Yoshinao Doi

Title: **Yoshinao Doi: A Pioneer in Membrane Technology**

Introduction

Yoshinao Doi, an accomplished inventor based in Kawasaki, Japan, holds a remarkable portfolio of 7 patents. His work primarily focuses on innovative porous membrane technologies, highlighting his expertise in the field. Doi's inventions showcase significant advancements in chemical resistance, filtering capabilities, and mechanical properties.

Latest Patents

Among his latest contributions, Doi has developed two notable patents. The first is a **polyvinylidene fluoride porous membrane** and the associated method for production. This membrane comprises a polyvinylidene fluoride resin structured in a uniform, three-dimensional network of pores. It is designed to exhibit excellent chemical resistance, exceptional filtering characteristics, and strong mechanical properties. The production process involves blending the resin with an organic liquid and powdery hydrophobic silica, then melt-molding it to create the membrane, followed by extraction of the organic liquid and silica.

The second patent features a **hydrophilic sulfonated polyolefin porous membrane**, which includes sulfonic groups that enhance its performance. This membrane showcases an impressive porosity of 30 to 85% and an average pore diameter ranging from 0.05 to 1 micrometer. Doi's innovation is recognized for its superior water permeability, mechanical strength, and elongation. The membrane can be effectively utilized as a fine microfilter and is fabricated by treating a polyolefin porous membrane with a sulfonating agent, preferably one that contains an inorganic filler.

Career Highlights

Doi has made substantial contributions in the arena of materials science throughout his career. He has worked with industry leaders such as Asahi Kasei Kogyo Kabushiki Kaisha, significantly impacting the field of membrane technology. His work in these organizations emphasizes the application of innovative polymer-based solutions in real-world scenarios.

Collaborations

During his professional journey, Doi has collaborated with notable coworkers, including **Shigeo Kaneko** and **Takeo Hanamura**. These collaborations have further enhanced the development of his cutting-edge technologies, contributing to advancements within the industry.

Conclusion

Yoshinao Doi stands as a key figure in the development of advanced porous membranes that cater to various industrial applications. With his significant patent portfolio and contributions to both research and collaboration, Doi continues to shape the landscape of materials science and engineering, paving the way for future innovations. His work not only exemplifies ingenuity but also a dedication to solving complex challenges in membrane technology.