Лако-красочные материалы — производство

The tinting strength of a colorant is its ability to impart color to a light scattering material by virtue of its absorption properties. Tin­ting strength corresponds to the effectiveness with which a unit quantity of a colorant changes the color of a material. Generally, tin­ting strength is expressed as the mass ratio in which the reference pigment (mass, mR) can be replaced by the test pigment (mass, mT) to give the same color quality in a white system. Tinting strength has an economic implication on paint formulation because the higher the tinting strength, the less pigment is required to achieve a standard depth of shade. Tinting strength of a colored pigment depends upon its light absorbing power, and therefore, factors such as chemical structure, purity and particle size largely govern tinting strength. In general, the smaller the particles, the higher will be their tinting strength. Generally, these factors are controlled during the pigment manufacturing process and not during paint manufacturing. The paint manufacturer can achieve maximum tinting strength from a given pigment by efficient dispersion of pigment particles.

The lightening power (the tinting strength of a white pigment, also referred as reducing power) is a measure of its ability to increase the reflectance of an absorbing black or colored medium by virtue of its scattering ability. Lightening power is the mass ratio at which the reference pigment can be replaced by the test pigment to give the same lightness in a colored system. Lightening power depends upon the scattering ability of the pigment particles, and therefore, important factors affecting lightening power are particle size and the refractive index of the pigment.