I believe that people with experience in the industry know that hiding power is an important technical indicator of chromium dioxide and all white pigments. This indicator will have a direct impact on the economic benefits of the pigment. Therefore, both the pigment producer and the user are very concerned about the hiding power of the pigment. However, at present, many manufacturers still use the traditional "black and white grid method" in the measurement of hiding power. Although this method is simple and convenient to operate, and the spreading rate data can be obtained quickly, it will have a great impact on the deviation of the results due to the following problems :
(1) Test changes in the intensity of ambient light;
(2) Test the difference between ambient temperature and ventilation conditions,
(3) Factors such as people's subjective differences in perception of color difference make the test results of this method deviate greatly.
Therefore, foreign pigment and coating industries have eliminated this method, and usually use the contrast ratio measurement method. In the past two years, we have begun to try out this method in the development of chromium dioxide for flat latex paints, and the introduction is as follows.
