JPS6033098B2 - Production method of high purity maleic acid monoalcohol ester - Google Patents

Description

[Detailed Description of the Invention] The present invention comprises maleic anhydride and various alcohols.
The present invention relates to an industrially advantageous method for producing highly pure maleic acid monoalcohol ester.

Conventionally, maleic acid monoalcohol esters have been produced by heating and reacting maleic anhydride and alcohol without a catalyst in an air atmosphere.

For example, Japanese Patent Publication No. 46-41 No. 7 Specification, U.S. Patent No. 2,316,234 (1943), U.S. Patent No.
Specification No. 028091 (1938 Wang), Journal of the Chemical Society of Japan No. 2 (197 Kuoh), pages 261-265.

Hiroshi Horiguchi "Synthetic surfactants (expanded edition)" Published by Shingyo in 1920, Publisher: Sankyo Publishing ■ Pages 203-204, Yukagaku No. 2 Torahitsu, No. 5 (1977) Pages 2-286, etc. The synthesis method is known, and the reaction conditions for these are as follows.
The reaction temperature is 90°C or higher, usually around 12°C. Moreover, the production of monoester is mostly measured by tracking the residual oxidation of maleic acid, and as time passes, the reaction rate rapidly increases, followed by a slight increase in the asymptote to 100% yield. In most cases, it is assumed that it is a relationship between reaction rate and time, and that it is all monoester products. However, according to the research conducted by the present inventors, when the reaction was traced by analysis of Mo/Ester and Gestel by potentiometric titration or analysis by thin layer chromatography, it was surprisingly found that the reaction temperature exceeded 100°C. It was found that when the reaction was continued for a long time, the monoester reached the maximum yield in a relatively short period of time, and then gradually decreased, and the gester increased correspondingly.

Therefore, we investigated various reaction conditions to economically obtain monoester with a high yield of 95 mol% or more, and found that there is a correlation between reaction temperature and reaction time. Although the yield is high and satisfactory, it has a momme point where the reaction time is extremely long.
On the other hand, we have found a contradictory relationship in that as the reaction temperature increases, the required reaction time becomes shorter, but the maximum yield of mos/esters decreases and the amount of gestels increases.

Therefore, under the monoester synthesis reaction conditions, we investigated catalysts that are selectively effective only for the monoester production reaction and are not effective for the gester production reaction, and we found that alkali metal salts of organic acids are effective. I found it.

Using this catalyst, it has become easy to find reaction conditions that allow a monoester to be obtained in a high yield of 95 moles or more in a short time even at low temperatures. The present invention provides a method for producing a maleic acid monoalcohol ester by reacting maleic anhydride with an alcohol, in which the molar ratio of the OH functional groups of maleic acid and the alcohol is 0. Group: 1.
02-1.02: 0.98, the temperature is 80°C or less, 0.1-5% by weight of an alkali metal salt of an organic acid is added as a catalyst, and the reaction is carried out in a nitrogen atmosphere to substantially form maleic acid dialcohol. This is a method for producing a high-purity maleic acid monoalcohol ester, which is characterized by producing a high-purity maleic acid monoalcohol ester that does not contain similar esters.

The alcohols used in the present invention include linear aliphatic primary alcohols such as methanol, ethanol, bro/gnol, butanol, octanol, decanol, and dodecanol, 2-ethylhex/ol, 2-methyldodecanol, Side-chain aliphatic primary alcohols usually produced by oxo synthesis such as monomethyltridecanol, isopropanol, isobutanol, 2-dodecanol, and linear paraffins having 8 to 20 carbon atoms are oxidized with acid The resulting random alcohols, secondary alcohols such as cyclohexyl, cyclooctanol, and cyclododecanol, as well as monoalcohols such as unsaturated alcohols such as aryl alcohol and oleyl alcohol, and all monoalcohols.
Contains files.

Also, alcohols with ethylene oxide, propylene oxide, butylene oxide, styrene oxide, etc. added to these alcohols, or those with two or more of these added in blocks or randomly in any proportion. good. Furthermore, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, other various polyethylene glycols, propylene glycol, dipropylene glycol, other various polypropylene glycols, and both may be used in block form or randomly. It may also be one obtained by addition polymerization.

Other common diols, such as butanediol, hexanediol, cyclohexanediol, carbon number 8-2
Random secondary diols obtained by oxidizing zero n-paraffins with shelf acids may also be used. Alternatively, a trihydric alcohol such as glycerin may be used. In the method of producing a maleic acid monoalcohol ester by reacting maleic anhydride and an alcohol according to the present invention, the molar ratio of maleic anhydride and the OH functional group of the alcohol to be subjected to the reaction is 0. Spots: 1.02-1.02:0. Group range is preferred.

The reaction temperature is preferably 80°C or lower, particularly preferably 70°C to 4 pi. As a catalyst, an alkali metal salt of an organic acid such as acetic acid, formic acid, propionic acid, maleic acid, fumaric acid, benzoic acid, or phthalic acid, or an alkali metal salt such as lithium, sodium, potassium, rubidium, or cesium can be used. It is valid. The amount of the catalyst depends on the temperature used, but it is usually 0.05 to 5% by weight, particularly 0.1 to 2% by weight, preferably present in the reaction zone. It is essential that the reaction be carried out in a nitrogen atmosphere to prevent coloration of the maleic acid monoalcohol ester product. The reaction pressure may be either atmospheric pressure or elevated pressure, but it is preferably carried out under an elevated pressure of 10 k9/G or less in order to prevent sublimation of maleic anhydride. The reaction time can be appropriately selected depending on the above conditions. The present invention will be described below with reference to Examples, but it is needless to say that the present invention is not limited to the Examples.

Example 1 Maleic anhydride 1.01 mol, an average 3 mol ethylene oxide adduct of a secondary alcohol with an average molecular weight of 201 and from which unreacted alcohols having 12 to 14 carbon atoms have been removed (trade name: SOFTAN○L■- 3o, manufactured by Nippon Shokubai Chemical Industry ■)
1 mol, and 0.1% by weight of sodium acetate as catalyst
The mixture was placed in an autoclave, the air was sufficiently replaced with nitrogen gas, and the reaction was allowed to proceed slowly at a nitrogen pressure of 5k9/gauge and a temperature of 70qC.

A reaction solution was taken at each predetermined reaction time and analyzed. The results were as shown in Table 1. The yield of monoester was determined by potentiometric titration. Furthermore, the gestal produced in the sequential reaction can be calculated by subtracting the acid values of the remaining maleic acid and the monoesteric acid produced, but it can also be confirmed separately by thin layer chromatography. Quantification can also be done by chromatography. Examples 2 to 3 In Example 1, the amount of sodium acetate added as a catalyst was changed to 0. The same procedure as in Example 1 was carried out except that the amount of Marugame was 0.5% by weight.

The results were as shown in Table 1. Example 4~
5 The same procedure as in Example 1 was carried out except that the reaction temperature was 40 qo and the amount of sodium acetate added as a catalyst was changed to 1.5% by weight and 3.0% by weight.

The results were as shown in Table 1. Comparative example 1~
4 In Example 1, the raw alcohol had an average molecular weight of 2
Secondary alcohol average 3 mole ethylene oxide adduct from which unreacted alcohols having 12 to 14 carbon atoms have been removed in 01 (trade name s○FTAN○L■-30 Nippon Shokubai Chemical Industry■
The reaction was carried out in the same manner as in Example 1, except that the reaction temperature was as shown in Table 1, and no catalyst was added.

The results were as shown in Table 1. Table 1 Examples 6 to 8 In Example 1, an average of 9 mole ethylene oxide adducts of 2-ethylhexyl alcohol, lauryl alcohol, and oxo alcohol having 12 to 15 carbon atoms shown in Table 2 was used as the raw alcohol. Example 1 was carried out in the same manner as in Example 1, except that the amount of sodium acetate added as a catalyst was 0.5% by weight, the reaction temperature was 70 qo, and the reaction time was 3 hours.

The results were as shown in Table 2. Comparative example 5~
7 In Examples 6 to 8, the same procedures as Examples 6 to 8 were performed except that no catalyst was added.

The results were as shown in the second section. Table 2 Examples 9 to 10 In Example 1, the average molecular weight of the raw alcohol was 2.
Same as Example 1 except that a random secondary alcohol having 12 to 14 carbon atoms and cyclohexanol were used in 01, 1.5% by weight of potassium propionate was used as a catalyst, the reaction temperature was 70 qo, and the reaction time was 5 hours. went.

The results were as shown in Table 3. Comparative example 8~
9 In Examples 9 and 10, the same procedure as in Examples 8 and 9 was carried out except that no catalyst was added.

The results were as shown in Table 3. Table 3 Examples 11 to 13 Obtained by shelf acid oxidation of 2.02 mol of maleic anhydride and ethylene glycol shown in Table 4 as raw alcohol, polyethylene glycol with a molecular weight of 6000, and n-paraffin having 12 to 14 carbon atoms. 1 mole of adduct of 3 moles of ethylene oxide on average of random secondary diol created with secondary alcohol and 0.5% by weight of potassium acetate as a catalyst.
The mixture was placed in an autoclave, the air was sufficiently replaced with nitrogen gas, and the mixture was reacted for 3 hours at a nitrogen pressure of 5k9' (gauge) and a temperature of 7-0 with slow stirring.

The results were as shown in Table 4. Comparative example 10
~12 Examples 11 to 13 were carried out in the same manner as Examples 11 to 13, except that no catalyst was added.

The results were as shown in Table 4. Table 4 Examples 14 to 16 In Example 1, the reaction time was 5 hours, and the soot contained 0.1% by weight of lithium acetate, 0.2% by weight of rubidium acetate, and 0.0% by weight of cesium acetate. The same procedure as in Example 1 was carried out except that % by weight of each sample was added.

The results were as shown in Table 5. Table 5

Claims (1)

[Claims] 1. In a method for producing a maleic acid monoalcohol ester by reacting maleic anhydride and an alcohol, the molar ratio of the OH functional group of the maleic acid and the alcohol is 0.98:1.02 to 1.02: 0.98, the temperature is 80℃ or less, and the organic acid alkali metal salt is 0.0 as a catalyst.
A high-purity maleic acid monoalcohol, which is characterized in that 5 to 5% by weight is added and reacted in a nitrogen atmosphere to produce a high-purity maleic acid monoalcohol ester substantially free of maleic acid dialcohol ester. Method for producing esters.