The film achieves this by utilizing its proprietary technologies including
resin synthesis technology, film coating technology, and size control technology
for adjusting the size of light-control particles based on nanotechnology.
Hitachi Chemical began mass production of SPD film in July 2009 and is supplying
commercially usable film to end-product licensees of Research Frontiers for the
automotive, architectural, marine and aircraft markets. With its newly completed
coating line dedicated to production of SPD film, Hitachi Chemical has expanded
its production capacity of SPD film to 400,000m2/year.
In recent years, the market for light-control glass has expanded due to the
increasing demands for energy efficiency and heat and light control, automated
shading, privacy, and design and engineering innovation. SPD film is laminated
between panes of glass or plastic to produce various dynamic light-control
products including windows, doors, skylights, atria and sunroofs. As a durable
laminate, it is available in many sizes, fabrications and shapes, and can be
used on curved surfaces. Other light-control technologies include liquid crystal
and electrochromic devices. However, with liquid crystal technology, it is
difficult to tune the level between white and transparent, and typically little
shading benefit is offered. Electrochromic devices have problems of relatively
slow and inconsistent response speed, difficulty in achieving larger sizes, and
limitations to the substrates that it can be used with, and restrictions on the
number of available light-control states. For these reasons and others, there is
growing demand for "smart" products that can be made in a large size and can
enable freedom in quickly controlling light transmittance.
Therefore, Hitachi Chemical has developed the volume production method for
SPD film based on its own unique polymer synthesis technologies and resin
technologies, which adjusts the size of light-control particles base on
nanotechnologies. It has succeeded in commercializing its SPD film to the world
market. The SPD film consists of two polyethylene terephthalate (PET) films
coated with a transparent conductive layer, and matrix resin dispersed with
microcapsules containing orientative particles sandwiched between two films. The
principle of light control is that when alternate voltage is applied to the
orientative particles, they become oriented and transparent. When the AC voltage
is not applied, the particles are not oriented so that their color is dark blue,
thus shielding light. The color tone can be changed from dark blue to
transparent to freely control the light transmittance. Its power consumption is
as low as 1.1 W/m2.
A wide range of applications of SPD film are expected, including the
application to buildings such as Indiana University in the USA, and windows of
boats and aircrafts, which have been already realized. Future potential
applications include automotives, home electric appliances, and partitions.)
Hitachi Chemical will strive to accelerate the use of SPD film, which holds
significant potential for growth. SPD film is positioned as one of the key
emerging products promoted by Hitachi Chemical