Silicone rubber is a linear polymer elastomer with inorganic and organic properties, with Si-O units as the main chain and monovalent organic groups as side groups.

Silicone rubber adhesive is a one-component or two-component adhesive composed of adhesive, crosslinking agent, catalyst, reinforcing agent, tackifier and heat stabilizer.

According to vulcanization temperature and application mode, it can be divided into heating vulcanization (i.e. curing) and room temperature vulcanization. The "single component room temperature vulcanization adhesive" is relatively simple and convenient to use.

Brief introduction to components of silicone rubber adhesive:

1. Adhesive:

The adhesive used for silicone rubber adhesive is mainly dimethyl silicone rubber and modified silicone rubber (such as methyl vinyl silicone rubber, phenyl silicone rubber, fluorosilicone rubber, nitrile silicone rubber, boron silicone rubber, etc.).

2. Crosslinking agent:

Substances that can increase the molecular weight of siloxane and improve the degree of crosslinking are also called "vulcanizing agents".

Commonly used crosslinking agents include tetraethyl orthosilicate, propyl orthosilicate, hydroxyaminosilane, silicon containing clear polysiloxane, butyl titanate, acetylsilane, oxime silane, alkoxysilane, aminosilane, amidosilane, organic peroxide, methyltriethoxysilane, etc.

3. Catalyst:

Also known as "accelerator", a substance that can accelerate the function of crosslinking agent.

Common catalysts include dibutyltin dilaurate, metal oxide, vinyl platinum complex, triethanolamine, etc.

They can accelerate the curing speed, reduce the amount of crosslinking agent, improve the operating conditions and the properties of the final product.

4. Reinforcing agent:

The reinforcing agent for silicone rubber is mainly natural or synthetic silica (including diatomite, silica by combustion and precipitation) and other inorganic fillers.

The particle size, surface properties and aggregation state of reinforcing agent have a great influence on the reinforcing effect of silicone rubber.

At present, the best reinforcement effect is silica (i.e. gas phase silica) prepared by combustion method, with an average particle size of 10 ~ 40 μ m. The specific surface area is 150 ~ 300m2 / g. The second is silica prepared by precipitation method, with an average particle size of 30 μ m. The specific surface area is 100 ~ 150m2 / g.

5. Tackifier:

It is an important component to obtain adhesion.

Mainly organic silane coupling agent, silicate ester, titanate, borate ester and silicone resin.

Characteristics of silicone rubber adhesive:

1. Excellent UV resistance and weather aging resistance. After years of atmospheric aging, cracking, embrittlement and peeling will not occur.

2. Extremely wide working temperature (- 115 ~ 300 ℃) and 100% deformation resistance in such a wide temperature range.

2. Good water resistance and medium resistance.

3. Shock and vibration resistance, good sealing performance.

4. Excellent electrical insulation characteristics.

5. Excellent weather resistance, good stability to ozone and ultraviolet light.

6. Non toxic and physiologically inert.

7. Low bonding strength, poor solvent resistance and corrosion resistance.

In order to improve the bonding strength of silicone rubber adhesive, it is necessary to add "coupling agent" or "treat the surface of the material to be bonded with coupling agent".

If active groups, such as acyloxy, nitrile, vinyl, etc., are introduced into silicone rubber molecules, or gaseous silica or epoxy resin and other polymers are added, the strength can be increased.

Silicone rubber adhesive can bond metal, rubber, plastic, ceramics, glass and other materials. It is widely used in aviation, aerospace, electronics, electrical, automobile, ship, construction, medical treatment, optical instruments and other industries.