Mold inhibitor is a kind of polymer material additive which can control the growth of mold and kill mold. It can protect the polymer material from erosion and maintain good appearance and physical and mechanical properties. The film forming material of coating is composed of all kinds of natural and synthetic polymer compounds, which must undergo the damage of oxygen, heat, light, chemical erosion and other environmental factors, and can also be damaged by a variety of organisms such as mold. Paint is polluted by microorganism, appear viscosity drops, pigment settles, produce stink, produce gas, container expands, PH value drift and system destroy to wait for a phenomenon, call rot. In solvent - based coatings, the problem of decay is not prominent. Mold erosion of the film, resulting in the film color change, sticky, perforation, damage and peeling, loss of adhesion, affect the protective performance of the film and material clean and appearance, reduce mechanical properties, shorten the service life, causing harm to the environmental health.

The natural high polymer material used in coating contains casein, soybean protein, alginate acid, starch, natural gum, cellulose derivative, fat and other substances that can be absorbed by mold, easy to be infested by mold. Most synthetic polymer materials have strong antibacterial properties. Some varieties (such as polyurethane, polyacrylate, polyvinyl acetate, polyvinyl alcohol, perchloroethylene, vinylidene chloride, etc.) have poor bacterial resistance due to their structures and are easy to be decomposed by molds. Coating auxiliaries (such as plasticizer, heat stabilizer, light stabilizer, organic fillers, colorants, etc.), is not only the nutrition source of mold, many varieties or bacteria, adding these auxiliaries is often the main cause of coating and coating bacteria damage. The dust adsorbed on the surface of the film is also the nutrient source of mold.

The ideal mildewproof agent should meet the following conditions in practical application: it has high killing ability to all kinds of molds that corrode coating and coating film, less dosage, wide application range and lasting effect; Harmless to humans and animals, low toxicity or non-toxic, no irritation to the skin and eyes; Does not affect the physical and chemical properties of the coating and the film; High stability, good heat resistance, light resistance and chemical resistance, less sublimation, not easy to be extracted by water, oil or solvent; Good compatibility with resin and other additives, no harmful chemical reactions; No corrosion or electrical corrosion to metal or various materials; No odor, light color, no pollution; Easy to use, low price. It is difficult, and sometimes impossible, to develop anti-mildew agents that fully meet the above requirements. All kinds of mildew inhibitors themselves have their own characteristics, some aspects show advantages, others show deficiencies. Compound anti-mildew agent can play the synergistic effect of two or more kinds of anti-mildew agents.

With the development of coating industry and the progress of coating technology, the application field of coating is gradually expanding, especially in light industrial household appliances, architectural decoration, ship aerospace, material anti-corrosion and ocean development and other aspects of the application of continuous exploration. The problems of rot and mildew of coatings and films have been paid more and more attention, and the research on mildew inhibitors has been developed accordingly.

The research and development trend of paint anti-mildew agent is: use a variety of anti-mildew agent together, develop compound anti-mildew agent, realize "1+1 BBB 0 2", improve the anti-mildew and sterilization performance, overcome the resistance, extend the period of validity, apply to a wider range, save the development cost of new anti-mildew agent. Develop more efficient, low toxicity, safety, wide spectrum of anti - mildew agents. By means of grafting and modification of active groups, some macromolecular mildew inhibitors are developed to combine with macromolecular materials more firmly, improve physical and mechanical properties of materials, prevent abnormal precipitation of mildew inhibitors from matrix materials, and make the durability of bacteria inhibition and mildew prevention better. The research and development of anti-mildew agent involves many disciplines and industries, such as microbiology, chemistry, material science, dosage form, analysis, information, etc., so it is necessary to strengthen the cooperation of all aspects. All countries in the world are committed to the manufacture and application of compound efficient and safe anti-mildew agents.