JPH0324474B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a method for producing glycidyl ethers useful as fiber modifiers, stabilizers for chlorinated organic compounds, reactive diluents and modifiers for synthetic resins, and the like. "Prior art" In producing the corresponding glycidyl ethers from alcohols and epihalohydrin, conventionally (a) ring-opening addition is performed to form the corresponding chlorohydrin in the presence of an acid catalyst, and then the molecule is added in the presence of an alkali. A method to obtain glycidyl ether by internal ring closure. (This is called a two-step method.) (b) A method for directly obtaining glycidyl ether in the presence of an alkali catalyst. (This is called the one-stage method.) has been adopted. However, both methods produce various by-products, making it difficult to separate and purify the desired glycidyl ethers.Furthermore, the one-stage method results in extremely low yields, so the two-stage method is usually adopted. Glycidyl ethers have been produced. On the other hand, since the one-stage method is advantageous in terms of the production process, the use of various catalysts has been proposed in order to improve the yield. For example, a method using a quaternary basic salt (see JP-A-54-141708), a method using a basic anion exchange resin (JP-A-54-141708),
141709), a method using a crown ether compound (see JP-A-54-141710), etc. have been proposed. However, in these methods, in addition to the raw materials alcohols, epihalohydrin, and the catalysts mentioned above, it is unavoidable to use an aqueous solution of caustic alkali equivalent to the raw materials, which reduces the efficiency of the reaction vessel. In addition to the problem of waste water treatment, for example, crown ether compounds have the disadvantage that they are extremely expensive and extremely difficult to recover. ``Problems to be Solved by the Invention'' In view of the above circumstances, the present inventors have discovered that glycidyl ether can be efficiently and in good yield even when using a one-stage method without using a large amount of alkaline aqueous solution as described above. We investigated to obtain a similar model. "Means for solving the problem" As a result of the above studies, it was found that if specific polyalkylene glycols were allowed to coexist in the reaction system without using a large amount of aqueous solution of caustic alkali, which was conventionally known,
The present invention was accomplished by discovering that the glycidyl ethers can be obtained efficiently and in good yields by allowing only the necessary amount of alkali metal hydroxide to be present. That is, the present invention involves reacting alcohols having 1 to 8 carbon atoms with epihalohydrin in the presence of an alkali metal hydroxide to produce glycidyl ethers, in which a polyalkylene glycol derivative represented by the following general formula is allowed to coexist. This is a method for producing glycidyl ethers, which is characterized by the following. [Here, R ₁ and R ₂ represent a hydroxyl group, the same or different alkoxy group having 1 to 4 carbon atoms, or a lower alkyl substituted or unsubstituted amino group, R ₃ represents a hydrogen atom or a methyl group, and n represents 4 ~ indicates a positive number of 20. ] The alcohols used in the method of the present invention preferably have 1 to 8 carbon atoms, and these alcohols may contain 1 to 3 hydroxyl groups. Among these, monohydric alcohols include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, t-butyl alcohol, saturated aliphatic alcohols such as 2-ethylhexanol, allyl alcohol, methallyl alcohol, etc. Examples include unsaturated alcohols. Furthermore, monoalkoxy substituted products of lower diols containing heteroatoms such as ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monobutyl ether, and 1,4-butanediol monomethyl ether are also included in the alcohol category of the present invention. . Examples of dihydric alcohols include ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, and triethylene glycol, and examples of trihydric alcohols include glycerin and trimethylolpropane. Epihalohydrin, which is another raw material used in the method of the present invention, can specifically include epichlorohydrin or epibromohydrin, but the halogen atoms of the hydrin are discharged as alkali metal halides after the reaction. Considering this, epichlorohydrin is preferably used in the method of the present invention. In carrying out the method of the present invention, the alkali metal hydroxide coexisting should be used alone, that is, in a non-aqueous state.In other words, it is an important feature of the present invention that it is added to the reaction system in a non-aqueous state. . The hydroxide can be used in granular or powdered form, but it is preferably added in powdered form in order to speed up the reaction. Even if added in a non-aqueous state, glycidyl ethers can be easily produced if the polyalkylene glycol derivative represented by the above general formula is present, and the small amount of water produced as the reaction progresses can be used if necessary. It is also possible to distill the mixture together with an inert azeotropic solvent and then separate and discharge it. In any case, the amount of water to be treated after the completion of the reaction is extremely small compared to conventionally known methods, and the economic advantage of the method of the present invention is clear. The alkali metal hydroxide used is preferably sodium hydroxide or potassium hydroxide. In implementing the method of the present invention, the polyalkylene glycol derivative to be coexisting is a compound represented by the above general formula, containing 4 to 20 oxyethylene groups and/or oxypropylene groups in one molecule,
Terminal groups R ₁ and R ₂ are hydroxyl groups, with the same or different number of carbon atoms (1)
-4, or a lower alkyl-substituted or unsubstituted amino group, and R ₁ and R ₂ may each be a different substituent as described above. To give some examples of these, R ₁ ,
When R ₂ is a hydroxyl group, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, decaethylene glycol, PEG
-600, tetrapropylene glycol, hexapropylene glycol, PPG-400, or polyalkylene glycols such as block or random adducts (average molecular weight of about 800) of ethylene oxide and propylene oxide; R ₁ is a hydroxyl group and R ₂ is an alkoxy group Or in the case of an amino group, tetraethylene glycol monomethyl ether, hexaethylene glycol monobutyl ether, addition of about 10 moles of ethylene oxide to ethyl alcohol, addition of ethylene oxide and propylene oxide to methyl alcohol in a block or random manner. (average molecular weight of about 600), polyalkylene glycol derivatives such as hexaethylene glycol monoamine and pentapropylene glycol monomethylamine; when R ₁ and R ₂ are the same or different alkoxy groups or amino groups, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, Examples include propylene glycol diethyl ether, dimethyl ether of PEG-300, dipropyl ether of PPG-500, tetraethylene glycol diamine, hexaethylene glycol monomethyl ether monoethylamine, and the like. The amount of epihalohydrin to be used relative to the hydroxyl group of the alcohol used in the present invention may range from 0.5 to 5.0 times by mole, and preferably from 1 to 3 times by mole. 0.5
If the amount used is less than twice the mole, the yield of the desired glycidyl ether will be extremely reduced, which is undesirable.
It is not necessary to use more than twice the molar amount. The amount of alkali metal hydroxide to be used may be in the range of 0.5 to 3 times the hydroxyl group of the alcohol,
1 to 2 times the molar amount is preferred. If the amount is less than 0.5 times the mole, the reaction will not proceed sufficiently, which is undesirable, and it is not necessary to use more than 3 times the mole. The amount of the polyalkylene glycol derivative represented by the above general formula, which is a feature of carrying out the method of the present invention, coexisting in this reaction is preferably 0.01 to 5 times the weight of the alcohol used, and 0.05 times to etc. Particularly preferred are ranges of amounts. If it is less than 0.01 times the weight, the characteristics of the method of the present invention will not be noticeable and it is not preferable, and if it exceeds 5 times the weight, it is not only unnecessary, but also
Side reactions other than the glycidyl ether production reaction may become significant, which is not preferable. The reaction temperature and reaction time when carrying out the method of the present invention vary depending on the raw materials used and the above-mentioned molar ratio, but generally the reaction temperature is preferably in the range of 0 to 12°C, and preferably in the range of 20 to 80°C. Particularly preferred is a reaction time of 1 to 24 hours. Further, in relation to the above-mentioned reaction temperature, there is no problem even if the pressure during the reaction is higher than normal pressure. In the method of the present invention, the reaction proceeds without any problems using only the above-mentioned raw materials, but if necessary, an inert solvent can be used for the reaction, such as diethyl ether, diisopropyl ether, ethylene glycol dimethyl ether, tetrahydrofuran. , acetone, methyl ethyl ketone, dimethyl formamide and the like. At the start of this reaction, there is no limitation on the method of charging the above-mentioned raw materials into the reactor, and the above-mentioned four types of raw materials may be charged all at once.Alcohols, epihalohydrin, powdered or granular alkali metal hydroxide The polyalkylene glycol derivatives may be sequentially added in random order. This reaction is usually carried out batchwise, but it can also be carried out continuously. As this reaction progresses, water is produced, but there is no problem in reacting while removing this produced water from the system or without removing it.
This does not reduce the effectiveness of the method of the invention. The target glycidyl ether can be isolated from the reaction mixture thus produced by any conventional known method, such as separating by-product alkali metal salts present in the mixture by filtration, etc. If there is an excess alkali, it is removed by neutralization or washing with water, and unreacted alcohols, unreacted epihalohydrin, the desired glycidyl ether, and organic solvent are separated by distillation according to their boiling points. Just use it. Furthermore, if necessary, the glycidyl ether fraction may be rectified. The polyalkylene glycol derivative added to this reaction can be recovered and reused; for example, the distillation-separated fraction described above may be used again;
In some cases, the residue that is not distilled out in the above-mentioned distillation may be reused as it is. "Example" The method of the present invention will be explained in detail below with reference to Examples and Comparative Examples, but the method is not limited thereto. In the following description, "parts" indicate parts by weight unless otherwise specified. Example 1 40 parts of allyl alcohol, 130 parts of epichlorohydrin, 45 parts of sodium hydroxide, and 10 parts of polyethylene glycol dimethyl ether having an average molecular weight of 300 were placed in a 300-volume glass reaction vessel and reacted with stirring at 35 to 40°C for 5 hours. After that, the reaction solution was neutralized with 17.5 parts of 12N concentrated hydrochloric acid, the salt present in the solution was separated, approximately 25 parts of the aqueous layer was separated, and the organic layer was distilled under reduced pressure to obtain the desired allyl. 71.3 parts of glycidyl ether were separated, and 65 parts of unreacted epichlorohydrin were also recovered. The yield of the obtained allyl glycidyl ether based on allyl alcohol was 90.8%, and the yield based on epichlorohydrin considering the recovery section was 89.0%. Furthermore, analysis of the obtained allyl glycidyl ether by gas chromatography revealed that its purity was 99%. Comparative Example 1 A reaction was attempted using the reaction vessel used in Example 1 and the well-known triethylbenzylammonium chloride as a catalyst, but since an aqueous solution of sodium hydroxide was used, the reaction was carried out in approximately the same volume as in Example 1. When I did this, the following conditions were met. That is, 30% of allyl alcohol is added to the reaction vessel.
1 part, 87 parts of a 40% aqueous sodium hydroxide solution, 98 parts of epichlorohydrin, and 1 part of triethylbenzylammonium chloride, and the mixture was stirred and reacted at 35 to 40°C for 5 hours. After that, the reaction solution was diluted with 12N concentrated hydrochloric acid.
After neutralizing with 100% of the solution, remove the salt present in the same solution and give approximately 90%
The aqueous layer was separated, and the organic layer was distilled under reduced pressure to collect 47.5 parts of the target allyl glycidyl ether, and further 38.6 parts of unreacted epichlorohydrin. The yield of the obtained allyl glycidyl ether based on allyl alcohol was 80.7%, and the yield based on epichlorohydrin considering the recovery section was 64.9%. Furthermore, analysis of the obtained allyl glycidyl ether by gas chromatography revealed that its purity was 99%. That is, in this example, by using a large amount of water at the start of the reaction, the efficiency of the reaction vessel and the efficiency of use of epichlorohydrin were significantly reduced compared to the method of the present invention. Example 2 42 parts of n-propyl alcohol, 130 parts of epichlorohydrin, 47 parts of potassium hydroxide, and 5 parts of tetraethylene glycol dimethyl ether were placed in a 300-volume reaction vessel and reacted with stirring at 35 to 40°C for 7 hours. Thereafter, the reaction solution was treated in the same manner as in Example 1 to obtain 71.9 parts of normal propyl glycidyl ether with a purity of 99%. The yield based on normal propyl alcohol was 88.7%. Example 3 In the method described in Example 1, 193 parts of epibromohydrin was used in place of epichlorohydrin, resulting in 70.5 parts of allyl glycidyl ether with a purity of 99%.
parts are obtained, and the yield based on allyl alcohol is:
It was 89.8%. Examples 4 to 7 The same reaction as in Example 1 was carried out using the raw materials shown in Table 1, and the obtained results are shown in Table 1.

【table】

[Table] Comparative Example 2 54 parts of allyl alcohol and 93 parts of 40% aqueous sodium hydroxide solution were placed in a 300 volume reaction vessel, and while stirring, 83 parts of epichlorohydrin was added at 30°C over 30 minutes, and then at 40°C for 8 hours. A ripening reaction was performed. After that, the reaction solution was filtered, separated, washed with water, and fractionated by distillation under reduced pressure in the same manner as in Example 1, but only 30.5 parts of allyl glycidyl ether with a purity of 99% was obtained, but the yield relative to allyl alcohol was It was as low as 30%. "Effects of the Invention" By using the method of the present invention, glycidyl ethers can be obtained more easily and efficiently than conventional methods.

Claims (1)

[Scope of Claims] 1. When glycidyl ethers are produced by reacting an alcohol having 1 to 8 carbon atoms with epihalohydrin in the presence of an alkali metal hydroxide, a polyalkylene glycol derivative represented by the following general formula is used. A method for producing glycidyl ethers, characterized by coexisting with the following. [Here, R ₁ and R ₂ represent a hydroxyl group, the same or different alkoxy group having 1 to 4 carbon atoms, or a lower alkyl substituted or unsubstituted amino group, R ₃ represents a hydrogen atom or a methyl group, and n represents 4 ~ indicates a positive number of 20. 2. The method according to claim 1, wherein the number of hydroxyl groups in one molecule of alcohol is 1 to 3. 3. The method according to claim 1 or 2, wherein the amount of the polyalkylene glycol derivative present is 0.01 to 5 times the weight of the alcohol.