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CN-122010872-A - Preparation method of piperazine pyrophosphate

CN122010872ACN 122010872 ACN122010872 ACN 122010872ACN-122010872-A

Abstract

The invention discloses a preparation method of piperazine pyrophosphate, which belongs to the field of chemical preparation and comprises the following steps of M1, taking acid ammonium pyrophosphate powder, M2, dissolving piperazine in water, adding acid for neutralization, cooling, M3, adding the acid ammonium pyrophosphate powder into the solution of M2, reacting for 2-4 hours at the temperature of 7-12 ℃ under the acid condition, filtering, cleaning and drying to obtain piperazine pyrophosphate, wherein the molar ratio of the piperazine to the acid ammonium pyrophosphate powder is 0.8-1.5:1. The invention reduces the cost of raw materials, reduces the consumption of hydrochloric acid, and simultaneously can utilize the byproduct ammonium chloride as fertilizer.

Inventors

  • YANG JINSONG
  • YANG BIN
  • LIU DACAI

Assignees

  • 什邡市长丰化工有限公司

Dates

Publication Date
20260512
Application Date
20251218

Claims (9)

  1. 1. The preparation method of the piperazine pyrophosphate comprises the following steps: m1, taking acid ammonium pyrophosphate powder; m2, dissolving piperazine in water, adding acid for neutralization, and cooling; M3, adding acid ammonium pyrophosphate powder into the solution of M2, reacting for 2-4 hours at the temperature of 7-12 ℃ and acidity, filtering, cleaning and drying to obtain piperazine pyrophosphate; The molar ratio of the piperazine to the acid ammonium pyrophosphate powder is 0.8-1.5:1.
  2. 2. The method for producing piperazine pyrophosphate according to claim 1, characterized in that said acidic ammonium pyrophosphate powder is produced by: S1, phosphoric acid, monoammonium phosphate and partial urea react for 1-3 hours at 150-180 ℃; s2, reacting the mixture after the reaction of S1, a polymerization inhibitor and residual urea for 1-3 hours at 185-210 ℃; s3, cooling to obtain acid ammonium pyrophosphate; in S1, the mass ratio of phosphoric acid to monoammonium phosphate is 98:103.5-98:127.5, the molar ratio of urea to phosphoric acid is 1:0.05-1:0.1, and in S2, the molar ratio of urea to phosphoric acid is 1:0.2-1:0.5.
  3. 3. The method for producing piperazine pyrophosphate according to claim 2, characterized in that the amount of said polymerization inhibitor is 0.05% to 0.2% of the total mass of phosphoric acid and monoammonium phosphate.
  4. 4. The method for preparing piperazine pyrophosphate according to claim 2, characterized in that in S2 urea is slowly added for 15 minutes to 35 minutes.
  5. 5. The method for producing piperazine pyrophosphate according to claim 3 wherein the pH of the reaction system in M3 is 3 to 4.
  6. 6. The method for producing piperazine pyrophosphate according to claim 5 wherein said acid is hydrochloric acid.
  7. 7. The method for producing piperazine pyrophosphate according to claim 6 wherein said hydrochloric acid is added in an amount based on the pH of the reaction system.
  8. 8. The method for producing piperazine pyrophosphate according to claim 6, characterized in that said hydrochloric acid concentration is 28 wt to 32wt%.
  9. 9. The method for preparing piperazine pyrophosphate according to claim 1, characterized in that the total weight of the acid ammonium pyrophosphate powder and piperazine is denoted by Q, and the water amount is q=1.5:1 to 4:1.

Description

Preparation method of piperazine pyrophosphate Technical Field The invention particularly relates to a preparation method of piperazine pyrophosphate. Background The acid ammonium pyrophosphate is ammonium acid salt, and pyrophosphate has strong coordination, and is commonly used as chelating agent, cleaning agent, preservative, stabilizer, emulsifier, etc. in industry, common salts include sodium pyrophosphate, disodium dihydrogen pyrophosphate, potassium pyrophosphate, etc. ammonium pyrophosphate is commonly used as fire retardant and fertilizer, such as fertilizer grade ammonium polyphosphate often contains partial ammonium pyrophosphate. At present, no production process for specially producing ammonium pyrophosphate is reported. Most of the production processes are those of fertilizer grade ammonium polyphosphate, and the fertilizer grade ammonium polyphosphate product contains part of ammonium pyrophosphate. CN201210119676.3 discloses a preparation method of low polymerization degree ammonium polyphosphate aqueous solution, using 100% to 120% polyphosphoric acid as main raw material, under the condition of proper quantity of water, mixing with ammonium bicarbonate under the condition of natural, low-temperature and normal pressure, stirring and reacting, and making mass production of low polymerization degree ammonium polyphosphate aqueous solution whose nitrogen content is above 11% and phosphorus pentoxide content is above 37%, and using dimer (ammonium pyrophosphate) as main material, its polymerization degree is 71%. The method has the advantages that the cost of the raw material polyphosphoric acid is high, and the ammonium pyrophosphate generation ratio in the produced product can only reach 70 percent. CN202110285470.7 discloses a two-step process for preparing water-soluble ammonium polyphosphate, which comprises the steps of feeding molten monoammonium phosphate and molten urea into a reaction kettle to react to obtain acidic ammonium polyphosphate melt, feeding the ammonium polyphosphate melt into a kneading reactor to react with solid urea for the second time to obtain ammonium polyphosphate semi-finished product, cooling and crushing the ammonium polyphosphate semi-finished product to obtain the water-soluble ammonium polyphosphate product. The preparation method is carried out in two steps, the primary reaction is carried out at a higher temperature (200-260 ℃) to obtain ammonium polyphosphate melt with multi-polymerization degree distribution, and the secondary reaction is carried out at a lower temperature (about 120-160 ℃) to further improve the polymerization rate. The ammonium polyphosphate obtained by the method has wide polymerization degree distribution, and the ammonium pyrophosphate accounts for 16-36%. CN 201610479295.4A process for preparing high-polymerization-rate water-soluble ammonium polyphosphate includes such steps as adding monoammonium phosphate and urea (0.8-1.8) to reactor, stirring, heating, and condensing at 110-180 deg.C. The method can obtain short-chain ammonium polyphosphate with average polymerization degree of about 3.5, and has high water solubility. Piperazine pyrophosphate (PPAP) is a novel nitrogen-phosphorus synergistic environment-friendly flame retardant, and is suitable for flame retardance of products such as polyolefin, thermoplastic elastomer and the like. Because of the excellent flame retardant property, the flame retardant is a research hot spot of phosphorus flame retardant materials. More reports have been made over the last decades regarding the preparation of nick-oxazine pyrophosphate. There are generally the following: (1) The double decomposition precipitation method is that anhydrous piperazine and anhydrous sodium pyrophosphate react in hydrochloric acid solution to form PPAP, which is then separated to obtain PPAP product. Subsequently, US4599375A discloses a similar method, which comprises the steps of adding 750g of sodium pyrophosphate decahydrate into a 5L reaction kettle, fully dissolving the sodium pyrophosphate decahydrate by 2500mL of water, cooling the material to 10 ℃, acidifying the material by 563mL of hydrochloric acid (37 wt% concentration) under the condition that the system temperature is not higher than 12 ℃, adding the acidified sodium pyrophosphate solution into piperazine solution (149 g of piperazine is dissolved in 625mL of water), maintaining stirring for 2-3 h (the temperature is kept at about 7 ℃) after crystals are separated out (pH is 3-4), filtering, washing a filter cake by water, and drying the filter cake in a 105 ℃ vacuum drying box for 6h to obtain 235g of PPAP (yield is 53%), wherein the thermal stability of the product is above 280 ℃. The method has the problems that the solubility of sodium pyrophosphate in hydrochloric acid solution is low, so that the concentration of reactants in the reaction process is low, the product yield is low, and meanwhile, part of sodium ions are difficult to clean, so t