TWI777016B - Additive for hydraulic composition and hydraulic composition - Google Patents

Abstract

Provided is an additive for hydraulic composition, which can reduce the viscosity of hydraulic composition in addition to alleviating the influence of particulate components or clay content contained in granules.

An additive for a hydraulic composition and a hydraulic composition are provided, comprising: a polymer having a structural unit formed of acrylic acid and/or its salts and having a mass average molecular weight of 1,000 or more and less than 100,000, as Component A; a vinyl copolymer having structural unit 1 and structural unit 2 in the molecule, and containing 1 to 99% by mass of structural unit 1 and 1 to 99% by mass of structural unit 2, as component B.

Description

Additive for hydraulic composition and hydraulic composition

The present invention relates to an additive for hydraulic composition. More specifically, it is about an additive for hydraulic compositions that can reduce the influence of fine particles contained in pellets or clay, and at the same time, can reduce the viscosity of hydraulic compositions, and can be applied to cement compositions and the like.

Conventionally, in order to impart fluidity to hydraulic compositions such as mortar and concrete, a ligninsulfonic acid-based dispersant, a naphthalenesulfonic acid-based dispersant, a melaminesulfonic acid-based dispersant, or a polycarboxylic acid-based dispersant has been used as a dispersant. agent. In recent years, in order to improve filling properties, labor saving, and workability, opportunities to use hydraulic compositions with further improved fluidity have increased, and the demand for such hydraulic compositions has been increasing.

In order to obtain such a hydraulic composition, various techniques have been proposed. For example, in Patent Document 1, by using a blending agent in which a specific polycarboxylic acid-based dispersant, a copolymer of a carboxylic acid monomer and a (m)acrylic ester is blended, it is possible to impart fluidity and material separation resistance to concrete. sex. In addition, Patent Document 1 discloses a method of supplying a specific polycarboxylic acid-based dispersant as a raw material component, a copolymer of a carboxylic acid monomer and a (m)acrylic ester, and supplying it as a one-liquid type blending agent.

In addition, in Patent Document 2, it is proposed that a concrete with high filling and high fluidity can be obtained by using a specific low-substituted hypromellose.

[Prior Art Literature]

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2001-89212

Patent Document 2: Japanese Patent Laid-Open No. 4-139047

As the pellets to be mixed into the hydraulic composition, coarse pellets, fine pellets, and the like are used. As the various coarse and fine particles, natural particles such as gravel, sand, etc., which are formed from rocks by natural action and produced from rivers, mountains, seas, and land, are used, and those obtained by artificially crushing rocks such as stone crushers are used. gravel and sand.

Due to the increasing depletion of high-quality natural pellet resources, and taking into account the viewpoint of resource conservation and the impact on the environment during cleaning, within the allowable range of quality, the particles attached to the natural pellets are sometimes not washed away. Use with ingredients or clay.

In addition, there are also cases of using crushed stone and crushed sand with particulate components or clay, and these particulate components or clay are produced when the rock is artificially crushed to produce crushed stone and crushed sand.

If the pellets are attached with various particulate components or clay, there is a problem that the amount of the dispersant added increases. In addition, there is also a problem that the viscosity of the hydraulic composition mixed with ingredients such as pellets, binders, dispersants, and antifoaming agents is increased.

These problems cannot be solved by the techniques disclosed in Patent Documents 1 and 2. Therefore, the problem to be solved by the present invention is to provide an additive for a hydraulic composition, which can alleviate the influence of the particulate components or the clay content in the granules without washing off the particulate components or the clay content attached to the granules, and At the same time, it can reduce the viscosity of hydraulic composition.

In order to achieve the above-mentioned subject, the inventors of the present invention have, as a result of intensive research, found that an additive for a hydraulic composition having a specific polymer is appropriately preferred. According to the present invention, the following additives for hydraulic compositions are provided.

[1] An additive for a hydraulic composition, comprising the following A component and the following B component: A component: a polymer, which has a structural unit formed by acrylic acid and/or its salts, and its mass average molecular weight It is 1000 or more and less than 100000; B component: a vinyl copolymer, which has the following structural unit 1 and structural unit 2 in the molecule, and contains 1 to 99 mass % of structural unit 1, and contains 1 to 99 mass % Structural unit 2: Structural unit 1: Structural unit formed by the following monomer 1; Structural unit 2: Structural unit formed by a carboxylic acid monomer with a vinyl group in the molecule; Monomer 1: The following structural formula Unsaturated (poly) alkanediol shown in (1):

In the structural formula (1), R ¹ , R ² and R ³ represent the same or different groups, and at least one group is selected from the organic groups represented by hydrogen atom, methyl group and -(CH ₂ )RCOOM, Only, at least one of R ¹ , R ² and R ³ represents a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group with a carbon number of 1 to 20, and R ⁵ O represents one or more carbon numbers of 2-4 oxyalkylene, p represents an integer from 0 to 5, q represents 0 or 1, m represents an integer from 1 to 300, R represents an integer from 0 to 2, and M represents a hydrogen atom or a metal atom.

[2] The additive for a hydraulic composition according to item [1], wherein the component B is a vinyl copolymer containing 0 to 30% by mass of the following structural unit 3: The monomer 1 and the carboxylic acid monomer carry out the copolymerization reaction of the monomer 3 in the form of into a structural unit.

[3] The additive for a hydraulic composition according to the item [1] or [2], wherein the mass % of the A component relative to the B component is 0.1 to 5 mass %.

[4] The additive for a hydraulic composition according to any one of the items [1] to [3], wherein the mass average molecular weight of the component A is 1,000 or more and less than 10,000.

[5] A hydraulic composition containing the additive for a hydraulic composition according to any one of [1] to [4].

[6] The hydraulic composition according to the item [5], further comprising a binder.

[7] The hydraulic composition according to item [6], wherein the total mass part of the A component and the B component is 0.1 to 2 parts by mass relative to 100 parts by mass of the binder.

The additive for a hydraulic composition according to the present invention can achieve the effect of reducing the influence of the particulate components or the clay content in the pellets without washing off the particulate components or the clay content adhering to the pellets, and simultaneously reducing the water The viscosity of hard compositions.

The following describes the embodiments of the present invention, but it should be understood that the present invention is not limited to the following embodiments, and those with ordinary knowledge in the technical field to which the present invention pertains can make appropriate changes and modifications to the following embodiments without departing from the scope of the present invention. modifications and still fall within the scope of the present invention. In addition, in the following Examples etc., unless otherwise stated, "%" means mass %, and "part" means mass part.

The additive for a hydraulic composition according to the present embodiment is an additive for a hydraulic composition containing the A component and the B component.

The A component used for the additive for hydraulic compositions of this embodiment is a polymer which has a structural unit which consists of acrylic acid and/or its salts. Here, the type of acrylate is not particularly limited, and examples thereof include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts and magnesium salts, ammonium salts, amine salts such as diethanolamine salts and triethanolamine salts, and the like. . From the viewpoint of easy handling or availability, sodium salt and ammonium salt are preferable, and sodium salt is more preferable. In addition, only one type of acrylic acid and/or its salts may be used, or two or more types may be used.

The polymer used in the component A of the additive for hydraulic compositions of the present embodiment has a mass average molecular weight of 1,000 or more and less than 100,000, preferably 1,000 or more and less than 70,000, more preferably 1,000 or more and less than 50,000 , preferably more than 1000 and less than 30000. Even more preferably, it is 1,000 or more and less than 10,000.

Component B used in the additive for a hydraulic composition of the present embodiment is a vinyl copolymer having structural unit 1 and structural unit 2 in the molecule.

Structural unit 1 is formed from monomer 1 . Monomer 1 is an unsaturated (poly)alkanediol represented by the following structural formula (1).

In the structural formula (1), R ¹ , R ² and R ³ represent the same or different groups, and at least one group is selected from the organic groups represented by hydrogen atom, methyl group and -(CH ₂ )RCOOM, However, at least one of R ¹ , R ² and R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. As such a hydrocarbon group, a methyl group, an ethyl group, a propyl group, a butyl group, etc. are mentioned. R ⁵ O represents one or more oxyalkylene groups having 2 to 4 carbon atoms. As such an oxyalkylene group, an oxyethylene group, an oxypropylene group, etc. are mentioned. In the case of two or more oxyalkylene groups, any addition form such as random addition, block addition, and alternating addition may be used. p represents an integer from 0 to 5, q represents 0 or 1, m represents an integer from 1 to 300, R represents an integer from 0 to 2, and M represents a hydrogen atom or a metal atom.

Examples of such a monomer 1 include α-vinyl-ω-hydroxy(poly)oxybutene (poly)ethylene oxide, α-allyl-ω-methoxy-(poly)ethylene oxide, α-ene Propylene-ω-methoxy-(poly)ethylene oxide (poly)propylene oxide, α-allyl-ω-hydroxy-(poly)ethylene oxide, α-allyl-ω-hydroxy-(poly)ethylene oxide (poly) Propylene oxide, α-Methyl-ω-hydroxy-(poly)ethylene oxide, α-Methyl-ω-methoxy-(poly)ethylene oxide, α-Methyl-ω-hydroxy-(poly)oxide Ethylene (poly) propylene oxide, α-methacrylate-ω-acetyl-(poly) ethylene oxide, α-(3-methyl-3-butene)-ω-hydroxy-(poly) ethylene oxide, α-( 3-Methyl-3-butene)-ω-butoxy-(poly)ethylene oxide, α-(3-methyl-3-butene)-ω-hydroxy-(poly)ethylene oxide (poly)propylene oxide, α -(3-Methyl-3-butene)-ω-acetyl-(poly)ethylene oxide (poly)propylene oxide, α-propylene oxide-ω-hydroxy-(poly)ethylene oxide, α-propylene oxide-ω- Methoxy-(poly)ethylene oxide, α-acrylonitrile-ω-butoxy-(poly)ethylene oxide, α-acrylonitrile-ω-methoxy-(poly)ethylene oxide (poly)propylene oxide, α-methyl group Acrylonitrile-ω-hydroxy-(poly)ethylene oxide, α-methacrylonitrile-ω-methoxy-(poly)ethylene oxide, α-methacrylonitrile-ω-butoxy-(poly)ethylene oxide, α - Acrylonitrile-ω-methoxy-(poly)ethylene oxide (poly)propylene oxide, α-methacrylonitrile-ω-hydroxy-(poly)ethylene oxide (poly)propylene oxide, α-methacrylonitrile-ω -Acetyl-(poly) ethylene oxide (poly) propylene oxide, maleic acid or fumaric acid, Iconic acid and other unsaturated dicarboxylic acids and (poly) ethylene oxide formed by monoester, cis-butane Monoesters formed by unsaturated dicarboxylic acids such as olefinic acid, fumaric acid, and itonic acid and (poly) ethylene oxide (poly) propylene oxide.

Structural unit 2 is formed from a carboxylic acid monomer. Here, the carboxylic acid monomer system refers to a monomer having no ester group or amide group. The carboxylic acid monomer has a vinyl group in its molecule. As such a carboxylic acid monomer, (m-)acrylic acid, crotonic acid, (anhydrous) maleic acid, (anhydrous) itonic acid, fumaric acid, its salt, etc. are mentioned, for example. The salt is not particularly limited, and examples thereof include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts and magnesium salts, amine salts such as ammonium salts, diethanolamine salts, and triethanolamine salts. Among them, sodium salt and calcium salt are preferred.

The vinyl copolymer used as the component B of the additive for a hydraulic composition of the present embodiment may further contain the structural unit 3 as an arbitrary structural unit in the molecule. The structural unit 3 may be formed of the monomer 3 which can be copolymerized with the monomer 1 and the carboxylic acid monomer.

The monomer 3 is not particularly limited as long as it can copolymerize with the monomer 1 and the carboxylic acid monomer, and examples thereof include alkyl (meta)acrylate-based monoacrylates such as methyl acrylate, methyl methacrylate, and butyl acrylate. (m)acrylamide, N,N-dimethyl (m)acrylamide and other unsaturated amides, (m)acrylonitrile and other unsaturated cyanides; maleic acid or fumaric acid Monoesters formed by unsaturated dicarboxylic acids and alcohols with alkyl or alkenyl groups of 1 to 22 carbon atoms; unsaturated dicarboxylic acids such as maleic acid or fumaric acid and (poly)alkane dicarboxylic acids Diesters of unsaturated dicarboxylic acids such as diesters formed by alcohols or alcohols with alkyl or alkenyl groups of 1 to 22 carbon atoms; unsaturated carboxylic acids or unsaturated dicarboxylic acids and amines of 1 to 22 carbon atoms Formed monoamide or diamide and other amide monomers; unsaturated carboxylic acid or unsaturated dicarboxylic acid and amine with carbon number of 1~22 formed by monoamide or diamide and other amide monomers Types; reactants formed by the condensation reaction of alkyl dicarboxylic acid and polyethylene polyamine, after adding ethylene oxide or propylene oxide to the nitrogen atom with active hydrogen, and then reacting with (m) acrylic acid ; amide monomers such as monoamide or diamide formed by unsaturated carboxylic acid or unsaturated dicarboxylic acid and amine with a carbon number of 1~22; the condensation of alkyl dicarboxylic acid and polyethylene polyamine After the reaction, ethylene oxide or propylene oxide is added to the nitrogen atom with active hydrogen, and then reacted with glycidyl (m) acrylate to form a reactant; polyamide polyamine monomers; from (m)Allylsulfonic acid or vinylsulfonic acid and salts thereof Sulfonic acid monomers formed by phosphonic acid 2-(methacryloyloxy)ethyl or phosphoric acid-bis[2-(methacryloyloxy)ethyl] and salts, etc. Phosphate monomers, etc.

In the B component used in the additive for hydraulic composition of the present embodiment, the structural unit 1 is contained in 1 to 99 mass %, preferably 70 to 99 mass %, more preferably 75 to 99 mass %, especially It is preferable to contain 80 to 99 mass %; in the B component, it is preferable to contain 1 to 99 mass % of the structural unit 2, preferably 1 to 30 mass %, more preferably 25 to 99 mass %, and particularly preferably 1 to 10 mass %. 20% by mass. In addition, in the B component used in the additive for a hydraulic composition of the present embodiment, it is preferable to contain 0 to 30 mass % of the structural unit 3, more preferably to contain 0 to 20 mass %, and still more preferably to contain 0 to 10 mass %. % by mass, or even more preferably 0 to 5% by mass.

In the B component of the additive for a hydraulic composition of the present embodiment, the total amount of the structural unit 1 and the structural unit 2 is preferably 80% by mass or more, more preferably 85% by mass or more, and particularly preferably 90% by mass or more. , and even more preferably 95% by mass or more.

The mass average molecular weight of the component B used in the additive for the hydraulic composition of the present embodiment can be measured by gel permeation chromatography, and in terms of polyethylene glycol, it is preferably 2,000 to 500,000, more preferably 5000~200000, preferably 10000~100000.

Such B component can be obtained by a well-known radical polymerization reaction. For example, it can be prepared by various methods. Among them, methods such as radical polymerization using water in a solvent, radical polymerization using an organic solvent in a solvent, and radical polymerization without a solvent can be exemplified. The reaction temperature during the radical polymerization is preferably 0 to 120°C, more preferably 20 to 100°C, and particularly preferably 50 to 90°C. Radical polymerization initiators used for radical polymerization include peroxides such as hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, etc.; 2,2-azobis(2-carboxamidino) Azo compounds such as propane) dihydrochloride and 2,2-azobis(isobutyronitrile). As long as it decomposes at the polymerization reaction temperature and generates free radicals, the type is not particularly limited. These can also be combined with reducing substances such as sulfites or L-ascorbic acid, and then combined with substances such as amines as redox substances. Starter used. Chains such as 2-mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, mercaptoacetic acid, thioglycerol, and thiomalic acid can also be used in order to obtain a mass average molecular weight of component B in a desired range. transfer agent. These radical polymerization initiators, reducing substances and chain transfer agents may be used independently, respectively, or two or more of them may be used in combination. There is no particular restriction on the pressure in the reaction system, but normal pressure is preferred.

In the additive for a hydraulic composition of the present embodiment, the concentrations of the A component and the B component are not particularly limited, but the mass % of the A component relative to the B component is preferably 0.1 to 5 mass %, more preferably 0.5 to 4 mass %. quality%.

Next, the hydraulic composition of this embodiment is demonstrated. The hydraulic composition of the present embodiment contains the additive for the hydraulic composition of the present embodiment.

With respect to the method of adding the additive for a hydraulic composition, the component A and the component B may be added independently or simultaneously. Component A and Component B can be added to the hydraulic composition slurry as powder, and Component A and Component B can also be added to the hydraulic composition in a state of being dispersed or dissolved in a liquid shrinkage inhibitor or a liquid defoamer. In the composition slurry, the A component and the B component may be added to the hydraulic composition slurry in a state of being dissolved in water.

In addition, when the vinyl copolymer as the component B is used as the aqueous solution, the pH of the 1 mass % aqueous solution of the component B is preferably 2 to 7, more preferably 2 to 6, from the viewpoint of the compatibility of the component A and the component B. , preferably 2 to 5.

The hydraulic composition of the present embodiment is prepared using the additive for the hydraulic composition of the present embodiment described above, and among them, cement compositions such as cement paste, mortar, and concrete are preferred. The cement composition uses at least one kind of cement as a binder, wherein the cement can be used alone, and in addition, it can also be used in combination with cement, buzuolan material or a mixed material with latent hydraulic fine powder. Examples of such cement include ordinary portland cement, early strength port Portland cement, moderate heat portland cement, low heat portland cement, etc., blast furnace cement, fly ash cement, silica fume cement and other mixed cements. Moreover, as a fine powder mixing material, a blast furnace ballast fine powder, silica fume, fly ash, etc. are mentioned.

The hydraulic composition of the present embodiment preferably contains pellets. As the pellets, any appropriate pellets such as fine pellets or coarse pellets can be used. Among such granules, examples of fine grains include river sand, mountain sand, land sand, silica sand, crushed sand, fine grains of blast furnace ballast, and the like; and examples of coarse grains include river gravel and hill gravel. , land gravel, gravel, blast furnace ballast, etc.

The granular material or clay is attached to the pellets, and the hydraulic composition will contain fine particles or clay when it is used without washing off the fine particles or clay. Only the hydraulic composition of this embodiment, In addition to the effects of various particulate components or clay, the viscosity of the hydraulic composition can be reduced.

In the hydraulic composition of the present embodiment, with respect to 100 parts by mass of the binder, the total mass part of the A component and the B component is preferably 0.1 to 2 parts by mass, more preferably 0.1 to 1.5 parts by mass, and particularly preferably 0.1 to 0.1 parts by mass. 1 part by mass.

In the hydraulic composition of this embodiment, it is preferable to use a water-to-binder ratio of 30-60%, which is easily affected by the fluidity of clay. In addition, the water-binder ratio refers to the mass parts of water in the hydraulic composition with respect to 100 parts by mass of a binder such as cement, and if the water is 50 parts by mass, the water-binder ratio is 50%.

The hydraulic composition of the present embodiment may suitably contain, within a range that does not impair its effects, an AE adjuster composed of, for example, an anionic surfactant, an oxane-based antifoaming agent, such as an oxycarboxylic acid Retarders composed of salts, hardening accelerators composed of alkanolamines, drying shrinkage inhibitors composed of polyoxyethylene alkyl ethers, preservatives composed of isothiazolines, such as those derived from higher fatty acids Water repellents composed of substances, such as rust inhibitors composed of nitrite, etc.

[Example]

Table 1 shows a summary of the polymers of acrylic acid and/or its salts used in test category 1 (polymer of acrylic acid and/or its salts as component A).

In Table 1,

A-1: Sodium polyacrylate (ARON T-210 manufactured by Toagosei Co., Ltd.)

A-2: Polyacrylic acid (polyacrylic acid 5,000 manufactured by Wako Pure Chemical Industries, Ltd.)

A-3: Polyacrylic acid (25,000 polyacrylic acid manufactured by Wako Pure Chemical Industries, Ltd.)

Ar-1: Polyacrylic acid (polyacrylic acid 1,000,000 manufactured by Wako Pure Chemical Industries, Ltd.)

Ar-2: Sodium polyacrylate (ARON A-20P-X manufactured by Toagosei Co., Ltd.)

Ar-3: Hypromellose (METOLOSE Hi90SH100000 manufactured by Shin-Etsu Chemical Co., Ltd.)

d-1: Structural unit formed by sodium acrylate

d-2: Structural unit formed from acrylic acid

d-3: Structural unit formed from acrylic acid

d-4: Structural unit formed from acrylic acid

d-5: Structural unit formed by sodium acrylate

Test Category 2 (Preparation of Vinyl Copolymer as Component B)

Preparation Example 1 {Preparation of Vinyl Copolymer (B-1)}

Distilled water 250g, α-(3-methyl-3-butene)-ω-hydroxy-poly(n=50)oxygen Pour 330 g of ethylene into a reaction vessel equipped with a thermometer, agitator, dropping funnel, and nitrogen conduit (hereinafter, the same equipment is used), and dissolve uniformly while stirring, then replace the ambient gas with nitrogen, and use a warm water bath to make the reaction system The temperature was maintained at 65°C. Next, 16 g of 1% hydrogen peroxide water was titrated for 3 hours. At the same time, 30 g of acrylic acid was uniformly dissolved in an aqueous solution of 80 g of ion-exchanged water by titration for 3 hours. At the same time, 2 g of L-ascorbic acid and hydrogen were titrated for 4 hours. 3 g of thioglycolic acid was dissolved in an aqueous solution of 14 g of ion-exchanged water. For the next 2 hours, the temperature of the reaction system was maintained at 65°C, and the polymerization reaction was terminated. After that, a 30% aqueous sodium hydroxide solution was added to the reaction system, adjusted to pH 3, and the concentration was adjusted to 40% with ion-exchanged water to obtain a reaction mixture. The reaction mixture was analyzed by gel permeation chromatography (GPC) and found to have a mass average molecular weight of 35,000. This reactant was taken as vinyl copolymer (B-1).

Preparation Example 2 {Preparation of Vinyl Copolymer (B-2)}

150 g of distilled water was poured into the reaction vessel, the ambient gas was replaced with nitrogen, and the temperature of the reaction system was maintained at 60° C. under the nitrogen ambient gas. Next, 150 g of distilled water, 20 g of methacrylic acid, 320 g of α-hydroxy-ω-methacryloyl-poly(n=2) propylene poly(n=113) ethylene oxide, 10 g of hydroxyethyl acrylate, and 3.5 g of 3-mercaptopropionic acid were added. g is mixed uniformly, and the monomer mixture aqueous solution is adjusted. This monomer mixture aqueous solution and 24 g of a 10% aqueous sodium persulfate solution were simultaneously titrated into the reaction vessel for 4 hours to perform a radical copolymerization reaction, and further, 6 g of a 10% aqueous sodium persulfate solution was titrated for 1 hour to react. After 1 hour, the temperature of the reaction system was maintained at 60°C, and the radical copolymerization reaction was performed. Next, after cooling the reaction system to room temperature, an aqueous sodium hydroxide solution was added to adjust the pH to 5, and the concentration was adjusted to 40% with distilled water to obtain a reaction mixture. The reaction mixture was analyzed by gel permeation chromatography (GPC) and found to have a mass average molecular weight of 43,000. This reactant was taken as vinyl copolymer (B-2).

Preparation Example 3 {Preparation of Vinyl Copolymer (B-3)}

Pour 150 g of distilled water into the reaction vessel, replace the ambient gas with nitrogen, and place it in a nitrogen atmosphere. The temperature of the reaction system was maintained at 60° C. Next, 150 g of distilled water, 35 g of methacrylic acid, 300 g of α-methoxy-ω-methacryloyl-poly(n=23)ethylene oxide, 5 g of methyl acrylate, and 3.5 g of 3-mercaptopropionic acid were uniformly mixed to prepare a monomer mixture. aqueous solution. This monomer mixture aqueous solution and 24 g of a 10% aqueous sodium persulfate solution were simultaneously titrated into the reaction vessel for 4 hours to perform a radical copolymerization reaction, and further, 6 g of a 10% aqueous sodium persulfate solution was titrated for 1 hour to react. After 1 hour, the temperature of the reaction system was maintained at 60°C, and the radical copolymerization reaction was performed. Next, after cooling the reaction system to room temperature, an aqueous sodium hydroxide solution was added to adjust the pH to 4, and the concentration was adjusted to 40% with distilled water to obtain a reaction mixture. The reaction mixture was analyzed by gel permeation chromatography (GPC) and found to have a mass average molecular weight of 43,000. This reactant was taken as vinyl copolymer (B-3). The vinyl copolymers prepared above are summarized in Table 2.

In Table 2,

*1: Type of vinyl copolymer as component B

*2: Kind of monomer 1 forming structural unit 1

*3: Kind of carboxylic acid monomer forming structural unit 2

*4: Kind of monomer 3 forming structural unit 3

Proportion: the unit is mass %

Monomers (e-1)~(e-4): The monomers represented by the structural formula (1) in Table 3 below are assembled

Monomer (f-1): acrylic acid

Monomer (f-2): methacrylic acid

Monomer (g-1): methyl acrylate

In Table 3,

EO: Ethylene oxide

PO: oxypropylene group

EO(113)+PO(2): Addition product of 113mol of EO and 2mol of PO in total of 115mol

Test Category 3 (Measurement of Mass Average Molecular Weight of Component A and Component B)

The mass average molecular weights of A component and B component were measured by the following method. The results are shown in Tables 1 and 2.

Determination of Mass Average Molecular Weight of Component A

The mass-average molecular weight of acrylic acid and/or its salts as component A is measured by gel permeation chromatography multi-angle light scattering method (GPC-MALS method) and/or gel permeation chromatography (GPC method) was performed under the following measurement conditions. In addition, since the mass average molecular weight of polyacrylic acid exceeds 500,000, it cannot be measured by the GPC method, so the GPC-MALS method is used for those with a mass average molecular weight exceeding 500,000. In addition, in A-3 and Ar-1, since the difference of the molecular weight of GPC-MALS method and GPC method is within ±3%, it is regarded as the same.

Measurement conditions

GPC-MALS method

Detectors: Differential Refractive Index Detector (RI), Multi-Angle Light Scattering Detector (MALS)

Column: OHpak SB-807 HQ+SB-806M HQ manufactured by Showa Denko

Elution solution: 0.1M Tris buffer (pH=0.9, add 0.1M potassium salt)/acetonitrile mix

Solvent (mixing volume ratio: 7/3)

Flow rate: 0.5mL/min

Column temperature: 40℃

GPC method

Detector: Refractive Index Detector (RI)

Column: OHpak SB-G+SB-806M HQ+SB-806M manufactured by Showa Denko

Eluent: 50mM sodium nitrate in water

Flow rate: 0.7mL/min

Column temperature: 40℃

Standard material: Sodium polyacrylate manufactured by Agilent Technologies Japan, Ltd.

Measurement of Mass Average Molecular Weight of Component B

The measurement of the mass average molecular weight of the vinyl copolymer as the component B was performed by gel permeation chromatography (GPC) under the following conditions.

Measurement conditions

Detector: Refractive Index Detector (RI)

Column: OHpak SB-G+SB-806M HQ+SB-806M manufactured by Showa Denko

Eluent: 50mM sodium nitrate in water

Flow rate: 0.7mL/min

Column temperature: 40℃

Standard material: polyethylene glycol/oxide (PEG/PEO) manufactured by Agilent Technologies Japan, Ltd.

Test Category 4 (Confirmation of Compatibility)

The compatibility of the solution was measured by the following criteria by visual observation when the vinyl copolymer of the component B was set to 20%, and the ratio of the component A and the component B shown in Table 4 was sufficiently stirred and mixed. For the concentration adjustment of the aqueous solution, distilled water was used.

Compatibility criteria

A: The degree of precipitation or settling cannot be determined

B: Thin cloudiness is confirmed

C: Precipitation or sedimentation confirmed

Test Category 5 (Preparation of Mortar as Hydraulic Composition)

A mortar mixer according to JIS R 5201 Physical Test Methods for Cement was used. And use ordinary portland cement (density 3.16g/cm ³ ) as a binder, use land sand from Oigawa water system (density 2.58g/cm ³ ) as fine particles, use bentonite (Reagent Wako Pure Chemical Industries) Co., Ltd.) as clay. With respect to 100 parts by mass of the adhesive, an antifoaming agent (manufactured by Takemoto Oil Co., Ltd., trade name AFK-2) was added at a ratio of 0.005 parts by mass, and at the same time, the additive for a hydraulic composition used in test classification 4 was added together with stirring water The mixture was put in, and the ingredients were stirred for 240 seconds under the mixing conditions described in Table 5 to prepare a mortar. In addition, additives and antifoams are considered part of the water.

Component stirring and the following tests were performed in an environment where the material temperature was set to 20±3°C, the room temperature was set to 20±3°C, and the humidity was set to 60% or more. The evaluation of the mortar fluidity of the obtained mortar was carried out with a target of 240±5 mm as the fluidity of the non-vibration mortar. The viscosity evaluation was performed according to the test method for fluidity of filled mortar (JSCE-F 541) using a _J14 funnel, and the one with a short flow down time was evaluated as a low viscosity one. The results are shown in Table 6. In addition, no separation was observed in any of the mortars visually.

In Table 6,

*1: Total parts by mass (solid content) of (A) component and (B) component relative to 100 parts by mass of the adhesive

result

As shown in Table 6, compared with Comparative Example 5 which does not contain component A but only contains component B, it can be observed that Example 7 and Example 10 containing both A and B components do not need to increase the addition rate of additives. Until the shedding time is shortened. Compared with Comparative Example 6 using polyacrylic acid with larger molecular weight, Example 7 using polyacrylic acid of component A can observe that the running time is significantly shortened without increasing the addition rate of additives. Compared with Comparative Example 7 using polyacrylate with larger molecular weight, Example 10 using polyacrylic acid of component A can observe that the running time is significantly shortened without increasing the addition rate of additives. Compared with Comparative Example 8 using hypromellose as a tackifier, Example 8 using polyacrylic acid of component A can observe that the running time is significantly shortened without increasing the addition rate of additives.

[Industrial Availability]

The additive for hydraulic compositions of the present invention can be used as an additive for preparing hydraulic compositions.

Claims (6)

An additive for a hydraulic composition, comprising the following A component and the following B component: A component: a polyacrylic acid, which has a structural unit formed by acrylic acid and/or its salts, and its mass average molecular weight is 1000 or more and less than 100000; B component: a vinyl copolymer, which has the following structural unit 1 and structural unit 2 in the molecule, and contains 1 to 99 mass % of structural unit 1, and contains 1 to 99 mass % of structural units 2; Structural unit 1: a structural unit formed by the following monomer 1; The formed structural unit; Monomer 1: unsaturated (poly)alkanediol represented by the following structural formula (1):

In the structural formula (1), R ¹ , R ² and R ³ represent the same or different groups, and at least one group is selected from the organic groups represented by hydrogen atom, methyl group and -(CH ₂ )RCOOM, Only, at least one of R ¹ , R ² and R ³ represents a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group with a carbon number of 1 to 20, and R ⁵ O represents one or more carbon numbers of Oxyalkylene of 2 to 4, p represents an integer of 0 to 5, q represents 0 or 1, m represents an integer of 1 to 300, R represents an integer of 0 to 2, and M represents a hydrogen atom or a metal atom, wherein relative to The mass % of the B component and the A component is 0.1 to 5 mass %. The additive for hydraulic composition according to claim 1, wherein the component B is a vinyl copolymer containing 0-30% by mass of the following structural unit 3: Structural unit 3: Monomer 1 and the carboxylic acid monomer 2 are in the form of monomer 3 in the copolymerization reaction into a structural unit. The additive for a hydraulic composition according to claim 1, wherein the mass-average molecular weight of the component A is 1,000 or more and less than 10,000. A hydraulic composition comprising the additive for hydraulic composition described in claim 1 of the scope of application. The hydraulic composition as described in item 4 of the claimed scope further contains a binder. The hydraulic composition according to item 5 of the scope of application, wherein the total mass parts of the A component and the B component is 0.1-2 mass parts relative to 100 mass parts of the adhesive.