JP7841324B2 - Polyalkylene ether glycol and method for producing the same - Google Patents

Description

This invention relates to polyalkylene ether glycol and a method for producing the same.

Polyether polyols are polyols with a wide range of applications, including as raw materials for soft segments such as elastic fibers, thermoplastic elastomers, and thermosetting elastomers. Representative polyether polyols include polyethylene glycol and polyalkylene ether glycols such as polytetramethylene ether glycol.

However, polyalkylene ether glycols composed of short-chain alkylenediols such as polytetramethylene ether glycol may have inferior physical properties, such as thermal stability. When compounded with urethanes or polyesters to form resins, this can lead to negative consequences such as a decrease in thermal decomposition temperature and the generation of decomposition gases. Therefore, for certain applications, polyalkylene ether glycols with higher thermal stability are desired. In recent years, polyalkylene ether glycols produced using long-chain alkylenediols as monomers have attracted attention. For example, polydecamethylene ether glycol using 1,10-decanediol is known (see, for example, Non-Patent Document 1).

One method for producing polydecamethylene ether glycol involves using a polycondensation catalyst, such as sulfuric acid or a cation exchange resin containing sulfone groups, to polycondense 1,10-decanediol and obtain polydecamethylene ether glycol with a number average molecular weight of 900 to 4000 (see, for example, Non-Patent Document 2).

Furthermore, it is known that the sulfuric acid ester contained in polyalkylene ether glycols produced by polycondensation using sulfuric acid as a catalyst causes emulsification during washing with water, making catalyst removal by washing difficult. Therefore, it has been proposed to treat polyalkylene ether glycols consisting of C2-C20 alkanediols produced by polycondensation with sulfuric acid under an acidic aqueous solution. For example, polyhexamethylene ether glycol and polyoctamethylene ether glycol have been obtained with an acid value of 0.03-0.1 (see, for example, Patent Document 1).

International Publication No. 99/01496

Journal of Applied Polymer Science 65 7 1997 p. 1319-1332 Polymer International 27 1992 p. 275-283

However, our studies have shown that even when using polyalkylene ether glycols having long-chain alkylene groups, such as polydecamethylene ether glycol, the thermal decomposition temperature decreases under heating conditions due to the volatilization of low molecular weight components, resulting in poor heat resistance. Furthermore, the above-described manufacturing method uses an acid catalyst, which presents the problem of polyalkylene ether glycols being prone to discoloration.

This invention has been made in view of the above circumstances, and its objectives are to provide a polyalkylene ether glycol with excellent heat resistance and a method for producing a polyalkylene ether glycol with excellent low coloration.

The present inventors, having conducted extensive research in light of the problems of the prior art, have discovered that the above objectives can be achieved by using a polyalkylene ether glycol represented by the following formula (1), and by using an aqueous solution of a specific concentration of acid catalyst as an acid catalyst in the method for producing the polyalkylene ether glycol. This led to the completion of the present invention. In other words, the gist of the present invention is as follows:

[1] A polyalkylene ether glycol represented by the following formula (1).
HO-(R ¹ -O) _n -(R ² -O) _m -H...(1)
(In formula (1), ^R1 represents a divalent hydrocarbon group derived from a dimeric diol having 36 to 44 carbon atoms, obtained by reducing a cyclic or acyclic dimeric acid, which is a dimer of an unsaturated fatty acid; ^R2 represents an alkylene group having 2 to 18 carbon atoms; n and m each independently represent a real number of 0 or more, and n/(n+m) is 0.1 or greater.)
[2] The polyalkylene ether glycol according to [1], wherein n/(n+m) in formula (1) is 0.25 or more.
[3] The polyalkylene ether glycol according to [1] or [2], wherein the number average molecular weight calculated from the hydroxyl value is 300 to 5,000.
[4] A polyalkylene ether glycol according to any one of items [1] to [3], wherein the molecular weight distribution is 1.1 to 3.0.
[5] The polyalkylene ether glycol according to any one of [1] to [4], wherein R ² in formula (1) is a 1,10-decylene group.
[6] A method for producing polyalkylene ether glycol, comprising a step of dehydrating and condensing a glycol component using an acid catalyst,
A method for producing polyalkylene ether glycol, wherein in the dehydration condensation step, an aqueous solution of an acid catalyst with a concentration of 70% by weight or less is used as the acid catalyst.
[7] The method for producing the polyalkylene ether glycol according to [6], wherein the polyalkylene ether glycol is represented by the following formula (1).
HO-(R ¹ -O) _n -(R ² -O) _m -H...(1)
(In formula (1), ^R1 represents a divalent hydrocarbon group derived from a dimeric diol having 36 to 44 carbon atoms, obtained by reducing a cyclic or acyclic dimeric acid, which is a dimer of an unsaturated fatty acid; ^R2 represents an alkylene group having 2 to 18 carbon atoms; and n and m each independently represent a real number of 0 or more.)

According to the present invention, it is possible to provide a polyalkylene ether glycol with excellent heat resistance, and a method for producing a polyalkylene ether glycol with excellent low coloration.

The embodiments of the present invention will be described in detail below. The following description of the constituent elements is an example (representative example) of the embodiments of the present invention, and the present invention is not limited to these contents unless it exceeds the gist of the invention.

[Polyalkylene ether glycol]
The polyalkylene ether glycol of the present invention (hereinafter also referred to as "compound (A)") has a structure represented by the following formula (1).
HO-(R ¹ -O) _n -(R ² -O) _m -H...(1)
In formula (1), ^R1 represents a divalent hydrocarbon group derived from a dimeric diol having 36 to 44 carbon atoms obtained by reduction of a cyclic or acyclic dimeric acid, which is a dimer of an unsaturated fatty acid; ^R2 represents an alkylene group having 2 to 18 carbon atoms; n and m each independently represent a real number of 0 or more, satisfying (n+m)>1 and n/(n+m) being 0.1 or greater.

In equation (1), n and m each independently represent a real number greater than or equal to 0.
n is preferably 0.1 to 50, more preferably 0.2 to 25, and even more preferably 0.3 to 10.
When n is greater than or equal to the lower limit mentioned above, high thermal stability is likely to be imparted.
If n is below the above upper limit, the crystallinity decreases, and flexibility can be increased.
m is preferably 0 to 100, more preferably 0 to 50, and even more preferably 0 to 25.
When m is above the lower limit mentioned above, high thermal stability is likely to be imparted.
If m is below the above upper limit, the crystallinity decreases, and flexibility can be increased.

n/(n+m) is 0.1 or greater.
n/(n+m) is more preferably 0.1 to 1, and even more preferably 0.25 to 1.
If n/(n+m) is greater than or equal to the lower limit mentioned above, high thermal stability is likely to be imparted.

In formula (1), ^R1 represents a divalent hydrocarbon group derived from a dimeric diol having 36 to 44 carbon atoms, which is obtained by reducing a cyclic or acyclic dimeric acid, which is a dimer of an unsaturated fatty acid.
Examples of dimeric diols include compounds represented by the following formula (2).
HO-(CH ₂ ) _s -Y-(CH ₂ ) _t -OH...(2)
In formula (2), Y represents a linear, branched, or cyclic divalent hydrocarbon group having 16 to 42 carbon atoms, which may have substituents; s represents an integer from 1 to 10; and t represents an integer from 1 to 10.
Y is a linear, branched, or cyclic divalent hydrocarbon group having 16 to 42 carbon atoms, which may have substituents. The number of carbon atoms in Y may be 16 to 36 or 18 to 30.
The divalent hydrocarbon group may be a divalent saturated hydrocarbon group or a divalent unsaturated hydrocarbon group.
Examples of substituents include linear, branched, or cyclic alkyl groups having 1 to 10 carbon atoms, or linear, branched, or cyclic alkenyl groups having 2 to 10 carbon atoms.
s is an integer between 1 and 10, preferably between 6 and 10, and preferably between 6 and 8.
t is an integer between 1 and 10, preferably between 6 and 10, and preferably between 6 and 8.

When the dimeric diol is a linear dimeric diol obtained by reducing an acyclic dimeric acid, it is preferable that Y in formula (2) is a group represented by the following formula (3).
-R ^a1 -X-R ^a2 -...(3)
In formula (3), R ^a1 and R ^a2 each independently represent a linear alkylene group having 8 to 21 carbon atoms, or a linear alkenylene group having 8 to 21 carbon atoms, and X represents a single bond or -O-.
The alkenylene group contains 1 to 3 unsaturated bonds.

When the dimeric diol is a branched dimeric diol obtained by reducing an acyclic dimeric acid, Y in formula (2) is preferably a group represented by the following formula (4).
-CH(R ^b1 )-CH(R ^b2 )- (4)
In formula (4), R ^b1 and R ^b2 each independently represent a linear alkylene group having 8 to 20 carbon atoms, or a linear alkenylene group having 8 to 20 carbon atoms.
The alkenylene group contains 1 to 3 unsaturated bonds.

When the dimeric diol is a cyclic dimeric diol obtained by reducing a cyclic dimeric acid, it is preferable that Y in formula (2) is the group represented by formula (5) below.

In formula (5), ring C represents a saturated hydrocarbon ring having 5 to 14 carbon atoms, or an unsaturated hydrocarbon ring having 5 to 14 carbon atoms, p is an integer from 1 to 6, and R ^c1 independently represents a straight-chain alkylene group having 1 to 16 carbon atoms, or a straight-chain alkenylene group having 1 to 16 carbon atoms.
Ring C may be a single ring, or a fused ring formed by the fusion of two or more single rings. The single ring may be a five-membered ring, or a six-membered ring.
p is an integer between 1 and 6, and is less than or equal to the number of carbon atoms in ring C minus 2. If ring C is a 6-membered monoring, p is between 1 and 4, and if ring C is a fused ring formed by the fusion of two 6-membered monorings, p is between 1 and 6.
An unsaturated hydrocarbon ring contains 1 to 3 unsaturated bonds.
The alkenylene group contains 1 to 3 unsaturated bonds.

The dimeric diol constituting the alkylene group of ^R1 can be obtained by dimerizing an unsaturated fatty acid having 18 to 22 carbon atoms and then reducing the resulting cyclic or acyclic dimeric acid.
Here, "cyclic dimeric acid" refers to a dimeric acid that has a cyclic structure, and "acyclic dimeric acid" refers to a dimeric acid that does not have a cyclic structure.
Examples of unsaturated fatty acids with 18 to 22 carbon atoms include oleic acid, elaidic acid, vaccenic acid, linoleic acid, linolenic acid, gamma-linolenic acid, pinolenic acid, eleostearic acid, beta-eleostearic acid, stearidonic acid, gadoleic acid, eicosenoic acid, eicosadienoic acid, meadic acid, dihomo-gamma-linolenic acid, eicosatrienoic acid, arachidonic acid, eicosatetraenoic acid, erucic acid, docosadenoic acid, and adrenaline. Among these, oleic acid, linoleic acid, linolenic acid, eicosenoic acid, and erucic acid are preferred due to their availability.

Examples of branched dimeric diols obtained by reducing acyclic dimeric acids include compounds represented by the following structural formulas.

Examples of cyclic dimeric diols obtained by reducing cyclic dimeric acids include compounds represented by the following structural formulas.

In formula (1), ^R1 is preferably a divalent hydrocarbon group represented by the following formula (7).
-(CH ₂ ) _s -Y-(CH ₂ ) _t - (7)
In equation (7), Y, s, and t are the same as those described above.

In formula (1), ^R2 represents an alkylene group having 2 to 18 carbon atoms. ^R2 is preferably an alkylene group having 6 to 16 carbon atoms, more preferably an alkylene group having 8 to 14 carbon atoms, and even more preferably an alkylene group having 8 to 12 carbon atoms.
Examples of ^R2 include 1,6-hexylene group (-( _CH2 ) _6- ), 1,7-heptylene group (-( _CH2 ) _7- ), 1,8-octylene group (-( _CH2 ) _8- ), 1,9-nonylene group (-( _CH2 ) _9- ), 1,10-decylene group (-( _CH2 ) _10- ), undecylene group (-( _CH2 ) _11- ), dodecylene group (-( _CH2 ) _12- ), octadecylene (-( _CH2 ) _18- ), etc., with 1,10-decylene group being preferred.

The degree of polymerization (i.e., n+m) of compound (A) is preferably 1 to 15, more preferably 1.1 to 13, even more preferably 1.2 to 12, and particularly preferably 1.3 to 11.
When the degree of polymerization of compound (A) is above the lower limit, it is easier to obtain the effect of increased molecular entanglement required for the soft segment of the elastomer.
If the degree of polymerization of compound (A) is below the above upper limit, its crystallinity will be reduced, and it will be able to be made flexible.
In this specification, the degree of polymerization is a value calculated using nuclear magnetic resonance spectroscopy from the integral intensity ratio of the methylene chain bonded to the terminal hydroxyl group and the methylene chain bonded to the ether group.

The number-average molecular weight of compound (A) on a standard polystyrene molecular weight basis (hereinafter also referred to as "number-average molecular weight (1)") is preferably 300 to 5,000, more preferably 500 to 3,000, even more preferably 700 to 2,500, and particularly preferably 800 to 2,300.
When the number-average molecular weight (1) of compound (A) is greater than or equal to the lower limit, the effect of increased molecular entanglement required for the soft segment of the elastomer is more easily obtained.
When the number-average molecular weight (1) of compound (A) is below the above upper limit, the crystallinity decreases, and the effect of providing flexibility is easily obtained.
In this specification, the number-average molecular weight (1) is the value calculated from the polystyrene calibration curve using GPC.

The mass-average molecular weight of compound (A) is preferably 300 to 25,000, more preferably 500 to 12,000, even more preferably 700 to 6,900, and particularly preferably 800 to 4,600.
When the mass-average molecular weight of compound (A) is above the above lower limit, the effect of increased molecular entanglement required for the soft segment of the elastomer is more easily obtained.
When the mass-average molecular weight of compound (A) is below the above upper limit, the crystallinity decreases, and the effect of providing flexibility is easily obtained.
In this specification, the mass-average molecular weight is the value calculated from the polystyrene calibration curve using GPC.

The molecular weight distribution of compound (A) is preferably 1.0 to 5.0, more preferably 1.0 to 4.0, even more preferably 1.1 to 3.0, and particularly preferably 1.1 to 2.0.
When the molecular weight distribution of compound (A) is below the above upper limit, it is easier to obtain the effect of stabilizing the quality when polymerizing the polyalkylene ether glycol as a monomer.
In this specification, the molecular weight distribution is expressed as [mass-average molecular weight] / [number-average molecular weight (1)], and is a value calculated from the mass-average molecular weight and number-average molecular weight (1) obtained using GPC.

The terminal olefinization rate of compound (A) is preferably 10.0 mol% or less, more preferably 5.0 mol% or less, even more preferably 2.0 mol% or less, and particularly preferably 1.0 mol% or less.
When the terminal olefinization rate of compound (A) is below the above upper limit, it is easier to obtain the effect of improving the degree of polymerization of the polymer when polymerizing the polyalkylene ether glycol as a monomer. In this specification, the terminal olefinization rate can be calculated using ^1H -NMR by the method described in the examples.

The terminal esterification rate of compound (A) is preferably 2.0 mol% or less, more preferably 1.5 mol% or less, even more preferably 1.0 mol% or less, and particularly preferably 0.8 mol% or less.
When the terminal esterification rate of compound (A) is below the above upper limit, it is easier to obtain the effect of improving the degree of polymerization of the polymer when polymerizing the polyalkylene ether glycol as a monomer.
In this specification, the terminal esterification rate can be calculated using ^1H -NMR by the method described in the examples.

The hydroxyl value of compound (A) is preferably 20 to 400, more preferably 35 to 220, even more preferably 40 to 160, and particularly preferably 50 to 150.
If the hydroxyl value of compound (A) is above the lower limit, its crystallinity will decrease, and it will be able to be made flexible.
When the hydroxyl value of compound (A) is below the above upper limit, the effect of increased molecular entanglement required for the soft segment of the elastomer is more easily obtained.
In this specification, the hydroxyl value can be measured by the method described in the examples.

The number-average molecular weight (hereinafter also referred to as "number-average molecular weight (2)") calculated from the hydroxyl value of compound (A) is preferably 300 to 5,000, more preferably 500 to 3,000, even more preferably 700 to 2,500, and particularly preferably 750 to 2,000.
When the number-average molecular weight (2) of compound (A) is greater than or equal to the lower limit, the effect of increased molecular entanglement required for the soft segment of the elastomer is more easily obtained.
When the number-average molecular weight (2) of compound (A) is below the above upper limit, the crystallinity decreases, and the effect of providing flexibility is easily obtained.
In this specification, the number-average molecular weight (2) can be calculated from the hydroxyl value by the method described in the examples.

The 5% weight loss temperature of compound (A) is preferably 250 to 500°C, more preferably 270 to 450°C, even more preferably 280 to 400°C, and particularly preferably 300 to 380°C.
If the 5% weight loss temperature of compound (A) is above the lower limit, it is easier to obtain the effect of increased heat resistance.
In this specification, the 5% weight loss temperature can be measured by the method described in the examples.

(Method for producing polyalkylene ether glycol)
The method for producing polyalkylene ether glycol according to the present invention is not particularly limited, but it can be produced by dehydrating and condensing the glycol component using an acid catalyst.

<Glycol component>
The glycol component includes dimeric diols containing 36 to 44 carbon atoms, which are normally present in alcohols obtained by reducing cyclic and acyclic dimeric acids obtained by dimerizing unsaturated fatty acids.
Examples of dimeric diols include compounds represented by the following formula (2).
HO-(CH ₂ ) _s -Y-(CH ₂ ) _t -OH...(2)
In equation (2), Y, s, and t are the same as those described above.

The glycol component may further contain a diol having an alkylene group with 2 to 18 carbon atoms.
Examples of diols having an alkylene group with 2 to 18 carbon atoms include 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,4-cyclohexanedimethanol, 1,9-nonanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,16-hexadecanediol, 1,17-heptadecanediol, and 1,18-octadecanediol. Among the above, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, and 1,18-octadecanediol are preferred from the viewpoint of thermal stability and melting point when polymerized, and 1,10-decanediol is the most preferred from the viewpoint of price and ease of availability.

The proportion of dimerized diols in the glycol components is preferably 10 to 100 mol%, more preferably 20 to 100 mol%, and even more preferably 25 to 100 mol%, relative to the total number of moles of glycol components.
When the glycol component contains a diol having an alkylene group with 2 to 18 carbon atoms, the proportion of the dimerized diol is preferably 10 to 99 mol%, more preferably 20 to 95 mol%, and even more preferably 25 to 90 mol%.
When the proportion of dimerized diols is above the lower limit mentioned above, it is easier to obtain the effect of increased heat resistance.
When the proportion of dimerized diols is below the above upper limit, the effect of improving the melting point is more likely to be obtained.

When the glycol component contains a diol having an alkylene group having 2 to 18 carbon atoms, the proportion of the diol having an alkylene group having 2 to 18 carbon atoms is preferably 1 to 90 mol%, more preferably 5 to 80 mol%, and even more preferably 10 to 75 mol%, relative to the total number of moles of the glycol component.
When the proportion of diols having alkylene groups with 2 to 18 carbon atoms is above the above lower limit, it is easier to obtain the effect of improving the melting point.
When the proportion of diols having alkylene groups with 2 to 18 carbon atoms is below the above upper limit, it is easier to obtain the effect of increased heat resistance.

Dehydration condensation reactions are preferably carried out under an inert gas atmosphere such as nitrogen or argon. The reaction pressure can be arbitrary as long as the reaction system remains in the liquid phase; atmospheric pressure is usually used. If desired, the reaction may be carried out under reduced pressure or an inert gas may be circulated through the reaction system to promote the desorption of water produced by the reaction.

The reaction temperature is typically 80 to 250°C, preferably 100 to 200°C, and more preferably 120 to 180°C. If the reaction temperature is too high, the raw materials may volatilize, the amount of terminal unsaturated groups may increase, and the polymer may become more prone to discoloration. If the temperature is too low, a sufficient reaction rate may not be obtained.

The reaction time varies depending on the amount of catalyst used, the reaction temperature, and the yield and properties of the resulting polymer, but is usually 0.5 to 50 hours, preferably 1 to 20 hours. The reaction is usually carried out without a solvent, but a solvent can be used if desired. The solvent can be appropriately selected from organic solvents commonly used in organic synthesis reactions. Examples include ethers such as tetrahydrofuran, diethyl ether, and dibutyl ether; hydrocarbons such as decane, toluene, and xylene; and amides such as N,N-dimethylformamide and N,N-dimethylacetamide.

As a dehydration condensation catalyst (also called a polycondensation catalyst), it is sufficient that polyalkylene ether glycol can be produced by the dehydration condensation reaction of alkylenediol, and acid catalysts are usually used. Examples of acid catalysts include mineral acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and boric acid; heteropoly acids such as phosphomolybdic acid, silicic acid, phosphotungstic acid, and silicatungstic acid; solid catalysts such as zeolites, montmorillonite, cation exchange resins, sulfuric acid trace metal oxides, and metal-organic frameworks (MOFs); carboxylic acids such as formic acid, acetic acid, and trifluoroacetic acid; sulfonic acids such as methanesulfonic acid, trifluoromethanesulfonic acid, nonafluorobutanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, and 10-camphorsulfonic acid; and Lewis acids such as scandium trifluoromethanesulfonate and zinc trifluoromethanesulfonate. Preferably, the acid is one having a sulfone group, from the viewpoint of acid strength and corrosiveness, such as sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, or 10-camphorsulfonic acid. More preferably, from the viewpoint of cost, sulfuric acid or p-toluenesulfonic acid is preferred.

When using an acid containing a sulfone group ( _-SO₃H ) in the dehydration condensation reaction, the amount used varies depending on the type of catalyst, but is usually 1 to 20 parts by weight, preferably 1 to 10 parts by weight, and more preferably 1 to 5 parts by weight, per 100 parts by weight of glycol component.

As the acid catalyst, it is preferable to use an aqueous solution of the acid catalyst. The concentration of the acid in the aqueous solution of the acid catalyst is preferably 90% by weight or less, more preferably 1 to 80% by weight, and even more preferably 5 to 70% by weight, based on the total weight of the aqueous solution of the acid catalyst.
When the acid concentration in the acid catalyst aqueous solution is above the lower limit mentioned above, the dehydration condensation reaction proceeds more easily.
If the acid concentration in the acid catalyst aqueous solution is below the above upper limit, discoloration during acid addition is easily reduced.
<Hydrolysis>

Polyalkylene ether glycols obtained by carrying out a dehydration condensation reaction in the presence of a polycondensation catalyst such as an acid catalyst usually have ester groups at some of their terminal ends. Therefore, hydrolysis in an acidic or basic aqueous solution can convert these terminal ester groups back to hydroxyl groups.
The hydrolysis temperature is higher than 60°C and 200°C or lower, preferably 80°C to 180°C, and more preferably 100°C to 160°C. If the temperature is too high, there is a concern that parts other than the polymer ends will decompose, and if it is too low, a sufficient reaction rate tends not to be obtained.
When the reaction temperature is within the above range, it is preferable to carry out the reaction under reflux or in a closed reactor such as an autoclave.
The reaction time varies depending on the concentration of the acid or base, the reaction temperature, the amount of terminal ester groups in the polyalkylene ether glycol, etc., but is usually 1 to 50 hours, preferably 2 to 30 hours, and more preferably 3 to 20 hours.
Polyalkylene ether glycols obtained by carrying out a dehydration condensation reaction in the presence of superacids such as trifluoromethanesulfonic acid and nonafluorobutanesulfonic acid as polycondensation catalysts usually do not produce ester groups at the ends, thus allowing the hydrolysis step to be omitted.

Water is typically used as the reaction solvent, but organic solvents can also be used if desired. The organic solvent can be appropriately selected from those commonly used in organic synthesis reactions. In addition to the organic solvents mentioned above, alcohols such as isopropanol and butanol can also be used. The amount of water added during hydrolysis varies depending on the concentration of the acid or base, but is typically 0.1 to 200 parts by weight, preferably 0.5 to 150 parts by weight, and more preferably 2 to 100 parts by weight, per 100 parts by weight of polyalkylene ether glycol. Too little water may increase the amount of terminally unsaturated groups, while too much water is undesirable as it requires a larger reactor.

As described above, the hydrolysis reaction is carried out under acidic or basic aqueous solution. The acid catalyst used in the dehydration condensation may be used as is, or a new acid or base may be added. Suitable acids include, for example, mineral acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and boric acid; carboxylic acids such as formic acid, acetic acid, and trifluoroacetic acid; and sulfonic acids such as methanesulfonic acid, trifluoromethanesulfonic acid, nonafluorobutanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, naphthalenesulfonic acid, and 10-camphorsulfonic acid. Suitable bases include alkali metal or alkaline earth metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and calcium hydroxide; carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, calcium carbonate, and cesium carbonate; and bicarbonates such as lithium bicarbonate, sodium bicarbonate, and potassium bicarbonate. However, alkali metal hydroxides are preferred, and sodium hydroxide and potassium hydroxide are even more preferred from the viewpoint of water solubility.
The amount of acid or base in the hydrolysis reaction varies depending on the amount and type of acid in the dehydration condensation reaction, but it is usually 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of water added.

<Oil/water separation process>
The manufacturing method of the present invention preferably includes an oil-water separation step after the hydrolysis reaction in order to reduce the amount of acid, base, and salt contained in the reaction solution. The oil-water separation step is a step of separating the polyalkylene ether glycol layer from the aqueous layer containing acid, base, and salt. However, if the number of hydroxyl groups of the polyalkylene ether glycol obtained after the dehydration condensation reaction is 1.970 to 1.999, the oil-water separation may be performed after the dehydration condensation reaction without going through the hydrolysis reaction.

The temperature of the oil-water separation process is preferably above the melting point of the polyalkylene ether glycol. While this varies depending on the number of carbon atoms in the alkylene chain of the polyalkylene ether glycol and the molecular weight of the polyalkylene ether glycol being produced, for example, if polydecamethylene ether glycol has a melting point of 75-80°C and a number-average molecular weight of 1000, the temperature of the oil-water separation process is preferably 80°C or higher. Normally, organic solvents are not used, but if the polyalkylene ether glycol has high viscosity and the phase separation operation is poor, an organic solvent may be used. When using an organic solvent, the temperature is usually 20°C or higher, more preferably 40°C or higher, depending on the type of organic solvent, the concentration and molecular weight of the polyalkylene ether glycol, etc. If the temperature is too low, the polyalkylene ether glycol tends to precipitate, making oil-water separation difficult.
The separation time in the oil-water separation process is not particularly limited, but is usually 0.01 to 10 hours, preferably 0.2 to 7 hours, and more preferably 0.5 to 5 hours. If the separation time is too short, the separation of the oil layer and the water layer tends to be poor, and if the separation time is too long, productivity tends to decrease.
If acids, bases, salts, etc. remain in the polymer layer obtained by stratification, the remaining impurities are removed by repeatedly adding water and separating the oil and water.

[Application]
The polyalkylene ether glycol of the present invention can be used as a raw material for polyesters, polycarbonates, and polyurethane resins, etc.
As a method for producing polyester using the polyalkylene ether glycol of the present invention as a raw material, conventional polyester production methods can be employed. For example, as examples of methods for producing polyether ester copolymers, there are methods such as transesterifying an aromatic dicarboxylic acid diester compound, an excess amount of aliphatic and/or alicyclic diol and the polyalkylene ether glycol of the present invention in the presence of a catalyst, and then polycondensing the resulting reaction product under reduced pressure; esterifying an aromatic dicarboxylic acid, an aliphatic and/or alicyclic diol and the polyalkylene ether glycol of the present invention in the presence of a catalyst, and then polycondensing the resulting reaction product under reduced pressure; and preparing a short-chain polyester (e.g., polybutylene terephthalate) in advance, and then adding another aromatic dicarboxylic acid and the polyalkylene ether glycol of the present invention to it and polycondensing.

The method for producing polycarbonate using the polyalkylene ether glycol of the present invention as a raw material can employ conventional polycarbonate production methods. For example, one example of a method for producing a polyether carbonate copolymer is a method of polycondensation of a diester carbonate compound, an aliphatic and/or alicyclic diol, and the polyalkylene ether glycol of the present invention by transesterification in the presence of a catalyst. Suitable diester carbonates include dialkyl carbonates, diaryl carbonates, or alkylene carbonates, and can be obtained by removing monohydroxy compounds or dihydroxy compounds, etc., produced as by-products in the transesterification reaction along with the polycondensation. The step of polycondensing the diester carbonate compound, an aliphatic and/or alicyclic diol, and the polyalkylene ether glycol of the present invention by transesterification in the presence of a catalyst may be carried out in multiple stages using multiple reactors, and the reaction can be in batch, continuous, or a combination of batch and continuous reactions.

Furthermore, as a method for producing polyurethane resin using polyalkylene ether glycol as a raw material according to the present invention, for example, the polyisocyanate component and the diol component can be reacted in a single step, or a prepolymer can be prepared by reacting the polyisocyanate component and the diol component beforehand, and then the polyisocyanate component or an active hydrogen compound component (polyhydric alcohol, amine compound, etc.) can be added to it and reacted. The reaction may be carried out in bulk state without the use of solvents, and the reaction format may be either batch or continuous.

In the resin obtained using the polyalkylene ether glycol of the present invention as a raw material, the content of the constituent units derived from the polyalkylene ether glycol of the present invention is preferably 10 to 90% by weight, more preferably 20 to 85% by weight, and even more preferably 30 to 80% by weight, based on the total weight of the resin.
When the content of constituent units derived from polyalkylene ether glycol is within the above range, it is easy to obtain a resin with excellent heat resistance and a good balance between flexibility and melting point.

The 5% weight loss temperature of the resin obtained using the polyalkylene ether glycol of the present invention as a raw material is preferably 380°C or higher, more preferably 385°C or higher, and even more preferably 390°C or higher.
If the 5% weight loss temperature falls within the above range, it is easier to obtain a resin with excellent heat resistance.

The reduced viscosity (ηsp/C) of the resin obtained using the polyalkylene ether glycol of the present invention as a raw material is preferably 0.48 dL/g or higher, more preferably 0.5 dL/g or higher, even more preferably 0.6 dL/g or higher, particularly preferably 0.7 dL/g or higher, and most preferably 0.8 dL/g or higher. The upper limit of the reduced viscosity is 3.0 dL/g or lower, preferably 2.5 dL/g or lower, and most preferably 2.0 dL/g or lower. If the reduced viscosity is less than 0.48 dL/g, it may not be possible to mold films or injection-molded products, and even if molding is possible, the strength may be insufficient and the product may not be suitable for use. Furthermore, if the reduced viscosity is greater than 3.0 dL/g, molding becomes difficult and is undesirable.
In this invention, the reduced viscosity of the resin (ηsp/C) was determined from the solution viscosity measured at 30°C in a phenol/tetrachloroethane (1:1 weight ratio) solution with a resin concentration of 0.5 g/dL.

The melting point (Tm1 in later examples) of the resin obtained using the polyalkylene ether glycol of the present invention as a raw material is preferably -10 to 100°C, more preferably -5 to 95°C, and even more preferably 0 to 90°C.
If the melting point is within the above range, it offers excellent handling properties.

The heat of fusion of the soft segment of the resin obtained using the polyalkylene ether glycol of the present invention as a raw material (corresponding to ΔHm1 in later examples) is typically around 0 to 50 J/g. A smaller value indicates superior flexibility of the soft segment component, which is preferable. Furthermore, the heat of fusion of the resin of the present invention (corresponding to ΔHm2 in later examples) is typically around 0 to 40 J/g. A smaller value indicates lower crystallinity of the hard segment and improved flexibility, which is preferable.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples and can be modified and implemented as desired without departing from the spirit of the invention. Examples 1, 6 and 7 are for reference only. The data in the examples and comparative examples were measured by the following method.

< ^1H -NMR analysis>
Deuterated chloroform was used as the solvent, and ^1H -NMR was measured using a JEOL Ltd. "ECZ-400" at a resonance frequency of 400 MHz, a flip angle of 45°, and a measurement temperature of room temperature.

<Measurement of number-average molecular weight (1), mass-average molecular weight, and molecular weight distribution>
Using GPC (Gel Permeation Chromatography), the number-average molecular weight (1), mass-average molecular weight, and molecular weight distribution were calculated from the calibration curve of polystyrene.
The GPC measurement conditions were as follows:
Columns: TSKgel GMHHR-N (Tosoh, 7.8mm, 300mm, 9mm) 2 pieces. Column oven temperature: 40℃
Mobile phase: THF 1mL/min
Analysis time: 30min
Detection: RI detector; Sample: 20-50 μL injection; Calibration method: Polystyrene equivalent; Calibration curve approximation formula: Cubic equation

<Calculation methods for the number of hydroxyl groups, terminal esterification rate, terminal olefination rate, degree of polymerization, and dimer diol content>
The terminal hydroxyl groups of polyalkylene ether glycols react with added acid to form esters, and also undergo intramolecular dehydration to form unsaturated groups. As a result, in ^1H -NMR analysis, signals originating from methylene groups bonded with primary hydroxyl groups are observed around 3.6 ppm, signals originating from methylene groups bonded with ester groups are observed around 4.0 ppm, and signals originating from terminal unsaturated groups ( _CH₂ =CH-) are observed in multiple concentrations around 5.0–6.0 ppm (solvent: deuterated chloroform). Signals originating from methylene groups bonded with ether groups generated by the desired dehydration condensation reaction are observed around 3.4 ppm.
The number of hydroxyl groups, terminal olefinization rate, and terminal esterification rate were calculated using the following formulas.
Number of hydroxyl groups = [(A/2)/(A/2+B/2+C/3)]×2
Terminal esterification rate = [(B/2)/(A/2 + B/2 + C/3)] × 100
End-olefinization rate = [(C/3)/(A/2 + B/2 + C/3)] × 100
Degree of polymerization=D/A+1
1,10-decanediol and dimer diol copolymer polyalkylene ether glycol dimer diol content = [(E/6)/(A/4+D/4)] × 100
(However, in the formula, A is the integral value of the signal originating from the methylene group bonded to a primary hydroxyl group at around 3.6 ppm; B is the integral value of the signal originating from the methylene group bonded to an ester group at around 4.0 ppm; C is the integral value of the signal originating from the terminal unsaturated group (CH2=CH-) at around 5.0–6.0 ppm; D is the integral value of the signal originating from the methylene group bonded to an ether group at around 3.4 ppm; and E is the integral value of the signal originating from the terminal methyl group of the dimerized diol at around 0.88 ppm.)
For polyalkylene ether glycols containing dimeric diols, the carbon (C) was corrected for the amount of olefin contained in the raw materials using the following formula.
C = C' - Cp/Ap × (A + D) × (Dimer diol content in 1,10-decanediol and dimer diol copolymerized polyalkylene ether glycol)
(However, C' is the integral value of the signal originating from the terminal unsaturated group ( _CH₂ =CH-) around 5.0–6.0 ppm in the product, Cp is the integral value of the signal originating from the terminal unsaturated group ( _CH₂ =CH-) around 5.0–6.0 ppm in the starting material dimer diol, and Ap is the integral value of the signal originating from the methylene group to which the primary hydroxyl group is attached around 3.6 ppm in the starting material dimer diol.)

<Toluene concentration measurement>
The signal was calculated from the integrated value of the methyl group-derived signal observed around 2.36 ppm using ^¹H -NMR analysis with deuterated chloroform as the solvent (with 1,1,2,2-tetrachloroethane as the internal standard).

<Moisture concentration measurement>
The moisture content was measured using a Karl Fischer moisture analyzer (CA-200, manufactured by Mitsubishi Chemical Analytec Co., Ltd.) with Aquamicron® AKX and Aquamicron® CXU (both manufactured by Mitsubishi Chemical Corporation) by coulometric titration.

<Method for measuring hydroxyl value and calculating number-average molecular weight>
The hydroxyl value of the polyalkylene ether glycol composition was measured using an automatic titrator (GT-200, manufactured by Mitsubishi Chemical Analytec Co., Ltd.) in accordance with ASTM E-1899-16.
The number-average molecular weight (Mn) was determined from the measured hydroxyl value using the following formula (I).
Number-average molecular weight = 2 × 56.1 / (hydroxyl value × ^10⁻³ ) …(I)

<Measuring the temperature at which TG-DTA loses 5% weight>
Using the Hitachi High-Tech Science STA200RV differential thermogravimetric analyzer, approximately 7 mg of sample was placed in an aluminum container, and its mass was measured from 30°C to 500°C at a heating rate of 10°C/min under a nitrogen atmosphere (nitrogen flow rate of 200 ml/min). The temperature at which a 5% weight loss occurred was defined as the 5% weight loss temperature (unit: °C). The 5% weight loss temperature is an indicator of heat resistance; a higher value indicates higher heat resistance.

<Yellowness (YI)>
Using a spectrophotometer (model: U4100, manufactured by Hitachi High-Technologies Corporation), the yellowness of test specimens (thickness: 4 mm) was measured using a C light source in accordance with ISO 17223. Three test specimens were used, and one measurement was taken for each specimen. The average value was defined as the yellowness (YI).

<Measurement of the number of colors>
The color number of dimerized diols and polyalkylene ether glycol compositions was measured using a cross-illumination photometric colorimeter (ZE-2000, manufactured by Nippon Denshoku Industries Co., Ltd.). The color number was measured as an APHA value (platinum-cobalt system) according to the American Society for Testing and Materials (ASTM) D-1209. Hazen colorimetric stock solution (No. 500), manufactured by Hayashi Pure Chemical Industries, Ltd., was used as the APHA 500 standard solution.

<Measurement of melting point 1, ΔHm1, melting point 2, and ΔHm2 using DSC>
The melting point (Tm, in °C) was measured using a differential scanning calorimeter "DSC7000x" manufactured by Hitachi High-Tech Science. The heating rate was set to 10 °C/min. The lower of the two maximum peaks was defined as Tm1 (melting point derived from the soft segment), and the higher peak as Tm2 (melting point of the polymer). The respective peak areas were defined as the heat of fusion ΔHm1 and ΔHm2 (mJ/mg). A smaller value of ΔHm indicates lower crystallinity.

<Measurement of reduced viscosity (ηsp/C)>
The reduced viscosity (ηsp/C) was determined from the solution viscosity measured at 30°C for a solution of the polyester resin obtained in the production example and comparative production example, prepared in phenol/1,1,2,2-tetrachloroethane (1:1 weight ratio) at a concentration of 0.5 g/dl.

<Measurement of tensile modulus, breaking strength, and elongation at break by tensile testing>
Using the polyester resin obtained in the production example and comparative production example, a press film with a thickness of 200 μm was prepared by hot pressing at 240°C using a tabletop hot press machine. Samples were punched out from the obtained press film into a dumbbell shape, and tensile tests were performed according to JIS K7127 to measure the tensile modulus, breaking strength, and elongation at breaking.

<Materials for the synthesis of polyalkylene ether glycol>
• Dimerized diol: Croda Japan Co., Ltd. Product name "Pripol 2033"
- 1,10-decanediol: Tokyo Chemical Industries, Ltd. or Toyokuni Oil Co., Ltd. - Trifluoromethanesulfonic acid: Tokyo Chemical Industries, Ltd. - p-toluenesulfonic acid monohydrate: Fujifilm Wako Pure Chemical Corporation

[Example 1]
<Example of manufacturing dimerized diol oligomer Mn1000>
535.3 g (0.998 mol) of dimerized diol (Prepol 2033, manufactured by Croda Japan Co., Ltd.) was placed in a four-necked flask equipped with a distillation tube, nitrogen inlet tube, thermocouple, and stirrer. The flask was heated to 50°C in an oil bath, and then the reactor was degassed under reduced pressure and purged with nitrogen. While supplying nitrogen at 0.20 NL/min, 2.69 g (17.9 mmol) of trifluoromethanesulfonic acid was slowly added while maintaining the temperature at 50°C. The flask was immersed in an oil bath and heated until the liquid temperature inside the flask reached 150°C in about 0.5-1 hours. The reaction started when the liquid temperature inside the flask reached 150°C, and thereafter the temperature was maintained at 148-152°C for 2.5 hours. The water produced by the reaction was removed by distillation accompanied by nitrogen.
The reaction mixture was allowed to cool to around 120°C, and 150 g of deionized water was added. The mixture was stirred at 90°C for approximately 10 to 30 minutes, then allowed to stand for 10 minutes to 2 hours to confirm separation into an oil layer and an aqueous layer, after which the aqueous layer was removed. The conductivity of the aqueous layer was measured, and the addition of deionized water and oil-water separation were repeated a total of seven times until the conductivity reached 0 to 10 μS/cm. After removing the oil layer, 100 mL of toluene was added, and azeotropic dehydration was performed by distilling off the toluene under reduced pressure at 60°C and 180 torr. Subsequently, 100 mL of toluene was added, and toluene was distilled off under reduced pressure at 70°C and 70 torr. The water content was measured, and azeotropic dehydration was repeated a total of five times until the water concentration reached 300 ppm or less. The oil bath was heated to 100°C, and defoliation was performed under reduced pressure for 4 hours using an oil rotary vacuum pump until the toluene concentration reached 0.1% by weight or less, to obtain the target polyalkylene ether glycol.
The degree of polymerization determined by NMR was 1.43, the terminal olefinization rate was 0.69 mol%, and the terminal esterification rate was below the NMR detection limit. The number-average molecular weight determined by GPC was 967, the mass-average molecular weight was 1268, and the molecular weight distribution was 1.31. The hydroxyl value was 145.7, and the number-average molecular weight calculated from this was 770. The APHA value determined by colorimeter was 59. The 5% weight loss temperature was 313.3°C.

[Example 2]
<Example of manufacturing 110-decanediol/Pripol 2033 (75/25) Mn1000>
128 g (0.736 mol) of 1,10-decanediol and 132 g (0.245 mol) of the dimerized diol (Prepol 2033, manufactured by Croda Japan Co., Ltd.) were placed in a four-necked flask equipped with a distillation tube, nitrogen inlet tube, thermocouple, and stirrer. After heating and melting in an oil bath, the reactor was degassed under reduced pressure and purged with nitrogen. The flask was immersed in the oil bath and heated while supplying nitrogen at 0.20 NL/min. When the temperature exceeded 160°C, 5.73 g (30.1 mmol) of p-toluenesulfonic acid monohydrate was slowly added. The reaction was started when the temperature of the liquid in the flask reached 170°C, and thereafter the temperature was maintained at 170-171°C for 13 hours. The water produced by the reaction was removed by distillation accompanied by nitrogen. 37 g of 10% by weight aqueous sodium hydroxide solution was added to the reaction mixture, which had been allowed to cool to around 90°C, and the mixture was heated under reflux at 110°C for 15 hours to hydrolyze the ester.
The reaction mixture was heated to approximately 90°C, and 500g of deionized water was added. The mixture was stirred at 90°C for about 15-30 minutes, then allowed to stand for 1-2 hours to confirm separation into an oil layer and an aqueous layer, after which the aqueous layer was removed. The conductivity of the aqueous layer was measured, and the addition of deionized water and oil-water separation were repeated a total of eight times until the conductivity reached 0-10 μS/cm. After removing the oil layer, 100 mL of toluene was added, and azeotropic dehydration was performed by distilling off the toluene under reduced pressure at 100°C and 20 torr. The water content was measured, and azeotropic dehydration was repeated a total of five times until the water concentration reached 300 ppm or less. The oil bath was heated to 120°C, and defoliation was performed under reduced pressure for 1 hour using an oil rotary vacuum pump until the toluene concentration reached 0.1% by weight or less, to obtain the target polyalkylene ether glycol.
The degree of polymerization determined by NMR was 3.71, the dimer diol content in the polyalkylene ether glycol was 26.6 mol%, the terminal olefinization rate was 0.67 mol%, and the terminal esterification rate was below the NMR detection limit. The number-average molecular weight determined by GPC was 956, the mass-average molecular weight was 2001, and the molecular weight distribution was 2.09. The hydroxyl value was 121.0, and the number-average molecular weight calculated from this was 927. The 5% weight loss temperature was 284.9°C.

[Example 3]
<110-decanediol/Pripol 2033 (75/25) Mn2000 manufacturing example>
247 g (1.415 mol) of 1,10-decanediol and 253 g (0.472 mol) of the dimerized diol (Prepol 2033, manufactured by Croda Japan Co., Ltd.) were placed in a four-necked flask equipped with a distillation tube, nitrogen inlet tube, thermocouple, and stirrer. After heating and melting in an oil bath, the reactor was degassed under reduced pressure and purged with nitrogen. The flask was immersed in the oil bath and heated while supplying nitrogen at 0.20 NL/min. When the temperature exceeded 100°C, a mixture of 5.01 g (33.4 mmol) of trifluoromethanesulfonic acid and 2.50 g of deionized water was slowly added. The flask was immersed in the oil bath and heated until the temperature inside the flask reached 150°C in about 0.5 hours. The reaction started when the temperature inside the flask reached 150°C, and thereafter the temperature was maintained at 149-151°C for 8.75 hours. The water produced by the reaction was removed by distillation, accompanied by nitrogen.
The reaction mixture was allowed to cool to around 120°C, and 300g of deionized water was added. The mixture was stirred at 90°C for approximately 10-30 minutes, then allowed to stand for 10 minutes to 2 hours to confirm separation into an oil layer and an aqueous layer, after which the aqueous layer was removed. The conductivity of the aqueous layer was measured, and the addition of deionized water and oil-water separation were repeated a total of 29 times until the conductivity reached 0-10 μS/cm. After removing the oil layer, 300 mL of toluene was added, and azeotropic dehydration was performed by distilling off the toluene under reduced pressure at 100°C and 20 torr. Next, 100 mL of toluene was added, the water content was measured, and azeotropic dehydration was repeated a total of four times until the water concentration reached 300 ppm or less. The oil bath was heated to 120°C, and defoliation was performed under reduced pressure for 2 hours using an oil rotary vacuum pump until the toluene concentration reached 0.1% by weight or less, to obtain the target polyalkylene ether glycol.
The degree of polymerization determined by NMR was 8.68, the dimer diol content in the polyalkylene ether glycol was 25.2 mol%, the terminal olefinization rate was 2.11 mol%, and the terminal esterification rate was below the NMR detection limit. The number-average molecular weight determined by GPC was 2441, the mass-average molecular weight was 5232, and the molecular weight distribution was 2.14. The hydroxyl value was 54.7, and the number-average molecular weight calculated from this was 2052. The 5% weight loss temperature was 371.6°C.

[Example 4]
<Example of manufacturing 110-decanediol/Pripol 2033 (90/10) Mn1000>
373 g (2.137 mol) of 1,10-decanediol and 128 g (0.237 mol) of the dimerized diol (Prepol 2033, manufactured by Croda Japan Co., Ltd.) were placed in a four-necked flask equipped with a distillation tube, nitrogen inlet tube, thermocouple, and stirrer. After heating and melting in an oil bath, the reactor was degassed under reduced pressure and purged with nitrogen. The flask was immersed in the oil bath and heated while supplying nitrogen at 1.0 NL/min. When the temperature exceeded 147°C, a mixture of 5.03 g (33.5 mmol) of trifluoromethanesulfonic acid and 2.51 g of deionized water was slowly added to initiate the reaction. Thereafter, the liquid temperature was maintained at 149-151°C and the reaction was carried out for 6 hours. After cooling to room temperature, the temperature was raised again and the reaction was carried out at 130°C for 15 minutes. The water produced by the reaction was removed by distillation accompanied by nitrogen.
The reaction mixture was allowed to cool to around 90°C, and 300g of deionized water was added. The mixture was stirred at 90°C for approximately 15-30 minutes, then allowed to stand for 0.5-1 hour to confirm separation into an oil layer and an aqueous layer, after which the aqueous layer was removed. The conductivity of the aqueous layer was measured, and the addition of deionized water and the separation of oil and water were repeated a total of eight times until the conductivity reached 0-10 μS/cm. After removing the oil layer, 300 mL of toluene was added, and azeotropic dehydration was performed by distilling off the toluene under reduced pressure at 100°C and 20 torr. Next, 200 mL of toluene was added, and azeotropic dehydration was performed at 100°C and 10 torr. From thereafter, 100 mL of toluene was added, the water content was measured, and azeotropic dehydration was repeated a total of five times until the water concentration reached 300 ppm or less. The oil bath was heated to 120°C, and defolation was carried out under reduced pressure using an oil rotary vacuum pump for 2 hours until the toluene concentration reached 0.1% by weight or less, thereby obtaining the target polyalkylene ether glycol.
The degree of polymerization determined by NMR was 4.88, the dimer diol content in the polyalkylene ether glycol was 10.2 mol%, the terminal olefinization rate was 0.93 mol%, and the terminal esterification rate was below the NMR detection limit. The number-average molecular weight determined by GPC was 969, the mass-average molecular weight was 2304, and the molecular weight distribution was 2.38. The hydroxyl value was 122.6, and the number-average molecular weight calculated from this was 915. The 5% weight loss temperature was 271.9°C.

[Example 5]
<110-decanediol/Pripol 2033 (90/10) Mn2000 manufacturing example>
373 g (2.138 mol) of 1,10-decanediol and 128 g (0.238 mol) of the dimerized diol (Prepol 2033, manufactured by Croda Japan Co., Ltd.) were placed in a four-necked flask equipped with a distillation tube, nitrogen inlet tube, thermocouple, and stirrer. After heating and melting in an oil bath, the reactor was degassed under reduced pressure and purged with nitrogen. The flask was immersed in the oil bath and heated while supplying nitrogen at 0.20 NL/min. When the temperature exceeded 100°C, a mixture of 5.03 g (33.5 mmol) of trifluoromethanesulfonic acid and 2.48 g of deionized water was slowly added. The flask was immersed in the oil bath and heated until the temperature inside the flask reached 150°C in about 0.5 hours. The reaction started when the temperature inside the flask reached 150°C, and thereafter the temperature was maintained at 149-151°C for 10.5 hours. The water produced by the reaction was removed by distillation, accompanied by nitrogen.
The reaction mixture was allowed to cool to around 120°C, and 300g of deionized water was added. The mixture was stirred at 90°C for approximately 10-30 minutes, then allowed to stand for 10 minutes to 2 hours to confirm separation into an oil layer and an aqueous layer, after which the aqueous layer was removed. The conductivity of the aqueous layer was measured, and the addition of deionized water and oil-water separation were repeated a total of 25 times until the conductivity reached 0-10 μS/cm. After removing the oil layer, 300 mL of toluene was added, and azeotropic dehydration was performed by distilling off the toluene under reduced pressure at 100°C and 20 torr. Next, 200 mL of toluene was added, and azeotropic dehydration was performed at 100°C and 20 torr. From thereafter, 100 mL of toluene was added, the water content was measured, and azeotropic dehydration was repeated a total of 5 times until the water concentration reached 300 ppm or less. The oil bath was heated to 120°C, and defolation was carried out under reduced pressure for 1.5 hours using an oil rotary vacuum pump until the toluene concentration reached 0.1% by weight or less, thereby obtaining the target polyalkylene ether glycol.
The degree of polymerization determined by NMR was 10.50, the dimer diol content in the polyalkylene ether glycol was 10.3 mol%, the terminal olefinization rate was 2.74 mol%, and the terminal esterification rate was below the NMR detection limit. The number average molecular weight determined by GPC was 2366, the mass average molecular weight was 5429, and the molecular weight distribution was 2.29. The hydroxyl value was 56.9, and the number average molecular weight calculated from this was 1970. The 5% weight loss temperature was 368.9°C.

[Comparative Example 1]
<PDMG Mn1000 production example>
Polymerization and Ester Decomposition Processes: 9.00 kg (5.16 mol) of 1,10-decanediol was charged into a four-necked flask equipped with a distillation tube, nitrogen inlet tube, thermocouple, and stirrer, while supplying nitrogen at a rate of 1.0 NL/min. 0.198 kg (1.04 mol) of p-toluenesulfonic acid monohydrate was slowly added while stirring. The flask was immersed in an oil bath and heated until the liquid temperature inside the flask reached 170°C in about 0.5–1 hour. The reaction began when the liquid temperature inside the flask reached 170°C, and the reaction was carried out for 18 hours while maintaining the liquid temperature at 168–172°C. The water produced by the reaction was removed by distillation accompanied by nitrogen. 0.90 kg of 10 wt% sodium hydroxide aqueous solution was added to the reaction solution, which had been allowed to cool to around 90°C, and the mixture was refluxed at 110°C for 20 hours to hydrolyze the ester.
- Washing and drying processes: The polymerization and ester decomposition processes were carried out in two batches. After cooling to around 90°C, the products from the two batches were mixed. 36 kg of deionized water heated to above 80°C was added. The mixture was stirred at 80°C for about 15 minutes, then allowed to stand for 1-2 hours to confirm separation into an oil layer and an aqueous layer. The aqueous layer was then removed. The conductivity of the aqueous layer was measured, and the addition of deionized water and the separation of oil and water were repeated a total of 10 times until the conductivity reached 0-10 μS/cm. After removing the oil layer, the target polydecamethylene ether glycol was obtained by drying under reduced pressure at 40°C.
The degree of polymerization determined by NMR was 5.51, the number-average molecular weight determined by GPC was 1210, the mass-average molecular weight was 2413, the molecular weight distribution was 1.99, the terminal olefinization rate determined by NMR was 0.68 mol%, and the terminal esterification rate was below the NMR detection limit. The hydroxyl value was 134.4, and the number-average molecular weight calculated from this was 835. The 5% weight loss temperature was 259.8°C.

[Comparative Example 2]
<PDMG Mn2000 manufacturing example>
450 g (2.58 mol) of 1,10-decanediol was charged into a four-necked flask equipped with a distillation tube, nitrogen inlet tube, thermocouple, and stirrer while supplying nitrogen at 0.2 NL/min. 9.07 g (60.4 mmol) of trifluoromethanesulfonic acid was slowly added while stirring. The flask was immersed in an oil bath and heated until the temperature inside the flask reached 150°C in about 0.5–1 hour. The reaction began when the temperature inside the flask reached 150°C, and the reaction was carried out for 7.5 hours while maintaining the temperature at 149–150°C. The water produced by the reaction was removed by distillation accompanied by nitrogen. 36 kg of deionized water heated to over 80°C was poured into the reaction mixture, which had been allowed to cool to around 90°C. The mixture was stirred at 80°C for about 15 minutes, then allowed to stand for 1–2 hours to confirm separation into an oil layer and an aqueous layer, after which the aqueous layer was removed. The conductivity of the aqueous layer was measured, and the addition of deionized water and the separation of oil and water were repeated 40 times until the conductivity reached 0–10 μS/cm. After removing the oil layer, the target polydecamethylene ether glycol was obtained by drying under reduced pressure at 40°C.
The degree of polymerization determined by NMR was 14.08, the number-average molecular weight determined by GPC was 2855, the mass-average molecular weight was 6231, the molecular weight distribution was 2.18, the terminal olefinization rate determined by NMR was 2.68 mol%, and the terminal esterification rate was below the NMR detection limit. The hydroxyl value was 55.9, and the number-average molecular weight calculated from this was 2009. The 5% weight loss temperature was 325.6°C.

The results obtained are shown in Table 1.
In Table 1, number-average molecular weight (1) is the number-average molecular weight obtained from GPC, and number-average molecular weight (2) is the number-average molecular weight converted from the hydroxyl value.

As shown in Table 1, the polyalkylene ether glycols of Examples 1 to 5 to which the present invention was applied exhibited excellent heat resistance and a high number of hydroxyl groups.
In formula (1), the polyalkylene ether glycol of Comparative Example 1, in which n/(n+m) is less than 0.1 and the number average molecular weight is 835, was inferior in heat resistance and hydroxyl value to Examples 1, 2, and 4, in which n/(n+m) is 0.1 or greater and the number average molecular weight is between 770 and 927.
In formula (1), the polyalkylene ether glycol of Comparative Example 2, in which n/(n+m) is less than 0.1 and the number average molecular weight is 2009, was inferior in heat resistance and hydroxyl group properties to Examples 3 and 5, in which n/(n+m) is less than 0.1 and the number average molecular weight is between 1970 and 2052.

[Example 6]
28.2 g (52.6 mmol) of dimerized diol (Prepol 2033, manufactured by Croda Japan Co., Ltd.) was placed in a 50 mL vial, and nitrogen was purged by bubbling. Then, while circulating nitrogen through the liquid, a mixture of 0.28 g (1.86 mmol, 1 wt% relative to the dimerized diol) of trifluoromethanesulfonic acid and 0.14 g of deionized water was slowly added. After stirring at room temperature under a nitrogen atmosphere for 1 hour, the yellowness (YI) and color number (APHA value) were measured.

[Example 7]
29.7 g (55.4 mmol) of dimerized diol (Prepol 2033, manufactured by Croda Japan Co., Ltd.) was placed in a 50 mL vial, and nitrogen was bubbled through the vial to purge it with nitrogen. Then, while circulating nitrogen through the liquid, a mixture of 0.27 g (1.80 mmol, 1 wt% relative to the dimerized diol) of trifluoromethanesulfonic acid and 0.06 g of deionized water was slowly added. The cap of this vial was closed, and the mixture was stirred in a sealed state for 1 hour. After stirring at room temperature under a nitrogen atmosphere for 1 hour, the yellowness (YI) and color number (APHA value) were measured.

[Comparative Example 3]
31.6 g (59.0 mmol) of dimerized diol (Prepol 2033, manufactured by Croda Japan Co., Ltd.) was placed in a 50 mL vial, and nitrogen was purged by bubbling. Then, while circulating nitrogen through the liquid, 0.32 g (2.15 mmol, 1 wt%) of trifluoromethanesulfonic acid was slowly added. After stirring at room temperature under a nitrogen atmosphere for 1 hour, the yellowness (YI) and color number (APHA value) were measured.

The yellowness (YI) and color number (APHA value) of the resulting reaction solution were measured. The results are shown in Table 2.

As shown in Table 2, in Examples 6 and 7, where the concentration of the acid catalyst aqueous solution was 90% by mass or less, discoloration during acid addition was suppressed.
Comparative Example 3, in which the concentration of the acid catalyst aqueous solution exceeded 90% by mass, failed to suppress the discoloration of the obtained polyalkylene ether glycol.

<Method for producing polyalkylene ether glycol copolymer polyester>
Polyester resins (terephthalic acid/butanediol/polyalkylene glycol copolymer polyesters) were produced using the polyalkylene ether glycols obtained in the examples and comparative examples as raw materials, and their physical properties were measured.

[Manufacturing Example 1]
<Example of manufacturing PBT-(1,10-decanediol/Pripol 2033 = 75/25 Mn = 1000) 70% by weight>
In a reaction vessel equipped with a stirrer, nitrogen inlet, heating device, thermometer, and vacuum port, the following raw materials were charged: 26.45 parts by weight of dimethyl terephthalic acid, 9.18 parts by weight of 1,4-butanediol, 70.00 parts by weight of polyalkylene ether glycol (1,10-decanediol) obtained in Example 2, and 0.71 parts by weight of a 1,4-butanediol solution in which 6.0% by weight of titanium tetrabutyrate was pre-dissolved.
While stirring the contents of the container, nitrogen gas was introduced into the container, and the system was subjected to a nitrogen atmosphere by vacuum displacement. Next, the system was heated to 150°C for 1 hour while stirring, and then increased to 210°C over 1 hour and 45 minutes, where it was reacted for 15 minutes. Then, 0.36 parts by weight of a 1,4-butanediol solution in which 6.0% by weight of titanium tetrabutyrate had been pre-dissolved was added, and the pressure was reduced over 1 hour and 30 minutes to 0.05 × 10³ Pa or less. 15 minutes after the start of vacuum reduction, the temperature was increased to 240°C over 45 minutes, and polymerization was continued for 4 hours and 15 minutes while maintaining the heated and vacuum state at 240°C, after which polymerization was terminated to obtain a polyester resin (terephthalic acid/butanediol/polyalkylene glycol copolymer polyester).

[Manufacturing Example 2]
<Example of manufacturing PBT-dimer diol oligomer Mn=1000 70% by weight>
The procedure was the same as in Production Example 1, except that the polyalkylene ether glycol (1,10-decanediol) obtained in Example 1 was used, and the raw materials and catalyst were charged in the same manner as in Production Example 1, and the polycondensation reaction was carried out, stopping the reaction when the target viscosity was reached.

[Comparative Manufacturing Example 1]
<PBT-PDMG 70% by weight production example>
The polycondensation reaction was carried out in the same manner as in Production Example 1, except that 70.00 parts by weight of polydecamethylene ether glycol was used instead of 70.00 parts by weight of polyalkylene ether glycol (1,10-decanediol) obtained in Example 2.

Table 3 shows the results for the reduced viscosity, melting point (Tm), heat of fusion (ΔHm), thermal decomposition temperature (Td5: 5% weight loss temperature), tensile test (tensile modulus, breaking strength, elongation at breaking), and elastomer properties of the polyester resin obtained in the production example and comparative production example.
In Table 3, "DMT" represents dimethyl terephthalic acid, and "1,4-BG" represents 1,4-butanediol.

Claims (6)

A polyalkylene ether glycol represented by the following formula (1).
HO-(R ¹ -O) _n -(R ² -O) _m -H...(1)
(In formula (1), ^R1 represents a divalent hydrocarbon group derived from a dimeric diol having 36 to 44 carbon atoms, obtained by reducing a cyclic or acyclic dimeric acid, which is a dimer of an unsaturated fatty acid; ^R2 represents an alkylene group having 6 to 18 carbon atoms; n and m each independently represent a real number of 0 or more, and n/(n+m) is between 0.1 and 0.99 .) The polyalkylene ether glycol according to claim 1, wherein n/(n+m) in formula (1) is 0.25 or more and 0.99 or less . The polyalkylene ether glycol according to claim 1 or 2, wherein the number average molecular weight, calculated from the hydroxyl value, is 300 to 5,000. A polyalkylene ether glycol according to any one of claims 1 to 3, wherein the molecular weight distribution is 1.1 to 3.0. The polyalkylene ether glycol according to any one of claims 1 to 4, wherein ^R2 in formula (1) is a 1,10-decylene group. A method for producing polyalkylene ether glycol, comprising a step of dehydrating and condensing a glycol component using an acid catalyst,
The method for producing polyalkylene ether glycol according to claim 1 , wherein in the dehydration condensation step, an aqueous solution of an acid catalyst with a concentration of 70% by weight or less is used as the acid catalyst.