Among the existing heat-resistant adhesives, silicone adhesives are one of the excellent varieties. Silicone adhesives can be classified into several types, including high-temperature-resistant adhesives, heat-resistant sealants, high-temperature-resistant strain adhesives, and heat-resistant pressure-sensitive adhesives. So, what are the applications of silicone adhesives?
Polysiloxane is a linear polymer composed of alternating silicon and oxygen atoms. After cross-linking and vulcanization, it has excellent properties such as resistance to high and low temperatures, resistance to atmospheric aging, electrical insulation, and elasticity. It can be used for a long time within the temperature range of -60°C to 200°C, and its physical and mechanical properties change very little. Therefore, it is widely used in industries such as construction, electronics, automobiles, packaging, and medical and health care, showing an excellent development trend. The applications of silicone adhesives and sealants are constantly expanding, and the varieties and usage amounts are also increasing year by year.
The siloxane in silicone resin can react with compounds containing hydroxyl groups, such as epoxy resins, phenolic resins, and polyesters. Therefore, these compound resins can be used to modify silicone adhesives.
Silicone adhesives with pure silicone resin as the main material generally use xylene as a solvent and are made by adding inorganic fillers such as asbestos powder, mica powder, titanium dioxide, and zinc oxide. It cross-links, polymerizes, and cures at a high temperature (270°C), has excellent high-temperature resistance, and can be used for a long time at 400°C. It is suitable for non-structural bonding and sealing at high temperatures.
Pure silicone resin adhesives are inconvenient to use due to their high curing temperature and have low bonding strength, so they can only be used as non-structural adhesives. By utilizing the -OH groups in epoxy resins, phenolic resins, and polyesters, which can react with the siloxane in silicone resin, these resins can be introduced for modification. In this way, the high-temperature resistance of silicone resin adhesives can be maintained, while their curing temperature can be reduced and the bonding strength can be improved.
Silicone resin can be used for anti-sticking jackets of rollers and is widely used in various fields such as the textile industry, printing and dyeing industry, paper-making industry, rubber processing, and plastic processing for the anti-sticking coatings of rollers, molds, pipelines, the inner walls of engines, food machinery, hoppers of printing machinery, frying pans, and baking trays, as well as the anti-rust and lubricating coatings of safety razors. Comparison between fluororesin non-stick coatings and silicone resin non-stick coatings: The former has disadvantages such as a high curing temperature, a complex construction process, low film gloss, and a single color, so its application range is limited; silicone resin non-stick coatings have advantages such as a relatively low curing temperature, high gloss, variable colors, and convenient coating, and are also very popular among users in actual construction applications. Of course, fluororesin non-stick coatings have a slight advantage over silicone resin non-stick coatings in terms of non-stick properties.
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