JP2018123014A - A method for producing a cement composition. - Google Patents

Abstract

【選択図】なしA method for producing a cement composition is provided.
A post-addition cement admixture containing a polycarboxylic acid copolymer having a specific monomer as a constituent unit in a specific ratio or a salt thereof is a flowable cement composition after a certain time has passed after kneading. Even when added to the above, the slump retention performance for a long time is excellent, the initial strength of the cement composition is excellent, and the generation of bleeding water can be suppressed. A method for producing a cement composition using the admixture. The polycarboxylic acid copolymer comprises at least each monomer represented by formula (1) and formula (2), an unsaturated carboxylic acid ester, and an unsaturated carboxylic acid monomer, Additive cement admixture. R ¹ —O— (A ¹ O) _n1 —R ² (1)

[Selection figure] None

Description

  The present invention relates to a method for producing a cement composition.

  In order to improve the workability and durability of the cement composition, it is effective to reduce the unit amount of water in the cement composition. However, it is known that when the unit water amount is decreased, the fluidity of the cement composition is lowered and the workability is impaired. Therefore, in order to ensure efficient workability of the cement composition even when the unit water amount is reduced, various dispersants having a function of dispersing cement particles are used.

  Furthermore, in recent years, with the decrease in ready-mixed concrete factories, the transport distance and transport time of concrete have increased, so various dispersants having the function of maintaining the slump retention of cement compositions have been developed. A method of producing a cement composition having an arbitrary fluidity by appropriately adding a cement admixture (hereinafter referred to as post-addition) to the fluid cement composition has been developed.

  Patent Documents 1, 2 and 3 exemplify copolymers having a specific unsaturated polyalkylene glycol monomer and a specific unsaturated carboxylic acid ester monomer.

  Patent Document 4 exemplifies an admixture for a hydraulic composition containing two types of copolymers of a specific unsaturated polyalkylene glycol monomer and a specific unsaturated carboxylic acid monomer, and polyethylene glycol. Has been.

  These dispersants include a unit that adsorbs to cement particles relatively early and exhibits dispersibility, and a unit that exposes adsorbing groups to cement after time has passed. It is said that it can satisfy the slump retention.

  Further, Patent Document 5 exemplifies a pumping aid in which oxycarboxylic acid or a salt thereof is granulated or flaked, and this admixture has long-term slump retention.

JP-A-10-81549 JP 2009-096672 A JP 2009-173527 A JP 2013-151403 A JP 2000-191354 A

  However, the cement admixtures described in Patent Documents 1 to 4 can maintain the slump retention property of the cement composition, but the cement admixture exhibits the fluidity of the cement composition immediately after the post-addition. As a result, the slump retention cannot be maintained for a long time. For this reason, it cannot be suitably used as a cement admixture for post-addition in which post-addition is performed on a fluid cement composition after kneading that has been required in recent years. Moreover, in the cement admixture described in Patent Document 5, it is possible to maintain the slump retention for a long time, but the initial strength expression of the cement composition is delayed, and bleeding water is easily generated. There is a problem in using as a cement admixture for post-addition. Therefore, there is a demand for a method for producing a cement composition using a post-addition cement admixture that does not affect water reduction immediately after post-addition, does not delay initial strength development, and can further suppress bleeding water. ing.

  Therefore, in the present invention, in order to solve the above-mentioned problems, even when added to a fluid cement composition that has passed for a certain period of time after kneading, it has excellent long-term slump retention performance and exhibits the initial strength of the cement composition. An object of the present invention is to provide a method for producing a cement composition using a post-addition cement admixture that is excellent and can suppress the generation of bleeding water.

  As a result of intensive studies to achieve the above object, the present inventors have found that a structural unit having an alkenyl group having a specific number of carbon atoms and a structural unit of an unsaturated monocarboxylic acid ester system having a specific number of carbon atoms. The above problem is solved by using a cement admixture containing a polycarboxylic acid copolymer containing a structural unit derived from a saturated carboxylic acid monomer or a salt thereof (A) as a cement admixture for post-addition. As a result, they have reached the present invention.

That is, the present invention includes the following [1] to [5].
[1] A method for producing a cement composition, comprising performing the following steps (1) to (2).
Step (1): A step of adding a cement admixture (D) to a base cement containing a hydraulic material and kneading.
Step (2): A step of adding and kneading a post-addition cement admixture containing at least the following component (A): polycarboxylic acid copolymer or salt (A) after 5 minutes or more of the kneading.
(A) component:
1 to 97% by weight of monomer (I) represented by the following general formula (1), 1 to 97% by weight of monomer (II) represented by the following general formula (2), and the following general formula (3) 1 to 97% by weight of monomer (III) represented by the formula, 0.1 to 50% by weight of unsaturated carboxylic acid monomer (IV), and copolymerized with monomers (I) to (IV) A polycarboxylic acid copolymer obtained by copolymerizing 0 to 50% by weight of other possible monomer (V) or a salt thereof (A).
R ¹ —O— (A ¹ O) _n1 —R ² (1)
(In the formula, R ¹ represents an alkenyl group having 2 to 5 carbon atoms. A ¹ O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. N1 represents an oxyalkylene group. (The average number of moles added represents a number of 1 to 200. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.)

（式中、Ｒ³、Ｒ⁴およびＲ⁵は、それぞれ独立に、水素原子または炭素原子数１〜３のアルキル基を表す。ｍは、０〜２の数を表す。Ａ²Ｏは、同一若しくは異なって、炭素原子数２〜１８のオキシアルキレン基を表す。ｎ２は、オキシアルキレン基の平均付加モル数であり、６〜２００の数を表す。Ｘは、水素原子または炭素原子数１〜３０の炭化水素基を表す。）

(In the formula, R ³ , R ⁴ and R ⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. M represents a number of 0 to ^2. A ² O is the same. Or, differently, it represents an oxyalkylene group having 2 to 18 carbon atoms, n2 is an average added mole number of the oxyalkylene group, and represents a number of 6 to 200. X is a hydrogen atom or 1 to 1 carbon atoms. Represents 30 hydrocarbon groups.)

（式中、Ｒ⁶、Ｒ⁷およびＲ⁸は、それぞれ独立に、水素原子または炭素原子数１〜３のアルキル基を表す。Ｙは、ヘテロ原子を含んでよい炭素原子数１〜１０の炭化水素基を表す。）
〔２〕前記ポリカルボン酸系共重合体またはその塩（Ａ）の単量体（ＩＩＩ）中のＹが、メチル基、エチル基、イソプロピル基、２−ヒドロキシエチル基、２−ヒドロキシプロピル基、２−ヒドロキシ−１−メチルエチル基から選ばれる少なくとも一つの単量体を含む〔１〕に記載のセメント組成物の製造方法。
〔３〕前記ポリカルボン酸系共重合体またはその塩（Ａ）の不飽和カルボン酸系単量体（ＩＶ）がアクリル酸またはその塩、メタクリル酸またはその塩、マレイン酸またはその塩から選ばれる少なくとも一つの単量体を含む〔１〕〜〔２〕のいずれかに記載のセメント組成物の製造方法。
〔４〕前記ポリカルボン酸系共重合体またはその塩（Ａ）の重量平均分子量が、ポリエチレングリコール換算で５，０００〜６０，０００である〔１〕〜〔３〕のいずれかに記載のセメント組成物の製造方法。
〔５〕前記セメント混和剤（Ｄ）が、下記（Ｂ）成分：ポリカルボン酸系共重合体またはその塩（Ｂ）および／または（Ｃ）成分：ポリカルボン酸系共重合体またはその塩（Ｃ）を含有する〔１〕〜〔４〕いずれかに記載のセメント組成物の製造方法。
（Ｂ）成分：
単量体（Ｉ）および単量体（ＩＶ）を、または、単量体（Ｉ）、単量体（ＩＶ）ならびに単量体（Ｉ）および（ＩＶ）と共重合可能なその他の単量体（ＶＩ）を、共重合させることにより得られるポリカルボン酸系共重合体またはその塩（Ｂ）。
（Ｃ）成分：
単量体（ＩＩ）および単量体（ＩＶ）を、または、単量体（ＩＩ）、単量体（ＩＶ）ならびに単量体（ＩＩ）および（ＩＶ）と共重合可能なその他の単量体（ＶＩＩ）を、共重合させることにより得られるポリカルボン酸系共重合体またはその塩（Ｃ）。

Wherein R ⁶ , R ⁷ and R ⁸ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Y represents a carbon atom having 1 to 10 carbon atoms which may contain a hetero atom. Represents a hydrogen group.)
[2] Y in the monomer (III) of the polycarboxylic acid copolymer or salt (A) thereof is a methyl group, an ethyl group, an isopropyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, The method for producing a cement composition according to [1], comprising at least one monomer selected from 2-hydroxy-1-methylethyl groups.
[3] The unsaturated carboxylic acid monomer (IV) of the polycarboxylic acid copolymer or salt (A) thereof is selected from acrylic acid or a salt thereof, methacrylic acid or a salt thereof, maleic acid or a salt thereof. The method for producing a cement composition according to any one of [1] to [2], comprising at least one monomer.
[4] The cement according to any one of [1] to [3], wherein the polycarboxylic acid copolymer or a salt thereof (A) has a weight average molecular weight of 5,000 to 60,000 in terms of polyethylene glycol. A method for producing the composition.
[5] The cement admixture (D) comprises the following component (B): polycarboxylic acid copolymer or salt thereof (B) and / or (C) component: polycarboxylic acid copolymer or salt thereof ( The method for producing a cement composition according to any one of [1] to [4], comprising C).
(B) component:
Monomer (I) and monomer (IV) or other monomer capable of copolymerization with monomer (I), monomer (IV) and monomers (I) and (IV) A polycarboxylic acid copolymer obtained by copolymerizing the body (VI) or a salt thereof (B).
Component (C):
Monomer (II) and monomer (IV) or other monomer capable of copolymerization with monomer (II), monomer (IV) and monomers (II) and (IV) A polycarboxylic acid copolymer obtained by copolymerizing the product (VII) or a salt thereof (C).

  According to the present invention, even when added to a flowable cement composition that has passed for a certain period of time after kneading, it has excellent long-term slump retention performance, excellent initial strength expression of the cement composition, and generation of bleeding water. A method for producing a cement composition using a post-addition cement admixture is provided.

That is, this invention is a manufacturing method of the cement composition characterized by performing the following process (1)-(2).
Step (1): A step of adding a cement admixture (D) to a base cement containing a hydraulic material and kneading.
Step (2): A step of adding and kneading a post-addition cement admixture containing at least the component (A) described later after the elapse of 5 minutes or more.

  In the above-described method for producing a cement composition, a specific post-addition cement admixture, which will be described later, is added after the initial kneading in the step (1), so that the initial strength development of the cement and the long-term slump retention performance are excellent. It was also found for the first time that a cement composition with suppressed bleeding water can be obtained.

  The time for adding the cement admixture for post-addition in the step (2) is important after the elapse of 5 minutes or more from the step (1), preferably in the range of 5 to 60 minutes, more preferably 10 to 40. The range of minutes. By satisfying this range, the cement composition can maintain the slump retention property for a long time.

<Cement composition (D)>
The cement admixture (D) is intended to be mixed (initial addition) before the kneading of the cement composition. Therefore, there is no particular limitation as long as it exhibits initial water-reducing and dispersibility. As such a thing, what uses a polycarboxylic acid type copolymer or a lignin sulfonic acid type compound as an active ingredient is mentioned, for example.

<(A) component>
Component (A) of the present invention is 1 to 97% by weight of monomer (I) represented by general formula (1) and 1 to 97% by weight of monomer (II) represented by general formula (2). 1 to 97% by weight of the monomer (III) represented by the general formula (3), 0.1 to 50% by weight of the unsaturated carboxylic acid monomer (IV), and (I) to (IV). It is a polycarboxylic acid copolymer obtained by copolymerizing 0 to 50% by weight of other polymerizable monomer (V) or a salt thereof (A).

  Component (A): The blending ratio of each monomer in obtaining the polycarboxylic acid copolymer or salt (A) is as follows. The blending ratio of the monomer (I) is 1% by weight to 97% by weight, preferably 3% by weight to 90% by weight, and more preferably 5% by weight to 70% by weight.

  The blending ratio of the monomer (II) is 1% by weight to 97% by weight, preferably 5% by weight to 97% by weight, and more preferably 5% by weight to 90% by weight.

  The blending ratio of the monomer (III) is 1% to 97% by weight, preferably 3% to 90% by weight, and more preferably 5% to 70% by weight.

The blending ratio of the monomer (IV) is 0.1 wt% to 50 wt%, preferably 0.1 wt% to 40 wt%, more preferably 0.1 wt% to 30 wt%. is there.
The blending ratio of the monomer (V) is 0 to 50% by weight, preferably 0 to 40% by weight.

  The blending ratio is as follows: monomer (I) blending ratio + monomer (II) blending ratio + monomer (III) blending ratio + monomer (IV) blending ratio + monomer (V) mixing ratio = 100 wt%.

  Component (A): In the polycarboxylic acid copolymer or salt (A) thereof, the ratio of the amount of monomer (II) to the amount of monomer (I) is preferably 1% by weight to 1000%. % By weight. The ratio of the amount of monomer (III) to the amount of monomer (I) is preferably 1% by weight to 1000% by weight. The ratio of the amount of monomer (IV) to the amount of monomer (I) is preferably 0.001% to 700% by weight. The ratio of the amount of monomer (V) to the amount of monomer (I) is preferably 0% by weight to 30% by weight, more preferably 0% by weight to 20% by weight.

  Hereinafter, first, the monomer (I) will be described.

  Monomer (I) is a polyalkylene glycol monoalkenyl ether represented by the following general formula (1).

R ¹ —O— (A ¹ O) _n1 —R ² (1)
(In the formula, R ¹ represents an alkenyl group having 2 to 5 carbon atoms. A ¹ O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. N1 represents an oxyalkylene group. (The average number of moles added represents a number of 1 to 200. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.)

R ¹ in the general formula (1) represents an alkenyl group having 2 to 5 carbon atoms. The number of carbon atoms of the alkenyl group is preferably 3-5. Examples of R ¹ include, but are not limited to, an allyl group, a methallyl group, a residue of 3-methyl-3-buten-1-ol, and the like.

A ¹ O in the general formula (1) is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. Examples of the oxyalkylene group include oxyethylene group (ethylene glycol unit), oxypropylene group (propylene glycol unit), oxybutylene group (butylene glycol unit), oxyethylene group (ethylene glycol unit), oxypropylene Groups (propylene glycol units) are preferred.

The above “same or different” means that when A ¹ O is contained in the general formula (1) (when n1 is 2 or more), each A ¹ O may be the same oxyalkylene group. Meaning that it may be different (two or more) oxyalkylene groups. In the case where a plurality of A ¹ O are contained in the general formula (1), the oxyethylene group (ethylene glycol unit), the oxypropylene group (propylene glycol unit) and the oxybutylene group (butylene glycol unit) are used. An embodiment in which two or more selected oxyalkylene groups are mixed is exemplified, and an embodiment in which an oxyethylene group (ethylene glycol unit) and an oxypropylene group (propylene glycol unit) are mixed, or an oxyethylene group (ethylene glycol unit) and oxy A mode in which a butylene group (butylene glycol unit) is mixed is preferable, and a mode in which an oxyethylene group (ethylene glycol unit) and an oxypropylene group (propylene glycol unit) are mixed is more preferable. In an embodiment in which different oxyalkylene groups are mixed, the addition of two or more oxyalkylene groups may be a block addition or a random addition. When the oxyethylene group and the oxypropylene group are mixed, the ratio of the average addition mole number of the oxyethylene group and the oxypropylene group is the average addition mole number of the oxyethylene group / average addition mole number of the oxypropylene group = 50 to 99. It is preferably 9% / 50 to 0.1%.

  N1 in General formula (1) is the average addition mole number of an oxyalkylene group, and represents the number of 1-200. n1 is preferably 1 to 70, more preferably 5 to 70, and still more preferably 8 to 70. In this specification, the average number of moles of oxyalkylene group added means the average number of moles of alkylene glycol units added to 1 mole of monomer.

R ² in the general formula (1) represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. When the number of carbon atoms increases, the cement dispersibility of the cement admixture may not be sufficiently exhibited. Therefore, R ² is preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. A hydrocarbon group of 1 to 5 is more preferable, and a hydrogen atom or a methyl group is most preferable.

  As the monomer (I), for example, (poly) ethylene glycol allyl ether, (poly) ethylene glycol methallyl ether, (poly) ethylene glycol 3-methyl-3-butenyl ether, (poly) ethylene (poly) propylene Glycol allyl ether, (poly) ethylene (poly) propylene glycol methallyl ether, (poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl ether, (poly) ethylene (poly) butylene glycol allyl ether, (poly) Ethylene (poly) butylene glycol methallyl ether, (poly) ethylene (poly) butylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene glycol allyl ether, methoxy (poly) ethylene glycol methallyl ether , Methoxy (poly) ethylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) propylene glycol allyl ether, methoxy (poly) ethylene (poly) propylene glycol methallyl ether, methoxy (poly) ethylene ( Poly) propylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) butylene glycol allyl ether, methoxy (poly) ethylene (poly) butylene glycol methallyl ether, methoxy (poly) ethylene (poly) butylene glycol 3-methyl-3-butenyl ether, (poly) ethylene glycol (poly) propylene glycol monoallyl ether, and ethylene oxide propylene oxide of 3-methyl-3-buten-1-ol De adducts. As the monomer (I), one or more of these may be used. However, since the hydrophilicity and hydrophobicity of the copolymer (A) can be excellent, (poly) It is preferable to include at least one selected from ethylene glycol (meth) allyl ether, (poly) ethylene glycol 3-methyl-3-butenyl ether, and (poly) ethylene (poly) propylene glycol allyl ether. The average added mole number of the oxyalkylene group (polyalkylene glycol unit) of the monomer (I) is preferably 1 to 70, more preferably 5 to 70, and further preferably 8 to 70. preferable. In the present specification, “(poly)” means that one or two or more constituent elements or raw materials described immediately after that are bonded. In the present specification, “(meth) allyl” means “allyl or methallyl”.

  The monomer (I) may contain only one type of monomer represented by the general formula (1), or may contain two or more types in combination.

  Monomer (II) is represented by the following general formula (2).

（式中、Ｒ³、Ｒ⁴およびＲ⁵は、それぞれ独立に水素原子または炭素原子数１〜３のアルキル基を表す。ｍは、０〜２の数を表す。Ａ²Ｏは、同一若しくは異なって、炭素原子数２〜１８のオキシアルキレン基を表す。ｎ２は、オキシアルキレン基の平均付加モル数であり、６〜２００の数を表す。Ｘは、水素原子または炭素原子数１〜３０の炭化水素基を表す。）

(In the formula, R ³ , R ⁴ and R ⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. M represents a number of 0 to ^2. A ² O is the same or Differently, it represents an oxyalkylene group having 2 to 18 carbon atoms, n2 is an average addition mole number of the oxyalkylene group, and represents a number of 6 to 200. X is a hydrogen atom or 1 to 30 carbon atoms. Represents a hydrocarbon group of

R ³ , R ⁴ and R ⁵ in the general formula (2) each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

A ² O in the general formula (2) is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. Examples of the oxyalkylene group include oxyethylene group (ethylene glycol unit), oxypropylene group (propylene glycol unit), oxybutylene group (butylene glycol unit), oxyethylene group (ethylene glycol unit), oxypropylene Groups (propylene glycol units) are preferred.

The above “same or different” means that each A ² O in the general formula (2) may be the same oxyalkylene group or different (two or more types) oxyalkylene groups. Means that. The embodiments where the general formula (2) A ² O in contains multiple oxyethylene group (ethylene glycol units), from the group consisting of oxypropylene groups (propylene glycol units) and oxybutylene group (butylene glycol units) An embodiment in which two or more selected oxyalkylene groups are mixed is exemplified, and an embodiment in which an oxyethylene group (ethylene glycol unit) and an oxypropylene group (propylene glycol unit) are mixed, or an oxyethylene group (ethylene glycol unit) and oxy A mode in which a butylene group (butylene glycol unit) is mixed is preferable, and a mode in which an oxyethylene group (ethylene glycol unit) and an oxypropylene group (propylene glycol unit) are mixed is more preferable. In an embodiment in which different oxyalkylene groups are mixed, the addition of two or more oxyalkylene groups may be a block addition or a random addition.

  N2 in General formula (2) is the average addition mole number of an oxyalkylene group, and represents the number of 6-200. n2 is preferably 6 to 150, more preferably 6 to 100, and still more preferably 6 to 70.

  Monomer (II) may be a single monomer represented by the general formula (2) or a combination of two or more.

  X in the general formula (2) represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. The dispersibility of the hydraulic composition of the hydraulic composition dispersant is sufficiently exhibited because the number of carbon atoms is not too large. Therefore, X is preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and a hydrogen atom or a methyl group. Most preferred.

  Examples of the monomer (II) include an unsaturated monocarboxylic acid such as (meth) acrylate (hereinafter, “(meth) acrylate” means “acrylate or methacrylate”), and (poly) ethylene glycol. , (Poly) ethylene (poly) propylene glycol, (poly) ethylene (poly) butylene glycol, methoxy (poly) ethylene glycol, methoxy (poly) ethylene (poly) propylene glycol, methoxy (poly) ethylene (poly) butylene glycol, etc. Of (poly) alkylene glycols. Also, for example, (poly) ethylene glycol (meth) acrylate, (poly) ethylene (poly) propylene glycol (meth) acrylate, (poly) ethylene (poly) butylene glycol (meth) acrylate, methoxy (poly) ethylene glycol (meth) Examples include (poly) alkylene glycol (meth) acrylates such as acrylate, methoxy (poly) ethylene (poly) propylene glycol (meth) acrylate, and methoxy (poly) ethylene (poly) butylene glycol (meth) acrylate. As the monomer (II), one or a combination of two or more of these can be used, but (poly) alkylene glycol (meth) acrylate is preferably used, and (poly) ethylene glycol (meth) More preferably, at least one of acrylate, (poly) propylene glycol (meth) acrylate and methoxy (poly) ethylene glycol (meth) acrylate is used. The average added mole number of (poly) alkylene glycol is preferably 6 to 200, more preferably 6 to 100, and even more preferably 6 to 70.

  Monomer (II) is not particularly limited and can be produced by a known method. Such methods include, for example, unsaturated monocarboxylic acids such as (meth) acrylic acid, (poly) ethylene glycol, (poly) ethylene (poly) propylene glycol, (poly) ethylene (poly) butylene glycol, methoxy Examples thereof include a method of esterifying with (poly) alkylene glycol such as (poly) ethylene glycol, methoxy (poly) ethylene (poly) propylene glycol, and methoxy (poly) ethylene (poly) butylene glycol.

  Monomer (III) is represented by the following general formula (3).

（式中、Ｒ⁶、Ｒ⁷およびＲ⁸は、それぞれ独立に、水素原子または炭素原子数１〜３のアルキル基を表す。Ｙは、ヘテロ原子を含んでよい炭素原子数１〜１０の炭化水素基を表す。）

Wherein R ⁶ , R ⁷ and R ⁸ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Y represents a carbon atom having 1 to 10 carbon atoms which may contain a hetero atom. Represents a hydrogen group.)

R ⁶ , R ⁷ and R ⁸ in the general formula (3) each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

  Y in General formula (3) represents a C1-C10 hydrocarbon group which may contain a hetero atom. When the ester group has an atomic group having not too many carbon atoms, the slump retention property of the cement admixture and the bleeding suppressing effect after aging are sufficiently exhibited. Therefore, Y is preferably a hydrocarbon group having 1 to 10 carbon atoms that may contain a hetero atom, more preferably a hydrocarbon group having 1 to 5 carbon atoms that may contain a hetero atom, Most preferably, it is a hydrocarbon group having 1 to 3 carbon atoms which may contain atoms.

  Examples of the monomer (III) include methyl (meth) acrylate, ethyl (meth) acrylate, normal propyl (meth) acrylate, isopropyl (meth) acrylate, normal butyl (meth) acrylate, isobutyl (meth) acrylate, hydroxy Methyl (meth) acrylate, 1-hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxy-1-methylethyl acrylate, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) Acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, diethylene glycol (meth) acrylate, dipropylene Glycol (meth) acrylate, nitromethyl (meth) acrylate, aminomethyl (meth) acrylate, 2-aminoethyl (meth) acrylate, and the number of carbon atoms in which Y in general formula (3) may include a hetero atom The compound represented by Formula (3) which is 1-3 hydrocarbon groups is preferable, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- Hydroxy-1-methylethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferred.

  The monomer (III) is not particularly limited and can be produced by a known method. As such a method, for example, esterification of unsaturated monocarboxylic acid such as (meth) acrylic acid and alcohol such as methanol or ethanol, or ring-opening addition of an epoxy compound such as ethylene oxide or propylene oxide. A method is mentioned.

  The copolymer (A) may further contain a structural unit derived from at least one monomer (IV) selected from acrylic acid or a salt thereof, methacrylic acid or a salt thereof, maleic acid or a salt thereof.

  Examples of the unsaturated carboxylic acid monomer (IV) include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and salts thereof (for example, monovalent metal salts, divalent metal salts, ammonium salts, Organic amine salts), dicarboxylic acids such as maleic acid and fumaric acid, and salts thereof (for example, monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts). The unsaturated carboxylic acid monomer (IV) may be one or more of these, preferably two or more of these, and more preferably two of these are used. More preferred. Among them, it is preferable to use at least one monomer selected from acrylic acid or a salt thereof, methacrylic acid or a salt thereof, maleic acid or a salt thereof, and it is more preferable to use two types in combination, acrylic acid or a salt thereof, It is even more preferable to use two types selected from methacrylic acid and salts thereof. When two types (monomer (IV-1) and monomer (IV-2)) are used in combination, the ratio when using monomer (IV-1) and monomer (IV-2) ( In general, (IV-1) / (IV-2) is (0.1% to 99.9%) / (99.9% to 0.1%), preferably Is (1% to 99%) / (99% to 1%). When three types (monomer (IV-1), monomer (IV-2), and monomer (IV-3)) are used in combination, monomer (IV-1) and monomer (IV -2) and monomer (IV-3) are used in a ratio (the total is 100% by weight). Usually, (IV-1) / (IV-2) / (IV-3) is (0 0.1% to 99.9%) / (0.1% to 99.9%) / (0.1% to 99.9%), preferably (1% to 99%) / (1% to 99%) / (1% to 99%).

  When acrylic acid is used as the unsaturated carboxylic acid monomer (IV), the ratio of acrylic acid dimer (the total is 100% by weight) is acrylic acid monomer / acrylic acid dimer = (90.0% by weight to 100% by weight). %) / (0 wt% to 10 wt%).

  Monomer (V) may be a monomer copolymerizable with one or more monomers selected from the group consisting of monomers (I), (II), (III) and (IV). If it does not specifically limit. The monomer (V) does not include the monomer (I), the monomer (II), the monomer (III), and the monomer (IV).

  Examples of the monomer (V) include the following, and one or more of these can be used;

  Formula (V-1):

で示されるジアリルビスフェノール類、例えば４，４’−ジヒドロキシジフェニルプロパン、４，４’−ジヒドロキシジフェニルメタン、４，４’−ジヒドロキシジフェニルスルホンの３および３’位アリル置換物；

Diallyl bisphenols, such as 4,4′-dihydroxydiphenylpropane, 4,4′-dihydroxydiphenylmethane, and 3 and 3 ′ allyl substitutes of 4,4′-dihydroxydiphenylsulfone;

  General formula (V-2):

で示されるモノアリルビスフェノール類、例えば４，４’−ジヒドロキシジフェニルプロパン、４，４’−ジヒドロキシジフェニルメタン、４，４’−ジヒドロキシジフェニルスルホンの３位アリル置換物；

Monoallyl bisphenols represented by the formula: for example, 4,4'-dihydroxydiphenylpropane, 4,4'-dihydroxydiphenylmethane, 3-position allyl substitute of 4,4'-dihydroxydiphenylsulfone;

  General formula (V-3):

で示されるアリルフェノール；

An allylphenol;

Half esters and diesters of unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid and alcohols having 1 to 30 carbon atoms;
Half amides and diamides of the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms;
Half esters and diesters of an alkyl (poly) alkylene glycol obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to the alcohol or amine and the unsaturated dicarboxylic acid;
Half esters and diesters of the above unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols;
Half amides of maleamic acid and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols;

(Poly) alkylene glycols such as triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate, etc. Di (meth) acrylates;
Polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate;
(Poly) alkylene glycol dimaleates such as triethylene glycol dimaleate and polyethylene glycol dimaleate;
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, (meth) acrylamidomethylsulfonic acid, (meth) acrylamidoethylsulfonic acid, 2- Unsaturated sulfonic acids such as methylpropanesulfonic acid (meth) acrylamide and styrenesulfonic acid, and monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts thereof;
Amides of unsaturated monocarboxylic acids such as methyl (meth) acrylamide and amines having 1 to 30 carbon atoms;
Vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene;
Alkanediol mono (meth) acrylates such as 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate;
Dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene;

Unsaturated amides such as (meth) acrylamide, (meth) acrylic alkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide;
Unsaturated cyanides such as (meth) acrylonitrile, α-chloroacrylonitrile;
Unsaturated esters such as vinyl acetate and vinyl propionate;
Unsaturation such as aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, vinylpyridine, etc. Amines;
Divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate;
Allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether;
Vinyl ethers or allyl ethers such as methoxypolyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether; and
Polydimethylsiloxanepropylaminomaleamic acid, polydimethylsiloxaneaminopropylaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (dipropylaminomaleamic acid), polydimethyl Siloxane- (1-propyl-3-acrylate), polydimethylsiloxane- (1-propyl-3-methacrylate), polydimethylsiloxane-bis- (1-propyl-3-acrylate), polydimethylsiloxane-bis- (1 Siloxane derivatives such as -propyl-3-methacrylate).

  Monomer (V) may be one type or a combination of two or more types.

  The monomer (V) preferably contains 3,4'-allyl substitutions of 4,4'-dihydroxydiphenylsulfone, and is a 3,4'-allyl substitution of 4,4'-dihydroxydiphenylsulfone. It is preferable.

  (A) component: In obtaining a polycarboxylic acid-type copolymer or its salt (A), monomer (I), monomer (II), monomer (III), a single quantity as needed Monomers other than the body (IV) and the monomer (V) may be used.

  In the present invention, the component (A): polycarboxylic acid copolymer or salt (A) thereof can be produced by copolymerizing each predetermined monomer by a known method. Examples of the method include polymerization methods such as polymerization in a solvent and bulk polymerization.

  Examples of the solvent used in the polymerization in the solvent include water; lower alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; aromatic hydrocarbons such as benzene, toluene and xylene; fats such as cyclohexane and n-hexane. Group hydrocarbons; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone. From the viewpoint of solubility of the raw material monomer and the resulting copolymer, it is preferable to use one or more selected from the group consisting of water and lower alcohols, and among these, water is more preferable.

  When copolymerization is performed in a solvent, each monomer and a polymerization initiator may be continuously dropped into each reaction vessel, or a mixture of each monomer and a polymerization initiator are dropped continuously into each reaction vessel. Also good. Alternatively, a solvent may be charged into the reaction vessel, and a mixture of the monomer and the solvent and a polymerization initiator solution may be continuously dropped into the reaction vessel, or a part or all of the monomer may be charged into the reaction vessel and polymerized. The initiator may be continuously dropped.

  When carrying out copolymerization in a solvent, it is preferable to mix each monomer in a container different from the reaction container previously set in the container in which the reaction is carried out and then continuously drop it into the reaction container.

  Component (A): The polycarboxylic acid copolymer or its salt (A) may be added to the cement admixture as it is, including the reaction solvent after completion of the copolymerization reaction, or You may add in the state which processed. Examples of the treatment include removal of the reaction solvent, concentration adjustment by concentration or dilution, purification, and pH adjustment. After the completion of the reaction, it is preferable to adjust the concentration and / or adjust the pH in a container installed after the reaction container. The method for adjusting the concentration is not particularly limited, but may be performed by, for example, concentration or dilution by hydration. The pH adjustment will be described later.

  Examples of the polymerization initiator that can be used for copolymerization include persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate; t-butyl hydroperoxide, hydrogen peroxide when copolymerization is performed in an aqueous solvent. And water-soluble organic peroxides. In this case, an accelerator such as sodium hydrogen sulfite and Mole salt and a reducing agent such as ascorbic acid and monosaccharide can be used in combination. When copolymerization is performed in a solvent such as a lower alcohol, aromatic hydrocarbon, aliphatic hydrocarbon, ester or ketone, for example, peroxides such as benzoyl peroxide and lauryl peroxide; cumene peroxide Hydroperoxides such as: aromatic azo compounds such as azobisisobutyronitrile can be used as the polymerization initiator. In this case, an accelerator such as an amine compound can be used in combination. Furthermore, when copolymerization is carried out in a water-lower alcohol mixed solvent, it can be used by appropriately selecting from the aforementioned polymerization initiator or a combination of a polymerization initiator and an accelerator. The polymerization temperature varies depending on the polymerization conditions such as the solvent used and the type of polymerization initiator, but is usually in the range of 50 to 120 ° C.

  In the copolymerization, the molecular weight can be adjusted using a chain transfer agent as required. Examples of the chain transfer agent used include mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, and 2- Known thiol compounds such as mercaptoethanesulfonic acid: phosphorous acid, hypophosphorous acid, and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionite, meta Lower oxide of bisulfite and its salts (sodium sulfite, potassium sulfite, sodium bisulfite, potassium bisulfite, sodium dithionite, potassium dithionite, sodium metabisulfite, potassium metabisulfite, etc.) and its Salt; and the like. These may be used alone or in combination of two or more. Furthermore, in order to adjust the molecular weight of the polycarboxylic acid copolymer or its salt (A), it is also effective to use a monomer (V) having a higher chain transfer property as a monomer for obtaining each. It is. Examples of the monomer (V) having a high chain transfer property include (meth) allylsulfonic acid (salt) monomers. The blending ratio of the monomer (V) is usually 20% by weight or less and preferably 10% by weight or less in the polycarboxylic acid copolymer or the salt (A) thereof. Note that, for (A), the blending ratio is the blending ratio of the monomer (I) + the blending ratio of the monomer (II) + the blending ratio of the monomer (III) + the blending of the monomer (IV). It is a blending ratio when the ratio + the blending ratio of the monomer (V) = 100% by weight.

When copolymerizing in an aqueous solvent, the pH at the time of polymerization usually becomes strongly acidic due to the influence of a monomer having an unsaturated bond, but this may be adjusted to an appropriate pH. If it is necessary to adjust the pH during polymerization, adjust the pH using an acidic substance such as phosphoric acid, sulfuric acid, nitric acid, alkylphosphoric acid, alkylsulfuric acid, alkylsulfonic acid, or (alkyl) benzenesulfonic acid. Can do. Among these acidic substances, it is preferable to use phosphoric acid because it has a pH buffering action. However, in order to eliminate the instability of the ester bond of the ester monomer, it is preferable to perform the polymerization at pH 2-7. Moreover, although there is no limitation in particular in the alkaline substance which can be used for adjustment of pH, alkaline substances, such as NaOH and Ba (OH) _2, are common. The pH adjustment may be performed on the monomer before polymerization or may be performed on the copolymer solution after polymerization. In addition, these may be subjected to polymerization by adding a part of an alkaline substance before polymerization, and then the pH of the copolymer may be further adjusted.

  Component (A): The weight average molecular weight of the polycarboxylic acid copolymer or salt (A) is preferably 5,000 or more, more preferably 6,000 or more, and 6,500 or more. More preferably, it is more preferably 9,000 or more. As a result, the cement dispersibility of the cement admixture is sufficiently exhibited, an excellent water reduction rate can be obtained, the fluidity or workability can be improved, and the desired effect as a cement admixture can be fully expressed. . The upper limit of the weight average molecular weight is preferably 60,000 or less, more preferably 50,000 or less, and still more preferably 30,000 or less. Thereby, the aggregation effect | action of a cement particle is suppressed and workability | operativity can be made favorable. The weight average molecular weight is preferably 5,000 to 60,000, more preferably 6,000 to 50,000, and even more preferably 9,000 to 30,000.

  Component (A): The molecular weight distribution (Mw / Mn) of the polycarboxylic acid copolymer or salt (A) is preferably 1.2 or more, and more preferably 1.25 or more. The upper limit is preferably 3.0 or less, and more preferably 2.50 or less. The molecular weight distribution is preferably in the range of 1.2 to 3.0.

  In addition, the weight average molecular weight in this invention can be measured by the well-known method converted into polyethyleneglycol by gel permeation chromatography (GPB).

Although there is no limitation in particular as GPB measurement conditions, the following conditions can be mentioned as an example. The weight average molecular weight in the latter examples is a value measured under these conditions.
Measuring device; column used by Tosoh; ShoCex Column OH-pak SB-806HQ, SB-804HQ, SB-802.5HQ
Eluent: 0.05 mM sodium nitrate / acetonitrile 8/2 (v / v)
Standard material: Polyethylene glycol (Tosoh, GL Science)
Detector: differential refractometer (manufactured by Tosoh)
Calibration curve; polyethylene glycol standard

  Component (A): The polycarboxylic acid copolymer or salt (A) thereof may be one kind or a combination of two or more kinds different from each other.

  In the post-addition cement admixture of the present invention, the content of the component (A): polycarboxylic acid copolymer or its salt (A) is not limited, but with respect to the total weight of the post-addition cement admixture, 10% by weight to 100% by weight is preferable.

  Component (A) of the present invention: the polycarboxylic acid copolymer or salt (A) can be used as a cement admixture (D) as a cement admixture for initial addition. In view of the compatibility and compatibility with the post-addition cement composition of the present invention, it is preferable to use the component (B) and / or the component (C) described later as the cement admixture (D).

<(B) component>
Component (B) of the present invention comprises monomer (I) and unsaturated carboxylic acid monomer (IV) represented by general formula (1), or monomer (I), monomer (IV) and a polycarboxylic acid copolymer obtained by copolymerizing monomer (I) and other monomer (VI) copolymerizable with monomer (IV) or a salt thereof ( B).
Component (B): Polycarboxylic acid copolymer or salt thereof (B) is different from polycarboxylic acid copolymer or salts (A) and (C) thereof in that monomer (II) is not copolymerized. Can be distinguished. Examples and preferred examples of the monomer (I) and the monomer (IV) are those of the monomers (I) and (IV) described in the polycarboxylic acid copolymer or the salt (A) thereof. It is the same as each example and a preferable example.

  The monomer (VI) may be copolymerizable with the monomers (I) and (IV), may be copolymerizable with the monomer (II), and the monomers (I) to (IV) It may be copolymerizable with other monomers. Examples and preferred examples of the monomer (VI) are the same as the examples and preferred examples of the monomer (V) described for the polycarboxylic acid copolymer or salt (A) thereof. Examples and preferred examples of the production method of the polycarboxylic acid copolymer or its salt (B) are the same as those of the production method and preferred examples of the polycarboxylic acid copolymer or its salt (A).

  (B) component: The compounding ratio of each monomer at the time of obtaining a polycarboxylic acid-type copolymer or its salt (B) is as follows. The blending ratio of the monomer (I) is preferably 40% by weight to 97% by weight, more preferably 50% by weight to 97% by weight, and still more preferably 60% by weight to 97% by weight. The blending ratio of the monomer (IV) is preferably 1% by weight to 60% by weight, more preferably 1% by weight to 50% by weight, and still more preferably 1% by weight to 40% by weight. The blending ratio of the monomer (VI) is preferably 0% by weight to 50% by weight, more preferably 0% by weight to 40% by weight, and still more preferably 0% by weight to 30% by weight. However, the blending ratio of the monomer (I) + the blending ratio of the monomer (IV) + the blending ratio of the monomer (VI) = 100% by weight.

  Component (B): In the polycarboxylic acid copolymer or salt (B) thereof, the ratio of the amount of monomer (IV) to the amount of monomer (I) is preferably 1% by weight to 70%. % By weight, more preferably 5% by weight to 70% by weight, and still more preferably 5% by weight to 60% by weight. The ratio of the amount of monomer (VI) to the amount of monomer (I) is preferably 0% to 50% by weight, more preferably 0% to 40% by weight, and still more preferably. Is 0% to 30% by weight.

  Component (B): The weight average molecular weight of the polycarboxylic acid copolymer or salt (B) is preferably 5,000 to 60,000, more preferably 6,000 to 50,000. .

  Component (B): The molecular weight distribution (Mw / Mn) of the polycarboxylic acid copolymer or salt (B) is preferably in the range of 1.2 to 3.0, preferably 1.25 to 2.5. More preferably.

  Component (B): The polycarboxylic acid copolymer or salt (B) thereof may be one kind or a combination of two or more kinds different from each other.

  When the component (B): polycarboxylic acid copolymer or salt (B) is used as the cement admixture (D) of the present invention, it is contained in the cement composition for post-addition in the cement composition ( Component (B): Polycarboxylic acid copolymer or salt (B) is 1% by weight to 500% by weight with respect to component (A): polycarboxylic acid copolymer or salt (A). Preferably, it is 1 to 300% by weight, more preferably 50 to 300% by weight.

<(C) component>
Component (C) of the present invention comprises monomer (II) and unsaturated carboxylic acid monomer (IV) represented by general formula (2), or monomer (II), monomer A polycarboxylic acid copolymer obtained by copolymerizing (IV) and other monomers (VII) copolymerizable with monomers (II) and (IV) or a salt thereof (C) is there.
Component (C): Polycarboxylic acid copolymer or salt thereof (C) does not copolymerize monomer (I). Component (A): Polycarboxylic acid copolymer or salt (A) thereof and Component (B): Different from polycarboxylic acid copolymer or salt (B). Component (C): In the polycarboxylic acid copolymer or salt (C) thereof, examples and preferred examples of the monomer (II) and the monomer (IV) are as follows: (A) component: polycarboxylic acid This is the same as the respective examples and preferred examples of the monomers (II) and (IV) described in the system copolymer or salt (A) thereof.

  The monomer (VII) may be copolymerizable with the monomers (II) and (IV), may be copolymerizable with the monomer (I), and the monomers (I) to (IV) It may be copolymerizable with other monomers. Examples and preferred examples of the monomer (VII) are the same as the examples and preferred examples of the monomer (V) described in the polycarboxylic acid copolymer or salt (A) thereof. Examples and preferred examples of the production method of the polycarboxylic acid copolymer or its salt (C) are the same as those of the polycarboxylic acid copolymer or its salt (A).

  Component (C): The blending ratio of each monomer in obtaining the polycarboxylic acid copolymer or its salt (C) is as follows. The blending ratio of the monomer (II) is preferably 40% by weight to 97% by weight, more preferably 50% by weight to 97% by weight, and still more preferably 60% by weight to 97% by weight. The blending ratio of the monomer (IV) is preferably 1% by weight to 60% by weight, more preferably 1% by weight to 50% by weight, and still more preferably 1% by weight to 40% by weight. The blending ratio of the monomer (VII) is preferably 0% to 50% by weight, more preferably 0% to 40% by weight, and still more preferably 0% to 30% by weight. However, the blending ratio of the monomer (II) + the blending ratio of the monomer (IV) + the blending ratio of the monomer (VII) = 100% by weight.

  Component (C): In the polycarboxylic acid copolymer or salt (C) thereof, the ratio of the amount of monomer (IV) to the amount of monomer (II) is preferably 1% by weight to 70%. % By weight, more preferably 5% by weight to 70% by weight, and still more preferably 5% by weight to 60% by weight. The ratio of the amount of monomer (VII) to the amount of monomer (II) is preferably 0% to 50% by weight, more preferably 0% to 40% by weight, still more preferably. Is 0% to 30% by weight.

  Component (C): The weight average molecular weight of the polycarboxylic acid copolymer or salt (C) is preferably 5,000 to 60,000, and more preferably 6,000 to 50,000. .

  Component (C): The molecular weight distribution (Mw / Mn) of the polycarboxylic acid copolymer or salt (C) is preferably in the range of 1.2 to 3.0, preferably 1.25 to 2.5. More preferably.

  Component (C): The polycarboxylic acid copolymer or salt (C) thereof may be one kind or a combination of two or more kinds different from each other.

  When (C) component: polycarboxylic acid copolymer or salt (C) is used as the cement admixture (D) of the present invention, the component contained in the cement admixture for post-addition in the cement composition (A): With respect to the polycarboxylic acid copolymer or salt (A), the component (C): the polycarboxylic acid copolymer or salt (C) is 1% by weight to 500% by weight. Is preferably 1% by weight to 300% by weight, and more preferably 50% by weight to 300% by weight.

  The monomers (I) to (VII) constituting the components (A), (B) and (C) of the present invention are independent of each other and may be the same or different.

  In the post-addition cement admixture of the present invention, the content of the component (A) is not limited, the component (A) may be included as it is, and a solution or dispersion in which the component (A) is dissolved in a solvent. You may mix | blend as a made-up dispersion liquid and a suspended suspension liquid. The dispersion may contain a commercially available dispersant. Moreover, the said (B) component and (C) component can be used together with (A) component in the range which does not inhibit the effect of this invention as needed, and can be used as a cement admixture for post addition. (When the post-addition cement admixture of the present invention contains the component (B) and / or the component (C), the solution, dispersion or suspension of the component (A) and the component (B), and the component (B) Separately, a solution in which the component (C) is dissolved in a solvent, a dispersed dispersion, and a suspended suspension are separately prepared, and these are blended to prepare a cement admixture for post-addition. May be.

  The post-addition cement admixture of the present invention can be used in the form of an aqueous solution or in the form of powder after drying.

  The post-addition cement admixture of the present invention can be used after being added to a cement composition (base cement) such as cement paste, mortar, concrete, plaster or the like containing a hydraulic material such as cement.

  The cement composition of this invention should just contain the cement admixture for post-addition, and the hydraulic material combined is not specifically limited. Examples of the hydraulic material include cement, gypsum (semihydrate gypsum, dihydrate gypsum, etc.), and dolomite. The most common hydraulic material is cement.

  The cement is not particularly limited. For example, Portland cement (ordinary, early strength, very early strength, moderate heat, sulfate-resistant and low alkali type of each), various mixed cements (blast furnace cement, silica cement, fly ash cement), white Portland cement, alumina cement, Super fast cement (1 clinker fast cement, 2 clinker fast cement, magnesium phosphate cement), grout cement, oil well cement, low exothermic cement (low exothermic blast furnace cement, fly ash mixed low exothermic blast furnace cement, belite High-content cement), ultra-high-strength cement, cement-based solidified material, eco-cement (cement produced using at least one of municipal waste incineration ash and sewage sludge incineration ash). Blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, limestone powder and other fine powder, gypsum and the like may be added to the cement.

  Moreover, the cement composition may contain the aggregate. The aggregate may be either a fine aggregate or a coarse aggregate. Examples of aggregates include sand, gravel, crushed stone; granulated slag; recycled aggregate, etc .; siliceous, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromic, magnesia Fireproof aggregates such as

  There is no particular limitation on the proportion of the post-addition cement admixture in the cement composition. For example, when the cement composition is mortar or concrete, the added amount (blending amount) of the polycarboxylic acid copolymer or salt (A) contained in the post-addition cement admixture is the total amount of cement. It is 0.01-5.0 weight% normally with respect to a weight, Preferably it is 0.02-2.0 weight%, More preferably, it is 0.05-1.0 weight%. By using this added amount, the obtained cement composition has various preferable effects such as a reduction in unit water amount, an increase in strength, and an improvement in durability. If the blending ratio is less than 0.01% by weight, the resulting cement composition may not be sufficient in terms of performance, and conversely, even if a large amount exceeding 5.0% by weight is used, the effect is substantially reduced. There is a risk that it will hit a peak and be disadvantageous in terms of economy.

  The cement composition is effective as, for example, ready mixed concrete, concrete for concrete secondary products (precast concrete), concrete for centrifugal molding, concrete for vibration compaction, steam-cured concrete, shotcrete, and the like. . Furthermore, medium-fluidity concrete (concrete with a slump value of 22 to 25 cm), high fluidity concrete (concrete with a slump value of 25 cm or more and a slump flow value of 50 to 70 cm), self-filling concrete, self-leveling material It is also effective as mortar or concrete that requires high fluidity such as.

  The cement admixture for post-addition of the present invention may further include other cement dispersants, water-soluble polymers, polymer emulsions, air entrainers, cement wetting agents, swelling agents, waterproofing agents, retarders, thickeners, and flocculants. , Drying shrinkage reducing agents, strength enhancers, curing accelerators, antifoaming agents, AE agents, and other known additives for concrete such as surfactants can be used in combination. These may be used alone or in combination of two or more.

  Examples of other cement dispersants include sulfonic acid-based dispersants (S) such as naphthalene sulfonic acid formaldehyde condensate, melamine sulfonic acid formaldehyde condensate, and lignin sulfonate. The content of the sulfonic acid dispersant (S) is 0.01% by weight to 50% by weight with respect to the total amount of the components (A), (B) and (C) of the present invention. Is preferred. In the present specification, when “the total amount of the component (A), the component (B), and the component (C)” is referred to, all of the component (A), the component (B), and the component (C) are included in the present invention. Not only the total amount when it is contained in the cement admixture of the present invention, but also when either of the component (B) and the component (C) is not contained in the cement additive for post-addition of the present invention. It also means the total amount when the weight of components not included is calculated as 0.

  Examples of the water-soluble polymer (P) include polyalkylene glycols and cellulose compounds. Specifically, polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, polyethylene polybutylene glycol, hydroxyethyl cellulose, hydroxymethyl cellulose, and methyl cellulose. And hydroxypropylmethylcellulose. The content of the water-soluble polymer (P) is 0.01% by weight to 50% by weight with respect to the total amount of the components (A), (B) and (C) of the present invention. preferable.

  Examples of the retarder include oxycarboxylic acids such as gluconic acid (salt) and citric acid (salt), sugars such as glucose, and sugar alcohols (G) such as sorbitol. The content of the sugar alcohols (G) is preferably 0.01% by weight to 50% by weight with respect to the total amount of the components (A), (B) and (C) of the present invention. .

  Examples of the curing accelerator include soluble calcium salts such as calcium chloride, calcium nitrite and calcium nitrate, chlorides such as iron chloride and magnesium chloride, and formate salts (K) such as thiosulfate, formic acid and calcium formate. Can be mentioned. It is preferable that the content rate of a hardening accelerator (K) is 0.01 to 50 weight% with respect to the total amount of (A) component of this invention, (B) component, and (C) component. .

  Examples of the thickener include hydroxypropylmethylcellulose, methylcellulose, carboxymethylcellulose, known cellulose nanofibers, and known cellulose nanocrystals (Z). The content of the thickener (Z) is preferably 0.01% by weight to 50% by weight with respect to the total amount of the components (A), (B) and (C) of the present invention. .

  The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. In the examples, unless otherwise indicated, “%” means “% by weight” and “parts” means “parts by weight”.

<(A) component>
<Production Example 1>
In a glass reaction vessel equipped with a thermometer, a stirrer, a reflux device, a nitrogen introduction tube and a dropping device, 148 parts of water and polyethylene polypropylene glycol monoallyl ether (average addition mole number of ethylene oxide 39, average addition mole of propylene oxide) 94 parts (random addition of ethylene oxide and propylene oxide) were charged, and the temperature was raised to 80 ° C. with stirring. Thereafter, 35 parts of methacrylic acid, 5 parts of acrylic acid (monomer / dimer = 99% by weight / 1% by weight), 63 parts of methoxypolyethylene glycol methacrylate (average number of moles of added ethylene oxide 13), 60 parts of 2-hydroxyethyl acrylate A monomer aqueous solution in which 8 parts of 3-mercaptopropionic acid and 165 parts of water were mixed, and a mixed liquid of 3 parts of ammonium persulfate and 47 parts of water were continuously added dropwise to a reaction vessel maintained at 80 ° C. for 2 hours each. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 100 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer I: II: III: IV: V = 37: 25: 23: 15: 0. The copolymer in the liquid was the copolymer (A-1) (weight average molecular weight 10,000, Mw / Mn 1.5).

<Production Example 2>
105 parts of water, 3 parts of a mixture of 2-hydroxypropyl acrylate and 2-hydroxy-1-methylethyl acrylate, and polyethylene polypropylene in a glass reaction vessel equipped with a thermometer, a stirring device, a reflux device, a nitrogen introduction tube and a dropping device Charge 26 parts of glycol monoallyl ether (average addition mole number of ethylene oxide 33, average addition mole number of propylene oxide 2, add 2 moles of propylene oxide to allyl unit, then add 33 moles of ethylene oxide) and react under stirring The vessel was purged with nitrogen and heated to 100 ° C. under a nitrogen atmosphere. Thereafter, 9 parts of methacrylic acid, 1 part of acrylic acid (monomer / dimer = 99% by weight / 1% by weight), 53 parts of methoxypolyethylene glycol methacrylate (average number of moles of ethylene oxide added 25), 2-hydroxypropyl acrylate and 2 A mixture of 84 parts of a hydroxy-1-methylethyl acrylate, 3 parts of 3-mercaptopropionic acid and 51 parts of water, and a mixture of 1 part of ammonium persulfate and 47 parts of water for 3 hours, The solution was continuously added dropwise to a reaction vessel maintained at 100 ° C. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 100 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer I: II: III: IV: V = 15: 30: 49: 6: 0. The copolymer in the liquid was a copolymer (A-2) (weight average molecular weight 19,000, Mw / Mn 1.4).

<Production Example 3>
137 parts of water and 52 parts of polyethylene glycol monoallyl ether (average added mole number of ethylene oxide 10) were charged into a glass reaction vessel equipped with a thermometer, a stirring device, a refluxing device, a nitrogen introducing tube and a dropping device. The reaction vessel was purged with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Thereafter, 5 parts of methacrylic acid, 5 parts of acrylic acid (monomer / dimer = 99% by weight / 1% by weight), 87 parts of methoxypolyethylene glycol methacrylate (average number of moles of ethylene oxide added 17), 20 parts of 2-hydroxyethyl acrylate , 20 parts of methyl methacrylate, 7 parts of 3-mercaptopropionic acid and 120 parts of water, and a reaction vessel in which a mixed solution of 2 parts of ammonium persulfate and 48 parts of water was kept at 80 ° C. for 2 hours each Was continuously dripped. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 100 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer I: II: III: IV: V = 28: 46: 21: 5: 0. The copolymer in the liquid was a copolymer (A-3) (weight average molecular weight 20,500, Mw / Mn 1.5).

<Production Example 4>
In a glass reaction vessel equipped with a thermometer, a stirrer, a reflux device, a nitrogen introduction tube and a dropping device, 155 parts of water and ethylene oxide propylene oxide adduct of 3-methyl-3-buten-1-ol (of ethylene oxide) 70 parts of average addition mole number 45, average addition mole number 3 of propylene oxide, random addition of ethylene oxide and propylene oxide) were charged, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 80 ° C. in a nitrogen atmosphere. Thereafter, 15 parts of methacrylic acid, 5 parts of acrylic acid (monomer / dimer = 99% by weight / 1% by weight), 33 parts of methoxypolyethylene glycol methacrylate (average number of moles of ethylene oxide added 13), 87 parts of 2-hydroxyethyl acrylate A monomer aqueous solution in which 3 parts of 3-mercaptopropionic acid and 119 parts of water were mixed, and a mixed liquid of 3 parts of ammonium persulfate and 47 parts of water were continuously added dropwise to a reaction vessel maintained at 80 ° C. for 2 hours each. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 100 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer I: II: III: IV: V = 33: 16: 41: 10: 0. The copolymer in the liquid was a copolymer (A-4) (weight average molecular weight 24,500, Mw / Mn 1.5).

<Production Example 5>
100 parts of water in a glass reaction vessel equipped with a thermometer, a stirrer, a reflux device, a nitrogen introducing tube and a dropping device, and an ethylene oxide adduct of 3-methyl-3-buten-1-ol (average addition of ethylene oxide) Mole number 67) 143 parts were charged, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 60 ° C. under a nitrogen atmosphere. Thereafter, 15 parts of methacrylic acid, 15 parts of acrylic acid (monomer / dimer = 99% by weight / 1% by weight), 34 parts of methoxypolyethylene glycol methacrylate (average number of moles of added ethylene oxide 25), 42 parts of 2-hydroxypropyl acrylate , A reaction in which an aqueous monomer solution obtained by mixing 6 parts of 3-mercaptopropionic acid, 5 parts of ascorbic acid, and 138 parts of water, and a mixed solution of 4 parts of hydrogen peroxide and 46 parts of water were maintained at 80 ° C. for 2 hours each. It was dripped continuously into the container. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 60 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer I: II: III: IV: V = 57: 14: 17: 12: 0. The copolymer in the liquid was a copolymer (A-5) (weight average molecular weight 20,200, Mw / Mn 1.6).

<Production Example 6>
195 parts of water, 21 parts of 2-hydroxyethyl acrylate, polyethylene polypropylene glycol monoallyl ether (average number of added moles of ethylene oxide: 10 in a glass reaction vessel equipped with a thermometer, a stirring device, a reflux device, a nitrogen introducing tube and a dropping device The average number of moles of propylene oxide added is 1, 50 moles of propylene oxide is added after adding 10 moles of ethylene oxide to the allyl unit, and the 3 and 3 'positions of 4,4'-dihydroxydiphenylsulfone are allyl substituted. 3 parts of the prepared compound was charged, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 80 ° C. in a nitrogen atmosphere. Thereafter, 40 parts of methacrylic acid, 5 parts of acrylic acid (monomer / dimer = 99% by weight / 1% by weight), 100 parts of methoxypolyethylene glycol methacrylate (average number of moles of added ethylene oxide 25), 60 parts of 2-hydroxyethyl acrylate A monomer aqueous solution in which 8 parts of 3-mercaptopropionic acid and 150 parts of water were mixed, and a mixed liquid of 3 parts of ammonium persulfate and 47 parts of water were continuously added dropwise to a reaction vessel maintained at 80 ° C. for 2 hours each. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 100 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer I: II: III: IV: V = 18: 36: 29: 16: 1. The copolymer in the liquid was a copolymer (A-6) (weight average molecular weight 11,600, Mw / Mn 1.5).

<Production Example 7>
195 parts of water and 55 parts of polyethylene glycol monoallyl ether (average number of moles of ethylene oxide added 10) were charged in a glass reaction vessel equipped with a thermometer, stirring device, refluxing device, nitrogen introduction tube and dropping device, and reacted under stirring. The vessel was purged with nitrogen and heated to 100 ° C. under a nitrogen atmosphere. Thereafter, 12 parts of methacrylic acid, 4 parts of acrylic acid (monomer / dimer = 99% by weight / 1% by weight), 57 parts of methoxypolyethylene glycol methacrylate (average number of moles of added ethylene oxide 9), methoxypolyethylene glycol methacrylate (ethylene The average added mole number of oxide 13) 35 parts of monomer, 8 parts of 3-mercaptopropionic acid, 150 parts of water mixed monomer aqueous solution, 3 parts of ammonium persulfate 3 parts of water and 47 parts of water, each for 2 hours, 100 ° C. The reaction vessel was continuously added dropwise to the reaction vessel. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 100 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer I: II: IV = 34: 56: 10. The copolymer in the liquid was a copolymer (A-7) (weight average molecular weight 11,600, Mw / Mn 1.5).

<(B) and (C) component>
<Production Example 8>
148 parts of water and 347 parts of polyethylene glycol monoallyl ether (average added mole number of ethylene oxide: 40) were charged into a glass reaction vessel equipped with a thermometer, a stirring device, a reflux device, a nitrogen introducing tube and a dropping device, and stirred. The reaction vessel was purged with nitrogen and heated to 80 ° C. in a nitrogen atmosphere. Thereafter, a monomer aqueous solution in which 90 parts of acrylic acid (monomer / dimer = 99% by weight / 1% by weight), 1 part of 30% aqueous NaOH solution, and 288 parts of water were mixed, and a mixed liquid of 7 parts of ammonium persulfate and 113 parts of water; Were continuously dropped into a reaction vessel maintained at 80 ° C. for 2 hours each. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 100 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer I: IV: VI = 79: 21: 0. The copolymer in the liquid was a copolymer (B-1) (weight average molecular weight 16,000, Mw / Mn 1.7).

<Production Example 9>
501 parts of water and ethylene oxide adduct of 3-methyl-3-buten-1-ol (average number of moles of ethylene oxide added) in a glass reaction vessel equipped with a thermometer, a stirrer, a reflux device, a nitrogen inlet tube and a dropping device 30) Charge 500 parts and 2 parts of a compound in which the 3 and 3 'positions of 4,4'-dihydroxydiphenylsulfone are allyl-substituted, purge the reaction vessel with nitrogen under stirring, and raise the temperature to 80 ° C under a nitrogen atmosphere. did. Thereafter, an aqueous monomer solution obtained by mixing 135 parts of acrylic acid (monomer / dimer = 99% by weight / 1% by weight) and 501 parts of water, and a mixed solution of 12 parts of ammonium persulfate and 188 parts of water were each added for 80 hours. The solution was continuously added dropwise to a reaction vessel maintained at ° C. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 100 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer I: IV: VI = 78: 21: 1. The copolymer in the liquid was a copolymer (B-2) (weight average molecular weight 20,200, Mw / Mn 1.7).

<Production Example 10>
A glass reaction vessel equipped with a thermometer, a stirrer, a reflux device, a nitrogen introduction tube and a dropping device was charged with 1052 parts of water, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 80 ° C. in a nitrogen atmosphere. Thereafter, 323 parts of methoxypolyethyleneglycol methacrylate (average added mole number of ethylene oxide 13), 2 parts of the compound in which 3 and 3 'positions of 4,4'-dihydroxydiphenylsulfone were allyl substituted, 39 parts of methacrylic acid, and 357 water The monomer aqueous solution mixed with 7 parts and a mixed solution of 7 parts of sodium persulfate and 113 parts of water were continuously added dropwise to a reaction vessel maintained at 80 ° C. for 2 hours each. Furthermore, the aqueous solution of the copolymer was obtained by making it react for 1 hour in the state hold | maintained at 100 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer II: IV: VII = 88: 11: 1. The copolymer in the liquid was a copolymer (C-1) (weight average molecular weight 19,000, Mw / Mn 1.5).

<Production Example 11>
100 parts of water was charged into a glass reaction vessel equipped with a thermometer, a stirrer, a reflux device, a nitrogen introduction tube and a dropping device, the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 75 ° C. under a nitrogen atmosphere. Thereafter, an aqueous monomer solution in which 90 parts of methoxypolyethylene glycol methacrylate (average added mole number of ethylene oxide 18), 5 parts of methacrylic acid, 21 parts of water, and 0.3 part of 3-mercaptopropionic acid were mixed with sodium persulfate 1 And 29 parts of water were continuously added dropwise to a reaction vessel maintained at 75 ° C. for 2 hours each. Furthermore, the aqueous solution of a copolymer was obtained by making it react for 1 hour in the state hold | maintained at 75 degreeC. The weight ratio of the monomer in the copolymer in the liquid was monomer II: IV: VII = 95: 5: 0. The copolymer in the liquid was a copolymer (C-2) (weight average molecular weight 26,000, Mw / Mn 1.7).

<Examples 1-12 and Comparative Examples 1-9>
A component: A-1, A-2, A-3, A-4, A-5, A-6, A-7, B component: B-1, B-2, C component: C-1 , C-2 were used in the combinations shown in Table 1 to give Examples 1 to 12 and Comparative Examples 1 to 9.

<Concrete test>
Concrete (cement composition, hydraulic composition) to which the cement admixtures of Examples 1 to 12 and Comparative Examples 1 to 9 were added was prepared according to the following procedure, and the obtained concrete was subjected to a slump test, air content measurement, viscosity. Evaluation and bleeding evaluation were performed.

<Procedure and Evaluation Method for Concrete Test: Examples 1 to 12, Comparative Examples 1 to 9>
At ambient temperature (20 ° C.), coarse aggregate, fine aggregate and cement blended as shown in Table 2 were added and mixed for 10 seconds by mechanical kneading with a forced biaxial mixer. Next, water and the cement admixture shown in Table 1 (initial addition) were added in the amounts shown in Table 1, and after mixing for 90 seconds, a portion of the concrete was discharged and fresh concrete test (slump test JIS). A 1101 (measurement of the spread of fresh concrete as a flow value), air amount JIS A 1128, concrete viscosity evaluation) was performed, and initial concrete evaluation was performed.
The concrete composition that was not used for the evaluation was 30 minutes after kneading, and after mixing the component A shown in Table 1 with 100 grams of water in the amount shown in Table 1, the concrete was further mixed for 60 seconds. The concrete was evaluated over time in the same manner as described above. The results are shown in Tables 3 and 4.
Note that the viscosity of concrete was evaluated according to the above-mentioned criteria by sensory evaluation by five evaluators.
[Evaluation criteria for viscosity]
A: Handling is very good when the concrete is cut back with a scoop, and the separation of the concrete from the scoop is very good.
○: Good handling when the concrete is cut back with a scoop, and separation of the concrete from the scoop is good.
X: Handling when the concrete is cut back with a scoop is poor, and the concrete is not separated from the scoop.

<BD (bleeding) evaluation>
Evaluation was performed by the method defined in JIS A1123. A smaller BD (bleeding) amount (cm ³ / cm ² ) indicates that the cement composition has material separation resistance. The results are shown in Tables 3 and 4.

  In Table 1, the value in parentheses is the weight percent of each admixture relative to the cement weight.

C: The following three types of cement are mixed in equal weight Normal Portland cement (Made by Ube Mitsubishi Cement Co., Ltd., specific gravity 3.16)
Ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., specific gravity 3.16)
Normal Portland cement (Made by Tokuyama Co., Ltd., specific gravity 3.16)
W: Tap water S1: Crushed lime sand from Tsukumi, Oita Prefecture (fine aggregate, specific gravity 2.66)
S2: Crushed stone from Shunan, Yamaguchi Prefecture (fine aggregate, specific gravity 2.66)
G1, G2: Crushed stone from Iwakuni, Yamaguchi Prefecture (coarse aggregate, specific gravity 2.73, 2.66)
Cement admixture (solid content conversion) See Table 1

  The “addition rate” of the cement admixture in Tables 3 and 4 indicates the solid content addition rate of the admixture to the cement. SLF indicates a slump flow.

  As is clear from Tables 3 and 4, the concrete of each example has a good long-term dispersion retention property of the concrete even after 120 minutes from immediately after mixing the concrete, compared to the concrete of each comparative example. I understand that. Moreover, the slump retention performance of the concrete of each Example was favorable. Furthermore, when the amount of bleeding water with time of each example is compared, it can be seen that the concrete of each example has a small bleeding and hardly separates aggregates. These results show that when the cement additive for post-addition of the present invention is excellent in slump retention performance and is made into a cement composition, it is possible to suppress an increase in bleeding of the cement composition, and to increase the time of concrete. It shows that a cement composition such as concrete suitable for transporting the water and pumping after a lapse of time can be produced.

Claims (5)

The manufacturing method of the cement composition characterized by performing following process (1)-(2).
Step (1): A step of adding a cement admixture (D) to a base cement containing a hydraulic material and kneading.
Step (2): A step of adding and kneading a post-addition cement admixture containing at least the following component (A): polycarboxylic acid copolymer or salt (A) after 5 minutes or more of the kneading.
(A) component:
1 to 97% by weight of monomer (I) represented by the following general formula (1), 1 to 97% by weight of monomer (II) represented by the following general formula (2), and the following general formula (3) 1 to 97% by weight of monomer (III) represented by the formula, 0.1 to 50% by weight of unsaturated carboxylic acid monomer (IV), and copolymerized with monomers (I) to (IV) A polycarboxylic acid copolymer obtained by copolymerizing 0 to 50% by weight of other possible monomer (V) or a salt thereof (A).
R ¹ —O— (A ¹ O) _n1 —R ² (1)
(In the formula, R ¹ represents an alkenyl group having 2 to 5 carbon atoms. A ¹ O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. N1 represents an oxyalkylene group. (The average number of moles added represents a number of 1 to 200. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.)

(In the formula, R ³ , R ⁴ and R ⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. M represents a number of 0 to ^2. A ² O is the same. Or, differently, it represents an oxyalkylene group having 2 to 18 carbon atoms, n2 is an average added mole number of the oxyalkylene group, and represents a number of 6 to 200. X is a hydrogen atom or 1 to 1 carbon atoms. Represents 30 hydrocarbon groups.)

Wherein R ⁶ , R ⁷ and R ⁸ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Y represents a carbon atom having 1 to 10 carbon atoms which may contain a hetero atom. Represents a hydrogen group.)   Y in the monomer (III) of the polycarboxylic acid copolymer or salt (A) thereof is methyl group, ethyl group, isopropyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 2-hydroxy The method for producing a cement composition according to claim 1, comprising at least one monomer selected from -1-methylethyl groups.   The unsaturated carboxylic acid monomer (IV) of the polycarboxylic acid copolymer or salt (A) is at least one selected from acrylic acid or a salt thereof, methacrylic acid or a salt thereof, maleic acid or a salt thereof. The manufacturing method of the cement composition as described in any one of Claims 1-2 containing a monomer.   The weight average molecular weight of the said polycarboxylic acid-type copolymer or its salt (A) is 5,000-60,000 in conversion of polyethyleneglycol, The cement composition as described in any one of Claims 1-3. Production method. The cement admixture (D) comprises the following component (B): polycarboxylic acid copolymer or salt (B) and / or component (C): polycarboxylic acid copolymer or salt (C). The manufacturing method of the cement composition as described in any one of Claims 1-4 contained.
(B) component:
Monomer (I) and monomer (IV) or other monomer capable of copolymerization with monomer (I), monomer (IV) and monomers (I) and (IV) A polycarboxylic acid copolymer obtained by copolymerizing the body (VI) or a salt thereof (B).
Component (C):
Monomer (II) and monomer (IV) or other monomer capable of copolymerization with monomer (II), monomer (IV) and monomers (II) and (IV) A polycarboxylic acid copolymer obtained by copolymerizing the product (VII) or a salt thereof (C).