Patent No. U.S. 6,875,800 B2
PPG Industries has been granted a
patent for a method of color matching
over the visible spectrum a preselected
protective and decorative coating.
It is comprised of determining the visible
color of a preselected coating by
measuring the absorbance or
reflectance of the preselected coating;
and selecting a plurality of colorants
which in combination with a resinous
binder produce a coating composition
which when deposited as a coating.
matches the visible color of the preselected
coating. The colorants are pigments
and the majority of the colorants
has a maximum haze of 10%
and exhibits an absorbance peak in
the visible spectrum wherein at least
60% of the total absorbance in the visible
spectrum occurs at wavelengths
within approximately 50 nm of the
wavelength of the peak absorbance