US2020095686A1PendingUtilityA1
A method of electroless deposition of platinum group metals and their alloys and a plating bath used therein
Est. expiryJun 6, 2037(~10.9 yrs left)· nominal 20-yr term from priority
C23C 18/44C23C 18/48Y02E10/542
43
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Claims
Abstract
The invention relates to a method of electroless deposition of platinum group metals and their alloys from a plating bath onto a substrate, comprising a reduction step of one or more platinum group metal precursors with a reducing agent, wherein the reducing agent is a primary or secondary monohydroxyalcohol or a mixture of primary or secondary monohydroxyalcohols. The invention also provides a plating bath suitable for use in said method.
Claims
exact text as granted — not AI-modified1 . A method of electroless deposition of platinum group metals and their alloys from a plating bath onto a substrate, comprising a reduction step of one or more platinum group metal precursors with a reducing agent, wherein the reducing agent is a primary or secondary monohydroxyalcohol or a mixture of primary or secondary monohydroxyalcohols.
2 . The method of claim 1 , wherein the monohydroxyalcohol has a general formula
wherein R 1 and R 2 are the same or different and each of them is independently selected from a group comprising hydrogen atom, a straight or branched C 1-7 -alkyl group, C 3-8 -aryl group, C 4-8 -aralkyl group and C 4-8 -alkaryl group.
3 . The method of claim 1 , wherein R 1 and R 2 are independently selected from a group comprising —H, —CH 3 , —C 2 H 5 , —C 3 H 7 , —CH(CH 3 ) 2 , —C 4 H 9 , —CH 2 CH(CH 3 ) 2 , —CH(CH 3 )C 2 H 5 , —C(CH 3 ) 3 , —C 5 H 11 , —CH(CH 3 )C 3 H 7 , —CH 2 CH(CH 3 )C 2 H 5 , —C 2 H 4 CH(CH 3 ) 2 , —C(CH 3 ) 2 C 2 H 5 , —CH(CH 3 )CH(CH 3 ) 2 , —CH 2 C(CH 3 ) 3 , —CH(C 2 H 5 ) 2 , —C 6 H 13 , —C 7 H 15 , and —CH(C 2 H 5 )(C 4 H 9 ).
4 . The method of claims 1 , wherein the monohydroxyalcohol is selected from a group comprising methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methylpropan-1-ol, 1-pentanol, 3-methylbutan-1-ol, 2-methylbutan-1-ol, 2,2-dimethylpropan-1-ol, 3-pentanol, 2-pentanol, 3-methyl-2-butanol, 1-hexanol, 2-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 4-methyl-1-pentanol, 3-methyl-2-pentanol, 4-methyl-2-pentanol, 2-methyl-3-pentanol, 2,2-dimethylbutan-1-ol, 2,3-dimethylbutan-1-ol, 3,3-dimethylbutan-1-ol, 3,3-dimethylbutan-2-ol, 2-ethylbutan-1-ol, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, 1-octanol, 2-octanol and 2-ethylhexan-1-ol.
5 . The method of claim 1 , wherein the monohydroxyalcohol is selected from the group comprising methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methylpropan-1-ol, 1-pentanol, 3-methylbutan-1-ol, 2-methylbutan-1-ol, 2,2-dimethylpropan-1-ol, 3-pentanol, 2-pentanol, 3-methyl-2-butanol, 1-hexanol, 1-heptanol and 1-octanol.
6 . The method of claim 1 , wherein the concentration of the monohydroxyalcohol in the plating bath is in the range from 0.02 to 12 M.
7 . The method of claim 6 , wherein concentration of the monohydroxyalcohol in the plating bath is in the range from 0.1 to 5 M.
8 . The method of claim 1 , wherein the platinum group metal precursor is selected from a group comprising H 2 PtCl 6 , H 6 Cl 2 N 2 Pt, PtCl 2 , PtBr 2 , K 2 [PtCl 4 ], Na 2 [PtCl 4 ], Li 2 [PtCl 4 ], H 2 Pt(OH) 6 , Pt(NO 3 ) 2 , [Pt(NH 3 ) 4 ]Cl 2 , [Pt(NH 3 ) 4 ](HCO 3 ) 2 , [Pt(NH 3 ) 4 ](OAc) 2 , (NH 3 ) 4 Pt(NO 3 ) 2 , (NH 4 ) 2 PtBr 6 , K 2 PtCl 6 , PtSO 4 , Pt(HSO 4 ) 2 , Pt(ClO 4 ) 2 , K 2 PtI 6 , K 2 [Pt(CN) 4 ], cis-[Pt(NH 3 ) 2 Cl 2 ], H 2 PdCl 6 , H 6 Cl 2 N 2 Pd, PdCl 2 , PdBr 2 , K 2 [PdCl 4 ], Na 2 [PdCl 4 ], Li 2 [PdCl 4 ], H 2 Pd(OH) 6 , Pd(NO 3 ) 2 , [Pd(NH 3 ) 4 ]Cl 2 , [Pd(NH 3 ) 4 ](HCO 3 ) 2 , [Pd(NH 3 ) 4 ](OAc) 2 , (NH 4 ) 2 PdBr 6 , (NH 3 ) 2 PdCl 6 , PdSO 4 , Pd(HSO 4 ) 2 , Pd(ClO 4 ) 2 , Pd(OAc) 2 , RuCl 2 ((CH3) 2 SO) 4 , RuCl 3 , [Ru(NH 3 ) 5 (N 2 )]Cl 2 , Ru(NO 3 ) 3 , RuBr 3 , RuF 3 , Ru(ClO 4 ) 3 , K 2 RuCl 6 , OsI, OsI 2 , OsBr 3 , OsCl 4 , OsF 5 , OsF 6 , OsOF 5 , OsF 7 , IrF 6 , IrCl 3 , IrF 4 , IrF 5 , Ir(ClO 4 ) 3 , K 3 [IrCl 6 ], K 2 [IrCl 6 ], Na 3 [IrCl 6 ], Na 2 [IrCl 6 ], Li 3 [IrCl 6 ], Li 2 [IrCl 6 ], [Ir(NH 3 ) 4 Cl 2 ]Cl, RhF 3 , RhF 4 , RhCl 3 , [Rh(NH 3 ) 5 Cl]Cl 2 , RhCl[P(C 6 H 5 ) 3 ] 3 , K[Rh(CO) 2 Cl 2 ], Na[Rh(CO) 2 Cl 2 ]Li[Rh(CO) 2 Cl 2 ], Rh 2 (SO 4 ) 3 , Rh(HSO 4 ) 3 , Rh(ClO 4 ) 3 , their hydrates and mixtures of these salts and/or hydrates.
9 . The method of claim 1 , wherein the reduction step of one or more platinum group metal precursors is carried out in the presence of a precursor or precursors of different metals, thus forming of alloy comprising one or more platinum group metal and a different metal.
10 . The method of claim 9 , wherein the formed alloy comprises two or more metals selected from a group comprising: platinum, palladium, rhodium, iridium, ruthenium, osmium, gold, nickel and copper
11 . The method of claim 1 , wherein the precursor concentration in the plating bath is in the range from 1 mM to 1 M, preferably 5 mM to 100 mM, and more preferably from 10 mM to 50 mM.
12 . The method of claim 1 , wherein the reduction step is carried out in the temperature between the freezing point and the boiling point of the plating bath.
13 . The method of claim 12 , wherein the reduction step is carried out in the temperature from −10 to 80° C., preferably from 0 to 40° C., and more preferably from 10 to 25° C.
14 . The method of claim 1 , wherein the plating bath further comprises pH buffer.
15 . The method of claim 1 , wherein the pH of the plating bath is below 7.
16 . The method of claim 15 , wherein the pH of the plating bath is between 3 and 5.
17 . The method of claim 16 , wherein the pH of the plating bath is about 4.
18 . The method of claim 1 , wherein the substrate is selected from a group comprising metals, metal alloys, polymeric materials, carbon and silicon.
19 . The method of claim 18 , wherein the substrate is selected from the group comprising platinum, palladium, nickel, gold, steel, iron-chromium-aluminum alloys, Nafion®, polyethylene, polypropylene, polyethylene terephthalate, graphite and silicon.
20 . The method of claim 1 , wherein prior to the reduction step of platinum group metal precursors the surface of the substrate is seeded.
21 . The method of claim 1 , wherein after the plating process is completed, the plated substrate undergoes a high temperature treatment.
22 . The method of claim 1 , wherein the plating bath further comprises brighteners.
23 . The method of claim 1 , wherein the plating bath further comprises an additional reducing agent, preferably a reducing agent selected from a group comprising hydrazine and its derivatives, borohydride or hydrogen hypophosphite
24 . The method of claim 1 , wherein the plating bath further comprises 2-methylpropan-2-ol.
25 . A plating bath for electroless deposition of platinum group metals and their alloys, wherein said bath is an aqueous solution comprising a primary or secondary monohydroxyalcohol, or a mixture of primary or secondary monohydroxyalcohols, as the reducing agent and one or more platinum group precursors.
26 . The bath of claim 25 , wherein the monohydroxyalcohol has a general formula
wherein R 1 and R 2 are the same or different and each of them independently is selected from a group comprising hydrogen atom, a straight or branched C 1-7 -alkyl group, C 3-8 -aryl group, C 4-8 -aralkyl group and C 4-8 -alkaryl group.
27 . The bath of claim 26 , wherein R 1 and R 2 are independently selected from a group comprising —H, —CH 3 , —C 2 H 5 , —C 3 H 7 , —CH(CH 3 ) 2 , —C 4 H 9 , —CH 2 CH(CH 3 ) 2 , —CH(CH 3 )C 2 H 5 , —C(CH 3 ) 3 , —C 5 H 11 , —CH(CH 3 )C 3 H 7 , —CH 2 CH(CH 3 )C 2 H 5 , —C 2 H 4 CH(CH 3 ) 2 , —C(CH 3 ) 2 C 2 H 5 , —CH(CH 3 )CH(CH 3 ) 2 , —CH 2 C(CH 3 ) 3 , —CH(C 2 H 5 ) 2 , —C 6 H 13 , —C 7 H 15 , and —CH(C 2 H 5 )(C 4 H 9 ).
28 . The bath of claim 27 , wherein the monohydroxyalcohol is selected from the group comprising methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methylpropan-1-ol, 1-pentanol, 3-methylbutan-1-ol, 2-methylbutan-1-ol, 2,2-dimethylpropan-1-ol, 3-pentanol, 2-pentanol, 3-methyl-2-butanol, 1-hexanol, 2-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 4-methyl-1-pentanol, 3-methyl-2-pentanol, 4-methyl-2-pentanol, 2-methyl-3-pentanol, 2,2-dimethylbutan-1-ol, 2,3-dimethylbutan-1-ol, 3,3-dimethylbutan-1-ol, 3,3- dimethylbutan-2-ol, 2-ethylbutan-1-ol, 1-heptanol, 2-heptanol, 3-heptanol, 4-heptanol, 1-octanol, 2-octanol and 2-ethylhexan-1-ol.
29 . The bath of claim 28 , wherein the monohydroxyalcohol is selected from the group comprising methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methylpropan-1-ol, 1-pentanol, 3-methylbutan-1-ol, 2-methylbutan-1-ol, 2,2-dimethylpropan-1-ol, 3-pentanol, 2-pentanol, 3-methyl-2-butanol, 1-hexanol, 1-heptanol and 1-octanol.
30 . The bath of claim 25 , wherein the concentration of the monohydroxyalcohol is in the range from 0.02 to 12 M, preferably in the range from 0.1 to 5 M.
31 . The bath of claim 25 , wherein it further comprises an additional reducing agent, preferably a reducing agent selected from a group comprising hydrazine and its derivatives, borohydride or hydrogen hypophosphite
32 . The bath of claim 25 , wherein the platinum group metal precursor is selected from a group comprising H 2 PtCl 6 , H 6 Cl 2 N 2 Pt, PtCl 2 , PtBr 2 , K 2 [PtCl 4 ], Na 2 [PtCl 4 ], Li 2 [PtCl 4 ], H 2 Pt(OH) 6 , Pt(NO 3 ) 2 , [Pt(NH 3 ) 4 ]Cl 2 , [Pt(NH 3 ) 4 ](HCO 3 ) 2 , [Pt(NH 3 ) 4 ](OAc) 2 , (NH 3 ) 4 Pt(NO 3 ) 2 , (NH 4 ) 2 PtBr 6 , K 2 PtCl 6 , PtSO 4 , Pt(HSO 4 ) 2 , Pt(ClO 4 ) 2 , K 2 PtI 6 , K 2 [Pt(CN) 4 ], cis-[Pt(NH 3 ) 2 Cl 2 ], H 2 PdCl 6 , H 6 Cl 2 N 2 Pd, PdCl 2 , PdBr 2 , K 2 [PdCl 4 ], Na 2 [PdCl 4 ], Li 2 [PdCl 4 ], H 2 Pd(OH) 6 , Pd(NO 3 ) 2 , [Pd(NH 3 ) 4 ]Cl 2 , [Pd(NH 3 ) 4 ](HCO 3 ) 2 , [Pd(NH 3 ) 4 ](OAc) 2 , (NH 4 ) 2 PdBr 6 , (NH 3 ) 2 PdCl 6 , PdSO 4 , Pd(HSO 4 ) 2 , Pd(ClO 4 ) 2 , Pd(OAc) 2 , RuCl 2 ((CH3) 2 SO) 4 , RuCl 3 , [Ru(NH 3 ) 5 (N 2 )]Cl 2 , Ru(NO 3 ) 3 , RuBr 3 , RuF 3 , Ru(ClO 4 ) 3 , K 2 RuCl 6 , OsI, OsI 2 , OsBr 3 , OsCl 4 , OsF 5 , OsF 6 , OsOF 5 , OsF 7 , IrF 6 , IrCl 3 , IrF 4 , IrF 5 , Ir(ClO 4 ) 3 , K 3 [IrCl 6 ], K 2 [IrCl 6 ], Na 3 [IrCl 6 ], Na 2 [IrCl 6 ], Li 3 [IrCl 6 ], Li 2 [IrCl 6 ], [Ir(NH 3 ) 4 Cl 2 ]Cl, RhF 3 , RhF 4 , RhCl 3 , [Rh(NH 3 ) 5 Cl]Cl 2 , RhCl[P(C 6 H 5 ) 3 ] 3 , K[Rh(CO) 2 Cl 2 ], Na[Rh(CO) 2 Cl 2 ]Li[Rh(CO) 2 Cl 2 ], Rh 2 (SO 4 ) 3 , Rh(HSO 4 ) 3 and Rh(ClO 4 ) 3 , their hydrates or mixtures of these salts and/or hydrates.
33 . The bath of claim 25 wherein the precursor concentration is in the range from 1 mM to 1 M.
34 . The bath of claim 33 , wherein the precursor concentration is in the range from 5 mM to 100 mM.
35 . The bath of claim 34 , wherein the precursor concentration is in the range from 10 mM to 50 mM.
36 . The bath of claim 25 , wherein the pH of the plating bath is below 7.
37 . The bath of claim 36 , wherein the pH is between 3 and 5.
38 . The bath of claim 37 , wherein the pH of the plating bath is about 4.
39 . The bath of claim 25 , wherein it further comprises pH buffer.
40 . The bath of claim 25 , wherein it further comprises brighteners.
41 . The bath of claim 25 , wherein it further comprises 2-methylpropan-2-ol.
43 . A method for electroless deposition of platinum group metals, comprising electroless depositing of platinum group metals and their alloys, the improvement wherein the electroless deposition of platinum group metals and their alloys is from the plating bath as defined in claim 25 .Cited by (0)
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