This inventor holds 6 USPTO granted patents and 2 EPO patents. Top assignees: Showa Denko K.k., Showa Denka K.k., Showa Denko Kabushiki Kaisha. Active years: 1991-2008.
Location History:
- Nagano, JP (2003)
- Tokyo, JP (2006 - 2007)
- Shiojiri, JP (1991 - 2008)
Company Filing History:
4 out of 1,961 
1 out of 11 
1 out of 405 Years Active: 1991-2008
Title: Inventor Hirohiko Ohtsubo: Innovating Abrasive Technology
Introduction
Hirohiko Ohtsubo, an accomplished inventor based in Shiojiri, Japan, has made significant contributions to the field of abrasive materials. With a total of six patents to his name, he has focused on advancing the technology surrounding cubic boron nitride, a material renowned for its hardness and thermal resistance.
Latest Patents
Among his latest inventions are two notable patents:
1. **Method for Producing Cubic Boron Nitride Abrasive Grains** - This invention pertains to a method for producing cubic boron nitride abrasive grains utilized in the manufacture of grinding wheels. The method involves maintaining a mixture of hexagonal boron nitride and seed crystals of cubic boron nitride under specific pressure and temperature conditions, ensuring the thermodynamic stability of cubic boron nitride. A key characteristic of the invention is that the seed crystals contain cubic boron nitride twin crystals.
2. **Method for Producing Cubic Boron Nitride** - This method offers a novel approach to producing cubic boron nitride by maintaining a mixture, containing hexagonal boron nitride and a catalyst, under pressure and temperature conducive to the stability of cubic boron nitride. This process enables the formation of composite lumps containing cubic boron nitride, which are then dissolved in an alkaline solution to retrieve the material. The invention is notable for including an essential step that reduces the low-pressure phase boron nitride in the composite lumps to 50% by mass or less before the dissolving step.
Career Highlights
Hirohiko Ohtsubo has worked at reputable companies, including Showa Denko K.K., where he honed his skills and fostered a deep understanding of materials science. His innovative work continues to influence the field significantly.
Collaborations
Throughout his career, Ohtsubo has collaborated with skilled professionals such as Eiji Ihara and Masakazu Maki. These partnerships have helped drive forward the research and development of cutting-edge abrasive technologies.
Conclusion
Hirohiko Ohtsubo exemplifies the spirit of innovation in the abrasive materials sector. His dedication to improving the production methods of cubic boron nitride is paving the way for advancements in grinding technologies. With several impactful patents under his belt, Ohtsubo's contributions are a testament to the importance of continued research and development in material sciences.