Pigments for water-based UV curing of inks

As a water-based UV curable ink composition Africa photosensitivity, pigment absorbs UV light initiator competition, which largely affects the UV curing system the curing characteristics. As part of the pigment capable of absorbing radiation energy, which will affect the light absorption of the initiator to light, and thus affect the concentration of free radicals that can be generated, the result will reduce cure speed. Color pigments of different wavelengths of light have different absorption rates (transmittance), the absorption rate of the pigment is smaller, the greater the transmission rate, the faster the cure the coating. Ultraviolet absorption ability of the carbon black is high, the slowest curing, highly reflective white pigment, also hinder the cure. In general the order of the UV absorption: Black> purple> blue> green> stunning> yellow> red.PVC plasticizer
The same ratio of the concentration of different pigments, the cure speed of the ink film is different. With the increasing amount of pigment, ink film curing rate of decline has different procedures. Wherein the amount of the yellow pigment in the ink film is greatest impact on cure rate, followed by a red pigment, a green pigment. UV absorption of the black maximum rate, such that the minimum transmittance of black ink, so the amount of the change of ink film curing rate but had no significant effect. When a pigment is too large, the cure rate of the ink film surface, although fast, but a large number of UV absorption of the pigment surface, reducing the transmittance of ultraviolet light, deep effect curing of the ink film, leading to curing the bottom surface of the ink film not curing, easy to produce, "wrinkled skin" phenomenon.intenal lubricant