Natural resin paint (code T) is made of drying vegetable oil and natural resin after thermal refining, adding pigments, driers and solvents. It can be divided into varnish, enamel, primer, putty, etc. This kind of paint is easy to get raw materials and easy to manufacture; it is cheap, convenient to construct, and has good performance; its quickness, gloss, hardness, adhesion, and flexibility are all better than oil-based paints. It can be widely used in wooden furniture . Its main disadvantage is poor durability. The natural resins currently used in the paint manufacturing industry mainly include rosin, shellac and natural lacquer, a special product in my country. The oils used are tung oil, catalpa oil, linseed oil, soybean oil and dehydrated castor oil.
Glycerin rosin is obtained by esterification of rosin and glycerin, and the paint refined with drying oil is called ester paint. Ester glue dries faster and has better gloss; but it has poor water resistance, acid and alkali resistance and weather resistance. Because of its low price , it has become the main variety of natural resin paint for buildings, doors and windows and woodware. Pentaerythritol rosin ester is obtained by esterification of rosin and pentaerythritol, and its performance in all aspects is better than that of glycerin rosin ester varnish. Calcium grease paint refined from lime rosin and drying oil is not as good as ester paint.
Shellac is dissolved in alcohol to make shellac paint, which dries quickly and has poor water resistance. It can be used for wood products and wood products as a primer.
Raw lacquer (lacquer) is the secretion obtained by cutting the trunk of sumac tree. Its paint film is hard and bright, with good acid resistance , oil resistance, water resistance, organic solvent resistance and soil corrosion resistance, good mechanical properties, but not alkali resistance. The lacquer made of raw lacquer and cooked tung oil is called Guangqi or gold lacquer, which is used for wood. Raw lacquer has poor adhesion , high toxicity, and troublesome construction and drying. Urushiol anti-corrosion coatings prepared after modification have good properties, such as urushiol formal resin coatings, urushiol epoxy coatings, urushiol styrene resins and urushiol silicone resin coatings. .
