Platinum electroforming and platinum electroplating

• US 5,310,475 A
• Filed: 06/21/1991
• Issued: 05/10/1994
• Est. Priority Date: 06/29/1990
• Status: Expired due to Term

• Current Assignee: Electroplating Engineers Of Japan Limited (Tanaka Holdings Company Limited)
• Original Assignee: Electroplating Engineers Of Japan Limited (Tanaka Holdings Company Limited)
• Inventors: Kitada, Katsutsugu, Yarita, Soumei
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): Mayekar, Kishor
• Application Number:
  US07/718,767
• Time in Patent Office: 1,054 Days
• Field of Search: 204/13, 204/44.6, 204/47, 205/67, 205/73, 205/264, 205/69, 205/70, 205/72, 205/67, 205/73, 205/257, 205/264
• US Class Current: 205/67
• CPC Class Codes: A44C 27/002 Metallic materials A44C27/006 takes precedence
• CPC Class Codes: C25D 3/50 of platinum group metals
• CPC Class Codes: C25D 3/567 containing more than 50% by weight of platinum group metals

Abstract

The invention relates to platinum electroforming and platinum electroplating capable of preparing a deposited platinum material having high hardness and increased thickness and size. The platinum electroforming or electroplating bath comprises at least one compound selected from the group consisting of chloroplatinic acid, chloroplatinates of alkali metals, hydrogen hexahydroxoplatinate, and hexahydroxoplatinates of alkali metals, 2-100 g/l as platinum and a hydroxylated alkali metal, 20-100 g/l.

Claims

1. A method for preparing a platinum product having a hardness in excess of 100 Hv consisting essentially of electrodepositing a layer of platinum material onto a die having a pre-determined shape, in a platinum electrolytic bath, with said die having been coated with a release material, wherein the platinum electrolytic bath comprises:

at least one compound selected from the group consisting of chloroplatinic acid, chloroplatinates of alkali metals, hydrogen hexahydroxoplatinate, and hexahydroxoplatinates of alkali metals, 2-100 g/l as platinum;

a hydroxylated alkali metal, 20-100 g/l; and

a soluble carboxylate;

and releasing said layer of platinum material from the die.

2. The platinum product material having a purity of above 99.9wt % and a hardness of above 100 H_v, which is prepared by the manufacturing method according to any of claim 1.

3. The platinum product material having a purity of not less than 95.0 wt % and of less than 99.9 wt % and a hardness of above 200 H_v, which is prepared by the manufacturing method according to any of claim 1.

4. The platinum product material having a purity of not less than 90.0 wt % and of less than 95.0 wt % and a hardness of above 250 H_v, which is prepared by the manufacturing method according to any of claim 1.

5. The platinum product material having a purity of not less than 85.0 wt % and of less than 90 wt % and a hardness of above 300 H_v, which is prepared by the manufacturing method according to any of claim 1.

6. The method according to claim 1 wherein the released layer of platinum material is in turn coated with a release material and is used as a second die, in a platinum electrolytic bath, for preparing a second platinum product having a shape corresponding to that of the pre-determined shape of the original die, said method further comprising electrodepositing a second layer of platinum material onto said released layer of platinum material, and releasing said second layer of platinum material from the original released layer of platinum material.

7. The method according to claim 1, wherein said platinum electrolytic bath further comprises alloying metal salts and whereby said layer of platinum material comprises a platinum alloy.

8. The method according to claim 1 wherein said layer of platinum material is electrodeposited at a temperature of not lower than 65°

C.

9. The method of claim 1, wherein said platinum electrolytic bath is comprised of H₂ Pt(OH)₆, KOH and K₂ C₂ O₄ ·

H₂ O.