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US4976777A Expired / Lapsed US ⏱️ 0.0 years remaining

Metal powder having controlled particle size distribution for metallic pigments and process for producing the same

Assignee: Showa Aluminum Powder KK
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Filing: 1989-09-11
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Granted: 1990-12-11
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Expires: 2009-09-11
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Abstract

Abstract Disclosed is a graded metal powder for metallic pigment, comprising a metal powder wherein the metal powder has a mean particle size of from about 2.5 to about 15.0 mu m, the content of particles having a particle size of not greater than 1 mu m is not larger than about 0.5% by volume, and the metal powder has a particle size distribution such that not smaller than 97% by volume of the particles of the metal powder fall within the range between half the mean particle size of the metal powder and double the mean particle size of the metal powder. Also is disclosed a process for producing a graded metal powder by classifying metal particles dispersed in a mineral oil containing a nonionic-anionic surfactant.

Inventors

  • 👤 Sinya Ozawa
  • 👤 Katsumi Kondo
  • 👤 Kajin Saito

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 23:05
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/62; B; B22; B22F; B22F1/00; B22F1/05; B22F1/052; C01; C01P; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/20; C01P2004/51; C01P2004/52; C01P2004/60; C01P2004/61

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 97 words
Graded metal powder for metallic pigment, comprising a metal powder wherein said metal powder has a mean particle size of from about 2.5 to about 15.0 μm, the content of particles having a particle size of not greater than 1 μm is not more than about 0.5% by volume, and said metal powder has a particle size distribution such that not less than 97% by volume of the particles of said metal powder fall within the range between half the mean particle size of said metal powder and double the mean particle size of said metal powder.
Claim 2
Dependent Claim 97 words
Graded metal powder for metallic pigment, comprising a metal powder wherein said metal powder has a mean particle size of from about 2.5 to about 15.0 μm, the content of particles having a particle size of not greater than 1 μm is not more than about 0.5% by volume, and said metal powder has a particle size distribution such that not less than 97% by volume of the particles of said metal powder fall within the range between half the mean particle size of said metal powder and double the mean particle size of said metal powder.
Claim 3
Dependent Claim 17 words
The graded metal powder for metallic pigment of claim 1, wherein the metal powder is aluminum powder.
Claim 4
Dependent Claim 58 words
The graded metal powder for metallic pigment of claim 1, wherein the metal powder has a particle size distribution such that not less than 98% by volume of the particles of said metal powder fall within the range between half the mean particle size of said metal powder and double the mean particle size of said metal powder.

References Cited (Backward Citations)

US4172720A Cited
US4235613A Cited
US4318747A Cited
JPS5974174A Cited
US4595413A Cited
US4655825A Cited
US4617056A Cited
US4659613A Cited
US4724172A Cited
JPS62278202A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-12-10 1994-06-11 1994-12-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-12-10 1998-06-11 1998-12-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-12-10 2002-06-11 2002-12-11 $7700.00 Window Closed / Lapsed

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