Method to determine light scattering efficiency of pigments
First Claim
Patent Images
1. A method to determine light scattering efficiency of a white pigment wherein the light scattering efficiency correlates with performance in an end-use application, comprising:
- (a) preparing a dilute slurry of a pigment in a continuous liquid medium having a known concentration, where concentration is the concentration of pigment in the slurry;
(b) measuring the total transmittance (T) of the slurry at a wavelength (λ
) of at least 600 nm;
(c) converting the transmittance measurement (T) to optical density (OD) by the equation
space="preserve" listing-type="equation">OD=-log (T)and(d) dividing the optical density by the concentration of the pigment in the slurry to determine light scattering efficiency of the pigment.
6 Assignments
0 Petitions
Accused Products
Abstract
A method for determining light scattering efficiency and a method to determine undertone of pigments are described. The methods are based on measuring total transmittance of pigment slurries at a wavelength of at least 600 nm. Transmittance measurements can be used to calculate light scattering efficiencies and undertone which correlate with performance in end-use applications.
-
Citations
16 Claims
-
1. A method to determine light scattering efficiency of a white pigment wherein the light scattering efficiency correlates with performance in an end-use application, comprising:
-
(a) preparing a dilute slurry of a pigment in a continuous liquid medium having a known concentration, where concentration is the concentration of pigment in the slurry; (b) measuring the total transmittance (T) of the slurry at a wavelength (λ
) of at least 600 nm;(c) converting the transmittance measurement (T) to optical density (OD) by the equation
space="preserve" listing-type="equation">OD=-log (T)and (d) dividing the optical density by the concentration of the pigment in the slurry to determine light scattering efficiency of the pigment. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15)
-
-
12. A method to determine undertone of a white pigment, comprising:
-
(a) preparing a dilute slurry of a pigment in a continuous medium having a known concentration (C), where concentration is the concentration of pigment in the slurry; (b) measuring total transmittance (T1) of the slurry at a wavelength, λ
1, between 500 and 650 nm;(c) measuring total transmittance (T2) of the slurry at a wavelength, λ
2, between 650 and 1000 nm;(d) converting the transmittance measurements to optical densities (OD) by the equation
space="preserve" listing-type="equation">OD=-log (T)(e) dividing the optical densities by the concentration (C) of the pigment in the slurry to calculate OD/C; (f) determining the undertone of the pigment by the degree of change in OD/C between λ
1 and λ
2. - View Dependent Claims (13, 14, 16)
-
Specification