The use of powder coating anti-mildew agent BJ-78

BJ-78 can be added in the mixing stage of powder production, it is recommended to add 0.3-0.5%, the amount of addition can be adjusted appropriately according to the performance of the coating products and the use environment.

Because the cation mechanism of aromatic amines and phenols are similar, for some monomers, aromatic amines and phenols polymerization inhibitors can be mixed in a certain ratio to obtain better resistance than when used alone. Poly effect. For example, when hydroquinone and diphenylamine or p-tert-butyl phthalate and phenothiazine are used in combination, the polymerization inhibition effect of methyl methacrylate is 300 times higher than that of using only one of them. Another example is for chloroprene monomers, when phenazine and one of catechol, pyrocatechol, p-tert-butylcatechol or N-nitrosodiphenylamine are mixed in 1+1, The polymerization inhibition effect is much higher than that of single use. This increase in polymerization inhibition effect may be caused by the interaction between the polymerization inhibitors. For example, diphenylamine reacts with ROO· to ​​generate diphenylamine free radicals, which immediately takes the hydrogen from hydroquinone and converts it back to amine. In this way, as long as there is phenol, only the phenol is oxidized to montan glycol wax msds semiquinone or aldehyde, while the aromatic amine will never be consumed. While improving the inhibitory effect of the polymerization inhibitor, the oxygen concentration in the monomer can be maintained for a long time.

The inhibitory activity of aromatic amine inhibitors is related to the nature of the substituents in the molecule:
① For aniline, when the benzene ring has an electron pushing group at the para position, the polymerization inhibition activity of amines is enhanced; when the hydrogen on the nitrogen atom is replaced by a methyl group, the polymerization inhibition activity is significantly reduced.

②For naphthylamine, the activity of amino group at position 1 is higher than at position 2. When the number of amino groups increases, the polymerization inhibitory activity increases; the electron withdrawing group on the naphthalene ring significantly reduces the polymerization inhibitory activity.

③For p-phenylenediamine, the derivatives formed by the substitution of alkyl and aryl groups with hydrogen on the amino group will increase the polymerization inhibitory activity.