Hexagonal system boron nitride powder

• US 5,854,155 A
• Filed: 01/15/1997
• Issued: 12/29/1998
• Est. Priority Date: 01/24/1996
• Status: Expired due to Term

• Current Assignee: Denki Kagaku Kogyo Kabushiki Kaisha (TDK Corporation)
• Original Assignee: Denki Kagaku Kogyo Kabushiki Kaisha (TDK Corporation)
• Inventors: Hara, Hiroyuki, Nishikawa, Hiroshi, Kawasaki, Takashi, Kuroda, Yukio
• Primary Examiner(s): GROUP, KARL E
• Application Number:
  US08/782,296
• Time in Patent Office: 713 Days
• Field of Search: 501/96.4, 423/290, 524/404, 524/428
• US Class Current: 501/96.4
• CPC Class Codes: C01B 21/064 with boron
• CPC Class Codes: C01P 2002/02 Amorphous compounds
• CPC Class Codes: C01P 2002/74 by peak-intensities or a ratio thereof only
• CPC Class Codes: C01P 2002/90 Other crystal-structural characteristics not specified above
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/45 Aggregated particles or particles with an intergrown morphology
• CPC Class Codes: C01P 2004/50 Agglomerated particles
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: C04B 35/583 based on boron nitride
• CPC Class Codes: C07D 251/54 Three nitrogen atoms

Abstract

Melamine borate particles each consisting essentially of needle crystal primary particles of melamine borate (C₃ N₆ H₆.2H₃ BO₃) which are aggregated to one another.

Claims

1. Hexagonal system boron nitride particles each consisting essentially of scaly primary particles of hexagonal system boron nitride which are aggregated to one another without orientation.

2. The hexagonal system boron nitride particles according to claim 1 wherein the primary particles are aggregated to one another in a pinecone form without a binder.

3. A hexagonal system boron nitride powder, which is a mixture comprising from 20 to 100 wt % of hexagonal system boron nitride particles as defined in claim 1 or 2 and from 80 to 0 wt % of other boron nitride particles, and which has a graphitization index (GI) of from 1.0 to 2.5 by powder X-ray diffractometry and a ratio of I₀₀₂ /I₁₀₀ of from 6 to 20, where I₀₀₂ is the intensity of the (002) diffraction line and I₁₀₀ is the intensity of the (100) diffraction line.

4. A composite comprising a resin and/or rubber, and a hexagonal system boron nitride powder as defined in claim 3, incorporated thereto.

5. A powder material for preparation of a sintered body of hexagonal system boron nitride, which contains a hexagonal system boron nitride powder as defined in claim 3 and has an oxygen content of from 0.5 to 2.5 wt %.

6. A hexagonal system boron nitride powder material for preparation of a pressureless sintered body, which comprises a hexagonal system boron nitride powder as defined in claim 3, and at least one member selected from the group consisting of boron oxides, alkaline earth metal oxides and alkaline earth metal borates, incorporated to the powder in an amount of from 1 to 20 wt %.