Air-dry colors based on cellulose nitrate are called instant colors, instant colors consist of two resin parts; Cellulose nitrate lacquer and short oil alkyd resin plasticizer.
Cellulose nitrate varnish includes a solution of solid cellulose nitrate granules or fibers that are dissolved in ester, ketone and alcohol solvents and produce a viscous resin called nitrocellulose varnish.
Due to its high polarity and high tg property, the varnish dries immediately at ambient temperature, but it will be very fragile, that’s why they are modified by a plasticizer resin.
The resin that has the role of plasticizer is short oil alkyd resin, short oil alkyd resin, which has a polar polyester structure and less fatty acid, is compatible with nitrocellulose lacquer and thus produces nitrocellulose paints.
The main short oil resins used in instant paints are based on soybean fatty acids, tall oil, coconut and castor oil, and soybean is the most widely used because soybean fatty acid has some of the positive properties of an alkyd resin.
In the production of instant coating colors, pigments and extenders are always added to the alkyd resin, and the nitrocellulose lacquer will be mixed with them as the second part.
On the basis of nitrocellulose paints, various coatings are produced in the paint industry, which include lacquers and instant glossy and matte paints, putty and instant sealers for use in the furniture industry, and also include the production of matching colors and repair car linings.
One of the advantages of instant paint is their easy use and quick drying, and with a suitable formulation, you can have good adhesion and surface hardness of them, but one of the disadvantages of instant paint is their weak light resistance, because of this, the structure of cellulose nitrate is susceptible to sunlight. It breaks apart and shows itself as yellowness, that’s why instant paints are mostly used indoors and away from sunlight or car lining.
