JP5581461B1 - Copolymer (salt) for cement admixture, method for producing the same, and cement composition using the same - Google Patents

Abstract

The present invention provides a means capable of further improving the performance (especially slump retention performance and compressive strength) of a cement admixture.
The first polyalkylene glycol di (meth) acrylate (a) X represented by the general formula (1) described in the specification is ₁ % by weight, the first (poly) represented by the general formula (2). ₂ % by weight of alkylene glycol (meth) acrylate (b) X, ₂ % by weight of the second polyalkylene glycol di (meth) acrylate (c) Y represented by the general formula (3), and the _{first represented} by the general formula (4) 2 polyalkylene glycol (meth) acrylate (d) Y ₂ % by weight, carboxylic acid-based monomer (e) Z represented by general formula (5) ₁ % by weight, and (a) to (e) Other copolymerizable monomer (f) Z ₂ wt% (where X ₂ + Y ₂ + Z ₁ + Z ₂ = 100, X ₂ : Y ₂ : Z ₁ : Z ₂ = 5 to 70) : 10 to 90: 5 to 40: 0 to 50 and _X 2 + ₂ = a 60 to _95, when the _{X 1 + X 2 + Y 1} + Y 2 = 100, a copolymer derived at a ratio of X ₁ + Y 1 = 0.1 to 10) or the copolymerization, A salt obtained by neutralizing the coalescence with an alkaline substance is used as a cement admixture.
[Selection figure] None

Description

  The present invention relates to a copolymer (salt) for a cement admixture, a production method thereof, and a cement composition using the same. More specifically, in a so-called cement composition such as cement paste, mortar, and concrete, a copolymer (salt) used in a slump-retaining cement admixture that prevents its fluidity from decreasing over time, and a method for producing the same, The present invention also relates to a cement composition containing the copolymer (salt).

  Since the early deterioration of concrete structures became a social problem in 1981, there has been a strong demand to reduce the unit water volume in concrete and improve its workability and durability. There has been a lot of technological innovation for cement dispersants that have great influence.

  As a conventional method, raw concrete with low fluidity (hereinafter referred to as “slump”) to which an AE agent or an AE water reducing agent is added is manufactured at a plant, transported to a setting site by a raw concrete car, and then flows into this. A fluidization method has been adopted in which a slumping agent is added and fluidized to increase the slump to a predetermined value. However, this method involves the environmental problems of noise and exhaust gas generated when adding a fluidizing agent to concrete in a concrete car and stirring and mixing, the responsibility for the quality of the obtained fluidized concrete, fluidized concrete. There were various problems such as a significant decrease in aging of slumps.

  Thus, development of so-called high-performance AE water reducing agents that can be added in a raw plant has been vigorously conducted by each admixture maker, and currently naphthalene-based, aminosulfonic acid-based and polycarboxylic acid-based ones are commercially available. Among them, the polycarboxylic acid-based high-performance AE water reducing agent has an excellent feature that the highest water reduction rate can be obtained, but it is used severely such as transporting the obtained ready-mixed concrete to a remote place in summer. Under the conditions, like other high-performance AE water reducing agents, there was a problem that slump loss could not be sufficiently suppressed.

  Here, the polycarboxylic acid-based high-performance AE water reducing agent polymerizes a monomer component containing polyalkylene glycol (meth) acrylate and (meth) acrylic acid (salt) as essential components in the presence of a polymerization initiator. It has the structure of the copolymer obtained by doing. And as an improvement technique of the said polycarboxylic acid type high performance AE water reducing agent for solving the subject mentioned above, for example, in patent document 1, at least 2 as polyalkylene glycol (meth) acrylate which is a component of a monomer component The average addition mole number of the oxyalkylene group in these at least two polyalkylene glycol (meth) acrylates is selected from the range of 1 to 97 and the range of 4 to 100 so that the difference is 3 or more. In addition, a technique for configuring a cement admixture by setting a mixing ratio of three essential components including (meth) acrylic acid (salt) within a predetermined range has been proposed.

  By the way, Patent Document 2 and Patent Document 3 are one of raw materials for producing polycarboxylic acid for cement admixture as a copolymer of polyalkylene glycol (meth) acrylate and (meth) acrylic acid (salt). Polyalkylene glycol (meth) acrylate obtained by esterification of a predetermined polyalkylene glycol and a predetermined (meth) acrylic monomer, and polyalkylene glycol di (meth) acrylate as an impurity Of 0 to 5% by weight (more preferably less than 1% by weight, more preferably less than 0.1% by weight, most preferably 0% by weight) based on polyalkylene glycol (meth) acrylate is used. Technology has been proposed. This technology is achieved by reducing the content of polyalkylene glycol di (meth) acrylate, which may be contained in polyalkylene glycol (meth) acrylate, which is one of the raw materials for producing polycarboxylic acids for cement admixtures. This suppresses an abnormal increase in molecular weight of the polycarboxylic acid for cement admixture obtained and prevents a decrease in cement dispersibility and slump retention.

  Thus, in the prior art, polyalkylene glycol di (meth) acrylate that can be contained in polyalkylene glycol (meth) acrylate, which is one of the raw materials for producing polycarboxylic acid for cement admixture, is positioned as an impurity. The lower the content, the better.

Japanese Patent No. 3423553 Japanese Patent No. 3221399 Japanese Patent No. 3285820

  Although the cement admixtures disclosed in Patent Documents 1 to 3 described above each exhibit certain excellent effects as cement admixtures, there is still a strong demand for the development of higher performance cement admixtures.

  Then, an object of this invention is to provide the means which can improve further the performance (especially slump retention performance and compressive strength) of a cement admixture.

  The present inventor has intensively studied in view of the above problems. As a result, surprisingly, contrary to the conventional technical common sense as described above, polyalkylene glycol di (meta) is contained in the monomer component which is a raw material for producing the polycarboxylic acid copolymer for cement admixture. ) When the acrylate is included in a certain amount, the co-weight with improved performance as a cement admixture, such as slump retention performance and compressive strength, compared to the case where it is not (preferred in the prior art) It was found that a coalescence (salt) was obtained. Based on this knowledge, the present inventor has completed the present invention.

  That is, the cement admixture copolymer (salt) according to the present invention has the following general formula (1):

In the formula, each R ₁ independently represents a hydrogen atom or a methyl group, R ₂ O represents an oxyalkylene group, m represents an added mole number of the oxyalkylene group, and represents a number of 2 to 194.
₁ % by weight of a _first polyalkylene glycol di (meth) acrylate (a) X represented by
The following general formula (2):

In the formula, R ₃ represents a hydrogen atom or a methyl group, R ₄ O represents an oxyalkylene group, p represents the number of added moles of the oxyalkylene group, represents a number of 1 to 97, and R ₅ represents a hydrogen atom or Represents an alkyl group having 1 to 22 carbon atoms,
The first (poly) alkylene glycol (meth) acrylate (b) X ₂ wt% represented by
The following general formula (3):

In the formula, each R ₆ independently represents a hydrogen atom or a methyl group, R ₇ O represents an oxyalkylene group, n represents an added mole number of the oxyalkylene group, and represents a number of 8 to 200 (provided that n−m ≧ 6),
In a second polyalkylene glycol di (meth) acrylate (c) _{Y 1} wt% as shown,
The following general formula (4):

In the formula, R ₈ represents a hydrogen atom or a methyl group, R ₉ O represents an oxyalkylene group, q represents an added mole number of the oxyalkylene group, and represents a number of 4 to 100 (provided that qp ≧ 3), R ₁₀ represents a hydrogen atom or an alkyl group having 1 to 22 carbon atoms,
₂ % by weight of a _second polyalkylene glycol (meth) acrylate (d) Y represented by
The following general formula (5):

In the formula, R ₁₁ represents a hydrogen atom or a methyl group, and M ¹ represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group, or an organic amine group.
₁ % by weight of a carboxylic acid monomer (e) Z represented by
₂ % by weight of other monomers (f) Z copolymerizable with the above (a) to (e),
(Where X ₂ + Y ₂ + Z ₁ + Z ₂ = 100, X ₂ : Y ₂ : Z ₁ : Z ₂ = 5 to 70:10 to 90: 5 to 40: 0 to 50 and X ₂ + Y ₂ = 60 to 95, and when X ₁ + X ₂ + Y ₁ + Y ₂ = 100, X ₁ + Y ₁ = 0.1 to 10)
It is characterized in that it is a copolymer derived at a ratio of 1 or a salt obtained by neutralizing the copolymer with an alkaline substance.

  Moreover, the manufacturing method of the copolymer (salt) for cement admixtures according to the present invention is represented by the following general formula (1):

In the formula, each R ₁ independently represents a hydrogen atom or a methyl group, R ₂ O represents an oxyalkylene group, m represents an added mole number of the oxyalkylene group, and represents a number of 2 to 194.
₁ % by weight of a _first polyalkylene glycol di (meth) acrylate (a) X represented by
The following general formula (2):

In the formula, R ₃ represents a hydrogen atom or a methyl group, R ₄ O represents an oxyalkylene group, p represents the number of added moles of the oxyalkylene group, represents a number of 1 to 97, and R ₅ represents a hydrogen atom or Represents an alkyl group having 1 to 22 carbon atoms,
The first (poly) alkylene glycol (meth) acrylate (b) X ₂ wt% represented by
The following general formula (3):

In the formula, each R ₆ independently represents a hydrogen atom or a methyl group, R ₇ O represents an oxyalkylene group, n represents an added mole number of the oxyalkylene group, and represents a number of 8 to 200 (provided that n−m ≧ 6),
In a second polyalkylene glycol di (meth) acrylate (c) _{Y 1} wt% as shown,
The following general formula (4):

In the formula, R ₈ represents a hydrogen atom or a methyl group, R ₉ O represents an oxyalkylene group, q represents an added mole number of the oxyalkylene group, and represents a number of 4 to 100 (provided that qp ≧ 3), R ₁₀ represents a hydrogen atom or an alkyl group having 1 to 22 carbon atoms,
₂ % by weight of a _second polyalkylene glycol (meth) acrylate (d) Y represented by
The following general formula (5):

In the formula, R ₁₁ represents a hydrogen atom or a methyl group, and M ¹ represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group, or an organic amine group.
₁ % by weight of a carboxylic acid monomer (e) Z represented by
₂ % by weight of other monomers (f) Z copolymerizable with the above (a) to (e),
(Where X ₂ + Y ₂ + Z ₁ + Z ₂ = 100, X ₂ : Y ₂ : Z ₁ : Z ₂ = 5 to 70:10 to 90: 5 to 40: 0 to 50 and X ₂ + Y ₂ = 60 to 95, and when X ₁ + X ₂ + Y ₁ + Y ₂ = 100, X ₁ + Y ₁ = 0.1 to 10)
It is characterized in that it includes a step of polymerizing a monomer component containing a copolymer to obtain a copolymer, and a step of neutralizing the copolymer with an alkaline substance as necessary.

  According to the present invention, it is possible to obtain a copolymer (salt) with further improved performance as a cement admixture (especially slump retention performance and compressive strength) even by adopting a configuration different from the prior art. it can.

According to one aspect of the present invention, a cement admixture copolymer (salt) is provided. The cement admixture copolymer (salt)
_-1 weight% of _1st polyalkylene glycol di (meth) acrylate (a) X shown by General formula (1),
- General first polyalkylene glycol represented by the formula (2) (meth) acrylate (b) _{X 2%} by weight,
_-1 weight% of 2nd polyalkylene glycol di (meth) acrylate (c) Y shown by General formula (3),
-2 weight% of _2nd polyalkylene glycol (meth) acrylate (d) Y shown by General formula (4),
_-1 % by weight of the carboxylic acid monomer (e) Z represented by the general formula (5), and
- wherein (a) ~ (e) and other copolymerizable monomer (f) _{Z 2} wt%,
(Where X ₂ + Y ₂ + Z ₁ + Z ₂ = 100, X ₂ : Y ₂ : Z ₁ : Z ₂ = 5 to 70:10 to 90: 5 to 40: 0 to 50 and X ₂ + Y ₂ = 60 to 95, and when X ₁ + X ₂ + Y ₁ + Y ₂ = 100, X ₁ + Y ₁ = 0.1 to 10)
Or a salt formed by neutralizing the copolymer with an alkaline substance. In the following, the above (a) to (f) will be described first.

[First polyalkylene glycol di (meth) acrylate (a) represented by the general formula (1)]
Component (a) is represented by the following general formula (1):

And a polyalkylene glycol di (meth) acrylate represented by the formula (also referred to herein as “first polyalkylene glycol di (meth) acrylate”).

In the general formula (1), each R ₁ independently represents a hydrogen atom or a methyl group, preferably a methyl group. In the general formula (1), R ₁ may be the same or different from each other, but is preferably the same.

In the general formula (1), R ₂ O represents an oxyalkylene group (that is, R ₂ represents an alkylene group). Here, the number of carbon atoms of R ₂ is preferably 2-18. That is, the oxyalkylene group represented by R ₂ O is preferably an alkylene oxide adduct having 2 to 18 carbon atoms. The structure of such an alkylene oxide adduct is, for example, a structure formed by one or more of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, 1-butene oxide, and 2-butene oxide. is there. Among such alkylene oxide adducts, ethylene oxide, propylene oxide, and butylene oxide adducts are more preferable, and ethylene oxide adducts are particularly preferable.

Further, in the general formula (1), m is the number of added moles of the oxyalkylene group (R ₂ O), which is a number from _{2 to} 194, preferably a number from 4 to 150, more preferably from 8 to 120. More preferably, it is a number of 8 to 100, and particularly preferably a number of 8 to 60. If m is less than 2, sufficient effects as a crosslinkable monomer may not be exhibited. On the other hand, if m exceeds 194, gelation may occur. In the present specification, the “added mole number” means an arithmetic average value of the number of moles of the oxyalkylene group added in 1 mole in each component of the general formula (2) and the general formula (4). It means that in each component of the general formula (1) and the general formula (3), it represents a representative value of the number of added moles of the oxyalkylene group measured by the method described in the column of Examples described later. Therefore, in the present specification, for each component of the general formula (1) and the general formula (3), the structure represented by the general formula is the same, and the added mole number of the oxyalkylene group measured by the above method As long as the representative values of are the same, they are treated as the same compound. Here, since m is a number of 2 or more, two or more oxyalkylene groups represented by R ₂ O in the general formula (1) are essential in the same compound, but represented by R ₂ O. Each of the oxyalkylene groups to be added may have any addition form such as random addition, block addition, and alternate addition (the same applies to R ₄ O described later).

[First (poly) alkylene glycol (meth) acrylate (b) represented by general formula (2)]
Component (b) is represented by the following general formula (2):

(Poly) alkylene glycol (meth) acrylate (also referred to herein as “first (poly) alkylene glycol (meth) acrylate”).

In the general formula (2), R ₃ represents a hydrogen atom or a methyl group, preferably a methyl group. R ₃ may be the same as or different from R ₁ in the general formula (1) described above, but is preferably the same as at least one of R ₁ in the general formula (1). In the most preferred form, two R ₁ in the general formula (1) and R ₃ in the general formula (2) are all the same. According to such a form, by controlling the conditions during the preparation of the first polyalkylene glycol (meth) acrylate (b), the first polyalkylene glycol di (meth) acrylate (a) and Monomers can be prepared in the state of a mixture, and a copolymer (salt) can be obtained by a simpler method.

In the general formula (2), R ₄ O represents an oxyalkylene group, and its definition and preferred embodiments are the same as R ₂ O in the above general formula (1). Omitted. In a preferred form, R ₂ O in general formula (1) and R ₄ O in general formula (2) both contain an oxyethylene group, and in a more preferred form, all R ₂ O in general formula (1) and All R ₄ O in the general formula (2) is an oxyethylene group.

Further, in the general formula (2), p is the molar number of addition of oxyalkylene group _(R 4 O), the number of 1-97, and preferably a number of from 2 to 75, more preferably 4 to 60 More preferably, the number is 4 to 50, and particularly preferably 4 to 30. When p exceeds 97, the viscosity of the composition containing the resulting polymer increases, and the state of the cement composition such as concrete may deteriorate.

In the general formula (2), _{R 5} represents a hydrogen atom or an alkyl group having 1 to 22 carbon atoms. The number of carbon atoms of R ₅ is preferably 1 to 15, more preferably 1 to 8, still more preferably 1 to 4, particularly preferably 1 to 2, and most preferably 1. Specific examples of such R ₅ include methyl group, ethyl group, n-propyl group, isopropyl group, 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, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, heneicosyl group, docosyl group, etc., among them methyl group, ethyl Group, n-propyl group, isopropyl group, n-butyl group or tert-butyl group is preferable, methyl group or ethyl group is more preferable, and methyl group is particularly preferable.

[Second polyalkylene glycol di (meth) acrylate (c) represented by the general formula (3)]
Component (c) is represented by the following general formula (3):

And a polyalkylene glycol di (meth) acrylate represented by the formula (also referred to herein as “first polyalkylene glycol di (meth) acrylate”).

In the general formula (3), R ₆ each independently represents a hydrogen atom or a methyl group, preferably a methyl group. In general formula (3), R ₆ may be the same as or different from each other, but is preferably the same as each other.

In the general formula (3), R ₇ O represents an oxyalkylene group, and its definition and preferred embodiments are the same as R ₂ O in the above general formula (1). Omitted.

Furthermore, in General formula (3), n is the addition mole number of an oxyalkylene group (R < ₇ > O), is the number of 8-200, Preferably it is the number of 10-156, More preferably, it is 14-126 More preferably, the number is 14 to 106, and particularly preferably 14 to 66. If n is less than 8, sufficient effects as a crosslinkable monomer may not be exhibited. On the other hand, if n exceeds 200, gelation may occur. Here, since n is a number of 4 or more, two or more oxyalkylene groups represented by R ₇ O in the general formula (3) are essential in the same compound, but represented by R ₇ O. Each of the oxyalkylene groups to be added may have any addition form such as random addition, block addition, and alternate addition (the same applies to R ₉ O described later).

Further, n, which is the added mole number of the oxyalkylene group (R ₇ O) in the general formula (3), is m, which is the added mole number of the oxyalkylene group (R ₂ O) in the general formula (1). It is necessary to satisfy the relationship of n−m ≧ 6. In the present invention, it is essential that the monomer component contains at least two types of polyalkylene glycol di (meth) acrylates (first and second polyalkylene glycol di (meth) acrylates). Performance as a cement admixture (especially slump retention performance) by forming monomer components so that the number of added oxyalkylene groups in each polyalkylene glycol di (meth) acrylate is different by 6 or more. The present inventors have found that a copolymer (salt) having further improved compression strength) can be obtained. In addition, the value of “nm” is preferably 6 to 150, more preferably 6 to 100, and further preferably 6 to 60.

In a preferred embodiment of the present invention, the number of moles of each oxyalkylene group added in the first polyalkylene glycol di (meth) acrylate (a) and the second polyalkylene glycol di (meth) acrylate (c) described above. An average value is defined. Here, the molar average value (an A ₁₎ has a number of moles (m _a first polyalkylene glycol in the copolymer (or the monomers leading to this) (meth) acrylate (a) The number of moles (m) of the oxyalkylene group in the first polyalkylene glycol di (meth) acrylate (a), the second polyalkylene glycol di in the copolymer (or the monomer component deriving it) (meth) number of moles of acrylate (c) (a m _c), and using a molar number of addition of oxyalkylene groups (n) in the first polyalkylene glycol di (meth) acrylate (c), a ₁ = Calculated as ((m × m _a + n × m _c ) / (m _a + m _c )). Then, as preferred forms, _{A 1} is preferably 5 to 150, more preferably from 5 to 100, more preferably from 10 to 60. If A ₁ is 5 or more values, easy to obtain the effect of the crosslinking monomer of component (a) and component (c). Further, if the value of A ₁ is 150 or less is preferable because the crosslinking occurs efficiently.

[Second polyalkylene glycol (meth) acrylate (d) represented by the general formula (4)]
Component (d) is represented by the following general formula (4):

And a polyalkylene glycol (meth) acrylate (also referred to herein as “second polyalkylene glycol (meth) acrylate”).

In the general formula (4), R ₈ represents a hydrogen atom or a methyl group, preferably a methyl group. R ₈ may be the same as or different from R ₆ in General Formula (3) described above, but is preferably the same as at least one of R ₆ in General Formula (3). In the most preferable form, two R _{6 in} the general formula (3) and R ₈ in the general formula (4) are all the same. According to such a form, by controlling the conditions during the preparation of the second polyalkylene glycol (meth) acrylate (d), the mixture of the second polyalkylene glycol di (meth) acrylate (c) The monomer can be prepared in a state, and a copolymer (salt) can be obtained by a simpler method.

In the general formula (4), R ₉ O represents an oxyalkylene group, and its definition and preferred embodiments are the same as R ₇ O in the above general formula (3). Omitted. In a preferred embodiment, R ₇ O in general formula (3) and R ₉ O in general formula (4) both contain an oxyethylene group, and in a more preferred embodiment, all R ₇ O in general formula (3) and All R ₉ O in the general formula (4) is an oxyethylene group.

Further, in the general formula (4), q is the number of moles added of the oxyalkylene group _(R 9 O), the number of 4 to 100, and preferably a number of 5-78, more preferably 7-63 More preferably, it is a number from 7 to 53, and particularly preferably a number from 7 to 33. When q is less than 4, there is a possibility that the cement dispersion performance of the resulting polymer may be significantly reduced. On the other hand, when q exceeds 100, the viscosity of the composition containing the resulting polymer is increased, and the state of the cement composition such as concrete may be deteriorated.

Further, an addition mole number of the general formula (4) in the oxyalkylene group (R 9 _O) q is the p is an addition mole number of the oxyalkylene group (R 4 _O) in the general formula (2) above It is necessary to satisfy the relationship of q−p ≧ 3. In the present invention, it is essential that the monomer component contains at least two (poly) alkylene glycol (meth) acrylates (first and second (poly) alkylene glycol (meth) acrylates). By constituting the monomer component so that the number of added moles of each oxyalkylene group in at least two kinds of (poly) alkylene glycol (meth) acrylates is different by 3 or more, performance as a cement admixture (particularly, A copolymer (salt) having excellent slump retention performance and compressive strength can be obtained. In addition, the value of “q−p” is preferably 3 to 75, more preferably 3 to 50, and further preferably 3 to 30.

In a preferred embodiment of the present invention, the number of moles of each oxyalkylene group added in the first (poly) alkylene glycol (meth) acrylate (b) and the second polyalkylene glycol (meth) acrylate (d) described above. An average value is defined. Here, the molar average value (referred to as A ₂ ) is the number of moles (m _b ) of the first (poly) alkylene glycol (meth) acrylate (b) in the copolymer (or the monomer component leading to it). The number of moles of oxyalkylene group added in the first (poly) alkylene glycol (meth) acrylate (b) (p), the second polyalkylene in the copolymer (or the monomer component leading to it) using glycol (meth) number of moles of acrylate (d) (a m _d), and a second polyalkylene glycol (meth) acrylate (d) in addition mole number of the oxyalkylene group (q), a ₂ = Calculated as ((p × m _b + q × m _d ) / (m _b + m _d )). Then, as a preferred form, _{A 2} is preferably 3 to 80, more preferably from 3 to 50, more preferably from 4 to 30. If A ₂ is 3 or more values, preferably cement dispersing performance of the resulting polymer becomes appropriate. Further, if the value of A ₂ is 80 or less is preferable because the state of the cement composition such as concrete is improved. The advantage is obtained.

Furthermore, as a preferred embodiment, the above-mentioned ratio value of A ₁ and A ₂ (A ₁ / A ₂ ) is preferably 1.0 to 10, more preferably 1.0 to 8.0, Preferably it is 1.5-6.0. A ratio of A ₁ / A ₂ of 1.0 or more is preferable because crosslinking occurs efficiently. On the other hand, if the value of this ratio is 10 or less, gelation hardly occurs.

Further, in the general formula _{(4), R 10} represents a hydrogen atom or an alkyl group having 1 to 22 carbon atoms. Specific embodiments when R ₁₀ is an alkyl group are the same as R ₅ in formula (2), a detailed description thereof will be omitted here.

[Carboxylic acid monomer (e)]
Component (e) is represented by the general formula (5):

It is a carboxylic acid monomer represented by

In the general formula (5), R ₁₁ represents a hydrogen atom or a methyl group, preferably a methyl group.

In the general formula (5), M ¹ represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or an organic amine group. Among these, M is preferably a monovalent metal atom or a divalent metal atom. Here, examples of the monovalent metal atom include alkali metal atoms such as lithium, sodium, and potassium, and examples of the divalent metal atom include alkaline earth metal atoms such as calcium and magnesium. The ammonium group is a functional group represented by “—NH 4 ⁺ ”. Examples of the organic amine group include residues derived from organic amines such as alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine; alkylamines such as monoethylamine, diethylamine, and triethylamine; and polyamines such as ethylenediamine and triethylenediamine. Groups.

  Examples of the carboxylic acid monomer (e) represented by the general formula (5) include acrylic acid, methacrylic acid, sodium acrylate, sodium methacrylate, ammonium acrylate, and ammonium methacrylate. Two or more of these may be used in combination. Among these, as the carboxylic acid monomer (e), (meth) acrylic acid is preferably used, and methacrylic acid is most preferably used. These compounds may use commercially available compounds, or may be prepared by self-synthesis.

[Other monomers copolymerizable with (a) to (e) (f)]
Component (f) is another monomer copolymerizable with the above-described (a) to (e). There is no restriction | limiting in particular about the specific structure of another monomer, What is necessary is just a compound copolymerizable with (a)-(e) mentioned above. As an example, the following compounds may be mentioned. Of course, compounds other than the following compounds may be used as other monomers.

  Half esters and diesters of unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid and citraconic acid and alcohols having 1 to 30 carbon atoms; the above unsaturated dicarboxylic acids and 1 to 30 carbon atoms Half-amides and diamides of the above-mentioned amines: Half-esters and diesters of alkyl (poly) alkylene glycols obtained by adding 1 to 500 moles of alkylene oxides having 2 to 18 carbon atoms to the above alcohols and amines and the above-mentioned unsaturated dicarboxylic acids Half-esters and diesters of the above unsaturated dicarboxylic acids with glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols; methyl (meth) acrylate, ethyl (meth) acrylate , Propyl (meth) acrylate, Esters of unsaturated monocarboxylic acids such as lysidyl (meth) acrylate, methyl crotonate, ethyl crotonate, propyl crotonate and alcohols having 1 to 30 carbon atoms; alcohols having 1 to 30 carbon atoms and carbon atoms Esters of alkoxy (poly) alkylene glycols to which 1 to 500 moles of 2 to 18 alkylene oxides are added and unsaturated monocarboxylic acids such as (meth) acrylic acid; (poly) ethylene glycol monomethacrylate, (poly) propylene 1-500 mole adducts of alkylene oxides of 2-18 carbon atoms to unsaturated monocarboxylic acids such as (meth) acrylic acid, such as glycol monomethacrylate, (poly) butylene glycol monomethacrylate; maleamic acid and carbon Glycols having 2 to 18 atoms or Half amides of polyalkylene glycols of addition mole number 2 to 500 of these glycols.

  Polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate; (poly) such as triethylene glycol dimaleate and polyethylene glycol dimaleate Alkylene glycol dimaleates; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (Meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutylsulfonate Unsaturated sulfonic acids such as (meth) acrylamidomethylsulfonic acid, (meth) acrylamidoethylsulfonic acid, 2-methylpropanesulfonic acid (meth) acrylamide and styrenesulfonic acid, and monovalent metal salts and divalent metal salts thereof , Ammonium salts and organic amine salts; amides of unsaturated monocarboxylic acids and amines having 1 to 30 carbon atoms such as methyl (meth) acrylamide; styrene, α-methylstyrene, vinyltoluene, p-methylstyrene, etc. Vinyl aromatics: alkanediol mono (meth) acrylates such as 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate and 1,6-hexanediol mono (meth) acrylate Butadiene, isoprene, 2-methyl-1, Dienes such as 3-butadiene and 2-chloro-1,3-butadiene.

  Unsaturated amides such as (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide; unsaturated cyanides such as (meth) acrylonitrile and α-chloroacrylonitrile Unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, Unsaturated amines such as dibutylaminoethyl acrylate and vinyl pyridine; divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate; (meth) allyl alcohol, glycidyl (meth) allyl ether, etc. Allyls; methoxy (poly ) Ethylene glycol monovinyl ether, (poly) ethylene glycol monovinyl ether, methoxy (poly) ethylene glycol mono (meth) allyl ether, (poly) ethylene glycol mono (meth) allyl ether, vinyl ethers or allyl ethers; (poly) Dimethylsiloxanepropylaminomaleamic acid, (poly) dimethylsiloxaneaminopropylaminomaleamic acid, (poly) dimethylsiloxane-bis- (propylaminomaleamic acid), (poly) dimethylsiloxane-bis- (dipropyleneaminomaleamide) Acid), (poly) dimethylsiloxane- (1-propyl-3-acrylate), (poly) dimethylsiloxane- (1-propyl-3-methacrylate), (poly) dimethylsiloxane Siloxane derivatives such as sun-bis- (1-propyl-3-acrylate) and (poly) dimethylsiloxane-bis- (1-propyl-3-methacrylate).

  In addition, it represents with the (poly) alkylene glycol di (meth) acrylate monomer applicable to the compound represented by General formula (1) or General formula (3), General formula (2), or General formula (4). A (poly) alkylene glycol (meth) acrylate monomer corresponding to the compound may be used as the other monomer (f). In this case, at least three (poly) alkylene glycol di (meth) acrylate monomers and at least three (poly) alkylene glycol (meth) acrylate monomers are included in the monomer component. In such a case, for each of the at least three (poly) alkylene glycol di (meth) acrylate monomers and at least three (poly) alkylene glycol (meth) acrylate monomers, any two When the seeds are the first (poly) alkylene glycol di (meth) acrylate monomer and the second (poly) alkylene glycol di (meth) acrylate monomer, respectively, any two kinds are the first (Poly) alkylene glycol (meth) acrylate monomer and second (poly) alkylene glycol (Meth) as long as it meets the essential element of the present invention when the acrylate monomer are intended to be encompassed in the technical scope of the present invention such a case.

  As described above, the copolymer (salt) for cement admixture according to the present embodiment is one in which the components (a) to (f) are “derived at a specific ratio”. ), The double bond contained in components (a) to (f) is cleaved to form a single bond, and the structure linked to the adjacent monomer via the single bond is continuous. Means. Also, the arrangement of each component is not particularly limited, and random polymerization, block polymerization, and the like are conceivable, but they are usually arranged in the form of random polymerization.

The copolymer (salt) for cement admixture according to the present invention is also characterized in that the contents of components (a) to (f) are defined. Hereinafter, the regulation of the contents of the components (a) to (f) will be described. In the present specification, the contents of the components (a) to (f) are determined as follows:
Ingredient (a) X ₁ % by weight
-Component (b) X ₂ % by weight
Ingredient (c) Y ₁ % by weight
Ingredient (d) Y ₂ % by weight
Ingredient (e) Z ₁ % by weight
-Component (f) Z ₂ wt%
First, one of the characteristics of the content of each component in the copolymer (salt) for cement admixture according to the present invention is the ratio (weight ratio) of the content of components other than polyalkylene glycol di (meth) acrylate. , X ₂ + Y ₂ + Z ₁ + Z ₂ = 100 [% by weight], X ₂ : Y ₂ : Z ₁ : Z ₂ = 5 to 70:10 to 90: 5 to 40: 0 to 50 and X ₂ + it is to satisfy the relationship of _Y 2 = 60 to 95. Preferably _{X 2: Y 2: Z 1} : Z 2 = 10~70: 10~80: 5~30: 0~30 and a _X 2 ₊ Y 2 = _60~95, more preferably _{X 2: Y 2:} Z ₁ : Z ₂ = 10 to 60:10 to 70: 5 to 25: 0 to 20 and X ₂ + Y ₂ = 70 to 95, and more preferably X ₂ : Y ₂ : Z ₁ : Z ₂ = 10. 50:20 to 70: 5 to 20: 0 to 10 and X ₂ + Y ₂ = 70 to 90.

Another feature of the content of each component in the cement admixture copolymer (salt) according to the present invention is a polyalkylene glycol di (meth) acrylate component (component (a) and component (c)). ) And (poly) alkylene glycol (meth) acrylate components (component (b) and component (d)) as a total amount of 100% by weight, polyalkylene glycol di (meth) acrylate components (component (a) and components) When the ratio (weight ratio) of (c)) is X ₁ + X ₂ + Y ₁ + Y ₂ = 100 [% by weight], the relationship of X ₁ + Y ₁ = 0.1 to 10 is satisfied. If a preferable form is given, the value of (X ₁ + Y ₁ ) when X ₁ + X ₂ + Y ₁ + Y ₂ = 100 [% by weight] is preferably 0.4 to 10, more preferably 0.4. It is -8, More preferably, it is 0.5-8, Most preferably, it is 0.5-6. As in the present invention, a copolymer for cement admixture using two or more kinds of polyalkylene glycol di (meth) acrylate components (acting as a crosslinkable monomer) having different addition mole numbers of oxyalkylene groups to some extent (essentially) In the case where the value of (X ₁ + Y ₁ ) when X ₁ + X ₂ + Y ₁ + Y ₂ = 100 [% by weight] is within such a range, the copolymer ( Salt) Performance as a cement admixture (especially slump retention performance and compressive strength) is particularly excellent. As described above, in the prior art, polyalkylene glycol di (meth) acrylate that can be contained in polyalkylene glycol (meth) acrylate, which is one of the raw materials for producing polycarboxylic acid for cement admixture, is positioned as an impurity. It was said that the smaller the content, the better. On the other hand, in the present invention, contrary to the common sense in the prior art, a certain amount of polyalkylene glycol di (meth) acrylate is included in a state where a certain difference is present in the number of moles of oxyalkylene group added. In other words, the performance of the copolymer (salt) as a cement admixture is improved, which is a remarkable effect that could not be predicted by those skilled in the art.

[Method for producing copolymer (salt) for cement admixture]
According to another embodiment of the present invention, a cement admixture copolymer (salt) comprising a step of polymerizing a monomer component containing the above (a) to (f) in the above amount to obtain a copolymer. A manufacturing method is also provided.

  In order to obtain the copolymer, a monomer component containing the above (a) to (f) in the above amount may be copolymerized using a polymerization initiator. Here, there is no restriction | limiting in particular about the specific method of preparing the monomer component which contains said (a)-(f) by said quantity, For example, prepare the component of (a)-(f) separately, respectively. The monomer component may be prepared by mixing them. In a preferred embodiment, (b) containing a predetermined amount of (a) is prepared by adjusting the conditions during synthesis, and / or a predetermined amount of (c) is included by adjusting the conditions during synthesis. A monomer component may be prepared by preparing (d) and mixing these with (e) and (f) if necessary. In addition, if the conditions at the time of synthesizing (b) and (d) are different, the amounts of (a) and (c) contained in the product will be different accordingly, and (a) contained in the product A technique for controlling the amount of (c) to a desired value is a technique well known to those skilled in the art.

  The copolymerization can be performed by a method such as polymerization in a solvent or bulk polymerization.

  Polymerization in a solvent can be carried out either batchwise or continuously. The solvent used here is water; lower alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, cyclohexane, n -Aromatic or aliphatic hydrocarbons such as hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; From the solubility of the raw material monomer and the resulting copolymer and the convenience during use of the copolymer, use at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. Is preferred. In that case, methyl alcohol, ethyl alcohol, isopropyl alcohol and the like are particularly effective among the lower alcohols having 1 to 4 carbon atoms.

  When polymerization is performed 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. In this case, an accelerator such as sodium hydrogen sulfite or a molle salt can be used in combination. For polymerization using a lower alcohol, aromatic hydrocarbon, aliphatic hydrocarbon, ester compound or ketone compound as a solvent, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; azo 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. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various polymerization initiators or combinations of polymerization initiators and accelerators. The polymerization temperature is appropriately determined depending on the solvent to be used and the polymerization initiator, but is usually within a range of 0 to 120 ° C.

  Bulk polymerization uses a peroxide such as benzoyl peroxide or lauroyl peroxide as a polymerization initiator; a hydroperoxide such as cumene hydroperoxide; an aliphatic azo compound such as azobisisobutyronitrile, and the like. Performed within the temperature range.

Moreover, a thiol chain transfer agent can be used in combination for adjusting the molecular weight of the obtained copolymer. The thiol chain transfer agent used in this case has a general formula HS-R ₁₂ -E _g (wherein R ₁₂ represents an alkyl group having 1 to 2 carbon atoms, and E represents —OH, —COOM ² , —COOR ₁₃ or —SO ₃ M ² group, M ² represents hydrogen, monovalent metal, divalent metal, ammonium group or organic amine group, and R ₁₃ represents an alkyl group having 1 to 10 carbon atoms. G represents an integer of 1 to 2, for example, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, 3- Examples thereof include octyl mercaptopropionate, and one or more of these can be used.

[Other forms]
The copolymer thus obtained can be used as a main component of the cement dispersant as it is, but if necessary, a copolymer salt obtained by further neutralization with an alkaline substance can be used as a cement admixture. May be. Preferred examples of such alkaline substances include inorganic substances such as hydroxides, chlorides and carbon salts of monovalent metals and divalent metals; ammonia; organic amines and the like.

  The weight average molecular weight (Mw) of the admixture copolymer (salt) according to the present invention is 500 to 500,000 in terms of polyethylene glycol by gel permeation chromatography (hereinafter also referred to as “GPC”). In particular, the range is preferably 5,000 to 300,000. A weight average molecular weight of less than 500 is not preferable because water reducing performance as a cement admixture is reduced. On the other hand, if the weight average molecular weight exceeds 500,000, the water reducing performance as a cement admixture and the ability to prevent slump loss are not preferable.

  The copolymer (salt) according to the present invention can be used as a cement admixture alone or as a mixture of two or more. Moreover, it can also be used combining a copolymer (salt) as a main component and another well-known cement admixture. Such known cement admixtures include, for example, conventional cement dispersants, air entrainers, cement wetting agents, expansion agents, waterproofing agents, retarders, quick setting agents, water-soluble polymer substances, thickeners, and agglomerates. Agents, drying shrinkage reducing agents, strength enhancers, curing accelerators, antifoaming agents and the like.

  In addition, when using a known cement dispersant, the blending mass ratio of the copolymer (salt) for cement admixture of the present invention and the known cement dispersant is the type, blending and testing of the known cement dispersant to be used. Although it is not uniquely determined depending on the difference in conditions and the like, 1 to 99/99 to 1 is preferable, and 5 to 95/95 to 5 is more preferable as the weight ratio (% by weight) in terms of solid content. -90 / 90-10 are more preferable. Examples of the known cement dispersant used in combination include cement dispersants as described below.

  Polyalkylaryl sulfonates such as naphthalene sulfonic acid formaldehyde condensates; Melamine formalin sulfonates such as melamine sulfonic acid formaldehyde condensates; Aromatic amino sulfonates such as aminoaryl sulfonic acid-phenol-formaldehyde condensates Various sulfonic acid-based dispersants having a sulfonic acid group in the molecule such as lignin sulfonates such as lignin sulfonates and modified lignin sulfonates; polystyrene sulfonates.

  As described in JP-B-59-18338 and JP-A-7-223852, polyalkylene glycol mono (meth) acrylic acid ester monomers, (meth) acrylic acid monomers, and single amounts thereof A copolymer obtained from a monomer copolymerizable with a polymer; described in JP-A-10-236858, JP-A-2001-220417, JP-A-2002-121055, JP-A-2002-121056 (Poly) oxyalkylene group and carboxyl group in the molecule such as copolymer obtained from unsaturated (poly) alkylene glycol ether monomer, maleic acid monomer or (meth) acrylic acid monomer And various polycarboxylic acid-based dispersants.

  In a molecule such as a copolymer obtained from (alkoxy) polyalkylene glycol mono (meth) acrylate, phosphoric monoester monomer, and phosphoric diester monomer as described in JP-A-2006-52381 And various phosphate dispersants having a (poly) oxyalkylene group and a phosphate group.

Moreover, as an antifoamer, the well-known antifoamers which are illustrated to the following (1)-(2) are suitable.
(1) Oxyalkylene-based antifoaming agent: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; polyoxyalkylene alkyl ethers such as diethylene glycol heptyl ether; polyoxyalkylene acetylene ethers; ) Oxyalkylene fatty acid esters; polyoxyalkylene sorbitan fatty acid esters; polyoxyalkylene alkyl (aryl) ether sulfate salts; polyoxyalkylene alkyl phosphate esters; polyoxypropylene polyoxyethylene laurylamine (propylene oxide 1-20) Mole additions, ethylene oxide 1-20 mol adducts, etc.), fatty acid-derived amines obtained from cured beef tallow added with alkylene oxide (propylene oxide 1-20 mol) Additionally, polyoxyalkylene alkyl amines ethylene oxide 20 mol adduct) or the like; polyoxyalkylene amide.
(2) Antifoaming agents other than oxyalkylene type: Mineral oil type, fat type, fatty acid type, fatty acid ester type, alcohol type, amide type, phosphate ester type, metal soap type, silicone type and the like.

  The cement admixture according to the present invention can be used for hydraulic cements such as Portland cement, belite-rich cement, alumina cement, various mixed cements, or hydraulic materials other than cement such as gypsum.

  The cement admixture according to the present invention exhibits an excellent effect even when added in a small amount as compared with the conventional cement admixture. For example, when used for mortar or concrete using hydraulic cement, 0.01 to 1.0%, preferably 0.02 to 0.5% of the cement weight is mixed at the time of mixing. It may be added to. By this addition, various desirable effects such as achievement of a high water reduction rate, improvement of slump loss prevention performance, reduction of unit water volume, increase of strength (compression strength), and improvement of durability are brought about. If the addition amount is 0.01% or more, sufficient performance is exhibited, and if it is 1.0% or less, it is advantageous from the economical aspect.

In the cement composition according to the present invention, the amount of cement used per 1 m ^{3 of} the cement composition and the unit water amount are not limited, but the unit water amount is 120 to 185 kg / m ³ , and the water / cement weight ratio = 0.15 It is recommended that 0.7, preferably a unit water amount of 120 to 175 kg / m ³ and a water / cement weight ratio of 0.2 to 0.5.

  The cement composition according to the present invention is also effective for ready-mixed concrete, concrete for secondary concrete products (precast concrete), centrifugal molded concrete, vibration compacted concrete, steam-cured concrete, shotcrete, etc. High fluidity of medium fluidity concrete (concrete with slump value of 22-25cm), high fluidity concrete (concrete with slump value of 25cm or more, slump flow value of 50-70cm), self-filling concrete, self-leveling material, etc. It is also effective for required mortar and concrete.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, the technical scope of this invention is not limited only to the following form.

[Production example]
(Production Example 1)
Method for producing methoxypolyethyleneglycol monomethacrylate [1] A glass reaction vessel equipped with a thermometer, stirrer, product water separator, reflux condenser, 1000 parts by weight of methoxypoly (n = 4) ethylene glycol, 620.9 methacrylic acid Part by weight, 0.8 part by weight of phenothiazine, 648.4 parts by weight of cyclohexane and 32.4 parts by weight of paratoluenesulfonic acid were charged, and the temperature was raised to 90 ° C. with stirring to initiate the esterification reaction. After confirming that a predetermined amount of generated water had been distilled off, 7.5 parts by weight of sodium hydroxide was added. After the cyclohexane was distilled off, a predetermined amount of water was added to obtain an 80% by weight aqueous solution of the monomer mixture [1]. In the obtained monomer mixture [1], polyethylene glycol dimethacrylate was not detected. In addition, in this specification, the determination method of the polyethyleneglycol dimethacrylate in the obtained monomer mixture and the measuring method of the addition mole number of an oxyethylene group are as follows.

(Quantitative method of polyethylene glycol dimethacrylate)
Column used: Inertsil ODS-2 manufactured by GL Sciences Inc.
Eluent: Water / acetonitrile mixed at a ratio of 65/35% by volume Sample injection amount: 100 μL
Column temperature: 30 ° C
Detector: Japan Waters 2998 photodiode array detector (wavelength 230 nm)
Analysis: Emperor Software made by Waters, Japan
Standard material for preparing calibration curve: NK ester 9G from Shin-Nakamura Chemical Co., Ltd. diluted to 1.0, 0.5, 0.25, 0.1, 0.05% by weight with the above eluent Calibration curve : The detection area and concentration (% by weight) of the sample were linearly approximated.

(Method for measuring the number of moles of oxyethylene group added in polyethylene glycol dimethacrylate)
When measuring about the polyethyleneglycol dimethacrylate in a monomer mixture, only a polyethyleneglycol dimethacrylate component is fractionated and concentrated beforehand, and it uses for the following analysis.
Column: Tosoh Co., Ltd. TSKgel G2500PWXL connected two Eluent: 0.1M NaNO3 in 30% acetonitrile Flow rate: 1.0 mL / min
Sample concentration: 5.0 g / L
Injection volume: 20 μL
Column temperature: 40 ° C
Detector: Japan Waters 2414 Differential Refractometer Detector Analysis: Japan Waters Empower Software
Standard material for preparing calibration curve: Polyethylene glycol dimethacrylate synthesized in Production Examples 7 to 10 Calibration curve: Prepared by a cubic equation based on the peak top molecular weight (Mp value) and elution time of the above polyethylene glycol dimethacrylate.
For various polyethylene glycol dimethacrylates, the molecular weight (Mp value) of the peak with the earliest elution time was read from the chart obtained by the above analytical method, and the added mole number of oxyethylene groups was calculated as an integer based on this value.

(Production Example 2)
Production method of methoxypolyethylene glycol monomethacrylate [2] 1000 parts by weight of methoxypoly (n = 4) ethylene glycol, 620.9 methacrylic acid in a glass reaction vessel equipped with a thermometer, stirrer, water separator and reflux condenser. Part by weight, 0.8 part by weight of phenothiazine, 243.1 parts by weight of cyclohexane and 81.1 parts by weight of paratoluenesulfonic acid were charged, and the temperature was raised to 120 ° C. with stirring to initiate the esterification reaction. After confirming that a predetermined amount of generated water had been distilled off, 18.8 parts by weight of sodium hydroxide was added. After the cyclohexane was distilled off, a predetermined amount of water was added to obtain an 80% by weight aqueous solution of the monomer mixture [2]. In the obtained monomer mixture [2], 0.5% by weight of polyethylene glycol dimethacrylate having 8 added moles was detected.

(Production Example 3)
Method for Producing Methoxypolyethylene Glycol Monomethacrylate [3] A glass reaction vessel equipped with a thermometer, stirrer, product water separator, reflux condenser, and 1000 parts by weight of methoxypoly (n = 9) ethylene glycol, 362.1 methacrylic acid Part by weight, 0.7 part by weight of phenothiazine, 544.8 parts by weight of cyclohexane, and 27.2 parts by weight of paratoluenesulfonic acid were charged, and the temperature was raised to 90 ° C. with stirring to initiate the esterification reaction. After confirming that a predetermined amount of generated water had been distilled off, 6.3 parts by weight of sodium hydroxide was added. After the cyclohexane was distilled off, a predetermined amount of water was added to obtain an 80% by weight aqueous solution of the monomer mixture [3]. In the obtained monomer mixture [3], polyethylene glycol dimethacrylate was not detected.

(Production Example 4)
Method for producing methoxypolyethylene glycol monomethacrylate [4] 1000 parts by weight of methoxypoly (n = 9) ethylene glycol in a glass reaction vessel equipped with a thermometer, stirrer, product water separator and reflux condenser, methacryl 362.1 parts by weight of acid, 0.7 part by weight of phenothiazine, 204.3 parts by weight of cyclohexane and 68.1 parts by weight of paratoluenesulfonic acid were charged, and the temperature was raised to 120 ° C. with stirring to initiate the esterification reaction. After confirming that a predetermined amount of generated water had been distilled off, 15.8 parts by weight of sodium hydroxide was added. After the cyclohexane was distilled off, a predetermined amount of water was added to obtain an 80% by weight aqueous solution of the monomer mixture [4]. In the obtained monomer mixture [4], polyethylene glycol dimethacrylate having an added mole number of 18 was detected by 0.6% by weight.

(Production Example 5)
Method for Producing Methoxypolyethylene Glycol Monomethacrylate [5] In a glass reaction vessel equipped with a thermometer, stirrer, product water separator and reflux condenser, 1500 parts by weight of methoxypoly (n = 23) ethylene glycol, 309.3 methacrylic acid Part by weight, 0.9 part by weight of phenothiazine, 542.8 parts by weight of toluene, and 54.3 parts by weight of methanesulfonic acid were charged, and the temperature was raised to 105 ° C. with stirring to initiate the esterification reaction. After confirming that a predetermined amount of generated water had been distilled off, 22.6 parts by weight of sodium hydroxide was added. After toluene was distilled off, a predetermined amount of water was added to obtain an 80% by weight aqueous solution of the monomer mixture [5]. In the obtained monomer mixture [5], 0.1% by weight of polyethylene glycol dimethacrylate having an added mole number of 46 was detected.

(Production Example 6)
Method for producing methoxypolyethylene glycol monomethacrylate [6] In a glass reaction vessel equipped with a thermometer, stirrer, product water separator, and reflux condenser, 1500 parts by weight of methoxypoly (n = 46) ethylene glycol, methacryl 282.7 parts by weight of acid, 0.9 part by weight of phenothiazine, 534.8 parts by weight of toluene, and 8.9 parts by weight of sulfuric acid were charged, and the temperature was raised to 105 ° C. with stirring to initiate the esterification reaction. After confirming that a predetermined amount of generated water had been distilled off, 7.27 parts by weight of sodium hydroxide was added. After toluene was distilled off, a predetermined amount of water was added to obtain an 80% by weight aqueous solution of the monomer mixture [6]. In the obtained monomer mixture [6], 1.0% by weight of polyethylene glycol dimethacrylate having an added mole number of 92 was detected.

(Production Example 7)
Production method of polyethylene glycol dimethacrylate [7] A glass reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser was charged with 100 parts by weight of polyethylene glycol (Mw370) and 83 parts by weight of methacrylic anhydride and stirred at 100 ° C. For 8 hours to complete the esterification reaction to obtain polyethylene glycol dimethacrylate [7]. In the obtained polyethylene glycol dimethacrylate [7], the number of added oxyethylene groups was 8 mol.

(Production Example 8)
Production Method of Polyethylene Glycol Dimethacrylate [8] A glass reaction vessel equipped with a thermometer, stirrer and reflux condenser was charged with 100 parts by weight of polyethylene glycol (Mw811) and 38 parts by weight of methacrylic anhydride and stirred at 100 ° C. For 8 hours to complete the esterification reaction to obtain polyethylene glycol dimethacrylate [8]. The resulting polyethylene glycol dimethacrylate [8] had 18 added oxyethylene groups.

(Production Example 9)
Production Method of Polyethylene Glycol Dimethacrylate [9] A glass reaction vessel equipped with a thermometer, stirrer, and reflux condenser was charged with 100 parts by weight of polyethylene glycol (Mw 2044) and 15 parts by weight of methacrylic anhydride and stirred at 100 ° C. For 8 hours to complete the esterification reaction to obtain polyethylene glycol dimethacrylate [9]. In the obtained polyethylene glycol dimethacrylate [9], the number of added oxyethylene groups was 46.

(Production Example 10)
Production Method of Polyethylene Glycol Dimethacrylate [10] A glass reaction vessel equipped with a thermometer, stirrer, and reflux condenser was charged with 100 parts by weight of polyethylene glycol (Mw4071) and 7.6 parts by weight of methacrylic anhydride and stirred. The esterification reaction was completed by heating at 100 ° C. for 8 hours to obtain polyethylene glycol dimethacrylate [10]. The number of moles of oxyethylene group added in the obtained polyethylene glycol dimethacrylate [10] was 92.

〔Example〕
Example 1
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser was charged with 164.8 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution in which 36.4 parts by weight of the monomer mixture [3] and 0.12 parts by weight of the polyethylene glycol dimethacrylate [8] are mixed; 250 parts by weight of the monomer mixture [5] and the polyethylene glycol dimethacrylate [ 9] 0.77 parts by weight of aqueous solution mixed; methacrylic acid 26.8 parts by weight; 3-mercaptopropionic acid 3.4 parts by weight and water 20 parts by weight; and ammonium persulfate 1.8 parts by weight An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (A) of the weight average molecular weight 24000 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.49% by weight.

(Example 2)
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube, and a reflux condenser was charged with 161.15 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution in which 33.5 parts by weight of the monomer mixture [3] and 2.23 parts by weight of the polyethylene glycol dimethacrylate [8] are mixed; 230 parts by weight of the monomer mixture [5] and the polyethylene glycol dimethacrylate [ 9] Aqueous solution mixed with 12.45 parts by weight; 23.4 parts by weight of methacrylic acid; an aqueous solution mixed with 3.2 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water; and 1.7 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (B) of the weight average molecular weight 24500 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 6.73% by weight.

Example 3
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 162.6 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution obtained by mixing 72.7 parts by weight of the monomer mixture [1] and 0.34 parts by weight of the polyethylene glycol dimethacrylate [7]; 215 parts by weight of the monomer mixture [3] and the polyethylene glycol dimethacrylate [ 8] An aqueous solution in which 1.43 parts by weight were mixed; 21.2 parts by weight of methacrylic acid; an aqueous solution in which 4.6 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water were mixed; and 2.4 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (C) of the weight average molecular weight 10500 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.72% by weight.

Example 4
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 165.2 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution prepared by mixing 107.2 parts by weight of the monomer mixture [3] and 1.78 parts by weight of the polyethylene glycol dimethacrylate [8]; 175 parts by weight of the monomer mixture [5] and the polyethylene glycol dimethacrylate [ 9] An aqueous solution in which 4.06 parts by weight were mixed; 24.6 parts by weight of methacrylic acid; an aqueous solution in which 3.6 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water were mixed; and 1.9 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (D) of the weight average molecular weight 15200 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 2.62% by weight.

(Example 5)
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 180.0 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution obtained by mixing 183.7 parts by weight of the monomer mixture [3] and 7.63 parts by weight of the polyethylene glycol dimethacrylate [8]; 90 parts by weight of the monomer mixture [5] and the polyethylene glycol dimethacrylate [ 9] An aqueous solution in which 3.48 parts by weight were mixed; 37.7 parts by weight of methacrylic acid; an aqueous solution in which 4.6 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water were mixed; and 2.4 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (E) of the weight average molecular weight 15500 was obtained. The proportion of polyethylene glycol dimethacrylate in the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 4.79% by weight.

(Example 6)
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser was charged with 154.3 parts by weight of water, and the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution obtained by mixing 222.4 parts by weight of the monomer mixture [5] and 2.06 parts by weight of the polyethylene glycol dimethacrylate [9]; 70 parts by weight of the monomer mixture [6] and the polyethylene glycol dimethacrylate [ 10] Aqueous solution mixed with 1.79 parts by weight; 26.9 parts by weight of methacrylic acid; aqueous solution containing 2.5 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water; and 1.3 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (F) of the weight average molecular weight 21000 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 2.01% by weight.

(Example 7)
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser was charged with 164.8 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution obtained by mixing 36.4 parts by weight of the monomer mixture [4] and 0.12 parts by weight of the polyethylene glycol dimethacrylate [8]; 250 parts by weight of the monomer mixture [5] and the polyethylene glycol dimethacrylate [ 9] 0.77 parts by weight of aqueous solution mixed; methacrylic acid 26.8 parts by weight; 3-mercaptopropionic acid 3.4 parts by weight and water 20 parts by weight; and ammonium persulfate 1.8 parts by weight An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (G) of the weight average molecular weight 26000 was obtained. The proportion of polyethylene glycol dimethacrylate in the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.56% by weight.

(Example 8)
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 162.6 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution prepared by mixing 72.7 parts by weight of the monomer mixture [2] and 0.34 parts by weight of the polyethylene glycol dimethacrylate [7]; 215 parts by weight of the monomer mixture [4] and the polyethylene glycol dimethacrylate [ 8] An aqueous solution in which 1.43 parts by weight were mixed; 21.2 parts by weight of methacrylic acid; an aqueous solution in which 4.6 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water were mixed; and 2.4 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (H) of the weight average molecular weight 12000 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 1.28% by weight.

Example 9
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 162.6 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution obtained by mixing 72.7 parts by weight of the monomer mixture [1] and 0.30 parts by weight of the polyethylene glycol dimethacrylate [8]; 215 parts by weight of the monomer mixture [3] and the polyethylene glycol dimethacrylate [ 9] Aqueous solution mixed with 1.30 parts by weight; 21.4 parts by weight of methacrylic acid; aqueous solution containing 4.5 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water; and 2.4 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (I) of the weight average molecular weight 12500 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.72% by weight.

(Example 10)
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 170.5 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution obtained by mixing 187.1 parts by weight of the monomer mixture [3] and 1.09 parts by weight of the polyethylene glycol dimethacrylate [8]; 110 parts by weight of the monomer mixture [5]; 25.0 parts by weight of methacrylic acid Parts: 3-mercaptopropionic acid in an aqueous solution mixed with 4.0 parts by weight and water in 20 parts by weight; and an aqueous solution in which 2.1 parts by weight of ammonium persulfate and 20 parts by weight of water were mixed in the reactor over 4 hours each. It was dripped. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (J) of the weight average molecular weight 15100 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.47% by weight.

(Example 11)
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser was charged with 166.8 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution prepared by mixing 176 parts by weight of the monomer mixture [5] and 1.09 parts by weight of the polyethylene glycol dimethacrylate [9]; 90 parts by weight of the monomer mixture [6] and the polyethylene glycol dimethacrylate [10] 1.18 parts by weight mixed aqueous solution; methacrylic acid 26.8 parts by weight; methyl methacrylate 12.6 parts by weight; 3-mercaptopropionic acid 3.6 parts by weight and water 20 parts by weight; An aqueous solution in which 1.9 parts by weight of ammonium sulfate and 20 parts by weight of water were mixed was dropped into the reactor over 4 hours. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (K) of the weight average molecular weight 23400 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 1.51% by weight.

(Example 12)
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 164 parts by weight of water, the inside of the reactor was purged with nitrogen under stirring, and the temperature was increased to 95 ° C. under a nitrogen atmosphere. The temperature rose. 179.2 parts by weight of the monomer mixture [5]; 110 parts by weight of the monomer mixture [6]; 25.6 parts by weight of methacrylic acid; 3.2 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water. A mixed aqueous solution; and an aqueous solution obtained by mixing 1.7 parts by weight of ammonium persulfate and 20 parts by weight of water were dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (L) of the weight average molecular weight 22800 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.44% by weight.

(Example 13)
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser was charged with 160.1 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. The monomer mixture [2] 52.2 parts by weight; the monomer mixture [3] 240 parts by weight and the polyethylene glycol dimethacrylate [8] 14.0 parts by weight; methacrylic acid 4.9 parts by weight Parts: an aqueous solution in which 3.8 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water were mixed; and an aqueous solution in which 2.0 parts by weight of ammonium persulfate and 20 parts by weight of water were mixed in the reactor for 4 hours each. It was dripped. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (M) of the weight average molecular weight 11700 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 5.53% by weight.

(Example 14)
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 170.8 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution obtained by mixing 149.7 parts by weight of the monomer mixture [3] and 0.50 parts by weight of the polyethylene glycol dimethacrylate [8]; 110 parts by weight of the monomer mixture [5] and the polyethylene glycol dimethacrylate [ 9] Aqueous solution mixed with 0.68 parts by weight; 38.0 parts by weight of the above monomer mixture [1]; 24.6 parts by weight of methacrylic acid; 4.2 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water. A mixed aqueous solution; and an aqueous solution obtained by mixing 2.2 parts by weight of ammonium persulfate and 20 parts by weight of water were dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (N) of the weight average molecular weight 10700 was obtained. The proportion of polyethylene glycol dimethacrylate in the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.61% by weight.

(Comparative Example 1)
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 165.8 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. Monomer mixture [1] 74.4 parts by weight; monomer mixture [3] 220 parts by weight; methacrylic acid 22.0 parts by weight; 3-mercaptopropionic acid 4.6 parts by weight and water 20 parts by weight. A mixed aqueous solution; and an aqueous solution in which 2.5 parts by weight of ammonium persulfate and 20 parts by weight of water were mixed were dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (O) of the weight average molecular weight 11000 was obtained. None of the methoxypolyethylene glycol monomethacrylate before dropping contained polyethylene glycol dimethacrylate. Therefore, the polycarboxylic acid (O) is outside the scope of the present invention.

(Comparative Example 2)
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser was charged with 164.0 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. 36.4 parts by weight of the monomer mixture [3]; 250 parts by weight of the monomer mixture [5]; 26.8 parts by weight of methacrylic acid; 3.4 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water. A mixed aqueous solution; and an aqueous solution obtained by mixing 1.8 parts by weight of ammonium persulfate and 20 parts by weight of water were dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (P) of the weight average molecular weight 22000 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.087% by weight. Therefore, the polycarboxylic acid (P) is outside the scope of the present invention because X ₁ + Y ₁ = 0.1 to 10 is not satisfied when X ₁ + X ₂ + Y ₁ + Y ₂ = 100.

(Comparative Example 3)
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser was charged with 115.3 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution prepared by mixing 36.4 parts by weight of the monomer mixture [3] and 0.003 parts by weight of the polyethylene glycol dimethacrylate [8]; 250 parts by weight of the monomer mixture [5] and the polyethylene glycol dimethacrylate [ 9] An aqueous solution in which 0.01 part by weight was mixed; 26.8 parts by weight of methacrylic acid; an aqueous solution in which 3.4 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water were mixed; and 1.8 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (Q) of the weight average molecular weight 23000 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.093% by weight. Therefore, polycarboxylic acid (Q) is outside the scope of the present invention because X ₁ + Y ₁ = 0.1 to 10 is not satisfied when X ₁ + X ₂ + Y ₁ + Y ₂ = 100.

(Comparative Example 4)
A glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, and reflux condenser was charged with 166.6 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution obtained by mixing 32.1 parts by weight of the monomer mixture [3] and 3.99 parts by weight of the polyethylene glycol dimethacrylate [8]; 220 parts by weight of the monomer mixture [5] and the polyethylene glycol dimethacrylate [ 9] An aqueous solution in which 25.52 parts by weight were mixed; 21.1 parts by weight of methacrylic acid; an aqueous solution in which 3.1 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water were mixed; and 1.6 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (R) of the weight average molecular weight 24000 was obtained. The proportion of polyethylene glycol dimethacrylate in the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 13.11% by weight. Therefore, since polycarboxylic acid (R) does not satisfy X ₁ + Y ₁ = 0.1 to 10 when X ₁ + X ₂ + Y ₁ + Y ₂ = 100, it is outside the scope of the present invention.

(Comparative Example 5)
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser was charged with 159.6 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. An aqueous solution obtained by mixing 7.1 parts by weight of the monomer mixture [3] and 0.06 parts by weight of the polyethylene glycol dimethacrylate [8]; 270 parts by weight of the monomer mixture [5] and the polyethylene glycol dimethacrylate [ 9] Aqueous solution mixed with 2.09 parts by weight; 26.3 parts by weight of methacrylic acid; 3.2 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water; and 1.7 parts by weight of ammonium persulfate; An aqueous solution mixed with 20 parts by weight of water was dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (S) of the weight average molecular weight 25000 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 1.09% by weight. In the polycarboxylic acid (S), since the ratio of the monomer mixture [3] as a raw material is small and X ₂ + Y ₂ + Z ₁ + Z ₂ = 100, X ₂ = 5 to 70 is not satisfied. Carboxylic acid (S) is outside the scope of the present invention.

(Comparative Example 6)
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser was charged with 154.1 parts by weight of water, and the inside of the reactor was purged with nitrogen under stirring. The temperature was raised to ° C. 69.8 parts by weight of the monomer mixture [3]; 210 parts by weight of the monomer mixture [6]; 21.4 parts by weight of methacrylic acid; 3.1 parts by weight of 3-mercaptopropionic acid and 20 parts by weight of water. A mixed aqueous solution; and an aqueous solution obtained by mixing 1.7 parts by weight of ammonium persulfate and 20 parts by weight of water were dropped into the reactor over 4 hours each. And after completion | finish of dripping, 95 degreeC was further maintained for 2 hours, and the polycarboxylic acid (T) of the weight average molecular weight 32200 was obtained. The ratio of polyethylene glycol dimethacrylate to the total weight of polyethylene glycol dimethacrylate and methoxypolyethylene glycol monomethacrylate before dropping was 0.74% by weight. Since the polyalkylene glycol di (meth) acrylate contained in the raw material of the polycarboxylic acid (T) is only one kind, the polycarboxylic acid (T) is outside the scope of the present invention.

[Concrete test]
Each of the polycarboxylic acids (A) to (N) of Examples obtained above and the polycarboxylic acids (O) to (T) of Comparative Examples were used as cement admixtures as they were, and cement compositions according to the following concrete test methods. The product was prepared and the slump value was measured. The results are shown in Table 1 below.

(Concrete test method)
Any of the polycarboxylic acids obtained above, ordinary Portland cement as cement (3 brand equivalents mixed: specific gravity 3.16), mixed fine sand of Oikawa water land sand and Kisarazu mountain sand (specific gravity 2. 6, FM 2.71), and Ome hard sandstone crushed stone (specific gravity 2.64, MS 20 mm) as coarse aggregate, a cement composition was prepared in a kneading amount 50L. The blending amount of the cement admixture contained in this cement composition is shown in Table 1 below. The blending conditions for blending the cement composition were a unit cement amount of 320 kg / m ³ , a unit water amount of 166 kg / m ³ (water / cement ratio of 51.9%) and a fine aggregate ratio of 47%. For cement compositions, the slump (cm) after 10 minutes, 30 minutes, and 60 minutes immediately after preparation is 0 minutes in accordance with Japanese Industrial Standards (JIS-A-1101, 1128), and the compressive strength is The amount of air was measured by a method based on the standard (JIS-A-1108, specimen preparation is JIS-A-1132) and the method based on the Japanese Industrial Standard (JIS-A-1128).

(Solid content measurement)
The polymer used for the performance test was measured for non-volatile content by the following procedure, and the concentration was calculated using the non-volatile content as a cement dispersant.

  First, about 0.5 g of polycarboxylic acid (aqueous solution) was weighed in an aluminum cup, and about 1 g of ion-exchanged water was added to spread it uniformly. This was dried at 130 ° C. for 1 hour in a nitrogen atmosphere, and the nonvolatile content was measured from the mass difference from that before drying.

(Preparation of cement admixture)
Weigh out a predetermined amount of polycarboxylic acid (aqueous solution), add defoaming agent MA404 (manufactured by Pozoris) to 10% by mass with respect to the polymer, and add ion exchange water to make a predetermined amount. It was uniformly dissolved.

(Measurement of weight average molecular weight of polycarboxylic acid)
The GPC measurement conditions are as follows.
Column used: TSK guard column SWXL manufactured by Tosoh Corporation
TSKgel G4000SWXL
TSKgel G3000SWXL
TSKgel G2000SWXL connected in this order.
Eluent: A solution prepared by dissolving 115.6 g of sodium acetate trihydrate in a solution of 6001 g of acetonitrile and 10999 g of water and adjusting the pH to 6.0 with acetic acid was used.
Sample: A polymer aqueous solution dissolved in the eluent so that the polymer concentration is 0.5% by mass.
Sample injection amount: 100 μL
Flow rate: 1.0 mL / min Column temperature: 40 ° C
Detector: Empower Software manufactured by Japan Waters
Standard material for preparing a calibration curve: polyethylene glycol [peak top molecular weight (Mp) 272500, 219300, 107000, 50000, 24000, 11840, 6450, 4250, 1470]
Calibration curve: Prepared by a cubic equation based on the Mp value and elution time of the above polyethylene glycol.

  From the results shown in Table 1, it can be seen that the cement admixture according to the present invention represented by Examples 1 to 14 exhibits excellent slump retention performance and high compressive strength.

Claims (9)

The following general formula (1):
In the formula, each R ₁ independently represents a hydrogen atom or a methyl group, R ₂ O represents an oxyalkylene group, m represents an added mole number of the oxyalkylene group, and represents a number of 2 to 194.
₁ % by weight of a _first polyalkylene glycol di (meth) acrylate (a) X represented by
The following general formula (2):
In the formula, R ₃ represents a hydrogen atom or a methyl group, R ₄ O represents an oxyalkylene group, p represents the number of added moles of the oxyalkylene group, represents a number of 1 to 97, and R ₅ represents a hydrogen atom or Represents an alkyl group having 1 to 22 carbon atoms,
₂ % by weight of a first polyalkylene glycol (meth) acrylate (b) X represented by
The following general formula (3):
In the formula, each R ₆ independently represents a hydrogen atom or a methyl group, R ₇ O represents an oxyalkylene group, n represents an added mole number of the oxyalkylene group, and represents a number of 4 to 200 (provided that n−m ≧ 6),
In a second polyalkylene glycol di (meth) acrylate (c) _{Y 1} wt% as shown,
The following general formula (4):
In the formula, R ₈ represents a hydrogen atom or a methyl group, R ₉ O represents an oxyalkylene group, q represents an added mole number of the oxyalkylene group, and represents a number of 4 to 100 (provided that qp ≧ 3), R ₁₀ represents a hydrogen atom or an alkyl group having 1 to 22 carbon atoms,
₂ % by weight of a _second polyalkylene glycol (meth) acrylate (d) Y represented by
The following general formula (5):
In the formula, R ₁₁ represents a hydrogen atom or a methyl group, and M ¹ represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group, or an organic amine group.
₁ % by weight of a carboxylic acid monomer (e) Z represented by
₂ % by weight of other monomers (f) Z copolymerizable with the above (a) to (e),
(Where X ₂ + Y ₂ + Z ₁ + Z ₂ = 100, X ₂ : Y ₂ : Z ₁ : Z ₂ = 5 to 70:10 to 90: 5 to 40: 0 to 50 and X ₂ + Y ₂ = 60 to 95, and when X ₁ + X ₂ + Y ₁ + Y ₂ = 100, X ₁ + Y ₁ = 0.1 to 10)
Or a copolymer (salt) for a cement admixture which is a salt formed by neutralizing the copolymer with an alkaline substance. The copolymer (salt) for a cement admixture according to claim ₁ , wherein X ₁ + Y ₁ = 0.5 to 6 when X ₁ + X ₂ + Y ₁ + Y ₂ = 100. Of Luo Kishiarukiren group put on the first polyalkylene glycol di (meth) acrylate addition mole number of the oxyalkylene groups in (a) (m) and the second polyalkylene glycol di (meth) acrylate (c) addition mole number of moles average of (n) is taken as a _1, a ₁ is from 5 to 150, according to claim 1 or 2 copolymer for a cement admixture according to (salt). Added moles of Luo Kishiarukiren group put on the first polyalkylene glycol (meth) addition mol number of oxyalkylene groups in the acrylate (b) (p) and the second polyalkylene glycol (meth) acrylate (d) the number of moles average of (q) is taken as _{a 2, a 2} is 3 to 80, a copolymer for a cement admixture according to any one of claims 1-3 (salt). Of Luo Kishiarukiren group put on the first polyalkylene glycol di (meth) acrylate addition mole number of the oxyalkylene groups in (a) (m) and the second polyalkylene glycol di (meth) acrylate (c) addition mole number of moles average of (n) and a _1, wherein the first polyalkylene glycol (meth) acrylate (b) in addition mole number of the oxyalkylene group and (p) the second polyalkylene glycol ( meth) acrylate (d) to put Luo Kishiarukiren addition molar number of groups the molar average of (q) is taken as _{a 2, a} 1 / _{a 2} is from 1.0 to 10, claim 1 The copolymer (salt) for cement admixtures of any one of -4. The following general formula (1):
In the formula, each R ₁ independently represents a hydrogen atom or a methyl group, R ₂ O represents an oxyalkylene group, m represents an added mole number of the oxyalkylene group, and represents a number of 2 to 194.
₁ % by weight of a _first polyalkylene glycol di (meth) acrylate (a) X represented by
The following general formula (2):
In the formula, R ₃ represents a hydrogen atom or a methyl group, R ₄ O represents an oxyalkylene group, p represents the number of added moles of the oxyalkylene group, represents a number of 1 to 97, and R ₅ represents a hydrogen atom or Represents an alkyl group having 1 to 22 carbon atoms,
₂ % by weight of a first polyalkylene glycol (meth) acrylate (b) X represented by
The following general formula (3):
In the formula, each R ₆ independently represents a hydrogen atom or a methyl group, R ₇ O represents an oxyalkylene group, n represents an added mole number of the oxyalkylene group, and represents a number of 4 to 200 (provided that n−m ≧ 6),
In a second polyalkylene glycol di (meth) acrylate (c) _{Y 1} wt% as shown,
The following general formula (4):
In the formula, R ₈ represents a hydrogen atom or a methyl group, R ₉ O represents an oxyalkylene group, q represents an added mole number of the oxyalkylene group, and represents a number of 4 to 100 (provided that qp ≧ 3), R ₁₀ represents a hydrogen atom or an alkyl group having 1 to 22 carbon atoms,
₂ % by weight of a _second polyalkylene glycol (meth) acrylate (d) Y represented by
The following general formula (5):
In the formula, R ₁₁ represents a hydrogen atom or a methyl group, and M ¹ represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group, or an organic amine group.
₁ % by weight of a carboxylic acid monomer (e) Z represented by
₂ % by weight of other monomers (f) Z copolymerizable with the above (a) to (e),
(Where X ₂ + Y ₂ + Z ₁ + Z ₂ = 100, X ₂ : Y ₂ : Z ₁ : Z ₂ = 5 to 70:10 to 90: 5 to 40: 0 to 50 and X ₂ + Y ₂ = 60 to 95, and when X ₁ + X ₂ + Y ₁ + Y ₂ = 100, X ₁ + Y ₁ = 0.1 to 10)
A step of polymerizing a monomer component containing a copolymer to obtain a copolymer, and
A step of neutralizing the copolymer with an alkaline substance, if necessary,
The manufacturing method of the copolymer (salt) for cement admixtures containing. Two R ₁ in the general formula (1) and R ₃ in the general formula (2) are all the same, and / or two R ₆ in the general formula (3), and the general formula ( 4 The production method according to claim 6, wherein all of R _{8 in} ) are the same.   A copolymer for cement admixture according to any one of claims 1 to 5, or a copolymer (salt) for cement admixture produced by the production method according to claim 6 or 7, cement and water. A cement composition containing at least.   The content of the copolymer for cement admixture is 0.01 to 1.0% by weight with respect to cement, and the weight ratio of water / cement is 0.15 to 0.7. 9. The cement composition according to 8.