Akio Otsuka

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Gunma, JP

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Patents Grantslast 30 patents

Information Patent Grant
High-packing silicon nitride powder and method for making
- Patent number 5,382,554
- Issue date Jan 17, 1995
- Shin-Etsu Chemical Co., Ltd.
- Haruyoshi Kuwabara
- C04 - CEMENTS CONCRETE ARTIFICIAL STONE CERAMICS REFRACTORIES
Information Patent Grant
High-packing silicon nitride powder and method for making
- Patent number 5,348,919
- Issue date Sep 20, 1994
- Shin-Etsu Chemical Co., Ltd.
- Haruyoshi Kuwabara
- C04 - CEMENTS CONCRETE ARTIFICIAL STONE CERAMICS REFRACTORIES