Shrinkage reducing agent for hydraulic compositions and hydraulic compositions

Abstract

To provide a shrinkage reducing agent for a hydraulic composition, capable of suppressing a change in an air content in a subsequent batch of the hydraulic composition while providing shrinkage reducing properties in a hardened body of a hydraulic composition such as mortar and concrete.SOLUTION: A shrinkage reducing agent for a hydraulic composition comprises, as its constituent units: a compound (A) represented by general formula (1); and a copolymer (B) containing a monomer having an anionic group and an unsaturated hydrocarbon monomer.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a shrinkage reducing agent for hydraulic compositions and a hydraulic composition. More specifically, it relates to a shrinkage reducing agent for hydraulic compositions that exhibits shrinkage reduction in hardened bodies of hydraulic compositions such as mortar and concrete, and can suppress changes in the air content (i.e., deviation of the air content from the assumption) in subsequent batches of hydraulic compositions, and a hydraulic composition.

Background Art

[0002] Conventionally, hardened bodies of hydraulic compositions such as mortar and concrete may dry shrink and crack, and such cracks were a cause of reducing the durability of the above-mentioned hardened bodies.

[0003] Therefore, in order to prevent cracks from occurring in the hardened body of a hydraulic composition, a shrinkage reducing agent (i.e., a shrinkage reducing agent for a hydraulic composition) is blended into the hydraulic composition (for example, see Patent Documents 1 and 2).

[0004] Here, in the production site of a hydraulic composition (i.e., a ready-mixed concrete plant), it is often the case that multiple batches are produced in one day using a single plant. That is, ready-mixed concrete (hydraulic composition) is continuously produced using a single plant. And the cleaning of the plant is basically once a day (at the stage when a series of production is completed), and it is not usually done to clean the inside of the plant between consecutive batches.

[0005] And these multiple batches may be hydraulic compositions of the same composition (blend) continuously, or subsequent batches may be hydraulic compositions of different compositions.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

[0007] As described above, in the manufacturing of hydraulic compositions, new hydraulic compositions are produced sequentially in batches, such as batch 1, batch 2, and batch 3, using a single plant. In this case, hydraulic compositions with the same composition may be produced in each batch, or hydraulic compositions with different compositions may be produced. In this case, if a hydraulic composition containing a shrinkage reducing agent is produced between batches of hydraulic compositions without a shrinkage reducing agent (normal hydraulic compositions), the amount of air (entrained air) in the normal hydraulic composition produced after the hydraulic composition containing the shrinkage reducing agent will not be the same as the amount of air in the normal hydraulic composition produced before the hydraulic composition containing the shrinkage reducing agent, but will change (increase or decrease). Although cleaning the plant after each batch would reduce the likelihood of such changes in air content, this is difficult to do due to the time and cost involved.

[0008] As described above, in actual manufacturing settings, there is a problem in that even with hydraulic compositions of the same formulation, the amount of air increases or decreases before and after the addition of a hydraulic composition containing a shrinkage-reducing agent.

[0009] Therefore, when manufacturing a conventional hydraulic composition after manufacturing a hydraulic composition containing a shrinkage-reducing agent, it is necessary to adjust the process accordingly, taking into account the change in air content. Such work is time-consuming and may also lead to a longer manufacturing time for the hydraulic composition.

[0010] Therefore, in view of the above circumstances, the object of the present invention is to provide a shrinkage reducing agent for hydraulic compositions and a hydraulic composition that can reduce shrinkage in hardened hydraulic compositions such as mortar and concrete, while suppressing changes in the amount of air in subsequent batches of hydraulic compositions. [Means for solving the problem]

[0011] The present inventors, through diligent research to solve the above problems, have found that the above problems can be solved by including a predetermined compound (A) (a compound represented by general formula (1)) and a predetermined copolymer (B). According to the present invention, the following shrinkage reducing agent for hydraulic compositions and hydraulic compositions are provided.

[0012] [1] Compound (A) represented by the following general formula (1), A copolymer (B) comprising constituent units derived from monomers having anionic groups and constituent units derived from unsaturated hydrocarbon monomers, Contains death, The mass ratio of compound (A) to copolymer (B) (compound (A) / polymer (B)) is between 99.99 / 0.01 and 70.0 / 30.0. A shrinkage reducing agent for hydraulic compositions characterized by the following features.

[0013] [ka] (In general formula (1), X is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, or a residue obtained by removing two hydroxyl groups from bisphenol. AO is an oxyalkylene group having 2 to 4 carbon atoms (however, if multiple oxyalkylene groups are present, one type or two or more types may be used). n is the average number of moles of AO added, and is a number between 1 and 300. R is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. a is an integer between 1 and 6 (however, n × a = 1 to 300).)

[0014] [2] The shrinkage reducing agent for hydraulic compositions according to [1], wherein the copolymer (B) comprises a constituent unit derived from a monomer having at least one selected from a carboxylic acid group, a carboxylic acid base, a sulfonic acid group, and a sulfonic acid base, and a constituent unit derived from an unsaturated hydrocarbon monomer having 2 to 10 carbon atoms.

[0015] [3] The shrinkage reducing agent for hydraulic compositions according to [1] above, wherein the copolymer (B) contains a structural unit derived from a monomer having at least one selected from a carboxylic acid group and a carboxylate group, and a structural unit derived from an unsaturated hydrocarbon monomer having 4 to 8 carbon atoms.

[0016] [4] The shrinkage reducing agent for hydraulic compositions according to [1] above, wherein the copolymer (B) contains a structural unit derived from at least one monomer selected from maleic acid and maleate, and a structural unit derived from diisobutylene.

[0017] [5] In the general formula (1), for the compound (A), X is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 15 carbon atoms, or a residue obtained by removing two hydroxy groups from bisphenol; AO is an oxyalkylene group having 2 to 3 carbon atoms; n is a number from 1 to 220; R is a hydrogen atom; and a is an integer from 1 to 3 (provided that n×a satisfies 1 to 220). The shrinkage reducing agent for hydraulic compositions according to any one of [1] to [4] above.

[0018] [6] In the general formula (1), for the compound (A), X is a hydrogen atom or an aliphatic hydrocarbon group having 1 to 8 carbon atoms; AO is an oxyalkylene group having 2 to 3 carbon atoms and 10 to 100 mol% thereof is composed of oxyethylene units; n is a number from 1 to 10; R is a hydrogen atom; and a is 1. The shrinkage reducing agent for hydraulic compositions according to [5] above.

[0019] [7] The shrinkage reducing agent for hydraulic compositions according to any one of [1] to [4] above, wherein the mass ratio of the compound (A) to the copolymer (B) (compound (A) / copolymer (B)) is 99.99 / 0.01 to 80.0 / 20.0.

[0020] [8] A hydraulic composition characterized by containing the shrinkage reducing agent for hydraulic compositions according to any one of [1] to [4] above.

Advantages of the Invention

[0021] The shrinkage reducing agent for hydraulic compositions of the present invention exhibits shrinkage reduction properties in hardened hydraulic compositions such as mortar and concrete, and has the effect of suppressing changes in the amount of air in subsequent batches of hydraulic compositions (i.e., deviations from the expected amount of air).

[0022] The hydraulic composition of the present invention, by containing the shrinkage-reducing agent for hydraulic compositions of the present invention, exhibits shrinkage-reducing properties in its cured body, thereby suppressing changes in the amount of air in subsequent batches of hydraulic compositions (i.e., deviations from the expected amount of air). [Modes for carrying out the invention]

[0023] Embodiments of the present invention will be described below. However, the present invention is not limited to the following embodiments. Therefore, it should be understood that, without departing from the spirit of the present invention, appropriate modifications and improvements may be made to the following embodiments based on the ordinary knowledge of those skilled in the art. In the following examples, unless otherwise stated, % means mass%, and parts means parts by mass.

[0024] (1) Shrinkage reducing agent for hydraulic compositions: The shrinkage reducing agent for hydraulic compositions of the present invention contains a compound (A) represented by the following general formula (1), and a copolymer (B) containing constituent units derived from an anionic monomer and constituent units derived from an unsaturated hydrocarbon monomer.

[0025] [ka]

[0026] However, in general formula (1), X is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, or a residue obtained by removing two hydroxyl groups from bisphenol. AO is an oxyalkylene group having 2 to 4 carbon atoms (however, if there are multiple such oxyalkylene groups, one type or two or more types may be used). n is the average number of moles of AO added, and is a number from 1 to 300. R is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. a is an integer from 1 to 6 (however, n × a = 1 to 300).

[0027] Such shrinkage-reducing agents for hydraulic compositions, by containing both a predetermined compound (A) and a predetermined copolymer (B), exhibit shrinkage-reducing properties in hardened hydraulic compositions such as mortar and concrete, and can suppress changes in the air content in subsequent batches of hydraulic compositions.

[0028] In the manufacturing of hydraulic compositions, a single plant is used to sequentially produce new hydraulic compositions in batches such as the first batch, second batch, and third batch. In this process, each batch may produce hydraulic compositions with the same composition (formulation), or it may produce hydraulic compositions with different compositions. In this case, if a hydraulic composition containing a shrinkage-reducing agent is produced between batches of hydraulic compositions without a shrinkage-reducing agent (normal hydraulic compositions), the amount of air (entrained air) in the normal hydraulic composition produced after the hydraulic composition containing the shrinkage-reducing agent will not be the same as the amount of air in the normal hydraulic composition produced before the hydraulic composition containing the shrinkage-reducing agent, but will change (increase or decrease). In other words, despite having the same formulation, there is a problem in that the amount of air increases or decreases before and after the hydraulic composition containing the shrinkage-reducing agent. To address these problems, the shrinkage reducing agent for hydraulic compositions of the present invention can be used to suppress changes in the amount of air in a conventional hydraulic composition manufactured after a hydraulic composition containing the shrinkage reducing agent (i.e., the amount of air deviates from the normally expected value (a difference occurs compared to the value before the manufacture of the hydraulic composition containing the shrinkage reducing agent)).

[0029] As described above, in the manufacturing of hydraulic compositions, new hydraulic compositions are produced sequentially in batches, such as the first batch, second batch, and third batch, using a single plant. In this case, hydraulic compositions with the same composition may be produced in each batch, or hydraulic compositions with different compositions may be produced. When producing concrete and other materials, there is a predetermined mix design that is assumed based on past performance and experience. However, when a hydraulic composition containing a shrinkage-reducing agent is manufactured, the amount of air (entrained air) in the next hydraulic composition produced, which does not contain a shrinkage-reducing agent, will not be the same as the assumed amount of air, but will change (increase or decrease). In other words, the amount of air deviates from what is assumed. Although such changes in the amount of air are less likely to occur if the plant is cleaned after each batch, this is not usually done because it is time-consuming and costly.

[0030] As described above, in actual manufacturing settings, problems arise such as an increase or decrease in air content when a hydraulic composition containing a shrinkage-reducing agent is manufactured after a hydraulic composition containing a shrinkage-reducing agent, even if the hydraulic composition has the same mix as previously manufactured concrete, etc. For example, even with the same mix, the amount of air content can increase or decrease depending on whether it is manufactured immediately before or immediately after a hydraulic composition containing a shrinkage-reducing agent.

[0031] Therefore, when manufacturing a conventional hydraulic composition after manufacturing a hydraulic composition containing a shrinkage-reducing agent, it is necessary to adjust the process as needed, taking into account the change in air content. Such work is time-consuming and may also lead to longer manufacturing times for the hydraulic composition. It is also conceivable that a separate formulation should be prepared that takes into account the manufacture of a hydraulic composition containing a shrinkage-reducing agent, but this would involve the extra effort of managing a separate formulation.

[0032] Furthermore, shrinkage reducing agents may be added not only during the mixing of concrete, etc., but also after the material has been transferred to transport vehicles such as agitators. Even when using such vehicles, if the agitator is not cleaned after transporting a hydraulic composition containing a shrinkage reducing agent, similar problems can occur, such as an increase or decrease in the air content of the concrete that is subsequently transferred.

[0033] (1-1) Compound (A): Compound (A) is a compound represented by the following general formula (1). The inclusion of this compound (A) results in reduced shrinkage in the hardened form of the hydraulic composition.

[0034] [ka]

[0035] However, in general formula (1), X is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, or a residue obtained by removing two hydroxyl groups from bisphenol. AO is an oxyalkylene group having 2 to 4 carbon atoms (however, if there are multiple such oxyalkylene groups, one type or two or more types may be used). n is the average number of moles of AO added, and is a number from 1 to 300. R is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. a is an integer from 1 to 6 (however, n × a = 1 to 300).

[0036] X is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, or a residue obtained by removing two hydroxyl groups from bisphenol. Among these, it is preferably a hydrogen atom, an aliphatic hydrocarbon group having 1 to 15 carbon atoms, or a residue obtained by removing two hydroxyl groups from bisphenol, more preferably a hydrogen atom or an aliphatic hydrocarbon group having 1 to 15 carbon atoms, and particularly preferably a hydrogen atom or an aliphatic hydrocarbon group having 1 to 8 carbon atoms. With such a configuration, good shrinkage reduction properties are exhibited in the hardened product of the hydraulic composition.

[0037] AO is an oxyalkylene group having 2 to 4 carbon atoms (however, if multiple such oxyalkylene groups are present, one type alone or two or more types may be used), and it is preferably an oxyalkylene group having 2 to 3 carbon atoms. With this configuration, good shrinkage reduction properties are exhibited in the cured product of the hydraulic composition.

[0038] n is the average number of moles of AO added, and is a number between 1 and 300. Preferably, n is a number between 1 and 220, and more preferably between 1 and 10. Within this range, shrinkage reduction properties are exhibited in the cured body of the hydraulic composition.

[0039] R is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and among these, a hydrogen atom is preferred. With this configuration, good shrinkage reduction properties are exhibited in the cured product of the hydraulic composition.

[0040] a is an integer between 1 and 6, preferably between 1 and 3, and more preferably 1. Within this range, shrinkage reduction properties are exhibited in the cured body of the hydraulic composition.

[0041] n×a satisfies 1 to 300, preferably 1 to 220, and more preferably 1 to 10. Within this range, shrinkage reduction properties are exhibited in the cured body of the hydraulic composition.

[0042] In general formula (1), the amount of polyoxyethylene units in AO is not particularly limited, but is preferably 10 to 100 mol%. Within this range, the shrinkage reduction properties in the cured product of the hydraulic composition are further improved.

[0043] (1-2) Copolymer (B): Copolymer (B) contains constituent units derived from monomers having anionic groups and constituent units derived from unsaturated hydrocarbon monomers. Including copolymer (B) containing these two types of constituent units suppresses changes in the air content in subsequent batches of hydraulic composition (concrete of the later batch) without inhibiting the shrinkage reduction function of compound (A) (i.e., the shrinkage reduction performance is maintained and exhibited).

[0044] (1-2a) Constituent units derived from monomers having anionic groups: There are no particular restrictions on the monomers having an anionic group that form the constituent units derived from monomers having an anionic group, and they can be used as appropriate.

[0045] The constituent units derived from monomers having anionic groups are preferably those derived from monomers having at least one selected from carboxylic acid groups, carboxylic acid bases, sulfonic acid groups, and sulfonic acid bases; more preferably those derived from monomers having at least one selected from carboxylic acid groups and carboxylic acid bases; and particularly preferably those derived from at least one monomer selected from maleic acid and maleate salts. By including such constituent units, changes in the air content in subsequent batches of hydraulic compositions (concrete of subsequent batches) can be suppressed.

[0046] The constituent units derived from monomers having anionic groups preferably account for 30 to 99% by mass of the total constituent units in copolymer (B).

[0047] (1-2b) Constituent units derived from unsaturated hydrocarbon monomers: The unsaturated hydrocarbon monomers that form the constituent units derived from unsaturated hydrocarbon monomers are not particularly limited and can be used as appropriate.

[0048] The constituent units derived from unsaturated hydrocarbon monomers are preferably those derived from unsaturated hydrocarbon monomers having 2 to 10 carbon atoms, more preferably those derived from unsaturated hydrocarbon monomers having 4 to 8 carbon atoms, and particularly preferably those derived from diisobutylene. By including such constituent units, changes in the air content in the subsequent batch of hydraulic composition (concrete of the later batch) can be suppressed.

[0049] The constituent units derived from unsaturated hydrocarbon monomers are preferably 1 to 70% by mass of the total constituent units in copolymer (B).

[0050] (1-2c) Other constituent units: Copolymer (B) may contain other constituent units in addition to those derived from monomers having anionic groups and those derived from unsaturated hydrocarbon monomers. There are no particular restrictions on the other constituent units as long as they are copolymerizable with the above constituent units, but examples include ester monomers such as methyl acrylate, methyl methacrylate, and butyl acrylate; unsaturated amides such as (meth)acrylamide and N,N-dimethyl(meth)acrylamide; unsaturated cyanides such as (meth)acrylonitrile; and unsaturated polyalkylene glycols such as polyethylene polypropylene glycol monoallyl ether.

[0051] The proportion of other constituent units can be appropriately determined within a range that does not impair the effects of the present invention, but can be 0 to 10% by mass of all constituent units in copolymer (B).

[0052] The copolymer (B) has no particular restrictions on its mass-average molecular weight, but it can be, for example, between 1,000 and 500,000. The mass-average molecular weight can be measured by gel permeation chromatography (GPC).

[0053] (1-3) Compound (A) / copolymer (B): The mass ratio of compound (A) to copolymer (B) (compound (A) / polymer (B)) is not particularly limited, but is preferably 99.99 / 0.01 to 80.0 / 20.0, and more preferably 99.99 / 0.01 to 95.0 / 5.0. By setting the ratio within this range, shrinkage reduction in the hardened body of hydraulic compositions such as mortar and concrete can be effectively reduced, and changes in the air content in subsequent batches of hydraulic compositions can be effectively suppressed.

[0054] (1-4) Other ingredients: The shrinkage reducing agent for hydraulic compositions of the present invention may further contain other components in addition to compound (A) and copolymer (B).

[0055] Other components may include, for example, air intake regulators such as AE (Air Entraining) agents and defoamers, other shrinkage-reducing components, thickeners, curing accelerators, curing retarders, antioxidants, and pH adjusters.

[0056] As for the content ratio of other components, for example, it can be 0 to 10 parts by mass, preferably 0 to 5 parts by mass, per 100 parts by mass of the total amount of compound (A) and copolymer (B).

[0057] (2) Hydraulic composition: The hydraulic composition of the present invention contains a shrinkage-reducing agent for hydraulic compositions of the present invention.

[0058] Such a hydraulic composition exhibits shrinkage reduction properties in its cured form by containing the shrinkage-reducing agent for hydraulic compositions of the present invention, thereby suppressing changes in the air content in subsequent batches of hydraulic compositions.

[0059] The hydraulic composition of the present invention may contain a binder (hydraulic binder), water, fine aggregate, and coarse aggregate, similar to conventionally known hydraulic compositions.

[0060] The hydraulic composition of the present invention has no particular limitations on the content of the shrinkage reducing agent for the hydraulic composition of the present invention, and can be set as appropriate. For example, the content of the shrinkage reducing agent for the hydraulic composition of the present invention is 1 m of the hydraulic composition 3 The amount can be between 0.1 and 40 kg per unit. By using such a content, the shrinkage reduction properties in the hardened body of the hydraulic composition are effectively exhibited, and the change in air content in subsequent batches of hydraulic compositions is further suppressed.

[0061] Examples of binders include various types of Portland cement such as ordinary Portland cement, moderate-heat Portland cement, low-heat Portland cement, rapid-hardening Portland cement, and sulfate-resistant Portland cement, as well as various types of cement such as blast furnace cement, fly ash cement, and silica fume cement.

[0062] Furthermore, various admixtures such as fly ash, blast furnace slag powder, limestone powder, stone powder, silica fume, and expansives may be used in combination as binders.

[0063] Examples of fine aggregates include river sand, mountain sand, land sand, sea sand, silica sand, crushed sand, and various slag aggregates, but they may also contain fine particles such as clay.

[0064] Examples of coarse aggregates include river gravel, mountain gravel, land gravel, crushed stone, various types of slag coarse aggregates, and lightweight aggregates.

[0065] The hydraulic composition of the present invention may further contain other components as appropriate, within a range that does not impair its effectiveness. Examples of such other components include setting retarders consisting of sugars or oxycarboxylates, various water-reducing agents, air-enhancing agents consisting of anionic surfactants, defoaming agents consisting of oxyalkylene compounds, curing accelerators consisting of alkanolamines, thickeners consisting of cellulose ether compounds, rapid setting agents consisting of calcium sulfonates, expanding agents consisting of calcium sulfoaluminates, preservatives consisting of isothiazolinone compounds, and rust inhibitors consisting of nitrites.

[0066] The content ratio of other components can be, for example, 0 to 5 parts by mass per 100 parts by mass of the binder.

[0067] The hydraulic composition of the present invention can appropriately adopt conventionally known ratios for the ratio of water to binder (water / binder ratio), for example, it can be 20 to 70% by mass. [Examples]

[0068] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0069] First, compound (A) (compounds (A-1), (A-5) to (A-10)) were synthesized as shown in synthesis examples 1 to 7 below.

[0070] For compound (A-2), commercially available butyl diglycol (manufactured by Nippon Emulsifier Co., Ltd.) was used as is. For compound (A-3), commercially available butycenol 40 (manufactured by KH Neochem Co., Ltd.) was used as is. For compound (A-4), commercially available reagent "Polypropylene Glycol 400" (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as is. For compound (A-11), commercially available reagent "Tripropylene Glycol Dimethyl Ether (Isomer Mixture)" (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as is.

[0071] (Synthesis Example 1) Synthesis of compound (A-1): 526.6 g of commercially available diethylene glycol monobutyl ether (a 2-mol adduct of n-butyl alcohol with ethylene oxide) and 1.0 g of potassium hydroxide were charged into a pressure vessel equipped with a stirrer, pressure gauge, and thermometer. The reaction system was then heated to 120°C. Subsequently, 377 g of propylene oxide was added to the reaction system over 3 hours at a gauge pressure of 0.4 MPa while maintaining the temperature at 130±5°C. The reaction was then maintained at the reaction temperature (130±5°C) for 1 hour to complete the reaction. After neutralization using "Kyoward 700 (manufactured by Kyowa Chemical Industry Co., Ltd.)", the mixture was filtered to obtain compound (A-1).

[0072] (Synthesis Example 2) Synthesis of compound (A-5): 318.9 g of "Nieuport BPE-60 (manufactured by Sanyo Chemical Industries, Ltd., an adduct of 6 moles of ethylene oxide to all hydroxyl groups of 2,2-bis(4-hydroxyphenyl)propane)" and 3.0 g of potassium hydroxide were charged into a pressure vessel equipped with a stirrer, pressure gauge, and thermometer. The reaction system was then heated to 120°C, and dehydration was carried out under reduced pressure for 1 hour. Subsequently, 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 the temperature at 130±5°C. The reaction was then maintained at the reaction temperature (130±5°C) for 1 hour to complete the reaction. After that, the system was neutralized with 85% phosphoric acid to pH 6, dehydrated, and filtered to obtain compound (A-5).

[0073] (Synthesis Example 3) Synthesis of compound (A-6): Compound (A-6) was obtained in the same manner as in Synthesis Example 2, except that the amount of ethylene oxide added (average number of moles added) was varied to satisfy Table 1.

[0074] (Synthesis Example 4) Synthesis of compound (A-7): 22.7 g of commercially available glycerin and 1.0 g of potassium hydroxide were charged into a pressure vessel equipped with a stirrer, pressure gauge, and thermometer. The reaction system was then heated to 120°C, and 977.30 g of ethylene oxide was added over 10 hours at a gauge pressure of 0.4 MPa while maintaining the temperature at 130±5°C. The reaction was then maintained at the reaction temperature (130±5°C) for 1 hour to complete the reaction. After neutralization using "Kyoward 700 (manufactured by Kyowa Chemical Industry Co., Ltd.)", the mixture was filtered to obtain compound (A-7).

[0075] (Synthesis Example 5) Synthesis of compound (A-8): 38.9 g of commercially available trimethylolpropane and 2.5 g of potassium hydroxide were charged into a pressure vessel equipped with a stirrer, pressure gauge, and thermometer. The reaction system was then heated to 120°C. Subsequently, 474.7 g of propylene oxide and 486.4 g of ethylene oxide were added to the reaction system over 3 hours at a gauge pressure of 0.4 MPa while maintaining the temperature at 130±5°C. The reaction was then maintained at the reaction temperature (130±5°C) for 1 hour to complete the reaction. After neutralization using "Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.)", the mixture was filtered to obtain compound (A-8).

[0076] (Synthesis Example 6) Synthesis of compound (A-9): Compound (A-9) was obtained in the same manner as in Synthesis Example 5, except that the amounts of ethylene oxide and propylene oxide added (average number of moles added) were varied to satisfy Table 1.

[0077] (Synthesis Example 7) Synthesis of compound (A-10): In a pressure vessel equipped with a stirrer, pressure gauge, and thermometer, 307.8 g of commercially available tetraethylene glycol monobutyl ether (butycenol 40: manufactured by KH Neochem) and 284.7 g of 28% sodium methoxide methanol solution were charged. The system was then depressurized using a vacuum pump, and the reaction system was heated to 120°C. After completely removing the methanol, 270.8 g of ethylene oxide was added to the reaction system over 3 hours at a gauge pressure of 0.4 MPa while maintaining the temperature at 130±5°C. The reaction was then maintained at the reaction temperature (130±5°C) for 1 hour to complete. After cooling to room temperature, 136.6 g of butyl chloride was added, and the reaction was carried out at 120°C for 2 hours. After the reaction was complete, the system was cooled to 60°C, filtered, and compound (A-10) was obtained.

[0078] [Table 1]

[0079] In Table 1, the number in parentheses in the "(AO)n" column indicates the average number of moles of the corresponding alkylene oxide added. In the "(AO)n" column, "blocked" indicates that multiple types of alkylene oxides (specifically, oxyethylene and oxypropylene) have been added in a blocked manner, while "random" indicates that multiple types of alkylene oxides have been added in a random manner.

[0080] Next, copolymers (B) (copolymers (B-1), (B-3) to (B-5), and (B-7)) were synthesized as shown in the following synthesis examples 8 to 12.

[0081] For copolymer (B-2), we used commercially available Squish 21B (manufactured by Kao Corporation) as is. For copolymer (B-6), we used commercially available VERSA-LT72 (manufactured by Shima Trading Co., Ltd.) as is.

[0082] In Table 2, BR-1 is "polyacrylic acid," which is polyacrylic acid (mass-average molecular weight 25,000) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. BR-2 is "naphthalene sulfonic acid formaldehyde condensate," which is "Mighty 150" manufactured by Kao Corporation. BR-3 was synthesized as shown in Synthesis Example 13. Note that BR-2, "naphthalene sulfonic acid formaldehyde condensate," is a dispersant, and BR-3 is an antifoaming agent.

[0083] (Synthesis Example 8) Synthesis of copolymer (B-1): A mixture of 98.1 g of maleic anhydride, 112.2 g of diisobutylene, and 400 g of toluene was charged into a reaction vessel equipped with a stirrer and a thermometer. The mixture was heated to 70°C under a nitrogen atmosphere, 4 g of benzoyl peroxide was added, and the mixture was polymerized at 75°C for 6 hours. After polymerization was complete, the precipitated copolymer was filtered and dried to obtain the copolymer. Water and sodium hydroxide were added to the obtained copolymer, and the mixture was stirred at 80°C until it dissolved transparently to obtain copolymer (B-1).

[0084] (Synthesis Example 9) Synthesis of copolymer (B-3): Copolymer (B-3) was obtained in the same manner as in Synthesis Example 8, except that the amounts of maleic anhydride, diisobutylene, and toluene added were varied, and the mixed polymerization conditions were set to 80-85°C for 10 hours.

[0085] (Synthesis Example 10) Synthesis of copolymer (B-4): 518.2 g of distilled water, 275.2 g of 30% sodium hydroxide aqueous solution, and 206.7 g of ISOBAM-04 (manufactured by Kuraray Co., Ltd.) were placed in a reaction vessel, and the reaction system was heated to 70°C. After stirring, the mixture was uniformly dissolved to obtain copolymer (B-4) containing constituent units derived from monomers containing anionic groups and constituent units derived from unsaturated hydrocarbon monomers.

[0086] (Synthesis Example 11) Synthesis of copolymer (B-5): Copolymer (B-5) was obtained in the same manner as in Synthesis Example 8, except that 104.2 g of styrene was used instead of diisobutylene, and the amount of benzoyl peroxide was adjusted as appropriate.

[0087] (Synthesis Example 12) Synthesis of copolymer (B-7): Copolymer (B-7) was obtained in the same manner as in Synthesis Example 8, except that 154.2 g of 2-vinylnaphthalene was used instead of diisobutylene, and the amount of benzoyl peroxide was adjusted as appropriate.

[0088] (Synthesis Example 13) Synthesis of copolymer (BR-3): First, 130.7 g of oleyl alcohol and 1.1 g of potassium hydroxide were added to a pressure vessel equipped with a stirrer, pressure gauge, and thermometer. The melting point of the alcohol (oleyl alcohol) is approximately 11°C, and it is in a liquid state at room temperature of around 20°C. In this state, after dehydration treatment, 217.8 g of ethylene oxide was injected under a gauge pressure of 0.4 MPa over 1 hour while maintaining the reaction system in the pressure vessel at 110 ± 5°C, and then aged for 2 hours. Furthermore, while maintaining the above reaction system at 135 ± 5°C, 777.4 g of propylene oxide was injected under a gauge pressure of 0.4 MPa over 5 hours, and then aged for 2 hours to complete the reaction. After that, neutralization treatment was performed using "Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.)" as an adsorbent, and the product was filtered and purified to obtain the purified product BR-3, an antifoaming agent (polyoxyalkylene compound).

[0089] [Table 2]

[0090] The mass-average molecular weight of copolymer (B) was measured using gel permeation chromatography (GPC) under the following measurement conditions.

[0091] <Measurement conditions for mass-average molecular weight> Equipment: Shodex GPC-101 (manufactured by Showa Denko Corporation) Column: OHpak SB-806M HQ + SB-806M HQ (manufactured by Showa Denko Corporation) Detector: Differential refractometer (RI) Eluent: 50 mM sodium nitrate aqueous solution Flow rate: 0.7mL / min Column temperature: 40℃ Sample concentration: Eluent solution with a sample concentration of 0.5% by mass. Standard substances: polyethylene glycol, polyethylene oxide (manufactured by Agilent Corporation)

[0092] (Examples 1-31, Comparative Examples 1-6) (1) Preparation of shrinkage reducing agents for hydraulic compositions: Shrinkage reducing agents for hydraulic compositions (SR-1 to SR-31, R-1 to R-5) were prepared by blending the compounds (A) and copolymers (B) obtained as described above in the types and proportions shown in Table 3 below.

[0093] [Table 3]

[0094] (3) Preparation of hydraulic composition (concrete composition): Next, various hydraulic compositions were prepared in order as follows: First, (i) a hydraulic composition that serves as a standard for air content without shrinkage reducing agents (standard concrete composition) (referred to as "standard concrete" in Tables 5 to 7) was prepared, then (ii) a hydraulic composition containing shrinkage reducing agents (referred to as "concrete containing shrinkage reducing agents" in Tables 5 to 7) was prepared, and then (iii) a hydraulic composition that does not contain shrinkage reducing agents (hydraulic composition for which air content is measured) (referred to as "concrete from the later batch" in Tables 5 to 7) was prepared.

[0095] (3-1) Preparation of standard concrete composition (standard concrete): First, using the mixing conditions shown in Table 4, a 55L pan-type forced mixer was used in a test chamber at 20°C to mix ordinary Portland cement (equal parts of cement manufactured by Taiheiyo Cement, Ube Mitsubishi Cement, and Sumitomo Osaka Cement, density = 3.16 g / cm³). 3 A hydraulic binder (cement) consisting of ) and land sand (from the Oi River system, density = 2.58 g / cm³) as fine aggregate. 3), and as coarse aggregate, crushed stone (Okazaki-produced crushed stone, density = 2.66 g / cm³). 3 A concrete composition with a volume of 30 L was prepared by adding ( ), and further using a water-reducing agent, an air-entraining agent, and an antifoaming agent.

[0096] Here, as shown in Table 4, "Tupol EX20 (manufactured by Takemoto Oil Co., Ltd.)", "Tupol EX60 (manufactured by Takemoto Oil Co., Ltd.)", and "Tupol HP-11 (manufactured by Takemoto Oil Co., Ltd.)" were used as water-reducing agents. "AE-300 (manufactured by Takemoto Oil Co., Ltd.)" was used as an air-entraining agent. "AFK-2 (manufactured by Takemoto Oil Co., Ltd.)" was used as an antifoaming agent. Subsequently, these water-reducing agents, air-entraining agents, and antifoaming agents were used as part of the mixing water (tap water), and the amounts of each were adjusted so that the slump was 18±1 cm and the air content was 4.5%, thereby preparing the concrete composition.

[0097] Furthermore, the temperature of each material was controlled before preparation so that the temperature of the finished concrete composition was within the range of 20±2℃. The temperature of the finished concrete composition was measured in accordance with JIS-A1156(2014).

[0098] [Table 4]

[0099] (3-2) Preparation of a hydraulic composition containing a shrinkage reducing agent (hydraulic composition of the present invention): Using the formulation No. 3 shown in Table 4, in a test chamber at 20°C, an equal mixture of ordinary Portland cement (manufactured by Taiheiyo Cement, Ube Mitsubishi Cement, and Sumitomo Osaka Cement, density = 3.16 g / cm³) was prepared in a 55 L pan-type forced mixer. 3 A hydraulic binder consisting of ) and terrestrial sand (from the Oi River system, density = 2.58 g / cm³) as fine aggregate. 3 ) and as coarse aggregate, crushed stone (Okazaki-produced crushed stone, density = 2.66 g / cm³) 3 A concrete composition with a volume of 30 L was prepared by adding (), a water-reducing agent, an air-entraining agent, and an antifoaming agent, as well as the amount of shrinkage-reducing agent for hydraulic compositions shown in Table 5 (see Table 3).

[0100] Here, "Tupole HP-11 (manufactured by Takemoto Oil Co., Ltd.)" was used as a water-reducing agent. "AE-300 (manufactured by Takemoto Oil Co., Ltd.)" was used as an air-entraining agent. "AFK-2 (manufactured by Takemoto Oil Co., Ltd.)" was used as an antifoaming agent. These water-reducing agent, air-entraining agent, and antifoaming agent were used as part of the mixing water (tap water), and the amounts of each were adjusted so that the slump was in the range of 18±1 cm and the amount of entrained air was in the range of 4.5±0.5%, thereby preparing a concrete composition (hydraulic composition containing shrinkage reducing agents).

[0101] (3-3) Preparation of the hydraulic composition (concrete from the later batch) to be measured for air content: First, 4% by mass of the "hydraulic composition containing a shrinkage-reducing agent" prepared as described above was added to a 55L pan-type forced-mixing mixer in a test room at 20°C. In this way, the mixture was prepared to a state similar to that in which the "hydraulic composition containing a shrinkage-reducing agent" remained.

[0102] Furthermore, in the manufacturing of concrete compositions, a single plant is used to sequentially produce new concrete compositions in batches such as the first batch, second batch, and third batch. At this time, a portion of the concrete composition produced before the current batch remains in each batch, and this remaining amount can usually be considered to be about 4% by mass of the newly produced concrete composition.

[0103] Subsequently, using this 55L pan-type forced mixer, a 30L concrete composition (a hydraulic composition for which air content was to be measured) was prepared in the same manner as the preparation of the standard concrete composition described above, that is, using the same amounts of water-reducing agent, air-entraining agent, and defoaming agent, and employing the same procedure.

[0104] (4) Various evaluations: Various evaluations (slump, air content (%), effect on air content of subsequent batches, shrinkage reduction performance (dry shrinkage at 26 weeks of age (μm)), and overall evaluation) were performed as appropriate for each prepared hydraulic composition. The evaluation results are shown in Tables 5 to 7. Note that slump is not shown in Tables 5 to 7.

[0105] The evaluation methods and criteria for various evaluations of hydraulic compositions (concrete compositions) are shown below.

[0106] (Slump (cm)) The concrete composition immediately after mixing was measured in accordance with JIS-A1101.

[0107] (Air volume %) The concrete composition immediately after mixing was measured in accordance with JIS-A1128.

[0108] (Effect on air volume in subsequent batches) The effect on the air content of the subsequent batch (i.e., the effect of the "hydraulic composition containing a shrinkage reducing agent" on the concrete of the subsequent batch) was evaluated by calculating the absolute difference between the air content (%) of the "reference concrete composition" and the air content (%) of the "hydraulic composition (concrete of the subsequent batch) for which air content was measured." The evaluation criteria are shown below. Note that in Tables 5 to 7, the "difference in air content (%)" in the column for the effect on the air content of the subsequent batch is the value calculated by the formula: |(air content (%) of the concrete of the subsequent batch (%)) - (air content (%) of the reference concrete composition (%)|. S: 0% or more, 0.5% or less A: More than 0.5%, less than 1.0% B: More than 1.0%, less than 1.5% C: More than 1.5%, less than 2.0% D: More than 2.0%

[0109] (Shrinkage reduction performance) For concrete compositions immediately after mixing, the length change rate was measured in accordance with JIS-A1129 and defined as the drying shrinkage (μm). The shrinkage reduction performance was then evaluated. The evaluation criteria are shown below. S: Drying shrinkage at 26 weeks of age is 550 μm or less. A: Drying shrinkage at 26 weeks of age is greater than 550 μm and less than or equal to 600 μm. B: Drying shrinkage at 26 weeks of age is greater than 600 μm and less than or equal to 650 μm. C: Drying shrinkage at 26 weeks of age is greater than 650 μm and less than or equal to 700 μm. D: Drying shrinkage at 26 weeks of age exceeds 700 μm

[0110] (comprehensive evaluation) Based on the evaluation results for "Influence on air volume in subsequent batches" (Evaluation 1) and "Shrinkage reduction performance" (Evaluation 2) described above, the following criteria were used for evaluation. S: When both the results of Evaluation 1 and Evaluation 2 are "S" A: When the result of Evaluation 1 is "S" and the result of Evaluation 2 is "A", or when the result of Evaluation 1 is "A" and the result of Evaluation 2 is "S" B: If the result of Evaluation 1 is "S" and the result of Evaluation 2 is "B", or if the result of Evaluation 1 is "B" and the result of Evaluation 2 is "S", or if both the result of Evaluation 1 and Evaluation 2 is "A". C: If the result of Evaluation 1 is "S" and the result of Evaluation 2 is "C", or if the result of Evaluation 1 is "C" and the result of Evaluation 2 is "S", or if the result of Evaluation 1 is "A" and the result of Evaluation 2 is "B", or if the result of Evaluation 1 is "B" and the result of Evaluation 2 is "A" D: If the result of Evaluation 1 or Evaluation 2 is "D"

[0111] [Table 5]

[0112] [Table 6]

[0113] [Table 7]

[0114] (result) As shown in Tables 5 to 7, it was confirmed that by adding the shrinkage reducing agent for hydraulic compositions of this embodiment to the hydraulic composition, shrinkage reduction properties can be imparted to the hardened body of the hydraulic composition, and furthermore, a hydraulic composition that can suppress changes in the air content in subsequent batches of hydraulic compositions (concrete of the later batch) can be obtained. [Industrial applicability]

[0115] The shrinkage-reducing agent for hydraulic compositions of the present invention can be used as an additive in hydraulic compositions such as concrete and mortar. Furthermore, the hydraulic composition of the present invention can be used to form hydraulic composition hardened bodies such as hardened concrete and hardened mortar.

Claims

1. Compound (A) represented by the following general formula (1), A copolymer (B) comprising constituent units derived from monomers having anionic groups and constituent units derived from unsaturated hydrocarbon monomers, It contains, A shrinkage reducing agent for hydraulic compositions, characterized in that the mass ratio (compound (A) / polymer (B)) of compound (A) to copolymer (B) is 99.99 / 0.01 to 70.0 / 30.

0. 【Chemistry 1】 (In general formula (1), X is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 30 carbon atoms, or a residue obtained by removing two hydroxyl groups from bisphenol. AO is an oxyalkylene group having 2 to 4 carbon atoms (however, if multiple oxyalkylene groups are present, one type or two or more types may be used). n is the average number of moles of AO added, and is a number from 1 to 300. R is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. a is an integer from 1 to 6 (however, n × a = 1 to 300).)

2. The shrinkage reducing agent for hydraulic compositions according to claim 1, wherein the copolymer (B) comprises a constituent unit derived from a monomer having at least one selected from a carboxylic acid group, a carboxylic acid base, a sulfonic acid group, and a sulfonic acid base, and a constituent unit derived from an unsaturated hydrocarbon monomer having 2 to 10 carbon atoms.

3. The shrinkage reducing agent for hydraulic compositions according to claim 1, wherein the copolymer (B) comprises a constituent unit derived from a monomer having at least one selected from a carboxylic acid group and a carboxylic acid base, and a constituent unit derived from an unsaturated hydrocarbon monomer having 4 to 8 carbon atoms.

4. The shrinkage reducing agent for hydraulic compositions according to claim 1, wherein the copolymer (B) comprises a structural unit derived from at least one monomer selected from maleic acid and maleate, and a structural unit derived from diisobutylene.

5. The shrinkage reducing agent for hydraulic compositions according to any one of claims 1 to 4, wherein in the general formula (1), X is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 15 carbon atoms, or a residue obtained by removing two hydroxyl groups from bisphenol, AO is an oxyalkylene group having 2 to 3 carbon atoms, n is a number from 1 to 220, R is a hydrogen atom, and a is an integer from 1 to 3 (provided that n × a = 1 to 220).

6. The shrinkage reducing agent for hydraulic compositions according to claim 5, wherein in the general formula (1), X is a hydrogen atom or an aliphatic hydrocarbon group having 1 to 8 carbon atoms, AO is an oxyalkylene group having 2 to 3 carbon atoms, and 10 to 100 mol% consists of oxyethylene units, n is a number from 1 to 10, R is a hydrogen atom, and a is 1.

7. A shrinkage reducing agent for hydraulic compositions according to any one of claims 1 to 4, wherein the mass ratio of compound (A) to copolymer (B) (compound (A) / copolymer (B)) is 99.99 / 0.01 to 80.0 / 20.

0.

8. A hydraulic composition characterized by containing a shrinkage reducing agent for hydraulic compositions according to any one of claims 1 to 4.

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