(1) Neutral curing silicone rubber, which has good bonding strength and sealing performance for most materials, and has good high and low temperature resistance. The temperature ranges from -45 °C to 350 °C, and the electrical performance is excellent. It is widely used for bonding and sealing industrial and electronic appliances.
Sealant can replace imported oil-resistant sealant. It is used for all automobile manufacturers, agricultural vehicle factories, forklift factories, diesel engine factories, shipyards and other manufacturers. It can be used in the sealing of oil, gas and water in electric power, chemical industry, machinery, gearbox, oil tank, oil bottom, cork mat, front and rear axle, front and rear end caps. It is also suitable for detachable seals on engines, pumps, valves, gearboxes, gearboxes, etc., for joint surfaces or flanges, and for detachable thread seals.
The adhesive has strong interstitial ability, anti-aging and surface curing of less than 20 minutes. In addition, the structure of the silicone product contains both "organic group" and "inorganic structure". This special composition and molecular structure make it combine the properties of organic matter with the function of inorganic substances, and has high and low temperature resistance. It has many excellent properties such as weathering resistance, electrical insulation, ozone resistance, water repellency, flame retardancy, non-toxicity, non-corrosion and physiological inertness. Some varieties also have oil, solvent and radiation resistance.
Compared with other polymer materials, the most outstanding properties of silicone products are: excellent temperature resistance, dielectric properties, weather resistance, physiological inertness and low surface tension; shockproof and moisture-proof bonding of various signs; mechanical and chemical equipment sealing of flanges; sealing of threaded pipes and screws.
(2) Silicone sealant can be divided into two types: silicone resin
and silicone rubber as the binder. The chemical structure of the two is different. Silicone resin is composed of a three-dimensional structure with a silicon-oxygen bond as the main chain. It can be further reduced to high-strength hard and brittle resin at high temperature, and silicone rubber is a linear type with a silicon-oxygen bond as the main chain. Relative molecular mass rubbery materials, with relative molecular masses ranging from tens of thousands to hundreds of thousands, must be condensed into elastomers with several cross-linking points under the action of curing agents and catalysts. Silicone sealant is characterized by high temperature resistance, low temperature resistance, corrosion resistance and radiation resistance. It also has excellent electrical insulation, water resistance and weather resistance. It can bond metals, plastics, rubber, glass, ceramics, etc. It has been widely used in the bonding and sealing of space navigation, aircraft manufacturing, electronics industry, machining, automobile manufacturing, and construction and medical. (1) Silicone resin: Silicone resin refers to a silicone resin which is finally cured and is a polyfunctional polysiloxane. The R/si value is less than 2, generally 1.3 to 1.5. The R/Si value is small, and the cured silicone resin is hard and brittle; when the value is large, the cured silicone resin has good flexibility.
: Silicone rubber mainly refers to chain oligosiloxane with functional groups at the molecular chain end. It is a binder for room temperature vulcanized silicone sealant. It is also a binder for most silicone sealants. The R/Si value is equal to 2.
Glue-linking agent: A cross-linking agent is a substance which can increase the relative molecular mass of oligosiloxane and increase the degree of crosslinking, and is a vulcanizing agent for vulcanized silicone rubber at room temperature or medium temperature.
Accelerators: Accelerators, also known as curing catalysts, are the substances that accelerate the action of crosslinkers, as is the case with organic acid metal salts such as dibutyltin dilaurate, metal oxides, vinyl platinum complexes, and the like.
Reinforcing agent: Silicon rubber has weak intermolecular force, low cohesive energy and poor mechanical properties, and can only be used for the packaging of electrical components.