JPH09295955A - Production of long chained formal derivatives - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a producing method of formal compounds having a long chained hydrocarbon group useful for solvents, additives for polymers, reagents for polymers, etc. SOLUTION: This long chained formal compounds expressed in formula R<1> OCH2 OR<1> is obtained by carrying out the contact of the formal compounds expressed in formula R<1> OCH2 OR<2> (R<1> is an aliphatic hydrocarbon group of CZ>=12, R<2> is an aliphatic hydrocarbon group of C<=4, and so forth) with a solid acid while removing the formal compound expressed in formula R<2> OCH2 OR<2> which is the reaction products of formula R<1> OCH2 OR1 and R<2> OCH2 OR<2> , by distillation.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a long-chain formal having an aliphatic hydrocarbon group having 12 or more carbon atoms.

[0002]

2. Description of the Related Art Conventionally, a method for producing methylal by heating methanol and formaldehyde with an acidic catalyst such as sulfuric acid has been well known. In the case of this method, the produced methylal is extracted from the reaction system by a distillation method. For example, the method of obtaining methylal by reactive distillation from methanol and formaldehyde disclosed in JP-B-4-15213 is one example. It is known that ethylal, propylal, butyral and the like can be obtained by the same method.

However, the method for producing formal from an alcohol having 4 or more carbon atoms and formaldehyde has a problem that it is difficult to separate the produced formal. In particular, when it is attempted to produce formal by reacting an alcohol having 10 or more carbon atoms with formaldehyde, the produced formal has a high boiling point and is difficult to remove from the top of the reactive distillation column. Couldn't be. Further, the reaction for obtaining formal from alcohol and formaldehyde is performed according to the following reaction formula.

[0004]

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That is, as seen from the above formula, the reaction is a dehydrogenation reaction and an equilibrium reaction. Therefore, when R is a long chain (that is, when the boiling point of formal is high), it is extremely difficult to proceed the reaction smoothly to the right and efficiently obtain formal. Although removal of water from the reaction system can promote the progress of the reaction, it is still difficult to efficiently remove water in a system in which formaldehyde coexists, and the reaction system containing raw materials mixed Obtaining long-chain formal without formaldehyde is extremely difficult.

Furthermore, when an aqueous solution of formalin is used as a raw material, a long-chain alcohol is poorly soluble in water, resulting in a heterogeneous reaction, which lowers the reaction efficiency, and moreover, it is often used to remove water in the system. Energy will be required.

As described above, when trying to obtain a long-chain formal by the conventional method, water, formaldehyde and a large amount of raw material alcohol remain, and many steps and labor are required to remove them. I was there.

The term "formal" as used in the present invention means a compound represented by the general formula ROCH ₂ OR '(R and R'represent an aliphatic hydrocarbon group, which may be the same or different from each other). . Therefore, for example, methylal, ethylal, propylal, butyral and the like are examples thereof.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the problem that it was difficult to separate formal, which is the object of the prior art, from formaldehyde, water, alcohol, etc. It is an object of the present invention to provide a new industrial and simple method for producing formal containing an easy alkyl group having 12 or more carbon atoms.

[0010]

In order to solve the above-mentioned problems, the present inventor has conducted extensive studies on a method for producing a long-chain formal by a disproportionation reaction of formal having a long-chain and a short-chain alkyl group, The present invention has been reached.

That is, the present invention relates to the general formula R ¹ OCH ₂
Formal represented by OR ² (wherein R ₁ is a carbon number 1
Two or more aliphatic hydrocarbon groups, and R ² represents an aliphatic hydrocarbon group having 4 or less carbon atoms. The same shall apply hereinafter) is contacted with a solid acid,
Generated general formulas R ¹ OCH ₂ OR ¹ and R ² OCH ₂ O
Of the formal represented by R ² , the general formula R ² OCH
_The general formula R ¹ OCH ₂ O is characterized in that the reaction is carried out while separating the formal represented by ₂ OR ² by a distillation method.
The present invention provides a method for producing a long-chain formal represented by R ¹ . The production method of the present invention will be described below with reference to the reaction formula.

[0012]

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As can be seen from the above formula, in the production method of the present invention, formaldehyde is not used as a raw material, so that there is no generation of water and the inconvenience caused by the coexistence of formaldehyde and water can be avoided, and the generated general formula R ² O
Since the short-chain formal represented by CH ₂ OR ² is a light component having a low boiling point, it can be easily separated by distillation.
Since the long-chain formal (target product) represented by the general formula R ¹ OCH ₂ OR ¹ thus produced is a heavy component, it can be easily separated by taking it out from the bottom of the column.

The raw material formal used in the present invention is a formal represented by the general formula R ¹ OCH ₂ OR ² (R ¹ is an aliphatic hydrocarbon group having 12 or more carbon atoms, R ² is an aliphatic hydrocarbon group having 4 or less carbon atoms). It shows a group). Examples of R ¹ include a lauryl group, a stearyl group, a behenyl group and the like, and an alkyl group having 26, 30, 40, 50 and 100 carbon atoms, preferably an alkyl group having 25 or more carbon atoms. . Examples of R ² include a methyl group, an ethyl group, a propyl group and a butyl group. These raw material formal may be used as a mixture of two or more kinds.

As the solid acid used in the present invention, a strongly acidic ion exchange resin having a sulfonic acid group, a fluorinated olefin resin having a sulfonic acid group (trade name Nafion)
And the like. It is also possible to use acid type zeolites.

In the method for producing a formal containing a long-chain alkyl group according to the present invention, the raw material formal R ¹ OCH ₂ OR ² is disproportionated in the presence of the solid acid as a catalyst to produce the formal. Short-chain formal R ² OCH
_{2 The} reaction proceeds while extracting ₂ OR ² from the reaction system by distillation. Therefore, the reaction is preferably carried out at the boiling point,
The reaction temperature is 40 to 120 ° C, preferably 40 to 100 ° C
Do with. Further, in order to carry out the reaction as a solution, a solvent such as hexane, heptane, benzene or toluene may be added.

After the alcohol produced by the reaction is taken out of the reaction system, the short-chain formal and the long-chain formal can be further separated by a distillation method.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to Examples, but these Examples do not limit the scope of the present invention.

[0019]

【Example】

Example 1 A long-chain formal was produced by the reaction process shown in FIG. In the figure, 1 is a pressure-type reactive distillation apparatus with a capacity of 2
Liters. Reference numeral 2 is a raw material supply port, and 3 is a discharge pipe for vapor generated from the reaction system. A is a catalyst-packed fixed bed, which is filled with a strongly acidic ion exchange resin (sulfonic acid group type ion exchange resin, total volume 200 ml).

First, 1000 g of laurylmethylformal is charged into the reactive distillation apparatus 1, and benzene is continuously supplied from the 2 liter supply port 2 per hour. Then, the content introduced into the reactive distillation apparatus 1 circulates through the fixed bed A packed with catalyst at 1 liter per minute. At this time, the content of the reactive distillation apparatus 1 was kept at 1.5 liters and the reaction temperature was set to 9 liters.
The temperature is set to 0 ° C., and benzene is continuously supplied for 3 hours while distilling methylal containing benzene from the reaction system through the vapor withdrawing pipe 3.

After the reaction was completed, all the reaction product was taken out, and 13
Bubbling nitrogen at 0 ° C. distills off excess benzene. -O of unreacted lauryl methyl formal in the residue
When the CH ₃ group was determined by the proton NMR method, it was 23% of the charged —OCH ₃ group. That is, the conversion rate of lauryl methyl formal to dilauryl formal was 77%. The formal and the raw formal were easily separated by a conventional distillation method.

Example 2 When stearylmethylformal was used and carried out in the same manner as in Example 1, the conversion rate was 83%.

Example 3 When behenylmethylformal was used and carried out in the same manner as in Example 1, the conversion was 86%.

Example 4 A conversion was 91% when carried out in the same manner as in Example 1 except that formal having an average carbon number of 26 as R ^{1 and a} methyl group as R ² was used.

Example 5 A conversion was 93% when carried out in the same manner as in Example 1 except that formal having an average carbon number of 30 as R ^{1 and a} methyl group as R ² was used.

Example 6 A conversion was 95% when carried out in the same manner as in Example 1 except that formal having an average carbon number of 40 as R ^{1 and a} methyl group as R ² was used.

Example 7 A conversion was 96% when carried out in the same manner as in Example 1 except that formal having an average carbon number of 50 as R ^{1 and a} methyl group as R ² was used.

Example 8 Using formal having an average carbon of 40 as R ¹ and an ethyl group as R ² , the same procedure as in Example 1 was carried out. As a result, the conversion rate was 92%.

Example 9 Stearyl methyl formal and behenyl methyl formal were used as raw material formal, and the same procedure as in Example 1 was conducted. As a result, a mixed formal containing distearyl formal, dibehenyl formal and stearyl behenyl formal was obtained at a conversion rate of 92%. I was able to synthesize it.

[0030]

INDUSTRIAL APPLICABILITY The present invention has an industrially excellent effect that a long-chain formal having 12 or more carbon atoms can be easily produced. These formal are useful as a solvent, a polymer additive such as a lubricant, a reaction agent such as a chain transfer agent for trioxane polymerization, and the like.

[Brief description of drawings]

FIG. 1 is a process drawing of a main part of a manufacturing method of the present invention.

[Explanation of symbols]

 1: Reactive distillation apparatus 2: Supply port 3: Vapor extraction pipe A: Catalyst packed fixed bed

Claims (1)

[Claims] 1. A general formula R ¹ OCH ₂ formal (wherein represented by OR ^2, R ₁ is an aliphatic hydrocarbon group having at least 12 carbon atoms, R ² represents an aliphatic hydrocarbon group having 4 or less carbon atoms The same shall apply hereinafter) is contacted with a solid acid to produce a general formula R
Of the formal represented by ¹ OCH ₂ OR ¹ and R ² OCH ₂ OR ² , the formal represented by the general formula R ² OCH ₂ OR ² is separated by a distillation method to carry out the reaction, and the general formula R ¹ is characterized. A method for producing a long-chain formal represented by OCH ₂ OR ¹ .