Chemicals
Based Technologies - Colour Changing Film
Introduction
Any paper covered with such film can
be used as reusable colour photocopier paper. Tetsu
Tatsuma of the Institute of Industrial Science, applied
photo chromic glass technology to develop the film.
This type of glass used for sunglasses, changes colour
when hit by light.
In the process, a solution, which includes titanium
oxide particles and silver ions, is applied to a glass
substrate to make the film brown. When the film is exposed
to a blue laser, its colour changes to blue, and then
to white when a white laser is used. The size and shape
of the silver ions change depending on the light shed
on the film, causing them to turn colours. When information
is written on the film, it lasts for at least a week.
The film returns to brown when exposed to ultra violet
light.
For More Information
(Source: Science & Technology in Japan).
Science & Technology Wing
Embassy of India
2-2-11, Kudan Minami, Chiyoda-ku
Tokyo 102-0074, Japan
Tel: +81-3-3262-2391 to 97,
Fax: +81-3-3234-4866
E-mail: tandonus@hotmail.com
