发明名称 |
Non-stoichiometric ytterbium phosphate powder of low infrared reflectivity |
摘要 |
Proposed is a powder of ytterbium phosphate having a non-stoichiometric phosphorus to ytterbium molar ratio of 1.08 to 2.0 and having a specified average particle diameter and specified diameter of the crystallites forming the particles. The powder is useful as an infrared-absorbing pigment in a printing ink invisible to naked eyes but detectable by an infrared detecting means for printing of stealth bar code patterns. The ytterbium phosphate powder can be prepared in a convenient and inexpensive method utilizing the precipitation reaction by mixing an aqueous phosphoric acid solution and ytterbium salt solution under specified conditions followed by calcination of the precipitates at a specified temperature and pulverization of the calcined precipitates to give the specified average particle diameter.
|
申请公布号 |
US5911921(A) |
申请公布日期 |
1999.06.15 |
申请号 |
US19970915083 |
申请日期 |
1997.08.20 |
申请人 |
SHIN-ETSU CHEMICAL CO., LTD. |
发明人 |
TAKAI, YASUSHI;KIMURA, YUJI;SAKAI, SHIGERU |
分类号 |
C09K3/00;C01B25/37;C01B25/45;C09D11/00;C09D11/02;C09K11/81;(IPC1-7):G02B5/20;C01F17/00 |
主分类号 |
C09K3/00 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|