Catalyst, preparation method thereof and use thereof in production of nitroxide radical piperidinols

Abstract

The invention discloses a catalyst, a preparation method thereof and use thereof in production of nitroxide radical piperidinols The catalyst for synthesizing nitroxide free radical piperidinol comprises, by total weight of the catalyst, 0.1-5.0% of a titanium element, 30-48% of a silicon element and the balance of an oxygen element. The catalyst is prepared by the following method: providing a mixed solution of tetraethyl silicate and water, wherein the mass ratio of tetraethyl silicate to water being 0.05-0.5; adjusting the pH value of the solution to 10.0-12.0, and stirring the solution; providing a mixed solution of tetraethyl titanate and absolute ethyl alcohol, wherein the mass ratio of tetraethyl titanate to absolute ethyl alcohol is 0.02-0.5; and mixing the two mixed solutions, and carrying out stirring and roasting to obtain a catalyst product.

Description

technical field [0001] The invention relates to a titanium-containing solid catalyst, a preparation method of the catalyst and its use in the preparation of nitroxide radical piperidinol (that is, 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide radical) use in . Background technique [0002] 2,2,6,6-Tetramethyl-4-hydroxypiperidine nitroxide radical (also known as nitroxide radical piperidinol or inhibitor 701) is a new type of polymerization inhibitor, which is a stable It is extremely stable to light and heat, can terminate the oxidation chain, and can be used as a polymerization inhibitor for polymer monomers, an anti-aging agent for polymer materials, a high-efficiency ultraviolet light absorber, and thermal degradation of polyformyl and polyvinylamine Inhibitors. Due to the excellent polymerization inhibition performance of 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide free radicals on unsaturated compounds, it can be applied to prevent polymerization fouling of ...

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Problems solved by technology

[0004] Although the prior art proposes using magnesium hydroxide as a catalyst, or using a sodium tungstate-ethylenediaminetetraacetic acid disodium catalyst system to oxidize 2,2,6,6-tetramethyl-4-hydroxypiperone with hydrogen peroxide in aqueous solution Pyridine synthesizes 2,2,6,6-tetramethyl-4-hydroxypiperidine nitroxide radical, but when magnesium hydroxide is used as a catalyst, because the catalytic activity is low, the amount of catalyst required is large, and the conversion rate of raw materials is low ; When sodium tungstate-edetate disodium is used as a catalyst, the catalyst is completely dissolved in the reaction system. Although the catalyst performance is good, it is difficult to recover the catalyst after the reaction, and the wastewater after the reaction contains a large amount of tungsten metal ions , wastewater treatment is difficult, environmental protection pressure is high

In addition, when magnesium hydroxide or sodium tungstate-ethylenediaminetetraacetic acid disodium is used as a catalyst, the raw hydrogen peroxide itself will decompose in large quantities to generate oxygen and water, resulting in a low effective utilization rate of hydrogen peroxide and an increase in production costs

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