Dispersant for hydraulic composition, hydraulic composition and hydraulic composition hardening body

Abstract

To provide a dispersant for a hydraulic composition that has initial dispersibility and fluidity retention, and can yield a hydraulic composition in which foam formation is suppressed (i.e., air entrainment is small).SOLUTION: A dispersant for a hydraulic composition includes, in a molecule, a water-soluble vinyl copolymer containing a constitutional unit 1 formed from a compound represented by a general formula (1), a constitutional unit 2 formed from a compound represented by a general formula (2), and a constitutional unit 3 formed from a compound represented by a general formula (3). The water-soluble vinyl copolymer contains, when the sum of a constitution ratio of the constitutional unit 1, the constitutional unit 2, and the constitutional unit 3 is 100 mass%, the constitutional unit 1 of 65 to 95 mass%, the constitutional unit 2 of 2 to 30 mass%, and the constitutional unit 3 of 0.1 to 25 mass% in proportions, and the mass average molecular weight is 5000 to 200000.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a dispersant for hydraulic compositions, a hydraulic composition, and a hardened product of the hydraulic composition. More specifically, the present invention relates to a dispersant for hydraulic compositions, a hydraulic composition, and a hardened product of the hydraulic composition, which are capable of obtaining a hydraulic composition having initial dispersibility and fluidity retention, and in which foaming is suppressed (i.e., air entrainment is small). [Background technology]

[0002] Conventionally, dispersants for hydraulic compositions have the function of improving the strength, durability, etc. of a set product of a hydraulic composition by increasing the fluidity of the hydraulic composition and reducing the water content of the hydraulic composition.

[0003] Known examples of dispersants for hydraulic compositions include naphthalene compounds and polycarboxylic acid compounds.

[0004] Among these, polycarboxylic acid compounds containing polyalkylene glycol chains are often used because they exhibit high dispersing performance (water-reducing effect).

[0005] On the other hand, polycarboxylic acid compounds have a high air entrainment property, so in many cases, an antifoaming agent is used in combination with them.

[0006] However, when an antifoaming agent (especially an antifoaming agent with high antifoaming performance) is added, there is a problem that the antifoaming agent is likely to separate in water, etc. Therefore, it has been reported that a nitrogen-containing oxyalkylene compound or the like is used in combination in place of the antifoaming agent (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 7-232945 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the cement additive composition described in Patent Document 1 is a mixture of a polycarboxylic acid compound and a nitrogen-containing polyoxyalkylene compound, and both a polycarboxylic acid compound and a nitrogen-containing polyoxyalkylene compound are required. In other words, a compound other than a polycarboxylic acid compound is required, and the polycarboxylic acid compound alone still results in high air entrainment.

[0009] Therefore, there has been a demand for the development of a polycarboxylic acid compound that reduces the air entrainment in hydraulic compositions.

[0010] In view of the above circumstances, an object of the present invention is to provide a dispersant for hydraulic compositions, which, when added to a hydraulic composition, can give a hydraulic composition having initial dispersibility and fluidity retention as well as suppressed foaming (i.e., low air entrainment), a hydraulic composition, and a hardened product of the hydraulic composition. [Means for solving the problem]

[0011] As a result of intensive research aimed at solving the above problems, the present inventors have found that the above problems can be solved by including a specific water-soluble vinyl copolymer. According to the present invention, the following dispersant for hydraulic compositions, hydraulic compositions, and hardened products of the hydraulic compositions are provided.

[0012] [1] A water-soluble vinyl copolymer containing, in the molecule, a structural unit 1 formed from a compound represented by the following general formula (1), a structural unit 2 formed from a compound represented by the following general formula (2), and a structural unit 3 formed from a compound represented by the following general formula (3), The water-soluble vinyl copolymer is When the total of the constituent proportions of the structural unit 1, the structural unit 2, and the structural unit 3 is 100% by mass, the structural unit 1 is contained in an amount of 65 to 95% by mass, the structural unit 2 is contained in an amount of 2 to 30% by mass, and the structural unit 3 is contained in an amount of 0.1 to 25% by mass, A dispersant for hydraulic compositions, characterized in that the dispersant has a mass average molecular weight of 5,000 to 200,000.

[0013] [ka] (In general formula (1), R 1 ,R 2 ,R 3 are each independently a hydrogen atom or a methyl group. 4 is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. AO is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of oxyalkylene groups are present, one type may be used alone or two or more types may be used). n is the average number of moles of AO added, and is a number from 2 to 150. p is an integer of 0 or 1. q is an integer of 0 to 2.

[0014] [ka] (In the general formula (2), R 5 ,R 6 ,R 7 are each independently a hydrogen atom or a methyl group. 1 is a hydrogen atom, a metal atom, an ammonium group, or an organic amine group.

[0015] [ka] (In the general formula (3), R 8 is a hydrogen atom or -COOM 2 R 9 is a hydrogen atom or -COOM 4 (However, r is 0 and R 8 If is a hydrogen atom, R 9 Ha-COOM 4 r is an integer from 0 to 2. M 2 ,M 3 ,M 4 is a hydrogen atom, a metal atom, an ammonium group, an organic amine group, or a hydrocarbon group having 1 to 18 carbon atoms. 3-COOM 2 or -COOM 4 In this case, M 3 ,M 2 ,M 4 does not exist.)

[0016] [2] In the structural unit 3, R 9 is a hydrogen atom, and r is 1.

[0017] [3] A hydraulic composition comprising the dispersant for hydraulic compositions according to [1] or [2].

[0018] [4] A hardened hydraulic composition, characterized in that it is a hardened product of the hydraulic composition described in [3] above. [Effects of the Invention]

[0019] The dispersant for hydraulic compositions of the present invention has the effect of being able to obtain a hydraulic composition that has initial dispersibility and fluidity retention, and in which foaming is suppressed (i.e., air entrainment is small).

[0020] The hydraulic composition of the present invention exhibits the effects of having initial dispersibility and fluidity retention, as well as being suppressed in foaming (i.e., having little air entrainment).

[0021] The hydraulic composition hardened product of the present invention exhibits the effect of exhibiting good strength development since foaming of the hydraulic composition forming the hydraulic composition is suppressed. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. Therefore, it should be understood that appropriate changes, modifications, etc. can be made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. In the following examples, % means % by mass, and parts means parts by mass, unless otherwise specified.

[0023] (1) Dispersant for hydraulic compositions: The dispersant for hydraulic compositions of the present invention contains a water-soluble vinyl copolymer containing, in its molecule, structural unit 1 formed from a compound represented by the following general formula (1), structural unit 2 formed from a compound represented by the following general formula (2), and structural unit 3 formed from a compound represented by the following general formula (3): When the total proportion of structural unit 1, structural unit 2, and structural unit 3 is taken as 100 mass%, this water-soluble vinyl copolymer contains structural unit 1 in proportions of 65 to 95 mass%, structural unit 2 in proportions of 2 to 30 mass%, and structural unit 3 in proportions of 0.1 to 25 mass%, and has a mass average molecular weight of 5,000 to 200,000.

[0024] This dispersant for hydraulic compositions has initial dispersibility and fluidity retention, and can give hydraulic compositions with reduced foaming (i.e., low air entrainment).

[0025] [ka] (In general formula (1), R 1 ,R 2 ,R 3 are each independently a hydrogen atom or a methyl group. 4 is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. AO is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of oxyalkylene groups are present, one type may be used alone or two or more types may be used). n is the average number of moles of AO added, and is a number from 2 to 150. p is an integer of 0 or 1. q is an integer of 0 to 2.

[0026] [ka] (In the general formula (2), R 5 ,R 6 ,R 7 are each independently a hydrogen atom or a methyl group. 1 is a hydrogen atom, a metal atom, an ammonium group, or an organic amine group.

[0027] [ka] (In the general formula (3), R 8 is a hydrogen atom or -COOM 2 R 9 is a hydrogen atom or -COOM 4 (However, r is 0 and R 8 If is a hydrogen atom, R 9 Ha-COOM 4 r is an integer from 0 to 2. M 2 , M 3 , M 4 is a hydrogen atom, a metal atom, an ammonium group, an organic amine group, or a hydrocarbon group having 1 to 18 carbon atoms. 3 -COOM 2 or -COOM 4 In this case, M 3 ,M 2 ,M 4 does not exist.)

[0028] (1-1) Water-soluble vinyl copolymer: The water-soluble vinyl copolymer contains a structural unit 1 formed from a compound represented by general formula (1), a structural unit 2 formed from a compound represented by general formula (2), and a structural unit 3 formed from a compound represented by general formula (3) in predetermined content ratios, respectively. By using a dispersant for hydraulic compositions containing such a water-soluble vinyl copolymer, it is possible to obtain a hydraulic composition that has initial dispersibility and flowability retention, as well as suppressed foaming (i.e., low air entrainment).

[0029] (1-1a) Structural unit 1 formed from a compound represented by general formula (1): R in general formula (1) 1 ,R 2 ,R 3 are each independently a hydrogen atom or a methyl group. 1 ,R 3 is a hydrogen atom, and R 2 is preferably a methyl group.

[0030] R in general formula (1) 4 is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.

[0031] In general formula (1), AO is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type may be used alone or two or more types may be used). Among these, an oxyalkylene group having 2 carbon atoms is preferred.

[0032] In the general formula (1), n ​​is the average number of moles of AO added, and is a number from 2 to 150, preferably a number from 2 to 140.

[0033] In the general formula (1), p is an integer of 0 or 1.

[0034] In the general formula (1), q is an integer of 0 to 2.

[0035] Specific examples of the compound represented by general formula (1) include α-methacryloyl-ω-methoxy-(poly)oxyethylene, α-methacryloyl-ω-methoxy-(poly)oxyethylene(poly)oxypropylene, α-methacryloyl-ω-hydroxy-(poly)oxyethylene, α-methacryloyl-ω-hydroxy-(poly)oxyethylene(poly)oxypropylene, α-methallyl-ω-methoxy-(poly)oxyethylene, α-methallyl-ω-methoxy-(poly)oxyethylene, α-methallyl-ω-methoxy-( Poly)oxyethylene (poly)oxypropylene, α-methallyl-ω-hydroxy-(poly)oxyethylene, α-methallyl-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene, α-(3-methyl-3-butenyl)-ω-methoxy-(poly)oxyethylene, α-(3-methyl-3-butenyl)-ω-methoxy-(poly)oxyethylene (poly)oxypropylene, α-(3-methyl-3-butenyl)-ω-hydroxy-(poly)oxyethylene Examples of the hydroxy-(poly)oxyethylene include α-(3-methyl-3-butenyl)-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene, α-allyl-ω-methoxy-(poly)oxyethylene, α-allyl-ω-methoxy-(poly)oxyethylene (poly)oxypropylene, α-allyl-ω-hydroxy-(poly)oxyethylene, α-allyl-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene, α-acryloyl-ω-methoxy-(poly)oxyethylene, α-acryloyl-ω-methoxy-(poly)oxyethylene (poly)oxypropylene, α-vinyl-ω-hydroxy-monooxybutylene(poly)oxyethylene α-vinyl-ω-methoxy-(poly)oxyethylene, α-vinyl-ω-methoxy-(poly)oxyethylene (poly)oxypropylene, α-vinyl-ω-hydroxy-(poly)oxyethylene, and α-vinyl-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene.

[0036] (1-1b) Structural unit 2 formed from a compound represented by general formula (2): R in general formula (2) 5 ,R 6 ,R 7are each independently a hydrogen atom or a methyl group. 5 ,R 7 is a hydrogen atom, and R 6 is preferably a hydrogen atom or a methyl group.

[0037] M in general formula (2) 1 is a hydrogen atom, a metal atom, an ammonium group, or an organic amine group. Of these, a hydrogen atom or a metal atom is preferred. In this specification, the term "organic amine" refers to a salt formed with a carboxylic acid.

[0038] Specific examples of the compound represented by general formula (2) include (meth)acrylic acid and salts thereof.

[0039] (1-1c) Structural unit 3 formed from a compound represented by general formula (3): R in general formula (3) 8 is a hydrogen atom or -COOM 2 is.

[0040] R in general formula (3) 9 is a hydrogen atom or -COOM 4 (However, r is 0 and R 8 If is a hydrogen atom, R 9 Ha-COOM 4 (That is).

[0041] In the general formula (3), r is an integer of 0 to 2. Among these, an integer of 0 to 1 is preferred.

[0042] M in general formula (3) 3 is a hydrogen atom, a metal atom, an ammonium group, an organic amine group, or a hydrocarbon group having a carbon number of 1 to 18. Of these, a hydrogen atom or a metal atom is preferred.

[0043] -COOM 3 -COOM 2 or -COOM 4In this case, M 3 ,M 2 ,M 4 In other words, the compound represented by the general formula (3) does not contain -COOM 3 But, -COOM 2 or -COOM 4 In this case, in the compound represented by general formula (3), M corresponding to the group subjected to the intramolecular dehydration condensation may be a carboxylic acid anhydride in which a cyclic structure is formed by intramolecular dehydration condensation with 3 ,M 2 ,M 4 does not exist.

[0044] Specific examples of the compound represented by general formula (3) include itaconic acid and its salts, itaconic anhydride, monoalkyl (C1-18) itaconates and their salts, maleic acid and its salts, maleic anhydride, monoalkyl (C1-18) maleates and their salts, etc.

[0045] In this structural unit 3, R 9 It is preferable that is a hydrogen atom and r is 1. In this way, a hydraulic composition having good initial dispersibility and fluidity retention as well as less air entrainment can be obtained.

[0046] The ratio of the content of structural unit 3 to the content of structural unit 2 (formula: content of structural unit 3 / content of structural unit 2) is preferably 0.05 to 3.50. Within this range, a hydraulic composition can be obtained that has initial dispersibility and fluidity retention, as well as low air entrainment.

[0047] (Content of structural units 1 to 3) The water-soluble vinyl copolymer contains 65 to 95 mass% of structural unit 1, 2 to 30 mass% of structural unit 2, and 0.1 to 25 mass% of structural unit 3, where the total proportion of structural unit 1, structural unit 2, and structural unit 3 is taken as 100 mass%. By doing so, a hydraulic composition can be obtained that has initial dispersibility and flowability retention, as well as low air entrainment.

[0048] Here, the constituent proportions of the constituent units 1 to 3 can be divided into the following cases depending on the range of n in the constituent unit 1.

[0049] When n in structural unit 1 is 2 to 15, when the total constituent proportions of structural units 1, 2, and 3 is taken as 100 mass%, the composition should preferably contain 65 to 91 mass% of structural unit 1, 2 to 30 mass% of structural unit 2, and 7 to 21 mass% of structural unit 3, and more preferably contain 65 to 87 mass% of structural unit 1, 2 to 30 mass% of structural unit 2, and 11 to 19 mass% of structural unit 3. By doing so, a hydraulic composition can be obtained that has good initial dispersibility and fluidity retention, and also has even less air entrainment.

[0050] When n in structural unit 1 is greater than 15 and equal to or less than 35, when the total constituent proportions of structural units 1, 2, and 3 is taken as 100 mass%, the composition should preferably contain 65 to 95 mass% of structural unit 1, 2 to 30 mass% of structural unit 2, and 1 to 17 mass% of structural unit 3, and more preferably contain 65 to 95 mass% of structural unit 1, 2 to 30 mass% of structural unit 2, and 3 to 13 mass% of structural unit 3. By doing so, a hydraulic composition can be obtained that has good initial dispersibility and fluidity retention, and also has even less air entrainment.

[0051] When n in structural unit 1 is greater than 35 and not greater than 150, the composition preferably contains 65 to 95 mass% of structural unit 1, 2 to 30 mass% of structural unit 2, and 1 to 13 mass% of structural unit 3, and more preferably contains 65 to 95 mass% of structural unit 1, 2 to 30 mass% of structural unit 2, and 1 to 7 mass% of structural unit 3. By doing so, a hydraulic composition can be obtained that has good initial dispersibility and flowability retention, and also has even less air entrainment.

[0052] The total content of structural units 1, 2, and 3 relative to all structural units in the water-soluble vinyl copolymer can be 85 to 100 mass%, preferably 90 to 100 mass%, and more preferably 95 to 100 mass%. By doing so, a hydraulic composition can be obtained that has good initial dispersibility and flowability retention, and also has even less air entrainment.

[0053] (1-1d) Other building blocks: The water-soluble vinyl copolymer may further have other structural units in addition to the above structural units 1 to 3. Examples of such other structural units include those formed from compounds such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, (meth)acrylic acid alkyl ester, (meth)allylsulfonic acid (salt), and (meth)acrylamide.

[0054] The mass average molecular weight of the water-soluble vinyl copolymer is 5000 to 200000, preferably 5000 to 150000, and more preferably 5000 to 100000. By adjusting the mass average molecular weight to such a range, it is possible to obtain a hydraulic composition that has initial dispersibility and flowability retention, and also has little air entrainment.

[0055] The weight average molecular weight is measured by gel permeation chromatography.

[0056] The content of the water-soluble vinyl copolymer in the dispersant for hydraulic compositions is not particularly limited, but can be, for example, 1 to 80 mass %, preferably 1 to 70 mass %, and more preferably 1 to 60 mass %.

[0057] (1-2) Other ingredients: The dispersant for hydraulic compositions of the present invention may contain other components in addition to the water-soluble vinyl copolymer.

[0058] Examples of other components include setting retarding components such as sugars and oxycarboxylates, components with dispersing properties such as sodium lignin sulfonate, air-entraining agents such as anionic surfactants, antifoaming agents such as oxyalkylene compounds, hardening accelerators such as alkanolamines, shrinkage reducers such as polyoxyalkylene alkyl ethers, thickeners such as cellulose ether compounds, preservatives such as isothiazolinone compounds, and rust inhibitors such as nitrites.

[0059] The other components may be used alone or in combination of two or more.

[0060] (2) Hydraulic composition: The hydraulic composition of the present invention contains the dispersant for hydraulic compositions of the present invention.

[0061] Such a hydraulic composition contains the dispersant for hydraulic compositions of the present invention, and thus has initial dispersibility and fluidity retention, and foaming is suppressed (i.e., air entrainment is small).

[0062] The hydraulic composition of the present invention may contain a binder (hydraulic binder), water, fine aggregate, coarse aggregate, etc., similar to conventionally known hydraulic compositions.

[0063] The content of the dispersant for hydraulic compositions of the present invention in the hydraulic composition of the present invention is not particularly limited and can be set appropriately. For example, the content of the dispersant for hydraulic compositions of the present invention can be 0.001 to 3.0 parts by mass in terms of solid content per 100 parts by mass of binder.

[0064] Examples of binders include various types of Portland cement such as ordinary Portland cement, moderate-heat Portland cement, low-heat Portland cement, high-early-strength 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.

[0065] Furthermore, various admixtures such as fly ash, ground granulated blast furnace slag, ground limestone, stone powder, silica fume, and expansive materials may be used in combination with the binder.

[0066] Examples of fine aggregate include river sand, mountain sand, land sand, sea sand, silica sand, crushed sand, and various fine slag aggregates, but those containing fine particles such as clay may also be used.

[0067] Examples of coarse aggregate include river gravel, mountain gravel, land gravel, crushed stone, various types of slag coarse aggregate, lightweight aggregate, and the like.

[0068] The hydraulic composition of the present invention may further contain other components as appropriate within the range that does not impair the effects thereof. Examples of such other components include setting retarders such as sugars and oxycarboxylates, various water-reducing agents, air-entraining agents such as anionic surfactants, antifoaming agents such as oxyalkylene compounds, hardening accelerators such as alkanolamines, shrinkage-reducing agents such as polyoxyalkylene alkyl ethers, thickeners such as cellulose ether compounds, preservatives such as isothiazolinone compounds, and rust inhibitors such as nitrites.

[0069] The content of the other components can be, for example, 0 to 5 parts by mass in terms of solid content per 100 parts by mass of the binder.

[0070] The ratio of water to binder (water / binder ratio) of the hydraulic composition of the present invention can be suitably selected from conventionally known ratios, and can be, for example, 20 to 70 mass %.

[0071] (3) Cured hydraulic composition: The hydraulic composition cured product of the present invention is a cured product of the hydraulic composition of the present invention. Such a hydraulic composition cured product has good strength development because foaming of the hydraulic composition forming the hydraulic composition is suppressed.

[0072] The hardened hydraulic composition specifically refers to hardened mortar (hardened mortar), hardened concrete (hardened concrete), and the like.

[0073] The hydraulic composition hardened product can be produced by a conventionally known method, specifically, a method in which the hydraulic composition is filled into a formwork or the like and cured at room temperature or by heat curing with steam, or the like. [Example]

[0074] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

[0075] (Examples 1 to 34, Comparative Examples 1 to 10) (Water-soluble vinyl copolymer) First, the water-soluble vinyl copolymers P-1 to P-34 and RP-1 to RP-10 used in the dispersants for hydraulic compositions in Examples 1 to 34 and Comparative Examples 1 to 10 are shown in Table 1 below.

[0076] [Table 1]

[0077] In Table 1, the monomers A-1 to A-9 that form the structural unit 1 are shown below. A-1: α-methacryloyl-ω-methoxypoly(n=23)oxyethylene A-2: α-methacryloyl-ω-methoxypoly(n=45)oxyethylene A-3: α-methacryloyl-ω-methoxypoly(n=68)oxyethylene A-4: α-methacryloyl-ω-methoxypoly(n=113)oxyethylene A-5: α-methacryloyl-ω-methoxypoly(n=9)oxyethylene A-6: α-(3-methyl-3-butenyl)-ω-hydroxypoly(n=53)oxyethylene A-7: α-(3-methyl-3-butenyl)-ω-hydroxypoly(n=10)oxyethylene A-8: α-methallyl-ω-hydroxypoly(n=53)oxyethylene A-9: α-methallyl-ω-hydroxypoly(n=10)oxyethylene

[0078] In Table 1, B-1 and B-2, which are monomers that form structural unit 2, are shown below. B-1: Methacrylic acid B-2: Acrylic acid

[0079] In Table 1, the monomers C-1 to C-6 that form the structural unit 3 are shown below. C-1: Itaconic acid C-2: Monomethyl itaconate C-3: Itaconic anhydride C-4: Maleic acid C-5: Monomethyl maleate C-6: Maleic anhydride

[0080] In Table 1, the monomers D-1 to D-2 that form the other structural units are shown below. D-1: Hydroxyethyl acrylate D-2: Methyl acrylate

[0081] Next, the methods for producing the water-soluble vinyl copolymers P-1 to P-34 and RP-1 to RP-10 will be described below.

[0082] Production Example 1 (Synthesis of Water-Soluble Vinyl Copolymer P-1) A 1000 ml round-bottom flask equipped with a stirrer, nitrogen inlet tube, and dropping funnel was charged with 388.35 g of ion-exchanged water, 335.3 g of α-methacryloyl-ω-methoxypoly(n=23)oxyethylene, 26.6 g of methacrylic acid, 18.9 g of itaconic acid, and 3.4 g of 3-mercaptopropionic acid, and the mixture was stirred to dissolve uniformly. Then, 9.4 g of a 30% aqueous solution of sodium hydroxide was added, the atmosphere was replaced with nitrogen, and the temperature of the reaction system was maintained at 65°C in a warm water bath.

[0083] Next, 4.0 g of sodium persulfate diluted with 16.0 g of ion-exchanged water was added to the reaction system to initiate the polymerization reaction.

[0084] The temperature of the reaction system was maintained at 65°C and the polymerization reaction was carried out for 2 hours. Thereafter, 1.7 g of sodium persulfate diluted with 8.2 g of ion-exchanged water was further added to the reaction system, and the temperature of the reaction system was maintained at 65°C and the polymerization reaction was carried out for 2 hours.

[0085] Next, a 30% aqueous solution of sodium hydroxide was added to the reaction system to adjust the pH to 7, and the concentration was further adjusted to 40% with ion-exchanged water to obtain a reaction mixture (dispersant for hydraulic compositions) containing water-soluble vinyl copolymer P-1.

[0086] When this reaction mixture was analyzed by gel permeation chromatography (GPC), it was found to have a mass average molecular weight of 26,000.

[0087] Production Examples 2 to 18, 23 to 29, 32 to 34, 37, 39, and 43 (Synthesis of Water-Soluble Vinyl Copolymers P-2 to P-18, P-23 to P-29, P-32 to P-34, RP-3, RP-5, and RP-9) Water-soluble vinyl copolymers P-2 to P-18, P-23 to P-29, P-32 to P-34, RP-3, RP-5, and RP-9 were produced in the same manner as in Production Example 1, except that the type and amount of each structural unit were changed as shown in Table 1, and the amount of 3-mercaptopropionic acid was changed so as to obtain the desired mass-average molecular weight shown in Table 1. In this manner, reaction mixtures (dispersants for hydraulic compositions) containing water-soluble vinyl copolymers P-2 to P-18, P-23 to P-29, P-32 to P-34, RP-3, RP-5, and RP-9 were obtained. The mass-average molecular weights are shown in Table 1.

[0088] Production Example 19 (Synthesis of water-soluble vinyl copolymer P-17) A 1000 mL round-bottom flask equipped with a stirrer, a nitrogen inlet tube, and a dropping funnel was charged with 78.9 g of ion-exchanged water, 430.2 g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(average 53 mol)oxyethylene, and 24.4 g of itaconic acid, and the mixture was stirred to dissolve uniformly. The atmosphere was then replaced with nitrogen, and the temperature of the reaction system was maintained at 60°C in a warm water bath.

[0089] Next, 29.3 g of a 3.5% aqueous solution of hydrogen peroxide was added dropwise to the reaction system over a period of 3 hours, and simultaneously, an aqueous solution prepared by uniformly dissolving 34.2 g of acrylic acid in 175.9 g of ion-exchanged water was added dropwise over a period of 3 hours, and further simultaneously, an aqueous solution prepared by dissolving 2.0 g of L-ascorbic acid and 5.9 g of 3-mercaptopropionic acid in 46.9 g of ion-exchanged water was added dropwise over a period of 4 hours.

[0090] Thereafter, the temperature of the reaction system was maintained at 60°C for 2 hours to terminate the polymerization reaction. Thereafter, a 30% aqueous solution of sodium hydroxide was added to the reaction system to adjust the pH to 7, and the concentration was adjusted to 50% with ion-exchanged water to obtain a reaction mixture (dispersant for hydraulic compositions) containing water-soluble vinyl copolymer P-17.

[0091] When this reaction mixture was analyzed by gel permeation chromatography (GPC), it was found to have a mass average molecular weight of 31,000.

[0092] Production Examples 20 to 22, 30 to 31 (Synthesis of Water-Soluble Vinyl Copolymers P-20 to P-22, P-30 to P-31) Water-soluble vinyl copolymers P-20 to P-22 and P-30 to P-31 were produced in the same manner as in Production Example 17, except that the type and amount of each structural unit was changed as shown in Table 1, and the amount of 3-mercaptopropionic acid was changed so as to obtain the predetermined mass-average molecular weight shown in Table 1. In this manner, reaction mixtures (dispersants for hydraulic compositions) containing water-soluble vinyl copolymers P-20 to P-22 and P-30 to P-31 were obtained. The mass-average molecular weights are shown in Table 1.

[0093] Production Example 35 (Synthesis of water-soluble vinyl copolymer RP-1) A 1000 mL round-bottom flask equipped with a stirrer, a nitrogen inlet tube, and a dropping funnel was charged with 422.2 g of ion-exchanged water, 305.9 g of α-methacryloyl-ω-methoxypoly(n=23)oxyethylene, 76.5 g of methacrylic acid, and 7.3 g of 3-mercaptopropionic acid, and the mixture was dissolved uniformly with stirring. The atmosphere was then replaced with nitrogen, and the temperature of the reaction system was maintained at 65°C in a warm water bath.

[0094] Next, 7.7 g of sodium persulfate diluted with 40.9 g of ion-exchanged water was added to the reaction system to initiate the polymerization reaction.

[0095] The polymerization reaction was carried out for 2 hours while maintaining the temperature of the reaction system at 65°C. Thereafter, 3.8 g of sodium persulfate diluted with 27.3 g of ion-exchanged water was further added to the reaction system, and the polymerization reaction was carried out for 2 hours while maintaining the temperature of the reaction system at 65°C.

[0096] Thereafter, a 30% aqueous solution of sodium hydroxide was added to the reaction system to adjust the pH to 7, and the concentration was further adjusted to 40% with ion-exchanged water to obtain a reaction mixture (dispersant for hydraulic compositions) containing the water-soluble vinyl copolymer RP-1.

[0097] When this reaction mixture was analyzed by gel permeation chromatography (GPC), it was found to have a mass average molecular weight of 20,000.

[0098] Production Examples 36, 38, 41 to 42 (Synthesis of Water-Soluble Vinyl Copolymers RP-2, RP-4, RP-7 to RP-8) Water-soluble vinyl copolymers RP-2, RP-4, RP-7 to RP-8 were produced in the same manner as in Production Example 33, except that the type and amount of each structural unit was changed as shown in Table 1, and the amount of 3-mercaptopropionic acid was changed so as to obtain the predetermined mass average molecular weight shown in Table 1. In this way, reaction mixtures (dispersants for hydraulic compositions) containing water-soluble vinyl copolymers RP-2, RP-4, RP-7 to RP-8 were obtained. The mass average molecular weights are shown in Table 1.

[0099] Production Example 40 (Synthesis of water-soluble vinyl copolymer RP-6) A 1000 mL round-bottom flask equipped with a stirrer, a nitrogen inlet tube, and a dropping funnel was charged with 137.3 g of ion-exchanged water and 449.1 g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(average 53 mol)oxyethylene, and the mixture was dissolved uniformly with stirring. The atmosphere was then replaced with nitrogen, and the temperature of the reaction system was maintained at 60°C in a warm water bath.

[0100] Next, 29.3 g of a 3.5% aqueous solution of hydrogen peroxide was added dropwise to the reaction system over a period of 3 hours, and simultaneously, an aqueous solution prepared by uniformly dissolving 39.1 g of acrylic acid in 117.2 g of ion-exchanged water was added dropwise over a period of 3 hours, and further simultaneously, an aqueous solution prepared by dissolving 2.0 g of L-ascorbic acid and 5.9 g of 3-mercaptopropionic acid in 46.9 g of ion-exchanged water was added dropwise over a period of 4 hours.

[0101] Thereafter, the temperature of the reaction system was maintained at 60°C for 2 hours to terminate the polymerization reaction. After that, a 30% aqueous solution of sodium hydroxide was added to the reaction system to adjust the pH to 7, and the concentration was adjusted to 50% with ion-exchanged water to obtain a reaction mixture (dispersant for hydraulic compositions) containing the water-soluble vinyl copolymer RP-5.

[0102] When this reaction mixture was analyzed by gel permeation chromatography (GPC), it was found that the mass average molecular weight was 33,000.

[0103] Production Example 44 (Synthesis of water-soluble vinyl copolymer RP-10) Water-soluble vinyl copolymer RP-10 was produced in the same manner as in Production Example 38, except that the type and amount of each structural unit was changed as shown in Table 1, and the amount of 3-mercaptopropionic acid was changed so as to obtain the specified mass average molecular weight shown in Table 1. In this way, reaction mixtures (dispersants for hydraulic compositions) containing water-soluble vinyl copolymer RP-10 were obtained. The mass average molecular weight is shown in Table 1.

[0104] (mass average molecular weight) The weight average molecular weight of each of the water-soluble vinyl copolymers P-1 to P-32 and RP-1 to RP-10 was measured by gel permeation chromatography (GPC) under the following conditions. <Measurement conditions> Apparatus: Shodex GPC-101 (Showa Denko) Column: OHpak SB-G + SB-804 HQ + SB-802.5 HQ (Showa Denko) Detector: Differential refractometer (RI) Eluent: 50mM 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 material: PEG / PEO (Agilent Technologies)

[0105] (2) Hydraulic composition: Next, hydraulic compositions were prepared using blends No. 1 to No. 3 shown in Table 2.

[0106] [Table 2]

[0107] Specifically, under the mixing conditions shown in Table 2, ordinary Portland cement (an equal mixture of Taiheiyo Cement Corporation, Ube Mitsubishi Cement Corporation, and Sumitomo Osaka Cement Co., Ltd., density = 3.16 g / cm) was first mixed in a 55 L pan-type forced mixer in a test room at 20°C. 3 ) as a hydraulic binder, and land sand (Oi River watershed, density = 2.57 g / cm3) as an aggregate. 3 ) and crushed stone (Okazaki crushed stone, density = 2.68 g / cm 3 ) were added. Furthermore, the dispersants for hydraulic compositions (see Table 1) prepared as described above were weighed out as part of the mixing water (Gamagori City tap water) in the amounts shown in Tables 3 to 5, added to the mixer, and mixed for 90 seconds.

[0108] Concrete compositions (hydraulic compositions) were prepared so that Mix No. 1 had a slump of 18±1 cm, Mix No. 2 had a slump flow of 500 to 550 mm, and Mix No. 3 had a slump of 20±1 cm.

[0109] (Initial dispersibility) The amount of dispersant for hydraulic compositions used when the hydraulic compositions were prepared so as to have a predetermined slump (0 min (cm)) and slump flow (0 min (mm)) was evaluated (initial dispersibility) (the amount of dispersant used (i.e., the mass % of the dispersant converted into solid content relative to the mass of cement, shown as "C x %" in Tables 3 to 5)). The smaller the amount of dispersant for hydraulic compositions used, the better the effect is, and a higher evaluation indicates better initial dispersibility.

[0110] The evaluation criteria for the initial dispersibility are as follows. When the amount of dispersant used was less than 0.18%, it was rated as "S". A grade of "A" was given when the amount of dispersant used was 0.18% or more and less than 0.20%. Cases where the amount of dispersant used was 0.20% or more were rated "B".

[0111] Next, the hydraulic composition was measured for air content (%), slump (cm), and slump flow (mm). The measurement methods are as follows.

[0112] (Air volume (volume%)) The concrete composition immediately after mixing was measured in accordance with JIS A 1128. The air content was measured at the same time as the slump and slump flow were measured.

[0113] (slump) Measurements were made in accordance with JIS A 1101 for the concrete compositions immediately after mixing (0 minutes), 30 minutes after mixing, and 60 minutes after mixing.

[0114] (Slump Flow) Measurements were made in accordance with JIS A 1150 for the concrete compositions immediately after mixing (0 minutes), 20 minutes after mixing, and 40 minutes after mixing.

[0115] (evaluation) Next, based on the measurement results of air content (%), slump (cm), and slump flow (mm), the slump retention, slump flow retention, and air content (air entrainment) were evaluated. The evaluation criteria are shown below.

[0116] (Slump retention) The difference between the slump immediately after mixing (0 minutes) and the slump after 60 minutes of mixing (slump change) was calculated using the formula: (slump immediately after mixing) - (slump after 60 minutes of mixing), and the fluidity retention (slump retention) was evaluated based on the calculated slump change. The smaller the slump change, the better the fluidity is retained. The results for Blend No. 1 and Blend No. 3 are shown below.

[0117] (Combination No.1) A slump change of less than 6 cm (including negative values ​​of 0 cm or less) was rated as "S." A slump change of 6 cm or more but less than 9 cm was rated as "A." A slump change of 9 cm or more but less than 12 cm was rated as "B." A slump change of 12 cm or more but less than 15 cm was rated as "C."

[0118] (Combination No.3) A slump change of less than 9.5 cm (including negative values ​​of 0 cm or less) was rated "S." A slump change of 9.5 cm or more but less than 11 cm was rated as "A." A slump change of 11 cm or more but less than 13 cm was rated as "B."

[0119] (Slump flow retention) The difference between the slump flow immediately after mixing (0 minutes) and the slump flow after 40 minutes of mixing (slump flow change) was calculated using the formula: (slump flow immediately after mixing) - (slump flow after 40 minutes of mixing), and the fluidity retention (slump flow retention) was evaluated based on the calculated change. The smaller the slump flow change, the better the fluidity is retained. This slump flow retention was evaluated for Blend No. 2.

[0120] A slump flow change of less than 200 mm (including negative values ​​of 0 m or less) was rated "S." A case where the change in slump flow was 200 mm or more but less than 250 mm was rated as "A." A case where the change in slump flow was 250 mm or more and less than 300 mm was rated as "B".

[0121] (Air content (foam reduction)) The air content (foaming reduction property) was calculated for Blends No. 1 to No. 3 based on the air content immediately after mixing in Comparative Examples 1, 4, and 6. The calculated values ​​were then evaluated according to the following criteria. The evaluation value was calculated using the formula: air content in each Example and Comparative Example / air content in Comparative Example 1 × 100 (%). A smaller foaming reduction property value indicates a smaller air entrainment property.

[0122] (Combination No.1) An evaluation score of less than 50% was given an "S" rating. An evaluation value of 50% or more but less than 70% was given an "A" rating. A rating of "B" was given when the evaluation value was 70% or more but less than 90%. A rating of 90% or higher was given as "C."

[0123] (Combination No.2) An evaluation score of less than 60% was given an "S" rating. An evaluation value of 60% or more but less than 80% was given an "A" rating. A rating of "B" was given when the evaluation value was 80% or more but less than 90%. A grade of "C" was given when the evaluation score was 90% or higher.

[0124] (Combination No.3) An evaluation score of less than 70% was given an "S" rating. An evaluation value of 70% or more but less than 80% was given an "A" rating. A rating of "B" was given when the evaluation value was 80% or more but less than 90%. A rating of 90% or higher was given as "C."

[0125] (3) Cured hydraulic composition: Three cylindrical tinplate concrete specimen molding forms (trade name "Summit Mold", manufactured by Sumitomo Cement Corporation, bottom diameter 100 mm, height 200 mm) were prepared in accordance with JIS A1132, and each was filled using the two-layer filling method. Two hours after the preparation of the hydraulic composition, the surface of the filled hydraulic composition was leveled, and polyethylene wrap was placed over the surface to prevent moisture evaporation. Then, 24 hours after the preparation of the hydraulic composition, the three hardened specimens were removed from the forms. Thereafter, the specimens were further cured in water at 20°C for 27 days, and the poured surface was polished to a smooth surface, yielding a 28-day-old hardened hydraulic composition.

[0126] The resulting hardened hydraulic composition was measured for compressive strength (N / mm 2 ) was measured.

[0127] (Compression strength (N / mm 2 )) The strength of the hardened hydraulic composition 28 days after production was measured in accordance with JIS A 1108. The measurement results are shown in Tables 3 to 5.

[0128] [Table 3]

[0129] [Table 4]

[0130] [Table 5]

[0131] (result) As shown in Tables 3 to 5, it can be seen that by adding the dispersant for hydraulic compositions of this example, it is possible to obtain a hydraulic composition having good initial dispersibility, slump (flow) retention (fluidity retention), and foam reduction. [Industrial Applicability]

[0132] The hydraulic composition dispersant of the present invention can be used as a dispersant for hydraulic compositions by adding it to a hydraulic composition. The hydraulic composition of the present invention can be used to prepare a hardened hydraulic composition such as concrete. The hardened hydraulic composition of the present invention can be used as a concrete product or the like.

Claims

1. The water-soluble vinyl copolymer contains, in the molecule, a structural unit 1 formed from a compound represented by the following general formula (1), a structural unit 2 formed from a compound represented by the following general formula (2), and a structural unit 3 formed from a compound represented by the following general formula (3): The water-soluble vinyl copolymer is When the total of the constituent proportions of the structural unit 1, the structural unit 2, and the structural unit 3 is 100% by mass, the structural unit 1 is contained in an amount of 65 to 95% by mass, the structural unit 2 is contained in an amount of 2 to 30% by mass, and the structural unit 3 is contained in an amount of 0.1 to 25% by mass, A dispersant for hydraulic compositions, characterized in that the dispersant has a mass average molecular weight of 5,000 to 200,000. 【Chemistry 1】 (In general formula (1), R １ , R ２ , R ３ are each independently a hydrogen atom or a methyl group. ４ is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. AO is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of oxyalkylene groups are present, one type may be used alone or two or more types may be used). n is the average number of moles of AO added, and is a number from 2 to 150. p is an integer of 0 or 1. q is an integer of 0 to 2. 【Chemistry 2】 (In general formula (2), R ５ , R ６ , R ７ are each independently a hydrogen atom or a methyl group. １ is a hydrogen atom, a metal atom, an ammonium group, or an organic amine group. 【Transformation 3】 (In general formula (3), R ８ is a hydrogen atom or -COOM ２ It is. ９ is a hydrogen atom or -COOM ４ (where r is 0 and R ８ When is a hydrogen atom, R ９ Ha-COOM ４ r is an integer from 0 to 2. M ２ , M ３ , M ４ is a hydrogen atom, a metal atom, an ammonium group, an organic amine group, or a hydrocarbon group having 1 to 18 carbon atoms. ３ Is -COOM ２ or -COOM ４ In this case, M ３ , M ２ , M ４ does not exist.)

2. In the structural unit 3, R ９ The dispersant for hydraulic compositions according to claim 1 , wherein is a hydrogen atom and r is 1.

3. A hydraulic composition comprising the dispersant for hydraulic compositions according to claim 1 or 2.

4. A hardened hydraulic composition, which is a hardened product of the hydraulic composition according to claim 3.

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