JPS6054337A - Preparation of alkenylsuccinate - Google Patents

Abstract

PURPOSE:In preparing an alkenylsuccinate by hydrolyzing an alkenylsuccinic anhydride with an alkali aqueous solution, to obtain the titled compound having small change in hue with day, improved storage stability, by aging the reaction solution at high temperature at high pH. CONSTITUTION:In preparing an alkenylsuccinate by hydrolyzing an alkenylsuccinic anhydride with an aqueous solution of an alkali such as KOH, or NaOH, when hydrolysis and neutralization are carried out, the alkali in an amount more excess than a theoretical alkali amount necessary for neutralization is added to the aqueous solution, the pH of the aqueous solution is adjusted to alkalinity, namely, >=10, the reaction solution after the hydrolysis is kept at >=70 deg.C, aged for preferably >=1hr. After the aging is over, the pH of the aqueous solution is optionally adjusted by adding an acid, to give an aqueous solution of alkenylsuccinate having extremely small deterioration in hue. USE:A surface active agent. A detergent, hair rinse agent, sizing agent for paper making, improver for high polymer, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing alkenyl succinates by hydrolyzing alkenyl succinic anhydrides with aqueous alkaline solutions. More specifically, when hydrolyzing alkenylsuccinic anhydride with an alkaline aqueous solution to produce alkenylconomate salts, aging under high temperature and high pH conditions results in stable storage with little change in hue over time. The present invention relates to a method for producing an alkenyl succinate having good properties.

Alkenyl succinates are compounds useful as surfactants and are used in a variety of applications such as p1 detergents, hair rinses, paper sizing agents, and polymer modifiers.

Conventionally, as a method for producing an aqueous alkenyl succinate solution, an alkenyl succinic anhydride is produced by reacting an olefin and maleic anhydride at 160 to 250 C, and then
A method of adding an aqueous alkali solution to a mixture of alkenylsuccinic anhydride and water while stirring, or a method of esterifying an alkenylsuccinic anhydride with an aliphatic alcohol and then saponifying and neutralizing it with an aqueous alkali solution (Japanese Patent Application Laid-Open No. 55-11102) -1
67247) is known.

However, when the 9-alkenyl succinate aqueous solution obtained by adding an alkaline aqueous solution equivalent to the alkyl group to a mixture of alkenyl succinic anhydride and water, the color of the product deteriorates during storage at room temperature, changing from yellow to brown. A phenomenon in which the degree of coloration increases occurs, and this coloration severely reduces the commercial value of alkenyl succinates in various uses, and becomes a practical hindrance.

A possible method for preventing such hue deterioration is to store the product in a nitrogen atmosphere, but although it is somewhat more effective than storing the product in an air atmosphere, it is not satisfactory. Furthermore, the addition of a phenolic stabilizer, BIT or BHA, which is generally used as an antioxidant, had no effect at all. In addition, the alkenyl succinic anhydride obtained in the reaction is distilled under high vacuum, mixed with water and neutralized with an alkaline aqueous solution, and the resulting alkenyl succinate aqueous solution is colorless to pale yellow. Although it is an excellent product with little hue deterioration, it is industrially disadvantageous, such as a decrease in yield and a complicated manufacturing process. Furthermore, JP-A-55-1
The alkenyl succinate aqueous solution obtained by the method of saponifying the ester with alcohol according to Publication No. 67247 is a product with little color deterioration, but the aqueous solution contains alcohol generated by saponification decomposition, and the alcohol The disadvantage is that the removal process or alcohol content is limited to applications where it is acceptable.

Therefore, the present inventors conducted intensive research to find a method that is industrially simple to prevent hue deterioration during storage of alknylsuccinate aqueous solutions, and as a result, they arrived at the present invention. That is, in the present invention, when producing an alkenyl succinate by hydrolyzing an alkenyl succinic anhydride with an alkaline aqueous solution,
A method for producing an alkenyl succinate with good storage stability and little change in hue over time, characterized by aging while maintaining the pH of the reaction solution at 10 or higher and the post-reaction temperature at 70 U or higher after completion of hydrolysis. It provides:

In the present invention, when an alkenylsuccinic anhydride is hydrolyzed (medium*1), an excess of alkali is added to the aqueous solution to make it alkaline, that is, pH 10 or higher, than the theoretical alkali concentration required for the middle portion, and After completion of hydrolysis, the temperature of the reaction solution is kept at 70C or higher for aging. The aging time is preferably 30 minutes or more, more preferably 1 hour or more. After aging, the pH of the aqueous solution is adjusted by adding an inorganic or organic acid as necessary. In this way, an aqueous alkenyl succinate solution with extremely little deterioration in hue can be obtained.

The alkenyl succinic anhydride used in the production of the alkenyl succinate according to the present invention is obtained by reacting an olefin with maleic anhydride and removing unreacted substances from the reaction product. The olefin used here may be a straight chain olefin or a side chain olefin, and may also be an alpha olefin or an internal olefin. Further, it may be a single olefin or a mixed olefin. The number of carbon atoms in olefin is 4~
l5O1 is preferably 6-24. When reacting the above-mentioned olefin and maleic anhydride, the molar ratio of the reaction between the olefin and maleic anhydride is not limited to 41flK, but the raw material used in excess is recovered in the distillation process after the reaction, and it is generally possible to reuse it.

In the present invention, the alkali used for the 5-hydrolysis of alkenylsuccinic anhydride is based on the periodic table @I
Hydroxides of alkali metals of group a and subgroup a, such as NaOH and KOH, are preferred.

The present invention, according to the above disclosure 1 and means, eliminates the coloring of alkenyl succinate and prevents the hue from changing over time. This made it possible to use it for round purposes as well.

Hereinafter, the present invention will be more specifically described with reference to Examples. I will clarify.

Example 1 22.4 kl of diisobutylene and maleic anhydride 9,81
The mixture was placed in a pressure-resistant reaction tank manufactured by BUS, and after being sufficiently purged with nitrogen gas, the mixture was reacted at a temperature of 200C for 6 hours. After the reaction is completed, unreacted diisobutylene and maleic anhydride are distilled off under reduced pressure to obtain yellow isooctenyl succinic anhydride.
I got 2kl. The saponification value of this isooctenyl succinic anhydride was 542 (KOHq/f) by oil and fat analysis, and the hue was Gardner 5.

Charge 207 f of the above isooctenyl succinic anhydride and 296 f of water into a 1 ton four-eye flask, add 172 f of 48 ml of steamed caustic soda at a temperature of 50 - aOC under a nitrogen gas atmosphere for hydrolytic neutralization, and after completing the addition of 90 ml of caustic soda. The pH of the neutralized product was 12.8. Furthermore, this neutralized product was heated to 8
After aging by stirring at 0 to 90C for 2 hours, the pH was adjusted to 8.7 with 50'Be sulfuric acid to obtain an aqueous solution of isooctenyl sodium succinate.

The hue stability test results are shown in Table 1.

Example 2 A 1 ton four-eye flask was charged with 207 t of isooctenyl succinic anhydride obtained in Example 1 and 296 volts of water, and 170 t of 48 ml of caustic soda was heated under a nitrogen gas atmosphere at a temperature of 50 to aO.
It was added at C for hydrolytic neutralization. The pH after the addition of caustic soda was 10.2. Furthermore, this neutralized product was heated to 8
After aging by stirring at 0 to 90C for 2 hours, the pH was adjusted to 8.7 with 50°Be sulfuric acid to obtain an aqueous solution of isooctenyl sodium succinate.

The hue stability test results are shown in Table 1.

Example 5 A 1 ton four-eye flask was charged with 2079 ml of isooctenyl succinic anhydride obtained in Example 1 and 296 volts of water, and 175 t of 48 hydroxide was added to 1 liter J [
50～aotl! was added for hydrolytic neutralization. After the addition of caustic soda, the pH was 1!1.4. Further, this neutralized product was stirred for 2 hours at a temperature of 80 to 90 tr to age it, and then gluted with 50' cisulfuric acid to pH 8.7 to obtain an aqueous solution of isooctenyl sodium succinate.90 Hue stability test results are shown in Table 1. show.

Comparative Example 1 1 ton of four-toned sulfur was charged with 9 isooctenyl succinic anhydride II 207 F obtained in Example 1 and 294 F of water, and 48 t of caustic soda 167 f'kiil was added under a nitrogen gas atmosphere.
i: 50-80 t: 10 times during hydrolysis. The pH after the addition of caustic soda was 8.7. Furthermore, this neutralized product was stirred at a temperature of 80 to 90C for 2 hours to age.

The hue stability test results are shown in Table 1.

Comparative Example 2 A 1 L four-eye flask was charged with the isopropyl alcohol obtained in Example 1, and 172 tons of 48'ip caustic soda was added at a temperature of 50 to 60 C under a nitrogen gas atmosphere to hydrolyze and neutralize the mixture. The pH after the addition of caustic soda was 12.9. 50°B immediately
e Adjust the pH to 7 with sulfuric acid to obtain an aqueous solution of sodium isooctenyl succinate. The results of the hue stability test are shown in Table 1. Save it for a month and check its hue change (APRM)
observed. The results are shown in Table 1〇9- Table 1 Hue stability of neutralized product 10-

Claims (1)

[Claims] When producing alkenyl succinate by hydrolyzing alkenyl succinic anhydride with an alkaline aqueous solution, after the hydrolysis is completed, the pH of the reaction solution is adjusted to 10 or higher and the temperature of the reaction solution is adjusted to 70 r.
A method for producing an alkenyl succinate having good storage stability and little change in hue over time, characterized by aging while maintaining the above temperature.