Shanxian Chemical
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Tetrakis Hydroxymethyl Phosphonium Chloride Production Insights
Production of tetrahydroxymethylphosphorus chloride
Raw material selection
Preparation of tetrahydroxymethylphosphorus chloride, raw material selection is crucial. With formaldehyde and phosphorus trichloride as the initial materials, formaldehyde needs to be selected with high purity. If there are few impurities, the reaction process will be smooth, and the product purity will also be good. The same is true for phosphorus trichloride, its quality is related to the reaction effect. Such as formaldehyde in the market, there are industrial grade and reagent grade. When preparing this product, choose the industrial grade medium and high quality, and the content should exceed 99%, in order to lay a solid foundation for the subsequent reaction.
Reaction process
1. ** Addition reaction **: In a suitable reactor, add formaldehyde and phosphorus trichloride in a certain ratio. Usually the molar ratio of formaldehyde to phosphorus trichloride is about 4:1. This ratio has been verified by many practices to make the reaction sufficient. Temperature control is within a specific range, generally 30-40 ° C. If the temperature is too high, side reactions will occur, and if it is too low, the reaction will be slow. The stirring speed is also particular. Moderate stirring can promote the material to mix evenly and accelerate the reaction. It is better to rotate at 200-300 rpm. The reaction time is about 2-3 hours, during which the reaction phenomenon, such as changes in temperature and pressure, is closely observed.
2. ** Hydrolysis Reaction **: After the addition of the reaction, transfer the reaction liquid to another container and slowly add hydrolysis. The ratio of water to the reaction liquid must be accurate, generally 1:1.5 - 1:2. The hydrolysis temperature rises to 50-60 ° C. At this stage, stirring is also required, and the speed is slightly slower, 150-200 revolutions per minute. The hydrolysis time is about 1-2 hours. After the hydrolysis is complete, the properties of the solution change significantly. This is the basis for judging the end point of the reaction.
Purification and Refinement
The crude product obtained from the reaction contains impurities and needs to be purified and refined. First, the insoluble matter is removed by filtration method, and the appropriate filter screen is selected. The mesh number is determined according to the particle size of the impurity, generally 200-300 mesh. The filtrate is concentrated by distillation, and the temperature is controlled at 100-110 ° C to remove low boiling point impurities. After the crystallization method to obtain high purity tetrahydroxymethyl phosphorus chloride, cooled to 5 - 10 ℃, the crystallization time is about 4 - 6 hours, after crystallization centrifugal separation, to obtain the finished product.
quality control
1. ** content determination **: chemical analysis method, such as silver quantity method to measure the chlorine content, in order to calculate the tetrahydroxymethyl phosphorus chloride content. Operation in accordance with standard procedures to ensure accurate results. High-quality finished product content should reach more than 98%.
2. ** impurity detection **: with the help of instrument analysis, such as high performance liquid chromatography, gas chromatography, to measure the type and content of impurities. The total amount of impurities must be strictly controlled, too high affect product performance and application.
In summary, the production of tetrahydroxymethylphosphorus chloride involves closely interlocking all aspects from raw materials to finished products, with fine operation and strict control to achieve high-quality products.
Raw material selection
Preparation of tetrahydroxymethylphosphorus chloride, raw material selection is crucial. With formaldehyde and phosphorus trichloride as the initial materials, formaldehyde needs to be selected with high purity. If there are few impurities, the reaction process will be smooth, and the product purity will also be good. The same is true for phosphorus trichloride, its quality is related to the reaction effect. Such as formaldehyde in the market, there are industrial grade and reagent grade. When preparing this product, choose the industrial grade medium and high quality, and the content should exceed 99%, in order to lay a solid foundation for the subsequent reaction.
Reaction process
1. ** Addition reaction **: In a suitable reactor, add formaldehyde and phosphorus trichloride in a certain ratio. Usually the molar ratio of formaldehyde to phosphorus trichloride is about 4:1. This ratio has been verified by many practices to make the reaction sufficient. Temperature control is within a specific range, generally 30-40 ° C. If the temperature is too high, side reactions will occur, and if it is too low, the reaction will be slow. The stirring speed is also particular. Moderate stirring can promote the material to mix evenly and accelerate the reaction. It is better to rotate at 200-300 rpm. The reaction time is about 2-3 hours, during which the reaction phenomenon, such as changes in temperature and pressure, is closely observed.
2. ** Hydrolysis Reaction **: After the addition of the reaction, transfer the reaction liquid to another container and slowly add hydrolysis. The ratio of water to the reaction liquid must be accurate, generally 1:1.5 - 1:2. The hydrolysis temperature rises to 50-60 ° C. At this stage, stirring is also required, and the speed is slightly slower, 150-200 revolutions per minute. The hydrolysis time is about 1-2 hours. After the hydrolysis is complete, the properties of the solution change significantly. This is the basis for judging the end point of the reaction.
Purification and Refinement
The crude product obtained from the reaction contains impurities and needs to be purified and refined. First, the insoluble matter is removed by filtration method, and the appropriate filter screen is selected. The mesh number is determined according to the particle size of the impurity, generally 200-300 mesh. The filtrate is concentrated by distillation, and the temperature is controlled at 100-110 ° C to remove low boiling point impurities. After the crystallization method to obtain high purity tetrahydroxymethyl phosphorus chloride, cooled to 5 - 10 ℃, the crystallization time is about 4 - 6 hours, after crystallization centrifugal separation, to obtain the finished product.
quality control
1. ** content determination **: chemical analysis method, such as silver quantity method to measure the chlorine content, in order to calculate the tetrahydroxymethyl phosphorus chloride content. Operation in accordance with standard procedures to ensure accurate results. High-quality finished product content should reach more than 98%.
2. ** impurity detection **: with the help of instrument analysis, such as high performance liquid chromatography, gas chromatography, to measure the type and content of impurities. The total amount of impurities must be strictly controlled, too high affect product performance and application.
In summary, the production of tetrahydroxymethylphosphorus chloride involves closely interlocking all aspects from raw materials to finished products, with fine operation and strict control to achieve high-quality products.
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