JP5886113B2 - Method for producing monocarboxylic anhydride - Google Patents

Description

  The present invention relates to a method for producing a monocarboxylic acid anhydride using a monocarboxylic acid as a raw material. More specifically, the present invention relates to a method for producing a monocarboxylic acid anhydride that is suitably used as an intermediate material such as a surfactant.

  As a method for producing a corresponding acid anhydride using carboxylic acid as a raw material, methods using a dehydrating agent such as acetic anhydride, thionyl chloride, phosphorus oxychloride, etc. are well known. It is not economical because it is necessary to use a stoichiometric amount and to remove a large amount of by-products such as a residue of a dehydrating agent and a salt generated by neutralization.

  On the other hand, a method is also known in which a carboxylic acid anhydride is obtained by directly dehydrating from a carboxylic acid without using a dehydrating agent. However, since this generally requires a high temperature, a large amount of energy is consumed. Therefore, as a solution to this problem, a method using a catalyst for the dehydration reaction has been proposed.

  For example, Patent Document 1 discloses a method of using an alkali metal sulfate or alkali metal dihydrogen phosphate in a reaction for obtaining citraconic anhydride by dehydration and isomerization of itaconic acid. Similarly, Patent Document 2 discloses a method of using an acid amine salt or the like as a catalyst in a reaction for obtaining citraconic anhydride from itaconic acid. Furthermore, Non-Patent Document 1 discloses a method of using a clay mineral such as aluminum-substituted montmorillonite as a catalyst in the synthesis of a cyclic anhydride of a dicarboxylic acid.

  However, all of the above examples relate to a method for producing a cyclic acid anhydride by intramolecular dehydration of a dicarboxylic acid, which can be obtained with relative ease even without a catalyst. Is not applicable.

  On the other hand, Patent Document 3 discloses a method of using a transition metal acetate such as palladium or cobalt as a catalyst in the dehydration reaction of a monocarboxylic acid. However, although the transition metal of the catalyst used in Patent Document 3 is expensive and has a yield of about 30% for short-chain octanoic acid, the yield is low for lauric acid having a relatively long chain length (300 mmol). 14-16 mmol acid anhydride from lauric acid), longer chain fatty acids, the yield is expected to be even worse.

US Pat. No. 2,966,498 JP-A-9-132572 U.S. Pat. No. 4,477,382 Richard W. McCABE et al., “Clay- and Zeolite-catalysed Cyclic Anhydride Formation”, J. Chem. Research, 1985, 356-357

  An object of the present invention is to provide a method capable of economically producing a monocarboxylic acid anhydride without using an expensive catalyst.

  As a result of various studies on the reaction conditions of such a method, the present inventors have found that the above-described problems can be solved by performing a reaction at a specific temperature using a specific acid catalyst.

That is, the present invention is a method for producing a monocarboxylic acid anhydride, in which a monocarboxylic acid having 10 to 22 carbon atoms is subjected to an anhydride reaction at a reaction temperature of 150 ° C. to 300 ° C. in the presence of an acid catalyst,
Monocarboxylic acid anhydride, wherein the acid catalyst is one or more selected from the group consisting of sulfuric acid, phosphoric acid, phosphotungstic acid, paratoluenesulfonic acid, zeolite, clay mineral, alumina, and sulfated zirconia. A manufacturing method is provided.

  According to the production method of the present invention, it is possible to economically produce a monocarboxylic anhydride that is suitably used as an intermediate raw material such as a surfactant without using an expensive catalyst as in the prior art. Further, in the production method of the present invention, the reaction proceeds easily, so that a carboxylic acid anhydride can be produced without using a solvent that forms an azeotropic mixture with water having a low boiling point. Moreover, since it can react at a comparatively low temperature, it is economically and environmentally advantageous.

  In particular, according to the method of the present invention when a solid catalyst is used as a catalyst, an acid anhydride is obtained without any soluble impurities in the system. Other reactions, such as producing the corresponding olefins.

  The reason why the specific acid catalyst of the present invention promotes the monocarboxylic acid anhydride reaction is not clear, but acid anhydride-induced acid catalysis is a reaction in which proton addition and elimination proceed in concert, and in particular, the present invention. When the acid catalyst used in the step is a solid acid catalyst, the distance between the solid acid points is appropriate, and it is considered that proton addition / deaddition is performed in concert at a plurality of sites.

  The structure of the monocarboxylic acid having 10 to 22 carbon atoms used in the present invention is not particularly limited, and may be saturated, unsaturated, partially cyclic, or contain a heteroatom. Saturated monocarboxylic acids are preferred, and linear saturated monocarboxylic acids are more preferred.

  The monocarboxylic acid used in the present invention preferably has 10 to 22 carbon atoms, more preferably 14 to 20 carbon atoms, and still more preferably 16 to 18 carbon atoms.

  Specific examples of monocarboxylic acids include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, eicosanoic acid, behenic acid, 10-undecenoic acid, oleic acid, 2,4-hexadecadienoic acid, 6-octadecin Examples thereof include acids, hydnocarpic acid, gol phosphoric acid, and ricinoleic acid.

  The catalyst used in the present invention is one or more acid catalysts selected from sulfuric acid, phosphoric acid, phosphotungstic acid, paratoluenesulfonic acid, zeolite, clay mineral, alumina, and sulfated zirconia. From the viewpoint of reaction rate, sulfuric acid, clay mineral, alumina and sulfated zirconia are more preferable, and clay mineral such as activated clay and sulfated zirconia are more preferable. Also, zeolite is particularly preferable from the viewpoint of reactivity at low temperatures.

  From the viewpoint of handling properties such as catalyst removal, a solid acid catalyst that can be easily removed by filtration, centrifugation, or the like is preferable. Here, the solid acid catalyst refers to a catalyst that is substantially insoluble in the reaction system, and one or more selected from the group consisting of zeolite, clay mineral, alumina, and sulfated zirconia are preferably used. It is done.

  Concentrated sulfuric acid is preferably used as the sulfuric acid, but from the viewpoint of improving handling properties, an aqueous solution diluted to an appropriate concentration may be used, and water may be removed later.

  As phosphoric acid, orthophosphoric acid, metaphosphoric acid, polyphosphoric acid and the like can be used. Also in this case, from the viewpoint of improving handling properties, an aqueous solution diluted to an appropriate concentration may be used, and water may be removed later.

  Zeolite is an aluminosilicate compound with many molecular-sized pores, and certain synthetic zeolites are also known as molecular sieves. In the method of the present invention, those of 3A, 4A, Y, 13X, ZSM-5 and the like are suitably used, but those of Y type are preferred from the viewpoint of reactivity. As the shape of the zeolite, a molded body such as a powder of 1 to 100 μm, a particle of 100 to 1000 μm, or a needle or a pellet is preferably used.

  Examples of the clay mineral include smectites such as activated clay, montmorillonite and bentonite, kaolinite and the like, and activated clay and montmorillonite are preferred from the viewpoint of reactivity. Although there is no restriction | limiting in particular in the particle size of a clay mineral, Usually, they are 0.1 micrometer-1 mm. It may be treated with a mineral acid or the like for improving catalytic activity, or may be subjected to organic treatment for improving dispersibility in the reaction system.

  Sulfated zirconia is obtained by impregnating zirconia with an appropriate amount of sulfuric acid and then baking. A preferable treatment amount of sulfuric acid is 1 to 100% by mass with respect to zirconia, and a firing temperature is 300 to 800 ° C.

  In this invention, 0.001-100 mass% is preferable with respect to monocarboxylic acid, and, as for the usage-amount of an acid catalyst, 0.1-10 mass% is more preferable, and 1-5 mass% is further more preferable.

  The dehydration reaction of the present invention does not substantially contain a solvent, but a solvent may be used from the viewpoint of dissolving the raw materials. From the viewpoint of reaction efficiency, the mass ratio of raw material / (raw material + solvent) is preferably 1/26 to 1/1, more preferably 1/5 to 1/1, and further preferably 1/2 to 1/1.

  Any solvent can be used as long as it does not adversely affect the reaction. For example, aromatic hydrocarbons such as dodecylbenzene, aliphatic hydrocarbons such as squalane, alicyclic hydrocarbons such as cyclodecane, alcohols such as ethylene glycol, ethers such as ethylene glycol dimethyl ether, etc. may be used. it can.

  In the present invention, the reaction temperature is preferably 150 ° C. or higher, more preferably 180 ° C. or higher, further preferably 200 ° C. or higher, further preferably 275 ° C. or higher, from the viewpoint of improving the reaction rate. From the viewpoint of catalyst life, the reaction temperature is preferably 300 ° C. or lower, more preferably 275 ° C. or lower, further preferably 250 ° C. or lower, and further preferably 225 ° C. or lower.

  Although there is no restriction | limiting in particular in reaction time, Usually, it is 0.5 to 24 hours. Moreover, it is preferable to perform reaction in inert gas atmosphere, such as nitrogen and argon. The pressure during the reaction is preferably from 0.1 to 100 kPa, more preferably from 0.5 to 30 kPa, and even more preferably from 1 to 5 kPa from the viewpoint of efficiently removing water and improving the reaction rate.

  The acid anhydride obtained by the above reaction can be used in the next reaction as it is or after appropriate purification. As a purification method, in the case of a homogeneous acid catalyst, the acid catalyst can be removed by an adsorbent or the like, and in the case of a solid acid catalyst, the acid catalyst can be removed by filtration, centrifugation or the like. It is also possible to obtain a pure acid anhydride by distillation or recrystallization after evaporating off the unreacted carboxylic acid.

  The monocarboxylic anhydride obtained by the present invention can be suitably used as an intermediate raw material such as a surfactant.

Example 1-1
To a 50 mL eggplant-shaped flask containing a stir bar, 50 g (175 mmol) of stearic acid (LUNAC S98 manufactured by Kao Corporation) and 1 g of sulfated zirconia (manufactured by Wako Pure Chemical Industries, Ltd.) were added, and the atmosphere was replaced with nitrogen. While maintaining 2.6 kPa, the mixture was stirred at 250 ° C. to conduct an anhydride reaction. After 6 hours, heating was stopped and the solid catalyst was removed by filtration, and then ¹ H-NMR (MERCURY 400 manufactured by Varian) was measured. The anhydride yield was calculated by comparing the integral ratio of the α-position methylene proton of the raw fatty acid and the α-position methylene proton of the fatty acid anhydride. As a result, stearic anhydride was obtained in a yield of 39.1%. I found out.

Examples 1-2 to 1-9, Comparative Examples 1-1 to 1-2
The reaction was conducted in the same manner as in Example 1-1 except that the sulfated zirconia was changed to 1 g of the acid catalyst shown in Table 1, and the product was analyzed. When a homogeneous acid catalyst was used, the catalyst was not removed and the NMR analysis was performed as it was. The results are shown in Table 1.

Examples 2-1 to 2-6, Comparative Examples 2-1 to 2-3
Using the acid catalyst shown in Table 2, the reaction was conducted in the same manner as in Example 1-1 except that the reaction temperature was 200 ° C. and the pressure during the reaction was 1.3 kPa, and the product was analyzed. The results are shown in Table 2.

  As described above, according to the present invention, it is possible to economically produce a monocarboxylic acid anhydride as compared with the case where a conventional catalyst as used in the comparative example is used. In particular, as shown in Table 2, when a non-catalyst or a conventionally used catalyst is used, the corresponding acid can be obtained by reacting a relatively long chain monocarboxylic acid even under temperature and pressure conditions where the reaction does not proceed at all. It can be an anhydride.

Claims (4)

A method for producing a monocarboxylic acid anhydride, in which a monocarboxylic acid having 10 to 22 carbon atoms is subjected to an anhydride reaction in the presence of an acid catalyst at a reaction temperature of 150 ° C to 300 ° C,
Wherein the acid catalyst is, Ze zeolite is one or more solid acid catalyst selected from the group consisting of clay minerals, alumina, and sulfated zirconia, method for producing a monocarboxylic acid anhydride. Method for producing the solid acid catalyst is a zeolite according to claim 1 monocarboxylic acid anhydrides according. The manufacturing method of the monocarboxylic acid anhydride of Claim 1 or 2 whose said reaction temperature is 200 to 275 degreeC. The method for producing a monocarboxylic acid anhydride according to any one of claims 1 to 3 , wherein the anhydration reaction is carried out under substantially no solvent.