Method for producing and removing odor of methyl silicone oil
Methyl silicone oil is one of the earliest commercialized, most widely used and most commonly used silicone polymers. The production methods of methyl silicone oil mainly include acid balance method and alkali balance method. The acid balance method is suitable for the production of low-viscosity silicone oil with a viscosity of less than 500mm2 / s. This method generally uses concentrated sulfuric acid as a catalyst and reacts at 50 ~ 60 ° C. Then it is washed with water to remove the acid, remove low-boiling matter, add activated carbon to decolorize, and transition to finished ; The alkali balance method is suitable for the production of medium and high viscosity silicone oils with a viscosity of more than 100mm2 / s. In the production of methyl silicone oil, the components in the raw material DMC (dimethyl mixed ring body) will be optimally activated at different temperatures, and ring-opening polymerization will be carried out separately, which will increase the conversion rate and greatly improve the production efficiency. .
After the ring-opening polymerization reaction is completed, it is difficult for the catalyst (CH3) 4NOH to be fully decomposed during the media breaking process; and the decomposed ammonia gas also dissolves in the system in a small amount, resulting in the odor of silicone oil. After the system is lowered, the temperature is lowered to below 140 ° C, and dry air is bubbled to increase the gas pressure of the system, so as to achieve the purpose of discharging irritating odors.
Using program temperature control method between 90 ~ 120 ℃ and lowering the temperature to 140 after removing it, bubbling with dry air to obtain methyl silicone oil which is colorless, odorless and qualified for all indicators, the average conversion rate is increased from 65% By more than 80%.