1. What is a solvent and what are the commonly used solvents?
Any volatile liquid used to dissolve film-forming substances such as oils, resins, and cellulose derivatives is called a solvent. The solvent also acts as a diluent. It is the main component of liquid paint.
(1) Turpentine. Colorless, pale yellow transparent liquid with special odor and normal volatilization speed. Can dissolve natural resins and oils. It is mostly used in cool glue paint, phenolic paint and alkyd paint.
(2) Pine perfume. Also known as No. 2oo solvent gasoline. It is a colorless and transparent liquid with a volatilization speed similar to turpentine, low toxicity and low price. It is a solvent used in large quantities in oil-based paints and alkyd paints.
(3) Benzene. Colorless transparent liquid with aromatic odor. Toxic, flammable and explosive. Fast volatilization and strong solvency. It is mostly used in nitro paint or paint remover.
(4) Toluene. Colorless transparent liquid, with aromatic smell, volatilization speed is second only to stupid, poisonous. Used as a thinner for alkyd, nitro, perchlorethylene, acrylic and other paints.
(5) Xylene. Colorless and transparent liquid with aromatic odor, moderate volatilization speed, inferior to toluene in dissolving power, but stronger than turpentine and turpentine water. The use is the same as that of toluene, and its toxicity is lower than that of this and toluene.
(6) Ethyl acetate, butyl acetate. Colorless flammable liquid with fruity aroma. Strong solvency, often used in nitro paint thinner and moisture-proof agent.
(7) Ethanol. It is a polar organic solvent. Colorless transparent flammable liquid with alcohol smell, quick volatilization and easy moisture absorption. Infinitely miscible with water. Can dissolve shellac and alcohol-soluble resins. When used in combination with the solvent of nitro lacquer, it can be used as a co-solvent for nitro lacquer. But the amount should not be too large, otherwise it will easily make the paint film white.
(8) Acetone. It is a very fast volatile organic solvent. It has a sour and bitter taste, colorless and flammable. Can dissolve oil, resin and rubber. Also miscible with water and ethanol. Easy to absorb moisture. It is mostly used in perchlorethylene paint and nitro paint.
(9) Cyclohexanone. It is a colorless oily liquid with acetone odor. Stable performance, not easy to volatilize. In the paint, it can improve the smoothness of the paint film, prevent the paint film from whitening, and is often used as a cosolvent for the paint.
(1o) Styrene, gasoline, kerosene, etc. Styrene is a colorless flammable liquid with aromatic odor, which is specially used in unsaturated polyester paint. Gasoline is volatile and flammable, and is mostly used for cleaning paint tools or preparing oil colors and primers. Kerosene is not volatile and cannot be mixed with paint. It can clean lacquer and tung oil tools. Adding sand wax can dilute the sand and make it easy to operate.
2. What is the effect of solvent on paint?
Solvents are an important part of liquid paint formulations. It is closely related to the manufacture, storage, construction and quality of the paint film. Its role is as follows:
(1) Dissolve and dilute the film-forming substances in the paint, reduce the viscosity of the paint, and facilitate the construction of brushing or spraying, dipping, and drenching.
(2) Increase the stability of paint storage and prevent gelation of film-forming substances. At the same time, after adding the solvent, the barrel will be filled with solvent vapor, which can reduce the skinning on the paint surface.
(3) The leveling property of the paint film will be good, and the disadvantages such as brush marks and wrinkling caused by too thick or too thin paint film or poor brushing performance can be avoided.
(4) Solvent is added to the paint, which can improve the wettability of the paint on the surface of the coated object and the adhesion of the permeability-enhanced coating (recommended instrument: paint film adhesion Tester).
(5) The solvent is a volatile liquid, which only dissolves and dilutes the film-forming substance. When the coating film dries, it volatilizes into the air and does not remain in the coating film.
