阅读说明：本技术 一种用于苯乙烯精馏的复配阻聚剂及其制备方法 (Compound polymerization inhibitor for styrene rectification and preparation method thereof ) 是由 黄占凯 张春丽 赵甲 赵阳 唐亚芳 于 2020-12-26 设计创作，主要内容包括：本发明涉及一种用于苯乙烯精馏的阻聚剂及其制备方法。该阻聚剂是由稳定自由基型化合物、醌类化合物、四甲基炔二醇化合物和有机溶剂组成。该体系中的四甲基炔二醇化合物能促进稳定自由基型化合物和醌类化合物在有机溶剂体系中的溶解,使该阻聚剂兼具缓阻和真阻聚剂的特点,提高阻聚效果,减少苯乙烯装置的焦油排放量,提高了苯乙烯精馏装置的生产能力。(The invention relates to a polymerization inhibitor for styrene rectification and a preparation method thereof. The polymerization inhibitor consists of a stable free radical type compound, a quinone compound, a tetramethyl alkynediol compound and an organic solvent. The tetramethyl alkynediol compound in the system can promote the dissolution of stable free radical type compounds and quinone compounds in an organic solvent system, so that the polymerization inhibitor has the characteristics of a slow-inhibition and a real polymerization inhibitor, the polymerization inhibition effect is improved, the tar discharge amount of a styrene device is reduced, and the production capacity of the styrene rectification device is improved.)

1. The polymerization inhibitor for styrene rectification is characterized by comprising the following components:

A) a stable free radical type compound selected from the group consisting of 4-hydroxy-2, 2,6, 6-tetramethylpiperidinyloxy radical (4-hydroxy-TEMPO), 4-carbonyl-2, 2,6, 6-tetramethylpiperidinyloxy radical (4-carbonyl-TEMPO), N-di-tert-butylnitroxide radical, 4-acetylamino-2, 2,6, 6-tetramethylpiperidinyloxy radical, 4-amino-2, 2,6, 6-tetramethylpiperidinyloxy radical, 4-methoxy-2, 2,6, 6-tetramethylpiperidinyloxy radical, tris (4-oxo-2, 2,6, 6-tetramethylpiperidinyloxy) phosphine radical, 1-diphenyl-2-picrazino radical (DPPH), At least one of 2, 6-di-tert-butyl- (3, 5-di-tert-butyl-4-oxo-2, 5-cyclohexadiene) -p-tolyloxy free radical or mixture of more thereof;

B) quinone compound selected from at least one or more of 2, 6-di-tert-butyl-4-phenylmethylene-2, 5-cyclohexadiene-1-one and its derivatives;

C) a 50% dipropylene glycol solution containing a tetramethyleneacetylenediol compound of formula I;

wherein n is 1, 2;

D) the organic solvent is a mixed solution of ethylbenzene and methanol;

wherein, the mass percent of the component A) is 7-10%, the mass percent of the component B) is 30-40%, the mass percent of the component C) is 0.1-0.5%, and the balance is organic solvent.

2. The styrene polymerization inhibitor according to claim 1, wherein the mass ratio of ethylbenzene to the quinone compound is not less than 1: 1.

3. A method for preparing a styrene polymerization inhibitor according to claim 1, comprising:

(1) adding the component A) into a methanol solution at room temperature, and stirring to fully dissolve the component A) to obtain a uniform and transparent solution;

(2) adding the component B) into an ethylbenzene solution under stirring, and stirring to fully dissolve the component B) to obtain a uniform and transparent solution;

(3) mixing and stirring the methanol solution of the component A), the ethylbenzene solution of the component B) and the component C) to obtain a uniform solution.

Technical Field

The invention relates to a polymerization inhibitor for a styrene rectifying device and a preparation method thereof, belonging to the field of chemical production auxiliaries.

Background

The ring-outside double bonds of styrene are very active, and in the rectification process, free radicals are generated by thermal initiation to polymerize and form high polymers, so that not only is the styrene monomer consumed and the product quality is influenced, but also the generated polymers can block equipment and pipelines of the next process, and the continuous production is seriously threatened. In order to reduce the self-polymerization of styrene, in addition to the vacuum operation to lower the rectification temperature, a polymerization inhibitor is generally added to react with the chain radicals of styrene to form non-radical species or low-activity radicals which cannot be initiated, thereby terminating the polymerization of styrene.

At present, polymerization inhibitors are mainly classified into a real polymerization inhibitor and a retarder, wherein the real polymerization inhibitor hardly generates polymers during induction, but is easily consumed by free radicals, and does not have a polymerization inhibition effect after the induction. Retarders such as DNBP are chemically stable, can effectively reduce the polymerization rate during polymerization inhibition, have less failure, but cannot generate a significant induction period, and therefore, lead to a slow increase in the polymer content. In order to combine the advantages of retarder and real polymerization inhibitor and overcome the disadvantages of single polymerization inhibitor, research on compound polymerization inhibitor has been started at home and abroad. Patent CN102249842 discloses a polymerization inhibitor compounded by nitroxide free radical compounds, nitrophenol compounds, hydroxylamine compounds and phosphite compounds. Patent CN1974503 discloses a compound polymerization inhibitor which is prepared by compounding piperidine derivatives, phenylenediamine compounds and nitrophenol compounds and has good polymerization inhibition effect. The disclosed compound polymerization inhibitor contains nitrophenol compounds, has high toxicity and is not environment-friendly. With the increasing national requirements on environmental protection and the increasing awareness of environmental protection, the dosage of the nitrophenol polymerization inhibitor is gradually reduced. The quinone compounds have low toxicity, and the quinone compounds begin to replace nitrophenol polymerization inhibitors at present, which is a trend of development of green polymerization inhibitors.

Disclosure of Invention

The invention aims to provide a compound styrene rectification polymerization inhibitor, which contains two effective components with synergistic effect in the styrene rectification process, has the advantages of a resistance-reducing agent and a real resistance-reducing agent, and can reduce and inhibit styrene free radicals generated by thermal initiation, thereby reducing the generation amount of polymers, reducing the generation amount of tar, improving the yield of styrene, ensuring the stable operation of a rectification device and improving the economic benefit. Meanwhile, the polymerization inhibitor does not contain nitrophenol, has low toxicity and is environment-friendly.

In order to achieve the purpose, the invention adopts the following technical scheme:

a novel compound polymerization inhibitor product comprises the following components:

A) a stable free radical type compound selected from the group consisting of 4-hydroxy-2, 2,6, 6-tetramethylpiperidinyloxy radical (4-hydroxy-TEMPO), 4-carbonyl-2, 2,6, 6-tetramethylpiperidinyloxy radical (4-carbonyl-TEMPO), N-di-tert-butylnitroxide radical, 4-acetylamino-2, 2,6, 6-tetramethylpiperidinyloxy radical, 4-amino-2, 2,6, 6-tetramethylpiperidinyloxy radical, 4-methoxy-2, 2,6, 6-tetramethylpiperidinyloxy radical, tris (4-oxo-2, 2,6, 6-tetramethylpiperidinyloxy) phosphine radical, 1-diphenyl-2-picrazino radical (DPPH), At least one of 2, 6-di-tert-butyl- (3, 5-di-tert-butyl-4-oxo-2, 5-cyclohexadiene) -p-tolyloxy free radical or mixture of more thereof;

B) quinone compound selected from at least one or more of 2, 6-di-tert-butyl-4-phenylmethylene-2, 5-cyclohexadiene-1-one and its derivatives;

C) a50% dipropylene glycol solution containing a tetramethylenealkynediol compound of formula I

Wherein n is 1 or 2

D) The organic solvent is a mixed solution of ethylbenzene and methanol

Wherein, the mass percent of the component A is 7-10%, the mass percent of the component B is 35-45%, the mass percent of the component C is 0.1-0.5%, and the balance is organic solvent.

The preparation method of the compound polymerization inhibitor comprises the following steps:

(1) adding the component A) into a methanol solution at room temperature, and stirring to fully dissolve the component A) to obtain a uniform and transparent solution. (ii) a

(2) Adding the component B) into an ethylbenzene solution under stirring, and stirring to fully dissolve the component B) to obtain a uniform and transparent solution. (ii) a

(3) Mixing and stirring the methanol solution of the component A), the ethylbenzene solution of the component B) and the component C) to obtain a uniform solution.

The polymerization inhibitor has the beneficial effects that: the mixed solvent of methanol and ethylbenzene is adopted, the problems of low solubility of a free radical compound in a nonpolar solvent and low solubility of a quinone compound in a polar solvent are solved, and the unique surface activity of the tetramethylalkynediol compound promotes the solubility of two different polar substances in the same system, so that the free radical compound and the quinone compound can stably exist in the same system. The free radical compound has the property of a real resistance agent, the quinone compound has the property of a resistance reducing agent, the two compounds generate a synergistic effect in the same system, so that the compound polymerization inhibitor has the characteristics of resistance reducing and real resistance, and can generate an induction period and reduce the polymerization inhibition rate in the polymerization inhibition process, thereby improving the polymerization inhibition effect. However, when the free radical compound and the quinone compound are used as two polymerization inhibitors and are respectively added into a styrene rectification system, the polymerization inhibition effect is poorer than that of a compound polymerization inhibitor even if the adding amount of the effective components is the same. The polymerization inhibitor has the following beneficial effects: the adopted components of the retarder do not contain nitrophenol compounds, and the retarder is low in toxicity and environment-friendly.

Detailed Description

In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.

1. Purification and treatment of styrene reagent

A certain amount of styrene is taken in a separating funnel, and is repeatedly washed by 5 percent sodium hydroxide solution (which reacts with phenol polymerization inhibitor in the styrene), and the styrene solution washed by the alkali solution is colorless or slightly yellow. Washing the solution with distilled water until the water layer is neutral, separating the water layer, adding anhydrous sodium sulfate, drying, and standing to be transparent. Filtering to remove desiccant, placing into a Kjeldahl flask, distilling under reduced pressure, and collecting the fraction at 44-45 deg.C/2666.44 Pa (20mmHg) or 59-60 deg.C/5332.8 Pa (40 mmHg). Pure styrene monomer is obtained.

2. Conditions of polymerization experiment

Taking a clean colorimetric tube with a plug, weighing 50g of purified styrene, then accurately injecting a certain amount of polymerization inhibitor solution by using a microsyringe, fully mixing, placing in an oil bath at a certain temperature, starting timing, taking a proper amount of reaction liquid after reacting for a period of time, and calculating the generation amount of the polymer by adopting a gravimetric method.

3. Polymer testing method

A1.2 μmGF/C filter paper baked to constant weight and cooled to room temperature was weighed (w 1). Weigh the sample into a 100ml beaker and record the sample weight (w)₂). Adding magneton and 50ml methanol, stirring, reacting for 60min, placing 1.2 μm filter paper into Buchner funnel, wetting with methanol, pouring reaction solution, vacuum filtering with vacuum pump, draining, washing with methanol, taking out filter paper and filter cake, oven drying at 105 deg.C for 1 hr, taking out, cooling in desiccator to room temperature, weighing (w is n is₃)。

Example one

The polymerization inhibitor comprises the following components:

4-carbonyl-2, 2,6, 6-tetramethylpiperidine nitroxide radical: 10 percent of

4-benzylidene-2, 6-di-tert-butyl-2, 5-cyclohexadien-1-one: 30 percent of

Methanol: 27.7 percent

Ethylbenzene: 30 percent of

2,5,8, 11-tetramethyl-6-dodecyne-5, 8-diol in 50% dipropylene glycol: 0.3 percent of

Example two

The polymerization inhibitor comprises the following components:

4-carbonyl-2, 2,6, 6-tetramethylpiperidine nitroxide radical: 8.5 percent

4-benzylidene-2, 6-di-tert-butyl-2, 5-cyclohexadien-1-one: 35 percent of

Methanol: 21.2 percent

Ethylbenzene: 35 percent of

2,5,8, 11-tetramethyl-6-dodecyne-5, 8-diol: 0.3 percent of

EXAMPLE III

The polymerization inhibitor comprises the following components:

4-carbonyl-2, 2,6, 6-tetramethylpiperidine nitroxide radical: 7 percent of

4-benzylidene-2, 6-di-tert-butyl-2, 5-cyclohexadien-1-one: 40 percent of

Methanol: 12.7 percent

Ethylbenzene: 40 percent of

2,5,8, 11-tetramethyl-6-dodecyne-5, 8-diol: 0.3 percent of

Comparative example 1

Real polymerization inhibitor

4-carbonyl-2, 2,6, 6-tetramethylpiperidine nitroxide radical: 10 percent of

Methanol: 90 percent of

Slow polymerization inhibitor

4-benzylidene-2, 6-di-tert-butyl-2, 5-cyclohexadien-1-one: 30 percent of

Ethylbenzene: 70 percent of

Comparative example 2

Real polymerization inhibitor

4-carbonyl-2, 2,6, 6-tetramethylpiperidine nitroxide radical: 7 percent of

Methanol: 93 percent

Slow polymerization inhibitor

4-benzylidene-2, 6-di-tert-butyl-2, 5-cyclohexadien-1-one: 40 percent of

Ethylbenzene: 40 percent of

Comparative example three

Real polymerization inhibitor

4-carbonyl-2, 2,6, 6-tetramethylpiperidine nitroxide radical: 8.5 percent

Methanol: 91.5 percent

Slow polymerization inhibitor

4-benzylidene-2, 6-di-tert-butyl-2, 5-cyclohexadien-1-one: 35 percent of

Ethylbenzene: 65 percent of

TABLE 1 Polymer content after reaction time 30min at 600ppm addition

TABLE 2 Polymer content after reaction time 60min at 600ppm addition