Production of coating will be added to a certain amount of plasticizer, such as chlorinated rubber paint is mostly used chlorinated paraffin plasticizer, plasticity can be understood as flexibility, individual chlorinated rubber is very brittle, without plasticizer difficult to film and no adhesion. It is used in many volatile dry coatings, and of course there are many other plasticizers such as methyl chloroformate.
Chlorinated methyl ester, the full name of chlorinated fatty acid methyl ester, as a new environmentally friendly plasticizer, its raw materials derived from natural oils and fats, in line with the current world environmental trends and requirements, and good compatibility with PVC, is an inexpensive DOP plasticizer substitutes, and does not contain harmful metals and O-benzene substances.
Coating added to a certain proportion of chlorinated paraffin or methyl chloride adhesion will be improved, of course, can also be through the 4 points to improve the adhesion of coatings: Generally speaking, the basic mechanism of adhesion is mechanical set, physical adsorption, forming hydrogen bonds and chemical bonds, mutual diffusion and other effects of these effects combined with the adhesion, Determines the adhesion between the paint film coating and the substrate. Therefore, the adhesion promoter also from these aspects to improve and improve the coating film on the substrate wetting and adhesion.
1. Improve the mechanical bonding force: through the improvement of the coating on the substrate permeability, wettability so that the coating as far as possible to the substrate hole, seam infiltration, to be cured after the formation of countless small anchor points, firmly grasp the substrate, thereby increasing the adhesion of the coating to the substrate.
2. Increase van der Waals: According to calculate when the distance between two planes is 1nm, van der Waals force can reach 9.81-98.1mpa. By increasing the wettability of the coating to the substrate, the coating can be completely wetted and close to the surface of the substrate before curing, thus improving the van der Waals and finally improving the adhesion of the coating to the substrate.
3. Improve the reactive groups, for the formation of hydrogen bonds, chemical bond environment: hydrogen bonds, chemical bonds stronger than van der Waals force, such as resin adhesion promoter is to improve amino, hydroxyl, carboxyl group, such as reactive groups or other active groups, it can be bonded to the oxygen atom or hydroxyl on the surface of the substrate to produce hydrogen bonds or chemical bonds to improve adhesion.
4. Diffusion: When the substrate is used as a polymer substrate, the use of strong solvent or chlorinated polypropylene resin adhesion promoter, which can promote the coating and the substrate molecules of the mutual diffusion and dissolution, resulting in the interface disappears, thereby improving the adhesion between the coating and the substrate. At the same time, the wettability of the substrate and the coating on the substrate adhesion has a direct impact, only when the surface tension of the coating is lower than the critical surface tension of the substrate, the coating can be effectively wetting the substrate, and only the coating before curing can fully wetting the substrate, thereby increasing the adhesion of the effective contact area and enhance the bonding between the interface, the paint film can obtain good adhesion.