3.4 One-component room temperature curing methyl phenyl silicone resin
Most of the conventional methyl phenyl silicone resins require heat curing or a drier to cure. Such a curing method is inconvenient for some specific uses, and is particularly unsuitable for applications of large-area coating and heat-curing. The above-mentioned application process defects can be easily solved by using a one-component methylphenyl silicone resin curable at room temperature. The one-component methyl phenyl silicone resin retains the excellent performance of the conventional methyl phenyl silicone resin, and has the advantages of no need to mix before use and fast curing at room temperature in a single package product.
One-component room temperature curing methyl phenyl silicone resin is a branched silicone polymer having a plurality of hydrolyzable reactive groups. After the silicone resin solution is applied to the surface of the substrate, the polymer absorbs moisture in the air and is active. The reaction group is hydrolyzed to cause a crosslinking reaction of the polymer until the coating film is cured by crosslinking.
In order to smoothly produce room temperature fast curing one-component methylphenyl silicone resin, the following technical key must be solved: 1 The synthetic silicone prepolymer should be excluded from the ring type or cage type silicone inert oligomer to achieve the finished silicone resin. The cured coating film does not return to tack; 2 also requires that the silanol group in the silicone polymer has a sufficiently high subsequent condensation reaction activity, that is, the silicon hydroxyl group retained in the silicone prepolymer should correspond to the methyl substitution position. Instead of the silanol group at the position substituted by the phenyl group, the subsequent condensation reaction is difficult to proceed smoothly due to the steric hindrance of the phenyl group and the electronegativity; 3 special process is needed to avoid the silicone prepolymer and the crosslinker. The condensation reaction of the reaction mixture may occur during the condensation reaction process; 4 the catalyst with moderate activity is selected to ensure the smooth reaction of the high activity silicone resin, and the catalyst does not affect the storage stability of the silicone resin; The type and amount of the agent can ensure the stable storage of the silicone resin without affecting the room temperature rapid curing of the silicone resin.
The economical and practical technical route for rapidly curing methyl phenyl silicone at room temperature can be co-hydrolyzed from methylchlorosilane and phenylchlorosilane in the presence of an organic solvent, and the obtained silanol mixture is washed with water to remove acid, and then The nucleophilic catalytic condensation reaction is carried out to prepare a silicone prepolymer having an appropriate amount of active silicon hydroxy group, and then a suitable crosslinking agent and a selective catalyst are added to further carry out a catalytic condensation conversion reaction to obtain a methyl group having a plurality of hydrolyzable reactive groups. Phenyl silicone branched polymer. Finally, a suitable amount of stabilizer and other auxiliary agents are added, and the solvent is adjusted to adjust the solid content, thereby obtaining a high-performance one-component methylphenyl silicone resin solution which can be rapidly cured at room temperature.
3.5 Silicone molding compound and foam plastic
Make full use of the high insulation and high heat resistance of methyl phenyl silicone resin, add silicone heat-insulating filler to prepare silicone molding compound, and can be used for heat-resistant insulating packaging materials or high-insulation moisture-proof protective materials for high-power electrical components. Considering the cost performance of silicone molding compound products, the economical silicone molding compound should be made of medium and low R/Si and low Ph/R silicone as the base polymer, quartz powder, chopped glass fiber, mica powder, etc. As a filler, mixed mastication, with a curing agent such as a metal organic acid salt, a molding plastic base material is prepared, and a silicone molding plastic product is processed by a transfer molding process.
Silicone molding compound is used for deep processing to prepare silicone foam, which is used to replace expensive polyimide foam for high temperature insulation materials. Starting from the cheap and easily available methylchlorosilane and phenylchlorosilane monomers, firstly obtain a medium-low R/Si solvent-free methylphenyl silicone resin by hydrolysis condensation reaction, adding chopped glass fiber and hollow glass microbeads. The light-weight filler, combined with a suitable foaming agent and curing agent, is processed by a transfer molding process to achieve a simultaneous curing reaction of the silicone resin and foaming of the molding compound to obtain a lightweight high-strength heat-resistant foam plastic.
4 Application prospects and social and economic benefits of high performance silicone resin production technology
Under the guidance of chemical theory, through the in-depth research and development of high-performance silicone resin production technology, the high-performance silicone resin products that have been tested and produced have achieved the expected results in practical applications, among which some high-performance silicone resins Played an important role in the defense military support.
High-performance silicone production technology opens up a new line of low-cost, high-performance silicone synthesis. Compared with traditional silicone production technology, the application of new technology not only produces high-performance silicone products, but also significantly reduces energy consumption and reduces organic solvents. Emissions. Expanding the flexibility to use these new technologies, it is also possible to synthesize and improve many types of high performance silicone new products.
Research and development of high-performance silicone resin, making greater contributions to the development of science and technology in China.
Contact：Sharon Song(Sales manager)
Zhejiang Runhe Organosilicone New Material Co.,Ltd(Factory)
Zhejiang Runhe Chemical New Material Co.,Ltd(Exporter)
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