Background and overview[1][2]
Diphenyl isooctyl phosphate (C20H27O4P) is a colorless and transparent oily liquid. It is mainly used as a flame retardant plasticizer. It is compatible with almost all resins and rubbers used in major industries and is compatible with polyvinyl chloride. It has better properties, low volatility, good plug resistance and weather resistance. When used in conjunction with phthalate plasticizers, it can improve the toughness and weather resistance of the product. When used in polyvinyl chloride films, it can improve the resistance to Tensile strength, improved wear resistance and moisture resistance. During the preparation process, the catalyst and phosphorus oxychloride were mixed unevenly, the catalyst efficiency was low, and it could not circulate in the reaction tower, resulting in more pollutants and insufficient reaction. Improper control of temperature and pressure can easily cause production safety hazards.
Diphenyl isooctyl phosphate
Preparation[2]
Method 1:
Put 76.5g (0.5mol) phosphorus oxychloride (first phosphorus oxychloride) into a preheater to preheat at a preheating temperature of 50-60°C. While preheating, add 0.75 g of Lewis acid (trichloride 1% of the weight of oxyphosphorus) and 94g (1mol) phenol are input into the reaction tower through a transport pump for reaction. The temperature of the reaction tower is 118~120℃, and the vacuum degree is 70~75KPa. After the materials react in the reaction tower for 30 minutes, Enter into the vacuum reaction kettle, reaching 120°C at the top of the tower, 150°C at the bottom of the tower, and a vacuum degree of 30 KPa. The monophenylphosphoryl chloride intermediate and part of the phosphorus oxychloride evaporated by vacuum distillation are recovered and reused under reduced pressure. The intermediates diphenylphosphoryl chloride 183g (1mol) and isooctyl alcohol 195 (1.5mol) remaining in the reaction kettle are pumped into the reaction tower for reaction. The temperature of the reaction tower is 68~70℃, and the vacuum degree is 70~byk. The accelerator is 75KPa and the reaction time is 30 minutes to obtain crude diphenylisooctyl phosphate. The obtained crude diphenylisooctylphosphate is washed with 3% sodium hydroxide solution in the reaction kettle, washed and layered, and distilled under reduced pressure to 100℃, vacuum degree is 70~75KPa, and the finished product diphenyl isooctyl phosphate is obtained, with a yield of 90%.
In this method, titanium tetrachloride, magnesium chloride or aluminum chloride is used as the catalyst instead of Lewis acid, and the same technical effect can be achieved.
Method 2:
1. Preheat phosphorus oxychloride to 55-60°C, add a catalyst to dissolve it in phosphorus oxychloride, then add the preheated phosphorus oxychloride into the reaction tower through an infusion pump, and add Phenol reacts at 100-120°C for 30-90 minutes. During the reaction, the volume of the reaction liquid increases. The increased reaction liquid is taken out into the vacuum kettle for continuous vacuum distillation. The steamed intermediate phenylphosphoryl chloride continues to return to the reaction tower. React with phosphorus oxychloride, connect to vacuum distillation, and obtain the intermediate diphenylphosphoryl chloride in the vacuum kettle to enter the next step of the reaction;
2. Add the intermediate diphenylphosphoryl chloride and isooctyl alcohol obtained in step 1 into the reaction tower at the same time at 35-65°C and continue the reaction under reduced pressure for 60-90 minutes. After the reaction, the polyurethane raw material isooctyl alcohol is evaporated to obtain the crude product. Diphenyl isooctyl phosphate;
3. The crude diphenylisooctyl phosphate obtained in step 2 is washed with alkali and water to obtain the finished product diphenylisooctylphosphate.
Further, the molar ratio of phosphorus oxychloride and phenol in step one is 1:1.3-2.0, and the preferred molar ratio is 1:1.55.
Further, the catalyst in step one is titanium tetrachloride, magnesium chloride or aluminum chloride, preferably titanium tetrachloride.
Further, the vacuum degree of the reduced pressure reaction in step one is 70-75KPa, preferably 72KPa, the reaction temperature in the reaction tower is 120°C, and the reaction time is 50 minutes.
Further, in the step one, the vacuum degree of the vacuum distillation of phenylphosphoryl chloride is 60-100kPa, preferably 70-72KPa, and the vacuum temperature is 140-160°C, preferably 150°C.
Further, the molar ratio of diphenylphosphoryl chloride and isooctyl alcohol in step 2 is 1:1-1.3, preferably 1:1.1.
Further, the vacuum degree of the reduced pressure reaction in step 2 is 60-100KPa, preferably 70-100KPa, the reaction temperature is 55-60°C, and the reaction time is 60-70min.
Further, in step three, 3%-5% sodium hydroxide solution is used for alkali washing. After alkali washing, water is washed with flowing water. During the water washing process, an acid-base tester is used to test the diphenyl phosphate to be washed. Full test of isooctyl ester.
Further, in step three, after washing with water, water is removed by vacuum distillation, the vacuum distillation temperature is 100-130°C, and the vacuum degree is 30-100KPa.
