JP2021080400A - Polymer and cement additive - Google Patents

Abstract

To provide a water-soluble polymer suited to a cement additive, a cement additive excellent in water-reducing performance, a cement composition excellent in flowability, and cement obtained by hardening a cement composition.SOLUTION: A polymer comprises a structural unit derived from general formula (I), and a (meth)acrylic acid (salt) unit. [In the formula, R1 to R4 are each an H atom, methyl group or ethyl group; o is from 1 to 200; and p is from 1 to 3.]SELECTED DRAWING: None

Description

The present invention relates to polymers and cement admixtures. More specifically, the present invention relates to a polymer that can be suitably used for cement compositions such as cement paste, mortar, and concrete, and a cement admixture containing the same.

Cement admixtures are used to reduce water content and increase fluidity of cement compositions such as cement pastes, mortars and concrete. In addition to water-reducing performance, cement admixtures are also required to have workability during construction of buildings and quality such as strength and durability of hardened products, so various studies are still underway.

Conventionally, a naphthalene-based water reducing agent has been used as the cement admixture, but on the other hand, a polycarboxylic acid-based water reducing agent containing a (poly) oxyalkylene chain has been proposed. Since the (poly) oxyalkylene chain acts as a dispersing group that disperses cement particles by its steric repulsion, it is effective in improving the fluidity of the cement composition.

As a polycarboxylic acid-based water reducing agent containing a (poly) oxyalkylene chain, for example, a polycarboxylic acid obtained by allowing ethylene oxide or the like to act on the hydroxyl group portion of metallic alcohol or 3-methyl-3-butene-1-ol. Water reducing agents have been reported (Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2015-157761 Japanese Unexamined Patent Publication No. 2014-166948

The polycarboxylic acid-based water reducing agent containing the (poly) oxyalkylene chain has one (poly) oxyalkylene chain in the corresponding monomer. However, when these polymers are used for the purpose of controlling the quality such as water reduction performance of the cement admixture and the fluidity of the cement composition, the content of the (poly) oxyalkylene chain is contained in the monomer ( Since it depends on the degree of polymerization of the poly) oxyalkylene group, there is no other way but to control this degree of polymerization. Therefore, the degree of freedom in designing and blending a cement composition using a cement admixture containing these polymers is small, and there is a limit to improving the performance of the cement composition such as fluidity.

The present invention has been made in view of the above problems, and cures a water-soluble polymer suitable for a cement admixture, a cement admixture having excellent water-reducing performance, a cement composition having excellent fluidity, and a cement composition. The purpose is to provide cement.

As a result of diligent studies, the present inventors have been able to improve the water-reducing performance of the cement admixture by using a polymer in which a compound having two or more (poly) oxyalkylene chains in the molecule is used as a monomer. Further, it was found that the fluidity of the cement composition was improved by using the cement water reducing agent in the cement composition, and further studies were carried out based on the finding to complete the present invention.

［一般式（Ｉ）中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４はそれぞれ独立して水素原子、メチル基又はエチル基を表し、Ｒ_ａは炭素数２〜１８のアルキレン基を表す。ｎは０〜３の任意の整数を表し、ｏは１〜２００の任意の整数を表し、ｐは１〜３の任意の整数を表す。］

［一般式（II）中、Ｒ^５、Ｒ^６及びＲ^７はそれぞれ独立して水素原子又はメチル基を表し、Ｍは水素原子、一価の金属原子、二価の金属原子及びアンモニウムからなる群より選ばれる少なくとも１つを表す。］
［２］一般式（II）に由来する構造単位及び下記一般式（III）に由来する構造単位を含む重合体。

［一般式（III）中、Ｒ^８及びＲ^９はそれぞれ独立して水素原子又は炭素数１〜６のアルキル基を表し、Ｒ_ｂ及びＲ_ｃはそれぞれ独立して炭素数２〜１８のアルキレン基を表す。ｌは０〜４の任意の整数を表し、ｍは１〜２００の任意の整数を表す。］
［３］さらに一般式（III）に由来する構造単位を含む、［１］に記載の重合体。
［４］一般式（II）中、Ｍが水素原子、一価の金属原子及び二価の金属原子からなる群より選ばれる少なくとも１つである、［１］〜［３］のいずれかに記載の重合体。
［５］一般式（Ｉ）中、Ｒ^１、Ｒ^２及びＲ^４が水素原子であり、Ｒ^３がメチル基であり、Ｒ_ａがエチレン基であり、ｎが１であり、ｐが２又は３である、［１］、［３］、［４］のいずれかに記載の重合体。
［６］一般式（III）中、Ｒ^８及びＲ^９が水素原子、Ｒ_ｂ及びＲ_ｃはエチレン基であり、ｌが２である、［２］〜［５］のいずれかに記載の重合体。
［７］［１］〜［６］のいずれかに記載の重合体を含む、セメント混和剤。
［８］［７］に記載のセメント混和剤を含む、セメント組成物。
［９］［８］に記載のセメント組成物を硬化してなる、コンクリート。
［１０］下記一般式（IV）で表される化合物。

［一般式（IV）中、ｏは１〜２００の任意の整数を表し、ｐは２又は３である。］
［１１］下記一般式（Ｖ）で表される化合物。

［一般式（Ｖ）中、Ｒ_ｂ及びＲ_ｃはそれぞれ独立して炭素数２〜１８のアルキレン基を表す。ｌは０〜４の任意の整数を表し、ｍは１〜２００の任意の整数を表す。］ The present invention provides the following [1] to [11].
[1] A polymer containing a structural unit derived from the following general formula (I) and a structural unit derived from the following general formula (II).

[Expressed in the general formula ^{(I), R 1, R} 2, R 3 and ^{R 4} are each independently a hydrogen atom, a methyl group or an ethyl group, _{R a} represents an alkylene group having 2 to 18 carbon atoms. n represents an arbitrary integer from 0 to 3, o represents an arbitrary integer from 1 to 200, and p represents an arbitrary integer from 1 to 3. ]

[In general formula (II), R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom or a methyl group, and M is a group consisting of a hydrogen atom, a monovalent metal atom, a divalent metal atom and ammonium. Represents at least one selected from. ]
[2] A polymer containing a structural unit derived from the general formula (II) and a structural unit derived from the following general formula (III).

[In the general formula (III), R ⁸ and R ⁹ independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R _b and R _c independently represent an alkylene group having 2 to 18 carbon atoms, respectively. Represents. l represents an arbitrary integer from 0 to 4, and m represents an arbitrary integer from 1 to 200. ]
[3] The polymer according to [1], which further contains a structural unit derived from the general formula (III).
[4] Described in any one of [1] to [3], wherein M is at least one selected from the group consisting of a hydrogen atom, a monovalent metal atom and a divalent metal atom in the general formula (II). Polymer.
[5] In the general formula (I), R ¹ , R ² and R ⁴ are hydrogen atoms, R ³ is a methyl group, _Ra is an ethylene group, n is 1, and p is 2 or. 3. The polymer according to any one of [1], [3], and [4].
[6] In the general formula (III), R ⁸ and R ⁹ are hydrogen atoms, R _b and R _c are ethylene groups, and l is 2, according to any one of [2] to [5]. Combined.
[7] A cement admixture containing the polymer according to any one of [1] to [6].
[8] A cement composition containing the cement admixture according to [7].
[9] A concrete obtained by hardening the cement composition according to [8].
[10] A compound represented by the following general formula (IV).

[In general formula (IV), o represents an arbitrary integer from 1 to 200, and p is 2 or 3. ]
[11] A compound represented by the following general formula (V).

[In the general formula (V), R _b and R _c each independently represent an alkylene group having 2 to 18 carbon atoms. l represents an arbitrary integer from 0 to 4, and m represents an arbitrary integer from 1 to 200. ]

According to the present invention, there are provided a water-soluble polymer suitable for a cement admixture, a cement admixture having excellent water-reducing performance, a cement composition having excellent fluidity, and concrete obtained by curing the cement composition.

[Polymer]
The present invention is a polymer containing a structural unit derived from the following general formula (I) and a structural unit derived from the following general formula (II), and this polymer is particularly excellent in water solubility and is a cement composition. Has excellent miscibility with respect to.

In the general formula ^{(I), R 1, R} 2, R 3 and ^{R 4} are each independently a hydrogen atom, a methyl group or an ethyl group, _{R a} represents an alkylene group having 2 to 18 carbon atoms. n represents an arbitrary integer from 0 to 3, o represents an arbitrary integer from 1 to 200, and p represents an arbitrary integer from 1 to 3.

In the general formula (I), the alkylene group having 2 to 18 carbon atoms includes an ethylene group, an n-propylene group, an n-butylene group, an n-pentylene group, an n-hexylene group, an n-heptylene group and an n-octylene. Examples thereof include a linear alkylene group such as a group, an n-nonylene group and an n-decylene group, a branched alkylene group such as a 2-methylpropylene group, a 2-methylhexylene group and a tetramethylethylene group, and the like. These may contain one kind or two or more kinds.

In the general formula (I), o is the average number of moles of _{oxyalkylene group (Ra O) added.} The average number of moles added is 1 to 200, preferably 1 to 80, more preferably 4 to 70, still more preferably 4 to 70, and particularly preferably 4 to 60. If o is less than 1, sufficient cement dispersion performance is not exhibited, which is not preferable. On the other hand, when o exceeds 200, the viscosity of the cement composition becomes high and it tends to be difficult to handle. In the present specification, the "average number of moles added" is the arithmetic mean value of the number of moles of the oxyalkylene group added in 1 mole of each component of the general formula (I) and the general formula (III) described later. Means. Further, when o is a number of 2 or more, two or more _{oxyalkylene groups represented by Ra} O in the general formula (I) are indispensably present in the same compound, but two or more plurality of oxys. When having an alkylene group, each may have any form such as random, block, and alternating.

^{In the general formula (I), R 1} , R ² and R can be introduced from the viewpoint that the solubility in water is good and two oxyalkylene groups can be introduced by one molecule while maintaining the reactivity of the double bond portion at the time of polymerization. ^{It is preferable that 4} is a hydrogen atom, R ³ is a methyl group, _Ra is an ethylene group, n is 1, and p is 2 or 3.

In order to introduce the structural unit derived from the general formula (I) into the polymer, it is preferable to use the compound represented by the following general formula (IV). By using this compound, it is possible to improve the productivity with excellent volumetric efficiency, and it is possible to introduce two oxyalkylene groups with one molecule while maintaining the reactivity of the double bond portion at the time of polymerization.

In general formula (IV), o represents any integer from 1 to 200, and p is 2 or 3.

In the general formula (II), R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom or a methyl group, and M is a group consisting of a hydrogen atom, a monovalent metal atom, a divalent metal atom and ammonium. Represents the one chosen. That is, the general formula (II) forms an ion pair.

In the general formula (II), examples of the monovalent metal atom include alkali metal atoms such as lithium, sodium and potassium, and examples of the divalent metal atom include alkaline earth metal atoms such as calcium and magnesium. Be done.

In the general formula (II), ammonium is a molecular monovalent cation containing a nitrogen atom and may contain a hydrogen atom. Examples of such ammonium include alkylammoniums such as methylammonium, ethylammonium, dimethylammonium, diethylammonium, trimethylammonium, and triethylammonium; ethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, and the like. Examples thereof include alkanolammonium such as hydroxyethyldiisopropanolamine, dihydroxyethylisopropanolamine, tetrakis (2-hydroxypropyl) ethylenediamine, and pentakis (2-hydroxypropyl) diethylenetriamine.

In the general formula (II), from the viewpoint of availability, M is preferably one selected from the group consisting of a hydrogen atom, a monovalent metal atom and a divalent metal atom, and is preferably a hydrogen atom or sodium. More preferably.

Specific examples of the unsaturated carboxylic acid-based monomer represented by the general formula (II) include acrylic acid, methacrylic acid, sodium acrylate, sodium methacrylate, ammonium acrylate, ammonium methacrylate, and the like. Two or more types may be used in combination.

As the unsaturated carboxylic acid-based monomer, (meth) acrylic acid is preferably used, and methacrylic acid is most preferably used. As these compounds, commercially available compounds may be used.

The present invention is a polymer containing a structural unit derived from the general formula (II) and a structural unit derived from the following general formula (III), and this polymer is particularly excellent in water solubility and is a cement composition. Has excellent miscibility with respect to.

In the general formula (III), R ⁸ and R ⁹ independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R _b and R _c independently represent an alkylene group having 2 to 18 carbon atoms. Represent. l represents an arbitrary integer from 0 to 4, and m represents an arbitrary integer from 1 to 200.

In the present invention, the examples and preferred embodiments of the general formula (II) are the same as those of the polymer containing the structural unit derived from the general formula (I) and the structural unit derived from the following general formula (II).

In the general formula (III), examples of the alkyl having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a pentyl group and a hexyl group.

In the general formula (III), the alkylene group having 2 to 18 carbon atoms includes an ethylene group, an n-propylene group, an n-butylene group, an n-pentylene group, an n-hexylene group, an n-heptylene group and an n-octylene. Examples thereof include a linear alkylene group such as a group, an n-nonylene group and an n-decylene group, a branched alkylene group such as a 2-methylpropylene group, a 2-methylhexylene group and a tetramethylethylene group, and the like. These may contain one kind or two or more kinds.

In the general formula (III) and the general formula (V) described later, m is the average number of moles of _{oxyalkylene groups (R b} O and R _{c O) added.} The average number of moles added is 1 to 200, preferably 1 to 80, more preferably 4 to 70, still more preferably 4 to 70, and even more preferably. It is a number from 4 to 60. If m is less than 1, sufficient cement dispersion performance is not exhibited, which is not preferable. On the other hand, when m exceeds 200, the viscosity of the cement composition becomes high and it tends to be difficult to handle. Each of the oxyalkylene groups represented by R _b O and R _c O may have any addition form such as random addition, block addition, and alternate addition.

In the general formula (III), from the viewpoint of having sufficient polymerizable property and introducing two oxyalkylene groups in one molecule, R ⁸ and R ⁹ have independently hydrogen atoms or 1 to 6 carbon atoms, respectively. Alkyl groups are preferable, hydrogen atoms or alkyl groups having 1 to 4 carbon atoms are more preferable, hydrogen atoms or alkyl groups having 1 to 2 carbon atoms are more preferable, and hydrogen atoms are even more preferable.

In the general formula (III), from the viewpoint of availability of raw materials, ^{it is preferable that R 8} and R ⁹ are hydrogen atoms, R _b and R _c are ethylene groups, and l is 2.

In order to introduce the structural unit derived from the general formula (III) into the polymer, it is preferable to use the compound represented by the following general formula (V). By using this compound, two oxyalkylene groups can be introduced per molecule while having sufficient polymerizable properties, and a polymer having a high oxyalkylene group density can be obtained.

In the general formula (V), R _b and R _c each independently represent an alkylene group having 2 to 18 carbon atoms. l represents an arbitrary integer from 0 to 4, and m represents an arbitrary integer from 1 to 200.

The monomer represented by the general formula (I) or the general formula (III) can be produced by various methods, and a typical production method is as follows.
Unsaturated diols having an alkenyl group with 2 to 10 carbon atoms such as 2- (1-methylethenyl) -1,3-propanediol and 3-methylene-1,5-pentanediol are mixed with potassium hydroxide and hydroxide. By adding 1 to 100 mol of an alkylene oxide having 2 to 18 carbon atoms in the presence of an alkaline catalyst such as sodium or an acid catalyst such as boron trifluoride or tin tetrachloride, the general formula (I) or the general formula ( The monomer represented by III) can be obtained.

In addition to the general formulas (I) and (II), the polymer of the present invention may further contain structural units derived from (III). By containing these structural units, a polymer having excellent water solubility can be obtained. can get.

The polymer of the present invention contains a component represented by the general formula (I) or the general formula (III) and an unsaturated carboxylic acid-based monomer represented by the general formula (II) as an essential component. It can be produced by copolymerization, but the production method is not limited to this. For example, instead of the monomer containing an unsaturated (poly) oxyalkylene chain, the monomer before adding the alkylene oxide, that is, unsaturated such as 2- (1-methylethenyl) -1,3-propanediol. Using an alcohol, this is copolymerized with an unsaturated carboxylic acid-based monomer in the presence of a polymerization initiator, and if necessary, other monomers copolymerizable with these monomers are further copolymerized. It can also be obtained by adding an average of 1 to 200 mol of the alkylene oxide. The above-mentioned polymerization reaction can be carried out by using a usual polymerization initiator, and can be carried out by a method such as polymerization in a solvent or bulk polymerization.

The polymerization in the above solvent can be carried out either continuously or in batches, and the solvent used at that time is water; lower alcohols such as methanol, ethanol and isopropyl alcohol; benzene, toluene, xylene, cyclohexane and normal. Aromatic or aliphatic hydrocarbons such as hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone are preferred. These may be used alone or in combination of two or more. From the solubility of the raw material monomer and the obtained polymer and the solubility of the polymer when used, it is preferable to use at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. ..

In the case of aqueous solution polymerization, as a radical polymerization initiator, for example, persulfate such as ammonium persulfate, sodium persulfate, potassium persulfate; hydrogen peroxide; 2,2'-azobis-2-methylpropion amidine hydrochloride and the like. Azoamidin compounds, cyclic azoamidin compounds such as 2,2'-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, and azonitrile compounds such as 2-carbamoylazoisobutyronitrile are started. Agents and the like are used, in which case alkali metal sulfites such as sodium hydrogen sulfite, metadibisulfites, sodium hypophosphate, Fe (II) salts such as molle salts, sodium hydroxymethanesulfinate dihydrate, hydroxyls. Accelerators such as amine hydrochloride, thiourea, L-ascorbic acid (salt), and erythorbic acid (salt) can also be used in combination. When hydrogen peroxide is used as the water-soluble polymerization initiator, it is preferably used in combination with an accelerator such as L-ascorbic acid (salt).

Further, for polymerization using a lower alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester compound or a ketone compound as a solvent, a peroxide such as benzoyl peroxide or lauroyl peroxide; a hydroperoxide such as cumene hydroperoxide; an azo; An azo compound such as bisisobutyronitrile is used as the polymerization initiator. At this time, an accelerator such as an amine compound can also be used in combination. Further, when a water-lower alcohol mixed solvent is used, it can be appropriately selected and used from the various polymerization initiators or combinations of the polymerization initiator and the accelerator described above. The polymerization temperature is appropriately determined depending on the solvent used and the polymerization initiator, but is usually 0 to 120 ° C.

The bulk polymerization uses a peroxide such as benzoyl peroxide or lauroyl peroxide; a hydroperoxide such as cumene hydroperoxide; an azo compound such as azobisisobutyronitrile as a polymerization initiator, and has a temperature of 50 to 200 ° C. It is done in.

The method of charging each monomer into the reaction vessel is not particularly limited, and the entire amount is initially charged into the reaction vessel in a batch, the entire amount is divided or continuously charged into the reaction vessel, and a part is initially charged into the reaction vessel. , The method of dividing the rest into the reaction vessel or continuously charging the rest may be used. Specific examples of the preferred charging method include the following methods (1) to (4).
(1) A method in which all of the monomers are continuously charged into the reaction vessel.
(2) A method in which all the monomers containing an unsaturated (poly) oxyalkylene chain are initially charged into the reaction vessel, and all the other monomers are continuously charged into the reaction vessel.
(3) A part of the monomer containing an unsaturated (poly) oxyalkylene chain is initially charged into the reaction vessel, and the rest of the monomer containing an unsaturated (poly) oxyalkylene chain and other single amounts. A method of continuously charging the entire body into a reaction vessel.
(4) A part of the monomer containing an unsaturated (poly) oxyalkylene chain and a part of other monomers are initially charged into the reaction vessel, and a simple substance containing an unsaturated (poly) oxyalkylene chain is charged. A method in which the remainder of the dimer and the rest of the other monomers are alternately added to the reaction vessel in several divided doses. Further, by continuously or stepwise changing the charging rate of each monomer into the reaction vessel during the reaction, the charging mass ratio of each monomer per unit time can be continuously or stepwise changed. A mixture of copolymers having different ratios of each structural unit in the polymer may be synthesized during the polymerization reaction. The radical polymerization initiator may be charged into the reaction vessel from the beginning, may be added dropwise to the reaction vessel, or these may be combined depending on the intended purpose.

A chain transfer agent can also be used in combination to control the molecular weight of the obtained polymer. Examples of the chain transfer agent include thiol-based chain transfer agents such as mercaptoethanol, thioglycerol, thioglycolic acid, 3-mercaptopropionic acid, thioapple acid, and 2-mercaptoethanesulfonic acid; secondary alcohols such as isopropyl alcohol; bisulfite. , Hypophosphate and its salts (sodium bisulfite, potassium hypophosphate, etc.), sulfite, hydrogen sulfite, nitionic acid, metabisulfite and its salts (sodium bisulfite, sodium bisulfite, nitione A known hydrophilic chain transfer agent such as a lower oxide of sodium bisulfite (sodium bisulfite, sodium bisulfite, etc.) and a salt thereof; can be used. Further, the use of a hydrophobic chain transfer agent is effective in improving the viscosity of the cement composition. Examples of the hydrophobic chain transfer agent include butane thiol, octane thiol, decane thiol, dodecane thiol, hexadecane thiol, octadecane thiol, cyclohexyl mercaptan, thiophenol, octyl thioglycolate, and octyl 3-mercaptopropionate having 3 or more carbon atoms. It is preferable to use a thiol-based chain transfer agent having a hydrocarbon group of. 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. Further, in order to adjust the molecular weight of the polymer, it is also effective to use a monomer having high chain transfer such as (meth) allylsulfonic acid (salt) as the above-mentioned other copolymerizable monomer. is there.

In the above polymerization, in order to obtain a polymer having a predetermined molecular weight with good reproducibility, it is necessary to allow the polymerization reaction to proceed stably. Therefore, in the case of solution polymerization, the dissolved oxygen concentration of the solvent used at 25 ° C. Is preferably 5 ppm or less. It is more preferably 0.01 to 4 ppm, further preferably 0.01 to 2 ppm, and most preferably 0.01 to 1 ppm. When nitrogen substitution or the like is performed after adding the monomer to the solvent, it is preferable that the dissolved oxygen concentration of the system including the monomer is within the above range.

The dissolved oxygen concentration of the solvent may be adjusted in the polymerization reaction tank, or the dissolved oxygen amount may be adjusted in advance. As a method for expelling oxygen in the solvent, the following (1) to (1) to ( The method of 5) is preferable.
(1) After pressure-filling an inert gas such as nitrogen in a closed container containing a solvent, the partial pressure of oxygen in the solvent is lowered by lowering the pressure in the closed container. The pressure in the closed container may be reduced under a nitrogen stream.
(2) The liquid phase portion is 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) The solvent contained in the container is bubbled with an inert gas such as nitrogen for a long time.
(4) After boiling the solvent once, it is cooled in an atmosphere of an inert gas such as nitrogen.
(5) A static mixer is installed in the middle of the pipe, and an inert gas such as nitrogen is mixed in the pipe that transfers the solvent to the polymerization reaction tank.

Each polymer obtained as described above can be used as it is by blending it with a cement admixture, but if necessary, it may be further neutralized with an alkaline substance. As the alkaline substance, inorganic salts such as hydroxides and carbonates of monovalent or divalent metals; ammonia; and organic amines are suitable. Further, after the reaction is completed, the concentration can be adjusted if necessary. After performing a copolymerization reaction using the corresponding unsaturated carboxylic acid ester-based monomer without using the unsaturated carboxylic acid-based monomer (general formula (II)) as the monomer component, the pH By adjusting the above, the ester-bonded portion of the structural unit derived from the unsaturated carboxylic acid ester-based monomer is partially hydrolyzed to form a structure derived from the unsaturated carboxylic acid-based monomer (for example, the general formula (for example, general formula (for example)). II)) can also be introduced into the polymer.

[Cement admixture]
The cement admixture of the present invention has excellent water-reducing performance by containing the polymer of the present invention. Further, if necessary, it may contain a non-polymerizable (poly) alkylene glycol having no alkenyl group, or the polymer of the present invention may be neutralized with an alkaline substance and used as a polymer salt. As such alkaline substances, inorganic substances such as hydroxides, chlorides and carbon salts of monovalent metals and divalent metals; ammonia; organic amines and the like are preferable.

When the polymer of the present invention is used as a cement admixture, the weight average molecular weight (Mw) of the polymer is 500 to 500,000 in terms of polystyrene by gel permeation chromatography (hereinafter referred to as "GPC"). In particular, it is preferably in the range of 5,000 to 300,000. If the weight average molecular weight is less than 500, the water reducing performance as a cement admixture is deteriorated, which is not preferable. On the other hand, if the weight average molecular weight exceeds 500,000, the water-reducing performance as a cement admixture and the ability to prevent slump loss are lowered, which is not preferable.

In addition, the polymer of the present invention can be used alone or as a mixture of two or more kinds as it is as a cement admixture. Further, the polymer of the present invention may be used as a main component in combination with other known cement admixtures. Examples of such known cement admixtures include conventional cement dispersants, air entraining agents, cement wetting agents, swelling agents, waterproofing agents, retarders, quick-setting agents, water-soluble polymer substances, thickeners, and agglomerates. Examples thereof include agents, drying shrinkage reducing agents, strength enhancers, hardening accelerators, defoaming agents and the like.

When a known cement dispersant is used, the compounding mass ratio of the polymer (salt) of the present invention and the known cement dispersant is 1/99 to 9% as a weight ratio (% by weight) in terms of solid content. 99/1 is preferable, 5/95 to 95/5 is more preferable, and 10/90 to 90/10 is even more preferable.

Examples of the known cement dispersant to be used in combination include polyalkylaryl sulfonates such as naphthalene sulfonate formaldehyde condensate; melamine formalin resin sulfonates such as melamine sulfonate formaldehyde condensate; aminoaryl sulfonic acid-. Aromatic aminosulfonates such as phenol-formaldehyde condensates; lignin sulfonates such as lignin sulfonates and modified lignin sulfonates; various sulfonates having sulfonic acid groups in molecules such as polystyrene sulfonates Examples thereof include cement dispersants such as acid-based dispersants.

Further, as the defoaming agent, known defoaming agents as exemplified in the following (1) to (2) are suitable.
(1) Oxyalkylene-based defoaming agent: Polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adduct; polyoxyalkylene alkyl ethers such as diethylene glycol heptyl ether; polyoxyalkylene acetylene ethers; (poly) ) Oxyalkylene fatty acid esters; polyoxyalkylene sorbitan fatty acid esters; polyoxyalkylene alkyl (aryl) ether sulfate esters; polyoxyalkylene alkyl phosphate esters; polyoxypropylene polyoxyethylene laurylamine (propylene oxides 1 to 20) Polyoxys such as amines derived from fatty acids (propylene oxide 1 to 20 mol additions, ethylene oxide 1 to 20 mol additions, etc.) obtained from hardened beef fat to which molar additions, ethylene oxide 1 to 20 mol additions, etc. Alkylenealkylamines; polyoxyalkyleneamide and the like.
(2) Defoamers other than oxyalkylene-based: Mineral oil-based, oil-based, fatty acid-based, fatty acid ester-based, alcohol-based, amide-based, phosphoric acid ester-based, metal soap-based, silicone-based defoaming agents.

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

The cement admixture of the present invention can be used for various hydraulic materials, that is, hydraulic materials other than cement such as cement and gypsum. A cement paste contains a hydraulic material, water, and the cement admixture of the present invention, and further contains fine aggregate (sand, etc.) and coarse aggregate (crushed stone, etc.) as needed. , Mortar, concrete and plaster are suitable.

[Cement composition]
Among the above hydraulic compositions, a cement composition using cement as a hydraulic material is the most common, and such a cement composition contains the cement admixture, cement and water of the present invention as essential components. It will be. Such a cement composition is also one of the present inventions.

The cements used in the cement composition of the present invention include Portoland cement (normal, early-strength, ultra-fast-strength, moderate heat, sulfate-resistant and low-alkali forms of each), various mixed cements (blast furnace cement, silica cement, etc.). Fly Ash Cement), White Portoland Cement, Alumina Cement, Ultra Fast Hard Cement (1 Clinker Fast Hard Cement, 2 Clinker Fast Hard Cement, Magnesium Phosphate Cement), Grout Cement, Oil Well Cement, Low Heat Cement (Low Heat Heat Type Cement) , Fly ash mixed low heat generation blast furnace cement, belite high content cement), ultra-high strength cement, cement-based solidifying material, eco-cement (cement manufactured from one or more of municipal waste incineration ash and sewage sludge incineration ash) Further, fine powders such as blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, limestone powder and the like may be added. In addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., aggregates include silica stone, clay, zirconite, high alumina, silicon carbide, graphite, chromium, chromog, magnesia. Fire-resistant aggregates such as, etc. can be used.

In the cement compositions of the present invention, the unit water amount per Part 1 m ^3, cement, fly ash and slag (hereinafter together these. Also referred to as "B") The total amount of, as well as water / B ratio The unit water amount is 100 to 185 kg / m ³ , the used B amount is 250 to 800 kg / m ³ , and the water / B ratio (mass ratio) is preferably 0.1 to 0.7, and more preferably the unit water amount is 120 to 175 kg. / ^{M 3} , amount of B used 270-800 kg / m ³ , water / B ratio (mass ratio) = 0.2 to 0.65, can be widely used from poor to rich, and has a large amount of unit B. It is effective for both high-strength cement and poorly mixed cement with a unit B amount of 300 kg / m ^{3 or less.}

The blending ratio of the cement admixture of the present invention in the cement composition of the present invention is 0 with respect to the total mass of cement, fly ash and slag, for example, when used for mortar or concrete using hydrohard cement. It is preferably 0.01 to 5.0%. This addition brings about various favorable effects such as reduction of unit water amount, increase of strength, and improvement of durability. If the above compounding ratio is less than 0.01%, the performance may be insufficient. On the contrary, even if a large amount exceeding 5.0% is used, the effect is substantially leveled off, which is disadvantageous in terms of economy. There is a risk of becoming. More preferably 0.02% or more, more preferably 2.0% or less, still more preferably 0.05% or more, and 1.0% or less, and adding an amount of such a ratio. do it. The preferable range of the blending ratio is more preferably 0.02 to 2.0%, and further preferably 0.05 to 1.0%.

The cement admixture of the present invention can be used in combination with those used as conventional cement dispersants, and can also be used in combination with a plurality of cement dispersants. When a conventional cement dispersant is used, the compounding mass ratio of the cement admixture of the present invention and the cement dispersant is uniquely determined by the difference in the type, compounding, test conditions, etc. of the cement dispersant. However, it is preferably 1 to 99/99 to 1, more preferably 5 to 95/95 to 5, and even more preferably 10 to 90/90 to 10.

[concrete]
The cement composition of the present invention is also effective for ready-mixed concrete, concrete for secondary concrete products (precast concrete), centrifugally formed concrete, vibration compaction concrete, steam curing concrete, sprayed concrete, etc. High fluidity of fluidized concrete (concrete with slump value of 22 to 25 cm), high fluidized concrete (concrete with slump value of 25 cm or more and slump flow value of 50 to 70 cm), self-filling concrete, self-leveling material, etc. It is also effective for mortar and concrete.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

Various materials used in Production Examples, Examples and Comparative Examples are shown below.
2- (1-methylethenyl) -1,3-propanediol: purity 91%, J. AM. CHEM. It can be produced by the production method described in Soc., 104,555 (1984).
3-Methylene-1,5-pentanediol: 95% pure, can be produced by the production method described in International Publication No. 2018/143104.
-3-Methyl-3-butene-1-ol: manufactured by Kuraray Co., Ltd., purity 98%
・ Ethylene oxide: manufactured by Nippon Catalyst Co., Ltd. ・ Sodium hydroxide: manufactured by Wako Pure Chemical Industries, Ltd. ・ Hydrogen hydrogen solution: manufactured by Wako Pure Chemical Industries, Ltd. ・ Acrylic acid: manufactured by Wako Pure Chemical Industries, Ltd. Made by 3-Mercaptopropionic Acid Co., Ltd .: Made by Tokyo Kasei Kogyo Co., Ltd.

In each example, ^{1 1} H-NMR, GPC, HPLC analysis was performed under the following conditions.
[GPC analysis conditions]
Analytical instrument: GPC-8020 (manufactured by Tosoh Corporation)
Detector: RI-8020 (manufactured by Tosoh Corporation)
Columns used: Shodex GPC KF-802, KF-802.5, KF-803L, KF-G (guard column) (manufactured by Showa Denko KK)
Analytical conditions Developing solution: THF
Flow rate: 0.9 mL / min
Column temperature: 40 ° C
Sample injection volume: 30 μL
Analysis: GPC-modelII (manufactured by Tosoh Corporation)
[ ^{1 1} H-NMR analysis]
Analytical instrument: ULTRA SHIELD 400 PLUS (manufactured by Bruker)
Solvent: Deuterated chloroform Number of integrations 120 times at room temperature Number of oxyalkylene groups added:
The number of oxyalkylenes added by determining the molar ratio from the integral ratio of each component derived from the unsaturated alcohol and the oxyalkylene group of the produced monomers and converting it into a mass ratio based on the molecular weight of each component. Asked.
[HPLC analysis]
Analytical instrument: Nexus X2 (manufactured by Shimadzu Corporation)
Column used: Mightysil RP-18 (length 250 mm, inner diameter 4.6 mm, particle size 5 μm) (manufactured by Kanto Chemical Co., Inc.)
Detector: SPD-M30A (manufactured by Shimadzu Corporation)
Developing solution: A solution in which 600 g of water, 400 g of methanol, and 0.8 g of phosphoric acid are mixed Analytical conditions: Flow rate 1.0 mL / min
Column temperature: 40 ° C
Sample injection volume: 100 μL

[Manufacturing Example 1] (IA)
30 g of unsaturated alcohol (2- (1-methylethenyl) -1,3-propanediol) and 0.5 g of sodium hydroxide as a catalyst in a SUS high-pressure reactor equipped with a thermometer, agitator, nitrogen and ethylene oxide introduction tubes. Was charged, the inside of the reaction vessel was replaced with nitrogen under stirring, and the internal temperature was raised to 100 ° C. Then, 910 g of ethylene oxide was introduced into the reactor while maintaining 100 ° C. for 6 hours, then heated and stirred for 2 hours, and then the reaction was terminated, and the unit amount represented by the following formula (IA) was completed. I got a body. ¹ The measurement results of 1 H-NMR are shown below.

_{^{1 H NMR (400MHz, CDCl 3}} ) δ1.8ppm (CH 2 = C (C H 3) -), 2.6ppm (CH 2 = C (CH 3) C H -), 3.5~3.9ppm ( oxyalkylene _{group), 4.8~4.9ppm (C H 2 =} C (CH 3) -). The integral ratio of the positions of 3.5 to 3.9 ppm and 4.8 to 4.9 ppm is 312. Since the oxyalkylene group has 4 protons and 2 OH chains, an average of 80 mol of ethylene oxide was added to the unsaturated alcohol as a raw material.

[Manufacturing Example 2] (III-A)
30 g of 3-methylene-1,5-pentanediol was used instead of 2- (1-methylethenyl) -1,3-propanediol as the unsaturated alcohol, and 0.3 g of sodium hydroxide was used as the catalyst. A monomer represented by the following (III-A) was obtained by the same procedure as in Production Example 1 except that the amount of ethylene oxide used was changed to 600 g.

_{^{1 H NMR (400MHz, CDCl 3}} ) δ2.4ppm (CH 2 = C (C H 2 -) 2 -), 3.5~3.9ppm ( oxyalkylene _{group), 4.8ppm (C H 2 =} C ( CH ₂ ) _2- ). The integral ratio of the positions of 3.5 to 3.9 ppm and 4.8 ppm is 209. Since the oxyalkylene group has 4 protons and two OH chains, an average of 50 mol of ethylene oxide was added to one molecule of unsaturated alcohol as a raw material.

[Manufacturing Example 3]
The procedure was the same as in Production Example 1 except that 50 g of 3-methyl-3-butene-1-ol was used as the unsaturated alcohol, 0.7 g of sodium hydroxide was used as the catalyst, and 1304 g of ethylene oxide was used as the catalyst. ) Was obtained.

_{^{1 H NMR (400MHz, CDCl 3}} ) δ1.8ppm (CH 2 = C (C H 3) -), 2.4ppm (CH 2 = C (CH 3) C H 2 -), 3.5~3.9ppm (oxyalkylene _{group), 4.7~4.8ppm (C H 2 =} C (CH 2) 2 -). The integral ratio of the positions of 3.5 to 3.9 ppm and 4.7 to 4.8 ppm is 202. Since the oxyalkylene group has 4 protons and one OH chain, an average of 50 mol of ethylene oxide was added to the unsaturated alcohol as a raw material based on these integral ratios.

The properties and solubility of the monomers obtained in Production Examples 1 to 3 at 25 ° C. and 50 ° C. in water were evaluated. The results are shown in Table 1.

From Table 1, the monomer obtained in Production Example 1 or Production Example 2 has a larger amount of dissolution in water at 25 ° C. than the monomer obtained in Production Example 3, and at an arbitrary ratio at 50 ° C. It can be seen that it mixes with water. From this result, the polymer using the monomer of Production Example 1 or Production Example 2 is superior in solubility in water to the polymer using the monomer of Production Example 3 which has been conventionally used. Can be easily guessed. Therefore, by using these polymers having excellent solubility in water as a cement admixture, the amount of water used to prepare the cement admixture can be reduced, and the cement composition using this cement admixture has volumetric efficiency. It is suggested that it is excellent and highly productive.

Subsequently, a polymer was produced using the monomers obtained with reference to Production Examples 1, 2 and 3, and the obtained polymer was evaluated as a cement admixture. In order to meet the conditions, the amount of ion-exchanged water in each example was the same.

[Example 1]
A glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser was replaced with nitrogen, and 29.3 g of ion-exchanged water and 98.7 g of the monomer obtained in Production Example 1 were charged. The temperature is raised to 60 ° C. 4.8 g of a 4% aqueous hydrogen peroxide solution was added thereto. Next, an aqueous solution obtained by diluting 8.2 g of acrylic acid with 1.6 g of ion-exchanged water was added dropwise over 4 hours. At the same time, an aqueous solution prepared by dissolving 0.12 g of L-ascorbic acid and 0.12 g of 3-mercaptopropionic acid in 31.8 g of ion-exchanged water was added dropwise over 4.5 hours. After completion of the dropping, stirring was continued for 1 hour to complete the polymerization reaction. Then, at a temperature equal to or lower than the polymerization reaction temperature, the reaction solution was neutralized to pH 6.5 with a 30% aqueous solution of sodium hydroxide to obtain an aqueous solution of a polycarboxylic acid-based copolymer having a weight average molecular weight (Mw) of 30,000. It was. By HPLC analysis, the conversion rate of the monomer at this time was 47%, and the conversion rate of acrylic acid was 99.9% or more. The obtained aqueous solution was adjusted by adding diluted water so that the concentration of the active ingredient was 10.0%.
Here, the active ingredient concentration is obtained by multiplying the active ingredient ratio calculated by using the reaction rates of the unsaturated carboxylic acid-based monomer which is a polymerizable monomer and the monomer of the production example by the solid content. It is a value and is a value defined by the following formula. The amount of the following monomers used is the amount of each monomer used in the polymerization. The solid content is an aqueous solution of the polycarboxylic acid-based copolymer obtained in Examples, which is distilled off under reduced pressure and dried.
Active ingredient concentration = [(a + b) / (A + B)] x NV
The abbreviations in the above formula are as follows.
A: Amount of unsaturated carboxylic acid-based monomer used B: Amount of monomer used in Production Example a: Amount of unsaturated carboxylic acid-based monomer used x conversion rate b: Use of monomer in Production Example Amount x conversion rate NV: solid content

[Example 2]
Instead of 98.7 g of the monomer obtained in Production Example 1, a monomer in which an average of 100 mol of ethylene oxide was added to 1 mol of 2- (1-methylethenyl) -1,3-propanediol (that is, production). A polycarboxylic acid system having a weight average molecular weight (Mw) of 26700 in the same manner as in Example 1 except that 98.7 g of a monomer containing twice the amount of ethylene oxide was used with respect to the monomer of Example 2. An aqueous solution of the copolymer was obtained. By HPLC analysis, the conversion rate of the monomer at this time was 49%, and the conversion rate of acrylic acid was 99.9% or more. The obtained aqueous solution was adjusted by adding diluted water so that the concentration of the active ingredient was 10.0%.

[Comparative Example 1]
The weight average molecular weight (Mw) was 25500 in the same manner as in Example 1 except that 98.7 g of the monomer obtained in Production Example 3 was used instead of 98.7 g of the monomer obtained in Production Example 1. An aqueous solution of the polycarboxylic acid-based copolymer of the above was obtained. By HPLC analysis, the conversion rate of the monomer at this time was 58%, and the conversion rate of acrylic acid was 99.9% or more. The obtained aqueous solution was adjusted by adding diluted water so that the concentration of the active ingredient was 10.0%.

Next, the cement admixture (Ad) was adjusted using the aqueous solutions of the copolymers produced in Examples 1, 2 and Comparative Example 1, and the physical properties of the cement using this cement admixture were measured. ..

As the cement (C), ordinary Portland cement (density 3.16 g / cm ³ ) manufactured by Taiheiyo Cement Co., Ltd. was used. As the fine aggregate (S), land sand from the Oi River system in Shizuoka Prefecture (surface dry density 2.66 g / cm ³ ) was used. As the coarse aggregate (G), sandstone crushed stone 2005 (surface dry density 2.66 g / cm ³ ) produced in Ome City, Tokyo was used. As the mixing water (W), tap water from Chigasaki City, Kanagawa Prefecture was used. The aggregate used in the test was adjusted so that the surface water content of the fine aggregate was 1% or less and the coarse aggregate was in a surface dry and saturated state. All the materials used were stored in a constant temperature and humidity chamber at 20 ° C., and were taken out and used immediately before use. The slump flow was based on JIS A 1150: 2014 “Concrete slump flow test method”. The slump was based on JIS A 1101: 2014 “Concrete slump test method”.
The concrete was kneaded by using a forced kneading mixer pan type having a capacity of 55 L and following the procedure shown below. The amount of concrete mixed was 30 L.
Fine aggregate (half amount), cement, and fine aggregate (half amount) are added, and after 10 seconds, dry kneading is performed, and then water and an admixture are added. The mixture was kneaded for 30 seconds, scraped off, coarse aggregate was added, and the mixture was further kneaded for 90 seconds, and then discharged and measured.

The compounding ratio of concrete is shown below.

The retention rate defined as the value obtained by dividing the flow value after 60 minutes by the flow value at the initial 0 minutes was used as an index, and the retention was evaluated based on the following evaluation criteria. The higher the retention rate value, the better the retention.
Retention evaluation criteria Evaluation A: Retention rate is 50% or more Evaluation X: Retention rate is 25% or more and less than 50%

It can be seen that Examples 3 and 4 show a higher value as the flow retention rate as compared with Comparative Example 2 which is a conventional cement admixture.

Claims (11)

A polymer containing a structural unit derived from the following general formula (I) and a structural unit derived from the following general formula (II).

[Expressed in the general formula ^{(I), R 1, R} 2, R 3 and ^{R 4} are each independently a hydrogen atom, a methyl group or an ethyl group, _{R a} represents an alkylene group having 2 to 18 carbon atoms. n represents an arbitrary integer from 0 to 3, o represents an arbitrary integer from 1 to 200, and p represents an arbitrary integer from 1 to 3. ]

[In general formula (II), R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom or a methyl group, and M is a group consisting of a hydrogen atom, a monovalent metal atom, a divalent metal atom and ammonium. Represents at least one selected from. ] A polymer containing a structural unit derived from the general formula (II) and a structural unit derived from the following general formula (III).

[In the general formula (III), R ⁸ and R ⁹ independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R _b and R _c independently represent an alkylene group having 2 to 18 carbon atoms, respectively. Represents. l represents an arbitrary integer from 0 to 4, and m represents an arbitrary integer from 1 to 200. ] The polymer according to claim 1, further comprising a structural unit derived from the general formula (III). The polymer according to any one of claims 1 to 3, wherein M is at least one selected from the group consisting of a hydrogen atom, a monovalent metal atom and a divalent metal atom in the general formula (II). In the general formula (I), R ¹ , R ² and R ⁴ are hydrogen atoms, R ³ is a methyl group, _Ra is an ethylene group, n is 1, and p is 2 or 3. , The polymer according to any one of claims 1, 3 and 4. The polymer according to any one of claims 2 to 5, wherein in the general formula (III), R ⁸ and R ⁹ are hydrogen atoms, R _b and R _{c are ethylene groups, and l is 2.} A cement admixture comprising the polymer according to any one of claims 1 to 6. A cement composition comprising the cement admixture according to claim 7. A concrete obtained by hardening the cement composition according to claim 8. A compound represented by the following general formula (IV).

[In general formula (IV), o represents an arbitrary integer from 1 to 200, and p is 2 or 3. ] A compound represented by the following general formula (V).

[In the general formula (V), R _b and R _c each independently represent an alkylene group having 2 to 18 carbon atoms. l represents an arbitrary integer from 0 to 4, and m represents an arbitrary integer from 1 to 200. ]