Method for preparing parabenzoquinone dioxime

Abstract

The invention discloses a method for preparing parabenzoquinone dioxime, relating to a catalytic synthesis method for parabenzoquinone dioxime. Under the existence of certain concentration of sulphuric acid, carrying out nitrosification on phenol dissolved in an NaOH solution with sodium nitrite to prepare parabenzoquinone monooxime; then adding hydroxylamine to the prepared parabenzoquinone monooxime and oximating to prepare parabenzoquinone dioxime. The parabenzoquinone dioxime is prepared by the residualtitration method which comprises the steps of dissolving the phenol in the 28%-32% NaOH solution and then mixing with 93%-97% sodium nitrite solution at -3 DEG C -5 DEG C, and then guiding into 28%-32% sulphuric acid solution at -3-5 DEG C by using a conduit. The invention has the advantages that the reaction yield is high; the purity of target matter can reach 98 percent; the content value of the nitrogen element in parabenzoquinone dioxime is not less than 20.26 percent; the carbon, hydrogen content and the nitrogen content of products are effectively increased and the quality stability of the products is effectively increased.

Description

technical field [0001] The present invention relates to a method for catalyzing the synthesis of p-benzoquinone dioxime. To be precise, it uses p-benzoquinone monoxime and hydroxylamine hydrochloride as raw materials, and catalyzes the synthesis of p-benzoquinone dioxime at a certain temperature in the next step, which belongs to organic synthesis. technical field. Background technique [0002] P-benzoquinone dioxime is a crosslinking agent, the product is suitable for: butyl rubber, ethylene propylene rubber, natural rubber, styrene butadiene rubber, polysulfide rubber, etc., especially for butyl rubber, ethylene propylene rubber. Product performance: easy to disperse in the rubber compound, fast vulcanization speed, high elongation strength of the rubber compound, heat and weather resistance, ozone resistance and electrical insulation performance, can be used as acrylic acid polymerization inhibitor, and can improve the heat dissipation of polyester fiber tire cord Resist...

AI Technical Summary

Problems solved by technology

[0003] In recent years, the industrial production of p-benzoquinone dioxime is mainly as follows: at 0°C, in the presence of a certain concentration of sulfuric acid, sodium nitrite nitrosates phenol dissolved in 30% NaOH solution to prepare p-benzoquinone monoxime, and then prepares p-benzoquinone monoxime. The p-benzoquinone monoxime is added with hydroxamine to produce the final product p-benzoquinone dioxime. The product purity is limited by this synthetic method (≤95%), and contains more impurities, which are specifically reflected in: 1) in the preparation of p-benzoquinone In the case of quinone monoxime, sulfuric acid solution is often dropped into sodium phenate and sodium nitrite solutions to obtain p-benzoquinone monoxime. At this time, dilute sulfuric acid is used to prepare strong nitrous acid. At the beginning, the amount of hydrogen ions in the solution less, the generated nitrous acid is extremely unstable and prone to hydrolysis reaction. Due to the small amount of hydrogen ions, nitrous acid reacts in the positive direction, and it is difficult to produce nitrous acid that meets the standard, which affects the quality of the quinone monoxime, thereby also Affect the quality of p-benzoquinone dioxime