1. Meet increasingly stringent environmental and technical regulations
2. Waterproof coating additives
3. Anti-graffiti additives
4. Coating additives that promote self-cleaning of coatings
5. New Nanotechnology
With the continuous enhancement of people's awareness of environmental protection and the improvement of daily life, countries around the world pay more and more attention to the water-based architectural coatings. Relevant regulations have been formulated to strictly limit the content of volatile organic compounds in architectural coatings. The proportion of solvent-based coatings is getting smaller and smaller, and water-based architectural coatings are replaced.
With the emergence of various buildings, especially high-rise buildings, functional architectural coatings have attracted more and more attention from the whole society. Functional architectural coatings mainly include fire-retardant coatings, waterproof coatings, anti-mildew and insect-proof coatings, anti-rust and anti-corrosion coatings, anti-static coatings, sound-absorbing (absorbing) coatings, heat-insulating coatings and elastic functional coatings. Among them, additives can give coatings many special functions, and the product quality and development level of additives also reflect the product quality and development level of coatings from the side.
Development Trend of Waterborne Coating Additives
1.
Meet increasingly stringent environmental and technical regulations
With the increasing awareness of the use of industrial raw materials that meet ecological and environmental protection requirements, coating raw material suppliers are also required to meet more and more environmental and legal regulations, and organic solvents in various coating systems are gradually being replaced by water. This recent trend is reflected in industrial coatings and transportation vehicle coatings, previously traditional high-gloss solvent-borne high-gloss acrylics, urethane-acrylics and urethane-poly Ester resins are now being gradually replaced by various water-based resins and composite modified resins.
2.
Waterproof coating additives
Building waterproof coating is a waterproof functional coating for building exterior walls. It is to apply the coating alone or in combination with reinforcing materials or layered construction on the base surface of the exterior wall that needs to be waterproofed, which can form a certain continuous and seamless whole with a certain thickness of the coating film waterproof layer, so as to meet the needs of industrial and civil buildings. The waterproof and anti-penetration requirements of roofing, underground engineering, floor and other parts. At present, conventional waterproof coatings are still mainly based on the properties of film-forming substances, such as polyhelium ester two-component curing, one-component moisture curing, spraying polyurea, acrylic emulsion and modified asphalt, etc. more mature development. The use of additives to give architectural coatings waterproof function is still a relatively new research topic. There are two advantages to the modification of coatings by additives. First, if it has reactive end groups, it can react and graft with the film-forming resin to obtain a lasting modification effect; second, if it is used as a post-addition, the film-forming resin will The selection range is widened, and the composite performance of the coating can be imparted through the synergistic effect of various additives.
Additives are one of the important core raw materials of coatings. Generally speaking, the proportion in the overall formulation of the coating usually does not exceed 1% of the total. Although its proportion is not large, its role is very core and crucial. It can not only reduce various quality and performance defects and the disadvantages of coating films for ordinary coatings, but also improve the production stability, storage stability, construction stability and various physical properties of coatings during production, construction, transportation and storage. good control. Adding water repellent additives to the paint can give the paint hydrophobic and water repellent effects. It is mainly to use some special modified surface active substances with low surface energy to reduce the surface energy of the coating film, or to form a directional arrangement of the eversion of hydrophobic groups on the surface of the coating film, forming a lotus leaf effect, and realizing the water-repellent and hydrophobic effect of the coating film. , so that the retention of water droplets can be reduced after the construction of the outer wall, the water resistance of the wall is greatly improved, and the service life will be prolonged.
3.
Anti-graffiti additives
Anti-graffiti coatings are also one of the hot topics of research in recent years, ranging from anti-fouling of marine hulls, anti-graffiti of building exterior walls, anti-ballpoint pen scribbling for household sofas and mattresses, anti-oil pollution of kitchen ceilings, and surface protection of automobiles and subways. have been widely used. Anti-graffiti coatings can minimize the damage to the coating and even the surface of the substrate due to wanton graffiti. The coating can be applied to the inner and outer surfaces of ships, vehicles, interior and exterior walls, furniture and boards, etc., without affecting the appearance of the original surface of the coating. The data shows that in the past few years, due to the continuous growth of the demand for anti-graffiti coatings in the United States, Canada, and Mexico, North America is the main market for anti-graffiti coatings in the world, followed by Europe, Asia-Pacific, South America, and the Middle East and Africa. Moreover, North America is expected to be the fastest growing region for the anti-graffiti coatings market in the coming years owing to the increasing demand for anti-graffiti coatings in North American countries.
The demand for coatings is also increasing with the improvement of people's living standards. According to the protective characteristics, it can be divided into sacrificial anti-graffiti, semi-permanent and permanent anti-graffiti coatings. The sacrificial anti-graffiti generally uses paraffin wax. After the surface of the coating film is contaminated, dissolve the paraffin wax with a solvent or hot water to remove the paraffin wax and the graffiti together; once this method is used, the surface of the substrate needs to be coated again, and the cost is relatively high. high. The semi-permanent anti-graffiti mostly uses acrylic resin, epoxy or polyester resin. After cross-linking, it realizes the anti-graffiti function and can resist more graffiti. The more severe it is, the final film will lose its anti-graffiti properties. Compared with semi-permanent coatings, permanent anti-graffiti coatings have longer coating life and more durable anti-graffiti performance; they are generally realized by fluorine and silicone resin, and the mechanism is also to impart low surface energy to the coating film, making it water-repellent and water-repellent. Oil, oil-resistant pens or ballpoint pens can also make it easier for ice and snow to collect on the surface for easy cleaning. The continuous growth of the market has also brought new developments to anti-graffiti additives, and various additive companies have launched additives with anti-graffiti properties. The principles of this are roughly divided into two types: one is realized by filling with nanomaterials, and the other is realized by using low surface tension substances such as silicone and fluorine. The latter is more commonly used, which is easier to add to In coatings, it is easy to construct, and there are reactive silicone additives directly involved in the curing of film-forming substances. There are two types of anti-graffiti additives: reactive and additive. The advantage of the reactive type is that it is grafted with the resin to form a denser and more durable film, but the hardness of the film is higher, and the transparency of the coating film is easily affected. The advantage of the additive type is that a low dosage can achieve a good anti-graffiti effect. Low dosage has little effect on the transparency and gloss of the coating film, but the migration will be stronger, resulting in the durability of the anti-graffiti performance of the coating film. be negatively affected.
4.
Coating additives that promote self-cleaning of coatings
Urban environmental pollution is increasing, among which dust pollution and gas pollution are particularly serious. The facades of high-rise buildings, a major landscape of the city, are being eroded more and more seriously. Building exterior paint can beautify the environment and rooms, but due to the poor washability of traditional paints, the walls will become mottled after a long time.
According to the self-cleaning principle of lotus leaves, through the selection and modification of inorganic particulate materials with special structure and morphology, the coating can form microscopic concave-convex morphology on the coating surface during the drying and film-forming process. The microscopic coating surface with concave-convex morphology can not only make dust particles adhere to the coating surface in a suspended state, greatly reduce the force between the dust particles and the coating surface, but also greatly increase the contact angle between water and the coating surface. It is conducive to the rolling of water droplets on the surface of the coating; at the same time, according to the self-layering principle of the coating, hydrophobic substances are introduced into the emulsion, so that the coating can be automatically layered during the drying process of film formation, thereby enriching a layer on the surface of the coating. The hydrophobic layer is beneficial to further reduce the force between dust particles and the coating surface and further improve the contact angle of water to the coating surface. Finally, the accumulated or adsorbed polluting particles can be separated from the coating surface under the erosion of wind and rain to achieve the purpose of self-cleaning.
5.
New Nanotechnology
An important direction for the development of fungicides for architectural coatings in the future is the use of nanotechnology.
Most of the current preservatives and antifungal agents are organic compounds, which have more or less certain side effects on the human body. The development of nanotechnology has brought the technology of antibacterial agents into a new era. Nanometer TiO2, ZnO and other nanomaterials are non-toxic to human body, have a wide range of antibacterials and excellent thermal stability. The mechanism of action of nanomaterials is based on photocatalytic reaction to decompose organic matter and play an antibacterial effect. Under sunlight and in the presence of air and water, atomic oxygen and hydroxyl radicals are generated, which can react with organic matter in bacteria to generate carbon dioxide and water. , with anti-mildew and antibacterial comprehensive effect. For example, the nano antibacterial powder can be widely used in indoor walls, hospitals, food workshops, etc. Some countries have begun to develop silver antibacterial nanomaterials, which can effectively kill microorganisms at a certain concentration of silver ions.
