# US 11,999,859 B1 · Preparation method of copper green rust pigment that can replace Hayeob pigment in traditional Dancheong

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- Number: US 11,999,859 B1
- Document ID: US11999859B1
- Status: Granted
- Kind: B1
- Application number: 18/450,965
- Filed: 2023-08-16
- Granted: 2024-06-04
- Earliest claimed: 2023-04-18
- Assignees: National Research Institute of Cultural Heritage
- Applicants: National Research Institute of Cultural Heritage
- Inventors: Yeong Seok Kang; Sun Myung Lee; Ju Hyun Park; Seong Woo Mun
- Web page: https://patentgrep.com/patent/US11999859B1

## CPC

- C09C 1/627: {Copper}
- B22F 1/145: Chemical treatment, e.g. passivation or decarburisation
- B22F 9/04: starting from solid material, e.g. by crushing, grinding or milling ({C22C1/1084 takes precedence}; crushing, grinding or milling, in general, see the relevant subclasses, e.g. B02C)
- C09C 1/622: {Comminution, shaping or abrasion of initially uncoated particles, possibly in presence of grinding aids, abrasives or chemical treating or coating agents; Particle solidification from melted or vaporised metal; Classification}
- C09C 3/006: {Combinations of treatments provided for in groups C09C3/04 - C09C3/12}
- C09C 3/041: {Grinding}
- C09C 3/06: Treatment with inorganic compounds {(C09C3/006, C09C3/048 take precedence)}
- C22C 9/02: with tin as the next major constituent
- C22C 9/04: with zinc as the next major constituent
- B22F 2301/10: Copper
- B22F 2998/10: Processes characterised by the sequence of their steps
- B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2004/03: obtained by SEM
- C01P 2006/63: a* (red-green axis)
- C22C 1/0425: {Copper-based alloys}
- C09C: TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES (treatment of materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone C04B14/00, C04B18/00, C04B20/00); PREPARATION OF CARBON BLACK {; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS}
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

The present invention relates to a preparation method of a copper green rust pigment, particularly a preparation method of a copper green rust pigment that can replace the traditional Dancheong Hayeob pigment comprising the following steps: a step of preparing a copper powder comprising at least one of copper; and a copper alloy comprising copper and at least one of tin (Sn), zinc (Zn), and lead (Pb); and a step of corroding the copper powder by mixing the copper powder with a corrosive agent containing sodium chloride and ammonium chloride. The corrosive agent includes 75 to 90 weight % of the sodium chloride and 10 to 25 weight % of the ammonium chloride based on the total weight.

## Claims

### Claim 1

A preparation method of a copper green rust pigment that can replace traditional Hayeob pigments comprising the following steps:
a step of preparing a copper powder comprising at least one of copper and a copper alloy comprising copper and at least one of tin (Sn), zinc (Zn), and lead (Pb); and
a step of corroding the copper powder by mixing the copper powder with a corrosive agent containing sodium chloride and ammonium chloride, in which the corrosive agent includes 75 to 90 weight % of the sodium chloride and 10 to 25 weight % of the ammonium chloride based on the total weight.

### Claim 2 (depends on 1)

The preparation method of a copper green rust pigment according to claim 1, wherein the corrosive agent includes 86 to 90 weight % of the sodium chloride and 10 to 14 weight % of the ammonium chloride based on the total weight.

### Claim 3 (depends on 1)

The preparation method of a copper green rust pigment according to claim 1, wherein the copper powder and the corrosive agent are mixed in a weight ratio of 1:2 to 1:4 in the step of corroding.

### Claim 4 (depends on 1)

The preparation method of a copper green rust pigment according to claim 1, wherein the corrosion is performed by artificial corrosion using a corrosion tester.

### Claim 5 (depends on 1)

The preparation method of a copper green rust pigment according to claim 1, wherein the preparation method further include a step of pulverizing and wet fractionating a corrosion product prepared in the step of corroding.

### Claim 6 (depends on 5)

The preparation method of a copper green rust pigment according to claim 5, wherein the preparation method further include a step of removing a residual corrosive agent by mixing the pulverized and wet fractionated powder with distilled water and removing a supernatant.

### Claim 7 (depends on 6)

The preparation method of a copper green rust pigment according to claim 6, wherein the preparation method further includes a step of purifying the powder from which the residual corrosive agent has been removed.