Dispersant composition for hydraulic compositions containing lignin derivative

Abstract

To provide a dispersant composition for hydraulic compositions that exhibits superior shape retention.SOLUTION: A dispersant composition for hydraulic compositions is produced that contains following components (A) and (B): (A) a lignin derivative and (B) a copolymer polymerized from a specific monomer.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a lignin derivative-containing dispersant composition for hydraulic compositions and a hydraulic composition containing a lignin derivative-containing dispersant. [Background technology]

[0002] Lignin is a natural polymeric substance found in trees, accounting for approximately 30% of wood. Lignin is found in large amounts in waste liquor from kraft pulp production (kraft pulp waste liquor) and waste liquor from sulfite pulp production (sulfite pulp waste liquor). From the perspective of reducing environmental impact in recent years, lignin has been attracting attention as one of the biomass resources.

[0003] Kraft lignin contained in kraft pulp waste liquor and lignosulfonic acid contained in sulfite pulp waste liquor each have different physical properties and are used for various purposes. In addition, lignin derivatives obtained by sulfomethylating kraft lignin with sulfite and formaldehyde, lignin derivatives obtained by partially desulfonating lignosulfonic acid or a salt of lignosulfonic acid, and lignin purified products obtained by ultrafiltration are widely used as lignin-based dispersants in a wide range of industrial fields, such as dyes, cement, inorganic pigments, organic pigments, gypsum, coal-water slurries, agricultural chemicals, and ceramics.

[0004] As a dispersant for hydraulic compositions such as cement, Patent Documents 1 and 2 disclose a polymer-shaped cement dispersant containing a lignin derivative containing lignin sulfonic acid or a salt thereof, and a copolymer of an acrylic acid and / or methacrylic acid derivative.

[0005] Patent Document 3 discloses a dispersant for hydraulic compositions, which contains Component A, which is water having an oxidation-reduction potential of 0 mV or more at 25° C.; Component B, which is at least one selected from (a) a polycarboxylic acid-based dispersant and (b) a lignin sulfonic acid-based dispersant; and Component C, which is an antiseptic component. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-158317 A [Patent Document 2] WO2020 / 195910A1 [Patent Document 3] Patent Publication No. 2022-37656 Summary of the Invention [Problem to be solved by the invention]

[0007] However, no evaluation has been made of the shape retention properties of such dispersants, and no optimal lignin derivative-containing dispersant composition for hydraulic compositions has been disclosed for this purpose. [Means for solving the problem]

[0008] The present invention relates to a dispersant for a hydraulic composition, comprising the following components (A) and (B): (A) Component: Lignin derivative. (B) Ingredients: General formula (b1) [ka] [In the formula, M b represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. A structural unit (B1) represented by the formula: and general formula (b2) [ka] [In the formula, R 2b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X b represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. nb represents the average number of moles added, which is 5 to 200. R 3brepresents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. A copolymer having a structural unit (B2) represented by the following formula: The present invention also relates to a hydraulic composition comprising the hydraulic composition dispersant. Effect of the Invention

[0009] According to the present invention, a dispersant composition for a hydraulic composition having excellent shape retention can be provided. Also, a hydraulic composition containing the dispersant composition of the present invention can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The dispersant composition for hydraulic compositions of the present invention comprises the following components (A) and (B): (A) Component: Lignin derivative. (B) Ingredients: General formula (b1) [ka] [In the formula, M b represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. and a structural unit (B1) represented by general formula (b2) [ka] [In the formula, R 2b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X b represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. nb represents the average number of moles added, which is 5 to 200. R 3b represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. A copolymer having a structural unit (B2) represented by the following formula: The present invention further relates to a hydraulic composition comprising the dispersant composition.

[0011] The dispersant composition for hydraulic compositions of the present invention contains lignin sulfonic acid or a salt thereof as component (A). Examples of counter cations of the salts include alkali metal ions such as lithium, sodium, potassium, etc., alkaline earth metal ions such as magnesium, calcium, etc., and organic cations such as quaternary ammonium ions. In terms of easy availability, salts whose counter cation is an alkali metal ion are preferred, and among these, salts whose counter cation is a sodium ion are preferred.

[0012] The dispersant composition for hydraulic compositions of the present invention contains a lignin derivative as component (A). Examples of the lignin derivative include pulp lignin such as kraft lignin, soda lignin, and lignosulfonic acid, lignophenol, phenolized lignin, and modified lignin. Kraft lignin is a lignin derivative whose molecular structure is modified after carbohydrates such as cellulose are extracted from wood in the paper and pulp industry. Lignosulfonic acid is a polymer electrolyte with functional groups such as sulfonic acid, carboxyl acid, and phenolic hydroxyl acid, and there are no particular limitations on its molecular weight or manufacturing method. Lignophenol can be obtained, for example, by treating lignin in lignocellulosic materials with a phenol derivative. There is no particular restriction on the structure. Phenolized lignin is lignin in a stabilized state in which a phenol derivative is chemically bonded to the molecular chains of lignin when lignin and cellulose are separated by treating a plant material with an acid. Modified lignin is lignin with polyethylene glycol chains attached to the backbone of the lignin. Of these, lignosulfonic acid and / or its salts are preferred.

[0013] It is difficult to uniformly specify the chemical structure of lignosulfonic acid and / or its salts by a general formula or the like, because lignin, which is the skeleton of lignosulfonic acid, has a very complex molecular structure.

[0014] The lignin sulfonic acid and / or its salt may be prepared or may be a commercially available product. Here, the preparation method of the lignin derivative is exemplified below. However, the lignin sulfonic acid and / or its salt is not limited to those prepared by the preparation method described below.

[0015] Examples of methods for preparing lignosulfonic acid and / or a salt thereof include a method in which a lignocellulosic raw material is subjected to a sulfite treatment, preferably a method in which a lignocellulosic raw material is subjected to a sulfite cooking treatment.

[0016] The lignocellulose raw material is not particularly limited as long as it contains lignocellulose in the structure, and examples thereof include pulp raw materials such as wood and non-wood. Examples of wood include coniferous trees such as Yezo spruce, red pine, cedar, and cypress, and broad-leaved trees such as white birch and beech. The age and location of the wood are not important. Therefore, wood harvested from trees of different ages or from different locations of a tree may be used in combination. Non-wood materials include, for example, bamboo, kenaf, reed, and rice. The lignocellulosic raw material may be one of these materials, or two or more of them may be used in combination.

[0017] The sulfite treatment can be carried out by contacting at least one of sulfurous acid and a sulfite salt with a lignocellulosic raw material to obtain an intermediate product. The conditions for the sulfite treatment are not particularly limited as long as they allow introduction of a sulfonic acid (salt) group to the α-carbon atom of the side chain of lignin contained in the lignocellulosic raw material.

[0018] The sulfite treatment is preferably carried out by a sulfite cooking method, which allows more quantitative sulfonation of the lignin in the lignocellulosic raw material. The sulfite cooking method is a method in which lignocellulosic raw materials are reacted at high temperatures in a solution of at least one of sulfurous acid and a sulfite salt (e.g., an aqueous solution: cooking liquor). This method has been established and is being used industrially as a method for producing sulfite pulp. Therefore, by carrying out the sulfite treatment by the sulfite cooking method, it is possible to improve the economic efficiency and ease of implementation.

[0019] When sulfite cooking is carried out, examples of the sulfite salt include magnesium salts, calcium salts, sodium salts and ammonium salts.

[0020] There is no limitation on the equipment used in the sulfite treatment, and for example, generally known dissolving pulp manufacturing equipment can be used.

[0021] The intermediate product may be separated from the solution of at least one of sulfurous acid and sulfite salt according to a conventional method, for example, a method for separating the sulfurous acid pulping wastewater after sulfurous acid pulping.

[0022] Next, the intermediate composition is washed and dehydrated to obtain a sulfite-treated product. By washing and dehydrating, components contained in the intermediate composition that cannot be completely removed by the sulfite treatment can be removed.

[0023] The washing may be carried out in the same manner as the washing of unbleached sulfite pulp obtained by the sulfite cooking method. The washing may be a single-stage washing or a multi-stage washing. By carrying out multi-stage washing, the washing can be carried out sufficiently. When carrying out multi-stage washing, dehydration may be carried out each time, or may be carried out only for some of the times. Washing is usually performed using a washing machine. The washing machine used for washing is not particularly limited. For example, a displacement washing type washing machine and a dilution dehydration washing type washing machine can be mentioned.

[0024] The dehydration can be carried out under ordinary conditions, for example, in the same manner as in the dehydration of unbleached sulfite pulp after washing obtained in the sulfite cooking method. Dehydration is usually performed using a dehydrator. The type of dehydrator used for dehydration is not particularly limited. For example, a drum-type squeeze dehydrator, a rotary press, or a continuous squeeze dehydrator may be used.

[0025] The sulfite-treated product is then washed and dehydrated, and separated and purified to obtain the desired lignin derivative. Examples of the separation and purification include an alkaline oxidation treatment step and an ultrafiltration treatment step.

[0026] When the alkaline oxidation treatment is carried out, after the sulfite-treated product is subjected to the alkaline oxidation treatment, insoluble matters can be centrifuged and recovered as a supernatant.

[0027] The alkaline oxidation treatment can be carried out by placing the sulfurous acid-treated product under alkaline conditions. Placing under alkaline conditions usually means placing the product in an aqueous solution having a pH value of 8 or more, preferably a pH value of 9 or more. The upper limit of the pH value is usually 14.

[0028] In the alkaline oxidation treatment, an alkaline substance is usually brought into contact with the sulfite treatment product. The alkaline substance is not particularly limited, but examples thereof include calcium hydroxide, magnesium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, and ammonia. Among these, sodium hydroxide is preferred. The alkaline substances may be used alone or in combination of two or more.

[0029] From the viewpoint of good shape retention, the amount of component (A) added is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and preferably 1.00% by mass or less, more preferably 0.50% by mass or less, and even more preferably 0.1% by mass or less, based on the hydraulic powder in the hydraulic composition.

[0030] From the viewpoint of production, the component (A) contains sugars. From the viewpoint of reducing the hardening property of the cement, the content of the sugars is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less.

[0031] Next, the component (B) will be described. The component (B) is represented by the general formula (b1): [ka] [In the formula, M b represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. and a structural unit (B1) represented by general formula (b2) [ka] [In the formula, R 2b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X b represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. nb represents the average number of moles added, which is 5 to 200. R 3b represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. It is a copolymer having a structural unit (B2) represented by the following formula:

[0032] The structural unit (B1) represented by general formula (b1) can be introduced into copolymer B by using a monomer represented by general formula (b1') as the raw material. [ka] [In the formula, M b represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium.

[0033] M in general formula (b1') b Examples of the cation include a hydrogen atom, alkali metals such as lithium, sodium, potassium, etc., and alkaline earth metals such as magnesium, calcium, etc. From the viewpoint of good shape retention, a hydrogen atom or an alkali metal is preferred.

[0034] The structural unit (B2) represented by general formula (b2) can be introduced into copolymer A by using a monomer represented by general formula (b2') as the raw material. [ka] [In the formula, R 2b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X b represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. nb represents the average number of moles added, which is 5 to 200. R 3b represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

[0035] R in general formula (b2') 2b Specific examples of the alkyl group include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, etc. From the viewpoint of good shape retention, a hydrogen atom and a methyl group are preferred, and a methyl group is more preferred.

[0036] X in general formula (b2') b Examples of the alkylene group include alkylene groups such as methylene, ethylene, propylene, and butylene, and carbonyl groups. From the viewpoint of good shape retention, alkylene groups having 1 to 4 carbon atoms are preferred, methylene or ethylene groups are more preferred, and methylene groups are even more preferred.

[0037] From the viewpoint of good shape retention, nb in general formula (b2') is preferably 5 or more, more preferably 20 or more, even more preferably 60 or more, and preferably 200 or less, more preferably 130 or less, even more preferably 100 or less.

[0038] R in general formula (b2') 3bSpecific examples of the alkyl group include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a hexyl group, a 2-ethylhexyl group, a cyclohexyl group, an octyl group, a cyclooctyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, etc. From the viewpoint of good shape retention, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred.

[0039] From the viewpoint of good shape retention, the proportion of the structural unit (B1) to the total of the structural units (B1) and (B2) is preferably at least 0.1 mass%, more preferably at least 0.2 mass%, and is preferably at most 9 mass%, even more preferably at most 7.5 mass%.

[0040] From the viewpoint of good shape retention, the weight average molecular weight (Mw) of component (B) is preferably 10,000 or more, more preferably 20,000 or more, even more preferably 50,000 or more, and preferably 100,000 or less, more preferably 80,000 or less, even more preferably 70,000 or less.

[0041] The (B) component can be produced under the conditions for copolymerization of general-purpose vinyl polymers. For example, water can be used as the solvent. The reaction temperature can be in the range of 50°C to 100°C. The reaction time varies depending on the reaction temperature, but can be in the range of 0.5 hours to 10 hours. The pH during production is preferably 3 or less.

[0042] The amount of component (B) added is, from the viewpoints of shape retention and economy, preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and even more preferably 0.1% by mass or less, based on the hydraulic powder in the hydraulic composition.

[0043] The component (B) may be added as it is in the form of a copolymer, or may be added together with a suitable solvent (or dispersion medium). The solvent (or dispersion medium) is preferably water, and adding it together with water is preferred from the viewpoint of convenience. When it is added as a water solution (or dispersion), it is necessary to add the amount of water to the amount of water essential for the composition of the present application, but this amount can be ignored when the concentration of the water solution (or dispersion) is high or the amount added is small.

[0044] The mass ratio of the (B) component to the (A) component, (B) / (A), is preferably 0.01 or more, more preferably 0.1 or more, even more preferably 0.2 or more, and is preferably less than 3.0, more preferably less than 2.0.

[0045] The hydraulic composition dispersant composition of the present invention may contain additives such as foaming agents, thickeners, foaming agents, preservatives, and antifoaming agents in addition to the components (A) and (B). These additives may be contained in an amount of 0.01% by mass or more and 2% by mass or less relative to the components (A) and (B). The antifoaming agents include one or more types of antifoaming agents selected from silicone-based antifoaming agents, fatty acid ester-based antifoaming agents, ether-based antifoaming agents, polyalkylene oxide-based antifoaming agents, alkyl phosphate ester-based antifoaming agents, and acetylene glycol-based antifoaming agents. The defoaming agent is preferably one or more defoaming agents selected from silicone-based defoaming agents, fatty acid ester-based defoaming agents, and ether-based defoaming agents.

[0046] The hydraulic composition dispersant composition of the present invention can be added to a hydraulic composition containing hydraulic powder and water. The hydraulic powder is a powder that hardens when mixed with water, and examples thereof include normal Portland cement, high-early-strength Portland cement, ultra-high-early-strength Portland cement, sulfate-resistant Portland cement, low-heat Portland cement, white Portland cement, and ecocement (e.g., JIS R5214, etc.). Among these, from the viewpoint of shortening the time required for the hydraulic composition to reach the required strength, cement selected from high-early-strength Portland cement, normal Portland cement, sulfate-resistant Portland cement, and white Portland cement is preferred, and cement selected from high-early-strength Portland cement and normal Portland cement is more preferred.

[0047] The hydraulic powder may contain blast furnace slag, fly ash, silica fume, anhydrous gypsum, etc., or may contain non-hydraulic limestone fine powder. As the hydraulic powder, blast furnace cement, fly ash cement, or silica fume cement, which is a mixture of cement and blast furnace slag, fly ash, silica fume, etc., may be used. It is preferable to contain blast furnace slag or fly ash from the viewpoint of using a low-quality hydraulic composition. Examples of blast furnace slag and fly ash include those described in JIS R5201.

[0048] The water contained in the hydraulic composition is preferably water that is free of impurities and is appropriately purified, but well water and industrial water may also be used. Tap water, purified water, and ion-exchanged water are preferred.

[0049] The ratio of water to the hydraulic powder is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less.

[0050] From the viewpoint of good shape retention, the amount of component (B) added is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and even more preferably 0.1% by mass or less, based on the hydraulic powder in the hydraulic composition.

[0051] The dispersant composition of the present invention can exhibit good shape retention for a hydraulic composition containing 40% by mass or more of water based on the hydraulic powder. In addition, a hydraulic composition containing the dispersant composition of the present invention can be provided. EXAMPLES

[0052] <Examples and Comparative Examples> The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following descriptions.

[0053] The materials used in the examples and comparative examples are shown below. <Component (A)> The sodium salt of lignin sulfonic acid was used as the lignin derivative of component (A). Ultragin NA, manufactured by Borregaard, with a sugar content of 1% or less, was used as the sodium salt of lignin sulfonic acid.

[0054] <(B) component> Copolymer B was produced using the following compounds as raw materials for the structural units (B1) and (B2). Raw materials for structural unit (B1): acrylic acid or methacrylic acid Raw material for structural unit (B2): polyethylene glycol isoprenyl ether (hereinafter referred to as TPEG) represented by the following general formula (1), [ka] [In the formula, p is 60 (referred to as TPEG60) or 66 (referred to as TPEG66).] Or, a polyethylene glycol methacrylate ester (hereinafter referred to as MEPEG) represented by the following general formula (2): [ka] [wherein q is 9 (referred to as MEPEG9) or 120 (referred to as MEPEG120)], Or, polyethylene glycol (2-methyl-2-propenyl) ether (hereinafter referred to as HPEG64) represented by the following formula (3): [ka]

[0055] <Production of component (B) by copolymerization reaction> Taking the component (B) of Comparative Example 2 as an example, a method for producing the component (B) will be described below. 200.0 parts of TPEG60 and 128.0 parts of water were charged into a glass reaction vessel equipped with a stirrer, and the mixture was replaced with nitrogen while stirring, and the temperature was raised to 80°C in a nitrogen atmosphere. Then, 0.9 parts of hydrogen peroxide (35%) was added. An aqueous solution of 27.8 parts of acrylic acid dissolved in 41.7 parts of water and an aqueous solution of 1.4 parts of 3-mercaptopropionic acid dissolved in 45.4 parts of water were dropped into the vessel over 3.0 hours, and an aqueous solution of 0.4 parts of L-ascorbic acid dissolved in 38.4 parts of water was dropped into the vessel over 3.5 hours. Then, the mixture was aged at the same temperature (80°C) for 1 hour. After the aging, the mixture was neutralized with 16.1 parts of a 48% aqueous sodium hydroxide solution to obtain an aqueous solution containing a copolymer (B) having a weight average molecular weight of 35,000. A reaction product containing and water was obtained. According to the above method, the component (B) of the examples and comparative examples shown in Table 1 was produced. [Table 1]

[0056] <Other materials> Cement: Ordinary Portland cement manufactured by Taiheiyo Cement Corporation and Sumitomo Osaka A 1:1 mixture of ordinary Portland cement (density 3.16 g / cm3) manufactured by Cement Co., Ltd. 3 ) Fine aggregate: mountain sand, density 2.72g / cm 3

[0057] <Production of hydraulic composition> 400 parts by weight of cement and 700 parts by weight of fine aggregate were added to a mortar mixer specified in JIS R5201, and dry mixing (60 rpm, 10 seconds) was performed. Then, 200 parts by mass of water containing components (A) and (B) in the ratio to the cement shown in Table 2 was added, and the mixture was kneaded (60 rpm, 120 seconds) to prepare the hydraulic composition shown in Table 2.

[0058] Using the hydraulic compositions of each of the Examples and Comparative Examples in Table 2, an evaluation of shape retention was carried out.

[0059] <Evaluation of shape retention> The hydraulic composition immediately after mixing was filled into two flow cones (upper diameter 70 mm x lower diameter 100 mm x height 60 mm) as specified in JIS R5201. The flow of one of the flow cones was immediately measured on a 30 cm x 30 cm plastic plate, and this was taken as the flow immediately after filling. The flow of the other flow cone was left for 3 minutes after filling, and then measured on a 30 cm x 30 cm plastic plate, and this was taken as the flow after leaving for 3 minutes. The difference between the flow immediately after filling and the flow after leaving for 3 minutes was taken as shape retention. The results are shown in Table 2.

[0060] [Table 2]

[0061] As is clear from Table 2, Examples 4 to 6, which used B-1 to 3 as the (B) component, showed good shape retention of 36 to 39 mm. On the other hand, Comparative Example 1, which did not contain the (B) component, Comparative Example 2, which used methacrylic acid as the (B1) component, and Comparative Example 3, which had a large (B1) / [(B1)+(B2)] of 12.1 mass%, showed shape retention of 30 to 33 mm. Thus, by using the lignin derivative as the (A) component and a suitable copolymer as the (B) component, a hydraulic composition showing good shape retention could be obtained.

Claims

1. A dispersant for hydraulic compositions, comprising the following components (A) and (B): Component (A): Lignin derivative. (B) Component: General formula (b1) 【Chemical 1】 [In the formula, M ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (half an atom), ammonium, or an organic ammonium. A structural unit (B1) represented by the formula: and general formula (b2) 【Chemistry 2】 [In the formula, R ２ｂ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ｂ represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. nb represents the average number of moles added of 5 to 200. R ３ｂ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. A copolymer having a structural unit (B2) represented by the following formula:

2. 2. The dispersant composition for hydraulic compositions according to claim 1, wherein the lignin derivative is lignin sulfonic acid and / or a salt thereof.

3. X in general formula (b2) ｂ The dispersant composition for hydraulic compositions according to claim 1, wherein is an alkylene group having 1 to 4 carbon atoms.

4. 2. The dispersant composition for hydraulic compositions according to claim 1, wherein the proportion of the structural unit (B1) relative to the total of the structural units (B1) and (B2) is 0.1% by mass or less and 9% by mass or less.

5. 2. The dispersant composition for hydraulic compositions according to claim 1, wherein the ratio of the component (B) to the component (A), (B) / (A), is 0.1 or more and less than 2.

0.

6. X in general formula (b2) ｂ The dispersant composition for hydraulic compositions according to claim 1, wherein is an alkylene group having 1 or 2 carbon atoms.

7. X in general formula (b2) ｂ The dispersant composition for hydraulic compositions according to claim 6, wherein is an alkylene group having 2 carbon atoms.

8. 2. The dispersant composition for hydraulic compositions according to claim 1, wherein the weight average molecular weight (Mw) of component (B) is 50,000 or more and 100,000 or less.

9. 2. The dispersant composition for hydraulic compositions according to claim 1, wherein nb in the general formula (b2) is an average number of moles added of 50 or more and 150 or less.

10. 2. The dispersant composition for hydraulic compositions according to claim 1, wherein the proportion of the structural unit (B1) relative to the total of the structural units (B1) and (B2) is 0.1% by mass or less and 7.5% by mass or less.

11. The dispersant composition for hydraulic compositions according to claim 1 , further comprising water.

12. A hydraulic composition comprising a hydraulic powder containing cement, water, and the dispersant composition for hydraulic compositions according to any one of claims 1 to 11.

13. The hydraulic composition according to claim 12, wherein the ratio of water to hydraulic powder is 40% by mass or more and 70% by mass or less.

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