The difference between silicone rubber and silicone resin Silicone rubber (English name: Silicone rubber), divided into thermal vulcanization type (high temperature vulcanized silica gel HTV), room temperature vulcanization type (RTV), of which room temperature vulcanization type is divided into condensation reaction type and addition reaction type.


High temperature silicone rubber is mainly used to manufacture various silicone rubber products, while room temperature silicone rubber is mainly used as an adhesive, potting material or mold. The hot vulcanization type has the largest amount, and the hot vulcanization type is divided into methyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ, the most amount and product brand), and methyl vinyl phenyl silicone rubber PVMQ, low temperature resistance and radiation resistance) , Others include silicone rubber, fluorosilicone rubber and so on.


Silicone resin, the scientific name polysiloxane resin (English name: Silicone resin) is a polyorganosiloxane with a highly cross-linked network structure. It has the dual characteristics of organic resin and inorganic material. Silicone resin has unique physical and chemical properties.


Classification of silicone resin Silicone resin is a cross-linked semi-inorganic polymer with silicon-oxygen-silicon as the main chain and organic groups connected to the silicon atoms. It is produced by the direct method of organic silicon monomer silicone resin with outstanding weather resistance, which is unmatched by any organic resin. Even under strong ultraviolet radiation, the silicone resin is also resistant to yellowing.


Silicone resin adhesives and organic silicone adhesives can be divided into silicone resin-based adhesives and silicone rubber-based adhesives according to the source of raw materials. The former is mainly used for bonding metals and heat resistance. Silicone resin is used for iron, aluminum and tin. Such metals have good bonding performance and are easy to bond to glass and ceramics, but they have poor adhesion to copper. Organic silicone adhesive based on pure silicone resin.


characteristic:


Silicone rubber has excellent heat resistance, cold resistance, dielectric properties, ozone resistance and atmospheric aging resistance. The outstanding performance of silicon rubber is its wide use temperature, which can be used at -60℃ (or lower temperature) to +250 ℃ (or higher temperature) for long-term use. However, the mechanical properties of silicone rubber such as tensile strength and tearing strength are poor, and its physical and mechanical properties are not as good as most synthetic rubbers at room temperature. In addition to nitrile silicone and fluorosilicone rubber, general silicone rubber has oil and solvent resistance. It is not good, so silicone rubber is not suitable for occasions under ordinary conditions, but it is very suitable for many specific occasions.


Silicone resin is mainly used as: insulating paint (including varnish, enamel, colored paint, impregnating paint, etc.) to impregnate H-class motor and transformer coils, and to impregnate glass cloth, glass cloth silk and asbestos cloth to make motor casings and electrical appliances Insulated windings, etc. Using organic silicon insulating varnish to bond mica can make a large area of mica sheet insulating material, which can be used as the main insulation of high-voltage motors.


In addition, silicone resin can also be used as heat-resistant, weather-resistant anti-corrosion coatings, metal protective coatings, waterproof and moisture-proof coatings for construction projects, release agents, adhesives, and secondary processing into silicone plastics for use in electronics, electrical and defense industries Above, as semiconductor packaging materials, electronic and electrical silicone resins can be roughly divided into silicone insulating varnishes, silicone coatings, silicone plastics and silicone adhesives according to their main uses and cross-linking methods.


 Silicone resins can include small-molecule organosilicon compounds, and the molecular weight does not have to be large. The silicone rubber must be a polyorganosilane with a certain molecular weight and a rubbery state.


Silicone resin coatings have many shortcomings: poor film-forming properties, including high curing temperature, long time, inconvenient large-area construction, and poor adhesion of the coating to the bottom layer. Modification by fluorination is mainly to increase the solvent resistance, oil repellency (anti-sticking) of the silicone resin and reduce the surface energy. The critical surface tension of silicone resin is lower than that of other resins, but higher than that of fluororesin.