silicone products have high, low temperature performance is good, can generally work at 180℃high temperature for a long time. Silicone rubber can also work longer hours at 250 ℃, instantaneous power more than 1000 degrees Celsius temperature. Organic silicon material low temperature resistance performance is good, can still work at -55 ℃. Some silicone rubber has elasticity at -110 ℃. Have very good electrical insulation properties of silicone materials, dielectric properties do not change with temperature changes; dielectric constant does not vary with the frequency increasing numerical; and arc resistance, corona resistance, leakage resistance; ozone resistance, radiation resistance, weather resistance, flame retardant, therefore, use a very wide range of. According to the following several kinds of silicone products, which gives a brief introduction of the part of the main purpose:
1. Silane coupling agent silane coupling agent is a kind of low molecular compounds, is connected with one end of the silicon atom is capable of hydrolyzing chlorine or alkoxy, hydrolysis can be connected with the inorganic matter; the other end groups can have various interaction with organic compounds, such as amino acid, vinyl, thiol, the silane coupling agent can be bridged by organic and inorganic substances. Silane coupling agent commonly used nearly 100 species. Such as coupling agent for FRP glass fiber to use containing vinyl to improve the wet strength. The current popular " green " tire on the large-scale use of silane coupling agent containing thiol; polyethylene vinyl three alkoxy silane crosslinked, its working temperature than the ordinary polyethylene and polyvinyl chloride is high, suitable for hot water, cable sheath.
2. Silicone oil, silicone oil is a low molecular polysiloxane containing single or different organic groups, and can be made into various viscosity. The low surface tension of silicone oil, and water contact angle is large, high-quality water repellent material. Temperature coefficient of viscosity change of silicone oil, will not be solidified under low temperature, base oil, aviation spacecraft is high temperature resistant and low temperature resistant oil, antifreeze and the gyroscope heat-resistant lubricating oil, hydraulic oil, oil and other instruments, and the vapor pressure of high vacuum diffusion pump oil low. Application of organic silicone oil or its modified agent in cosmetics in recent years is growing fast. Silicone oil paint on the skin is not greasy, feel smooth, comfortable, can be made of a variety of skin cream.
3. According to thesilicone rubber vulcanization mechanism, silicone rubber can be divided into high temperature vulcanized silicone rubber ( HTV ); room temperature vulcanized silicone rubber ( RTV ) and additional liquid silicone rubber ( LSR ), with comprehensive performance characteristics of heat resistance, cold resistance, resistance to ultraviolet radiation, ozone, atomic oxygen resistant, resistant to cosmic rays and waterproof, shock-proof etc.. LSR liquid silicone rubber ( also known as silicon gel ) is sealing and protection materials semiconductor chip and electronic device excellent; light transmittance of silicone gel reaches as high as 91% is the middle high temperature resistance, moisture resistance, not yellow aircraft three windscreen adhesive layer. LSR silicon rubber mould glue used in precision casting of engine parts. HTV and RTV production accounts for a large share in the silicone products ( usually accounts for 40% ~ 50% ), the use of HTV than RTV. ( 1 ) RTV at room temperature curing silicone rubber RTV is generally low molecular weight silicone hydroxyl terminated ( 107 gel ), with fillings such as catalyst, made of two-component or single component, the use of silicone rubber is convenient and can be cured at room temperature, of glass, ceramics, metal bond, concrete and other materials good adhesion, is widely applied in full view of glass curtain wall, aluminum alloy doors and windows and other structural parts of the seal, and the family bathroom, restroom, plugging and sealing. RTV silicone rubber based ablative heat insulating coating small thermal conductivity, convenient construction, used for nozzle rocket and returns the type of space vehicles from ablation, important material but also the production of spacecraft components. Flexible die RTV silicone rubber or various artistic carved decorative building materials. ( 2 ) HTV high temperature vulcanized silicone rubber HTV is high molecular weight ( 400000 ~ 800000 ) of the polysiloxane, adding reinforcing filler and other additives, curing, forming cross-linked rubber. High-voltage HTV silicon rubber composite insulators used, not only the weight of only porcelain insulator of 1/5 ~ 1/10, easy to use, and high pollution flashover performance is good, can operate safely in the high-voltage power grid. Using carbon black as conductive medium HTV silicone rubber used as key pad, widely used in mobile phone and computer keyboard; silicone rubber gasket seal, a lot to manufacture, oil seal, industrial rubber roller, rubber shock absorber, insulation products, medical products. Silicon rubber insulated flame-retardant wire, cable for ships, aircraft and other requirements of high reliability. Silicone rubber has physiological inertia, no clotting, easy disinfection and other characteristics, can be made of silicon rubber parts can be implanted in the human body and various silicone rubber catheter intubation, long time use, hydrocephalus drainage tube, peritoneal dialysis tube, as well as the artificial heart lung machine blood transfusion pump etc.. In addition silicone rubber has the permeability, gas permeability is different in different. Oxygen transmission rate in synthetic polymers is the highest, the gas can be enriched membrane, membrane separation.
4. Insulation material made of silicone resin with heat resistance and good insulating property and belongs to class H, motor volume production of small, light weight, high reliability, in the short-time overheating, overload condition will not burn. Silicone resin and preparation of 500 degrees high temperature resistant coating; modified acrylic resin coatings of good weather resistance, and hydrophobic, anti-pollution, advanced coatings for exterior wall. The microswitch silicon Plastic silicon resin system for aircraft engine with high voltage, high current, arc resistance. In use of silicone materials is very extensive, the effect is very significant. ( three ) a lot of silicone products silicone products category, can be roughly divided into five categories, namely: 1 high temperature vulcanized silicone rubber has the most commonly used methyl vinyl silicone rubber, silicone rubber, cold resistance, oil resistance, solvent resistance of fluorosilicone rubber and nitrile silicone rubber, radiation resistant phenylene silicone rubber. For ease of use often to prepare compound is provided to the user. 2 room temperature vulcanized silicone rubber by packaging forms two component and single component of. Two component consists of methyl, phenyl, nitrile silicone, fluorosilicone, phenylene points; divided into acid type, dealcoholization type of single component, oxime, amine removal, deamidation, ketonic type etc.. 3 silicone oil, silicone oil can be divided into methyl silicone oil, silicone oil, ethyl methyl phenyl silicone oil, amino silicone oil, methyl hydrogen silicone oil, chlorinated phenyl silicone oil, silicone oils, nitrile silicone oil, silicone oil, long chain alkane oil diffusion pump and modified silicone oil. There is a large amount of silicone products, namely, silicone oil emulsion, such as fabric treatment agent as an example.
5. Silicone resin according to the composition can be divided into methyl silicone resin, methyl phenyl silicone resin; according to the forms of solvent type, solvent free. Silicone resin has made coating, molding powder and modified. 5 according to the functional classification of silane coupling agent, silane coupling agent are vinyl silane, amino silane, epoxy silane, mercapto silane and methacryloxy silane.