EP0428387A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for producing powder material for lead perovskite ceramic
Assignee: National Institute for Materials Science
•
Filing: 1990-11-13
•
Granted: —
•
Expires: 2010-11-13
Abstract
Abstract A process for producing a powder material for niobium-containing lead perovskite ceramics represented by the general formula: PbA x Nb 1-x O₃, wherein X = 1/2 or 1/3 and A represents at least one element selected from Fe, Co, Cr, Ni, Mn, Mg, Zn, Cd, Zr, In, Cu and Hf. A dried mixture of a sol or suspension of a hydroxide of A (which has a lower activity than Pb) and a niobic acid sol is first calcined A Pb compound is then added to the mixture and the resultant mixture is calcined again.
Inventors
- 👤 Yasujiko Terada
- 👤 Hajime Uno
- 👤 Kazunobu Abe
- 👤 Shinichi Shirasaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 19:09
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/495; C04B35/497; B; B82; B82Y; B82Y30/00; C01; C01G; C01G33/00; C01G33/006; C01G45/00; C01G45/12; C01G45/1221; C01G45/125; C01G45/1264; C01G49/00; C01G49/009; C04B35/622; C04B35/626; C01P; C01P2002/00; C01P2002/30; C01P2002/34; C01P2002/50; C01P2002/52; C01P2004/00; C01P2004/60; C01P2004/64; C01P2006/00; C01P2006/12; C01P2006/60; C01P2006/64
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
78 words
A process for producing a powder material for lead perovskite ceramics represented by the general formula: PbA x NB 1-x O₃, wherein X = 1/2 or 1/3, A represents at least one element selected from the Fe, Co, Cr, Ni, Mn, Mg, Zn, Cd, Zr, In, Cu and Hf, said process comprising the steps of calcining a dry mixture of compound of A and niobic acid sol, adding Pb compound to said mixture and calcining the resultant mixture.
Claim 2
Dependent Claim
78 words
A process for producing a powder material for lead perovskite ceramics represented by the general formula: PbA x NB 1-x O₃, wherein X = 1/2 or 1/3, A represents at least one element selected from the Fe, Co, Cr, Ni, Mn, Mg, Zn, Cd, Zr, In, Cu and Hf, said process comprising the steps of calcining a dry mixture of compound of A and niobic acid sol, adding Pb compound to said mixture and calcining the resultant mixture.
Claim 3
Dependent Claim
39 words
A process according to claim 1 wherein said niobic acid sol is one obtainable by reacting a strong acid suspension of niobium hydroxide and hydrogen peroxide and forming a sol from the resulting aqueous solution of niobium peroxide complex.
Claim 4
Dependent Claim
52 words
A process according to claim 1 wherein said niobic acid sol is a purified peroxoniobic acid sol obtainable by reacting a strong acid suspension of niobium hydroxide and hydrogen peroxide, forming the resulting aqueous solution of niobium peroxide complex into a sol, and deionizing said sol by the ultrafiltration of ionic impurities.
Claim 5
Dependent Claim
36 words
A process according to any of Claims 1 to 3 wherein said compound of A is obtainable by neutralizing hydroxide or salt of A with alkali and washing said hydroxide or salt of A with water.
Claim 6
Dependent Claim
35 words
A process according to any of Claims 1 to 3 wherein said compound of A is obtainable by anion exchange reaction between an aqueous or alcoholic solution of salt of A and anion exchange resin.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.