Method for producing ammonium polyphosphate by using stepwise reaction and polymerization

Abstract

The invention discloses a method for producing ammonium polyphosphate by using a stepwise reaction and polymerization, relates to a method for producing ammonium polyphosphateproducts with different polymerization degrees in the same set of device, in particular to a production method of ammonium polyphosphate with high purity, high polymerization degree and the average polymerization degree larger than 1000. The method comprises the following steps in sequence: a. adding a polycondensation agent into polyphosphoric acid as a raw material in the weight ratio of 1:1 and mixing evenly; b. adding the material obtained by the step a into a continuous synthetic reactor for reacting; and c. further polymerizing products obtained in the step b for 30-300 minutes at the pressure of 0.00MPa-0.6MPa and the temperature of 120DEG C-500DEG C to obtain the high-purity ammonium polyphosphate products with the polymerization degree of 10-1,800. The invention has the advantages of convenient production and control, high yield, low energy consumption and benefit for large-scale continuous industrial production.

Description

technical field The invention relates to a production method for producing ammonium polyphosphate products with different polymerization degrees in the same set of devices, in particular to a production method for high-purity and high-polymerization-degree ammonium polyphosphate with an average polymerization degree. Background technique Ammonium polyphosphate, referred to as APP. It is an inorganic halogen-free and environment-friendly flame retardant developed rapidly in recent decades. It has the advantages of good flame retardant effect, good thermal stability and environmental friendliness. It is one of the main components of intumescent flame retardant (IFR) , are widely used in the field of flame retardant. The degree of polymerization of ammonium polyphosphate products is divided into high and low, and the average degree of polymerization directly affects its application effect and application range as a flame retardant. APP with a low degree of polymerization is ...

AI Technical Summary

Problems solved by technology

In view of the problems existing in the existing ammonium polyphosphate production methods, such as: phosphoric acid is highly corrosive to equipment at high temperatures, and the requirements for equipment materials are relatively high; in the method of using phosphate as raw material, in order to improve the degree of reaction And the dispersant that adds needs to remove the problem after reaction finishes again; And phosphorus pentoxide (P 2 o 5 ) has strong hygroscopicity and reactivity, and is difficult to control

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