Objective
- Development of photochromic coating materials based on organic photochromic dyes with
response times of seconds, which can be applied on transparent substrates (glass,
polymers) or on non transparent substrates (ceramics, polymers, paper) for the preparation
of coatings with thickness of 5 - 50 m m
Method
- Incorporation of spirooxazines, pyrans and fulgids into the matrix of an
organic-inorganic composite, which is prepared by a specially developed sol-gel process
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Results
- Darkening from 90 % to 10 % transmission
- By components of the matrix, the kinetic behaviour of the photochromic dye is adaptable
to the different applications
- Half life times for darkening and fading (t0,5) of 2 s - 10 min
- Neutral tints (grey or brown) by mixing different photochromic dyes
- High scratch resistance
- High long term stability by special additives (decrease of the darkening
DA0 to half of its
initial value after
60 - 80 h of an accelerated suntest)
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Laboratory Technology
