发明名称 |
Yttrium oxide-aluminum oxide composite particles and method for the preparation thereof |
摘要 |
<p>Provided by the invention is a powder of alumina-yttria composite particles of which each particle has a structure consisting of a core of alumina and cladding layer of yttria. By virtue of the microscopically intimate and uniform mixing condition of the two oxide components, the powder is useful as a base material of sintered ceramic bodies or as an ingredient in a protective film on fluorescent lamps. The composite particles are prepared by a process comprising the steps of: suspending alumina particles in an aqueous solution containing a water-soluble yttrium salt such as nitrate; dissolving urea in the aqueous suspension; heating the suspension at an elevated temperature to effect hydrolysis of urea into ammonia and carbon dioxide forming a layer of yttrium basic carbonate on the alumina particles; and calcining the basic carbonate-clad particles of alumina at a specified temperature to convert the basic carbonate of yttrium into yttrium oxide.</p> |
申请公布号 |
EP0889005(A1) |
申请公布日期 |
1999.01.07 |
申请号 |
EP19980111936 |
申请日期 |
1998.06.27 |
申请人 |
SHIN-ETSU CHEMICAL CO., LTD. |
发明人 |
WATAYA, KAZUHIRO |
分类号 |
C04B35/10;C01F7/02;C01F17/00;C04B35/117;C04B35/505;C04B35/628;(IPC1-7):C01F17/00;C04B35/111;C01B13/36 |
主分类号 |
C04B35/10 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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