Performance Characteristics of Polyurethane Varnish

Performance characteristics of polyurethane paint
Polyurethane paint, or polyurethane paint, refers to a paint that contains a considerable number of urethane bonds in its paint film. Polyurethane paint is a two-component anticorrosive coating with tough coating film, solvent resistance, corrosion resistance, and excellent decoration. Polyurethane paint has a wide range of applications in various fields of industry, and its own characteristics take into account both protection and decoration functions, and it has more advantages than other anti-corrosion coatings.
1. The ester bond in polyurethane paint is characterized by the formation of acyclic and/or cyclic hydrogen bonds between polymer molecules: under the action of external force, the hydrogen bonds can be separated to absorb external energy. When the external force is removed, hydrogen bonds can be formed again. Such hydrogen bond cleavage and re-formed reversible repetition make the polyurethane paint film highly mechanical, wear-resistant and tough. Compared with other types of coatings, polyurethane paint film has the highest elongation at break under the same hardness conditions due to the effect of hydrogen bonds, so it is widely used as floor paint, deck paint, etc.
2. Some varieties of coatings (such as epoxy, chlorinated rubber, etc.) have good protective functions but poor decoration; some varieties (such as nitro paint, etc.) have good decoration but poor protective functions. However, polyurethane paint has both protective and decorative properties, and can be used for the coating of high-end woodware, pianos, and large passenger aircraft.
3. Strong coating film adhesion. Polyurethane, like epoxy, can be formulated into an excellent adhesive. Therefore, the coating film has excellent adhesion to a variety of surfaces. But for some metal surfaces, the adhesion of polyurethane paint is slightly inferior to epoxy paint; but for rubber, polyurethane paint is better than epoxy paint.
4. The elasticity of the coating film can be adjusted according to the needs of its composition ratio, which can be adjusted from extremely hard to extremely flexible elastic coating, while general coatings such as epoxy, unsaturated polyester, amino alkyd, etc. can only be made Rigid coating is difficult to impart high elasticity.
5. Polyurethane coating film has excellent chemical resistance, acid, alkali, salt solution, and petroleum products, so it can be used as maintenance coating for drilling platforms, ships, and chemical plants, as well as the inner wall lining of petroleum storage tanks.
6. It can be dried at high temperature and cured at low temperature. In typical room temperature curing coatings: epoxy, polyurethane, and unsaturated polyester, epoxy and unsaturated polyester are difficult to cure below 10°C, and only polyurethane can be cured normally at 0°C, so it can be applied in the season long. Because it can cure quickly at room temperature, it can be constructed at room temperature for large projects such as large oil tanks and large airplanes to obtain an effect better than ordinary baking paint.
7. Polyurethane paint can be made into varieties resistant to low temperature of -40℃. It can also be made into high temperature resistant insulating varnish with performance close to polyimide.
8. Magnet wires coated with polyurethane paint can be automatically tinned in the molten solder without scraping paint, which is especially suitable for the assembly of telecommunication equipment and meters.
9. It can be combined with polyester, polyether, epoxy, alkyd, polyacrylate, cellulose acetate butyrate, vinyl chloride vinyl acetate copolymer resin, asphalt, drying oil, etc. to make paint, and can be made according to different requirements Into many varieties.
10. It can be made into solvent type, liquid solvent-free type, powder, water-based, single-tank, two-tank and other forms to meet different needs.