Preparing method for tert-butyl group hydroquinol

A technology of tertiary butyl hydroquinone and hydroquinone, which is applied in the field of preparation of synthetic tertiary butyl hydroquinone, can solve problems such as pollution, solvent residue, use, etc., and achieve reduction of environmental pollution and high yield , The effect of simplifying the equipment

Inactive Publication Date: 2005-02-23
GUANGZHOU YOUBAO IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] There are not many patent reports on the preparation of TBHQ, and acid is often used as a catalyst, and tert-butanol or isobutylene is used to react with hydroquinone, such as patent GB761613, which uses phosphoric acid or sulfuric acid as a catalyst to prepare TBHQ in toluene solvents, and patent WO9716402 uses water and Alkylation with benzenesulfonic acid in methanol, all of these methods use organic solvents, which are likely to cause large pollution, and the problem of solvent residues must be solved when the product is purified
Patent WO0198242 purifies TBHQ with a mixed solvent of water and toluene, and US5087771 uses a similar method to purify IBHQ with a mixed solvent of water and naphtha. They all use non-polar solvents to dissolve 2,5-di-tert-butylhydroquinone DTBHQ makes its content less than 0.2%, but there are deficiencies in the use of organic solvents, and the process efficiency is not high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Add 60kg of hydroquinone, 40kg of tert-butanol and 200kg of 85% phosphoric acid into the reactor, stir and heat up to 90°C, react for 1 hour, stop heating and cool down to 70°C to discharge, filter the reaction mixture, recover phosphoric acid, use a small amount of Rinse the crude TBHQ in cold water. Wherein the content of TBHQ is 55.6%, and the yield is 41.8% according to hydroquinone.

Embodiment 2

[0019] Add 40kg of the above crude product, 500kg of water, 2kg of sodium sulfite, and 4kg of hydrochloric acid into the reaction kettle, stir and heat up to 90°C, keep it warm for 1 hour, discharge at this temperature, filter, and the filter residue is DTBHQ, which is collected for other use. After the filtrate is cooled to room temperature, filter, rinse with a small amount of cold water, weigh 20.6kg after vacuum drying, the recovery rate is 92.6%, the TBHQ content is 99.6%, and the DTBHQ content is less than 0.2%.

Embodiment 3

[0021] As in Example 2, sodium sulfite consumption is 3kg, phosphoric acid is 2kg, the TBHQ recovery rate is 93.1, the content is 99.7%, and the DTBHQ content is less than 0.2%.

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PUM

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Abstract

A process for preparing tert-butyl hydroquinone (TBHQ) includes such steps as dewatering alkylation reaction between hydroqainone and tert-butanol under catalysis of acid to obtain TBHQ, and purifying by reducing agent and acid.

Description

technical field [0001] The invention relates to a preparation method of an antioxidant, in particular to a preparation method for synthesizing tert-butylhydroquinone (TBHQ) by taking hydroquinone and tert-butanol as raw materials. technical background [0002] TBHQ is a low toxicity, high-efficiency antioxidant. It was approved for use in the United States in 1972. By 1995, more than 20 countries and regions had allowed its use. It was approved for use in my country in 1991. It has good safety and high antioxidant performance, and it is more effective for unsaturated oils than other commonly used antioxidants. TBHQ has excellent oil solubility, does not change color and flavor when it encounters copper and iron metals, and does not produce peculiar smell and odor when added to any oil and grease food. This makes it widely used in edible oils and oily foods. In addition, TBHQ can also be used as an intermediate in organic synthesis, polyester raw materials, photosensitizers,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C37/11C07C39/08
Inventor 刘立国刘远红
Owner GUANGZHOU YOUBAO IND
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