Room temperature vulcanized silicone rubber
Characteristics
It can be cured in situ without heating or pressing at room temperature, which is extremely convenient to use.
Therefore, it has quickly become an important part of the entire silicone product. At room temperature, vulcanized silicone rubber has been widely used as an adhesive, sealant, protective coating, potting and molding material, and has its use in various industries.


classification
According to composition, vulcanization mechanism and process
One-component room temperature vulcanized silicone rubber
Features: easy to use, but deep curing speed is difficult


Two-component condensation type room temperature vulcanized silicone rubber
Features: curing does not exotherm, shrinkage is small, no expansion, deep vulcanization;


Two-component addition molding room temperature vulcanized silicone rubber
Features: temperature adjustment can control vulcanization speed


One-component room temperature vulcanized silicone rubber - referred to as RTV-1
1 principle
The vulcanization reaction of the one-component room temperature vulcanized silicone rubber is vulcanized into an elastomer by acting on moisture in the air. The vulcanization reaction proceeds gradually from the surface to the depth. The thicker the rubber layer, the slower the curing. The vulcanization time of the one-component room temperature vulcanized silicone rubber depends on the vulcanization system, temperature, humidity, and thickness of the silicone rubber layer. Increasing the temperature and humidity of the environment can accelerate the vulcanization process. Under typical environmental conditions, after 5-30 minutes, the surface of the silicone rubber may be non-tacky, and a layer of 0.3 cm thick may be cured within one day. The depth and strength of curing will gradually increase in about three weeks.


Although the one-component room temperature vulcanized silicone rubber is convenient to use, since the vulcanization is based on the moisture in the lazy atmosphere, the thickness of the vulcanized magnetic needle is limited, and it can only be used in applications requiring a thickness of 6 mm or less. The addition of magnesium oxide accelerates the vulcanization of the deep glue.


2 types
The one-component room temperature vulcanized silicone rubber can be various types such as deacidification type, depurination type, dealcoholization type, deamination type, deamidation type and deketone type.


3 use temperature
They maintain flexibility over a long period of time from minus 60 degrees to 200 degrees.


4 performance
One-component room temperature vulcanized silicone rubber has excellent electrical properties and chemical inertness, as well as heat resistance, natural aging resistance, flame resistance, moisture resistance, and gas permeability.


5 bonding
It does not absorb heat during heat curing, does not release heat, has a small shrinkage after curing, and has good adhesion to materials. Therefore, it is mainly used as an adhesive and sealant, and other applications include in-situ molded gaskets, protective coatings and caulking materials. Many single component silicone rubber adhesive formulations exhibit automatic bonding properties to a variety of materials such as most metals, glass, ceramics and coagulation. When the bonding is difficult, the substrate may be primed to improve the bonding strength. The primer may be a silane monomer or a resin having a hydrating activity, and when they are cured on the substrate, a modified layer is formed. On the surface of silicone bonding.


6 uses
It can adapt to the practical requirements in the fields of construction engineering and electronic engineering, so it shows a promising development vision.