Лако-красочные материалы — производство

Water-based epoxy primers are ideal for damp porous substrates, as such primers will penetrate to an adequate depth to ensure good adhesion and produce a sound surface for bonding. Emulsifiable resins and hardeners are available, and the better systems deactivate the emulsifier system during cure to ensure that the cured system is not unduly water sensitive (Section VI. A). Solventless epoxy primers are used for bonding new concrete to existing concrete. Polyamide hardeners are preferred because of their ability to cure satis­factorily in the presence of water. Accelerators and diluents may be added, but fillers are generally omitted. The primer is applied to the existing concrete, and the fresh concrete cast before the resin has set (Section VI. B).

Epoxy adhesives are suitable for tiling, both for floor tiles in applications requiring acid or chemical resistance and in high-hygiene areas and also for tiling on vertical sur­faces, where it is essential that tiles should not delaminate. Epoxy tiling systems are suitable for glazed tiles, clay and ceramic tiles, and decorative marble or granite tiles, where priming is recommended. Adhesives will usually be filled and thixotropic, especially for vertical tiling. Epoxies are also used for decorative paving in commercial and residen­tial properties. Flooring made of small pebbles of different colors and textures bonded with relatively small proportions of epoxy are attractive and provide good drainage of water in areas such as swimming pool surrounds. Light-colored systems with good ultra­violet (UV) resistance are required. Hardeners should be based on isophorone diamine because of its good color stability, and UV stabilizers may be included.

Self-leveling floors are produced from low-viscosity epoxy systems. Low-exotherm, unfilled systems are preferred. The entire floor should be cast in one operation, and thickness should preferably be at least 5 mm over the entire area. Because of their excellent chemical resistance to a wide range of chemicals, epoxies are often selected for flooring in chemical plants. Systems vary from trowelable to pourable or brushable and are usually filled. Choice of hardener and filler will depend on the specific chemicals encountered. Although tables of chemical resistance from suppliers will aid in selection of a suitable system, this system should always be tested using the chemicals that the floor is expected to withstand.