Regeneration method for gold plating solution

Patent metadata

Field	Value
Publication number	US-2023203665-A1
Application number	US-202218147530-A
Country	US
Kind code	A1
Filing date	Dec 28, 2022
Priority date	Dec 28, 2021
Publication date	Jun 29, 2023
Grant date	—

Abstract

A gold plating solution containing a gold cyanide salt, a reducing agent that is formaldehyde or its precursor, and an iron cyanide compound, and not containing a chelate compound having two or more iminodiacetic acid groups or aminomethylenephosphonic acid groups, is brought into contact with a chelating resin having an iminodiacetic acid group or an aminomethylenephosphonic acid group, thereby removing iron ions from the gold plating solution.

First claim

What is claimed is:

1 . A regeneration method for a gold plating solution, the method comprising:
bringing a gold plating solution containing a gold cyanide salt, a reducing agent that is formaldehyde or its precursor, and an iron cyanide compound, and not containing a chelate compound having two or more iminodiacetic acid groups or aminomethylenephosphonic acid groups, into contact with a chelating resin having an iminodiacetic acid group or an aminomethylenephosphonic acid group, thereby removing iron ions from the gold plating solution.

2 . The regeneration method of claim 1 , wherein
the chelating resin is a resin containing a polystyrene resin as a base material, the chelating resin having the iminodiacetic acid group or the aminomethylenephosphonic acid group as a functional group.

3 . The regeneration method of claim 1 , wherein
the gold plating solution contains an amine compound expressed by a general formula (1) or a general formula (2) shown below:
[Chemical 1]
R 1 —NH—C 2 H 4 —NH—R 2   (1)

[Chemical 2]
R 3 —(CH 2 —NH—C 2 H 4 —NH—CH 2 ) n —R 4   (2)

where in the general formula (1) and the general formula (2), R 1 , R 2 , R 3 , and R 4 indicate —OH, —CH 3 , —CH 2 OH, —C 2 H 4 OH, —CH 2 N(CH 3 ) 2 , —CH 2 NH(CH 2 OH), —CH 2 NH(C 2 H 4 OH), —C 2 H 4 NH(CH 2 OH), —C 2 H 4 NH(C 2 H 4 OH), —CH 2 N(CH 2 OH) 2 , —CH 2 N(C 2 H 4 OH) 2 , —C 2 H 4 N(CH 2 OH) 2 , or —C 2 H 4 N(C 2 H 4 OH) 2 , which is same or different, and n is an integer from 1 to 4.

4 . The regeneration method of claim 1 , wherein
the iron cyanide compound is at least one kind selected from the group consisting of pentacyanonitrosyl iron(III) acid or its salt (i.e., pentacyanonitrosylferrate(III)); pentacyanoammine iron(II) acid or its salt (i.e., pentacyanoammineferrate(II)); hexacyanido iron(II) acid or its salt (i.e., hexacyanidoferrate(II)); and hexacyanido iron(III) acid or its salt (i.e., hexacyanidoferrate(III)).

5 . The regeneration method of claim 4 , wherein
the iron cyanide compound is at least one of potassium ferrocyanide or potassium ferricyanide.

Assignees

• Uemura Kogyo Kk

Inventors

• Kaneko Yohei
• Tanabe Katsuhisa
• Maeda Tsuyoshi
• Nishimura Naoshi

Classifications

• C23C18/44 Primary

  using reducing agents · CPC title

• C23C18/1617 Primary

  Purification and regeneration of coating baths · CPC title

• Y02P10/20

  Recycling · CPC title

• C25D21/22 Primary

  by ion-exchange · CPC title

• C02F1/42

  by ion-exchange (ion-exchange in general B01J) · CPC title