JP2000154049A - Storage and transfer method of alkoxypolyalkylene glycol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably perform the storage and transfer of alkoxypolyalkylene glycol by storing and transferring it in an atmosphere within a container the gaseous contents of which is substituted by an inert gas and/or to the inside of which a radical scavenger is added. SOLUTION: In this method, alkoxypolyalkylene glycol to be stored or transferred is a compound represented by the formula R1O(R2O)nH (wherein R1 is a 1-30C hydrocarbon group; R2O is a 2-18C oxyalkylene group and the R2O repeating units are optionally the same as or different from each other, and when R2O is a mixture of at least two such oxyalkylene groups, the respective repeating units of these oxyalkylene groups are optionally added in a random or block manner; and n is a numerical value of 1-300). Also, when the gaseous contents of a container is substituted by an inert gas, preferably, air in the container is substituted by the inert gas of >=70 vol.% of the total air in the container. Further, as a radical scavenger to be added to the atmosphere, t- butylhydroxytoluene is preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for storing and transferring an alkoxypolyalkylene glycol used as a raw material for a cement dispersant. More specifically, by suppressing the formation of peroxide during storage and transfer and the formation of a gel during the subsequent esterification reaction, the alkoxypolyalkylene glycol used as a raw material of the cement dispersant can be stably stored and stored. The present invention relates to a method for transferring a polymer, a method for producing a polymer used for a cement dispersant using the thus-stored and transferred alkoxypolyalkylene glycol, and a cement dispersant having the polymer.

[0002]

2. Description of the Related Art Since the early deterioration of concrete structures became a social problem in 1981, there has been a strong demand for reducing the unit water content in concrete to improve its durability and workability. Development of a cement composition that satisfies the above condition and a cement dispersant that has a great influence on the quality and performance of the cement composition has been actively conducted.

Of these, Japanese Patent Application Laid-Open No. 9-328,346
In the official gazette, the general formula (1)

[0004]

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(Wherein, R ¹ is a group having 1 to 2 carbon atoms.
And R ² O represents one or a mixture of two or more oxyalkylene groups having 2 to 4 carbon atoms.
In the case of more than one kind, they may be added in block form or in random form, and m is the average number of moles of oxyalkylene group added and represents a number of 1 to 100. An alkoxypolyalkylene glycol represented by the general formula (2):

[0006]

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(Wherein, R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents an alkyl group having 1 to 22 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms). General formula (3) obtained by subjecting the obtained (meth) acrylic acid ester to a transesterification reaction in the presence of a basic catalyst

[0008]

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(Wherein, R ¹ , R ² O and R ³
Is as described above, and n is the average number of added moles of the oxyalkylene group, and represents a number of 1 to 100. 5) to 95% by weight of an alkoxypolyalkylene glycol mono (meth) acrylate monomer (a) represented by the formula (4):

[0010]

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(Wherein, R ³ is as described above, and M ¹ represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or an organic amine group). ) Acrylic acid (salt) monomer (b) 95-
5% by weight, and 0 to 50% by weight of a monomer (c) copolymerizable with these monomers (provided that the total of (a), (b) and (c) is 100% by weight). (A) and / or a polymer salt (B) obtained by further neutralizing the polymer (A) with an alkaline substance, which is excellent in water-reducing performance and has moderate air Mention dispersants with entrainment and good slump retention are disclosed.

However, when the alkoxypolyalkylene glycol used as a raw material of the cement dispersant is stored in an air atmosphere, the peroxide content increases, whereby the alkoxypolyalkylene glycol and (meth) acrylic acid (or (Ester), and has the property of easily forming a gel during the esterification reaction. Further, when polymerization is performed using the monomer mixture obtained by the esterification reaction between the alkoxy polyalkylene glycol in the state where the gel is present and the (meth) acrylic ester according to the method described in the above publication, There is a problem that the molecular weight distribution of the polymer as a product is different from that when no gel is present, and the performance such as cement dispersibility is reduced. Therefore, when the alkoxypolyalkylene glycol is stored in the air for a certain period of time, the gel formed during the esterification reaction must be removed by filtration or the like, and then subjected to a polymerization reaction, which takes time and labor. It is not preferable from an economic viewpoint. Further, for the same reason, it is not preferable from an economical viewpoint to produce an alkoxypolyalkylene glycol at a certain place and then transfer it to another place for use in the esterification reaction.

[0013] Therefore, there is no means for stably storing and transferring the alkoxypolyalkylene glycol. In view of such various problems, the alkoxypolyalkylene glycol has conventionally been used immediately before being subjected to the esterification reaction. Had to be manufactured.

[0014]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for storing and storing alkoxypolyalkylene glycol.
An object of the present invention is to provide a method for stably storing and transferring an alkoxypolyalkylene glycol used as a raw material of a cement dispersant by effectively suppressing the generation of peroxide during a transfer period.

Another object of the present invention is to suppress the formation of peroxide during the storage and transfer of the alkoxypolyalkylene glycol, whereby the subsequent formation of the alkoxypolyalkylene glycol and (meth) acrylic acid (ester) can be prevented. An object of the present invention is to provide a method for stably storing and transferring an alkoxypolyalkylene glycol used as a raw material of a cement dispersant excellent in various properties such as cement dispersibility by preventing gel formation in an esterification reaction.

It is a further object of the present invention to provide a method for producing a polymer used in a cement dispersant using an alkoxypolyalkylene glycol stored and transported by such a method.

It is yet another object of the present invention to provide a cement dispersant having a polymer produced using the alkoxy polyalkylene glycol stored and transported in such a manner.

[0018]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, the alkoxypolyalkylene glycol has been substituted with an inert gas and / or a radical scavenger has been added. Storage / transfer in a humid atmosphere, the formation of peroxide during storage / transfer, and the formation of a gel in the subsequent esterification reaction between alkoxypolyalkylene glycol and (meth) acrylic acid (or ester). They discovered that they were effectively prevented and suppressed, and based on this finding, completed the present invention.

That is, the above objects are as follows:
(F) achieved by any of the above.

(A) In a method for storing and transferring an alkoxypolyalkylene glycol used as a raw material of a cement dispersant, a compound represented by the formula (1):

[0021]

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(Wherein R ¹ represents a hydrocarbon group having 1 to 30 carbon atoms, R ² O represents an oxyalkylene group having 2 to 18 carbon atoms, and the repeating unit of each R ² O is The repeating units of each R ² O may be the same or different, and when R ² O is in the form of a mixture of two or more kinds, the repeating units of each R ² O may be added in blocks or added in a random manner. And n represents the average number of moles of the oxyalkylene group added,
And the inside of the container was replaced with an inert gas, and / or
Alternatively, a method for storing / transferring an alkoxypolyalkylene glycol, which comprises storing / transferring in a vessel an atmosphere containing a radical scavenger.

(A) The above (A), wherein the alkoxypolyalkylene glycol is stored and transported in an atmosphere replaced with an inert gas by 70% or more of the total volume of air in the container. A method for storing and transferring an alkoxypolyalkylene glycol.

(C) The method for storing and transferring an alkoxypolyalkylene glycol according to (A), wherein the radical scavenger is t-butylhydroxytoluene.

(D) The amount of the radical scavenger added is
1 to the amount of alkoxypolyalkylene glycol
The method for storing / transporting an alkoxypolyalkylene glycol according to the above (A) or (C), which is 0 to 1500 ppm.

(E) Equation (1):

[0027]

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(Wherein R ¹ represents a hydrocarbon group having 1 to 30 carbon atoms, R ² O represents an oxyalkylene group having 2 to 18 carbon atoms, and the repeating unit of each R ² O is The repeating units of each R ² O may be the same or different, and when R ² O is in the form of a mixture of two or more kinds, the repeating units of each R ² O may be added in blocks or added in a random manner. And n represents the average number of moles of the oxyalkylene group added,
An esterification reaction between an alkoxypolyalkylene glycol represented by the formula (3) and (meth) acrylic acid, and the formula (3):

[0029]

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(Wherein, R ¹ , R ² and n are as described above, and R ³ represents a hydrogen atom or a methyl group). The obtained alkoxypolyalkylene glycol mono (meth) acrylate, (meth) acrylic acid (salt) and, if necessary, the alkoxypolyalkylene glycol mono (meth) acrylate or (meth) acrylic acid (salt) In the method for producing a polymer used for a cement dispersant, comprising polymerizing a copolymerizable monomer, the alkoxypolyalkylene glycol is preferably prepared by converting the (a) to (d)
The production method according to any one of the above.

(F) A cement dispersant comprising at least a polymer produced by the method described in (e).

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

According to a first aspect of the present invention, a method for storing and transferring an alkoxypolyalkylene glycol is provided in an atmosphere substituted with an inert gas and / or containing a radical scavenger. A method for storing and transferring an alkoxypolyalkylene glycol, which comprises storing and transferring a polyalkylene glycol (hereinafter, also simply referred to as "alkoxypolyalkylene glycol").

In the method of the present invention, the alkoxypolyalkylene glycol is a compound represented by the following formula (1).

[0035]

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In the above formula (1), R ¹ represents a hydrocarbon group having 1 to 30 carbon atoms, preferably 1 to 18 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n -Butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group, 2-ethylhexyl group, decyl group, dodecyl group, undecyl group, tridecyl group, tetradecyl group, pentadecyl group,
Alkyl groups such as hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, heneicosyl group, docosyl group; aryl groups such as phenyl group;
An alkylphenyl group such as a benzyl group and a nonylphenyl group; a cycloalkyl group such as a cyclohexyl group; an alkenyl group; an alkynyl group. Of these, a methyl group, an ethyl group, a propyl group, a butyl group and a phenyl group are preferred. R ² O has 2 to 2 carbon atoms.
18, preferably 2 to 8 linear or branched oxyalkylene groups, such as an oxyethylene group, an oxypropylene group, an oxybutylene group, and an oxystyrene group. , An oxypropylene group and an oxybutylene group. At this time, the repeating unit of each R ² O may be the same or different, and when R ² O is in the form of a mixture of two or more, each R ² O
The repeating units of ² O may be added in block form or in random form. Further, n is R
Represents the average number of moles of repeating units of ² O (oxyalkylene group), 1 to 300, preferably 5 to 200,
The number is more preferably 8 to 150.

In the present invention, the storage / transfer form of the alkoxypolyalkylene glycol represented by the formula (1) is
Even if one kind is present alone or 2
It may be in the form of a mixture of more than one species.
Further, when the alkoxypolyalkylene glycol represented by the formula (1) is present in the form of a mixture of two or more, the presence form is not particularly limited.
It is sufficient that at least one of R ¹ , R ² O and n is used in a mixture of two or more different types. Preferably, R ¹ is composed of two types, a methyl group and a butyl group. , R ² O is composed of two kinds of oxyethylene group and oxypropylene group, n is 1 to 10
, And 11 to 100, and a combination of 〜 and 適宜 as appropriate.

In the present invention, the inert gas when the alkoxypolyalkylene glycol is stored / transferred in an atmosphere replaced with an inert gas is not particularly limited, but includes nitrogen gas, helium gas and argon gas. Among them, nitrogen gas and helium gas, particularly nitrogen gas, are preferably used in consideration of cost and ease of handling.

In the present invention, when the alkoxypolyalkylene glycol is stored and transported in an atmosphere in which the inert gas is replaced, the atmosphere in the container is completely replaced with the inert gas. Needless to say, it is preferable to store and transfer the alkoxypolyalkylene glycol. However, the volume of air in the container is usually 70% or more, preferably 80% by volume, relative to the total volume of air in the container. % Or more, more preferably 90% or more, and most preferably 95% or more. At this time, if the replacement ratio of the inert gas is less than 70%, the air in the container is not sufficiently replaced by the inert gas, and the formation of peroxide and the formation of a gel during the subsequent esterification reaction are effectively performed. Not suppressed and not preferred.

In the present invention, the radical scavenger used when the alkoxypolyalkylene glycol is stored and transported in an atmosphere containing the radical scavenger is t-butylhydroxytoluene (2,6-di- -T-butyl-p-cresol (2,6-di-t-butyl-p-cres
ol) (hereinafter sometimes simply referred to as "BHT"),
α, α-diphenyl-β-picrylhydrazyl, N,
N, N ′, N′-tetraethyl-p-phenylenediamine, N- (3-N-oxyanilino-1,3-dimethylbutylidene) aniline oxide, p, p′-difluorodiphenylamino, chloranil, iodine, and Iron (III) chloride and the like. Of these, t-butylhydroxytoluene is preferably used in the present invention.

The amount of the radical scavenger added in the above embodiment is an amount that effectively suppresses the formation of peroxide in the container during the storage / transfer period and / or the formation of a gel during the subsequent ester reaction. It is not particularly limited as long as it is present, but is usually 10 to 1500 ppm, preferably 100 to 120 ppm based on the amount of the alkoxypolyalkylene glycol.
0 ppm, more preferably within the range of 200 to 1000 ppm. At this time, the amount of the radical scavenger added was 10 p.
If it is less than pm, the effect of the addition of the radical scavenger is insufficient, and the formation of peroxide and the formation of gel during the subsequent esterification reaction are not effectively suppressed, which is not preferable. On the other hand, when the added amount of the radical scavenger is 150
If it exceeds 0 ppm, the effect corresponding to the excessive addition cannot be obtained, which is also not preferable.

In the present invention, the alkoxypolyalkylene glycol can be stored and transported in a sufficiently stable state in an atmosphere replaced with an inert gas or in an atmosphere to which a radical scavenger is added. If this is the case, the alkoxypolyalkylene glycol may be stored and transported in a state in which these are combined, that is, in an atmosphere in which an inert gas is substituted and a radical scavenger is added.

According to a second concept of the present invention, an esterification reaction between an alkoxypolyalkylene glycol according to the first concept (hereinafter simply referred to as an alkoxypolyalkylene glycol) and (meth) acrylic acid is carried out,
Equation (3):

[0044]

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(Wherein, R ¹ , R ² and n are as described above, and R ³ represents a hydrogen atom or a methyl group). The alkoxypolyalkylene glycol mono (meth) acrylate, (meth) acrylic acid (salt) and, if necessary, the alkoxypolyalkylene glycol mono (meth) acrylate or (meth) There is provided a method for producing a polymer used in a cement dispersant comprising polymerizing a monomer copolymerizable with acrylic acid (salt). By the above method, the alkoxypolyalkylene glycol used as a raw material for the esterification reaction can be stably stored and transferred for a long period of time without generating peroxide. Even when it is used, it can be directly used for the polymerization reaction without requiring a step of removing the gel formed after the esterification reaction by filtration or the like, which is very preferable from an economic viewpoint.

The production method of the above concept will be described in detail below, divided into an esterification reaction and a polymerization reaction.

(I) Esterification Reaction The esterification reaction between the alkoxypolyalkylene glycol and (meth) acrylic acid according to the above concept is not particularly limited except that the alkoxypolyalkylene glycol according to the first concept is used as a raw material. Instead, a conventionally known method is used. More specifically,
8,338, JP-A-9-86,990 and JP-A-9-286,645, or in the same manner as known methods, or if necessary, a dehydrating solvent, an acid, or the like. An esterification reaction between an alkoxypolyalkylene glycol and (meth) acrylic acid in the presence of a catalyst or a polymerization inhibitor may be mentioned. An embodiment of the esterification step particularly suitable in the present invention will be described below.

First, an alkoxypolyalkylene glycol according to the first concept, (meth) acrylic acid, a dehydrating solvent, an acid catalyst and a polymerization inhibitor as raw materials are charged into a reaction system (reaction tank). Until a predetermined esterification ratio is reached.

As the (meth) acrylic acid that can be used in the above ester reaction, acrylic acid and methacrylic acid may be used alone or in combination, and the mixing ratio may be arbitrarily determined. Can be adopted.

The mixing ratio of the above raw materials used in the esterification reaction is stoichiometrically 1: 1 (molar ratio).
In practice, there is no particular limitation as long as the esterification reaction between the alkoxypolyalkylene glycol and (meth) acrylic acid proceeds efficiently, but usually, one of the raw materials is excessively used to carry out the esterification. To speed up the reaction,
From the point of purification of the desired esterified product, an excess of a raw material having a lower boiling point which is easily distilled off is used. In the present invention,
When the reaction product water and the dehydrating solvent are azeotropically distilled during the esterification reaction, part of the low-boiling point (meth) acrylic acid is also distilled out and taken out of the reaction system. It is preferable that the amount of (meth) acrylic acid used (the amount charged) is added in excess of the amount calculated stoichiometrically with respect to the amount). In particular,
The amount of (meth) acrylic acid to be used is generally 1.0 to 30 mol, preferably 1.2 to 10 mol, per 1 mol of the alkoxypolyalkylene glycol. When the amount of the (meth) acrylic acid is less than 1.0 mol per 1 mol of the alkoxypolyalkylene glycol, the esterification reaction does not proceed smoothly, and the yield of the desired esterified product is insufficient. On the other hand, if it exceeds 30 moles, no improvement in yield corresponding to the addition is observed, which is uneconomical and is not preferred.

The above-mentioned esterification reaction may be carried out in the presence of an acid catalyst or a basic catalyst. However, considering that the reaction proceeds quickly, the esterification reaction may be carried out in the presence of an acid catalyst. desirable. In this case, examples of the acid catalyst that can be used for the esterification reaction include sulfuric acid, methanesulfonic acid, paratoluenesulfonic acid, paratoluenesulfonic acid hydrate, xylenesulfonic acid, xylenesulfonic acid hydrate, and naphthalene. Sulfonic acid, naphthalene sulfonic acid hydrate, trifluoromethane sulfonic acid, “Nafion” resin, “Amberlyst”
15 "resin, phosphotungstic acid, phosphotungstic acid hydrate, hydrochloric acid and the like, among which sulfuric acid,
Examples thereof include p-toluenesulfonic acid, p-toluenesulfonic acid hydrate, and methanesulfonic acid. Of these, considering the difficulty of cutting the alkoxypolyalkylene glycol raw material, which is the cause of the formation of the impurity diester which causes the deterioration of the quality and performance of the produced esterified product, paratoluenesulfonic acid and paratoluenesulfonic acid are considered. Acid hydrates are particularly preferably used.

The amount of the acid catalyst to be used is not particularly limited as long as the desired catalytic action can be effectively exhibited, but it is usually 0.4 meq / g or less, preferably 0.4 meq / g or less. It is in the range of 0.36 to 0.01 meq / g, more preferably 0.32 to 0.05 meq / g. At this time, if the amount of the acid catalyst used exceeds 0.4 meq / g, the amount of diester formed in the reaction system at the time of the esterification reaction increases, and the ester is synthesized using the esterified product obtained by the esterification reaction. The use performance of the cement dispersant or the like, for example, the cement dispersing ability or the like is reduced.

In the present specification, the amount of use of the acid catalyst (milli-equivalent / g) is based on the number of equivalents of H ⁺ of the acid catalyst used in the reaction (milli-equivalent), and It is represented by a value obtained by dividing by the total amount (g) of acrylic acid charged. More specifically, it is a value calculated by the following equation.

[0054]

(Equation 1)

The above-mentioned acid catalyst may be added to the reaction system all at once, continuously or sequentially. However, from the viewpoint of workability, it is preferable to charge the acid catalyst together with the raw materials in the reaction tank.

The esterification reaction according to the above concept is
The reaction is preferably performed in the presence of a polymerization inhibitor. By using a polymerization inhibitor, it is possible to prevent polymerization of the raw materials of alkoxypolyalkylene glycol and (meth) acrylic acid, an esterified product of the product, or a mixture thereof. As the polymerization inhibitor that can be used in the above esterification reaction, a known polymerization inhibitor can be used and is not particularly limited. For example, phenothiazine, tri-p-nitrophenylmethyl, di-p-fluoro Phenylamine, diphenylpicrylhydrazyl,
N- (3-N-oxyanilino-1,3-dimethylbutylidene) aniline oxide, benzoquinone, hydroquinone, methoquinone, butylcatechol, nitrosobenzene, picric acid, dithiobenzoyl disulfide, cuperon, copper (II) chloride and the like. . Of these,
Phenothiazine, hydroquinone, and methoquinone are preferably used because of the solubility of the dehydrating solvent and generated water. These polymerization inhibitors may be used alone or in combination of two or more. Above all, phenothiazine, hydroquinone and methoquinone,
As described above, after the esterification reaction, even when the dehydrating solvent is distilled off by azeotropic distillation with water, the polymerization inhibition ability can be extremely effectively achieved without using a water-soluble polymerization inhibitor having weak but polymerization activity. Is very useful because the formation of a high molecular weight body can be effectively suppressed.

The amount of the polymerization inhibitor used is 0.001 to 1% by weight based on the total charged amount of the alkoxypolyalkylene glycol and (meth) acrylic acid as the raw materials.
Preferably it is in the range of 0.001 to 0.1% by weight.
When the amount of the polymerization inhibitor is less than 0.001% by weight,
The polymerization inhibitor is not sufficiently developed, and it is difficult to effectively prevent polymerization of the alkoxypolyalkylene glycol as the raw material, (meth) acrylic acid, the esterified product as the product, or a mixture thereof. If the amount exceeds 1% by weight, the amount of the polymerization inhibitor remaining in the product esterified product increases, which is not preferable in terms of quality and performance, and also has an additional effect commensurate with excessive addition. It is not preferable from an economic viewpoint.

Further, the esterification reaction according to the above concept is preferably carried out in a dehydrating solvent. In the present specification, the dehydration solvent is defined as a solvent that azeotropes with water. That is, by using a dehydrating solvent,
The reaction product water generated by the esterification reaction can be efficiently azeotropically distilled. As a dehydrating solvent,
For example, benzene, toluene, xylene, cyclohexane, dioxane, pentane, hexane, heptane, chlorobenzene, isopropyl ether and the like can be mentioned, and these can be used alone or in combination of two or more. Among them, those having an azeotropic temperature with water of 150 ° C. or lower, more preferably in the range of 60 to 90 ° C. are preferable, and specific examples thereof include cyclohexane, toluene, dioxane, benzene, isopropyl ether, hexane, heptane and the like. No. If the azeotropic temperature with water exceeds 150 ° C., it is not preferable in terms of handling (including control of the temperature in the reaction system during the reaction and control of the condensation and liquefaction of the azeotrope).

It is desirable that the dehydrating solvent be refluxed while being azeotropically oxidized with the reaction water outside the reaction system, and condensed and liquefied to form the reaction water and separating and removing the water. 1 to 1 with respect to the total charged amount of the alkoxypolyalkylene glycol and the (meth) acrylic acid.
00% by weight, preferably in the range of 2 to 50% by weight. When the amount of the dehydrating solvent is less than 1% by weight, the reaction water generated during the esterification reaction cannot be sufficiently removed from the reaction system by azeotropic distillation, and the equilibrium reaction of the esterification does not easily proceed. No dehydrating solvent usage is 100
If the amount exceeds 10% by weight, an effect equivalent to excessive addition cannot be obtained, and a large amount of heat is required to maintain a constant reaction temperature, which is not preferable from an economic viewpoint.

In the present invention, the esterification reaction can be performed either batchwise or continuously, but is preferably performed batchwise.

The reaction conditions for the esterification reaction may be any conditions under which the esterification reaction proceeds smoothly. For example, the reaction temperature is 30 to 140 ° C., preferably 6 to 140 ° C.
0 to 130 ° C, more preferably 90 to 125 ° C, particularly preferably 100 to 120 ° C.
This is a general (in a broad sense) esterification reaction condition of the present invention, in which the above-mentioned dehydrating solvent is azeotroped with the reaction product water outside the reaction system, and the reaction product water is condensed and liquefied and refluxed while being separated and removed. This is one example, and is included in these ranges, but does not completely match. ). When the reaction temperature is lower than 30 ° C., the reflux of the dehydrating solvent is slow and dehydration takes a long time, and the esterification reaction does not easily proceed, which is not preferable. On the other hand, when the reaction temperature exceeds 140 ° C., the cleavage of the alkoxypolyalkylene glycol as a raw material generates an excessive amount of diester, and in addition to the cement dispersing performance, the dispersing performance and the thickening property in various applications are reduced, It is still unfavorable, such as deterioration of the performance and quality of the product esterified product, such as polymerization of the raw material or an increase in the amount of the raw material mixed into the azeotrope. Further, the reaction time is such that the esterification rate is at least 70 as described later.
%, Preferably at least up to 80%, but is usually between 1 and 50 hours, preferably between 3 and 40 hours. Further, the esterification reaction according to the present invention may be carried out under normal pressure or under reduced pressure, but is preferably carried out under normal pressure from the viewpoint of facilities.

The esterification rate in the esterification reaction according to the present invention is 70% or more, more preferably 70 to 99.
%, Most preferably 80-98%. If the esterification rate is less than 70%, the yield of the produced esterified product is insufficient, and the application performance of a cement dispersant or the like obtained using the esterified product as a raw material, for example, the cement dispersing ability or the like is reduced. As used herein, the term "esterification ratio" refers to the amount of an alkoxypolyalkylene glycol, which is a starting material for esterification, at the time of preparation and at the time of completion of the esterification reaction. The area of the LC was measured by chromatography (LC) to determine the amount of reduction of the alkoxypolyalkylene glycol, and the reduction was divided by the amount of the alkoxypolyalkylene glycol at the time of preparation to obtain a value (%) calculated by: More specifically, it means a value obtained by the following equation.

[0063]

(Equation 2)

Esterification ratio measurement conditions Analyzer: Waters Millennium chromatography manager Detector: Waters 410 RI detector Column used: GL Sciences Inertsyl ODS-2 3 columns Temperature: 40 ° C. Eluent: 8946 g of acetonitrile 6000 g acetic acid 54 g was mixed and adjusted to pH 4.0 with a 30% aqueous sodium hydroxide solution. Flow rate: 0.6 ml / min Since the esterification rate was determined by the above equation, the esterification rate was 100%. Never exceed. Therefore, in the present invention, it is assumed that the esterification reaction has been completed when the esterification ratio has exceeded the specified value.

Although the esterification step has been described above, when the esterification reaction (I) is carried out in the presence of an acid catalyst, the acid catalyst is interposed between this step and the polymerization reaction described in detail below. Or a partial neutralization step of neutralizing all of the acid catalyst and a part of the (meth) acrylic acid, and after the partial neutralization step,
It is desirable to carry out a solvent removing step of removing the dehydrated solvent from the reaction solution by azeotropic distillation with water. Therefore, the partial neutralization step and the solvent removal step will be described below.

(II) Partial Neutralization Step This step is carried out in the step of distilling off the dehydrating solvent after the esterification reaction, when azeotropic distillation is carried out by adding water, or in order to carry out further polymerization using an esterified product. When an aqueous solution of an esterified product is prepared by adding water for adjustment later, hydrolysis is caused by an acid catalyst, resulting in deterioration of the quality and performance of the esterified product. When the esterification product is used to synthesize a polymer used in a cement dispersant, the hydrolysis product becomes an impurity not involved in the polymerization. In order to solve the problem that the polymerization rate (and thus the productivity) is reduced and the quality and performance of the polymer are deteriorated, the esterification step (I) After the reaction,
It consists of neutralizing the acid catalyst with an alkali at 90 ° C. or lower. This makes it possible to obtain a high-purity and high-quality esterified product without producing a hydrolysis product in the treatment process after the esterification reaction.

(III) Solvent Evaporation Step In this step, as described in the above (I), since the esterification reaction is performed in a dehydrated solvent, the esterification reaction was carried out in the above esterification step (I). Subsequently, the dehydrating solvent is distilled off from the reaction solution. Further, when the esterification reaction is carried out in the presence of an acid catalyst, after the esterification reaction is carried out in the esterification step of the above (I), the above (II)
And a part of the (meth) acrylic acid is neutralized by the partial neutralization step, and then the dehydrating solvent is distilled off from the reaction solution.

According to a preferred embodiment of the solvent distillation step,
This will be described below.

In the present invention, after completion of the esterification reaction (partial neutralization treatment is carried out if necessary), when the dehydrating solvent is distilled off from the reaction solution in the solvent distilling step, the alkoxypolyether as a raw material is removed. Preferably 1000 ppm based on the total amount of the alkylene glycol and the (meth) acrylic acid used.
The method is characterized in that a water-soluble polymerization inhibitor of 500 ppm or less, still more preferably 300 ppm or less, is added to the reaction solution, particularly preferably without addition. That is, by adding a water-soluble polymerization inhibitor that was originally added for the purpose of inhibiting polymerization, the polymerization inhibitor is weak but has polymerization activity. The polymerization of the esterified product or a mixture thereof, which is a product, was found to have resulted in the formation of a high molecular weight product, and the polymerization inhibitor added at the time of the esterification reaction was effective even when the dehydrating solvent was distilled off. And found that the generation of a high molecular weight product can be prevented without using any of these water-soluble polymerization inhibitors. Therefore, when the amount of the water-soluble polymerization inhibitor used exceeds 1000 ppm based on the total amount of the alkoxypolyalkylene glycol and (meth) acrylic acid used as the raw materials, the polymerization activity of the water-soluble polymerization inhibitor causes , 2.0% by area or more of high molecular weight substances, and when an esterified product containing these is used as a monomer component, it is not preferable because it affects a cement dispersant using the obtained polymer. .

In the present solvent distillation step, the esterification reaction is carried out in the presence of a polymerization inhibitor. However, as described above, the polymerization inhibitor reacts after the esterification reaction (further, after the partial neutralization treatment). If also works,
In the present solvent distilling step, it is not necessary to newly replenish the polymerization inhibitor with the solution in the system, but if the partial neutralization treatment is performed using a low-concentration alkaline aqueous solution, the reaction solution There is a relatively large amount of water. Therefore, for example, only when the polymerization inhibitor used in performing the esterification reaction is hardly soluble or insoluble in water and cannot function so effectively after the esterification reaction (and further after the partial neutralization treatment). Since unreacted raw materials and esterified products may be dissolved in water and polymerized, the relationship between the polymerization activity of the water-soluble polymerization inhibitor due to its polymerization activity and the inherent polymerization inhibition ability From, within a range in which the polymerization inhibiting ability can be more effectively exhibited than the polymerization activity (the range defined above), a water-soluble polymerization inhibitor is added to the reaction solution, and then the temperature is raised to the temperature specified below, and the dehydrating solvent is removed. It is desirable to distill off by azeotropic distillation with water.

Here, the water-soluble polymerization inhibitor that can be used is not particularly limited, and examples thereof include hydroquinone, methoquinone, catechol and derivatives thereof (for example, pt-butyl catechol and the like).
Hydroquinone monomethyl ether and the like can be mentioned. Among them, hydroquinone and methoquinone are preferred because they have relatively low polymerization activity. These water-soluble polymerization inhibitors may be used alone or in combination of two or more.

Further, in the present invention, after the esterification reaction is completed (partial neutralization treatment is performed if necessary), in the solvent removal step, when the dehydrating solvent is distilled off from the reaction solution, By contacting with an inert gas, the dehydrating solvent dissolved in the reaction solution can be expelled very efficiently by the inert gas, and even if the resulting esterified product is prevented from generating a solvent odor. Good.

Here, the polymerization reaction according to the present invention will be described in detail below.

(IV) Polymerization Reaction The polymerization reaction according to the present invention does not depart from the above-mentioned object of the present invention, and the alkoxypolyalkylene glycol mono (meth) acrylate of the formula (3) obtained by the above step is obtained. It is not particularly limited except that it is obtained by using a monomer (hereinafter, also simply referred to as an esterified monomer) as a monomer component. For example, Japanese Patent Publication No. 59-18338 Gazette, JP-A-9-869
In the same manner as in a known method such as the method described in JP-A No. 90-90 and JP-A-9-286645, the esterified monomer, (meth) acrylic acid (salt), and, if necessary, A monomer copolymerizable with a body component (hereinafter, also simply referred to as another monomer) can be subjected to a polymerization reaction, but is not limited thereto, and each of the publications exemplified in the detailed description It goes without saying that not only the polymerization methods described in (1) to (5) above, but also various conventionally known polymerization methods can be applied.

Specifically, for example, the polymer according to the present invention is obtained by converting an esterified monomer into a (meth) acrylic acid (salt)
It can be obtained by a polymerization reaction with a monomer and, if necessary, a monomer copolymerizable with these monomers. At this time, the mixing ratio of the esterified monomer, (meth) acrylic acid (salt), and if necessary, other monomers is not particularly limited as long as the desired polymer can be obtained. However, specifically, the mixing ratio of the esterified monomer is preferably 99 to 5% by weight, more preferably 95 to 10% by weight, based on the weight of all raw materials, and (meth)
The mixing ratio of acrylic acid (salt) is based on the weight of all raw materials,
It is preferably from 95 to 1% by weight, more preferably from 90 to 5% by weight, and the mixing ratio of other monomers is preferably from 0 to 50% by weight, more preferably from 0 to 50% by weight, based on the weight of all raw materials. -10% by weight.

In the present polymerization step, the content of the high-molecular-weight compound in the esterified monomer is preferably 2.0% by area or less. The content of the high molecular weight substance is calculated based on the area ratio calculated by the liquid chromatogram measurement method, and specifically, in the graph measured under the following liquid chromatogram measurement conditions, Represents the ratio of the area of the measured peak portion of the high molecular weight substance detected in addition to the measured peak portion of the target esterified product to the area of the measured peak portion of the esterified product.

<Liquid chromatogram measurement conditions> Analyzer: CR-4A manufactured by Shimadzu Corporation Detector: 410 RI detector manufactured by Waters 496 UV detector manufactured by Waters Column used: ODS-120P manufactured by Tosoh Corporation One Tosoh stock One ODS-80PS manufactured by the company Column temperature: 40 ° C Eluent: 1% phosphoric acid aqueous solution 1000 ml Acetonitrile 1000 ml was prepared by mixing.

Flow rate: 1.0 ml / min Here, in order to obtain a desired polymer, the above-mentioned esterified monomer component and the like may be copolymerized using a polymerization initiator.
The copolymerization can be performed by a method such as polymerization in a solvent or bulk polymerization.

The polymerization in a solvent can be carried out either batchwise or continuously.
Water; lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane, and n-hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone. And the like. From the solubility of the monomer component of the raw material esterified product and the obtained copolymer and the convenience at the time of using the copolymer, at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. It is preferable to use one kind. In that case, among lower alcohols having 1 to 4 carbon atoms, methyl alcohol, ethyl alcohol, isopropyl alcohol and the like are particularly effective.

When the polymerization is carried out in an aqueous medium, a water-soluble polymerization initiator such as ammonium or alkali metal persulfate or hydrogen peroxide is used as the polymerization initiator.
At this time, an accelerator such as sodium bisulfite and Mohr's salt can be used in combination. For polymerization using a lower alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester compound or a ketone compound as a solvent, a peroxide such as benzoyl peroxide or lauroyl peroxide; a hydroperoxide such as cumene hydroperoxide; An aromatic azo compound such as bisisobutyronitrile is used as a polymerization initiator. In this case, an accelerator such as an amine compound can be used in combination. Further, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various polymerization initiators or a combination of the polymerization initiator and the accelerator. The polymerization temperature is appropriately determined depending on the solvent and the polymerization initiator used.
It is performed within the range of 20 ° C.

The bulk polymerization is carried out using a polymerization initiator such as peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; aliphatic azo compounds such as azobisisobutyronitrile; It is performed within a temperature range of 200 ° C.

For controlling the molecular weight of the obtained polymer, a thiol chain transfer agent can be used in combination. The thiol-based chain transfer agent used at this time has the general formula HS
-R ⁵ -E _g (wherein, R ⁵ represents an alkyl group having 1 to 2 carbon atoms, and E represents -OH, -COOM ² , -C
OOR ⁶ or —SO ₃ M ² represents a group, wherein M ² is hydrogen,
Represents a monovalent metal, a divalent metal, an ammonium group or an organic amine group, R ⁶ represents an alkyl group having 1 to 10 carbon atoms, and g represents an integer of 1 to 2. And, for example, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, and octyl 3-mercaptopropionate. One or more of these can be used.

The polymer thus obtained can be used as it is as a main component of a cement dispersant. If necessary, a polymer salt obtained by further neutralizing with an alkaline substance can be used as a cement dispersant. May be used as a main component of various applications. Preferred examples of such an alkaline substance include inorganic substances such as hydroxides, chlorides and carbon salts of monovalent metals and divalent metals; ammonia; and organic amines.

In the polymerization step according to the present invention, the esterified monomer components represented by the above formula (3) which can be used may be used alone or as a mixture of two or more. May be. In particular, when a mixture of two or more types is used, it is desirable to appropriately combine types having different expression characteristics so that desired characteristics (function, performance, etc.) can be exhibited. , The following two combinations are advantageous.

That is, in the esterified product of the formula (3), the average number of added moles n is 1 to 97, preferably 1 to 10
Represents an integer. A) a first esterified compound (a)
¹ ) and the average number of added moles n is 4 to 100, preferably 1
Represents an integer of 1 to 100. Second ester represented by) (a mixture of a ²⁾ (provided that the second esterified product (a ²⁾ the average number of moles of added towards the average addition mole number of the first esterified product (a ¹⁾ Greater than 3) is advantageous.

The method for producing such a mixture of the first esterified product (a ¹ ) and the second esterified product (a ² ) is as described in the method for producing the esterified product. The first and second esterified compounds (a ¹ ) and (a ² ) may be separately produced by an esterification reaction, or a mixture of the corresponding alkoxypolyalkylene glycol and (meth) acrylic acid, respectively. It may be produced by a reaction. In particular, the latter method can provide an industrially inexpensive production method.

In this case, the weight ratio of the first esterified product (a ¹ ) to the second esterified product (a ² ) is 5: 95-9.
The ratio is 5: 5, preferably 10:90 to 90:10.

Examples of the ^first esterified product (a ¹ ) include methoxy (poly) ethylene glycol mono (meth) acrylate, methoxy (poly) propylene glycol mono (meth) acrylate, and methoxy (poly) butylene glycol mono (meth) acrylate. ) Acrylate, methoxy (poly) ethylene glycol (poly) propylene glycol mono (meth) acrylate, methoxy (poly) ethylene glycol (poly) butylene glycol mono (meth) acrylate, methoxy (poly) propylene glycol (poly) butylene glycol mono ( (Meth) acrylate, methoxy (poly) ethylene glycol (poly) propylene glycol (poly) butylene glycol mono (meth) acrylate, ethoxy (poly) ethylene glycol mono (meth) acryl Ethoxy (poly) propylene glycol mono (meth) acrylate, ethoxy (poly) butylene glycol mono (meth) acrylate, ethoxy (poly) ethylene glycol (poly) propylene glycol mono (eta) acrylate, ethoxy (poly) ethylene glycol (Poly) butylene glycol mono (meth) acrylate, ethoxy (poly) propylene glycol (poly) butylene glycol mono (meth) acrylate, ethoxy (poly) ethylene glycol (poly) propylene glycol (poly) butylene glycol mono (meth) acrylate, etc. Is exemplified. First
It is important that the esterified product (a ¹ ) has hydrophobicity in the short-chain alcohol of its side chain.

From the viewpoint of easy copolymerization, the side chain preferably contains a large amount of ethylene glycol units. Therefore, (a ¹ ) is preferably (alkoxy) (poly) ethylene glycol mono (meth) acrylate having an average addition mole number of 1 to 97, preferably 1 to 10.

Examples of the ^second esterified product (a ² ) include methoxypolyethylene glycol mono (meth) acrylate and methoxypolyethylene glycol (poly)
Propylene glycol mono (meth) acrylate, methoxy polyethylene glycol (poly) butylene glycol mono (meth) acrylate, methoxy polyethylene glycol (poly) propylene glycol (poly) butylene glycol mono (meth) acrylate, ethoxy polyethylene glycol mono (meth) acrylate, Examples include ethoxy polyethylene glycol (poly) propylene glycol mono (meth) acrylate, ethoxy polyethylene glycol (poly) butylene glycol mono (meth) acrylate, and ethoxy polyethylene glycol (poly) propylene glycol (poly) butylene glycol mono (meth) acrylate. You.

In order to obtain high water reduction, it is important to disperse the cement particles due to steric repulsion and hydrophilicity caused by the alcohol chain having an average addition mole number of the second esterified product (a ² ) of 4 to 100. . For this purpose, it is preferable that a large number of oxyethylene groups be introduced into the polyalkylene glycol chain, and a polyethylene glycol chain is most preferable. Therefore, the average addition mole number n of the alkylene glycol chain of the second esterified product (a ² ) is 4 to 100, preferably 11 to 100.

Examples of the (meth) acrylic acid (salt) monomer which can be used in the method for producing a polymer of the present invention include acrylic acid, methacrylic acid and monovalent metal salts of these acids, Examples thereof include divalent metal salts, ammonium salts, and organic amine salts, and one or more of these can be used.

In the polymerization step according to the present invention, an esterified monomer and (meth)
Examples of monomers copolymerizable with the monomer component of acrylic acid (salt) monomer include dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid; HO (R ¹¹ O) _r R ¹² (However,
R ¹¹ O represents one or a mixture of two or more oxyalkylene groups having 2 to 4 carbon atoms, and in the case of two or more, they may be added in blocks or in random form; r represents the average number of moles of the oxyalkylene group and represents an integer of 1 to 100; R ¹² represents hydrogen or an alkyl group having 1 to 22, preferably 1 to 15 carbon atoms. Monoesters or diesters with alcohols represented by the following formulas); unsaturated amides such as (meth) acrylamide and (meth) acrylalkylamide; vinyl esters such as vinyl acetate and vinyl propionate; vinylsulfonic acid and (meth) Unsaturated sulfonic acids such as allylsulfonic acid, sulfoethyl (meth) acrylate, 2-methylpropanesulfonic acid (meth) acrylamide and styrenesulfonic acid, and monovalent metal salts, divalent metal salts, almonium salts, and organic amine salts thereof; Styrene, α-
Aromatic vinyls such as methylstyrene; having 1 to 1 carbon atoms
8, preferably 1 to 15 esters of a phenyl group-containing alcohol such as an aliphatic alcohol or benzyl alcohol with (meth) acrylic acid; polyalkylene glycol mono (meth) acrylate; polyalkylene glycol mono (meth) allyl ether And one or more of these can be used.

The polymer thus obtained (which includes any of the above-mentioned esterified monomers polymerized using one kind or two or more kinds, and if necessary,
Further, a polymer salt obtained by neutralization with an alkaline substance) has a weight average molecular weight of 5 in terms of polyethylene glycol by gel permeation chromatography.
It is preferably in the range of from 00 to 500,000, particularly preferably from 5,000 to 300,000. The value obtained by subtracting the peak top molecular weight from the weight average molecular weight of the polymer is 0 to 80.
00, preferably 0-7000
It is. If the weight average molecular weight is less than 500, the water reducing performance of the cement dispersant is undesirably reduced. on the other hand,
If the molecular weight exceeds 500,000, the water dispersibility of the cement dispersant and the ability to prevent slump loss are undesirably reduced. On the other hand, if the value obtained by subtracting the peak top molecular weight from the weight average molecular weight exceeds 8,000, the resulting cement dispersant has poor slump retention performance, which is not preferable.

According to a third concept, a cement dispersant comprising a polymer produced according to the process of the invention; ie, the interior of the container has been replaced with an inert gas and / or the radical scavenger in the container. Storage in an atmosphere containing
Performing an esterification reaction between the transferred alkoxypolyalkylene glycol of formula (1) and (meth) acrylic acid,
Furthermore, the alkoxypolyalkylene glycol mono (meth) acrylate of formula (3) obtained by the esterification reaction, (meth) acrylic acid (salt) and, if necessary, the alkoxypolyalkylene glycol mono (meth) acrylic acid There is provided a cement dispersant comprising a polymer obtained by polymerizing a monomer copolymerizable with an ester or a (meth) acrylic acid (salt).

In the above concept, in addition to the polymer component defined above, the cement dispersant may be a conventionally known naphthalene cement dispersant, aminosulfonic acid cement dispersant, polycarboxylic acid cement dispersant and lignin cement dispersant. At least one cement dispersant selected from the group consisting of cement dispersants may be further added. That is, in the cement dispersant of the present invention, the above polymer may be used alone, or if necessary, various components shown above and below can be blended in order to further add value. There is a great difference in the composition of these components depending on the presence or absence of the desired additional function. From 100% by weight (total amount) of the polymer component to the main component, the polymer component is highly added. As a value component, there is a variety of modes in which an appropriate amount is added to a conventional cement dispersant, and it cannot be uniquely defined.

The cement dispersant of the present invention includes, in addition to a conventionally known cement dispersant, an air entrainer, a cement wetting agent, a swelling agent, a waterproofing agent, a retarder, a quick-setting agent, a water-soluble polymer substance. , Thickener, flocculant, drying shrinkage reducing agent, strength enhancer,
A curing accelerator, an antifoaming agent and the like can be blended.

The thus obtained cement dispersant containing a polymer as a main component promotes the dispersion of the cement by being added to a cement composition comprising at least cement and water.

The cement dispersant of the present invention can be used for hydraulic cements such as portland cement, high-belite cement, alumina cement, various mixed cements, and hydraulic materials other than cements such as gypsum.

Since the cement dispersant of the present invention has the above-mentioned effects, the cement dispersant exerts excellent effects even when added in a small amount as compared with the conventional cement dispersant. For example, when used for mortar or concrete using hydraulic cement, an amount of 0.001 to 5%, preferably 0.01 to 1% of the cement weight may be added at the time of kneading. . By this addition, various favorable effects such as achievement of high water reduction rate, improvement of slump loss prevention performance, reduction of unit water amount, increase of strength, and improvement of durability are brought about. If the added amount is less than 0.001%, the performance is insufficient. Conversely, even if a large amount exceeding 5% is used, the effect is substantially flattened and the economical disadvantage is disadvantageous.

The cement dispersant of the present invention has a specific weight-average molecular weight as described above, and a cement containing a polymer having a specific value obtained by subtracting the peak top molecular weight from the weight-average molecular weight as a main component. Desirably, it is a dispersant.

[0102]

The present invention will now be described more specifically with reference to examples.

Example 1 An autoclave equipped with a thermometer and a stirrer was charged with 32 g of methanol and 0.23 g of sodium hydroxide, and the inside of the vessel was sufficiently purged with nitrogen gas.
The temperature was raised to 0 ° C. Next, 132 g of ethylene oxide was added to this autoclave over 1 hour, and the reaction temperature was maintained at 70 ° C. for 1 hour to complete the addition reaction of ethylene oxide to methanol. Methoxy poly (n = 3) ethylene glycol [CH ₃ O (C
H ₂ CH ₂ O) ₃ H]. Subsequently, the temperature of this solution was increased to 155 ° C., and ethylene oxide 30
After adding 8 g into the autoclave, for another 1 hour,
By maintaining the reaction temperature at 155 ° C., the addition reaction of ethylene oxide to methoxy poly (n = 3) ethylene glycol was completed, and methoxy poly (n = 10) ethylene glycol [CH ₃ O] as alkoxypolyalkylene glycol (1) was used. (CH ₂ CH ₂ O) ₁₀ H].

The peroxide value of the thus obtained alkoxypolyalkylene glycol (1) immediately after the addition reaction was measured as follows.
g.

<Method for Measuring Peroxide Value> 10 g of alkoxypolyalkylene glycol (1), chloroform 35
ml and 35 ml of acetic acid were placed in a flask, 1 ml of saturated potassium iodide was added to the flask while replacing the inside of the flask with nitrogen gas, and the mixture was stirred for 20 minutes to prepare a brown test solution. Next, 0.01 N sodium thiosulfate was added dropwise to the test solution until the brown color of the test solution disappeared, and the titer of sodium thiosulfate at this time (ml)
Was measured, and the peroxide value was calculated according to the following equation. In addition, the blank value (ml) was obtained by performing the same operation as described above except that a test solution to which the alkoxypolyalkylene glycol (1) was not added was used instead of the test solution.

[0106]

(Equation 3)

Example 2 1000 g of the alkoxypolyalkylene glycol (1) obtained in Example 1 was placed at 60 ° C. in a sealable glass bottle (internal volume: 2 liters) whose inside was completely replaced with nitrogen gas. This was stored for one week, and this was designated as alkoxypolyalkylene glycol (2). After the lapse of a predetermined period, the peroxide value of this alkoxypolyalkylene glycol (2) was measured in the same manner as in Example 1, and was found to be 0.2 meq / g.

Example 3 1000 g of the alkoxypolyalkylene glycol (1) obtained in Example 1 was added with a radical scavenger in an amount of 0.1 (weight or volume)% based on the amount of the alkoxypolyalkylene glycol, so that the plug was sealed. Glass bottle (Contents: 2
Liter) at 60 ° C. for one week, and this was designated as alkoxypolyalkylene glycol (3). After a lapse of a predetermined period, the peroxide value of this alkoxypolyalkylene glycol (3) was measured in the same manner as in Example 1, and was found to be 0.2 meq / g.

Comparative Example 1 A glass bottle capable of sealing 1000 g of the alkoxypolyalkylene glycol (1) obtained in Example 1 (internal volume:
2 liters) and stored in a container at 60 ° C. for 1 week in an air atmosphere without replacing the inside of the container with nitrogen gas.
This was designated as alkoxypolyalkylene glycol (4). After a lapse of a predetermined period, the peroxide value of this alkoxypolyalkylene glycol (4) was measured in the same manner as in Example 1, and it was 0.8 meq / g.

The results obtained in Examples 2, 3 and Comparative Example 1 are summarized in Table 1 below.

[0111]

[Table 1]

From the results shown in Table 1, when the alkoxypolyalkylene glycol (1) was stored in a nitrogen atmosphere (Example 2) or in an atmosphere containing BHT (Example 3), it took one week. Although the peroxide value does not change, the peroxide value increases from 0.2 meq / g to 0.8 meq / g after one week when the alkoxypolyalkylene glycol (1) is stored in the air. It was shown that.

Example 4 Example 2 was placed in a glass reactor (internal volume: 3 liters) equipped with a thermometer, a stirrer, a produced water separator and a reflux condenser.
Alkoxypolyalkylene glycol obtained in (2)
1346 g, 654 g of methacrylic acid, 660 g of benzene as a dehydrating solvent, 20 g of sulfuric acid as an acid catalyst, and 0.5 g of hydroquinone as a polymerization inhibitor were charged, and the mixture was stirred to raise the temperature to 90 ° C. to perform esterification. The reaction was started. After confirming that 52 ml of produced water was distilled off, 118 g of a 30% aqueous sodium hydroxide solution and 370 g of water were added, and benzene was driven off by azeotropic distillation with water. A mixture aqueous solution (1) was obtained. No gel was formed during the esterification reaction.

Next, 1900 g of water was charged into a glass reactor (internal volume: 3 liters) equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reactor was stirred while stirring. The atmosphere was replaced with nitrogen gas, and the temperature of water was heated to 95 ° C. under a nitrogen atmosphere. Furthermore, water 10% was added to 1000 g of the 80% aqueous monomer mixture solution (1) obtained above.
The solution to which 00g was added was dropped into the reaction vessel over 4 hours, and then 13.5 g of ammonium persulfate was added to 86.000 g of water.
An aqueous solution dissolved in 5 g was added dropwise over 5 hours. After completion of the dropwise addition, the reaction temperature was maintained at 95 ° C. for 1 hour to complete the polymerization reaction, the reaction solution was neutralized to pH 7 with a 30% aqueous sodium hydroxide solution, and the weight average molecular weight (gel permeation chromatography) (GPC)
(The same as hereinafter). 33,000 aqueous polymer solution (1) of the present invention was obtained.

Example 5 An esterification reaction was carried out in the same manner as in Example 4 except that the alkoxypolyalkylene glycol (3) obtained in Example 2 was used instead of the alkoxypolyalkylene glycol (2). An 80% monomer mixture aqueous solution (2) was obtained. No gel was formed during the esterification reaction.

Next, the polymerization reaction was completed and neutralized in the same manner as in Example 4 except that this 80% monomer mixture aqueous solution (2) was used to obtain a polymer having a weight average molecular weight of 33,000. An aqueous polymer solution (2) of the present invention was obtained.

Comparative Example 2 An esterification reaction was started in the same manner as in Example 4 except that the alkoxypolyalkylene glycol (4) obtained in Comparative Example 1 was used instead of the alkoxypolyalkylene glycol (2). However, after a while, a large amount of gel adhered to the stirring blade, the stirring rod, and the thermometer, so that the esterification reaction was stopped. The methoxy poly (n = 10) ethylene glycol monomethacrylate was isolated by filtering the reaction mixture and removing the gel.

Next, the methoxypoly (n = 10) ethylene glycol monomethacrylate (1000 g) thus obtained and methacrylic acid (265 g) added thereto were used instead of the 80% monomer mixture aqueous solution (1) in Example 4. Except for using, the polymerization reaction was completed and neutralized in the same manner as in Example 4 to obtain a weight average molecular weight of 33,
Thus, 000 comparative polymer aqueous solutions (1) were obtained.

The results obtained in Examples 4, 5 and Comparative Example 2 are summarized in Table 2 below.

[0120]

[Table 2]

From the results shown in Table 2, it was found that the alkoxypolyalkylene glycol (2) stored for one week in a nitrogen atmosphere or the alkoxypolyalkylene glycol (3) stored for one week in an atmosphere to which BHT was added was used. When the esterification reaction is carried out, no gel is formed. On the other hand, when the esterification reaction is carried out using alkoxypolyalkylene glycol (4) stored in the air for one week, a large amount of gel is formed. Is shown.
Further, the aqueous solution of the monomer mixture obtained by the esterification reaction using the alkoxypolyalkylene glycol (2) or the alkoxypolyalkylene glycol (3) can be directly used for the polymerization reaction without performing any pretreatment. Alkoxy polyalkylene glycol (4)
When an aqueous solution of a monomer mixture obtained by an esterification reaction using a compound was used, it was found that an extra step of removing a gel formed in advance before the polymerization reaction was required.

[0122]

As described above, the method for storing and transferring an alkoxypolyalkylene glycol according to the present invention is represented by the formula (1).
Is stored and transported in an atmosphere in which the inside of the container is replaced with an inert gas and / or a radical scavenger is added in the container. Therefore, according to the method of the present invention, since the alkoxypolyalkylene glycol can be stored and transported in a stable state for a long period of time, the place for producing the alkoxypolyalkylene glycol and the place for producing the cement dispersant using the same are located in the same place. There is no need to perform the process, and the production and storage of the alkoxypolyalkylene glycol has become possible.

Further, since peroxides and gels do not form in the alkoxypolyalkylene glycol even when stored for a long period of time, the esterified product which has been subjected to the esterification reaction using this is directly subjected to the polymerization reaction without any treatment. Which is very preferable from an industrial and economical viewpoint.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C04B 103: 40

Claims (6)

[Claims] 1. A method for storing and transferring an alkoxypolyalkylene glycol used as a raw material of a cement dispersant, comprising the step of preparing a compound represented by the formula (1): (However, R ¹ represents a hydrocarbon group having 1 to 30 carbon atoms, R ² O represents an oxyalkylene group having 2 to 18 carbon atoms, and the repeating unit of each R ² O is the same.) And when R ² O is in the form of a mixture of two or more, the repeating unit of each R ² O may be added in block form or added in random form. And n represents the average number of moles of the oxyalkylene group added and is a number of 1 to 300), and the inside of the vessel is replaced with an inert gas and / or the radical A method for storing / transferring an alkoxypolyalkylene glycol, which comprises storing / transferring in an atmosphere to which a scavenger has been added. 2. The method according to claim 1, wherein the alkoxypolyalkylene glycol is stored and transported in an atmosphere replaced with an inert gas by 70% or more of the total volume of air in the container. . 3. The method according to claim 1, wherein said radical scavenger is t-butylhydroxytoluene. 4. The amount of the radical scavenger added is 10 to 15 with respect to the amount of the alkoxypolyalkylene glycol.
4. The method according to claim 1, wherein the amount is 00 ppm. (5) Formula (1): (However, R ¹ represents a hydrocarbon group having 1 to 30 carbon atoms, R ² O represents an oxyalkylene group having 2 to 18 carbon atoms, and the repeating unit of each R ² O is the same.) And when R ² O is in the form of a mixture of two or more, the repeating unit of each R ² O may be added in block form or added in random form. And n represents the average number of moles of oxyalkylene group added and is a number from 1 to 300), and an esterification reaction of (meth) acrylic acid with an alkoxypolyalkylene glycol represented by the formula (3) : (Wherein, R ¹ , R ² and n are as described above, and R ³ represents a hydrogen atom or a methyl group)
To obtain an alkoxypolyalkylene glycol mono (meth) acrylate represented by the formula:
Cement dispersion comprising polymerizing (meth) acrylic acid (salt) and, if necessary, a monomer copolymerizable with the alkoxypolyalkylene glycol mono (meth) acrylate or (meth) acrylic acid (salt) A method for producing a polymer used in an agent, wherein the alkoxypolyalkylene glycol is one according to any one of claims 1 to 4. 6. A cement dispersant comprising at least a polymer produced by the method according to claim 5.