It is widely used in water-based systems such as water-based paints for interior and exterior walls, emulsion paints, acrylic emulsions, acetate emulsions, polypropylene emulsions, whites, mortars, water-based putties, etc. to sterilize and prevent corrosion.
Regardless of whether the early yellowing of the coating involves changes in the cross-linking network structure, the deepening of the chromaticity means that the overall light absorption capacity of the coating is enhanced, and the tendency for degradation reactions such as photooxidation to occur increases. There is a sasol wax c80 regular relationship between the active amine structure of light-curable coatings and the yellowing resistance. Generally speaking, straight-chain aliphatic tertiary amines have a high tendency to undergo photoyellowing, such as the Michael addition product of di-n-butylamine and polyacrylate; tertiary amines containing β-hydroxyl have a lower yellowing tendency, such as N-methyl The Michael addition products of ethanolamine and polyacrylates, etc. Most of the early studies on the photo-aging behavior of coatings came from several well-known research groups in Europe, such as Ran by, Allen, Decker and other research groups. The basic composition of light-curable coatings is acrylic monomers, epoxy acrylates, urethane acrylates, polyester acrylates, etc.
Therefore, the more common structures or groups in the cured film are saturated ester bonds, ether bonds, and urethane bonds. And substituted aromatic ring structures, among which polyacrylate segments are the most common, and the cationic light curing system has a higher concentration of ether bonds. Research by Gis mondi et al. pointed out that the pure acrylate cross-linking system itself has higher anti-light aging performance, and the amine and aromatic ring structure contained therein are the main reasons why it is prone to light aging . O’Hara pointed out through the heat aging and light aging research of the light-cured film that the epoxy acrylate cross-linking system is not as good as aliphatic urethane acrylate cured film. Allen’s research also reached a similar conclusion and pointed out that the benzophenone light The photo-yellowing tendency of the initiator is lower than that of the cleavage HCP K photoinitiator. This conclusion seems to be contrary to the experience of most people. There are often inconsistent results in light aging research. This may be due to the differences in research methods and test materials. For example, the most basic epoxy acrylate can be synthesized by amine catalyzed and non-amine catalyzed. For products catalyzed by tertiary amines, the remaining amine catalysts will seriously affect the photo-aging behavior of the cured film.
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