It is a preparation added to paint (emulsion paint) to prepare anti-mildew paint. After the coating mold, it will lead to viscosity and adhesion loss, the mold on the surface of the paint film not only makes the coating lose protection and decorative function, mold scattered in the environment, but also cause pollution to the environment, usually add the coating anti-mold agent is an effective way to prepare anti-mold coating, from mold erosion.
Anti-mildew coatings prepared with paint anti-mildew agent can be widely used in food, pharmaceuticals, beverages, brewing and other special industries with high health requirements.
The interweaving of the photo-yellowing of the photo-initiated system and the photo-aging yellowing of the coating cross-linked network
Stage A reflects that some unstable colored conjugated by-products, including enamines, imines, and a, β unsaturated structures related to the amine center, are generated by the photolysis and oxidation of the system during the photocuring process. In the light-proof placement stage (stage B) after curing, the colored and unstable structure in the cured film may continue to oxidize and turn into a colorless structure; or absorb moisture, hydrolyze, and also turn into a colorless structure.
In the early stage of the photo-aging test (stage C), the residual photoinitiator and active amine in the cured film absorb light again, and photolysis and photooxidation reactions occur, resulting in a colored and unstable intermediate structure, which gradually deepens the yellowness of the coating. Under continuous light, these colored and unstable structures may further decompose or absorb moisture and hydrolyze, sasol wax c80 sds and turn into colorless products (in the early stage of stage D). At the same time, the resin cross-linked network itself may begin to undergo photooxidative degradation, resulting in a yellowness index.
The situation of rising again (late stage D). What is discussed here is a typical situation. When the photoinitiator and active amine are ideally matched, the above stage A may not be obvious. It may also happen that the initiator and the active amine match badly, that is, after the photo-curing process is completed, the yellowness index of the coating continues to increase to a certain level during storage in the dark, and then it stabilizes or begins to slowly decay. It may involve initiating the slow oxidation and decomposition reaction of the photolysis products of the system under dark conditions. Due to structural constraints, the production of colored photolysis products may be relatively slow. Combining the above discussion also helps us understand why some light-cured films enter the gradual growth stage after undergoing a rising-falling stage in the early stage of the photo-aging test (usually within 200h).
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