WO2006121111A1

WO2006121111A1 - Method for producing polyether polyol

Info

Publication number: WO2006121111A1
Application number: PCT/JP2006/309469
Authority: WO
Inventors: Takanori Taniguchi
Original assignee: Mitsubishi Chemical Corporation
Priority date: 2005-05-13
Filing date: 2006-05-11
Publication date: 2006-11-16

Abstract

A method for producing a polyether polyol having a high polymerization degree in good yield by the dehydration condensation of a polyol is provided. A method for producing a polyether polyol by a dehydration condensation reaction of a polyol containing 50 mole % or more of 1,3-propandiol, wherein the reaction is carried out in the presence of a compound of a metal selected from the metals belonging to 4 or 13 Group and an acid catalyst.

Description

Method for producing polyether polyol

Technical field

The present invention relates to a method for producing a polyether polyol by a dehydration condensation reaction of a polyol.

Background art

[0002] Polyether polyol is a polymer having a wide range of uses, including raw materials for soft segments such as elastic fibers and plastic elastomers. Typical examples of polyether polyols include polyethylene glycol, poly (1,2-propanediol), and polytetramethylene ether glycol. Among these, poly (1,2-propane diol) is widely used because it is liquid at room temperature, easy to handle and inexpensive. However, since poly (1,2-propanediol) has a primary hydroxyl group and a secondary hydroxyl group, the difference in physical properties of these hydroxyl groups becomes a problem depending on the application. In contrast, polytrimethylene ether glycol, which is a dehydration condensate of 1,3 propanediol, has recently attracted attention because it has only primary hydroxyl groups and a low melting point.

[0003] Generally, polyether polyols can be produced by a dehydration condensation reaction of corresponding polyols. However, ethylene glycol, 1,4 butanediol, 1,5 pentanediol and the like produce 5- or 6-membered cyclic ethers, that is, 1,4-dioxane, tetrahydrofuran and tetrahydropyran, respectively, upon dehydration condensation. Therefore, a polyether polyol corresponding to a polymer of ethylene glycol and 1,4 butanediol is produced by ring-opening polymerization of a corresponding cyclic ether, that is, ethylene oxide and tetrahydrofuran. A polyether polyol corresponding to a polymer of 1, pentanediol is difficult to obtain because tetrahydropyran, which is a cyclic ether, is thermodynamically advantageous.

[0004] The production of a polyether polyol by a dehydration condensation reaction of a polyol is generally performed using an acid catalyst. Catalysts include inorganic acids such as iodine, hydrogen iodide and sulfuric acid, organic acids such as paratoluenesulfonic acid, and perfluoroalkylsulfonic acid groups. Combinations of coconut resin, sulfuric acid, activated clay, zeolite, organic sulfonic acid, heteropoly acid, etc., in the side chain with salt and cuprous cup have been proposed. As a reaction method, first, a dehydration condensation reaction is performed under a nitrogen atmosphere! Next, a dehydration condensation reaction is performed under reduced pressure in the next step.

(See Patent Document 1) has also been proposed.

[0005] On the other hand, as a method for improving the polymerization rate and coloration, a method in which a reaction is carried out in the presence of a catalyst comprising an acid and a base has been proposed (see Patent Document 2).

Patent Document 1: US Patent Application Publication No. 2002Z0007043

Patent Document 2: Pamphlet of International Publication No. 2004Z048440

Disclosure of the invention

Problems to be solved by the invention

[0006] According to the study by the present inventors, in these conventionally proposed methods, a reaction at a high temperature or a long time is required to produce a polyether polyol having a high degree of polymerization. There was a problem that the polyether polyol obtained was colored. Further, even when the method disclosed in Patent Document 2 was used, the polymerization rate was improved and the chromaticity was also improved, but there was a problem that the polymerization rate was industrially insufficient. Therefore, the present invention intends to provide a method for producing a polyether polyol having a high degree of polymerization in a short time by dehydrating condensation of a polyether polyol under mild conditions.

Means for solving the problem

According to the present invention, when a polyether polyol is produced by a dehydration condensation reaction of a polyol, the reaction is performed in the presence of an acid catalyst and at least one metal compound selected from the group consisting of Group 4 and Group 13. As a result, a method for efficiently producing a polyether polyol having a high degree of polymerization was found, and the present invention was completed.

That is, the first gist of the present invention is selected from the group consisting of groups 4 and 13 when producing a polyether polyol by a dehydration condensation reaction of a polyol containing 50 mol% or more of 1,3-propanediol. The present invention resides in a method for producing a polyether polyol, wherein the reaction is carried out in the presence of at least one metal compound and an acid catalyst.

[0008] The second gist of the present invention is that the polyether polyol according to claim 1, wherein the abundance of the metal compound is 0.01 mol% or more in terms of metal atom with respect to the polyol used as a raw material. Lies in the manufacturing method of the tool.

The third gist of the present invention resides in the above method for producing a polyether polyol, wherein the reaction is carried out at 120 ° C. or higher and 250 ° C. or lower.

The invention's effect

[0009] According to the present invention, it is possible to provide a method for producing a polyether polyol having a high polymerization degree in a short time by dehydrating condensation of a polyether polyol under mild conditions. BEST MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, the present invention will be described in detail.

The present invention is based on the long periodic table (based on the group 18 system recommended by IUPAC in 1989, the same applies below) when producing a polyether polyol by dehydration condensation polymerization reaction of polyol. Powerful group force It is characterized by using at least one kind of metal compound and acid as a catalyst.

[0011] (1) Metal compound catalyst

Examples of the Group 4 and Group 13 metals constituting the metal compound in the present invention include titanium, zirconium, hafnium, aluminum, gallium, indium, and thallium. Among these, titanium, zirconium, aluminum, and gallium are dehydrating polyols. Aluminum is particularly preferred because it is readily available and inexpensive because it promotes the condensation reaction.

[0012] In using the Group 4 and Z or Group 13 metals, those in which a metal salt is formed with these metals and an acid are preferably used. Specific examples of the metal compound selected from the group consisting of Group 4 and Group 13 include inorganic acid salts and organic acid salts, and specific examples include sulfates, hydrogen sulfates, halides, phosphorus compounds. Salts of mineral acids such as acid salts, hydrogen phosphates and borates, organic sulfonates such as trifluoromethanesulfonate, paratoluenesulfonate, methanesulfonate, formate, acetate, etc. Examples thereof include carboxylates. Further, in the reaction system, when a metal compound selected from Group 4 and Z or Group 13 and an acid catalyst described later coexist, the acid forming these metal compounds and the acid of the acid catalyst are the same. It is preferable.

[0013] In this case, an acid catalyst and a metal compound selected from the group consisting of Group 4 and Group 13 are used. However, the desired acid catalyst can be obtained by reacting a metal carbonate, hydrogen carbonate, hydroxide, metal simple substance, etc. selected from the group consisting of Group 4 and Group 13 with an excess acid catalyst. It is also possible to prepare a metal compound of a metal and an acid selected from the group consisting of Group 13 and Group 13. For example, it is possible to react a Group 4 and Z or 13 metal carbonate with sulfuric acid in a polyol which is a reaction substrate to obtain a solution containing sulfuric acid and a Group 4 and Z or 13 metal salt of sulfuric acid.

[0014] These catalysts can be used alone or as a mixed catalyst of two or more.

The amount of the metal compound selected from the group consisting of Group 4 and Group 13 used for the production is usually 0.01 mol%, more preferably 0.02 mol%, in terms of metal atom, relative to the raw material polyol. Particularly preferred is 0.05 mol%. The upper limit is usually 1. 0 molar ^_0/0, so that preferably 0.9 mol ^_0/0, more preferably 0.7 mol ^_0/0, and particularly preferably a 0.5 molar% It is good to use for. If the amount of the metal compound used is too large, the reaction rate will not increase, and it will tend to be difficult to separate the metal catalyst in the post-treatment process, and if it is too small, the reaction rate will not increase.

[0015] (2) Acid catalyst

As the acid catalyst used in the present invention, it is known that an ether bond is generated by a conventional dehydration condensation reaction of an alcoholic hydroxyl group, and any one can be used. The acid may be either dissolved in the reaction system and acting as a homogeneous catalyst, or not dissolved but acting as a heterogeneous catalyst. Examples of such acids include heteropoly acids such as sulfuric acid, phosphoric acid, fluorosulfuric acid, and phosphotungstic acid, methanesulfonic acid, trifluoromethanesulfonic acid, octanessulfonic acid, 1, 1, 2, 2 -Alkyl chains such as tetrafluoroethane sulfonic acid may be fluorinated, but alkyl sulfonic acid, benzene sulfonic acid or ring having an alkyl side chain may be benzene sulfonic acid such as para Examples of the latter, such as aryl sulfonic acid such as toluene sulfonic acid, include activated clay, zeolite, metal composite oxides such as silica alumina and silica zircourea, and a resin having a perfluoroalkyl sulfonic acid group in the side chain. Etc. Of these, sulfuric acid, phosphoric acid, benzene sulfonic acid, paratoluene sulfonic acid, etc. are preferred because sulfuric acid is the most easily available and inexpensive. preferable.

[0016] The acid catalyst is usually used at a lower limit of 0.001 times by weight and an upper limit of 0.3 times the weight of the starting polyol. Preferably, the lower limit is 0.002 times by weight and the upper limit is 0.2 times by weight. In the case of an acid that acts as a homogeneous catalyst, the lower limit is usually 0.005 times by weight and the upper limit is usually 0.2 times by weight, preferably the lower limit is usually 0.001 times by weight and the upper limit is usually 0.1. Weight times.

[0017] The lower limit of the amount of the acid catalyst used for the metal compound selected from the group consisting of Group 4 and Group 13 is usually 0.01 equivalents, more preferably 0.02 equivalents, and particularly preferably 0.05. Equivalent. The upper limit is usually 1.0 equivalent, preferably 0.9 equivalent, more preferably 0.7 equivalent, and particularly preferably 0.5 equivalent. If this ratio is too large, the reaction rate will not increase, and it will tend to be difficult to remove the metal catalyst in the post-treatment process. If it is too small, the reaction rate will not increase.

[0018] When an acid acting as a heterogeneous catalyst such as a resin having a perfluoroalkyl sulfonic acid group in the side chain is used in a continuous reaction, this is not extracted together with the reaction solution. It is possible to employ a method in which the raw material polyol is continuously supplied to the reactor, and the raw material polyol is continuously supplied thereto. In this case, the lower limit is usually 0.1 times by weight and the upper limit is usually 10000 times by weight, and preferably the lower limit is 1 times by weight and the upper limit is usually 0.1 times the weight of the acid staying in the reactor. The raw material polyol is supplied in 1 hour at 1000 times the weight. In this case, the equivalent ratio of the metal compound selected from the group consisting of Group 4 or Group 13 to the acid in the reactor may decrease over time, so if necessary, together with the raw material polyol. Supplying a compound of a metal that also has a group force of group 4 or group 13 power, and maintaining an equivalent ratio of the compound of at least one metal that also has a group force of group 4 and group 13 power to the acid to the desired value Like that.

[0019] <Raw material polyol>

Polyols used as raw materials for polyether polyols are 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,6 monohexanediol, 1, 7 — It is preferable to use a diol having two primary hydroxyl groups, such as heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol. However, two primary hydroxyl groups Even if it is a diol, ethylene glycol, 1,4 butanediol, 1,5 pentanediol, etc. are not preferable as the raw material of the method of the present invention because they produce a cyclic ether ether by the dehydration condensation reaction as described above. Usually, the ability to use these polyols alone can be used as a mixture of two or more polyols if desired.

[0020] However, in the present invention, the lower limit of 1,3 propanediol needs to be 50 mol% with respect to the total polyol of the raw material. More preferably, the lower limit is 60 mol%, particularly preferably 70 mol%, and the upper limit is usually 100 mol%. If this content is too small, the production of the high molecular weight product tends to take time.

[0021] These diols can be used in combination with di- to 9-mer oligomers obtained by the dehydration condensation reaction of the main diols. Furthermore, triol or higher polyols such as trimethylolethane, trimethylolpropane, pentaerythritol, or oligomers of these polyols can be used in combination. However, even in these cases, 1,3 propanediol should account for more than 50 mol%. Normally, diols with 3 to 10 carbon atoms with two primary hydroxyl groups, except for those that produce 5- or 6-membered cyclic ethers by dehydration condensation reactions such as 1,4-butanediol and 1,5-pentanediol Or a mixture of this and other polyols in which the ratio of the other polyols is less than 50 mol% is subjected to the reaction. Preferably, 1,3 propanediol, 2-methyl-1,3 propandiol, 2,2 dimethyl-1,3 diols selected from the group consisting of propanediol, or 1,3 propanediol and other polyols. A mixture having a ratio of other polyols of less than 50 mol% is used for the reaction.

The production of the polyether polyol by the dehydration condensation reaction of the polyol according to the method of the present invention can be carried out either batchwise or continuously. In the case of a batch system, a raw material polyol and catalyst acid and a metal compound selected from the group consisting of Group 4 and Group 13 may be charged into the reactor and reacted with stirring. In the case of continuous reaction, for example, a polyol and a catalyst as raw materials and a one-stop force of a reaction apparatus in which a large number of stirring tanks are connected in series or a flow-type reaction apparatus are continuously supplied, and the inside of the apparatus is in a piston flow or a mode close to this. It is possible to use a method in which the reaction solution is continuously extracted by moving the other end force. [0023] The lower limit of the temperature of the dehydration condensation reaction is usually 120 ° C and the upper limit is usually 250 ° C, preferably the lower limit is 140 ° C and the upper limit is 200 ° C, more preferably the lower limit is 150 ° C. ° C, upper limit is 190 ° C. If this temperature is too high, the coloring tends to be poor, and if it is too low, the reaction rate tends not to increase.

The reaction is preferably carried out in an inert gas atmosphere such as nitrogen or argon. The reaction pressure is arbitrary as long as the reaction system is maintained in a liquid phase, and it is usually carried out under normal pressure. If desired, the reaction can be carried out under reduced pressure or an inert gas can be circulated through the reaction system to promote the elimination of water produced by the reaction from the reaction system.

[0024] The reaction time varies depending on the amount of catalyst used, the reaction temperature, and the yield and physical properties desired for the dehydration condensate to be produced, but the lower limit is usually 0.5 hours and the upper limit is usually 50 hours. The lower limit is 1 hour and the upper limit is 20 hours.

The reaction is usually carried out without a solvent, but a solvent can be used if desired. The solvent should be appropriately selected from organic solvents used in ordinary organic synthesis reactions in consideration of vapor pressure, stability, solubility of raw materials and products under the reaction conditions.

[0025] Separation / recovery of the produced polyether polyol can be performed by a conventional method. When an acid that acts as a heterogeneous catalyst is used, the suspended acid is first removed from the reaction solution by filtration or centrifugation. Next, by distilling or extracting with water or the like, an oligomer having a low boiling point or at least one metal compound having a group force of group 4 and group 13 is removed to obtain a target polyether polyol. When an acid that acts as a homogeneous catalyst is used, first, water is added to the reaction solution, and a polyether polyol layer and an acid, at least one metal compound selected from the group consisting of Group 4 and Group 13, and And an aqueous layer containing oligomers. Since some of the polyether polyols form an acid and an ester used as a catalyst, water is added to the reaction solution and then heated to hydrolyze the ester to separate the force. In this case, if an organic solvent having an affinity for both the polyether polyol and water is used together with water, hydrolysis can be promoted. In addition, when the polyether polyol has a high viscosity and the operability of the separation layer is not good, it is preferable to use an organic solvent that has an affinity for the polyether polyol and can be easily separated from the polyether polyol by distillation. Better ,. Polyether obtained by layering The polyol phase is distilled to remove the remaining water and organic solvent to obtain the desired polyether polyol. If acid remains in the polyether polyol phase obtained by layer separation, it can be washed with water or an aqueous alkali solution or treated with a solid base such as calcium hydroxide to remove the remaining acid. And then used for distillation.

The obtained polyether polyol is usually stored under an inert gas atmosphere such as nitrogen or argon.

The number average molecular weight of the polyether polyol of the present invention can be adjusted according to the type of catalyst used and the amount of catalyst used. The lower limit is usually 80, preferably 600, more preferably 1000, and the upper limit force S is usually 10,000. Better <is 7000, more preferred <is 5000.

[0027] The number average molecular weight is an average molecular weight per molecule.

The Hazen color number of the polyether polyol is preferably as close to 0, and the upper limit is usually 500, preferably 400, more preferably 200.

The polytrimethylene ether glycol obtained by the method of the present invention can be used for applications such as elastic fibers, thermoplastic polyester elastomers, thermoplastic polyurethane elastomers, and coating materials.

Example

[0028] The present invention will be described more specifically with reference to the following examples.

The yield calculation method is as follows.

Yield (%) = (Weight of polytrimethylene glycol after polymerization) 100 / {Weight of 1,3-pump pan diol (Weight of 1,3-propanediol) 18/76}

The molecular weight of the polyether polyol after the polymerization reaction was measured by nuclear magnetic resonance (NMR). Black mouth form 1 d (ALDRICH, TMS 0.03 v / v%, 99.8 + atom%

D, lot: 09904PB), the sample was dissolved and analyzed by ¹ H-NMR apparatus (AVANC E400 (400 MHz) manufactured by BRUKER). Sulfuric acid esters are formed, all of which are hydrolyzed The molecular weight when decomposed was determined by the following formula (ppm is based on TMS).

Molecular weight = 58 (3.4 to 3.7 ppm methylene peak integration value) Z (3.8 ppm methylene peak integration value +4.3 to 4.4 ppm methylene peak integration value) + 18

The degree of coloration of the polyether polyol is represented by the Hazen color number specified in the standard of the Hazen color number American Public Health Association (APH A). The Hazen color number was obtained by colorimetry according to JIS K0071 1 using a standard solution prepared by diluting APHA color number standard solution (NO. 500) manufactured by Kishida Chemical Co., Ltd. The color difference meter was a colorimetric color difference meter ZE 2000 manufactured by Nippon Denshoku Industries Co., Ltd., and the cell thickness was measured under the condition of 10 mm.

[0029] Example 1

<1, 3 Distillative purification of propanediol>

In a 1 L eggplant flask equipped with a reflux condenser and a stirrer, under nitrogen atmosphere, 500. Og of 1,3 propanediol (Aldrich reagent, purity 98%, Batch # 04427AB), 50 0. Og of demineralized water, 6. Charged 78 g of concentrated sulfuric acid (95%). The flask was placed in an oil bath and heated to reflux for 8 hours. Remove the flask from the oil bath and let it cool to room temperature. After cooling, slowly add a sodium hydroxide aqueous solution (a solution of sodium hydroxide 5.26 g in 1 Og of demineralized water) while stirring. . After filtering through a 4 m filter to remove insoluble matter, the filtrate was heated to 80 ° C. and water was distilled off under reduced pressure. The reaction solution cooled to room temperature was transferred to a 1 L four-necked flask, and water remaining at about 100 ° C. was completely removed under reduced pressure. Next, simple distillation was performed at about 100 ° C under reduced pressure, 20 g of the first fraction was discarded, and 380 g of distillate was recovered.

[0030] <1,3 Dehydration condensation reaction of propanediol>

50 g of 1,3 propanediol purified by the above method was charged into a lOOmL four-necked flask equipped with a distillation tube, a nitrogen inlet tube, a mercury thermometer and a stirrer while supplying nitrogen at lOONmLZmin. To this was added 0.207 g of aluminum sulfate (14-18 hydrate), and then slowly added 0.678 g of concentrated sulfuric acid (95%) with stirring. The flask was immersed in an oil bath and heated, and the liquid temperature in the flask reached 170 ° C. in about 1 hour. The reaction starts when the liquid temperature in the flask reaches 170 ° C. Thereafter, the liquid temperature is maintained at 170 to 172 ° C. And allowed to react for 8 hours. The water produced by the reaction was distilled off accompanying nitrogen. The reaction solution was allowed to cool to room temperature, transferred to a 300 mL two-necked flask containing 50 g of demineralized water using 50 g of 1-butanol, and gently refluxed for 2 hours to hydrolyze the sulfate. After cooling to room temperature and cooling, the lower layer (water layer) separated into two layers was removed. After adding 50 ml of water to the upper layer (oil layer) and stirring, the oil layer was washed with water by performing an operation of leaving still and removing the aqueous layer once. 1-Butanol and water were distilled off under reduced pressure by heating to 60 ° C. The obtained oil layer was vacuum-dried in an oil bath at 60 ° C. for 3 hours to obtain polytrimethylene ether diol, which was used to measure the Hazen color number.

[0031] Comparative Example 1

A polytrimethylene ether glycol was obtained in the same manner as in Example 1 except that aluminum sulfate was not added. The results are shown in Table 1.

Comparative Example 2

A polytrimethylene ether glycol was obtained in exactly the same manner as in Example 1 except that 0.0348 g of sodium carbonate was used instead of aluminum sulfate. The results are shown in Table 1.

[0032] Example 2

Polytrimethylene ether glycol was obtained in exactly the same manner as in Example 1 except that the amount of concentrated sulfuric acid (95%) added was 0.577 g. The results are shown in Table 1.

Example 3

Polytrimethylene ether glycol was obtained in the same manner as in Example 1 except that 0.247 g of gallium sulfate (18 hydrate) was used instead of aluminum sulfate. The results are shown in Table 1.

[0033] Example 4

Polytrimethylene ether glycol was obtained in exactly the same manner as in Example 1, except that 0.217 g of titanium (IV) sulfate (4-6 hydrate) was used instead of aluminum sulfate. The results are shown in Table 1.

Example 5

Concentrated sulfuric acid (95 ^_0/0)添力卩量0. 664 g [stiffness of, except for using zirconium sulfate instead [this 0. 0234G sulfate Noreminikumu (IV) (4 hydrates) of Example 1 Polytri in exactly the same way Methylene ether glycol was obtained. The results are shown in Table 1.

[table 1]

According to the method of the present invention, a polyether polyol having a high degree of polymerization can be obtained in a high yield.

Claims

The scope of the claims

In producing a polyether polyol by a dehydration condensation reaction of a polyol containing 1,3-propanediol at 50 mol% or more, at least one compound selected from the group consisting of Group 4 and Group 13 and an acid catalyst A method for producing a polyether polyol, wherein the reaction is carried out in the presence of.

2. The method for producing a polyether polyol according to claim 1, wherein the abundance of the metal compound is 0.01 mol% or more in terms of metal atom with respect to the polyol used as a raw material.

3. The method for producing a polyether polyol according to claim 1, wherein the reaction is performed at 120 ° C. or more and 250 ° C. or less.