Alumina particle

Patent metadata

Field	Value
Publication number	US-11401169-B2
Application number	US-201917042899-A
Country	US
Kind code	B2
Filing date	Apr 2, 2019
Priority date	Apr 6, 2018
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

The present invention provides alumina particles having a fixed card-house structure formed of three or more flat plate-like alumina particles and having an average particle diameter of 3 to 1000 μm. Also, there is provided alumina particles having an average particle diameter of 3 to 1000 μm and having a fixed card-house structure in which the three or more flat plate-like alumina are aggregated to be crossed each other at two or more plurality of positions, and the plane directions of the flat plates crossed each other are in a state of disordered arrangement.

First claim

What is claimed is:

1. Alumina particles having a fixed card-house structure formed of three or more flat plate-like alumina and having an average particle diameter of 3 to 1000 μm, wherein the three or more flat plate-like alumina are aggregated to be crossed each other at two or more plurality of positions, and plane directions of the flat plates crossed each other are in a state of disordered arrangement, and the alumina particles further contain a silicon atom and/or inorganic silicon compound, one flat plate-like alumina has a ratio [Si]/[Al]% of 2.0 to 50.0%, and an amount of the silicon atom and/or inorganic silicon compound in terms of silicon atom is 0.003 to 0.09 moles relative to 1 mole of aluminum metal of a raw material of the alumina particles.

2. The alumina particles according to claim 1 , wherein the alumina particles are composed of alumina having an α crystallization rate of 90% or more.

3. The alumina particles according to claim 1 , wherein the flat plate-like alumina has a polygonal plate-like shape and an aspect ratio of 2 to 500.

4. The alumina particles according to claim 1 , wherein the angle of repose is 50° or less.

5. The alumina particles according to claim 1 , wherein the crushing strength is 1 MPa to 100 MPa.

6. The alumina particles according to claim 1 , wherein the void ratio inside the alumina particles is 10% to 90%.

7. The alumina particles according to claim 1 , wherein a volume-based maximum encircling surface of a card-house structure of one unit has a spherical or substantially spherical shape.

Assignees

• Dainippon Ink & Chemicals

Inventors

• Takada Shingo
• Itoya Kazuo
• Yuan Jian-Jun
• Kanematsu Takayuki
• Hayashi Masamichi
• Maekawa Fumihiko
• Sano Yoshiyuki

Classifications

• C01P2004/54

  Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension · CPC title

• C01P2004/50

  Agglomerated particles · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C01P2002/85

  by XPS, EDX or EDAX data · CPC title

• C01P2006/21

  Attrition-index or crushing strength of granulates · CPC title