WO2019181080A1

WO2019181080A1 - Shrinkage reducing agent and hydraulic composition

Info

Publication number: WO2019181080A1
Application number: PCT/JP2018/044280
Authority: WO
Inventors: 章宏古田; 竜平小林
Original assignee: 竹本油脂株式会社
Priority date: 2018-03-19
Filing date: 2018-11-30
Publication date: 2019-09-26
Also published as: JP6649533B1; JPWO2019181080A1; TW201938511A; TWI790330B

Abstract

Provided is a shrinkage reducing agent that, when used in a hydraulic composition, reduces the shrinkage of hardened products obtained from the hydraulic composition, imparts excellent freeze-thaw resistance, and makes it possible to stabilize desired performance. A shrinkage reducing agent that is for use in a hydraulic composition that includes water, an aggregate, and a hydraulic binding material that contains cement. The shrinkage reducing agent includes a prescribed polyoxyalkylene compound and an antioxidant.

Description

Shrinkage reducing agent and hydraulic composition

The present invention relates to a shrinkage reducing agent and a hydraulic composition. More specifically, the present invention, when used in a hydraulic composition, not only reduces the shrinkage of the cured body but also imparts excellent freeze-thaw resistance and stably exhibits desired performance. The present invention relates to a shrinkage-reducing agent and a hydraulic composition.

The hydraulic composition is widely used as a cement composition such as cement paste, mortar, and concrete. In recent years, high durability of a cured body of this hydraulic composition has been required.

Causes of decreasing the durability of the cured body are (1) cracking of the cured body due to drying shrinkage, and (2) degradation and destruction due to freeze-thaw action in cold regions, and the hydraulic composition was cured. In order to improve the durability of the cured body, it is necessary to suppress the occurrence of the cause of reducing the durability of the cured body as described above.

A shrinkage reducing agent (that is, a shrinkage reducing agent for a hydraulic composition) is regarded as important as a means for preventing cracking of a cured product due to drying shrinkage. Examples of the shrinkage reducing agent for hydraulic compositions include alkylene oxide adducts of alcohols having 1 to 4 carbon atoms (see Patent Document 1), polypropylene glycol in the oligomer region (see Patent Document 2), and alkylene oxides of bisphenols. Additives (see Patent Document 3) and the like are disclosed.

Japanese Patent Publication No. 56-51148 JP 59-152253 A Japanese Patent Publication No. 5-40714

However, the problem that the freeze-thaw resistance of the cured product of the hydraulic composition is lowered when the shrinkage reducing agent for hydraulic composition of Patent Documents 1 to 3 is used has not been sufficiently solved. Therefore, in cold regions, there is a problem that the use of the shrinkage reducing agent for hydraulic compositions of Patent Documents 1 to 3 is limited.

The present invention has been made in view of such problems of the prior art, and the problem is not only to reduce the shrinkage of the cured product when used in a hydraulic composition, An object of the present invention is to provide a shrinkage reducing agent and a hydraulic composition that can impart excellent freeze-thaw resistance and can stably exhibit desired performance.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a specific compound as a shrinkage reducing agent.

According to the present invention, the following shrinkage reducing agent and hydraulic composition are provided.

[1] A shrinkage reducing agent used for a hydraulic composition containing cement, a hydraulic binder containing aggregate, an aggregate, and water,
A shrinkage reducing agent comprising a polyoxyalkylene compound represented by the following formula (1) and an antioxidant.

R ¹ : a residue obtained by removing two hydroxyl groups from a compound having an aromatic hydrocarbon group having 6 to 25 carbon atoms and two phenolic hydroxyl groups X and Y: each independently a hydrogen atom or 1 to 22 alkyl groups OR ² , R ³ O: each independently an oxyalkylene group having 2 to 4 carbon atoms m, n: an integer having 1 to 299 and satisfying m + n = 60 to 300

[2] The shrinkage reducing agent according to the above [1], wherein in the formula (1), R ¹ is a group having a bis (4-hydroxyphenyl) skeleton represented by the following formula (2).

However, in the formula (2), Z is a linear or branched alkyl group having 1 to 13 carbon atoms or a sulfonyl group.

[3] In the formula (1), R ¹ is a group selected from 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane, or bis (4-hydroxyphenyl) sulfone. The shrinkage reducing agent according to the above [1] or [2], which is a residue excluding a hydroxyl group.

[4] The shrinkage reducing agent according to any one of [1] to [3], wherein in the formula (1), X and Y are hydrogen atoms.

[5] Shrinkage reduction according to any one of [1] to [4], wherein 90% by mole or more of all oxyalkylene groups of OR ² and R ³ O in formula (1) is an oxyethylene group. Agent.

[6] In any one of [1] to [5], in the formula (1), m and n are each an integer of 1 to 219, and m + n is an integer satisfying 70 to 220. Shrinkage reducing agent.

[7] The antioxidant is a phenolic antioxidant, and the content of the antioxidant is 20 mass ppm to 0.5 mass% with respect to the polyoxyalkylene compound represented by the formula (1). The shrinkage reducing agent according to any one of the above [1] to [6].

[8] The shrinkage reducing agent according to any one of the above [1] to [7], further comprising a solvent and in a liquid state.

[9] A hydraulic composition containing a cement-containing hydraulic binder, aggregate, and water,
A hydraulic composition containing the shrinkage reducing agent according to any one of [1] to [8] at a ratio of 0.2 to 10 parts by mass per 100 parts by mass of the hydraulic binder.

[10] The hydraulic composition according to [9], further including a dispersant and an air entraining agent.

[11] The hydraulic composition as described in [9] or [10] above, wherein the amount of entrained air immediately after mixing is in the range of 3 to 7% by volume.

The shrinkage reducing agent of the present invention has an effect of reducing cracks due to drying shrinkage of the obtained hydraulic composition and having high resistance to freezing and thawing, and can achieve high durability of a cured body of the hydraulic composition. Is.

Since the hydraulic composition of the present invention contains the shrinkage reducing agent of the present invention, it has the effect of reducing cracking due to drying shrinkage and high resistance to freezing and thawing, and making the cured product highly durable. It is.

Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that modifications, improvements, and the like appropriately added to the embodiments described above fall within the scope of the present invention.

[1] Shrinkage reducing agent:
The present invention relates to a shrinkage reducing agent used for a hydraulic composition containing cement, a hydraulic binder containing aggregate, and water, and a polyoxyalkylene compound represented by the following formula (1) and an oxidation agent. A shrinkage reducing agent containing an inhibitor.

[1-1] Polyoxyalkylene compound represented by the formula (1):
Examples of R ¹ in the polyoxyalkylene compound represented by the formula (1) in the shrinkage reducing agent of the present invention (hereinafter referred to as the shrinkage reducing agent of the present invention) include hydroquinone, catechol, binaphthol, 4,4′-biphenol, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 2,2-bis (4-hydroxyphenyl) butane, bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) sulfone, 5,5 ′-(1-methylethylidene) -bis [1,1 ′-(bisphenyl)- 2-ol] propane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 1,1-bis (4-hydride) Roxyphenyl) cyclohexane, a residue obtained by removing a hydroxyl group. R ¹ may be a group (residue) having a bis (4-hydroxyphenyl) skeleton represented by the following formula (2). Among these, a residue obtained by removing two hydroxyl groups from 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane, and bis (4-hydroxyphenyl) sulfone is preferable. . These residues exhibit excellent freeze-thaw resistance in addition to good shrinkage reduction effects.

In the formula (2), Z is a linear or branched alkyl group having 1 to 13 carbon atoms or a sulfonyl group.

X in formula (1) includes a hydrogen atom or an alkyl group having 1 to 22 carbon atoms. Examples of the alkyl group having 1 to 22 carbon atoms include methyl, ethyl, butyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, pentadecyl, hexadecyl, and the like. Group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, heneicosyl group, docosyl group, 2-methyl-pentyl group, 2-ethyl-hexyl group, 2-propyl-heptyl group, 2-butyl-octyl group, 2- Examples include pentyl-nonyl group, 2-hexyl-decyl group, 2-heptyl-undecyl group, 2-octyl-dodecyl group, 2-nonyl-tridecyl group and the like. Among these, as X, a hydrogen atom or a methyl group is preferable, and a hydrogen atom is more preferable.

Moreover, the same thing as X can be mentioned about Y in Formula (1).

Here, it is preferable that X and Y are hydrogen atoms from the viewpoints of ease of synthesis of the compound, availability of raw materials, and economical efficiency.

In the formula (1), OR ² represents an oxyalkylene group having 2 to 4 carbon atoms. When a plurality of OR ² are present, two or more types of oxyalkylene groups may be used. Specifically, OR ² preferably contains an oxyethylene group and / or an oxypropylene group, more preferably contains 50 mol% or more of oxyethylene groups, and more preferably 90 mol% of oxyethylene groups. It contains above. In addition, when two or more types of oxyalkylene groups are added, the order of bonding is not particularly limited, and random bonding or block bonding may be used.

Further, R ³ O in the formula (1) is the same as described for OR ² .

In OR ² and R ³ O, it is preferable that 90 mol% or more of all oxyalkylene groups obtained by summing OR ² and R ³ O are oxyethylene groups. In addition to exhibiting a good shrinkage reducing effect, it exhibits excellent freeze-thaw resistance.

In the formula (1), m and n represent the number of added moles of the polyoxyalkylene group, and m + n represents the total number of added moles of the polyoxyalkylene group. m and n are each an integer of 1 to 299, preferably an integer of 1 to 219. Further, m + n is 60 ≦ m + n ≦ 300, and preferably 70 ≦ m + n ≦ 220. If m + n is smaller than 60, the freeze-thaw resistance is remarkably lowered, and if m + n is too large, the production cost is increased and it is not realistic.

The method for producing a polyoxyalkylene compound in which X and Y in formula (1) are hydrogen atoms is not particularly limited, and can be produced by a known production method.

For example, it can be obtained by adding alkylene oxide to a compound having two phenolic hydroxyl groups as R ¹ . A catalyst can be used when adding an alkylene oxide. As a catalyst for addition polymerization of alkylene oxide, alkali catalysts such as alkali metals and alkaline earth metals, their hydroxides, alcoholates, Lewis acid catalysts, and composite metal catalysts can be used. is there.

Examples of the alkali catalyst include sodium, potassium, sodium potassium amalgam, sodium hydroxide, potassium hydroxide, sodium hydride, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, potassium butoxide and the like. . Sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, and potassium butoxide are preferable.

Examples of Lewis acid catalysts include tin tetrachloride, boron trifluoride, boron trifluoride diethyl ether complex, boron trifluoride di-n-butyl ether complex, boron trifluoride tetrahydrofuran complex, boron trifluoride phenol complex, three Examples thereof include boron trifluoride compounds such as a boron fluoride acetic acid complex.

[1-2] Antioxidant:
Examples of the antioxidant in the shrinkage reducing agent of the present invention include the following phenol compounds, phosphite compounds, and amine compounds.

[1-2a] Phenolic compounds:
(1) Examples of phenolic compounds include hydroquinone, hydroquinone monomethyl ether, 2-tert-butyl-4-methoxyphenol, 2-tert-butyl-4-methylphenol, 2,6-di-tert-butylphenol, 2 -Tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, n-octadecyl-3- (4'- Hydroxy-3,5-di-tert-butylphenyl) propionate, 6- (4-oxy-3,5-di-tert-butyl-anilino) -2,4-bis- (n-octylthio) -1,3 , 5-triazine, 4,4′-thiobis (6-tert-butyl-3-methylphenol), 4,4′-butylide Bis (6-tert-butyl-3-methylphenol), 4,4′-methylenebis (6-tert-butylphenol), 4,4′-bis (2,6-di-tert-butylphenol), 4,4 ′ -Thiobis (6-tert-butyl-o-cresol), 2,2'-methylenebis (4-methyl-6-tert-butyl-phenol), 2,2'-thiobis (6-tert-butyl-4-methyl) Phenol), 1,6-bis (3,5-di-tert-butyl-4-hydroxy-2-methylphenyl) butane, 1,1,3-tris (5-tert-butyl-4-hydroxy-2-) Methylphenyl) butane, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) mesitylene, 1,3,5-tris (3,5-di-tert-butyl) 4-hydroxybenzyl) mesitylene, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, tetrakis [β- (3,5-di-tert-butyl- 4-hydroxyphenyl) propionyloxymethyl] methane and the like.

[1-2b] Phosphite compound:
(2) Phosphite compounds include, for example, phosphite, triphenyl phosphite, trisnonylphenyl phosphite, triethyl phosphite, trilauryl phosphite, trioleyl phosphite, dioctadecyl-4-hydroxy -3,5-di-tert-butylbenzylphosphonate, diethyl-4-hydroxy-3,5-di-tert-butylbenzylphosphonate, tris (2-ethylhexyl) phosphite and the like.

[1-2c] Amine compound:
(3) Examples of amine compounds include n-butyl-p-aminophenol, 4,4′-dimethyldiphenylamine, 4,4′-dioctyldiphenylamine, 4,4′-bis-α, α′-dimethylbenzyl. Examples include diphenylamine.

These antioxidants may be used alone or in combination of two or more. Among these, phenolic antioxidants are more preferable. When a phenolic antioxidant is used, there is an advantage that there is no coloring or precipitation, and there is almost no influence on the hydraulic composition. Among these, hydroquinone, hydroquinone monomethyl ether, and 2,6-di-tert-butyl-4-methylphenol are preferable from the viewpoint of exhibiting an antioxidant effect and economical efficiency.

The content of the antioxidant can be 20 to 5000 mass ppm (20 mass ppm to 0.5 mass%), preferably 40 to 3000, with respect to the polyoxyalkylene compound represented by the formula (1). It can be used at a mass ppm, more preferably 40 to 1000 ppm by mass. By adding the antioxidant in the above content ratio, the desired performance is exhibited without the polyoxyalkylene compound being decomposed. When the content ratio of the antioxidant is small, the above effect is small, and even if the content ratio of the antioxidant is too large, the influence of the effect does not increase so much.

The shrinkage reducing agent of the present invention preferably contains a solvent and is liquid. That is, it is preferable that the shrinkage reducing agent of the present invention is appropriately diluted with a solvent and used as a liquid. By making it liquid, when the shrinkage reducing agent is added to the hydraulic composition, water used for kneading and the shrinkage reducing agent can be added simultaneously, and the shrinkage reducing agent is easily mixed uniformly. In addition, when a hydraulic composition that has not yet solidified after being kneaded is transported by an agitator truck, a shrinkage reducing agent may be added to the agitator. When added to, it has the advantage of being easily mixed uniformly.

[1-3] Solvent:
The solvent for diluting the shrinkage reducing agent of the present invention is not particularly limited as long as it is liquid within the temperature range in which the shrinkage reducing agent is used. Since it uses for a hydraulic composition, a highly water-soluble thing is preferable. Specifically, alcohols such as water and ethanol, glycols such as ethylene glycol, propylene glycol, and diethylene glycol, and alkylene oxide adducts of alcohols having 1 to 4 carbon atoms having a shrinkage reducing effect (Patent Document 1) See also oligomer polypropylene region (see Patent Document 2). Among these, water is preferably used as a solvent from the viewpoint of cost and safety.

The shrinkage reducing agent of the present invention is used by being added to a hydraulic composition containing cement used in civil engineering, construction, secondary products (for example, precast members), etc., but its use is particularly limited. Is not to be done. In addition, the hydraulic composition in which the shrinkage reducing agent of the present invention functions well is at least water, a paste containing cement, mortar, or concrete.

The shrinkage reducing agent of the present invention can be used in combination with a known additive (additive). For example, various dispersing agents such as AE (Air Entraining) water reducing agent, high performance AE water reducing agent, AE agent, antifoaming agent, other shrinkage reducing agent, thickening agent, curing accelerator, Examples thereof include a retarder for curing, blast furnace slag, fly ash, silica fume, fine limestone powder, and an expanding material.

The amount of the shrinkage reducing agent of the present invention is not particularly limited, but is preferably 0.2 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, per 100 parts by mass of the hydraulic binder containing cement. It is. The usage amount of the shrinkage reducing agent of the present invention can also be indicated by the usage amount per unit volume when applied to concrete. In that case, if the amount of cement and 300 kg / ^{m 3,} can be a 0.6 ~ 30kg / ^{m 3,} preferably 1.5 ~ 24kg / ^{m 3.}

[2] Hydraulic composition:
The hydraulic binder used for preparing the hydraulic composition of the present invention contains cement. Examples of the cement include various mixed cements such as blast furnace cement, fly ash cement, and silica fume cement, in addition to various portland cements such as ordinary portland cement, early-strength portland cement, and moderately heated cement.

Also, the hydraulic composition of the present invention contains aggregate. Examples of the aggregate include fine aggregate and coarse aggregate. Examples of the fine aggregate include river sand, mountain sand, sea sand, crushed sand, slag fine aggregate, and the like. Examples of the coarse aggregate include river gravel, crushed stone, and lightweight aggregate.

In the hydraulic composition of the present invention, the ratio of the water / hydraulic binder (percentage of water (mass%) with respect to the hydraulic binder in the composition) is preferably 10 to 70 mass%, preferably 20 to 60 mass%. Is more preferable, 30 to 55% by mass is particularly preferable, and 35 to 55% by mass is most preferable.

The hydraulic composition of the present invention preferably contains 0.2 to 10 parts by mass of the shrinkage reducing agent of the present invention per 100 parts by mass of the hydraulic binder. When the shrinkage reducing agent of the present invention is contained at such a ratio, the shrinkage reducing effect is improved and the freeze-thaw resistance is further increased.

The hydraulic composition of the present invention is preferably prepared using a cement-containing hydraulic binder, aggregate, water, the shrinkage reducing agent of the present invention, a dispersant and an air entraining agent. Also in this case, it is preferable to contain the shrinkage reducing agent of the present invention in a proportion of 0.2 to 10 parts by mass per 100 parts by mass of the hydraulic binder. In addition, a conventionally well-known thing can each be employ | adopted suitably for a dispersing agent and an air entraining agent, respectively.

Further, the hydraulic composition of the present invention preferably has an entrained air amount in the range of 3 to 7% by volume (particularly concrete) immediately after kneading. In this case, the shrinkage reduction effect and the freeze / thaw resistance are increased, and a remarkable desired effect is exhibited. The “entrained air amount immediately after mixing” refers to the value of the entrained air amount measured according to JIS-A1128.

Hereinafter, in order to make the configuration and effects of the present invention more specific, examples and the like will be described. However, the present invention is not limited to these examples. In the following examples and comparative examples, “part” means “part by mass”, “%” means “mass%”, and “ppm” means mass ppm.

Example 1
-Manufacture of shrinkage reducing agent (EX-1) In a pressure vessel equipped with a stirrer, a pressure gauge, and a thermometer, "New Pole BPE-60 (manufactured by Sanyo Chemical Co., Ltd., 2,2-bis (4-hydroxyphenyl)" All hydroxyl groups of propane were charged with 257.3 g of a total of 6 mol of ethylene oxide adduct) ”and 1.5 g of potassium hydroxide. Subsequently, after raising the temperature of the reaction system to 120 ° C., the system was dehydrated for 1 hour under reduced pressure. Thereafter, 1242.7 g of ethylene oxide (indicated as “EO” in Table 1) was added to the reaction system at a gauge pressure of 0.4 MPa over 5 hours while maintaining the temperature at 130 ± 5 ° C. Thereafter, the reaction temperature (130 ± 5 ° C.) was maintained for 1 hour. Then, after neutralization using “Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.)” and filtration, 2,6-di-tert-butyl-4-methylphenol (in Table 1, (Labeled “OX1”) was added to the filtered collection. Further, ion-exchanged water is added as a solvent to obtain a liquid shrinkage reducing agent (EX-1) containing 200 ppm of antioxidant and having a polyoxyalkylene compound represented by formula (1) having a mass concentration of 50%. It was.

Example 2
-Manufacture of shrinkage reducing agent (EX-2) In a pressure vessel equipped with a stirrer, a pressure gauge and a thermometer, "New Pole BPE-60 (manufactured by Sanyo Chemical Co., Ltd., 2,2-bis (4-hydroxyphenyl)" All the hydroxyl groups of propane were charged with 318.9 g of a total of 6 mol of ethylene oxide adduct) ”and 3.0 g of potassium hydroxide. Subsequently, after raising the temperature of the reaction system to 120 ° C., the system was dehydrated for 1 hour under reduced pressure. Thereafter, 2681.1 g of ethylene oxide was added to the reaction system over 6 hours at a gauge pressure of 0.4 MPa while maintaining at 130 ± 5 ° C. Then, it hold | maintained at reaction temperature (130 +/- 5 degreeC) for 1 hour, and collect | recovered after that. Hydroquinone (referred to as “OX2” in Table 1) was added to the recovered product as an antioxidant. Furthermore, tap water was added as a solvent to obtain a liquid shrinkage reducing agent (EX-2) containing 500 ppm of antioxidant and having a polyoxyalkylene compound represented by formula (1) having a mass concentration of 50%. .

Example 3
-Manufacture of shrinkage reducing agent (EX-3) In a pressure vessel equipped with a stirrer, a pressure gauge, and a thermometer, "New Pole BPE-60 (manufactured by Sanyo Chemical Co., Ltd., 2,2-bis (4-hydroxyphenyl)" All the hydroxyl groups of propane were charged with 338.5 g of a total of 6 moles of ethylene oxide adduct) ”and 10.0 g of potassium tert-butoxy. Subsequently, after raising the temperature of the reaction system to 120 ° C., the system was dehydrated for 1 hour under reduced pressure. Thereafter, 4661.5 g of ethylene oxide was added to the reaction system over 7 hours at a gauge pressure of 0.4 MPa while maintaining the temperature at 130 ± 5 ° C. Then, it hold | maintained at reaction temperature (130 +/- 5 degreeC) for 1 hour, and collect | recovered after that. After neutralization using "KYOWARD 600 (manufactured by Kyowa Chemical Industry Co., Ltd.)" and filtration, 2,6-di-tert-butyl-4-methylphenol (OX1) as an antioxidant was collected by filtration. Added to. Furthermore, tap water was added as a solvent to obtain a liquid shrinkage reducing agent (EX-3) containing 200 ppm of antioxidant and having a polyoxyalkylene compound represented by formula (1) having a mass concentration of 50%. .

Example 4
-Manufacture of shrinkage reducing agent (EX-4) In a pressure vessel equipped with a stirrer, a pressure gauge and a thermometer, "New Pole BPE-60 (manufactured by Sanyo Chemical Co., Ltd., 2,2-bis (4-hydroxyphenyl) All the hydroxyl groups of propane were charged with 272.5 g of ethylene oxide total 6 mol adduct) ”and 5.0 g of potassium hydroxide. Subsequently, after raising the temperature of the reaction system to 130 ° C., dehydration was performed for 1 hour in the system under reduced pressure. Thereafter, 4727.5 g of ethylene oxide was added to the reaction system at a gauge pressure of 0.4 MPa over 8 hours while maintaining at 130 ± 5 ° C. Then, it hold | maintained at reaction temperature (130 +/- 5 degreeC) for 1 hour, and collect | recovered after that. 85% phosphoric acid (a reagent manufactured by Kishida Chemical Co., Ltd.) was added to neutralize to pH 6, and 2,6-di-tert-butyl-4-methylphenol (OX1) was added thereto as an antioxidant. Furthermore, ion-exchanged water was added to obtain a liquid shrinkage reducing agent (EX-4) containing 1000 ppm of antioxidant and having a mass concentration of the polyoxyalkylene compound represented by the formula (1) of 50%.

Example 5
-Production of shrinkage reducing agent (EX-5) In a pressure vessel equipped with a stirrer, a pressure gauge, and a thermometer, 250.3 g of commercially available bis (4-hydroxyphenyl) sulfone and 8.0 g of tert-butoxypotassium were charged. It is. Subsequently, after raising the temperature of the reaction system to 120 ° C., 176 g of ethylene oxide was charged and the reaction was started. After confirming that the pressure decreased, 4224.0 g of ethylene oxide was added to the reaction system over 8 hours at a gauge pressure of 0.4 MPa while maintaining the temperature at 130 ± 5 ° C. The reaction temperature was maintained for 1 hour and then recovered. After neutralization using Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.) and filtration, hydroquinone monomethyl ether (OX3) was added to the filtered product as an antioxidant. Further, ion-exchanged water is added as a solvent to obtain a liquid shrinkage reducing agent (EX-5) containing 150 ppm of antioxidant and having a polyoxyalkylene compound represented by formula (1) having a mass concentration of 50%. It was.

Example 6
-Production of Shrinkage Reducing Agent (EX-6) As shown in Table 1, the shrinkage reducing agent (EX-6) was replaced with bis (4-hydroxyphenyl) sulfone used in Example 5 instead of bis (4-hydroxyphenyl) sulfone. This was prepared in the same manner as in Example 5 except that hydroxyphenyl) methane was used and the amount of ethylene oxide was changed.

Example 7
-Manufacture of shrinkage reducing agent (polyoxyalkylene compound) (EX-7) In a pressure vessel equipped with a stirrer, a pressure gauge, and a thermometer, "New Pole BPE-60 (manufactured by Sanyo Chemical Co., Ltd., 2,2-bis 700.3 g of a total of 6 moles of ethylene oxide added to all hydroxyl groups of (4-hydroxyphenyl) propane ”) and 5.5 g of potassium hydroxide were charged. Subsequently, after raising the temperature of the reaction system to 120 ° C., the system was dehydrated for 1 hour under reduced pressure. Thereafter, 4634 g of ethylene oxide was added to the reaction system at a gauge pressure of 0.4 MPa over 5 hours while maintaining the temperature at 130 ± 5 ° C. Thereafter, the reaction temperature (130 ± 5 ° C.) was maintained for 1 hour. Further, 165 g of propylene oxide (denoted as “PO” in Table 1) was added at the same temperature, held at the reaction temperature (130 ± 5 ° C.) for 1 hour, and then recovered. After neutralization using Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.) and filtration, 2,6-di-tert-butyl-4-methylphenol (OX1) was added as an antioxidant. Further, ion exchange water was added to obtain a liquid shrinkage reducing agent (EX-7) containing 200 ppm of antioxidant and having a mass concentration of the polyoxyalkylene compound represented by the formula (1) of 50%.

Example 8
-Manufacture of shrinkage reducing agent (polyoxyalkylene compound) (EX-8) As shown in Table 1, the shrinkage reducing agent (EX-8) is composed of ethylene oxide (referred to as "EO" in Table 1) and propylene oxide ( It was produced in the same manner as in Example 7 except that the amount of “PO” in Table 1 was changed.

Example 9
-Manufacture of shrinkage reducing agent (polyoxyalkylene compound) (EX-9) In a pressure vessel equipped with a stirrer, a pressure gauge, and a thermometer, "New Pole BPE-60 (manufactured by Sanyo Chemical Co., Ltd., 2,2-bis (All the hydroxyl groups of (4-hydroxyphenyl) propane were adducts with a total of 6 mol of ethylene oxide) ”, 628.4 g and 4.0 g of potassium hydroxide were charged. Subsequently, after raising the temperature of the reaction system to 120 ° C., the system was dehydrated for 1 hour under reduced pressure. Thereafter, 3371.7 g of ethylene oxide was added to the reaction system over 5 hours at a gauge pressure of 0.4 MPa while maintaining the temperature at 150 ± 5 ° C. Then, it hold | maintained at reaction temperature (150 +/- 5 degreeC) for 1 hour, and collect | recovered after that. After neutralization using Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.) and filtration, 2,6-di-tert-butyl-4-methylphenol (OX1) was added as an antioxidant. Further, ion exchange water was added to obtain a liquid shrinkage reducing agent (EX-9) containing 200 ppm of antioxidant and having a mass concentration of the polyoxyalkylene compound represented by the formula (1) of 50%.

Comparative Example 1
-Production of shrinkage reducing agent (RE-1) 106 g of commercially available diethylene glycol and 4.4 g of potassium hydroxide were charged into a pressure vessel equipped with a stirrer, a pressure gauge, and a thermometer. Next, the temperature of the reaction system was raised to 120 ° C. Thereafter, 4312 g of ethylene oxide was added to the reaction system over 5 hours at a gauge pressure of 0.4 MPa while maintaining the temperature at 130 ± 5 ° C. Then, it hold | maintained at reaction temperature (130 +/- 5 degreeC) for 1 hour, and collect | recovered after that. After neutralization using Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.) and filtration, ion exchanged water was added to obtain a liquid shrinkage reducing agent (RE-1) having a concentration of 50%.

Comparative Example 2
The one using “New Pole BPE-100 (manufactured by Sanyo Chemical Co., Ltd.)” as it was was used as a shrinkage reducing agent (RE-2).

Comparative Example 3
-Manufacture of shrinkage reducing agent (RE-3) In a pressure vessel equipped with a stirrer, a pressure gauge, and a thermometer, "New Pole BPE-40 (manufactured by Sanyo Chemical Co., Ltd., 2,2-bis (4-hydroxyphenyl) propane" 451.1 g of ethylene oxide total 4 mol adduct) ”and 1.5 g of potassium hydroxide were charged to all hydroxyl groups. Subsequently, after raising the temperature of the reaction system to 120 ° C., the system was dehydrated for 1 hour under reduced pressure. Thereafter, 1048.9 g of ethylene oxide was added to the reaction system over 5 hours at a gauge pressure of 0.4 MPa while maintaining the temperature at 150 ± 5 ° C. Then, it hold | maintained at reaction temperature (150 +/- 5 degreeC) for 1 hour, and collect | recovered after that. After neutralization using Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.) and filtration, ion exchange water was added thereto to obtain a liquid shrinkage reducing agent (RE-3) having a concentration of 50%.

Comparative Example 4
-Production of Shrinkage Reducing Agent (RE-4) Shrinkage reducing agent (RE-4) was prepared except that the amount of potassium hydroxide was 3.0 g and the amount of ethylene oxide was changed as shown in Table 1. Manufactured in the same manner as Comparative Example 3.

Comparative Example 5
・ Production of shrinkage reducing agent (RE-5) Shrinkage reducing agent (RE-5) is an example except that ethylene oxide addition, potassium hydroxide neutralization and filtration were carried out, and no antioxidant was added. 1 was produced in the same manner.

Table 1 summarizes the contents of each shrinkage reducing agent prepared above.

The description in Table 1 will be described below.
* 1 “R ¹ ” in Formula (1) is a residue obtained by removing a hydroxyl group from the compound described in this column.
* 2 For RE-2, “New Pole BPE-100 (manufactured by Sanyo Chemical Co., Ltd.)” was used as it was.
* 3 The amount of antioxidant (ppm) relative to the polyoxyalkylene compound represented by formula (1). Specifically, it is a value calculated by antioxidant / polyoxyalkylene compound × 106.
OX1: 2,6-di-tert-butyl-4-methylphenol OX2: Hydroquinone OX3: Hydroquinone monomethyl ether m + n (average total added moles) is the sum of “EO moles” and “PO moles” It is.

Examples 10 to 20, Comparative Examples 6 to 11
The following evaluation was performed by adding the shrinkage reducing agent (shrinkage reducing agent for hydraulic composition) shown in Table 1 to concrete.

Specifically, under the blending conditions shown in Table 2, ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd., Ube Mitsubishi Cement Co., Ltd., and Sumitomo Osaka Cement Co., Ltd.) was added to a 50 L pan-type forced kneading mixer in a 20 ° C. test room. Equal volume mixing, density = 3.16 g / cm ³ ) hydraulic binder, land sand (Oikawa water system, density = 2.58 g / cm ³ ) and crushed stone (Okazaki crushed stone, density = 2) .66 g / cm ³ ) and “TUPOL EX60 (manufactured by Takemoto Yushi Co., Ltd.)” as an AE water reducing agent, 0.7 to 1.0% with respect to cement, and the addition shown in Table 3 The amount of shrinkage reducing agent (see Table 1) and air entraining agent “AE-300 (manufactured by Takemoto Yushi Co., Ltd.)”, respectively, and a predetermined amount and anti-foaming agent “AFK-2 (manufactured by Takemoto Yushi Co., Ltd.)” Kneaded as 0.002% of the above cement Weighed as part of the (tap water), mixed for 90 seconds mixing was poured into a mixer. The concrete composition (hydraulic composition) was prepared by adjusting the amounts of the AE water reducing agent and the air entraining agent so that the slump was 15 ± 1 cm and the entrained air amount was 4.5 ± 0.5%.

The prepared concrete compositions were evaluated for slump, entrained air volume, compressive strength, drying shrinkage rate, and freeze / thaw durability as an index of freeze / thaw resistance, and the results are summarized in Table 3.

・ Slump (cm):
Simultaneously with the measurement of the amount of entrained air, it was measured according to JIS-A1101.

・ Entrained air volume (volume%):
The concrete composition immediately after kneading was measured according to JIS-A1128.

-Durability index (freeze-thaw durability):
A hardened body of each concrete composition was prepared, and a value calculated by a durability index of ASTM-C-666-75 was obtained using a value measured for this hardened body in accordance with JIS-A1148. This numerical value shows that the maximum value is 100, and the closer to 100, the better the resistance to freezing and thawing.

・ Length change rate (dry shrinkage):
In accordance with JIS-A1129, the dry shrinkage strain was measured by a comparator method for a specimen of 26 weeks of age in which each concrete composition was stored under the condition of 20 ° C. × 60% RH, and the dry shrinkage rate was determined. The smaller this value, the smaller the drying shrinkage.

・ Compressive strength (N / mm ² )
The test was conducted according to JIS-A1108. The steel mold was filled and cured in a constant temperature room of 20 ° C. × 80% RH, demolded at a material age of 1 day, and cured to a predetermined age in a curing tank at a water temperature of 20 ° C.

In Table 2, “cement” indicates the above-mentioned ordinary Portland cement. “Fine aggregate” indicates the above-mentioned land sand (Oikawa water system, density = 2.58 g / cm ³ ), and “Coarse aggregate” indicates crushed stone (Okazaki crushed stone, density = 2.66 g / cm ³ ). Indicates. The “fine aggregate ratio (%)” indicates a value calculated by the formula: fine aggregate / coarse aggregate × 100. “Water / cement ratio (%)” indicates a value calculated by the formula: water / cement × 100.

The description in Table 3 will be described below.
Addition amount: Addition amount of shrinkage reducing agent per unit volume of concrete (kg / m ³ )
* 1: A shrinkage reducing agent stored for 1 year at 20 ° C. in a container with air holes after production was used. During storage, volatile water was appropriately supplemented.
“% With respect to cement” means parts by mass with respect to 100 parts by mass of cement (hydraulic binder).

As described above, the shrinkage reducing agent of the present invention reduces drying shrinkage of the obtained hydraulic composition and has high freeze-thaw resistance, and can achieve high durability of the cured body of the hydraulic composition. I understood. And it has been found that the shrinkage reducing agent of the present invention can stably obtain desired performance even after a period of time has elapsed since the production of the shrinkage reducing agent by using an antioxidant.

The shrinkage reducing agent of the present invention can be used as a shrinkage reducing agent used in a hydraulic composition. The hydraulic composition of the present invention can be used as a cement composition such as cement paste, mortar, and concrete.

Claims

A shrinkage-reducing agent used for a hydraulic binder containing cement, a hydraulic binder, an aggregate, and water,
A shrinkage reducing agent comprising a polyoxyalkylene compound represented by the following formula (1) and an antioxidant.

R 1 : a residue obtained by removing two hydroxyl groups from a compound having an aromatic hydrocarbon group having 6 to 25 carbon atoms and two phenolic hydroxyl groups X and Y: each independently a hydrogen atom or 1 to 22 alkyl groups OR 2 , R 3 O: each independently an oxyalkylene group having 2 to 4 carbon atoms m, n: an integer having 1 to 299 and satisfying m + n = 60 to 300
The shrinkage reducing agent according to claim 1, wherein in the formula (1), R 1 is a group having a bis (4-hydroxyphenyl) skeleton represented by the following formula (2).

However, in the formula (2), Z is a linear or branched alkyl group having 1 to 13 carbon atoms,
Alternatively, it is a sulfonyl group.
In the above formula (1), R 1 is obtained by removing two hydroxyl groups from 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane, or bis (4-hydroxyphenyl) sulfone. The shrinkage reducing agent according to claim 1, wherein the shrinkage reducing agent is a residue.
The shrinkage reducing agent according to any one of claims 1 to 3, wherein, in the formula (1), X and Y are hydrogen atoms.
The shrinkage reducing agent according to any one of claims 1 to 4, wherein in the formula (1), 90 mol% or more of all oxyalkylene groups of OR 2 and R 3 O is an oxyethylene group.
The shrinkage reducing agent according to any one of claims 1 to 5, wherein, in the formula (1), m and n are each an integer of 1 to 219 and m + n is an integer satisfying 70 to 220. .
The antioxidant is a phenolic antioxidant, and the content of the antioxidant is 20 mass ppm to 0.5 mass% with respect to the polyoxyalkylene compound represented by the formula (1). Item 7. The shrinkage reducing agent according to any one of Items 1 to 6.
The shrinkage reducing agent according to any one of claims 1 to 7, further comprising a solvent and in a liquid state.
A hydraulic composition containing cement, a hydraulic binder, an aggregate, and water,
A hydraulic composition comprising the shrinkage reducing agent according to any one of claims 1 to 8 in a proportion of 0.2 to 10 parts by mass per 100 parts by mass of the hydraulic binder.
The hydraulic composition according to claim 9, further comprising a dispersant and an air entraining agent.
The hydraulic composition according to claim 9 or 10, wherein the amount of entrained air immediately after mixing is in the range of 3 to 7% by volume.