Inorganic chemistry and ceramics, Polymer chemistry

# A Novel Waterborne Paint Based on Nano-composite Emulsion

Keyword: Acrylic/Silica Nano-composite Emulsion, Non-Soiling Wall Paint, Effect on Prevention of Global Warming

Organizations Involved

○ Yoshiharu Kimura,

Professor of the Graduate School of Kyoto Institute of Technology

O Tsutomu Mizutani, Executive Director, Mizutani Paint Mfg. Co., Ltd.

Prof. Kimura

【Abstract】 The nanocomposite emulsion (NCE) consisting of acrylic/silica hybrid particles of 50-60 nm in diameter has been developed by a simple method utilizing special surfactants (Fig. 1). While the film formed from the conventional emulsion is wholly composed of organic polymer, the one from NCE consists of ultra-fine particles of inorganic silica dispersed in the organic polymer evenly and densely (Fig. 2). This structure provides the characteristics of showing both organic and inorganic functions. We succeeded in applying NCE to an environmentally benign wall paint named “Nanocomposite W”, which is currently attracting the highest attention in the paint industry.

## [Summary of the technology transfer]

## Technological Impact

NCE is a very interesting new material, having both the inertness coming from inorganic materials and the flexibility originated from organic materials. However, there has been no practical application of NCE because of the complexity of its synthetic method, the high cost of the raw materials, and the fragile properties of the film prepared from it. Kyoto Institute of Technology (KIT) has devised a simple synthetic method of NCE based on the surfactant selection and succeeded in applying the NCE to new waterborne wall paints in cooperation with Mizutani Paint to establish this creative state-of-the-art technology. In particular, the anti-soiling property and the least use of organic components are superior to those of the conventional paints to meet the market needs, conscious of prevention of global warming. The environmentally benign wall paint named "Nanocomposite W" is now spreading rapidly.

The resin to silica ratio used in this study was 50:50 by weight. It was impossible to disperse such a great quantity of silica particles into the film by the conventional dispersion technology based on the mechanical blending. However, we found out that our newly synthesized nanocomposite emulsion can enable to incorporate in such a high inorganic ratio with a high cost-performance maintained.

## ●Special Features of the Collaboration

The company dispatched researchers to the university to perform this study. At that time, the facilities of the Cooperative Research Center of KIT could be utilized effectively.

This technology will be evaluated as an advanced basic technology to contribute to the economical growth of Japan and to compete with inexpensive products imported from other countries.

This success is a typical example of the industry-university cooperation in which a company could introduce the creative research outcomes of a university into the market place. This feature is highly evaluated by both the academic and economical worlds.

## Project Background

Dr. Mizutani (and his company) and Prof. Kimura (and his laboratory) discussed new paint resins that can be synthesized from both inorganic or polymeric materials repeatedly over many years. The development was a result of this. In 1996, the development started in a laboratory of the Cooperative Research Center of KIT.

## Funding History

1.1998: Adopted as a creative research products development project by the Japan Science and Technology Agency.

[Fig. 1 NCE structure]

2.2003: Adopted as a research products optimal transfer project by the Japan Science and Technology Agency.

3.2003: A contract to share outcomes with this agency was made.

## I ntellectual property protection

“Aqueous Dispersing Elements and Their Manufacturing Methods, and Paint Components,” Patent Application Tokugan 1998-14477

· "A Method to Improve Solvent Resistance of Components and Films of Aqueous Coatings," Patent Application Tokugan 2003-152025 Patent No. JP-3806417

[Fig. 2 Filming process]

## Turning point in the Project

Although this development was very simple in itself, a great number of trials and errors were repeated to reach the final products, and this was the key to success. We appreciated the Japan Science and Technology Agency that had funded timely when we had met difficulty to continue the long development taking over eight years.