JP4724697B2 - Drying shrinkage-reducing cement dispersant - Google Patents

Description

  The present invention relates to a cement composition, that is, a dry shrinkage-reducing cement dispersant used for cement paste, grout, mortar, concrete and the like. Specifically, the dry shrinkage-reducing cement dispersant of the present invention has a dry shrinkage-reducing effect and high water reduction, and is excellent in storage stability, and is free from cracking due to dry shrinkage of the cement composition. It suppresses and improves durability.

In general, cement compositions show a decrease in volume with hardening or drying. Among these, the volume reduction due to drying is called “drying shrinkage”, which is the main cause of cracks in the walls and floor boards of concrete structures.
This crack not only reduces the function of the concrete structure, decreases the rigidity, water tightness and aesthetics, but also promotes the neutralization of the concrete by allowing water and air to permeate into the concrete from the cracked part. In order to promote the occurrence of rust in the steel bars, the cracks of the hardened concrete are further promoted, and the durability of the concrete structure is significantly impaired.

As a means for suppressing drying shrinkage of concrete, a method of adding an expansion material mainly composed of calcium sulfoaluminate, calcium oxide or the like is performed.
In order to reduce drying shrinkage, it is an effective means to reduce the amount of water mixed in concrete (unit water amount), and the Architectural Institute of Japan defines the upper limit value of unit water amount of highly durable concrete as 175 kg or less. Yes. In order to meet this requirement, high performance AE water reducing agents with high water reduction are commonly used.
Further, for the purpose of reducing the drying shrinkage of concrete itself, polyoxyalkylene alkyl ether (see Japanese Patent Publication No. 56-51148), alkoxy polyalkylene fatty acid ester (see Japanese Patent Laid-Open No. 3-290342), alcohol (Japanese Patent Laid-Open No. Dry shrinkage reducing agents such as those described in Japanese Patent No. 6500) have been proposed.

However, the method using the above expansion material cannot follow the drying shrinkage over a long period of time because the expansion of the concrete ends very early in the process of hardening the cement. In addition, the expansion material has a drawback that it is difficult to determine an appropriate blending amount for reducing drying shrinkage.
Moreover, the method of reducing the unit water quantity of concrete using a high-performance AE water reducing agent has not yet achieved a sufficiently satisfactory shrinkage reduction effect.
Furthermore, the above-mentioned drying shrinkage reducing agent is not economical because the amount added for obtaining a sufficient drying shrinkage reducing effect is not economical, and has the disadvantage that excessive air is entrained in the concrete. The combined use is indispensable, and in order to reduce the unit water amount of concrete, the combined use with an AE water reducing agent or a high performance AE water reducing agent is indispensable. Generally, the drying shrinkage reducing agent is rarely used alone, and an antifoaming agent, an AE water reducing agent or a high performance AE water reducing agent is used in combination. When these agents are used in combination, the metering / adding apparatus becomes complicated, so these agents are used in a mixed state. However, the mixed solution of these agents has poor storage stability and has a drawback that the antifoaming agent is separated when stored for a long time.

  Therefore, an object of the present invention is to combine the drying shrinkage reducing effect of the conventional drying shrinkage reducing agent with the high water reducing effect of the conventional high performance AE water reducing agent, and the unit water amount of the cement composition with an extremely small amount of use. It is an object of the present invention to provide a dry shrinkage-reducing cement dispersant that drastically reduces dry shrinkage and is excellent in storage stability.

  The above-mentioned problems are solved by a dry shrinkage-reducing cement dispersion characterized by containing a graft polymer in which oligoalkylene glycols and / or polyhydric alcohols are chemically bonded to a side chain of a polycarboxylic acid or a salt thereof. And a drying agent characterized by containing a graft polymer in which an oligoalkylene glycol and / or a polyhydric alcohol and a polyalkylene glycol or a derivative thereof are chemically bonded to a side chain of a polycarboxylic acid or a salt thereof. The solution is drastically solved by shrinkage-reducing cement dispersant.

  The polycarboxylic acid or salt thereof according to the present invention includes a styrene-maleic anhydride copolymer, a partial ester thereof and a salt thereof having a weight average molecular weight of 9000 to 100,000 (see JP-A-1-92212). , Allyl ether-maleic anhydride copolymers and derivatives thereof and salts thereof having a weight average molecular weight of 1000 to 200000 (see JP-A-63-285140), (meth) acrylic acid- (meth) acrylic acid Ester copolymers, derivatives thereof and salts thereof having a weight average molecular weight of 1,000 to 500,000 (see Japanese Patent Application Laid-Open No. 58-74552, Japanese Patent Application No. 6-122808 and Japanese Patent Application Laid-Open No. 1-2226757) And isobutylene-maleic anhydride copolymers and their derivatives and their salts 1,000 to 30,000 (see JP-A-60-103062). Examples, and as these salts, alkali metal salts, alkaline earth metal salts, lower amine salts, lower alkanol amine salts can be exemplified.

  Examples of the oligoalkylene glycols of the present invention include oligoalkylene glycol monoalkyl ethers, alkylamino oligoalkylene glycols, oligoalkylene glycol alkyl phenyl ethers, and derivatives thereof. Examples of these derivatives include ester groups and epoxy groups. And compounds containing polyhydric alcohols.

  Examples of the oligoalkylene glycol monoalkyl ether include diethylene glycol-dipropylene glycol monobutyl ether, tetraethylene glycol-tetrapropylene glycol monobutyl ether, diethylene glycol-propylene glycol monobutyl ether, tetrapropylene glycol monomethyl ether, tetraethylene glycol monoisopropyl ether or the like. The derivative | guide_body can be illustrated.

  Examples of the alkylamino oligoalkylene glycol include N, N-dimethylethanolamine, N, N-dibutylethanolamine and derivatives thereof.

  Examples of the oligoalkylene glycol alkylphenyl ether include dodecapropylene glycol phenyl ether, pentadecapropylene glycol dimethylphenyl ether, and triethylene glycol-dodecapropylene glycol nonylphenyl ether.

  Examples of the polyhydric alcohols of the present invention include neopentyl glycol, pentaerythritol, neopentyl glycol hydroxypivalate, or derivatives thereof.

  The polyalkylene glycol or derivative thereof according to the present invention may be a block copolymer of ethylene oxide and propylene oxide having a foam-suppressing property, a polymer of ethylene oxide, a polymer of propylene oxide, or a monoalkyl ( C1-C14) ethers or their monoesters or derivatives thereof. Examples of these derivatives include acetylene, fatty acid esters and phosphate esters.

The amount of use of the dry shrinkage-reducing cement dispersant of the present invention is basically an amount capable of expressing the desired cement dispersibility, that is, an amount capable of expressing the desired concrete water reduction in the case of ready-mixed concrete. It is.
The dry shrinkage-reducing cement dispersant according to the present invention comprises the graft polymer as an active ingredient, and within a range that can achieve the object of the present invention, the active ingredient is mixed with other active ingredients. I can do it. Any other admixture component may be used as long as it is generally used as a cement additive or a concrete admixture (material). For example, AE water reducing agent, water reducing agent, high performance water reducing agent, high performance AE water reducing water can be used. Examples thereof include an agent, an AE agent, a setting retarder, a setting / curing accelerator, an antifoaming agent, and a thickening agent.

[Action]
The dry shrinkage-reducing cement dispersant of the present invention exhibits an excellent effect when added in a very small amount as compared with conventional dry shrinkage reducing agents.
The basis for this is not necessarily clarified in theory, but conventional drying shrinkage reducing agents may be incorporated into the initial hydrate of cement during the production of concrete, or may exist in concrete for a long time due to volatilization or the like. It can be difficult.
On the other hand, the dry shrinkage-reducing cement dispersant of the present invention is incorporated into cement hydrates because oligoalkylene glycols and / or polyhydric alcohols or their derivatives are chemically bonded. Or volatilization is prevented, and it is considered that the effect can be exhibited with a remarkably small addition amount.
Further, since polyalkylene glycol or a derivative thereof is chemically bonded, it is considered that excellent storage stability is exhibited without layer separation.

Hereinafter, the present invention will be specifically described with reference to production examples and examples.
[Production example]
1) Production of polycarboxylic acid Production Example 1 Styrene-maleic anhydride copolymer (sample symbol S)
In a glass reaction vessel equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel, reflux condenser, methyl isobutyl ketone (MIBK); 321.4 parts by weight, maleic anhydride; 147.0 parts by weight, dodecyl mercaptan ( DOMER; chain transfer agent); 6.0 parts by weight; with stirring, the inside of the reaction vessel was purged with nitrogen, heated to 110 ° C. in a nitrogen atmosphere, and azobisisobutylnitrile (AIBN; polymerization initiator); 6.0 Parts by weight, styrene; 156.0 parts by weight are added dropwise over 1 hour. Thereafter, the reaction is allowed to proceed for 2.5 hours while stirring, and then cooled to room temperature. As a result, a styrene-maleic anhydride copolymer (SMA polymer) having a weight average molecular weight of 21000 (in terms of polyethylene glycol (PEG)) as sample symbol S is obtained.

Production Example 2 Allyl ether-maleic anhydride copolymer (sample symbols A (A), A (B))
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel, a nitrogen inlet tube, and a reflux condenser, methoxy 6 ethylene glycol allyl ether (manufactured by NOF Corporation); 336 parts by weight, maleic anhydride; 98 0.0 parts by weight, benzoyl peroxide (BP); 6.0 parts by weight, toluene; 566.0 parts by weight, and the inside of the vessel was purged with nitrogen under stirring, then heated to 80 ° C. and heated for 4 hours. The reaction was allowed to proceed. Subsequently, toluene was distilled off at 110 ° C. under a reduced pressure of 10 mmHg, and the mixture was then brought to room temperature and normal pressure. The weight average molecular weight 23000 (converted to PEG) allyl ether-maleic anhydride copolymer (AMA polymer (A )) Get.
The allyl ether is changed to methoxy 11 ethylene glycol allyl ether, and the AMA polymer (B) as sample symbol A (B) is obtained under the same conditions as described above.

Production Example 3 Allyl ether-styrene-maleic anhydride copolymer (sample symbol A (C)
In a glass reaction vessel equipped with a thermometer, stirrer, suitable funnel, nitrogen inlet tube, reflux condenser, methoxy 12 ethylene glycol allyl ether (manufactured by NOF Corporation); 201.6 parts by weight, styrene; 41 0.08 parts by weight, maleic anhydride: 98.0 parts by weight, B · P: 6.0 parts by weight, toluene: 566.0 parts by weight, and the inside of the vessel was purged with nitrogen under stirring until 80 ° C. The reaction was allowed to proceed by heating and maintaining the temperature for 4 hours. Subsequently, toluene is distilled off at 110 ° C. under a reduced pressure of 10 mmHg, and then the mixture is brought to normal temperature and normal pressure to obtain an allyl ether-maleic anhydride copolymer (AMA polymer (C)).

2) Production of graft polymer Production Example 4 (sample symbol S01)
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel and a reflux condenser, sample symbol S produced in Production Example 1; 200.7 parts by weight (solid content 101 parts by weight), MIBK; 150.0 Parts by weight, tributylamine (TBAm); 13.3 parts by weight, heated to 110 ° C. and charged in a dropping funnel, polyethylene glycol monomethyl ether (M-PEG500: Mw = 500); 500.0 parts by weight, polyalkylene Glycol derivative (polyoxyethylene polyoxypropylene adduct, trade name: Pluronic L-61: manufactured by Adeka Co., Ltd.); 58.0 parts by weight, TBAm; 13.3 parts by weight were added dropwise, and the temperature was maintained for 3 hours with stirring. Subsequently, MIBK is removed to obtain a graft polymer of sample symbol S01.

Production Example 5 (sample symbols S02 to 08)
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel and a reflux condenser, sample symbol S produced in Production Example 1; 200.7 parts by weight (solid content 101 parts by weight), MIBK; 150.0 Parts by weight, TBAm; 13.3 parts by weight, heated to 110 ° C., and charged in a dropping funnel; M-PEG 500; 250.0 parts by weight and diethylene glycol dipropylene glycol monobutyl ether (trade name: GE-42-2P; Nisso Maruzen Chemical Co., Ltd.); 139.0 parts by weight, Pluronic L-61; 58.0 parts by weight, TBAm; 13.3 parts by weight were added dropwise, and the temperature was maintained for 3 hours and stirring was continued. Removal of the graft polymer of sample symbol S02 is obtained. S03-08 changed the kind of oligoalkylene glycol, and S07 and 08 were manufactured on the same conditions as said S02, without adding pluronic L-61.

Production Example 6 (sample symbol S09, 10)
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel and a reflux condenser, sample symbol S produced in Production Example 1; 200.7 parts by weight (solid content 101 parts by weight), MIBK; 150.0 M-PEG500; 250.0 parts by weight and dimethylaminoethanol; 44.5 parts by weight, Pluronic L-61; 58 charged by weight, TBAm; 13.3 parts by weight and heated to 110 ° C. 0.03 parts by weight, TBAm; 13.3 parts by weight were added dropwise, and the temperature was maintained for 3 hours and stirring was continued. Then, MIBK was removed to obtain a graft polymer of sample symbol S09.
S10 was produced under the same conditions as S09, except that the dimethylaminoethanol was changed to dibutylaminoethanol.

Production Example 7 (sample symbols S11 to 13)
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel and a reflux condenser, sample symbol S produced in Production Example 1; 200.7 parts by weight (solid content 101 parts by weight), MIBK; 150.0 1 part by weight, TBAm; 13.3 parts by weight, heated to 110 ° C., and charged in a dropping funnel; M-PEG 500; 250.0 parts by weight and oligoalkylene glycol phenyl ether; 473.5 parts by weight, TBAm; After 3 parts by weight were dropped and the temperature was maintained for 3 hours and stirring was continued, MIBK was removed to obtain a graft polymer of sample symbol S11.
S12 and 13 were produced under the same conditions as in S11 by changing the type of the oligoalkylene glycol phenyl ether.

Production Example 8 (sample symbols S14 to 16)
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel and a reflux condenser, sample symbol S produced in Production Example 1; 200.7 parts by weight (solid content 101 parts by weight), MIBK; 150.0 52 parts by weight and neopentyl glycol (NPG: manufactured by Mitsubishi Gas Chemical Co., Ltd.); 52 parts by weight, TBAm: 13.3 parts by weight, heated to 110 ° C. and charged in a dropping funnel 0.04 parts by weight, Pluronic L-61; 58.0 parts by weight, TBAm; 13.3 parts by weight were added dropwise, and after stirring for 3 hours, MIBK was removed to obtain a graft polymer of sample symbol S14 .
S15 and 16 are the same conditions as S14, except that the type of polyhydric alcohol is changed to pentaerythritol (PE: manufactured by Mitsubishi Gas Chemical Co., Ltd.) and neopentyl glycol hydroxypivalate (ESG: manufactured by Mitsubishi Gas Chemical Co., Ltd.). Manufactured by.

Production Example 9 (sample symbols A01, 03, 04)
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel, and a reflux condenser, sample symbols A (A) produced in Polymer Production Example 2; 108.5 parts by weight, MIBK; 150.0 parts by weight GE-42-2P; 173.8 parts by weight, polyalkylene glycol derivative (polyoxyethylene polyoxypropylene adduct, trade name: Pluronic L-64: Adeka Co., Ltd.) 46.0 parts by weight, TBAm; 13.3 parts by weight were added dropwise and heated to 110 ° C., kept at the temperature for 3 hours and kept stirring, then MIBK was distilled off under reduced pressure, cooled to room temperature, The graft polymer of sample symbol A01 is obtained as a 40% aqueous solution by dilution. A03 was prepared under the same conditions as A01, except that Pluronic L-64 was not added, and A04 was substituted with PE for half of GE-42-2P.

Production Example 10 (sample symbol A02)
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel, and a reflux condenser, sample symbols A (A) produced in Polymer Production Example 2; 108.5 parts by weight, MIBK; 150.0 parts by weight Diethylene glycol propylene glycol monobutyl ether (trade name: GE-42-1P: manufactured by Nisso Maruzen Chemical Co., Ltd.); 139.1 parts by weight, TBAm; 13.3 parts by weight Was added dropwise, heated to 110 ° C. and kept stirring for 3 hours, then MIBK was distilled off under reduced pressure, cooled to room temperature and diluted with water to obtain a graft polymer of sample symbol A02 as a 40% aqueous solution.

Production Example 11 (sample symbol A05, 06)
A glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel and a reflux condenser was charged with sample symbol A (B) produced in Production Example 2 of polymer: 113.7 parts by weight, toluene: 150 parts by weight 110 45.5 parts by weight of PE charged in the dropping funnel and 13.3 parts by weight of TBAm were added dropwise and heated to 110 ° C. and maintained at the temperature for 3 hours, and then the toluene was distilled under reduced pressure. The sample is cooled to room temperature and diluted with water to obtain a graft polymer of sample symbol A05 as a 40% aqueous solution.
A06 was produced under the same conditions as A05 without adding Pluronic L-64.

Production Example 12 (sample symbol A07 to 10)
A glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel, and a reflux condenser was charged with sample symbol A (C) produced in Polymer Production Example 3; 113.7 parts by weight, MIBK; 150 parts by weight. GE-42-2P; 181.2 parts by weight, Pluronic L-64; 52.0 parts by weight, TBAm; 13.3 parts by weight were added dropwise to the dropping funnel and heated to 110 ° C. for 3 hours. After maintaining the temperature and stirring, MIBK was distilled off under reduced pressure, cooled to room temperature and diluted with water to obtain a graft polymer of sample symbol A07 as a 40% aqueous solution.
A08 was prepared by adding Pluronic L-64, A09 and A10 were changed from GE-42-2P to PE, and A09 was prepared under the same conditions as A07 without adding Pluronic L-64.

Production Example 13 (sample symbol B01)
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel and a reflux condenser, an isobutylene-maleic anhydride copolymer (trade name: Isoban 600, Mw = 6000: Kuraray Co., Ltd.) as sample symbol B 77 parts by weight, sodium hydroxide; 16.0 parts by weight, water; 200, toluenesulfonic acid (PTS: acid catalyst); 1.0 part by weight is charged and heated to 100 ° C. with stirring, and added dropwise. M-PEG500; 500 parts by weight, Pluronic L-61; 58.0 parts by weight, and water; 500 parts by weight charged in the funnel were added dropwise, and the reaction was allowed to proceed for 3 hours, followed by cooling to room temperature. As a result, a graft polymer of sample symbol B01 is obtained.

Production Example 14 (sample symbols B02 to 05)
In a glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel, and a reflux condenser, Isoban 600, 77 parts by weight, sodium hydroxide; 16.0 parts by weight, water; 200, PTS; 1.0 weight M-PEG500; 250 parts by weight, GE-42-2P; 139 parts by weight, Pluronic L-61; 58.0 parts by weight, water Dropping 500 parts by weight and allowing the reaction to proceed for 3 hours, then cooling to room temperature. As a result, a graft polymer of sample symbol B02 is obtained.
B03 to 05 were produced under the same conditions as B02, except that the type of oligoalkylene glycol was changed.

Production Example 15 (MAA polymer, sample symbol M01)
Acrylic acid chloride: 120 parts by weight, GE-42-2P; 306 parts by weight, triethylamine; 100.0 parts by weight, toluene; 500 in a glass reaction vessel equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser A weight part is prepared, and it heats at 80 degreeC and makes it react for 10 hours. After cooling to room temperature, extraction with diethyl ether yields acrylic acid (GE422P) ester. Similarly, GE-42-2P is changed to a polyalkylene glycol derivative (acetylene alcohol polyoxyethylene adduct, trade name: Surfynol 440; manufactured by Nissin Chemical Co., Ltd.), and acrylic acid (Surfinol 440) ester is changed. obtain.
A glass reaction vessel equipped with a thermometer, a stirrer, a suitable funnel, a nitrogen inlet tube, and a reflux condenser was charged with 195.0 parts by weight of isopropyl alcohol (IPA), and the inside of the reaction vessel was purged with nitrogen. Heat to. Methoxy 9 ethylene glycol methacrylate (trade name: NK-M90G: manufactured by Kyoeisha Yushi Chemical Co., Ltd.); 66.5 parts by weight, methacrylic acid; 23.1 parts by weight, acrylic acid (GE422P) ester 29.6 parts by weight, the acrylic acid (Surfinol 440) ester; 2.3 parts by weight, BP; 1.2 parts by weight, IPA; P: 0.245 parts by weight and IPA: 5 parts by weight are added, and 30 minutes later, BP: 0.245 parts by weight and IPA; 5 parts by weight are added again. Thereafter, stirring is continued for 1 hour and 30 minutes while maintaining the temperature to allow the reaction to proceed. Cool to room temperature, add 30% sodium hydroxide solution; 15 parts by weight and water; 100 parts by weight to neutralize and distill off IPA with an evaporator to obtain a graft polymer of sample symbol M01 having a molecular weight of 32000 (converted to PEG). .

Production Example 16 (MAA polymer, sample symbol M02 to 10)
Acrylic acid chloride: 120 parts by weight, dibutylaminoethanol: 190 parts by weight, triethylamine: 100.0 parts by weight, toluene: 500 parts by weight in a glass reaction vessel equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser Is heated to 80 ° C. and allowed to react for 10 hours. After cooling to room temperature, extraction with diethyl ether yields acrylic acid (dibutylaminoethanol) ester.
Into a glass reaction vessel equipped with a thermometer, a stirrer, an appropriate funnel, a nitrogen inlet tube and a reflux condenser, 195.0 parts by weight of IPA is charged, the inside of the reaction vessel is purged with nitrogen, and heated to 80 ° C. NK-M90G charged in a dropping funnel; 66.5 parts by weight, methacrylic acid; 23.1 parts by weight, acrylic acid (dibutylaminoethanol) ester; 29.6 parts by weight, acrylic acid (Surfinol 440) ester; After 2.3 parts by weight, B · P; 1.2 parts by weight, IPA; 120.0 parts by weight were dropped over 2 hours, B · P; 0.245 parts by weight and IPA; 5 parts by weight were added. 30 minutes later, B · P; 0.245 parts by weight and IPA; 5 parts by weight are added. Thereafter, stirring is continued for 1 hour and 30 minutes while maintaining the temperature to allow the reaction to proceed. Cool to room temperature, add 30% sodium hydroxide solution; 15 parts by weight and water; 100 parts by weight to neutralize and distill off IPA with an evaporator to obtain a graft polymer of sample symbol M07 with a molecular weight of 32000 (converted to PEG). .
M02 to 06 and 08 to 10 were produced under the same conditions as those for M01 and M07, with different monomer compositions and functional groups.

As described above, according to Production Examples 1 to 16, the graft polymer represented by the following general formula S (styrene-maleic anhydride copolymer and its partial ester and derivatives thereof), the graft polymer represented by the general formula A (allyl) Ether-maleic anhydride copolymer and derivatives thereof), graft polymer represented by general formula B (isobutylene-maleic anhydride copolymer and derivatives thereof), graft polymer represented by general formula M ((meth) acrylic) Acid- (meth) acrylic acid ester copolymer and derivatives thereof).
Various graft polymers produced are shown in Table 1. The monomer compositions a, b, c, d and n in Table 1 are symbols meaning a, b, c, d and n in the general formula shown below, and Bu in the R column is Butyl group, Me represents methyl group, iPr represents isopropyl group, Ph represents phenyl group, EO represents ethylene oxide residue, PO represents propylene oxide residue, NPG represents neopentyl glycol, PE represents pentaerythritol, ESG Represents neopentyl glycol hydroxypivalate, L61 and L64 in the L column represent Pluronic L-61 and Pluronic L-64 manufactured by Adeka, respectively, and 440 represents Surfynol 440 manufactured by Nissin Chemical. The molecular weight is a weight average molecular weight determined by GPC, and is expressed as a PEG conversion value. It was the same as cleat Mixing sample concentration in water.

［式中、Ｍは水素、アルカリ金属、アルカリ土類金属、低級アミンまたは、低級アルカノールアミンを表し、Ｐｈはフェニル基を、Ｍｅはメチル基を、Ｒはオリゴアルキレングリコール類および／または多価アルコール類を、Ｌは、水素、ポリアルキレングリコールまたはその誘導体を表す。ＥＯはエチレングリコール残基であり、ｎは０〜１００の整数である。
ａは１、ｂは０．５、ｃは０．５〜０．４５、ｄは０〜０．０５］ Formula S

[Wherein, M represents hydrogen, alkali metal, alkaline earth metal, lower amine or lower alkanolamine, Ph represents a phenyl group, Me represents a methyl group, R represents an oligoalkylene glycol and / or a polyhydric alcohol. And L represents hydrogen, polyalkylene glycol or a derivative thereof. EO is an ethylene glycol residue, and n is an integer of 0-100.
a is 1, b is 0.5, c is 0.5 to 0.45, d is 0 to 0.05]

［式中、Ｍは水素、アルカリ金属、アルカリ土類金属、低級アミンまたは、低級アルカノールアミンを表し、Ｐｈはフェニル基を、Ｍｅはメチル基を、Ｒはオリゴアルキレングリコール類および／または多価アルコール類を、Ｌは、水素、ポリアルキレングリコールまたはその誘導体を表す。ＥＯはエチレングリコール残基であり、ｎは０〜１００の整数である。
ａは０．５〜１、ｂは０〜０．５、ｃは０．９５〜１、ｄは０〜０．０５］ Formula A

[Wherein, M represents hydrogen, alkali metal, alkaline earth metal, lower amine or lower alkanolamine, Ph represents a phenyl group, Me represents a methyl group, R represents an oligoalkylene glycol and / or a polyhydric alcohol. And L represents hydrogen, polyalkylene glycol or a derivative thereof. EO is an ethylene glycol residue, and n is an integer of 0-100.
a is 0.5 to 1, b is 0 to 0.5, c is 0.95 to 1, and d is 0 to 0.05]

［式中、Ｍは水素、アルカリ金属、アルカリ土類金属、低級アミンまたは、低級アルカノールアミンを表し、Ｍｅはメチル基を、Ｒはオリゴアルキレングリコール類および／または多価アルコール類を、Ｌは、水素、ポリアルキレングリコールまたはその誘導体を表す。ＥＯはエチレングリコール残基であり、ｎは０〜１００の整数である。
ａは１、ｂは０．５、ｃは０．５〜０．４５、ｄは０〜０．０５］ Formula B

[Wherein, M represents hydrogen, alkali metal, alkaline earth metal, lower amine or lower alkanolamine, Me represents a methyl group, R represents an oligoalkylene glycol and / or a polyhydric alcohol, and L represents Represents hydrogen, polyalkylene glycol or a derivative thereof. EO is an ethylene glycol residue, and n is an integer of 0-100.
a is 1, b is 0.5, c is 0.5 to 0.45, d is 0 to 0.05]

［式中、Ｍは水素、アルカリ金属、アルカリ土類金属、低級アミンまたは、低級アルカノールアミンを表し、Ｍｅはメチル基を、Ｒはオリゴアルキレングリコール類および／または多価アルコール類を、Ｌは、水素、ポリアルキレングリコールまたはその誘導体を表す。ＥＯはエチレングリコール残基であり、ｎは０〜１００の整数である。
ａは０．５〜５、ｂは０．５〜１０、ｃは０．１〜５、ｄは０〜０．２］ Formula M

[Wherein, M represents hydrogen, alkali metal, alkaline earth metal, lower amine or lower alkanolamine, Me represents a methyl group, R represents an oligoalkylene glycol and / or a polyhydric alcohol, and L represents Represents hydrogen, polyalkylene glycol or a derivative thereof. EO is an ethylene glycol residue, and n is an integer of 0-100.
a is 0.5-5, b is 0.5-10, c is 0.1-5, d is 0-0.2]

[Example]
1) Preparation of cement dispersant Cement dispersants comprising solutions containing the respective graft polymers produced in Production Examples 1 to 16 were prepared (Table 3, Examples 1 to 39). For comparison, a cement dispersant comprising a mixture of a high-performance AE water reducing agent and / or a defoaming agent and a graft polymer not chemically bonded to the high performance AE water reducing agent and / or antifoaming agent (Table 3, Comparative Examples 1 to 10) were prepared.
2) Storage stability test of solution Graft polymer (sample name: M02-05, M07-10, B02, B04, B05, A01, A02, A04) chemically bonded with polyalkylene glycol or its derivative having antifoaming property , A05, A07, A10, S02-06, S09, S10, S12-14, S16) Mixed solution of graft polymer S07 and antifoaming agent which are not chemically bonded with cement dispersant and antifoaming agent comprising solution Each of these cement dispersants was allowed to stand and stored in an atmosphere of 50 ° C., and the storage stability was tested by visually observing the degree of compatibility of the solution.
As a result of the test, the mixed solution of S07 and the antifoaming agent [polyalkylene glycol derivative (manufactured by Adeka Co., Ltd., trade name: Pluronic L-61)] was separated into two layers after 24 hours. On the other hand, the graft polymer solution in which the polyalkylene glycol having a foam-suppressing property or a derivative thereof was chemically bonded remained uniformly compatible even after one month, and no separation was observed.
3) Manufacture of concrete 3-1) Manufacture of concrete As for concrete, plain concrete (blend I) not containing the admixture shown in Table 2 is blended, and the amount of unit water is reduced by 18% from plain concrete (blend II). Designed with a target slump of 18.5 ± 1.5 cm and a target air volume of 4.5 ± 0.5% by volume, each material was weighed so that the mixing amount would be 80 liters. Examples 1 to 39 shown in Table 3 after mixing all materials including the cement dispersant containing the graft polymer produced in Production Examples 1 to 16 into the liter pan type forced mixer and mixing for 90 seconds. The concrete of Comparative Examples 1-10 was manufactured. The amount of air was prepared using an antifoaming agent and an AE agent as necessary.

3-2) Materials used a. Fine aggregate: Oikawa water-based land sand (specific gravity = 2.60, coarse particle rate = 2.76)
b. Coarse aggregate: Ome hard sandstone crushed stone (specific gravity = 2.65, maximum dimension = 20 mm) c. Cement: Ordinary Portland cement (specific gravity = 3.16, mixed with equal amounts of Chichibu Onoda, Sumitomo, and Mitsubishi cement)
d. High performance AE water reducing agent:
EMBOO Corporation Leo Build SP-8N (abbreviated as SP8) EMB Corporation Corporation Leo Build SP-9N (abbreviated as SP9) e. Drying shrinkage reducing agent:
・ Diethylene glycol dipropylene glycol monobutyl ether, manufactured by Nisso Maruzen Chemical Co., Ltd. GE-42-2P (abbreviated as GE2P)
・ Neopentyl glycol, manufactured by Mitsubishi Gas Chemical Co., Ltd. (abbreviated as NPG)
f. Antifoaming agent: Air volume adjustment agent No. 404 (main component: polyalkylene glycol derivative)
g. Polycarboxylic acid and graft polymer: Graft polymer produced in Production Examples 1 to 16 The amounts of polycarboxylic acid and graft polymer used in Table 3 represent solid content conversion values.

4) Concrete test method a. Slump: JIS A 1101 was used immediately after mixing and 60 minutes after mixing.
b. Length change: According to JIS A 1132 and JIS A 1129.
c. Air volume: According to JIS A 1128.
d. Setting time: According to JIS A 6204 Annex 1.
e. Compressive strength: Measured at a material age of 28 days according to JIS A 1132 and JIS A 1108.

5) Concrete test results The concrete test results are as shown in Table 3, and the following effects are confirmed. a. Water Reduction Examples Examples 1 to 39 using the graft polymers according to the present invention (S02 to S16, A01 to A10, B02 to B05, M01 to M10) are high in the compound II in which water is reduced by 18% from the compound I of plain concrete. The slump (fluidity) equivalent to Comparative Examples 2 and 3 using the performance AE water reducing agent (SP8, SP9) and Comparative Examples 4 to 7 using the polycarboxylate (S01, B, A01, M) is shown. Its water reduction is equivalent to a high performance AE water reducing agent.
Further, as is clear from the comparison between Comparative Example 4 and Examples 1 to 15, Comparative Example 5 and Examples 16 to 25, Comparative Example 6 and Examples 26 to 29, and Comparative Example 7 and Examples 30 to 39, The graft polymer according to the present invention provides equivalent water reduction with the same amount of use as the polycarboxylate.
b. Slump reduction over time Examples 1-39 show a small decrease in slump over time compared to Comparative Example 1, and the slump value after 60 minutes is the slump value immediately after kneading as in Comparative Examples 2 and 3. The slump reduction with time is extremely small as with the high-performance AE water reducing agent.

c. Drying shrinkage reduction effect (see Fig. 1)
Although the drying shrinkage rate of Comparative Examples 2 to 7 (using a high-performance AE water reducing agent alone) is slightly reduced as compared with Comparative Example 1, it is not a sufficient drying shrinkage reduction effect.
Examples 1 to 39 and Comparative Examples 8 and 9 exhibit excellent drying shrinkage reduction effects as compared with Comparative Examples 1 and 2 to 7.
In addition, as is clear from the comparison between Examples 1 to 39 and Comparative Examples 8 and 9, the amount used in Examples 1 to 39 is 0.15 to 0.38% with respect to the cement weight, which is an extremely small addition amount. In Comparative Examples 8 and 9, in order to obtain the same dry shrinkage reduction effect as in Examples 1 to 39, 0.2% of the polycarboxylic acid salt is exhibited. Further, it is necessary to add a large amount of 2.0% of the drying shrinkage reducing agent GE2P or 0.18% of the polycarboxylate and 2.3% of the drying shrinkage reducing agent NPG.
Moreover, although the comparative example 8 is an example which used together polycarboxylic acid salt and the same amount of GE2P as Example 1, the drying shrinkage reduction effect of GE2P is not recognized. On the other hand, Example 1 which chemically combined GE2P with the polycarboxylate salt exhibits an excellent drying shrinkage reduction effect.
d. Air entrainment Examples 1-5, 8, 9, 11-13, 15-17, 19, 20, 22, 25, 26, using graft polymers chemically bonded with polyalkylene glycol having antifoaming properties Since 28, 29, 31-34, and 36-39 do not have air entrainment, the amount of air was adjusted using an AE agent. In Examples 6, 7, 10, 14, 16, 18, 21, 23, 24, 27, 30, and 35, the amount of air was adjusted using an antifoaming agent.

e. Setting time The setting time of Examples 1-39 is comparable to Comparative Examples 2 and 3, and there is almost no setting delay property.
f. Compressive strength The strength development properties of Examples 1 to 39 are comparable to or higher than those of Comparative Examples 2 and 3.

  The dry shrinkage-reducing cement dispersant according to the present invention is excellent in storage stability, reduces the dry shrinkage of the cement composition with an extremely small amount of use, and also has a water-reducing property, thereby reducing the unit water amount. In addition, it is possible to economically produce a cement composition having excellent durability.

Represents the age and length change rate of concrete.

Claims (5)

The carboxyl groups of the polycarboxylic acid or a salt thereof, containing the oligo alkylene glycols and / or polyhydric alcohols, a graft polymer and polyalkylene ring recall is ester bond,
The oligoalkylene glycol is an alkylamino oligoalkylene glycol, an oligoalkylene glycol alkyl phenyl ether, an oligoalkylene glycol monoalkyl ether composed of a plurality of types of alkylene glycol, or a derivative thereof.
Drying shrinkage reduction cement dispersant. Polycarboxylic acids or their salts of styrene - maleic acid copolymer and its partial esters anhydrides, allyl ether - maleic anhydride copolymer, or is a derivative or a salt thereof thereof copolymer, the salt is an alkali The drying shrinkage-reducing cement dispersant according to claim 1, which is a metal salt, an alkaline earth metal salt, a lower amine salt, or a lower alkanolamine salt.   The polycarboxylic acid or a salt thereof is an isobutylene-maleic anhydride copolymer, a (meth) acrylic acid- (meth) acrylic acid ester copolymer, or a derivative of the copolymer or a salt thereof, and the salt is The drying shrinkage-reducing cement dispersant according to claim 1, which is an alkali metal salt, alkaline earth metal salt, lower amine salt, or lower alkanolamine salt.   The dry shrinkage-reducing cement dispersant according to any one of claims 1 to 3, wherein the polyhydric alcohol is neopentyl glycol, pentaerythritol, neopentyl glycol hydroxypivalate, or a derivative thereof. Polyalkylene ring recall is, block copolymers of ethylene oxide and propylene oxide having a depressive foaming, polymer of ethylene oxide, which is either a polymer of propylene oxide, drying according to any one of claims 1 to 4 Shrinkage-reducing cement dispersant.

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