Composition comprising 2-methylene-1,3-propanediol diacetate

Abstract

Provided is a composition comprising 2-methylene-1,3-propanediol diacetate (P) and an isomer (Pi) of 2-methylene-1,3-propanediol diacetate, wherein the content of the isomer (Pi) of 2-methylene-1,3-propanediol diacetate is 100-100,000 mass ppm with respect to the content of 2-methylene-1,3-propanediol diacetate (P).

Description

Composition containing 2-methylene-1,3-propanediol diacetate

[0001] The present invention relates to a composition comprising 2-methylene-1,3-propanediol diacetate.

[0002] 2-Methylene-1,3-propanediol diacetate (hereinafter sometimes abbreviated as MPDAc) has a 2,2-substituted carbon-carbon unsaturated bond and two acyl groups within the same molecule. The former is applicable to, for example, radical addition reactions, hydrosilylation reactions, or hydroformylation reactions, while the latter is applicable to, for example, saponification reactions and transesterification reactions. For this reason, MPDAc is used as a raw material for the manufacture of various chemicals based on its reactivity (for example, Patent Documents 1 and 2). In addition, several methods for producing MPDAc have been proposed (for example, Patent Documents 3 to 5).

[0003] The acetoxy group of MPDAc is hydrolyzable. Therefore, hydrolysis progresses when MPDAc is stored, producing 2-methylene-1,3-propanediol monoacetate (hereinafter sometimes abbreviated as MPDMA) and 2-methylene-1,3-propanediol (hereinafter sometimes abbreviated as MPDA). Such hydrolysis is undesirable from the viewpoint of reducing the amount of MPDAc. Adding a dehydrating agent (e.g., molecular sieves) can be considered to prevent the progression of hydrolysis, but using a dehydrating agent increases the effort required for solid-liquid separation, which makes it difficult to efficiently produce MPDAc.

[0004] Japanese Patent Publication No. 2013-177576, Japanese Patent Publication No. Hei 2-264781, Japanese Patent Publication No. Sho 47-28965, International Publication No. 2020 / 022364, Chinese Patent Application Publication No. 112341314, Specification

[0005] As a result of various studies conducted by the present inventors, it was found that by adding an isomer of 2-methylene-1,3-propanediol diacetate (hereinafter also referred to as "MPDAc isomer") to MPDAc, the MPDAc isomer, which has a high hydrolysis rate, is preferentially hydrolyzed, and the hydrolysis of MPDAc itself is suppressed. Furthermore, it was found that when a large amount of MPDAc isomer is added, an odor is generated due to the formation of aldehydes by the hydrolysis of the MPDAc isomer, reducing the handling properties of the composition containing MPDAc. However, it was found that if the amount of MPDAc isomer added is below a predetermined value, the composition containing MPDAc can be used without any problems. On the other hand, the above-mentioned Patent Documents 3 to 5 do not describe controlling the amount of MPDAc isomer relative to MPDAc within a predetermined range, and thereby suppressing odor generation while improving storage stability. The inventions described in Patent Documents 3 to 5 do not possess such a technical concept. Therefore, the problem that the present invention aims to solve is to improve the storage stability of MPDAc without causing a decrease in handling properties due to odor.

[0006] The inventors of this invention proceeded with their research in view of the above-mentioned problems and completed the present invention. That is, the present invention is as follows.

[0007] [1] A composition comprising 2-methylene-1,3-propanediol diacetate (P) and an isomer (Pi) of 2-methylene-1,3-propanediol diacetate, wherein the total mass content of the isomer (Pi) of 2-methylene-1,3-propanediol diacetate is 100 to 100,000 ppm by mass relative to the mass content of 2-methylene-1,3-propanediol diacetate (P). [2] The composition according to [1], wherein the isomer (Pi) of 2-methylene-1,3-propanediol diacetate comprises at least one compound selected from the group consisting of a compound represented by the following formula (1) (Pi1) and a compound represented by the following formula (2) (Pi2). [3] The total content mass of the compound (Pi1) represented by the formula (1) and the compound (Pi2) represented by the formula (2) is 100 to 50,000 mass ppm with respect to the content mass of the 2-methylene-1,3-propanediol diacetate (P), and the composition according to [2] above. [4] The content mass M Ｐｉ２ of the compound (Pi1) represented by the formula (1) with respect to the content mass M Ｐｉ１ of the compound (Pi2) represented by the formula (2) is the ratio M Ｐｉ１ / M Ｐｉ２ is 0.1 to 1.2, and the composition according to [2] or [3] above. [5] The content mass of the 2-methylene-1,3-propanediol diacetate (P) in the composition is 95.00 mass% or more, and the composition according to any one of [1] to [4] above. [6] The content mass of 2-methylene-1,3-propanediol diacetate (P) in the composition before storage at 40 ° C for 25 days is M Ｐ , and the content mass M Ｐａ of 2-methylene-1,3-propanediol diacetate (P) after storage at 40 ° C for 25 days. When, R = (M Ｐ - M Ｐａ ) / M Ｐ The hydrolysis rate R defined by is 3 mass% or less, and the composition according to any one of [1] to [5] above. [7] When the composition after storage at 40 ° C for 25 days is analyzed by gas chromatography, the value obtained by dividing the total peak area of aldehydes by the peak area of 2-methylene-1,3-propanediol diacetate (P) is 4.5% or less, and the composition according to any one of [1] to [6] above.

[0008] According to the present invention, there is provided a composition that improves the storage stability of 2-methylene-1,3-propanediol diacetate without causing a decrease in handling properties due to odor.

[0009] Hereinafter, the present invention will be described in detail. In this specification, the defined provisions that are considered preferable can be arbitrarily adopted, and a combination of preferable ones can be said to be more preferable. In this specification, the description "XX to YY" means "XX or more and YY or less".

[0010] [Composition] One or more embodiments of the present invention are compositions comprising 2-methylene-1,3-propanediol diacetate (hereinafter sometimes abbreviated as MPDAc) (P), represented by formula (3), and an isomer of 2-methylene-1,3-propanediol diacetate (hereinafter sometimes abbreviated as MPDAc isomer) (P), wherein the total mass content of the isomer of 2-methylene-1,3-propanediol diacetate (P) is 100 to 100,000 ppm by mass relative to the mass content of 2-methylene-1,3-propanediol diacetate (P).

[0011] In the above composition, the MPDAc isomer (Pi) is preferentially hydrolyzed, and the hydrolysis of MPDAc (P) is suppressed, thus improving the storage stability of the composition without the use of a dehydrating agent. Furthermore, because the content mass of MPDAc isomer (Pi) is within a predetermined range, the generation of odors caused by hydrolyzed products of MPDAc isomer (Pi) is suppressed. In addition, since the addition and recovery of a dehydrating agent are unnecessary, the handling of the composition is improved, and problems such as contamination by foreign matter are less likely to occur. In the following disclosure, each element constituting the above composition is associated with one or more embodiments of the present invention.

[0012] Examples of isomers (Pi) of 2-methylene-1,3-propanediol diacetate include the compound represented by formula (1) below (Pi1), the compound represented by formula (2) below (Pi2), and the compound represented by formula (3) below (Pi3). From the viewpoint of ease of production of the isomers (Pi) of 2-methylene-1,3-propanediol diacetate, it is preferable that the isomers (Pi) of 2-methylene-1,3-propanediol diacetate include at least one compound selected from the group consisting of the compound represented by formula (1) below (Pi1) and the compound represented by formula (2) below (Pi2).

[0013]

[0014]

[0015]

[0016] Hereinafter, the compound represented by formula (1) above (Pi1) may be referred to as the "MPDAc isomer (Pi1)" or simply as the "compound (Pi1)". Similarly, the compound represented by formula (2) above (Pi2) may be referred to as the "MPDAc isomer (Pi2)" or simply as the "compound (Pi2)". Furthermore, the compound represented by formula (3) above (Pi3) may be referred to as the "MPDAc isomer (Pi3)" or simply as the "compound (Pi3)".

[0017] MPDAc(P) reacts with water and decomposes into 2-methylene-1,3-propanediol monoacetate represented by formula (4) (hereinafter sometimes abbreviated as MPDMA) and 2-methylene-1,3-propanediol represented by formula (5) (hereinafter sometimes abbreviated as MPDA) and acetic acid. The resulting acetic acid acts as an acid catalyst and further promotes the hydrolysis of MPDAc(P), making it difficult to maintain a high purity of MPDAc(P).

[0018]

[0019]

[0020] When the inventors investigated hydrolysis, they found that the hydrolysis rate of the MPDAc isomer (Pi) is higher than that of MPDAc (P). The compound (Pi1) represented by the above formula (1), which is a typical MPDAc isomer (Pi), has a vinyl ester structure, and the compounds (Pi2) represented by the above formula (2) and the compound (Pi3) represented by the above formula (3) have two acetoxy groups on the same carbon. Therefore, in both cases, the δ+ property of the carbonyl carbon is increased by the inductive effect, and it is considered that the hydrolyzability is increased. The following formula (6) represents the hydrolysis reaction of MPDAc. Formulas (7) to (9) represent the hydrolysis reactions of the MPDAc isomers (Pi), which are the hydrolysis reactions of the compound (Pi1), the hydrolysis reaction of the compound (Pi2), and the hydrolysis reaction of the compound (Pi3), respectively. By utilizing the above phenomenon that there is a difference in the hydrolysis rate, in a composition containing MPDAc (P), MPDAc isomers (Pi), and water, the MPDAc isomers (Pi) are hydrolyzed prior to the hydrolysis of MPDAc (P), and it is possible to suppress the hydrolysis of MPDAc (P). As a result, the storage stability of the composition is improved. Further, MPDAc (P) becomes an alcohol after hydrolysis, whereas the compound (Pi1) of the above formula (1), the compound (Pi2) of the above formula (2), and the compound (Pi3) of the above formula (3) become aldehydes after hydrolysis. By setting the total content mass of the compound (Pi1) of the above formula (1) and the compound (Pi2) of the above formula (2) to 10% by mass or less (that is, 100,000 mass ppm) with respect to the mass of MPDAc (P), it is possible to avoid a decrease in the handling property of the composition due to the odor caused by aldehydes after hydrolysis.

[0021]

[0022]

[0023]

[0024]

[0025] In the compositions according to the embodiments of the present invention, from the viewpoint of easily securing a sufficient amount of MPDAc(P), the mass content of 2-methylene-1,3-propanediol diacetate (MPDAc)(P) is preferably 89.50% by mass or more, more preferably 90.00% by mass or more, even more preferably 93.00% by mass or more, even more preferably 95.00% by mass or more, even more preferably 97.00% by mass or more, even more preferably 98.40% by mass or more, even more preferably 98.60% by mass or more, and particularly preferably 99.00% by mass or more, relative to the composition. Furthermore, the mass content of MPDAc(P) in the composition is 99.99% by mass or less, and from the viewpoint of ease of manufacture, it is preferably 99.98% by mass or less, and more preferably 99.97% by mass or less. In other words, the mass content of MPDAc(P) in the composition is preferably 89.50 to 99.99% by mass.

[0026] 2-methylene-1,3-propanediol diacetate (MPDAc) (P) can be produced by known methods. Examples of known methods include the method for producing 1,3-diacetoxy-2-methylenepropane (P) by reacting 1,3-dichloro-2-methylenepropane with sodium acetate, as described in Macromolecules, 1993, 26, 737-743, and the method for producing it according to the procedure described in Example 13 of Japanese Patent Application Publication No. 2023-24128.

[0027] The compositions according to the embodiments of the present invention include, as isomers (MPDAc isomers) (Pi) of 2-methylene-1,3-propanediol diacetate, at least one compound selected from the group consisting of, for example, the compound represented by formula (1) (Pi1), the compound represented by formula (2) (Pi2), and the compound represented by formula (3) (Pi3), preferably at least one compound selected from the compound represented by formula (1) (Pi1) and the compound represented by formula (2) (Pi2). The compound of formula (1) (Pi1) has a vinyl ester structure, and the compound of formula (2) (Pi2) and the compound represented by formula (3) (Pi3) have two acetoxy groups on the same carbon. For this reason, the δ+ character of the carbonyl carbon is increased by the inductive effect in all of them, and the hydrolyzability is increased.

[0028] The isomers (MPDAc isomers) (Pi) of 2-methylene-1,3-propanediol diacetate are produced by known methods or a combination of known methods. For example, the compound (Pi1) of formula (1) above is synthesized by the following method: The compound represented by formula (10) below is converted to the compound represented by formula (11) below by an oxidation method (Swern oxidation) in dichloromethane solvent, with the addition of dimethyl sulfoxide and oxalyl chloride, followed by the addition of triethylamine. Then, referring to the method described in Org. Lett. 2007, 9, 18, 3623-3625, the compound represented by formula (1) above (Pi1) is synthesized by adding dimethylaminopyridine to a mixture of the compound represented by formula (12) below, acetic anhydride, and triethylamine. Furthermore, the compound (Pi2) represented by formula (2) above can be produced, for example, by reacting methacrolein with acetic anhydride using a boron trifluoride diethyl ether complex as a catalyst, as described in Journal of Chemical Research, 2015, 39, 555-557. It can also be produced by the method described in the examples.

[0029]

[0030]

[0031] From the viewpoint of improving storage stability, the total mass content of MPDAc isomers (Pi) is preferably 150 ppm by mass or more, more preferably 500 ppm by mass or more, even more preferably 1,000 ppm by mass or more, even more preferably 3,000 ppm by mass or more, and particularly preferably 5,000 ppm by mass or more, relative to MPDAc(P). Furthermore, from the viewpoint of making it easier to reduce odor generation, the total mass content of MPDAc isomers (Pi) is preferably 95,000 ppm by mass or less, more preferably 85,000 ppm by mass or less, even more preferably 70,000 ppm by mass or less, even more preferably 60,000 ppm by mass or less, and particularly preferably 50,000 ppm by mass or less, relative to MPDAc(P). In other words, the total mass of the MPDAc isomer (P) is preferably 150 to 95,000 ppm by mass relative to MPDAc (P).

[0032] The total content of the compound represented by formula (1) (Pi1) and the compound represented by formula (2) (Pi2) is preferably 100 to 95,000 ppm by mass, more preferably 100 to 85,000 ppm by mass, even more preferably 100 to 70,000 ppm by mass, even more preferably 100 to 60,000 ppm by mass, even more preferably 100 to 50,000 ppm by mass, even more preferably 150 to 50,000 ppm by mass, even more preferably 500 to 50,000 ppm by mass, and particularly preferably 1,000 to 50,000 ppm by mass, relative to the mass of 2-methylene-1,3-propanediol diacetate (P), in order to easily achieve both storage stability and odor suppression.

[0033] The total mass content of the compound represented by formula (1) (Pi1), the compound represented by formula (2) (Pi2), and the compound represented by formula (3) in the MPDAc isomer (Pi) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, relative to the total mass of the MPDAc isomer (Pi), from the viewpoint of easily achieving both storage stability and odor suppression. There is no particular upper limit, and it may be 100% by mass, 99% by mass or 98% by mass. In other words, the total mass content of the compound (Pi1), the compound (Pi2), and the compound (Pi3) in the MPDAc isomer (Pi) is preferably 80 to 100% by mass, relative to the total mass of the MPDAc isomer (Pi).

[0034] If the composition according to the embodiment of the present invention contains a compound (Pi1) represented by formula (1) and a compound (Pi2) represented by formula (2), the content M of the compound (Pi2) represented by formula (2) Ｐｉ２ The content M of the compound (Pi1) represented by formula (1) above. Ｐｉ１ Ratio M Ｐｉ１ / M Ｐｉ２ From the viewpoint of isomer boiling points, the boiling point is preferably 0.1 to 1.2, more preferably 0.3 to 1.1, even more preferably 0.5 to 1.0, even more preferably 0.7 to 1.0, and particularly preferably 0.9 to 1.0. Between compound (Pi1) and compound (Pi2), compound (Pi1) has a higher boiling point, and 2-methylene-1,3-propanediol diacetate (P) and compound (Pi1) exhibit similar vapor-liquid equilibrium data. Therefore, compositional changes are less likely to occur during long-term storage, making it easier to ensure long-term storage stability.

[0035] The compositions according to the embodiments of the present invention may contain other components as long as they do not impair the effects of the present invention. Examples of other components include antioxidants, polymerization inhibitors, dehydrating agents, and drying agents. From the viewpoint of easily obtaining the effects of the present invention, the content of other components in the compositions according to the embodiments of the present invention is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less. There is no particular lower limit, and it may be 0% by mass or 1% by mass. In other words, the content of other components in the above compositions is preferably 0 to 10% by mass.

[0036] [Physical Properties of the Composition] <Hydrolysis Rate> From the viewpoint of suppressing the decrease in the amount of MPDAc (P) and avoiding the addition and recovery of dehydrating agents, the mass of 2-methylene-1,3-propanediol diacetate (P) in the composition before storage at 40°C for 25 days is M Ｐ The mass of 2-methylene-1,3-propanediol diacetate (P) after storage at 40°C for 25 days is M. Ｐａ When R = (M Ｐ -M Ｐａ ) / M Ｐ The hydrolysis rate R defined by is preferably 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less. The hydrolysis rate R is set to the above range by controlling the content mass of the MPDAc isomer (Pi) within the above predetermined range.

[0037] <Amount of aldehyde after storage at 40°C for 25 days> From the viewpoint of preventing a decrease in handling properties due to odor generation, it is preferable that the amount of aldehyde in the composition be as low as possible, and most preferably it be absent. However, considering that aldehyde is generated by the hydrolysis of the MPDAc isomer (P), if the amount of aldehyde after long-term storage at high temperature is below a predetermined value, problems caused by odor are less likely to occur. From this viewpoint, when the composition is analyzed by gas chromatography after being stored at 40°C for 25 days, the value obtained by dividing the total peak area of ​​aldehyde by the peak area of ​​2-methylene-1,3-propanediol diacetate (P) is preferably 4.5% or less, more preferably 4.0% or less, even more preferably 3.5% or less, even more preferably 3.0%, and particularly preferably 2.0%. The lower limit is most preferably undetectable, but from the viewpoint of ease of manufacture, etc., it is, for example, 0.01%. In other words, the amount of aldehyde measured under the above conditions after storage at 40°C for 25 days is preferably undetectable to 4.5% or less, more preferably undetectable to 4.0% or less, even more preferably undetectable to 3.5% or less, even more preferably undetectable to 3.0% or less, and particularly preferably undetectable to 2.0% or less, for example, 0.01 to 4.5%, 0.01 to 3.5%, 0.01 to 3.0%, and 0.01 to 2.0%. Examples of aldehydes produced after storage at 40°C for 25 days include methacrolein, 2-formyl-2-methylethyl acetate, and isobutyraldehyde. The amount of aldehyde in the composition after storage at 40°C for 25 days is measured in detail by the method described in the examples.

[0038] The present invention also provides the following embodiments. <E1 Embodiment> A compound comprising 2-methylene-1,3-propanediol diacetate (P) and an isomer (Pi) of 2-methylene-1,3-propanediol diacetate, wherein the isomer (Pi) of 2-methylene-1,3-propanediol diacetate comprises at least one compound selected from the group consisting of the compound represented by formula (1) above (Pi1) and the compound represented by formula (2) above (Pi2), the total mass content of the compound represented by formula (1) (Pi1) and the compound represented by formula (2) (Pi2) is 100 to 50,000 ppm by mass relative to the mass content of 2-methylene-1,3-propanediol diacetate (P), and the mass content of the compound represented by formula (2) (Pi2) is M Ｐｉ２ The content mass M of the compound (Pi1) represented by formula (1) above Ｐｉ１ Ratio M Ｐｉ１ / M Ｐｉ２ A composition in which the ratio is 0.1 to 1.2.

[0039] <Aspect E2> The composition in aspect E1, wherein the mass content of 2-methylene-1,3-propanediol diacetate (P) in the composition is 95.00% by mass or more.

[0040] <Aspect E3> A composition comprising 2-methylene-1,3-propanediol diacetate (P) and an isomer of 2-methylene-1,3-propanediol diacetate (P), wherein the total mass content of the isomer of 2-methylene-1,3-propanediol diacetate (P) is 100 to 100,000 ppm by mass relative to the mass content of 2-methylene-1,3-propanediol diacetate (P), the mass content of 2-methylene-1,3-propanediol diacetate (P) in the composition is 95.00% by mass or more, and the mass content of 2-methylene-1,3-propanediol diacetate (P) in the composition before storage at 40°C for 25 days is M Ｐ The mass of 2-methylene-1,3-propanediol diacetate (P) after storage at 40°C for 25 days is M. Ｐａ When R = (M Ｐ -M Ｐａ ) / M ＰA composition having a hydrolysis rate R defined by 3% by mass or less.

[0041] <E4> A composition comprising 2-methylene-1,3-propanediol diacetate (P) and an isomer of 2-methylene-1,3-propanediol diacetate (P), wherein the total mass content of the isomer of 2-methylene-1,3-propanediol diacetate (P) is 100 to 100,000 ppm by mass relative to the mass content of 2-methylene-1,3-propanediol diacetate (P), the mass content of 2-methylene-1,3-propanediol diacetate (P) in the composition is 95.00% by mass or more, and the value obtained by dividing the total peak area of ​​aldehydes by the peak area of ​​2-methylene-1,3-propanediol diacetate (P) when the composition is gas-chromatographically analyzed after storage at 40°C for 25 days is 4.5% or less.

[0042] <Aspect E5> The composition contains 2-methylene-1,3-propanediol diacetate (P) and an isomer of 2-methylene-1,3-propanediol diacetate (P), wherein the total mass of the isomer of 2-methylene-1,3-propanediol diacetate (P) is 100 to 100,000 ppm by mass relative to the mass of 2-methylene-1,3-propanediol diacetate (P), and the mass of 2-methylene-1,3-propanediol diacetate (P) in the composition before storage at 40°C for 25 days is M Ｐ The mass of 2-methylene-1,3-propanediol diacetate (P) after storage at 40°C for 25 days is M. Ｐａ When R = (M Ｐ -M Ｐａ ) / M Ｐ A composition in which the hydrolysis rate R, as defined by [formula], is 3% by mass or less, and the value obtained by dividing the total peak area of ​​aldehydes by the peak area of ​​2-methylene-1,3-propanediol diacetate (P) when the composition is analyzed by gas chromatography after being stored at 40°C for 25 days is 4.5% or less.

[0043] <Aspect E6> The composition in aspect E5, wherein the mass content of the 2-methylene-1,3-propanediol diacetate (P) in the composition is 95.00% by mass or more.

[0044] [Method for Producing the Composition] The composition according to the embodiment of the present invention is produced, for example, by mixing MPDAc(P) and an MPDAc isomer (Pi). More specifically, high-purity MPDAc(P) can be obtained by following the procedure described in Example 13 of Japanese Patent Application Publication No. 2023-24128, or by purifying MPDAc obtained by various conventionally known methods. Alternatively, for example, an MPDAc isomer (Pi1) can be obtained by isomerizing the above MPDAc(P) according to the procedure described in International Publication No. 2009 / 133950, and an MPDAc isomer (Pi2) can be obtained by reacting methacrolein with acetic anhydride, as described in Journal of Molecular Catalysis A: Chemical 238 (2005) 138-141. The above composition is obtained by mixing the high-purity MPDAc (P) obtained in this way with the MPDAc isomer (Pi).

[0045] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. The evaluation methods used in the following examples and comparative examples are shown below.

[0046] • Gas chromatography analysis (GC analysis) Analytical instrument: GC-2025 (Shimadzu Corporation) Detector: FID Column used: DB-1 (length 60m, film thickness 0.50μm, inner diameter 0.25mm, Agilent Corporation) Analytical conditions: vaporization chamber temperature 250℃, detector temperature 250℃ Heating conditions: Hold at 50℃ for 5 minutes → heat increase at 10℃ / min → hold at 250℃ for 10 minutes Internal standard: Tridecane

[0047] ・Hydrolysis rate of MPDAc(P) (Storage stability test after 25 days at 40°C) The compositions containing MPDAc(P) obtained in the examples and comparative examples described later were sealed in 50 mL glass bottles. Before sealing, 1 mL of the mixture was taken out and the MPDAc(P) content of the composition before storage was measured. The measurement was performed using gas chromatography, injecting a solution of MPDAc(P) and tridecane in a weight ratio of 1:1 diluted 10 times with acetone, and measuring the peak area of ​​MPDAc(P) detected at a retention time of 18.0 minutes and the peak area of ​​tridecane detected at a retention time of 20.7 minutes. The mixture sealed in the glass bottles was stored in a constant temperature bath at 40°C for 25 days. After storage, the temperature was returned to 23°C, and MPDAc(P) was diluted under the same conditions and measured by gas chromatography. The purity of MPDAc(P) (in other words, the mass of MPDAc(P) contained in the composition) was measured by the internal standard method with tridecane as the internal standard. Then, the mass of MPDAc(P) in the composition before storage at 40°C for 25 days (i.e., immediately after manufacturing) is M Ｐ The mass of MPDAc(P) after storage at 40°C for 25 days is calculated as M Ｐａ When R = (M Ｐ -M Ｐａ ) / M Ｐ The hydrolysis rate R, as defined by [the formula], was calculated.

[0048] - Amount of aldehyde after storage stability test The compositions of the examples and comparative examples described later were stored at 40°C for 25 days using the same procedure as for measuring the hydrolysis rate above, and the amount of aldehyde was quantified from the results of gas chromatography analysis after the storage stability test. Specifically, the retention times of the generated aldehydes in gas chromatography were 7.9 minutes for 2-methyl-3-oxopropyl acetate and 5.3 minutes for methacrolein. The sum of the peak areas of each was divided by the peak area of ​​2-methylene-1,3-propanediol diacetate (MPDAc) (P), and the value was expressed as a percentage to determine the amount of aldehyde in the composition after the storage stability test.

[0049] - Odor Assessment Test After the storage stability test at 40°C for 25 days, the top of the glass tube containing the composition was fanned by hand, and the odor was detected by the sense of smell of multiple experimenters (5 people). The composition was evaluated using the following three evaluation criteria, and the evaluation that received the most votes was used as the evaluation of the composition. A: No aldehyde odor is detected. B: An aldehyde odor is detected, but it is at a level that does not pose a practical problem. C: A strong aldehyde odor is detected, and it is not suitable for practical use.

[0050] [Production Example 1] Production of MPDAc(P) and MPDAc isomer (Pi) MPDAc(P), MPDAc isomer (Pi1), and MPDAc isomer (Pi2) were synthesized as follows.

[0051] (1) Production of MPDAc(P) MPDAc(P) was obtained by following the procedure described below, with reference to Example 13 of Japanese Patent Publication No. 2023-24128. Under a nitrogen atmosphere, 100 parts by mass (1.00 molar equivalent) of 2-methylene-1,3-propanediol, 54.5 parts by mass (0.80 molar equivalent) of acetic acid, and 1.93 parts by mass (0.005 molar equivalent) of tetrabutoxytitanium were added to a reaction distillation apparatus equipped with a heat transfer jacket and a stirrer, and the mixture was stirred. The reaction temperature (reaction solution temperature) was raised to 150°C by heating the heat transfer jacket, and the esterification reaction was carried out under atmospheric pressure and reflux conditions, with the temperature at the top of the column being 85 to 100°C. From 1 hour after the start of the reaction, an additional 6.8 parts by mass (0.1 molar equivalent) of acetic acid was added every hour, and the reaction was carried out for a total of 20 hours. The water produced during the reaction was collected as a distillate in a condenser cooled to 10°C at the top of the column. Subsequently, the addition of acetic acid was stopped, and an additional 34.8 parts by mass (0.3 molar equivalents) of acetic anhydride was added, and the reaction was carried out at 150°C for 2 hours. The reaction mixture temperature was maintained at 100-150°C, and the pressure was reduced to 600-400 Torr using a steam ejector. Stirring was continued for a further 3 hours, and distillation was continued until no more distillates of acetic acid, water, and acetic anhydride were produced. After removing the distillate from the receiving tank, the reaction tank was reduced to 50 Torr, and MPDAc(P) was obtained by vacuum distillation. The purity of the purified MPDAc(P) was 99.1%.

[0052] (2) Preparation of MPDAc isomer (Pi1) Based on International Publication No. 2009 / 133950, the MPDAc isomer (Pi1) was obtained by isomerizing MPDAc(P) obtained by the method described above. Specifically, 100 mL of toluene was added to a three-necked flask and 4.9 mg (0.0075 mmol, 75 ppm by mass) of Tris(2,4-di-tert-butylphenyl)Phosphite was dissolved. Then, 20.8 mg (0.003 mmol, 30 ppm by mass) of Rh(acac)(CO) was added and the mixture was stirred. 1.72 g (100 mmol) of MPDAc(P) was added and the mixture was stirred, after which hydrogen was introduced into the reactor to activate the catalyst. After stirring for 30 minutes, the temperature was raised and the reaction was carried out under reflux conditions for 2 hours. After cooling, dilute with water three times, then MgSO ４ The solution was dehydrated. After filtration and removal of the solvent under reduced pressure, it was purified by silica gel chromatography. The obtained solution was a mixture of MPDAc(P) and MPDAc isomer (Pi1). When the amount of MPDAc(P) in the solution was quantified, it was found to be a 20% solution of MPDAc isomer (Pi1).

[0053] (3) Preparation of MPDAc isomer (Pi2) It was synthesized by the method described in Journal of Molecular Catalysis A: Chemical 238 (2005) 138-141, which involves reacting methacrolein with acetic anhydride. Specifically, methacrolein (3 mol), acetic anhydride (5 mol), and lithium perchlorate anhydride (2 equivalents) were added to a 300 mL flask and stirred at 60°C for 2 hours. After cooling, 100 mL of methylene chloride was added and the mixture was filtered. The resulting filtrate was purified by removing the solvent under reduced pressure and then purifying it by column chromatography to obtain the target product.

[0054] [Examples 1-13, Comparative Examples 1-4] Compositions for Examples 1-13 and Comparative Examples 1-4 were prepared by adding and mixing MPDAc(P) obtained as described above with MPDAc isomer (Pi1) and MPDAc isomer (Pi2) in the mass ratios shown in Table 1. For each of the obtained compositions, the content mass of compound (Pi1), compound (Pi2), MPDAc(P), aldehyde, hydrolysis rate, and odor were measured and evaluated using the procedure described above. The results are shown in Table 1. In Table 1, "N.D." means that the target component was not detected.

[0055]

[0056] As shown in Table 1, the compositions of Examples 1 to 15, which contained a predetermined mass of MPDAc isomer (P), showed suppressed hydrolysis rates of MPDAc(P) to 0.15% by mass or less, and also suppressed odor. In particular, the compositions of Examples 1 to 13, in which the mass content of MPDAc isomer (P) was 50,000 ppm by mass or less, showed sufficiently suppressed odor. In contrast, the compositions of Comparative Examples 1 and 2, in which the mass content of MPDAc isomer (P) was less than 100 ppm by mass, showed suppressed odor, but the hydrolysis rate of MPDAc(P) was significantly higher than that of the compositions of Examples 1 to 15, indicating that hydrolysis had progressed considerably. Furthermore, the compositions of Comparative Examples 3 and 4, in which the mass content of MPDAc isomer (P) exceeded 100,000 ppm by mass, showed low hydrolysis rates of MPDAc(P), but the odor assessment deteriorated significantly. From these results, it can be seen that using a composition containing a predetermined mass of MPDAc isomer (Pi) is effective in achieving both the suppression of hydrolysis of MPDAc (P) and the suppression of odor caused by formaldehyde.

Claims

1. A composition comprising 2-methylene-1,3-propanediol diacetate (P) and an isomer of 2-methylene-1,3-propanediol diacetate (P), wherein the total mass of the isomer of 2-methylene-1,3-propanediol diacetate (P) is 100 to 100,000 ppm by mass relative to the mass of 2-methylene-1,3-propanediol diacetate (P).

2. The composition according to claim 1, wherein the isomer (Pi) of 2-methylene-1,3-propanediol diacetate comprises at least one compound selected from the group consisting of a compound represented by the following formula (1) (Pi1) and a compound represented by the following formula (2) (Pi2).

3. The composition according to claim 2, wherein the total mass of the compound represented by formula (1) (Pi1) and the compound represented by formula (2) (Pi2) is 100 to 50,000 ppm by mass relative to the mass of the 2-methylene-1,3-propanediol diacetate (P).

4. The content M of the compound (Pi2) represented by formula (2) above. Ｐｉ２ The content mass M of the compound (Pi1) represented by formula (1) above Ｐｉ１ Ratio M Ｐｉ１ / M Ｐｉ２ The composition according to claim 2, wherein is 0.1 to 1.

2.

5. The composition according to claim 1 or 2, wherein the mass content of 2-methylene-1,3-propanediol diacetate (P) in the composition is 95.00% by mass or more.

6. Let the mass content of 2-methylene-1,3-propanediol diacetate (P) in the composition before storage at 40°C for 25 days be M Ｐ and the mass content M Ｐａ of 2-methylene-1,3-propanediol diacetate (P) after storage at 40°C for 25 days. When R = (M Ｐ - M Ｐａ ) / M Ｐ is defined, the hydrolysis rate R is 3% by mass or less. The composition according to claim 1 or 2 7. The composition according to claim 1 or 2, wherein, after gas chromatography analysis of the composition stored at 40°C for 25 days, the value obtained by dividing the total peak area of ​​aldehydes by the peak area of ​​2-methylene-1,3-propanediol diacetate (P) is 4.5% or less.

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