STUDY ON THE MODIFICATION OF SHELLAC

The paper deals with the research on the modification of shellac by the utilization of tannic acid, rosinate calcium, oxalic acid and ureaformaldehyde resin. Through a lot of tests, the results hsvc shown that the heat resistance and adhesive force of shellac were enhanced by adding tannic acid and rosinate calcium; that the corrosion resistance of shellac was increased by adding ureaformaldehyde resin; that the colour of shellac was improved by adding oxalic acid. The result of "salt-fog" experiment has shown that the corrosion resistance of coat of lac paint was increased by 1.38 times.