JPS611680A - Preparation of alkenylsuccinic anhydride - Google Patents

Abstract

PURPOSE:In preparing the titled compound by reacting an olefin or its oligomer with maleic anhydride, to purify highly an unreacted substance, and to reuse it effectively, by combining a distillation and separation process with a cooling process, and a washing process. CONSTITUTION:An olefin or its oligomer is reacted with maleic anhydride, the reaction product is introduced into a simple distillation column 1, an unreacted substance is separated at a low temperature at the beginning, an alkenylsuccinic acid is separated at a high temperature, and collected in the product tank 5. The unreacted substance separated earlier than it is cooled by the cooler 6, maleic anhydride is separated and recovered, then, the residue is washed by the cleaner 9, to give a purified olefin or its oligomer. The first distillation is carried out usually at 10-50mm.Hg reduced pressure at 40-80 deg.C, and the second distillation is preferably carried out at 10-20mm.Hg reduced pressure at 155-210 deg.C.

Description

[Detailed description of the invention] The present invention relates to a method for producing alkenyl succinic anhydride.

More specifically, when producing alkenyl succinic anhydride by reacting an olefin or olefin oligomer with maleic anhydride, unreacted products can be highly purified and unreacted products can be effectively reused. This invention relates to a method for producing phosphoric acid anhydride.

Alkenyl succinic anhydride obtained by reacting an olefin or olefin oligomer with maleic anhydride is used for various purposes, for example, as a sizing agent for paper manufacturing. Various methods are known for producing this alkenyl succinic anhydride, but in the conventional production method, there are difficulties in purifying unreacted materials, especially unreacted olefins or unreacted olefin oligomers, and it is difficult to reuse them. However, even if it were mixed with other useful substances, such as lamps and light oil, it could not be used as it was.

The object of the present invention is to provide a method for producing alkenyl succinic anhydride that eliminates the above-mentioned conventional drawbacks by skillfully combining a steam separation step, a cooling step, and a washing step.

That is, the present invention is a method for producing alkenyl succinic anhydride by reacting an olefin or an olefin oligomer with maleic anhydride, which comprises sequentially passing through the following steps (A) to (C). It provides:

(A) separating the reaction product of an olefin or olefin oligomer and maleic anhydride by a single distillation column initially at low temperature to separate a mixture of unreacted olefin or unreacted olefin oligomer and unreacted maleic anhydride;
Next, a step of separating alkenyl succinic anhydride at a high temperature, (B) cooling the separated mixture of the unreacted olefin or unreacted olefin oligomer and unreacted maleic anhydride, and then separating the unreacted maleic anhydride. (C) A step of washing the unreacted olefin or unreacted olefin oligomer containing unreacted maleic anhydride to obtain a purified olefin or purified olefin oligomer.Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings. Explain. FIG. 1 is a schematic diagram showing the flow of the method of the present invention.

In the present invention, first, the reaction product obtained by reacting an olefin or olefin oligomer with maleic anhydride is mixed with unreacted olefin or unreacted olefin oligomer and unreacted anhydride in a single distillation column 1 at a low temperature. A step (hereinafter referred to as step (A)) of separating the mixture with maleic acid and then separating alkenyl succinic anhydride at a high temperature is performed.

In addition, as the olefin or olefin oligomer which is a raw material here, those commonly used can be used, and examples of the olefin include octadecene, hexadecene, and tetradecene. Examples of olefin oligomers include isobutylene oligomers and propylene oligomers.

Furthermore, there are no particular limitations on the conditions for the reaction between the olefin or olefin oligomer and maleic anhydride, and the reaction may be carried out under the conditions of a conventional method. In addition, the middle mark in the figure! J-2 is a reactor, and 3 is a cleaning solvent tank.

The reaction product thus obtained is collected in a single distillation column 1.
It is initially distilled at low temperature. This first distillation is usually carried out at a temperature of 40 to 80°C under a reduced pressure of 10 to 5' OmmHg. Through this first distillation operation, a mixture X of unreacted olefin or unreacted olefin oligomer and maleic anhydride is distilled and separated.

Next, distillation is carried out using the same distillation column I, this time at a higher temperature.

This second distillation is typically 10-20 m m lI
It is carried out at a temperature of 155-210° C. under a reduced pressure of 1.3 g. Through this second distillation operation, alkenyl succinic anhydride Y is distilled and separated. Incidentally, residual aroma extracted from the bottom of the distillation column 1 is collected in a slop tank 4 and used as slop.

The separated alkenyl succinic anhydride Y is collected in a product tank 5 and used as a product.

After completing the above step (A), the mixture X of the separated unreacted olefin or unreacted olefin oligomer and unreacted maleic anhydride is cooled, and then filtered and left to stand to separate unreacted maleic anhydride.

Collect - (B) step is performed.

Here, the cooling operation is performed using a cooler 6, and is usually cooled to about room temperature (about 20° C.). This cooling operation causes unreacted maleic anhydride to precipitate as a solid.

Therefore, by filtering and leaving to stand, for example, using the filtration/standing tank 7, liquid unreacted olefin or unreacted olefin oligomer, - and solid unreacted maleic anhydride are separated. . Note that there are no particular limitations on the method of filtration, and for example, filter paper, filter cloth, a centrifuge, etc. may be used. The maleic anhydride separated and recovered in this way is collected and stored in a hopper 8, etc.
It is reused as a raw material in the method of the present invention.

In addition, since a small amount of unreacted maleic anhydride is mixed in the liquid unreacted olefin or unreacted olefin oligomer obtained by the separation operation as described above, it is difficult to recycle it as it is.

Therefore, following the above step (B), the step (C) of washing the unreacted olefin or unreacted olefin oligomer containing unreacted maleic anhydride to obtain a purified olefin or purified olefin oligomer is performed.
``Here, the cleaning operation is performed using a washer 9 or the like, and cleaning water is introduced into the washer 9. This washing operation may be performed only once, but it is more preferable to perform it multiple times, for example, about 2 to 3 times. Further, as a cleaning method, in addition to washing with pure water, alkaline washing using an aqueous alkaline solution having a concentration of about 1% may be performed.

The amount of washing water used in this washing operation is usually 10 parts by weight per 100 parts by weight of unreacted olefin or unreacted olefin oligomer containing unreacted maleic anhydride.
-50 parts by weight, preferably 20-30 parts by weight.

Purified olefins or olefin oligomers can be obtained in this manner.

According to the method of the present invention, it is possible to highly purify unreacted substances, particularly unreacted olefins or unreacted olefin oligomers, which are by-produced during the production of alkenyl succinic anhydride. Therefore, this unreacted material can be effectively reused, and can also be blended as it is with other useful materials such as kerosene and light oil for effective use.

Therefore, the present invention can be said to be an extremely excellent method in terms of resource saving, and can be effectively used in fields such as the paper manufacturing industry.

Next, examples of the present invention will be shown.

Examples 1 to 3 and Comparative Example 1 Polybutene (isobutylene oligomer with a molecular weight of 200)
Using a single distillation column, the reaction product of maleic anhydride and maleic anhydride was distilled under reduced pressure (approximately 5 mm 1 g) to remove unreacted maleic anhydride and polybutene at a distillation temperature of 40 to 80°C, and then to distill maleated polybutene. Obtained at an exit temperature of 155-210°C. The reaction between polybutene and maleic anhydride was carried out under the conditions that the molar ratio of polybutene to maleic anhydride used was 1.0, the reaction temperature was 220° C., and the reaction time was 5 hours.

Next, maleic anhydride was precipitated in the distilled unreacted maleic anhydride and polybutene, and further filtered and allowed to stand using a filtration/standing tank to separate maleic anhydride and polybutene.

Add 100 parts of polybutene separated from maleic anhydride to 30 parts of water.
(Example 1). Table 1 shows the amount of maleic anhydride in the polybutene after washing.

In addition, when washing with water was performed twice in the same manner (Example 2),
When cleaning was performed using a 1% alkaline aqueous solution as the cleaning liquid (Example 3) and when no cleaning was performed (Comparative Example 1)
) The amount of maleic anhydride in the polybutene is also shown in Table 1.

Table 1 Examples 4 to 6 and Comparative Example 2 The reaction product of octadecene (molecular weight 252) and maleic anhydride was purified under reduced pressure (approximately 5 mm/1 g) using a single distillation column.
) to obtain unreacted maleic anhydride and octadecene at a distillation temperature of 40 to 160°C, and then maleated octadecene at a distillation temperature of 210 to 240°C. In addition, in the reaction between octadecene and maleic anhydride, the molar ratio of octadecene and maleic anhydride used was 1.0, the reaction temperature was 220°C,
The reaction was carried out under conditions of a reaction time of 5 hours.

Next, the distilled unreacted maleic anhydride and octadecene are cooled to room temperature (approximately 20°C) using a cooler to precipitate maleic anhydride, and then filtered using a filtration and standing tank.
The mixture was allowed to stand to separate maleic anhydride and octadecene.

Add 100 parts of octadecene separated from maleic anhydride to 3 parts of water.
Washed with 0 parts (Example 4). Table 2 shows the amount of maleic anhydride in octadecene after washing.

In addition, when washing with water was performed twice in the same manner (Example 5),
When cleaning was performed using a 1% alkaline aqueous solution as the cleaning liquid (Example 6) and when no cleaning was performed (Comparative Example 2).
Table 2 shows the amount of maleic anhydride in octadecene.

Table-2

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the flow of the method of the present invention. 1... Steam tower, 2... Reactor. 3...Solvent tank, 4...Slop tank. 5...Product tank, 6...Cooler. 7...filtration/stationary tank, 8...hopper. 9...Cleaning device. X: A mixture of unreacted olefin or unreacted olefin oligomer and unreacted maleic anhydride.

Claims (2)

[Claims] (1) A method for producing alkenyl succinic anhydride by reacting an olefin or olefin oligomer with maleic anhydride, which comprises sequentially performing the following steps (A) to (C). (A) separating the reaction product of an olefin or olefin oligomer and maleic anhydride by a single distillation column initially at low temperature to separate a mixture of unreacted olefin or unreacted olefin oligomer and unreacted maleic anhydride; (B) cooling the separated mixture of the unreacted olefin or unreacted olefin oligomer and unreacted maleic anhydride; then separating the unreacted maleic anhydride; (C) A step of washing unreacted olefin or unreacted olefin oligomer containing unreacted maleic anhydride to obtain purified olefin or purified olefin oligomer. Claim 1, wherein step (2) (C) is a step of washing the unreacted olefin or unreacted olefin oligomer containing unreacted maleic anhydride multiple times to obtain a purified olefin or purified olefin oligomer. the method of.