In what coating materials painters and varnishers use acrylic resins as binders?
Painters and varnishers use acrylic resins as binders in plaster primers, in dispersion paints, paints drying by evaporation of the thinner, in two-component fillers, varnishes and paints. Also, dispersion varnishes usually contain acrylic resins as binders.
What are the properties of coatings made with acrylic varnishes?, drying naturally?
Acrylic varnishes, naturally drying, have excellent adhesion to all strong surfaces. Because acrylic resins do not saponify, Coatings made of them can also be used on all alkaline substrates – however, they must be dry. These coatings show good weather and chemical resistance. Acrylic varnishes, naturally drying, they give thermoplastic coatings.
Please justify, why two-component acrylic varnishes managed, despite the higher price, replace traditional alkyd car paints in a short time
The drying and hardening time of two-component acrylic varnishes is much shorter than that of alkyd varnishes. As a result, a lower temperature in the drying cabin is sufficient, and this energy saving lowers costs. Two-component varnishes can be sanded and polished after several hours of drying. Alkyd varnishes require several weeks for full hardening. in addition, two-component acrylic varnishes are harder, they keep their shine longer and are less sensitive to gasoline.
Why two-component acrylic varnishes can also be referred to as polyurethane-acrylic varnishes?
Polyisocyanates are used as hardeners for two-component acrylic lacquers. In the process of chemical curing by polyaddition, the polyisocyanate is bound to form polyurethane groups. A three-dimensional cross-linking occurs, largely identical to the cross-linking of polyurethanes.
In the case of two-component acrylic lacquers, the presence of moisture constantly causes the formation of "craters" in the surface of the coating. Please explain, how this fault arises The polyisocyanate hardener is very sensitive to moisture, it enters into a chemical reaction with water, which releases carbon dioxide. This gas breaks the paint film that is just hardening, which can no longer dissolve. Then, small "craters" remain in the painted surface.