CN116770375B - Plating solution for black chromium plating layer, and preparation method and application thereof - Google Patents
Plating solution for black chromium plating layer, and preparation method and application thereof Download PDFInfo
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- CN116770375B CN116770375B CN202310664723.0A CN202310664723A CN116770375B CN 116770375 B CN116770375 B CN 116770375B CN 202310664723 A CN202310664723 A CN 202310664723A CN 116770375 B CN116770375 B CN 116770375B
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- 238000007747 plating Methods 0.000 title claims abstract description 166
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 title claims abstract description 100
- 239000011651 chromium Substances 0.000 title claims abstract description 97
- 229910052804 chromium Inorganic materials 0.000 title claims abstract description 95
- 238000002360 preparation method Methods 0.000 title claims abstract description 34
- 150000001844 chromium Chemical class 0.000 claims abstract description 32
- 150000003839 salts Chemical class 0.000 claims abstract description 26
- 238000009713 electroplating Methods 0.000 claims abstract description 23
- -1 transition metal salt Chemical class 0.000 claims abstract description 22
- 239000008139 complexing agent Substances 0.000 claims abstract description 21
- 229910052945 inorganic sulfide Inorganic materials 0.000 claims abstract description 20
- 229910052723 transition metal Inorganic materials 0.000 claims abstract description 19
- BJEPYKJPYRNKOW-REOHCLBHSA-N (S)-malic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O BJEPYKJPYRNKOW-REOHCLBHSA-N 0.000 claims abstract description 18
- BJEPYKJPYRNKOW-UHFFFAOYSA-N alpha-hydroxysuccinic acid Natural products OC(=O)C(O)CC(O)=O BJEPYKJPYRNKOW-UHFFFAOYSA-N 0.000 claims abstract description 18
- 235000011090 malic acid Nutrition 0.000 claims abstract description 18
- 239000001630 malic acid Substances 0.000 claims abstract description 18
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 claims abstract description 17
- 239000002994 raw material Substances 0.000 claims abstract description 15
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 14
- GRWVQDDAKZFPFI-UHFFFAOYSA-H chromium(III) sulfate Chemical compound [Cr+3].[Cr+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O GRWVQDDAKZFPFI-UHFFFAOYSA-H 0.000 claims abstract description 12
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000004327 boric acid Substances 0.000 claims abstract description 11
- 239000004202 carbamide Substances 0.000 claims abstract description 11
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims abstract description 7
- CKLJMWTZIZZHCS-REOHCLBHSA-N L-aspartic acid Chemical compound OC(=O)[C@@H](N)CC(O)=O CKLJMWTZIZZHCS-REOHCLBHSA-N 0.000 claims abstract description 5
- 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 abstract description 5
- 235000003704 aspartic acid Nutrition 0.000 claims abstract description 5
- OQFSQFPPLPISGP-UHFFFAOYSA-N beta-carboxyaspartic acid Natural products OC(=O)C(N)C(C(O)=O)C(O)=O OQFSQFPPLPISGP-UHFFFAOYSA-N 0.000 claims abstract description 5
- 235000002906 tartaric acid Nutrition 0.000 claims abstract description 5
- 239000011975 tartaric acid Substances 0.000 claims abstract description 5
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 claims abstract description 3
- 235000013877 carbamide Nutrition 0.000 claims abstract description 3
- 238000000034 method Methods 0.000 claims description 33
- 238000004519 manufacturing process Methods 0.000 claims description 28
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 18
- 239000012141 concentrate Substances 0.000 claims description 17
- 239000000080 wetting agent Substances 0.000 claims description 15
- 239000002270 dispersing agent Substances 0.000 claims description 14
- 238000002156 mixing Methods 0.000 claims description 11
- ZMZDMBWJUHKJPS-UHFFFAOYSA-M Thiocyanate anion Chemical compound [S-]C#N ZMZDMBWJUHKJPS-UHFFFAOYSA-M 0.000 claims description 2
- 150000001868 cobalt Chemical class 0.000 claims description 2
- 238000007865 diluting Methods 0.000 claims description 2
- ZMZDMBWJUHKJPS-UHFFFAOYSA-N hydrogen thiocyanate Natural products SC#N ZMZDMBWJUHKJPS-UHFFFAOYSA-N 0.000 claims description 2
- CVHZOJJKTDOEJC-UHFFFAOYSA-N saccharin Chemical compound C1=CC=C2C(=O)NS(=O)(=O)C2=C1 CVHZOJJKTDOEJC-UHFFFAOYSA-N 0.000 claims description 2
- 229940081974 saccharin Drugs 0.000 claims description 2
- 235000019204 saccharin Nutrition 0.000 claims description 2
- 239000000901 saccharin and its Na,K and Ca salt Substances 0.000 claims description 2
- 239000000243 solution Substances 0.000 description 124
- 239000010410 layer Substances 0.000 description 45
- 239000011248 coating agent Substances 0.000 description 31
- 238000000576 coating method Methods 0.000 description 31
- 239000007864 aqueous solution Substances 0.000 description 28
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 24
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 21
- 238000012360 testing method Methods 0.000 description 17
- 239000000463 material Substances 0.000 description 13
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 12
- 239000012535 impurity Substances 0.000 description 12
- 229910052759 nickel Inorganic materials 0.000 description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 11
- 238000005868 electrolysis reaction Methods 0.000 description 11
- 239000000203 mixture Substances 0.000 description 11
- 230000008569 process Effects 0.000 description 11
- 238000003756 stirring Methods 0.000 description 11
- 230000008021 deposition Effects 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- 239000004094 surface-active agent Substances 0.000 description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 8
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 8
- 239000010936 titanium Substances 0.000 description 8
- 229910052719 titanium Inorganic materials 0.000 description 8
- 238000001914 filtration Methods 0.000 description 7
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 6
- 230000001502 supplementing effect Effects 0.000 description 6
- 230000007797 corrosion Effects 0.000 description 5
- 238000005260 corrosion Methods 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 4
- 239000007921 spray Substances 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 239000002202 Polyethylene glycol Substances 0.000 description 3
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000003153 chemical reaction reagent Substances 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000008236 heating water Substances 0.000 description 3
- 229920001223 polyethylene glycol Polymers 0.000 description 3
- 239000011241 protective layer Substances 0.000 description 3
- 229910052708 sodium Inorganic materials 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- 229910052938 sodium sulfate Inorganic materials 0.000 description 3
- 235000011152 sodium sulphate Nutrition 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000004448 titration Methods 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 2
- DBMJMQXJHONAFJ-UHFFFAOYSA-M Sodium laurylsulphate Chemical compound [Na+].CCCCCCCCCCCCOS([O-])(=O)=O DBMJMQXJHONAFJ-UHFFFAOYSA-M 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000003595 mist Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 239000013589 supplement Substances 0.000 description 2
- 238000009827 uniform distribution Methods 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 229910000599 Cr alloy Inorganic materials 0.000 description 1
- FBPFZTCFMRRESA-KVTDHHQDSA-N D-Mannitol Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@H](O)CO FBPFZTCFMRRESA-KVTDHHQDSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229930195725 Mannitol Natural products 0.000 description 1
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229910001245 Sb alloy Inorganic materials 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000002140 antimony alloy Substances 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000000788 chromium alloy Substances 0.000 description 1
- 229910001430 chromium ion Inorganic materials 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 229910000361 cobalt sulfate Inorganic materials 0.000 description 1
- 229940044175 cobalt sulfate Drugs 0.000 description 1
- KTVIXTQDYHMGHF-UHFFFAOYSA-L cobalt(2+) sulfate Chemical compound [Co+2].[O-]S([O-])(=O)=O KTVIXTQDYHMGHF-UHFFFAOYSA-L 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- XJRPTMORGOIMMI-UHFFFAOYSA-N ethyl 2-amino-4-(trifluoromethyl)-1,3-thiazole-5-carboxylate Chemical compound CCOC(=O)C=1SC(N)=NC=1C(F)(F)F XJRPTMORGOIMMI-UHFFFAOYSA-N 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 238000005805 hydroxylation reaction Methods 0.000 description 1
- 239000005457 ice water Substances 0.000 description 1
- 239000000594 mannitol Substances 0.000 description 1
- 235000010355 mannitol Nutrition 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 description 1
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 1
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 239000006174 pH buffer Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- OTYBMLCTZGSZBG-UHFFFAOYSA-L potassium sulfate Chemical compound [K+].[K+].[O-]S([O-])(=O)=O OTYBMLCTZGSZBG-UHFFFAOYSA-L 0.000 description 1
- 229910052939 potassium sulfate Inorganic materials 0.000 description 1
- 235000011151 potassium sulphates Nutrition 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 239000008213 purified water Substances 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- PFUVRDFDKPNGAV-UHFFFAOYSA-N sodium peroxide Chemical compound [Na+].[Na+].[O-][O-] PFUVRDFDKPNGAV-UHFFFAOYSA-N 0.000 description 1
- 229940074404 sodium succinate Drugs 0.000 description 1
- ZDQYSKICYIVCPN-UHFFFAOYSA-L sodium succinate (anhydrous) Chemical compound [Na+].[Na+].[O-]C(=O)CCC([O-])=O ZDQYSKICYIVCPN-UHFFFAOYSA-L 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- DGSDBJMBHCQYGN-UHFFFAOYSA-M sodium;2-ethylhexyl sulfate Chemical compound [Na+].CCCCC(CC)COS([O-])(=O)=O DGSDBJMBHCQYGN-UHFFFAOYSA-M 0.000 description 1
- CHLCPTJLUJHDBO-UHFFFAOYSA-M sodium;benzenesulfinate Chemical compound [Na+].[O-]S(=O)C1=CC=CC=C1 CHLCPTJLUJHDBO-UHFFFAOYSA-M 0.000 description 1
- BFXAWOHHDUIALU-UHFFFAOYSA-M sodium;hydron;difluoride Chemical compound F.[F-].[Na+] BFXAWOHHDUIALU-UHFFFAOYSA-M 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000012086 standard solution Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 150000004763 sulfides Chemical class 0.000 description 1
- 230000009469 supplementation Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 238000011179 visual inspection Methods 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
- C25D3/04—Electroplating: Baths therefor from solutions of chromium
- C25D3/08—Deposition of black chromium, e.g. hexavalent chromium, CrVI
Abstract
The invention discloses a plating solution for a black chromium plating layer, a preparation method and application thereof, and belongs to the technical field of electroplating. The plating solution of the black chromium plating layer provided by the invention comprises the following preparation raw materials in concentration: 260-320 g/L of conductive salt, wherein the conductive salt comprises sulfate and boric acid; the preparation method of the chromium salt concentrated solution comprises the steps of reacting chromium sulfate and malic acid for 2-15 hours at 70-100 ℃, wherein the mass ratio of the chromium sulfate to the malic acid is 3.5-4.5:1; an organic sulfide; an inorganic sulfide; a transition metal salt; complexing agent, which comprises at least one of urea, tartaric acid and aspartic acid. The plating solution provided by the invention can effectively blackness and compact coverage of the black chromium layer and improve operation safety. The invention also provides a preparation method and application of the plating solution.
Description
Technical Field
The invention relates to the technical field of electroplating, in particular to a plating solution for a black chromium plating layer, a preparation method and application thereof.
Background
The electroplating layer is widely used as a protective coating and a functional coating because of its high hardness (hardness range 400 to 1200 HV), good wear resistance (small friction coefficient), good chemical stability (no reaction with alkali, sulfide, nitric acid and most organic acids), and plays an important role in the electroplating industry.
The chromium plating layers are classified according to functions, appearance, etc., and generally include decorative chromium layers, black chromium, loose-pore chromium, milky white chromium, hard chromium, etc. Except black chromium, the material of other chromium layers is usually chromium simple substance or chromium alloy, so that the compactness is good and a plating layer with higher glossiness can be formed unless the material is manually treated; however, the black chromium contains about 44% of metallic chromium, and the rest is mainly chromium oxide, which is usually present in the form of particles, and therefore is generally inferior in glossiness and slightly inferior in corrosion resistance to hard chromium, white chromium, and the like.
In the prior art, the valence state of chromium in the chromium plating solution is hexavalent, but the chromium plating solution has the problems of low dispersing capability, low current efficiency, severe device, serious environmental influence caused by the toxic hexavalent chromium and the like, and the hexavalent chromium plating solution is gradually forbidden to be used.
In order to solve the problems, a trivalent chromium plating solution is adopted in the prior art, but black chromium formed by the trivalent chromium plating solution in the prior art still has the problems of poor brightness and coverage.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, compared with the traditional trivalent black chromium plating layer, the plating solution for the black chromium plating layer provided by the invention can effectively improve the blackness, corrosion resistance and compact coverage of the black chromium layer and improve the operation safety.
The invention also provides a preparation method of the plating solution.
The invention also provides application of the plating solution.
According to an embodiment of the first aspect of the present invention, there is provided a plating solution for a black chromium plating layer, the plating solution comprising preparation raw materials having the following concentrations:
conductive salt, 260-320 g/L, wherein the conductive salt comprises sulfate and boric acid;
the preparation method of the chromium salt concentrated solution comprises the steps of reacting chromium sulfate and malic acid for 2-15 hours at 70-100 ℃, wherein the mass ratio of the chromium sulfate to the malic acid is 3.5-4.5:1;
an organic sulfide;
an inorganic sulfide;
a transition metal salt;
and the complexing agent comprises at least one of urea, tartaric acid and aspartic acid.
The plating solution according to the embodiment of the invention has at least the following beneficial effects:
(1) Other conditions were the same, the thickness of the black chromium coating that could be deposited per unit time and the concentration of active chromium showed a positive correlation. Trivalent chromium readily forms Cr (H) in water 2 O) 6 Or Cr (OH) 6 3- Is hardly reactive, i.e. cannot be deposited to form a black chromium coating, during the electroplating process.
In the chromium salt concentrated solution adopted by the invention, the malic acid can be promoted to replace water/hydroxyl in the inert coordination structure by a preparation method with special temperature and time length, or simultaneously, the hexacoordination structure of trivalent chromium can be promoted to be converted into a tri-coordination structure; that is, the invention firstly reacts malic acid with chromium sulfate to obtain chromium salt concentrated solution, which promotes the formation of trivalent chromium with deposition activity, so that the plating solution provided by the invention can adopt chromium sulfate with lower concentration to obtain thicker black chromium coating. The low total chromium concentration also greatly reduces the cost of the later water treatment.
(2) It was found that in the chromium salt concentrate, if the concentration of malic acid is increased, the deposition rate of the black chromium layer is rather reduced, probably because when the amount of malic acid occupying the trivalent chromium coordination sites is increased, the conversion of active chromium into inactive chromium is rather promoted; therefore, the dosage ratio of chromium sulfate to malic acid needs to be controlled.
(3) In the plating solution provided by the invention, the deposition speed and the achievable deposition thickness of the black chromium plating layer can be obviously improved through the collocation of the chromium salt concentrated solution and the complexing agent; solves the problem that the trivalent chromium plating solution in the prior art is difficult to realize thicker black chromium plating.
(4) In the plating solution provided by the invention, the organic sulfide, the inorganic sulfide and the transition metal salt are matched, so that the obtained black chromium plating layer has higher blackness and brightness, and the type and concentration of the conductive salt, the chromium salt concentrated solution, the complexing agent and the like are matched, so that the deposition uniformity and the density of the obtained black chromium plating layer are also obviously improved, and the problems of poor coverage and poor corrosion resistance of the black chromium plating layer obtained by the traditional technology are solved.
(5) Compared with the traditional hexavalent chromium system, the trivalent chromium system is adopted, so that the toxicity of the plating solution is obviously reduced, the environmental safety and the operation safety are improved, and the coverage and the potential capability are also improved. Compared with the traditional chloride system, the invention adopts a sulfate system, does not generate chlorine, has lower corrosiveness to equipment and better stability.
According to some embodiments of the invention, the sulfate comprises at least one of sodium sulfate and potassium sulfate.
According to some embodiments of the invention, the mass ratio of sulfate to boric acid is 1-2:1. Wherein boric acid has the function of a pH buffer in addition to the function of a conductive salt, thereby consuming hydroxyl radicals generated on the surface of a cathode in the electroplating process and avoiding the generation of hydroxyl complex (deactivation) of trivalent chromium.
The invention ensures the uniform distribution of the electric charge of the plating solution in the electroplating process by controlling the concentration of the conductive salt, so that the deposition of the obtained black chromium plating layer is more uniform.
According to some embodiments of the invention, the mass ratio of sulfate to boric acid is 1.5-1.6:1.
According to some embodiments of the invention, the concentration of the conductive salt in the plating solution is 280-300 g/L.
According to some embodiments of the invention, the concentration of the chromium sulfate in the chromium salt concentrate is 1.5 to 4.5mol/L. For example, the concentration may be specifically 2.5 to 3.5mol/L. Further specifically, about 3mol/L is possible.
According to some embodiments of the invention, the chromium salt concentrate has a ratio of the amounts of the chromium sulfate and the malic acid in the range of 3.8 to 4.2:1. And more specifically may be about 4:1.
According to some embodiments of the invention, the concentration of the chromium salt concentrate in the plating bath is 140 to 160ml/L. For example, it may be about 150ml/L.
According to some embodiments of the invention, the reaction temperature is 80-90 ℃.
According to some embodiments of the invention, the chromium salt concentrate is prepared by a method having a reaction time of 10-12 hours.
According to some embodiments of the invention, the organic sulfide comprises saccharin. The organic sulfide has the effects of promoting the uniform distribution of chromium, further promoting the uniformity of the material quality of the black chromium coating and maintaining the color of the black chromium coating.
According to some embodiments of the invention, the organic sulfide is added to the plating solution as an aqueous solution of organic sulfide.
In the organic sulfide aqueous solution, the concentration of the organic sulfide is 10-20wt%.
The organic sulfide aqueous solution also comprises a surfactant.
In the organic sulfide aqueous solution, the concentration of the surfactant is 0.5-1.25%. The surfactant includes SAS (secondary sodium alkyl sulfonate).
According to some embodiments of the invention, the concentration of the aqueous organosulfide solution in the plating solution is 5-10 mL/L.
According to some embodiments of the invention, the inorganic sulfide includes thiocyanate. The inorganic sulfide has the function of adjusting the appearance blackness of the black chromium coating and maintaining the color of the black chromium coating.
According to some embodiments of the invention, the inorganic sulfide is added to the plating solution as an aqueous solution of inorganic sulfide.
In the inorganic sulfide aqueous solution, the concentration of the inorganic sulfide is 10-20wt%.
The inorganic sulfide aqueous solution also comprises a surfactant.
In the inorganic sulfide aqueous solution, the concentration of the surfactant is 0.5-1.25%. The surfactant includes SAS (secondary sodium alkyl sulfonate).
According to some embodiments of the invention, the concentration of the aqueous inorganic sulfide solution in the plating solution is 5 to 10mL/L.
According to some embodiments of the invention, the concentration of the aqueous inorganic sulfide solution in the plating solution is 7 to 8ml/L.
According to some embodiments of the invention, the transition metal salt comprises a water-soluble cobalt salt. For example, cobalt sulfate may be mentioned. The transition metal salt can be used as an alloy to improve the hardness, coverage compactness and the like of a black chromium coating, and has the effects of adjusting the appearance blackness and maintaining the color of a coating.
According to some embodiments of the invention, in the plating solution, the transition metal salt is added in the form of an aqueous solution of a transition metal salt.
In the transition metal salt aqueous solution, the concentration of the transition metal salt is 10-20wt%.
The transition metal salt aqueous solution also comprises a surfactant.
In the transition metal salt aqueous solution, the concentration of the surfactant is 0.5-1.25%. The surfactant includes SAS (secondary sodium alkyl sulfonate).
According to some embodiments of the invention, the concentration of the transition metal salt aqueous solution in the plating solution is 3-8 mL/L.
According to some embodiments of the invention, the complexing agent comprises urea and aspartic acid. The mass ratio of the urea to the aspartic acid is 1-1.5:1.
According to some embodiments of the invention, the complexing agent is used in the form of an aqueous complexing agent solution. In the complexing agent aqueous solution, the concentration of solute is 0.2-0.8 g/mL.
According to some embodiments of the invention, the concentration of the complexing agent aqueous solution in the plating solution is 40-80 mL/L.
According to some embodiments of the invention, the concentration of the complexing agent aqueous solution in the plating solution is 45-55 mL/L. For example, it may be about 50mL/L.
According to some embodiments of the invention, the plating solution is prepared from a raw material further comprising a dispersant.
According to some embodiments of the invention, the dispersant is added to the plating solution in the form of an aqueous dispersant solution.
The concentration of the dispersant aqueous solution is 10-20wt%.
According to some embodiments of the invention, the concentration of the aqueous solution of the dispersant in the plating solution is 5-10 ml/L.
According to some embodiments of the invention, the dispersant comprises polyethylene glycol. The number average molecular weight of the polyethylene glycol is 200-4000. The polyethylene glycol has a dispersing function, so that chromium is uniformly distributed in the plating solution, the pH value at the interface of the cathode can be reduced, further, the hydroxylation reaction of trivalent chromium ions on the surface of the cathode can be avoided, and the upper limit of the thickness of a black chromium layer which can be formed by the plating solution is increased.
According to some embodiments of the invention, the plating solution is prepared from a feedstock that further includes a wetting agent.
According to some embodiments of the invention, the wetting agent comprises at least one of Sodium Dodecyl Sulfate (SDS), sodium benzene sulfinate, sodium ethylhexyl sulfate, and sodium succinate.
According to some embodiments of the invention, the wetting agent is added to the plating solution in the form of an aqueous wetting agent solution.
According to some embodiments of the invention, the concentration of the aqueous wetting agent solution in the plating solution is 1-3 ml/L. For example, it may be about 2ml/L.
According to some embodiments of the invention, the pH of the plating solution is 3.3 to 3.8. The agent for adjusting the pH of the plating solution comprises at least one of sulfuric acid solution and sodium hydroxide solution. Wherein the concentration of the sulfuric acid solution is 15-25 wt%; the concentration of the sodium hydroxide solution is 15-25 wt%.
According to some embodiments of the invention, the wetting agent is added to the plating solution in the form of an aqueous wetting agent solution.
The concentration of the wetting agent aqueous solution is 10-20wt%.
According to some embodiments of the invention, the plating solution is prepared from a starting material that also includes water. To determine the concentration of each component in the bath. According to an embodiment of the second aspect of the present invention, there is provided a method for preparing the plating solution, the method comprising diluting the conductive salt, chromium salt concentrate with water, adjusting pH, and mixing with other preparation raw materials.
The preparation method adopts all the technical schemes of the plating solution of the embodiment, so that the preparation method has at least all the beneficial effects brought by the technical schemes of the embodiment. Furthermore, the preparation method provided by the invention is characterized in that the chromium salt concentrated solution is prepared first, so that the proportion of active chromium in the plating solution is obviously improved.
According to some embodiments of the invention, the plating solution may be prepared directly in the bath for the electroplating or transferred to the bath after preparation elsewhere.
According to some embodiments of the invention, the temperature of the preparation process is 45-60 ℃.
According to some embodiments of the invention, the water is added for dilution by heating water accounting for 70% of the volume of the plating solution to 55-60 ℃ and then mixing with the conductive salt, and after mixing the obtained mixture with the chromium salt concentrate, adding water to a volume of 90% of the volume of the plating solution.
According to some embodiments of the invention, the pH is adjusted to a pH in the range of 3.3 to 3.8. A pH exceeding 3.8 can seriously affect the performance of the bath.
According to some embodiments of the invention, the pH is adjusted to a temperature of 45-50 ℃.
To avoid pH unevenness (local excess), vigorous stirring is required during pH adjustment.
According to some embodiments of the invention, the preparation method further comprises maintaining the temperature for 12h or more after adjusting the pH.
According to some embodiments of the invention, the method further comprises adding water to fix volume and readjusting pH after all preparation materials are mixed. And the pH value is regulated again to be 3.3-3.5.
According to some embodiments of the invention, the method of preparation comprises the steps of:
s1, heating water accounting for 70% of the volume of the plating solution to 55-60 ℃ and mixing with the conductive salt;
s2, mixing the mixture obtained in the step S1 with the chromium salt concentrated solution, and then adding water to fix the volume to 90% of the volume of the plating solution;
s3, adjusting the pH value of the mixture obtained in the step S2 to 3.3-3.8 at 45-50 ℃ under the stirring state, and keeping the constant temperature for more than or equal to 12 hours;
s4, sequentially mixing the mixture obtained in the step S3 with the dispersing agent, the organic sulfide, the inorganic sulfide, the transition metal salt and the wetting agent, and adding water to fix the volume to the volume required by the plating solution;
s5, adjusting the pH value of the mixture obtained in the step S4 to 3.3-3.5.
According to an embodiment of the third aspect of the present invention, there is provided a production method of a black chromium plating layer, the production method including electroplating with the plating solution.
The production method adopts all the technical schemes of the plating solution of the embodiment, so that the method has at least all the beneficial effects brought by the technical schemes of the embodiment. The production method provided by the invention has simple and easily controlled process.
According to some embodiments of the invention, the apparatus for electroplating comprises:
the groove body comprises a main groove and an auxiliary groove which are adjacently arranged;
the exhaust unit is arranged at the top end of the groove body;
a stirring unit; the stirring unit comprises a pipeline for communicating the top end and the bottom end of the tank body and a pump arranged on the pipeline;
a filtering unit; the filtering unit is arranged on the wall of the main groove and/or the auxiliary groove.
Therefore, the arrangement of the double grooves can facilitate the simultaneous electroplating of different parts; the exhaust unit can timely exhaust the hydrogen precipitated on the surface of the cathode, so that mist bad is avoided to be generated on the surface of the black chromium coating; the stirring unit pumps out the plating solution from the bottom end of the tank body and flows out from the top end, so that convection is formed in the tank body, the uniformity of the plating solution in the electroplating process is improved, and the uniformity of the black chromium plating layer is improved; both organic impurities and inorganic metal chips affect the performance and appearance of the coating, so that at least one stage of filtering unit is needed; if desired, the number of stages of the filter unit may be increased.
According to some embodiments of the invention, the stirring unit further comprises air stirring. To supplement the mechanical agitation of the tubing.
According to some embodiments of the invention, the tank is further provided with at least one feed inlet. Whereby the consumed components can be added as needed during the electroplating process.
According to some embodiments of the invention, the apparatus further comprises a temperature control unit located in the tank.
According to some embodiments of the invention, the temperature control unit comprises a titanium heating tube. Automatic constant temperature control can be realized.
According to some embodiments of the invention, the combination further comprises a pH meter. Whereby the pH of the plating solution in the tank can be monitored.
According to some embodiments of the invention, the method of production comprises using a clean instrument. For example, using entirely new instruments; or soaking the instrument (if old) with 1-1.5% by volume aqueous sulfuric acid for 8-10 hours at 55-65 c, which may be about 60 c in particular, and washing the instrument after soaking. Thereby avoiding pollution of the plating solution by impurity ions such as hexavalent chromium and the like.
According to some embodiments of the invention, each component of the apparatus is operated without interruption in the production process. The production method is specifically carried out under the conditions of constant temperature, stirring and pH control.
According to some embodiments of the invention, the electroplated anode comprises a titanium-based material and a noble metal coating.
The titanium-based material includes at least one of metallic titanium and a titanium alloy.
The anode comprises at least one of a pure titanium-based material, or a material comprising a titanium-based material coating.
Compared with the traditional graphite electrode and lead-base alloy electrode, the anode provided by the invention can remarkably avoid the problems of plating solution pollution and the like caused by anode dissolution, and can improve the current density and the production benefit.
Further, when only the titanium-based material coating is included in the anode, the anode is still periodically cleaned and inspected to avoid excessive consumption (peeling and breakage of the protective layer) of the surface coating, although the suitability with the black chromium plating is high.
According to some embodiments of the invention, the electroplated cathode includes a substrate and a nickel plating layer overlying a surface of the substrate. The properties of the nickel coating may influence the properties of the black chromium coating to a certain extent, for example, if the roughness of the nickel coating is high, the roughness of the resulting black chromium coating is also high.
According to some embodiments of the invention, the area ratio of the anode to the cathode is 1.5-2:1.
According to some embodiments of the invention, the temperature of the plating solution is 45-55 ℃. For example, it may be about 50 ℃. The higher the temperature is, the faster the electroplating speed is, but the coverage is reduced, i.e. the compactness of the resulting black chromium deposit is reduced.
According to some embodiments of the invention, the pH of the plating solution is 3.3-3.8. For example, it may be about 3.4.
According to some embodiments of the invention, the method of production comprises the steps of:
D1. carrying out electrolysis by adopting the anode and the cathode, removing the obtained pre-plating layer, and resetting a nickel plating layer on the surface of the obtained cathode;
D2. electroplating by adopting the cathode obtained in the step D1.
Since the performance of the new plating solution is unstable, the uniformity and performance of the black chromium plating layer obtained by the initial plating are not stable enough, and therefore, the step D1 is required to be set, which is equivalent to the preheating of the whole system.
According to some embodiments of the invention, in step D1, the current density of the electrolysis is between 4 and 5AH/L.
According to some embodiments of the invention, in step D1, the electrolysis is performed for a period of time ranging from 1.5 to 2.5 hours. For example, it may be about 2 hours. This electrolysis period may already cause the plating bath to go through an unstable period.
According to some embodiments of the invention, in step D2, the electroplating period is 3-8 min. For example, it may be about 5 minutes.
According to some embodiments of the invention, in step D2, the current density of the cathode in the electroplating is 7-15A/dm 2 . For example, it may be about 12A/dm 2 。
According to some embodiments of the invention, in step D2, it is necessary to add a preparation raw material to ensure stable performance of the plating solution. The reason for this is that the preparation raw materials are consumed or carried out. The added nodes can be added in amounts after testing the concentration or automatically in ampere hours. Specific:
according to some embodiments of the invention, the conductive salt is replenished by concentration testing.
According to some embodiments of the invention, the method of producing comprises replenishing the chromium salt concentrate in an amount of 800-1000 ml/KAH during the production process.
According to some embodiments of the invention, the chromium salt concentrate may be supplemented by quantitative supplementation after concentration testing.
According to some embodiments of the invention, the method of production comprises replenishing the dispersant in an amount of 300 to 500ml/KAH during production.
According to some embodiments of the invention, the method of producing comprises replenishing the organosulfide in an amount of 400-500 ml/KAH during production.
According to some embodiments of the invention, the method of producing comprises replenishing the inorganic sulfide in an amount of 100 to 200ml/KAH during the production process.
According to some embodiments of the invention, the method of production comprises replenishing the transition metal salt in an amount of 100-200 ml/KAH during production.
According to some embodiments of the invention, the method of production comprises replenishing the complexing agent in an amount of 800-1000 ml/KAH during production.
According to some embodiments of the invention, the surface tension of the plating solution is controlled to be less than or equal to 40dyn/cm. Otherwise, the wetting agent may be supplemented in an amount of 0.5 to 1.0 ml/L.
In the production process, in the unit of the supplementary substance, mL represents the volume of the corresponding aqueous solution. For example, the complexing agent is supplemented in an amount of 800-1000 mL/KAH, which means that 800-1000 mL of complexing agent aqueous solution is supplemented per KAH, and the concentration and the proportion of the complexing agent aqueous solution are as described above.
According to some embodiments of the invention, the impurity content of the plating solution is controlled according to the following criteria:
nickel <30ppm; copper <10ppm; zinc <10ppm; iron <10ppm; hexavalent chromium <5ppm; lead <5ppm; fluoride <5ppm; bromide <5ppm.
Therefore, the cathode, the anode and the like need to be strictly washed before entering the tank body, so that the introduction of impurity ions is avoided. If introduced carelessly, the impurities need to be removed by electrolysis or by adding impurity removing agents. The specific washing times are more than or equal to 5 times.
Further, the bath solution is required to be treated with active carbon at regular intervals, and the active carbon has little loss to additives (raw materials for preparing a wetting agent, etc.), and it is recommended to perform carbon core filtration every week to remove organic impurities carried in from the nickel bath (cathode nickel plating layer formation process) and organic impurities generated by decomposition of the additives (raw materials for preparing a plating solution); in particular, the nickel plating layer is not thoroughly cleaned after being formed, and organic impurities can cause the black chromium plating layer to be whitish, dark and poor in covering capability. The active carbon powder is added with hydrogen peroxide once per month, the hydrogen peroxide is added to maintain the plating solution in an optimal state, if the solution is idle for a long time and is not used, the hydrogen peroxide and the active carbon are added for treatment, the adding amount of the hydrogen peroxide is 0.5ml/L, and the adding amount of the hydrogen peroxide is not more than 1ml/L at most; the active carbon and the hydrogen peroxide can consume the dispersant and the complexing agent, and the dispersant and the complexing agent need to be additionally supplemented after large treatment.
If the production process needs to be suspended for a long time, it is necessary to stop heating and adjust the pH of the plating solution to 2 or less. To avoid precipitation, valence changes, etc. of trivalent chromium.
If the plating solution is restarted after long-time pause, the temperature is required to be increased to the operating temperature again, and after the components of the plating solution are ensured to be uniform, the normal electroplating is carried out after the step D1 is repeated.
According to an embodiment of the fourth aspect of the present invention, there is provided a black chrome plating layer produced by the production method, the black chrome plating layer having an L value of 45 to 55.
The black chromium coating adopts all the technical schemes of the plating solution of the embodiment, so that the black chromium coating has at least all the beneficial effects brought by the technical schemes of the embodiment. The production method provided by the invention has simple and easily controlled process. The black chromium plating layer provided by the invention is a bright and dark black chromium plating layer.
According to some embodiments of the invention, the black chrome plating has an L value of 48 to 52, which may be about 50, for example.
The term "about" as used herein, unless otherwise specified, means that the tolerance is within + -2%, for example, about 100 is actually 100 + -2%. Times.100.
Unless otherwise specified, the term "between … …" in the present invention includes the present number, for example "between 2 and 3" includes the end values of 2 and 3.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:
FIG. 1 is a photograph of a plated article obtained by using the plating solution obtained in example 1 in the application example.
FIG. 2 is a photograph of a plated article obtained by using the plating solution obtained in comparative example 3.
Detailed Description
The conception and the technical effects produced by the present invention will be clearly and completely described in conjunction with the embodiments below to fully understand the objects, features and effects of the present invention. It is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments, and that other embodiments obtained by those skilled in the art without inventive effort are within the scope of the present invention based on the embodiments of the present invention.
In the description of the present invention, the descriptions of the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Unless otherwise specified, the method for testing the concentration of the conductive salt (the medium boric acid) in the plating solution comprises the following steps:
sucking 2ml of bath solution (plating solution in the electroplating process) into a 250ml conical flask; about 20ml of distilled water was added; adding 2-3 drops of boric acid indicator (0.5% bromocresol purple and 0.1ml 0.5N sodium hydroxide); a 0.5N NaOH solution was added dropwise until the blue end point. Adding 5g mannitol; titration with 0.5N NaOH was performed to a blue endpoint. (note the reading of NaOH at this time). Conductive salt concentration (g/L) =titration milliliters×65. In the conductive salt, the consumption rate ratio of boric acid and sodium sulfate is equal to the original concentration ratio thereof, and after the boric acid concentration is obtained by testing, the concentration of sodium sulfate can be calculated and supplemented as required.
If not specified, the method for testing the concentration of the chromium salt concentrated solution in the plating solution comprises the following steps:
the 5ml tank was sucked up to a 250ml conical flask, and then purified water was added to about 100ml. 2 g of sodium peroxide and anti-bumping particles were added. The liquid was heated to boiling and held for 30min, rinsing the walls of the cup, taking care not to burn dry. 100ml of pure water are added and the liquid is cooled to room temperature, then 1 g of sodium bifluoride, 5ml of 20% KI and 20ml of 50% HCl are added. Titrating with a 0.1N standard solution of sodium thiosulfate, adding a starch indicator until the end point. And (3) calculating: chromium salt concentrate (ml/L) =titration milliliters×5.
Example 1
The plating solution is prepared in this example, the specific composition of the preparation raw materials is shown in table 1, the container is a tank body (brand new first use) used for producing the black chromium plating layer, and the preparation method comprises the following steps:
s1, heating water accounting for 70% of the volume of the plating solution to 60 ℃ and mixing with conductive salt;
s2, mixing the mixture obtained in the step S1 with the chromium salt concentrated solution, and adding water to fix the volume to 90% of the volume of the plating solution; the preparation method of the chromium salt concentrated solution comprises the steps of mixing and reacting the preparation raw materials of the chromium salt concentrated solution for 10 hours at 90 ℃.
S3, adjusting the pH value of the mixture obtained in the step S2 to 3.3 at 50 ℃ under the stirring state, and keeping the temperature for 12 hours;
s4, sequentially mixing the mixture obtained in the step S3 with a dispersing agent (aqueous solution), an organic sulfide (aqueous solution), an inorganic sulfide (aqueous solution), a transition metal salt (aqueous solution) and a wetting agent (aqueous solution), and adding water to fix the volume to the volume required by the plating solution;
s5, adjusting the pH value of the mixture obtained in the step S4 to 3.4.
The reagent used for adjusting the pH in this case is a 20wt% aqueous sodium hydroxide solution or a 20wt% aqueous sulfuric acid solution.
TABLE 1 preparation starting materials for example 1
In table 1, chromium salt concentrates, dispersants, organic sulfides, inorganic sulfides, transition metal salts, complexing agents and wetting agents were all added in the form of their aqueous solutions, with specific concentrations being set forth in the composition column of table 1.
Comparative example 1
This example produced a plating solution, which differs from example 1 in that:
and (3) replacing malic acid in the chromium salt concentrated solution with urea with equal mass, and replacing urea in the complexing agent with malic acid with equal mass.
The addition amount and the sequence of the reagents in the preparation method are correspondingly adjusted.
Comparative example 2
This example produced a plating solution, which differs from example 1 in that:
the malic acid in the chromium salt concentrated solution is replaced by tartaric acid with equal mass.
Comparative example 3
This example produced a plating solution, which differs from example 1 in that:
in step S2, the chromium salt concentrate is prepared at 60 ℃.
Application example
The black chromium coating is prepared by the method specifically comprising the following steps:
D1. pretreatment:
d1a. obtaining a pre-plating layer:
electrolysis was performed using the electrolytes obtained in example 1 and comparative examples 1 to 3, in which:
the anode is made of copper-based material with a protective layer, and the protective layer is made of lead-antimony alloy;
the cathode is made of steel with nickel plating; the area ratio of anode to cathode was 1.5:1.
the current density of electrolysis is 4.5AH/L, the duration is 2 hours, and the temperature is 50 ℃;
d1b. removing the pre-plating layer: the pre-plating layer formed on the cathode surface was removed by the method described in example 1 of CN107338469 a.
D1c. bright nickel plating: forming a nickel coating on the surface of the cathode from which the pre-coating is removed.
The electrolyte adopted is 240g/L nickel sulfate, 50g/L nickel chloride, 45g/L boric acid, 10g/L super-high SC-230 auxiliary agent, 0.5g/L Nistar7003 main gloss agent, pH4.5, temperature 55 ℃ and cathode current density 5A/dm 2 The electroplating time is 10min.
In the step, each sub-step is carried out in different electrolysis systems, and before the sub-step is transferred to another electrolysis system, the cathode is washed by water for more than 5 times, so that the pollution of the solution in the former electrolysis tank to the latter electrolysis tank is avoided.
D2. Returning the cathode obtained in the step D1c to the system of the step D1a for electroplating, wherein the current density of the electroplated cathode is 12A/dm 2 The temperature is 50 ℃ and the duration is 5min. And taking out the cathode (plated part) after finishing, washing for more than 5 times, and drying to obtain the cathode.
In the step D1a and the step D2, the pH value of the plating solution needs to be monitored to be 3.3-3.8, and if the plating solution deviates, the plating solution needs to be adjusted in time (the used reagent is the same as that in the embodiment 1); and the concentration of the conductive salt is detected to be 260-320 g/L, and the conductive salt needs to be replenished at any time if the concentration is insufficient; it is also desirable to detect a surface tension of the bath at 40dyn/cm or less, otherwise it is desirable to supplement the wetting agent in an amount of about 1 ml/L. The continuous production process requires supplementing chromium salt concentrate in an amount of 900ml/KAH, supplementing dispersant in an amount of 400ml/KAH, supplementing organic sulfide in an amount of 450ml/KAH, supplementing inorganic sulfide in an amount of 150ml/KAH, supplementing transition metal salt in an amount of 150ml/KAH, and supplementing complexing agent in an amount of 900 ml/KAH.
In addition, in the continuous electroplating process, the filtration is also needed to be carried out regularly so as to remove solid impurities; and an activated carbon treatment, wherein the amount of each component is measured and quantitatively supplemented after the activated carbon treatment. If the impurity content exceeds nickel <30ppm; copper <10ppm; zinc <10ppm; iron <10ppm; hexavalent chromium <5ppm; lead <5ppm; fluoride <5ppm; the bromide content was <5ppm, and the removal of impurities was required (in this example, a fresh plating solution was used, and thus the operation in this stage was not required).
If the operation is interrupted for a long time, the pH of the plating solution needs to be adjusted to be less than or equal to 2, and the use amount of each preparation raw material needs to be re-measured for quantitative replenishment when restarting (in this example, a new plating solution is adopted, so that the operation of this stage is not needed).
The apparatus used in the steps D1a and D2 of this example comprises:
the device comprises a tank body, a temperature control unit (titanium heating pipe) and a pH meter, wherein the tank body comprises a main tank and an auxiliary tank which are adjacently arranged;
the exhaust unit is arranged at the top end of the tank body;
a stirring unit; the stirring unit comprises a pipeline which is communicated with the top end and the bottom end of the tank body, and a pump which is arranged on the pipeline;
a filtering unit; the filtering unit is arranged on the wall of the main groove and/or the auxiliary groove.
Test case
The performance of the black chromium coating obtained in the application example is tested in this example, and the following specific:
whether the obtained black chromium coating has obvious apparent defects or not is observed by adopting a visual inspection method.
The binding force was measured by a thermal shock test according to JB2111-1977 test method for binding Strength of Metal coating. The obtained plating piece is heated to 190 ℃, is put into water with room temperature for quenching, and has no bubbling and falling of the plating layer and good binding force.
And (3) performing a neutral salt spray test on the obtained plating piece for 96 hours according to GB/T10125-2012 artificial atmosphere corrosion test salt spray test, wherein the passing of the plating piece is indicated if the surface of the plating piece has no adverse phenomena such as white corrosions, and otherwise the passing of the plating piece does not occur.
L value test, adopting a color separation colorimeter to test chromaticity value, and the equipment model: CM-700d, taking 10 points respectively, testing the average value of the L value, and calculating the extreme difference of the L value.
Hardness: hardness was measured at room temperature using a microhardness tester.
Thickness: and performing differential measurement by using a micrometer to obtain 10 test points, measuring the average value of the thickness, and calculating the extreme difference of the thickness.
The results of the above tests are shown in table 2.
Table 2 application example properties of black chrome plating layers obtained using the plating solutions obtained in example 1 and comparative examples 1 to 3
The results in Table 2 show that the plating solution provided by the invention can significantly improve the deposition rate of the black chromium plating layer, and the appearance of the obtained black chromium plating layer is a black mirror surface (the apparent graph is shown in FIG. 1); the uniformity of the whole thickness is higher; and has an L value of about 50, and high blackness uniformity; the hardness is more than or equal to 350, and the salt spray resistance and the binding force are excellent.
As is clear from comparative examples 1 and 1, the use of urea and trivalent chromium for coordination can exert similar technical effects as malic acid, but may be due to the lower limiting concentration of the active complex formed by urea and trivalent chromium (low utilization of urea) or may be due to the low activity of the complex formed by urea and trivalent chromium, so that the deposition rate of the resulting black chromium coating is slightly reduced.
As is clear from comparative examples 1 and 2, the latter has one more hydroxyl group than the former, but the effect of the hydroxyl group is relatively large during the complexation, and the concentration and activity of the trivalent chromium active complex are directly affected. The tartaric acid is used for replacing malic acid, and the thickness uniformity, the blackness uniformity, the binding force and the salt spray resistance of the black chromium plating layer are obviously reduced although the deposition of the black chromium plating layer can be performed. This also shows that the black chromium plating layer prepared using the plating solution obtained in comparative example 2 has poor uniformity and poor coverage, as compared with example 1, and thus is likely to cause penetration of the test medium when exposed to salt mist, ice water, or the like, affecting the performance of the black chromium plating layer.
Comparative examples 1 and 3 show that the formation of the active complex of malic acid and trivalent chromium requires the formation under specific temperature and time conditions. Comparative example 3 a chromium salt concentrate was formulated at a lower temperature and the plating solution produced a very poor black chromium coating because no effective active chromium complex was formed and the plating time employed in the present invention was short and therefore a fully covered coating could not be formed. This phenomenon is equivalent to that in the conventional art. The specific appearance of the black chromium deposit obtained in comparative example 3 is shown in FIG. 2.
In conclusion, the plating solution provided by the invention can be used for obtaining the black chromium plating layer which has good covering performance, good bonding capability, high hardness, uniform thickness and thicker thickness, and the obtained black chromium plating layer is expected to be widely applied in the optical field and the decoration field.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present invention. Furthermore, embodiments of the invention and features of the embodiments may be combined with each other without conflict.
Claims (13)
1. The plating solution for the black chromium plating layer is characterized by comprising the following preparation raw materials:
conductive salt, 260-320 g/L, wherein the conductive salt comprises sulfate and boric acid;
the preparation method of the chromium salt concentrated solution comprises the steps of reacting chromium sulfate and malic acid for 2-15 hours at 70-100 ℃, wherein the mass ratio of the chromium sulfate to the malic acid is 3.5-4.5:1;
an organic sulfide;
an inorganic sulfide;
a transition metal salt;
and the complexing agent comprises at least one of urea, tartaric acid and aspartic acid.
2. The plating solution according to claim 1, wherein the concentration of the chromium sulfate in the chromium salt concentrate is 1.5 to 4.5mol/L.
3. The plating solution according to claim 1 or 2, wherein the plating solution is prepared from a raw material further comprising a dispersant.
4. The plating solution according to claim 1 or 2, characterized in that the plating solution is prepared from a raw material further comprising a wetting agent.
5. The plating solution according to claim 1 or 2, wherein the organic sulfide comprises saccharin.
6. The plating solution according to claim 1 or 2, wherein the inorganic sulfide comprises thiocyanate.
7. The plating solution according to claim 1 or 2, wherein the transition metal salt comprises a water-soluble cobalt salt.
8. A method for preparing a plating solution according to any one of claims 1 to 7, comprising diluting the conductive salt and chromium salt concentrate with water, adjusting pH, and mixing with other preparation raw materials.
9. The method according to claim 8, wherein the pH is adjusted to a pH range of 3.3 to 3.8.
10. The preparation method according to claim 8, wherein the temperature of the preparation method is 45 to 60 ℃.
11. A method for producing a black chrome plating layer, characterized in that the production method comprises electroplating with the plating solution according to any one of claims 1 to 7.
12. The production method according to claim 11, characterized in that the production method comprises replenishing the chromium salt concentrate in an amount of 800-1000 ml/KAH during production.
13. The method of claim 11, comprising replenishing the complexing agent in an amount of 800-1000 ml/KAH during the production process.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102912387A (en) * | 2012-10-26 | 2013-02-06 | 南京大地冷冻食品有限公司 | Chloride type trivalent chromium black chromium plating solution |
| CN103510131A (en) * | 2012-06-26 | 2014-01-15 | 张益诚 | Electrochemical method for forming black trivalent chromium oxide coating and black trivalent chromium oxide coating |
| CN103534388A (en) * | 2011-05-03 | 2014-01-22 | 安美特德国有限公司 | Electroplating bath and method for producing dark chromium layers |
| CN107099824A (en) * | 2017-06-19 | 2017-08-29 | 四维尔丸井(广州)汽车零部件有限公司 | A kind of black chromium plating bath, composite deposite and preparation method thereof |
| CN107419310A (en) * | 2017-09-28 | 2017-12-01 | 永星化工(上海)有限公司 | A kind of trivalent chrome plating and preparation method thereof |
| CN109154092A (en) * | 2016-04-21 | 2019-01-04 | 麦克德米德尖端有限公司 | Electrodeposit based on dark chromium |
| CN112226791A (en) * | 2020-10-26 | 2021-01-15 | 厦门市金宝源实业有限公司 | Trivalent chromium plating solution, preparation method thereof and trivalent chromium plating method |
| JP2022079007A (en) * | 2020-11-14 | 2022-05-26 | 睦技研株式会社 | Plating method |
| WO2022258621A1 (en) * | 2021-06-10 | 2022-12-15 | Atotech Deutschland GmbH & Co. KG | Method for adjusting the brightness l* of an electroplated chromium layer |
| CN116024623A (en) * | 2022-12-27 | 2023-04-28 | 南通申海工业科技有限公司 | Tail pipe mist black chromium plating process |
-
2023
- 2023-06-06 CN CN202310664723.0A patent/CN116770375B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103534388A (en) * | 2011-05-03 | 2014-01-22 | 安美特德国有限公司 | Electroplating bath and method for producing dark chromium layers |
| CN103510131A (en) * | 2012-06-26 | 2014-01-15 | 张益诚 | Electrochemical method for forming black trivalent chromium oxide coating and black trivalent chromium oxide coating |
| CN102912387A (en) * | 2012-10-26 | 2013-02-06 | 南京大地冷冻食品有限公司 | Chloride type trivalent chromium black chromium plating solution |
| CN109154092A (en) * | 2016-04-21 | 2019-01-04 | 麦克德米德尖端有限公司 | Electrodeposit based on dark chromium |
| CN107099824A (en) * | 2017-06-19 | 2017-08-29 | 四维尔丸井(广州)汽车零部件有限公司 | A kind of black chromium plating bath, composite deposite and preparation method thereof |
| CN107419310A (en) * | 2017-09-28 | 2017-12-01 | 永星化工(上海)有限公司 | A kind of trivalent chrome plating and preparation method thereof |
| CN112226791A (en) * | 2020-10-26 | 2021-01-15 | 厦门市金宝源实业有限公司 | Trivalent chromium plating solution, preparation method thereof and trivalent chromium plating method |
| JP2022079007A (en) * | 2020-11-14 | 2022-05-26 | 睦技研株式会社 | Plating method |
| WO2022258621A1 (en) * | 2021-06-10 | 2022-12-15 | Atotech Deutschland GmbH & Co. KG | Method for adjusting the brightness l* of an electroplated chromium layer |
| CN116024623A (en) * | 2022-12-27 | 2023-04-28 | 南通申海工业科技有限公司 | Tail pipe mist black chromium plating process |
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