TWI400252B - A process for inhibiting polymerization of an aromatic vinyl compound - Google Patents

Description

Method for inhibiting polymerization of aromatic vinyl compounds

The present invention relates to a method for inhibiting polymerization of an aromatic vinyl compound or a process fluid containing the same in the steps of producing, purifying, storing or transporting an aromatic vinyl compound.

The aromatic vinyl compound, particularly styrene, is an industrially important compound which is a raw material for production of polystyrene, synthetic rubber, or ABS resin, and is industrially produced in large quantities.

In general, the aromatic vinyl compound is highly polymerizable, and it is easy to polymerize by heating or the like in the production or purification step, and the yield of the aromatic vinyl compound monomer is lowered, and the generation of dirt (dirt) in the related equipment hinders the operation of the equipment. The problem. It is recommended to add a method of suppressing the polymerization agent to the process stream as a countermeasure for practical use. For example, a method of using phenol, nitrosophenol, or nitrophenol (for example, refer to Patent Document 1) or a method using piperidin-1-hydroxyl (for example, refer to Patent Document 2), and using nitrophenol and piperidine-1- A method of combining a hydroxyl group (for example, refer to Patent Document 3), a method of combining an alkylsulfonic acid and a dialkylhydroxylamine (for example, refer to Patent Document 4), and a method of combining a phosphate ester and an alkylsulfonic acid (for example, refer to Patent Document 5) A method for suppressing the increase in viscosity of an olefin process, and adding a phenol-based, amine-based, nitroso-based polymerization inhibitor, dodecylbenzenesulfonic acid, and a salt thereof (for example, see Patent Document 6) for preventing treatment In the ethylene compound step, a method of adding a benzophenone-based, hydroquinone-based, nitroso-based or phenylenediamine-based amine-based polymerization inhibitor and dodecylbenzenesulfonic acid and the salt (for example, refer to Patent Document 7). ). Most of them use nitrophenol 2,6-dinitrophenol (DNP), 2,6-dinitro-4-methylphenol, 2,4-dinitro-6-sec-butylphenol (DNBP). As a polymerization inhibitor for aromatic vinyl compounds. However, these agents show a tendency to slowly decrease the polymerization inhibition force, and since they are equivalent to toxic substances, care must be taken during the treatment. For this reason, it is strongly desired to maintain the controlled polymerization effect of such agents, and to reduce the amount of use.

[Patent Document 1] Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. [Patent Document 5] Japanese Patent Publication No. 4, 425, 223 (Patent Document 6) Japanese Laid-Open Patent Publication No. Hei No. Hei No. Hei.

Therefore, an object of the present invention is to provide a step of producing, purifying, storing, transporting, and transporting an aromatic vinyl compound, suppressing initial polymerization, and suppressing polymerization for a long period of time, and suppressing aromaticity which is excellent in handleability. A method of polymerizing a vinyl compound.

The present inventors examined in detail the results of the characteristics of the polymerization reaction of the ethylene compound, and found that the combination of the specific nitrogen-containing aromatic compound and the sulfonic acid compound can be used to obtain a synergistic effect of suppressing polymerization superiorly when used alone. The present invention has been completed.

That is, the invention of claim 1 is characterized in that at least one of (A) is selected from the following general formula (I), (II) in the step of producing, purifying, storing or transporting the aromatic vinyl compound; And (B) a method of inhibiting polymerization of an aromatic vinyl compound by a sulfonic acid compound represented by the following general formula (V).

(wherein R ₁ to R ₇ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 2 to 12 carbon atoms, or carbon; a 6 to 14 aryl group, an amine group, a linear or branched alkyl group having 1 to 12 carbon atoms or a dialkylamino group, one having an aryl group having 6 to 12 carbon atoms or a diarylamine a group, a fluorenyl group, a carboxyl group, an aminomethyl fluorenyl group, a sulfonic acid group, may have an alicyclic or aromatic structure adjacent to two substituents; X is an oxygen atom or a sulfur atom, and Y is an oxygen atom or a nitrogen atom. ;)

(wherein R ₈ to R ₁₅ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 2 to 12 carbon atoms, or carbon; a 6 to 14 aryl group, an amine group, a linear or branched alkyl group having 1 to 12 carbon atoms or a dialkylamino group, one having an aryl group having 6 to 12 carbon atoms or a diaryl group Amine, formazan, carboxyl, aminomethyl sulfonyl, sulfonic acid group, may have an alicyclic or aromatic structure adjacent to two substituents; X is an oxygen atom or a sulfur atom, and Z is a formic acid ion, acetic acid Ions, propionic acid ions, sulfate ions, chloride ions, nitrate ions;)

(wherein R ₁₆ to R ₂₅ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an aromatic group having 6 to 14 carbon atoms; a group, an amine group, one or a dialkylamino group having a linear or branched alkyl group having 1 to 12 carbon atoms, one or a diarylamino group having a carbon number of 6 to 12, and a fluorenyl group. a carboxyl group, an aminomethyl sulfonyl group or a sulfonic acid group, which may have an alicyclic or aromatic ring structure in the vicinity of two substituents;

(wherein R ₂₆ to R ₃₁ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 2 to 12 carbon atoms, or carbon; a 6 to 14 aryl group, an amine group, an alkyl-substituted amine group having at least one linear or branched alkyl group having 1 to 12 carbon atoms or an aromatic group having at least one carbon number of 6 to 14 a substituted amino group, R ₂₆ and R ₂₇ , R ₂₈ and R ₂₉ , R ₂₉ and R ₃₀ or R ₃₀ and R ₃₁ may each be linked to each other to form an alicyclic or aromatic ring structure; (wherein R ₃₂ is a hydroxyl group, a linear or branched alkyl group having 1 to 32 carbon atoms, an alkyl-substituted phenyl group or an alkyl group having at least one linear or branched alkyl group having 1 to 32 carbon atoms; Substituted naphthyl.)

The invention of claim 2 is the method for inhibiting polymerization of an aromatic vinyl compound according to claim 1, wherein the nitrogen-containing aromatic compound represented by the general formula (I) of the component (A), At least one selected from the group consisting of methylene violet, resorufin and phenothiazine-3-oxide.

The invention of claim 3 is the method for inhibiting polymerization of an aromatic vinyl compound according to claim 1, wherein the nitrogen-containing aromatic compound represented by the general formula (II) of the component (A) is At least one selected from the group consisting of cresyl violet, sulfur only, and methylene blue.

The invention of claim 4 is the method for inhibiting polymerization of an aromatic vinyl compound according to claim 1, wherein the nitrogen-containing aromatic compound represented by the general formula (III) of the component (A) is Indigo and / or sulfonated indigo.

The invention of claim 5 is the method for inhibiting polymerization of an aromatic vinyl compound according to claim 1, wherein the nitrogen-containing aromatic compound represented by the general formula (IV) of the component (A) is At least 1 is selected from the group consisting of phenazine, 2-methylphenazine, 2-ethylphenazine, quinoxaline, 2-methylquinoxaline, 2-phenylquinoxaline, 3-amino-7-hydroxy- 2-methylphenazine and tetrabenzo[a,c,h,j]phenazine are grouped.

The invention of claim 6 is the method for inhibiting polymerization of an aromatic vinyl compound according to any one of claims 1 to 5, wherein the sulfonate of the general formula (V) of the component (B) The acid compound is at least one selected from the group consisting of toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, and dinonylnaphthalenesulfonic acid.

The invention of claim 7 is the method for inhibiting polymerization of an aromatic vinyl compound according to any one of claims 1 to 6, wherein the nitrogen-containing aromatic compound of the component (A) is added and the The sulfonic acid compound of the component B) is combined in a weight ratio of 5:95 to 95:5.

According to the present invention, it is possible to effectively suppress polymerization of an aromatic vinyl compound or a process fluid containing the same, and since the effect can be continued for a long period of time, the amount of dirt (dirt) generated in the related device is minimized, and the safety of the device is facilitated. The advantages of operation and cutting production costs.

[The best form for implementing the invention]

The step of suppressing polymerization of the present invention is a step of producing an aromatic vinyl compound, a step of purifying the aromatic vinyl compound after the production, and storing and storing the purified aromatic vinyl compound, and also containing the aromatic A follower device, a collateral device, and a recycle system or a recovery system containing the ethylene compound step. Aromatic ethylene a dehydrogenation reaction column or a synthesis reaction column of an alkyl aromatic compound in the compound production step, a reactant discharge line or a recovery recycle line after the reaction, and a feed pipe or a preheating line for the aromatic vinyl compound in the purification column in the purification step and The cooling pipeline is further circulated, the storage tank or the storage tank in the storage step, the transport tank and the transport tank, and the transport pipeline.

The aromatic vinyl compound is styrene and an alkyl styrene having an alkyl group having 1 to 10 carbon atoms, an α-alkylstyrene having an alkyl group having a carbon number of 1 to 10 at the α position, and a carbon having a β position. A styrene derivative having a polymerizable vinyl group such as a β-alkylstyrene having an alkyl group of 1 to 10 or more. Specificity is: styrene, methyl styrene (ortho, meta, para, and mixtures of these), ethyl styrene (ortho, meta, para and these Mixture), propylstyrene (ortho, meta, para, and mixtures thereof), butyl styrene (ortho, meta, para, and mixtures thereof), xin Styrene (ortho, meta, para, and mixtures thereof), mercaptostyrene (ortho, meta, para, and mixtures thereof), dimercaptostyrene (ortho-, meta-, para- and mixtures of such), α-methylstyrene (2-phenylpropene), 1-phenyl-1-propene (β-methylstyrene: cis a formula, a trans form, and the mixture), 2-phenyl-2-butene (cis, trans, and mixtures), stilbene (cis, trans, and mixtures) )Wait.

The nitrogen-containing aromatic compound represented by the general formulae (I) to (IV) which inhibits the polymerization of the aromatic vinyl compound is a hetero atom and has a cyclic structure. Among these compounds, The polycyclic imine compound represented by the general formulae (I) and (II), wherein R ₁ to R ₇ and (II) in the formula (I), R ₈ to R ₁₅ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 14 carbon atoms, an amine group, and having a carbon number of 1 to One of a straight or branched alkyl group of 12 or a dialkylamino group, one of the aryl groups having a carbon number of 6 to 12 or a diarylamine group, a decyl group, a carboxyl group, an aminomethyl sulfonyl group, a sulfonyl group Acid base. Further, it may have an alicyclic or aromatic structure in the vicinity of two substituents. X is an oxygen atom or a sulfur atom, and Y is an oxygen atom or a nitrogen atom. Z is not particularly limited as long as it is an anion formed by a polycyclic imine compound and a chlorine compound, and generally, an organic acid such as formic acid ion, acetic acid ion or propionic acid ion, a mineral acid such as a chloride ion, a sulfate ion or a nitrate ion can be exemplified. Anion. Specific examples of the polycyclic imine compound include resorufin, methylene violet, phenothiazine-3-oxide, cresy violet acetate, sulfur only, methylene violet, and the like.

Further, in the indigo compound represented by the general formula (III), wherein R ₁₆ to R ₂₅ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, and a carbon number of 2 to 12 Alkenyl group, aryl group having 6 to 14 carbon atoms, amine group, one or dialkylamino group having a linear or branched alkyl group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms The one or diarylamino group, a decyl group, a carboxyl group, an aminomethyl fluorenyl group, or a sulfonic acid group may have an alicyclic or aromatic ring structure adjacent to two substituents. Specificity As the indigo compound, indigo, sulfonated indigo, and the like are exemplified. These compounds are present in the structural tautomers, but indigo also contains such tautomeric compounds.

Further, a compound represented by the general formula (IV): wherein R ₂₆ to R ₃₁ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, and a carbon number of 2 to 12; a linear or branched alkenyl group, an aryl group having 6 to 14 carbon atoms, an amine group, an alkyl-substituted amine group having at least one linear or branched alkyl group having 1 to 12 carbon atoms or at least 1 The aryl group of 6 to 14 carbon atoms is substituted with an amine group, and R ₂₆ and R ₂₇ , R ₂₈ and R ₂₉ , R ₂₉ and R ₃₀ or R ₃₀ and R ₃₁ may each be linked to each other to form an alicyclic or aromatic group. Ring structure. As the specific compound, phenazine, 2-methylphenazine, 2-ethylphenazine, quinoxaline, 2-methylquinoxaline, 2-phenylquinoxaline, 3-amino group- 7-Hydroxy-2-methylphenazine and tetrabenzo[a,c,h,j]phenazine.

a sulfonic acid compound represented by the above general formula (V) which is a component (B) used in combination with the nitrogen-containing aromatic compound represented by the general formulae (I) to (IV) of the component (A), wherein R ₃₂ is a hydroxyl group, a linear or branched alkyl group having 1 to 32 carbon atoms, an alkyl-substituted phenyl group or an alkyl-substituted naphthyl group having at least one linear or branched alkyl group having 1 to 32 carbon atoms. The sulfonic acid compound is selected from one or more of these. Specific examples of the sulfonic acid compound include sulfuric acid, toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, and dinonylnaphthalenesulfonic acid. In particular, the solubility, price, and the like of the aromatic vinyl compound are preferably pentadecylbenzenesulfonic acid or dodecylbenzenesulfonic acid.

The mixing ratio of the nitrogen-containing aromatic compound of the component (A) of the present invention and the sulfonic acid compound of the component (B) is appropriately determined according to the purpose of suppressing the polymerization of the aromatic vinyl compound, and is not uniformly defined. Generally, the nitrogen-containing aromatic compound of the (A) component of the aromatic vinyl compound to be used and the sulfonic acid compound of the component (B) are in a weight ratio of 95:5 to 5:95 and 80:20 to 20:80. Preferably, it is preferably added in a combination of 70:30 to 30:70.

The addition amount of the step of the nitrogen-containing aromatic compound of the component (A) and the sulfonic acid compound of the component (B) varies depending on the conditions of the target step, the necessity of inhibiting the polymerization, and the like, and is not uniformly defined. In general, the aromatic vinyl compound to be used is a nitrogen-containing aromatic compound of the component (A) in an amount of from 1 to 3,000 ppm, preferably from 10 to 2,000 ppm, preferably from 100 to 1,000 ppm, and the sulfonic acid compound of the component (B) is 1 ~3000ppm, preferably from 10 to 2000 ppm, preferably from 100 to 1000 ppm. The addition amount of these is found to be an appropriate range for suppressing the polymerization of the aromatic vinyl compound to be exerted, and if it is less than this range, the effect is insufficient, and even if the effect is more than this range, the effect of the addition ratio is not It will become bigger and not economically.

The nitrogen-containing aromatic compound of the component (A) and the sulfonic acid compound of the component (B) of the present invention are not particularly limited in the step, but are usually polymerized from aromatic ethylene to form a problem in which the fouling is added to the upstream process. . For example, styrene is produced by a dehydrogenation reaction of general ethylbenzene, and the styrene and unreacted ethylbenzene which have been produced are continuously distilled and separated, and supplied to the distillation column group after the hydrogenation of ethylbenzene.

The method of adding the nitrogen-containing aromatic compound of the component (A) and the sulfonic acid compound of the component (B) in the present invention is not particularly limited, but is generally added to a specific portion or dispersed at a fractional fraction. The method has to be properly selected. In this case, the components (A) and (B) are separately added, but the two are dissolved in the same liquid of the process fluid in a suitable mixing ratio, for example, if it is styrene, it is dissolved in ethylbenzene or crude styrene. It is actually very convenient.

In addition to the components (A) and (B), the present invention is not limited thereto, and it is not limited to the range of effects of the present invention and other known polymerization inhibitors.

[Examples]

The invention is further illustrated by the examples, but the invention is not limited to the following examples.

[Assessing the compound used]

(A) component (nitrogen-containing aromatic compound) A-1: methylene violet (manufactured by Tokyo Chemical Industry Co., Ltd.) A-2: resorufin (manufactured by Tokyo Chemical Industry Co., Ltd.) A-3: cresol Aluminium (made by Aldrich Chemical Co., Ltd.) A-4: sulfur only (made by Aldrich Chemical Co., Ltd.) A-5: methylene blue (manufactured by Tokyo Chemical Industry Co., Ltd.) A-6: indigo A-7: sulfonated indigo A -8: quinoxaline A-9: 1-methylquinoxaline A-10: phenazine A-11: 3-amino-7-hydroxy-2-methylquinoxaline A-12: tetrabenzo [a, c, h, j] phenazine

(B) component (sulfonic acid compound) B-1: dodecylbenzenesulfonic acid B-2: pentadecylbenzenesulfonic acid B-3: xylenesulfonic acid B-4: cumenesulfonic acid B- 5: p-toluenesulfonic acid B-6: methanesulfonic acid B-7: sulfuric acid (98%)

(Other) DNBP: 2,4-Dinitro-6-sec-butylphenol H-TEMPO: 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-hydroxyl

(Inhibition polymerization test-1) Into a four-port separable flask equipped with a reflow cooler, 100 g of styrene monomer was placed, and a predetermined amount (the blending ratio of each agent is shown below) was added to the polymerization inhibitor of Table 1, and the mixture was blown in. The high purity nitrogen gas was used to remove dissolved oxygen for 30 minutes. Then, this was kept at 120 ° C, and a part of the contents was taken as a sample at a certain time to measure the amount of polymer produced in the liquid (ppm). The polymer in the suspension was suspended by adding methanol having a capacity of 9 times the sample solution, and the weight of the polymer was measured by filtration and weighed to determine the amount of polymer produced as a monomer. Before starting this experiment, the styrene monomer was washed with alkali to remove the polymerization inhibitor (tert-butyl catechol) contained in the monomer, washed with water, and dried. The results obtained are shown in Table 1.

As a result of the results shown in Table 1, it was found that the nitrogen-containing aromatic compound of the component (A) and the sulfonic acid compound of the component (B) did not exhibit a specific polymerization inhibitory effect, but a synergistic effect was exerted by combining the two. The polymerization effect is continued for a long time.

Claims (6)

A method for inhibiting polymerization of an aromatic vinyl compound, characterized in that at least one of (A) is selected from the following general formulas (I) and (III) in the step of producing, purifying, storing or transporting an aromatic vinyl compound; And a nitrogen-containing aromatic compound represented by (IV), and (B) a sulfonic acid compound represented by the following general formula (V); (wherein R ₁ to R ₇ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 2 to 12 carbon atoms, or carbon; a 6 to 14 aryl group, an amine group, a linear or branched alkyl group having 1 to 12 carbon atoms or a dialkylamino group, one having an aryl group having 6 to 12 carbon atoms or a diaryl group An amine group, a decyl group, a carboxyl group, an aminomethanyl group, a sulfonic acid group, or an alicyclic or aromatic structure in the adjacent two substituents; X is an oxygen atom or a sulfur atom, and Y is an oxygen atom or Nitrogen atom); (wherein R ₁₆ to R ₂₅ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an aromatic group having 6 to 14 carbon atoms; a group, an amine group, one or a dialkylamino group having a linear or branched alkyl group having 1 to 12 carbon atoms, one or a diarylamino group having a carbon number of 6 to 12, and a fluorenyl group. a carboxyl group, an aminomethyl sulfonyl group or a sulfonic acid group, which may have an alicyclic or aromatic ring structure in addition to two substituents; (wherein R ₂₆ to R ₃₁ are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 2 to 12 carbon atoms, or carbon; a 6 to 14 aryl group, an amine group, an alkyl-substituted amine group having at least one linear or branched alkyl group having 1 to 12 carbon atoms or an aromatic group having at least one carbon number of 6 to 14 a substituted amine group, R ₂₆ and R ₂₇ , R ₂₈ and R ₂₉ , R ₂₉ and R ₃₀ or R ₃₀ and R ₃₁ may each be linked to each other to form an alicyclic or aromatic ring structure; (wherein R ₃₂ is a hydroxyl group, a linear or branched alkyl group having 1 to 32 carbon atoms, an alkyl-substituted phenyl group or an alkyl group having at least one linear or branched alkyl group having 1 to 32 carbon atoms; Substituted naphthyl). A method for inhibiting polymerization of an aromatic vinyl compound according to the first aspect of the invention, wherein the nitrogen-containing aromatic compound represented by the general formula (I) of the component (A) is at least one selected from the group consisting of methylene violet, Resorufin and phenothiazine-3-oxide. A method for inhibiting polymerization of an aromatic vinyl compound according to the first aspect of the invention, wherein the nitrogen-containing aromatic compound represented by the general formula (III) of the component (A) is indigo and/or sulfonated indigo. A method for inhibiting polymerization of an aromatic vinyl compound according to the first aspect of the invention, wherein the nitrogen-containing aromatic compound represented by the general formula (IV) of the component (A) is at least one selected from the group consisting of phenazine and 2- Methylphenazine, 2-ethylphenazine, quinoxaline, 2-methylquinoxaline, 2-phenylquinoxaline, 3-amino-7-hydroxy-2-methylphenazine and tetraphenyl And [a, c, h, j] phenazines are grouped. The method for inhibiting polymerization of an aromatic vinyl compound according to any one of claims 1 to 4, wherein the sulfonic acid compound represented by the general formula (V) of the component (B) is at least one selected from the group consisting of toluene Sulfonic acid, xylene sulfonic acid, cumene sulfonic acid, dodecyl benzene sulfonic acid, pentadecyl benzene sulfonic acid and dinonyl naphthalene sulfonic acid. The method for inhibiting polymerization of an aromatic vinyl compound according to any one of claims 1 to 4, wherein the nitrogen-containing aromatic compound of the component (A) is added in combination in a weight ratio of 5:95 to 95:5. And the A sulfonic acid compound of the component (B).