JP2005035844A - Cement admixture and cement composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cement admixture showing high dispersion and dispersion keeping property at a high water reduction ratio region, showing high initial dispersion property and viscosity reduction property at a low temperature, and improving workability, and a cement composition therewith. <P>SOLUTION: This cement admixture contains four components as essential components, that is, a copolymer (A), an unsaturated (poly)alkylene glycol ether monomer (a1), an unsaturated polyalkylene glycol ether monomer (a2), and a non-polymerizable (poly)alkylene glycol (B) having no alkenyl group, and total of (a1) and (a2) is 1-100 mass % of the copolymer (A) and the content of (B) is 1-50 mass % of the copolymer (A). The copolymer (A) has as its essential structural units, a structural unit (I) coming from (a1), a structural unit (II) coming from (a2), and a structural unit (III) coming from a maleic acid type monomer (b). This cement composition contains as an essential component the cement mixing agent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cement admixture and a cement composition using the same.

  Cement compositions are widely used in applications such as building outer wall materials and building structures because they give a hardened cement product with excellent strength and durability. Examples of such a cement composition include cement paste in which water is added to cement, mortar in which sand that is fine aggregate is mixed, concrete in which pebbles that are coarse aggregate are further mixed, etc. Cement admixtures have been added to enhance air entrainment and fluidity, but in recent years, their importance has been recognized and technological innovation has been actively conducted.

  The mission of the cement admixture is to maintain sufficient fluidity and workability even when the cement composition is reduced in water, ensuring its fluidity and workability. There exists a place which acquires dispersibility and obtains a favorable cement composition. In the concrete industry in recent years, there is a strong demand for concrete that achieves such performance. To achieve this, reduction of unit water volume and prevention of fluidity deterioration are important issues.

  Among various cement admixtures, in particular, polycarboxylic acid-based cement dispersants are advantageous in that they exhibit high dispersion performance compared to other cement dispersants such as naphthalene, and as such cement dispersants, A cement dispersant containing a copolymer derived by using a specific unsaturated polyalkylene glycol ether monomer and a maleic acid monomer in a specific ratio has been proposed (for example, Patent Document 1, Patent Reference 2 and Patent Reference 3).

  However, these polycarboxylic acid-based cement dispersants have not yet completely eliminated the deterioration in dispersion performance over time, and in the high water reduction rate area required for high-strength concrete, Problems such as reduced workability of concrete compositions have arisen. That is, in the high water reduction rate region, the fluidity of the concrete is lowered, the viscosity is increased particularly under a high shear, and the pump load during pumping is extremely large, causing a negative effect on pumping. . In particular, when the temperature is 15 ° C. or lower in winter, the temperature of the concrete is reduced in the same way as the temperature, the viscosity of the concrete is increased, the workability is significantly reduced, and the initial dispersion of the cement dispersant is increased. As a result, there is a problem that the required amount of addition increases or the kneading takes a long time to reduce the productivity. Specifically, cement compositions such as cement paste, mortar, and concrete are used in fields such as civil engineering, construction, and secondary concrete products, so they are used in large quantities and produce kneading time during production. It has a huge impact on sex. If initial dispersibility is low and the time required for kneading takes a long time, not only will the number of daily productions be reduced, but the burden on the mixer will also increase and the amount of kneading per batch will need to be reduced. Problems such as a decrease in the amount and significant wear of the mixer occur.

As a cement admixture exhibiting high dispersibility and slump loss prevention properties in a high water reduction rate region and having excellent viscosity reducing properties, the present inventors have developed specific unsaturated polyalkylene glycol ether monomers and maleic compounds. A cement admixture mainly composed of a copolymer derived using an acid monomer at a specific ratio was proposed (see Patent Document 4), while maintaining high dispersion retention in a high water reduction rate region. In terms of preventing an increase in viscosity and a decrease in kneadability at low temperatures, it was not satisfactory.
Therefore, there is room for devising a cement dispersant that can exhibit high dispersibility and dispersion retention even in a high water reduction rate region, and that exhibits sufficient viscosity reduction and initial dispersibility even at low temperatures. It was.

JP-A-57-118058 (first page)

JP-A-5-310458 (page 1-2) JP-A-9-142905 (page 1-2) JP 2003-95722 A (page 1-2)

  The present invention has been made in view of the above situation, and exhibits high dispersibility and dispersion retention even in a high water reduction rate region, and also exhibits sufficient initial dispersibility and viscosity reduction at low temperatures. Thus, a cement admixture capable of improving workability and a cement composition using the same are provided.

  As a result of intensive studies, the inventors of the present invention have developed specific unsaturated (poly) alkylene glycol ether monomers (a1), unsaturated polyalkylene glycol ether monomers (a2), and maleic monomers ( a specific copolymer (A) having a (poly) oxyalkylene group and a carboxyl group in the molecule obtained by copolymerizing b), and a specific unsaturated (poly) alkylene glycol ether monomer ( a blend essentially comprising four components: a1), a specific unsaturated polyalkylene glycol ether monomer (a2), and a non-polymerizable (poly) alkylene glycol (B) having no alkenyl group, It is found to be useful as a cement admixture that exhibits high dispersibility and dispersion retention even in a high water reduction rate region, and is excellent in initial dispersibility and viscosity reduction at low temperatures. , Which resulted in the completion of the present invention.

  That is, this invention consists of a structure shown to the following 1) -3).

1) Copolymer (A), unsaturated (poly) alkylene glycol ether monomer (a1), unsaturated polyalkylene glycol ether monomer (a2) ) Alkylene glycol (B) 4 components as essential components, and total amount of unsaturated (poly) alkylene glycol ether monomer (a1) and unsaturated polyalkylene glycol ether monomer (a2) Is 1 to 100% by mass with respect to the copolymer (A), and the content of the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is 1 to 1% with respect to the copolymer (A). 50% by weight cement admixture,
The copolymer (A) includes a structural unit (I) derived from an unsaturated (poly) alkylene glycol ether monomer (a1), a structural unit derived from an unsaturated polyalkylene glycol ether monomer (a2) ( II) and the structural unit (III) derived from the maleic monomer (b) as essential structural units, and the structural unit (I), the structural unit (II) and the structural unit (III) are all present. It occupies 1% by mass or more of the structural unit,
The unsaturated (poly) alkylene glycol ether monomer (a1) has the following general formula (1):
Y ¹ O (R ¹ O) m ₁ R ² (1)
(In the formula, Y ¹ represents an alkenyl group having 2 to 4 carbon atoms, R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and R ¹ O represents an oxy group having 2 to 18 carbon atoms. Represents one kind or a mixture of two or more kinds of alkylene groups, and m ₁ represents the average number of added moles of oxyalkylene groups and represents a number of 1 to 100).
The unsaturated polyalkylene glycol ether monomer (a2) is represented by the following general formula (2):
Y ² O (R ³ O) m ₂ R ⁴ (2)
(In the formula, Y ² represents an alkenyl group having 2 to 4 carbon atoms, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and R ³ O represents an oxy group having 2 to 18 carbon atoms. Represents one or a mixture of two or more alkylene groups, and m ₂ represents the average number of moles added of the oxyalkylene group, represents a number of 6 to 500, and m ₂ −m ₁ ≧ 5. Cement admixture characterized by being a thing.

2) The oxyalkylene group constituting the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms, In the above 1), the terminal group of the non-polymerizable (poly) alkylene glycol having no alkenyl group is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a (alkyl) phenyl group. The cement admixture described.
3) A cement composition comprising the cement admixture according to 1) or 2), cement and water as essential components.

  The cement admixture of the present invention exhibits high dispersibility and dispersion retention even in a high water reduction rate region, and exhibits sufficient initial dispersibility and viscosity reduction even at low temperatures to improve workability. It is possible. Moreover, according to the cement composition which mix | blended the cement admixture of this invention, the outstanding fluidity | liquidity can be shown and the problem in quality control can be improved.

The present invention will be described in detail below.

  The cement admixture of the present invention comprises a copolymer (A), an unsaturated (poly) alkylene glycol ether monomer (a1) (hereinafter also referred to as monomer (a1)), an unsaturated polyalkylene glycol ether type. It contains four components of monomer (a2) (hereinafter also referred to as monomer (a2)) and non-polymerizable (poly) alkylene glycol (B) having no alkenyl group as essential components, and unsaturated ( The total amount of the poly) alkylene glycol ether monomer (a1) and the unsaturated polyalkylene glycol ether monomer (a2) is 1 to 100% by mass relative to the copolymer (A), and the alkenyl group It is a cement admixture in which the content of non-polymerizable (poly) alkylene glycol (B) not containing 1 to 50% by mass with respect to the copolymer (A).

  The said copolymer (A) is a polymer for cement admixtures, exhibits high dispersion performance in a cement composition, and can give a cement hardened material excellent in strength and durability. In the present invention, the copolymer (A), the monomer (a1), the monomer (a2) and the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group may be used alone. Alternatively, two or more types may be used in combination, and three or four or more types may be used in combination. The copolymer (A) is composed of the structural unit (I) derived from the unsaturated (poly) alkylene glycol ether monomer (a1) represented by the general formula (1) and the structural unit (I) represented by the general formula (2). The structural unit (II) derived from the saturated polyalkylene glycol ether monomer (a2) and the structural unit (III) derived from the maleic monomer (b) are essential structural units. Each of the units (I), (II) and (III) may be one type or two or more types. The cement admixture of the present invention comprises a copolymer (A), a monomer (a1), a monomer (a2), and a non-polymerizable (poly) alkylene glycol (B) having no alkenyl group. Due to the synergistic effect, it is possible to exhibit high dispersibility and slump loss prevention even in a high water reduction rate region, and it is possible to improve workability by also exhibiting viscosity reduction.

  The copolymer (A) is represented by the structural unit (I) derived from the unsaturated (poly) alkylene glycol ether monomer (a1) represented by the general formula (1) and the general formula (2). It is a polymer having the structural unit (II) derived from the unsaturated polyalkylene glycol ether monomer (a2) and the structural unit (III) derived from the maleic acid monomer (b) as essential structural units. The copolymer (A) may have a structural unit (IV) derived from the monomer (c) described later. Each of these structural units may be one kind or two or more kinds.

  In the copolymer (A), it is necessary that the structural unit (I), the structural unit (II), and the structural unit (III) each occupy 1% by mass or more of all the structural units. Furthermore, it is preferable that the total proportion of the structural unit (I) and the structural unit (II) is 50 mol% or less in all the structural units. When the proportion of the structural unit (I) is less than 1% by mass, the proportion of the short-chain oxyalkylene group derived from the unsaturated (poly) alkylene glycol ether monomer (a1) present in the copolymer (A). If the proportion of the structural unit (II) is less than 1% by mass, the long-chain oxygen derived from the unsaturated polyalkylene glycol ether monomer (a2) present in the copolymer (A) If the proportion of the alkylene group is too small and the proportion of the structural unit (III) is less than 1% by mass, the proportion of the carboxyl group derived from the maleic monomer (b) present in the copolymer (A) is small. Therefore, in any case, sufficient dispersibility cannot be exhibited. On the other hand, the total proportion of the constituent unit (I) and the constituent unit (II) is the unsaturated (poly) alkylene glycol ether monomer (a1) and the unsaturated polyalkylene glycol ether monomer (a2). In view of the low polymerizability, it is preferably 50 mol% or less of all the structural units. The proportion of the structural unit (I) is preferably 2% by mass or more, more preferably 3% by mass or more, further preferably 4% by mass or more, and most preferably 5% by mass or more. On the other hand, the proportion of the structural unit (II) is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, particularly preferably 20% by mass or more, and most preferably 30% by mass or more. preferable. Moreover, as a total ratio (mass%) of the structural unit (I), the structural unit (II), and the structural unit (III) in the copolymer (A), 50 to 100 mass of the entire copolymer (A). % Is preferable, 60 to 100% by mass is more preferable, and 70 to 100% by mass is further preferable.

  The ratio of each structural unit constituting the copolymer (A) is structural unit (I) / structural unit (II) / structural unit (III) / structural unit (IV) = 1 to 98/1 to 98/1. The range of ˜98 / 0 to 70 (mass%) is appropriate, but it is preferable that the content of the structural unit (II) is larger than the content of the structural unit (I), so that the structural unit (I) / Structural unit (II) / Structural unit (III) / Structural unit (IV) = 2 to 94/5 to 97/1 to 50/0 to 50 (mass%) is preferable, and structural unit (I) / structure The range of unit (II) / structural unit (III) / structural unit (IV) = 3 to 88/10 to 95/2 to 45/0 to 40 (mass%) is more preferable, and constituent unit (I) / structural unit. (II) / Structural unit (III) / Structural unit (IV) = 4 to 82/15 to 93/3 to 40/0 to 30 ( %) Is more preferable, and the structural unit (I) / structural unit (II) / structural unit (III) / structural unit (IV) = 5-77 / 20-92 / 3-35 / 0-30 (mass) %) Is particularly preferable, the structural unit (I) / structural unit (II) / structural unit (III) / structural unit (IV) = 5 to 66/30 to 91/4 to 30/0 to 30 (mass%) ) Is most preferable (however, the total of the structural unit (I), the structural unit (II), the structural unit (III) and the structural unit (IV) is 100% by mass). In order to obtain a desired cement admixture with excellent performance, it is preferable to set the ratio of each structural unit within the above range.

  In the copolymer (A), the number of milliequivalents of carboxyl groups (meq / g) per 1 g of the copolymer (A) obtained by converting the carboxyl groups in the copolymer (A) to an unneutralized type is The ratio of each structural unit is preferably set so as to be 0.2 to 5.0. When the number of milliequivalents of the carboxyl group exceeds 5.0 meq / g, the dispersion retention may tend to decrease, and when it is less than 0.2 meq / g, the initial dispersibility may decrease. is there. The number of milliequivalents of the carboxyl group (meq / g) is more preferably 0.3 or more, and further preferably 0.4 or more. Moreover, 4.5 or less is more preferable, 4.0 or less is further more preferable, and 3.5 or less is especially preferable. The range of the number of milliequivalents of the carboxyl group (meq / g) is more preferably 0.3 to 4.5, further preferably 0.3 to 4.0, and particularly preferably 0.4 to 3.5. In addition, what is necessary is just to set the upper limit of the ratio of structural unit (III) so that the milliequivalent number of a carboxyl group when converting the carboxyl group in a copolymer (A) into a non-neutralized type may become the said range. .

  The copolymer (A) may have other structural units having a carboxyl group in addition to the structural unit (III) having a carboxyl group derived from the maleic acid monomer (b). The number of milliequivalents of the carboxyl group in the copolymer (A) is not necessarily attributed to the carboxyl group derived from the structural unit (III).

The “number of milliequivalents of carboxyl groups per 1 g of the copolymer (A) in which the carboxyl groups in the copolymer (A) are converted to an unneutralized type (meq / g)” means the copolymer (A ) Considers the case of forming a salt, and the calculation method in the case of forming an acid and a salt is listed below. In the following calculation, only the carboxyl group derived from the structural unit (III) is illustrated, but when other structural units having a carboxyl group are included, this must also be included in the number of milliequivalents of the carboxyl group. Don't be.
(Calculation Example 1): Maleic acid is used as the monomer (b), and the copolymer composition ratio is monomer (a1) / monomer (a2) / monomer (b) = 30/60/10 ( Mass%), the molecular weight of maleic acid is 116, and maleic acid is a divalent acid having two carboxyl groups in one molecule, so the carboxyl group derived from monomer (b) Is the number of milliequivalents of carboxyl groups per 1 g of the polymer (meq / g) = 0.1 / (0.9 + 0.1) / (116/2) × 1,000 = 1. 72.
(Calculation Example 2): Disodium maleate is used as the monomer (b), and the copolymer composition ratio is monomer (a1) / monomer (a2) / monomer (b) = 30/60 / In the case of 10 (mass%), the molecular weight of disodium maleate is 160, the molecular weight of maleic acid is 116, and maleic acid is a divalent acid having two carboxyl groups in one molecule. The number of milliequivalents of carboxyl groups per gram of the polymer (meq / g) = (0.1 × 116/160) / (0. 9 + 0.1 × 116/160) / (116/2) × 1,000 = 1.29. This calculation example is the same when maleic acid is used during polymerization and the carboxyl group derived from maleic acid is completely neutralized with sodium hydroxide after polymerization.

  The number of milliequivalents of the carboxyl group (meq / g) is calculated by a calculation method based on the monomer as described above, and the type of the counter ion of the carboxyl group of the copolymer (A) is taken into consideration. Thus, it can also be calculated by measuring the acid value of the copolymer (A).

In the general formula (1) representing the unsaturated (poly) alkylene glycol ether monomer (a1), the alkenyl group represented by Y ¹ and the unsaturated polyalkylene glycol ether monomer (a2) In general formula (2) representing Y ² , the number of carbon atoms of the alkenyl group represented by Y ² is suitably 2 to 4, and specifically, vinyl group, allyl group, methallyl group, 3-butenyl group, etc. However, an alkenyl group having 3 to 4 carbon atoms is more preferable, and an allyl group or a methallyl group is particularly preferable. The alkenyl groups Y ¹ and Y ² may have the same or different carbon atoms, but the alkenyl groups Y ¹ and / or Y ² are preferably alkenyl groups having 4 carbon atoms. Particularly preferred is a methallyl group.

In the general formula (1) representing the unsaturated (poly) alkylene glycol ether monomer (a1), the oxyalkylene group represented by R ¹ O and the unsaturated polyalkylene glycol ether monomer ( In the general formula (2) representing a2), the number of carbon atoms of the oxyalkylene group represented by R ³ O is suitably 2-18, preferably 2-8, more preferably 2-4. Moreover, any two or more types of alkylene oxide adducts selected from ethylene oxide, propylene oxide, butylene oxide, styrene oxide, etc. may be in any form such as random addition, block addition, and alternate addition. In order to secure a balance between hydrophilicity and hydrophobicity, the oxyalkylene group preferably has an oxyethylene group as an essential component, more preferably 50 mol% or more is an oxyethylene group, and 90 mol% or more. Is more preferably an oxyethylene group. The lower the proportion of oxyethylene groups in the oxyalkylene group, the lower the hydrophilicity of the polymer and the lower the dispersion performance.

As a combination of the average addition mole number m _{1 of} the oxyalkylene group in the general formula (1) and the average addition mole number m ₂ of the oxyalkylene group in the general formula (2), m ₂ is more than m ₁ . A large combination of m ₁ being ₁ to 100, m ₂ being 6 to 500, and m ₂ −m ₁ ≧ 5 is suitable, but the larger the difference between m ₁ and m ₂ , the more dispersed In order to improve performance, slump loss prevention property, etc., a range of m ₂ −m ₁ ≧ 10 is preferable, a range of m ₂ −m ₁ ≧ 15 is more preferable, and a range of m ₂ −m ₁ ≧ 20 is further preferable, A range of m ₂ −m ₁ ≧ 25 is particularly preferred. _The value of m 2 -m ₁ is, as _{the m 1} is _increased, because it is preferable to increase the value of m 2 -m _1, the range of _m 2 -m ₁ ≧ 10 when _{m 1} is 10 or more Preferably, when m ₁ is 15 or more, m ₂ −m ₁ ≧ 15 is preferable, and when m ₁ is 20 or more, m ₂ −m ₁ ≧ 20 is preferable, m _{When 1} is 25 or more, m ₂ −m ₁ ≧ 25 is preferable. Also, as the value of _{m 1,} the number of 1 to 100 is suitable, preferably a number of 2 to 100, more preferably the number of from 2 to 80, more preferably the number of 3 to 60, 5 to 50 Numbers are particularly preferred, and numbers from 5 to 40 are most preferred. On the other hand, as the value of m ₂ , a number of 6 to 500 is appropriate, but as this value decreases, the hydrophilicity decreases and the dispersion performance decreases, and conversely, the reactivity decreases as this value increases. The number of 10 to 500 is preferable, the number of 15 to 300 is more preferable, the number of 20 to 250 is more preferable, the number of 30 to 200 is particularly preferable, and the number of 40 to 200 is more preferable. Most preferred. Here, as an example of a preferable combination of m ₁ and m ₂ , an example in which m ₁ is a number of 5 to 40 and m ₂ is a number of 40 to 200 and m ₂ −m ₁ ≧ 5 is given. be able to. Furthermore, two or more types of either the structural unit (I) or the structural unit (II) may be used in combination, and m _{1 in the} case of using one type of structural unit (I) and two types of structural unit (II). Specific examples of the combination of m ₂ and m ₂ include combinations of m ₁ being a number of ₁ to 20, m ₂ being a number of 20 to 50, and a number of 50 to 300. The average added mole number means an average value of the number of moles of the organic group added in 1 mole of the monomer.

R ² in the general formula (1) representing the unsaturated (poly) alkylene glycol ether monomer (a1) and the general formula (2) representing the unsaturated polyalkylene glycol ether monomer (a2). R ^{4 in} can be a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. Examples of the hydrocarbon group having 1 to 30 carbon atoms include an alkyl group having 1 to 30 carbon atoms (fatty acid). Aromatic group or alicyclic alkyl group), a phenyl group having 6 to 30 carbon atoms, an alkylphenyl group, a phenylalkyl group, a phenyl group substituted with a (alkyl) phenyl group, an aromatic having a benzene ring such as a naphthyl group Family groups and the like. In R ² and R ⁴ , as the number of carbon atoms of the hydrocarbon group increases, the hydrophobicity increases and the dispersibility decreases, so the number of carbon atoms when R ² and / or R ⁴ is a hydrocarbon group Is preferably 1 to 22, more preferably 1 to 18, still more preferably 1 to 12, particularly preferably 1 to 4, particularly preferably R ² and / or R ⁴ is a hydrogen atom, R ² and R ⁴ Is most preferably a hydrogen atom.

  As an unsaturated (poly) alkylene glycol ether monomer (a1) represented by the general formula (1) and an unsaturated polyalkylene glycol ether monomer (a2) represented by the general formula (2) Can be produced by adding an alkylene oxide to an unsaturated alcohol such as allyl alcohol or methallyl alcohol. Specifically, (poly) ethylene glycol (meth) allyl ether, (poly) ethylene ( Examples include poly) propylene glycol (meth) allyl ether, (poly) ethylene (poly) butylene glycol (meth) allyl ether, and the like. In the present invention, as the monomer (a1) giving the structural unit (I) and the monomer (a2) giving the structural unit (II), one of these can be used alone, or two or more of them can be used in combination. be able to.

  As the maleic acid monomer (b) which gives the structural unit (III) used in the present invention, the following general formula (3);

(In the formula, X represents —OM ₂ or —Z— (R ⁵ O) nR ⁶ , and M ₁ and M ₂ each independently represent a hydrogen atom, a monovalent metal, a divalent metal, an ammonium group, or an organic group. Represents an ammonium group, —Z— represents —O— or —NH—, R ⁵ O represents one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms, and R ⁶ represents , A hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a phenyl group, an aminoalkyl group, an alkylphenyl group or a hydroxyalkyl group (the number of carbon atoms in the alkyl group in the aminoalkyl group, alkylphenyl group and hydroxyalkyl group is 1 R is the average number of moles of oxyalkylene group added, and represents a number from 0 to 500, provided that oxygen to which M ₁ is bonded, carbon to which X is bonded, and Combined Including those which form the anhydride group (-CO-O-CO-), in this case, the monomer represented by _{M 1} and X is absent.) Are preferred.

  Although it does not specifically limit as an example of the said maleic acid type monomer (b), Maleic acid and its derivative (s) can be mentioned, These 1 type (s) or 2 or more types can be used. Although it does not specifically limit as a derivative of maleic acid, For example, maleic anhydride; Half ester of maleic acid and C1-C30 alcohol; Half of maleic acid and C1-C30 amine Amides; half amides or half esters of maleic acid and amino alcohols having 1 to 30 carbon atoms; average addition of 1 to 500 moles of alkylene oxide having 2 to 18 carbon atoms to alcohols having 1 to 30 carbon atoms A half ester of compound (J) and maleic acid; a half amide of maleic acid and a compound obtained by amination of the hydroxyl group at one end of compound (J); a glycol having 2 to 18 carbon atoms or maleic acid Half esters of these glycols with polyalkylene glycols having an average addition mole number of 2 to 500; maleamic acid Half-amides of glycols having 2 to 18 carbon atoms or polyalkylene glycols having an average addition mole number of these glycols of 2 to 500; and monovalent metal salts, divalent metal salts, ammonium salts and organic ammonium salts thereof Is mentioned. The monovalent metal is preferably an alkali metal such as sodium or potassium, the divalent metal is preferably an alkaline earth metal such as calcium or magnesium, and the organic ammonium is a protonated organic amine. Alkanol ammonium such as ethanolammonium, diethanolammonium and triethanolammonium, and alkylammonium such as triethylammonium are suitable. Among them, it is preferable to use one or more monomers selected from the group consisting of maleic acid and salts thereof, maleic anhydride and maleic esters, and it is particularly preferable to use maleic acid or salts thereof.

The copolymer (A) comprises an unsaturated (poly) alkylene glycol ether monomer (a1) that gives the structural unit (I), an unsaturated polyalkylene glycol ether monomer that gives the structural unit (II) ( It can be produced by copolymerizing a monomer component containing 3 components of a maleic monomer (b) giving a structural unit (III) as essential components. When doing so, you may further copolymerize the other monomer (c) copolymerizable with the said monomer as needed. The structural unit (IV) is formed by such a monomer (c). In addition, it is preferable that the ratio for which the structural unit (IV) derived from a monomer (c) accounts is 70 mass% or less in all the structural units of a copolymer (A), and it is 50 mass% or less. More preferably, it is more preferably 30% by mass or less.
The monomer (d) giving the structural unit (IV) is a monomer copolymerizable with the monomer (a1), the monomer (a2) and the monomer (b). These can be used, and one or more of these can be used.

  Unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, and monovalent metal salts, divalent metal salts, ammonium salts and organic ammonium salts thereof; unsaturated dicarboxylic acids such as fumaric acid, itaconic acid and citraconic acid , And these monovalent metal salts, divalent metal salts, ammonium salts, organic ammonium salts; half esters and diesters of unsaturated dicarboxylic acids such as 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; alkyls (poly) obtained by adding 1 to 500 moles of alkylene oxides having 2 to 18 carbon atoms to the above alcohols and amines Half esters and diesters of alkylene glycol and the above unsaturated dicarboxylic acids; Half esters and diesters of saturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or polyalkylene glycols having an addition mole number of these glycols of 2 to 500; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meta ) Esters of unsaturated monocarboxylic acids such as acrylate, glycidyl (meth) acrylate, methyl crotonate, ethyl crotonate, propyl crotonate and alcohols having 1 to 30 carbon atoms; alcohols having 1 to 30 carbon atoms Esters of alkoxy (poly) alkylene glycols to which 1 to 500 moles of alkylene oxide having 2 to 18 carbon atoms have been added and unsaturated monocarboxylic acids such as (meth) acrylic acid; (poly) ethylene glycol monomethacrylate, ( Poly) propire Glycol monomethacrylate, (poly) such as butylene glycol monomethacrylate, (meth) 1 to 500 molar adducts of alkylene oxide having 2 to 18 carbon atoms to unsaturated monocarboxylic acids such as acrylic acid.

  (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; triethylene glycol dimaleate, polyethylene glycol (Poly) alkylene glycol dimaleates such as dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acrylate Xylpropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- ( Unsaturated sulfonic acids such as (meth) acryloxybutyl sulfonate, (meth) acrylamide methyl sulfonic acid, (meth) acrylamide ethyl sulfonic acid, 2-methylpropane sulfonic acid (meth) acrylamide, styrene sulfonic acid, and monovalents thereof Metal salts, divalent metal salts, ammonium salts and organic ammonium salts; amides of unsaturated monocarboxylic acids and amines having 1 to 30 carbon atoms such as methyl (meth) acrylamide; styrene, α-methylstyrene, vinyl Vinyl aromatics such as toluene and p-methylstyrene; 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, etc. Alkanediol mono (meth) acrylates; dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene and the like.

  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; polydimethyl Roxanpropylaminomaleamic acid, polydimethylsiloxane aminopropylaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (dipropyleneaminomaleamic acid), polydimethylsiloxane -(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).

  In order to obtain the copolymer (A) in the present invention, the monomer component may be copolymerized using a polymerization initiator. In the present invention, the type and amount of the monomer contained in the monomer component are appropriately set so that the monomer unit constituting the copolymer (A) is as described above. Become.

  In the cement admixture of the present invention, two or more types of copolymers (A) can be used in combination, and a combination of three or more types and four or more types of copolymers (A) is also suitable. Examples of the combination of two or more types of copolymers (A) include, for example, the structural unit (I) derived from the unsaturated (poly) alkylene glycol ether monomer (a1) and the unsaturated polyalkylene glycol ether monomer. Two or more types of copolymers having different ratios (mass ratio or molar ratio) between the total amount of the structural unit (II) derived from (a2) and the structural unit (III) derived from the maleic monomer (b) Combinations of (A) are possible. Maleic acid and the total amount of structural unit (I) derived from unsaturated (poly) alkylene glycol ether monomer (a1) and structural unit (II) derived from unsaturated polyalkylene glycol ether monomer (a2) When combining two or more types of copolymers (A) having different proportions (mass ratio) with the structural unit (III) derived from the system monomer (b), the maleic acid system in each copolymer (A) The proportion of the structural unit (III) derived from the monomer (b) is preferably at least 1% by mass or more, more preferably at least 2% by mass or more, and at least 3% by mass or more. More preferably. When two or more kinds of copolymers (A) are combined, the number of carboxyl groups per gram of the copolymer (A) in which the carboxyl group in each copolymer (A) is converted to an unneutralized type. The number of equivalents (meq / g) is preferably at least 0.1 or more, more preferably at least 0.2 or more, and even more preferably at least 0.3 or more.

  In order to obtain the copolymer (A), a monomer component containing the monomer may be polymerized using a polymerization initiator. The polymerization can be performed by a method such as polymerization in a solvent or bulk polymerization. The solution polymerization can be carried out batchwise or continuously, and the solvent used in that case is not particularly limited. For example, water; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, Aromatic or aliphatic hydrocarbons such as cyclohexane and n-hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; cyclic ether compounds such as tetrahydrofuran and dioxane; It is preferable to use at least one selected from the group consisting of water and a lower alcohol having 1 to 4 carbon atoms, from among the solubility of the resulting polymer, and among them, using water as a solvent eliminates the solvent removal step. It is further preferable in that it can be performed.

  When the aqueous solution polymerization is performed, a water-soluble polymerization initiator, for example, a persulfate such as ammonium persulfate, sodium persulfate, or potassium persulfate; hydrogen peroxide; 2,2′-azobis is used as the radical polymerization initiator. Azoamidine compounds such as 2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, 2-carbamoylazoisobutyronitrile, etc. Water-soluble azo initiators such as azonitrile compounds are used, and in this case, Fe (II) salts such as alkali metal sulfites such as sodium hydrogen sulfite, metabisulfites, sodium hypophosphite and molle salts, hydroxymethane Sodium sulfinate dihydrate, hydroxylamine hydrochloride, thiourea, L-ascorbic acid (salt), eryso It may be used in combination accelerator such as bottles acid (salt) (reducing agent). Among them, a combination of hydrogen peroxide and an organic reducing agent is preferable. As the organic reducing agent, L-ascorbic acid (salt), L-ascorbic acid ester, erythorbic acid (salt), erythorbic acid ester, and the like are preferable. is there. These radical polymerization initiators and accelerators (reducing agents) may be used alone or in combination of two or more.

  In addition, when performing solution polymerization using a lower alcohol, aromatic or aliphatic hydrocarbon, ester compound, or ketone compound as a solvent, or when performing bulk polymerization, benzoyl peroxide, lauroyl peroxide, sodium peroxide Peroxides such as oxides; hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; azo compounds such as azobisisobutyronitrile and the like are used as radical polymerization initiators. 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 radical polymerization initiators or combinations of radical polymerization initiators and accelerators. In addition, although superposition | polymerization temperature is suitably determined by the solvent and polymerization initiator to be used, it is normally performed within the range of 0-150 degreeC.

  It is preferable that the usage-amount of all the monomer components in the said copolymerization is 30 mass% or more with respect to all the raw materials containing another raw material. If the amount of all monomer components used is too lower than this range, it is not preferable because the polymerization rate is lowered and the productivity is lowered. Since the polymerizable properties of the unsaturated (poly) alkylene glycol ether monomer (a1) and the unsaturated polyalkylene glycol ether monomer (a2) are low, the amount of all monomer components used may be other raw materials. It is more preferable that it is 40-99 mass% with respect to all the raw materials containing this, It is more preferable that it is 50-99 mass%, It is especially preferable that it is 55-95 mass%, It is 60-90 mass% Most preferred.

  The method of charging each monomer into the reaction vessel is not particularly limited, the method of initially charging the entire amount into the reaction vessel at once, the method of dividing or continuously charging the entire amount into the reaction vessel, and the initial charging into the reaction vessel. Any method may be employed in which the remainder is divided or continuously charged into the reaction vessel. As a preferable charging method, specifically, a method of continuously charging all of the monomer (a1), the monomer (a2) and the monomer (b) into the reaction vessel, the monomer (a1) and / or Alternatively, a part of the monomer (a2) is initially charged into the reaction vessel, and the monomer (a1) and / or the remainder of the monomer (a2) and all of the monomer (b) are continuously added to the reaction vessel. A method of charging, or a monomer (a1) and / or a part of the monomer (a2) and a part of the monomer (b) are initially charged into the reaction vessel, and the monomer (a1) and For example, there may be mentioned a method in which the remainder of the monomer (a2) and the remainder of the monomer (b) are alternately divided into several times in a reaction vessel. Furthermore, by changing the charging rate of each monomer into the reaction vessel during the reaction continuously or stepwise, the charging mass ratio of each monomer per unit time can be changed continuously or stepwise to You may make it synthesize | combine the mixture of the copolymer from which the ratio of structural unit (I), structural unit (II), and structural unit (III) in a polymer (A) differs in a polymerization reaction. The radical polymerization initiator may be charged into the reaction vessel from the beginning, may be dropped into the reaction vessel, or may be combined according to the purpose.

  A chain transfer agent can be used for adjusting the molecular weight of the resulting copolymer (A). The chain transfer agent is not particularly limited. For example, thiol chain transfer agents such as mercaptoethanol, thioglycerol, thioglycolic acid, 3-mercaptopropionic acid, thiomalic acid, and 2-mercaptoethanesulfonic acid; 2 such as isopropyl alcohol Secondary alcohol: Phosphorous acid, hypophosphorous acid and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionite, metabisulfite and salts thereof (sodium sulfite, sulfurous acid) Known hydrophilic chain transfer agents such as lower oxides of sodium hydrogen, sodium dithionite, sodium metabisulfite, and the like and salts thereof can be used. Furthermore, the use of a hydrophobic chain transfer agent is effective for improving the viscosity of the cement composition. Hydrophobic chain transfer agents include 3 or more carbon atoms such as butanethiol, octanethiol, decanethiol, dodecanethiol, hexadecanethiol, octadecanethiol, cyclohexyl mercaptan, thiophenol, octyl thioglycolate, octyl 3-mercaptopropionate, etc. It is preferable to use a thiol chain transfer agent having the following hydrocarbon group. Two or more types of chain transfer agents can be used in combination, and a hydrophilic chain transfer agent and a hydrophobic chain transfer agent may be used in combination. Furthermore, in order to adjust the molecular weight of the copolymer (A), it is also effective to use a monomer having a high chain transfer property such as (meth) allylsulfonic acid (salt).

  In the above copolymerization, in order to obtain a copolymer having a predetermined molecular weight with good reproducibility, it is necessary to allow the copolymerization reaction to proceed stably. Therefore, in the case of solution polymerization, the solvent used at 25 ° C. The dissolved oxygen concentration is preferably in the range of 5 ppm or less. Preferably it is the range of 0.01-4 ppm, More preferably, it is the range of 0.01-2 ppm, Most preferably, it is the range of 0.01-1 ppm. When nitrogen substitution or the like is performed after the monomer is added to the solvent, the dissolved oxygen concentration of the system including the monomer is within the above range.

The adjustment of the dissolved oxygen concentration of the solvent may be performed in a polymerization reaction tank, or a solution in which the amount of dissolved oxygen is adjusted in advance may be used. As a method for expelling oxygen in the solvent, for example, the following (1) The method of (5) is mentioned.
(1) After pressure-filling an inert gas such as nitrogen in a sealed container containing a solvent, the partial pressure of oxygen in the solvent is lowered by lowering the pressure in the sealed container. You may reduce the pressure in an airtight container under nitrogen stream.
(2) The liquid phase portion is vigorously stirred for a long time while the gas phase portion in the container containing the solvent is replaced with an inert gas such as nitrogen.
(3) An inert gas such as nitrogen is bubbled in the solvent in the container for a long time.
(4) The solvent is once boiled and then cooled in an inert gas atmosphere such as nitrogen.
(5) A static mixer (static mixer) is installed in the middle of the pipe, and an inert gas such as nitrogen is mixed in the pipe for transferring the solvent to the polymerization reaction tank.

  The copolymer (A) obtained by the above copolymerization is used as it is as an essential component of the cement admixture of the present invention, but from the viewpoint of handleability, it is adjusted to a pH range of weak acid or higher in an aqueous solution state. Preferably, the pH is in the range of pH 4 or more, more preferably pH 5 or more, particularly preferably pH 6 or more. On the other hand, the copolymerization reaction may be carried out at a pH of 7 or more. In this case, however, the polymerization rate decreases, and at the same time, the copolymerizability deteriorates and the dispersion performance deteriorates. It is preferable to carry out the reaction, more preferably less than pH 6, more preferably less than pH 5.5, particularly preferably less than pH 5. Therefore, it is preferable to adjust to a higher pH by adding an alkaline substance after carrying out the copolymerization reaction at a low pH. Specifically, as a preferred embodiment, the alkaline substance is specifically used after carrying out the copolymerization reaction at a pH of less than 6. To adjust the pH to 6 or more by adding a pH, a method of adding an alkaline substance after carrying out a copolymerization reaction at a pH below 5, and adding an alkaline substance after carrying out a copolymerization reaction at a pH below 5 or less. The method etc. which adjust to pH6 or more are mentioned. The pH can be adjusted using, for example, an alkaline substance such as inorganic salt such as hydroxide or carbonate of monovalent metal or divalent metal; ammonia; organic amine; Also, when it is necessary to lower the pH, particularly when pH adjustment is required during polymerization, phosphoric acid, sulfuric acid, nitric acid, alkyl phosphoric acid, alkyl sulfuric acid, alkylsulfonic acid, (alkyl) benzenesulfonic acid, etc. It is possible to adjust the pH using an acidic substance, and among these acidic substances, phosphoric acid is preferred from the viewpoint of having a pH buffering action. Further, after the reaction, the concentration can be adjusted if necessary.

  The weight average molecular weight of the copolymer (A) is suitably 1,000 to 500,000 in terms of polyethylene glycol by gel permeation chromatography (hereinafter also referred to as “GPC”), but is 5,000 to 300. 10,000 is preferable, and 10,000 to 150,000 is more preferable. By selecting such a weight average molecular weight range, a cement admixture exhibiting higher dispersion performance can be obtained.

  In the cement admixture of the present invention, the unsaturated (poly) alkylene glycol ether monomer (a1) represented by the general formula (1) and the unsaturated polyalkylene glycol ether single monomer represented by the general formula (2) are used. It is important that the total amount with the monomer (a2) is 1 to 100% by mass with respect to the copolymer (A). More preferably, it is 2-100 mass%, More preferably, it is 3-90 mass%, Most preferably, it is 5-80 mass%. In the present invention, when the total content of the monomers (a1) and (a2) is less than the above range, the dispersion retention and viscosity reducing properties are not sufficient, and on the other hand, exceed the above range. In such a case, dispersibility with respect to cement is lowered, which is not preferable. The unsaturated (poly) alkylene glycol ether monomers (a1) and (a2) are the unsaturated (poly) alkylene glycol ether monomers (a1) used for the polymerization of the copolymer (A). And the unsaturated polyalkylene glycol ether monomer (a2), that is, the unsaturated (poly) alkylene glycol ether monomer (a1) derived from the structural unit (I) of the copolymer (A) and the copolymer It may be the same as or different from the unsaturated polyalkylene glycol ether monomer (a2) from which the structural unit (II) of the union (A) is derived. Further, two or more types of monomers (a1) and (a2) may be used as the monomers (a1) and (a2), respectively.

  In the cement admixture of the present invention, it is important that 1 to 50% by mass of the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is contained with respect to the copolymer (A). More preferably, it is 1.5-50 mass%, More preferably, it is 2-40 mass%, Most preferably, it is 2.5-30 mass%. In the present invention, when the content of the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is less than the above range, the viscosity reducing property is not sufficient, and on the other hand, exceeds the above range. In such a case, dispersibility with respect to cement is lowered, which is not preferable.

  The number of carbon atoms of the oxyalkylene group of the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is suitably 2-18, preferably 2-8, more preferably 2-4. . Further, the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is preferably water-soluble, and has a highly hydrophilic oxyalkylene group having 2 carbon atoms, that is, an oxyethylene group as an essential component. As for it, it is more preferable that 50 mol% or more is an oxyethylene group, and it is still more preferable that 90 mol% or more is an oxyethylene group. Moreover, the repeating unit of the oxyalkylene group may be the same or different, and when the oxyalkylene group is in the form of a mixture of two or more, block-like addition, random addition, alternating addition, etc. Any of these additional forms may be used. The terminal group of the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is suitably a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an (alkyl) phenyl group. Is preferably 1 to 22, more preferably 1 to 18, still more preferably 1 to 12, particularly preferably 1 to 4, and most preferably a hydrogen atom.

  The weight average molecular weight of the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is preferably 100 or more in terms of polyethylene glycol by GPC. More preferably, it is 500 or more, More preferably, it is 1,000 or more. Moreover, 200,000 or less is preferable. More preferably, it is 100,000 or less, More preferably, it is 50,000 or less. Moreover, as a suitable range, Preferably, it is 100-200,000, More preferably, it is 500-100,000, More preferably, it is 1,000-50,000.

  Specific examples of the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group in which both terminal groups are hydrogen atoms include (poly) ethylene glycol, (poly) propylene glycol, (poly) ethylene (poly) ) Propylene glycol, (poly) ethylene (poly) butylene glycol, and the like. Non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is preferably water-soluble, A (poly) alkylene glycol containing a high oxyethylene group as an essential component is preferred, and a (poly) alkylene glycol containing 90 mol% or more of an oxyethylene group as an essential component is more preferred. Among them, (poly) ethylene glycol or (poly) ethylene (poly) propylene glycol is preferable, and (poly) ethylene glycol is most preferable. The non-polymerizable (poly) alkylene glycol (B) having no alkenyl group may be used alone or in combination of two or more.

  The non-polymerizable (poly) alkylene glycol (B) having no alkenyl group, which is an essential component of the cement admixture of the present invention, may be blended after the production of the copolymer (A). In producing the union (A), the unsaturated (poly) alkylene glycol ether monomer (a1), the unsaturated polyalkylene glycol ether monomer (a2), and the maleic monomer ( In addition to the monomer component containing b) as an essential component, a copolymerization reaction is carried out using a composition containing a non-polymerizable (poly) alkylene glycol (B) having no alkenyl group as a raw material. A cement admixture containing the combination (A) and a non-polymerizable (poly) alkylene glycol (B) having no alkenyl group can be obtained.

  The unsaturated (poly) alkylene glycol ether monomer (a1) used in the present invention can be obtained by adding 1 to 100 mol of alkylene oxide to unsaturated alcohols such as allyl alcohol and methallyl alcohol. The unsaturated polyalkylene glycol ether monomer (a2) can be obtained by adding 6 to 500 mol of alkylene oxide to unsaturated alcohols such as allyl alcohol and methallyl alcohol. In the reaction, if a compound having an active hydrogen such as saturated aliphatic alcohols (methanol, ethanol, etc.) or water other than the unsaturated alcohol is present in the reaction system, the single product which is the main product (Poly) alkylene starting from the compound having active hydrogen in addition to isomers (a1) and (a2) Composition comprising a recall as a by-product. In the present invention, the monomers (a1) and (a2), which are main products, are removed without removing the (poly) alkylene glycol by-produced during the production of the monomers (a1) and (a2). In addition, a copolymerization reaction for preparing the copolymer (A) can be carried out using a composition containing (poly) alkylene glycol as a by-product as a raw material. A composition containing A) and a non-polymerizable (poly) alkylene glycol (B) having no alkenyl group can be obtained. A cement admixture produced by such a production method is one of the preferred embodiments of the present invention.

  The (poly) alkylene glycol produced as a by-product in the production of the monomers (a1) and (a2) is a (poly) alkylene glycol having both terminal groups as hydrogen atoms, that is, (poly) ethylene glycol or (poly). ) In the case of ethylene (poly) propylene glycol and the like, since the starting material is water having two active hydrogens, the molecular weight of the (poly) alkylene glycol starts with unsaturated alcohols having one active hydrogen. It exceeds the molecular weights of the monomers (a1) and (a2) as substances, and usually has an average molecular weight of about the same or twice. Further, after the production of the copolymer (A), a non-polymerizable (poly) alkylene glycol (B) having no alkenyl group may be blended. The alkylene glycol (B) may be the same as or different from the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group contained as a by-product.

  Further, when the copolymer (A) is produced, an unsaturated (poly) alkylene glycol ether monomer (a1), an unsaturated polyalkylene glycol ether monomer (a2), a maleic acid monomer In addition to (b) and a non-polymerizable (poly) alkylene glycol (B) having no alkenyl group, a copolymer ( A) A cement admixture containing a non-polymerizable (poly) alkylene glycol (B) having no alkenyl group and an oxyalkylene antifoaming agent can be obtained. The oxyalkylene antifoaming agent having high hydrophobicity has a disadvantage that it is easily separated when blended with the copolymer (A) and has poor storage stability. However, as described above, an oxyalkylene antifoaming agent is blended in advance. By carrying out a copolymerization reaction using the composition as a raw material, a cement admixture with good storage stability can be obtained.

  Examples of the oxyalkylene-based antifoaming agent include polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene Polyoxyalkylene alkyl ethers such as 2-ethylhexyl ether and higher alcohols having 12 to 14 carbon atoms such as oxyethyleneoxypropylene adducts; polyoxyalkylene (alkyl) such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether ) Aryl ethers; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohol such as -1-butyn-3-ol; (poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate; Polyoxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan trioleate; polyoxyalkylene alkyl (aryl) such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecyl phenyl ether sulfate ) Ether sulfate esters; Polyoxyalkylates such as polyoxyethylene stearyl phosphate Alkyl phosphates; polyoxypropylene polyoxyethylene laurylamine (1-20 mol addition of propylene oxide, 1-20 mol addition product of ethylene oxide, etc.), cured beef tallow amine added with alkylene oxide (1-20 mol addition of propylene oxide, And polyoxyalkylene alkylamines such as 1 to 20 mol adducts of ethylene oxide; polyoxyalkylene amides and the like. Two or more of these oxyalkylene-based antifoaming agents may be used in combination.

  In the composition in which the oxyalkylene-based antifoaming agent is blended, the blending ratio of the oxyalkylene-based defoaming agent is in the range of 0.01 to 10% by mass with respect to the total amount of the monomer components that undergo the copolymerization reaction. Preferably, the range of 0.05-5 mass% is more preferable.

  The unsaturated (poly) alkylene glycol ether monomer (a1), unsaturated polyalkylene glycol ether monomer (a2) and non-polymerizable having no alkenyl group used for the copolymerization reaction ( In the composition containing poly) alkylene glycol (B), the total amount of unsaturated (poly) alkylene glycol ether monomer (a1) and unsaturated polyalkylene glycol ether monomer (a2) is 100% by mass. The proportion of non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is preferably 50% by mass or less. When the proportion of the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group exceeds 50% by mass, the monomer concentration during the polymerization reaction is lowered, and the molecular weight of the copolymer (A) is reduced. May decrease. More preferably, it is 40 mass% or less, More preferably, it is 30 mass% or less, Most preferably, it is 20 mass% or less. Further, the non-polymerizable (poly (poly) alkylene glycol ether monomer (a1) and non-polymerizable poly (alkylene glycol ether monomer) having no alkenyl group with respect to the total amount of 100% by mass of the unsaturated polyalkylene glycol ether monomer (a2). ) The proportion of alkylene glycol (B) is preferably 0.5% by mass or more. More preferably, it is 1 mass% or more, More preferably, it is 1.5 mass% or more, Most preferably, it is 2.0 mass% or more. Moreover, as a suitable range, Preferably it is 0.5-50 mass%, More preferably, it is 1-40 mass%, More preferably, it is 1.5-30 mass%, Especially preferably, It is 2.0-20 mass%. In order to make it less than the said range, it has an alkenyl group by-produced at the time of manufacture of unsaturated (poly) alkylene glycol ether monomer (a1) and unsaturated polyalkylene glycol ether monomer (a2). It is necessary to reduce the production rate of the non-polymerizable (poly) alkylene glycol (B) that does not. For this purpose, it is possible to remove impurities having active hydrogen such as water in various raw materials used in the addition reaction of alkylene oxides such as unsaturated alcohols or on the wall surface or gas phase part of the reaction apparatus from the reaction system. It takes a long time for the dehydration process or the like, or a purification step for removing the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group after completion of the addition reaction of alkylene oxide is required. Since productivity of (a1) and (a2) falls, it is not preferable.

  The unsaturated (poly) alkylene glycol ether monomer (a1) and unsaturated polyalkylene glycol ether monomer (a2) may be blended after the production of the copolymer (A). Polymerization is carried out when the total amount of monomers (a1) and (a2) used as raw materials is 1 to 100% by mass with respect to the copolymer (A) when the coalescence (A) is produced. By stopping the reaction, in addition to the copolymer (A), the monomers (a1) and (a2) are included, and the total amount of the monomers (a1) and (a2) is the copolymer (A1). It is preferable because a composition of 1 to 100% by mass can be obtained.

  In the production of the cement admixture of the present invention, the ratio of the total amount of the remaining unsaturated (poly) alkylene glycol ether monomer (a1) and unsaturated polyalkylene glycol ether monomer (a2) is If it is less than the range, the workability of the concrete composition may be reduced, whereas if it exceeds the range, the dispersibility to cement may be reduced. More preferably, when the polymerization reaction is stopped, the total amount of the unsaturated (poly) alkylene glycol ether monomer (a1) and the unsaturated polyalkylene glycol ether monomer (a2) is The time when 2% by mass or more remains with respect to the coalescence (A), more preferably 3% by mass or more, particularly preferably 4% by mass or more, and most preferably 5% by mass or more. It is. Further, it is more preferably 90% by mass or less, further preferably 80% by mass or less, particularly preferably 70% by mass or less, and most preferably 50% by mass or less. The preferred range is preferably when 2 to 100% by mass remains, more preferably 3 to 90% by mass, still more preferably 4 to 80% by mass, and particularly preferably 5 to 70%. % By weight, most preferably 5 to 50% by weight.

  The copolymer (A) may be further mixed with an unsaturated (poly) alkylene glycol ether monomer (a1) and / or an unsaturated polyalkylene glycol ether monomer (a2). The unsaturated (poly) alkylene glycol ether monomer (a1) and / or the unsaturated polyalkylene glycol ether monomer (a2) to be blended are the unsaturated ( It may be the same as or different from the poly) alkylene glycol ether monomer (a1) and the unsaturated polyalkylene glycol ether monomer (a2).

  A preferred production method of the copolymer (A) for obtaining the cement admixture of the present invention includes the unsaturated (poly) alkylene glycol ether monomer (a1) and the unsaturated polyalkylene glycol ether monomer. In addition to the monomer component containing the three components of (a2) and the maleic monomer (b) as essential components, the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is also included. A copolymerization reaction is performed using the composition as a raw material, and the total amount of the unsaturated (poly) alkylene glycol ether monomer (a1) and the unsaturated polyalkylene glycol ether monomer (a2) In this method, the polymerization reaction is stopped when 1 to 100% by mass of the combined (A) remains. By this method, the copolymer (A), the unsaturated (poly) alkylene glycol ether monomer (a1), the unsaturated polyalkylene glycol ether monomer (a2) and the non-polymerizable compound having no alkenyl group The cement admixture of the present invention containing four components of (poly) alkylene glycol (B) can be easily obtained. A cement admixture produced by such a production method is one of the preferred embodiments of the present invention.

  The cement admixture of the present invention does not have a copolymer (A), an unsaturated (poly) alkylene glycol ether monomer (a1), an unsaturated polyalkylene glycol ether monomer (a2), and an alkenyl group. Although it contains four components of non-polymerizable (poly) alkylene glycol (B) as essential components, it may be used as a main component of a cement admixture in the form of an aqueous solution, or two components such as calcium and magnesium. Neutralized with a valent metal hydroxide to form a polyvalent metal salt, dried, supported on inorganic powder such as silica fine powder, dried, drum-type drying device, disk-type drying device or belt It may be used after being pulverized by drying and solidifying it into a thin film on a support using a type drying apparatus. Also, the powdered cement admixture of the present invention is blended in advance into a cement composition not containing water such as cement powder and dry mortar, and used as a premix product for plastering, floor finishing, grout, etc. Alternatively, it may be blended when the cement composition is kneaded.

  The cement admixture of the present invention can be used for various hydraulic materials, that is, cement compositions such as cement and gypsum and other hydraulic materials. As a specific example of a hydraulic composition containing such a hydraulic material, water and the cement admixture of the present invention, and further containing fine aggregate (sand, etc.) and coarse aggregate (crushed stone, etc.) as necessary Examples include cement paste, mortar, concrete, plaster and the like.

  Among the hydraulic compositions, a cement composition that uses cement as a hydraulic material is the most common, and the cement composition includes the cement admixture of the present invention, cement, and water as essential components. . Such a cement composition is one of the preferred embodiments of the present invention.

  There is no limitation in particular as a cement used in the said cement composition. 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-concentration cement), ultra-high-strength cement, cement-based solidified material, eco-cement (city waste incineration ash, sewage sludge incineration ash as a raw material), blast furnace slag, fly ash , Cinder ash, clinker ash, Squash, silica fume, silica powder, a fine powder and gypsum limestone powder may be added. In addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., the aggregate includes siliceous, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromic, magnesia. Refractory aggregate such as can be used.

In the cement composition, the unit water amount per 1 m ³ , the cement use amount and the water / cement ratio are as follows: unit water amount 100 to 185 kg / m ³ , use cement amount 200 to 800 kg / m ³ , water / cement ratio ( (Mass ratio) = 0.1 to 0.7, more preferably, unit water amount 120 to 175 kg / m ³ , amount of cement used 250 to 800 kg / m ³ , water / cement ratio (mass ratio) = 0. .2 to 0.65 is recommended, and can be used widely from poor blends to rich blends. The cement admixture of the present invention has a high water reduction rate region, that is, a region with a low water / cement ratio such as water / cement ratio (mass ratio) = 0.15 to 0.5 (preferably 0.15 to 0.4). In addition, it is effective for both high-strength concrete having a large unit cement amount and a small water / cement ratio, and poor-mixed concrete having a unit cement amount of 300 kg / m ³ or less.

  As a mixing ratio of the cement admixture of the present invention in the cement composition, for example, when used for mortar or concrete using hydraulic cement, the cement mass is 0.01 to 10.0 mass in terms of solid content. % Is preferable. Such an added amount brings about various preferable effects such as reduction in unit water amount, increase in strength, and improvement in durability. If the blending ratio is less than 0.01%, the performance may not be sufficient. On the other hand, even if a large amount exceeding 10.0% is used, the effect is practically peaked and also from the economical aspect. May be disadvantageous. The preferred range of the blending ratio is more preferably 0.02 to 5.0% by mass, still more preferably 0.05 to 3.0% by mass, and particularly preferably 0.1 to 2.0% by mass. It is.

  The cement composition has high dispersibility and dispersion holding performance even in a high water reduction rate region, and exhibits sufficient initial dispersibility and viscosity reduction even at low temperatures, and has excellent workability. , Ready mixed concrete, concrete for concrete secondary products (precast concrete), centrifugal molding concrete, concrete for vibration compaction, steam-cured concrete, sprayed concrete, etc. High fluidity is required such as concrete in the range of 22-25 cm), high-fluidity concrete (concrete with a slump value of 25 cm or more and a slump flow value of 50-70 cm), self-filling concrete, self-leveling material, etc. It is also effective for mortar and concrete.

  The cement admixture of the present invention can be used in combination with a known cement dispersant, and a plurality of known cement dispersants can be used in combination. As a well-known cement dispersant used together, the sulfonic acid-type dispersing agent (S) which has a sulfonic acid group in a molecule | numerator is preferable. By using a sulfonic acid-based dispersant (S) having a sulfonic acid group in the molecule, cement brand and lot no. Regardless of this, the cement admixture exhibits stable dispersion performance. The sulfonic acid dispersant (S) is a dispersant that exhibits dispersibility with respect to cement due to electrostatic repulsion mainly caused by sulfonic acid groups, and various known sulfonic acid dispersants can be used. A compound having an aromatic group in the molecule is preferable. Specifically, polyalkylaryl sulfonates such as naphthalene sulfonic acid formaldehyde condensate, methyl naphthalene sulfonic acid formaldehyde condensate, anthracene sulfonic acid formaldehyde condensate; melamine formalin resin sulfonate such as melamine sulfonic acid formaldehyde condensate Aromatic aminosulfonates such as aminoaryl sulfonic acid-phenol-formaldehyde condensates; lignin sulfonates such as lignin sulfonates and modified lignin sulfonates; various sulfonic acids such as polystyrene sulfonates System dispersants. In the case of concrete with a high water / cement ratio, a lignin sulfonate-based dispersant is preferably used, while in the case of a concrete with a medium water / cement ratio that requires higher dispersion performance, Dispersants such as alkylaryl sulfonate, melamine formalin sulfonate, aromatic amino sulfonate, and polystyrene sulfonate are preferably used. Two or more sulfonic acid-based dispersants (S) having a sulfonic acid group in the molecule may be used in combination.

  The cement admixture of the present invention can be used in combination with the oxycarboxylic acid compound (D) in addition to the sulfonic acid dispersant (S). By including the oxycarboxylic acid compound (D), higher dispersion retention performance can be exhibited even in a high temperature environment. As the oxycarboxylic acid compound (D) used in the present invention, an oxycarboxylic acid having 4 to 10 carbon atoms or a salt thereof is preferable, for example, gluconic acid, glucoheptonic acid, aravic acid, malic acid, citric acid, These include inorganic or organic salts such as sodium, potassium, calcium, magnesium, ammonium, triethanolamine and the like. Among these, gluconic acid or a salt thereof is preferably used. In addition, these may be used independently and may use 2 or more types together. In particular, in the case of poor blended concrete, a lignin sulfonate-based dispersant is used as the sulfonic acid-based dispersant (S) having a sulfonic acid group in the molecule, and gluconic acid or oxycarboxylic acid-based compound (D) is gluconic acid or It is preferable to use the salt.

  When the cement admixture of the present invention and the sulfonic acid dispersant (S) are used in combination, the blending ratio of the copolymer (A) and the sulfonic acid dispersant (S) in the cement admixture of the present invention, that is, The (copolymer (A) / sulfonic acid dispersant (S)) (mass%) in terms of solid content is preferably from 1 to 99/99 to 1, more preferably from 5 to 95/95 to 5, 10-90 / 90-10 are more preferable, and 20-80 / 80-20 are especially preferable. When the cement admixture of the present invention and the oxycarboxylic acid compound (D) are used in combination, the blending ratio of the copolymer (A) and the oxycarboxylic acid compound (D) in the cement admixture of the present invention That is, (copolymer (A) / oxycarboxylic acid compound (D)) (mass%) in terms of solid content is preferably from 1 to 99/99 to 1, more preferably from 5 to 95/95 to 5. Preferably, 10-90 / 90-10 are more preferable, and 20-80 / 80-20 are especially preferable. Furthermore, when the three components of the cement admixture of the present invention, the sulfonic acid group dispersant (S) having a sulfonic acid group in the molecule and the oxycarboxylic acid compound (D) are used in combination, The blending ratio of the copolymer (A), the sulfonic acid-based dispersant (S) having a sulfonic acid group in the molecule and the oxycarboxylic acid-based compound (D), that is, in terms of solid content (copolymer (A) / As the sulfonic acid-based dispersant (S) / oxycarboxylic acid-based compound (D)) (% by mass) having a sulfonic acid group in the molecule, 1 to 98/1 to 98/1 to 98 is preferable, 90 / 5-90 / 5-90 are more preferable, 10-90 / 5-85 / 5-85 are still more preferable, and 20-80 / 10-70 / 10-70 are especially preferable.

Moreover, the said cement composition can contain the other well-known cement additive (material) which is illustrated to the following (1)-(11).
(1) Water-soluble polymer material: polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), unsaturated carboxylic acid polymer such as sodium salt of acrylic acid / maleic acid copolymer; methylcellulose , Nonionic cellulose ethers such as ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, hydroxypropyl cellulose; alkylated or hydroxyalkylated derivatives of polysaccharides such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, etc. Hydrophobic substituents in which some or all of the hydroxyl atoms have a hydrocarbon chain having 8 to 40 carbon atoms as a partial structure, sulfonic acid groups or Polysaccharide derivatives substituted with an ionic hydrophilic substituent having a partial structure of these salts; yeast glucan, xanthan gum, β-1.3 glucans (which may be either linear or branched, examples include Polysaccharides produced by microbial fermentation such as curdlan, paramylon, pachyman, scleroglucan, laminaran, etc.); polyacrylamide; polyvinyl alcohol; starch; starch phosphate ester; sodium alginate; gelatin; A copolymer of acrylic acid having quaternary compounds and quaternary compounds thereof.
(2) Polymer emulsion: Copolymers of various vinyl monomers such as alkyl (meth) acrylate.
(3) Curing retarders other than oxycarboxylic acid compounds (D): monosaccharides such as glucose, fructose, galactose, saccharose, xylose, apiose, ribose, isomerized sugar, oligosaccharides such as disaccharide and trisaccharide, Or oligosaccharides such as dextrin, or polysaccharides such as dextran, sugars such as molasses containing them; sugar alcohols such as sorbitol; magnesium silicates; phosphoric acid and salts thereof or boric acid esters; Salt; Alkali-soluble protein; Humic acid; Tannic acid; Phenol; Polyhydric alcohol such as glycerin; Aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriamine Penta (methylenephosphonic acid) and these Alkali metal salts, and phosphonic acids and derivatives thereof such as alkaline earth metal salts.
(4) Early strengthening agents / accelerators: soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide and calcium iodide; chlorides such as iron chloride and magnesium chloride; sulfates; potassium hydroxide; Sodium hydroxide; carbonate; thiosulfate; formate such as formic acid and calcium formate; alkanolamine; alumina cement; calcium aluminate silicate.
(5) Antifoaming agents other than oxyalkylene-based: mineral oil-based antifoaming agents such as coconut oil and liquid paraffin; fat and oil-based antifoaming agents such as animal and vegetable oils, sesame oil, castor oil, and these alkylene oxide adducts; , Fatty acid-based antifoaming agents such as these alkylene oxide adducts; fatty acid ester-based antifoaming agents such as glycerin monoricinoleate, alkenyl succinic acid derivatives, sorbitol monolaurate, sorbitol trioleate, natural wax; octyl alcohol, hexadecyl Alcohol-based antifoaming agents such as alcohol, acetylene alcohol and glycols; Amide-based antifoaming agents such as acrylate polyamines; Phosphate-based antifoaming agents such as tributyl phosphate and sodium octyl phosphate; Aluminum stearate, calcium oleate, etc. Metal soap defoaming ; Dimethyl silicone oil, silicone paste, silicone emulsion, organic modified polysiloxane (dimethyl polysiloxane polyorganosiloxane), silicone anti-foaming agent such as fluorosilicone oil.
(6) AE agent: resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, ABS (alkyl benzene sulfonic acid), LAS (linear alkyl benzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl) ether , Polyoxyethylene alkyl (phenyl) ether sulfate or a salt thereof, polyoxyethylene alkyl (phenyl) ether phosphate or a salt thereof, protein material, alkenyl sulfosuccinic acid, α-olefin sulfonate, and the like.
(7) Other surfactants: aliphatic monohydric alcohol having 6 to 30 carbon atoms in the molecule such as octadecyl alcohol and stearyl alcohol, and 6 to 30 carbon atoms in the molecule such as abiethyl alcohol Intramolecular such as alicyclic monohydric alcohol, dodecyl mercaptan, etc. Intramolecular such as monovalent mercaptan having 6-30 carbon atoms in the molecule, such as nonylphenol, alkylphenol having 6-30 carbon atoms in the molecule, dodecylamine, etc. 10 mol or more of an alkylene oxide such as ethylene oxide and propylene oxide was added to a carboxylic acid having 6 to 30 carbon atoms in the molecule such as amine having 6 to 30 carbon atoms, lauric acid and stearic acid. Polyalkylene oxide derivatives having an alkyl group or an alkoxy group as a substituent Good, alkyl diphenyl ether sulfonates in which two phenyl groups having a sulfone group are ether-bonded; various anionic surfactants; various cationic surfactants such as alkylamine acetate and alkyltrimethylammonium chloride; various nonionic interfaces Activators; various amphoteric surfactants.
(8) Waterproofing agent: fatty acid (salt), fatty acid ester, oil and fat, silicon, paraffin, asphalt, wax and the like.
(9) Rust inhibitor: nitrite, phosphate, zinc oxide and the like.
(10) Crack reducing agent: polyoxyalkyl ether and the like.
(11) Expansion material: Ettlingite, coal, etc.

  Other known cement additives (materials) include cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancers, self-leveling agents, rust preventives, colorants, and antifungal agents. An agent etc. can be mentioned. These known cement additives (materials) may be used alone or in combination of two or more.

  In the above cement composition, the following (1) to (4) may be mentioned as particularly preferred embodiments for components other than cement and water.

  (1) <1> A combination comprising two components of the cement admixture of the present invention and <2> an oxyalkylene-based antifoaming agent. As the oxyalkylene-based antifoaming agent, polyoxyalkylenes, polyoxyalkylene alkyl ethers, polyoxyalkylene acetylene ethers, polyoxyalkylene alkylamines and the like can be used, but polyoxyalkylene alkylamines are particularly preferable. Is preferred. The blending mass ratio of the oxyalkylene antifoaming agent <2> is preferably in the range of 0.01 to 20% by mass with respect to the cement admixture <1>.

  (2) A combination comprising two components of <1> the cement admixture of the present invention and <2> a material separation reducing agent. Examples of the material separation reducing agent include various thickeners such as nonionic cellulose ethers, a hydrophobic substituent composed of a hydrocarbon chain having 4 to 30 carbon atoms as a partial structure, and an alkylene oxide having 2 to 18 carbon atoms. A compound having a polyoxyalkylene chain added in an average addition mole number of 2 to 300 can be used. The blending mass ratio of the cement admixture <1> and the material separation reducing agent <2> is preferably 10/90 to 99.99 / 0.01, and 50/50 to 99.9 / 0. 1 is more preferable. The cement composition of this combination is suitable as high fluidity concrete, self-filling concrete and self-leveling material.

  (3) A combination comprising two components, <1> the cement admixture of the present invention and <2> an accelerator. As the accelerator, soluble calcium salts such as calcium chloride, calcium nitrite and calcium nitrate, chlorides such as iron chloride and magnesium chloride, formates such as thiosulfate, formic acid and calcium formate, and the like can be used. The blending mass ratio of the <1> cement admixture and the <2> accelerator is preferably 10/90 to 99.9 / 0.1, and more preferably 20/80 to 99/1.

  (4) A combination comprising essentially the three components of <1> the cement admixture of the present invention, <2> an oxyalkylene-based antifoaming agent, and <3> an AE agent. As the oxyalkylene-based antifoaming agent, polyoxyalkylenes, polyoxyalkylene alkyl ethers, polyoxyalkylene acetylene ethers, polyoxyalkylene alkylamines and the like can be used, but polyoxyalkylene alkylamines are particularly preferable. Is preferred. The blending mass ratio of the cement admixture <1> and the antifoaming agent <2> is preferably 0.01 to 20% by mass with respect to the cement admixture <1>. On the other hand, the blending mass ratio of the AE agent <3> is preferably 0.001 to 2 mass% with respect to the cement.

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. Unless otherwise specified, “%” represents mass% and “part” represents mass part.

  In the production examples, the amount of polyalkylene glycol produced as a by-product during production of the unsaturated (poly) alkylene glycol ether monomer was measured under the following conditions.

<Measurement conditions for polyalkylene glycol production>
Model: Shimadzu Corporation LC-10
Detector: Differential refractometer (RI) detector (HITACHI 3350 RI MONITOR)
Eluent: Type Ion exchange water
Flow rate 1.5 ml / min Column: Type Showa Denko KK, “Shodex GF-310” 4.6 × 300 mm
Temperature 40 ℃

In the production examples, the reaction rate of each monomer and the weight average molecular weight of the obtained copolymer were measured under the following conditions.

<Reaction rate measurement conditions for each raw material monomer>
Model: JASCO Borwin
Detector: Differential refractometer (RI) detector (HITACHI 3350 RI MONITOR)
Eluent: Type Acetonitrile / 0.1% Phosphate ion exchange aqueous solution = 50/50 (vol%)
Flow rate 1.0 ml / min Column: Type Tosoh Co., Ltd., “ODS-120T” + “ODS-80Ts” each 4.6 × 250 mm
Temperature 40 ℃

<Conditions for measuring weight average molecular weight of copolymer>
Model: Waters LCM1
Detector: differential refractometer (RI) detector (Waters 410)
Eluent: Type Acetonitrile / 0.05M sodium acetate ion exchange aqueous solution = 40/60 (vol%), adjusted to pH 6.0 with acetic acid
Flow rate 0.6 ml / min Column: Type Tosoh Corporation “TSK-GEL G4000SWXL” + “G3000SWXL” + “G2000SWXL” + “GUARD COLUMN” 7.8 × 300 mm, 6.0 × 40 mm
Temperature 40 ℃
Calibration curve: Polyethylene glycol standard

<Production Example 1>
982 parts of methallyl alcohol (2-methyl-2-propen-1-ol) as unsaturated alcohol and sodium hydroxide as addition reaction catalyst in a stainless steel high-pressure reactor equipped with a thermometer, stirrer, nitrogen and alkylene oxide introduction tube 3.5 parts was charged, the inside of the reaction vessel was purged with nitrogen under stirring, and heated to 150 ° C. in a nitrogen atmosphere. Then, 6279 parts of ethylene oxide was introduced into the reactor while maintaining 150 ° C. under a safe pressure, and the reaction was terminated by maintaining the temperature until the alkylene oxide addition reaction was completed. The obtained reaction product (hereinafter referred to as M-1) was an unsaturated polyalkylene glycol ether monomer (hereinafter referred to as MAL-10) obtained by adding an average of 10 moles of ethylene oxide to methallyl alcohol. In addition, non-polymerizable polyalkylene glycol (polyethylene glycol) having no alkenyl group is included as a by-product, and the amount of polyethylene glycol produced is 4 with respect to the unsaturated polyalkylene glycol ether monomer. It was 0 mass%.

<Production Examples 2 to 4>
An alkylene oxide addition reaction to an unsaturated alcohol was conducted in the same manner as in Production Example 1 except that the type and amount of unsaturated alcohol, addition reaction catalyst sodium hydroxide and alkylene oxide were changed as shown in Table 1. Then, reaction products (M-2) to (M-4) containing an unsaturated polyalkylene glycol ether monomer and a non-polymerizable polyalkylene glycol having no alkenyl group were obtained. All alkylene oxide addition reactions were carried out at 150 ° C. Table 1 shows the production amount (% by mass) of non-polymerizable polyalkylene glycol having no alkenyl group by-produced with respect to the unsaturated polyalkylene glycol ether monomer in the obtained reaction product.

<Production Example 5-Production of Copolymer (A-1)>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 281.5 parts of ion-exchanged water, 99.8 reaction product (M-1) obtained in Production Example 1 Parts (containing 96.0 parts of MAL-10 and 3.8 parts of polyethylene glycol), 319.2 parts of reaction product (M-2) obtained in Production Example 2 (300.0 parts of MAL-100, 19.2 parts of polyethylene glycol) and 60.9 parts of maleic acid were charged, and the temperature was raised to 65 ° C. With the reaction vessel kept at 65 ° C., an aqueous hydrogen peroxide solution consisting of 0.530 parts hydrogen peroxide and 10.07 parts ion-exchanged water was added. Subsequently, an aqueous solution in which 0.687 parts of erythorbic acid was dissolved in 13.04 parts of ion-exchanged water was dropped into the reaction vessel over 1 hour. Thereafter, the temperature was maintained at 65 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (mass% concentration with respect to all raw materials of all monomer components) was 60%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature not higher than the polymerization reaction temperature to obtain an aqueous solution containing the copolymer (A-1).

<Production Example 6 Production of Copolymer (A-2)>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube and a reflux condenser, 322.4 parts of ion-exchanged water, reaction product (M-1) 156.0 obtained in Production Example 1 Parts (containing 150.0 parts of MAL-10 and 6.0 parts of polyethylene glycol), 319.2 parts of reaction product (M-2) obtained in Production Example 2 (300.0 parts of MAL-100, 19.2 parts of polyethylene glycol) and 69.2 parts of maleic acid were charged and heated to 65 ° C. A hydrogen peroxide aqueous solution consisting of 0.822 parts of hydrogen peroxide and 15.62 parts of ion-exchanged water was added while maintaining the reaction vessel at 65 ° C. Next, 18.2 parts of acrylic acid was dropped into the reaction vessel over 1 hour, and at the same time, an aqueous solution in which 1.065 parts of L-ascorbic acid was dissolved in 20.23 parts of ion-exchanged water was added to the reaction vessel. It was added dropwise over time. Thereafter, the temperature was maintained at 65 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (mass% concentration with respect to all raw materials of all monomer components) was 60%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature not higher than the polymerization reaction temperature to obtain an aqueous solution containing the copolymer (A-2).

<Production Example 7-Production of copolymer (A-3)>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 333.8 parts of ion exchange water, reaction product (M-1) 178.3 obtained in Production Example 1 Parts (containing 171.4 parts of MAL-10 and 6.9 parts of polyethylene glycol), 319.2 parts of reaction product (M-2) obtained in Production Example 2 (300.0 parts of MAL-100, 19.2 parts of polyethylene glycol) and 62.1 parts of maleic acid were charged and heated to 65 ° C. Hydrogen peroxide 0.721 with the reaction vessel kept at 65 ° C.
A hydrogen peroxide aqueous solution consisting of 13 parts and ion-exchanged water 13.71 parts was added. Next, 14.3 parts of 2-hydroxyethyl acrylate was dropped into the reaction vessel over 1 hour, and at the same time, an aqueous solution in which 0.934 parts of erythorbic acid was dissolved in 17.75 parts of ion-exchanged water was placed in the reaction vessel. The solution was added dropwise over 1 hour. Thereafter, the temperature was maintained at 65 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (mass% concentration with respect to all raw materials of all monomer components) was 60%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature not higher than the polymerization reaction temperature to obtain an aqueous solution containing the copolymer (A-3).

<Production Example 8-Production of Copolymer (A-4)>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 154.4 parts of ion-exchanged water, 89.1 of the reaction product (M-3) obtained in Production Example 3. Parts (containing 85.7 parts of AL-25 and 3.4 parts of polyethylene glycol), 319.2 parts of reaction product (M-2) obtained in Production Example 2 (300.0 parts of MAL-100, 19.2 parts of polyethylene glycol) and 31.1 parts of maleic acid were charged and heated to 65 ° C. A hydrogen peroxide aqueous solution consisting of 0.556 parts of hydrogen peroxide and 10.57 parts of ion-exchanged water was added while maintaining the reaction vessel at 65 ° C. Next, an aqueous solution in which 0.720 parts of erythorbic acid was dissolved in 13.69 parts of ion-exchanged water was dropped into the reaction vessel over 1 hour. Thereafter, the temperature was maintained at 65 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (mass% concentration of all monomer components with respect to all raw materials) was 70%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature not higher than the polymerization reaction temperature to obtain an aqueous solution containing the copolymer (A-4).

<Production Example 9-Production of Copolymer (A-5)>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube and a reflux condenser, 201.2 parts of ion-exchanged water and the reaction product (M-3) 167.4 obtained in Production Example 3 Parts (containing 163.6 parts of AL-25 and 3.8 parts of polyethylene glycol), 309.6 parts of the reaction product (M-4) obtained in Production Example 4 (300.0 parts of AL-75, Polyethylene glycol (9.6 parts contained) and maleic acid 59.3 parts were charged, and the temperature was raised to 65 ° C. While maintaining the reaction vessel at 65 ° C., an aqueous hydrogen peroxide solution comprising 2.018 parts of hydrogen peroxide and 8.07 parts of ion-exchanged water was added. Next, an aqueous solution in which 2.614 parts of L-ascorbic acid was dissolved in 14.81 parts of ion-exchanged water was dropped into the reaction vessel over 1 hour. Thereafter, the temperature was maintained at 65 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (mass% concentration of all monomer components with respect to all raw materials) was 70%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature to obtain an aqueous solution containing the copolymer (A-5).

<Production Example 10—Production of Comparative Copolymer (C-1)>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 242.2 parts of ion-exchanged water, reaction product (M-1) 312.0 obtained in Production Example 1 Parts (containing 300.0 parts of MAL-10 and 12.0 parts of polyethylene glycol) and 145.0 parts of maleic acid were heated to 65 ° C. A hydrogen peroxide aqueous solution consisting of 1.248 parts of hydrogen peroxide and 23.72 parts of ion-exchanged water was added while maintaining the reaction vessel at 65 ° C. Next, an aqueous solution in which 1.617 parts of erythorbic acid was dissolved in 30.72 parts of ion-exchanged water was dropped into the reaction vessel over 1 hour. Thereafter, the temperature was maintained at 65 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (mass% concentration with respect to all raw materials of all monomer components) was 60%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the polymerization reaction temperature to obtain an aqueous solution containing a comparative copolymer (C-1).

<Production Example 11—Production of Comparative Copolymer (C-2)>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, 273.0 parts of ion-exchanged water, reaction product (M-2) 425.6 obtained in Production Example 2 Parts (containing 400.0 parts of MAL-100 and 25.6 parts of polyethylene glycol) and 21.8 parts of maleic acid were heated to 65 ° C. A hydrogen peroxide aqueous solution consisting of 0.189 parts of hydrogen peroxide and 3.59 parts of ion-exchanged water was added while maintaining the reaction vessel at 65 ° C. Next, an aqueous solution in which 0.245 parts of erythorbic acid was dissolved in 4.65 parts of ion-exchanged water was dropped into the reaction vessel over 1 hour. Thereafter, the temperature was maintained at 65 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (mass% concentration with respect to all raw materials of all monomer components) was 60%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature lower than the polymerization reaction temperature to obtain an aqueous solution containing a comparative copolymer (C-2).

<Production Example 12-Production of Comparative Copolymer (C-3)>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 131.2 parts of ion-exchanged water and 306.9 of the reaction product (M-3) obtained in Production Example 3 Parts (containing 300.0 parts of AL-25 and 6.9 parts of polyethylene glycol) and 65.0 parts of maleic acid were heated to 65 ° C. A hydrogen peroxide aqueous solution consisting of 2.228 parts of hydrogen peroxide and 8.91 parts of ion-exchanged water was added while maintaining the reaction vessel at 65 ° C. Next, an aqueous solution in which 2.886 parts of L-ascorbic acid was dissolved in 16.35 parts of ion-exchanged water was dropped into the reaction vessel over 1 hour. Thereafter, the temperature was maintained at 65 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (mass% concentration of all monomer components with respect to all raw materials) was 70%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the polymerization reaction temperature to obtain an aqueous solution containing a comparative copolymer (C-3).

<Production Example 13-Production of comparative copolymer (C-4)>
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 167.4 parts of ion exchange water, reaction product (M-4) 412.8 obtained in Production Example 4 Parts (containing 400.0 parts of AL-75 and 12.8 parts of polyethylene glycol) and 28.7 parts of maleic acid were heated to 65 ° C. A hydrogen peroxide aqueous solution consisting of 0.997 parts of hydrogen peroxide and 8.97 parts of ion-exchanged water was added while maintaining the reaction vessel at 65 ° C. Subsequently, an aqueous solution in which 1.291 parts of erythorbic acid was dissolved in 7.31 parts of ion-exchanged water was dropped into the reaction vessel over 1 hour. Thereafter, the temperature was maintained at 65 ° C. for 1 hour, and then the polymerization reaction was terminated. The polymerization component concentration (mass% concentration of all monomer components with respect to all raw materials) was 70%. Thereafter, the reaction solution was neutralized to pH 7 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the polymerization reaction temperature to obtain an aqueous solution containing a comparative copolymer (C-4).

In each production example, the reaction rate of each raw material monomer (%) and the analysis result of the copolymer contained in the obtained aqueous copolymer solution [copolymerization composition ratio (% by mass), unsaturated (poly) alkylene glycol Total amount (mol%) of structural units derived from ether monomers (monomer (a1) and monomer (a2)), carboxylic acid amount (meq / g) in terms of unneutralized copolymer, Weight average molecular weight, total amount (mass%) of unsaturated (poly) alkylene glycol ether monomer (a1) and unsaturated polyalkylene glycol ether monomer (a2) with respect to neutralized copolymer, Table 2 shows the content (% by mass) of non-polymerizable (poly) alkylene glycol (B) having no alkenyl group relative to the sum-type copolymer.

In Table 2, the following abbreviations were used.
AO 1: Unsaturated (poly) alkylene glycol ether monomer (a1)
AO body 2: unsaturated polyalkylene glycol ether monomer (a2)
MA: maleic acid AA: acrylic acid HEA: 2-hydroxyethyl acrylate

<Concrete test>
A concrete composition was prepared with the following composition using ordinary Portland cement (manufactured by Taiheiyo Cement) as cement, Oikawa water-based land sand as fine aggregate, Ome crushed stone as coarse aggregate, and tap water as kneaded water. In addition, the temperature of the material used for the test, the forced kneading mixer, and the measuring instruments are adjusted in the above test temperature atmosphere so that the temperature of the concrete composition is 15 ° C. The kneading and each measurement are performed as described above. The test was performed under an atmosphere of the test temperature.

The concrete composition was prepared as follows. First, 658 kg / m ³ of fine aggregate (Oikawa water-based land sand) was kneaded for 10 seconds with a 50 L forced-type pan mixer, then 580 kg / m ³ of cement (Pacific Cement Corp. normal Portland cement) was added and kneaded for 10 seconds. did. Thereafter, 174 kg / m ^{3 of} tap water containing an amount of cement admixture with an initial slump flow value of 600 ± 50 mm was added and kneaded for 150 seconds. Thereafter, 895 kg / m ³ of coarse aggregate (Ome crushed stone) was further added and kneaded for 90 seconds to obtain a concrete composition. In order to avoid the influence of air bubbles in the concrete composition on the fluidity of the concrete composition, an AE agent (Binsole W (trade name, resin soap type, manufactured by Yamaso Chemical Co., Ltd.)) and an oxyalkylene antifoaming agent (Surfinol 440 (trade name, acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohol, manufactured by Nissin Chemical Industry Co., Ltd.)), the initial air amount becomes 5.5 ± 0.5%. Adjusted in the same way. The water / cement ratio (mass ratio) = 0.30, and the fine aggregate ratio [fine aggregate / (fine aggregate + coarse aggregate)] (volume ratio) = 0.424.

In addition, solid content [nonvolatile component] in the aqueous solution containing the copolymer is obtained by removing a volatile component by weighing an appropriate amount of the aqueous solution containing the copolymer obtained in the above production example and drying by heating at 130 ° C. When measured and blended with cement, an aqueous solution containing a polymer was weighed and used so that a predetermined amount of solid content [non-volatile component] was included.
Amount (% by mass) of copolymer (A) based on cement, and total amount (mass) of unsaturated (poly) alkylene glycol ether monomer (a1) and unsaturated polyalkylene glycol ether monomer (a2). %), The amount (% by mass) of the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group and the total amount (% by mass) as a cement admixture are shown in Table 3.

  Evaluation test items and measurement methods are as follows.

  1) Change in slump flow value over time; measured according to JIS-A-1101. As a retention rate, the ratio (%) of the slump flow value after 120 minutes to the slump flow value after 5 minutes was calculated.

  2) Spreading speed (Evaluation test method for effect of viscosity reduction of concrete composition): When measuring the initial slump flow value, measure the time required to reach the flow value of 500 mm after lifting the slump cone. The time was set as the speed (second). In addition, it shows that the viscosity reduction effect under a high shear is excellent, so that this time is short.

  3) Air amount: Measured according to JIS-A-1128.

4) Kneading time: After adding cement to fine aggregate, tap water containing cement admixture and starting kneading until the entire cement composition becomes uniform and the apparent fluidity does not change The time required for this was measured, and this time was taken as the kneading time. In addition, the shorter this time, the better the initial dispersibility.
The evaluation results are shown in Table 3.

From Table 3, in Comparative Examples 1 and 3 using the aqueous solution containing the comparative copolymer (C-1) or the comparative copolymer (C-3), the spreading speed is fast and the kneading time is short. It can be seen that the change in flow value with time is remarkably large. On the other hand, in the case of Comparative Examples 2 and 4 using the aqueous solution containing the comparative copolymer (C-2) or the comparative copolymer (C-4), the change in the slump flow value with time is small, but the spreading speed is slow. It can be seen that the kneading time is also long. On the other hand, Examples using the cement admixture of the present invention using the copolymer (A-1), (A-2), (A-3), (A-4) or (A-5) In the case of 1-5, it turns out that the spreading speed is fast, the kneading time is short, and the change with time of the slump flow value is small.

Claims (3)

Copolymer (A), unsaturated (poly) alkylene glycol ether monomer (a1), unsaturated polyalkylene glycol ether monomer (a2), and non-polymerizable (poly) alkylene having no alkenyl group 4 components of glycol (B) as essential components, and the total amount of unsaturated (poly) alkylene glycol ether monomer (a1) and unsaturated polyalkylene glycol ether monomer (a2) It is 1-100 mass% with respect to a polymer (A), and content of nonpolymerizable (poly) alkylene glycol (B) which does not have an alkenyl group is 1-50 mass with respect to a copolymer (A). % Cement admixture,
The copolymer (A) comprises a constituent unit (I) derived from the unsaturated (poly) alkylene glycol ether monomer (a1) and a constituent derived from the unsaturated polyalkylene glycol ether monomer (a2). The structural unit (III) derived from the unit (II) and the maleic monomer (b) is an essential structural unit, and the structural unit (I), the structural unit (II), and the structural unit (III) Each occupies 1% by mass or more of all structural units,
The unsaturated (poly) alkylene glycol ether monomer (a1) has the following general formula (1):
Y ¹ O (R ¹ O) m ₁ R ² (1)
(In the formula, Y ¹ represents an alkenyl group having 2 to 4 carbon atoms, R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and R ¹ O represents an oxy group having 2 to 18 carbon atoms. Represents one kind or a mixture of two or more kinds of alkylene groups, and m ₁ represents the average number of added moles of oxyalkylene groups and represents a number of 1 to 100).
The unsaturated polyalkylene glycol ether monomer (a2) is represented by the following general formula (2):
Y ² O (R ³ O) m ₂ R ⁴ (2)
(In the formula, Y ² represents an alkenyl group having 2 to 4 carbon atoms, R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, and R ³ O represents an oxy group having 2 to 18 carbon atoms. Represents one or a mixture of two or more alkylene groups, and m ₂ represents the average number of moles added of the oxyalkylene group, represents a number of 6 to 500, and m ₂ −m ₁ ≧ 5. Cement admixture characterized by being a thing. The oxyalkylene group constituting the non-polymerizable (poly) alkylene glycol (B) having no alkenyl group is one or a mixture of two or more oxyalkylene groups having 2 to 18 carbon atoms. The terminal group of the non-polymerizable (poly) alkylene glycol having no group is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an (alkyl) phenyl group. Cement admixture. A cement composition comprising the cement admixture according to claim 1 or 2, cement and water as essential components.