JP2002012660A - Method for producing polyoxyalkylene glycol and catalyst used for acid-catalyzed reaction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyoxyalkylene glycol having a relatively low molecular weight and a sharp distribution of the molecular weight by carrying out ring opening polymerization of a cyclic ether and to obtain a catalyst used for an acid-catalyzed reaction such as the ring opening polymerization. SOLUTION: The catalyst comprises a porous inorganic oxide consisting essentially of alumina and a sulfuric acid component supported thereon in the method for producing the polyoxyalkylene glycol comprising carrying out the ring opening polymerization of the cyclic ether in the presence of the catalyst. The pore volume of the catalyst within the range of ±20% of median pore diameter is preferably >=50% based on the total pore volume. Furthermore, the median pore diameter of the catalyst is preferably 2-25 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyoxyalkylene glycol by ring-opening polymerization of a cyclic ether in the presence of a catalyst, and particularly to a method for easily separating a catalyst and having a sharp molecular weight distribution. To obtain a polyoxyalkylene glycol. Further, the present invention relates to a catalyst used for an acid-catalyzed reaction such as a ring-opening polymerization reaction.

[0002]

2. Description of the Related Art Polyoxyalkylene glycols are linear polyether glycols and are generally produced by ring-opening polymerization of cyclic ethers. Among them, a compound having industrial significance is polytetramethylene ether glycol (PTMEG) produced by ring-opening polymerization of tetrahydrofuran (THF). PT
MEG is widely and industrially used as a raw material for materials requiring elasticity and elasticity, such as elastic fibers and elastomers.

[0003] As a method for producing PTMEG, a method of performing a reaction in a homogeneous system using a strong acid catalyst such as fluorosulfuric acid has been widely known. However, in such a method, 1) the corrosiveness of the catalyst is high, and an expensive corrosion-resistant material is required for the reaction apparatus. 2) A large amount of waste acid that cannot be recovered and reused is generated, and the waste acid is expensive. There was a problem that processing was required. In order to solve these problems, a method using a solid catalyst has been studied.

As a method for producing PTMEG using a solid catalyst, a method using zirconia sulfate as a catalyst (Japanese Unexamined Patent Publication No.
505515, JP-A-8-73586), a method using a zeolite as a catalyst (JP-A-7-228684), a method using a composite metal oxide as a catalyst (JP-A-4-306228, JP-A-8-231706) and the like. I have.

[0005]

However, in general, a PTMEG production reaction using a solid catalyst has a relatively low molecular weight,
For example, there is a problem that it is difficult to obtain a molecular weight of 500 to 1500 and the molecular weight distribution becomes broad. An object of the present invention is to provide a method for producing a polyoxyalkylene glycol having a relatively low molecular weight and a sharp molecular weight distribution by ring-opening polymerization of a cyclic ether. Another object of the present invention is to provide a catalyst used for an acid-catalyzed reaction such as ring-opening polymerization.

[0006]

The present invention relates to a method for producing a polyoxyalkylene glycol by ring-opening polymerization of a cyclic ether in the presence of a catalyst, wherein the catalyst comprises a porous inorganic oxide mainly composed of alumina. And a sulfuric acid component carried thereon. ± 20% of the median pore diameter of the catalyst
Is preferably 50% or more of the total pore volume, and more preferably, the central pore diameter of the catalyst is 2 to 25 nm.

The catalyst used in the acid-catalyzed reaction according to the present invention is a catalyst containing a porous inorganic oxide containing alumina as a main component and a sulfuric acid component supported on the porous inorganic oxide. The pore volume in the range of ± 20% is 50% or more of the total pore volume. The catalyst has a central pore diameter of 2 to 25
Further preferably, the acid-catalyzed reaction is a reaction for obtaining a polyoxyalkylene glycol by ring-opening polymerization of a cyclic ether in the presence of a catalyst.

[0008] The polyoxyalkylene glycol obtained in the present invention contains a polyoxyalkylene glycol derivative such as a polyoxyalkylene glycol monoester and a polyoxyalkylene glycol diester whose terminals are esterified.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The catalyst used in the present invention contains a porous inorganic oxide containing alumina as a main component and sulfuric acid supported on the porous inorganic oxide. ± 20 of the median pore diameter of the catalyst
% Of the total pore volume is 50% or more of the total pore volume, and furthermore, the median pore diameter of the catalyst is 2 to 25 nm.
It is preferred that

[Porous Inorganic Oxide] Consists of a porous inorganic oxide containing alumina as a main component. Examples of the inorganic oxide include alumina, which is an oxide of aluminum, tungsten, molybdenum, zinc, boron, and germanium. , Phosphorus, titanium, zirconium, hafnium, vanadium, chromium, manganese, iron, silicon, tin, gallium,
An oxide containing at least one element such as selenium, tellurium, or copper, or a composite metal oxide containing these may be included. The oxide here is defined including the case where it contains a hydrated oxide. Of the total metal weight constituting the carrier, aluminum is 20% by weight or more, especially 8% by weight as the metal weight.
It is preferably contained at 0% by weight or more, more preferably at 90% by weight or more. The porous inorganic oxide containing alumina as a main component preferably has a crystalline structure, particularly a crystal structure of γ-alumina or η-alumina.

[Pore Structure of Catalyst] It is necessary that the pore distribution be sharp. Specifically, the pore volume in the range of ± 20% of the median pore diameter of the catalyst is defined as the total pore volume. Of 50
% Or more. Further, the pore volume in a range of ± 40% of the central pore diameter is preferably 80% or more of the total pore volume.

The central pore diameter of the catalyst is preferably in the range from 2 to 25 nm, in particular from 3 to 15 nm, more preferably from 4 to 10 nm. When synthesizing a polyoxyalkylene glycol having a molecular weight of 500 to 1500, the median pore diameter is 4
It is preferably about 9 nm. The specific surface area of the catalyst is 10
0 m ² / g or more, especially 150 m ² / g or more, and more preferably 20 m ² / g or more.
It is preferably 0 m ² / g or more. The pore volume having a pore diameter of 2 to 30 nm, which is the total pore volume, is 0.2 cm ³ / g.
As described above, particularly, 0.25 to 0.55 cm ³ / g is preferable. The pore structure of the catalyst can be measured by a nitrogen adsorption method in the range of pore diameter of 2 to 30 nm. Pore diameter 2nm
The pore volume in the range from to the central pore diameter is equal to the pore volume in the range from the central pore diameter to the pore diameter of 30 nm.

As the shape of the catalyst, powder, granules, columns, spheres and the like can be used. 0.4 m of catalyst
m or more, in particular, 0.4 to 20 mm, further 0.7
It is preferable to mold to an average particle size of 15 mm because the catalyst and the reaction product are easily separated. The average crushing strength of the formed catalyst is 3 kg or more, especially 5 kg to 15 kg.
By setting the weight in kg, the catalyst is less likely to be damaged during separation.

[Supported Sulfuric Acid Content] The amount of sulfuric acid carried is preferably 0.5 to 10% by weight, more preferably 1 to 7% by weight, based on the weight of the catalyst. Supporting the sulfuric acid content, a method of kneading an inorganic oxide precursor such as aluminum hydrated oxide powder, sulfuric acid or a sulfur-containing compound, and calcining, or including a sulfur-containing compound in the inorganic oxide Thereafter, a method of baking or the like can be used. In some cases, the firing for carrying is not performed.

The sulfur-containing compounds that can be used are:
It is a compound containing sulfuric acid or a compound containing sulfur which can be converted into sulfuric acid by a subsequent treatment such as baking. As the sulfur-containing compound, sulfuric acid, ammonium sulfate, sulfurous acid, ammonium sulfite, thionyl chloride,
Examples thereof include dimethyl sulfuric acid, and a sulfuric acid-containing compound is preferably used. Ammonium sulfate and dimethyl sulfuric acid are preferable because they have low corrosiveness in a production apparatus. Particularly, ammonium sulfate is most preferably used.

[Support of Catalyst] The shaped catalyst is preferably produced by supporting a sulfuric acid component on a support made of an inorganic oxide. The method for producing the carrier is not particularly limited. For example, an inorganic oxide precursor such as an inorganic oxide or a hydroxide is used as a powdery raw material, and water, an organic solvent and the like are added to the powder. It can be formed as a paste or clay. This molding is extrusion molding,
It can be performed by pressure molding, application to a processed sheet, or the like. After forming, the formed support can be obtained by drying and, if necessary, firing. The gel or slurry raw material can be formed into a sphere by dispersing it in a dry gas by spray drying or the like and drying it. Further, the sol or slurry raw material may be formed into a spherical shape in the liquid. Further, as a molding method for directly molding the raw material of the powder, there is a method in which a molding aid is added to the raw material powder as needed, and a method in which the raw material powder is subjected to pressure molding with a tablet machine or a method in which the raw material powder is molded by rolling granulation. . In addition, the inorganic oxide precursor may be subjected to a chemical reaction at the time of molding or drying and drying after molding.
It becomes an inorganic oxide by firing or the like.

The formed support is made of aluminum hydrated oxide having a boehmite structure such as pseudo-boehmite (hereinafter referred to as “boehmite”).
Water-containing alumina powder) is kneaded and molded, and can be preferably produced. The burning loss (moisture percentage) of the hydrated alumina powder used as a raw material of the carrier is 20 to 40% by weight, particularly 25.
Preferably it is ~ 35% by weight. This burning loss
It can be measured by weight loss after sintering hydrated alumina at a temperature of 1400 ° C. for 1 hour.

The kneading method is not particularly limited, and a kneader generally used for catalyst preparation can be used. Usually, a method in which water is added to the raw materials, and the resulting mixture is mixed with a stirring blade is preferably used. Water is usually added during kneading, but the liquid to be added may be an organic solvent such as ethanol, 2-propanol, acetone, methyl ethyl ketone, and methyl isobutyl ketone. The temperature and kneading time during kneading vary depending on the powder such as hydrated alumina powder as the raw material, but conditions for obtaining a preferable pore structure are selected. Similarly, as long as the catalytic performance of the present invention is maintained, an acid such as nitric acid, a base such as ammonia, an organic compound, a binder, a ceramic fiber, a surfactant, a zeolite, or the like can be added and kneaded.

The molding method after kneading is not particularly limited, and a molding method generally used for catalyst preparation can be used. In particular, extrusion molding using a screw-type extruder or the like is preferably used because it can be efficiently molded into an arbitrary shape such as a pellet shape or a honeycomb shape. The size of the molded product is not particularly limited, but usually, the cross-sectional length is 0.5 to
It is molded to a size of 20 mm. For example, in the case of a cylindrical pellet, the diameter is usually 0.5 to 10 mm and the length is 0.5 to
Those having a size of about 15 mm can be easily obtained.

The firing after the molding is performed in a gas atmosphere such as air or nitrogen gas, but is preferably performed in air. The preferable firing temperature varies depending on other firing conditions such as the firing time and the gas flow rate.
0-800 ° C, especially 500-800 ° C, and even 600
~ 800 ° C is preferred. The firing time varies depending on other firing conditions such as the firing temperature, but is generally 0.05 to 20 hours, preferably 0.1 to 10 hours, and more preferably 0.2 to 5 hours. In addition, this baking can be performed after supporting a sulfuric acid component.

[Acid-Catalyzed Reaction] As the acid-catalyzed reaction using the catalyst of the present invention, an acid catalyst which conventionally used a Lewis acid catalyst represented by an aluminum chloride-based catalyst or a Bronsted acid catalyst represented by sulfuric acid was used. Reactions can be mentioned. In particular, isomerization, disproportionation, nitration, decomposition,
It is preferably used for various reactions such as alkylation, esterification, acylation, etherification, rearrangement, and polymerization. Among them, it is preferably used for an acid-catalyzed reaction for obtaining a polyoxyalkylene glycol by ring-opening polymerization of a cyclic ether in the presence of an acid catalyst.

[Cyclic ether] As the cyclic ether used as a raw material of the polyoxyalkylene glycol, 3 to 7
Specific examples include a membered cyclic ether, and specifically, tetrahydrofuran, ethylene oxide, oxetane, oxepane, 1,4-dioxane and the like are used. Propylene oxide, butene-1-oxide, butene-2-
Alkyl groups having about 1 to 4 carbon atoms, such as oxides, cyclohexene oxides, styrene oxides, epichlorohydrin, 3,3-bischloromethyloxetane, 2-methyltetrahydrofuran, and 3-methyltetrahydrofuran, and alkoxyl- or phenoxy-substituted alkyls A cyclic ether substituted with a group, a halogen atom or the like can also be used. Among these, tetrahydrofuran and substituted tetrahydrofuran are particularly preferably used. The substituted tetrahydrofuran is obtained by replacing the hydrogen of tetrahydrofuran with an alkyl group having about 1 to 4 carbon atoms, an alkyl group substituted with alkoxyl or phenoxy, a halogen atom, or the like. Also, a combination of tetrahydrofuran, a substituted tetrahydrofuran and another cyclic ether is suitably used.

In the present invention, the reaction is carried out in a system in which water is present in the reaction raw material, usually in a condition containing 0.001 to 0.1 parts by weight of water per 100 parts by weight of the cyclic ether. Can be. Generally 0.001 in cyclic ether
０．１0.1% by weight of water, which need not be removed, simplifying the manufacturing process.

[Polymerization Conditions] Ring-opening polymerization can be carried out by bringing the above-mentioned catalyst into contact with a cyclic ether. However, in order to obtain a polyoxyalkylene glycol having a low molecular weight and a narrow molecular weight distribution, a dihydric alcohol must be present. Preferably. The dihydric alcohol is not particularly limited as long as it has two hydroxyl groups.
Ethylene glycol, 1,3-propanediol, 1,
4-butanediol, 1,5-pentanediol, 1,
6-hexanediol, 1,9-nonanediol, 1,
2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-methyl-1,
4-butanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanedimethanol, 1,4
-Dihydroxymethylbenzene, bisphenol A, bisphenol F, polyoxyalkylene glycol and the like. When THF is used as a cyclic ether and 1,4-butanediol is used as a dihydric alcohol, PTMEG can be obtained. When other dihydric alcohols are used, a copolymerized polyoxyalkylene glycol can be obtained. it can. Although copolymerized polyoxyalkylene glycols have been conventionally synthesized by combining a plurality of types of cyclic ethers, the range of copolymers obtained in molecular design is very narrow because the cyclic ethers are limited. Was. However, in the present invention, since the above-mentioned cyclic ether can be used, the range of the copolymerized polyoxyalkylene glycol becomes very wide.

Further, the ring-opening polymerization reaction can be carried out using a co-catalyst system. Carboxylic anhydride is used as a co-catalyst,
Specifically, acetic anhydride, succinic anhydride, maleic anhydride and the like can be used, but acetic anhydride is particularly preferably used.

When carboxylic anhydride is used as a cocatalyst, the terminal of the polyoxyalkylene glycol obtained by polymerization is esterified. If necessary, a polyoxyalkylene glycol having hydroxyl groups at both ends can be obtained by performing an alcoholysis step using methyl alcohol or the like or a hydrolysis step using water.

In the polymerization reaction of the present invention, a carboxylic acid, a diacetate of polyoxyalkylene glycol, or a hydrocarbon compound may be added to the cyclic ether as a reaction raw material. Acetic acid is preferably used as the carboxylic acid,
As the hydrocarbon compound, a saturated hydrocarbon, an aromatic hydrocarbon, or the like is suitably used. A gas component may be circulated in the reaction system. As the gas component, nitrogen, hydrogen, carbon dioxide, argon and the like are preferably used. In addition, as the reaction type of the polymerization reaction of the present invention, those generally used such as a tank type and a tower type are used, and either a batch type or a continuous type may be used.

The reaction type can be a batch type or a flow type. Specifically, in the case of a PTMEG production reaction,
A method in which tetrahydrofuran, acetic anhydride, and a solid acid catalyst are charged into a reactor and polymerized (batch method), and tetrahydrofuran, acetic anhydride, and a solid acid catalyst are continuously charged into a reactor so as to have an appropriate residence time. A method of extracting a reaction crude liquid containing a solid acid catalyst, or
A method in which a solid acid catalyst is confined in a reactor, tetrahydrofuran and acetic anhydride are continuously charged into the reactor so as to have an appropriate residence time, and a reaction crude liquid is continuously withdrawn. Either method can be used. Also in the former case, the catalyst can be easily filtered from the reaction solution after polymerization. In addition, the used catalyst can be used repeatedly as it is, but when the activity is reduced, it can be recycled by regenerating treatment such as washing and heat treatment.

In the case of the batch type reaction, preferably 0.1 to 100 parts by weight, more preferably 1 to 50 parts by weight, of the catalyst is used per 100 parts by weight of the cyclic ether, and preferably 1 to 30 parts by weight. More preferably, 1 to 20 parts by weight of a cocatalyst (such as acetic anhydride) is used. The polymerization reaction time of the batch-type reaction is determined based on the quality, economical efficiency and the like of the target polyoxyalkylene glycol, but is usually 0.1 to 20 hours, preferably about 1 to 10 hours.

The conditions for the continuous reaction are preferably such that the feed rate of the cyclic ether to the solid acid catalyst is 0.1 to 20 / h, particularly 0.25 to 10 / h as WHSV. . Further, the feed amount of the co-catalyst to the solid acid catalyst is 0.0005 to 6 as WHSV.
/ H, particularly preferably 0.0025 to 2 / h.

By setting the polymerization reaction temperature to 0 to 150 ° C., the quality and productivity of the target polyoxyalkylene glycol are excellent, particularly 10 to 100 ° C., and more preferably 2 to 150 ° C.
The range of 0-80 degreeC is preferable. If the reaction temperature is too low,
The yield of the reaction product is low, which is not practically preferable. If the reaction temperature is too high, the quality of the product is deteriorated due to coloring or the like, which is not preferable. The polymerization reaction pressure is preferably in a pressure range in which the reaction raw material and the product are in a liquid phase.

[Properties of Polyoxyalkylene Glycol] The number average molecular weight (Mn) of the polyoxyalkylene glycol obtained by the polymerization reaction of the present invention is 500 to 500.
0, preferably 500-4000, more preferably 6
50 to 4000. The preferred molecular weight distribution of the polyoxyalkylene glycol obtained by the polymerization reaction of the present invention is such that weight average molecular weight / number average molecular weight (Mw / Mn) is 1.0 to 3.0, more preferably 1.0 to 2.5. In particular, 1.
1 to 2.0. Further, a polyoxyalkylene glycol having almost no coloring can be obtained. Specifically, a product having an APHA value of 20 or less, particularly 10 or less is obtained. The APHA value here is ASTM D4890
Can be measured by the method defined in

[0033]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. First, the measurement method used in the examples will be described.

[Method of Measuring Ignition Loss (Water Content) of Hydrous Alumina Powder] 50 g of a sample powder was placed in a crucible, kept at 1400 ° C. for 1 hour or more in an air atmosphere, and the weight loss rate was measured to determine the ignition loss. .

[Method of Measuring Pore Structure] The pore structure having a specific surface area and a pore diameter in the range of 2 to 50 nm is determined by Mi.
The measurement was performed by a nitrogen adsorption method using an ASAP2400 type measuring device manufactured by Cromerics.

[Measurement Method of Average Crushing Strength] Using a TH-203MP tablet breaking strength measuring device manufactured by Toyama Sangyo Co., Ltd.
The side crushing strength was measured using a sample which was extruded into a cylindrical shape, dried and fired. The measuring probe used had a tip having a circular shape with a diameter of 4.5 mm. The operation of measuring the sample by applying it to the center of the side of the cylindrical sample
This was repeated 0 times, and the average value was calculated.

[Measurement Method of Average Molecular Weight] The number average molecular weight (Mn) and weight average molecular weight (Mw) of polyoxyalkylene glycol were determined by gel permeation chromatography (GP).
C) Measurement was performed using an apparatus.

[Preparation Method of Catalyst] Among commercially available pseudo-boehmite powders, a powder having a loss on ignition of 25% by weight was selected and used as hydrated alumina powder. To 2.0 kg of the hydrated alumina powder, 0.3 kg of ammonium sulfate was added as an aqueous solution, and kneaded with a kneader equipped with stirring blades for 15 minutes. The obtained kneaded material was extruded from an extruder having a circular opening having a diameter of 1.6 mm to form a cylindrical pellet, and dried at 130 ° C. to obtain a dried pellet. The dried pellets are then
After calcination at 5 ° C. for 1 hour, and allowed to cool in dry air, what was sealed and stored was used as catalyst A. Also, a catalyst B was prepared in the same manner as the catalyst A except that the amount of ammonium sulfate was changed to 0.6 kg.

The formed catalyst A had an average diameter of 1.5 mm,
It is cylindrical with an average length of 5 mm and has an average crushing strength of 6.7.
kg. The sulfuric acid content of Catalyst A was 3.9% by elemental sulfur. The specific surface area of the catalyst A is 297 m ² /
g, pore volume of 2 to 30 nm is 0.396 cm
³ / g, and the average pore diameter was 4.7 nm. A pore volume in the range of ± 20% of the average pore diameter is 51.5% of the total pore volume, and a pore volume in the range of ± 40% of the median pore diameter is 83% of the total pore volume. 0.8%.

The formed catalyst B also had an average diameter of 1.5 mm,
It has a cylindrical shape with an average length of 5 mm and an average crush strength of 9.8.
kg. The sulfuric acid content of Catalyst B was 5.7% as elemental sulfur. The specific surface area of the catalyst B is 229 m ² /
g, pore volume of pore diameter 2 to 30 nm is 0.31 cm ³
/ G, and the average pore diameter was 4.6 nm. The pore volume in the range of ± 20% of the average pore diameter is 56.5% or more of the total pore volume, and the pore volume in the range of ± 40% of the central pore diameter is the total pore volume. 84.1%.

[Ring-Opening Polymerization Method 1] 0.5 g of Catalyst A, 4.5 g of THF (containing 200 ppm by weight of water), and 0.675 g of acetic anhydride are placed in a glass container, and shaken under a nitrogen atmosphere. The reaction was carried out at normal pressure at 35 ° C. for 3 hours.
As the shaker, an incubator personal manufactured by Taiyo Kagaku Kogyo KK was used. After completion of the reaction, the obtained PTMEG was analyzed and the reaction was evaluated.
%, The number average molecular weight Mn of PTMEG is 1373, and the weight average molecular weight indicating the molecular weight distribution / number average molecular weight (Mw / M
n) was 2.4 and the hue APHA was 5 or less.
The unreacted THF can be recovered and reused, and the separated catalyst can be repeatedly recycled.

[Comparative Example 1] Strongly acidic ion-exchange resin Na manufactured by du Pont, which was previously dried at 120 ° C under reduced pressure
0.5 g of fion NR50 and THF (200
4.5 g (including ppm by weight) and 0.675 g of acetic anhydride were placed in a glass container and reacted at normal pressure and 35 ° C. for 3 hours while shaking under a nitrogen atmosphere. As the shaker, an incubator personal manufactured by Taiyo Kagaku Kogyo KK was used. After completion of the reaction, the obtained PTMEG was analyzed and the reaction was evaluated. The PTMEG yield was 54%, the number average molecular weight Mn of PTMEG was 2074, and the weight average molecular weight / number average molecular weight (Mw / Mn) was 8.7 and the hue APHA was 100 or more. The ion exchange resin had a surface area of 0.27 m ² / g, and the pore structure could not be measured.

[Ring-Opening Polymerization Method 2] An average particle diameter of 1.
12.0 g of catalyst B sized to 0 to 0.7 mm was charged with an inner diameter of 1
After filling in a tube reactor of 0 mm and length of 300 mm and drying at 130 ° C. under nitrogen flow, THF and acetic anhydride were added to W
The reaction was carried out under the conditions of HSV = 0.25 / Hr. The reaction temperature was 35 ° C., and the weight ratio of THF and acetic anhydride was 100/15. After 7 hours from the start of the reaction, PTMEG obtained from the reactor outlet was analyzed and the reaction was evaluated. The PTMEG yield was 71%, the number average molecular weight Mn of PTMEG was 1087, and the weight average molecular weight indicating the molecular weight distribution. / Number average molecular weight (Mw / Mn) was 1.8. Furthermore, when PTMEG 48 hours after the start of the reaction was similarly evaluated, the PTMEG yield was 71%, the number average molecular weight Mn was 1094, the weight average molecular weight / number average molecular weight (Mw / Mn) was 1.7, and Hue APHA was 5 or less.

[Ring-Opening Polymerization Method 3] 20 g of catalyst A and TH
100 g of F was placed in a glass container and reacted at normal pressure and 40 ° C. for 6 hours while stirring under a nitrogen atmosphere. After completion of the reaction, the catalyst was removed by filtration from the reaction solution, and unreacted THF was distilled off. As a result, PTMEG having hydroxyl groups at both ends was directly obtained. The PTMEG was analyzed and evaluated.
2%, number average molecular weight 4200, molecular weight distribution (Mw / M
n) 2.9.

[Ring-Opening Polymerization Method 4] Catalyst A 40 g, TH
F and 0.3 g of 1,4-butanediol were placed in a glass container and stirred under a nitrogen atmosphere at normal pressure and 6 g.
The reaction was performed at 5 ° C. for 6 hours. After completion of the reaction, the catalyst was removed by filtration from the reaction solution, and unreacted THF was distilled off. As a result, PTMEG having hydroxyl groups at both ends was directly obtained. This PTME
When G was analyzed and evaluated, the yield was 21%, the number average molecular weight was 2,200, and the molecular weight distribution (Mw / Mn) was 2.7.

[0046]

According to the present invention, since a porous inorganic oxide containing alumina as a main component and a catalyst containing sulfuric acid supported thereon are used, the catalyst can be easily removed from the reaction system after the reaction. In addition, the acid component does not transfer to the reaction system, so that waste acid treatment and the like are unnecessary, and in the ring-opening polymerization of the cyclic ether, it is possible to obtain a polyoxyalkylene glycol having a sharp molecular weight distribution and a high yield without coloring. it can. When a cocatalyst is not used, both ends are hydroxyl group P
TMEG can be obtained directly. Further, the catalyst contains a porous inorganic oxide containing alumina as a main component and a sulfuric acid component supported on the porous inorganic oxide, and has a center pore diameter of ± 20% of the catalyst.
% Of the total pore volume is 50% or more of the total pore volume, and the catalyst has a sharp pore distribution in an acid-catalyzed reaction such as a polymerization reaction to efficiently synthesize a target product. be able to.

Continued on the front page F term (reference) 4J005 AA02 AA03 AA04 AA06 AA07 AA08 AA09 AA10 BB02

Claims (8)

[Claims] 1. A method for producing a polyoxyalkylene glycol by ring-opening polymerization of a cyclic ether in the presence of a catalyst, wherein the catalyst comprises a porous inorganic oxide mainly composed of alumina,
A method for producing a polyoxyalkylene glycol containing a sulfuric acid carried thereon. 2. The method for producing a polyoxyalkylene glycol according to claim 1, wherein the pore volume in a range of ± 20% of the central pore diameter of the catalyst is 50% or more of the total pore volume. 3. The method for producing a polyoxyalkylene glycol according to claim 1, wherein the catalyst has a central pore diameter of 2 to 25 nm. 4. The method according to claim 1, wherein a carboxylic anhydride is added to the reaction system as a co-catalyst during the ring-opening polymerization of the cyclic ether in the presence of a catalyst. The method for producing the polyoxyalkylene glycol described in the above. 5. The method according to claim 1, wherein a dihydric alcohol is added to the reaction system during the ring-opening polymerization of the cyclic ether in the presence of a catalyst. A method for producing oxyalkylene glycol. 6. A catalyst containing a porous inorganic oxide containing alumina as a main component and sulfuric acid supported on the porous inorganic oxide, and
A catalyst for use in an acid-catalyzed reaction, wherein a pore volume in a range of ± 20% of a central pore diameter of the catalyst is 50% or more of a total pore volume. 7. The catalyst according to claim 6, wherein the catalyst has a central pore diameter of 2 to 25 nm. 8. The catalyst used in the acid catalyzed reaction according to claim 6, wherein the acid catalyzed reaction is a reaction for obtaining a polyoxyalkylene glycol by ring-opening polymerization of a cyclic ether in the presence of a catalyst.