Preparation method of rosin-base coating agent

• Main Authors: ZHU TAIHAI, TIAN YUTING
• Format: Patent
• Language: Chinese; English
• Published: 10.09.2021
• Subjects: CHEMICAL RIPENING OF FRUIT OR VEGETABLES; FOODS OR FOODSTUFFS; HUMAN NECESSITIES; PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT,VEGETABLES, EDIBLE SEEDS; THE PRESERVED, RIPENED, OR CANNED PRODUCTS; THEIR TREATMENT, NOT COVERED BY OTHER CLASSES

The invention discloses a preparation method of a rosin-based coating agent, which comprises the following steps: weighing the following components: rosin, unsaturated acid, polyol, a catalyst, shellac resin, dry oil and a solvent; heating rosin until the rosin is molten, adding unsaturated acid while stirring, and performing reflux reaction for 1-4 hours to obtain a rosin adduct; and slowly adding polyol and a catalyst into the rosin adduct, and performing reflux reaction for 1-6 hours to obtain the rosin ester. Accordiong to the invention, after the shellac resin is modified by a polymer containing the basic group and an unsaturated acidified dry oil, carboxyl and hydroxyl of the shellac can be closed, so that the shellac loses the opportunity of esterification and cross bond generation, the problem that white spots appear on a film layer in a high-temperature and high-humidity environment is fundamentally solved, and meanwhile, the prepared coating agent is easily dissolved in an alcohol solvent, and neutr