concentration widely ranges, e.g., from a few g/I to that of the upper solubility limit.
- the present invention also provides the rhodium-plated articles having the practically sufficient wear resistance and the enhanced blackness through the anodic treatment of the rhodium-plated articles as aforementioned.
- a bath of pH 4.0 obtained by mixing rhodium sulfate (rhodium: 4 g/I), phthalic acid (2 g/I) and sulfuric acid were set a titanium anode plated with platinum and a cathode of a brass watch case plated with a nickel strike.
- the watch case was electroplated for ten minutes under conditions of a bath temperature of 30°C and a current density of 0.5 A/dm 2 .
- the resultant plating film presented black color and mirror-like gloss provided with 0.3 micron thickness and good adhesion.
- the same article was electroplated for one minute under the same conditions.
- the resultant plating film was 0.03 micron thick provided with mirror-like gloss and blue color.
- the resultant watch case was tested with respect to the corrosion resistance through a CAS-testing manner and exposure testing in an ammonia atmosphere. No corrosion was observed thus exhibiting the good corrosion resistance.
- the articles showed a hardness compatible with the level of the rhodium-plated white coating according to the conventional manner.
- Rhodium-plating was carried out under the conditions as shown in Table I otherwise in the same condition as disclosed in Example 1, the results being also disclosed in Table 1. All the sample pieces showed properties equivalent to those of Example 1 with respect to the mirror-like gloss, corrosion resistance, hardness and adhesion.
- the resultant plating film presented black color with mirror-like gloss.
- the film was 0.5 micron thick having good adhesion.
- Example 1 Testing in the manner as disclosed in Example 1 revealed the good corrosion resistance and a hardness compatible with conventional white rhodium plating.
- Rhodium plating was carried out under conditions as shown in Table 2 otherwise under the same conditions as disclosed in Example 9, the results being also disclosed in Table 2.
- the resultant platings showed mirror-like gloss, the good corrosion resistance and hardness.
- Electroplating with rhodium was carried out under the conditions as shown in Table 3, otherwise under the same condition as in Example 1.
- the resultant plating film was 0. 1 micron thick having good adhesion.
- the good corrosion resistance was exhibited through the same testing as in Example 1, and the hardness compatible with the conventional white rhodium plating was exhibited.
- the resultant plating developed blue color provided with the thickness of 0.02. micron and other good properties as in the black rhodium plating.
- Rhodium plating was carried out under conditions as shown in Table 3 otherwise under the same conditions as in Example 1, the results being also disclosed in Table 3.
- the resultant platings showed the mirror-like gloss, the good corrosion-resistance and hardness as in Example 18.
- Example 1 The rhodium-plated brass plate with the black color and the thickness of 0.3 micron which was obtained in Example 1 was subjected to anodic treatment under conditions disclosed in Table 4.
- the wear resistance was measured by rubbing the sample plate surface of 10 cm on a backside of the cow leather under the application of 600 g load at a reciprocal movement speed of 1 cycle/second.
- the color difference and gloss were measured according to the measuring method of mirror surface gloss, JIS Z 8741-1978 "gloss measurement method" by using a color difference meter of Nippon Denshoku Kogyo K.K. (type ND-5). The smaller is the value, the deeper or stronger blackness is represented.
- Example 2 The resultant article as obtained in Example 2 having the 0.4 micron thick plating provided with the black mirror-like gloss was subjected to the anodic treatment under the same condition as in Example 31, resulting in the same good properties as in Example 31.
- Example 1 Phthalic acid (2 g/I) in Example 1 was replaced with metanilic acid (I g/I), under which condition rhodium plating was effected otherwise under the same condition as in Example 1. The resultant sample pieces were treated. as in Examples 31 - 37, resulting in the same good properties as in Example 31 - 37.
- Example 2 Benzoic acid (2 g/I) in Example 2 was replaced with ethylenediamine (50 ml/1), under which condition otherwise the same conditions as in Example 2 rhodium plating was effected.
- the resultant sample pieces were treated as in Example 38, resulting in the same good properties as in Example 38.
- Example 31 The same rhodium-plated brass plate as used in Example 31 (thus Example 1) was subjected to anodic treatment under conditions of electrolyte composition, concentration and electrolysis conditions as shown in Table 6 otherwise in the same manner as in Example 31.
- the resultant pieces showed rhodium-plating films with the enhanced blackness and wear resistance.
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Abstract
Description
- The present invention relates to a novel article which is plated with rhodium developing black or blue color, a process for making the same and a novel bath for rhodium-plating.
- All the colors of the platings which are obtainable through known rhodium-plating baths are white, the known rhodium baths comprising various rhodium salts, e.g., sulfate or phosphate.
- Rhodium-plating has been generally employed for use in electric contacts, lead frames and ornamental articles due to its good hardness, wear resistance, corrosion or erosion resistance and stability in the contact resistance. Furthermore, it has been desired to develop rhodium plating with different colors besides white, as it will enhance the practical value of the rhodium plating.
- On the other hand, known manners for black plating or black coloring such as black chrome plating, black nickel plating, blackening with copper carbonate all encounter difficulties in obta.ining gloss, some of them yielding clouding, that is to say, these all being less valuable in the ornamental effect. There have been further problems in the manufacturing process, wherein they showed bad reproducibility in operation conditions, difficulties in mass production or the like. Thus there has been much to be desired in the prior art and it has long been desired to develop black color plating of noble metal in the ornamental article industries.
- Accordingly, an object of the present invention is to provide a noble rhodium-plated article with black or blue color as well as mirror-like gloss.
- Another object of the present invention is to provide a process and a plating bath for making such rhodium-plated article with black or blue color.
- A further object of the present invention is to provide a process for improving the wear resistance of the rhodium plating with the black color.
- Still further objects of the invention wilI become apparent from the disclosure hereinbelow.
- The inventors have become aware of the following fact after investigations for developing a bath composition for plating ("plating bath" or "bath" hereinafter) which provides a plating suitable for ornamental articles, particularly glasses, watches, accessories, cosmetics or dinner wares; rhodium-plating with black or blue color and mirror-like gloss is obtainable through a normal plating manner in an acid rhodium-plating bath comprising an additive consisting of at least one selected from the group consisting of organocarboxylic acid, aromatic sulfonic acid or salts of these, amine, gelatine, butynediol and hypophosphite, the resultant rhodium-plating providing good adhesion and good corrosion or erosion resistance. Based on such finding, the inventors have completed the present invention.
- It has been revealed that further improvement in the wear resistance of the black rhodium plating is obtainable through anodic electrolysis treatment (or "anodic treatment" hereinafter) of the rhodium-plated article with the black color.
- The rhodium-plated articles of the present invention are suitable for, e.g., frames or glasses, cases, faces and bands of watches, necktie pins, lighters, necklaces, rings, compacts, caps for lipsticks and the like. The articles of the present invention may be utilized not only in the ornamental purpose but in various fields which require such a good plated. coating.
- The present invention will be described hereinbelow with reference to preferred embodiments which will, however, serve to- better illustration of the invention and not to limitation thereof. Modifications may be done without aparting from the gist of the present invention.
- The plating bath of the present invention comprises a normal acid rhodium plating bath comprising rhodium salt and free acid (known per se), and an additive consisting of at least one selected from the group consisting of organocarboxylic acid, aromatic sulfonic acid or salts of these, amine, gelatine, butynediol and hypophosphite (referred to "additive" hereinafter). This plating bath is used for placing treatment of the articles resulting in rhodium-plated articles with desired properties.
- Normally, the plating bath comprising three ingredients of rhodium salt, free acid and the additive such as organocarboxylic acid hereinabove mentioned will be sufficient for accomplishing the purpose of the present invention.
- Rhodium salts which are normally used in the conventional rhodium plating, e.g., sulfate, phosphate, sulfamic acid and the like are employed as the rhodium salt for the plating bath.
- The rhodium salt concentration in the bath ranges within a conventional, normal concentration, i.e., from 0.1 g/I to 20 g/I. At a concentration below 0.1 g/l- the speed of electrodesposition will be undesirably reduced. At a concentration exceeding 20 g/I the expensive rhodium would be used without effective utilization.
- The free acid encompasses acids which are normally used in the acid plating bath, such as sulfuric acid, phosphoric acid, sulfamic acid and the like.
- Among the. additives of the invention, organocarboxylic acid and aromatic sulfonic acid are used in either a free acid form or a salt form, only one of these being sufficient, however, two or more being applicable. The terms organocarboxylic acid or aromatic sulfonic acid denote also their salts hereinafter. Such salts encompass sodium or potassium salt.
- The concentration of organocarboxylic acid and/or aromatic sulfonic acid should be determined relating to the concentration of rhodium, and, however, be not less than 0.01 g/I, a lower concentration of which would deteriorat- ingly affect upon color development. These additives may be added to the bath up to a solubility limit in the bath, however, used at a concentration which is practically sufficient.
- Organocarboxylic acid of the invention encompasses acetic acid and benzoic acid which have only one carboxylic group and no other functional group, phthalic acid and thiomalic acid which have two carboxylic groups, and salts of each.
- The concentration of aromatic sulfonic acid in the bath approximates to that of organocarboxylic acid. Aromatic suifonic acid encompasses benzenesulfonic acid, nitrobenzenesulfonic acid, phenosulfonic acid, metanilic acid or the like and salts of these acids.
- The additives to the bath in the present invention further encompasses amine, gelatine and butynediol. Amine encompasses ethylenediamine, triethanolamine, sulfuric hydroxylamine, diethylenetriamine or the like. One amine among those as the additive is sufficient, however two or more amines or amine(s) with other additives may be used.
- The concentration of amine, gelatine and butynediol in the bath approximates to that of organocarboxylic acid.
- Hypophosphite as the additive encompasses alkali metal salts (sodium or potassium salt), alkaline earth metal salts (calcium or magnesium salt), other divalent metal salts (Co-, Ni-, Fe-, or Mn- salt) and the like. Among those salts alkali metal salts or alkaline earth metal salts are preferred.
- The concentration of hypophosphite as the additive in the bath approximately ranges from 0.5 to 10 g/I. A lower concentration less than 0.5 g/I does not develop sufficient effect, and that exceeding 10 g/I would cause to get cloudy, i.e., to loose the gloss. This additive of hypophosphite requires slightly different conditions of plating with respect to pH, bath temperature or the like from the other additives aforementioned. For hypophosphite the pH should be below 2.5 as a higher pH would cause cracks or precipitation in the bath. An optimum temperature for hypophosphite approximately ranges from 20 to 45 C. A higher temperature exceeding 45°C is not preferred as it enhances the possibility of the partial clouding. However, the current density at a conventional, normal range (e.g., approximately 0.5 - 5 A/dm2) may be adopted.
- The additives as hereinabove mentioned belong to essential ingredients of the bath according to the present . invention, however, a further agent as a brightener may be added to the bath, i.e., 0.1- - 10 mg./I or nonionic surfactant may be used. Such nonionic surfactant encompasses that of the ether type, e.g. polyoxyethylene- alkylether, polyoxyethylenealkylphenylether or the like, which are generally used as the brightener in the prior art, however, further serve to inhibit the plating from forming microcracks, partial clouding and to produce a uniform color tone.
- Again turning to the additives of the invention other than hypophosphite, the pH value of the bath should not exceed 6. At a higher pH value than 6, rhodium in t.he bath will form hydroxide to form precipitation to disadvantage.
- The color of the rhodium-plated coating or film relates to the thickness thereof, wherein a thinner coating will produce blue color while a thicker coating black color. Provided that benzoic acid is used as organocarboxylic acid, the plating of the thickness less than 0.05 micron produces the blue color, whereas the thickness of 0.1 micron or more produces the black color, and the thickness between 0.05 and 0.1 micron will produce bluish black color. The thickness of 5 microns shows still the black color. Other organocarboxylic acid develops also the similar results in the color as well as the other additives aforementioned.
- In the practical operation, it is also affected by plating conditions, whether the plating becomes black or blue, the plating conditions encompassing concentrations in the bath of the rhodium salt and the additive(s), bath temperature current density, plating time, and the like. Such factors should be determined through a preparatory test plating under consideration such factors. In the practical plating procedure, the control or choice of the color is preferably made mainly by changing the plating time under a predetermined bath condition.
- The bath temperature and current density for plating procedure are adopted within the values as adopted in the conventional manner. A bath temperature of 10 - 80°C should be adopted. At a lower temperature less than 10 C, the current density will not sufficiently rise resulting in the low electrodeposition efficiency. At a temperature higher than 80°C, the disadvantage of violent vaporization of the bath will overcome the advantage of enhancement in the electrodeposition efficiency. The current density having close relation with the color tone should be 0.1 - 10 A/dm2. A higher current density than 10 A/dm2 will cause violent evaporation of gas at a cathode in the bath accompanied by a deteriorated color tone.
- Materials for anode and cathode which are employed upon rhodium plating in the prior art may be used. The cathode may be selected from known material having a metallic surface such as brass, German silver (nickel silver), stainless steel or the like (however, iron, aluminium and zinc cannot be plated directly thereon). The cathode material further encompasses articles coated with strike (substrate coating), e.g., nickel strike or paradium-nickel strike. The cathode material encompasses also non-metallic articles coated with such substrate coating.
- One of insoluble electrodes is sufficient for the anode, e.g., platinum electrode, titanium electrode coated , with platinum or platinum-rhodium plating.
- Other known manner generally applicable to the plating process may be optionally applied in the plating procedure in the present invention.
- The article thus obtainable according to the present invention, however, has the mirror-like gloss with its surface, the black or blue color, good adhesion, good corrosion or erosion resistance, and the hardness. compatible with the conventional rhodium plated articles without applying other conventional agents for various purposes..In other words, the rhodium-plated article with the black or blue color is obtainable through applying a bath essentially consisting of three ingredients, i.e., rhodium salt, free acid and the additive of the invention, the additive being organocarboxylic acid, aromatic sulfonic acid or one of other members aforementioned.
- Thus the present invention is applicable in the industries with advantage.
- Further development of the present invention is accomplished through applying anodic electrolysis treatment (or so-called anodic treatment) to the rhodium-plated article with the black color resulti-ng in the improvement in the wear resistance and adhesion as well as the blackness.
- Plated articles with the black color to be treated through the anodic treatment are those which were rhodium-plated on the surface and have the black color as aforementioned.
- General manners for the anodic treatment, known per se, may be employed in the anodic treatment of the invention. A bath for this treatment is such that accompanies a reaction generating oxygen, provided that the plated coating or substrate of plating should not be corroded or eroded upon dipping the articles for treatment or during the treatment. Thus, strong acid such as sulfuric acid, hydrochloric acid, nitric acid or the like, and strong alkali such as sodium hydroxide and potassium hydroxide are not preferred.
- Electrolyte applicable to the anodic treatment encompasses organic and inorganic substances either alone or in combination. The pH value and the temperature of the bath for anodic treatment may be adopted according to such conditions that are applicable in the conventional plating or electrolytic treatment.
- Counted as the electrolyte for such purpose are as follows: organic acid such as citric acid, glutamic acid, tartaric acid, acetic acid, stearic acid, lactic acid, succinic acid, sulfamic acid,. or salts thereof with sodium, potassium or ammonium; inorganic acid such as pyrophosphoric acid, phosphoric acid, carbonic acid, cyanic acid, boric acid, silicic acid, or salts of _ these inorganic acids; methyl alcohol, ehtyl alcohol, ethyleneglycohol, benzilamine, cycrohexane, EDTA, sodium saccharinate, polyacrylamide, or polyethylene imine.
- Upon the anodic treatment, an insoluble cathode of known nature, e.g., platinum, titanium-rhodium alloy, titanium-platinum alloy, stainless steel, carbon or the like may be employed.
- The anodic treatment of the present invention is successfully effected, e.g., under the following conditions: a bath temperature at 30 - 60°C, a concentration of the electrolyte at 10 - .100 g/I, a current density of 0.1 - 20 A/dm2 and a treating period of 3- 60 minutes. However, deviation from these conditions may be done optionally.
- The composition of the bath generally affects upon the bath potential, anode current density and treating time, which makes it necessary to choose each optimal condition for each treating bath, thus such treatment conditions cannot be unconditionally or generally determined without specifying the bath composition. This reason is understood by that the oxygen overvoltage for each electrolyte is different.
- For instance, provided that a bath comprising 50 g/I sodium citrate is used, the. anode current density of not less than 0.1 A/dm2 is sufficient at a treatment time of three minutes, whereas a shorter treatment time suffices at a higher. current density, or a longer treatment time is applied if the current density is small. The concentration of the electrolyte in the bath is so adopted that oxygen can be released at the anode, which concentration widely ranges, e.g., from a few g/I to that of the upper solubility limit.
- Accordingly, the present invention also provides the rhodium-plated articles having the practically sufficient wear resistance and the enhanced blackness through the anodic treatment of the rhodium-plated articles as aforementioned.
- Now, in the followings, the present invention will be described in more detail by way of preferred embodiments thereof, which will not serve to limitation of the invention.
- In a bath of pH 4.0 obtained by mixing rhodium sulfate (rhodium: 4 g/I), phthalic acid (2 g/I) and sulfuric acid were set a titanium anode plated with platinum and a cathode of a brass watch case plated with a nickel strike. The watch case was electroplated for ten minutes under conditions of a bath temperature of 30°C and a current density of 0.5 A/dm 2 .
- The resultant plating film presented black color and mirror-like gloss provided with 0.3 micron thickness and good adhesion.
- The same article was electroplated for one minute under the same conditions. The resultant plating film was 0.03 micron thick provided with mirror-like gloss and blue color.
- The resultant watch case was tested with respect to the corrosion resistance through a CAS-testing manner and exposure testing in an ammonia atmosphere. No corrosion was observed thus exhibiting the good corrosion resistance. The articles showed a hardness compatible with the level of the rhodium-plated white coating according to the conventional manner.
- *N.B , exposure in the ammonia atmosphere:
- Sample pieces were put in a desiccator, charged with ammonia water of the
- density 0.96 on the bottom, the sample
- pieces were kept therein at 20°C for 24
- hours exposed to an ammonia atmosphere. After the exposure, color change and bulging on the surface were observed.
- Rhodium-plating was carried out under the conditions as shown in Table I otherwise in the same condition as disclosed in Example 1, the results being also disclosed in Table 1. All the sample pieces showed properties equivalent to those of Example 1 with respect to the mirror-like gloss, corrosion resistance, hardness and adhesion.
- In a bath obtained by mixing rhodium sulfate (rhodium: 2 g/I), o-nitrobenzenesulfonic acid (10 g/I) and sulfuric acid (total: 6 g/I) were set the same anode as used in Example 1 and a cathode of a stainless steel watch case with a nickel strike. The watch case was electroplated for 10 minutes under conditions of a bath temperature of 50°C and the current density at 1 A/dm2.
- The resultant plating film presented black color with mirror-like gloss. The film was 0.5 micron thick having good adhesion.
- After one minute electroplating otherwise under the same conditions, a 0.05 micron thick plating with mirror-like gloss was obtained.
- Testing in the manner as disclosed in Example 1 revealed the good corrosion resistance and a hardness compatible with conventional white rhodium plating.
-
- Electroplating with rhodium was carried out under the conditions as shown in Table 3, otherwise under the same condition as in Example 1. The resultant plating film was 0. 1 micron thick having good adhesion.
- The good corrosion resistance was exhibited through the same testing as in Example 1, and the hardness compatible with the conventional white rhodium plating was exhibited.
- By electroplating for 4 minutes otherwise under the same conditions as above, the resultant plating developed blue color provided with the thickness of 0.02. micron and other good properties as in the black rhodium plating.
- Rhodium plating was carried out under conditions as shown in Table 3 otherwise under the same conditions as in Example 1, the results being also disclosed in Table 3. The resultant platings showed the mirror-like gloss, the good corrosion-resistance and hardness as in Example 18.
-
- The rhodium-plated brass plate with the black color and the thickness of 0.3 micron which was obtained in Example 1 was subjected to anodic treatment under conditions disclosed in Table 4.
- The resultant sample pieces were tested with respect to the surface conditions such as the wear resistance, color difference, gloss and the like. The results are shown in Table 5.
- The wear resistance was measured by rubbing the sample plate surface of 10 cm on a backside of the cow leather under the application of 600 g load at a reciprocal movement speed of 1 cycle/second.
- The color difference and gloss were measured according to the measuring method of mirror surface gloss, JIS Z 8741-1978 "gloss measurement method" by using a color difference meter of Nippon Denshoku Kogyo K.K. (type ND-5). The smaller is the value, the deeper or stronger blackness is represented.
- As is shown in these results, the rhodium-plated article with the good wear-resistance and the much stronger blackness is obtainable according to these embodiments.
- The resultant article as obtained in Example 2 having the 0.4 micron thick plating provided with the black mirror-like gloss was subjected to the anodic treatment under the same condition as in Example 31, resulting in the same good properties as in Example 31.
-
- Phthalic acid (2 g/I) in Example 1 was replaced with metanilic acid (I g/I), under which condition rhodium plating was effected otherwise under the same condition as in Example 1. The resultant sample pieces were treated. as in Examples 31 - 37, resulting in the same good properties as in Example 31 - 37.
- Benzoic acid (2 g/I) in Example 2 was replaced with ethylenediamine (50 ml/1), under which condition otherwise the same conditions as in Example 2 rhodium plating was effected. The resultant sample pieces were treated as in Example 38, resulting in the same good properties as in Example 38.
- The same rhodium-plated brass plate as used in Example 31 (thus Example 1) was subjected to anodic treatment under conditions of electrolyte composition, concentration and electrolysis conditions as shown in Table 6 otherwise in the same manner as in Example 31. The resultant pieces showed rhodium-plating films with the enhanced blackness and wear resistance.
Claims (25)
Applications Claiming Priority (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP134039/80 | 1980-09-25 | ||
JP13403980A JPS5757883A (en) | 1980-09-25 | 1980-09-25 | Production of black or blue rhodium coated articles and plating bath for this |
JP13403880A JPS5757882A (en) | 1980-09-25 | 1980-09-25 | Black or blue rhodium coated articles, production thereof and plating bath used therefor |
JP134038/80 | 1980-09-25 | ||
JP134040/80 | 1980-09-25 | ||
JP13404080A JPS5757884A (en) | 1980-09-25 | 1980-09-25 | Production of black or blue rhodium plated articles and plating bath for this |
JP56045522A JPS604920B2 (en) | 1981-03-30 | 1981-03-30 | Method for manufacturing black rhodium plated articles with good wear resistance |
JP45522/81 | 1981-03-30 |
Related Child Applications (1)
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EP85111660.8 Division-Into | 1981-09-22 |
Publications (2)
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EP0048929A1 true EP0048929A1 (en) | 1982-04-07 |
EP0048929B1 EP0048929B1 (en) | 1987-12-09 |
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Application Number | Title | Priority Date | Filing Date |
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EP19810107517 Expired EP0048929B1 (en) | 1980-09-25 | 1981-09-22 | Rhodium-plated article with black or blue color, process for making the same and bath therefor |
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---|---|
EP (1) | EP0048929B1 (en) |
DE (1) | DE3176572D1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0056590B1 (en) * | 1981-01-15 | 1985-04-24 | Degussa Aktiengesellschaft | Galvanic bath for the deposition of rhodium coatings |
IT201700084504A1 (en) * | 2017-07-25 | 2019-01-25 | Valmet Plating S R L | GALVANIC BATHROOM, ELECTRODEPTIFICATION PROCEDURE USING THE GALVANIC BATH AND METALLIC ALLOY OBTAINABLE THROUGH THAT PROCEDURE |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR793197A (en) * | 1935-06-04 | 1936-01-18 | Heraeus Gmbh W C | Process for obtaining dark electrolytic deposits of rhodium and objects covered with said deposit |
DE692122C (en) * | 1938-03-13 | 1940-06-13 | Wieland Fa Dr Th | Rhodium bath |
US3592750A (en) * | 1967-11-10 | 1971-07-13 | Ici Ltd | Electrodes for use in aqueous alkali metal chloride electrolytes |
FR2427404A1 (en) * | 1978-05-30 | 1979-12-28 | Oxy Metal Industries Corp | AQUEOUS ACIDIC RHODIUM COATING BATHS AND ELECTROLYTIC RHODIUM COATING COMPOSITIONS CONTAINING THESE BATHS |
-
1981
- 1981-09-22 DE DE8181107517T patent/DE3176572D1/en not_active Expired
- 1981-09-22 EP EP19810107517 patent/EP0048929B1/en not_active Expired
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR793197A (en) * | 1935-06-04 | 1936-01-18 | Heraeus Gmbh W C | Process for obtaining dark electrolytic deposits of rhodium and objects covered with said deposit |
DE692122C (en) * | 1938-03-13 | 1940-06-13 | Wieland Fa Dr Th | Rhodium bath |
US3592750A (en) * | 1967-11-10 | 1971-07-13 | Ici Ltd | Electrodes for use in aqueous alkali metal chloride electrolytes |
FR2427404A1 (en) * | 1978-05-30 | 1979-12-28 | Oxy Metal Industries Corp | AQUEOUS ACIDIC RHODIUM COATING BATHS AND ELECTROLYTIC RHODIUM COATING COMPOSITIONS CONTAINING THESE BATHS |
Non-Patent Citations (2)
Title |
---|
Chem. Zentralblatt, Vol. 138, No. 22, 1967, page 55, Abstract 0583, Shigeo Shibata: "Elektrolytische Bildung und Auflosung einder Oxidschicht aif Rhodium in Saurer Losung" & Bull. Chem. Soc. Japan 38, 1330-1337, 1965 * the whole document * * |
Metal Finishing Abstracts, Vol. 22, No. 5, September-October 1980, Hampton Hill (GB) "Gold Plating of Contacts", page 326B * the whole document * * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0056590B1 (en) * | 1981-01-15 | 1985-04-24 | Degussa Aktiengesellschaft | Galvanic bath for the deposition of rhodium coatings |
IT201700084504A1 (en) * | 2017-07-25 | 2019-01-25 | Valmet Plating S R L | GALVANIC BATHROOM, ELECTRODEPTIFICATION PROCEDURE USING THE GALVANIC BATH AND METALLIC ALLOY OBTAINABLE THROUGH THAT PROCEDURE |
Also Published As
Publication number | Publication date |
---|---|
EP0048929B1 (en) | 1987-12-09 |
DE3176572D1 (en) | 1988-01-21 |
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