No. 386: A transparent film that transmits 95% of the light and blocks 90% of the heat (December 21, 2011)

A research team led by Prof. Masayoshi Fuji of Nagoya Institute of Technology developed a film with high thermal insulation performance. It has dispersed hollow particles inside the film made of polymer resin. It is 10 micrometers thick, and it transmits 95 of the light and blocks 90% of the heat. In the substantiative experiment, the film reduced the power consumption of an air-conditioner by 30%. It will be put on the market in the spring of 2012 through Toyohozai and sold for 2,000-3,000 yen per square meter.

The research team applied silica to the surfaces of calcium carbonate particles, each of which 10-300 nanometers in diameter, and synthesized hollow silica particles by dissolving calcium carbonate by acid. After the surfaces of silica particles are reformed to adapt to polymer, they are combined with raw materials of polymer resin to make a film. A high degree of cutoff performance was achieved because silica particles are dispersed uniformly. The existing film does not have as high a degree of cutoff performance as the newly developed film because it is made only of polymer resin without further processing. In the substantiative test, the power consumption of an air-conditioner operated in a room with windows on which the new film is attached was 6,000 kW per hour on average for 24 hour continuous running at a temperature of 25.0 degrees centigrade, 30% less than the power consumption in a room with normal windows.