Methyl hydrogen silicone fluid
is one of the earliest commercialized, most widely and commonly used organosilicon polymers. The production methods of methyl hydrogen silicone fluid mainly include acid balance method and base balance method. Acid balance method is suitable for the production of low viscosity hydrogen silicone fluid with viscosity below 500mm2/s. Concentrated sulfuric acid is generally used as the catalyst. React in 50 ~ 60 ℃, wash to remove acid, take off the low boiling, transit to finished product; the law of base balance is suitable for the production of medium and high viscosity hydrogen silicone fluid with a viscosity of over 100mm2/s. In the production of methyl hydrogen silicone fluid, the components in the DMC (dimethyl mixed ring body) of the raw material will reach the optimal activation state at different temperatures, respectively open the ring polymerization, and improve the conversion rate, thus greatly improving the production efficiency.
After the ring-opening polymerization, the catalyst (CH3)4NOH can hardly be fully decomposed in the process of breaking the catalyst; in addition, a small amount of decomposed ammonia is also mixed in the system, which leads to the peculiar smell of hydrogen silicone fluid. Adopt the method of blowing through dry air after using the system of lowering the temperature to 140℃. Increase the pressure of the gas phase of the system, so as to achieve the purpose of discharging pungent odor.
Between 90 ~ 120 ℃, adopt the method of the program temperature control, blow through dry air after lowering the temperature to 140℃, thus colorless, odorless and qualified methyl hydrogen silicone fluid can be obtained, and the average conversion rate increased from 65% to more than 80%.