Zinc oxide particle, method for producing the same, ultraviolet shielding agent, and cosmetic

Patent metadata

Field	Value
Publication number	US-9789037-B2
Application number	US-201415107805-A
Country	US
Kind code	B2
Filing date	Dec 25, 2014
Priority date	Dec 27, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

It is one of the objects of the present disclosure to provide hexagonal plate-shaped zinc oxide particles having suitable performances derived from the shape thereof, that is, zinc oxide particles having improved ultraviolet shielding ratio at the wavelength of 400 nm or less without impairing the direct transition properties of electronic excitation thereof and having remarkably improved ultraviolet shielding ratio for UV-B radiation and UV-A radiation.
A zinc oxide particle containing a solid solution of a Ti element and/or a Fe element and a Zn element in at least a portion thereof, and having a hexagonal plate shape.

First claim

The invention claimed is:

1. A coated zinc oxide particle comprising a zinc oxide particle and a layer covering a surface of the zinc oxide particle,
wherein the zinc oxide particle has a hexagonal plate shape with an aspect ratio of 2.5 or more and a primary particle diameter of 0.01 μm to 100 μm, and
the layer is formed essentially of Zn 2 TiO 4 and/or ZnFe 2 O 4 .

2. The coated zinc oxide particle according to claim 1 , wherein an amount of a Ti element and/or a Fe element is 5 wt % or more and 30 wt % or less relative to 100 wt % of the zinc oxide particle in terms of TiO 2 and/or Fe 2 O 3 .

3. A method for producing the coated zinc oxide particle according to claim 1 , comprising a step (1-1) of adding an aqueous solution of a titanium salt and/or an iron salt and an alkaline aqueous solution to a water-based slurry of raw zinc oxide particles having a hexagonal plate shape at a temperature of 10° C. to 90° C. while keeping a pH at 9±3, and a step (1-2) of baking the coated zinc oxide particle obtained in the step (1-1).

4. A method for producing the coated zinc oxide particle according to claim 1 , comprising a step (2-1) of adding raw zinc oxide particles to an aqueous solution of a zinc salt obtained by dissolving a titanium salt and/or an iron salt and heat aging the raw zinc oxide particles, and a step (2-2) of baking the titanium hydroxide-containing zinc oxide particle and/or iron hydroxide-containing zinc oxide particle obtained in the step (2-1).

5. A coated zinc oxide particle obtained by the method according to claim 3 .

6. An ultraviolet shielding agent comprising the coated zinc oxide particle according to claim 1 .

7. A cosmetic comprising the coated zinc oxide particle according to claim 1 .

Assignees

• Sakai Chemical Industry Co

Inventors

• Sueda Satoru
• Hashimoto Mitsuo
• Wada Mizuho

Classifications

• C01P2004/84

  one phase coated with the other · CPC title

• C01P2004/22

  with a polygonal circumferential shape · CPC title

• C01P2002/50

  Solid solutions · CPC title

• A61K8/0254

  Platelets; Flakes · CPC title

• A61K2800/412

  Microsized, i.e. having sizes between 0.1 and 100 microns · CPC title