JP2013221021A - Sucrose aromatic monocarboxylic acid ester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sucrose aromatic monocarboxylic acid ester capable of improving an odor of a 2-cyanoacrylate-based adhesive without deteriorating its adhesion performance even when its content is increased.SOLUTION: A sucrose aromatic monocarboxylic acid ester is an ester between sucrose and an aromatic monocarboxylic acid represented by general formula (I) (wherein R-Rare each independently a group selected from a hydrogen atom, an alkyl group and an alkoxy group). In the sucrose aromatic monocarboxylic acid ester, a furfural content is ≤50 ppm, and a hydroxymethylfurfural content is ≤500 ppm.

Description

  The present invention relates to an extender for a 2-cyanoacrylate adhesive, and more specifically, the odor can be improved without deteriorating the adhesive performance of the adhesive, and the content of a predetermined impurity is a certain percentage or less. The present invention relates to a sucrose aromatic monocarboxylic acid ester, a 2-cyanoacrylate adhesive comprising the ester as an odor improving / extending agent, and a method for producing the ester.

  2-Cyanoacrylate adhesive has the property that it can be applied to the bonding of different materials with high adhesion to most materials regardless of wood, plastics, and metal, and can be bonded at a high speed. Have. The adhesive is more expensive than other general-purpose adhesives, but the amount of use is steadily increasing year by year because of the great merits described above.

  In 2-cyanoacrylate adhesives, sucrose benzoate is used as a bulking agent for the purpose of cost reduction and odor improvement (Patent Document 1). However, the improvement of odor was never satisfactory.

JP-A-5-222340

  The present invention is intended to provide a sucrose aromatic monocarboxylic acid ester that can improve the odor of a 2-cyanoacrylate adhesive without deteriorating its adhesive performance even when the amount is increased. It is.

  As a result of diligent research aimed at solving the above-mentioned problems, the present inventors have reduced the content of the predetermined impurities in the sucrose aromatic monocarboxylic acid ester to reduce the content of the 2-cyanoacrylate-based adhesive. As a bulking agent, it was found that the odor can be improved without deteriorating its adhesion performance, and further studies were made to complete the present invention.

（式中、Ｒ¹〜Ｒ⁵は、独立に、水素原子、アルキル基およびアルコキシ基から選択される基である。）
で示される芳香族モノカルボン酸とのエステルであって、フルフラールの含有量が５０ｐｐｍ以下かつヒドロキシメチルフルフラールの含有量が５００ｐｐｍ以下であるショ糖芳香族モノカルボン酸エステルに関する。 That is, the present invention
Sucrose and general formula (I)

(In the formula, R ^{1 to} R ⁵ are groups independently selected from a hydrogen atom, an alkyl group, and an alkoxy group.)
It is an ester with the aromatic monocarboxylic acid shown by these, Comprising: It is related with the sucrose aromatic monocarboxylic acid ester whose content of a furfural is 50 ppm or less and whose content of hydroxymethylfurfural is 500 ppm or less.

  The sucrose aromatic monocarboxylic acid ester preferably has an average degree of esterification of 6.0 or less.

  The present invention also relates to a 2-cyanoacrylate adhesive comprising the sucrose aromatic monocarboxylic acid ester as an odor improving / extending agent.

（式中、Ｒ¹〜Ｒ⁵は、独立に、水素原子、アルキル基およびアルコキシ基から選択される基である。）
で示される芳香族モノカルボン酸とのエステルであり、
該ショ糖芳香族モノカルボン酸エステルの有機溶媒溶液を、厚さ１０ｃｍ以下の液膜の状態で加熱面と接触させて乾燥することを含んでなる、ショ糖芳香族モノカルボン酸エステルの製造方法に関する。 Furthermore, the present invention is a method for producing a sucrose aromatic monocarboxylic acid ester having a furfural content of 50 ppm or less and a hydroxymethylfurfural content of 500 ppm or less,
The sucrose aromatic monocarboxylic acid ester is sucrose and the general formula (I)

(In the formula, R ^{1 to} R ⁵ are groups independently selected from a hydrogen atom, an alkyl group, and an alkoxy group.)
An ester with an aromatic monocarboxylic acid represented by
A method for producing a sucrose aromatic monocarboxylic acid ester, comprising drying the organic solvent solution of the sucrose aromatic monocarboxylic acid ester in contact with a heating surface in a liquid film state having a thickness of 10 cm or less. About.

  The drying is preferably vacuum drying.

  The drying under reduced pressure is preferably performed under conditions of an in-machine pressure of 0.01 to 15 KPa · abs and a heating temperature of 90 to 300 ° C.

  The drying under reduced pressure is preferably performed using one or two or more machines selected from a vacuum drum dryer, a vacuum belt dryer, a thin film distiller, a flash distiller, and a vacuum extruder. .

  The sucrose aromatic monocarboxylic acid ester according to the present invention has an excellent feature that the odor can be improved without deteriorating the adhesive performance as an extender of the 2-cyanoacrylate adhesive. Therefore, it can be used as an odor improving / extending agent for the adhesive.

  Further, according to the production method of the present invention, a sucrose aromatic monocarboxylic acid ester exhibiting such excellent characteristics can be produced easily and efficiently, which is industrially advantageous.

  Each element constituting the present invention will be described below.

<Object>
The object of the present invention is the above-mentioned predetermined sucrose aromatic monohydrate having a furfural content of 50 ppm or less and a hydroxymethylfurfural (HMF: 5- (hydroxymethyl) -2-furaldehyde) content of 500 ppm or less. Carboxylic acid ester. That is, in the predetermined sucrose aromatic monocarboxylic acid ester, by suppressing the content of these two impurities low, the adhesive composition when blended with a 2-cyanoacrylate adhesive as an extender is used. The odor is significantly improved. The content of furfural is preferably 5 ppm or less, more preferably 0.5 ppm or less. On the other hand, the HMF content is preferably 50 ppm or less, more preferably 5 ppm or less.

  In the sucrose aromatic monocarboxylic acid ester of the present invention, the average value of the esterification rate of the alcohol portion of sucrose (hereinafter referred to as “average esterification degree”) is preferably 6.0 or less, more preferably 5 0.0 or less. When the average degree of esterification exceeds 6.0, the odor reduction effect tends to be small. On the other hand, the average degree of esterification is preferably 3.0 or more, more preferably 4.5 or more. When the average degree of esterification is less than 3.0, the adhesiveness tends to decrease.

In the aromatic monocarboxylic acid (I) of the sucrose aromatic monocarboxylic acid ester, each of R ^{1 to} R ⁵ is preferably independently a hydrogen atom or an alkyl group, and benzoic acid or all of which are hydrogen atoms More preferably, one of these (preferably R ³ ) is an alkyl group and the remainder is a hydrogen atom.

  As an alkyl group, a C1-C20 thing is mentioned, Among these, a C1-C5 thing is preferable, More preferably, they are a methyl group, an ethyl group, a propyl group, or an isopropyl group. Examples of the alkoxy group include those having 1 to 20 carbon atoms, and among these, those having 1 to 5 carbon atoms are preferable, and a methoxy group, an ethoxy group, a propyloxy group, or an isopropyloxy group is more preferable.

<Production method>
(Purification process)
The sucrose aromatic monocarboxylic acid ester according to the present invention may be produced by any known method as long as the furfural can be 50 ppm or less and the HMF can be 500 ppm or less. For example, purification of an ester obtained by subjecting sucrose and an aromatic monocarboxylic acid to a normal esterification reaction can be mentioned. The purification may be carried out by first adjusting only furfural to 50 ppm or less and then HMF to 500 ppm or less, or vice versa. However, from the viewpoint of simplicity and efficiency, both are simultaneously performed. It is preferable to set it to a predetermined concentration or less.

  For example, an ester obtained by subjecting sucrose and an aromatic monocarboxylic acid to a normal esterification reaction is a method of setting both at a predetermined concentration or less, that is, furfural is 50 ppm or less and HMF is 500 ppm or less. The body is dissolved in an organic solvent such as toluene, o-xylene, m-xylene, and the solution is dried. The concentration of the ester in the organic solvent is preferably 10% by weight or more, more preferably 30% by weight or more. If the concentration is less than 10% by weight, it is industrially inefficient. On the other hand, the concentration is preferably 80% by weight or less, and more preferably 50% by weight or less. When the concentration exceeds 80% by weight, the viscosity is very high and it tends to be difficult to adapt to a vacuum concentrator. The organic solvent may be used alone or in combination of two or more.

  As a means for drying the organic solvent solution of the sucrose aromatic monocarboxylic acid ester, any conventionally known method can be used. Specifically, for example, the solution is brought into contact with the heating surface to obtain a solvent. Etc. are distilled off. In contact with the heating surface, the solution is preferably contacted in the form of a liquid film having a thickness of 10 cm or less, more preferably 5 cm or less, still more preferably 5 mm or less, and even more preferably 1 mm or less. When the thickness of the liquid film exceeds 10 cm, furfural and HMF tend to increase during drying. On the other hand, the lower limit value of the thickness of the liquid film is not particularly limited as long as it is a practicable thickness. However, if the thickness is small, the purification cost increases accordingly, which tends to be industrially disadvantageous. Here, the “thickness of the liquid film” of the organic solvent solution of the sucrose aromatic monocarboxylic acid ester is specifically the surface on the opposite side from the lower surface of the liquid film in contact with the heating surface. Is the distance to the top surface.

  The drying is preferably reduced pressure drying performed under reduced pressure. The conditions for drying under reduced pressure vary depending on various conditions such as the amount of raw material used, the required drying efficiency, and the type of organic solvent used, but the pressure is usually preferably 0.01 KPa · abs or more. To make the pressure less than 0.01 KPa · abs, the equipment tends to be expensive. On the other hand, the pressure is preferably 15 KPa · abs or less, more preferably 4 KPa · abs or less. When the pressure exceeds 15 KPa · abs, the drying efficiency tends to be low. Further, the temperature of the heating surface in drying (referred to as “heating temperature”) is preferably 90 ° C. or higher, more preferably 100 ° C. or higher. If the heating temperature is less than 90 ° C., the drying efficiency tends to be low. On the other hand, the heating temperature is preferably 300 ° C. or lower, more preferably 200 ° C. or lower, and further preferably 160 ° C. or lower. When the heating temperature exceeds 300 ° C., furfural and HMF tend to increase.

  The contact of the organic solvent solution of the sucrose aromatic monocarboxylic acid ester with the heating surface is, for example, a vacuum drum dryer, a vacuum belt dryer, a thin film distillation machine, a flash distillation machine, a vacuum extruder, a stirring tank, etc. Can be implemented using equipment. These devices may be used alone, or two or more of the same or different devices may be used in combination. When two or more are used in combination, it is preferable to connect them, particularly in series, since the level of purification is improved. Specific examples of connection include, for example, connection between a thin film distiller and a thin film distiller, connection between a flash distiller and a thin film distiller, connection between a stirring tank and a thin film distiller, connection between a stirring tank and a vacuum extruder, and the like. Is mentioned. In addition, when using a monotube type concentrating type apparatus (in the examples, a monotube type concentrating flash distillation machine is used), the diameter of the pipe for introducing the organic solvent solution (introducing pipe diameter) is set to the organic solvent. It can be regarded as the “liquid film thickness” of the solution.

  Drying can be carried out either in a batch mode or in a continuous mode. However, since furfural and HMF tend to increase as the heating time is extended, a continuous mode that can suppress the thermal history is preferable.

(Ester synthesis)
In the present invention, a sucrose aromatic monocarboxylic acid ester (referred to as “crude sucrose aromatic monocarboxylic acid ester” or “crude ester” for convenience in the present specification), which is a raw material for the purification step, A sugar and an aromatic monocarboxylic acid (I) can be produced by an esterification reaction by a conventional method. Examples of the esterification reaction include those disclosed in JP-A-61-4839 and JP-B-40. According to the method for producing sucrose benzoate described in No. 5688, it can be carried out by reacting sucrose with a chloride of aromatic monocarboxylic acid (I).

  For example, in the case of following the method described in JP-A-61-4839, sucrose and an aromatic monocarboxylic acid (I) chloride are mixed with a hydrophilic solvent and water in the presence of an alkaline compound. , React.

  Suitable hydrophilic solvents include, for example, ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone, ether solvents such as dioxane and tetrahydrofuran, ester solvents such as methyl acetate, and alcohol solvents such as tertiary butanol. Can be used.

  Examples of the alkaline compound include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonia, trimethylamine, and triethylamine.

  The mixing ratio of the hydrophilic solvent and water is preferably such that the water content of the uniform liquid layer composed of both is 7 to 80%. This is because these hydrophilic solvents dissolve the aromatic monocarboxylic acid chloride, which is one of the raw materials, and the crude ester, which is the product, while sucrose, which is the other raw material, does not dissolve at all. From the viewpoint of reaction efficiency, it dissolves only to the extent that it is not practically used. However, by mixing water, which is a good solvent for sucrose, it becomes possible to dissolve sucrose to the extent that the liquid mixture is practically used. Because. Therefore, by utilizing such properties of the hydrophilic solvent, the reaction rate of sucrose and the aromatic monocarboxylic acid chloride can be regulated, and as a result, the sucrose / aromatic monocarboxylic acid chloride Depending on the charged amount (molar ratio), it is possible to produce crude esters having different ratios of low substitution products and different degrees of average ester substitution. For example, by increasing the amount of aromatic monocarboxylic acid chloride charged relative to the amount of sucrose charged, a crude ester having a relatively low proportion of low-substituted products or a relatively large average degree of ester substitution can be obtained. On the contrary, by reducing the amount of aromatic monocarboxylic acid chloride charged relative to the amount of sucrose, the proportion of low-substituents is relatively high or the average degree of ester substitution is relative A small crude ester can be obtained.

  As a method for the reaction, sucrose and an aromatic monocarboxylic acid chloride are dissolved or suspended in a mixture of a hydrophilic solvent and water, and an equivalent amount or a slight excess of an alkaline compound is mixed with the aromatic monocarboxylic acid chloride. Add or drop sucrose and alkaline compound in the mixed solution, drop the aromatic monocarboxylic acid chloride, or dissolve or suspend sucrose in the mixed liquid and add the aromatic monocarboxylic acid chloride And the alkaline compound can be dropped simultaneously or alternately.

  Although reaction temperature can be employ | adopted to -15 degreeC-100 degreeC, More preferably, it is -10 degreeC-30 degreeC. However, after all the reaction raw materials have been dropped, the reaction may be completed in a high temperature range in order to promote the completion of the reaction.

  It is desirable to keep the pH during the reaction weakly alkaline. On the other hand, under strong alkalinity (for example, pH 13 or higher depending on the reaction temperature, etc.), the side reaction of hydrolysis of the aromatic monocarboxylic acid is remarkable.

  The reaction time is not particularly limited as long as the reaction between the raw materials can sufficiently complete the reaction. Although the specific time depends on the amount of the raw material compound and various conditions, it is usually sufficient to perform for about 1 hour.

  On the other hand, when conforming to the method described in JP-B-40-5688, the esterification reaction is carried out by using the above hydrophilic solvent as another solvent, that is, an aromatic or substituted aromatic hydrocarbon, a chlorinated aliphatic hydrocarbon, It can be carried out in place of one or more solvents selected from lower aliphatic ethers. Here, examples of the aromatic or substituted aromatic hydrocarbon include benzene, toluene, xylene, ethylbenzene, chlorobenzene, chlorotoluene, and the like, and examples of the chlorinated aliphatic hydrocarbon include methylene dichloride, chloroform, carbon tetrachloride, Examples thereof include tetrachloroethylene, and examples of the lower aliphatic ether include diethyl ether and diisopropyl ether.

  The reaction temperature can be from −15 ° C. to 50 ° C., and the reaction time depends on various conditions, but it is usually sufficient to carry out for about 3 hours.

<Application>
The sucrose aromatic monocarboxylic acid ester of the present invention can be used as a bulking agent and an odor improving agent for a 2-cyanoacrylate adhesive. As an adhesive component of 2-cyanoacrylate adhesive, 2-cyanoacrylic acid methyl ester, 2-cyanoacrylic acid ethyl ester, 2-cyanoacrylic acid propyl ester, 2-cyanoacrylic acid butyl ester, 2-cyanoacrylic acid Various 2-cyanoacrylates including allyl ester, 2-cyanoacrylic acid methoxyethyl ester, 2-cyanoacrylic acid ethoxyethyl ester, 2-cyanoacrylic acid 2-chloroethyl ester, 2-cyanoacrylic acid cyclohexyl ester Although used, 2-cyanoacrylic acid ethyl ester is particularly preferable.

  The blending amount of the sucrose aromatic monocarboxylic acid ester of the present invention into the 2-cyanoacrylate adhesive when preparing the adhesive composition is 5 parts or more with respect to 100 parts of the adhesive. Is more preferable, and 15 parts or more is more preferable. If the amount is less than 5 parts, the effect of adding the sucrose aromatic monocarboxylic acid ester tends to be insufficient. On the other hand, the amount is preferably 60 parts or less, more preferably 30 parts or less. When the blending amount exceeds 60 parts, the adhesion performance tends to decrease. However, even if the ratio of the sucrose aromatic monocarboxylic acid ester becomes extremely large and the adhesive strength may decrease, it is rather preferable for the purpose of temporary adhesion. The blending ratio of the acid ester is not limited.

  The adhesive composition of the present invention includes, in addition to the 2-cyanoacrylate adhesive component and the sucrose aromatic monocarboxylic acid ester of the present invention, various conventionally used additives such as storage stabilizers, organic solvents , Plasticizers, thickeners (polymers), fillers, thixotropy improvers, heat resistance imparting agents, polarity reducing agents, adhesion strengthening agents, curing accelerators, curing inhibitors, colorants, carbonate compounds, and other additives Can be added as appropriate.

  When the sucrose aromatic monocarboxylic acid ester of the present invention is added to the 2-cyanoacrylate adhesive component, it easily dissolves in the 2-cyanoacrylate adhesive component at an arbitrary ratio, and at that time, the sucrose benzoate ester Shows an excellent action of hardly changing the fast adhesiveness, adhesive strength, stability, viscosity and the like of the 2-cyanoacrylate adhesive component.

In the present specification, the term “parts” simply means “parts by weight”. The amount of “furfural” and “HMF” in the sucrose aromatic monocarboxylic acid ester is determined by high performance liquid chromatography (HPLC), and the amount of “toluene” is determined by gas chromatography (GC). is there. The “average degree of esterification” in the sucrose aromatic monocarboxylic acid ester is a value determined by proton nuclear magnetic resonance ( ¹ H-NMR).

  The present invention will be described in detail based on examples, but the present invention is not limited to these examples.

1. Synthetic production example 1 of crude sucrose benzoate (crude sucrose benzoate (1) (average degree of esterification: 5.5))
In a 1 L five-necked flask equipped with a stir bar, thermometer, cooling condenser, dropping funnel, pH electrode connected to a pH meter, 30.0 parts of sucrose and 70.0 parts of water were charged and dissolved. While cooling to below ℃, 100 parts of cyclohexanone containing 67.7 parts of benzoyl chloride was gradually added. Thereafter, while maintaining the temperature at 20 ° C. or lower, 42.9 parts of a 48% sodium hydroxide aqueous solution was added from the dropping funnel at such a rate that the pH was maintained at 10-11. After removing the water bath and stirring for 1 hour at room temperature of 20-30 ° C. to complete the reaction, a small amount of sodium carbonate was added and heated to convert the remaining trace of benzoyl chloride into sodium benzoate. . Thereafter, the aqueous phase was separated and removed by allowing to stand for about 30 minutes.
100 parts of water was newly added, the temperature was raised to 40 to 50 ° C. in a hot water bath, the mixture was stirred for 30 minutes, and allowed to stand for about 30 minutes to separate and remove the aqueous phase. The solvent was distilled off under reduced pressure to obtain the title compound (crude SB (1)).

Production Example 2 (crude sucrose benzoate (2) (average degree of esterification: 4.9))
The title compound (crude SB (2)) was obtained in the same manner as in Production Example 1 except that 50.0 parts of sucrose and 60.3 parts of benzoyl chloride were used.

Production Example 3 (Rough sucrose benzoate ester (3) (average degree of esterification: 4.5))
The title compound (crude SB (3)) was obtained in the same manner as in Production Example 1 except that 30.0 parts of sucrose and 55.4 parts of benzoyl chloride were used.

Production Example 4 (crude sucrose benzoate (4) (average degree of esterification: 5.7))
The title compound (crude SB (4)) was obtained in the same manner as in Production Example 1 except that 30.0 parts of sucrose and 70.2 parts of benzoyl chloride were used.

Production Example 5 (crude sucrose benzoate ester (5) (average esterification degree: 4.8))
The title compound (crude SB (5)) was obtained in the same manner as in Production Example 1 except that 30.0 parts of sucrose and 59.1 parts of benzoyl chloride were used.

2. Purification step (removal of furfural and HMF)
Example 1
The crude SB (1) obtained above was dissolved in toluene to prepare a toluene solution of 50 wt% crude sucrose benzoate (crude SB). This solution was heated using a monotube type concentrating flash distillation apparatus at a flow rate of 1.5 L / h of a 50 wt% crude SB toluene solution, a thickness of a liquid film consisting of the same solution in the apparatus of 10 cm, an in-machine pressure of 13 KPa · abs and heating. It dried under the conditions of the surface temperature of 130 degreeC, and obtained sucrose benzoate ester (1) (SB (1)). For SB (1), the amount of furfural (ppm), the amount of HMF (ppm), the amount of toluene (ppm) and the average degree of esterification were measured.

Examples 2-8
The corresponding raw material compounds were treated in the same manner as in Example 1 except that the conditions described in Table 1 were followed, to obtain sucrose benzoate esters (2) to (8) (SB (2) to SB (8)). . For each, the amount of impurities and the degree of esterification were measured.

Comparative Example 1
The corresponding starting material compound was treated in the same manner as in Example 1 except that the conditions described in Table 1 were followed, to obtain sucrose benzoate ester (I) (SB (I)). The amount of impurities and the degree of esterification were measured.

  The results are shown in Table 1.

3. Production of Adhesive Composition Each adhesive composition was prepared using each SB obtained above as an extender. That is, to 100 parts of 2-cyanoacrylic acid ethyl ester containing a small amount of stabilizer (SO ₂ and hydroquinone), 30 parts of each SB was added and dissolved, and adhesive compositions (1) to (8) and An adhesive composition (I) was obtained.

4). Adhesive performance evaluation (accelerated test)
Each adhesive composition was filled in a 20 ml polyethylene container, sealed, and kept at 70 ° C. for 5 days. In Table 1, “Normal” indicates the state before the accelerated test, and “After Test” indicates the state after the accelerated test.
(Set time)
The set time was measured according to JIS K-6861 using a 25 mm × 100 mm × 1.6 mm cold rolled steel sheet.
(Tensile shear strength)
Tensile shear strength was measured using a 25 mm × 100 mm × 1.6 mm cold rolled steel plate polished and degreased, superposed at a contact area of 12.5 mm × 25 mm, and a 24-hour post-curing tensile tester.
(Odor)
The odor was judged based on the following criteria based on the case where sucrose benzoate was not added (C).
A: When odor reduction is remarkable B: When odor reduction is observed C: When sucrose benzoate is not added D: On the contrary, when odor becomes strong

  The results are shown in Table 1.

  As described above, when the sucrose aromatic monocarboxylic acid ester of the present invention is used as a bulking agent, an excellent effect that the odor can be significantly reduced without substantially affecting the set time and tensile shear strength. Play.

  Since the sucrose aromatic monocarboxylic acid ester according to the present invention has an excellent feature that the odor can be improved without deteriorating the adhesive performance as an extender of the 2-cyanoacrylate adhesive, It is useful as an odor improving / bulking agent.

Claims (7)

Sucrose and general formula (I)

(In the formula, R ^{1 to} R ⁵ are groups independently selected from a hydrogen atom, an alkyl group, and an alkoxy group.)
A sucrose aromatic monocarboxylic acid ester having a furfural content of 50 ppm or less and a hydroxymethylfurfural content of 500 ppm or less. The sucrose aromatic monocarboxylic acid ester according to claim 1, wherein the average degree of esterification is 6.0 or less. A 2-cyanoacrylate adhesive comprising the sucrose aromatic monocarboxylic acid ester according to claim 1 or 2 as an odor improving / extending agent. A method for producing a sucrose aromatic monocarboxylic acid ester having a furfural content of 50 ppm or less and a hydroxymethylfurfural content of 500 ppm or less,
The sucrose aromatic monocarboxylic acid ester is sucrose and the general formula (I)

(In the formula, R ^{1 to} R ⁵ are groups independently selected from a hydrogen atom, an alkyl group, and an alkoxy group.)
An ester with an aromatic monocarboxylic acid represented by
A method for producing a sucrose aromatic monocarboxylic acid ester, comprising drying the organic solvent solution of the sucrose aromatic monocarboxylic acid ester in contact with a heating surface in a liquid film state having a thickness of 10 cm or less. . The method for producing a sucrose aromatic monocarboxylic acid ester according to claim 4, wherein the drying is drying under reduced pressure. The method for producing a sucrose aromatic monocarboxylic acid ester according to claim 5, wherein the drying under reduced pressure is performed under conditions of a pressure of 0.01 to 15 KPa · abs and a heating temperature of 90 to 300 ° C. The vacuum drying is performed using one or more machines selected from a vacuum drum dryer, a vacuum belt dryer, a thin film distiller, a flash distiller, and a vacuum extruder. A process for producing a sucrose aromatic monocarboxylic acid ester according to 5 or 6.