JP2001097911A - Method for producing vinyl ether - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently and readily producing a vinyl ester containing a fixed substituent in the molecule. SOLUTION: This method for producing a vinyl ether comprises transetherifying an alkyl vinyl ether of general formula (1): CH2=CHOR1 with an alcohol of general formula (2): R2(OH)m to give a vinyl ether of general formula (4): (CH2=CHO)mR2. The transetherification is carried out in the presence of a cobalt complex catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing vinyl ether.

[0002]

2. Description of the Related Art Vinyl ether is used as an intermediate of resin raw materials and various compounds.
It is suitably applied as a polymer modifier for synthetic resins in various fields such as molding resins, coating resins, adhesives and pressure-sensitive adhesives. Such vinyl ethers are industrially important because they can impart various properties to synthetic resins and the like. For example, in a photopolymerizable cationic polymerizable resin, when vinyl ether is used as a polymer modifier, the vinyl ether functions as a unit having photopolymerizability, so that excellent photopolymerizability is obtained.

[0003] Vinyl ethers can exhibit various properties as a polymer modifier depending on the type of substituent in the molecule. The polymer modifier is required to be able to supply various types in accordance with the use in which it is used, required characteristics, demand, and the like. Therefore, it is extremely industrially necessary that vinyl ether can be supplied as desired by changing the type of the substituent in the molecule in accordance with the use, required characteristics, demand, and the like in which it is used. It is important.

[0004] As a method for changing the type of substituent in the molecule of vinyl ether, a method of ether-exchanging an alkyl vinyl ether with an alcohol is industrially useful. This method is usually performed in the presence of a bipyridyl complex such as mercury acetate, palladium chloride and palladium acetate, a mercury complex catalyst such as a phenanthroline complex and a palladium complex catalyst. However, since the reaction for transesterification is an equilibrium reaction, when these catalysts were used, the yield of transesterified vinyl ether as a product was low.

[0005] The Journal of American Chemical Society (J. of American Che
medical Society) 79 [5] (1957)
p. No. 2828-2833 discloses a technique in which an alkyl vinyl ether and an alcohol are ether-exchanged in the presence of a weak acid mercury salt catalyst to change the alkyl group in the molecule of the alkyl vinyl ether. In this transesterification reaction, simply performing the transesterification in the presence of a mercury salt catalyst of a weak acid results in a low yield of the transesterified alkyl vinyl ether, which is a product, so that the boiling point of the transesterified alkyl vinyl ether is low. Therefore, it was necessary to improve the yield of the product by removing the product by using the above or by changing the chemical equilibrium by charging an excessive amount of alcohol. Also,
Further, there is room for improving the yield of the product.

The Journal of American Chemical Society 79 [5] (1957) p. 2833
-2836 discloses a technique in which an alkyl vinyl ether and an alcohol are ether-exchanged in the presence of a mercury or silver salt catalyst of a weak acid to change the alkyl group in the molecule of the alkyl vinyl ether. However, the ether exchange reaction has the same problem as described above.

[0007] Tetrahedro
n) 28 (1972) p. 233-238 discloses a technique for stably performing ether exchange by performing palladium in the presence of a complex coordinated with a nitrogen atom through a sigma bond in the ether exchange between an alkyl vinyl ether and an alcohol. I have. However, even in this ether exchange reaction, there is room for improving the yield of the product, and there has been a problem that the device for improving the yield is not sufficient.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a method for efficiently and easily producing a vinyl ether having a desired substituent in a molecule. It is assumed that.

[0009]

The present invention provides a compound represented by the following general formula (1):

[0010]

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[In the formula, R ¹ represents an alkyl group having 1 to 18 carbon atoms. An alkyl vinyl ether represented by
The following general formula (2);

[0012]

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[Wherein R ² is different from R ^1, and is an alkyl group having 1 to 18 carbon atoms, an alkylene group having 1 to 18 carbon atoms, R ³ (OR ⁴ ) n-, -R ⁵ (OR ⁶ )
p-, a glycidyl group, or the following general formula (3);

Embedded image Represents a group represented by R ³ represents an alkyl group having 1 to 18 carbon atoms. R ⁴ represents an alkylene group having 1 to 18 carbon atoms. R ⁵ and R ⁶ are the same or different and represent an alkylene group having 1 to 18 carbon atoms. R ⁷ and R ⁸ are the same or different and represent an alkylene group. Where R ⁷
And the total number of carbon atoms of R ⁸ is 5 to 15. m is 1
Or an integer of 2. n represents an integer of 1 to 1000. p represents an integer of 1 to 1000. q is 1 to 25
Represents an integer. Ether exchange with an alcohol represented by the following general formula (4):

[0014]

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Wherein R ² and m are the same as above. Wherein the ether exchange is carried out in the presence of a cobalt complex catalyst. Hereinafter, the present invention will be described in detail.

The process for producing the vinyl ether of the present invention is described by the following reaction formula.

[0017]

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In the formula, R ¹ , R ² and m are the same as described above. In the above reaction, the alkyl vinyl ether represented by the general formula (1) and the alcohol represented by the general formula (2) are ether-exchanged, and the vinyl ether represented by the general formula (4) is converted to the vinyl ether represented by the general formula (4). And alcohol represented by the formula (5). In the above reaction, a chemical equilibrium is established between the reaction raw material before the ether exchange and the reaction product after the ether exchange.

According to the process for producing vinyl ether of the present invention, the above ether exchange is carried out in the presence of a cobalt complex catalyst to improve the yield of the desired product, vinyl ether represented by the above general formula (4). That can be done.

In the above general formulas (1), (2), (4) and (5), the above R
¹ and the R ² is different from each other. R ¹ above
Represents an alkyl group having 1 to 18 carbon atoms. If the carbon number of R ¹ exceeds 18, the alkyl vinyl ether represented by the general formula (1) may not be easily available.

The above R^Two Is an alkyl having 1 to 18 carbons
Group, an alkylene group having 1 to 18 carbon atoms, R ^Three (OR^Four ) N
-, -R^Five (OR⁶ ) P-, glycidyl group, or general
Represents a group represented by the formula (3). R^Three Has 1 to 18 carbon atoms
Represents an alkyl group. R^Four Is an alk having 1 to 18 carbon atoms
Represents a len group. R^Five And R⁶ Are the same or different
Represents an alkylene group having 1 to 18 carbon atoms. R⁷ And R
⁸ Are the same or different and each represents an alkylene group. Was
But R⁷ And R⁸ Has a total carbon number of 5 to 15.
You. m represents an integer of 1 or 2. n is 1 to 1000
Represents an integer. p represents an integer of 1 to 1000. q
Represents an integer of 1 to 25.

When R ² is an alkyl group or an alkylene group and the number of carbon atoms exceeds 18, the vinyl ether represented by the general formula (4) may not be practical as a polymer modifier or the like. is there. Since the vinyl ether represented by the general formula (4) can be suitably applied as a polymer modifier for a photopolymerizable cationic polymerizable resin, the above R ² is an alkyl group or an alkylene group. In this case, the number of carbon atoms is preferably 10 to 16. More preferably, it is 12-14.

R ² is R ³ (OR ⁴ ) n-, -R ⁵
(OR ⁶ ) In the case of p- or a group represented by the general formula (3), the number of carbon atoms of R ³ , R ⁴ , R ⁵ and R ⁶ , and R ⁷
And total or number of carbon atoms in R ^8, n, when p and q is greater than the above range, respectively, vinyl ethers represented by the general formula (4) is likely to be not as practical as the polymer modifier and the like . Since the vinyl ether represented by the general formula (4) can be suitably applied as a polymer modifier, the above R ² is R ³ (OR ⁴ ) n−,
Or, -R ⁵ if (OR ⁶⁾ p-of, R ^3, R ^4,
R ⁵ and R ⁶ preferably have 1 to 5 carbon atoms. Further, n and p are preferably integers of 1 to 1000. More preferably, R ³ , R ⁴ , R ⁵ and R
⁶ has 1 to 3 carbon atoms, and n and p are 1 to 200.
Is an integer. When R ² is a group represented by the general formula (3), the total number of carbon atoms of R ⁷ and R ⁸ is preferably 7 to 13. Further, q is preferably an integer of 1 to 15. More preferably, the total number of carbon atoms of R ⁷ and R ⁸ is 9 to 11, and q is an integer of 1 to 10.

The alkyl group having 1 to 18 carbon atoms is not particularly limited, and may be a straight-chain or branched one, for example, a methyl group, an ethyl group, an n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, n-amyl group, i-amyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, Undecyl group, dodecyl group,
Examples include a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group.

The alkylene group having 1 to 18 carbon atoms is not particularly restricted but includes, for example, a methylene group, an ethylene group,
Propylene group, butylene group, amylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group, etc. Can be

The alkyl vinyl ether represented by the above formula (1) and the alcohol represented by the above formula (2) may be used alone or in combination of two or more. When the vinyl ether represented by the general formula (4) is isolated by a distillation operation, the operation becomes complicated when the types of compounds present in the reaction system increase, and therefore it is preferable to use each of them alone.

The R ¹ of the alkyl vinyl ether represented by the general formula (1) is not particularly limited as long as it is an alkyl group having 1 to 18 carbon atoms. For example, the R ¹ is represented by the general formula (4) When the vinyl ether is isolated by a distillation operation, the alkyl group is selected such that the boiling point of the vinyl ether represented by the general formula (4) is lower than the boiling point of the alcohol represented by the general formula (5). Is preferred.

The molar ratio between the alkyl vinyl ether represented by the general formula (1) and the alcohol represented by the general formula (2) is not particularly limited, and is, for example, represented by the general formula (2). When the alcohol has one hydroxyl group, the alcohol 1 represented by the general formula (2)
It is preferable that the amount of the alkyl vinyl ether represented by the general formula (1) is 1 mol or more with respect to the mol. When the alcohol represented by the general formula (2) has two hydroxyl groups, the alcohol represented by the general formula (2)
It is preferable that the amount of the alkyl vinyl ether represented by the general formula (1) is 2 mol or more per 1 mol of the alcohol represented by the formula (1).

In order to efficiently and easily produce a vinyl ether having a substituent in the molecule as desired, in the above-mentioned ether exchange, the alkyl vinyl ether represented by the above general formula (1) is converted into the above general formula (4) It is necessary to improve the yield of the vinyl ether represented by the general formula (4) by changing the chemical equilibrium so as to improve the conversion to the vinyl ether represented by the general formula (4).

As a result of intensive studies, the present inventors conducted the above-mentioned ether exchange in the presence of the above-mentioned cobalt complex catalyst to obtain the above-mentioned alkyl vinyl ether represented by the above general formula (1). ) Was found to dramatically improve the conversion to vinyl ether, and found that vinyl ethers having desired substituents in the molecule could be efficiently and easily produced, and arrived at the present invention. It was done.

In this specification, the chemical equilibrium is established between the conversion of the alkyl vinyl ether represented by the general formula (1) to the vinyl ether represented by the general formula (4) in the ether exchange. Sometimes {(the number of moles of the vinyl ether represented by the above general formula (4)) / (the total number of moles of the alkyl vinyl ether represented by the above general formula (1) used as a raw material)} × 100
Means represented by

The cobalt complex catalyst is not particularly restricted but includes, for example, Co (acac) ₂ .2H ₂ O;
Cobalt carbonyl catalysts such as (CO) ₄ and Co ₂ (CO) ₈ are exemplified. These may be used alone,
More than one species may be used in combination. Among these, since the general formula (1) General formula alkyl vinyl ether represented by the conversion to vinyl ethers represented by (4) is _{improved, Co (acac) 2 · 2H} 2 O are preferred.

The above Co (acac) ₂ .XH ₂ O is represented by the following general formula (6):

[0034]

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And an organic transition metal complex having two acetylacetones as ligands with a divalent cobalt atom as a central metal. X is 1 or 2
Is an integer. By performing the ether exchange in the presence of the cobalt complex catalyst, the conversion of the alkyl vinyl ether represented by the general formula (1) to the vinyl ether represented by the general formula (4) is dramatically improved. Although the reason why this is possible is not always clear, the following may be considered. That is, in a reaction system using an organic transition metal complex catalyst, sufficient stability of the catalyst is required so that the catalyst can be stably present in the reaction system in order to improve the yield of the product. However, it is considered that the cobalt complex catalyst has sufficient stability in the reaction system in which the ether exchange is performed. In the above ether exchange, the cobalt complex catalyst has a sufficient catalytic activity and, in addition, converts the alkyl vinyl ether represented by the general formula (1) to the vinyl ether represented by the general formula (4). It is considered to have an effect of sufficiently improving the conversion. Furthermore, by acting synergistically, it is possible to dramatically improve the conversion of the alkyl vinyl ether represented by the general formula (1) into the vinyl ether represented by the general formula (4). Conceivable.

The form of the above-mentioned cobalt complex catalyst is not particularly limited. For example, it may be used as it is, or may be one supported on a carrier. The carrier is not particularly limited, and may be, for example, a metal oxide such as silica gel, alumina, or zeolite, activated carbon, or the like, or a copolymer or the like.

The method for preparing the above-mentioned cobalt complex catalyst is not particularly limited. For example, Experimental Chemistry Course, 4th edition (1st edition)
7), p. 278 (edited by The Chemical Society of Japan) as described below. Dissolve sodium hydroxide (16 g, 0.4 mol) in water (150 ml) and stir with acetylacetone (40 g,
0.4 mol) slowly (while the liquid temperature is 40
Be careful not to exceed ℃. ). A white solid is formed, but after it has completely dissolved, the solution is prepared using the previously prepared cobalt (II) chloride hexahydrate Co.
_{Cl 2 · 6H 2 O (47.6g} , 0.2mol) with vigorous stirring to water (250 ml) solution of is added dropwise took 10 minutes. The resulting rose red precipitate is filtered off,
Rinse with water until almost no color is applied to the washing solution (about 50
0 ml of water is required). The wet product is dissolved in a hot mixture of 95% ethanol (390 ml) and chloroform (260 ml), allowed to cool slowly to room temperature, and then cooled with ice. The orange needle crystals are filtered off with suction, washed with cold 95% ethanol and air-dried. Store in amber bottle. (Yield 40
g, yield 68%)

The amount of the cobalt complex catalyst used is not particularly limited. For example, the reactivity between the alkyl vinyl ether represented by the general formula (1) and the alcohol represented by the general formula (2) and the ether It may be appropriately set depending on the reaction conditions for the exchange, etc., and is 1/3 to 1 mol of the alkyl vinyl ether represented by the general formula (1).
000 to 1/10 mol is preferred. If the amount is less than 1/3000 mol, the conversion of the alkyl vinyl ether represented by the general formula (1) into the vinyl ether represented by the general formula (4) may decrease. Production costs may increase.

The method for causing the cobalt complex catalyst to be present in the reaction system is not particularly limited. For example, the method may be carried out by adding the cobalt complex catalyst to the reaction system, or the alkyl complex represented by the general formula (1) may be used. It may be mixed with a vinyl ether or an alcohol represented by the above general formula (2), and charged into the reaction system so as to be present in the reaction system.

The above cobalt complex catalyst can be used repeatedly in the vinyl ether production method of the present invention. In order to repeatedly use the cobalt complex catalyst in the method for producing a vinyl ether of the present invention, for example,
After the completion of the ether exchange, distillation can be performed, and the cobalt complex catalyst alone can be recovered as a residue.

The reaction method for the above-mentioned ether exchange is not particularly limited. For example, the conversion method is to improve the conversion of the alkyl vinyl ether represented by the general formula (1) into the vinyl ether represented by the general formula (4). An operation for changing the chemical equilibrium may be performed.

The operation for changing the chemical equilibrium is not particularly limited. For example, the vinyl ether represented by the general formula (4) or the alcohol represented by the general formula (5) is removed, It can be carried out by, for example, charging the alkyl vinyl ether represented by 1) or the alcohol represented by the general formula (2) in excess.

The reaction conditions for the above-mentioned ether exchange are not particularly limited. For example, the reactivity of the alkyl vinyl ether represented by the general formula (1) with the alcohol represented by the general formula (2) and the reaction system The reaction temperature, the reaction time, the pressure in the reaction system, and the like may be appropriately set according to the characteristics of the compound present therein.

The reaction temperature at which the above-mentioned ether exchange is carried out depends on the reactivity between the alkyl vinyl ether represented by the above general formula (1) and the alcohol represented by the above general formula (2) and the compound present in the reaction system. The temperature may be appropriately set in consideration of the boiling point and the like. When the temperature is lower than 20 ° C., the reactivity between the alkyl vinyl ether represented by the general formula (1) and the alcohol represented by the general formula (2) decreases, so that the yield of the vinyl ether represented by the general formula (4) decreases. The rate may decrease. If the reflux temperature is exceeded, safety during production may become a problem. In addition, the vinyl group of the vinyl ether may react to produce a by-product. Further, the stability of the cobalt complex catalyst may be reduced. More preferably, the temperature is from 30C to the reflux temperature.

The reaction time for the above-mentioned ether exchange is appropriately set in consideration of the reactivity of the alkyl vinyl ether represented by the general formula (1) with the alcohol represented by the general formula (2), the reaction temperature, and the like. For example, 2-96
Preferably, it is time. When the time is less than 2 hours, the alkyl vinyl ether represented by the general formula (1) and the alcohol represented by the general formula (2) do not sufficiently react with each other, so that the yield of the vinyl ether represented by the general formula (4) May decrease. When the time exceeds 96 hours, the yield of the vinyl ether represented by the general formula (4) does not change any more, and the vinyl group of the vinyl ether may react to produce a by-product. More preferably, 4
~ 72 hours.

The pressure in the reaction system for carrying out the ether exchange may be normal pressure, or may be increased or decreased. For example,
When the reaction temperature is increased so as to improve the yield of the vinyl ether represented by the general formula (4), the pressure may be increased so that the compound present in the reaction system is not vaporized. In the case of distillation, the pressure may be reduced.

In the method for producing the vinyl ether of the present invention, the method for extracting the vinyl ether represented by the general formula (4) is not particularly limited. For example, the method may be carried out by distillation, and the alcohol may be dissolved in an aqueous solvent such as water. Alternatively, the alcohol may be separated by extraction in the above step.
If the form of the cobalt complex catalyst is insoluble, the cobalt complex catalyst may be separated by filtration.

In the method for producing vinyl ether of the present invention, the yield of the vinyl ether represented by the above general formula (4) is improved in the above-mentioned ether exchange, so that the substituent in the molecule is changed to a desired one. It can easily and efficiently produce vinyl ether. Further, it can be easily manufactured without requiring an industrially complicated process. Therefore, it can be suitably applied to the production of vinyl ethers used as polymer modifiers for synthetic resins and intermediates of various compounds in various fields such as molding resins, coating resins, adhesives and pressure-sensitive adhesives. You can do it.

[0049]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0050] To a solution containing Example 1 Butyl vinyl ether 15.33g of 1-dodecanol _{5.88g, Co (acac) 2 ·} 2H 2
0.09 g of O was added, and the mixture was stirred while maintaining the temperature at 40 ° C. After 8 hours, the reaction solution was analyzed by high performance liquid chromatography, and it was found that the target product, dodecyl vinyl ether, was produced at a yield of 85.1% (based on 1-dodecanol).

Example 2 The same operation as in Example 1 was repeated, except that 1.48 g of glycidol was used in place of 1-dodecanol.
The yield was found to be 2.5% (based on glycidol).

[0052] To a solution containing Example 3 Ethyl vinyl ether 10.82g of 1-dodecanol _{5.88g, Co (acac) 2 ·} 2H 2
0.09 g of O was added, and the mixture was stirred under reflux.
After 24 hours, the reaction solution was analyzed by high performance liquid chromatography, and it was found that the target product, dodecyl vinyl ether, was produced in a yield of 75.1% (based on 1-dodecanol).

Example 4 The same operation as in Example 1 was repeated except that 0.93 g of ethylene glycol was used instead of 1-dodecanol. As a result, the target product, ethylene glycol divinyl ether, was 65.4% ( Ethylene glycol standard)
It was found that the product was produced with a yield of.

[0054]

The method for producing a vinyl ether of the present invention comprises:
Since a vinyl ether having a desired substituent in the molecule can be efficiently and easily produced, a molding resin,
It can be suitably applied to the production of vinyl ethers used as polymer modifiers for synthetic resins and intermediates of various compounds in various fields such as coating resins, adhesives and pressure-sensitive adhesives.

Claims (2)

[Claims] 1. The following general formula (1): [In the formula, R ¹ represents an alkyl group having 1 to 18 carbon atoms. And an alkyl vinyl ether represented by the following general formula (2): [Wherein, R ² is different from R ^1, and is an alkyl group having 1 to 18 carbon atoms, an alkylene group having 1 to 18 carbon atoms, R ³ (OR ⁴ ) n −, —R ⁵ (OR ⁶ ) p-, glycidyl group or the following general formula (3); Represents a group represented by R ³ represents an alkyl group having 1 to 18 carbon atoms. R ⁴ represents an alkylene group having 1 to 18 carbon atoms. R ⁵ and R ⁶ are the same or different and represent an alkylene group having 1 to 18 carbon atoms. R ⁷ and R ⁸ are the same or different and represent an alkylene group. Where R ⁷
And the total number of carbon atoms of R ⁸ is 5 to 15. m is 1
Or an integer of 2. n represents an integer of 1 to 1000. p represents an integer of 1 to 1000. q is 1 to 25
Represents an integer. With ether represented by the following general formula (4): Wherein R ² and m are the same as above. A method for producing a vinyl ether to obtain a vinyl ether represented by the formula
The method for producing a vinyl ether, wherein the ether exchange is performed in the presence of a cobalt complex catalyst. 2. The method according to claim 1, wherein the cobalt complex catalyst is Co (aca).
c) ₂ · XH ₂ O [X is an integer of 1 or 2. The method for producing vinyl ether according to claim 1, wherein