A method for synthesizing crystalline type II ammonium polyphosphate by polyphosphoric acid catalysis

A polyphosphoric acid catalysis method and polyphosphoric acid catalyst technology, applied in the direction of phosphorus compounds, chemical instruments and methods, inorganic chemistry, etc., can solve problems such as easy moisture absorption, and achieve the effects of easy control of reaction conditions, improved efficiency, and stable crystal form
CN105084337BActive Publication Date: 2017-06-09YUNNAN CHEM RES INST
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Patent Information

Authority / Receiving Office
CN Β· China
Patent Type
Patents(China)
Current Assignee / Owner
YUNNAN CHEM RES INST
Publication Date
2017-06-09

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Abstract

The invention discloses a method for synthesizing crystalline type II ammonium polyphosphate by polyphosphoric acid catalysis. In this method, polyphosphoric acid is used as a reaction catalyst and phosphorus pentoxide is used as a raw material to obtain crystalline type II ammonium polyphosphate with stable crystal form through one-step reaction. Mix phosphorus pentoxide, monoammonium phosphate and melamine, mix them evenly and put them into the polymerization reactor, and add the reaction catalyst polyphosphoric acid at the same time, and complete the process at 240℃~350℃, 0.15~0.4MPa ammonia and nitrogen mixed atmosphere pressure reaction to obtain crystalline type II ammonium polyphosphate product. The reaction equipment adopted in the one-step preparation method of the present invention is a continuous reaction device with strong crushing effect and sealing and pressure bearing effect. The invention has the advantages of easy operation and short total reaction time.
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Description

technical field

[0001] The invention discloses a method for synthesizing crystalline type II ammonium polyphosphate by polyphosphoric acid catalysis, and in particular relates to a method for synthesizing a phosphorus-based flame retardant. It belongs to the field of inorganic phosphorus chemical industry. Background technique

[0002] Ammonium polyphosphate (hereinafter referred to as APP), as a halogen-free intumescent flame retardant, has been widely used in various fields of the flame retardant material industry for its non-toxic, tasteless, non-toxic gas, and excellent performance. application. There are currently six known crystal forms of APP, namely type I to type VI, but only type I, type II and type V are stable crystal forms. Among the currently known stable crystal forms of APP, since type II has better water resistance, heat resistance and stability than type I, it has wider applications and better flame-retardant application properties.

[0003] Type I and T...

Claims

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