2021-10-25 Pageview:689
1, often wet and moldy indoor walls.
2, Wet and moldy walls formed by condensation caused by insulation.
3, often moldy, moldy paint walls every year.
4, on the requirements of mold removal effect is very long-lasting users pay attention to the mold caused by water leakage.
5, Building, office, living room 1-2%, easy to grow moldy workshop, plant use 1-2% increase.
Iron aromatic photoinitiator
The most representative iron arene photoinitiator is Ciba’s Irg a cure 261, which is prepared by the catalyzed ligand exchange between ferrocene and cumene to obtain cumene ferrocene chloride. By substitution, nf-cumene ferrocene hexafluorophosphate is obtained, in which the iron element is +2 valence, the ring has a negative charge, and the structure is shown in formula (7-20). Irg a cure 261 is a light yellow powder with high photoreactivity. It can be used as a cationic photoinitiator and has good thermal stability. It will not decompose when heated above 300℃. Even if it is mixed with epoxy monomer, it can be heated to 210°C without curing. For example, instead of cumene with polynuclear aromatics such as naphthalene and pyrene, other iron aromatic photoinitiators with longer absorption wavelength can be synthesized, such as the other two in formula (7-20).
n cumene ferrocene ion n*-tea ferrocene ion to “pyrene ferrocene ion
The iron aromatic initiator has a strong light absorption performance in the ultraviolet light region, with an extinction coefficient of more than 10 orders of magnitude, and weak absorption in the short-wave visible light region, with an extinction coefficient of about 10° order of magnitude, and v-cumene ferrocene is only a benzene ring As a ligand, the light absorption effect in the visible light region is poor. After replacing the cumene ligand with a pyrene ring ligand, the maximum absorption wavelength can reach 440nm, and the corresponding extinction coefficient is as high as about 1000. Therefore, the light absorption carnauba wax additive properties of iron arenes can be adjusted by changing the aromatic ring ligands. The iron aromatic hydrocarbons decompose under light irradiation, the benzene-based ligands leave the excited state molecules, and other ligands in the system with little or no conjugation effect combine with the light-resolved monoferrocene, resulting in photo-induced ligand replacement , The light absorption performance of the newly produced monoferrocene complex is far inferior to the iron arene itself. The overall effect is that the absorption of iron aromatics at long wavelengths is reduced, that is, iron aromatics have photobleaching function L42.,
In the coexistence of epoxy and other monomers, the iron aromatic hydrocarbon will be photodegraded according to the following mechanism, ligand replacement, and cationic polymerization will be initiated.
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