Method for producing methyl methacrylate, composition, polymer, cured product, and molded product

Abstract

The present invention provides a method for producing odor-suppressed methyl methacrylate, a composition, a polymer, a cured product, and a molded article. The method for producing methyl methacrylate includes a step of contacting a composition containing methyl methacrylate and odorous components with an adsorbent.

Description

[Technical field]

[0001] The present disclosure relates to a method for producing methyl methacrylate, a composition, a polymer, a cured product, and a molded article. [Background technology]

[0002] Poly(methyl(meth)acrylate) obtained by polymerizing methyl(meth)acrylate is used in various fields as a resin material with excellent transparency and weather resistance. In recent years, due to the rise in resource prices and the growing awareness of environmental issues, products (molded articles) containing poly(methyl(meth)acrylate) used for various applications as described above are being collected and recycled.

[0003] Methods for recycling polymethyl(meth)acrylate include, for example, material recycling, in which the recovered molded bodies are subjected to a molding process again to produce new molded bodies; chemical recycling, in which the recovered molded bodies are heat-treated to thermally decompose (depolymerize) the polymethyl(meth)acrylate to recover the methyl(meth)acrylate, and the recovered methyl(meth)acrylate (sometimes referred to as recycled MMA or recycled MA) is used to produce new molded bodies; and thermal recycling, in which the recovered molded bodies are burned as fuel and the combustion energy is used directly as a heat source and further to generate electricity.

[0004] For example, Patent Document 1 describes a method for recovering methyl (meth)acrylate through a process in which a gaseous pyrolysis product obtained by heating polymethyl (meth)acrylate is cooled and liquefied, and then the liquefied pyrolysis product is purified by distillation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-321571 A Summary of the Invention [Problem to be solved by the invention]

[0006] Methyl (meth)acrylate, which is used as a raw material for poly(methyl (meth)acrylate), may emit an unpleasant odor. Therefore, it is desirable to suppress the odor of methyl (meth)acrylate from the viewpoint of improving the handling property. In view of the above circumstances, an object of the present disclosure is to provide a method for producing methyl methacrylate, a composition, a polymer, a cured product, and a molded article, which have a suppressed odor. [Means for solving the problem]

[0007] Means for solving the above problems include the following embodiments. <1> A method for producing methyl methacrylate, comprising a step of contacting a composition containing methyl methacrylate and an odorous component with an adsorbent. <2> The amount of the adsorbent contacted with the composition is 1 part by mass to 30 parts by mass per 100 parts by mass of the composition. <1> The method for producing methyl methacrylate according to claim 1. <3> The concentration of the odorous component in the composition after the step of contacting the composition with the adsorbent is less than 450 ppm by mass based on the entire composition; <1> or <2> The method for producing methyl methacrylate according to claim 1. <4> The odor components include at least one selected from the group consisting of alcohols, aldehydes, ketones, fatty acids, sulfur-containing compounds, and nitrogen-containing compounds. <1> ~ <3> The method for producing methyl methacrylate according to any one of claims 1 to 5. <5> The adsorbent comprises zeolite or activated carbon; <1> ~ <4> The method for producing methyl methacrylate according to any one of claims 1 to 5. <6> The adsorbent comprises a zeolite containing silver ions; <5> The method for producing methyl methacrylate according to claim 1. <7> The adsorbent is in the form of beads, and the particle size is 1 mm to 7 mm. <1> ~ <6> The method for producing methyl methacrylate according to any one of claims 1 to 5. <8> The method further includes a step of recovering methyl methacrylate contained in the composition from a pyrolysis product of polymethyl methacrylate before the step of contacting the composition with an adsorbent. <1> ~ <7> The method for producing methyl methacrylate according to any one of claims 1 to 5. <9> Contains methyl methacrylate and odorous components, A composition having an odorous component concentration of more than 0 ppm by mass and less than 450 ppm by mass of the entire composition. <10> The content of methyl methacrylate in the entire composition is 85% by mass or more. <9> The composition described in <11> The content of methyl methacrylate in the entire composition is 90% by mass or more. <9> or <10> The composition described in <12> The odor components include at least one selected from the group consisting of alcohols, aldehydes, ketones, fatty acids, sulfur-containing compounds, and nitrogen-containing compounds. <9> ~ <11> The composition according to any one of claims 1 to 5. <13> The odor components include at least a sulfur-containing compound or a nitrogen-containing compound. <12> The composition described in <14> The methyl methacrylate comprises recycled methyl methacrylate or bio-derived methyl methacrylate; <9> ~ <13> The composition according to any one of claims 1 to 5. <15> Further containing (meth)acrylic acid esters other than methyl methacrylate, <9> ~ <14> The composition according to any one of claims 1 to 5. <16> Further comprising a polymer containing a structural unit derived from methyl methacrylate; <9> ~ <15> The composition according to any one of claims 1 to 5. <17> <9> ~ <16> A polymer comprising a structural unit derived from methyl methacrylate contained in the composition according to any one of claims 1 to 5. <18> <17> A molded article comprising the polymer according to claim 1. <19> <9> ~ <16> 2. A cured product of the composition according to claim 1. <20> <19> A molded article comprising the cured product according to claim 1. Effect of the Invention

[0008] According to the present disclosure, there are provided a method for producing odor-suppressed methyl methacrylate, a composition, a polymer, a cured product, and a molded article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described, however, the present invention is not limited to the following embodiment. In this specification, the numerical range indicated using "~" includes the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In the present specification, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. In addition, in the present specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples.

[0010] <Method for producing methyl methacrylate> One embodiment of the present disclosure is a method for producing methyl methacrylate, comprising contacting a composition containing methyl methacrylate and odorous components with an adsorbent.

[0011] As shown in the examples described later, contacting a composition containing methyl methacrylate and an odorous component with an adsorbent is effective in suppressing the odor of methyl methacrylate. Furthermore, because the method of the present disclosure uses an adsorbent as a means of suppressing odor, it can be carried out more easily and at lower cost than methods such as distillation.

[0012] The type of adsorbent to be brought into contact with the composition is not particularly limited, and can be selected depending on the type, concentration, etc. of odorous components contained in the composition. From the viewpoint of the odor suppression effect and ease of handling of the adsorbent, the adsorbent preferably contains zeolite or activated carbon, more preferably contains zeolite, and even more preferably contains zeolite containing silver ions. The adsorbent to be contacted with the composition may be of one type or two or more types.

[0013] From the viewpoint of the odor suppression effect and handling of the adsorbent, the adsorbent is preferably in the form of pellets, beads or powder, more preferably in the form of beads. The particle diameter of the adsorbent may be, for example, 10 mm or less, preferably 1 mm to 7 mm, and more preferably 6 mm or less. The adsorbent is more preferably in the form of beads having a particle diameter of 1 mm to 7 mm.

[0014] The amount of the adsorbent to be brought into contact with the composition is not particularly limited, and can be selected depending on the type, concentration, etc. of odorous components contained in the composition. From the viewpoint of fully exerting the odor suppression effect of the adsorbent, the amount of the adsorbent brought into contact with the composition is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 5 parts by mass or more, per 100 parts by mass of the composition. From the viewpoint of efficiency and economy of operations after contacting the composition with the adsorbent (e.g., operations of removing the adsorbent from the composition), the amount of adsorbent contacted with the composition is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of the composition.

[0015] After the step of contacting the composition with the adsorbent, the adsorbent may be removed from the composition. The time for contacting the composition with the adsorbent (the time from the start of contact to the time the adsorbent is removed) is not particularly limited, and can be selected depending on the type, concentration, etc. of odorous components contained in the composition. The time for contacting the adsorbent with the adsorbent can be adjusted within a range in which the desired odor suppression effect can be obtained, and can be selected, for example, from 1 hour to 1 week. The time for contacting the adsorbent with the adsorbent can be, for example, 3 hours, 6 hours, or 24 hours, or can be any other time.

[0016] The concentration of the odorous component in the composition after the step of contacting the composition with the adsorbent is preferably less than 450 mass ppm relative to the entire composition. When the concentration of the odorous component is less than 450 mass ppm relative to the entire composition, the degree of discomfort felt by a person handling the composition is effectively reduced. The concentration of odorous components in the composition after the step of contacting the composition with an adsorbent may be 300 ppm by mass or less, 250 ppm by mass or less, 200 ppm by mass or less, 150 ppm by mass or less, 100 ppm by mass or less, 90 ppm by mass or less, 50 ppm by mass or less, or 25 ppm by mass or less with respect to the entire composition. The lower the concentration of the odorous component in the composition after the step of contacting the composition with the adsorbent, the better. The concentration of the odorous component may be, for example, 0 ppm by mass, more than 0 ppm by mass, 2 ppm by mass or more, 5 ppm by mass or more, or 10 ppm by mass or more with respect to the entire composition. When the composition contains two or more odorous components, the concentrations of the odorous components mentioned above are the concentrations of each odorous component.

[0017] The type of odor component contained in the composition is not particularly limited. The odor component may include at least one selected from the group consisting of alcohols, aldehydes, ketones, fatty acids, sulfur-containing compounds, and nitrogen-containing compounds. In certain embodiments, the composition may include a sulfur-containing compound or a mercaptan compound as an odor component. In certain embodiments, the composition may include a nitrogen-containing compound or an amine compound as an odor component. The composition may contain only one type of odorant or two or more types of odorants.

[0018] The method of the present disclosure may include a step of recovering methyl methacrylate contained in the composition from a pyrolysis product of polymethyl methacrylate prior to the step of contacting the composition with an adsorbent. Methyl methacrylate recovered from the pyrolysis product of polymethyl methacrylate may contain substances that are inevitably mixed into the recovered polymethyl methacrylate and may cause odor. For example, mercaptan compounds such as n-butyl mercaptan, n-octyl mercaptan, and n-dodecyl mercaptan, which are added to the composition as a polymerization regulator, may be contained in polymethyl methacrylate as odorous components. The method for carrying out the step of recovering methyl methacrylate from the pyrolysis product of polymethyl methacrylate is not particularly limited and can be selected from known methods. In one embodiment, the step of recovering methyl methacrylate from a pyrolysate of poly(methyl methacrylate) may include the steps of heating poly(methyl (meth)acrylate) to obtain a gaseous pyrolysate, cooling the gaseous pyrolysate to liquefy it, and purifying the liquefied pyrolysate by distillation.

[0019] The method of the present disclosure may include a step of removing substances other than methyl methacrylate and odorous components contained in the composition. Substances other than methyl methacrylate and odorous components include additives contained in polymethyl methacrylate recovered for recycling, and other materials recovered together with polymethyl methacrylate. The method for carrying out the step of removing substances other than methyl methacrylate and odorous components contained in the composition is not particularly limited, and can be selected from known methods. The step of removing substances other than methyl methacrylate and odorous components contained in the composition may be carried out before or after the step of contacting the composition with an adsorbent. The method for removing substances other than methyl methacrylate and odorous components contained in the composition is not particularly limited, and can be selected from known purification techniques.

[0020] In the method of the present disclosure, the composition to be contacted with the adsorbent is not particularly limited as long as it contains methyl methacrylate and an odorous component. For details and preferred embodiments of the composition for contacting the adsorbent, reference can be made to the details and preferred embodiments of the composition of the present disclosure described below.

[0021] <Composition> One embodiment of the present disclosure comprises methyl methacrylate and an odor component, The composition has an odorous component concentration of more than 0 ppm by mass and less than 450 ppm by mass of the entire composition.

[0022] Even if the composition of the present disclosure contains an odorous component together with methyl methacrylate, the degree to which the composition causes discomfort to a person handling the composition is low.

[0023] The concentration of the odorous components in the composition is not particularly limited as long as it is less than 450 ppm by mass relative to the entire composition. The concentration of the odorous components may be 300 ppm by mass or less, 250 ppm by mass or less, 200 ppm by mass or less, 150 ppm by mass or less, 100 ppm by mass or less, 90 ppm by mass or less, 50 ppm by mass or less, or 25 ppm by mass or less relative to the entire composition. The concentration of the odorous component in the composition is preferably as low as possible. The concentration of the odorous component may be, for example, 0 ppm by mass, more than 0 ppm by mass, 2 ppm by mass or more, 5 ppm by mass or more, or 10 ppm by mass or more, based on the entire composition. When the composition contains two or more odorous components, the concentrations of the odorous components mentioned above are the concentrations of each odorous component.

[0024] The type of odor component contained in the composition is not particularly limited. The odor component may include at least one selected from the group consisting of alcohols, aldehydes, ketones, fatty acids, sulfur-containing compounds, and nitrogen-containing compounds. In certain embodiments, the composition may include a sulfur-containing compound or a mercaptan compound as an odor component. In certain embodiments, the composition may include a nitrogen-containing compound or an amine compound as an odor component. The composition may contain only one type of odorant or two or more types of odorants.

[0025] (Methyl methacrylate) In the method of the present disclosure, the composition contacting the adsorbent comprises methyl methacrylate. In the present disclosure, "methyl methacrylate" refers to methyl methacrylate that is essentially free of impurities such as by-products generated during the synthesis of methyl methacrylate. However, the methyl methacrylate in the present disclosure is not limited thereto, provided that the purpose of the invention is not impaired. In other words, "methyl methacrylate" may contain impurities that cannot be completely removed by conventional purification methods, or may contain impurities at a content that cannot be detected by conventional detection methods.

[0026] The content of methyl methacrylate in the composition is not particularly limited and can be selected depending on the application of polymethyl methacrylate obtained using the composition, etc. The content of methyl methacrylate may be, for example, 85 mass% or more, 90 mass% or more, 95 mass% or more, or 99 mass% or more of the entire composition. When the content of methyl methacrylate in the composition is within the above range, it is preferable from the viewpoint of at least the heat resistance or transparency (light transmittance) of a polymer obtained by polymerizing the composition and a molded article containing the same.

[0027] The methyl methacrylate contained in the composition may be synthesized by a known synthesis method. The synthesis method is not particularly limited, and may be the ACH method, the C4 direct acid method, or the alpha method.

[0028] The methyl methacrylate contained in the composition may include recycled methyl methacrylate. In this disclosure, recycled methyl methacrylate means methyl methacrylate obtained by depolymerization of polymethyl methacrylate (a reaction in which a polymer is decomposed to produce a monomer). Depolymerization of polymethyl methacrylate can be effected, for example, by subjecting polymethyl methacrylate to heat treatment. The source of polymethyl methacrylate, which is a raw material for regenerated methyl methacrylate, is not particularly limited as long as it is possible to recover methyl methacrylate. For example, the source of polymethyl methacrylate may be a molded body containing polymethyl methacrylate.

[0029] The methyl methacrylate included in the composition may include bio-derived methyl methacrylate. In the present disclosure, bio-derived methyl methacrylate means methyl methacrylate synthesized from a raw material of biological origin. The raw material of biological origin may be a raw material of plant origin or an animal origin, and is preferably a raw material derived from vegetable oil.

[0030] If necessary, the composition may contain a component other than methyl methacrylate and odorous components. For example, the composition may contain a (meth)acrylic acid ester other than methyl methacrylate, a polymer containing a structural unit derived from methyl methacrylate, a low content component, or an additive, as described below.

[0031] ((Meth)acrylic acid ester) The composition may contain, in addition to methyl methacrylate, a (meth)acrylic acid ester other than methyl methacrylate (hereinafter also simply referred to as a (meth)acrylic acid ester). Specific examples of (meth)acrylic acid esters include methyl acrylate, (meth)acrylic Examples of the acrylates include ethyl acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and cyclopentanyl (meth)acrylate. Among these, methyl acrylate or ethyl acrylate is preferred, and methyl acrylate is more preferred. These may be used alone or in combination of two or more. In the present disclosure, "(meth)acrylic acid ester" indicates that it may be either an acrylic acid ester or a methacrylic acid ester. The (meth)acrylic acid ester may be included in the composition as a by-product produced during the production of methyl methacrylate or during the regeneration treatment of polymethyl methacrylate, or may be intentionally mixed into the composition.

[0032] When the composition contains a (meth)acrylic acid ester, the concentration thereof is preferably 50,000 ppm by mass or less, more preferably 40,000 ppm by mass or less, and even more preferably 30,000 ppm by mass or less, of the entire composition. When the composition contains a (meth)acrylic acid ester, the concentration thereof may be 1 ppm by mass or more, 2 ppm by mass or more, or 5 ppm by mass or more of the total composition.

[0033] The composition may contain, in addition to methyl methacrylate, a polymer containing a structural unit derived from methyl methacrylate. This polymer may be a homopolymer of methyl methacrylate, or a copolymer of methyl methacrylate and other (meth)acrylic acid esters polymerizable therewith, as long as it contains a structural unit derived from methyl methacrylate. Examples of other (meth)acrylic acid esters polymerizable with methyl methacrylate include the same as those mentioned above.

[0034] (low content ingredients) The composition may contain low content components other than odor components. The low content components may be included in the composition as by-products produced during the production of methyl methacrylate or during the regeneration process of polymethyl methacrylate. In the present disclosure, a low content component means a component that is contained in the composition at a concentration of 10,000 ppm by mass or less.

[0035] Minor content components that the composition may contain include carboxylic acid esters, aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, alcohols, butyl acrylate, and the like. The composition may contain only one type of low content component or two or more types of low content components.

[0036] Specific examples of carboxylate esters include methyl isobutyrate, methyl propionate, methyl 2,4-dimethyl-4-pentenoate, methyl 2-methyl-3-butenoate, methyl tiglate, methyl 3-methyl-3-butenoate, methyl 3-methyl-2-butenoate, dimethyl itaconate, and dimethyl 2-methyl-5-methylenehexanedioate. Specific examples of the aromatic hydrocarbon compound include toluene and styrene. Specific examples of the aliphatic hydrocarbon compounds include 1-octene and 1-octadecene.

[0037] When the composition contains low content components other than odorous components, the concentration of each low content component is preferably 8000 ppm by mass or less of the total composition, more preferably 6000 ppm by mass or less, and even more preferably 5000 ppm by mass or less. When the composition includes low content components other than odorous components, the concentration of each low content component may be 1 ppm by weight or more, 2 ppm by weight or more, or 5 ppm by weight or more of the total composition.

[0038] (Additives) If necessary, the composition may contain additives, such as a release agent, a polymerization regulator, a polymerization initiator, an ultraviolet absorber, and a colorant. The composition may contain only one type of additive, or two or more types of additives.

[0039] Examples of release agents that the composition may contain include higher fatty acid esters, higher fatty alcohols, higher fatty acids, higher fatty acid amides, higher fatty acid metal salts, and fatty acid derivatives. Specific examples of release agents include sodium di-(2-ethylhexyl)sulfosuccinate, stearyl alcohol, methyl stearate, and stearic acid amide.

[0040] The composition may contain one type of release agent or two or more types of release agents. The content of the release agent in the composition can be, for example, 0.01% by mass to 1.0% by mass of the entire composition.

[0041] The composition may contain a polymerization regulator (an additive for controlling the polymerization rate in a polymerization reaction) and may be any suitable polymerization regulator known in the art. For example, a compound capable of controlling the polymerization rate in a direction to decrease the polymerization rate may be used as the polymerization regulator. Specific examples of the polymerization regulator include mercaptan compounds such as n-butyl mercaptan, n-octyl mercaptan, and n-dodecyl mercaptan; terpenoid compounds such as limonene, myrcene, α-terpinene, β-terpinene, γ-terpinene, terpinolene, β-pinene, and α-pinene; and α-methylstyrene dimer.

[0042] The composition may contain one or more types of polymerization regulator. The content of the polymerization regulator in the composition can be, for example, 0.001% by mass to 0.5% by mass of the entire composition.

[0043] Polymerization initiators that the composition may contain include radical polymerization initiators, diacyl peroxide initiators, dialkyl peroxide initiators, peroxyester initiators, percarbonate initiators, and peroxyketal initiators.

[0044] Specific examples of radical polymerization initiators include azo compounds such as 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4,4-trimethylpentene), 2,2'-azobis(2-methylpropane), 2-cyano-2-propylazoformamide, 2,2'-azobis(2-hydroxymethylpropionate), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], and dimethyl 2,2'-azobis(2-methylpropionate).

[0045] Specific examples of diacyl and dialkyl peroxide initiators include dicumyl peroxide, tert-butylcumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide, and lauroyl peroxide.

[0046] Specific examples of peroxyester initiators include tert-butylperoxy-3,3,5-trimethylhexanoate, tert-butylperoxylaurate, tert-butylperoxyisobutyrate, tert-butylperoxyacetate, di-tert-butylperoxyhexahydroterephthalate, di-tert-butylperoxyazelate, tert-butylperoxy-2-ethylhexanoate, 1,1,3,3-tert-butylperoxyethylhexanoate, ... tetramethylbutylperoxy-2-ethylhexanoate, and tert-amylperoxy-2-ethylhexanoate.

[0047] Specific examples of percarbonate initiators include tert-butyl peroxy allyl carbonate, and tert-butyl peroxy isopropyl carbonate.

[0048] Specific examples of peroxyketal initiators include 1,1-di-tert-butylperoxycyclohexane, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and 1,1-di-tert-hexylperoxy-3,3,5-trimethylcyclohexane.

[0049] The composition may contain one type of polymerization initiator or two or more types of polymerization initiators. The content of the polymerization initiator in the composition can be, for example, 0.01% by mass to 5% by mass of the entire composition.

[0050] UV absorbers that the composition may contain include benzophenone UV absorbers, cyanoacrylate UV absorbers, benzotriazole UV absorbers, malonate UV absorbers, and oxalanilide UV absorbers.

[0051] Specific examples of ultraviolet absorbers include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-hydroxy-4-n-octylbenzophenone, 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-pentylphenyl)benzotriazole, and 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate.

[0052] The composition may contain one or more types of ultraviolet absorbents. The content of the ultraviolet absorber in the composition can be, for example, 0.001% by mass to 1% by mass of the entire composition.

[0053] Colorants that the composition may contain include perylene dyes, perinone dyes, pyrazolone dyes, methine dyes, coumarin dyes, quinophthalone dyes, quinoline dyes, anthraquinone dyes, asdolapyridone dyes, thioindigo dyes, coumarin dyes, isoindolinone pigments, sichetopyrrolopyrrole pigments, condensed azo pigments, benzimidazolone pigments, dioxazine pigments, copper phthalocyanine pigments, and quinacridone pigments.

[0054] The composition may contain only one type of colorant, or two or more types of colorants. The content of the colorant in the composition is, for example, 1.0×10 -8 The content can be 0.5% by mass to 0.5% by mass.

[0055] When the composition contains additives, the total content thereof may be 15 mass % or less, 10 mass % or less, 5 mass % or less, or 1 mass % or less of the total composition. When the composition contains additives, the total content thereof may be 0.01 mass % or more, 0.05 mass % or more, or 0.1 mass % or more of the total composition.

[0056] The composition of the present disclosure may be used immediately after preparation, or may be stored before use. The storage conditions for storage are not particularly limited, but may be, for example, 0°C to 45°C. From the viewpoint of ensuring good quality, the storage temperature is preferably selected from the range of 0°C to 39°C, more preferably selected from the range of about 25°C±10°C, and even more preferably selected from the range of about 25°C to 30°C.

[0057] <Polymers, cured products and molded articles> The polymer of the present disclosure is a polymer containing a structural unit derived from methyl methacrylate contained in the composition of the present disclosure. Here, the polymer is a polymer obtained by polymerizing the components involved in polymerization contained in the composition, and has a structural unit derived from the components involved in polymerization. The polymer of the present disclosure may contain a structural unit derived from methyl methacrylate contained in the composition of the present disclosure and a structural unit derived from another polymerization component. The weight average molecular weight of the polymer of the present disclosure is not particularly limited and can be selected according to the application of the polymer. The cured product of the present disclosure is a cured product of the composition of the present disclosure described above. Here, the cured product is a cured composition, and may contain components that are not involved in polymerization. However, depending on the method for curing the composition, it may be considered to be the same as the above-mentioned polymer (i.e., it does not contain components that are not involved in polymerization). The molded article of the present disclosure includes the polymer or cured product of the present disclosure. When the cured product can be regarded as the same as the polymer, the molded article includes a polymer of the composition of the present disclosure. The molded article is preferably a molded article including a cured product obtained by curing only the composition of the present disclosure. The molded article may be an object obtained by molding the polymer or the cured product into any shape.

[0058] Whether or not the polymer, cured product, and molded article of the present disclosure contain methyl methacrylate, odorous components, or other components can be determined by known analytical methods, such as gas chromatography and liquid chromatography.

[0059] The polymer, cured product, and molded article of the present disclosure contain odorous components, and the concentration of the odorous components is more than 0 ppm by mass and less than 450 ppm by mass relative to the total mass of the polymer, cured product, or molded article. The concentration of odorous components contained in the polymer, cured product, or molded product may be 300 ppm by mass or less, 250 ppm by mass or less, 200 ppm by mass or less, 150 ppm by mass or less, 100 ppm by mass or less, 90 ppm by mass or less, 50 ppm by mass or less, or 25 ppm by mass or less. The concentration of the odorous component contained in the polymer, cured product, or molded product is preferably as low as possible. The concentration of the odorous component may be, for example, 0 ppm by mass, more than 0 ppm by mass, 2 ppm by mass or more, 5 ppm by mass or more, or 10 ppm by mass or more, based on the entire composition.

[0060] When the concentration of the odorous components contained in the polymer, the cured product, or the molded article is in the range of less than 450 ppm by mass, the odor of the polymer, the cured product, or the molded article is effectively suppressed.

[0061] <Production method of polymethyl methacrylate> The method for producing polymethyl methacrylate of the present disclosure includes a step of polymerizing the methyl methacrylate contained in the composition of the present disclosure. Here, the polymethyl methacrylate of the present disclosure includes a polymer obtained from the composition of the present disclosure and a cured product obtained from the composition.

[0062] The method for polymerizing methyl methacrylate contained in the composition is not particularly limited, and may be carried out by a known method, such as bulk polymerization, cell cast polymerization, solution polymerization, suspension polymerization, or emulsion polymerization.

[0063] Specifically, the composition of the present disclosure can be used to obtain a sheet (molded product) of a methyl methacrylate polymer by bulk polymerization, for example. In cell cast polymerization, the composition is heated under a predetermined heating condition to cause a polymerization reaction to proceed, thereby obtaining a cured product (molded product) of the composition.

[0064] In the method for polymerizing methyl methacrylate contained in the composition of the present disclosure or the method for producing a molded body, the heating temperature and heating time among the heating conditions can be set, for example, taking into consideration the type and content of the selected polymerization regulator, polymerization initiator, and / or other components.

[0065] In the cell cast polymerization, when producing a cured product and its molded article, the heating temperature can be, for example, 50° C. to 120° C. The heating time can be, for example, 1 hour to 20 hours. The heat treatment can be a heat treatment including a plurality of steps with different heating temperatures and / or heating times.

[0066] The cured product obtained by cell cast polymerization and its molded article can be produced, for example, by carrying out a heat treatment under heating conditions including the following steps 1 to 7.

[0067] Step 1: Raise the temperature from room temperature to 68°C over 20 minutes. Step 2: Hold at 68°C for 90 minutes. Step 3: Reduce the temperature from 68°C to 64°C over 20 minutes. Step 4: Hold at 64°C for 90 minutes. Step 5: Increase temperature from 64°C to 123°C over 10 minutes. Step 6: Hold at 123°C for 120 minutes. Step 7: The temperature is reduced from 123°C to room temperature over 78 minutes.

[0068] In the method for producing a cured product and a molded article thereof, by carrying out the above steps 1 to 7 in this order, heat generation during the polymerization reaction can be suppressed and the polymerization can be stably completed.

[0069] When the composition of the present disclosure is subjected to a heat treatment, for example, a cell casting method (cell casting polymerization) using a cell capable of defining an enclosed space of a predetermined shape inside can be applied to form a molded body of a predetermined shape. The manufacturing method of a molded body by the cell casting method will be specifically described below.

[0070] In manufacturing a green body by the cell casting method, a cell is first prepared. Here, an example of forming a green body that is a plate-like body (sometimes called a cast plate) will be described. Such a cell can be composed of at least two flat plate-like members and a sealing material (gasket) that is arranged so as to be sandwiched between the two flat plate-like members and can seal the gap between the two opposing flat plate-like members as an airtight space.

[0071] The flat plate member may be in the form of a sheet or a belt. The flat plate member is made of a material that is not dissolved by the composition of the present disclosure, does not inhibit the polymerization reaction of the composition, and has sufficient heat resistance to the heating temperature in the heat treatment. Examples of suitable materials for the flat plate member include glass and metal.

[0072] As the sealing material, any suitable sealing material known in the art can be used. The sealing material is made of a material that is not dissolved by the composition of the present disclosure, does not inhibit the polymerization reaction of the composition, and has sufficient heat resistance to the heating temperature in the heat treatment. A specific example of a suitable sealing material is a gasket made of vinyl chloride resin.

[0073] Next, the composition of the present disclosure is injected into the gap (void) defined by the prepared cell by any suitable conventional method. After that, the cell is heat-treated under the heating conditions already described. The method of heat-treating the cell into which the composition of the present disclosure is injected is not particularly limited. The method of heat-treating the cell can be, as in the conventional cell casting method, a method of directly heat-treating the cell from the outside using a hot air circulating oven, an infrared heater, or the like, or a method of further providing any suitable conventional jacket on the outside of the cell and introducing a heat medium such as hot air, hot water, or water vapor into the jacket.

[0074] <Uses of polymethyl methacrylate and its molded bodies> The polymethyl methacrylate obtained from the composition of the present disclosure and its molded article are excellent in light transmittance, heat resistance, and weather resistance, and therefore can be suitably applied to various applications that may be exposed to the external environment and further to heat and light sources, such as lighting fixtures, automobile parts, signs, and building materials. EXAMPLES

[0075] Hereinafter, embodiments of the present disclosure will be described based on examples, but the present disclosure is not limited to these examples. The results of the sensory evaluation of the odor of the compositions shown in the table were evaluated according to the following criteria. <Odor Strength> 5: Extremely strong 4: Very strong 3: Strong 2: Somewhat strong 1: Odorless or not noticeable <Uncomfort level> 5: Extremely uncomfortable 4: Very uncomfortable 3: Unpleasant 2: Somewhat uncomfortable 1: Odorless or not unpleasant

[0076] <Example 1> The gaseous pyrolysis product obtained by pyrolyzing polymethyl methacrylate was cooled to obtain a condensate. This condensate (unpurified) was used as a composition containing methyl methacrylate. The content of methyl methacrylate was 95% by mass of the entire composition. To 3 g of the composition, 0.3 g of silver ion-containing zeolite (Zeomic BG02N, manufactured by Sinanen Zeomic Corporation) was added as an adsorbent, and the mixture was mixed. After contacting the adsorbent with the composition and leaving it to stand for 24 hours, a sensory evaluation of odor was carried out (by testers: one male and one female). The results are shown in Table 1.

[0077] <Example 2> A sensory evaluation of odor was carried out in the same manner as in Example 1, except that the adsorbent contacted with the composition was changed to the same amount of a zeolite-based deodorant (Dashlight 3MH, manufactured by Sinanen Zeomic Co., Ltd.). The results are shown in Table 1.

[0078] <Example 3> A sensory evaluation of odor was carried out in the same manner as in Example 1, except that the adsorbent contacted with the composition was changed to the same amount of a zeolite-based deodorant (Dashlight 9MH, manufactured by Sinanen Zeomic Co., Ltd.). The results are shown in Table 1.

[0079] <Comparative Example 1> Except for not contacting the composition with an adsorbent, a sensory evaluation of odor was carried out in the same manner as in Example 1. The results are shown in Table 1.

[0080] [Table 1]

[0081] <Example 4> Except for changing the amount of the adsorbent brought into contact with the composition to 0.5 g, the odor sensory evaluation was carried out in the same manner as in Example 1. The results are shown in Table 2.

[0082] <Example 5> Except for changing the amount of the adsorbent brought into contact with the composition to 0.1 g, a sensory evaluation of odor was carried out in the same manner as in Example 1. The results are shown in Table 2.

[0083] <Example 6> A sensory evaluation of odor was carried out in the same manner as in Example 1, except that the adsorbent brought into contact with the composition was changed to the same amount of activated carbon (manufactured by Daiso Industries Co., Ltd.). The results are shown in Table 2.

[0084] <Example 7> A sensory evaluation of odor was carried out in the same manner as in Example 1, except that the composition to be contacted with the adsorbent was changed to a purified condensate. The content of methyl methacrylate was 97% by mass of the entire composition. The results are shown in Table 2.

[0085] <Example 8> A sensory evaluation of odor was carried out in the same manner as in Example 7, except that the amount of adsorbent brought into contact with the composition was changed to 0.1 g. The results are shown in Table 2.

[0086] <Comparative Example 2> Except for not contacting the composition with an adsorbent, a sensory evaluation of odor was carried out in the same manner as in Example 7. The results are shown in Table 2.

[0087] <Comparative Example 3> A sensory evaluation of odor (by one male tester) was carried out in the same manner as in Example 1, except that the composition was contacted with the same amount of sodium bicarbonate (a substance that exerts a deodorizing function by a neutralization reaction with an acidic substance, manufactured by Daiso Industries Co., Ltd.) instead of the adsorbent. The results are shown in Table 2.

[0088] [Table 2]

[0089] <Example 9> The gaseous pyrolysate obtained by pyrolyzing polymethyl methacrylate was cooled to obtain a condensate. This condensate (unpurified) was used as a composition containing methyl methacrylate. 0.5 g of silver ion-containing zeolite (Zeomic BG02N, manufactured by Sinanen Zeomic Co., Ltd.) was added as an adsorbent to 3 g of the composition and mixed. A sensory evaluation of odor (evaluation subject: odor intensity, tester: one man) was performed on the composition before contact with the adsorbent (0 hours), and 1 hour, 3 hours, 6 hours, and 24 hours after the start of contact with the adsorbent. The results are shown in Table 3.

[0090] <Example 10> A sensory evaluation of odor was carried out in the same manner as in Example 9, except that the amount of adsorbent brought into contact with the composition was changed to 0.1 g. The results are shown in Table 3.

[0091] <Example 11> A sensory evaluation of odor was carried out in the same manner as in Example 9, except that the composition contacted with the adsorbent was changed to the purified condensate. The results are shown in Table 3.

[0092] <Example 12> Except for changing the amount of the adsorbent brought into contact with the composition to 0.1 g, the odor sensory evaluation was carried out in the same manner as in Example 11. The results are shown in Table 3.

[0093] [Table 3]

[0094] <Odor component concentration measurement> The odor of the composition containing methyl methacrylate is presumed to be caused by n-octyl mercaptan added as a polymerization regulator to the raw material polymethyl methacrylate. Therefore, the following concentration measurement tests 1 and 2 were carried out to confirm whether the concentration of n-octyl mercaptan contained in the composition changes due to contact with the adsorbent.

[0095] (Concentration measurement test 1) In Example 9, the concentration of n-octyl mercaptan was measured by gas chromatography for the composition before contact with the adsorbent (0 hour), and 2 hours, 3 hours, 7 hours, and 24 hours after the start of contact. The measurement conditions are shown below.

[0096] (Measurement conditions) Equipment: GC-2010 Plus (manufactured by Shimadzu Corporation) Column: DB-1 (Agilent Technologies, Inc.) Detector: FID 2010 Plus (Shimadzu Corporation) Column oven conditions Initial temperature: 40℃ (hold time 1 minute) Heating rate: 8℃ / min Intermediate temperature: 120℃ (hold time 0 minutes) Heating rate: 20℃ / min Final temperature: 300℃ (hold time 10 minutes) Sample vaporization conditions Vaporization chamber temperature: 300℃ Carrier gas: Helium Pressure: 50kPa Total flow rate: 220.1mL / min Column flow rate: 1.08 mL / min Linear speed: 31.1cm / sec Purge dose: 3.0mL / min Split ratio: 200 Detector conditions Detector temperature: 300℃ Sampling rate: 40msec Make-up gas: N2 Make-up flow rate: 30mL / min H2 flow rate: 40mL / min Air flow rate: 400mL / min Autosampler Conditions Injection volume: 1μL

[0097] The peak area (a1) corresponding to octyl mercaptan and the peak area (b1) corresponding to dodecanol detected when the sample (composition contacted with the adsorbent) was measured under the above measurement conditions were measured. From these peak areas, the peak area ratio A (=a1 / b1) was calculated.

[0098] A standard sample with a mass ratio of octyl mercaptan content to dodecanol content of W0 (known) was measured under the above measurement conditions, and the peak area (a0) corresponding to the detected n-octyl mercaptan and the peak area (b0) corresponding to dodecanol were measured. From these peak areas, the peak area ratio A0 (=a0 / b0) was calculated. Next, the factor f (=W0 / A0) was calculated from the peak area ratio A0 and the above mass ratio W0.

[0099] Next, the mass ratio W of n-octyl mercaptan to dodecanol contained in the composition was calculated by multiplying the peak area ratio A by the factor f. The concentration of n-octyl mercaptan contained in the composition (OM concentration, mass ppm) was calculated from the calculated mass ratio W and the mass of the composition. The results are shown in Table 4.

[0100] [Table 4]

[0101] (Concentration measurement test 2) For the above Examples 1 and 4 to 8, the concentration of n-octyl mercaptan (OM concentration, mass ppm) was measured when a sensory evaluation of odor was performed (compositions after standing for 24 hours). The measurement method was the same as the above. The results are shown in Table 5.

[0102] [Table 5]

[0103] The results shown in Tables 1 to 3 suggest that contacting a composition containing polymethyl methacrylate with an adsorbent is effective in suppressing the odor of the composition. The results shown in Tables 4 and 5 suggest that the adsorbent in contact with the composition adsorbs substances contained as odorous components, contributing to a reduction in the concentration of odorous components in the composition.

Claims

1. The method includes a step of contacting a composition containing methyl methacrylate and an odor component with an adsorbent, the odor components include at least one selected from the group consisting of alcohols, aldehydes, ketones, fatty acids, sulfur-containing compounds, and nitrogen-containing compounds; A method for producing methyl methacrylate, wherein the adsorbent contains zeolite containing silver ions, is in the form of beads, and has a particle diameter of 1 mm to 7 mm.

2. The method for producing methyl methacrylate according to claim 1, wherein the amount of the adsorbent contacted with the composition is 1 part by mass to 30 parts by mass per 100 parts by mass of the composition.

3. 2. The method for producing methyl methacrylate according to claim 1, wherein the concentration of the odorous component in the composition after the step of contacting the composition with an adsorbent is less than 450 ppm by mass with respect to the entire composition.

4. The method for producing methyl methacrylate according to claim 1, further comprising a step of recovering methyl methacrylate contained in the composition from a pyrolysis product of polymethyl methacrylate prior to the step of contacting the composition with an adsorbent.

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