Expanded flame-retardant silicon rubber and preparation method thereof

Abstract

The invention discloses an expanded flame-retardant silicon rubber and a preparation method thereof. The method comprises the following steps of: putting methyl vinyl silicone rubber into a rubber open mill, covering rolls, alternately adding gaseous white carbon black and hydroxy silicon oil by 2 to 4 batches, mixing for 10 to 30 minutes, thinning, discharging sheets, thermally treating the silicon rubber sheets at the temperature of between 180 and 200 DEG C, and cooling; putting the mixed rubber after the thermal treatment into the open mill again, adding a carbonation agent, a carbonationaccelerator and an expansion agent, mixing uniformly, finally adding 2,5-dimethyl-2,5-ditertiary butyl hexane hyperoxide serving as a vulcanizing agent, and thinning the mixed rubber for 3 to 5 timesin the open mill; and vulcanizing the mixed rubber on a flat vulcanizing machine for 8 to 30 minutes at the temperature of between 150 and 180 DEG C, then discharging sheets, and performing secondaryvulcanization for 2 to 6 hours at the temperature of between 180 and 200 DEG C in a hot blast drying oven to prepare the expanded flame-retardant silicon rubber. The silicon rubber has good flame-retardant performance and mechanical performance, and can be widely applied in the fields of electronics, electrics, mechanics, chemical industry and the like.

Description

technical field [0001] The invention relates to intumescent flame-retardant silicone rubber and a preparation method thereof, belonging to the field of rubber and plastic modification and molding processing. technical background [0002] Silicone rubber has the advantages of non-toxic and tasteless, high and low temperature resistance, weather resistance, and good electrical insulation performance. It is widely used in the fields of electronics, machinery, automobiles, chemicals, aviation, aerospace, and ships. However, silicone rubber itself will continue to burn when it encounters an open flame. The flammability of silicone rubber limits its application in various fields of the national economy. Therefore, research on the flame retardancy of silicone rubber is a work of great significance. [0003] The research on halogen-free flame-retardant silicone rubber is very extensive. Among them, magnesium hydroxide and aluminum hydroxide have become commonly used inorganic fla...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art that there is a large amount of inorganic flame retardant added, the mechanical properties of the polymer flame retardant system are not good, and the vertical combustion level is difficult to reach the UL 94 V-0 level, and to provide a flame retardant Intumescent flame-retardant silicone rubber with less dosage, flame-retardant performance reaching UL 94 V-0 level, and excellent mechanical properties