JPH0418049A - Method for oxygen oxidative decomposition of ozonized unsaturated fatty acid lower alkyl esters - Google Patents

Abstract

PURPOSE:To safely, industrially and advantageously carry out oxidative decomposition with oxygen by bringing a lower alkyl ester of an unsaturated fatty acid into contact with ozone-containing oxygen gas and continuously bringing the resultant ozonized substance into contact with oxygen gas not containing the ozone under prescribed temperature conditions. CONSTITUTION:A lower alkyl ester of an unsaturated fatty acid expressed by the formula (R is hydrocarbon containing 1-3 double bonds; R' is alkyl) is brought into contact with ozone-containing oxygen gas to provide an ozonized substance. An oxidative decomposition product of the ester compound expressed by the formula with oxygen preferably as a diluent is previously added to the resultant ozonized substance and oxygen gas not containing the ozone is continuously brought into contact with the aforementioned substance in a reactor under temperature conditions of 100-150 deg.C to safely and efficiently carry out oxidative decomposition with the oxygen on an industrial scale. Thereby, a monobasic or dibasic acid of a short chain or an ester compound thereof is obtained. The resultant compound has uses in the field of perfumes, polymer materials and other various fields.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application The present invention relates to a method for oxygen oxidative decomposition of ozonized products of unsaturated fatty acid lower alkyl esters. The present invention relates to a method for obtaining basic acids or their ester compounds.

・-No. 1 and ■ are L-kiriyo j (Jshi 11 dishes) It has been known that an oxidative decomposition reaction is carried out by applying oxygen to ozonized unsaturated fatty acids (Japanese Patent Publication No. 36-4717) ).

However, although the publication states that the oxygen oxidative decomposition reaction of unsaturated fatty acid ozonide is carried out at a temperature of 75 to 125°C, in reality it is limited to temperatures below 100°C, and the oxygen oxidative decomposition reaction takes a long time. It was time consuming and inefficient. In this case, if the reaction is carried out at a high temperature of 100°C or higher, especially 125°C or higher, oxidation will occur rapidly, causing safety problems, and a portion of the final product will be oxidized to carbon dioxide and water, resulting in byproducts. There was also a problem in terms of yield because organisms were likely to form.

Therefore, it has been desired to develop an industrially advantageous oxidative decomposition method for ozonized unsaturated fatty acids.

The present invention was made in view of the above circumstances, and is a method for oxygen oxidative decomposition of ozonized unsaturated fatty acids, which can safely and efficiently decompose ozonized unsaturated fatty acids on an industrial scale. The purpose is to provide

Means and action for determining hydrocarbon group,
R' is a lower alkyl group. ) An oxygen oxidative decomposition product of the ester compound of the above formula (I) is added in advance, preferably as a diluent, to the ozonide obtained by contacting the unsaturated fatty acid lower alkyl ester represented by the formula (I) with oxygen gas containing ozone. in a reactor with 100-150
By continuously contacting with ozone-free oxygen gas under the temperature condition of ℃, the ozonized product of the unsaturated fatty acid lower alkyl ester of the above formula (I) can be safely produced.
It was discovered that oxygen oxidative decomposition can be carried out efficiently on an industrial scale, and the present invention was completed.

That is, the present invention uses an ozonide of an unsaturated fatty acid lower alkyl ester as an ozonide to be decomposed by oxygen oxidation. The reaction rate is extremely low at temperatures lower than 100°C.
The reaction rate increases significantly with the critical point of 100~
The oxygen oxidation decomposition reaction can be carried out at a high reaction rate at a high temperature of 150°C, and there is no safety problem even if the reaction is carried out at such a high temperature, and there are no inconveniences such as the production of by-products. It is possible to quickly remove the reaction heat generated by the oxygen oxidation decomposition reaction, and therefore there is almost no problem with stirring and local heating that occurs when fatty acids are used as raw materials. It was found that no decrease in the yield of the final product was observed.

In this case, if the oxygen oxidative decomposition product of the ester compound of formula (I) is used as a diluent and the reaction is carried out continuously in a reactor to which this diluent has been added in advance, Therefore, from this point of view, it is possible to prevent the raw material ozonide from accumulating in high concentrations, and from this point of view, it can be used safely even under high-temperature conditions of 100 to 150°C and with a higher reaction rate without producing by-products. As the reaction progresses, the reaction rate increases more markedly, so the conventional drawbacks, such as the reduction in production efficiency per unit time and the possibility of abnormal reactions, can be more reliably solved, and as a result, the industrial It is more advantageous to carry out the oxygen oxidative decomposition reaction of ozonized unsaturated fatty acid lower alkyl esters efficiently on a large scale in a short time, and the final reaction product can be obtained in a higher yield.

Therefore, the present invention provides an ozonide obtained by contacting the unsaturated fatty acid lower alkyl ester of formula (I) with an oxygen gas containing ozone at a temperature of 100 to 150°C.
Provided is a method for oxygen oxidative decomposition of ozonized unsaturated fatty acid lower alkyl esters, which comprises contacting with oxygen gas not containing ozone under temperature conditions of .

The present invention will be explained in more detail below.

The method of oxygen oxidation decomposition of ozonized unsaturated fatty acid lower alkyl ester according to the present invention is to apply ozone to the ozonated product obtained by contacting unsaturated fatty acid lower alkyl ester with ozone-containing oxygen gas under specific temperature conditions. This is to bring into contact oxygen gas that does not contain oxygen.

Here, as the unsaturated fatty acid lower alkyl ester,
The following general formula (I) % formula % (I) (wherein R is a hydrocarbon group containing 1 to 3 double bonds,
Preferably represents a straight chain hydrocarbon group having 15 to 17 carbon atoms,
R' represents a lower alkyl group, preferably an alkyl group having 1 to 4 carbon atoms. ) are used, specifically compounds obtained by esterifying unsaturated fatty acids with unsaturated bonds such as palmitoleic acid, oleic acid, linoleic acid, lylunic acid, etc. with lower alcohols, especially those having 16 to 18 carbon atoms. Unsaturated fatty acid lower alkyl esters containing 1 to 3 double bonds can be effectively used.

Furthermore, ozonized products of unsaturated fatty acid lower alkyl esters can be obtained by contacting unsaturated fatty acid lower alkyl esters with ozone-containing oxygen gas,
In particular, it is preferable to use the ozonization method described in Japanese Patent Application No. 2-29257.

That is, unsaturated fatty acid lower alkyl esters, and if necessary, saturated fatty acid esters, saturated fatty acids, alcohols,
A solution containing a solvent such as a hydrocarbon or a halogenated hydrocarbon is made into a thin film flow, and oxygen gas containing ozone is brought into contact with this solution. , it is preferable to flow in cocurrent at a flow rate of 10 to 100 m/sec.

Further, although the molar ratio of unsaturated fatty acid lower alkyl ester to ozone is usually 1, a slightly larger amount of ozone may be supplied. Further, from the viewpoint of reaction heat and reaction efficiency, the ozone concentration in the supplied oxygen is preferably 1 to 7% by volume, particularly 2 to 4% by volume.

Too high an ozone concentration may be disadvantageous in terms of reaction control, while too low an osine concentration may be disadvantageous in terms of reaction efficiency.

Further, the reaction is preferably carried out at 10 to 50°C, particularly 20 to 45°C. If the reaction temperature is higher than 50°C, thermal decomposition of ozone is likely to occur, and if the temperature is lower than 10°C, the reaction will proceed, but the viscosity of the thin film stream may increase due to the reaction products, which may inhibit the formation of the thin film. be. The reaction between unsaturated fatty acid lower alkyl ester and ozone is an exothermic reaction, and therefore it is necessary to remove the reaction heat so that the reaction temperature does not exceed 50'C. Since the flow is a thin film, the heat of reaction can be easily removed.

Note that the reaction time depends on the ozone concentration, the ozone-containing oxygen gas, the feed rate of the raw material solution, etc., but after the gas-liquid contact,
It is a very short time, usually within 1 minute.

In the present invention, the ozonized product of the unsaturated fatty acid lower alkyl ester of formula (I) described above is oxidized and decomposed with oxygen gas that does not contain ozone, and this oxygen oxidative decomposition reaction is carried out using, for example, an apparatus as shown in the drawings. can be done.

That is, the drawing shows a two-stage continuous type reactor in which reactors la and lb are installed in series, and a stirring device 2 is inserted into each of the reactors 1a and lb, and an opening of this reactor 1a is inserted. The raw material solution A is gradually supplied from the raw material introduction pipe 3 to allow it to flow down naturally into the reactor 1a, and the gas introduction pipes 4 attached to the bottoms of the reactors 1a and 1b are respectively installed. Oxygen gas B, which does not contain ozone, is introduced at a predetermined rate.

Furthermore, the reactants in the reactor 1a are transferred to the reactor 1b through the reactant transfer tube 5, and after being brought into contact with ozone-free gaseous oxygen again in the reactor 1b, the final product is transferred to the product transfer tube. This is extracted from 6. In addition to the above-mentioned multi-stage continuous barrel reactor, the reactor used in the present invention can also be used in combination with a reaction tower such as a cap tower or a perforated plate tower, and is limited to the illustrated apparatus. It's not a thing.

Here, it is preferable to gradually introduce the ozonized product of unsaturated fatty acid lower alkyl ester, which is the raw material solution, into the reactor.
Introduction rates of 0 to 200 g/hour, especially 50 to 150 g/hour are preferred.

In addition, in the above-mentioned multi-stage continuous barrel reactor, the transfer rate of the reactant from one reactor to the other and the rate of withdrawal of the product can be within the same range as above.

Furthermore, the introduction rate of oxygen gas that does not contain ozone is 3 to 3
It is preferable to set it as 0Q/hour, especially 5-20Q/hour. Note that during the reaction, it is desirable that the oxygen pressure be in a slightly pressurized state, but normal pressure may also be used.

In the present invention, the molar ratio of ozonide to oxygen gas not containing ozone is preferably ozonide/oxygen=1/1 to 10, particularly 1/1.5 to 7.5.

In addition, in the present invention, it is preferable to use an oxygen oxidative decomposition product of the ester of formula (I) as a diluent, and to add this oxygen oxidative decomposition product into the reactor in advance. It is possible to prevent ozonide from accumulating at a high concentration in the container.

Here, the amount of the diluent added is not particularly limited, but an efficient reaction can be carried out by adding it in an amount of 10% by weight or more, preferably 30% by weight or more, based on the ozonide.

Further, the oxygen oxidative decomposition reaction is carried out at 100 to 150°C, preferably 125 to 150°C, more preferably 125 to 135°C.
The reaction temperature is 100℃.
If it is lower than 15, the reaction will not proceed sufficiently and the reaction rate will decrease.
If the temperature exceeds 0°C, the reaction will proceed rapidly and the yield of the target substance will decrease in either case.

In addition, when using a multi-stage continuous seed reactor as a reactor, it is efficient to gradually increase the temperature from the first reactor to the second and third reactors within the above reaction temperature range. be.

Furthermore, the reaction time depends on the raw material solution, the supply rate of oxygen gas, etc., but can usually be within 4 to 6 hours.

After the oxygen oxidative decomposition reaction is completed, short-chain monobasic acids and dibasic acids can be fractionated as final products by performing hydrolysis treatment, etc., if necessary, and then distilling under reduced pressure.

According to the present invention, by using an unsaturated fatty acid lower alkyl ester as a raw material, the reaction can be carried out safely at high temperatures compared to the method of oxygen oxidative decomposition of ozonized products of unsaturated fatty acids. Therefore, the oxidative decomposition reaction rate is increased and the production efficiency per unit time is also good, and it is suitably adopted as a method for producing oxygen oxidative decomposition products of unsaturated fatty acid lower alkyl esters on an industrial scale. .

The oxygen oxidation decomposition products obtained in this way can be fractionated under reduced pressure to obtain monobasic acids, dibasic acids, or their ester compounds, which are used in many fields including perfumery and polymer materials fields. It is possible to expand the application to

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example, comparative example]

Oleic acid methyl ester or olein W7! (Purity 9
0% or more) was continuously subjected to an ozonation reaction while forming a thin film under the conditions shown below according to the method described in Japanese Patent Application No. 2-29257.

Ozonation conditions Reactor length: 2 m Cylindrical reactor inner diameter: φ = 2 tna Direct raw material supply M: 1,5 g/min Ozone concentration:
3%102 Oxygen supply amount: 4 N (I/min Linear velocity: 50 m/sec) Next, an oxygen oxidative decomposition reaction was carried out under the conditions shown below.The reaction rate was calculated based on the decrease in ozonide. -(/N
Measured by MR method.

Using the apparatus shown in the drawings, 100 g of the oxidative decomposition reaction product of the raw material ozonide was added to two consecutive containers equipped with a stirrer, a temperature sensor, and an oxygen introduction tube. Next, the inside of the container was raised to 1 reactor temperature, and the raw material ozonide was added to 75 g/
The reactants were transferred from the first vessel to the second vessel at the same rate, and the product was withdrawn from the second vessel at the same rate. Note that 02 gas was introduced at a rate of 12 Q/hour.

The results are shown in Table 1.

Table 1 From the results shown in Table 1, it was confirmed that oleic acid methyl ester ozonide provides a reaction system with good yield and safety at high temperatures.

[Brief explanation of the drawing]

The drawing is a schematic sectional view showing an example of an apparatus used to implement the present invention. Applicant Lion Co., Ltd. Agent Patent Attorney Takashi Kojima (1 other person)

Claims (1)

[Claims] 1. The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R is a hydrocarbon group containing 1 to 3 double bonds,
R' is a lower alkyl group. ) is characterized in that an ozonide obtained by contacting an unsaturated fatty acid lower alkyl ester represented by A method for oxygen oxidative decomposition of ozonized unsaturated fatty acid lower alkyl esters.