	US 11,753,302 B2
	Method of producing beta-sialon fluorescent material
Kenichi Aoyagi, Itano-gun (JP); Takashi Kaide, Anan (JP); Yuya Takahashi, Myozai-gun (JP); and Shoji Hosokawa, Tokushima (JP)
Assigned to NICHIA CORPORATION, Anan (JP)
Filed by NICHIA CORPORATION, Anan (JP)
Filed on Oct. 3, 2022, as Appl. No. 17/937,766.
Application 17/937,766 is a continuation of application No. 17/033,576, filed on Sep. 25, 2020.
Claims priority of application No. 2019-177138 (JP), filed on Sep. 27, 2019.
Prior Publication US 2023/0045233 A1, Feb. 9, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C01B 21/082 (2006.01); C01F 17/30 (2020.01); C09K 11/08 (2006.01); C09K 11/77 (2006.01)

CPC C01B 21/0826 (2013.01) [C01F 17/30 (2020.01); C09K 11/0883 (2013.01); C09K 11/7734 (2013.01); C09K 11/77348 (2021.01)]

18 Claims

1. A method of producing a β-sialon fluorescent material, the method comprising:

providing a first composition containing aluminium, an oxygen atom, and a europium-containing silicon nitride;

pulverizing the first composition with a europium compound to obtain a pulverized product;

second heat treating in a nitrogen atmosphere the pulverized product to obtain a second heat treated composition;

further first heat treating the second heat treated composition;

contacting the first heat-treated composition and a basic substance; and

contacting the composition contacted with the basic substance and an acidic liquid medium containing an acidic substance.