Composition containing methyl methacrylate

Abstract

The present invention relates to a composition containing methyl methacrylate. The present invention provides a molded body having excellent heat resistance. A composition containing methyl methacrylate, methyl isobutyrate, and methyl acrylate, wherein the content of methyl methacrylate is 99.5 mass% or more, the concentration of methyl isobutyrate is 20 mass ppm to 300 mass ppm, and the concentration of methyl acrylate is 5 mass ppm to 200 mass ppm.

Description

Technical Field

[0001] This invention relates to compositions, and more particularly to compositions with methyl methacrylate as the main component. Background Technology

[0002] Polymethyl methacrylate (PMMA), a polymer obtained by polymerizing methyl methacrylate, has excellent transparency and weather resistance. Therefore, PMMA is widely used as a material for components in automobiles, signage, display devices, and the like.

[0003] Representative examples of methods for manufacturing methyl methacrylate as a raw material for such polymethyl methacrylate include the following methods: the "ACH (acetone cyanohydrin) method" implemented using acetone and hydrogen cyanide (hydrogen cyanide) as raw materials, the "C4 direct oxidation method" implemented using isobutylene or tert-butanol as raw materials, and the "α method" implemented using ethylene as raw materials.

[0004] However, regardless of which of the above methods is used to manufacture methyl methacrylate, the resulting reaction product (methyl methacrylate) will inevitably contain impurities such as byproducts.

[0005] Moreover, especially when methyl isobutyrate is present as an impurity, the properties of polymethyl methacrylate and its molded parts may deteriorate when the manufactured methyl methacrylate is used to produce polymethyl methacrylate.

[0006] Therefore, in the past, the method of reducing the content of methyl isobutyrate as much as possible by strictly purifying the manufactured methyl methacrylate has been adopted, and various purification methods have been studied to date (see Patent Document 1).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Publication No. 1-47454 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] However, the purification method described in Patent Document 1 requires not only large equipment such as more than one distillation column and water separation tank, but also extremely complex and cumbersome procedures. Therefore, there is a need for a composition with methyl methacrylate as the main component that can manufacture polymethyl methacrylate and its molded bodies with excellent properties such as high heat resistance, even without implementing such a purification method.

[0012] means for solving problems

[0013] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that the above-mentioned problems could be solved even without specifically applying the strict purification method disclosed in Patent Document 1, thereby completing the present invention.

[0014] That is, the present invention provides the following [1] to [8].

[0015] [1] A composition comprising methyl methacrylate, methyl isobutyrate and methyl acrylate, wherein...

[0016] The content of methyl methacrylate is 99.5% by mass or higher.

[0017] The concentration of methyl isobutyrate is 20 ppm to 300 ppm by mass, and

[0018] The concentration of methyl acrylate is 5 ppm to 200 ppm by mass.

[0019] [2] The composition as described in [1], wherein the concentration of methyl isobutyrate is 20 ppm to 140 ppm by mass.

[0020] [3] The composition as described in [1] or [2], wherein the concentration of methyl acrylate is 20 ppm to 200 ppm by mass.

[0021] [4] The composition of any one of [1] to [3] wherein the concentration of methyl acrylate is in the ratio of 0.1 to 6.0 to the concentration of methyl isobutyrate.

[0022] [5] The composition as described in any one of [1] to [4], wherein,

[0023] The composition also contains methyl propionate, and

[0024] The concentration of methyl propionate is 5 ppm to 200 ppm by mass.

[0025] [6] The composition as described in [5], wherein the concentration of methyl propionate is 20 ppm to 200 ppm by mass.

[0026] [7] The composition as described in [5] or [6], wherein the concentration of methyl propionate is in the ratio of methyl isobutyrate to methyl propionate is 1.0 to 4.0.

[0027] [8] A method for manufacturing a polymer, wherein the method comprises a step of polymerizing the composition described in any one of [1] to [7].

[0028] Invention Effects

[0029] According to the present invention, it is possible to provide a composition that can be easily and at low cost to form a polymethyl methacrylate molded body, which has particularly excellent resistance to heat that may be exposed during use. Detailed Implementation

[0030] Hereinafter, specific embodiments of the present invention will be described. The present invention is not limited to the following description, and elements of the embodiments of the present invention may be appropriately modified without departing from the spirit of the present invention.

[0031] 1. Composition

[0032] The composition of this embodiment is a composition containing methyl methacrylate, methyl isobutyrate and methyl acrylate, wherein the content of methyl methacrylate is 99.5% by mass or more, the concentration of methyl isobutyrate is 20 ppm by mass to 300 ppm by mass, and the concentration of methyl acrylate is 5 ppm by mass to 200 ppm by mass.

[0033] According to the composition of this embodiment, polymethyl methacrylate and its molded articles can be manufactured, wherein the polymethyl methacrylate and its molded articles are particularly heat resistant, specifically, able to prevent or suppress the increase of yellowness, and able to prevent or suppress the decrease of light transmittance.

[0034] The components that may be contained in the composition of this embodiment will be described in detail below.

[0035] (1) Methyl methacrylate

[0036] In this specification, "methyl methacrylate" refers to methyl methacrylate that is substantially free of impurities such as byproducts (especially methyl isobutyrate). However, this is not a limitation without prejudice to the purpose of the invention. In other words, "methyl methacrylate" may contain impurities that cannot be completely removed by conventional purification methods, or may contain impurities in amounts that are undetectable by conventional detection methods.

[0037] There are no particular limitations on the method for manufacturing methyl methacrylate, which can be used as a raw material for the composition of this embodiment. Examples of methods for manufacturing methyl methacrylate, which are the raw materials for this embodiment, include the ACH method, the C4 direct oxidation method, and the α method, which have already been described. Methyl methacrylate, as a raw material, can be manufactured by any of these methods.

[0038] As a raw material for the composition of this embodiment, a mixture (hereinafter referred to as methyl methacrylate mixture) can be used, wherein the mixture contains, in addition to methyl methacrylate manufactured by the above manufacturing method, methyl isobutyrate, or both methyl isobutyrate and methyl acrylate, to a degree that is unavoidably mixed in according to the above manufacturing method.

[0039] Methyl methacrylate (or a mixture of methyl methacrylates) that can be used as a raw material for the composition of this embodiment and that are manufactured by the above manufacturing method can be purified by any suitable purification method known in the past.

[0040] When the total amount of the methyl methacrylate mixture is set to 100 parts by mass, the methyl methacrylate mixture used as a raw material for the composition of this embodiment may contain methyl isobutyrate with a content greater than 0 ppm by mass and less than or equal to 300 ppm by mass, and / or the methyl methacrylate mixture may contain methyl acrylate with a content of 0 ppm by mass to 200 ppm by mass.

[0041] (2) Methyl isobutyrate

[0042] As for methyl isobutyrate, in addition to methyl isobutyrate that is inevitably mixed in by implementing the methyl methacrylate manufacturing method already described, especially from the viewpoint of adjusting the content of methyl isobutyrate in the composition, methyl isobutyrate separately manufactured by any suitable manufacturing method known in the past can also be used.

[0043] Examples of methods for manufacturing such methyl isobutyrate include: a method for obtaining methyl isobutyrate by esterifying isobutyramide, a method for obtaining methyl isobutyrate by methoxycarbonylating propylene, and a method for obtaining methyl isobutyrate by methyl esterifying isobutyric acid.

[0044] In this specification, "methyl isobutyrate" refers to methyl isobutyrate that is substantially free of impurities such as byproducts. However, this is not a limitation without prejudice to the purpose of the invention. In other words, the specially added "methyl isobutyrate" may contain impurities that cannot be completely removed by conventional purification methods, or may contain impurities in a quantity that is undetectable by conventional detection methods.

[0045] Methyl isobutyrate can also be used as a commercially available reagent or other form of methyl isobutyrate.

[0046] In the composition of this embodiment, the concentration of methyl isobutyrate is 20 ppm to 300 ppm by mass.

[0047] In the composition of this embodiment, the concentration of methyl isobutyrate is preferably 20 ppm to 140 ppm by mass, more preferably 40 ppm to 120 ppm by mass.

[0048] (3) Methyl acrylate

[0049] As methyl acrylate, in addition to methyl acrylate that is inevitably mixed in by the method for manufacturing methyl methacrylate as described above, methyl acrylate that is separately manufactured by any suitable manufacturing method known in the past can also be used.

[0050] Examples of methods for manufacturing methyl acrylate include: a method for obtaining methyl acrylate by methoxycarbonylation of acetylene, a method for obtaining methyl acrylate by alcoholysis of acrylonitrile, and a method for obtaining methyl acrylate by methyl esterification of acrylic acid.

[0051] Methyl acrylate can also be used as a commercially available methyl acrylate in the form of reagents, etc.

[0052] In this specification, "methyl acrylate" refers to methyl acrylate that is substantially free of impurities such as byproducts. However, this is not a limitation without prejudice to the purpose of the invention. In other words, the specially added "methyl acrylate" may contain impurities that cannot be completely removed by conventional purification methods, or may contain impurities in amounts that are undetectable by conventional detection methods.

[0053] The concentration of methyl acrylate in the composition of this embodiment may be 5 ppm to 200 ppm by mass.

[0054] In the composition of this embodiment, the concentration of methyl acrylate is preferably 20 ppm to 200 ppm by mass, more preferably 50 ppm to 160 ppm by mass.

[0055] According to the composition of this embodiment, by containing methyl acrylate at the above-mentioned concentration, even if the composition contains methyl isobutyrate, the heat resistance of polymethyl methacrylate and its molded articles manufactured using the composition of this embodiment can be improved. Specifically, it is possible to prevent or suppress the increase in yellowness of the manufactured polymethyl methacrylate and its molded articles over time due to use, and it is possible to prevent or suppress the decrease in light transmittance.

[0056] (4) Methyl propionate

[0057] In addition to the methyl methacrylate, methyl isobutyrate, and methyl acrylate described above, the composition of this embodiment may also contain methyl propionate.

[0058] As methyl propionate, in addition to methyl propionate that is inevitably produced by the method for manufacturing methyl methacrylate as described above, methyl propionate that is separately manufactured by any suitable manufacturing method known in the past may also be used.

[0059] Examples of methods for producing methyl propionate include: a method for obtaining methyl propionate by methoxycarbonylation of ethylene, and a method for obtaining methyl propionate by methyl esterification of propionic acid.

[0060] Methyl propionate can also be used as a commercially available methyl propionate in the form of reagents, etc.

[0061] In this specification, "methyl propionate" refers to methyl propionate that is substantially free of impurities such as byproducts. However, this is not a limitation without prejudice to the purpose of the invention. In other words, the specially added "methyl propionate" may contain impurities that cannot be completely removed by conventional purification methods, or may contain impurities in a quantity that is undetectable by conventional detection methods.

[0062] The concentration of methyl propionate in the composition of this embodiment may be 5 ppm to 200 ppm by mass.

[0063] In the composition of this embodiment, the concentration of methyl propionate is preferably 20 ppm to 200 ppm by mass, more preferably 50 ppm to 100 ppm by mass.

[0064] According to the composition of this embodiment, by further containing methyl propionate at the above-mentioned concentration, even if the composition contains methyl isobutyrate, the heat resistance of polymethyl methacrylate and its molded articles manufactured using the composition of this embodiment can be improved. Specifically, it is possible to more effectively prevent or suppress the increase in yellowing of the manufactured polymethyl methacrylate and its molded articles over time due to use, and it is possible to more effectively prevent or suppress the decrease in light transmittance.

[0065] (5) Other ingredients

[0066] The composition of this embodiment may contain, without prejudice to the purpose of the present invention, other components such as release agents, polymerization regulators, polymerization initiators, ultraviolet absorbers, and colorants, in addition to the methyl methacrylate, methyl isobutyrate, methyl acrylate, and methyl propionate mentioned above, which may be added to form a molded body with specified properties.

[0067] Hereinafter, other components that may be included in the composition of this embodiment will be described.

[0068] (i) Release agent

[0069] The composition of this embodiment may contain a release agent, which is used to improve the release properties of the molded articles, particularly when manufacturing polymethyl methacrylate and its molded articles using the composition.

[0070] Examples of release agents that may be contained in the composition of this embodiment include: higher fatty acid esters, higher aliphatic alcohols, higher fatty acids, higher fatty acid amides, higher fatty acid metal salts, and fatty acid derivatives.

[0071] Specific examples of release agents that may be included in the composition of this embodiment include: sodium di(2-ethylhexyl) sulfosuccinate, stearyl alcohol, methyl stearate, and stearamide. In the composition of this embodiment, the release agents exemplified above may be used individually or in combination of two or more.

[0072] When the total amount of the composition is set to 100 parts by mass, the content of the release agent in the composition of this embodiment can be, for example, 0.01 parts by mass to 1.0 parts by mass.

[0073] (ii) Polymerization regulators

[0074] The composition of this embodiment may contain a polymerization regulator capable of adjusting the polymerization rate in the polymerization reaction.

[0075] As a polymerization regulator that may be included in the composition of this embodiment, any suitable polymerization regulator known in the art can be used. For example, a compound capable of adjusting the polymerization rate in a direction that delays polymerization can be used.

[0076] Preferred examples of polymerization regulators include: thiols such as n-butylthiol and n-octylthiol; terpenoids such as limonene, myrcene, α-terpinene, β-terpinene, γ-terpinene, terpinene oleene, β-pinene, and α-pinene; and α-methylstyrene dimers. Terpinene oleene, as a terpenoid, is preferred as a polymerization regulator.

[0077] In the composition of this embodiment, the polymerization regulators exemplified above can be used individually or in combination of two or more.

[0078] When the total amount of the composition is set to 100 parts by mass, the content of the polymerization regulator in the composition of this embodiment can be, for example, 0.001 parts by mass to 0.5 parts by mass.

[0079] (iii) Polymerization initiator

[0080] Examples of polymerization initiators that may be contained in the composition of this embodiment include: free radical polymerization initiators, diacyl peroxide initiators, dialkyl peroxide initiators, ester peroxide initiators, percarbonate initiators, and ketal peroxide initiators.

[0081] Specific examples of free radical polymerization initiators include: 1,1'-azobis(cyclohexane-1-carboxynitrile), 2,2'-azobis(2,4,4-trimethylpentene), 2,2'-azobis(2-methylpropane), 2-cyano-2-propylazocarboxamide, 2,2'-azobis(methyl 2-hydroxypropionate), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], and 2,2'-azobis(2-methylpropionic acid) dimethyl ester, etc.

[0082] Specific examples of diacyl peroxide initiators and dialkyl peroxide initiators include: dicumyl peroxide, tert-butylcumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide, and lauroyl peroxide.

[0083] Specific examples of ester peroxide initiators include: tert-butyl peroxide-3,3,5-trimethylhexanoate, tert-butyl peroxylaurate, tert-butyl peroxyisobutyrate, tert-butyl peroxyacetate, di-tert-butyl peroxyhexahydroterephthalate, di-tert-butyl peroxyazelate, tert-butyl peroxide-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxide-2-ethylhexanoate, and tert-amyl peroxide-2-ethylhexanoate.

[0084] Specific examples of percarbonate initiators include allyl percarbonate tert-butyl peroxide and isopropyl percarbonate tert-butyl peroxide.

[0085] Specific examples of peroxide ketal initiators include: 1,1-di-tert-butylperoxide-cyclohexane, 1,1-di-tert-butylperoxide-3,3,5-trimethylcyclohexane, and 1,1-di-tert-hexylperoxide-3,3,5-trimethylcyclohexane.

[0086] In the composition of this embodiment, the polymerization initiators exemplified above can be used individually or in combination of two or more.

[0087] When the total amount of the composition is set to 100 parts by mass, the content of the polymerization initiator in the composition of this embodiment can be, for example, 0.01 parts by mass to 5 parts by mass.

[0088] (iv) Ultraviolet absorbers

[0089] To further improve the weather resistance of the manufactured polymethyl methacrylate and its molded articles, the composition of this embodiment may contain an ultraviolet absorber.

[0090] Preferred examples of UV absorbers that may be contained in the composition of this embodiment include: benzophenone UV absorber, cyanoacrylate UV absorber, benzotriazole UV absorber, malonic acid ester UV absorber, and oxaloaniline UV absorber.

[0091] 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.

[0092] In the composition of this embodiment, the ultraviolet absorbers exemplified above can be used individually or in combination of two or more.

[0093] When the total amount of the composition is set to 100 parts by mass, the content of the ultraviolet absorber in the composition of this embodiment can be, for example, 0.001 parts by mass to 1 part by mass.

[0094] (v) Coloring agents

[0095] The composition of this embodiment may contain a colorant used to color the manufactured polymethyl methacrylate and its molded articles into any suitable color.

[0096] Preferred examples of colorants that may be contained in the composition of this embodiment include: perylene dyes, violet ketone dyes, pyrazolone dyes, methine dyes, coumarin dyes, quinoline dyes, anthraquinone dyes (e.g., Sumiplast Violet B), anthraquinone dyes, thioindolinone dyes, isoyindolone pigments, diketopyrrolopyrrole pigments, condensed azo pigments, benzimidazolone pigments, and dioxindolone pigments. Azine pigments, copper phthalocyanine pigments, and quinacridone pigments.

[0097] The colorants exemplified above can be used individually or in combination of two or more.

[0098] When the total amount of the composition is set to 100 parts by mass, the content of the colorant in the composition of this embodiment can be, for example, 1.0 × 10⁻⁶ parts by mass. -8 Parts by weight ~ 0.001 parts by weight.

[0099] The composition of this embodiment is generally in the form of a solution, but is not limited thereto.

[0100] In the composition of this embodiment, the ratio of the concentration of methyl acrylate to the concentration of methyl isobutyrate (concentration of methyl acrylate / concentration of methyl isobutyrate) is preferably 0.1 to 6.0, more preferably 0.1 to 4.0.

[0101] If the ratio of methyl acrylate concentration to methyl isobutyrate concentration is within such a range, it can effectively prevent or inhibit the time-related deterioration of the properties of the polymer and its molded parts, especially those caused by heat, such as increased yellowness and decreased light transmittance.

[0102] In the composition of this embodiment, the ratio of the concentration of methyl propionate to the concentration of methyl isobutyrate (concentration of methyl propionate / concentration of methyl isobutyrate) is preferably 1.0 to 4.0, more preferably 1.0 to 3.0.

[0103] If the ratio of methyl propionate concentration to methyl isobutyrate concentration is within such a range, it can effectively prevent or inhibit the degradation of the polymer and its molded parts, especially that caused by heat over time, such as an increase in yellowness and a decrease in light transmittance.

[0104] 2. Method for manufacturing the composition

[0105] The composition of this embodiment can be manufactured by mixing the above-described components under any suitable conditions using any suitable conventionally known method.

[0106] Specifically, it can be manufactured by preparing the above-mentioned components in a predetermined amount and mixing these components, for example, in a mixing tank in which the temperature can be controlled at a constant temperature using a jacket or the like.

[0107] In this way, the method for manufacturing the composition according to this embodiment enables the composition to be manufactured easily and at low cost without the use of large equipment, and the composition can be used to manufacture polymers (molded articles) with the excellent properties already described.

[0108] 3. Manufacturing method of polymethyl methacrylate (polymer) and its molded articles

[0109] There are no particular limitations on the method for preparing the composition of this embodiment into a polymer. The polymer can be obtained by polymerizing the composition using any suitable method selected considering the components contained in the composition and their content. Examples of methods for preparing the polymer include methods for polymerizing the composition of this embodiment by bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc.

[0110] Specifically, for example, in cell cast polymerization in which polymethyl methacrylate sheets can be obtained from a composition by bulk polymerization, a polymerization reaction is carried out by subjecting the composition to any appropriate heat treatment under specified heating conditions, thereby obtaining a polymer formed by polymerizing and curing the composition.

[0111] The heating temperature and heating time in the heating conditions can be set by taking into account, for example, the type and content of the selected polymerization regulator, polymerization initiator and / or other components, as well as the content of methyl methacrylate, methyl isobutyrate, methyl acrylate and methyl propionate, etc.

[0112] In this embodiment, during the molding polymerization process, the heating temperature can be, for example, 50°C to 120°C, and the heating time can be, for example, 1 hour to 20 hours.

[0113] The heat treatment in the manufacturing method of the polymer and its molded articles in this embodiment may be a heat treatment that includes multiple steps with different heating temperatures and / or heating times.

[0114] The polymer and its molded articles of this embodiment can be manufactured, for example, by heat treatment under heating conditions including steps 1 to 7 described below.

[0115] Step 1: Heat from room temperature to 72°C over 30 minutes.

[0116] Step 2: Keep at 72°C for 72 minutes.

[0117] Step 3: Cool down from 72℃ to 68℃ in 18 minutes.

[0118] Step 4: Keep at 68°C for 198 minutes.

[0119] Step 5: Increase the temperature from 68℃ to 120℃ in 36 minutes.

[0120] Step 6: Keep at 120°C for 42 minutes.

[0121] Step 7: Cool down from 120℃ to room temperature over 78 minutes.

[0122] In the manufacturing method of the polymer and its molded articles according to this embodiment, if steps 1 to 7 described above are carried out sequentially, the heat generated during polymerization can be suppressed, and polymerization can be completed stably.

[0123] When the composition of this embodiment is heat-treated, for example by applying a cell casting method (cell casting polymerization), a molded body of a predetermined shape can be formed. This cell casting method uses a cell that can define a closed space of a predetermined shape inside. Hereinafter, a method for manufacturing a molded body using the cell casting method will be specifically described.

[0124] When manufacturing molded bodies using the groove casting method, the groove mold is first prepared. Here, an example of a molded body forming a plate-like shape (sometimes called a cast plate) is explained.

[0125] Such a groove mold can be composed of at least two flat plate members and a sealing material (gasket) configured between the two flat plate members and capable of sealing the gap between the two opposing flat plate members into a closed space.

[0126] The flat plate component can be in the form of a sheet or a strip. The flat plate component is made of a material that is not dissolved by the composition of this embodiment, does not hinder the polymerization reaction, and has sufficient heat resistance to the heating temperature during heat treatment. Preferred examples of materials for the flat plate component include: glass and metal.

[0127] As a sealing material, any suitable sealing material known in the art can be used. The sealing material is composed of materials that are not dissolved by the composition of this embodiment, do not hinder the polymerization reaction, and have sufficient heat resistance to the heating temperature during heat treatment. A preferred specific example of a sealing material is a gasket made of vinyl chloride resin.

[0128] Then, the composition of this embodiment is injected into the gap defined by the groove mold prepared as described above using any suitable method known in the art.

[0129] Next, the mold is heat-treated under the heating conditions already described. There are no particular limitations on the method for heat-treating the mold into which the composition of this embodiment is injected. The method for heat-treating the mold is the same as conventional mold casting methods, and for example, it can be a method of directly heat-treating the mold from the outside using a hot air circulating furnace, an infrared heater, or the like; or a method of further providing any suitable conventionally known jacket on the outside of the mold and introducing a heat medium such as hot air, hot water, or steam into the jacket.

[0130] 4. Applications of polymers and their molded articles

[0131] The polymer of the composition of this embodiment and its molded articles exhibit excellent light transmittance, heat resistance, and weather resistance. Therefore, it is suitable for various applications such as lighting fixtures, automotive parts, signs, and building materials that may be exposed to the external environment and heat sources or light sources.

[0132] Example

[0133] Embodiments of the present invention will be described below. The present invention is not limited to the embodiments described below.

[0134] <Example 1 of the preparation of methyl methacrylate products>

[0135] Methyl methacrylate was synthesized by esterification of methacrylic acid and methanol in a reactor. Unreacted methanol was then removed by an extraction tower, and the product was further purified by repeated distillation in multiple distillation towers to obtain methyl methacrylate product containing extremely high purity.

[0136] The obtained methyl methacrylate product contained methyl isobutyrate (10.9 ppm by mass) and methyl acrylate (1.1 ppm by mass). The content of methyl methacrylate in the obtained methyl methacrylate product was 99.99% by mass.

[0137] <Example 1>

[0138] • Preparation of Composition 1

[0139] Methyl isobutyrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Wako I) and methyl acrylate (manufactured by Tokyo Chemical Industries, Ltd.) were further added to the methyl methacrylate product prepared according to Preparation Example 1 above and mixed to prepare Composition 1. The resulting Composition 1 is in solution form.

[0140] The content of methyl methacrylate in the obtained composition 1 is 99.97% by mass. The concentration of methyl isobutyrate in composition 1 is 40.9 ppm by mass, and the concentration of methyl acrylate in composition 1 is 151.1 ppm by mass. The composition of composition 1 is also shown in Table 1 below.

[0141] In addition, the ratio of the concentration of methyl acrylate to the concentration of methyl isobutyrate in composition 1 (concentration of methyl acrylate / concentration of methyl isobutyrate) is 3.7.

[0142] Preparation of Composition 1'

[0143] Add the following to a glass container: composition 1 (99.83 parts by weight) prepared as described above; sodium di(2-ethylhexyl) sulfosuccinate (0.07 parts by weight) as a release agent; terpinene (0.01 parts by weight) as a polymerization regulator; 2,2'-azobisisobutyronitrile (0.08 parts by weight) as a polymerization initiator; 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (0.01 parts by weight) as a UV absorber; and Sumiplast Violet B (7.5 × 10⁻⁶) as a colorant.-7 The components (in parts by weight) were mixed to obtain composition 1' for forming a molded body (cast plastic sheet). The obtained composition 1' is in the form of a solution.

[0144] • Fabrication of Cast Plastic Board 1

[0145] A 3.8 mm thick vinyl chloride resin gasket is sandwiched between two opposing glass plates to prepare a mold capable of defining a gap sealed by the vinyl chloride resin gasket and the two glass plates. The composition 1' prepared as described above is injected into the gap within this mold. The mold containing composition 1' is placed in an oven, and methyl methacrylate is polymerized by heat treatment under heating conditions sequentially including steps 1 to 7 described below, thereby producing a cast plastic plate 1, which is a 3 mm thick, 250 mm square molded body.

[0146] (Heating conditions)

[0147] Step 1: Heat from room temperature to 72°C over 30 minutes.

[0148] Step 2: Keep at 72°C for 72 minutes.

[0149] Step 3: Cool down from 72℃ to 68℃ in 18 minutes.

[0150] Step 4: Keep at 68°C for 198 minutes.

[0151] Step 5: Increase the temperature from 68℃ to 120℃ in 36 minutes.

[0152] Step 6: Keep at 120°C for 42 minutes.

[0153] Step 7: Cool down from 120℃ to room temperature over 78 minutes.

[0154] • Production of Experimental Piece 1

[0155] The cast plastic plate 1 prepared as described above was cut into strips with a length of 25cm and a width of 5cm. The cut surfaces were then ground using a grinding machine (manufactured by Megarotechnica, PLA-BEAUTY PB-500) to produce test piece 1.

[0156] Evaluation of Test Piece 1

[0157] For the obtained test piece 1, the transmittance at 25cm was measured every 5nm in the wavelength range of 380nm to 780nm using a spectrophotometer (Hitachi High-Tech Co., Ltd., U-4000). The average value of the measured values ​​(Tt at 25cm) was then calculated. Based on the measured transmittance at 25cm, the XYZ values ​​were calculated using the C light source weighting coefficient according to the method described in JIS Z8722. Then, the yellowness (YI at 25cm) was calculated according to the method described in JIS K7373. The results are shown in Table 2 below.

[0158] Then, test piece 1 was placed in an oven and heated at 100°C for 100 hours. After the heat treatment, test piece 1 was cooled to room temperature, and the transmittance (Tt) and yellowness (YI) at 25cm were calculated using the same method as above. The results are shown in Table 2 below.

[0159] Then, ΔTt and ΔYI are calculated according to equations (1) and (2). The results are shown in Table 2 below.

[0160] ΔTt=(Tt after heating when passing through 25cm)-(Tt before heating when passing through 25cm) (1)

[0161] ΔYI=(YI after heating and passing through 25cm)-(YI before heating and passing through 25cm) (2)

[0162] <Example 2>

[0163] Preparation of Composition 2

[0164] Methyl isobutyrate and methyl acrylate were further added to the methyl methacrylate product prepared according to Preparation Example 1 above and mixed to prepare composition 2. The resulting composition 2 is in solution form.

[0165] The content of methyl methacrylate in composition 2 is 99.98% by mass. The concentration of methyl isobutyrate in composition 2 is 40.9 ppm by mass, and the concentration of methyl acrylate in composition 2 is 81.1 ppm by mass. The composition of composition 2 is also shown in Table 1 below.

[0166] In addition, the ratio of the concentration of methyl acrylate to the concentration of methyl isobutyrate in composition 2 (concentration of methyl acrylate / concentration of methyl isobutyrate) is 2.0.

[0167] Except for using composition 2 prepared as described above, composition 2' was prepared in the same manner as in Example 1. A cast plastic plate 2 was made, a test piece 2 was made, and a heat treatment was performed. The Tt and YI when passing through 25cm were measured before and after the heat treatment, and then ΔTt and ΔYI were calculated. The results are shown in Table 2.

[0168] <Example 3>

[0169] • Preparation of Composition 3

[0170] Methyl isobutyrate and methyl acrylate were further added to the methyl methacrylate product prepared according to Preparation Example 1 above and mixed to prepare composition 3. The resulting composition 3 is in solution form.

[0171] The obtained composition 3 contains 99.98% by mass of methyl methacrylate. The concentration of methyl isobutyrate in composition 3 is 40.9 ppm by mass, and the concentration of methyl acrylate in composition 3 is 51.1 ppm by mass. The composition of composition 3 is also shown in Table 1 below.

[0172] In addition, the ratio of the concentration of methyl acrylate to the concentration of methyl isobutyrate in composition 3 (concentration of methyl acrylate / concentration of methyl isobutyrate) is 1.2.

[0173] Except for using composition 3 prepared as described above, composition 3' was prepared in the same manner as in Example 1. A cast plastic plate 3 was made, a test piece 3 was made, and a heat treatment was performed. The Tt and YI when passing through 25cm were measured before and after the heat treatment, and then ΔTt and ΔYI were calculated. The results are shown in Table 2 below.

[0174] <Example 4>

[0175] • Preparation of Composition 4

[0176] Methyl isobutyrate and methyl acrylate were added to the methyl methacrylate product prepared according to Preparation Example 1 above and mixed to prepare composition 4. The resulting composition 4 is in solution form.

[0177] The obtained composition 4 contains 99.98% by mass of methyl methacrylate. The concentration of methyl isobutyrate in composition 4 is 110.9 ppm by mass, and the concentration of methyl acrylate in composition 4 is 51.1 ppm by mass. The composition of composition 4 is also shown in Table 1 below.

[0178] In addition, the ratio of the concentration of methyl acrylate to the concentration of methyl isobutyrate in composition 4 (concentration of methyl acrylate / concentration of methyl isobutyrate) is 0.5.

[0179] Except for using composition 4 prepared as described above, composition 4' was prepared in the same manner as in Example 1. A cast plastic plate 4 was made, a test piece 4 was made, and a heat treatment was performed. The Tt and YI when passing through 25cm were measured before and after the heat treatment, and then ΔTt and ΔYI were calculated. The results are shown in Table 2 below.

[0180] <Example 5>

[0181] • Preparation of Composition 5

[0182] Methyl isobutyrate and methyl acrylate were added to the methyl methacrylate product prepared according to Preparation Example 1 above and mixed to prepare composition 5. The resulting composition 5 is in solution form.

[0183] The content of methyl methacrylate in the obtained composition 5 is 99.97% by mass. The concentration of methyl isobutyrate in composition 5 is 210.9 ppm by mass, and the concentration of methyl acrylate in composition 5 is 51.1 ppm by mass. The composition of composition 5 is also shown in Table 1 below.

[0184] In addition, the ratio of the concentration of methyl acrylate to the concentration of methyl isobutyrate in composition 5 (concentration of methyl acrylate / concentration of methyl isobutyrate) is 0.2.

[0185] Except for using composition 5 prepared as described above, composition 5' was prepared in the same manner as in Example 1. A cast plastic plate 5 was made, a test piece 5 was made, and a heat treatment was performed. The Tt and YI when passing through 25cm were measured before and after the heat treatment, and then ΔTt and ΔYI were calculated. The results are shown in Table 2 below.

[0186] <Example 6>

[0187] • Preparation of Composition 6

[0188] Composition 6 was prepared by adding methyl isobutyrate, methyl acrylate, and methyl propionate (manufactured by Tokyo Chemical Industry Co., Ltd.) to the methyl methacrylate product prepared according to Preparation Example 1 above and mixing them. The resulting composition 6 is in solution form.

[0189] The obtained composition 6 contains 99.98% by mass of methyl methacrylate. The concentration of methyl isobutyrate in composition 6 is 40.9 ppm by mass, the concentration of methyl acrylate in composition 6 is 51.1 ppm by mass, and the concentration of methyl propionate in composition 6 is 50.0 ppm by mass. The composition of composition 6 is also shown in Table 1 below.

[0190] In addition, the ratio of the concentration of methyl propionate to the concentration of methyl isobutyrate in composition 6 (concentration of methyl propionate / concentration of methyl isobutyrate) is 1.2.

[0191] Except for using composition 6 prepared as described above, composition 6' was prepared in the same manner as in Example 1. A cast plastic plate 6 was made, a test piece 6 was made, and a heat treatment was performed. The Tt and YI when passing through 25cm were measured before and after the heat treatment, and then ΔTt and ΔYI were calculated. The results are shown in Table 2 below.

[0192] <Example 7>

[0193] • Preparation of Composition 7

[0194] Methyl isobutyrate, methyl acrylate, and methyl propionate were added to and mixed with the methyl methacrylate product prepared according to Preparation Example 1 above, thereby preparing composition 7. The resulting composition 7 is in solution form.

[0195] The content of methyl methacrylate in the obtained composition 7 is 99.97% by mass. The concentration of methyl isobutyrate in composition 7 is 40.9 ppm by mass, the concentration of methyl acrylate in composition 7 is 51.1 ppm by mass, and the concentration of methyl propionate in composition 7 is 100.0 ppm by mass. The composition of composition 7 is also shown in Table 1 below.

[0196] In addition, the ratio of the concentration of methyl propionate to the concentration of methyl isobutyrate in composition 7 (concentration of methyl propionate / concentration of methyl isobutyrate) is 2.4.

[0197] Except for using the composition 7 prepared as described above, composition 7' ​​was prepared in the same manner as in Example 1. A cast plastic plate 7 was made, a test piece 7 was made, and a heat treatment was performed. The Tt and YI when passing through 25 cm were measured before and after the heat treatment, and then ΔTt and ΔYI were calculated. The results are shown in Table 2 below.

[0198] <Preparation Example 2 of Methyl Methacrylate Product>

[0199] Methyl methacrylate was synthesized by esterification of methacrylic acid and methanol in a reactor. Unreacted methanol was then removed using an extraction tower, and the product was repeatedly purified using multiple distillation towers to obtain a methyl methacrylate product with methyl methacrylate as the main component. The obtained methyl methacrylate product contained methyl isobutyrate (6.6 ppm by mass) and methyl acrylate (2.2 ppm by mass). The methyl methacrylate content of the obtained methyl methacrylate product was 99.99% by mass.

[0200] <Comparative Example 1>

[0201] Preparation of Composition C1

[0202] Methyl isobutyrate was added to the methyl methacrylate product prepared according to Preparation Example 2 above and mixed to prepare composition C1. The resulting composition C1 is in solution form.

[0203] The obtained composition C1 contains 99.99% by mass of methyl methacrylate. The concentration of methyl isobutyrate in composition C1 is 36.6 ppm by mass, and the concentration of methyl acrylate in composition C1 is 2.2 ppm by mass. The composition of composition C1 is also shown in Table 1 below.

[0204] In addition, the ratio of the concentration of methyl acrylate to the concentration of methyl isobutyrate in composition C1 (concentration of methyl acrylate / concentration of methyl isobutyrate) is 0.06.

[0205] Except for using the composition C1 prepared as described above, composition C1' was prepared in the same manner as in Example 1. A cast plastic plate C1 was made, a test piece C1 was made, and a heat treatment was performed. The Tt and YI when passing through 25cm were measured before and after the heat treatment, and then ΔTt and ΔYI were calculated. The results are shown in Table 2 below.

[0206] <Comparative Example 2>

[0207] Preparation of composition C2

[0208] Methyl isobutyrate was added to the methyl methacrylate product prepared according to Preparation Example 2 above and mixed to prepare composition C2. The resulting composition C2 is in solution form.

[0209] The obtained composition C2 contains 99.98% by mass of methyl methacrylate. The concentration of methyl isobutyrate in composition C2 is 106.6 ppm by mass, and the concentration of methyl acrylate in composition C2 is 2.2 ppm by mass. The composition of composition C2 is also shown in Table 1 below.

[0210] In addition, the ratio of the concentration of methyl acrylate to the concentration of methyl isobutyrate in composition C2 (concentration of methyl acrylate / concentration of methyl isobutyrate) is 0.02.

[0211] Except for using composition C2 prepared as described above, composition C2' was prepared in the same manner as in Example 1. A cast plastic plate C2 was made, a test piece C2 was made, and a heat treatment was performed. The Tt and YI when passing through 25cm were measured before and after the heat treatment, and then ΔTt and ΔYI were calculated. The results are shown in Table 2 below.

[0212] Table 1

[0213]

[0214] Table 2

[0215]

Claims

1. A composition comprising methyl methacrylate, methyl isobutyrate, and methyl acrylate, wherein, The content of methyl methacrylate is 99.5% by mass or higher. The concentration of methyl isobutyrate is 20 ppm to 300 ppm by mass, and The concentration of methyl acrylate is 20 ppm to 200 ppm by mass. The composition also contains methyl propionate, and The concentration of methyl propionate is 5 ppm to 200 ppm by mass.

2. The composition of claim 1, wherein, The concentration of methyl isobutyrate is 20 ppm to 140 ppm by mass.

3. The composition according to claim 1 or 2, wherein, The concentration of methyl acrylate is 50 ppm to 160 ppm by mass.

4. The composition according to any one of claims 1 to 3, wherein, The concentration ratio of methyl acrylate to methyl isobutyrate is 0.1 to 6.

0.

5. The composition according to any one of claims 1 to 4, wherein, The concentration of methyl propionate is 20 ppm to 200 ppm by mass.

6. The composition according to any one of claims 1 to 5, wherein, The ratio of methyl propionate concentration to methyl isobutyrate concentration is 1.0 to 4.

0.

7. A method for manufacturing a polymer, wherein, The method for manufacturing the polymer includes the step of polymerizing the composition according to any one of claims 1 to 6.

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