The utility model relates to a compound odorless photoinitiator for UV curable coatings

UV-curable coatings contain almost no volatile organic solvents and have the advantages of low energy consumption, fast reaction speed, clean and environmental protection. A UV-curable coating formulation system consists of at least three components: ①Photosensitive resin (or prepolymer, oligomer), is the source of the most basic physical and chemical properties of paint and film, determines the curing rate of the whole formula system and the properties of the material; ②Active diluent, mainly used to adjust the viscosity of coating formulation system; ③Photoinitiator, under the irradiation of ultraviolet light, produces active groups (radicals or cations) that can initiate the photopolymerization of the two substances.

Net flavour coating technology is currently one of the development direction of UV curing coating. According to the mechanism of photoinitiation, photoinitiators can be divided into radical photoinitiators and cationic photoinitiators. According to the mechanism of generating active free radicals, free radical photoinitiators can be divided into hydrogen snatching photoinitiators and pyrolysis photoinitiators. Free radical photoinitiator is the most widely used in UV curing coatings. Although the amount of photoinitiator in the whole formulation system is not high, the mass content is usually between 1-10%, but the photoinitiator is one of the key components of uv curable coatings. The ideal photoinitiator has the following four characteristics: ①High photoinitiation efficiency; ②Higher extinction coefficient; ③Better storage stability; ④Better environmental protection: The photoinitiator and its photocracking products should be low in toxicity and odor.

According to the chemical composition of molecules, photoinitiators can be divided into organic photoinitiators, inorganic photoinitiators, macromolecular photoinitiators, etc. Deodorant coating technology is one of the development directions of UV curable coatings, but the effect of photoinitiator on deodorant effect of UV curable coatings has not been reported so far.

A compound odorless photoinitiator consisting of the following percentage by weight:

Zinc oxide 30～70％

Macromolecule photoinitiator 30～70％

Wherein, the macromolecule photoinitiator is prepared by the photoinitiator containing hydroxyl, isocyanate and acrylic acid containing hydroxyl.

The compound odorless photoinitiator of the invention adopts zinc oxide and a specific macromolecule initiator. Among them, the zinc oxide as a kind of inorganic light initiator, won't produce odorous after photolysis products, with specific macromolecular initiator to strengthen zinc oxide light efficiency, formation of inorganic/organic composite net light initiator and can effectively overcome the organic light initiator photolysis after the release of the smell of the volatile organic small molecules. Moreover, the pure flavor light initiator has high initiation efficiency and can improve the conversion rate of uv curable coatings, thus further reducing the odor and volatile organic compounds released by unreacted raw materials in the residual coating, making the paint film after photopolymerization clean flavor and excellent performance.