Method for preparing diisobutylphosphine from liquid hydrogen phosphide

Abstract

The invention relates to a method for preparing diisobutylphosphine from liquid phosphine, which comprises the following steps: adding low-temperature liquid phosphine and liquid isobutene into a reaction kettle in sequence, uniformly mixing, heating to a target reaction temperature, slowly dropwise adding an initiator solution into the reaction kettle through a diaphragm metering pump, and initiating free radical addition reaction; and after the reaction is finished, carrying out rectification separation on the obtained reaction product to obtain the target product diisobutylphosphine. The method not only improves the purity of the sodium hypophosphite byproduct phosphine as a raw material, but also creates conditions for low-pressure feeding of liquid phosphine and isobutene; purified liquid phosphine is used as a raw material, liquid-phase uniform mixing reaction of phosphine and isobutene is achieved, large-amount use of organic reaction solvents such as methylbenzene is avoided, and reaction efficiency is improved; meanwhile, compared with a hydrogen phosphide gas compression method, the reaction pressure of the system is reduced, and the reaction safety is improved. In addition, an addition reaction byproduct is selected as the initiator solvent, no new solvent substance is introduced into the system, and separation and recovery of the initiator solvent are avoided.

Description

technical field [0001] The invention relates to a method for preparing diisobutylphosphine from liquid phosphine as a by-product in the production process of sodium hypophosphite. Background technique [0002] Sodium hypophosphite is an important variety of inorganic phosphorus chemical products. A large amount of phosphine tail gas is inevitably produced in the production process, and about 20-25% of the raw material yellow phosphorus consumption is converted into phosphine. The main components of the by-product phosphine are (V / V%): PH 3 =35-45%, H 2 =50-60%, N 2 =5-10%, CO 2 =0.01-0.1%. At present, the treatment methods of sodium hypophosphite by-product phosphine mainly include: [0003] 1. Use phosphine tail gas as raw material to synthesize quaternary phosphonium salt series flame retardants and fungicides. For example, using phosphine tail gas directly as raw material, after washing with water or alkali, reacting with formaldehyde and sulfuric acid to obtain tet...

AI Technical Summary

Problems solved by technology

[0009] The process of reacting phosphine with olefins to synthesize organophosphorus products was developed as early as the 1950s, but the source of phosphine has always been the key to this process, among which yellow phosphoric acid process and phosphorous acid pyrolysis process are the main ones Mainly, in addition, the by-product phosphine of the sodium hypophosphite process is another important source, but the by-product phosphine tail gas contains hydrogen and a small amount of nitrogen with a volume ratio of up to 60%, and the phosphine of this purity can only be produced in a low yield. and uneconomical synthesis of organophosphorus products, while the reaction pressure is as high as 9 ~ 10MPa