Silicone rubber has excellent high and low temperature resistance, weather resistance, electrical insulation and physiological laziness, etc. it is widely used in aerospace, electronic and electrical, construction, car machinery and other industries, as well as medical and health, daily life in various fields.
The primary application of silicone rubber is a variety of vulcanized products, including all kinds of rubber plates, washers, leather bowls, valves, thin films, shock absorbers, electric plugs, cots, potentiometer insulation sleeves, waveguides and keys, etc. extruded in the finished product of all kinds of rubber hose, rubber strip, rubber rope, wire and cable sheath and so on.
Gasket, diaphragm, barrier cloth in the finished product of adhesive tape.
Nowadays, most silicone rubber products are produced by high-temperature molding using peroxide as vulcanizing agent.
The compound is mixed silicone rubber without vulcanizing agent.
The curing presses include benzoyl peroxide, 2.4 dichlorobenzoyl peroxide, tert butyl benzoyl peroxide, di tert butyl peroxide, dicumyl peroxide, 2.5-dimethyl, 2.5-di-tert-butyl hexane peroxide, the most commonly used are 2.5-dimethyl, 2.5-di-tert-butyl hexane peroxide and 2.4 dichlorobenzoyl peroxide, 2.5-dimethyl,
The addition of 2.5-di-tert-butyl hexane peroxide referred to as "double two-five" is 0.5%. It is used for the production of silicone rubber products in the molding method, and the vulcanization temperature is generally 165 ℃-200 ℃. However, the production method of this silicone rubber product has the following defects:
With the use of "double two-five" vulcanizing agent, a lot of harmful waste gas is produced due to the differentiation of vulcanizing agent in the production process, which affects the operating environment.
The molding curing temperature is as high as 165Mel 190 ℃, which consumes a lot of power resources, and also constitutes an increase in the temperature of the molding production environment, especially in the summer in the southern region, many plate vulcanizing presses gather together, and the staff are very hot and sad.
Silicone rubber product residual vulcanizing agent differentiation of goods, the occurrence of unpleasant smell, need to carry out secondary sulfur to remove, if the "double two-five" vulcanizing agent is not pure or mixed with benzoyl peroxide, then the silicone rubber product also simply presents a "frosting" scene, that is, the differentiation of the vulcanizing agent commodity, transferred to the silicone rubber appearance, forming a white crystal scene.
2.4 Dichlorobenzoyl peroxide is referred to as "double 24". The addition of paste with an effective content of 50% is 1.0% Muth1.5%, which is mainly used for hot air vulcanization molding, such as the production of silicone rubber pipes, wires and plates. the use of "double 24" has the following defects:
With the use of "double 24" vulcanizing agent, a lot of harmful waste gas is produced due to the differentiation of vulcanizing agent in the production process, which affects the operating environment.
The residual vulcanizing agent in the finished silicone rubber product divides the product, which needs to be vulcanized twice before it can be removed, and the finished silicone rubber product simply presents a scene of "frosting", especially the black silicone product, which looks like "moldy" after it has been placed for a few months.
Low-temperature vulcanized mixed silicone rubber, no longer need to participate in vulcanizing agent, can be directly plasticized and molded, and has the following advantages:
When producing silicone rubber products, molding molding can vulcanize at a lower temperature of 110 Mel 130 ℃, resulting in short vulcanization time, high production efficiency and energy saving.
When the finished silicone rubber is produced by using the method, the waste gas such as chemical differentiation commodities will not occur, and the finished silicone rubber is odorless, does not need secondary sulfur addition and has excellent physical and mechanical functions.
Silicone rubber product scale is stable, can directly meet the requirements of FDA specifications of environmentally friendly silicone cloth.