JP2012144434A - Cement admixture and cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cement admixture showing high dispersibility, excellent in slump retention, capable of developing strength at an early stage, and to provide a cement composition containing such a cement admixture.SOLUTION: This cement admixture contains as an indispensable component, a copolymer containing a structural unit (I) originated in an unsaturated polyalkylene glycol ether-based monomer (a) and a structural unit (II) originated in an unsaturated monocarboxylic acid-based monomer (b), wherein the copolymer satisfies a specific condition.

Description

The present invention relates to a cement admixture and a cement composition.

Cement paste in which water is added to cement, mortar in which fine aggregate sand is mixed, and pebbles in coarse aggregate are mixed, and concrete with improved fluidity by cement admixture is a variety of structural materials Etc. are used in large quantities. In such concrete, the demand for secondary concrete products (precast) is increasing mainly in Europe and the United States. Secondary concrete products are made by pouring concrete into the formwork at the factory. And the concrete member made will be transported to the site and assembled. In such a concrete secondary product manufacturing method, for the purpose of increasing the productivity in the factory, it is required to remove the mold from the mold at an early stage. With ordinary admixtures, the degree of cure delay is large. , It takes a long time to demold. In general, steam curing is performed in a factory, but even in such a case, it is required to increase the rotation of the mold and improve the productivity.

Even in the field of ready-mixed concrete, if the mold can be removed from the mold quickly after placing the concrete, it will be possible to move quickly to the next process. There is a need for such cement admixtures. In addition, hardening of cement starts during the placement of ready-mixed concrete, and impairing workability lowers work efficiency, so long working time is secured (retainability) and high early strength can be developed after the start of hardening. It is also required to make it.

As conventional cement admixtures, various polycarboxylic acid cement admixtures have been proposed (see, for example, Patent Documents 1 to 4). However, there was room for further improvement in terms of early strength and higher retention.

JP 2001-220417 A JP 2002-121055 A JP 2002-121056 A JP 2004-519406 A

The present invention has been made in view of the above situation, and includes a cement admixture that exhibits high dispersibility, is excellent in slump retention, and can develop strength at an early stage, and such a cement admixture. An object of the present invention is to provide a cement composition.

The inventors of the present invention have made various studies on cement admixtures, and first noticed that the polycarboxylic acid-based copolymer can exhibit water-reducing performance with respect to the cement composition and the like. In the copolymer, when it contains a structural unit derived from an unsaturated polyalkylene glycol ether monomer more than a specific ratio, it has been found that early strength development is good and it can also exhibit slump retention. It was. That is, it is conceived that the above-mentioned problem can be solved by specifying the mass proportion of the structural unit in the copolymer according to the type of the structural unit derived from the unsaturated polyalkylene glycol ether monomer. The present invention has been achieved.

That is, the present invention relates to a structural unit (I) derived from an unsaturated polyalkylene glycol ether monomer (a) represented by the following general formula (1) and an unsaturated monocarboxylic acid represented by the following general formula (2). A cement admixture containing, as an essential component, a copolymer comprising a structural unit (II) derived from a system monomer (b), wherein the copolymer has the following conditions (a), (b ) And (c).
(A) When Y in General Formula (1) represents an alkenyl group having 2 to 3 carbon atoms, the structural unit (I) contained in 100% by mass of the copolymer is 90% by mass or more.
(B) When Y in the general formula (1) represents an alkenyl group having 4 to 8 carbon atoms and the average addition mole number n of the oxyalkylene group is less than 80, the copolymer contained in 100% by mass of the copolymer The structural unit (I) is 92% by mass or more.
(C) When Y in the general formula (1) represents an alkenyl group having 4 to 8 carbon atoms and the average addition mole number n of the oxyalkylene group is 80 or more, the copolymer contained in 100% by mass of the copolymer The structural unit (I) is 94% by mass or more.

(In General Formula (1), Y represents an alkenyl group having 2 to 8 carbon atoms. T is the same or different and represents an alkylene group having 1 to 5 carbon atoms or an aryl group having 6 to 9 carbon atoms. R ¹ O represents one or more of oxyalkylene groups having 2 to 18 carbon atoms, m represents 0 or 1, n represents the average number of moles added of the oxyalkylene group, and 1 to 500 Represents the number of

(In General Formula (2), R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or a methyl group. M represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or Represents an organic amine group.)

The present invention is also a cement composition comprising the cement admixture, cement and water as essential components.
The present invention is described in detail below.

The cement dispersant of the present invention comprises the structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) and the unsaturated compound represented by the general formula (2). A copolymer containing the structural unit (II) derived from the monocarboxylic acid monomer (b) and satisfying any of the above-mentioned conditions (a), (b) and (c). is there. Furthermore, one or more copolymers that satisfy the above conditions (a), (b), or (c) may be mixed and used.

In the general formula (1), the number of carbon atoms of the alkenyl group represented by Y is suitably 2-8, but more preferably 5 or less. Examples of the alkenyl group having 2 to 8 carbon atoms include vinyl group, allyl group, methallyl group, 3-butenyl group, 3-methyl-3-butenyl group, 3-methyl-2-butenyl group, 2-methyl-3- A butenyl group, a 2-methyl-2-butenyl group, and a 1,1-dimethyl-2-propenyl group are preferable. Among these, an allyl group, a methallyl group, and a 3-methyl-3-butenyl group are preferable.

T in the general formula (1) is the same or different and represents an alkylene group having 1 to 5 carbon atoms or an aryl group having 6 to 9 carbon atoms, and m represents 0 or 1.
In the general formula (1), and the number of carbon atoms of ^{R 1} in ^the oxyalkylene group ^{R 1} O, but 2 to 18 are suitable, preferably from 2 to 8, 2 to 4 is more preferred. Further, any two or more alkylene oxide adducts selected from ethylene oxide, propylene oxide, butylene oxide, styrene oxide and the like can be used in any of random addition, block addition, alternating addition, and the like. In order to secure a balance between hydrophilicity and hydrophobicity, it is preferable to include an oxyethylene group as an essential component in the oxyalkylene group, and 50 mol% or more of the oxyethylene group is 100 mol% or more of the oxyethylene group. More preferably, 90 mol% or more is more preferably an oxyethylene group.

In the above general formula (1), the average addition mole number n of the oxyalkylene group is suitably 1 to 500. The smaller the average number of added moles, the lower the hydrophilicity of the resulting polymer and the lower the dispersion performance. When it exceeds 500, the copolymerization reactivity tends to decrease. It is preferably 2 or more, more preferably 5 or more, still more preferably 10 or more, particularly preferably 15 or more, most preferably 20 or more, and 300 or less. Moreover, as a suitable range, 2-500 are preferable, More preferably, it is 5-500, More preferably, it is 10-500, Most preferably, it is 15-500, Most preferably, it is 20-300.
The unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) is a combination of two or more different in the range where the average added mole number n of the oxyalkylene group is 1 to 500. May be.

Examples of the unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) include polyalkylene glycol vinyl ethers and polyalkylene glycol allyl ethers. More specifically, The compound which added 1-500 mol of alkylene oxides to unsaturated alcohols, such as allyl alcohol, can be mentioned, These 1 type (s) or 2 or more types can be used.

In the general formula (2), M represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or an organic amine group (protonated organic amine). Examples of the monovalent metal atom include Lithium, sodium, potassium and the like are preferable, and the divalent metal atom is preferably a divalent metal atom such as an alkaline earth metal atom such as calcium or magnesium. Moreover, as an organic amine group, alkanolamine groups, such as an ethanolamine group, a diethanolamine group, a triethanolamine group, and a triethylamine group are suitable, for example.

Examples of the unsaturated monocarboxylic acid monomer (b) represented by the general formula (2) include acrylic acid, methacrylic acid, crotonic acid, or monovalent metal salts, divalent metal salts, and ammonium salts thereof. , Organic amine salts, and the like, and one or more of these can be used. Among these, acrylic acid, methacrylic acid or a salt thereof is particularly preferable.

In the present invention, the unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (1) and the unsaturated monocarboxylic acid monomer (b) represented by the general formula (2) In order for the polymer obtained by copolymerizing the monomer component to be contained to exhibit high early strength, the mass ratio of the monomer (a) contained in the actually obtained copolymer must be large. desired. Many of the unsaturated polyalkylene glycol ether monomers (a) represented by the general formula (1) have low homopolymerization, and the reaction rate after polymerization does not reach 100%. Since it often remains, the composition of the charge and the composition of the actually obtained copolymer may differ greatly. Performances such as early strength greatly depend on the composition of the actually obtained copolymer rather than the charged composition.
The mass ratio of the monomer described below indicates the mass composition (actual composition) in the actually obtained copolymer. Moreover, the measuring method of the mass composition in the actually obtained copolymer is mentioned later.

(A) When Y in the general formula (1) is an alkenyl group having 2 to 3 carbon atoms, the structural unit (I) contained in 100% by mass of the actually obtained copolymer is 90%. It is suitable that it is at least mass%. If it is less than 90% by mass, the early strength development is not sufficient, and the slump retention may not be sufficiently improved. Preferably it is 91 mass% or more, More preferably, it is 92 mass% or more, More preferably, it is 93 mass% or more.

(B) When Y in the general formula (1) represents an alkenyl group having 4 to 8 carbon atoms and the average number of added moles n of the oxyalkylene group is less than 80, the actually obtained copolymer 100 The mass composition of the structural unit (I) contained in the mass% is suitably 92 mass% or more. If it is less than 92% by mass, as in the case of the above-mentioned condition (a), the early strength development is not sufficient, and the slump retention may not be sufficiently improved. Preferably it is 92.5 mass% or more, More preferably, it is 93 mass% or more, More preferably, it is 93.5 mass% or more.

(C) When Y in the general formula (1) represents an alkenyl group having 4 to 8 carbon atoms and the average addition mole number n of the oxyalkylene group is 80 or more, the actually obtained copolymer 100 The mass composition of the structural unit (I) contained in the mass% is 94 mass% or more. If it is less than 94% by mass, the early strength development is not sufficient as in the case described above, and the slump retention may not be sufficiently improved. Preferably it is 94.5 mass% or more.

Here, when the average addition mole number n of the oxyalkylene group increases, the mole number of the unsaturated polyalkylene glycol ether monomer (a) at the same mass ratio decreases. That is, the charge ratio (mass ratio) of the unsaturated polyalkylene glycol ether monomer (a) and the unsaturated monocarboxylic acid monomer (b) is large and small in average addition mole number n. ) Are the same, but when n is large, the ratio of the number of moles of the monomer (b) and the monomer (a) increases, so that the polymerization rate (reaction rate) increases. When the ratio is small, the ratio of the number of moles is small, so the polymerization rate (reaction rate) is low.
In the present invention, from such an aspect, the case of the above condition (b) and the case of the condition (c) are specified separately, but included in 100% by mass of the actually obtained copolymer. Only when the mass composition of the structural unit (I) is 92% by mass or more in the above condition (b) and 94% by mass or more in the above condition (c), high dispersibility is exhibited and the slump is retained. The effect of this invention that it is excellent in property and can express intensity | strength at an early stage can be exhibited.

In the present invention, the unsaturated polyalkylene glycol ether monomer (a) is preferably obtained by adding an alkylene oxide to an unsaturated alcohol having an alkenyl group represented by Y. However, when Y is an alkenyl group having 2 to 3 carbon atoms, that is, when the unsaturated alcohol is allyl alcohol, vinyl alcohol or the like, when Y is an alkenyl group having 4 to 8 carbon atoms, That is, the polymerization rate (reaction rate) is lower than when the unsaturated alcohol is methallyl alcohol or 3-methyl-3-buten-1-ol. Therefore, when Y is an alkenyl group having 2 to 3 carbon atoms, the proportion of the monomer (a) in the actual composition tends to be smaller than when Y is an alkenyl group having 4 to 5 carbon atoms. is there.
In the present invention, from such an aspect, the case of the above condition (a) is distinguished from the case of the condition (b) and the condition (c). Only when the mass composition of the structural unit (I) contained in the mass% is 90 mass% or more in the above condition (a), similarly to the above conditions (b) and (c), high dispersibility is obtained. In addition, the effect of the present invention can be exhibited that it is excellent in slump retention and can exhibit strength at an early stage.

As the copolymer essential for the cement admixture of the present invention, in addition to the structural unit (I) and the structural unit (II), the copolymer with the monomer (a) and / or the monomer (b) is used. It may contain the structural unit (III) derived from the polymerizable monomer (c).
As such a monomer (c), 1 type (s) or 2 or more types, such as the following compounds, can be used, for example.
Unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid and the like, and their monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts; the above unsaturated dicarboxylic acids and the number of carbon atoms Half esters and diesters with 1 to 30 alcohols; half amides and diamides of the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms; and alkylene oxides having 2 to 18 carbon atoms on the alcohols and amines. Half ester and diester of alkyl (poly) alkylene glycol added with 1 to 500 moles and the above unsaturated dicarboxylic acids; 2 moles of the above unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or addition of these glycols 2 Half-ester and die with ~ 500 polyalkylene glycols Unsaturated monocarboxylic acids such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, glycidyl (meth) acrylate, methyl crotonate, ethyl crotonate, propyl crotonate, and 1 carbon atom Esters with -30 alcohols; alkoxy (poly) alkylene glycols obtained by adding 1 to 500 moles of alkylene oxides having 2 to 18 carbon atoms to alcohols having 1 to 30 carbon atoms, and unsaturated monomonos such as (meth) acrylic acid Esters with carboxylic acids; number of carbon atoms to unsaturated monocarboxylic acids such as (meth) acrylic acid, such as (poly) ethylene glycol monomethacrylate, (poly) propylene glycol monomethacrylate, (poly) butylene glycol monomethacrylate 2-18 Alky 1-500 mole adducts of oxides; half amides of maleamic acid and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 moles of addition of these glycols; triethylene glycol di (meth) acrylate , (Poly) alkylene glycol di (meth) acrylates such as (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate; hexane Polyfunctional (meth) acrylates such as diol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate; triethylene glycol dimaleate, polyethylene glycol (Poly) alkylene glycol dimaleates such as recall dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth) acryloxy- 2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutyl sulfonate, (meth) acrylamide Unsaturated sulfonic acids such as methylsulfonic acid, (meth) acrylamide ethylsulfonic acid, 2-methylpropanesulfonic acid (meth) acrylamide, and styrenesulfonic acid, and monovalent metal salts, divalent metal salts thereof, Moniumu salts, organic amine salts;

Amides of unsaturated monocarboxylic acids and amines having 1 to 30 carbon atoms such as methyl (meth) acrylamide; vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene; Alkanediol mono (meth) acrylates such as 4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate; butadiene, isoprene, 2- Dienes such as methyl-1,3-butadiene and 2-chloro-1,3-butadiene; (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) Unsaturated amides such as acrylamide; (meth) acrylonitrile, α-chloroa Unsaturated cyanides such as acrylonitrile; unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, (meta ) Unsaturated amines such as dimethylaminopropyl acrylate, dibutylaminoethyl (meth) acrylate, vinylpyridine; divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate; (meth) allyl alcohol, glycidyl Allyls such as (meth) allyl ether; Vinyl ethers or allyl ethers such as methoxypolyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether; Dimethylsiloxanepropylaminomaleamic acid, polydimethylsiloxaneaminopropylaminomaleamic 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);
Among these, unsaturated dicarboxylic acid monomers such as maleic acid are preferred as the monomer (c) having a carboxyl group other than the unsaturated monocarboxylic acid monomer (b).

The copolymer which is an essential component of the cement admixture of the present invention can be easily obtained by, for example, copolymerizing the monomer component in the presence of a polymerization initiator, but only in such a form. It is not limited. For example, instead of the monomer (a), a monomer before addition of an alkylene oxide, that is, an unsaturated alcohol such as allyl alcohol is used, and this monomer (b) is added in the presence of a polymerization initiator. (If necessary, another monomer (c) copolymerizable with these monomers may be further copolymerized), and then an average of 1 to 500 moles of alkylene oxide is added. The copolymer of the present invention can also be obtained by the method.

The copolymerization for obtaining the copolymer can be performed by a known method such as solution polymerization or bulk polymerization. The solution polymerization can be carried out batchwise or continuously, and the solvent used in this case is water; alcohol such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, cyclohexane, n-hexane, etc. Aromatic or aliphatic hydrocarbons; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; cyclic ether compounds such as tetrahydrofuran and dioxane; and the like. From the viewpoint of solubility, 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, and among these, it is more preferable to use water as a solvent because the solvent removal step can be omitted. .

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- Azoamidine compounds such as 2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, and azonitriles such as 2-carbamoylazoisobutyronitrile Water-soluble azo initiators such as compounds are used. In this case, alkali metal sulfites such as sodium hydrogen sulfite, metabisulphite, sodium hypophosphite, Fe (II) salts such as Mole salt, hydroxymethanesulfine Acid sodium dihydrate, hydroxylamine hydrochloride, thiourea, L-ascorbic acid (salt), erysol It can also be used in combination accelerator such as phosphate (salt). Among these, a combination of hydrogen peroxide and an accelerator such as L-ascorbic acid (salt) is preferable.

For solution polymerization using a lower alcohol, aromatic or aliphatic hydrocarbon, ester compound, or ketone compound as a solvent, peroxides such as benzoyl peroxide, lauroyl peroxide, sodium peroxide; t-butyl hydroperoxide, Hydroperoxides such as 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.
Further, 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.

When performing the above bulk polymerization, as radical polymerization initiators, peroxides such as benzoyl peroxide, lauroyl peroxide and sodium peroxide; hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; azobisisobuty An azo compound such as ronitrile is used.

The reaction temperature during the copolymerization is not particularly limited. For example, when persulfate is used as the initiator, the reaction temperature is suitably in the range of 40 to 90 ° C, preferably in the range of 42 to 85 ° C. The range of 45-80 degreeC is more preferable. Further, when hydrogen peroxide and L-ascorbic acid (salt) as a promoter are combined to form an initiator, the reaction temperature is suitably in the range of 30 to 90 ° C, preferably in the range of 35 to 85 ° C, 40 A range of ˜80 ° C. is more preferable.
Although the polymerization time in the case of the said copolymerization is not specifically limited, For example, the range of 0.5 to 10 hours is suitable. If the polymerization time is too long or too short from this range, the polymerization rate and productivity are lowered, which is not preferable. The range is preferably 0.5 to 8 hours, more preferably 1 to 6 hours.

It is preferable that the usage-amount of all the monomer components in the case of the said copolymerization is 30-95 mass% with respect to 100 mass% of all the raw materials containing another raw material. In particular, if the amount of all the monomer components used is too lower than this range, the polymerization rate and productivity may be lowered. Preferably it is 40-93 mass%, More preferably, it is 50-90 mass%, More preferably, it is 60-90 mass%.

The method of charging each monomer into the reaction vessel is not particularly limited, a method in which the entire amount is initially charged into the reaction vessel, a method in which the entire amount is divided or continuously charged into the reaction vessel, and a part is initially in the reaction vessel. Any of the methods may be employed in which the remainder is divided into the reaction vessel or continuously charged. Specifically, a method in which the total amount of monomer (a) and the total amount of monomer (b) are continuously charged into the reaction vessel, a part of monomer (a) is initially charged into the reaction vessel, A method in which the remainder of the monomer (a) and the entire amount of the monomer (b) are continuously charged into the reaction vessel, a part of the monomer (a) and a part of the monomer (b) in the reaction vessel In the initial stage, and the remainder of the monomer (a) and the remainder of the monomer (b) are alternately charged into the reaction vessel in several batches. Furthermore, by changing the charging speed of each monomer into the reaction vessel during the reaction continuously or stepwise, the charging mass ratio per unit time of each monomer is changed continuously or stepwise, You may make it synthesize | combine simultaneously the 2 or more types of copolymer from which the ratio of structural unit (I) and structural unit (II) differs. The radical polymerization initiator may be charged into the reaction vessel from the beginning, may be dropped into the reaction vessel, or these may be combined according to the purpose.

In the copolymerization, a chain transfer agent can be used to adjust the molecular weight of the obtained copolymer. In particular, it is preferable to use a chain transfer agent when the polymerization reaction is performed at a high concentration of 30% by mass or more with respect to 100% by mass of the total amount of raw materials used during polymerization. . Examples of chain transfer agents include mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2-mercaptoethanesulfonic acid, etc. These thiol chain transfer agents can be used, and two or more types of chain transfer agents can be used in combination. Furthermore, in order to adjust the molecular weight of the copolymer, it is also effective to use a monomer having high chain mobility such as (meth) allylsulfonic acid (salt) as the monomer (c).

In order to obtain a copolymer having a predetermined molecular weight with good reproducibility, it is important to allow the copolymerization reaction to proceed stably. Therefore, when performing solution polymerization, the dissolved oxygen concentration at 25 ° C. of the solvent to be used is set. 5 ppm or less is preferable. More preferably, it is 0.01-4 ppm, More preferably, it is 0.01-2 ppm, Most preferably, the range of 0.01-1 ppm is good. In addition, what is necessary is just to make the dissolved oxygen density | concentration of the type | system | group containing a monomer into the said range, when nitrogen substitution etc. are performed after adding a monomer to a solvent.
The dissolved oxygen concentration of the solvent may be adjusted in a polymerization reaction tank, or a solvent whose dissolved oxygen amount is adjusted in advance may be used. Examples of the method for driving off oxygen in the solvent include the following methods (1) to (5).

(1) After an inert gas such as nitrogen is pressure-filled 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 obtained as described above can be used as it is as a main component of the cement dispersant, but it is preferable to adjust the pH to 5 or more from the viewpoint of handleability. Polymerization may be carried out at a pH of 5 or more. In this case, the polymerization rate is lowered, and at the same time, the copolymerizability is deteriorated and the performance as a cement dispersant is lowered. It is preferable to adjust the pH to 5 or more later. 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; Further, after the reaction is completed, the concentration can be adjusted if necessary. The copolymer may be used as a main component of the cement dispersant as it is in the form of an aqueous solution, or may be neutralized with a divalent metal hydroxide such as calcium or magnesium to obtain a polyvalent metal salt. After drying, it may be dried, or supported on an inorganic powder such as silica-based fine powder and dried to be pulverized for use.

The weight average molecular weight of the copolymer is preferably in the range of 10,000 to 300,000 in terms of polyethylene glycol by gel permeation chromatography (hereinafter referred to as “GPC”). By selecting such a range of weight average molecular weight, a cement dispersant exhibiting higher dispersion performance can be obtained. More preferably, it is the range of 10000-100,000, More preferably, it is the range of 10000-80000, Most preferably, it is the range of 10000-70000.
In addition, in this specification, the weight average molecular weight of a polymer is a value measured by GPC measurement conditions mentioned later.

The cement dispersant of the present invention essentially comprises the above copolymer. The content of the copolymer in the cement dispersant of the present invention is not particularly limited, but it is preferably 20% by mass or more, and 40% by mass or more in the solid content in the dispersant, that is, in the nonvolatile content of 100% by mass. It is more preferable that

The cement admixture of the present invention may also be a combination of two or more types of copolymers. For example, a combination of two or more kinds of copolymers having different ratios of the structural unit (I) and the structural unit (II), or the oxyalkylene group of the structural unit (I) introduced by the monomer (a) A combination of two or more kinds of copolymers having different average added mole numbers is possible. Moreover, the copolymer which satisfy | fills said conditions (a), (b) or (c), and the copolymer which satisfy | fills conditions different from this copolymer among these conditions may be included. .

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. And as a specific example of the hydraulic composition containing a hydraulic material, water and the cement dispersant of the present invention, and further containing fine aggregate (sand, etc.) and coarse aggregate (crushed stone, etc.) as necessary. , Cement paste, mortar, concrete, plaster and the like.
Among the hydraulic compositions exemplified above, a cement composition using cement as a hydraulic material is the most common, and such cement composition requires the cement admixture of the present invention, cement and water. Comprising as an ingredient. Thus, the cement composition comprising the cement admixture, cement and water as essential components is also one aspect of the present invention.

In the above cement composition, the cement is not particularly limited. For example, Portland cement (ordinary, early strength, very early strength, moderate heat, sulfate-resistant and low alkali types thereof), 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 heat generation Cement (low heat generation type blast furnace cement, fly ash mixed low heat generation type blast furnace cement, high content of belite), ultra-high strength cement, cement-based solidified material, eco-cement (city waste incineration ash, sewage sludge incineration ash) Cement produced as a raw material) Further, blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, it may be added fine powders or gypsum limestone powder. In addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., as aggregate, siliceous, clay, zircon, high alumina, silicon carbide, graphite, chromium, chromic, magnesia, etc. The refractory aggregate can be used.

In the cement composition, there are no particular restrictions on the unit water amount per 1 m ³ , the cement use amount, and the water / cement ratio. For example, the unit water amount is 100 to 185 kg / m ³ , and the cement amount used is 250 to 800 kg / m ^3. , Water / cement ratio (mass ratio) = 0.1 to 0.7, preferably unit water amount 120 to 175 kg / m ³ , used cement amount 270 to 800 kg / m ³ , water / cement ratio (mass ratio) = 0. 15-0.65 is recommended. As described above, the cement composition of the present invention can be widely used from poor blending to rich blending, and can be used for both high-strength concrete with a large amount of unit cement and poor blended concrete with a unit cement amount of 300 kg / m ³ or less. It is valid. Further, the cement composition of the present invention has a relatively high water reduction rate region, that is, water / cement ratio (mass ratio) = 0.15 to 0.5 (preferably 0.15 to 0.4). Even in a low cement ratio region, it can be used satisfactorily.

The blending ratio of the cement dispersant of the present invention in the cement composition is not particularly limited. However, when used for mortar, concrete, or the like using hydraulic cement, it is preferably 0. What is necessary is just to add the quantity of the ratio used as 01-10 weight part, More preferably, 0.02-5 weight part, More preferably, 0.05-3 weight part. By this addition, various preferable effects such as reduction in unit water amount, increase in strength, and improvement in durability are brought about. If the blending ratio is less than 0.01 parts by weight, the performance is not sufficient. Conversely, even if a large amount exceeding 10 parts by weight is used, the effect is substantially peaked and disadvantageous from the economical aspect.

The above cement composition is also effective for concrete for concrete secondary products, concrete for centrifugal molding, concrete for vibration compaction, steam-cured concrete, sprayed concrete, and the like. It is also effective for mortar and concrete that require high fluidity, such as self-leveling materials.

The cement composition of the present invention may contain a known cement dispersant. Known cement dispersants that can be used are not particularly limited, and various sulfonic acid dispersants having a sulfonic acid group in the molecule, and various polycarboxylic acid types having a polyoxyalkylene chain and a carboxyl group in the molecule. A dispersing agent is mentioned.
Examples of the sulfonic acid dispersant include lignin sulfonate; polyol derivative; naphthalene sulfonic acid formalin condensate; melamine sulfonic acid formalin condensate; polystyrene sulfonate; aminoaryl sulfonic acid-phenol-formaldehyde condensate, etc. An aminosulfonic acid type | system | group etc. are mentioned.

Examples of the polycarboxylic acid-based dispersant include, for example, a polyalkylene glycol mono (meth) acrylic acid ester-based monomer having a polyoxyalkylene chain in which an alkylene oxide having 2 to 18 carbon atoms is added in an average addition mole number of 2 to 300. Copolymer obtained by copolymerizing a monomer component containing a monomer and a (meth) acrylic acid-based monomer as essential components; 2 to 300 additions of an average number of moles of alkylene oxide having 2 to 3 carbon atoms Three types of monomers, poly (alkylene glycol) mono (meth) acrylate monomers having a polyoxyalkylene chain, (meth) acrylic acid monomers and (meth) acrylic acid alkyl esters as essential components A copolymer obtained by copolymerizing a monomer component containing; a poly having an average addition mole number of 2 to 300 carbon atoms of alkylene oxide; Polyalkylene glycol mono (meth) acrylic acid ester monomer having a xyalkylene chain, (meth) acrylic acid monomer and (meth) allyl sulfonic acid (salt) (or vinyl sulfonic acid (salt) or p- (Meth) allyloxybenzenesulfonic acid (any of salts)), a copolymer obtained by copolymerizing a monomer component containing three types of monomers as essential components; 3 types of single quantities of polyalkylene glycol mono (meth) acrylate ester monomer having added polyoxyalkylene chain, (meth) acrylic acid monomer and (meth) allylsulfonic acid (salt) (Meth) acrylamide and / or 2- (meth) acrylamide-2- further to a copolymer obtained by copolymerizing a monomer component containing a body as an essential component Copolymer obtained by graft polymerization of tilpropane sulfonic acid; average addition mole number of polyethylene glycol mono (meth) acrylate ester monomer having a polyoxyalkylene chain with addition of 5 to 50 average addition mole number of ethylene oxide and ethylene oxide 1 to 30 added polyethylene glycol mono (meth) allyl ether monomer, (meth) acrylic acid monomer and (meth) allylsulfonic acid (salt) (or p- (meta) ) Copolymer obtained by copolymerizing monomer components containing 4 types of monomers of any one of allyloxybenzenesulfonic acid (salt) as essential components; average of alkylene oxide having 2 to 18 carbon atoms Polyalkylene glycol mono (meta) having a polyoxyalkylene chain added by 2 to 300 addition moles ) A copolymer obtained by copolymerizing a monomer component containing an allyl ether monomer and a maleic acid monomer as essential components; an alkylene oxide having 2 to 4 carbon atoms in terms of an average addition mole number of 2 Copolymerizing a monomer component containing, as essential components, a polyalkylene glycol mono (meth) allyl ether monomer having a polyoxyalkylene chain added with ~ 300 and a polyalkylene glycol ester monomer of maleic acid Copolymer to be obtained: polyalkylene glycol 3-methyl-3-butenyl ether monomer having a polyoxyalkylene chain obtained by adding 2 to 300 carbon atoms of an alkylene oxide having 2 to 4 carbon atoms and maleic acid And a copolymer obtained by copolymerizing a monomer component containing an essential monomer as an essential component. The above-mentioned known cement dispersants can be used in combination.

When the known cement dispersant is used, the blending mass ratio between the cement dispersant of the present invention and the known cement dispersant is unambiguous depending on the kind of the known cement dispersant to be used, blending, test conditions, and the like. Although it is not determined, it is preferably in the range of 5:95 to 95: 5, more preferably 10:90 to 90:10.

The cement composition may further contain other known cement additives (materials) as exemplified in the following (1) to (20).
(1) Water-soluble polymer substance: unsaturated carboxylic acid polymer such as polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), sodium salt of acrylic acid / maleic acid copolymer; methyl Nonionic cellulose ethers such as cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, and hydroxypropyl cellulose; polysaccharides such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose A part of or all of the hydroxyl groups of the alkylated or hydroxyalkylated derivatives of the above are a hydrophobic substituent having a hydrocarbon chain having 8 to 40 carbon atoms as a partial structure, a sulfonic acid group or Polysaccharide derivatives substituted with ionic hydrophilic substituents containing these salts as a partial structure; yeast glucan, xanthan gum, β-1.3 glucans (both linear and branched) For example, polysaccharides produced by microbial fermentation such as curdlan, paramylon, pachyman, scleroglucan, laminaran); polyacrylamide; polyvinyl alcohol; starch; starch phosphate ester; sodium alginate; gelatin; Copolymers of acrylic acid having groups and quaternary compounds thereof.
(2) Polymer emulsion: Copolymers of various vinyl monomers such as alkyl (meth) acrylate.

(3) retarder: oxycarboxylic such as gluconic acid, glucoheptonic acid, arabonic acid, malic acid or citric acid, and inorganic salts or organic salts thereof such as sodium, potassium, calcium, magnesium, ammonium, triethanolamine, etc. Acids: monosaccharides such as glucose, fructose, galactose, saccharose, xylose, apiose, ribose, isomerized sugar, oligosaccharides such as disaccharide and trisaccharide, oligosaccharides such as dextrin, polysaccharides such as dextran, etc. Sugars such as molasses; sugar alcohols such as sorbitol; magnesium silicofluoride; phosphoric acid and its salts or borate esters; aminocarboxylic acids and salts thereof; alkali-soluble proteins; humic acid; tannic acid; Polyhydric alcohols such as glycerin; Phosphonic acid and derivatives thereof such as phonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) and alkali metal salts and alkaline earth metal salts thereof etc.
(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) Mineral oil-based antifoaming agent: cocoon oil, liquid paraffin, etc.
(6) Fat and oil-based antifoaming agents: animal and vegetable oils, sesame oil, castor oil, alkylene oxide adducts thereof and the like.
(7) Fatty acid-based antifoaming agent: oleic acid, stearic acid, and these alkylene oxide adducts.

(8) Fatty acid ester antifoaming agent: glycerin monoricinoleate, alkenyl succinic acid derivative, sorbitol monolaurate, sorbitol trioleate, natural wax and the like.
(9) Oxyalkylene antifoaming agents: polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene (Poly) oxyalkyl ethers such as 2-ethylhexyl ether and oxyethyleneoxypropylene adducts to higher alcohols having 12 to 14 carbon atoms; (poly) oxy such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether Alkylene (alkyl) aryl ethers; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1 − Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylenic alcohol such as tin-3-ol; (poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate; polyoxyethylene (Poly) oxyalkylene sorbitan fatty acid esters such as sorbitan monolaurate and polyoxyethylene sorbitan trioleate; (poly) oxyalkylene alkyl such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecylphenol ether sulfate ( Aryl) ether sulfate salts; (poly) oxyethylene stearyl phosphates, etc. Sialic sharp emission alkyl phosphate esters; polyoxyethylene such as polyoxyethylene lauryl amine (poly) oxyalkylene alkyl amines; polyoxyalkylene amide.

(10) Alcohol-based antifoaming agent: octyl alcohol, hexadecyl alcohol, acetylene alcohol, glycols and the like.
(11) Amide antifoaming agent: acrylate polyamine and the like.
(12) Phosphate ester antifoaming agent: tributyl phosphate, sodium octyl phosphate, etc.
(13) Metal soap type antifoaming agent: aluminum stearate, calcium oleate, etc.
(14) Silicone antifoaming agent: dimethyl silicone oil, silicone paste, silicone emulsion, organically modified polysiloxane (polyorganosiloxane such as dimethylpolysiloxane), fluorosilicone oil and the like.
(15) 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.

(16) Other surfactants: aliphatic monohydric alcohols having 6 to 30 carbon atoms in the molecule such as octadecyl alcohol and stearyl alcohol, and those having 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 or propylene oxide was added to a carboxylic acid having 6 to 30 carbon atoms in the molecule such as an amine having 6 to 30 carbon atoms, lauric acid or stearic acid. Polyalkylene oxide derivatives having an alkyl or alkoxy group as a substituent Alkyldiphenyl 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 nonionics Surfactant; various amphoteric surfactants.
(17) Waterproofing agent: fatty acid (salt), fatty acid ester, oil and fat, silicon, paraffin, asphalt, wax and the like.
(18) Rust preventive: nitrite, phosphate, zinc oxide and the like.
(19) Crack reducing agent: polyoxyalkyl ether and the like.
(20) Expansion material: Ettlingite, coal, etc.

Other known cement additives (materials) include, for example, cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancers, self-leveling agents, rust inhibitors, colorants, An antifungal agent etc. can be mentioned. The above-mentioned known cement additives (materials) can be used in combination.

In the cement composition of the present invention, the following 1) to 7) are particularly preferable 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. The blending mass ratio of the oxyalkylene antifoaming agent (2) is preferably in the range of 0.01 to 10 parts by weight with respect to 100 parts by weight of the cement admixture (1).
2) (1) Cement admixture of the present invention, (2) Polyalkylene glycol mono (meth) acrylic acid ester having a polyoxyalkylene chain obtained by adding 2 to 300 average addition moles of alkylene oxide having 2 to 18 carbon atoms A copolymer comprising a monomer based on (meth) acrylic acid monomer and a monomer copolymerizable with these monomers (Japanese Patent Publication No. 59-18338, Japanese Patent Laid-Open No. 7-223852) , JP-A-9-241056, etc.), (3) A combination comprising essentially three components of an oxyalkylene antifoaming agent. The blending mass ratio of the cement dispersant (1) and the copolymer (2) is preferably in the range of 5:95 to 95: 5, and more preferably in the range of 10:90 to 90:10. The blending mass ratio of the oxyalkylene-based antifoaming agent (3) is 0.01 to 10 parts by weight with respect to 100 parts by weight of the total amount of the cement admixture (1) and the copolymer (2). A range is preferred.

3) (1) A combination containing two components of the cement admixture of the present invention and (2) a sulfonic acid-based dispersant having a sulfonic acid group in the molecule. Examples of the sulfonic acid dispersant include lignin sulfonate, naphthalene sulfonic acid formalin condensate, melamine sulfonic acid formalin condensate, polystyrene sulfonate, aminoaryl sulfonic acid-phenol-formaldehyde condensate and the like. An agent or the like can be used. The blending mass ratio of the cement dispersant (1) and the sulfonic acid dispersant (2) is preferably in the range of 5:95 to 95: 5, more preferably in the range of 10:90 to 90:10. preferable.
4) (1) A combination containing two components of the cement admixture of the present invention and (2) lignin sulfonate as essential. The blending mass ratio of the cement dispersant (1) and the lignin sulfonate salt (2) is preferably in the range of 5:95 to 95: 5, and more preferably in the range of 10:90 to 90:10. .

5) A combination that essentially comprises two components, (1) the cement admixture of the present invention and (2) a material separation reducing agent. As a material separation reducing agent, various thickeners such as nonionic cellulose ethers, a hydrophobic substituent consisting of a hydrocarbon chain having 4 to 30 carbon atoms as a partial structure and an alkylene oxide having 2 to 18 carbon atoms are added on average. A compound having a polyoxyalkylene chain having 2 to 300 moles added can be used. The blending mass ratio of the cement admixture (1) and the material separation reducing agent (2) is preferably in the range of 10:90 to 99.99: 0.01, and 50:50 to 99.9: A range of 0.1 is more preferred. A cement composition comprising this combination is suitable as high fluidity concrete, self-filling concrete, and self-leveling material.
6) (1) A combination containing two components of the cement dispersant of the present invention and (2) retarder. As the retarder, oxycarboxylic acids such as gluconic acid (salt) and citric acid (salt), sugars such as glucose, sugar alcohols such as sorbitol, phosphonic acids such as aminotri (methylenephosphonic acid), and the like can be used. . The blending mass ratio of the cement dispersant (1) and the retarder (2) is preferably in the range of 50:50 to 99.9: 0.1, and in the range of 70:30 to 99: 1. More preferred.
7) (1) A combination comprising two components of the cement dispersant 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 cement dispersant (1) and the accelerator (2) is preferably in the range of 10:90 to 99.9: 0.1, and in the range of 20:80 to 99: 1. More preferred.

The cement admixture of the present invention exhibits high dispersibility, is excellent in slump retention, and can develop strength at an early stage. A cement composition comprising such a cement admixture is It is very useful in various fields such as civil engineering and architecture.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by mass”, “%” means “% by mass”, and in the table, acrylic acid is “AA”, sodium acrylate is “SA”, 2-hydroxyethyl acrylate is abbreviated as “HEA”.
In the following examples and the like, the slump flow value, the amount of air, and the compressive strength of the hardened concrete were measured in accordance with Japanese Industrial Standards JIS A1101 (1998), 1128 (1999), 6204 (2000). .

In the following production examples and the like, the amount of polyalkylene glycol produced as a by-product during the production of the unsaturated polyalkylene 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-exchanged water flow rate: 1.5 ml / min Column: Type “ShodexGF-310” 4.6 × 300 mm manufactured by Showa Denko KK
Temperature: 40 ° C

The reaction rate of each monomer in the following production examples and the weight average molecular weight of the obtained copolymer were measured under the following conditions. The reaction rate of the unsaturated polyalkylene glycol ether monomer is the total amount of the unreacted unsaturated polyalkylene glycol ether monomer remaining in the following measurement and the polyalkylene glycol by-produced during the production of the monomer. Was calculated from the amount of mass decrease of the unsaturated polyalkylene glycol ether monomer containing the charged polyalkylene glycol.

<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 “ODS-120T + ODS-80Ts” manufactured by Tosoh Corporation 4.6 × 250 mm each
Temperature: 40 ° C

<Conditions for measuring weight average molecular weight (Mw) 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 x 300mm, 6.0 x 40mm each
Temperature: 40 ° C
Calibration curve: Polyethylene glycol standard

<Calculation method of mass composition in actually obtained copolymer>
The amount of the remaining unsaturated polyalkylene glycol ether monomer and unsaturated monocarboxylic acid monomer is quantified according to the above <reaction rate measurement conditions for each raw material monomer>. The mass composition in the actually obtained copolymer is calculated on the assumption that all the monomers other than the remaining monomer are incorporated as a copolymer.

Production Example 1 (Copolymer (1))
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, 676.00 g of water, as an unsaturated polyalkylene glycol ether monomer, 3-methyl 3-butene-1- 1104.00 g of ethylene oxide adduct of all (average number of moles of ethylene oxide added: 50 mol, including 6.7% by mass of polyethylene glycol), 2.00 g of acrylic acid as an unsaturated carboxylic acid monomer, and reaction with stirring The inside of the container is purged with nitrogen, and the temperature is raised to 58 ° C. in a nitrogen atmosphere, and then an unsaturated carboxylic acid monomer aqueous solution in which 52.00 g of acrylic acid is dissolved in 60.00 g of water is dropped over 3 hours. As soon as the acrylic acid aqueous solution starts to be dropped, 3.52 of an aqueous solution of a chain transfer agent consisting of 1.92 g of mercaptoethanol and 130.00 g of water, and an aqueous initiator solution obtained by dissolving 5.86 g of sodium persulfate in 130.00 g of water. It was added dropwise over time. Thereafter, the temperature was maintained at 58 ° C. for 2 hours to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (1) of the weight average molecular weight 33000. Further, the residual amount of unsaturated alcohol adduct obtained by adding 50 mol of ethylene oxide to 3-methyl-3-buten-1-ol and acrylic acid was measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate of saturated alcohol was 78.80%, and the polymerization rate of acrylic acid was 100.00%.

Production Example 2 (Copolymer (2))
252.14 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, and 3-methyl-3-butene-1 as an unsaturated polyalkylene glycol ether monomer -51.94 g of an ethylene oxide adduct of all (containing 50 mol of ethylene oxide and 6.7% by mass of polyethylene glycol), 0.98 g of acrylic acid as an unsaturated carboxylic acid monomer, and a reaction vessel under stirring The inside was purged with nitrogen, and the temperature was raised to 58 ° C. in a nitrogen atmosphere. Then, an unsaturated carboxylic acid monomer aqueous solution in which 26.67 g of acrylic acid was dissolved in 92.69 g of water was added dropwise over 5 hours. A chain transfer agent aqueous solution consisting of 0.51 g of mercaptoethanol and 49.94 g of water and sodium persulfate The .91g was added dropwise over 5.5 hours an initiator aqueous solution prepared by dissolving in water 55.23G. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution of the copolymer (2) of the weight average molecular weight 30000 was obtained. The unsaturated alcohol adduct obtained by adding ethylene oxide to 3-methyl-3buten-1-ol and the residual amount of acrylic acid were measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate was 93.5%, and the polymerization rate of acrylic acid was 99.90%.

Production Example 3 (Copolymer (3))
253.27 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, and 3-methyl-3-butene-1 as an unsaturated polyalkylene glycol ether monomer -All ethylene oxide adduct (ethylene oxide average addition mole number 50 mol, polyethylene glycol 6.7% by weight) 521.27 g, as unsaturated carboxylic acid monomer, 0.98 g of acrylic acid was charged and stirred under reaction vessel The inside was replaced with nitrogen, and the temperature was raised to 58 ° C. in a nitrogen atmosphere. Then, an unsaturated carboxylic acid monomer aqueous solution in which 24.52 g of acrylic acid was dissolved in 98.05 g of water was added dropwise over 5 hours. A chain transfer agent aqueous solution consisting of 0.47 g of mercaptoethanol and 46.05 g of water and sodium persulfate The .77g was added dropwise over 5.5 hours an initiator aqueous solution prepared by dissolving in water 52.62G. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (3) of the weight average molecular weight 30000. The unsaturated alcohol adduct obtained by adding ethylene oxide to 3-methyl-3buten-1-ol and the residual amount of acrylic acid were measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate was 91.4%, and the polymerization rate of acrylic acid was 99.90%.

Production Example 4 (Copolymer (4))
257.65 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, 3-methyl-3-butene-1 as an unsaturated polyalkylene glycol ether monomer -All ethylene oxide adduct (average number of added moles of ethylene oxide 50 mol, containing 6.7% by weight of polyethylene glycol) 530.28 g, charged with 1.00 g of acrylic acid as an unsaturated carboxylic acid monomer, and stirred under reaction vessel The interior was purged with nitrogen, and the temperature was raised to 58 ° C. under a nitrogen atmosphere. Then, an unsaturated carboxylic acid monomer aqueous solution in which 15.93 g of acrylic acid was dissolved in 94.51 g of water was added dropwise over 5 hours. A chain transfer agent comprising 0.26 g of mercaptoethanol, 0.31 g of L-ascorbic acid, and 55.61 g of water at the same time as the dropping of the aqueous solution is started. Solution, and was added dropwise sodium persulfate 2.22g over 5.5 hours an initiator aqueous solution prepared by dissolving in water 42.22G. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (4) of the weight average molecular weight 30000. The unsaturated alcohol adduct obtained by adding ethylene oxide to 3-methyl-3buten-1-ol and the residual amount of acrylic acid were measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate was 69.6%, and the polymerization rate of acrylic acid was 100.00%.

Production Example 5 (Copolymer (5))
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, 597.03 g of water was used as an unsaturated polyalkylene glycol ether monomer, and 3-methyl-3-butene-1 -Ole ethylene oxide adduct (average number of added moles of ethylene oxide 50 mol, including polyethylene glycol 6.7% by mass) 1060.46 g, the inside of the reaction vessel was purged with nitrogen under stirring, and the temperature was raised to 78 ° C. in a nitrogen atmosphere. Thereafter, an unsaturated carboxylic acid monomer aqueous solution in which 33.86 g of acrylic acid was dissolved in 73.04 g of water was added dropwise over 5 hours, and at the same time as the acrylic acid aqueous solution started to be added, 1.23 g of L-ascorbic acid and water An aqueous reducing agent solution consisting of 123.28 g and an aqueous initiator solution in which 4.44 g of sodium persulfate was dissolved in 106.66 g of water were 5.5. It was added dropwise over a period of between. Thereafter, it continued for 1 hour, and maintained at 78 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (5) of the weight average molecular weight 32000. The unsaturated alcohol adduct obtained by adding ethylene oxide to 3-methyl-3buten-1-ol and the residual amount of acrylic acid were measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate was 77.00%, and the polymerization rate of acrylic acid was 100.00%.

Production Example 6 (Copolymer (6))
254.34 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, 3-methyl-3-butene-1 as an unsaturated polyalkylene glycol ether monomer -523.46 g of ethylene oxide adduct of all (containing 50 moles of ethylene oxide average addition moles and 6.7% by weight of polyethylene glycol), 0.98 g of acrylic acid as an unsaturated carboxylic acid monomer, and under stirring The reaction vessel was purged with nitrogen, heated to 58 ° C. in a nitrogen atmosphere, and then unsaturated carboxylic acid monomer in which 15.98 g of acrylic acid and 7.75 g of 2-hydroxyethyl acrylate were dissolved in 17.53 g of water The aqueous solution was added dropwise over 3 hours, and at the same time as the unsaturated carboxylic acid monomer aqueous solution was added dropwise, 0.40 g of L-ascorbic acid and water 39. A reducing agent aqueous solution consisting of 90 g and an aqueous initiator solution prepared by dissolving 1.44 g of sodium persulfate in 138.23 g of water were added dropwise over 3.5 hours. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 6.5 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (6) of the weight average molecular weight 31000. The unsaturated alcohol adduct obtained by adding ethylene oxide to 3-methyl-3buten-1-ol and the residual amount of acrylic acid were measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate was 77.40%, and the polymerization rates of acrylic acid and 2-hydroxyethyl acrylate were 100.00%.

Comparative Production Example 1 (Comparative Copolymer (1))
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, 696.00 g of water as an unsaturated polyalkylene glycol ether monomer, 3-methyl 3-butene-1- 1104.00 g of ethylene oxide adduct of all (average number of moles of ethylene oxide added: 50 mol, including 6.7% by mass of polyethylene glycol), 2.00 g of acrylic acid as an unsaturated carboxylic acid monomer, and reaction with stirring The inside of the container was purged with nitrogen, heated to 58 ° C. in a nitrogen atmosphere, 23.25 g of a 4% by mass hydrogen peroxide aqueous solution was added thereto, and 66.60 g of acrylic acid was dissolved in 60.00 g of water. A saturated carboxylic acid monomer aqueous solution was added dropwise over 3 hours. At the same time as the dropping of the acrylic acid aqueous solution, 3.05 g of 3-mercaptopropionic acid, an aqueous chain transfer agent composed of 130.00 g of water, and an aqueous initiator solution in which 1.26 g of L-ascorbic acid was dissolved in 130.00 g of water. Was added dropwise over 3.5 hours. Subsequently, the polymerization reaction was completed by maintaining the temperature at 58 ° C. for 2 hours. After cooling to 30 ° C., the copolymer was neutralized to pH 7.0 with a 30% aqueous sodium hydroxide solution, and a comparative copolymer (1) having a weight average molecular weight of 33,000. An aqueous solution of was obtained. Further, the residual amount of unsaturated alcohol adduct obtained by adding 50 mol of ethylene oxide to 3-methyl-3-buten-1-ol and acrylic acid was measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate of saturated alcohol was 83.10%, and the polymerization rate of acrylic acid was 99.90%. The mass composition ratio in the obtained comparative copolymer (1) is shown in Table 1.

Comparative Production Example 2 (Comparative Copolymer (2))
247.55 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, 3-methyl-3-butene-1 as an unsaturated polyalkylene glycol ether monomer -50.49 g of ethylene oxide adduct of all (average number of moles of ethylene oxide added: 50 mol, including 6.7% by mass of polyethylene glycol), 0.96 g of acrylic acid as an unsaturated carboxylic acid monomer, and a reaction vessel under stirring The inside was replaced with nitrogen, and the temperature was raised to 58 ° C. in a nitrogen atmosphere. Then, an unsaturated carboxylic acid monomer aqueous solution in which 35.31 g of acrylic acid was dissolved in 59.70 g of water was added dropwise over 5 hours. A chain transfer agent aqueous solution consisting of 0.79 g of mercaptoethanol and 77.07 g of water and sodium persulfate The .46g was added dropwise over 5.5 hours an initiator aqueous solution prepared by dissolving in water 65.68G. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution of the comparative copolymer (2) of the weight average molecular weight 30000 was obtained. The unsaturated alcohol adduct obtained by adding ethylene oxide to 3-methyl-3buten-1-ol and the residual amount of acrylic acid were measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate was 80.2%, and the polymerization rate of acrylic acid was 99.90%.

Production Example 7 (Copolymer (7))
258.64 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, ethylene oxide adduct of methallyl alcohol (ethylene oxide) as an unsaturated polyalkylene glycol ether monomer As an unsaturated carboxylic acid monomer, 1.00 g of acrylic acid was charged, and the inside of the reaction vessel was purged with nitrogen under stirring. After raising the temperature to 58 ° C. under a nitrogen atmosphere, 4.01 g of a 4% by mass hydrogen peroxide aqueous solution was added thereto, and an unsaturated carboxylic acid monomer aqueous solution in which 15.99 g of acrylic acid was dissolved in 138.03 g of water was added. The solution was added dropwise over 3 hours. At the same time as the addition of the acrylic acid aqueous solution, 0.33 g of mercaptoethanol and 0.21 of L-ascorbic acid were added. , Of water 52.87G, it was added dropwise over a moving aqueous solution for 3.5 hours. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (7) of the weight average molecular weight 30000. Moreover, when the residual amount of the unsaturated alcohol adduct obtained by adding ethylene oxide to methallyl alcohol and acrylic acid was measured by liquid chromatography (LC) to obtain the polymerization rate, the polymerization rate of the unsaturated alcohol was 59.10. %, The polymerization rate of acrylic acid was 100.00%.

Comparative Production Example 3 (Comparative Copolymer (3))
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, 234.06 g of water, an unsaturated polyalkylene glycol ether monomer, an ethylene oxide adduct of methallyl alcohol (ethylene oxide) 481.72 g (containing an average addition mole number of 50 mol, including 2.5% by weight of polyethylene glycol), 0.91 g of acrylic acid as an unsaturated carboxylic acid monomer, and the inside of the reaction vessel was purged with nitrogen under stirring. After raising the temperature to 58 ° C. in a nitrogen atmosphere, an aqueous solution of an unsaturated carboxylic acid monomer in which 15.37 g of a 4 mass% hydrogen peroxide aqueous solution was added and 64.23 g of acrylic acid was dissolved in 100.22 g of water was added. Add dropwise over 3 hours, start dropping acrylic acid aqueous solution at the same time 1.73 g of 3-mercaptopropionic acid, L-ascorbic acid .80G, of water 100.96G, was added dropwise over a moving aqueous solution for 3.5 hours. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution of the comparative copolymer (3) of the weight average molecular weight 33000 was obtained. Further, the residual amount of the unsaturated alcohol adduct obtained by adding ethylene oxide to methallyl alcohol and acrylic acid was measured by liquid chromatography (LC) to obtain the polymerization rate. The polymerization rate of the unsaturated alcohol was 92.50. %, The polymerization rate of acrylic acid was 98.00%.

Production Example 12 (Copolymer (12))
166.00 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, ethylene oxide adduct of allyl alcohol (ethylene oxide average) as an unsaturated polyalkylene glycol ether monomer (Additional mole number 50 mol, including 2.5% of polyethylene glycol) 410 g, As an unsaturated carboxylic acid monomer, 1.00 g of acrylic acid is charged, the inside of the reaction vessel is purged with nitrogen under stirring, and under a nitrogen atmosphere After the temperature was raised to 80 ° C., 12.62 g of a 20.0% hydrogen peroxide aqueous solution was added thereto, and an unsaturated carboxylic acid monomer aqueous solution in which 12.10 g of acrylic acid was dissolved in 138.03 g of water was added for 3 hours. At the same time as dropping the acrylic acid aqueous solution, 0.30 g of 3-mercaptopropionic acid, 0.96 L-ascorbic acid , Of water 52.87G, it was added dropwise over a moving aqueous solution for 3.5 hours. Thereafter, the polymerization reaction was completed by maintaining the temperature at 80 ° C. for 1 hour. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution of the copolymer (12) of the weight average molecular weight 38000 was obtained. Further, the residual amount of the unsaturated alcohol adduct obtained by adding ethylene oxide to allyl alcohol and acrylic acid was measured by liquid chromatography (LC) to determine the polymerization rate. The polymerization rate of the unsaturated alcohol was 42.00. %, The polymerization rate of acrylic acid was 98.40%.

Comparative Production Example 8 (Comparative Copolymer (8))
166.00 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, ethylene oxide adduct of allyl alcohol (ethylene oxide average) as an unsaturated polyalkylene glycol ether monomer (Additional mole number 50 mol, including 2.5% of polyethylene glycol) 410 g, As an unsaturated carboxylic acid monomer, 1.00 g of acrylic acid is charged, the inside of the reaction vessel is purged with nitrogen under stirring, and under a nitrogen atmosphere After the temperature was raised to 80 ° C., 12.62 g of a 20.0% aqueous hydrogen peroxide solution was added thereto, and an unsaturated carboxylic acid monomer aqueous solution in which 53.10 g of acrylic acid was dissolved in 138.03 g of water was added for 3 hours. At the same time as the acrylic acid aqueous solution starts to be dropped, 0.99 g of 3-mercaptopropionic acid, 3.26 L-ascorbic acid , Of water 52.87G, it was added dropwise over a moving aqueous solution for 3.5 hours. Thereafter, the polymerization reaction was completed by maintaining the temperature at 80 ° C. for 1 hour. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (8) of the weight average molecular weight 36000. Further, the residual amount of unsaturated alcohol adduct obtained by adding ethylene oxide to allyl alcohol and acrylic acid was measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate of the unsaturated alcohol was 65.00. %, The polymerization rate of acrylic acid was 97.80%.

Production Example 8 (Copolymer (8))
2555.06 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, and 3-methyl-3-butene-1 as an unsaturated polyalkylene glycol ether monomer -Ethylene oxide adduct of ol (average number of moles of ethylene oxide added 25 mol, including polyethylene glycol 4.6% by mass) 524.94 g, As unsaturated carboxylic acid monomer, 0.99 g of acrylic acid was charged and stirred. The reaction vessel was purged with nitrogen, heated to 58 ° C. in a nitrogen atmosphere, and then an unsaturated carboxylic acid monomer aqueous solution in which 20.18 g of acrylic acid was dissolved in 90.31 g of water was added dropwise over 5 hours. At the same time that the acrylic acid aqueous solution starts to be dropped, an aqueous reducing agent solution comprising 0.39 g of L-ascorbic acid and 38.05 g of water, and sodium persulfate 3 The 50g was added dropwise over 5.5 hours an initiator aqueous solution prepared by dissolving in water 65.58G. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (8) of the weight average molecular weight 60000. Further, the residual amount of unsaturated alcohol adduct obtained by adding ethylene oxide to 3-methyl-3-buten-1-ol and acrylic acid was measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate of alcohol was 65.10%, and the polymerization rate of acrylic acid was 100.00%.

Comparative Production Example 4 (Comparative Copolymer (4))
249.66 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, 3-methyl-3-butene-1 as an unsaturated polyalkylene glycol ether monomer -51.82 g of ethylene oxide adduct of all (containing 25 moles of ethylene oxide on average, including 4.6% by weight of polyethylene glycol), 0.97 g of acrylic acid as an unsaturated carboxylic acid monomer, and under stirring The reaction vessel was purged with nitrogen, heated to 58 ° C. in a nitrogen atmosphere, and then an unsaturated carboxylic acid monomer aqueous solution in which 30.50 g of acrylic acid was dissolved in 65.14 g of water was dropped over 5 hours, At the same time that the acrylic acid aqueous solution starts to be dropped, an aqueous reducing agent solution comprising 0.58 g of L-ascorbic acid and 56.55 g of water, and sodium persulfate 4 The 14g was added dropwise over 5.5 hours an initiator aqueous solution prepared by dissolving in water 78.66G. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution of the comparative copolymer (4) of the weight average molecular weight 58000 was obtained. The unsaturated alcohol adduct obtained by adding ethylene oxide to 3-methyl-3buten-1-ol and the residual amount of acrylic acid were measured by liquid chromatography (LC), and the polymerization rate was determined. The polymerization rate was 78.00%, and the polymerization rate of acrylic acid was 100.00%.

Production Example 9 (Copolymer (9))
255.06 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, ethylene oxide adduct of diethylene glycol monovinyl ether (ethylene oxide) as an unsaturated polyalkylene glycol ether monomer 527.86 g (average addition mole number 23 mol (25 mol in total)), 0.99 g of acrylic acid as an unsaturated carboxylic acid monomer was charged, the inside of the reaction vessel was purged with nitrogen under stirring, and 30 under a nitrogen atmosphere. After raising the temperature to 0 ° C., 5.02 g of 4 mass% aqueous hydrogen peroxide solution was added thereto, and unsaturated carboxylic acid obtained by dissolving 20.31 g of acrylic acid and 7.88 g of 30% aqueous sodium hydroxide solution in 124.74 g of water. The monomer aqueous solution was dropped over 3 hours, and the acrylic acid aqueous solution was started to drop at the same time as 3-mercaptopropion. 0.53 g, L-ascorbic acid 0.26 g, of water 78.57G, was added dropwise over a moving aqueous solution for 3.5 hours. Thereafter, it continued for 1 hour, and maintained at 30 ° C. to complete the polymerization reaction. And it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution of the copolymer (9) of the weight average molecular weight 27000 was obtained. Further, the residual amount of unsaturated alcohol adduct obtained by adding ethylene oxide to diethylene glycol monovinyl ether and acrylic acid was measured by liquid chromatography (LC) to obtain the polymerization rate. The polymerization rate of the unsaturated alcohol was 67.00. %, The polymerization rate of acrylic acid was 100.00%.

Comparative Production Example 5 (Comparative Copolymer (5))
245.34 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, ethylene oxide adduct of diethylene glycol monovinyl ether (ethylene oxide) as an unsaturated polyalkylene glycol ether monomer 504.94 g of average addition mole number 23 mol (total 25 mol)), 0.95 g of acrylic acid as an unsaturated carboxylic acid monomer was charged, and the inside of the reaction vessel was purged with nitrogen under stirring, and 30 under a nitrogen atmosphere. After the temperature was raised to ° C., 10.15 g of a 4 mass% aqueous hydrogen peroxide solution was added thereto, and unsaturated carboxylic acid obtained by dissolving 42.04 g of acrylic acid and 15.91 g of 30% aqueous sodium hydroxide solution in 128.29 g of water. The monomer aqueous solution was added dropwise over 3 hours, and at the same time the acrylic acid aqueous solution was added dropwise, 3-mercaptopropi Phosphate 1.14 g, L-ascorbic acid 0.53 g, of water 66.63G, was added dropwise over a chain transfer agent solution 3.5 hours. Thereafter, it continued for 1 hour, and maintained at 30 ° C. to complete the polymerization reaction. And it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the comparative copolymer (5) of the weight average molecular weight 28000. Further, the residual amount of unsaturated alcohol adduct obtained by adding ethylene oxide to diethylene glycol monovinyl ether and acrylic acid was measured by liquid chromatography (LC) to determine the polymerization rate. The polymerization rate of the unsaturated alcohol was 80.00. %, The polymerization rate of acrylic acid was 99.70%.

Copolymers (1) to (9) and (12) obtained in Production Examples 1 to 9 and 12, and Comparative copolymers (1) to (5) obtained in Comparative Production Examples 1 to 5 and 8 ) And (8) are summarized in Table 1. In the table, the AO form means a compound obtained by adding an alkylene oxide to an unsaturated alcohol, that is, an unsaturated polyalkylene glycol ether monomer (a), and the type of the unsaturated alcohol. The symbols “A” to “D” shown are as follows.
A: 3-methyl-3-buten-1-ol B: methallyl alcohol C: diethylene glycol monovinyl ether D: allyl alcohol

Here, in Production Example 7 and Production Example 12, the charged compositions of the unsaturated polyalkylene glycol ether monomer (a) and the unsaturated carboxylic acid monomer (b) were both 96/4 (mass). %) And the alkylene oxide chain length is the same. On the other hand, as shown in Table 2, in Production Example 12 using the monomer (a) obtained using allyl alcohol, the monomer (a) had a low reaction rate, and the monomer (a The actual composition of a) is low. In Comparative Production Example 3 and Comparative Production Example 8, the proportion of monomer (a) in the charged composition of monomer (a) and monomer (b) is higher in Comparative Production Example 8. Nevertheless, in Comparative Production Example 8 using the monomer (a) obtained using allyl alcohol, the reaction rate of the monomer (a) is low, and the monomer (a) The actual composition is low.

Examples 1-9, 12, Comparative Examples 1-5, 8
A predetermined amount of the obtained cement admixture (copolymer aqueous solution) was added to cement, coarse aggregate, and fine aggregate to prepare a cement composition, which was subjected to the test under the following conditions. The results are shown in Table 3.
<Concrete test conditions>
1) Material Cement: Taiheiyo Cement Coarse Aggregate: Ome Crushed Fine Aggregate: Ogasayama / Chiba Prefecture Kimitsu Mountain Sand 2) Unit Amount (kg / m ³ )
W / C = 51.9
s / a = 49.0
Air = 45.0
Water = 166.0
Cement = 320.0
Stone = 942.0
Sand = 846
As an AE agent, MA202 (manufactured by Pozoris Bussan Co., Ltd.) was blended in an amount of 0.008% to cement.
3) Used mixer Taiheiyo Koki TM55 (55 liter forced kneading bread type mixer), kneading amount 30 liter 4) Kneading method and test method Fine aggregate and cement are put into a mixer, kneaded for 10 seconds, and then mixed with cement. After adding water and coarse aggregate containing the agent and kneading for 90 seconds, the concrete was discharged, the slump value and the amount of air were measured, and the slump value was measured at each measurement time.

Example 1 ', Comparative Example 1'
Using the aqueous solutions of the obtained copolymer (1) and comparative copolymer (1), the copolymer is added so that the amount of the copolymer is as shown in Table 4, and the concrete test is performed under the following conditions. went. The obtained results are shown together in Table 4.

<Concrete test conditions>
A predetermined amount of the obtained cement admixture (copolymer aqueous solution) was added to cement, coarse aggregate, and fine aggregate to prepare a cement composition, which was subjected to a compressive strength test.
1) Material cement: TYPE I / II manufactured by Ashgrove, USA
Coarse aggregate: Limestone from Hachinohe (MS20)
Fine aggregate: Kimitsusan sand from Chiba (5mm cut)
2) Unit amount (kg / m3)
W / C = 39.5
s / a = 43.0
Air = 45.0
Water = 158.0
Cement = 400.0
Stone = 1060.0
Sand = 800.0
3) Used mixer Taiheiyo Kiko TM55 (55 liter forced mixing bread type mixer), kneading amount 30 liter 4)
(4) Kneading method and measuring method Fine aggregate and cement are put into a mixer and kneaded for 10 seconds. Next, water and coarse aggregate containing cement admixture are added and kneaded for 120 seconds, and then the concrete is discharged. The flow value and the amount of air were measured to prepare a sample for compressive strength test, and the compressive strength after 20 hours and 24 hours was measured under the following conditions.
Specimen preparation: 100 mm × 200 mm Paper specimen 3 specimens curing: Temperature 20 ° C., humidity 60%, constant temperature and humidity air curing Specimen polishing: Specimen surface polishing (Using specimen polishing finisher)
Compressive strength measurement: Automatic compressive strength meter (Maekawa Seisakusho)

Production Example 10 (Copolymer (10))
259.79 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, ethylene oxide adduct of methallyl alcohol (ethylene oxide) as an unsaturated polyalkylene glycol ether monomer (Average addition mole number 100 moles, polyethylene glycol 3.4% by weight) 532.61 g, as unsaturated carboxylic acid monomer, 1.00 g of acrylic acid was charged, and the reaction vessel was purged with nitrogen under stirring. After raising the temperature to 58 ° C. in a nitrogen atmosphere, an unsaturated carboxylic acid monomer aqueous solution in which 3.98 g of a 4 mass% hydrogen peroxide aqueous solution was added thereto and 15.87 g of acrylic acid was dissolved in 73.17 g of water was obtained. Add dropwise over 3 hours, start adding acrylic acid aqueous solution at the same time, 0.15-g 3-mercaptopropionic acid, L-ascorbic acid 0 21g, of water 114.22G, was added dropwise over a moving aqueous solution for 3.5 hours. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (10) of the weight average molecular weight 52000. Further, the residual amount of the unsaturated alcohol adduct obtained by adding ethylene oxide to methallyl alcohol and acrylic acid was measured by liquid chromatography (LC) to determine the polymerization rate. The polymerization rate of the unsaturated alcohol was 54.20. %, The polymerization rate of acrylic acid was 80.00%.

Comparative Production Example 6 (Comparative Copolymer (6))
248.91 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, ethylene oxide adduct of methallyl alcohol as an unsaturated polyalkylene glycol ether monomer (ethylene oxide) (Average addition mole number 100 mol, polyethylene glycol 3.4 mass% included) 512.28 g, as unsaturated carboxylic acid monomer, 0.96 g of acrylic acid was charged, the inside of the reaction vessel was purged with nitrogen under stirring, After raising the temperature to 58 ° C. in a nitrogen atmosphere, 8.35 g of a 4 mass% hydrogen peroxide aqueous solution was added thereto, and an unsaturated carboxylic acid monomer aqueous solution in which 34.43 g of acrylic acid was dissolved in 113.19 g of water was added. Add dropwise over 3 hours, start adding acrylic acid aqueous solution at the same time, 1.56g 3-mercaptopropionic acid, L-ascorbic acid .43G, of water 79.89G, was added dropwise over a moving aqueous solution for 3.5 hours. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution of the comparative copolymer (6) of the weight average molecular weight 61000 was obtained. Further, the residual amount of the unsaturated alcohol adduct obtained by adding ethylene oxide to methallyl alcohol and acrylic acid was measured by liquid chromatography (LC) to determine the polymerization rate. The polymerization rate of the unsaturated alcohol was 85.30. %, The polymerization rate of acrylic acid was 95.20%.

Production Example 11 (Copolymer (11))
258.22 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, ethylene oxide adduct of methallyl alcohol as an unsaturated polyalkylene glycol ether monomer (ethylene oxide) (Average addition mole number 150 mol, polyethylene glycol 6.0 mass% included) 531.45 g, as unsaturated carboxylic acid monomer, 1.00 g of acrylic acid was charged, and the inside of the reaction vessel was purged with nitrogen under stirring, After raising the temperature to 58 ° C. in a nitrogen atmosphere, an unsaturated carboxylic acid monomer aqueous solution in which 4.18 g of a 4% by mass aqueous hydrogen peroxide solution was added thereto and 16.72 g of acrylic acid was dissolved in 61.34 g of water was obtained. Add dropwise over 3 hours, start dropping acrylic acid aqueous solution at the same time 0.44 g 3-mercaptopropionic acid, L-ascorbic acid 0 22 g, of water 126.42G, was added dropwise over a moving aqueous solution for 3.5 hours. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and obtained the aqueous solution of the copolymer (11) of the weight average molecular weight 52000. Further, the residual amount of the unsaturated alcohol adduct obtained by adding ethylene oxide to methallyl alcohol and acrylic acid was measured by liquid chromatography (LC) to obtain the polymerization rate. The polymerization rate of the unsaturated alcohol was 55.80. %, The polymerization rate of acrylic acid was 78.00%.

Comparative Production Example 7 (Comparative Copolymer (7))
254.85 g of water in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube, reflux condenser, ethylene oxide adduct of methallyl alcohol as an unsaturated polyalkylene glycol ether monomer (ethylene oxide) 524.85 g (containing an average addition mole number of 150 mol, including 6.0% by weight of polyethylene glycol), 0.99 g of acrylic acid as an unsaturated carboxylic acid monomer, and the inside of the reaction vessel was purged with nitrogen under stirring. After raising the temperature to 58 ° C. in a nitrogen atmosphere, an aqueous solution of an unsaturated carboxylic acid monomer in which 5.73 g of a 4 mass% aqueous hydrogen peroxide solution was added thereto and 23.31 g of acrylic acid was dissolved in 91.94 g of water was obtained. Add dropwise over 3 hours, start adding acrylic acid aqueous solution at the same time, 0.68g 3-mercaptopropionic acid, L-ascorbic acid 0 30g, of water 97.72G, was added dropwise over a moving aqueous solution for 3.5 hours. Thereafter, the reaction was continued for 1 hour, and maintained at 58 ° C. to complete the polymerization reaction. And after cooling to 30 degreeC, it neutralized to pH 7.0 with 30% sodium hydroxide aqueous solution, and the aqueous solution of the comparative copolymer (7) of the weight average molecular weight 41000 was obtained. Moreover, when the residual amount of the unsaturated alcohol adduct obtained by adding ethylene oxide to methallyl alcohol and acrylic acid was measured by liquid chromatography (LC) and the polymerization rate was determined, the polymerization rate of the unsaturated alcohol was 76.40. %, The polymerization rate of acrylic acid was 92.50%.

Table 5 summarizes the copolymers (10) to (11) obtained in Production Examples 10 to 11 and the comparative copolymers (6) to (7) obtained in Comparative Production Examples 6 to 7. . The AO body is as described above.

Examples 10-11, Comparative Examples 6-7
A predetermined amount of the obtained cement admixture (copolymer aqueous solution) was added to cement, coarse aggregate, and fine aggregate to prepare a cement composition, which was subjected to the test under the following conditions. The results are shown in Table 6.
<Concrete test conditions>
1) Material Cement: Taiheiyo Cement Coarse Aggregate: Ome Crushed Fine Aggregate: Ogasayama / Chiba Prefecture Kimitsu Mountain Sand 2) Unit Amount (kg / m ³ )
W / C = 30.0
s / a = 47.0
Air = 45.0
Water = 172.0
Cement = 573.0
Stone = 863.0
Sand = 738
3) Used mixer Taiheiyo Koki TM55 (55 liter forced kneading bread type mixer), kneading amount 30 liter 4) Kneading method and test method Fine aggregate and cement are put into a mixer, kneaded for 10 seconds, and then mixed with cement. After adding water and coarse aggregate containing the agent and kneading for 120 seconds, the concrete was discharged, the slump value and the air amount were measured, and the slump value was measured at each measurement time.

Examples 10 ′ to 11 ′, Comparative Examples 6 ′ to 7 ′
A predetermined amount of the obtained cement admixture (copolymer aqueous solution) was added to cement, coarse aggregate, and fine aggregate to prepare a cement composition, which was subjected to the test under the following conditions. The results are shown in Table 7.
<Concrete test conditions>
1) Material Cement: Taiheiyo Cement Coarse Aggregate: Ome Crushed Fine Aggregate: Ogasayama / Chiba Prefecture Kimitsu Mountain Sand 2) Unit Amount (kg / m ³ )
W / C = 30.0
s / a = 47.0
Air = 45.0
Water = 172.0
Cement = 573.0
Stone = 863.0
Sand = 738
3) Used mixer Taiheiyo Koki TM55 (55 liter forced kneading bread type mixer), kneading amount 30 liter 4) Kneading method and test method Fine aggregate and cement are put into a mixer, kneaded for 10 seconds, and then mixed with cement admixture. Water and coarse aggregate were added and kneaded for 120 seconds, then the concrete was discharged, the amount of air was measured, a sample for compressive strength test was prepared, and the compressive strength after 24 hours was measured under the following conditions. It was measured.
Specimen preparation: 100 mm × 200 mm Paper specimen 3 specimens curing: Temperature 20 ° C., humidity 60%, constant temperature and humidity air curing Specimen polishing: Specimen surface polishing (Using specimen polishing finisher)
Compressive strength measurement: Automatic compressive strength meter (Maekawa Seisakusho)

Claims (4)

The structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a) represented by the following general formula (1), and the unsaturated monocarboxylic acid monomer represented by the following general formula (2) ( a cement admixture containing as an essential component a copolymer comprising the structural unit (II) derived from b),
The copolymer satisfies any one of the following conditions (a) and (b):
(A) When Y in the general formula (1) represents an alkenyl group having 2 to 3 carbon atoms, the structural unit (I) contained in 100% by mass of the copolymer is 90% by mass or more (provided that The ratio of the structural unit (II) is a value obtained by converting the amount of the unsaturated monocarboxylic acid monomer (b) in terms of its sodium salt.)
(B) When Y in the general formula (1) represents an alkenyl group having 4 to 8 carbon atoms and the average addition mole number n of the oxyalkylene group is less than 80, the copolymer contained in 100% by mass of the copolymer The structural unit (I) is 92% by mass or more (provided that the proportion of the structural unit (II) is a value obtained by converting the amount of the unsaturated monocarboxylic acid monomer (b) by its sodium salt). .

(In General Formula (1), Y represents an alkenyl group having 2 to 8 carbon atoms. T is the same or different and represents an alkylene group having 1 to 5 carbon atoms or an aryl group having 6 to 9 carbon atoms. R ¹ O represents one or more of oxyalkylene groups having 2 to 18 carbon atoms, m represents 0 or 1, n represents the average number of moles added of the oxyalkylene group, and 1 to 500 Represents the number of

(In General Formula (2), R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or a methyl group. M represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or Represents an organic amine group.) 2. The cement admixture according to claim 1, wherein, in the condition (b), the structural unit (I) contained in 100% by mass of the copolymer is 92.5% by mass or more. The structural unit (I) derived from the unsaturated polyalkylene glycol ether monomer (a) represented by the following general formula (1), and the unsaturated monocarboxylic acid monomer represented by the following general formula (2) ( a cement admixture containing as an essential component a copolymer comprising the structural unit (II) derived from b),
The structural unit (I) contained in 100% by mass of the copolymer is 94% by mass or more (provided that the proportion of the structural unit (II) is the amount of the unsaturated monocarboxylic acid monomer (b)). Is the value converted to its sodium salt.)

(In General Formula (1), Y represents an alkenyl group having 4 to 8 carbon atoms. T is the same or different and represents an alkylene group having 1 to 5 carbon atoms or an aryl group having 6 to 9 carbon atoms. R ¹ O represents one or more of oxyalkylene groups having 2 to 18 carbon atoms, m represents 0 or 1, n represents the average number of moles added of the oxyalkylene group, and 150 to 500 Represents the number of

(In General Formula (2), R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or a methyl group. M represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or Represents an organic amine group.) A cement composition comprising the cement admixture according to any one of claims 1 to 3, cement and water as essential components.