Paint Science: Relationship between Pigment Oil Absorption and Dispersion

in 100 grams of weight of pigment, the refined flax oil added drop by drop, and with the use of ink knife (scraper) pinch, the initial refueling, the pigment remains loose, with the increase in the amount of fuel loose grain sintering each other, until the last added a drop of oil, so that all the pigment salineThe oil used in this test is the amount of oil absorbed by the pigmentthe size and dispersion of the amount of oil absorbed by the pigmentThere are two explanations: one is that the amount of oil absorption is related to the gap between pigment particlesWhen increasing dispersion, the particle I gap decreases and the oil absorption should decreaseAnother view is that pigmentsIt is related to the surface phenomenon at the paint interfaceIncreased dispersion helps pigment particles to increase than the surface, so the amount of oil absorption should also be increased accordinglystudied the relationship between the properties of group green, chromium oxide and iron red and their dispersion, it was concluded that if the particle size of pigments is distributed within a narrow range, the factors that determine their oil absorption are not only free spaces between particles, nor are they determined by surface phenomena, but also in the white space between particles, and in the absorption capacity of pigmentsthe test, when large pigments are fine-looking, the following changes occur between pigment particles, due to the destruction of aggregates to reduce the porousness of particles, flattened the surface of the particles, increased than the surfaceThe reduction of porousness and the flattening of the surface causes a decrease in oil absorption, but an increase in the amount of oil than the surface should cause an increase in oil absorptionIf the pigment is fine-cut, the reduction of porousness and the uneven flattening of the surface, the effect is greater than the increase of the surface, the oil absorption will decrease;tests showed that the oil absorption of chromium oxide and group green decreased with the increase of dispersion, but the oil absorption of iron red increased with the increase of dispersionThe following image