# US 2021/0276881 A1 · Method for producing metal oxide particles, method for producing dispersion of metal oxide particles, and method for producing infrared shielding film

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- Number: US 2021/0276881 A1
- Document ID: US20210276881A1
- Status: Published application
- Kind: A1
- Application number: 16/482,804
- Filed: 2018-01-26
- Published: 2021-09-09
- Earliest claimed: 2017-02-06
- Assignees: Mitsubishi Materials Corporation
- Applicants: Mitsubishi Materials Corporation
- Inventors: Satoko Higano; Kazuhiko Yamasaki
- Web page: https://patentgrep.com/patent/US20210276881A1

## CPC

- C01G 15/00: Compounds of gallium, indium or thallium
- C01G 30/02: Antimonates; Antimonites {(C01G30/001 takes precedence)}
- C01G 9/02: Oxides; Hydroxides
- C01G 19/00: Compounds of tin
- C01G 19/006: {Compounds containing tin, with or without oxygen or hydrogen, and containing two or more other elements}
- C01G 30/00: Compounds of antimony
- G02B 5/208: {for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation}
- G02B 5/22: Absorbing filters {(G02B5/201 - G02B5/208 take precedence)}
- C01P 2002/01: depicted by a TEM-image
- C01P 2002/54: one element only
- C01P 2004/51: Particles with a specific particle size distribution
- C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

Production method for metal oxide fine particles includes: a step of mixing a fatty acid represented by CnH2nO2 (n=5 to 14) and a metal source consisting of a metal, metal oxide, or metal hydroxide of at least two metal elements selected from the group consisting of Zn, In, Sn, and Sb to obtain a mixture; a step of heating the mixture at a temperature that is equal to or higher than a melting temperature of the fatty acid and lower than a decomposition temperature of the fatty acid to obtain a metal soap which is a precursor of metal oxide fine particles; and a step of heating the precursor at a temperature that is equal to or higher than a melting temperature of the precursor and lower than a decomposition temperature of the precursor to obtain metal oxide fine particles having an average particle diameter of 80 nm or less.

## Claims

### Claim 1

A method for producing metal oxide fine particles, the method comprising:
a step of mixing a fatty acid represented by CnH2nO2 (n=5 to 14) and a metal source consisting of a metal, metal oxide, or metal hydroxide of at least two metal elements selected from the group consisting of Zn, In, Sn, and Sb to obtain a mixture;
a step of heating the mixture at a temperature that is equal to or higher than a melting temperature of the fatty acid and lower than a decomposition temperature of the fatty acid to obtain a metal soap which is a precursor of metal oxide fine particles; and
a step of heating the precursor at a temperature that is equal to or higher than a melting temperature of the precursor and lower than a decomposition temperature of the precursor to obtain metal oxide fine particles having an average particle diameter of 80 nm or less.

### Claim 2 (depends on 1)

The method for producing metal oxide fine particles according to claim 1, wherein the heating temperature for the mixture is set to be in a range of 130° C. to 250° C., and the heating temperature for the precursor is set to be in a range of 200° C. to 350° C.

### Claim 3 (depends on 1)

A method for producing a dispersion of metal oxide fine particles, the method comprising:
a step of mixing the metal oxide fine particles produced by the method according to claim 1 and a hydrophobic solvent to obtain a dispersion of the metal oxide fine particles.

### Claim 4 (depends on 3)

A method for producing an infrared shielding film, the method comprising:
a step of applying the dispersion of the metal oxide fine particles produced by the method according to claim 3 to a substrate to obtain an infrared shielding film.

### Claim 5 (depends on 2)

A method for producing a dispersion of metal oxide fine particles, the method comprising:
a step of mixing the metal oxide fine particles produced by the method according to claim 2 and a hydrophobic solvent to obtain a dispersion of the metal oxide fine particles.

### Claim 6 (depends on 5)

A method for producing an infrared shielding film, the method comprising:
a step of applying the dispersion of the metal oxide fine particles produced by the method according to claim 5 to a substrate to obtain an infrared shielding film.