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At present, domestic users’ blind admiration for foreign preservatives and antifungals places significant pressure on domestic manufacturers of such products. It is difficult for domestic preservative products to gain a larger share of the market. In an effort to expand their market share, domestic manufacturers have driven down prices, which in turn has led to a decline in product quality. The preservative industry has thus fallen into a vicious cycle: price cuts lead to a drop in quality, and the resulting decline in quality again forces further price cuts. Do domestic preservative manufacturers really have to take this path? Are domestic preservatives really that bad? In my opinion, working in the field of preservatives is just like working in the pharmaceutical industry. Pharmaceuticals should be made with integrity; there’s no need to pursue low prices to meet market demands. What matters most is product quality. It’s necessary to invest adequately in research and development, and to have the capability to solve all the problems that clients encounter in the field of preservatives! It is absolutely impossible to pursue a path of disorderly competition based on low prices and low quality, as this will ultimately harm all Chinese factories that use preservatives! What is often overlooked here is the fact that preservatives are one of the most crucial ingredients in determining product quality; if preservation fails, even the best products will end up as worthless, stinky messes with nowhere to be disposed of ! As a manufacturer in the preservative industry, we have been committed to developing new products and improving existing ones. At present, our product series can be used in over 20 water-based and oil-based systems. In addition to careful selection of materials, we place emphasis on the beneficial effects of the ingredients in the formulations. The concentration of antibacterial components has been significantly increased compared to similar products available in foreign markets, taking into account the current usage trends of preservatives and antibacterials in the domestic market. Meanwhile, a range of new and practical preservatives have been developed, such as those for wood preservation. We can assure our clients that we are able to design practical anti-corrosion solutions for them, as well as address any anti-corrosion failure issues that may arise in the industry! The following are merely some insights summarized by our company’s after-sales service and R&D departments, for your reference only. If you have any better suggestions, feel free to contact us! Special Topic on Anticorrosive and Antifungal Agents in Water-Based Coatings I. The Role of Anticorrosive and Antifungal Agents in the Coating Industry Anticorrosive agents prevent coatings from being damaged by bacteria and molds during storage in drums or tanks; hence they are known as intra-tank anticorrosive agents. If coatings are to be stored in drums for an extended period of time, it is necessary to add such anticorrosive agents. Mold inhibitors are substances that ensure the paint film does not develop mold over a period of 5-10 years after application; they are known as dry-film mold inhibitors. High-end coatings not only require the use of preservatives but also include antifungal agents to enhance their antifungal performance after being applied to walls, thereby raising the overall quality of these coatings; this has made them the mainstream in the coating market. II. The importance of adding preservatives and antifungals to paints. Paint preservatives are the most crucial among paint additives; if preservation fails, the entire quality system of the paint will collapse. However, due to the low amounts of preservatives and antifungals used, as well as insufficient promotion of their use in China, paint manufacturers do not fully recognize the importance of these substances. As a result, corrosion failures occur frequently, causing significant losses to both paint manufacturers and those who use the paints. III. Main factors leading to the failure of paint corrosion protection. Due to the presence of nutrients such as water and cellulose in the paint system, if the preservatives do not eliminate bacteria thoroughly, or if secondary contamination occurs due to inadequate packaging after sterilization, it can lead to problems with the paint. This is especially true in hot summer conditions, when the paint is more prone to such issues. Generally, when paint is stored in a bucket, there is air at the top; this air contains bacteria. In hot summer conditions, these bacteria become more active. Especially when the paint is stored outdoors, and there are temperature differences between day and night, the air at the top of the paint container condenses into water droplets that fall into the paint. These droplets contain a large number of bacteria. If the amount of preservatives in the paint is not sufficient to eliminate these bacteria, it can lead to the failure of the entire paint system. Furthermore, it is clear that the deterioration of the coating begins first at the surface of the coating and in those areas of the packaging container where the seal is not tight; in such places, the coating has usually already turned black. Furthermore, after the paint is applied to the walls, if a dry-film antifungal agent is not used, bacteria will attack the paint film under suitable temperature and humidity conditions, causing mold to grow on the walls and turning them black. This leads to the peeling of the paint film, as well as an unclean and unsightly appearance of the entire area. In underground garages, air-raid shelters, ships, hospitals, biological laboratories, pharmaceutical factories, as well as in humid and hot environments in the south, coatings with mold inhibitors must be used to extend their performance and service life. IV. Strategies for effectively protecting coatings 1. Use relatively clean packaging drums with inner bags as much as possible; it is even better to apply a layer of paint inside the drum. Some coating manufacturers in Shanghai are already using this method, and it has proven very effective. Additionally, a sealed package must be ensured! Store at room temperature, avoiding direct sunlight. 2. Use long-acting and potent fungicides. The commonly used Carson has the following insurmountable defects: it can only be used at temperatures below 40°C, and its decomposition is accelerated at temperatures above 50°C. The pH at which carbosun stabilizes is 2–4; once it is added to the coating system, the ambient pH rises to 7–9, accelerating its decomposition. Therefore, after being added to the coating system, Casson can provide immediate sterilization, but it decomposes very rapidly as well; generally, its half-life is reached within 24–48 hours, after which it loses its protective effect on the coating. Regarding antifungal agents in coatings, those in the form of an emulsion with a particle size of 7–10 microns are generally used. The smaller the particle size, the more evenly the antifungal agent is dispersed within the coating per unit weight; this results in a denser protective network formed by the antifungal agent once the coating is applied to the wall, thereby enhancing its effectiveness. Generally speaking, mold inhibitors in pure liquid form can be used on interior walls, but when applied to exterior walls they cannot withstand the impact of rain and tend to wash away, such as Rohm and Haas’ M-8. Rocima 361 from Rohm and Haas is an excellent antifungal agent, but its active ingredient content is 20%, with a dosage range of 0.5%–1.2%. 3. Mainstream preservatives and antifungals – TD Preservative series: These products contain a formaldehyde-release-controlled bactericide in their formula; the free formaldehyde content is 0.07%. An addition level of 0.1% does not cause the formaldehyde level in the paint to exceed 100 ppm. Once added to the paint formulation, in addition to killing bacteria within the paint itself, the slowly released formaldehyde rises into the air above the paint container, where it kills any bacteria present there, thereby keeping the entire system sterile or inhibiting bacterial growth. For example, 6D®LFM is equivalent to LFM from German company Corning ； Additionally, the DF series products from German Sumei also fall into the same category. However, due to the strict regulations on formaldehyde content in China, most domestic paint manufacturers are not optimistic about this type of bactericide that releases formaldehyde slowly. TB preservative series products: TB20 is an environmentally friendly bactericidal and preservative agent based on a water-based matrix and represents the next generation of such products. It contains no metal ions, volatile solvents, formaldehyde, or other highly toxic substances. It is widely used in water-based emulsions, latex paints, water-based adhesives, household cleaning products, inks, papermaking and paper sizing agents, metal cutting fluids, and color pastes. The recommended addition amount is 0.05–0.1% (W/W) ； At addition levels of 0.2–0.5% (W/W), it can provide immediate sterilization of ** aqueous systems, and effectively remove the colors and odors caused by **, making it the most effective sterilant available today. CD50 antifungal agent series: The CD50 antifungal agent builds on the excellent antifungal formula of Rohm and Haas’ Rocima 361; it contains no metal ions, volatile solvents, formaldehyde, or other highly toxic substances. While maintaining the same level of antifungal efficacy, its active ingredient concentration has been increased from 20% to 50%. The addition amount is 0.15–0.8%, and it includes effective fungicidal and algicidal components. It is widely used in water-based emulsions, latex paints, and water-based adhesives. V. Precautions for using preservatives and antifungals: 1. It is necessary to ensure that they are added separately, and not mixed with other additives, to avoid chemical reactions that could render them ineffective! This phenomenon of mixing things together is quite common. 2. Anticorrosives and antifungals are biocides; avoid contact with skin. If contact with skin occurs or if it gets into the eyes, rinse immediately with plenty of water! No delay! 3. Anticorrosives and antifungals should be added as far as possible at the final dispersion step in coating production to ensure effective dispersion. The temperature of the system should not exceed 40°C when adding it. 4. When using preservatives and antifungal agents, it is necessary to carefully read the product instructions and determine the optimal dosage based on experimental conditions, so as to achieve the desired preservative and antifungal effects without waste!