Production process of deketoxime silane crosslinker
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Overview of process flow In theory, ketoxime silane crosslinker can be prepared by reacting organochlorosilane, organoalkoxysilane, and organoacyloxysilane with ketoxime under the action of acid absorbent and catalyst. Considering operation, separation, quality and cost, it is still prepared by reacting organochlorosilane with ketoxime. The most common ketoxime is butanone oxime. The organochlorosilane can be monomethyltrichlorosilane or vinyltrichlorosilane.
In industry, monomethyltrichlorosilane and butanone oxime are often used as raw materials, and 120# solvent oil is used as solvent (after normal production, salt residue and front fraction are added). Monomethyltrichlorosilane is added dropwise to the reactor to react with butanone oxime in the reactor to generate methyltributanoneoxime silane semi-finished product and butanone oxime hydrochloride (referred to as "oxime salt"), and a large amount of heat will be released during the reaction. Another industrial method is to introduce monomethyltrichlorosilane, butanone oxime and solvent into the reactor at the same time in a certain proportion for continuous reaction, and remove the heat generated by the reaction through external circulation cooling. After the reaction is completed, the materials enter the layering device for stratification, the lower layer is the oxime salt containing a small amount of semi-finished product, and the upper layer is the acidic semi-finished product containing a small amount of oxime salt. The main synthesis reaction is as follows: CH3SiCl3+6CH3C2H5CNOH→CH3Si(ONCCH3C2H5)3+3CH3C2H5CNOH·HCl2CH3Si(ONCCH3C2H5)3+H2O→CH3Si(ONCCH3C2H5)2-O-SiCH3(ONCCH3C2H5)2+2CH3C2H5CNOH. Oxime salt extraction, neutralization, butanone oxime refining process: The oxime salt in the lower layer of the layerer first enters the extraction tower and is extracted by 120# solvent to complete the recovery of semi-finished products. The extracted oxime salt enters the oxime salt neutralization system for neutralization. The extracted solvent returns to the extraction solvent tank and then returns to the reactor for recycling. The oxime salt neutralization system uses ammonia water (15-20%) to neutralize the extracted oxime salt. The neutralized material containing butanone oxime and ammonium chloride aqueous solution is placed in a butanone oxime separator for separation. The upper layer is water-containing butanone oxime, which enters the butanone oxime distillation system for distillation and purification, and the lower layer of ammonium chloride aqueous solution enters the evaporation crystallization system to recover ammonium chloride. The water-containing butanone oxime first enters the system's first tower for vacuum distillation, and the collected gas phase is condensed into high-water butanone oxime and returned to the butanone oxime separator. The bottom material of the first tower enters the second tower for further distillation, and the collected gas phase is condensed to recover butanone oxime. The bottom material of the second tower enters the third tower for further distillation to recover the residual butanone oxime in the bottom material, and finally the bottom material is processed by the recovery system. The main reaction equation involving oxime salt neutralization is as follows: CH3C2H5CNOH·HCl+NH3·H2O→CH3C2H5CNOH +NH4Cl+H2O One and two effect evaporation crystallization process: The ammonium chloride aqueous solution enters the evaporation crystallization system, and the high-temperature supersaturated ammonium chloride solution and ammonia-containing soda water are obtained through one and two effect separation. The supersaturated ammonium chloride is condensed to precipitate ammonium chloride, and the ammonium chloride salt is obtained by centrifugation and fluidized bed evaporation and sold as a by-product, which can be used as agricultural fertilizer and industrial raw material. The ammonia-containing steam water is cooled and blended in the form of ammonia water for the oxime salt neutralization process. 2. MVR evaporation crystallization process: The ammonium chloride aqueous solution from the bottom of the butanone oxime demixer is neutralized by adding hydrochloric acid in the raw material tank, and the neutralized material is transferred to the crystallizer, the circulation pump is started and starts to bring negative pressure, the compressor is started, and the steam is fed until the temperature of the MVR crystallizer reaches 80°C, then the main steam is turned off, and the system continuously feeds and discharges materials normally. The water vapor evaporated in the crystallizer is compressed by the MVR steam compressor, and the temperature rises and enters the heater jacket to heat the crystallizer material. The hot water from the heater enters the condensed water tank, and then enters the soft water tank to prepare ammonia water. After being concentrated by the crystallizer, the ammonium chloride solution is first separated by a hydrocyclone, and the high-solid ammonium chloride solution material enters the crystal slurry tank, and the dilute solution enters the mother liquid tank; the crystal slurry tank material cools down and crystallizes, and then enters the centrifuge, and the centrifugal filtrate enters the mother liquid tank. The solid ammonium chloride particles enter the vibrating fluidized bed for drying and packaging; the material in the mother liquid tank is transferred to the raw material. 3. Product neutralization and product distillation process: The acidic semi-finished product on the upper layer of the first and second level separators enters the product neutralization system and is neutralized with ammonia. The small amount of oxime salt in the acidic semi-finished product is neutralized into ammonium chloride, and then mixed with the semi-finished product and enters the static tank for static stratification. After standing, the upper clear liquid passes through a precision filter to become an alkaline semi-finished product, and then enters the product distillation system for purification. The lower layer of ammonium chloride and semi-finished product mixture (salt residue) returns to the reactor for recycling. After the alkaline crude product enters the solvent evaporator, most of the solvent and butanone oxime are extracted and separated by the gas-liquid separator. The gas phase is condensed to form a recovered solvent, which is returned to the reactor for recycling. The unvaporized material in the solvent evaporator enters the scraper evaporator, and the residual solvent, butanone oxime, impurities and a small amount of product are extracted, condensed to form the fore fraction, and returned to the reactor for recycling. Finally, a high-content methyl trisbutyl oxime silane is obtained. The main reaction equation for the neutralization of the product is as follows: CH3C2H5CNOH·HCl+NH3→CH3C2H5CNOH+NH4Cl