JP2010132803A - Method for producing polyoxyalkylene compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method by which a high molecular weight polyoxyalkylene compound can be efficiently obtained by bringing an alkylene oxide into an addition reaction to a polyhydric alcohol with usual production equipment while inhibiting the formation of a by-product. <P>SOLUTION: The method for producing a polyoxyalkylene compound is a method for obtaining a polyoxyalkylene compound with an alkylene oxide added in a total amount of ≥60 moles by bringing an alkylene oxide into an addition reaction to a saturated compound having ≥3 hydroxy groups per molecule. The method includes an initial step (I) of obtaining an alkylene oxide low-mole adduct by adding ≥5 mole alkylene oxide to 1 mole hydroxy group of the hydroxy group-containing saturated compound, and an addition mole number adjustment step (II) of adding ≥5 mole alkylene oxide to 1 mole hydroxy group of the alkylene oxide low-mole adduct obtained at the initial step, wherein the alkylene oxide low-mole adduct obtained at the initial step (I) is liquid at 25°C. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a process for producing a polyoxyalkylene compound in which alkylene oxide is added to a polyhydric alcohol having 3 or more hydroxyl groups per molecule by addition reaction of alkylene oxide with a high molar amount. The said compound is useful for the use of the additive for hydraulic materials, such as a high performance AE water reducing agent and the shrinkage reducing agent for concrete.

  Polyoxyalkylene compounds obtained by adding alkylene oxide to hydroxyl group-containing compounds such as alcohols are, for example, esterification reactions with unsaturated carboxylic acids such as (meth) acrylic acid and esters with (meth) acrylic acid alkyl esters. It is useful for obtaining a polycarboxylic acid suitable for an additive for hydraulic materials such as a high-performance AE water reducing agent by copolymerizing with an unsaturated carboxylic acid after introducing an unsaturated group by an exchange reaction. Widely used as a raw material for polymers used in applications such as cement additives. In such a case, it is well known that a higher molecular weight of the polyoxyalkylene compound is preferable in order to further improve performance such as dispersibility.

  In order to produce a polyoxyalkylene compound having a large molecular weight, it is sufficient to add more alkylene oxide to the hydroxyl group-containing compound. In this case, however, the capacity of the product is very large relative to the charged capacity of the raw material. Become. For this reason, it is usually necessary to use a specially shaped reactor or a special stirring device, and there are various restrictions on usable production equipment.

  To solve this problem, Patent Document 1 discloses a method of adding an alkylene oxide to an active hydrogen-containing compound in two stages under specific conditions. Patent Document 2 discloses a hydroxyl group. When adding an alkylene oxide to a contained saturated compound, a method of adding in a plurality of stages under specific conditions has been proposed.

  On the other hand, polyoxyalkylene compounds obtained by addition reaction of alkylene oxides with polyhydric alcohols having 3 or more hydroxyl groups per molecule are significantly different from polyoxyalkylene compounds of monovalent saturated alcohol compounds. Met.

  Therefore, as a problem when producing the polyoxyalkylene compound, an alkylene oxide adduct of a polyhydric alcohol having 3 or more hydroxyl groups per molecule greatly varies depending on the number of moles of alkylene oxide added. In the same manner as in the case of the alkylene oxide adduct of a monovalent saturated alcohol compound, even if an attempt is made to add alkylene oxide in multiple stages, the intermediate obtained in the initial stage reaction is cooled, stored or There was a problem of solidifying when transferred to the process. In order to prevent such solidification, a heat retaining device is necessary for the container, the device, and the piping, and a step of heating and melting again is necessary.

  That is, even if the method of the above-mentioned patent document is adopted, a polyoxyalkylene compound obtained by adding a high molar amount of alkylene oxide to a polyhydric alcohol having 3 or more hydroxyl groups per molecule cannot be produced with high productivity. Met.

JP 2007-321103 A JP 2005-526159 A

  An object of the present invention is to efficiently add a polyoxyalkylene compound obtained by adding an alkylene oxide to a polyhydric alcohol having 3 or more hydroxyl groups per molecule and adding a high molar amount of alkylene oxide, using a normal production facility. It is to provide a method of manufacturing.

  As a result of intensive studies to solve the above problems, the present inventor obtained a high molecular weight polyoxyalkylene compound by subjecting a polyhydric alcohol having 3 or more hydroxyl groups per molecule to a high molar addition reaction with alkylene oxide. In this case, first, alkylene oxide is added to the polyhydric alcohol to obtain an alkylene oxide low-mol adduct in a liquid state at 25 ° C., and further alkylene oxide is added to the alkylene oxide low-mol adduct. It was found that this can be solved. The liquid state in this case means a state having fluidity, and even if it partially contains a solid component, it only needs to have fluidity as a whole.

That is, the method for producing a polyoxyalkylene compound according to the present invention comprises a polyoxyalkylene compound in which an alkylene oxide is added to a polyhydric alcohol having 3 or more hydroxyl groups per molecule to add 60 mol or more of alkylene oxide in total. An initial step (I) of obtaining an alkylene oxide low molar adduct by adding 5 mol or more of alkylene oxide to 1 mol of hydroxyl group of the polyhydric alcohol,
An addition mole number adjusting step (II) of adding 5 moles or more of alkylene oxide to 1 mole of hydroxyl group of the alkylene oxide low mole adduct to the alkylene oxide low mole adduct obtained in the initial step,
The alkylene oxide low molar adduct obtained in the initial step (I) is in a liquid state at 25 ° C.

  In a preferred embodiment, all or part of the alkylene oxide low molar adduct obtained in the initial step (I) is transferred to the addition molar number adjusting step (II) in the liquid state in the presence of an alkali catalyst. is there.

  In addition, in the addition mole number adjusting step (II), it is preferable to add an alkali catalyst to add alkylene oxide.

  Further, the alkylene oxide is preferably ethylene oxide, and the polyhydric alcohol having 3 or more hydroxyl groups per molecule is trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol, glycerin and polyhydric acid. It is preferable that it is at least 1 type of polyhydric alcohol selected from the group which consists of glycerol, or its alkylene oxide 3-6 mol addition product.

  Moreover, the polyoxyalkylene compound obtained by this invention is used suitably as additives for hydraulic materials, such as a shrinkage reducing agent of concrete.

  In the present invention, the number of added moles means the average number of moles added and means the average number of moles added per mole of hydroxyl group.

  Examples of the polyhydric alcohol having 3 or more hydroxyl groups per molecule that can be used in the present invention include trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol, glycerin, and polyglycerin. In order to obtain a polyoxyalkylene compound having a high addition mole number, it is preferable to use at least one polyhydric alcohol selected from the group consisting of 3 to 6 mol adducts thereof. Among these, trimethylolpropane or its alkylene oxide 3-6 mol adduct or pentaerythritol or its alkylene oxide 3-6 mol adduct is particularly preferred.

  The alkylene oxide that can be used in the present invention is not particularly limited, but is preferably an alkylene oxide having 2 to 4 carbon atoms from the viewpoint of good reactivity. Specifically, for example, ethylene oxide, propylene, and the like. Examples thereof include oxide and butylene oxide, and one or more of these can be used. Of these, ethylene oxide is particularly preferable.

Initial step for obtaining alkylene oxide low molar adduct (I)
The production method of the present invention includes an initial step (I) in which 5 moles or more of alkylene oxide is added to 1 mole of hydroxyl group of the polyhydric alcohol to obtain a low mole adduct of alkylene oxide in a liquid state at 25 ° C.

  The amount of alkylene oxide added in the initial step (I) is not particularly limited as long as it is 5 mol or more on average with respect to 1 mol of the hydroxyl group of the polyhydric alcohol, but preferably 5 mol or more and 50 mol or less, more preferably 5 mol. It is at least 30 mol and more preferably at least 10 mol but not more than 20 mol. Thereby, the range in which the volume change before and after the reaction in the initial step (I) can be handled by ordinary production equipment, for example, preferably 28 times or less, more preferably 22 times or less, further preferably 16 times or less, and even more preferably. It can be suppressed to 10 times or less.

  Moreover, it is essential that the alkylene oxide low molar adduct obtained in the initial step (I) is in a liquid state at 25 ° C. The liquid state only needs to be in a fluid state, and even if it partially contains a solid component, it may be fluid as a whole. By doing so, operations such as heating during transfer and storage are unnecessary and handling is easy, and productivity such as continuous production is improved.

  The alkylene oxide low molar adduct has a viscosity at 25 ° C. of usually 10 to 5000 mPa · s, preferably 10 to 3000 mPa · s, and more preferably 10 to 2000 mPa · s. The viscosity of the alkylene oxide low-mole adduct may be selected appropriately according to the viscosity using a Brookfield rotary viscometer at a measurement temperature of 25 ° C., and the viscosity value is measured at the time of measurement. Is obtained by calculating from the value (reading value) displayed on the screen and a coefficient determined from the spindle number-rotation speed.

  The number of moles of alkylene oxide added in the low-molecular-weight adduct of alkylene oxide obtained in the initial step (I) is comprehensively defined because the properties of the low-molecular-weight adduct of alkylene oxide differ depending on the type of polyhydric alcohol used for addition, and are not constant. Usually, it is preferably 5 mol or more and 50 mol or less, more preferably 5 mol or more and 30 mol or less, and further preferably 10 mol or more and 20 mol or less with respect to 1 mol of the hydroxyl group of the polyhydric alcohol. is there.

  In the initial step (I), the reaction temperature for adding the alkylene oxide is not particularly limited, but is preferably in the range of 60 to 180 ° C, more preferably in the range of 70 to 170 ° C, and still more preferably in the range of 80 to It is good to set it within the range of 160 degreeC. When the reaction temperature exceeds 180 ° C., by-products such as polyalkylene oxide tend to increase. For example, when a polymer for cement dispersant is obtained using the obtained polyoxyalkylene compound, performance such as water reduction performance Tends to decrease. On the other hand, when the reaction temperature is less than 60 ° C., the addition rate becomes slow and the productivity may be lowered.

  When adding alkylene oxide in the initial step (I), as a catalyst, for example, alkali metals, alkaline earth metals, and hydroxides thereof are preferable, and sodium, sodium amalgam, sodium halide, water are more preferable. One or more of sodium oxide, potassium, potassium amalgam, potassium halide, potassium hydroxide and the like can be used. In addition, although there is no restriction | limiting in particular about the usage-amount of a catalyst, It is preferable to set it as 10-5000 ppm with respect to a polyoxyalkylene compound.

  The addition reaction in the initial step (I) may be carried out batchwise or continuously. Usually, while adding a polyhydric alcohol and, if necessary, the catalyst, an alkylene oxide is continuously added. Done.

  The addition reaction is preferably performed in an inert gas atmosphere such as nitrogen, argon or helium, and particularly preferably in a nitrogen atmosphere. The addition reaction is preferably performed under pressure.

Additional mole number adjustment step (II)
In the production method of the present invention, the number of added moles is adjusted by adding 5 moles or more of alkylene oxide to 1 mole of the hydroxyl group of the alkylene oxide low mole adduct to the alkylene oxide low mole adduct obtained in the initial step (I). It has process (II). As described above, the addition mole number adjustment step (II) is characterized by using the alkylene oxide low-mol adduct in the liquid state at 25 ° C. obtained in the initial step (I).

  In the addition mole number adjusting step (II) in the present invention, the total amount or a part of the alkylene oxide low mole adduct obtained in the initial step (I) can be used. ) Using a portion of the alkylene oxide low molar adduct obtained in the initial step (I), using ordinary equipment without taking into account the increase in product volume relative to the charged capacity, A polyoxyalkylene compound having a high added mole number of alkylene oxide can be produced, which is preferable. Furthermore, according to this method, since it is not necessary to reduce the amount of raw material charged in consideration of the product volume, it is possible to prevent an increase in the relative amount of moisture mixed from the apparatus with respect to the amount of raw material charged. , Increase of by-products such as polyalkylene oxide is suppressed.

  When using a partial amount of the alkylene oxide low molar adduct obtained in the initial step (I), the remaining alkylene oxide low molar adduct not used is temporarily stored in a tank or the like, and further added molar. You may use for number adjustment process (II).

  Moreover, among the total amount of the alkylene oxide low molar adduct obtained in the initial step (I), the addition mole number adjusting step (II) is performed using a part of the amount, and further using at least a part of the remaining amount. It is preferable to carry out the additional mole number adjusting step (II) in two or more times in order to sufficiently exhibit the effects of the present invention.

  The amount of the alkylene oxide low molar adduct used in the addition mole number adjustment step (II) in the present invention is preferably 60% or less of the total capacity of the reactor used in the step. More preferably, it is 55% or less, more preferably 50% or less, still more preferably 45% or less, and particularly preferably 40% or less. In the addition mole number adjustment step (II) in the present invention, since the change in capacity before and after the reaction is small, the addition mole number of alkylene oxide can be improved using ordinary equipment. If the amount of the product used exceeds 60% of the total capacity of the reactor, the amount of alkylene oxide used is limited in ordinary equipment, and it may be difficult to add the alkylene oxide to the desired number of moles. is there.

  In the present invention, when a polyoxyalkylene compound having a very high added mole number is to be obtained, it is preferable to carry out the added mole number adjusting step (II) in two or more steps. Specifically, for example, when a polyoxyalkylene compound having an addition mole number of 200 or more is desired, as an example, a 150 mole adduct of alkylene oxide is added in the first addition mole number adjustment step (II). Then, 50 moles or more of alkylene oxide may be further added to a part of the 150 mole adduct of alkylene oxide obtained.

  In the present invention, in the addition mole number adjustment step (II), after the initial step (I), a part of the obtained alkylene oxide low molar adduct is extracted and transferred to a storage tank or the like, and is the same as the initial step (I). The reaction may be performed using a reactor, or a part of the alkylene oxide low molar adduct obtained in the initial step (I) may be transferred to another reactor and performed in a reactor different from the initial step (I). good.

  In addition mole number adjustment process (II), it is preferable that the usage-amount of allene oxide shall be an average of 400 mol or less with respect to 1 mol of alkylene oxide low molar adducts. The amount of alkylene oxide used is more preferably an average of 300 mol or less, further preferably an average of 250 mol or less, and even more preferably an average of 200 mol or less. Thereby, the range (for example, preferably 25 times or less, more preferably 22 times or less, more preferably 16 times or less, more preferably, the capacity change before and after the reaction in the addition mole number adjusting step (II) can be handled with normal production equipment) More preferably, it can be suppressed to 10 times or less.

  When the amount of alkylene oxide used in the addition mole number adjustment step (II) exceeds 400 moles on average with respect to 1 mole of the alkylene oxide low mole adduct, the capacity change before and after the reaction increases, and a special reactor shape or special A special stirring device must be used. In addition, it is conceivable to reduce the amount of alkylene oxide low-mole adduct used and use normal equipment. In this case, however, the amount of water mixed from the apparatus increases, and by-products such as polyalkylene oxide increase. This is not preferable.

  In the addition mole number adjustment step (II), the reaction temperature for adding the alkylene oxide is not particularly limited, but is preferably in the range of 80 to 180 ° C, more preferably in the range of 90 to 170 ° C, and still more preferably. Is preferably in the range of 100 to 160 ° C. When the reaction temperature exceeds 180 ° C, by-products such as polyalkylene oxide tend to increase. For example, when a polymer for cement additive is obtained using the obtained polyoxyalkylene compound, shrinkage reduction performance, etc. There is a tendency for performance to decrease. On the other hand, when the reaction temperature is less than 80 ° C., the addition rate becomes slow and the productivity decreases, which is not preferable.

  When adding alkylene oxide in the addition mole number adjustment step (II), as the catalyst, for example, alkali metals, alkaline earth metals, and their hydroxides are preferable, and sodium, sodium amalgam, sodium are more preferable. One or more of halide, sodium hydroxide, potassium, potassium amalgam, potassium halide, potassium hydroxide and the like can be used. These catalysts may be added only in the initial step (I) because the catalyst remaining in the product obtained in the initial step (I) acts in the addition mole number adjustment step (II). It is preferable to add both in the initial step (I) and the added mole number adjusting step (II). In addition, although there is no restriction | limiting in particular about the usage-amount of a catalyst, It is preferable to set it as 10-5000 ppm with respect to a polyoxyalkylene compound.

  In addition mole number adjustment process (II), it is a preferable aspect to add the said catalyst and to add an alkylene oxide further.

  The addition reaction in the addition mole number adjustment step (II) may be carried out batchwise or continuously. Usually, while adding the alkylene oxide low molar adduct and, if necessary, the catalyst, Alkylene oxide is continuously added.

  The addition reaction is preferably performed in an inert gas atmosphere such as nitrogen, argon or helium, and particularly preferably in a nitrogen atmosphere. The addition reaction is preferably performed under pressure.

  In addition, the initial step (I) and the added mole number adjustment step (II) may be performed in the same reaction vessel, or each step may be performed in separate reaction vessels, and obtained in the initial step (I). It is a preferred embodiment that the whole or part of the resulting alkylene oxide low molar adduct is transferred and transported in the liquid state to the addition mole number adjusting step (II) in the presence of the catalyst. The temperature of the alkylene oxide low molar adduct during transfer and transportation is not particularly limited as long as the alkylene oxide low molar adduct is in a liquid state, but it is not necessary to perform operations such as heating during transportation or transportation. Above preferred. In addition, in the addition mole number adjustment step (II), when the alkylene oxide is further added by adding the catalyst, if the temperature of the alkylene oxide low molar adduct is high, side reactions are likely to occur. The temperature of the alkylene oxide low molar adduct upon addition of the catalyst is preferably 100 ° C. or lower, more preferably 80 ° C. or lower, still more preferably 60 ° C. or lower, and most preferably 40 ° C. or lower.

  After the addition mole number adjusting step (II), a step of adjusting the concentration of the polyoxyalkylene compound aqueous solution by diluting with water may be provided as necessary.

  According to the present invention, a polyoxyalkylene compound having a total of 60 moles or more of alkylene oxide added can be obtained efficiently. The total number of added moles of alkylene oxide of the polyoxyalkylene compound obtained is preferably 60 to 1000 moles, more preferably 100 to 900 moles, and still more preferably 200 to 800 moles.

  A particularly preferred application of the polyoxyalkylene compound obtained by the production method of the present invention is a cement additive, which is particularly suitable for a drying shrinkage reducing agent. The polyoxyalkylene compound obtained by the production method of the present invention may be used as a main component of the cement additive as it is in the form of an aqueous solution, or may be used in combination with other known cement additives. Other known cement additives include, for example, cement dispersants, air entrainers, cement wetting agents, expansion agents, waterproofing agents, retarders, quick setting agents, separation reducing agents, thickeners, flocculants, drying shrinkage Examples thereof include a reducing agent, a strength enhancer, a self-leveling agent, a rust inhibitor, a colorant, a fungicide, a curing accelerator, and an antifoaming agent.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the examples. Unless otherwise specified, “parts” and “%” described in Examples and Comparative Examples represent “parts by weight” and “% by weight”, respectively.

Example 1 (Production of polyoxyalkylene compound (TMP225))
Initial process (I):
A stainless steel high-pressure reaction vessel equipped with a thermometer, stirrer, nitrogen and ethylene oxide introduction tube was charged with 190 parts of trimellirol propane and 8.59 parts of 48% aqueous sodium hydroxide solution, and the inside of the reaction vessel was purged with nitrogen. The temperature was raised to 80 ° C. in an atmosphere and the mixture was heated and stirred. While heating and stirring, a small amount of nitrogen was circulated, the inside of the reaction vessel was decompressed, the internal temperature was raised to 120 ° C., and dehydration was performed at an internal pressure of 50 mmHg for 1 hour. After dehydration for 1 hour, pressurize with nitrogen, raise the internal temperature to 150 ° C, and increase the internal temperature to 150 ° C under safe pressure (conditions where the nitrogen partial pressure in the reaction vessel is always higher than the ethylene oxide partial pressure). 1871.4 parts of ethylene oxide was introduced into the reaction vessel over 6 hours. Furthermore, the temperature was maintained for 30 minutes to complete the ethylene oxide addition reaction, to obtain 2061.4 parts of ethylene oxide low-mole adduct (A) obtained by adding 10 mol of ethylene oxide per mol of hydroxyl group to trimellirol propane. It was. The resulting ethylene oxide low molar adduct (A) was in a liquid state at 25 ° C. and had a viscosity of 1400 mPa · s.

Additional mole number adjustment step (II):
To another stainless steel high-pressure reaction vessel equipped with a thermometer, a stirrer, nitrogen and an ethylene oxide introduction tube, 340 parts of the ethylene oxide low molar adduct (A) obtained in the first stage was sent through a pipe. Introduced, the inside of the reaction vessel was replaced with nitrogen, the internal temperature was raised to 150 ° C., and the internal temperature was increased to 150 under a safe pressure (a condition in which the nitrogen partial pressure in the reactor was always higher than the ethylene oxide partial pressure) While maintaining the temperature, 2006.3 parts of ethylene oxide was introduced into the reaction vessel over 7 hours. Further, while maintaining the temperature for 30 minutes, 65 mol of ethylene oxide per mol of hydroxyl group was added to the ethylene oxide low mol adduct (A). As a result, 2346.3 parts of a polyoxyalkylene compound (TMP225) in which 225 mol of ethylene oxide was added in total to 1 mol of trimethylolpropane was obtained.

Example 2 (Production of polyoxyalkylene compound (PNT800))
Initial process (I):
A stainless steel high-pressure reaction vessel equipped with a thermometer, stirrer, nitrogen and ethylene oxide introduction tube was charged with 140 parts of pentaerythritol EO 4 mol adduct and 0.67 part of 48% sodium hydroxide, and the inside of the reaction vessel was purged with nitrogen. The mixture was heated to 80 ° C. in a nitrogen atmosphere and stirred with heating. While heating and stirring, a small amount of nitrogen was circulated, the inside of the reaction vessel was decompressed, the internal temperature was raised to 120 ° C., and dehydration was performed at an internal pressure of 50 mmHg for 1 hour. After dehydration for 1 hour, pressurize with nitrogen, raise the internal temperature to 150 ° C, and increase the internal temperature to 150 ° C under safe pressure (conditions where the nitrogen partial pressure in the reaction vessel is always higher than the ethylene oxide partial pressure). In this state, 697.3 parts of ethylene oxide was introduced into the reaction vessel over 5 hours. Further, by maintaining the temperature for 30 minutes to complete the alkyloxide addition reaction, 837.3 parts of ethylene oxide low-mole adduct (B) obtained by adding 10 mol of ethylene oxide per mol of hydroxyl group to pentaerythritol was obtained. It was. The resulting ethylene oxide low molar adduct (B) was in a liquid state at 25 ° C. and had a viscosity of 1100 mPa · s.

Additional mole number adjustment step (II):
400 parts of ethylene oxide low molar adduct (B) obtained in the first stage was sent through a pipe to another stainless steel high-pressure reaction vessel equipped with a thermometer, stirrer, nitrogen and ethylene oxide introduction pipe. Then, 0.315 part of a 48% sodium hydroxide aqueous solution was added, the inside of the reaction vessel was replaced with nitrogen, and the temperature was raised to 80 ° C. in a nitrogen atmosphere, followed by stirring with heating. While heating and stirring, a small amount of nitrogen was circulated, the inside of the reaction vessel was decompressed, the internal temperature was raised to 120 ° C., and dehydration was performed at an internal pressure of 50 mmHg for 1 hour. After dehydration for 1 hour, pressurize with nitrogen, raise the internal temperature to 150 ° C, and increase the internal temperature to 150 ° C under safe pressure (conditions where the nitrogen partial pressure in the reaction vessel is always higher than the ethylene oxide partial pressure). While being held in place, 370.1 parts of ethylene oxide was introduced into the reaction vessel over 4 hours. Furthermore, the temperature was maintained for 30 minutes, and 10 moles of ethylene oxide per mole of hydroxyl group was added to the ethylene oxide low mole adduct (B). As a result, 770.1 parts of a polyoxyalkylene compound (PNT800) in which 80 mol of ethylene oxide was added in total to 1 mol of pentaerythritol was obtained.

Comparative Example 1 :
Initial process (I):
A stainless steel high-pressure reaction vessel equipped with a thermometer, stirrer, nitrogen and ethylene oxide introduction tube was charged with 120 parts of trimellirol propane and 4.35 parts of 48% aqueous sodium hydroxide solution, and the inside of the reaction vessel was purged with nitrogen. The temperature was raised to 80 ° C. in an atmosphere and the mixture was heated and stirred. While heating and stirring, a small amount of nitrogen was circulated, the inside of the reaction vessel was decompressed, the internal temperature was raised to 120 ° C., and dehydration was performed at an internal pressure of 50 mmHg for 1 hour. After dehydration for 1 hour, pressurize with nitrogen, raise the internal temperature to 150 ° C, and increase the internal temperature to 150 ° C under safe pressure (conditions where the nitrogen partial pressure in the reaction vessel is always higher than the ethylene oxide partial pressure). 3545.8 parts of ethylene oxide was introduced into the reaction vessel over 10 hours. Further, the temperature was maintained for 30 minutes to complete the alkyloxide addition reaction, and 3665.8 parts of ethylene oxide low mole adduct (C) obtained by adding 30 moles of ethylene oxide per mole of hydroxyl group to trimellirol propane. Obtained. When the obtained ethylene oxide low molar adduct (C) was cooled to room temperature, it became a solid and it was difficult to transfer, measure, etc. as it was.

Additional mole number adjustment step (II):
A predetermined amount of ethylene oxide low molar adduct (C) is heated and melted to 60 ° C., then transferred, weighed, charged into another reaction vessel as in Example 1, and reacted in the same manner as in Example 1. However, production efficiency was greatly reduced.

[Evaluation of shrinkage reduction]
The polyoxyalkylene compound obtained in the examples was evaluated as a concrete shrinkage reducing agent by a mortar test. As a comparative reference example, an EO6 molar adduct of trimellirolpropane was also evaluated.
(1) Kneading of mortar Kneading of mortar was performed as follows. 225 g of a predetermined amount of polyoxyalkylene compound weighed and diluted with water, 450 g of ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) and standard sand for cement strength test (5.1.3 of JIS R5201-1997 Annex 2) 1350 g of a mortar was kneaded according to the method of JIS R5201-1997 using a Hobart mortar mixer: Model No. N-50 (manufactured by Hobart).

Further, the mortar air amount was adjusted using an air amount adjusting agent as necessary so that the mortar air amount became an air amount ± 3 vol% of the mortar (reference mortar) to which no polyoxyalkylene compound was added. The mortar air amount was measured using a 500 ml graduated cylinder in accordance with JIS A1174 (unit volume mass test method of polymer cement mortar not yet solidified and test method (mass method) based on mass of air amount).
(2) Evaluation of drying shrinkage reduction mortar kneading was carried out by the same method as in item (1) above.
Next, preparation of a mortar specimen (4 × 4 × 16 cm) for evaluating drying shrinkage reduction was performed according to JIS A1129.

  Silicone grease was applied to the mold in advance to stop the water and make it easy to remove the mold. In addition, gauge plugs were attached to both ends of the specimen. The formwork into which the mortar obtained by kneading was poured was put in a container, sealed and stored at 20 ° C., and initial curing was performed. One day later, the mold was removed from the mold, and the silicon grease adhering to the specimen was washed with water using a scourer, and then cured in still water at 20 ° C. for 6 days (water curing).

  A dial gauge (manufactured by West Japan Testing Machine Co., Ltd.) was used according to JIS A1129. After wiping off the water on the surface of the specimen cured in still water for 6 days with a paper towel, the length was measured immediately, and the length at this point was used as a reference. Thereafter, the sample was stored in a constant temperature and humidity chamber set at a temperature of 20 ° C. and a humidity of 60%, and measured in a timely manner. At this time, the length change ratio is the ratio of the shrinkage amount of the polyoxyalkylene compound-added mortar to the shrinkage amount of the reference mortar, as shown by the following formula (2). .

Length change ratio = {(shrinkage amount of mortar added with polyoxyalkylene compound) / (shrinkage amount of reference mortar)} × 100

  As shown in Table 1, it can be seen that the polyoxyalkylene compound of the present invention exhibits good shrinkage reduction performance when used as a concrete shrinkage reducing agent.

  According to the method for producing a polyoxyalkylene compound of the present invention, the number of added moles of alkylene oxide is suppressed using ordinary equipment without suppressing the formation of by-products and considering the increase in the volume of the product relative to the charged capacity. Can be produced with good workability and productivity. In addition, it is not necessary to keep warm when the intermediate obtained in the initial step (I) is once stored in a tank, and after that, even when adding a reaction additive such as a catalyst, it can be mixed at room temperature. There also exists an advantage which can suppress the production | generation of the by-product by heating.

Claims (6)

In this method, an alkylene oxide is added to a polyhydric alcohol having 3 or more hydroxyl groups per molecule to obtain a polyoxyalkylene compound in which a total of 60 moles or more of alkylene oxide is added to 1 mole of the polyhydric alcohol. There,
Initial step (I) of adding 5 moles or more of alkylene oxide to 1 mole of hydroxyl groups of the polyhydric alcohol to obtain an alkylene oxide low mole adduct;
An addition mole number adjusting step (II) of adding 5 moles or more of alkylene oxide to 1 mole of hydroxyl group of the alkylene oxide low mole adduct to the alkylene oxide low mole adduct obtained in the initial step (I); Including
The method for producing a polyoxyalkylene compound, wherein the alkylene oxide low molar adduct obtained in the initial step (I) is in a liquid state at 25 ° C.     All or a part of the alkylene oxide low molar adduct obtained in the initial step (I) is transferred to the addition mole number adjusting step (II) in a liquid state in the presence of an alkali catalyst. The manufacturing method of the polyoxyalkylene compound of Claim 1.     The method for producing a polyoxyalkylene compound according to claim 1 or 2, wherein in the addition mole number adjusting step (II), an alkali catalyst is further added to add alkylene oxide.     The method for producing a polyoxyalkylene compound according to any one of claims 1 to 3, wherein the alkylene oxide is ethylene oxide.     The polyhydric alcohol is at least one polyhydric alcohol selected from the group consisting of trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol, glycerin and polyglycerin, or 3 to 6 mol of alkylene oxide thereof. The method for producing a polyoxyalkylene compound according to claim 1, wherein the method is a product.     The manufacturing method according to claim 1, wherein the polyoxyalkylene compound is used as a shrinkage reducing agent for concrete.