JPS6039253B2 - Method for producing polyol ether - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 2-hydroxyalkyl ethers of polyols (polyhydric alcohols), ie polyol ethers in which the position of one of the hydroxyl groups and the ether bond is specified.

This can be expressed as a chemical formula as follows. In the formula, RI is an alkyl group having 4 or more and less than 28 carbon atoms, R2R3 is hydrogen, a methyl group or an ethyl group, A is a residue obtained by removing a hydroxyl group from a polyol, and n is an integer of 1 to 5.

That is, one starting material of the present invention is an asymmetric epoxyalkane (alkoxy-substituted ethylene oxide) having a long chain of 6 or more and less than 30 carbon atoms, in which only one of the alkyl substituents has an RI of C4 or more. A compound that is alkyl.

The object of the present invention is a (mono)2-hydroxy long chain alkyl ether of a polyol in which only one epoxyalkane is added to only one of the hydroxyl groups of the polyol. The alkyl group RI is attached to the 2-position carbon atom of the 2-hydroxyalkyl group, and forms the last chain (Q or more and less than C3) together with the ethylene oxide carbon. Such polyol ethers are covered by British Patent No.
No. 13564 and is useful as a detergent. Bacyl alcohol, a diol ether obtained from natural products, is used as a valuable material for adding to cosmetics to improve skin feel, but the present invention can provide a wealth of synthetic products for similar uses. The polyol ether obtained by the present invention is also useful as an antibacterial and antibacterial agent. The reaction of polyols such as glycerin with epoxy alkanes such as propylene oxide is widely used in the production of polyol polyethers for polyurethanes. However, in this case, the epoxyalkane does not have six or more carbon atoms as used in the present invention,
It also belongs to a field different from the present invention in that a large number of propylene oxides are added to each polyol molecule to create a polyether with ether bonds. When a polyol is reacted with an asymmetric long-chain epoxy alkane such as the one used in the present invention, there are two types of polyol (mono)ethers produced by addition of the first 1 mole.

2-Hydroxyalkyl ether 1-(hydroxymethyl) alkyl ether (b) Epoxyalkane is further combined with each n contained in (1) and (b).
Since it is also possible to react with +1 OH groups, it sequentially gives rise to multimolar adducts, ie polyol polyols.

In addition to addition reactions, side reactions such as the production of cyclic ethers by condensation of OH may occur. The present invention selectively and in high yield converts the (mono)2-hydroxyalkyl ether of the polyol represented by formula (1) in this type of addition reaction that can produce such complex products. This is a method of manufacturing.

The British patent is a prior art closer to the present invention in that it reacts one last-chain hydroxyalkane per molecule of polyol.

In this technology, the catalyst is an acid catalyst such as SnC14 or N
Although it is said that a base catalyst such as aOC melon can be used, SnC14 is exclusively used in the examples. In addition, in a study published on page 663 of an industrial chemistry magazine, Mr. Shibata et al. carried out the reaction of a long mirror hydroxyalkane with ethylene glycol, glycerin, etc. in the presence of an acid catalyst (concentrated sulfuric acid) and an alkali catalyst (sodium). ing. According to this research, a product in which a polyol is 2-hydroxyalkylated can be obtained using an alkaline catalyst as in the present invention, but despite the harsh reaction conditions of 19,000 mol of glycerin using 6 times the mole of glycerin, The yield of the adduct was as low as 53%, and the reaction was not easy. On the other hand, the acid-catalyzed reaction is about 95
Although the reaction progresses in 0.1 hour, the product is considered to be a ring-opening reaction that produces a primary alcohol (product of the type (b) above), unlike in the case of an alkali catalyst. In addition, the British patent specification describes a formula in which only one 2-hydroxyalkyl group is introduced using a SnC14 catalyst, but additional tests by the inventor revealed that a significant side reaction occurs with the SnC14 catalyst. In addition to the co-production of the two types of 1-mole adducts shown in the research by Shibata et al., the formation of multi-molar adducts and the formation of 1,4-dioxane-type compounds due to intramolecular dehydration cyclization, etc. It seems to be happening. As described above, in the prior art, acid-based catalysts containing SnC14 are not suitable for 2-hydroxyalkylation in terms of selectivity of reaction products, and alkaline catalysts have poor reaction activity and cannot produce long-chain 2-hydroxyalkylated products in high yields. Couldn't get it at the rate. The object of the present invention is to overcome these difficulties and provide a method for producing useful polyol ethers by selectively and rapidly reacting a polyol with a long-chain hydroxyalkane.

This problem was solved by using tertiary amines as catalysts. That is, the present invention relates to a method for obtaining a 2-hydroxyalkyl ether by reacting a polyol with the longest chain hydroxyalkane, in which the reaction is carried out in the presence of a tertiary amine, and only one long chain per molecule of the polyol is obtained. This is a method for producing polyol ether, characterized by selectively introducing 2-hydroxyalkyl groups. The use of tertiary amines as catalysts in the production of polyol polyethers is known (US Pat. No. 29,024).
78 2927918 etc.) In these methods of adding propylene oxide, a 1 molar adduct cannot be obtained,
Polyethers with multiple molar additions were obtained in all cases.

Surprisingly, contrary to this, in the case of the present invention, which uses a hydroxyalkane having a long chain, that is, 6 or more carbon atoms.
Molar adducts are selectively obtained. The closest chain hydroxyalkane used in the present invention is one having 6 or more carbon atoms, such as 1,2-hydroxyhexane, 1,2-
Particularly preferred are hydroxyalkanes having up to 18 carbon atoms, such as hydroxydodecane and 1,2-hydroxyoctadecane.

Hydroxyalkanes having a larger number of carbon atoms than this have lower reactivity with polyols and require harsher reaction conditions (than those for C6-, 8-carbon alkanes). As the hydroxyalkane, those with a side chain R2 such as 2-ethyl-1,2-hydroxydodecane, and internal epoxides such as 3,4-hydroxydecane (R3=ethyl) can also be used.
Of course, a mixture can also be used. For example, an epoxyalkane (R2=R
A mixture consisting mainly of 3=days and a small amount of R2=methyl, R3=days, etc.) is suitable as a raw material for the present invention. The polyol preferably has at least one primary hydroxyl group, such as dihydric alcohols such as ethylene glycol, propylene glycol, and 1,3-butylene glycol, trihydric alcohols such as glycerin and trimethylolpropane, and condensation of these polyols. Diethylene glycol, triethylene glycol, diglycerin (an example of a tetrahydric alcohol), etc., which can be obtained by the above method, can be used.

The polyol and long-chain epoxy alkane are preferably those that can become liquid at a reaction temperature of around 10,000 ℃. Raw materials with high melting points, such as pentaerythritol and linear epoxy alkanes with carbon numbers of 30 or more, have poor reactivity. Tertiary amines used as catalysts include trimethylamine, methylbutylamine, triethylamine, dimethylpropylamine, triptylamine, and dimethylbenzyl. Various tertiary amines such as amine, tetramethylethylenediamine, tetramethyl-1,3-diaminopro/f, tetramethyl-1,6-diaminohexane, and triethylenediamine can be used alone or as a mixture.

Among the above compounds, those having a methyl group are all tertiary amines having a methyl group attached to the nitrogen atom, and in the present invention, these compounds are particularly preferred because of their high activity. These catalysts are normally used in an amount of 0.1-5% by weight based on the long-chain epoxy alkane. Prior art uses a large excess of polyol relative to long mirror epoxy alkane; for example, Example 1 of the British patent uses 10 to 2 sonic moles, while Shibata et al.
However, in the present invention, it is not necessary to use such a large excess of polyol, and even with equimolar amounts, a 1-mole adduct can be obtained with a considerable yield.

If an excess of polyol is used, the selectivity to 1 molar adduct will further improve, but if 4 times the polyol is used, the selectivity to 90%
% or more yield can be obtained. As shown in Comparative Example 1, Sn
With the C14 catalyst, the yield of 1 mole adduct at the same 4 mole ratio is 5
In comparison, the tertiary amine catalyst method of the present invention requires a large excess of polyol to obtain a 1 mol adduct in high yield. does not require. The reaction temperature can be 50 to 2000°, but usually 1
The reaction proceeds at about 00qo.

Severe temperatures such as 190 degrees Celsius for sodium catalysts are rarely used unless the reactivity is extremely poor due to the raw material. Even under such mild reaction conditions, polyol ether as a 1 mol adduct can be obtained with a yield of 90% or more, which was unimaginable with the alkali catalyst method. The reaction time varies depending on the raw materials, the type of catalyst, and the temperature, but is about 1 hour to 1 day. Long mirror epoxy alkanes and polyols often have poor mutual solubility, but as the reaction progresses, the polyol ether produced promotes melting and homogenization. It is also possible to accelerate the reaction by adding a certain amount of the reaction product from the beginning. S
On the contrary, the reaction using the nC14 catalyst proceeds heterogeneously throughout. The British patent specification also mentions that the upper layer is separated, but the comparative example in this specification also shows a heterogeneous phase.
Significant differences in the solubility of the products were observed compared to the present invention. As shown in the comparative example, the reactant of the SnC14 catalyst is gask. Because it shows multiple peaks and has a small hydroxyl value, it is not only a 1-mole adduct mentioned in the specification, but also a 1,4-dioxane type compound (J. big.
Chem. It is thought that it is a mixture with by-products including (see page 1766 of Kamekaya 2). This does not occur with the method of the present invention, which is as good as the alkali catalyst method in terms of selectivity, and far superior to the alkali catalyst method in terms of reactivity, and has a long mirror 2-hydroxyalkyl stalk of 1. A reaction product containing the desired polyol ether in high yield is obtained by introducing only the mole amount into the polyol.

(Depending on the reaction conditions and purpose of use, the reaction product may contain some unreacted raw materials, by-products, catalysts, and their neutralized products.)
It can be used as is without any separation treatment. However, in order to obtain a highly pure polyol ether, a separation treatment is performed. Polyol ethers have low volatility, although the extent varies depending on the chain length and number of hydroxyl groups in the epoxyalkane, so it is known to obtain the desired product by distilling off unreacted polyol under reduced pressure and then performing molecular distillation. It is also applicable to inventions. A separation treatment method that does not involve costly molecular distillation is also desired, and the examples of the British patent mentioned above also describe an extraction separation method using water and water in addition to the molecular distillation method. However, even when water and ether were added to the reaction solution of the present invention (which is a homogeneous layer as described above), no phase separation occurred at all, and it became clear that simple extraction separation could not be applied. As extractants for aqueous solutions, in addition to ether, hydrocarbons such as hexane and benzene, chlorinated carbons such as chloroform, esters such as ethyl acetate, other alcohols, ketones, etc. are commonly known.

However, even when many of these substances are used in place of ether, they do not separate at all, but even if they do separate, the interface and aqueous layer become emulsified, resulting in poor separation. It was recognized that some substances were difficult to separate. However, as a result of extensive research into an advantageous method for separating and purifying a polyol ether having only one 2-hydroxyalkyl group obtained using a tertiary amine catalyst from a reaction product, the present inventors found that methyl ethyl ketone , methyl acetate, and methylal, a good separation state from the aqueous solution can be obtained, and the desired product can be obtained in high yield and quality. I found it.

These are among the organic compounds that have a strong ability to dissolve water, and are rarely used as extraction solvents.However, in the present invention, they act as excellent extractants specifically for polyol ethers. That's surprising. When these specific organic solvents are added to the reaction mixture together with water to carry out the known distillation operation, it is preferable to neutralize the tertiary amine catalyst with an acid prior to or at the same time. The tertiary amine salt and the reacted polyol remain in the aqueous solution, and the polyol ether is selectively extracted. The present invention will be explained below with reference to Examples. Example 1 1.2-epoxytetradecane 318 mol (1.5 mol)
, 552 moles of glycerin (6 mol) and 5.2 moles of tetramethyl-1,6-diaminohexane (0.03 mole) as catalyst.
mol) was charged into a fly-azusa reactor and reacted at 100 qC for 4 hours.

The reaction solution, which was initially heterogeneous, became transparent in about 1 hour.
It remained transparent until the end of the reaction. The reaction product was separated and purified by centrifugal molecular distillation to obtain polyol ether 433 (yield 95%). Comparative Example 1 SnC147 as a catalyst
．． 1,2-epoxytetradecane (0.03 mol) was used, and the other raw materials were the same as in Example 1. Even after the 1,2-epoxytetradecane was consumed, the reaction solution remained in two layers. It was separated.

The upper layer was obtained, and the glycerin was distilled off under reduced pressure, and the resulting layer was subjected to the analysis described below. The products obtained in Analysis Example 1 and Comparative Example 1 were subjected to infrared absorption, gas chromatography, NM calm and chemical analysis, and the results are shown in Table 1.

However, gas chromatography was performed on the trimethylsilylated sample, and the integral ratio of NMR absorption is a relative ratio with 22 being the peak of 1.24 peaks with 6 values due to 11 methylene groups. From this result, the polyol ether obtained in Example 1 is 2-epoxytetradecyl glyceryl ether, but the product of Comparative Example 1 has an epoxyl number and NMR that do not match this, and gas chromatography shows that a large number of products are formed. I realized that something was happening. Note that BF3 was used instead of SnC14 as a catalyst.
Almost similar results were obtained when sulfuric acid and sulfuric acid were used. Example
2 184 moles (1 mole) of 1.2-epoxydodecane, 368 moles (4 moles) of glycerin, and 3.4 moles of tetramethyl-1,6-diaminohexane were reacted at 10 psi for 4 hours.

The catalyst was neutralized with hydrochloric acid, and 500 g each of water and methyl ethyl ketone were added to the reaction solution for extraction. Separation of the aqueous and organic layers was good. Methyl ethyl ketone was distilled off from the organic layer to obtain 2-hydroxydodecylglyceryl ether 260% (94.2%). The product was confirmed by the same analytical method as in Example 1 (Hydroxyl number: 601 (theoretical value 60)
9), IR: 3400 cm-1, Gask o: single peak, NM old). Table 1 Example 3 The same procedure as in Example 2 was carried out except that methyl acetate was used as the extraction solvent. The separation of the two layers was similarly good, and 2-hydroxydodecyl glyceryl ether was obtained in a yield of 72.4%. Obtained.

The same is true when methylal is used as the extraction solvent, yield 6.
It was 8.3%. Analysis of the products indicated that they were all obtained from the same material as Example 2. When the same machine was treated with various solvents for comparison, the following substances were separated to some extent, but the interface and aqueous layer were emulsified, resulting in poor separation and poor yield (enter the % yield in the box). ).

Hexane (39.8), Heptane (14.3), Octane (37.1), Benzene (61.2), Toluene (66)
．． 1), xylene (53.3), carbon tetrachloride (58.8
), petroleum benzine (18.8), petroleum ether (37.
4) Also, the following was emulsified and did not separate at all.

Chloroform, butanol, bentanol, hexanol, ethyl acetate, methylpropylketone, methylbutylketone, 3-heptanone, ethyl ether, isof.

Lopylether Example 4 1.2-Epoxide dodecane and 4 times the molar amount of glycerin were reacted at 100°C in the presence of various tertiary amine catalysts.

The yield of 2-epoxide dodecyl glyceryl ether obtained by molecular distillation is shown in Table 2. When a tertiary amine with a methyl group was used, high yields were achieved even at short reaction times. As in Example 2, all the products were single mono-2-epoxy alkyl ethers. Table 2 Example 5 1.2-Epoxydodecane or 1.2-epoxyhexadecane was reacted with various polyols in the presence of tetramethyl-1.6-diaminohexane for 1000 hours for 4 hours.
Separated by molecular distillation.

Although the polyol was used in an equimolar amount with the epoxide without using an excess amount, 2-epoxychethyl ether of the polyol could be obtained with a yield of about 70% (Table 3). The analytical confirmation method for the products in Examples 5, 6 and 7 of Table 3 is the same as in Examples 1 and 2.

Hydroxyl number: Table 5 (C, 2 day 0 adduct is the measured value for the product obtained in Example 7), IR, single gas chromatography peak, NM town data are all type (1)
This shows that an adduct of .

Table 5 Raw materials 0, 2 days 2400 16 days 320
01 Rainbow 360 Glycerin 601 497
460 ethylene glycol 449 36
2 335 Raw materials 0.2 days 2400, 6 days 3200, 8 days 360 diethylene glycol 3
80 315 297 Triethylene glycol
329 280 264 Propylene glycol
425 347 3201,3 Polyethylene glycol 401 331 306 Example 6 Into an autoclave, 55 parts of 1,2-epoxydodecane, 110 parts of glycerin, and 0.7 parts of trimethylamine were charged.
The reaction was carried out at 100 qo for 4 hours.

2-Epoxide dodecyl glyceryl ether 7 by molecular distillation
Four samples were obtained (yield: 89.4%). Example 7 1.2-epoxydodecane or 1.2-epoxyoctadeca was reacted with 4 times the molar amount of various polyols in the presence of tetramethyl-1,6-diaminohexane for 100.4 hours, and the catalyst After neutralization, the mixture was extracted and separated with methyl ethyl ketone.

In all cases, polyol ethers were obtained with good separation without turbidity at the interface (Table 4). Table 4

Claims (1)

[Claims] 1. A long-chain epoxy alkane adduct of the polyol is obtained by reacting an asymmetric epoxy alkane having 6 or more and less than 30 carbon atoms with a polyol, with or without separation from the reaction product. In the method for obtaining polyol 1, the reaction is carried out in the presence of a tertiary amine.
A method for producing a polyol ether, characterized by introducing only one 2-hydroxy long chain (C_6 or more and less than C_3_0) alkyl group per molecule. 2. The method for producing polyol ether according to claim 1, wherein the separation treatment is a treatment of extracting and separating the product using a solvent selected from the group consisting of methyl ethyl ketone, methyl acetate, and methylal.