acrylonitrile

Abstract

DEPCT68 An acrylonitrile composition containing 1 part per million or more and less than 100 parts per million. Per million parts of at least one type selected from the nitrile compounds represented by the general formula (I). and nitrile compounds represented by the general formula (II) relating to acrylonitrile: [Chemistry 1] (Chemical formula)(Chemical formula) (I)(II) [In the formula, each R independently represents any type of hydrogen and one or five alkyl groups.] [carbon atom];

Description

Acrylonitrile composition

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

[0002] Acrylonitrile is a petroleum-derived compound that has long been widely used in fiber and resin applications, and is used as a raw material for polyacrylonitrile (PAN), which is made from acrylonitrile as the sole constituent raw material, and for resin applications, it is used as a raw material for ABS, which is made from acrylonitrile as well as butadiene, styrene, etc. Acrylonitrile easily polymerizes through radical reactions, and the reaction continues even when stored, so products with added polymerization inhibitors such as monomethyl ether hydroquinone or hydroquinone methyl ether (hereinafter referred to as "MEHQ") are commercially available.

[0003] When acrylonitrile is used as a raw material to polymerize PAN or ABS, the acrylonitrile is usually stored in a metal tank for use, but Non-Patent Document 1 discloses that when storing acrylonitrile, trace impurities contained in the acrylonitrile oxidize to peroxides, which hinder the promotion of polymerization, that it is best to store acrylonitrile in mild steel or the like, that copper, lead, magnesium, and aluminum are undesirable because they tend to cause or accelerate chemical changes in acrylonitrile, and that when storing in an iron container, carrying out the polymerization reaction without removing the iron oxide that gets mixed in has an adverse effect, and therefore the iron component in acrylonitrile should be 0.2 ppm or less. Patent Document 1 also discloses pH control by adding an organic acid as a means of improving the stability of crude acrylonitrile in the crude tank.

[0004] Japanese Patent Application Laid-Open No. 2020-19793

[0005] Acrylonitrile - Its Chemistry and Industry - (Gihodo, 1959, pp. 42-43)

[0006] The present inventors have found that an increase in the iron content in acrylonitrile leads to a decrease in stability.

[0007] 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 alloy containing iron.

[0008] The present inventors have conducted extensive research to solve the above problems and have found that a specific nitrile compound has the effect of improving the stability of acrylonitrile in the presence of iron, thereby completing the present invention. That is, the present invention comprises the following (1) to (8): (1) An acrylonitrile composition containing at least one nitrile compound selected from the group consisting of a nitrile compound represented by general formula (I) and a nitrile compound represented by general formula (II) in an amount of 1 ppm or more and less than 100 ppm relative to acrylonitrile.

[0009]

[0010] [In the formula, each R independently represents hydrogen or an alkyl group having 1 to 5 carbon atoms.] (2) The acrylonitrile composition according to (1), wherein the nitrile compound is a nitrile compound containing any one of 2-methyl-2-butenenitrile, 2-butenenitrile, 2-methyl-3-butenenitrile, 3-methyl-3-butenenitrile, and 3-butenenitrile. (3) Polyacrylonitrile produced by polymerizing the acrylonitrile composition according to (1) or (2). (4) A method for producing polyacrylonitrile by polymerizing the acrylonitrile composition according to (1) or (2). (5) An acrylonitrile copolymer produced by copolymerizing the acrylonitrile composition according to (1) or (2) and a vinyl-based compound. (6) A method for producing an acrylonitrile copolymer by copolymerizing the acrylonitrile composition according to (1) or (2) and a vinyl-based compound. (7) Polyacrylonitrile fiber produced by a process comprising the following steps (A) and (B): (A) A step of producing polyacrylonitrile by the method described in (4), (B) A step of spinning the polyacrylonitrile obtained by the step (A), and (8) A resin molded product produced by a process including the following steps (C) and (D): (C) A step of producing an acrylonitrile copolymer by the method described in (6), and (D) A step of molding the acrylonitrile copolymer obtained by the step (C).

[0011] According to the present invention, an acrylonitrile composition having improved stability when stored in a container made of iron or an alloy containing iron can be provided.

[0012] Preferred embodiments of the present invention will be described in detail below. It should be understood that the present invention is not limited to the embodiments described below, but also includes various modifications that are implemented within the scope of the present invention.

[0013] [Acrylonitrile Composition] The acrylonitrile composition of the present invention contains a nitrile compound, which will be described later, in an amount of 1 ppm or more and less than 100 ppm relative to acrylonitrile, thereby improving the stability when stored in a container made of iron or an alloy containing iron. The content of the nitrile compound is more preferably 1 ppm or more and less than 90 ppm, even more 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 the acrylonitrile composition contains components other than the nitrile compound, the content is determined based on the amount of acrylonitrile.

[0014] The method for preparing an acrylonitrile composition containing a nitrile compound is not particularly limited, but as an example, it can be obtained by adding a nitrile compound to acrylonitrile. The nitrile compound may be added before or during the reaction to produce acrylonitrile, or a compound that is converted into a nitrile compound during the reaction to produce acrylonitrile may be added before the reaction. Acrylonitrile that already contains a compound that is converted into a nitrile compound can also be preferably used.

[0015] The reaction for producing acrylonitrile is not particularly limited, but examples thereof include the ammoxidation of propane / propylene, which is a conventional industrial method for producing acrylonitrile, as well as the reaction of 3-hydroxypropionic acid with ammonia, the ammoxidation of glycerol, and the reaction of acrylic acid with ammonia.

[0016] The acrylonitrile composition may contain other components that do not inhibit the effects of the present invention, and the acrylonitrile content in the acrylonitrile composition is not particularly limited, but is preferably 90% by weight or more, more preferably 95% by weight or more, and particularly preferably 99% by weight or more.

[0017] [Nitrile Compound] The nitrile compound is at least one selected from the nitrile compounds represented by the following general formula (I) and the nitrile compounds represented by the following general formula (II).

[0018]

[0019] [In the formula, each R independently represents an alkyl group having 1 to 5 carbon atoms.] Specific examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, and a tert-pentyl group.

[0020] As the nitrile compound, 2-butenenitrile, 2-methyl-2-butenenitrile, 3-butenenitrile, 2-methyl-3-butenenitrile, and 3-methyl-3-butenenitrile, which are represented by the following formulas (I-1), (I-2), (II-1), (II-2), and (II-3), respectively, are preferred from the viewpoint of availability, and 2-butenenitrile (I-1) and 2-methyl-2-butenenitrile (I-2) are more preferred from the viewpoint of economy.

[0021]

[0022] [Production of Polyacrylonitrile] Polyacrylonitrile can be produced by polymerizing the acrylonitrile composition of the present invention. In the present invention, polyacrylonitrile refers to a polymer in which at least acrylonitrile is the main constituent component of the polymer skeleton, and the main constituent component usually refers to a constituent component that occupies 90 to 100 mol % of the polymer skeleton. In the present invention, polyacrylonitrile preferably contains a copolymerization component from the viewpoint of improving spinnability and, when producing carbon fiber, efficiently carrying out a flame retardant treatment. When polyacrylonitrile is obtained in the present invention, the method may be selected from known polymerization methods.

[0023] [Production of Polyacrylonitrile Fiber] Polyacrylonitrile fiber can be produced by spinning the polyacrylonitrile of the present invention. When spinning, polyacrylonitrile can be dissolved in a known solvent to obtain a spinning dope. Such a spinning dope can be spun by a dry-wet spinning method, a wet spinning method, or a dry spinning method. When using a dry-wet spinning method or a wet spinning method, it is preferable that the coagulation bath for coagulating the spinning dope contains the solvent used as the solvent for the spinning dope and a so-called coagulation-promoting component such as water.

[0024] [Production of Acrylonitrile Copolymer] An acrylonitrile copolymer can be produced by copolymerizing the acrylonitrile composition of the present invention and a vinyl compound.

[0025] The vinyl compound used in the present invention is not particularly limited, and examples thereof include styrene, α-methylstyrene, orthomethylstyrene, paramethylstyrene, para-t-butylstyrene, halogenated styrenes, acrylic acid and its derivatives, methacrylic acid and its derivatives, and carboxyl group-containing vinyl compounds, and one or more of these can be used. Styrene and α-methylstyrene are particularly preferred, and styrene is more preferred.

[0026] The acrylonitrile copolymer of the present invention may also be mixed with a rubbery polymer, examples of which include diene rubber, acrylic rubber, ethylene rubber, 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-isobutylene), poly(ethylene-methyl acrylate), etc. Of these rubbery polymers, polybutadiene, poly(butadiene-styrene), and ethylene-propylene rubber are particularly preferably used.

[0027] The method for copolymerizing the acrylonitrile composition of the present invention with a vinyl compound is not particularly limited, and the copolymer can be produced by emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization, or a combination thereof.

[0028] The acrylonitrile copolymer of the present invention may be a high nitrile content vinyl copolymer, and as a polymerization method for obtaining the high nitrile content vinyl copolymer, aqueous suspension polymerization is preferred from the viewpoints of controlling the proportion of vinyl cyanide monomer components in the remaining monomers, reducing oligomers, and preventing inhibition of thermal discoloration stability during melting by auxiliary materials such as emulsifiers and solvents.

[0029] There are no particular limitations on the mixing, blending, and melt-extrusion of the acrylonitrile copolymer of the present invention and the rubbery polymer, and any commonly known method can be used. For example, a ribbon blender, a V-type blender, a Henschel mixer, etc. can be used. The acrylonitrile copolymer can be obtained by kneading 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.

[0030] [Production of Resin Molded Articles of Acrylonitrile Copolymer] The acrylonitrile copolymer of the present invention can be molded into a resin molded article by any of the commonly known methods such as injection molding, extrusion molding, inflation molding, blow molding, etc. Examples of the resin molded article include films, sheets, fibers / fabrics (woven fabrics, knitted fabrics, nonwoven fabrics), injection molded articles, extrusion molded articles, vacuum / compressed air molded articles, blow molded articles, and composites with other materials.

[0031] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples.

[0032] In the present examples, the stability of the acrylonitrile composition and the content of the additives were evaluated by the following gas chromatography (GC) analysis.

[0033] [GC analysis conditions] GC apparatus: "GC2010 plus" (Shimadzu Corporation) Column: "DB-5", length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm (Agilent Technologies Inc.) Carrier gas: helium, constant linear velocity (20.0 cm / sec) Vaporization chamber temperature: 250°C Detector temperature: 250°C Column oven temperature: 50°C → (10°C / min) → 230°C (total 18 min) Detector: FID.

[0034] [Reference Example 1] The acrylonitrile used in the present Examples, Comparative Examples 2, 3 and 4, and Reference Example was obtained by distilling and purifying (at a temperature of 60°C and a pressure of 250 mmHg) acrylonitrile (manufactured by Tokyo Chemical Industry Co., Ltd., containing 40 ppm of monomethyl ether hydroquinone (MEHQ)). GC analysis confirmed that MEHQ had been removed from the acrylonitrile obtained by distillation. １ It was confirmed by H NMR analysis and water content measurement that the acrylonitrile obtained by distillation had a weight purity of 99.9% or more.

[0035] [Production of Acrylonitrile Composition (1)] 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).

[0036] [Stability test of acrylonitrile (1)] 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. After stirring, approximately 0.04 g of the content of the vial was weighed into a 5 mL volumetric flask, and the 1,4-dioxane solution was diluted to 5 mL with 1,4-dioxane (Sigma-Aldrich Co.), and analyzed by GC. The value obtained by dividing the GC area of ​​acrylonitrile in GC analysis by the concentration of the vial contents in the 1,4-dioxane solution was used as the reference (100) (Reference Example 1 in Table 1). Next, 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, 10 g of the acrylonitrile compositions obtained in Examples 1 and 2 and Comparative Examples 2 and 3, and 0.1 g of iron powder (150 μm or less) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 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. After stirring, approximately 0.04 g of the vial contents was weighed into a 5 mL volumetric flask, and the 1,4-dioxane solution diluted 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 contents of the vial in the 1,4-dioxane solution, and the value obtained was compared with the standard in Reference Example 1 to calculate the residual rate of acrylonitrile. The results are shown in Table 1.

[0037] Reference Example 2 A stability test was carried out in the same manner as in Comparative Example 3, except that no iron powder was added to the acrylonitrile composition obtained in Comparative Example 3. The results are shown in Table 1.

[0038]

[0039] Comparative Example 1 showed that an acrylonitrile composition containing MEHQ, a commonly used stabilizer, had poor stability in the presence of iron. Comparative Examples 2 and 3 and Examples 1 and 2 showed that by adding 2-methyl-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 increased, that is, the stability of acrylonitrile improved. Furthermore, Reference Example 2 showed that 2-methyl-2-butenenitrile itself did not change the stability of acrylonitrile.

[0040] [Production of Acrylonitrile Composition (2)] 2-Butenenitrile (manufactured by Sigma-Aldrich Co.) 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, and 5, and Comparative Example 4).

[0041] [Stability test of acrylonitrile (2)] 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. After stirring, approximately 0.04 g of the content of the vial was weighed into a 5 mL measuring flask and diluted to 5 mL with γ-butyrolactone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). The γ-butyrolactone solution was analyzed by GC. The value obtained by dividing the GC area of ​​acrylonitrile in GC analysis by the concentration of the vial contents in the γ-butyrolactone solution was used as the reference (100) (Reference Examples 3 and 4 in Table 2). Next, 10 g of commercially available acrylonitrile (manufactured by Tokyo Chemical Industry Co., Ltd., containing 40 ppm of MEHQ, Comparative Example 5), 10 g of 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 Industries, Ltd.) 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. After stirring, approximately 0.04 g of the 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 contents of the vial in the γ-butyrolactone solution, and the value obtained was compared with the standard in Reference Example 3 or 4 to calculate the residual rate of acrylonitrile. The results are shown in Table 2.

[0042]

[0043] Examples 3 and 4 show that the residual rate of acrylonitrile in the presence of iron increases, that is, the stability of acrylonitrile improves, by incorporating 2-butenenitrile in an amount of 1 ppm or more and less than 100 ppm relative to acrylonitrile. Comparative Example 4 shows that acetonitrile does not change the stability of acrylonitrile in the presence of iron. Reference Example 4, Comparative Example 5, and Example 5 show that the acrylonitrile composition described in the present application certainly has high stability in the presence of iron.

[0044] An acrylonitrile composition having improved stability when stored in a container made of iron or an alloy containing iron can be provided.

Claims

DEPCT681. An acrylonitrile element containing 1 part per million or more and less than 100 parts per million of at least one of the selected types from the nitrile compounds represented by general formula (I) and nitrile compounds represented by general formula (II) relating to acrylonitrile: [Chemistry1](Chemical Formula)(Chemical Formula)(I)(II)[In the formula, each R independently represents any type of hydrogen and alkyl group containing 1–5 carbon atoms].

2. An acrylonitrile element of claim 1 in which a nitrile compound is a nitrile compound ... Any amount of 2-methyl-2-butene nitrile, 2-butene nitrile, 2-methyl-3-butene nitrile, 3-methyl-3-butene nitrile, and 3-butene nitrile.

3. Polyacrylonitrile produced by polymerization of acrylonitrile components according to Patent 1 or 2.

4. Methods for the production of polyacrylonitrile, methods which include the polymerization of acrylonitrile components according to Patent 1 or 2.

5. Acrylonitrile copolymer produced by copolymerization of acrylonitrile components according to Patent 1 or 2 and vinyl compounds. 6.Methods for the production of acrylonitrile copolymer, methods which include the copolymerization of acrylonitrile components according to claim 1 or 2 and vinyl compounds.

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

8. Resin-molded objects produced by a process which includes the following steps (C) and (D): (C) the step of producing acrylonitrile copolymer by the method according to claim 6; and (D) the step of molding the acrylonitrile copolymer obtained in step (C).