CN1276904C - Improved process for preparing edible grease antioxidant 2-tert-butyl hydroquinone - Google Patents

Abstract

The present invention relates to a production method of an improved edible grease antioxidant TBHQ, which comprises the following steps: (A) a tert-butylation reaction of hydroquinone and isobutylene is carried out in a binary mix solvent system composed of fragrance hydrocarbon solvent and ketone solvent, and 70% phosphoric acid is used as catalysts; (B) a principal product TBHQ and a by-product DTBHQ are generated in a separation reaction; (C) the by-product DTBHQ, the hydroquinone and the hydroquinone with the tert-butylation reaction to be carried out in the next batch are mixed in the binary mix solvent system, acid catalysts are added for backflow, and an alkyl transferring reaction is carried out; (D) the transferring reaction catalysts are separated from the reaction system, and 70% phosphoric acid is added to the reaction system to be used as catalysts; (E) the processes of step (A) to (D) are repeated in a circulating way. The complete circulation production process of TBHQ fundamentally does not generate DTBHQ needing discarding, and excessive separation or other complex operation processes do not need to be added. The production method of the present invention has the advantages of mild condition, good product quality and greatly reduced production cost.

Description

A kind of production method of improved edible grease antioxidant 2-tert-butyl Resorcinol

Technical field

The present invention relates to the production method of a kind of edible grease antioxidant 2-tert-butyl Resorcinol (TBHQ).

Background technology

2-Tert. Butyl Hydroquinone (TBHQ) is a kind of ten minutes edible grease antioxidant efficiently, and its antioxidant effect is 3～6 times of other edible grease antioxidant commonly used, and is effective especially to oxidized easily vegetative grease especially.The production of TBHQ be with Resorcinol (HQ) and iso-butylene under the effect of an acidic catalyst, the tertiary butyl one substitution reaction takes place on the Resorcinol phenyl ring and generate.2,5 di tert butyl hydroquinone (DTBHQ) is the by product that is easy to generate when producing TBHQ.The generation of two substitution reaction by product DTBHQ has reduced the utilization ratio of Resorcinol, has also increased the production cost of TBHQ; In addition, DTBHQ anorexia usefulness is as aldehydes matter, as discarding contaminate environment.

In order to reduce the generation of DTBHQ, promptly improve the selectivity of TBHQ and reduce side reaction such as oxidation, generally use water soluble acid, with arene or contain the mixed solvent of arene binary as solvent as catalyzer, and the concentration of control acid, but still have the DTBHQ of more amount to produce.For example: Japanese patent laid-open 6-228031, the phosphoric acid with 70% are as catalyzer, and as solvent, heating feeds the iso-butylene of the HQ 1.5 times (mol ratios) that feeds intake relatively with dimethylbenzene.Contain TBHQ 74.4%, unreacted HQ 0.5%, DTBHQ 22.8% in the reaction mixture, this shows that nearly Resorcinol more than 20% is converted into DTBHQ and loses.

Japanese patent laid-open 8-176044 and for example, the phosphoric acid with 70% are as catalyzer, and as the mixed solvent of binary, heating feeds the iso-butylene of the HQ 1.1 times (mol ratios) that feeds intake relatively with dimethylbenzene/methyl iso-butyl ketone (MIBK).Contain TBHQ 77%, unreacted HQ 9.8%, DTBHQ 14.2% in the reaction mixture, this shows that nearly 15% Resorcinol is converted into DTBHQ and loses.

Japanese patent laid-open 8-176044 has reported that also a kind of DTBHQ that tells is converted into the method for TBHQ through dealkylation reactive moieties DTBHQ dealkylation from reactant system.Its primary process is: 18 gram DTBHQ residues (containing a small amount of TBHQ) add 18 gram dimethylbenzene and make solvent, and 0.4 gram tosic acid is made catalyzer, 140 ℃ of following stirring reactions 4 hours, and the iso-butylene that produces is collected in cooling.Actual experiment proves that because DTBHQ solubleness in dimethylbenzene is very little, TBHQ solubleness in dimethylbenzene is much bigger on the contrary, so the DTBHQ dealkylation is converted into TBHQ seldom, the almost whole dealkylations of TBHQ are converted into HQ on the contrary.And at high temperature can produce a large amount of dark oil by products, product is difficult to make with extra care.

Summary of the invention

The object of the present invention is to provide the production method of a kind of improved edible grease antioxidant 2-tert-butyl Resorcinol (TBHQ), this method does not produce substantially needs depleted 2,5-di-tert-butyl hydroquinone (DTBHQ), and need not to increase too much separation or other complex operations process.

The production method of a kind of improved edible grease antioxidant 2-tert-butyl Resorcinol provided by the invention (TBHQ) may further comprise the steps:

(A) with Resorcinol (HQ) and iso-butylene in a kind of dual blending solvent system of forming by aromatic hydrocarbon solvent and ketones solvent, the phosphoric acid with 70% carries out tertiary butyl reaction as catalyzer;

(B) the principal product 2-Tert. Butyl Hydroquinone (TBHQ) and by product 2,5 di tert butyl hydroquinone (DTBHQ) of separating reaction generation, and the first water of unreacted Resorcinol (HQ) washes out;

(C) in above-mentioned dual blending solvent system with by product 2,5-di-tert-butyl hydroquinone (DTBHQ) is mixed with the Resorcinol (HQ) that next batch desires to carry out tertiary butyl reaction, and the adding an acidic catalyst refluxes, carry out transalkylation reaction (be that the tertiary butyl on a part of DTBHQ phenyl ring is transferred on the phenyl ring of a part of HQ, thereby DTBHQ of this part or HQ all being converted into TBHQ);

(D) transfer reaction activator is separated from reaction system, reaction system adds 70% phosphoric acid as catalyzer;

(E) process of circulation repeating step (A)～(D).Wherein:

Aromatic hydrocarbon solvent is toluene, dimethylbenzene, trimethylbenzene or ethylbenzene etc. described in the step (A); Described ketones solvent is acetone, methyl iso-butyl ketone (MIBK) or butanone etc.; The weight proportion of aromatic hydrocarbon solvent and ketones solvent is 1: 0.5～3.

An acidic catalyst described in the step (C) is the vitriol oil, Phenylsulfonic acid, toluene sulfonic acide, thionamic acid, macropore sulfonic acid type polystyrene ion-exchange resin, phospho-molybdic acid, phospho-wolframic acid or silicotungstic acid etc.

The time of transalkylation reaction described in the step (C) is 2～5 hours, and then to be converted into the transformation efficiency of TBHQ be 60～70% to DTBHQ, long as the reaction times, and then reaction conversion ratio improves slowly, and other by product increases, and the reaction solution color and luster is deepened.Because DTBHQ that follow-up tertiary butyl reaction produced and the basic equivalent of DTBHQ that is transformed do not need depleted DTBHQ so the full cycle production process does not produce substantially.The temperature of transalkylation reaction is 70～140 ℃, is advisable with 100～120 ℃.

Transalkylation reaction finishes in the step (D), the method of separating transfer reaction activator from reaction system is: when insoluble catalyzer such as use macropore strong acid resin, after reaction was finished, direct filtration was removed while hot, can use after handling with ordinary method such as filtration method again; When using sulfuric acid, Phenylsulfonic acid etc. for the soluble catalyzer of reaction system, after finishing, reaction, can remove these water-soluble big catalyzer while hot with the less water washing, notice that the water yield can not be too many, in order to avoid TBHQ or HQ loss.

The method that the method for tertiary butyl reaction is refered in particular to Japanese patent laid-open 8-176044 in the step (A), the phosphoric acid of adding 70% in removing the transalkylation reaction reaction liquid with catalyst, and the iso-butylene of the unconverted relatively HQ of feeding 1.1 times (mol ratios) carries out tertiary butyl reaction.When carrying out tertiary butyl reaction with this method, the DTBHQ amount that the amount of the DTBHQ pair of by-product and front conversion reaction transform is approximately consistent, thus whole process of production by-product DTBHQ not.

Principal product TBHQ and the isolating method of by product DTBHQ are taked the described dioxane adducts of Japanese patent laid-open 6-228031 crystalline method in the step (B).The purity of separating the DTBHQ that obtains with this method is about 99.2%, can be used for the transalkylation reaction of next batch.Take above-mentioned separation method in the past in order to get rid of unreacted HQ to isolating interference, water washes out the HQ in the crude reaction earlier, and the HQ of recovery can be reused for reaction.

Compared with prior art, the full cycle production process of TBHQ of the present invention does not produce substantially needs depleted DTBHQ, and need not to increase too much separation or other complex operations process; condition is gentle; good product quality, production cost reduces greatly, and helps environment protection.

Embodiment

The present invention all can realize purpose of the present invention by above relevant processing condition of putting down in writing and material, and not only is confined to following examples.

Embodiment 1

In 1 liter there-necked flask, drop into mixed solvent 270 grams of binary that Resorcinol (HQ) 110 gram (1 mole), 70% phosphatase 11 10 grams and dimethylbenzene/methyl iso-butyl ketone (MIBK) are formed according to 1: 1 weight ratio.Stirring is warming up to 90 ℃, begins to feed the iso-butylene of 59 grams (1.1 moles), and insulation reaction finished after 2 hours.The reaction solution standing demix is emitted lower floor's acid layer, to be recycled applying mechanically while hot; The organic layer on upper strata steam desolventize the TBHQ crude product, wherein contain TBHQ 74.4%, unreacted HQ 0.5%, DTBHQ 22.8% (not comprising residual solvent and a small amount of other impurity).

Embodiment 2

In 1 liter there-necked flask, drop into purity and be mixed solvent 270 gram and the D001 type macropore strong acid resin catalysts of binary that 99.2% DTBHQ 33 grams (0.15 mole), Resorcinol (HQ) 110 grams (1 mole), dimethylbenzene/methyl iso-butyl ketone (MIBK) are formed according to 1: 1 weight ratio.Under good the stirring, be warming up to about 110 ℃, insulation reaction 2.5 hours.Elimination resin catalyst while hot.The reaction solution analysis that takes a morsel wherein contains DTBHQ12.8 gram (about 0.06 mole), unconverted HQ101 gram (about 0.91 mole), TBHQ2.8 gram (about 0.18 mole) (not comprising residual solvent and a small amount of other impurity).

The phosphatase 11 10 of adding 70% restrains, and begins to feed the iso-butylene of 56 grams (1 mole), and insulation reaction finished after 2 hours.The reaction solution standing demix is emitted lower floor's acid layer, to be recycled applying mechanically while hot; The organic layer on upper strata steam desolventize the TBHQ crude product, wherein contain DTBHQ 32.6 grams (about 0.15 mole), unconverted HQ10.1 gram (about 0.09 mole), TBHQ164 gram (about 1 mole) (not comprising residual solvent and a small amount of other impurity).

Embodiment 3

Reflux in the crude product adding 500ml water of embodiment 2, the cooling post crystallization filters the crude product that has obtained removing HQ.

The above-mentioned crude product of having removed HQ adds dimethylbenzene 600ml, dioxane 100 grams (0.18 mole), is warming up to 90 ℃, makes solid molten entirely, be cooled to slowly then 30 ℃ separate out the dioxane adducts of DTBHQ, filter out this adducts; Filtrate contains the dioxane adducts of TBHQ, and distillation is cooled off partial crystallization again and got TBHQ after reclaiming dioxane, and dry back purity is 99.5%, 129.5 ℃ of fusing points, and outward appearance is the white crystals sprills; The above-mentioned DTBHQ adducts that filters out, cools off partial crystallization again and gets the DTBHQ29.8 gram after dioxane is reclaimed in distillation with the dimethylbenzene rising temperature for dissolving of 4 times of volumes, and dry back purity is 99.2%.

Embodiment 4～13

Repeat embodiment 2 and embodiment 3 totally 10 times, be about to the DTBHQ that embodiment 3 obtains and all be used for embodiment 2.DTBHQ amount behind these 10 times tertiary butyl reactions of obtaining of experiment in the crude product with separate dried purity and see the following form:

The embodiment sequence number	The amount of DTBHQ in the crude product (gram)	Separate dried purity (%)
			4	33.1	99.2
5	31.9	99.2
			6	32.6	99.0
7	35.3	99.5
			8	33.2	99.4
9	30.8	99.2
			10	33.0	99.1
11	33.9	99.6
			12	33.5	99.2
13	33.4	99.3

The foregoing description proof generates in successive TBHQ production process and the basic equivalent of DTBHQ that is transformed, not the trend of sustainable growth.Whole process of production does not generate substantially like this needs depleted by product DTBHQ.

Claims (7)

1, a kind of production method of improved edible grease antioxidant 2-tert-butyl Resorcinol is characterized in that may further comprise the steps:

(A) with Resorcinol and iso-butylene in a kind of dual blending solvent system of forming by aromatic hydrocarbon solvent and ketones solvent, the phosphoric acid with 70% carries out tertiary butyl reaction as catalyzer;

(B) the principal product 2-Tert. Butyl Hydroquinone and the by product 2,5 di tert butyl hydroquinone of separating reaction generation, and unreacted Resorcinol elder generation water washes out;

(C) it is mixed by product 2,5 di tert butyl hydroquinone and next batch to be desired to carry out the Resorcinol of tertiary butyl reaction in above-mentioned dual blending solvent system, and adds an acidic catalyst and reflux, and carries out transalkylation reaction;

(D) transfer reaction activator is separated from reaction system, reaction system adds 70% phosphoric acid as catalyzer;

(E) process of circulation repeating step (A)～(D).

2, production method according to claim 1 is characterized in that aromatic hydrocarbon solvent is toluene, dimethylbenzene, trimethylbenzene or ethylbenzene described in the step (A); Described ketones solvent is acetone, methyl iso-butyl ketone (MIBK) or butanone.

3, production method according to claim 1 and 2, the weight proportion that it is characterized in that described aromatic hydrocarbon solvent and ketones solvent is 1: 0.5～3.

4, production method according to claim 1 is characterized in that an acidic catalyst described in the step (C) is the vitriol oil, Phenylsulfonic acid, toluene sulfonic acide, thionamic acid, macropore sulfonic acid type polystyrene ion-exchange resin, phospho-molybdic acid, phospho-wolframic acid or silicotungstic acid.

5, production method according to claim 1, the time that it is characterized in that transalkylation reaction described in the step (C) is 2～5 hours.

6, production method according to claim 1, the temperature that it is characterized in that transalkylation reaction described in the step (C) is 70～140 ℃.

7, production method according to claim 1 is characterized in that the method that transalkylation reaction finishes to separate transfer reaction activator in the back from reaction system in the step (D) can adopt WATER-WASHING METHOD or filtration method.