Polyalkylene oxide and method for producing the same

Abstract

To provide a polyalkylene oxide which is useful as a material of an isocyanate group terminal prepolymer and a polyurethane resin, has a small volatilization content of harmful acetaldehyde and propionaldehyde, and is stable even in long-term storage.SOLUTION: A polyalkylene oxide contains 10-50 ppm of iminophosphazenium cation, and contains 10-70 ppm of the total of acetaldehyde and propionaldehyde.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to a polyalkylene oxide with excellent long-term storage stability and a method for producing the same. [Background technology]

[0002] A method has been reported for producing polyalkylene oxide using an iminophosphazenium salt as a catalyst, mixing at least one acid selected from solid acids and organic acids in the presence of 3 to 12 parts by weight of water in a ratio of more than 1.5 moles to 3.5 moles per mole of iminophosphazenium salt, and then removing the iminophosphazenium salt with an adsorbent to produce polyalkylene oxide with a residual iminophosphazenium cation of 100 ppm or less and a pH of 5.5 to 8.0 (see, for example, Patent Document 1). Furthermore, a polyalkylene oxide with excellent storage stability has been reported that suppresses the increase in acid value due to oxidative degradation by containing an iminophosphazenium cation obtained by producing a polyalkylene oxide using a basic iminophosphazenium salt as a catalyst in the range of 50 to 200 ppm. (See Patent Document 2.) [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2012-131897 (see, for example, the claims). [Patent Document 2] Japanese Patent Publication No. 2016-56219 (see, for example, the claims). [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the method proposed in Patent Document 1 aims to have an iminophosphazenium cation of 100 ppm or less, and does not take into consideration the storage stability of the resulting polyalkylene oxide or the volatilization of acetaldehyde and propionaldehyde.

[0005] Furthermore, while the polyalkylene oxide described in Patent Document 2 contains 50 to 200 ppm of a specific iminophosphazenium cation, thereby suppressing oxidative degradation of the polyalkylene oxide and improving storage stability, it does not take into account the effects of acetaldehyde and propionaldehyde on the iminophosphazenium cation, nor the amount of acetaldehyde and propionaldehyde volatilized from the polyalkylene oxide before and after storage. In recent years, there has been a strong demand for reducing volatile organic compounds (VOCs) and odors from polyalkylene oxides. Therefore, there is a need for polyalkylene oxides that can suppress discoloration caused by iminophosphatizenium cations and the increase in volatilization of acetaldehyde (a VOC) and propionaldehyde (an odorous substance) even after long-term storage.

[0006] This invention solves these problems and provides a novel polyalkylene oxide that exhibits excellent storage stability, with no discoloration during long-term storage and low volatilization of acetaldehyde and propionaldehyde from the polyalkylene oxide. [Means for solving the problem]

[0007] Each aspect of the present invention is as follows: [1] to [5]. [1] A polyalkylene oxide containing an iminophosphazenium cation represented by the following general formula (1) in the range of 10 to 50 ppm, and containing acetaldehyde and propionaldehyde in a total range of 10 to 70 ppm.

[0008] [ka]

[0009] (Here, R1 and R2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. R1 and R2 may be bonded to each other to form a ring structure, or R1s may be bonded to each other, or R2s to each other to form a ring structure.) [2] The polyalkylene oxide according to [1], wherein the molar ratio of the total content of acetaldehyde and propionaldehyde to iminophosphazenium cation is in the range of 0.2 to 1.5. [3] A polyalkylene oxide as described in [1] or [2], having a pH in the range of 5.5 to 8.0. [4] A polyalkylene oxide according to any one of [1] to [3], wherein the ratio of the amount of acetaldehyde and propionaldehyde volatilized after 6 months to the initial amount of volatilized acetaldehyde is in the range of 0.8 to 1.5. [5] Add 1 × 10⁻¹⁶ of the basic iminophosphazenium salt represented by the following general formula (2) per mole of the active hydrogen compound. -4 ~5×10 -1 A method for producing polyalkylene oxide according to any one of [1] to [4], comprising: mixing in a molar range; heat treatment under reduced pressure in the range of 80 to 130°C and 0.5 to 5 kPa; adding alkylene oxide under conditions of 80 to 130°C and 0.05 to 1 MPa; reacting at the same temperature for 0.5 to 1 hour after the addition; polymerization carried out at 110°C until the pressure decrease ceases to produce crude polyalkylene oxide; then adding water and an adsorbent to the crude polyalkylene oxide; raising the temperature to 80 to 120°C to adsorb and remove iminophosphazenium cations; dehydrating under reduced pressure of 0.5 to 50 kPa; and separating the adsorbent by filtration.

[0010] [ka]

[0011] (Here, R1 and R2 are the same as those described in the general formula (1) above. X - (This represents a hydroxyl group.) [Effects of the Invention]

[0012] One aspect of the present invention can provide a polyalkylene oxide having high storage stability capable of suppressing an increase in the volatilization amounts of acetaldehyde and propionaldehyde without coloring even during long-term storage. Another aspect of the present invention can provide a method for producing the polyalkylene oxide. Still another aspect of the present invention is that since the polyalkylene oxide is suitable for reacting with a polyisocyanate to produce an isocyanate group-terminated prepolymer and further a polyurethane resin, its industrial value is extremely high.

Embodiments for Carrying Out the Invention

[0013] Exemplary embodiments for carrying out the present invention are described in detail below.

[0014] The polyalkylene oxide which is one aspect of the present invention contains an iminophosphazenium cation represented by the above general formula (1) in a range of 10 ppm or more and 50 ppm or less.

[0015] Here, the polyalkylene oxide may be any one belonging to the category generally known as polyalkylene oxide. For example, polyethylene oxide, polypropylene oxide, poly(1,2-butylene oxide), poly(2,3-butylene oxide), polyisobutylene oxide, polybutadiene oxide, polypentene oxide, polystyrene oxide, polycyclohexene oxide, etc. and copolymers having these as copolymerization components can be mentioned. Among them, polyethylene oxide, polypropylene oxide, and a polypropylene oxide-polyethylene oxide block copolymer are preferable.

[0016] Further, the iminophosphazenium cation may be any one belonging to the iminophosphazenium cation represented by the above general formula (1).

[0017] Here, R1 and R2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. Note that R1 and R2 may be bonded to each other to form a ring structure, or R1s may be bonded to each other, or R2s may be bonded to each other to form a ring structure. Examples of hydrocarbon groups having 1 to 20 carbon atoms include methyl group, ethyl group, vinyl group, n-propyl group, isopropyl group, cyclopropyl group, allyl group, n-butyl group, isobutyl group, t-butyl group, cyclobutyl group, n-pentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, phenyl group, heptyl group, cycloheptyl group, octyl group, cyclooctyl group, nonyl group, cyclononyl group, decyl group, cyclodecyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, and the like. Furthermore, examples of ring structures in which R1 and R2 are bonded to each other include pyrrolidinyl groups, pyrrolyl groups, piperidinyl groups, indolyl groups, isoindolyl groups, etc. Examples of ring structures in which R1 groups are bonded to each other or R2 groups are bonded to each other include structures in which one substituent is an alkylene group such as an ethylene group, propylene group, or butylene group, and is bonded to the other substituent to form a ring structure. In order to provide polyalkylene oxides with superior long-term storage stability, it is preferable that R1 and R2 of the iminophosphazenium cation be methyl groups, ethyl groups, or isopropyl groups.

[0018] Specific examples of the iminophosphazenium cation include tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium cation, tetrakis(1,1,3,3-tetraethylguanidino)phosphazenium cation, tetrakis(1,1,3,3-tetra(n-propyl)guanidino)phosphazenium cation, tetrakis(1,1,3,3-tetraisopropylguanidino)phosphazenium cation, tetrakis(1,1,3,3-tetra(n-butyl)guanidino)phosphazenium cation, and tetrakis(1,1,3 Examples include the ,3-tetraphenylguanidino)phosphazenium cation, the tetrakis(1,1,3,3-tetrabenzylguanidino)phosphazenium cation, and the tetrakis(1,3-dimethylimidazolidin-2-imino)phosphazenium cation, among which the tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium cation, the tetrakis(1,1,3,3-tetraethylguanidino)phosphazenium cation, and the tetrakis(1,1,3,3-tetraisopropylguanidino)phosphazenium cation are preferred.

[0019] The iminophosphazenium cation content in the polyalkylene oxide of the present invention is in the range of 10 ppm to 50 ppm, and is preferably in the range of 15 ppm to 40 ppm, as this provides excellent long-term storage stability, suppresses discoloration when used as polyurethane, and suppresses an increase in aldehyde volatilization from the polyalkylene oxide. However, if the iminophosphazenium cation content is less than 10 ppm, the amount of aldehyde volatilization after long-term storage tends to increase. On the other hand, if the iminophosphazenium cation content exceeds 50 ppm, it may not only lead to molding defects and a decrease in resin properties when manufacturing polyurethane resin, but may also cause discoloration of the polyalkylene oxide.

[0020] Furthermore, the polyalkylene oxide of the present invention contains a total of 10 to 70 ppm of acetaldehyde and propionaldehyde generated during the manufacturing process.

[0021] Acetaldehyde is present as an impurity in ethylene oxide, but it is also produced in the propylene oxide addition reaction and the ethylene oxide addition reaction. Propionaldehyde is mainly produced in the propylene oxide reaction, and the amounts of acetaldehyde and propionaldehyde produced can be adjusted to some extent by controlling reaction conditions such as reaction temperature and reaction time.

[0022] Furthermore, the amount of acetaldehyde and propionaldehyde produced can be controlled by controlling the temperature and time of purification processes such as adsorption and dehydration, which remove catalysts using adsorbents such as solid acids, as well as filtration processes.

[0023] If the total content of acetaldehyde and propionaldehyde is less than 10 ppm, the iminophosphazenium cation becomes unstable, which may cause discoloration during long-term storage. Also, if the total content of acetaldehyde and propionaldehyde exceeds 70 ppm, the amount of aldehyde volatilization from the polyalkylene oxide increases during long-term storage. Therefore, the total content of acetaldehyde and propionaldehyde is preferably in the range of 12 to 60 ppm, and more preferably in the range of 15 to 45 ppm.

[0024] In one aspect of the present invention, the ratio of the total amount of acetaldehyde and propionaldehyde to the iminophosphazenium cation in a polyalkylene oxide affects the long-term storage stability of the polyalkylene oxide. For excellent long-term storage stability, the molar ratio of the total content of acetaldehyde and propionaldehyde to the iminophosphazenium cation is preferably in the range of 0.2 to 1.5, and more preferably in the range of 0.3 to 1.4.

[0025] One embodiment of the present invention, a polyalkylene oxide, exhibits excellent long-term storage stability, which can be indicated by discoloration after 6 months and an increase in the amount of acetaldehyde and propionaldehyde volatilized from the initial measurement. In particular, for excellent long-term storage stability, it is preferable that there is no discoloration after 6 months and that the ratio of the amount of acetaldehyde and propionaldehyde volatilized after 6 months to the initial amount of acetaldehyde and propionaldehyde volatilized is in the range of 0.8 to 1.5.

[0026] One embodiment of the present invention is a method for producing polyalkylene oxides, in which the polyalkylene oxide is produced by any method as long as it contains the iminophosphazenium cation in the range of 10 to 50 ppm and the total amount of acetaldehyde and propionaldehyde in the range of 10 to 70 ppm. For example, one method is to heat-treat a basic iminophosphazenium salt represented by the following general formula (2) with an active hydrogen-containing compound, and then perform ring-opening polymerization of the alkylene oxide.

[0027] [ka]

[0028] (Here, R1 and R2 are the same as those described in general formula (1) above. X- represents a hydroxyl group.) The basic iminophosphazenium salt can be obtained by any method, and can be produced, for example, by the method described in Japanese Patent Application Publication No. 2013-112646.

[0029] Specific examples of the basic iminophosphazenium salt include tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide, tetrakis(1,1,3,3-tetraethylguanidino)phosphazenium hydroxide, tetrakis(1,1,3,3-tetra(n-propyl)guanidino)phosphazenium hydroxide, tetrakis(1,1,3,3-tetraisopropylguanidino)phosphazenium hydroxide, tetrakis(1,1,3,3-tetra(n-butyl)guanidino)phosphazenium hydroxide, tetrakis(1,1, Examples include 3,3-tetraphenylguanidino)phosphazenium hydroxide, tetrakis(1,1,3,3-tetrabenzylguanidino)phosphazenium hydroxide, and tetrakis(1,3-dimethylimidazolidine-2-imino)phosphazenium hydroxide, with tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide, tetrakis(1,1,3,3-tetraethylguanidino)phosphazenium hydroxide, and tetrakis(1,1,3,3-tetraisopropylguanidino)phosphazenium hydroxide being preferred.

[0030] There are no particular restrictions on active hydrogen-containing compounds as long as they have one or more active hydrogen atoms. Examples include hydroxy compounds, amine compounds, carboxylic acid compounds, phenol compounds, thiol compounds, etc. More specifically, examples include hydroxy compounds such as water, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, hexanetriol, pentaerythritol, diglycerin, sorbitol, sucrose, and glucose; amine compounds such as ethylenediamine, N,N'-dimethylethylenediamine, piperidine, and piperazine; carboxylic acid compounds such as adipic acid; phenol compounds such as bisphenol; and thiol compounds such as ethanedithiol and butanedithiol. Furthermore, polyether polyols having hydroxyl groups can also be used, such as polypropylene glycol and polypropylene glycol glycerin ether. In this case, there are no particular restrictions on the molecular weight of the polyalkylene glycol, but among them, polyalkylene glycols with a molecular weight of 200 to 3,000, which have low viscosity and excellent fluidity, are preferred. These active hydrogen-containing compounds may be used individually or as a mixture of several types.

[0031] The ratio of basic iminophosphazenium salt to active hydrogen-containing compound is arbitrary, but among these ratios, it is possible to efficiently produce polyalkylene oxides, so a ratio of 1 × 10⁻¹⁶ of basic iminophosphazenium salt per mole of active hydrogen-containing compound is used. -4 ~5×10 -1 The range that constitutes a mole, preferably 5 × 10 -3 ~1 × 10 -1 It is preferable to use it within the range that constitutes a mole.

[0032] Then, by heat-treating the basic iminophosphazenium salt and the active hydrogen-containing compound, preferably under reduced pressure, a catalyst is obtained that has ring-opening polymerization ability for alkylene oxides. By performing ring-opening polymerization of the alkylene oxide, a polyalkylene oxide can be obtained. The reaction temperature during heat treatment is preferably 80 to 130°C, and the pressure is preferably 0.5 to 5 kPa.

[0033] Examples of alkylene oxides used in the production of polyalkylene oxides include alkylene oxides having 2 to 20 carbon atoms, specifically ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide, butadiene monooxide, pentene oxide, styrene oxide, cyclohexene oxide, etc. Among these, ethylene oxide and propylene oxide are preferred due to their easy availability and high industrial value. Alkylene oxides may be used individually or as a mixture of two or more. When using a mixture of two or more, for example, the first alkylene oxide may be reacted first, followed by the second alkylene oxide, or two or more alkylene oxides may be reacted simultaneously.

[0034] An alkylene oxide is added to the catalyst described above, and after the addition is complete, the reaction is carried out at the same temperature for 0.5 to 1 hour. Then, ring-opening polymerization of the alkylene oxide is carried out at 110°C until the pressure does not decrease, in order to produce crude polyalkylene oxide. The pressure during ring-opening polymerization of the alkylene oxide is, for example, in the range of 0.05 to 1.0 MPa, preferably in the range of 0.1 to 0.5 MPa, and more preferably in the range of 0.4 MPa or less. The reaction temperature is, for example, in the range of 80 to 130°C, preferably in the range of 90 to 110°C, because if it is too low the reaction rate will be slow and the reaction time will be long, and if it is too high the degree of unsaturation will increase significantly and the amount of aldehydes produced will increase. If the reaction temperature is 110°C or lower, the reaction time can be shortened and the production of aldehydes can be suppressed by raising the temperature to 110°C over 0.5 to 1 hour after the supply of alkylene oxide is complete. The reaction time varies depending on the amount of catalyst used and the reaction temperature, but is in the range of 1 to 48 hours, preferably in the range of 2 to 24 hours.

[0035] The catalyst components contained in the crude polyalkylene oxide obtained by ring-opening polymerization of alkylene oxides can be removed by known methods, for example, by contacting the catalyst components with an adsorbent such as water and a solid acid for a specific time within a specific temperature range to adsorb iminophosphazenium cations onto the adsorbent, followed by dehydration under reduced pressure at a specific temperature, and then separating the adsorbent from the polyalkylene oxide by filtration.

[0036] While higher temperatures promote the adsorption of iminophosphazenium cations, they also increase the adsorption of aldehydes. Therefore, a temperature range of 80-120°C is preferred, and a range of 90-110°C is more preferred.

[0037] The adsorbent is not particularly limited as long as it can adsorb iminophosphazenium salts, but specific examples include synthetic aluminum silicate, activated clay, zeolite, and acid clay. There are many commercially available adsorbents, specifically (product name) KW-600BUP-S (manufactured by Kyowa Chemical Industry Co., Ltd.), (product name) KW-700PEL (manufactured by Kyowa Chemical Industry Co., Ltd.), (product name) KW-700SL (manufactured by Kyowa Chemical Industry Co., Ltd.), (product name) KW-700SEN (manufactured by Kyowa Chemical Industry Co., Ltd.), and (product name) KW-700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.).

[0038] Furthermore, the iminophosphazenium cation content can be adjusted by the type and amount of adsorbent used. If the amount of adsorbent used is too small, a large amount of iminophosphazenium cation will remain, and if the amount used is too large, the iminophosphazenium cation content will be less than 10 ppm, and the effect of the iminophosphazenium cation will not be obtained. Therefore, the amount used is preferably in the range of 0.5 to 2.5% by weight relative to the weight of crude polyalkylene oxide, and more preferably in the range of 0.7 to 1.5% by weight.

[0039] The polyalkylene oxide of the present invention may also contain an antioxidant together with the iminophosphazenium cation, to the extent that it does not depart from the object of the present invention. Examples of such antioxidants include phenolic compound antioxidants, amine compound antioxidants, and phosphite ester compound antioxidants. Specifically, examples of phenolic compound antioxidants include 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4-methoxyphenol, 2,6-di-tert-butylphenol, 6-tert-butyl-2,4-methylphenol, and pentaerythritol tetrakis[3-(3,5- Examples of antioxidants include phenolic antioxidants such as di-tert-butyl-4-hydroxyphenylpropionate (e.g., BASF Irganox 1010), octadecyl 3,5-bis-tert-butyl-4-hydroxybenzenepropanoate (e.g., BASF Irganox 1076), and isooctyl 3,5-bis-tert-butyl-4-hydroxybenzenepropanoate (e.g., BASF Irganox 1135); and amine antioxidants such as n-butyl-p-aminophenol, 4,4-dimethyldiamine, and 4,4-dioctyldiphenylamine. These antioxidants may be used individually or in combination of two or more.

[0040] The amount of antioxidant added is preferably 100 to 3000 ppm, and particularly preferably 300 to 2000 ppm, per 100 parts by weight of the polyalkylene oxide.

[0041] A polyalkylene oxide composition according to one aspect of the present invention exhibits excellent urethane formation reactivity. The polyalkylene oxide composition preferably has a pH of 5.5 to 8.0, as measured according to the method described in JIS K-1557-5. A pH of 5.5 to 8.0 is preferable because it further improves the reactivity when the polyalkylene oxide composition is mixed with an isocyanate compound to synthesize a polyurethane-forming composition.

[0042] Furthermore, a polyalkylene oxide according to one aspect of the present invention is characterized by a low degree of unsaturation, and when its hydroxyl value is 5 to 200 mg KOH / g, the degree of unsaturation is preferably 0.001 to 0.05 meq / g, and particularly preferably 0.005 to 0.03 meq / g.

[0043] One embodiment of the present invention, a polyalkylene oxide, is suitable for reacting with a polyisocyanate to produce an isocyanate-terminated prepolymer, and further, a polyurethane resin. [Examples]

[0044] The present invention will be described below with reference to examples, but these examples are not intended to limit the present invention in any way.

[0045] The evaluation and measurement methods used in the examples and comparative examples are shown below. (1) Measurement of hydroxyl value, total unsaturation degree and pH Measurements were taken in accordance with the measurement methods described in JIS K 1557-1, JIS K 1557-3, and JIS K 1557-5. (2) Measurement of the iminophosphazenium cation content Measurements were performed using a trace nitrogen analyzer (Mitsubishi Chemical Co., Ltd., product name TN-100). The measurement conditions were: heater temperature T1 = 800°C, T2 = 900°C, argon gas flow rate = 100 ml / min, oxygen gas flow rate = 600 ml / min, and ozone gas flow rate = 200 ml / min.

[0046] A cyclohexane solution of polyalkylene oxide was used as a sample, and the amount of nitrogen was quantified using the absolute calibration curve method. (3) Measurement of the number of colors (Hazen unit color count) Measurements were taken in accordance with the method described in JIS-K-0071-1. (4) Measurement of acetaldehyde and propionaldehyde volatilization from polyalkylene oxides 10 g of polyalkylene oxide was placed in an impinger (manufactured by Suenaga Rikagaku Co., Ltd., volume: 30 ml), and while heating at 65°C for 2 hours, nitrogen gas that had been passed through a hydrocarbon trap at 65°C was blown in at a flow rate of 0.5 L / min. The gas after ventilation was collected in a 2,4-dinitrophenylhydrazine (DNPH) cartridge, and the adsorbed components were eluted using 5 ml of an eluent. High Performance Liquid Chromatography (HPLC) measurement of the eluate was performed to measure the volatilization amounts of aldehyde and propionaldehyde from the polyalkylene oxide. <Synthesis Example 1> (tetrakis(tetramethylguanidino)phosphazenium hydroxide (((Me2N)2C=N)4P + OH - (In the general formula (2), R1 and R2 are methyl groups, and X is a hydroxy group.) - Production of 2-propanol solution) 96 g (0.46 mol) of phosphorus pentachloride (manufactured by Aldrich) was placed in a 2-liter four-necked flask equipped with a thermometer, a dropping funnel, a condenser, and a Teflon (registered trademark) stirring blade under a nitrogen atmosphere, and all subsequent operations were carried out under a nitrogen atmosphere. 800 ml of dehydrated toluene (manufactured by Wako Pure Chemical Industries, Ltd.) was added to make a slurry solution. This slurry solution was cooled to 15°C in a water bath, and after the internal temperature was adjusted to 20°C, 345 g (2.99 mol) of 1,1,3,3-tetramethylguanidine was dropped from the dropping funnel over 3 hours under strong stirring. A large amount of white slurry was generated in the reaction solution. After the dropping was completed, the water bath was removed, and the temperature was raised to room temperature. Further, after the slurry solution was heated to 100°C, 107 g (0.92 mol) of 1,1,3,3-tetramethylguanidine was dropped over 1 hour. Then, it was heated and stirred at 100°C for 14 hours to obtain a white slurry solution. After cooling to 80°C, 250 ml of ion-exchanged water was added to the reaction solution, and it was stirred for 30 minutes. When the stirring was stopped, all the slurry dissolved, and liquid-liquid separation was performed to recover the aqueous phase.

[0047] 100 ml of dichloromethane was added to the obtained aqueous phase and stirred. Then, the oil-water separation was repeated twice by washing with water to extract tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium chloride with dichloromethane. Furthermore, the obtained dichloromethane solution was washed with 100 ml of deionized water. This dichloromethane solution was transferred to a 2-liter four-necked flask equipped with a thermometer, dropping funnel, condenser, and Teflon® stirring blade. 900 g of 2-propanol was added, and the temperature was raised to 80 to 100°C under atmospheric pressure to remove the dichloromethane. 58% by weight (865 g) of the solvent was removed. The obtained tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium chloride-2-propanol solution was allowed to cool to 60°C while stirring. After cooling, 32 g of potassium hydroxide (1.1 mol equivalent relative to tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium chloride) was added and the mixture was reacted at 60°C for 2 hours. The ion exchange rate after 2 hours was 99.5%. The temperature was cooled to 25°C, and the precipitated by-product salt was removed by filtration to obtain 535 g of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide-2-propanol solution.

[0048] The resulting tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide-2-propanol solution contained 214 g of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide, a basic iminophosphazenium salt, yielding a tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide-2-propanol solution with a concentration of 40.0% by weight. The yield of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide was 93.0%.

[0049] The product is, 1 Identification was performed using 1H-NMR and GC-MS.

[0050] 1 H-NMR (deuterated solvent: D2O): Chemical shift: 2.92 ppm (methyl group derived from phosphazenium salt).

[0051] GC-MS(FAB+) measurement results: m / z = 487 (matches the molecular weight of the tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium cation).

[0052] Example 1 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 90°C. After the supply of propylene oxide was completed, the reaction was carried out at 90°C for about 1 hour, and then the temperature was raised to 110°C over about 1 hour. After the reaction continued at 110°C until the pressure drop was eliminated, the unreacted propylene oxide was removed under reduced pressure. After raising the temperature from 110°C to 120°C, the addition reaction was carried out by continuously supplying ethylene oxide. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0053] 460 g of the obtained crude polyalkylene oxide was transferred to a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line. At an internal temperature of 80°C, 11.5 g of water, 4.6 g of KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) as an adsorbent, and 0.35 g of Irganox 1076 (manufactured by BASF) as an antioxidant were added. The mixture was stirred at 80°C for 1 hour, then the temperature was raised to 120°C and heated and stirred for 3 hours. Subsequently, the pressure was reduced to 0.5 kPa, and dehydrated under reduced pressure at 120°C for 3 hours. Finally, a 400 ml stainless steel filter was heated to 80°C and filtered under pressure at 0.3 MPa to obtain polyalkylene oxide.

[0054] The obtained polyalkylene oxide had a hydroxyl value of 24.0 mg KOH / g, a degree of unsaturation of 0.026 meq / g, and a pH of 6.8. Table 1 shows the results of measuring the iminophosphazenium cation content (simply referred to as "cation" in Table 1) by trace nitrogen analysis, the total amount of acetaldehyde and propionaldehyde, the volatilization amounts of acetaldehyde and propionaldehyde immediately after production, and the Hazen color number. Subsequently, the volatilization amounts of acetaldehyde and propionaldehyde after storage in the temperature range of 0 to 40°C for 6 months were measured, and the results are shown in Table 1.

[0055] Example 2 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 95°C for 2 hours. After purging the reactor with nitrogen, propylene oxide was continuously added at 95°C to carry out addition polymerization. After the supply of propylene oxide was completed, the reaction was carried out at 95°C for about 1 hour, and then the temperature was raised to 110°C over about 1 hour. After the reaction continued at 110°C until the pressure drop was eliminated, the unreacted propylene oxide was removed under reduced pressure, and the temperature was raised to 120°C, after which ethylene oxide was continuously supplied to carry out the addition reaction. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0056] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 4.0 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as an adsorbent.

[0057] The obtained polyalkylene oxide had a hydroxyl value of 24.0 mg KOH / g, a degree of unsaturation of 0.024 meq / g, and a pH of 6.1. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0058] Example 3 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 90°C. After the supply of propylene oxide was completed, the reaction was carried out at 90°C for about 1 hour, and then the temperature was raised to 110°C over about 1 hour. After the reaction continued at 110°C until the pressure drop was eliminated, the unreacted propylene oxide was removed under reduced pressure, and the addition reaction was carried out by continuously supplying ethylene oxide at 110°C. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0059] 460 g of the obtained crude polyalkylene oxide was transferred to a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1.

[0060] The obtained polyalkylene oxide had a hydroxyl value of 24.1 mg KOH / g, a degree of unsaturation of 0.026 meq / g, and a pH of 7.0. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0061] Comparative Example 1 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 90°C. After the supply of propylene oxide was completed, the reaction was continued at 90°C until the pressure drop was eliminated. Then, the unreacted propylene oxide was removed under reduced pressure, and after raising the temperature to 120°C, the addition reaction was carried out by continuously supplying ethylene oxide. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0062] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 6.5 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as the adsorbent.

[0063] The obtained polyalkylene oxide had a hydroxyl value of 23.8 mg KOH / g, a degree of unsaturation of 0.025 meq / g, and a pH of 6.4. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0064] Comparative Example 2 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 90°C. After the supply of propylene oxide was completed, the reaction was continued at 90°C until the pressure drop was eliminated. Then, the unreacted propylene oxide was removed under reduced pressure, and after raising the temperature to 110°C, the addition reaction was carried out by continuously supplying ethylene oxide. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0065] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 3.0 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as an adsorbent.

[0066] The obtained polyalkylene oxide had a hydroxyl value of 24.0 mg KOH / g, a degree of unsaturation of 0.027 meq / g, and a pH of 8.1. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0067] Comparative Example 3 Polyalkylene oxides were prepared in the same manner as in Comparative Example 1, except that 5.34 g (15 mmol%) of a 50% aqueous solution of potassium hydroxide was used instead of 6.0 g (1.5 mmol%) of a 40% solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide in 2-propanol, and the temperature of the addition reaction of propylene oxide was changed from 90°C to 110°C.

[0068] The obtained polyalkylene oxide had a hydroxyl value of 24.3 mg KOH / g, a degree of unsaturation of 0.097 meq / g, and a pH of 7.0. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0069] Example 4 The crude polyalkylene oxide was polymerized using the same polymerization procedure as in Example 3.

[0070] 460 g of the obtained crude polyalkylene oxide was transferred to a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line. Polyalkylene oxide was then produced in the same manner as in Example 1, except that 6.5 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as the adsorbent. The obtained polyalkylene oxide had a hydroxyl value of 24.2 mg KOH / g, a degree of unsaturation of 0.025 meq / g, and a pH of 6.7. Measurements were performed in the same manner as in Example 1, and the results are shown in Table 1.

[0071] Example 5 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 105°C. After the supply of propylene oxide was completed, the reaction was carried out at 105°C for about 1 hour, and then the temperature was raised to 110°C over about 0.5 hours. After the reaction continued at 110°C until the pressure drop was eliminated, the unreacted propylene oxide was removed under reduced pressure, and the temperature was raised to 130°C, after which the addition reaction was carried out by continuously supplying ethylene oxide. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0072] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 4, except that 3.9 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as the adsorbent.

[0073] The obtained polyalkylene oxide had a hydroxyl value of 24.0 mg KOH / g, a degree of unsaturation of 0.045 meq / g, and a pH of 5.6. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0074] Example 6 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 90°C. After the supply of propylene oxide was completed, the reaction was carried out at 90°C for about 1 hour, and then the temperature was raised to 110°C over about 1 hour. After the reaction continued at 110°C until the pressure drop was eliminated, the unreacted propylene oxide was removed under reduced pressure, and the addition reaction was carried out by continuously supplying ethylene oxide at 110°C. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0075] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 4.4 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as the adsorbent.

[0076] The obtained polyalkylene oxide had a hydroxyl value of 24.1 mg KOH / g, a degree of unsaturation of 0.021 meq / g, and a pH of 7.1. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0077] Example 7 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, propylene oxide was continuously added at 100°C to carry out addition polymerization. After the supply of propylene oxide was completed, the reaction was carried out at 100°C for about 0.5 hours, and then the temperature was raised to 110°C over about 0.5 hours. After the reaction continued at 110°C until the pressure drop was eliminated, the unreacted propylene oxide was removed under reduced pressure, and after raising the temperature to 120°C, ethylene oxide was continuously supplied to carry out the addition reaction. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0078] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 4.4 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as the adsorbent.

[0079] The obtained polyalkylene oxide had a hydroxyl value of 24.1 mg KOH / g, a degree of unsaturation of 0.040 meq / g, and a pH of 6.9. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0080] Example 8 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 90°C. After the supply of propylene oxide was completed, the reaction was carried out at 90°C for about 1 hour, and then the temperature was raised to 110°C over about 1 hour. After the reaction continued at 110°C until the pressure drop was eliminated, the unreacted propylene oxide was removed under reduced pressure, and the temperature was raised to 120°C, after which the addition reaction was carried out by continuously supplying ethylene oxide. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0081] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 4.4 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as the adsorbent.

[0082] The obtained polyalkylene oxide had a hydroxyl value of 24.1 mg KOH / g, a degree of unsaturation of 0.037 meq / g, and a pH of 6.8. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0083] Example 9 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 95°C. After the supply of propylene oxide was completed, the reaction was carried out at 95°C for about 1 hour, and then the temperature was raised to 110°C over about 1 hour. After the reaction continued at 110°C until the pressure drop was eliminated, the unreacted propylene oxide was removed under reduced pressure, and the addition reaction was carried out by continuously supplying ethylene oxide at 110°C. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0084] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 4.3 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as the adsorbent.

[0085] The obtained polyalkylene oxide had a hydroxyl value of 24.1 mg KOH / g, a degree of unsaturation of 0.027 meq / g, and a pH of 6.3. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0086] Example 10 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 100°C. After the supply of propylene oxide was completed, the reaction was carried out at 100°C for about 0.5 hours, and then the temperature was raised to 110°C over about 0.5 hours. After the reaction continued at 110°C until the pressure drop was eliminated, the unreacted propylene oxide was removed under reduced pressure, and the addition reaction was carried out by continuously supplying ethylene oxide at 110°C. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0087] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 4.4 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as the adsorbent.

[0088] The obtained polyalkylene oxide had a hydroxyl value of 24.1 mg KOH / g, a degree of unsaturation of 0.035 meq / g, and a pH of 6.2. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0089] Comparative Example 4 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 90°C. After the supply of propylene oxide was completed, the reaction was continued at 90°C until the pressure drop was eliminated. Then, the unreacted propylene oxide was removed under reduced pressure, and the addition reaction was carried out by continuously supplying ethylene oxide at 90°C. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0090] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 4.4 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as the adsorbent.

[0091] The obtained polyalkylene oxide had a hydroxyl value of 24.1 mg KOH / g, a degree of unsaturation of 0.020 meq / g, and a pH of 7.4. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0092] Comparative Example 5 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 110°C. After the supply of propylene oxide was completed, the reaction was continued at 110°C until the pressure drop was eliminated. Then, the unreacted propylene oxide was removed under reduced pressure, and after raising the temperature to 130°C, the addition reaction was carried out by continuously supplying ethylene oxide. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0093] 460 g of the obtained crude polyalkylene oxide was transferred to a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1.

[0094] The obtained polyalkylene oxide had a hydroxyl value of 24.1 mg KOH / g, a degree of unsaturation of 0.045 meq / g, and a pH of 5.3. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0095] Comparative Example 6 83 g of polypropylene triol with a molecular weight of 250 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. The 2-propanol and water were removed under reduced pressure at 100°C for 2 hours. After purging the reactor with nitrogen, addition polymerization was carried out by continuously adding propylene oxide at 110°C. After the supply of propylene oxide was completed, the reaction was continued at 110°C until the pressure drop was eliminated. Then, the unreacted propylene oxide was removed under reduced pressure, and after raising the temperature to 130°C, the addition reaction was carried out by continuously supplying ethylene oxide. The unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0096] Of the obtained crude polyalkylene oxide, 460 g was taken out into a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line, and polyalkylene oxide was produced in the same manner as in Example 1, except that 3.5 g of (product name) KW700SEN-S (manufactured by Kyowa Chemical Industry Co., Ltd.) was used instead of 4.6 g as an adsorbent.

[0097] The obtained polyalkylene oxide had a hydroxyl value of 24.1 mg KOH / g, a degree of unsaturation of 0.040 meq / g, and a pH of 6.8. The same measurements as in Example 1 were performed, and the results are shown in Table 1.

[0098] Comparative Example 7 175 g of polypropylene triol with a molecular weight of 1000 and 6.0 g (1.5 mmol) of a 40% 2-propanol solution of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide obtained in Synthesis Example 1 were added to the reactor. After purging the reactor with nitrogen, the 2-propanol and water were removed under reduced pressure of 0.2 kPa at 80°C for 2 hours. After purging the reactor with nitrogen again, the addition reaction was carried out by continuously supplying propylene oxide at 90°C. After the supply of propylene oxide ended, the reaction was continued at 90°C until the pressure drop was eliminated. Subsequently, unreacted propylene oxide was removed under reduced pressure, and then the addition reaction was carried out by continuously supplying ethylene oxide at 90°C. Subsequently, unreacted ethylene oxide was removed under reduced pressure to obtain crude polyalkylene oxide.

[0099] 460 g of the obtained crude polypropylene oxide was placed in a 1-liter four-necked flask equipped with a stirrer, nitrogen line, and vacuum line. 11.5 g of deionized water and sulfuric acid (in the form of a 2% by weight aqueous solution) equivalent to 2.5 mol per 1 mol of tetrakis(1,1,3,3-tetramethylguanidino)phosphazenium hydroxide used were added (the amount of water at this time was 5.5 parts by weight per 100 parts by weight of polypropylene oxide), and a neutralization reaction was carried out at 85°C for 3 hours.

[0100] To the neutralized polypropylene oxide, 0.5 parts by weight of synthetic aluminum silicate (product name KW-700PEL: manufactured by Kyowa Chemical Industry Co., Ltd.) as a solid acid and 0.1 parts by weight of hydrotalcite (product name KW-500SN: manufactured by Kyowa Chemical Industry Co., Ltd.) as a solid base were added, along with 2,6-di-tert-butyl-4-methylphenol (antioxidant) equivalent to 750 ppm (adsorbent ratio:solid acid:solid base = 5:1; 0.6 parts by weight). The mixture was stirred at 85°C for 1 hour. Then, dehydration was started while increasing the temperature and reducing the pressure, and finally, dehydration was carried out under reduced pressure at 105°C and 0.5 kPa for 3 hours. Finally, diatomaceous earth was added as a filter aid, and the mixture was filtered using a pressure filter.

[0101] The obtained polypropylene oxide had a hydroxyl value of 24 mg KOH / g, a degree of unsaturation of 0.025 meq. / g, and a pH of 6.3. The results are shown in Table 1.

[0102] [Table 1] [Industrial applicability]

[0103] The polyalkylene oxide of the present invention exhibits excellent stability, suppressing discoloration and the increase in the volatilization of harmful aldehydes such as acetaldehyde and propionaldehyde even during long-term storage, making it useful as a material for isocyanate-terminated prepolymers and polyurethane resins.

Claims

1. It contains an iminophosphazenium cation represented by the following general formula (1) in a range of 10 to 50 ppm, and a total of acetaldehyde and propionaldehyde in a range of 10 to 70 ppm. The molar ratio of the total content of acetaldehyde and propionaldehyde relative to the iminophosphazenium cation is in the range of 0.2 to 1.

5. A polyalkylene oxide in which the ratio of the amount of acetaldehyde and propionaldehyde volatilized after 6 months to the initial amount of volatilized acetaldehyde is in the range of 0.8 to 1.

5. 【Chemistry 1】 (Here, R １ and R ２ Each of these independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. １ and R ２ They may be bonded to each other to form a ring structure, or R １ Same or R ２ They may also be bonded to each other to form a ring structure.

2. The polyalkylene oxide according to claim 1, wherein the pH is in the range of 5.5 to 8.

0.

3. The basic iminophosphazenium salt represented by the general formula (2) below is added in a quantity of 1 × 10⁻¹⁶ per mole of the active hydrogen compound. －４ ~5 x 10 －１ A method for producing polyalkylene oxide according to claim 1 or 2, comprising: mixing in a molar range; heat treatment under reduced pressure in the range of 80 to 130°C and 0.5 to 5 kPa; adding alkylene oxide under conditions of 80 to 130°C and 0.05 to 1 MPa; reacting at the same temperature for 0.5 to 1 hour after the addition; polymerization at 110°C until the pressure decrease ceases to produce crude polyalkylene oxide; then adding water and an adsorbent to the crude polyalkylene oxide; raising the temperature to 80 to 120°C to adsorb and remove iminophosphazenium cations; dehydrating under reduced pressure of 0.5 to 50 kPa; and separating the adsorbent by filtration. 【Chemistry 2】 (Here, R １ and R ２ are the same as those described in the above general formula (1). X － represents a hydroxy group.)

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