Modification of Pigments and Fillers with Silane*(IV)
Silane coupling agent treats pigments or fillers so that they are easily wetted by the base material. Pigments or fillers are dispersed stably in the base material to prevent precipitation and agglomeration. After the filler surface is modified by silane coupling agent, the viscosity of the coating decreases greatly. Even if the amount of pigments or fillers is increased, the flow of the coating will not be affected, and the output of the coating will be increased and the production cost will be reduced. Silane can be used as a surface modifier when the organic functional group of silane is not a reactive group but a silicon-based bond. The hydrophilic surface of most mineral fillers and pigments can be changed into vegetable water surface, which can improve the compatibility with organic resin on vegetable water surface. When alkyl silane is combined with the surface of filler particles, the water-vegetable interaction can make it easier to disperse in the resin. Silicon and aluminium hydroxide minerals are mostly easy to combine with alkoxysilane. Silica (which can produce smoke and precipitate), glass beads, quartz, sand, talc powder, mica, clay and silica lime can be effectively treated by silane coupling agents in filler polymers. Other metal hydroxides, such as magnesium hydroxide, iron oxide, copper oxide and tin oxide, have been treated with these chemicals with good results: - - increasing adhesion between minerals and polymers - - - enhancing waterproofing through surface polymers - - - enhancing dispersion of minerals in polymers - - - enhancing electronic properties - - - increasing Strong mechanical properties - reduce the filler / polymer mixture of the viscous silane used in acrylic emulsion synthesis and waterborne coatings: with the progress of society, people's quality of life improved, for environmental protection requirements, coatings increasingly require water as solvent. Although silane hydrolyzes in the presence of water, this does not mean that it can not be used in water systems at all. For example, DB-550 aminosilane is a very good bonding promoter and hardener. It is completely soluble in water, very stable in aqueous solution, and has a variety of organic resin phase agents. Organic functional silane is used in acrylic emulsion synthesis and waterborne coatings. The advantages are: - improve water resistance and solvent resistance; - improve scrubbing resistance, scratch resistance and abrasion resistance; - improve durability and anti-aging performance; - improve adhesion and hardness. Acrylic ester and styrene monomer can be copolymerized with silane to synthesize silylated acrylate emulsion, so that it can be made into room temperature crosslinking curable acrylate coatings. In the emulsion synthesis containing acrylate and styrene, it is generally recommended that 151 vinyl triethoxy silane 172 vinyl three (methoxy ethoxy) silane 570. Methacryloxypropyl trimethoxysilane (vinyl triisopropoxysilane silane) is a vinyl silane monomer used for crosslinking acrylic acid and vinyl latex. It can be used in OEM products and building coatings. The silane is easily copolymerized into the backbone of acrylic acid and vinyl latex. Hard and highly cross-linked coatings can be obtained after curing with a formula containing the recommended catalyst. The unique structure of the silane enables it to have good stability in the water-based system and does not react or cross-link before the coating is condensed. The water-based coating formulation containing vinyl three isopropyl silane silane is stable and effective after one year of aging. The product recommendation: the typical step of emulsion synthesis: the reaction is highly exothermic. Typically, only a few copolymer premixes are polymerized in the reactor, and then the remaining parts are slowly added from a buffer tank. Typical steps are as follows: 1. Water, surfactant and retarder are added to the reactor. 2. Adding 5%-10% copolymer premix (without silane) to the reactor. 3. Heating the mixture above to the optimum temperature that the manufacturer has, the typical temperature is controlled at about 65-75 degrees Celsius. 4. Adding all the catalysts and initiators to the reactor. 5. Controlling the adding rate of residual copolymer monomer premix to the reactor, the typical time range is 4-6 hours. 6. Additional silane is added to the buffer tank when the pre-mixture of copolymer monomer is still 10%. The silane and the remaining 10% copolymer monomer premix were completely mixed and continued to be added to the reactor at the controlled rate. 7. After adding the pre-mixtures of copolymer monomers, enough time is maintained to obtain the maximum degree of polymerization. Note: 1. Delayed monomer polymerization is used to improve the properties of the emulsion. 2. If the typical dosage of 151, 172 and 570 is less than 1% of the total weight of the monomer, higher dosage may reduce the storage life of the product.
Conversion from Ipax Coupling Agent