JP5207219B2 - Monoester production method - Google Patents

Description

  The present invention relates to a method for producing a monoester of a polyhydric alcohol and a carboxylic acid by transesterifying a polyhydric alcohol and a carboxylic acid ester.

  As a method for selectively obtaining a monoester of a polyhydric alcohol and a carboxylic acid by transesterifying a polyhydric alcohol and a carboxylic acid ester, for example, the following method has been proposed.

(1) A method in which a monoester is selectively obtained by transesterification of an alkanediol and a carboxylic acid ester using a silica-supported metal sulfate as a catalyst (Non-patent Document 1). In the method described in this document, a metal sulfate is supported on a support and used, and the catalyst becomes an acidic solid.
(2) A method of selectively obtaining a monoester by a transesterification reaction between an alkanediol and a carboxylic acid ester using a strongly acidic ion exchange resin as a catalyst (Non-patent Document 2).
(3) A method of selectively obtaining a monoester from a polyhydric alcohol by a combination of several raw materials and a catalyst (Patent Document 1).
(4) A method of selectively obtaining monoesters from alkanediols using an acidic ion exchange resin as a catalyst (Patent Document 2).
(5) A method in which a transesterification reaction is performed using distanoxane as a catalyst and purified to obtain a monoester (Patent Documents 3 to 5).
(6) A method of obtaining a monoester by performing a transesterification reaction using a montmorillonite catalyst (Patent Document 6).
Takeshi Nishiguchi and 1 other, "Journal of the American Chemical Society" (USA), 1989, Vol. 111, p. 9102-9103 Takeshi Nishiguchi and four others, “Journal of Organic Chemistry” (USA), 1994, Vol. 59, p. 1191-1195 JP-A-48-29881 JP 10-298143 A JP 2000-159727 A JP 2000-159726 A JP 2000-128831 A JP 59-204153 A

However, it has been clarified that these methods cause the following problems.
(I) When an acidic catalyst is used, a large amount of impurities having an ether structure derived from a dehydration reaction between alcohols is generated. In particular, when a polyhydric alcohol having a small number of carbon atoms such as ethylene glycol is used, the amount of impurities having an ether structure increases.
(Ii) When an ester exchange reaction between an α, β-unsaturated carboxylic acid and a polyhydric alcohol is performed using a homogeneous strong basic catalyst soluble in the reaction solution, a Michael adduct is by-produced.
(Iii) When a neutral to basic homogeneous catalyst soluble in the reaction solution (for example, a tin catalyst such as distanoxane or a basic catalyst such as tetramethylammonium hydroxide pentahydrate) is used, depending on conditions Increases the amount of by-produced polyvalent esters (diester, triester, etc.).
(Iv) When a homogeneous catalyst soluble in the reaction solution is used, a purification step for removing the catalyst is necessary after the reaction, and it may be industrially disadvantageous, such as disposal of the catalyst residue. Many.

  Accordingly, an object of the present invention is to provide a method capable of producing a monoester with high selectivity while suppressing side reactions (ether formation reaction, polyvalent ester formation reaction, Michael addition reaction).

Method for producing monoesters of the present invention, the polyhydric alcohol and the reaction solution containing the carboxylic acid ester is an ester exchange reaction in the presence of a catalyst, a process for the preparation of mono-esters of polyhydric alcohols and carboxylic acids, the multi The monohydric alcohol is a diol having 4 or less carbon atoms, the carboxylic acid ester is a saturated aliphatic carboxylic acid ester or an unsaturated aliphatic carboxylic acid ester, and basic ion exchange insoluble in the reaction solution as the catalyst. Resin is used.
The molar ratio of the polyhydric alcohol and the carboxylic acid ester (polyhydric alcohol / carboxylic acid ester) before the transesterification reaction is preferably 0.1 / 1 to 10/1.

  According to the method for producing a monoester of the present invention, a monoester can be produced with high selectivity while suppressing side reactions (ether production reaction, polyvalent ester production reaction, Michael addition reaction).

  Hereinafter, the compound represented by Formula (1) is referred to as Compound (1). The same applies to compounds represented by other formulas. Moreover, (meth) acrylic acid ester means methacrylic acid ester or acrylic acid ester.

The method for producing a monoester of the present invention comprises a polyhydric alcohol and a carboxyl in a reaction solution containing a polyhydric alcohol (R ¹ (OH) _m ), a carboxylic acid ester (R ² C (O) OR ³ ), and a catalyst. When the acid ester is transesterified to produce a monoester (R ² C (O) OR ¹ (OH) _m-1 ) of a polyhydric alcohol and a carboxylic acid, the catalyst is insoluble in the reaction solution. This is a method using a basic solid catalyst. However, R ¹ is an m-valent organic group, m is an integer of 2 or more, and R ² and R ³ are organic groups.

Examples of the polyhydric alcohol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5- Alkanediols such as pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol; glycerin, pentaerythritol, trimethylol Examples thereof include polyhydric alcohols such as propane.
As the polyhydric alcohol, a diol having 4 or less carbon atoms is preferable, and ethylene glycol is more preferable because the effect of the present invention is larger as the carbon number is smaller.

The carboxylic acid esters, for example, acetic esters, propionic acid esters, saturated aliphatic carboxylic acid esters such as butanoic acid ester, acrylic acid esters, unsaturated aliphatic carboxylic acid esters such as methacrylic acid ester le; benzoic acid ester Aromatic carboxylic acid esters such as
As the carboxylic acid ester, acetate ester and (meth) acrylic acid ester are preferable from the viewpoint of reactivity and selectivity, and (meth) acrylic acid ester is more preferable from the viewpoint of selectivity. The carboxylic acid ester is preferably an ester of a carboxylic acid having a small number of carbon atoms such as carboxylic acid methyl ester or carboxylic acid ethyl ester, from the viewpoint of reactivity and removal of by-produced alcohol.

  As the catalyst, a basic solid catalyst insoluble in the reaction solution (hereinafter also referred to as a basic solid catalyst) is used. “Insoluble in the reaction solution” means that the elution of the active ingredient is 1% or less when left in the reaction solution under the same conditions as the reaction conditions (temperature, time). About the elution amount of an active ingredient, it can quantify by the method of measuring the mass of solid content after drying a reaction liquid. Further, “basic” means showing the properties of a base. The basicity of the basic solid catalyst is judged by immersing the solid catalyst in water, adding an acidic aqueous solution, and showing neutrality in the initial stage. “Solid” means that a solid state can be maintained in the reaction solution at the reaction temperature.

  Examples of the basic solid catalyst include basic ion exchange resins containing amino groups; solid bases in which a metal is supported on a carrier such as silica or silica alumina. Examples of the metal include alkali metals, alkaline earth metals, and group 13 elements, and sodium, potassium, lithium, calcium, magnesium, and aluminum are preferable from the viewpoint of price and availability. It is presumed that the metal is supported in an oxide state.

  0.01-20 mass% is preferable in a reaction liquid (100 mass%), and, as for the quantity of a basic solid catalyst, 0.1-5 mass% is more preferable. When the amount of the basic solid catalyst is 0.01% by mass or more, the reaction time does not become too long. When the amount of the basic solid catalyst is 20% by mass or less, side reactions are sufficiently suppressed and the selectivity is sufficiently high.

  The molar ratio between the polyhydric alcohol and the carboxylic acid ester (polyhydric alcohol / carboxylic acid ester) is preferably 0.1 / 1 to 10/1 before the transesterification reaction. When the molar ratio is 0.1 / 1 or more, the production of diester is sufficiently suppressed, and the purification load can be suppressed. When the molar ratio is 10/1 or less, unreacted polyhydric alcohol is reduced, and the purification load can be suppressed.

  The reaction solution may contain water. The amount of water is preferably 100 parts by mass or less and more preferably 0.001 to 50 parts by mass with respect to 100 parts by mass of the basic solid catalyst. When the amount of water is 100 parts by mass or less, inhibition of the transesterification reaction is sufficiently suppressed. If the amount of water is 0.001 part by mass or more, it may contribute to the improvement of monoester selectivity.

The reaction solution may contain an organic solvent. As the organic solvent, an organic solvent inert to the transesterification reaction is preferable, and from the viewpoint of improving the selectivity of the monoester, a relatively low-polar organic solvent capable of dissolving the monoester is preferable. Examples of the organic solvent include toluene, hexane, heptane, cyclohexane and the like.
The amount of the organic solvent is preferably 200 parts by volume or less with respect to a total of 100 parts by volume of the polyhydric alcohol and the carboxylic acid ester. When the amount of the organic solvent is 200 parts by volume or less, the productivity is good.

  When a polymerizable unsaturated aliphatic carboxylic acid ester ((meth) acrylic acid ester or the like) is used as the carboxylic acid ester, the reaction solution may contain a polymerization inhibitor. Examples of the polymerization inhibitor include known polymerization inhibitors. For example, quinone compounds such as hydroquinone and hydroquinone monomethyl ether, hydroxy-N, N′-diisopropylparaphenylenediamine, N, N′-di-2-naphthylpara Amine compounds such as phenylenediamine, N-phenyl-N ′-(1,3-dimethylbutyl) paraphenylenediamine, phenothiazine; 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4 -N-oxyl compounds such as benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, compound (1), and the like. A polymerization inhibitor may be used individually by 1 type, and may use 2 or more types together.

However, n is 0 to 18, R ^11, R ¹² are both hydrogen atoms, or, one is a hydrogen atom, the other is methyl ^{group, R 13, R 14, R} 15, R 16 are, A linear or branched alkyl group having 1 to 6 carbon atoms, and R ¹⁷ is a hydrogen atom, an acryloyl group, or a methacryloyl group.

The reaction temperature of the transesterification reaction is preferably −50 to 300 ° C., more preferably 0 to 200 ° C. When the reaction temperature is −50 ° C. or higher, a sufficient reaction rate can be obtained. If reaction temperature is 300 degrees C or less, a side reaction is fully suppressed.
The transesterification reaction may be performed under normal pressure or under reduced pressure.

The transesterification reaction may be performed batchwise or continuously.
As the reaction apparatus, a known apparatus can be used.
The state of the basic solid catalyst in the apparatus may be a state packed in a column installed in the apparatus, a fixed bed state, or a fluidized bed state.
The reactor is preferably equipped with a distillation apparatus in order to remove by-produced alcohol. As the distillation apparatus, a multistage distillation column is preferable.

In the production method of the monoester of the present invention described above, since a basic solid catalyst insoluble in the reaction solution is used as a catalyst, side reactions (ether formation reaction, polyvalent ester formation reaction, Michael addition reaction) ) And a monoester can be produced with high selectivity.
Further, when the molar ratio of the polyhydric alcohol to the carboxylic acid ester (polyhydric alcohol / carboxylic acid ester) is 0.1 / 1 to 10/1, the purification load can be minimized.
Thus, the manufacturing method of the monoester of this invention is a manufacturing method which has industrially sufficient productivity.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.
Monoester selectivity and carboxylic acid ester conversion were calculated from the following formulas.
Selectivity (%) = A / (A + B + C) × 100.
Conversion (%) = (D−E) / D × 100.
However, A is the number of moles of the produced compound (2), B is the number of moles of the produced compound (3), C is the number of moles of the produced compound (4), and D is E is the number of moles of unreacted methyl methacrylate. A, B, C, and E were determined by gas chromatography (hereinafter referred to as GC) analysis of the reaction solution.

[Example 1]
(Basic ion exchange resin)
A basic ion exchange resin (Amberlite IRA96SBAG, manufactured by Organo Corporation) was prepared as a basic solid catalyst insoluble in the reaction solution. The basic ion exchange resin was basic because it was neutral even when an acidic solution was added in an aqueous solution. Moreover, it confirmed that it did not melt | dissolve in a reaction liquid.

(Production of Compound (2) (2-hydroxyethyl methacrylate))
In a 500 mL glass flask equipped with a cooling tube, a thermometer and an air introduction tube, 62.07 g (1 mol) of ethylene glycol, 200.24 g (2 mol) of methyl methacrylate, 20 g of a basic ion exchange resin previously dried, 4-hydroxy 0.2 g of 2,2,6,6-tetramethylpiperidine-N-oxyl was added and stirred while heating in a 110 ° C. bath. The temperature of the reaction liquid became 92-95 degreeC. Three hours after the start of the reaction, GC analysis of the reaction solution was performed. The selectivity and conversion are shown in Table 1.

[ Reference example ]
(Preparation of silica-supported base catalyst)
Silica (manufactured by Fuji Silysia Co., Ltd., Silica Q-10, 10-20 mesh) was impregnated with 150 g of 0.1N aqueous ammonia solution and allowed to stand at room temperature for 1 week. The silica was filtered and washed with water, and then impregnated with an aqueous aluminum chloride solution (aluminum chloride hexahydrate 0.047 g / water 2 g) for 3 hours. The silica was filtered, washed with water, and dried under reduced pressure at 120 ° C. To the silica, 0.1129 g of a 28% by mass sodium methoxide methanol solution was added, filtered, washed with methanol, and dried under reduced pressure at 120 ° C. 0.2539 g of a silica-supported base catalyst having methoxyaluminum and sodium oxyaluminum supported on silica was obtained. It was confirmed that the silica-supported basic catalyst was basic because it showed neutrality even when an acidic solution was added in an aqueous solution, and was not dissolved in the reaction solution.

(Production of Compound (2))
In a 200 mL glass flask equipped with a cooling tube, a thermometer, and an air introduction tube, 1.24 g (0.02 mol) of ethylene glycol, 0.4 g (0.004 mol) of methyl methacrylate, 0.2 g of silica-supported base catalyst, 4 -Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (0.0004 g) was added and stirred while heating in a 105 ° C bath. Three hours after the start of the reaction, GC analysis of the reaction solution was performed. The selectivity and conversion are shown in Table 1.

Example 3
The following reaction was carried out using the same ion exchange resin as in Example 1 as a catalyst. It was confirmed that the catalyst was insoluble.
(Production of Compound (2))
In a 2 L glass flask equipped with a cooling tube, a thermometer and an air introduction tube, 62.07 g (1 mol) of ethylene glycol, 901.08 g (9 mol) of methyl methacrylate, 20 g of a basic ion exchange resin previously dried, 4-hydroxy 0.2 g of 2,2,6,6-tetramethylpiperidine-N-oxyl was added and stirred while heating in a 110 ° C. bath. The temperature of the reaction solution was 90 to 94 ° C. Three hours after the start of the reaction, GC analysis of the reaction solution was performed. The selectivity and conversion are shown in Table 1.

Example 4
The following reaction was carried out using the same ion exchange resin as in Example 1 as a catalyst. It was confirmed that the catalyst was insoluble.
(Production of Compound (2))
In a 1 L glass flask equipped with a cooling tube, a thermometer, and an air introduction tube, 558.63 g (9 mol) of ethylene glycol, 100.12 g (1 mol) of methyl methacrylate, 20 g of a basic ion exchange resin previously dried, 4-hydroxy 0.2 g of 2,2,6,6-tetramethylpiperidine-N-oxyl was added and stirred while heating in a 110 ° C. bath. The temperature of the reaction solution was 93 to 95 ° C. Three hours after the start of the reaction, GC analysis of the reaction solution was performed. The selectivity and conversion are shown in Table 1.

[Comparative Example 1]
A strong acidic ion exchange resin (manufactured by Organo Corporation, Amberlyst 15dry) was prepared as a catalyst. The strongly acidic ion exchange resin was acidic because it displayed neutrality even when a basic solution was added in an aqueous solution.

  In a 200 mL glass flask equipped with a cooling tube, a thermometer, and an air introduction tube, 1.24 g (0.02 mol) of ethylene glycol, 0.4 g (0.004 mol) of methyl methacrylate, 0.2 g of strongly acidic ion exchange resin, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (0.0004 g) was added and stirred while heating in a 105 ° C. bath. Three hours after the start of the reaction, GC analysis of the reaction solution was performed. The selectivity and conversion are shown in Table 1.

[Comparative Example 2]
Tetramethylammonium hydroxide pentahydrate was prepared as a catalyst. The entire amount of the compound was dissolved in the reaction solution.

In a 500 mL glass flask equipped with a cooling tube, a thermometer, and an air introduction tube, 62.07 g (1 mol) of ethylene glycol, 200.24 g (2 mol) of methyl methacrylate, 0.2 g of tetramethylammonium hydroxide pentahydrate ( 0.0011 mol), 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl 0.2 g was added and stirred while heating in a 110 ° C. bath. The temperature of the reaction liquid became 87-93 degreeC. Three hours after the start of the reaction, GC analysis of the reaction solution was performed. The selectivity and conversion are shown in Table 1.
In Examples 1 , 3, 4 and Reference Examples , separation of the catalyst after the reaction was easy. On the other hand, in Comparative Example 2, it was difficult to separate the catalyst.

According to the production method of the present invention, a monoester can be produced with high selectivity. Thereby, compared with the conventional manufacturing method, a refinement | purification process can be simplified and a monoester body can be manufactured cheaply.

Claims (1)

In a method for producing a monoester of a polyhydric alcohol and a carboxylic acid by transesterifying a reaction solution containing the polyhydric alcohol and a carboxylic acid ester in the presence of a catalyst,
The polyhydric alcohol is a diol having 4 or less carbon atoms,
The carboxylic acid ester is a saturated aliphatic carboxylic acid ester or an unsaturated aliphatic carboxylic acid ester,
A method for producing a monoester, wherein a basic ion exchange resin insoluble in a reaction solution is used as the catalyst.