Film-forming metal solution and method of forming metal coating

Patent metadata

Field	Value
Publication number	US-12110605-B2
Application number	US-201916429297-A
Country	US
Kind code	B2
Filing date	Jun 3, 2019
Priority date	Jun 5, 2018
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

Abstract

The present disclosure relates to a film-forming metal solution for use in a method in which a solid electrolyte membrane having sulfonic acid groups is disposed between an anode and a substrate serving as a cathode, the solid electrolyte membrane is brought into contact with the substrate, and a voltage is applied between the anode and the substrate to deposit a metal onto a surface of the substrate from metal ions supplied into the solid electrolyte membrane and thereby form a metal coating on the surface of the substrate, the film-forming metal solution being adapted to supply metal ions into the solid electrolyte membrane, wherein the film-forming metal solution comprises an aqueous metal solution, a solvent, and a nonionic surfactant, and the nonionic surfactant has a linear hydrophilic group having ethylene oxide units and a hydrophobic group having a cyclic structure and a maximum length of 40 Å or less.

First claim

What is claimed is:

1. A method of forming a tin coating, the method comprising:
disposing a solid electrolyte membrane having sulfonic acid groups between an anode and a substrate serving as a cathode;
bringing a film-forming metal solution into contact with the solid electrolyte membrane to supply tin ions into the solid electrolyte membrane; and
in conjunction with the supply of the tin ions, applying a voltage between the anode and the substrate while keeping the solid electrolyte membrane in contact with the substrate to deposit tin coating onto a surface of the substrate from the supplied tin ions,
wherein the film-forming metal solution comprises:
an aqueous tin sulfate solution,
a solvent comprising isopropyl alcohol, and
a nonionic surfactant,

wherein the nonionic surfactant has a linear hydrophilic group having ethylene oxide units, and a hydrophobic group having a cyclic structure,
wherein the hydrophobic group of the nonionic surfactant has a minimum length of less than 10 Å, a maximum length of 10 Å or less, and the maximum length is greater than the minimum length,
wherein the hydrophilic group of the nonionic surfactant has 11 to 15 mol of the ethylene oxide units,
wherein a concentration of the nonionic surfactant in the film-forming metal solution is 0.01 to 0.08 M,
wherein an amount of the tin sulfate in the film-forming metal solution is 30 to 50 g/l, and
wherein the nonionic surfactant has a hydrophilic-lipophilic balance of 13 to 15.

2. The method of forming a tin coating according to claim 1 , wherein the minimum length of the hydrophobic group is 5 Å or more.

3. The method of forming a tin coating according to claim 1 , wherein the hydrophilic group has 11 to 13 mol of the ethylene oxide units.

4. The method of forming a tin coating according to claim 1 , wherein the nonionic surfactant is a cumylphenol ethylene oxide adduct.

5. The method of forming a tin coating according to claim 1 , wherein a concentration of the nonionic surfactant in the film-forming metal solution is 0.02 to 0.08 M.

6. The method of forming a tin coating according to claim 1 , wherein a pH of the film-forming metal solution is in the range of −0.1 to 0.4.

7. The method of forming a tin coating according to claim 1 , wherein the nonionic surfactant is a cumylphenol ethylene oxide adduct having 11 to 13 mol of ethylene oxide units.

8. The method of forming a tin coating according to claim 1 , wherein a surface roughness (ten-point average height, Rz.J94 (μm)) of the tin coating is 3 μm or less.

9. The method of forming a tin coating according to claim 1 , wherein the solid electrolyte membrane having sulfonic acid groups is a perfluorosulfonic acid-based ion-exchange membrane.

10. The method of forming a tin coating according to claim 1 , wherein the solid electrolyte membrane having sulfonic acid groups has a main chain in the form of polytetrafluoroethylene (PTFE) skeleton and a side chain containing an ether bond and a sulfonic acid group.

Assignees

• Toyota Motor Co Ltd

Inventors

• Iisaka Hirofumi

Classifications

• C25D17/14

  for pad-plating · CPC title

• C25D3/00 Primary

  Electroplating: Baths therefor · CPC title

• C25D3/32

  characterised by the organic bath constituents used · CPC title

• C25D17/002

  Cell separation, e.g. membranes, diaphragms · CPC title

• C25D3/30 Primary

  of tin · CPC title