JP2005053833A - Method for suppressing polymerization of substituted styrene derivative - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for suppressing the polymerization of a substituted styrene compound efficiently for a long time as well as in early stages in good handleability in the process of producing or refining the compound. <P>SOLUTION: The method for suppressing the polymerization of the substituted styrene compound comprises adding a combination of the following compounds in the process of producing or refining the substituted styrene compound. The compounds to be added are as follows: (A) one or more piperidine-1-oxyl compounds selected from tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl and 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl, (B) a 2-nitrophenol compound such as 2,4-dinitrophenol, 2,6-dinitrophenol, dinitro-o-cresol, dinitro-p-cresol or 2,4-dinitro-6-sec-butylphenol and/or (C) a sulfonic acid compound such as toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid or dinonylnaphthalenesulfonic acid. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides a method for suppressing polymerization in a substituted styrene derivative or a process fluid containing the same in a production process or a purification process of a substituted styrene derivative.

  Substituted styrene derivatives, particularly tert-butoxystyrene, are extremely useful as intermediate materials for functional polymers, medical and agricultural chemicals, and resist materials. This tert-butoxystyrene is synthesized using halogenated styrene such as chlorostyrene as a starting material.

  Substituted styrene derivatives are generally very easy to polymerize, and in the production process or purification process, they are polymerized due to factors such as the addition of heat, thereby reducing the yield of the substituted styrene derivative monomer, which is the target product. This causes fouling (dirt) and troubles the operation of the equipment. As a countermeasure, a method of adding a polymerization inhibitor into the process stream has been proposed and put into practical use. As such a polymerization inhibitor, for example, a method of performing distillation in the presence of N-nitrosophenylhydroxylamine aluminum salt, N-nitrosophenylhydroxylamine ammonium salt, 2,4-dinitrophenol or the like (for example, patent literature) 1), a method using a benzoquinone derivative (for example, see Patent Document 2), a method using an alkylhydroquinone derivative (for example, see Patent Document 3), and the like. In addition, there is a method using a piperidine-1-oxyl compound for styrene, methylstyrene and divinylbenzene (for example, see Patent Document 4).

JP 2000-327617 A JP 2003-64017 A JP 2003-81900 A JP 2001-39901 A

  However, a substituted styrene derivative having a substituent such as a tert-butoxy group or a carboxyl group generally has a high temperature (80 to 150 ° C.) in its production process and purification process, and is operated under conditions of low dissolved oxygen. Because of the coexistence of the substituted styrene derivative of the product and the halogenated styrene of the raw material, the initial polymerization inhibition is not sufficient with dinitrophenol compounds, quinone compounds, hydroquinone compounds, etc. used in conventional styrene compounds. In order to obtain a certain effect, a relatively large amount of addition was required.

  The object of the present invention is not only to suppress initial polymerization in the production process or purification process of a substituted styrene derivative, but also to suppress polymerization efficiently for a long time and to suppress polymerization of a substituted styrene derivative having excellent handling properties. It is to provide a method.

  As a result of detailed studies on the characteristics of the polymerization reaction of a styrene derivative substituted with an alkoxy group, a halogen atom or the like, the present inventors added a specific piperidine-1-oxyl compound in combination with a dinitrophenol compound and / or a sulfonic acid compound. As a result, it was found that the polymerization was extremely effectively suppressed, and the present invention was achieved.

That is, the invention according to claim 1 has the general formula (1) [R ¹ is a chlorine atom, a fluorine atom, a tert-butoxy group, a carboxyl group, R ² is a hydrogen atom, a methyl group, and n is 1, 2. . In the production process or purification process of the substituted styrene derivative represented by formula (A): 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6 -One or more piperidine-1-oxyl compounds selected from tetramethylpiperidine-1-oxyl and 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl; and (B) the general formula ( 2) (wherein R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent hydrogen, a nitro group, a carboxyl group, a hydroxyl group, or a linear or branched alkyl group having 1 to 12 carbon atoms). 2-nitrophenol compound and / or (C) the general formula (3) (wherein represented, ^{R 7} is a hydroxyl group, an alkyl group having 1 to 32 carbon atoms, also at least one straight-chain 1 to 32 carbon atoms Ku is the polymerization inhibiting method of the substituted styrene derivatives comprising adding a combination of a sulfonic acid compound represented by.) Represents an alkyl phenyl group or an alkyl naphthyl group having a branched alkyl group.

  The invention according to claim 2 is the method for inhibiting polymerization of the substituted styrene derivative according to claim 1, wherein (B) the 2-nitrophenol compound is 2,4-dinitrophenol, 2,6-dinitrophenol, 2,4 -One or more selected from dinitro-6-methylphenol, 2,6-dinitro-4-methylphenol, 2,4-dinitro-6-secondary butylphenol, 2,6-dinitro-4-secondary butylphenol It is.

  The invention according to claim 3 is the method for inhibiting polymerization of the substituted styrene derivative according to claim 1, wherein (C) the sulfonic acid compound is toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, dodecylbenzenesulfonic acid, pentadecyl. One or more selected from benzenesulfonic acid and dinonylnaphthalenesulfonic acid.

  As an effect of the present invention, the initial and long-term polymerization of the substituted styrene derivative is efficiently suppressed, the amount of fouling (dirt) generated in the related apparatus is reduced, and the safe operation of the facility can be facilitated.

  The present invention uses (A) a piperidine-1-oxyl compound together with (B) a 2-nitrophenol compound and / or (C) a sulfonic acid compound, thereby inhibiting polymerization in the production process or purification process of the substituted styrene derivative. This method is a polymerization inhibiting method that can effectively achieve prevention of contamination caused by the method and polymerization.

The substituted styrene derivative of the present invention (hereinafter referred to as “substituted styrene derivative”) is represented by the general formula (1), R ¹ is a chlorine atom, a fluorine atom, a tert-butoxy group, a carboxyl group, and R ² is A hydrogen atom and a methyl group. Specifically, m-tert-butoxystyrene, p-tert-butoxystyrene, m-chlorostyrene, p-chlorostyrene, p-fluorostyrene, p-chloro-α-methylstyrene, p-fluoro-α-methyl Examples include styrene.

  (A) Piperidine-1-oxyl compound used in the present invention is 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6-tetramedyl. Piperidine-1-oxyl and 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl are used, or one or more of these may be used in combination.

The (B) 2-nitrophenol compound used in the present invention is a 2-nitrophenol compound in which the hydroxyl group bonded to the benzene ring and the nitro group are in the ortho-positional position as represented by the general formula (2). And its derivatives. R < ³ >, R < ⁴ >, R < ⁵ >, R < ⁶ > in a formula shows a hydrogen atom, a nitro group, a carboxyl group, a hydroxyl group, and a C1-C12 linear or branched alkyl group each independently. Specifically, 2,4-dinitrophenol, 2,6-dinitrophenol, 2,4-dinitro-6-methylphenol, 2,6-dinitro-4-methylphenol, 2,4-dinitro-6- Dibutylphenol, 2,6-dinitro-4-secondary butylphenol, etc., preferably 2,4-dinitrophenol, 2,6-dinitrophenol, 2,6-dinitro-4-methylphenol, 2,4-dinitro -6-secondary butylphenol. One or more of these are used in combination.

The sulfonic acid compound of the component (C) used in the present invention is represented by the general formula (3), in which R ⁷ is a hydroxyl group, an alkyl group having 1 to 32 carbon atoms, and at least one carbon atom having 1 to 32 carbon atoms. An alkylphenyl group having a linear or branched alkyl group or an alkylnaphthyl group. Specific examples include sulfuric acid, toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, and the like. . The sulfonic acid compound in the present invention is a free sulfonic acid compound, and the effects of the present invention cannot be obtained with alkali metal salts such as sodium and potassium, alkaline earth metal salts such as calcium and magnesium, amine salts and ammonium salts. .

  The present invention relates to (A) piperidine-1-oxyl compound and (B) 2-nitrophenol compound, (A) piperidine-1-oxyl compound and (C) sulfonic acid compound, or (A) piperidine-1-oxyl compound. And (B) a dinitrophenol compound and (C) a sulfonic acid compound in combination. This combination, selection of individual compounds, and the amount of each addition are determined by the target process, process conditions, and the like.

  (A) The general addition amount of a piperidine-1-oxyl compound is 0.1-1,000 ppm with respect to a substituted styrene derivative. This addition amount range has been found as a suitable range for exhibiting the intended polymerization inhibitory effect of the present invention, and if it is smaller than this range, the effect is not sufficient, and if it is more than this range, it is effective. Is sufficient, but the effect may not be great for the amount added. (B) The 2-nitrophenol compound and the (C) sulfonic acid compound are combined with the (A) piperidine-1-oxyl compound to synergistically enhance the effect of inhibiting polymerization, and a synergistic effect is expected. (B) 2-nitrophenol compound is 10 to 500 parts by weight with respect to 10 parts by weight of (A) piperidine-1-oxyl compound, and (C) sulfonic acid compound is 10 parts by weight of (A) piperidine-1-oxyl compound. 10 to 100 parts by weight per part. When combining the three of (A) piperidine-1-oxyl compound, (B) 2-nitrophenol compound, and (C) sulfonic acid compound, (B) 2 for (A) piperidine-1-oxyl compound The nitrophenol compound and the (C) sulfonic acid compound are appropriately determined in consideration of the above range.

  The place where (B) the 2-nitrophenol compound and (C) the sulfonic acid compound are added to the (A) piperidine-1-oxyl compound and the method thereof are not limited in the present invention. The substituted styrene derivative is added to the upstream portion of the process including the substituted styrene derivative, or is added to a portion where a problem occurs, such as a distillation tower, a top part of a reaction tower, a lower part of the tower. For the addition, it is convenient to dissolve the solvent in a solvent that does not hinder the process. At this time, (A) piperidine-1-oxyl compound, (B) 2-nitrophenol compound, and (C) sulfonic acid compound may be added separately or mixed in advance and added. Good.

  The polymerization inhibitor of the present invention may be added together with other polymerization inhibitors, polymerization inhibitors, dispersants, etc., but is not limited as long as the effects of the present invention are not hindered.

  The present invention is a method that suppresses the polymerization of the substituted styrene derivative in these steps, suppresses contamination of related equipment such as fouling, and further reduces the loss of the substituted styrene derivative.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not a thing limited to a following example.

(Piperidin-1-oxyl compound)
HTEMPO: 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl OTEMPO: 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl

(2-nitrophenol compound)
2,4-DNP: 2,4-dinitrophenol 2,6-DNP: 2,6-dinitrophenol 2,4-DNMP: 2,4-dinitro-6-methylphenol 2,6-DNMP: 2,6-dinitro-4-methylphenol, 2,4-DNBP: 2,4-dinitro-6-sec-butylphenol

(Sulphonic acid compound)
DBS: dodecylbenzenesulfonic acid PBS: pentadecylbenzenesulfonic acid XS: xylene sulfonic acid QS: cumene sulfonic acid DNS: dinonylnaphthalene sulfonic acid

(Other)
・ BQ: Benzoquinone ・ HQ: Hydroquinone

[Inhibition of polymerization of p-chlorostyrene and p-tert-butoxystyrene mixture]
Into a four-necked separable flask equipped with a reflux condenser, 50 g of p-chlorostyrene monomer and 50 g of p-tert-butoxystyrene monomer are added, and a predetermined amount of the present invention or a comparative polymerization inhibitor is added (the mixing ratio of each drug is The high-purity nitrogen gas was blown in for 30 minutes to remove dissolved oxygen. Next, this was maintained at 115 ° C., and a part of the contents was taken out at regular intervals, and the amount of polymer produced in the liquid was measured. The amount of polymer produced is 9 times the volume of the sampled liquid (volume). When the polymer is suspended in the liquid, it is filtered and weighed to determine the polymer weight. As a percentage. The obtained results are shown in Table 1.

  From the above results, by adding a combination of (A) piperidine-1-oxyl compound and (B) 2-trophenol compound and / or (C) sulfonic acid compound to the substituted styrene compound, compared to conventional drugs It can be seen that the initial polymerization inhibitory effect is excellent and the excellent polymerization inhibitory effect lasts for a long time.

  According to the present invention, in the production process or purification process of a substituted styrene compound, initial polymerization can be efficiently suppressed, the effect can be maintained for a long time, and the amount of fouling (dirt) generated in the related apparatus can be reduced. As a result, the related facilities can be stably operated for a long period of time, and safe operation can be also achieved.

Claims (3)

Formula ^{(1) [R} 1 is a chlorine atom, a fluorine atom, tert- butoxy group, a carboxyl group, ^{R 2} is a hydrogen atom, a methyl radical, n is 1, 2. In the production process or purification process of the substituted styrene derivative represented by formula (A): 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6 -One or more piperidine-1-oxyl compounds selected from tetramethylpiperidine-1-oxyl and 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl; and (B) a general formula ( 2) (wherein R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent hydrogen, a nitro group, a carboxyl group, a hydroxyl group, or a linear or branched alkyl group having 1 to 12 carbon atoms). 2-nitrophenol compound and / or (C) the general formula (3) (wherein represented, ^{R 7} is a hydroxyl group, an alkyl group having 1 to 32 carbon atoms, also at least one straight-chain 1 to 32 carbon atoms Ku polymerization inhibiting method of the substituted styrene derivatives comprising adding a combination of a sulfonic acid compound represented by.) Represents an alkyl phenyl group or an alkyl naphthyl group having a branched alkyl group.

  (B) the 2-nitrophenol compound is 2,4-dinitrophenol, 2,6-dinitrophenol, 2,4-dinitro-6-methylphenol, 2,6-dinitro-4-methylphenol, 2,4 The method for inhibiting polymerization of a substituted styrene derivative according to claim 1, wherein the method is one or more selected from -dinitro-6-secondary butylphenol and 2,6-dinitro-4-secondary butylphenol. The (C) sulfonic acid compound is at least one selected from toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, and dinonylnaphthalenesulfonic acid. The method for inhibiting polymerization of a substituted styrene derivative according to claim 1.