Acrylonitrile composition

Abstract

The present invention pertains to an acrylonitrile composition containing 1 ppm or more and less than 100 ppm of at least one compound selected from the group consisting of nitrile compounds represented by general formula (I) and nitrile compounds represented by general formula (II) relative to acrylonitrile, # imgabs0 # [in the formula, R each independently represents any one of hydrogen and an alkyl group having 1-5 carbon atoms. ].

Description

Technical Field

[0001] The present invention relates to an acrylonitrile composition. Background Art

[0002] Acrylonitrile is a petroleum-derived compound that has been widely used in fiber and resin applications since ancient times. In fiber applications, it is used as a raw material for polyacrylonitrile (PAN) that uses acrylonitrile as a single constituent raw material. In resin applications, it is used as a raw material for ABS that uses not only acrylonitrile as a constituent raw material but also butadiene, styrene, etc. as constituent raw materials. Acrylonitrile easily polymerizes through a radical reaction, and the reaction proceeds even during storage. Therefore, products containing a polymerization inhibitor such as hydroquinone monomethyl ether or hydroquinone methyl ether (hereinafter referred to as "MEHQ") are circulated industrially.

[0003] When polymerizing PAN and ABS using acrylonitrile as a raw material, acrylonitrile is usually stored in a metal tank and used. However, in Non-Patent Document 1, it is disclosed that during the storage of acrylonitrile, trace impurities contained in acrylonitrile are oxidized to form peroxides, which hinder the promotion of polymerization; acrylonitrile is preferably stored in mild steel, etc.; copper, lead, magnesium, and aluminum tend to cause chemical changes in acrylonitrile or promote such chemical changes, and thus are not preferred; when stored in an iron container, if the polymerization reaction is carried out without removing the mixed iron oxide, there will be an adverse effect, and therefore the iron component in acrylonitrile is 0.2 ppm or less.

[0004] In Patent Document 1, as a method for improving the stability of crude acrylonitrile in a crude tank, it is disclosed that the pH is controlled by adding an organic acid.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-19793

[0008] Non-Patent Documents

[0009] Non-Patent Document 1: Acrylonitrile - Its Chemistry and Industry - (Kibundo, 1959, pp. 42 - 43) Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] The inventors of the present invention have found the problem that the stability decreases when the iron content in acrylonitrile increases.

[0012] Therefore, an object of the present invention is to provide an acrylonitrile composition having improved stability when stored in a container made of iron or an iron-containing alloy.

[0013] Means for Solving the Problems

[0014] The inventors of the present invention have conducted extensive research to solve the above problems and found that for specific nitrile compounds, the stability of acrylonitrile in the presence of iron can be improved, thus completing the present invention. That is, the present invention consists of the following (1) to (8).

[0015] (1) An acrylonitrile composition comprising at least one selected from the group consisting of a nitrile compound represented by the general formula (I) and a nitrile compound represented by the general formula (II) in an amount of 1 ppm or more and less than 100 ppm relative to acrylonitrile,

[0016] [Chemical formula 1]

[0017]

[0018] [In the formula, each R independently represents any one of hydrogen and an alkyl group having 1 to 5 carbon atoms.].

[0019] (2) The acrylonitrile composition according to (1), wherein the nitrile compound is a nitrile compound comprising any one of 2-methyl-2-butene nitrile, 2-butene nitrile, 2-methyl-3-butene nitrile, 3-methyl-3-butene nitrile, and 3-butene nitrile.

[0020] (3) A polyacrylonitrile produced by polymerizing the acrylonitrile composition according to (1) or (2).

[0021] (4) A method for producing polyacrylonitrile, wherein the acrylonitrile composition according to (1) or (2) is polymerized.

[0022] (5) An acrylonitrile copolymer produced by copolymerizing the acrylonitrile composition according to (1) or (2) and a vinyl-based compound.

[0023] (6) A method for producing an acrylonitrile copolymer, wherein the acrylonitrile composition according to (1) or (2) and a vinyl-based compound are copolymerized.

[0024] (7) A polyacrylonitrile fiber produced by a process comprising the following steps (A) and (B),

[0025] (A) A step of producing polyacrylonitrile by the method according to (4);

[0026] (B) A step of spinning the polyacrylonitrile obtained in step (A).

[0027] (8) A resin molded body produced by a process comprising the following steps (C) and (D),

[0028] (C) A step of producing an acrylonitrile copolymer by the method according to (6);

[0029] (D) Step of molding the acrylonitrile copolymer obtained in step (C).

[0030] Effects of the Invention

[0031] According to the present invention, an acrylonitrile composition with improved stability during storage in a container made of iron or an iron-containing alloy can be provided. Detailed Description of the Invention

[0032] Hereinafter, suitable embodiments of the present invention will be described in detail. It should be noted that the present invention is not limited to the embodiments described below, and various modifications implemented within the scope of not changing the gist of the present invention should also be understood to be included.

[0033] [Acrylonitrile Composition]

[0034] The acrylonitrile composition of the present invention contains the nitrile compound described below in an amount of 1 ppm or more and less than 100 ppm relative to acrylonitrile, thereby improving the stability during storage in a container made of iron or an iron-containing alloy. The content of the nitrile compound is more preferably 1 ppm or more and less than 90 ppm, further preferably 1 ppm or more and less than 80 ppm, and particularly preferably 1 ppm or more and less than 70 ppm. The content of the nitrile compound can be measured by gas chromatography. In addition, when components other than the nitrile compound are contained in the acrylonitrile composition, the content is determined based on the amount of acrylonitrile.

[0035] There is no particular limitation on the method for preparing the acrylonitrile composition containing the nitrile compound. As an example, it can be obtained by adding the nitrile compound to acrylonitrile. In addition, the nitrile compound can be added before or during the reaction for generating acrylonitrile, or a compound that can be converted into the nitrile compound during the reaction for generating acrylonitrile can be added before the reaction. In addition, acrylonitrile pre-containing a compound that can be converted into the nitrile compound can also be preferably used.

[0036] Here, there is no particular limitation on the reaction for generating acrylonitrile. In addition to the usual industrial method for manufacturing acrylonitrile, i.e., the ammoxidation of propane / propylene, the reaction of 3-hydroxypropionic acid with ammonia, the ammoxidation of glycerol, and the reaction of acrylic acid with ammonia can also be exemplified.

[0037] In the acrylonitrile composition, other components that do not hinder the effects of the present invention may also be contained. There is no particular limitation on the acrylonitrile content in the acrylonitrile composition, and it is preferably 90% by weight or more, more preferably 95% by weight or more, and particularly preferably 99% by weight or more.

[0038] [Nitrile Compound]

[0039] As the nitrile compound, it is at least one selected from the nitrile compounds represented by the following general formula (I) and the nitrile compounds represented by the general formula (II).

[0040] [Chemical formula 2]

[0041]

[0042] [In the formula, each R independently represents any one of alkyl groups having 1 to 5 carbon atoms].

[0043] Here, the alkyl group having 1 to 5 carbon atoms, specifically, examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl, sec-pentyl, 3-pentyl, tert-pentyl.

[0044] As the nitrile compound, from the viewpoint of availability, 2-butenenitrile, 2-methyl-2-butenenitrile, 3-butenenitrile, 2-methyl-3-butenenitrile, 3-methyl-3-butenenitrile represented by the following formulas (I-1), (I-2), (II-2), (II-3) are preferred. From the viewpoint of economy, 2-butenenitrile (I-1) and 2-methyl-2-butenenitrile (I-2) are further preferred.

[0045] [Chemical formula 3]

[0046]

[0047] [Manufacture of polyacrylonitrile]

[0048] By polymerizing the acrylonitrile composition of the present invention, polyacrylonitrile can be manufactured. In the present invention, polyacrylonitrile refers to a substance in which at least acrylonitrile is a main constituent of the polymer skeleton. The main constituent usually refers to a constituent that accounts for 90 to 100 mol% of the polymer skeleton. In the present invention, from the viewpoints of improving the spinnability and efficiently performing the flame resistance treatment in the case of carbon fiberization, etc., polyacrylonitrile preferably contains a copolymer component. In the present invention, when obtaining polyacrylonitrile, as the method, it can be selected from known polymerization methods.

[0049] [Manufacture of polyacrylonitrile fiber]

[0050] By spinning the polyacrylonitrile of the present invention, polyacrylonitrile fibers can be manufactured. When spinning polyacrylonitrile, a spinning dope can be obtained by dissolving it in a known solvent. The spinning dope can be spun by a dry-wet spinning method, a wet spinning method, or a dry spinning method. In the case of using a dry-wet spinning method or a wet spinning method, as the coagulation bath for coagulating the spinning dope, it preferably contains a solvent used as the solvent of the spinning dope and a so-called coagulation promoting component such as water.

[0051] [Manufacture of Acrylonitrile Copolymer]

[0052] An acrylonitrile copolymer can be manufactured by copolymerizing the acrylonitrile composition of the present invention and a vinyl-based compound.

[0053] There is no particular limitation on the vinyl-based compound used in the present invention, and examples thereof include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, and halogenated styrene, acrylic acid and its derivatives, methacrylic acid and its derivatives, vinyl compounds containing a carboxyl group, etc., and one or more than two kinds can be used. Styrene and α-methylstyrene are particularly preferred, and styrene is further preferred.

[0054] In addition, the acrylonitrile copolymer of the present invention can also be mixed with a rubbery polymer. As an example, there are diene rubbers, acrylic rubbers, ethylene rubbers, etc. Specific examples include polybutadiene, poly(butadiene-styrene), polyisoprene, poly(butadiene-butyl acrylate), poly(butadiene-methyl acrylate), poly(butadiene-methyl methacrylate), poly(butyl acrylate-methyl methacrylate), poly(butadiene-ethyl acrylate), ethylene-propylene rubber, ethylene-propylene-diene rubber, poly(ethylene-isobutene), poly(ethylene-methyl acrylate), etc. Among these rubbery polymers, polybutadiene, poly(butadiene-styrene), and ethylene-propylene rubber are particularly preferably used.

[0055] There is no particular limitation on the copolymerization method of the acrylonitrile composition of the present invention and the vinyl-based compound, and it can be manufactured by emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization, and polymerization methods obtained by combining them.

[0056] The acrylonitrile copolymer of the present invention can also be a vinyl-based copolymer containing high-nitrile. As a polymerization method for obtaining a vinyl-based copolymer containing high-nitrile, from the viewpoints of controlling the proportion of vinyl cyanide-based monomer components in the residual monomer, reducing oligomers, and hindering the thermal coloring stability during melting caused by auxiliary raw materials such as emulsifiers and solvents, aqueous suspension polymerization is preferred.

[0057] There is no particular limitation on the mixing / compounding / melt extrusion of the acrylonitrile copolymer and the rubbery polymer of the present invention, and generally known methods can be adopted. For example, a ribbon blender, a V-type blender, a Henschel mixer, etc. can be used. Then, through a kneading treatment using an extruder such as a single-screw extruder or a twin-screw extruder, or a Banbury mixer, a mixing roll, a pressure kneader, etc., an acrylonitrile copolymer can be obtained.

[0058] [Manufacture of Resin Moldings of Acrylonitrile Copolymer]

[0059] The acrylonitrile copolymer of the present invention can be used to manufacture a resin molded article by molding using any commonly known method such as injection molding, extrusion molding, blow molding, or blow molding. Examples of the resin molded article include a film, a sheet, a fiber / cloth (fabric, knitted fabric, non-woven fabric), an injection molded product, an extrusion molded product, a vacuum pressure forming product, a blow molded product, or a composite with other materials.

[0060] Example

[0061] Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to the following examples.

[0062] In this example, the stability evaluation of the acrylonitrile composition and the quantification of the additive content were performed by the following gas chromatography (GC) analysis.

[0063] 〔GC analysis conditions〕

[0064] GC device: "GC2010plus" (manufactured by Shimadzu Corporation)

[0065] Column: "DB-5", length 30m, inner diameter 0.32mm, film thickness 0.25μm (manufactured by Agilent Technologies, Inc.)

[0066] Carrier gas: helium, constant linear velocity (20.0 cm / sec)

[0067] Vaporization chamber temperature: 250°C

[0068] Detector temperature: 250°C

[0069] Column oven temperature: 50°C → (10°C / minute) → 230°C (total 18 minutes)

[0070] Detector: FID.

[0071] [Reference Example 1]

[0072] The acrylonitrile used in the examples, comparative examples 2, 3, and 4, and reference examples of the present application was a substance obtained by distilling and refining acrylonitrile (manufactured by Tokyo Chemical Industry Co., Ltd., containing 40 ppm of hydroquinone monomethyl ether (MEHQ)) (temperature 60°C, pressure 250 mmHg). According to GC analysis, it was confirmed that MEHQ was removed from the acrylonitrile obtained by distillation. In addition, according to 1 1H NMR analysis and moisture measurement, it was confirmed that the weight purity of the acrylonitrile obtained by distillation was 99.9% or more.

[0073] [Manufacture of acrylonitrile composition (1)]

[0074] 2-Methyl-2-butenenitrile (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the acrylonitrile obtained in Reference Example 1 to obtain the acrylonitrile compositions shown in Table 1 (Examples 1 and 2, Comparative Examples 2 and 3).

[0075] [Stability Test (1) of Acrylonitrile]

[0076] 10 g of the acrylonitrile obtained in Reference Example 1 was placed in a 30-mL glass vial with a screw cap, shielded from light with aluminum foil, and stirred at room temperature for 5 hours. Approximately 0.04 g of the stirred vial contents was weighed into a 5-mL volumetric flask, and the 1,4-dioxane solution obtained by diluting to 5 mL with 1,4-dioxane (manufactured by Sigma Aldrich) was analyzed by GC. The GC area of acrylonitrile in the GC analysis was divided by the concentration of the vial contents in the 1,4-dioxane solution, and the resulting value was set as the reference (100) (in Table 1, Reference Example 1).

[0077] Next, 10 g of commercially available acrylonitrile (manufactured by Tokyo Chemical Industry Co., Ltd., containing 40 ppm of MEHQ, Comparative Example 1), the acrylonitrile obtained in Reference Example 1, the acrylonitrile compositions obtained in Examples 1 and 2, Comparative Examples 2 and 3, and 0.1 g of iron powder (150 μm or less) (manufactured by Fujifilm Wako Pure Chemical Corporation) were placed in a 30-mL glass vial with a screw cap, shielded from light with aluminum foil, and stirred at room temperature for 5 hours. Approximately 0.04 g of the stirred vial contents was weighed into a 5-mL volumetric flask, and the 1,4-dioxane solution obtained by diluting to 5 mL with 1,4-dioxane was analyzed by GC. The GC area of acrylonitrile in this GC analysis was divided by the concentration of the vial contents in the 1,4-dioxane solution, and the resulting value was compared with the reference of Reference Example 1 to calculate the acrylonitrile residue rate. The results are shown in Table 1.

[0078] [Reference Example 2]

[0079] A stability test was carried out in the same manner except that no iron powder was added to the acrylonitrile composition obtained in Comparative Example 3. The results are shown in Table 1.

[0080] [Table 1]

[0081]

[0082] MEHQ: Methylhydroquinone

[0083] According to Comparative Example 1, it is shown that in an acrylonitrile composition containing MEHQ which is a commonly used stabilizer, the stability in the presence of iron is poor. From Comparative Examples 2 and 3, and Examples 1 and 2, it can be seen that by containing 2-methyl-2-butene nitrile in an amount of 1 ppm or more and less than 100 ppm relative to acrylonitrile, the residual rate of acrylonitrile in the presence of iron increases, that is, the stability of acrylonitrile is improved. In addition, from Reference Example 2, it can be seen that 2-methyl-2-butene nitrile itself does not change the stability of acrylonitrile.

[0084] [Manufacture of acrylonitrile composition (2)]

[0085] 2-Butene nitrile (manufactured by Sigma Aldrich) or acetonitrile (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the acrylonitrile obtained in Reference Example 1 to obtain the acrylonitrile compositions shown in Table 2 (Examples 3, 4, 5, Comparative Example 4).

[0086] [Stability test of acrylonitrile (2)]

[0087] 10 g of the acrylonitrile obtained in Reference Example 1 was added to a 30 mL glass vial with a screw cap, shielded from light with aluminum foil, and stirred at room temperature for 5 hours or 18 hours. Approximately 0.04 g of the stirred vial contents was weighed into a 5 mL volumetric flask, and the γ-butyrolactone solution diluted to 5 mL with γ-butyrolactone (manufactured by Fujifilm Wako Pure Chemical Corporation) was analyzed by GC. The GC area of acrylonitrile in the GC analysis was divided by the concentration of the vial contents in the γ-butyrolactone solution, and the resulting value was taken as the reference (100) (in Table 2, Reference Examples 3, 4).

[0088] Next, 10 g of commercially available acrylonitrile (manufactured by Tokyo Chemical Industry Co., Ltd., containing 40 ppm of MEHQ, Comparative Example 5), the acrylonitrile compositions obtained in Examples 3, 4, 5, and Comparative Example 4, and 0.1 g of iron powder (150 μm or less) (manufactured by Fujifilm Wako Pure Chemical Corporation) were added to a 30 mL glass vial with a screw cap, shielded from light with aluminum foil, and stirred at room temperature for 5 hours or 18 hours. Approximately 0.04 g of the stirred vial contents was weighed into a 5 mL volumetric flask, and the γ-butyrolactone solution diluted to 5 mL with γ-butyrolactone was analyzed by GC. The GC area of acrylonitrile in this GC analysis was divided by the concentration of the vial contents in the γ-butyrolactone solution, and the resulting value was compared with the reference of Reference Example 3 or 4 to calculate the acrylonitrile residual rate. The results are shown in Table 2.

[0089] [Table 2]

[0090]

[0091] ME; HQ: Hydroquinone monomethyl ether

[0092] As can be seen from Examples 3 and 4, by containing 2-butenenitrile in an amount of 1 ppm or more and less than 100 ppm relative to acrylonitrile, the residual rate of acrylonitrile in the presence of iron increases, that is, the stability of acrylonitrile is improved. In addition, as can be seen from Comparative Example 4, acetonitrile does not change the stability of acrylonitrile in the presence of iron. According to Reference Example 4, Comparative Example 5, and Example 5, it is shown that the acrylonitrile composition described in the present application is indeed highly stable in the presence of iron.

[0093] Industrial Applicability

[0094] An acrylonitrile composition with improved stability when stored in a container made of iron or an iron-containing alloy can be provided.

Claims

1. An acrylonitrile composition, wherein, it contains at least one selected from the nitrile compounds represented by the general formula (I) and the nitrile compounds represented by the general formula (II) in an amount of 1 ppm or more and less than 100 ppm relative to acrylonitrile, [Chemical formula 1] In the formula, each R independently represents any one of hydrogen and an alkyl group having 1 to 5 carbon atoms.

2. The acrylonitrile composition according to claim 1, wherein, the nitrile compound is a nitrile compound containing any one of 2-methyl-2-butene nitrile, 2-butene nitrile, 2-methyl-3-butene nitrile, 3-methyl-3-butene nitrile, and 3-butene nitrile.

3. A polyacrylonitrile produced by polymerizing the acrylonitrile composition according to claim 1 or 2.

4. A method for producing polyacrylonitrile, wherein, the acrylonitrile composition according to claim 1 or 2 is polymerized.

5. An acrylonitrile copolymer produced by copolymerizing the acrylonitrile composition according to claim 1 or 2 and a vinyl-based compound.

6. A method for producing an acrylonitrile copolymer, wherein, the acrylonitrile composition according to claim 1 or 2 and a vinyl-based compound are copolymerized.

7. A polyacrylonitrile fiber produced by a process comprising the following steps (A) and (B): (A) A step of producing polyacrylonitrile by the method according to claim 4; (B) A step of spinning the polyacrylonitrile obtained in step (A).

8. A resin molded article produced by a process comprising the following steps (C) and (D): (C) A step of producing an acrylonitrile copolymer by the method according to claim 6; (D) A step of molding the acrylonitrile copolymer obtained in step (C).

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