In the environment of environmental protection, the water-based coatings in China are developing at an unprecedented speed, and the coatings industry is accelerating the "water-based". Compared with solvent-based coatings, water-based coatings can save a lot of resources, eliminate potential safety hazards, improve the working environment of construction workers, reduce air pollution, and be more beneficial to human health. In addition, the performance of water-based coatings is not inferior to that of solvent-based coatings, and the effect after construction is more natural and rich.

With the emergence of a series of resins such as water-based polyurethane, water-based alkyd resin, water-based epoxy, water-based fluorocarbon, and water-based silicone, the types and properties of water-based coatings have been greatly enriched, especially the advent of solvent-free water-based coatings. The problem of ensuring the function of water-based coatings in the case of solvents can be safely applied even in a closed environment. Among the many types of coatings, silicone coatings have gained widespread attention due to their special properties.
Overview of silicone resin coatings
Silicone resin coating is a kind of elemental organic coating with silicone resin or modified silicone resin as the main film-forming substance, referred to as silicone coating. Elemental organic coatings are a general term for coatings with elemental organic polymers as the main film-forming substance, including organic silicon, organic titanium, organic fluorine, organic aluminum, and organic zirconium coatings. Among them, silicone resin coatings have the largest output. Element organic coatings are a compound between organic polymers and inorganic compounds. They have special thermal stability, insulation, high temperature resistance, chemical resistance, water resistance, and weather resistance. They are widely used in the defense industry. , electrical industry and other industries.
Silicone generally refers to polysiloxane with -Si-O-Si- main bond and organic side chains. Because the main chain of polysiloxane is -Si-O-Si-structure, it has the properties of safety, reliability, non-toxicity, pollution-free, non-corrosion, aging resistance and long service life of inorganic silica; It contains organic groups and has the characteristics of flexibility and easy processing of polymer materials. Silicone coatings are coatings with silicone polymers or silicone modified polymers as the main film-forming substance. They have excellent heat and cold resistance, electrical insulation, corona resistance, radiation resistance, moisture resistance and hydrophobicity, weather resistance, and Contamination and chemical corrosion resistance and other characteristics.
Solvent-free pure silicone resin emulsion and water-based silicone resin special functional coating
Silicone resin has excellent thermal oxidation stability, weather resistance, electrical insulation, water repellency and corrosion resistance, and has been widely used in high and low temperature resistant insulating paints, special coatings, adhesives, film plastics, etc. However, at present, silicone resin high and low temperature resistant insulating paint, silicone waterproof coating and special coating mainly use organic substances such as aromatic hydrocarbons and alcohols as solvents, which will produce a large amount of VOC (volatile organic compounds), which will cause great harm to the environment and human body. Therefore, the water-based silicone resin is the current research hotspot and development trend.
Water-based silicone resin is a silicone resin emulsion that makes silicone resin water-based and uses water as the dispersion medium. At present, it is widely used in silicone-modified coatings, such as silicon-modified acrylic emulsion, silicon-modified polyurethane emulsion, and silicon-modified polyester. Emulsion, etc., the introduction of silicone into traditional polymer emulsion can enhance its performance such as aging resistance, waterproof, high and low temperature resistance, and hardening. By introducing silicone chains into the molecular structure of polymers during emulsion polymerization, the commonly used silicone precursors are silane coupling agents, such as silane coupling agents 171, 560, 570, etc. These silane coupling agents The linking agent is a trifunctional alkoxy structure. In the water phase system, the alkoxy group is hydrolyzed into a hydroxyl group, and the hydroxyl group is further dehydrated and condensed to form a cross-linked structure. When the degree of cross-linking is too large, it will affect the stability of the emulsion and cause a gel. Therefore, there is a certain limit to the amount of silane coupling agent used. Generally, the amount is 1-10%. If the amount is too small, the modification effect will not be obvious. If the amount is too large, it will affect the stability of the emulsion. The limit of the amount determines The effect of silicon modification is limited or even insignificant.
Furthermore, the silane coupling agent undergoes a hydrolysis reaction in the water phase, and by-products such as methanol and ethanol are low-molecular alcohols, which are flammable and toxic components. For water-based coatings, they are VOCs, and VOCs are strictly controlled by water-based coatings. Therefore, the water-based coating modified by silane coupling agent cannot fundamentally solve the problem of low VOC and zero VOC, which will eventually limit the application.
The industrialization of solvent-free pure silicone resin emulsion just solves the above problems. Solvent-free pure silicone resin is the silane coupling agent pre-hydrolyzed and condensed into a solid silicone resin. The solid silicone resin does not contain alkoxy groups, which avoids The release of alcohols, and then adopt a special emulsification process to disperse the solid silicone resin evenly in water to form a stable emulsion. Solvent-free pure silicone resin not only avoids the introduction of solvents but also avoids the release of by-product solvents, and is fundamentally environmentally friendly and zero VOC.
In terms of application, solvent-free pure silicone resin emulsion can be compatible with acrylic emulsion, polyurethane emulsion, polyester emulsion, alkyd resin emulsion, fluorocarbon emulsion, wax emulsion and other emulsions in any proportion, no special production process is required, as long as the dispersion is uniform It can be used immediately without causing gel or demulsification. The unlimited introduction of silicone components can maximize the performance of silicone. It can be formulated with silicon-modified coatings or modified silicone coatings, giving full consideration to the performance of both. .
Solvent-free pure silicone resin emulsion can also be used directly as varnish, and it can be used directly in occasions that require high transparency, such as wood lacquer. Emulsion and polyurethane emulsion have higher hardness, water resistance and stain resistance, and have been successfully applied to concrete, stone, rock wool, clay, wood, paper, cultural relics, metal and other waterproof protection and water-in-water (sand), real stone paint, etc. Exterior wall cladding.
Solvent-free pure silicone resin emulsion retains the properties of solvent-based silicone resin, and can also be formulated with special functional coatings, such as silicone heat-resistant coatings, silicone weather-resistant coatings, silicone insulating coatings, silicone elastic coatings, and silicone waterproof coatings etc. Today, with increasingly higher requirements for environmental protection, water-based special functional coatings undoubtedly have a broader development space.
Solvent-free pure silicone resin emulsion can be cured at room temperature or heat cured. It can be made into a two-component system or a one-component system. It can be used directly or compounded, which fundamentally achieves Healthy, environmentally friendly, green, and efficient are a great innovation in water-based coatings. Solvent-free pure silicone resin emulsion has boosted the rapid development of water-based coatings. It can be said without humility that water-based paints have ushered in the era of water-based silicone resin!

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