The curing reaction of one-component room temperature vulcanized silicone rubber is initiated by the moisture in the air. The commonly used cross-linking agent is methyltriacetoxysilane. Its Si-OC bond is easily hydrolyzed. Acetoxy groups are combined with hydrogen groups in water to form acetic acid, and the hydroxyl groups in water are transferred to the original acetoxy groups. In position, it becomes trihydroxymethylsilane. Trihydroxymethylsilane is extremely unstable and easily condenses with linear silicones whose terminal groups are hydroxyl groups to form a cross-linked structure. In general, the silicone rubber containing silanol end groups and various compounding agents such as fillers, catalysts, and cross-linking agents are packed into sealed hoses. When used, they are squeezed out of the container and vulcanized by the moisture in the air. Elastomer, release low molecular weight at the same time. In addition to the methyl triacetoxysilane, the cross-linking agent may be a silane containing an alkoxy group, an oxime group, an amine group, an amide group, or a ketone group. When crosslinked with alkoxy group, alcohol is released, which is called dealcoholized one-component room temperature vulcanized silicone rubber. When crosslinked with oxime group, oxime is formed, called deoxidized room temperature vulcanized silicone rubber. Different types of agents, one-component room temperature vulcanized silicone rubber can be deacidified, deoxidized, dealcoholized, deamined, deamidated, and deketoned. One.

The curing time of 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 speed up the vulcanization process. Under typical environmental conditions, after 15-30 minutes, the surface of the silicone rubber may not be tacky, and a 0.3 cm thick adhesive layer can be cured within one day. The depth and strength of curing will gradually increase in about three weeks.

One-component room temperature vulcanized silicone rubber has excellent electrical properties and chemical inertness, as well as heat resistance, natural aging resistance, flame resistance, humidity resistance, and breathability. They can remain elastic for a long time in the range of -60 to 200 ° C. It does not absorb heat or heat when cured, 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 molding of gaskets, protective coatings and caulking materials. Many formulations of one-component silicone rubber adhesives exhibit automatic bonding properties on a variety of materials such as most metals, glass, ceramics, and coagulation, such as bare aluminum with a shear strength of 200 psi 2. Tear strength up to 20 lbs./inch2 (0.35 Joules / cm2). When adhesion is difficult, a primer can be applied to the substrate to improve the bonding strength. The primer can be a reactive silane monomer or resin. When they are cured on the substrate, a layer of modified On silicone bonded surfaces.

Although the single-component room temperature vulcanized silicone rubber is convenient to use, the thickness of the vulcanizate is limited due to its vulcanization due to the moisture in the atmosphere, and it can only be used in situations where the thickness is less than 6 mm.

The curing reaction of the one-component room temperature vulcanized silicone rubber proceeds gradually from the surface to the deeper. The thicker the rubber layer, the slower the curing. When deep curing is also required, layered pouring and stepwise vulcanization can be adopted. Some rubber compounds can be added each time, and the material can be added after vulcanization, which can reduce the total vulcanization time. The addition of magnesium oxide can accelerate the vulcanization of deep glue.

Two-component room temperature vulcanized silicone rubber Two-component room temperature vulcanized silicone rubber can be divided into condensation type and addition molding