JP5232433B2 - Method for producing polymer, polymer for cement admixture, cement admixture, and cement composition - Google Patents

Description

  The present invention relates to a polymer production method, a polymer for cement admixture, a cement admixture, and a cement composition. Specifically, a method for producing a polymer that can be applied to a cement admixture, a polymer for cement admixture that can provide a cement admixture with excellent slump retention performance, and a cement admixture containing such a polymer for cement admixture And a cement composition comprising such a cement admixture.

  Cement compositions such as mortar and concrete have reduced consistency due to the hydration reaction between cement and water, etc., resulting in a decrease in workability. This phenomenon is generally called slump loss.

  Slump loss in a cement composition causes obstacles in raw concrete, such as limitation of transport time, quality change due to waiting time at the site of placement, poor workability, and reduced durability due to cold joints. Also, in concrete secondary product manufacturing factories, etc., pumping of cement composition is temporarily interrupted due to lunch breaks or troubles, and when pumping is resumed after that, the pumping pressure suddenly increases or the pump is blocked. In addition, problems such as unfilling occur when molding such as compaction is delayed for some reason after the cement composition is driven into the mold.

  Therefore, slump loss in a cement composition is an important issue that must be solved for quality control of the cement composition and improvement of workability in a ready-mixed concrete factory, a secondary product manufacturing factory, and the like.

  Cement admixture is used to prevent slump loss, that is, to improve slump retention performance. A cement admixture has the effect | action which improves the intensity | strength, durability, etc. of hardened | cured material by raising the fluidity | liquidity of a cement composition and water-reducing a cement composition. Among such cement admixtures, those containing a polycarboxylic acid polymer (see Patent Documents 1 to 4) exhibit high water reduction performance compared to conventional naphthalene-based cement admixtures, and thus have high performance. It has a track record as an AE water reducing agent.

A crosslinked polymer of a water-soluble polymer has been reported as a cement admixture excellent in slump retention performance (see Patent Document 5). However, since the viscosity is greatly increased as the crosslinking proceeds, there is a problem that the dispersion stability and handleability deteriorate. In addition, due to the thickening, when blended in the cement composition, it is difficult to adjust to water, the cement composition becomes non-uniform, and the local presence of the cement admixture tends to cause poor curing.
JP 2001-220417 A JP 2002-121055 A JP 2002-121056 A JP 2004-519406 A Japanese Patent No. 2978560

  An object of the present invention is to provide a method for producing a polymer, which is a cross-linked polymer of a water-soluble polymer and can be applied to an excellent cement admixture capable of realizing a low viscosity while maintaining a good slump retention performance. There is. Moreover, it is providing the polymer for cement admixtures excellent in such slump retention performance. Furthermore, it is providing the cement composition containing such a polymer for cement admixtures, and the cement composition containing such a cement admixture.

The method for producing a polymer of the present invention is a crosslinked polymer having a bond containing at least one linking group represented by the general formula (1) between main chains of a water-soluble polymer structure having a weight average molecular weight of 500 to 100,000. Shear.

  In a preferred embodiment, the crosslinked polymer is obtained by reacting a water-soluble polymer having a weight average molecular weight of 500 to 100,000 with a crosslinking agent of 3.4 to 5.7% by weight based on the water-soluble polymer.

  In a preferred embodiment, the viscosity of the crosslinked polymer after shearing in a 20% by weight aqueous solution or aqueous dispersion at 25 ° C. is 120 cps or more.

  In a preferred embodiment, the viscosity of the crosslinked polymer after shearing in a 20% by weight aqueous solution or aqueous dispersion at 2000C is 2000 cps or less.

  In a preferred embodiment, the shearing is performed on the aqueous solution or dispersion of the crosslinked polymer.

  In a preferred embodiment, the shearing is performed at a rotational speed of 1000 to 20000 rpm.

  According to another aspect of the present invention, a polymer for cement admixture is provided. The polymer for cement admixture of the present invention is obtained by the production method of the present invention.

According to another aspect of the present invention, a polymer for cement admixture is provided. The polymer for a cement admixture of the present invention has a crosslink weight having a bond containing at least one linking group represented by the general formula (1) between main chains of a water-soluble polymer structure having a weight average molecular weight of 30,000 to 50,000. The viscosity at 120C in a 20 wt% aqueous solution or dispersion is 120 to 2000 cps.

  In a preferred embodiment, the crosslinked polymer is obtained by reacting a water-soluble polymer having a weight average molecular weight of 30,000 to 50,000 with 3.4 to 5.7% by weight of a crosslinking agent based on the water-soluble polymer.

  According to another aspect of the present invention, a cement admixture is provided. The cement admixture of the present invention contains the polymer for cement admixture of the present invention.

  According to another aspect of the present invention, a cement composition is provided. The cement composition of the present invention contains the cement admixture of the present invention.

  According to the present invention, there is provided a method for producing a polymer, which is a cross-linked polymer of a water-soluble polymer and can be applied to an excellent cement admixture capable of realizing a low viscosity while maintaining a good slump retention performance. be able to. Moreover, the polymer for cement admixtures excellent in such slump retention performance can be provided. Furthermore, a cement admixture comprising such a polymer for cement admixture and a cement composition comprising such a cement admixture can be provided.

  The effects as described above can be manifested by performing a shearing treatment on a specific crosslinked polymer in the polymer production method. In addition, as a polymer for cement admixture, it is expressed by adopting a specific crosslinked polymer having a viscosity of 120 to 2000 cps at 25 ° C. in a 20 wt% aqueous solution or aqueous dispersion. Can do.

[Production method of polymer]
The method for producing a polymer of the present invention is a crosslinked polymer having a bond containing at least one linking group represented by the general formula (1) between main chains of a water-soluble polymer structure having a weight average molecular weight of 500 to 100,000. Shear. The polymer is preferably a cement admixture polymer.

  In the production method of the present invention, the crosslinked polymer before shearing (hereinafter sometimes simply referred to as “crosslinked polymer”) has a general formula between main chains of a water-soluble polymer structure having a weight average molecular weight of 500 to 100,000. It has a bond containing at least one linking group represented by (1).

  In the present invention, the crosslinked polymer has a structure in which two or more main chains are crosslinked with each other. This main chain consists only of carbon-carbon bonds or has a structure mainly composed thereof.

（ここで、Ｒ^２０は、例えば、アルキレンオキシドから導かれる２価の基をあらわす。）

（ここで、Ｒ^２１は、例えば、アルキレン基を表す。なお、Ｒ^２１が２個以上ある場合、すべてのＲ^２１が同一の基である必要はない。）

（ここで、Ｒ^２１は、例えば、アルキレン基を表す。なお、Ｒ^２１が２個以上ある場合、すべてのＲ^２１が同一の基である必要はない。） The bridge is a bond containing at least one linking group represented by the general formula (1). This bond (crosslinked structure) has an ester bond, but its position is important. That is, when the main chain carbon atom is separated from at least one carbon atom and has an ester bond, or when the ester bond is directly bonded to the main chain carbon atom, the structure of the general formula (1) In which R ² is any one of —CH ₂ (OH) —CH—. Any appropriate bond can be adopted as such a bond. For example, three represented by general formula (2)-(4) are mentioned.

(Here, R ²⁰ represents a divalent group derived from, for example, an alkylene oxide.)

^{(Wherein, R 21} represents, for example, an alkylene group. In ^the case ^{where R 21} is 2 or more, all of ^{R 21} need not be the same group.)

^{(Wherein, R 21} represents, for example, an alkylene group. In ^the case ^{where R 21} is 2 or more, all of ^{R 21} need not be the same group.)

  In the production method of the present invention, the water-soluble polymer structure in the crosslinked polymer has a weight average molecular weight of 500 to 100,000, preferably 3,000 to 50,000, more preferably 5,000 to 50,000, still more preferably 10,000 to 50,000, particularly preferably. Is 20000 to 50000, most preferably 30000 to 50000. If the weight average molecular weight of the water-soluble polymer structure is out of the above range, the dispersion stability may be inferior, or the air amount may increase abnormally.

（ただし、ｍは０または１〜５０の整数であり、ｎは０または１であり、Ｍは水素、一価金属、二価金属、三価金属、アンモニウム基、および有機アミノ基のいずれかであり、Ｒ^５およびＲ^６はそれぞれ独立に炭素数２〜４のアルキレン基であり、Ｒ^７は炭素数１〜５のアルキレン基である。なお、ｍが２以上である場合、複数のＲ^５Ｏはすべて同じ基である必要はなく、また、複数のＲ^５Ｏが互いに異なる基である場合、それらの配列は規則的でもランダムでもよい。） In the present invention, the water-soluble polymer structure in the crosslinked polymer preferably contains at least one functional group represented by the general formulas (5) to (9).

(However, m is 0 or an integer of 1-50, n is 0 or 1, and M is any one of hydrogen, monovalent metal, divalent metal, trivalent metal, ammonium group, and organic amino group. Each of R ⁵ and R ⁶ is independently an alkylene group having 2 to 4 carbon atoms, and R ⁷ is an alkylene group having 1 to 5 carbon atoms, and when m is 2 or more, a plurality of R ⁵ O need not all be the same group, and when a plurality of R ⁵ Os are different from each other, their arrangement may be regular or random.)

  M is any one of hydrogen, monovalent metal, divalent metal, trivalent metal, ammonium group, and organic amino group. Examples of the monovalent metal include sodium and potassium. Examples of the divalent metal include magnesium, calcium, and barium. An example of the trivalent metal is aluminum. Examples of the organic amino group include a trimethylamino group, a triethylamino group, and a triethanolamino group.

（ただし、ｐは１〜１０の整数であり、ｑは０または１〜１００の整数であり、ｒおよびｓはそれぞれ１〜３の整数であり、ｔおよびｕはそれぞれ１〜１００の整数、Ａ^１は炭素数２〜４のアルキレンイミンの２価または３価の開環基（２価の場合、直鎖状であり、３価の場合、分岐状である）であり、Ｒ^５は炭素数２〜４のアルキレン基であり、Ｒ^８はＣＨ_３またはＣ_２Ｈ_５であり、Ｒ^９はＨ、ＣＨ_３またはＣ_２Ｈ_５であり、Ｒ^１０はＨまたは炭素数１〜５のアルキル基であり、Ｘ⁻はアニオン性対イオンである。なお、ｐが２以上の場合、複数のＡ^１はすべて同じ基である必要はなく、また、複数のＡ^１が互いに異なる基である場合、それらの配列は規則的でもランダムでもよい。ｑが０でない場合、Ａ^１とＲ^５Ｏとの配列は順番が逆でもよく、また、規則的でもランダムでもよい。ｑが２以上である場合、ｔが２以上である場合およびｕが２以上である場合、それぞれ、複数のＲ^５Ｏはすべて同じ基である必要はなく、また、複数のＲ^５Ｏが互いに異なる基である場合、それらの配列は規則的でもランダムでもよい。１つの式中に同じ記号で表される基が２以上含まれる場合、すべて同一の基である必要はない。） In the present invention, the water-soluble polymer structure in the crosslinked polymer preferably contains at least one functional group represented by the general formulas (10) to (16).

(Wherein p is an integer of 1 to 10, q is an integer of 0 or 1 to 100, r and s are each an integer of 1 to 3, t and u are each an integer of 1 to 100, A ¹ is a divalent or trivalent ring-opening group of an alkyleneimine having 2 to 4 carbon atoms (in the case of divalent, it is linear, and in the case of trivalent, it is branched), and R ⁵ is the number of carbons An alkylene group having 2 to 4; R ⁸ is CH ₃ or C ₂ H ₅ ; R ⁹ is H, CH ₃ or C ₂ H ₅ ; and R ¹⁰ is H or an alkyl group having 1 to 5 carbon atoms. And X ⁻ is an anionic counter ion, and when p is 2 or more, the plurality of A ¹ need not all be the same group, and when the plurality of A ¹ are groups different from each other, Their arrangement may be regular or random: when q is not 0, the arrangement of A ¹ and R ⁵ O The order may be reversed, and may be regular or random: when q is 2 or more, t is 2 or more, and u is 2 or more, each of the plurality of R ⁵ Os is the same. It is not necessary to be a group, and when a plurality of R ⁵ O are different from each other, their arrangement may be regular or random, and two or more groups represented by the same symbol are included in one formula All need not be the same group.)

  The functional group represented by the general formula (10) is, for example, at least an alkyleneimine of alkyleneimine and alkylene oxide with respect to the -COOM group of a water-soluble polymer having a -COOM group by any appropriate method. It can be obtained by addition reaction. Alkyleneimine may be added alone, or alkyleneimine and alkylene oxide may be coadded. In the case of co-addition, they can be reacted simultaneously with a -COOM group, or alkylene oxide can be reacted after sequential reaction with alkylene imine. The alkyleneimine includes any suitable alkyleneimine. Examples thereof include ethyleneimine and propyleneimine.

  In the production method of the present invention, the crosslinked polymer can be obtained by polymerizing a monomer for constructing a water-soluble polymer structure and a monomer for constructing a crosslinked structure in combination. (Method I).

  In the production method of the present invention, the crosslinked polymer is prepared by first polymerizing a monomer for constructing a water-soluble polymer structure to produce a water-soluble polymer, and adding a crosslinking agent for constructing the crosslinked structure thereto. It can be obtained by reaction (Method II).

  In the above method II, the crosslinked polymer is preferably obtained by reacting a water-soluble polymer having a weight average molecular weight of 500 to 100,000 with a crosslinking agent of 3.4 to 5.7% by weight based on the water-soluble polymer. . The amount of the crosslinking agent is more preferably 3.5 to 5.6% by weight, still more preferably 3.6 to 5.5% by weight. If the amount of the cross-linking agent is out of the above range, there is a possibility that the cross-linked polymer cannot sufficiently exhibit the effects of the present invention.

（ただし、ｍは０または１〜５０の整数であり、ｎは０または１であり、Ｍは水素、一価金属、二価金属、三価金属、アンモニウム基および有機アミノ基のうちのいずれかであり、Ｒ^３およびＲ^４はそれぞれ独立にＨまたはＣＨ_３であり、Ｒ^５およびＲ^６はそれぞれ独立に炭素数２〜４のアルキレン基であり、Ｒ^７は炭素数１〜５のアルキレン基である。なお、ｍが２以上である場合、複数のＲ^５Ｏはすべて同じ基である必要はなく、また、複数のＲ^５Ｏが互いに異なる基である場合、それらの配列は規則的でもランダムでもよい。１つの式中に同じ記号で表される基または数が２以上含まれる場合、すべて同一の基または数である必要はない。）

（ただし、ｒおよびｓはそれぞれ１〜３の整数であり、ｔおよびｕはそれぞれ１〜１００の整数であり、Ｒ^３およびＲ^４はそれぞれ独立にＨまたはＣＨ_３であり、Ｒ^５は炭素数２〜４のアルキレン基であり、Ｒ^８はＣＨ_３またはＣ_２Ｈ_５であり、Ｒ^９はＨ、ＣＨ_３またはＣ_２Ｈ_５であり、Ｒ^１０はＨまたは炭素数１〜５のアルキル基であり、Ｘ⁻はアニオン性対イオンである。なお、ｔが２以上である場合およびｕが２以上である場合、それぞれ、複数のＲ^５Ｏはすべて同じ基である必要はなく、また、複数のＲ^５Ｏが互いに異なる基である場合、それらの配列は規則的でもランダムでもよい。１つの式中に同じ記号で表される基が２以上含まれる場合、すべて同一の基である必要はない。） In the above method I and method II, the monomer for constructing the water-soluble polymer structure is, for example, a single monomer represented by general formulas (i) to (vi) or general formulas (ix) to (xiv) The body is mentioned. These monomers may be used alone or in combination of two or more.

(However, m is 0 or an integer of 1 to 50, n is 0 or 1, and M is any one of hydrogen, monovalent metal, divalent metal, trivalent metal, ammonium group and organic amino group. R ³ and R ⁴ are each independently H or CH ₃ , R ⁵ and R ⁶ are each independently an alkylene group having 2 to 4 carbon atoms, and R ⁷ is an alkylene group having 1 to 5 carbon atoms. It should be noted that when m is 2 or more, the plurality of R ⁵ Os need not all be the same group, and when the plurality of R ⁵ Os are different from each other, their arrangement may be regular. (It may be random. When two or more groups or numbers represented by the same symbol are contained in one formula, they need not all be the same group or number.)

(Wherein r and s are each an integer of 1 to 3, t and u are each an integer of 1 to 100, R ³ and R ⁴ are each independently H or CH ₃ , and R ⁵ is the number of carbon atoms. An alkylene group having 2 to 4; R ⁸ is CH ₃ or C ₂ H ₅ ; R ⁹ is H, CH ₃ or C ₂ H ₅ ; and R ¹⁰ is H or an alkyl group having 1 to 5 carbon atoms. And X ⁻ is an anionic counter ion, wherein when t is 2 or more and u is 2 or more, it is not necessary that all of the plurality of R ⁵ Os are the same group, When a plurality of R ⁵ O groups are different from each other, their arrangement may be regular or random, and when two or more groups represented by the same symbol are contained in one formula, they must all be the same group. No.)

  Examples of the monomer (i) include acrylic acid, methacrylic acid, and monovalent metal salts, divalent metal salts, trivalent metal salts, ammonium salts, and organic amine salts thereof. 1 type (s) or 2 or more types can be used.

  Examples of the monomer (ii) include maleic acid, citraconic acid, their anhydrides, and monovalent metal salts, divalent metal salts, trivalent metal salts, ammonium salts, and organic amine salts thereof. 1 type, or 2 or more types of these can be used.

  Examples of the monomer (iii) include 2-sulfoethyl (meth) acrylate, 2-sulfopropyl (meth) acrylate, 3-sulfopropyl (meth) acrylate, 1-sulfopropan-2-yl (meth) acrylate, 2-sulfobutyl (meth) acrylate, 3-sulfobutyl (meth) acrylate, 4-sulfobutyl (meth) acrylate, 1-sulfobutan-2-yl (meth) acrylate, 1-sulfobutan-3-yl (meth) acrylate, 2- Sulfobutan-3-yl (meth) acrylate, 2-methyl-2-sulfopropyl (meth) acrylate, 2-methyl-3-sulfopropyl (meth) acrylate, 1,1-dimethyl-2-sulfoethyl (meth) acrylate, etc. Sulfoalkyl (meth) acrylates and their monovalence Metal salt, divalent metal salt, trivalent metal salt, ammonium salt or organic amine salt; sulfoethoxypolyethylene glycol mono (meth) acrylate, sulfopropoxypolyethylene glycol mono (meth) acrylate, sulfobutoxypolyethylene glycol mono (meth) acrylate, Sulfoalkoxypolyalkylene glycol mono (meth) acrylates such as sulfoethoxypolypropylene glycol mono (meth) acrylate, sulfopropoxypolypropylene glycol mono (meth) acrylate, sulfobutoxypolypropylene glycol mono (meth) acrylate, and monovalent metal salts thereof; Examples thereof include valent metal salts, trivalent metal salts, ammonium salts, and organic amine salts. One or more of these can be used. .

  Examples of monomer (iv) include acrylamide methane sulfonic acid, acrylamide ethane sulfonic acid, acrylamide propane sulfonic acid, 2-acrylamido-2-methyl propane sulfonic acid, methacrylamide methane sulfonic acid, methacrylamide ethane sulfonic acid, and Examples thereof include monovalent metal salts, divalent metal salts, trivalent metal salts, ammonium salts, and organic amine salts, and one or more of these can be used.

  Examples of the monomer (v) include ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, and monovalent metal salts, divalent metal salts, trivalent metal salts, ammonium salts, and organic amine salts thereof. 1 type, or 2 or more types of these can be used.

  Examples of monomers (vi) include sulfonated styrene such as p-styrene sulfonic acid, and monovalent metal salts, divalent metal salts, trivalent metal salts, ammonium salts, and organic amine salts thereof. 1 type, or 2 or more types of these can be used.

  Examples of the monomer (ix) include dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like, and one or more of these can be used.

  Examples of the monomer (x) are those obtained by reacting the monomer (ix) with any appropriate quaternizing agent, for example, alkyl halides, halogenated aralkyls, dialkylsulfuric acid and the like. And one or more of these can be used.

  Examples of the monomer (xi) include dimethylaminopropyl acrylamide, diethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide, diethylaminopropyl methacrylamide, and the like, and one or more of these can be used. .

  Examples of the monomer (xii) are those obtained by reacting the monomer (xi) with any appropriate quaternizing agent, for example, halogenated alkyls, halogenated aralkyls, dialkyl sulfuric acid, etc. And one or more of these can be used.

  Examples of monomers (xiii) are polyethylene glycol monoallyl ether, polypropylene glycol monoallyl ether, polyethylene glycol polypropylene glycol monoallyl ether, polyethylene glycol monomethallyl ether, polypropylene glycol monomethallyl ether, polyethylene glycol polypropylene glycol monomethallyl ether. And polyalkylene glycol mono (meth) allyl ethers can be used, and one or more of these can be used.

  Examples of monomers (xiv) include hydroxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polybutylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono (meth) Acrylate, methoxypolypropylene glycol mono (meth) acrylate, methoxypolybutylene glycol mono (meth) acrylate, ethoxypolyethylene glycol mono (meth) acrylate, ethoxypropylene glycol mono (meth) acrylate, ethoxypolybutylene glycol mono (meth) acrylate , Polyethylene glycol polypropylene glycol mono (meth) acrylate, polyethylene glycol polytetramethylene Can be exemplified recalls mono (meth) acrylate, it can be used alone or in combination of two or more thereof.

  In the above method I, any appropriate monomer can be adopted as the monomer (X) for constructing the crosslinked structure as long as it can construct the crosslinked structure. Examples thereof include monomers obtained by the following reactions (a) to (e).

  (A) Reaction of at least one of monoester diol and polyester polyol with a polymerizable monomer having a functional group capable of reacting with a hydroxyl group of these compounds.

  (B) Reaction of at least one of monoester dicarboxylic acid and polyester polycarboxylic acid with a polymerizable monomer having a functional group capable of reacting with a carboxyl group of these compounds.

  (C) Reaction of at least one of a polyol and a polyepoxy compound with a polymerizable monomer having a carboxyl group at least one carbon atom away from the polymerizable double bond.

  (D) Reaction of polycarboxylic acid with a polymerizable monomer having a hydroxyl group or an epoxy group at least one carbon atom away from the polymerizable double bond.

  (E) Reaction of at least one of a monoester polyepoxy compound and a polyester polyepoxy compound with a polymerizable monomer having a functional group capable of reacting with an epoxy group of these compounds.

  The monoester diol and polyester polyol in the production method (a) are diol compounds such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl. Reaction products of glycols and the like with dibasic acids such as succinic acid, adipic acid, phthalic acid, hexahydrophthalic acid and tetrahydrophthalic acid; the dibasic acids and cyclic ethers such as ethylene oxide and propylene oxide Reaction product; reaction product such as diol compound and oxycarboxylic acid such as glycolic acid, α-hydroxyacrylic acid, salicylic acid, mandelic acid; reaction product of oxycarboxylic acid and cyclic ether; Polyhydric alcohols such as pentaerythritol, trimethylolpropane, trimethylolethane, ditrimethylolpropane, dipentaerythritol and the like and lactones such as β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, etc. Reaction products; and the like.

  Examples of the polymerizable monomer having a functional group capable of reacting with a hydroxyl group in the production method (a) include acrylic acid, methacrylic acid, maleic acid, glycidyl (meth) acrylate, (meth) acryloylaziridine, and (meth) acryloyl. Examples include oxyethylaziridine, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, isocyanate ethyl (meth) acrylate, (meth) acryloyl chloride, and allyl chloride.

  The monoester dicarboxylic acid and / or polyester polycarboxylic acid in the production method (b) can be obtained by using the same compounds as those exemplified in the production method (a).

  As the polymerizable monomer having a functional group capable of reacting with a carboxyl group in the production method of (b) above, allyl alcohol, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acryloylaziridine, (Meth) acryloyloxyethylaziridine, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, isocyanate ethyl (meth) acrylate and the like.

  Examples of the polyol in the production method (c) include polycarbonate polyol, polyether polyol, polybutadiene polyol, hydrogenated polybutadiene polyol and the like in addition to the polyester polyol exemplified in the production method (a). Examples of the polycarbonate polyol include 1,6-hexanediol, neopentyl glycol, 1,4-butanediol, 1,8-octanediol, 1,4-bis- (hydroxymethyl) -cyclohexane, and 2-methylpropanediol. , Dipropylene glycol, dibutylene glycol, bisphenol A ethylene oxide 2 to 6 mol addition reaction product or the above diol compound and dicarboxylic acid such as oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, hexahydrophthalic acid A polycarbonate polyol having a diol component such as a diol component, or a diol compound and a polyester diol, which is a reaction product of addition of ε-caprolactone or δ-valerolactone, with the diol compound; And polycarbonate polyol which is an addition reaction product of ethylene oxide or propylene oxide or ε-caprolactone or δ-valerolactone. Such a polycarbonate polyol can be easily obtained as a commercial product. For example, desmophen 2020E (manufactured by Sumitomo Bayer Polyurethane Co., Ltd., average molecular weight 2000), DN-980 (manufactured by Nippon Polyurethane Co., Ltd., average molecular weight 2000), DN-981 (manufactured by Nippon Polyurethane Co., Ltd., average molecular weight 1000), etc. Is mentioned. Examples of polyether polyols include polyethers obtained by polymerizing cyclic ethers such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using diol compounds such as ethylene glycol, propylene glycol, and 1,4-butanediol as initiators. A polyol etc. are mentioned. Such a polyether polyol can be easily obtained as a commercial product. For example, Sannix PP-1000 (manufactured by Sanyo Chemical Co., Ltd., polypropylene glycol, molecular weight 1000), PTG-500P (manufactured by Yasugaya Chemical Co., Ltd., polytetramethylene glycol, molecular weight 2000) and the like can be mentioned. Examples of the polybutadiene polyol include 1,4-butadiene or 1,2-butadiene polymer having a hydroxyl group at the molecular end. Examples of the hydrogenated polybutadiene polyether include those obtained by hydrogenating unsaturated double bonds in the molecule of the polybutadiene polyol. These can be easily obtained as commercial products. For example, NISSO-PB G-1000, G-2000, G-3000 (manufactured by Nippon Soda Co., Ltd., liquid polybutadiene glycol), NISSO-PB GI-1000, GI-2000, GI-3000 (manufactured by Nippon Soda Co., Ltd.) , Hydrogenated polybutadiene glycol), Polybd R-45TH (manufactured by Idemitsu Petrochemical Co., Ltd., liquid polybutadiene glycol) and the like.

  Examples of the polymerizable monomer having a carboxyl group at least one carbon atom away from the polymerizable double bond in the production method (c) include 2-carboxyethyl (meth) acrylate and 4-carboxyphenyl (meth). Examples include acrylate, β- (meth) acryloyloxyethyl hydrogen phthalate, β- (meth) acryloyloxyethyl hydrogen succinate, β- (meth) acryloyloxypropyl hydrogen phthalate, (meth) acryloyloxyethyl trimellitic acid, and the like.

  Examples of the polycarboxylic acid in the production method (d) include succinic acid, adipic acid, phthalic acid, hexahydrophthalic acid, in addition to the monoester dicarboxylic acid and polyester polycarboxylic acid exemplified in the production method (b). , Tetrahydrophthalic acid, tricarbaric acid, benzenetricarboxylic acid, benzenetetracarboxylic acid and the like.

  Examples of the polymerizable monomer having a hydroxyl group at least one carbon atom away from the polymerizable double bond in the production method (d) include allyl alcohol, 2-hydroxyethyl (meth) acrylate, 2-hydroxycyclohexyl ( (Meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-[(2-methyl-1-oxo-2-propenyl) )] Oxy] propyl acrylate and the like.

  Examples of the polymerizable monomer having an epoxy group at least one carbon atom away from the polymerizable double bond in the production method (d) include oxiranylmethyl (meth) acrylate, 9-oxiranylnonyl ( And (meth) acrylate, (3-methyloxiranyl) methyl (meth) acrylate, 9,10-epoxidized oleyl acrylate (manufactured by Shin Nippon Rika Co., Ltd., Rica Resin ESA), and the like.

As the monoester polyepoxy compound and the polyester polyepoxy compound in the production method of (e), a reaction product of monoester dicarboxylic acid and / or polyester polycarboxylic acid and epichlorohydrin exemplified in the production method of (b), Examples include terephthalic acid diglycidyl ester, o-phthalic acid diglycidyl ester, and compounds having the following structural formula.

  As the polymerizable monomer having a functional group capable of reacting with an epoxy group in the production method of (e) above, (meth) acrylic acid, maleic acid, allyl alcohol, 2-hydroxyethyl (meth) acrylate, vinylethylamine, Examples include bityl butylamine and aminoethyl (meth) acrylate.

  The monomer (X) is not only obtained by the above production method, but also can be easily obtained as a commercial product. Examples thereof include KAYARAD MANDA, HX-220, HX-620, R-526, DPCA-20, DPCA-30, DPCA-60, DPCA-120 (manufactured by Nippon Kayaku Co., Ltd.).

  In the above method I, in addition to the monomers (i) to (vi), the monomers (ix) to (xiv), the monomer (X), any suitable other copolymerizable with these Monomer (g) may be used. The amount used is preferably 0 to 30% by weight with respect to the total amount of monomers (i) to (vi), monomers (ix) to (xiv) and monomer (X).

  Other monomers (g) include esters of aliphatic alcohols having 1 to 20 carbon atoms and (meth) acrylic acid; (meth) acrylamides; maleic acid, fumaric acid, or these acids and carbon numbers. Monoesters or diesters of 1 to 20 aliphatic alcohols or glycols having 2 to 4 carbon atoms or addition of these glycolic acids with polyalkylene glycols of 2 to 100; Acetic acid alkenyl esters such as vinyl acetate and propenyl acetate; Aromatic vinyl such as styrene and p-methylstyrene; vinyl chloride; and the like can be used, and one or more of these can be used.

In the above method I, the monomers are preferably used in the following combinations.
(Combination I-1) Monomer (i), Monomer (xiv), Monomer (X)
(Combination I-2) Monomer (i), Monomer (iv), Monomer (X)
(Combination I-3) Monomer (i), Monomer (iv), Monomer (xiv), Monomer (X)
(Combination I-4) Monomer (i), Monomer (iii), Monomer (X)
(Combination I-5) Monomer (i), Monomer (iii), Monomer (xiv), Monomer (X)

In the above method II, preferably, a monomer is used in the following combination to obtain a water-soluble polymer.
(Combination II-1) Monomer (i), Monomer (xiv)
(Combination II-2) Monomer (i), Monomer (iv)
(Combination II-3) Monomer (i), Monomer (iv), Monomer (xiv)
(Combination II-4) Monomer (i), Monomer (iii)
(Combination II-5) Monomer (i), Monomer (iii), Monomer (xiv)

  In the case of the above (Combination I-1), monomer (X), monomer (xiv), and monomer (i) are monomer (X) 0.1 to 50% by weight, monomer (X xiv) 1-98.9% by weight, monomer (i) 1-98.9% by weight (provided that the total of monomer (X), monomer (xiv) and monomer (i) is 100) It is preferably used in a ratio of% by weight).

  In the case of the above (Combination I-2), monomer (X), monomer (iv), and monomer (i) are monomer (X) 0.1 to 50% by weight, monomer (X iv) 1-98.9% by weight, monomer (i) 1-98.9% by weight (provided that the total of monomer (X), monomer (iv), monomer (i) is 100) It is preferably used in a ratio of% by weight).

  In the case of the above (Combination I-3), monomer (X), monomer (xiv), monomer (iv), and monomer (i) are monomer (X) 0.1-50. % By weight, monomer (xiv) 1 to 70% by weight, monomer (iv) 1 to 97.9% by weight, monomer (i) 1 to 97.9% by weight (provided that the monomer (X ), Monomer (xiv), monomer (iv), monomer (i) is preferably 100% by weight), and monomer (X) 1 to 20% by weight %, Monomer (xiv) 5 to 59% by weight, monomer (iv) 1 to 49% by weight, monomer (i) 39 to 93% by weight (provided that monomer (X), monomer (Xiv), monomer (iv), and monomer (i) are preferably used in a ratio of 100% by weight.

  In the case of the above (Combination I-4), monomer (X), monomer (iii), and monomer (i) are monomer (X) 0.1 to 50% by weight, monomer (X iii) 1-98.9% by weight, monomer (i) 1-98.9% by weight (provided that the total of monomer (X), monomer (iii), monomer (i) is 100) It is preferably used in a ratio of% by weight).

  In the case of the above (Combination I-5), the monomer (X), the monomer (xiv), the monomer (iii), and the monomer (i) are monomer (X) 0.1-50. % By weight, monomer (xiv) 1 to 70% by weight, monomer (iii) 1 to 97.9% by weight, monomer (i) 1 to 97.9% by weight (provided that the monomer (X ), Monomer (xiv), monomer (iii), and monomer (i) are preferably in a ratio of 100% by weight, and the monomer (X) is 1 to 20% by weight. %, Monomer (xiv) 5 to 59% by weight, monomer (iii) 1 to 49% by weight, monomer (i) 39 to 93% by weight (provided that monomer (X), monomer (Xiv), monomer (iii), and monomer (i) are preferably used in a ratio of 100% by weight.

  In the case of the above (Combination II-1), monomer (xiv) and monomer (i) are monomer (xiv) 1 to 99.9% by weight and monomer (i) 99 to 0.00. It is preferably used in a ratio of 1% by weight (provided that the total of the monomer (xiv) and the monomer (i) is 100% by weight), and the monomer (xiv) is 50 to 80% by weight and More preferably, the monomer (i) is used in a ratio of 20 to 50% by weight (provided that the total of the monomer (xiv) and the monomer (i) is 100% by weight). If the amount of monomer (xiv) is too small, the slump retention performance may be inferior, and if it is too large, entrained air may increase. Moreover, when there are too few monomers (i), there exists a possibility that a dispersibility may be inferior, and when too large, there exists a possibility that hardening retardation may appear.

  In the case of the above (Combination II-2), monomer (iv) and monomer (i) are monomer (iv) 1 to 99% by weight and monomer (i) 1 to 99% by weight ( However, the ratio of the monomer (iv) and the monomer (i) is preferably 100% by weight), preferably 1 to 40% by weight of the monomer (iv) and the monomer (i ) 60 to 99% by weight (however, the total of monomer (iv) and monomer (i) is 100% by weight) is more preferably used. If the monomer (iv) or the monomer (i) is out of the above range, the dispersibility may be insufficient, material separation may occur, or slump loss may increase.

  In the case of the above (Combination II-3), monomer (iv), monomer (i), and monomer (xiv) are monomer (iv) 1 to 98% by weight, monomer (i) 1 to 98% by weight, monomer (xiv) 1 to 70% by weight (however, the sum of monomer (iv), monomer (i) and monomer (xiv) is 100% by weight) It is preferably used in a ratio of 1 to 50% by weight of monomer (iv), 39 to 94% by weight of monomer (i), and 5 to 60% by weight of monomer (xiv) (provided that monomer ( iv), the monomer (i), and the monomer (xiv) are preferably used in a ratio of 100% by weight. If any of monomer (iv), monomer (i), and monomer (xiv) is out of the above range, there is a risk of insufficient dispersibility, material separation, increased slump loss, or increased air amount.

  In the case of the above (Combination II-4), the monomer (iii) and the monomer (i) are 1 to 99% by weight of the monomer (iii) and 1 to 99% by weight of the monomer (i) ( However, the ratio of the monomer (iii) and the monomer (i) is preferably 100% by weight), preferably 1 to 40% by weight of the monomer (iii) and the monomer (i ) 60 to 99% by weight (provided that the total of monomer (iii) and monomer (i) is 100% by weight). If the body (i) is out of the above range, the dispersibility may be insufficient, material separation may occur, or slump loss may increase.

  In the case of (Combination II-5), monomer (iii), monomer (i), and monomer (xiv) are monomer (iii) 1 to 98% by weight, monomer (i) 1 to 98% by weight, monomer (xiv) 1 to 70% by weight (however, the sum of monomer (iii), monomer (i) and monomer (xiv) is 100% by weight) It is preferably used in a ratio, and monomer (iii) 1 to 50% by weight, monomer (i) 39 to 94% by weight, monomer (xiv) 5 to 60% by weight (provided that monomer ( iii), the monomer (i), and the monomer (xiv) are more preferably used in a ratio of 100% by weight. If any of the monomer (iii), the monomer (i), and the monomer (xiv) is out of the above range, insufficient dispersibility, material separation, increased slump loss, or increased air amount may occur.

  Any appropriate cross-linking agent can be adopted as the cross-linking agent for constructing the cross-linked structure used in Method II. Preferably, a compound having a functional group capable of reacting with a functional group (for example, a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, etc.) of the water-soluble polymer is used. For example, ethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, polyglycerin, propylene glycol, diethanolamine, triethanolamine, polyoxypropylene, oxyethyleneoxypropylene block copolymer, pentaerythritol, sorbitol, sorbitan fatty acid Polyhydric alcohols such as esters; ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, propylene Glycol diglycidyl A Le, polypropylene glycol diglycidyl ether, resorcin diglycidyl ether, 1,6-hexanediol diglycidyl ether, adipic acid diglycidyl ester, polyglycidyl compounds such as such as o- phthalic acid diglycidyl ester; and the like.

  When a polyhydric alcohol is used as the crosslinking agent, a monomer having a carboxyl group at least one carbon atom away from the polymerizable double bond when polymerizing the water-soluble polymer, such as 2-methacryloyloxyethyl A cross-linked polymer having the desired structure can be obtained by copolymerizing succinic acid, 2-methacryloyloxyethyl phthalic acid, and the like and further esterifying with a polyhydric alcohol as a cross-linking agent.

  The amount of the crosslinking agent used is the functional group molar ratio (functional group of the crosslinking agent / functionality of the water-soluble polymer) relative to the functional group of the water-soluble polymer (such as carboxyl group and / or hydroxyl group and / or sulfonic acid group). Group) is preferably used in an amount of 0.001 to 1.0, more preferably 0.01 to 0.3. If this molar ratio is less than the above range, the effect of preventing slump loss is not sufficient, and there is a possibility that the performance of the cement admixture may not be obtained. There is a risk of handling problems.

  Any appropriate polymerization method can be adopted as the polymerization of the monomer that can be carried out in the above-mentioned method I and method II. For example, the monomer may be polymerized using a polymerization initiator. As the polymerization, any appropriate polymerization format such as solution polymerization or bulk polymerization can be adopted.

  Solution polymerization can be carried out either batchwise or continuously. Solvents that can be used in solution polymerization include water; lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane, and n-hexane; ethyl acetate; acetone And ketone compounds such as methyl ethyl ketone; From the viewpoint of the solubility of the raw material monomer and the resulting water-soluble polymer and the handleability when using the water-soluble polymer, at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms is used. It is preferable. Among the lower alcohols having 1 to 4 carbon atoms, methyl alcohol, ethyl alcohol, and isopropyl alcohol are particularly preferable.

  When the polymerization is carried out in an aqueous medium, a water-soluble polymerization initiator such as ammonium or alkali metal persulfate or hydrogen peroxide can be used as the polymerization initiator. In this case, an accelerator such as sodium bisulfite can be used in combination. For polymerization using a lower alcohol, aromatic hydrocarbon, aliphatic hydrocarbon, ethyl acetate, or ketone compound as a solvent, peroxides such as benzoyl peroxide and lauroyl peroxide: hydroperoxides such as cumene hydroperoxide; Aliphatic azo compounds such as azobisisobutyronitrile; etc. are used as the polymerization initiator. In this case, an accelerator such as an amine compound can be used in combination. When a mixed solvent of water and a lower alcohol is used, it can be appropriately selected from the above-mentioned various polymerization initiators or combinations of polymerization initiators and accelerators. The polymerization temperature is appropriately determined depending on the solvent and polymerization initiator used, but is preferably in the range of 0 to 120 ° C.

  In the bulk polymerization, as a polymerization initiator, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; aliphatic azo compounds such as azobisisobutyronitrile; and the like can be used. The polymerization temperature is preferably within the range of 50 to 150 ° C.

  Method II (First, a monomer for constructing a water-soluble polymer structure is polymerized to produce a water-soluble polymer, and then a cross-linking agent for constructing a cross-linked structure is reacted therewith to produce a cross-linked polymer) Any suitable method can be adopted as a method for reacting the water-soluble polymer with the crosslinking agent. For example, a method in which a water-soluble polymer is directly reacted with a crosslinking agent in an aqueous solvent, and a method in which the water-soluble polymer is suspended and dispersed in a hydrophobic organic solvent and the crosslinking agent is reacted (reverse phase suspension method). It is done.

  When using Method II, any appropriate temperature can be adopted as the reaction temperature. For example, 20-200 degreeC is preferable and 50-100 degreeC is more preferable.

  The crosslinked polymer thus obtained has a viscosity at 25 ° C. in a 20 wt% aqueous solution or aqueous dispersion of preferably 10,000 cps or less.

  In the production method of the present invention, the crosslinked polymer obtained as described above, that is, a linkage represented by the general formula (1) between main chains of a water-soluble polymer structure having a weight average molecular weight of 500 to 100,000. Shearing is performed on the crosslinked polymer having a bond containing at least one group.

  In general, a polymer is like a chain (or a thread) formed by long one-dimensional groups of constituent units. In a solution, such a molecule is called a random coil. It has a bent shape. In dilute solutions, the polymer exists as an independent thread, but at higher concentrations, the threads overlap each other and the polymer becomes intricately entangled. In a cross-linked polymer, cross-linking within a polymer chain and cross-linking between polymer chains exist, and in particular, in a cross-linked polymer in which cross-linking between polymer chains exists, the entanglement between polymers becomes complicated. On the other hand, the cross-linked polymer of the water-soluble polymer is excellent in slump retention performance, but greatly increases in viscosity as the cross-linking proceeds, so that the dispersion stability and handleability deteriorate. In addition, due to the thickening, when blended in the cement composition, it is difficult to adjust to water, the cement composition becomes non-uniform, and the local presence of the cement admixture tends to cause poor curing. If the degree of crosslinking is reduced to reduce this thickening, excellent slump retention performance cannot be maintained, and until now it has been extremely difficult to achieve both excellent slump retention performance and low viscosity due to a highly crosslinked state. . In the present invention, it was considered to “shear” the crosslinked polymer as a means for realizing low viscosity while maintaining excellent slump retention performance due to the highly crosslinked state. By “shearing” the crosslinked polymer, the entanglement between the crosslinked polymers (polymer molecules) can be released while maintaining the excellent slump retention performance due to the highly crosslinked state. It was considered that low viscosity could be achieved while maintaining the performance. And as a result of repeated verification based on this idea, it has a bond containing at least one linking group represented by the general formula (1) between the main chains of the water-soluble polymer structure having a weight average molecular weight of 500 to 100,000. It was found that when the crosslinked polymer was sheared, a low viscosity could be realized while maintaining excellent slump retention performance due to the highly crosslinked state. In particular, a polycarboxylic acid-based water-soluble polymer having a polyalkylene glycol chain in the side chain is likely to form an interpolymer complex via a hydrogen bond, so that the cross-linked polymers (polymer molecules) tend to be entangled with each other. Therefore, it is possible to realize a low viscosity while maintaining excellent slump retention performance due to a highly crosslinked state.

  As a shearing condition in the production method of the present invention, any appropriate condition can be adopted as long as the object of the present invention can be achieved.

  The rotational speed of shearing is preferably 1000 to 20000 rpm, more preferably 2000 to 15000 rpm, and further preferably 2500 to 10,000 rpm. If the rotational speed of the shear is out of the above range, it may be difficult to achieve both a high crosslinked state and a low viscosity in the crosslinked polymer.

  Any appropriate shearing device can be adopted as the device used for shearing. For example, a homomixer, a pipeline mixer, etc. are mentioned.

  Shearing can be performed in any suitable state for the crosslinked polymer. Preferably, the aqueous solution or aqueous dispersion of the crosslinked polymer is sheared.

  The viscosity of the crosslinked polymer after shearing in a 20% by weight aqueous solution or aqueous dispersion at 25 ° C. is preferably 120 cps or more, more preferably 130 cps or more, still more preferably 140 cps or more, and particularly preferably 150 cps or more. . When the said viscosity is less than 120 cps, there exists a possibility that the outstanding slump retention performance cannot be expressed.

  The viscosity of the crosslinked polymer after shearing in a 20% by weight aqueous solution or aqueous dispersion at 25 ° C. is preferably 2000 cps or less, more preferably 1500 cps or less, still more preferably 1200 cps or less, and particularly preferably 1000 cps or more. . When the viscosity exceeds 2000 cps, it may be difficult to achieve both excellent slump retention performance and low viscosity due to a highly crosslinked state.

[Polymer for cement admixture]
The cement admixture polymer of the present invention is a cement admixture polymer obtained by the production method of the present invention (hereinafter, this cement admixture polymer is referred to as “cement admixture polymer A”). Is).

  As a particularly preferred embodiment, the cement admixture polymer of the present invention also has at least a linking group represented by the general formula (1) between main chains of a water-soluble polymer structure having a weight average molecular weight of 30,000 to 50,000. A cross-linked polymer having one bond and having a viscosity of 120 to 2000 cps at 25 ° C. in a 20% by weight aqueous solution or aqueous dispersion (hereinafter, this cement admixture polymer is referred to as “a cement admixture heavy”). May be referred to as “Borge B”).

  The above “viscosity at 25 ° C. in a 20 wt% aqueous solution or aqueous dispersion” can be an index for specifying the cement admixture polymer of the present invention.

  The lower limit of the viscosity is preferably 130 cps or more, more preferably 140 cps or more, and even more preferably 150 cps or more. When the said viscosity is less than 120 cps, there exists a possibility that the outstanding slump retention performance cannot be expressed.

  The upper limit of the viscosity is preferably 1500 cps or less, more preferably 1200 cps or less, and still more preferably 1000 cps or more. When the viscosity exceeds 2000 cps, it may be difficult to achieve both excellent slump retention performance and low viscosity due to a highly crosslinked state.

  The polymer B for cement admixture is a crosslinked polymer having a bond containing at least one linking group represented by the general formula (1) between main chains of a water-soluble polymer structure having a weight average molecular weight of 30,000 to 50,000. is there. The weight average molecular weight is preferably 30000-45000, more preferably 30000-40000. If the weight average molecular weight is out of the above range, it may be difficult to achieve both excellent slump retention performance and low viscosity due to a highly crosslinked state.

  Arbitrary appropriate methods can be employ | adopted as a method of manufacturing the polymer B for cement admixtures. Preferably, it manufactures using the method similar to the manufacturing method of this invention. In this case, particularly preferably, the crosslinked polymer to be used is obtained by reacting a water-soluble polymer having a weight average molecular weight of 30,000 to 50,000 with a crosslinking agent of 3.4 to 5.7% by weight based on the water-soluble polymer. It is. By producing under such conditions, the viscosity at 25 ° C. in a 20 wt% aqueous solution or aqueous dispersion can be adjusted to 120 to 2000 cps.

[Cement admixture]
The cement admixture of the present invention contains the polymer for cement admixture of the present invention. That is, the cement admixture of the present invention contains the polymer A for cement admixture and / or the polymer B for cement admixture.

  In the cement admixture of the present invention, the polymer for cement admixture of the present invention may be dissolved or dispersed in water. Thus, when the polymer for cement admixture of the present invention is dissolved or dispersed in water, there is an advantage that it is easy to handle, and part or all of the kneaded water is prepared when preparing a cement composition. Available as In addition, dispersion stability problems (such as sedimentation) do not occur. When the polymer for cement admixture of the present invention is dissolved or dispersed in water in advance, any appropriate ratio can be adopted as the ratio of the polymer for cement admixture of the present invention and water.

  The cement admixture of the present invention exhibits high fluidity without bringing about a large retarding curing property to cement compositions such as cement mortar and concrete, and has excellent slump retention performance. In construction and concrete construction, workability is significantly improved.

  The cement admixture of the present invention can be effectively used as a fluidizing agent for concrete including, for example, ready-mixed concrete. In particular, it has a high water reduction ratio as a high-performance AE water reducing agent simultaneously added to the plant. The ready-mixed concrete can be easily manufactured and its fluidity can be kept constant. Furthermore, it can be effectively used as a high-performance water reducing agent for producing concrete secondary products.

  The cement admixture of the present invention includes, for example, cement milk, mortar grouting aids, cement blends placed by tremy tubes, underwater concrete, continuous underground wall concrete fluidity retention and material separation prevention, etc. It can be used effectively for other purposes.

  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, cement compositions that use cement as the hydraulic material are the most common. Such a cement composition preferably contains the cement admixture of the present invention, cement, and water as essential components.

[Cement composition]
The cement composition of the present invention contains the cement admixture of the present invention. Preferably, the cement admixture of the present invention, cement, and water are included as essential components.

  In the cement composition of the present invention, any appropriate cement can be adopted as the cement. For example, Portland cement (ordinary, early strength, very early strength, moderate heat, sulfate-resistant and low alkali type of each), various mixed cements (blast furnace cement, silica cement, fly ash cement), white Portland cement, alumina cement, Super fast cement (1 clinker fast cement, 2 clinker fast cement, magnesium phosphate cement), grout cement, oil well cement, low exothermic cement (low exothermic blast furnace cement, fly ash mixed low exothermic blast furnace cement, belite High-concentration cement), ultra-high-strength cement, cement-based solidified material, eco-cement (city waste incineration ash, sewage sludge incineration ash as a raw material), blast furnace slag, fly ash , Cinder ash, clinker ash, Squash, silica fume, silica powder, 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, chrome, chromic, magnesia, etc. The refractory aggregate can be used.

In the cement composition of the present invention, any appropriate value can be adopted as the unit water amount per 1 m ³ , the amount of cement used, and the water / cement ratio. For example, preferably, the unit water amount is 100 to 185 kg / m ³ , the used cement amount is 250 to 800 kg / m ³ , and the water / cement ratio (mass ratio) is 0.1 to 0.7, and more preferably, the unit water amount is 120. ˜175 kg / m ³ , amount of cement used 270 to 800 kg / m ³ , water / cement ratio (mass ratio) = 0.15 to 0.65. 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.

  Any appropriate ratio can be adopted as the blending ratio of the cement admixture of the present invention in the cement composition of the present invention. For example, when used for mortar, concrete, or the like using hydraulic cement, it is preferably 0.01 to 10 parts by weight, more preferably 0.02 to 5 parts by weight, and even more preferably 0 to 100 parts by weight of cement. What is necessary is just to add the quantity of the ratio used as 0.05-3 weight part. This addition brings about favorable effects such as a reduction in the amount of unit water, an increase in strength, and an improvement in durability. If the blending ratio is less than 0.01 parts by weight, the performance as a cement composition may not be sufficiently exerted, and even if an amount exceeding 10 parts by weight is used, the effect is substantially peaked and from the economical aspect. May be disadvantageous.

  The cement composition of the present invention is effective for concrete for concrete secondary products, concrete for centrifugal molding, concrete for vibration compaction, steam-cured concrete, shotcrete, and the like, and is also highly fluidized concrete and self-filling concrete. 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 any appropriate cement dispersant. Examples thereof include various sulfonic acid-based dispersants having a sulfonic acid group in the molecule, and various polycarboxylic acid-based dispersants having a polyoxyalkylene chain and a carboxyl group in the molecule. These cement dispersants may be used alone or in combination of two or more.

  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. Aminosulfonic acid compounds; and the like.

  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.

  When the cement composition of the present invention contains the cement dispersant as described above, any appropriate ratio is adopted as the blending weight ratio of the cement admixture of the present invention and the cement dispersant as described above. obtain. Preferably it is 5: 95-95: 5, More preferably, it is 10: 90-90: 10.

  The cement composition of the present invention may further contain other cement additives (materials) as exemplified in the following (1) to (20). These other cement additives (materials) may be used alone or in combination of two or more.

  (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, etc.); polyacrylamide; polyvinyl alcohol; starch; starch phosphate ester; sodium alginate; gelatin; Copolymer of acrylic acid having a group and its quaternary compound;

  (2) Polymer emulsion: copolymer 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; and the like.

  (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 Surfactants; 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.

  In addition to the above, the cement composition of the present invention includes, for example, a cement wetting agent, a thickening agent, a separation reducing agent, an aggregating agent, a drying shrinkage reducing agent, a strength enhancing agent, self A leveling agent, a rust preventive agent, a coloring agent, a fungicide, etc. can be used.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited by these Examples.
(Measurement of weight average molecular weight)
Gel permeation chromatography (GPC) was used to measure polyethylene glycol as a standard substance.
(Measurement of viscosity)
Viscosity was measured using a Brookfield viscometer.

[Production Example 1]: Production of water-soluble polymer (1) In a glass reactor (internal volume: 1 liter) equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser (condenser), 4690 g of water was charged, and the reaction was purged with nitrogen under stirring, and the temperature was raised to 95 ° C. under a nitrogen atmosphere. Next, a mixed solution of 1572.5 g of methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added 10), 375.0 g of methacrylic acid, 52.5 g of sodium methacrylate, and 3000 g of water was put in the reactor over 4 hours. At the same time, 310.0 g of a 5 wt% aqueous solution of ammonium persulfate was dropped over 5 hours. After completion of the dropwise addition, the reaction mixture was further maintained at 95 ° C. for 1 hour and then cooled to room temperature to obtain an aqueous polymer solution.
Half of the obtained polymer aqueous solution, 5 kg, is taken, 184.1 g of a 30 wt% aqueous sodium hydroxide solution is added, the solid content concentration is concentrated to 50 wt% with an evaporator, and a water-soluble polymer (pH = 6.5) An aqueous solution of 1) was obtained. The weight average molecular weight of the water-soluble polymer (1) was 35000.

[Production Example 2]: Production of water-soluble polymer (2) The remaining half of 5 kg of the polymer aqueous solution obtained in Production Example 1 is taken, and the solid content concentration is concentrated to 50% by weight with an evaporator, pH = 4 An aqueous solution of water-soluble polymer (2) of 0.5 was obtained. The weight average molecular weight of the water-soluble polymer (2) was 35,000.

[Example 1-1]
To a 40 liter kneader equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser (condenser), 27% of the aqueous solution of the 50 wt% water-soluble polymer (1) obtained in Production Example 1 was added. Charged 0.000 kg, 2.649 g of water were added, the kneader was purged with nitrogen while stirring at 43 rpm, and the temperature was raised to 95 ° C. in a nitrogen atmosphere. Next, 351 g of Denacol EX-721 (orthophthalic acid diglycidyl ester, manufactured by Nagase ChemteX Corp.) (2.60% by weight based on the solid content of the water-soluble polymer aqueous solution (1)) was added, and the internal temperature was adjusted to 90 to Maintained at 95 ° C. for 3 hours. The appearance at the time of reaction proceeded in a uniform system throughout, and an aqueous solution of the crosslinked polymer (1-1) (solid content concentration 20.0% by weight) was obtained.
The viscosity (25 ° C.) immediately after the crosslinking reaction of the aqueous solution of the crosslinked polymer (1-1) (solid content concentration 20.0% by weight) was 600 cps.

[Example 1-2]
In a 300 ml beaker, 200 g of the aqueous solution (solid content concentration 20.0% by weight) of the crosslinked polymer (1-1) obtained in Example 1-1 was put, and a homomixer (manufactured by Special Machine Industries, Ltd., HV-M Type) was sheared at a rotational speed of 10,000 rpm. At this time, it was cooled with water or ice so that water would not evaporate due to heat.
The viscosity (25 ° C.) of the aqueous solution (solid content concentration 20.0 wt%) of the crosslinked polymer (1-2) after shearing was stable at 490 cps.

[Example 2-1]
To a 40 liter kneader equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser (condenser), 27% of the aqueous solution of the 50 wt% water-soluble polymer (1) obtained in Production Example 1 was added. Charged 0.000 kg, 2.649 g of water were added, the kneader was purged with nitrogen while stirring at 43 rpm, and the temperature was raised to 95 ° C. in a nitrogen atmosphere. Next, 371 g of Denacol EX-721 (orthophthalic acid diglycidyl ester, manufactured by Nagase ChemteX Corp.) (2.75% by weight based on the solid content of the water-soluble polymer aqueous solution (1)) was added, and the internal temperature was adjusted to 90 to Maintained at 95 ° C. for 3 hours. The appearance at the time of reaction proceeded in a uniform system throughout, and an aqueous solution of the crosslinked polymer (2-1) (solid content concentration 20.0% by weight) was obtained.
The viscosity (25 ° C.) immediately after the crosslinking reaction of the aqueous solution of the crosslinked polymer (2-1) (solid content concentration 20.0% by weight) was 1010 cps.

[Example 2-2]
In a 300 ml beaker, 200 g of the aqueous solution (solid content concentration 20.0% by weight) of the crosslinked polymer (2-1) obtained in Example 2-1 was placed, and a homomixer (made by Tokushu Kika Kogyo Co., Ltd., HV-M). Type) was sheared at a rotational speed of 10,000 rpm. At this time, it was cooled with water or ice so that water would not evaporate due to heat.
The viscosity (25 ° C.) of the aqueous solution (solid content concentration 20.0 wt%) of the crosslinked polymer (2-2) after shearing was stable at 580 cps.

[Example 3-1]
To a 40 liter kneader equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube, and a reflux condenser (condenser), 27% of the aqueous solution of the 50 wt% water-soluble polymer (1) obtained in Production Example 1 was added. 0.000 kg was charged, 2.595 g of water was added, the kneader was purged with nitrogen while stirring at 43 rpm, and the temperature was raised to 95 ° C. in a nitrogen atmosphere. Next, 405 g of Denacol EX-721 (orthophthalic acid diglycidyl ester, manufactured by Nagase ChemteX Corp.) (3.00% by weight based on the solid content of the water-soluble polymer aqueous solution (1)) was added, and the internal temperature was adjusted to 90 to 90%. Maintained at 95 ° C. for 3 hours. The appearance at the time of reaction proceeded in a uniform system throughout, and an aqueous solution of the crosslinked polymer (3-1) (solid content concentration 20.0% by weight) was obtained.
The viscosity (25 ° C.) immediately after the crosslinking reaction of the aqueous solution of the crosslinked polymer (3-1) (solid content concentration: 20.0% by weight) was 4460 cps.

[Example 3-2]
In a 300 ml beaker, 200 g of the aqueous solution (solid content concentration 20.0% by weight) of the crosslinked polymer (3-1) obtained in Example 3-1 was placed, and a homomixer (made by Tokushu Kika Kogyo Co., Ltd., HV-M). Type) was sheared at a rotational speed of 10,000 rpm. At this time, it was cooled with water or ice so that water would not evaporate due to heat.
The viscosity (25 ° C.) of the aqueous solution (solid content concentration 20.0% by weight) of the crosslinked polymer (3-2) after shearing was stable at 930 cps.

[Example 3-3]
In a 300 ml beaker, 200 g of the aqueous solution (solid content concentration 20.0% by weight) of the crosslinked polymer (3-1) obtained in Example 3-1 was placed, and a homomixer (made by Tokushu Kika Kogyo Co., Ltd., HV-M). The mold was sheared at a rotational speed of 5000 rpm. At this time, it was cooled with water or ice so that water would not evaporate due to heat.
The viscosity (25 ° C.) of the aqueous solution (solid content concentration 20.0 wt%) of the crosslinked polymer (3-3) after shearing was stable at 1290 cps.

[Example 3-4]
In a 300 ml beaker, 200 g of the aqueous solution (solid content concentration 20.0% by weight) of the crosslinked polymer (3-1) obtained in Example 3-1 was placed, and a homomixer (made by Tokushu Kika Kogyo Co., Ltd., HV-M). The mold was sheared at a rotational speed of 2500 rpm. At this time, it was cooled with water or ice so that water would not evaporate due to heat.
The viscosity (25 ° C.) of the aqueous solution (solid content concentration 20.0 wt%) of the crosslinked polymer (3-4) after shearing was stable at 1990 cps.

[Example 4-1]
A 50 wt% water-soluble polymer obtained in Production Example 2 (with a content of 1 liter) was added to a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube, and a reflux condenser (condenser). 320 g of the aqueous solution of 2) was added, 472.2 g of water was added, the reactor was purged with nitrogen while stirring, and the temperature was raised to 95 ° C. under a nitrogen atmosphere. Next, 7.8 g of Denacol EX-721 (orthophthalic acid diglycidyl ester, manufactured by Nagase ChemteX Corp.) (4.90% by weight based on the solid content of the water-soluble polymer aqueous solution (1)) was added, and the internal temperature was adjusted. The temperature was maintained at 90 to 95 ° C. for 3 hours. The appearance at the time of reaction proceeded in a heterogeneous system throughout, and an aqueous solution of the crosslinked polymer (4-1) (solid content concentration 20.0% by weight) was obtained.
The viscosity (25 ° C.) immediately after the crosslinking reaction of the aqueous solution of the crosslinked polymer (4-1) (solid content concentration 20.0% by weight) was 850 cps.

[Example 4-2]
In a 300 ml beaker, 200 g of the aqueous solution (solid content concentration 20.0% by weight) of the crosslinked polymer (4-1) obtained in Example 4-1 was placed, and a homomixer (manufactured by Special Machine Industries Co., Ltd., HV-M). Type) was sheared at a rotational speed of 10,000 rpm. At this time, it was cooled with water or ice so that water would not evaporate due to heat.
The viscosity (25 ° C.) of the aqueous solution (solid content concentration 20.0 wt%) of the crosslinked polymer (4-2) after shearing was stable at 240 cps.

[Reference Example 1] Mortar test of water-soluble polymer (1) At room temperature, 125 g of cement (ordinary Portland cement), 125 g of sand (Toyoura standard sand), water containing water-soluble polymer (1) obtained in Production Example 1 60 g was weighed into a container and stirred with a spatula. Mortar was sampled every predetermined time and the flow value was measured. The flow value is obtained by filling a hollow cylinder with an internal diameter of 50 mm and a height of 50 mm made of SUS, which is placed on a horizontal stainless steel plate, until it is ground up, and then gently lifting it to spread the long and short diameters of the mortar perpendicular to each other. The average value.
The results are shown in FIG.

[Reference Example 2] Mortar test of crosslinked polymer (2-2) At room temperature, 125 g of cement (ordinary Portland cement), 125 g of sand (Toyoura standard sand), and the crosslinked polymer obtained in Example 2-2 (2 -2) 60 g of water was measured into a container, and was continuously stirred by hand using a spatula. Mortar was sampled every predetermined time and the flow value was measured. The flow value is obtained by filling a hollow cylinder with an internal diameter of 50 mm and a height of 50 mm made of SUS, which is placed on a horizontal stainless steel plate, until it is ground up, and then gently lifting it to spread the long and short diameters of the mortar perpendicular to each other. The average value.
The results are shown in FIG.

[Reference Example 3] Mortar test of crosslinked polymer (2-1) At room temperature, 125 g of cement (ordinary Portland cement), 125 g of sand (Toyoura standard sand), the crosslinked polymer obtained in Example 2-1 (2 60 g of water containing -1) was weighed into a container and stirred by hand kneading with a spatula. Mortar was sampled every predetermined time and the flow value was measured. The flow value is obtained by filling a hollow cylinder with an internal diameter of 50 mm and a height of 50 mm made of SUS, which is placed on a horizontal stainless steel plate, until it is ground up, and then gently lifting it to spread the long and short diameters of the mortar perpendicular to each other. The average value.
The results are shown in FIG.

[Evaluation of mortar test]
According to FIG. 1, the flow value in 1 minute of hand kneading was 118 mm for the crosslinked polymer (2-2), whereas it was as low as 92 mm for the crosslinked polymer (2-1). However, the flow value increased with time, and after 3 minutes, the crosslinked polymer (2-2) showed almost the same flow value as the crosslinked polymer (2-1).

  The polymer obtained by the production method of the present invention or the polymer for cement admixture of the present invention can be suitably used for a cement admixture and a cement composition excellent in slump retention performance.

It is a figure showing a mortar test result.

Claims (6)

A crosslinked polymer having a bond containing at least one linking group represented by the general formula (1) between main chains of a water-soluble polymer structure having a weight average molecular weight of 500 to 100,000, wherein the water- soluble polymer structure is generally The manufacturing method of a polymer which shears the crosslinked polymer containing the functional group represented by Formula (16) , and performs this shear with respect to the aqueous solution or aqueous dispersion of this crosslinked polymer .

(However, u is an integer of 1 to 100, when ^{R 5} is an alkylene group having 2 to 4 carbon ^{atoms, R 10} is .u is H or an alkyl group having 1 to 5 carbon atoms is 2 or more In each case, the plurality of R ⁵ Os need not all be the same group, and when the plurality of R ⁵ Os are different from each other, their arrangement may be regular or random.)   The production according to claim 1, wherein the crosslinked polymer is obtained by reacting a water-soluble polymer having a weight average molecular weight of 500 to 100,000 with a crosslinking agent of 3.4 to 5.7% by weight based on the water-soluble polymer. Method.   The manufacturing method of Claim 1 or 2 whose viscosity in 25 degreeC in the 20 weight% aqueous solution or aqueous dispersion of the crosslinked polymer after the shearing is 120 cps or more.   The production method according to any one of claims 1 to 3, wherein a viscosity of the crosslinked polymer after shearing at 25 ° C in a 20 wt% aqueous solution or aqueous dispersion is 2000 cps or less. The monomer for constructing the water-soluble polymer structure includes a monomer represented by the general formula (i) and a monomer represented by the general formula (xiv). The manufacturing method in any one of.

(However, M is any one of hydrogen, a monovalent metal, a divalent metal, a trivalent metal, an ammonium group, and an organic amino group, and R ³ is H or CH _3. )

(However, u is an integer of 1 to 100, ^{R 3} is H or CH _3, ^{R 5} is an alkylene group having 2 to 4 carbon ^{atoms, R 10} is H or an alkyl group having 1 to 5 carbon atoms In addition, when u is 2 or more, it is not necessary that each of the plurality of R ⁵ Os is the same group, and when the plurality of R ⁵ Os are groups different from each other, their arrangement is a rule. Or random.) The said shear is a manufacturing method in any one of Claim 1-5 performed by the rotation speed of 1000-20000 rpm.

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