JP4015088B2 - Dispersant for hydraulic composition - Google Patents

Description

  The present invention relates to a dispersant for a hydraulic composition. In particular, the present invention relates to a dispersant for a hydraulic composition that is excellent in the flow stability of the hydraulic composition after a short time has elapsed after kneading, a hydraulic composition containing the dispersant, and a hydraulic composition molded body.

  Many of the conventional polycarboxylic acid-based high-performance AE water reducing agents correspond to the long-term retention required for ready-mixed concrete. For example, the esterification reaction product disclosed in Patent Document 1 has a 60% after slump kneading. The minute shift does not decrease rapidly, and the slump flow after 30 minutes has elapsed rather greatly with the agents disclosed in Patent Document 2 and Patent Document 3.

  Furthermore, the conventional polycarboxylic acid-based high-performance AE water reducing agent has a rapid decrease in fluidity when the concrete temperature is high, and the fluidity cannot be secured until about 15 minutes after kneading, and the dispersibility is low when the concrete temperature is low. It decreases rapidly, the fluidity does not sufficiently develop in the same kneading time, the overdispersed state continues after kneading, and the fluidity will continue to increase even after 30 minutes after kneading. Water / hydraulic powder ratio [weight percentage (% by weight) of water and hydraulic powder in the hydraulic composition, hereinafter referred to as W / P. ] Becomes more prominent as it decreases.

  As a technique for reducing such temperature dependence, there is a technique disclosed in Patent Document 4. However, in the concretely disclosed range, in a concrete system having a lower W / P, it is not possible to sufficiently suppress fluctuations in flow retention due to temperature, and to sufficiently reduce viscosity. Can not.

JP-A-6-271347 JP-A-9-227192 JP-A-9-268042 JP 2001-322854 A

When manufacturing concrete products, civil engineering and building structures, or placing them on the site using ready-mixed concrete, concrete is poured into the formwork and compacted with an internal or external vibrator, such as piles, poles, and fume pipes. It is common to place concrete in a mold and centrifuge it.
In such a field, it is necessary to knead concrete having good workability. In particular, concrete within 30 minutes after kneading is required to have stable fluidity retention and low viscosity.

  In many cases, concrete products are filled in the mold within 30 minutes after kneading, so sufficient low viscosity and fluidity are required even after about 30 minutes after kneading. It is preferable that the fluidity is lowered in order to ensure the property and suppression of breathing.

  On the other hand, in the field placement with ready-mixed concrete, in order to secure the state of the concrete at the site placement after 1 to 3 hours, it is possible to manage the mixing conditions by looking at the flow state of the concrete around 15 minutes after the mixing. Therefore, it is necessary that the fluidity of the concrete after a short period of time after kneading is stable with respect to the concrete material and the concrete temperature.

Conventionally, so-called retarders ("Concrete admixture development technology" popular version, pp94-pp107, CMC, 1998) are used to ensure fluidity retention. It is used to ensure fluidity retention after 30 minutes after kneading.
Therefore, it is necessary that the fluidity after 30 minutes decreases rather rapidly, and the use of a retarder in concrete products that are often accelerated by steam curing will cause excessive fluidity over the long term. However, this is not preferable in that the steam curing strength is significantly reduced.

  In some cases, it is preferable to use various high-performance AE water reducing agents as a method for favorably maintaining the flow state of the concrete around 15 minutes after kneading ("Concrete admixture development technology" popular version, pp 58 to pp 69, CMC Corporation, 1998). In particular, the polycarboxylic acid-based high-performance AE water reducing agent is excellent for kneading concrete with low W / P necessary for ensuring the durability of the concrete. However, the conventional polycarboxylic acid-based high-performance AE water reducing agent secures the fluidity up to 30 minutes after kneading required for concrete products at a constant concrete temperature, and the fluidity rapidly decreases thereafter. Although there are some which can be made to do so, there is a drawback that such performance varies greatly with temperature.

  The present invention provides a concrete that has low W / P and has low viscosity of mortar, fluidity within a short time after kneading is stable against fluctuations in concrete temperature, good filling property and easy quality control. It aims at obtaining the dispersing agent for hydraulic compositions which can provide a product or a concrete structure.

The present invention
(A) an alkylene glycol ether monomer unit represented by the general formula (1),
(B) one or more carboxylic acid monomer units selected from maleic anhydride, maleic acid, maleate, and (c) one or more carboxylic acids selected from maleic anhydride, maleic acid, maleate. And the alkylene glycol compound represented by the general formula (2) has a half ester monomer unit, and the ratio of (C) in the total of 100 mol% of (A), (B) and (C) is 1 mol%. It is related with the dispersing agent for hydraulic compositions containing the copolymer (I) which is super 45 mol% or less.
R ¹ —O— (R ² O) _n R ³ (1)
[Where,
R ¹ : Alkenyl group R ² O: One kind or a mixture of two or more kinds of oxyalkylene groups having 2 to 4 carbon atoms. In the case of two kinds or more, they may be added in a block form or a random form.
R ^3: a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, a phenyl group, or alkylphenyl group n: an average value [n] is an integer of 1 or more which is a 15 to 100. ]
R ⁴ —O— (R ⁵ O) _m H (2)
[Where,
R ⁴ : Alkenyl group R ⁵ O: One type or a mixture of two or more types of oxyalkylene groups having 2 to 4 carbon atoms, and in the case of two or more types, they may be added in block or random form.
m: An integer of 1 or more with an average value [m] of 15 to 100. ]

Further, the present invention, the hydraulic composition containing hydraulic composition dispersant of the present invention, and to a hydraulic composition MonoNaru features that were molded water hydraulic composition.

  According to the dispersant for a hydraulic composition of the present invention, the hydraulic composition has low mortar viscosity, the fluidity within a short time after kneading does not vary with temperature, is stable, and has excellent filling properties and iron finishing properties. Can be obtained. As a result, excellent concrete products and concrete structures can be obtained.

In the alkylene glycol ether monomer unit represented by the general formula (1), the alkenyl group R ¹ includes a vinyl group, an allyl group, a methallyl group, an isopropenyl group, a butenyl group, a pentenyl group, and the like. General purpose and preferable.

R ² O is alkylene glycol (hereinafter referred to as AO), such as ethylene oxide (hereinafter referred to as EO) or propylene oxide (hereinafter referred to as PO). Preferably all are EO. R ³ is preferably an alkyl group having 1 to ³ carbon atoms, and examples thereof include a methyl group, an ethyl group, and a propyl group, and a methyl group is particularly preferable.

  In the general formula (1), the added mole number n of AO is an integer of 1 or more, and if the average added mole number [n] is less than 15, the dispersion force is weak, and the added amount becomes excessive to flow the concrete. As a result, the fluidity of the concrete increases even after 30 minutes or more after kneading. From the viewpoint of the dispersion force, AO polymerizability, and mortar viscosity, [n] is 15 to 100, preferably 15 to 90, more preferably 15 to 75, further 15 to 50, further 20 to 50, particularly 25 to 50. Is preferred.

In the alkylene glycol compound represented by the general formula (2), R ⁴ that is an alkenyl group includes a vinyl group, an allyl group, a methallyl group, an isopropenyl group, a butenyl group, a pentenyl group, and the like. And preferred.

R ⁵ O is AO, such as EO, PO, and the addition form may be any of single, random, block, or alternating. Preferably all are EO.

  In the general formula (2), the added mole number m of AO is an integer of 1 or more, and the average added mole number [m] is the same as [n] for dispersibility, AO polymerizability and mortar viscosity. From this point of view, it is 15 to 100, preferably 15 to 90, more preferably 15 to 75, further 15 to 50, further 20 to 50, and particularly preferably 25 to 50.

  One or more carboxylic acid monomers selected from maleic anhydride, maleic acid, and maleate used in the present invention (hereinafter also referred to as maleic acid-based dicarboxylic acid) are derivatives thereof, α, β-non Saturated carboxylic acids such as (anhydrous) citraconic acid (salt), (anhydrous) itaconic acid (salt) may be contained.

  The half ester in the present invention is a partial ester of maleic acid-based dicarboxylic acid, and the hydroxyl group of general formula (2) is 0.8 to 1.2 with respect to 1 equivalent of the acid anhydride group of maleic acid-based dicarboxylic acid. It refers to a reactant bound in an equivalent, preferably 1 equivalent ratio. In addition, when this ratio is less than 1, maleic acid type dicarboxylic acid will exist, but this should just be included in a monomer unit (b).

  The copolymer (I) of the present invention comprises a monomer that is a half ester in advance and an alkylene glycol ether monomer and a maleic dicarboxylic acid monomer represented by the general formula (1). The alkylene glycol ether monomer represented by the general formula (1) and the maleic dicarboxylic acid monomer may be copolymerized, and then the alkylene glycol compound represented by the general formula (2) may be polymerized. Although it may be obtained by esterification, since the half ester state of maleic dicarboxylic acid and the copolymerization amount for each monomer are clear, it is more possible to obtain the copolymer (I) by the former method. preferable. When the half ester is obtained by the former or the latter method, it is preferable to select maleic anhydride from maleic dicarboxylic acids from the viewpoint of reactivity.

Copolymer molar ratios of the structural units (I), (B) and (C) of the copolymer (I) of the present invention are as follows when (A) + (B) + (C) is 100 mol%. Is preferably in the following range (unit: mol%).
From the viewpoint of dispersibility and copolymerization, (A) is preferably 40 mol% ≦ (A) ≦ 60 mol%, and more preferably 45 mol% ≦ (A) ≦ 55 mol%.
From the viewpoints of dispersibility and fluidity, (C) is 1 mol% <(C) ≦ 45 mol%, preferably 2 mol% ≦ (C) ≦ 35 mol%, and 5 mol% ≦ (C). ≦ 30 mol% is more preferable, and 10 mol% ≦ (C) ≦ 25 mol% is further preferable. 10 mol% ≦ (C) ≦ 20 mol% is particularly preferable.
In this molar ratio, if the ratio of (c) is 1 mol% or less, the fluidity retention after a short time after kneading does not sufficiently develop, and if it exceeds 45 mol%, the fluidity retention becomes excessive. In some cases, the fluidity does not decrease even after 30 minutes from kneading.

  Moreover, the preferable weight average molecular weight of copolymer (I) is 3000-300,000 from the point of fluid provision | providing, 5000-100,000 are more preferable, and 10,000-70,000 are more preferable. The weight average molecular weight is determined by gel permeation chromatography (converted to standard substance polyethylene glycol).

  In the copolymer (I) of the present invention, monomer units other than (A), (B), and (C) can be copolymerized with these as necessary, as long as the effects of the invention are not impaired. Can be introduced.

  Examples of other monomers include one-terminal aminated products of unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, citraconic acid and alkylamines having 1 to 20 carbon atoms and glycols having 2 to 4 carbon atoms, or these Monoamides and diamides with one-terminal amination product of polyalkylene glycols having 2 to 100 moles of glycol addition; addition moles of maleic acid and alkyl alcohols having 1 to 20 carbon atoms and glycols having 2 to 4 carbon atoms or these glycols Diesters of polyalkylene glycols having 2 to 100, and one-terminal amination products of these acids with alkylamines having 1 to 20 carbon atoms and glycols having 2 to 4 carbon atoms, or addition mole number of these glycols 2 Diamides with ˜100 polyalkylene glycol single-terminal aminations; (meth) Unsaturated carboxylic acids such as crylic acid, and their monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts, these acids, alkyl alcohols having 1 to 20 carbon atoms, and glycols having 2 to 4 carbon atoms, or these Esters of polyalkylene glycols having 2 to 100 moles of addition of glycols, single-terminal aminations of glycols having 2 to 4 carbon atoms, or fragments of polyalkylene glycols having 2 to 100 moles of addition of these glycols Amides with terminal aminations; unsaturated sulfonic acids such as sulfoethyl (meth) acrylate, 2-methylpropanesulfonic acid (meth) acrylamide, styrenesulfonic acid, and monovalent metal salts, divalent metal salts, ammonium salts thereof And organic amine salts; (meth) acrylamide, (meth) acrylic Unsaturated amides such as alkylamide; Unsaturated amino compounds such as dimethylaminoethyl (meth) acrylate; Vinyl esters such as vinyl acetate and vinyl propionate; Aromatic vinyls such as styrene, etc. 1 type (s) or 2 or more types can be used.

  Since the copolymer (I) of the present invention maintains good concrete fluidity after a short time after kneading, it is particularly used for concrete product applications that require stability of fluidity retention for 30 minutes after kneading. Can achieve the purpose sufficiently by using a single structure, but in order to obtain more stable fluid retention, they have different structures corresponding to the copolymer (I). A plurality of mixtures are preferred.

  The ratio of the copolymer (I) of the present invention in the dispersant for hydraulic composition is such that the flow retention after kneading (about 15 minutes after kneading) and the flow reducing property after kneading (about 30 minutes after kneading). From the viewpoint, it is preferably 5 to 95% by weight, more preferably 15 to 85% by weight, and still more preferably 25 to 75% by weight.

  Further, the copolymer (I) of the present invention is combined with the copolymer (II) related to the dispersant for a conventional polycarboxylic acid-based hydraulic composition, so that the conventional dispersant is insensitive to the concrete temperature. It was possible to stabilize the fluidity retention after a short time after kneading, which was stable, and to make good concrete as a whole.

In particular, examples of the copolymer (II) include the following (II-1) to (II-4).
(II-1): a copolymer of an alkenyl ether represented by the following general formula (A) and a maleic dicarboxylic acid or a salt thereof R ^1a O (AO) _n1 R ^2a (A)
(In the formula, R ^1a is an alkenyl group having 2 to 5 carbon atoms, AO is an oxyalkylene group having 2 to 3 carbon atoms, n 1 is a number having 2 to 300, and R ^2a is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Represents.)
(II-2): at least one monomer selected from the monomer (a) represented by the following general formula (B) and the compounds represented by the following general formulas (C) and (D) Copolymer obtained by polymerizing monomer mixture containing body (b)

(Wherein R ^1b and R ^2b are hydrogen atoms or methyl groups, m1 is a number of 0 to 2, AO is an oxyalkylene group having 2 to 3 carbon atoms, n2 is a number of 1 to 300, and X is a hydrogen atom or carbon. Represents an alkyl group of formulas 1 to 3.)

Wherein R ^{1c to} R ^3c are hydrogen atoms, methyl groups or (CH ₂ ) _m ² COOM ² , R ^1d is a hydrogen atom or methyl group, M ¹ , M ² and Y are hydrogen atoms or cations, and m 2 is 0. Represents the number of ~ 2.

(II-3): at least one monomer represented by the following general formula (a1) (A1) and at least one monomer represented by the following general formula (a2) (A2) A copolymer mixture (A) obtained by copolymerization of the monomers (A1) and (A2) in which the molar ratio (A1) / (A2) is changed at least once during the reaction

(Where
R ¹¹ , R ¹² : hydrogen atom or methyl group
m11: Number from 0 to 2
R ¹³ : hydrogen atom or —COO (AO) _n11 X ¹
p: Number of 0 or 1
AO: C2-C4 oxyalkylene group or oxystyrene group
n11: Number from 2 to 300
X ¹ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. )

(Where
R ¹⁴ to ¹⁶ : a hydrogen atom, a methyl group, or (CH ₂ ) _m ¹² COOM ¹² , and (CH ₂ ) _m ¹² COOM ¹² may form an anhydride with COOM ¹¹ or other (CH ₂ ) _m ¹² COOM ¹² In that case, M ¹¹ and M ¹² of these groups are not present.
M ¹¹ , M ¹² : hydrogen atom, alkali metal, alkaline earth metal, ammonium group, alkylammonium group or substituted alkylammonium group
m12: represents a number from 0 to 2. )

(II-4): a unit derived from an ethylenically unsaturated monomer (a) represented by the following general formula (4A), and an ethylenically unsaturated monodicarboxylic acid represented by the following general formula (4B) Having as structural units a unit derived from the ester monomer (b)

(Where
R ⁴¹ , R ⁴² : hydrogen atom or methyl group
AO: C2-C3 oxyalkylene group n ': 25-300 number X': hydrogen atom or C1-C3 alkyl group)

(Where
R ⁴³ : hydrogen atom or methyl group
R ^44: alkyl group or alkenyl group having 1 to 18 carbon atoms, or a hydroxyalkyl group having 2 to 6 carbon atoms)

<Copolymer (II-1)>
In the general formula (A) of the alkenyl ether constituting the above (II-1), the alkenyl group having 2 to 5 carbon atoms represented by R ^1a is preferably a vinyl group, an allyl group, a methallyl group, etc. In particular, an allyl group is versatile and preferred. AO is EO, PO or styrene oxide, and the addition form may be any of single, random, block or alternating. EO is preferred. R ^2a is preferably an alkyl group having 1 to 3 carbon atoms, and examples thereof include a methyl group, an ethyl group, and a propyl group. A methyl group is particularly preferable.

<Copolymer (II-2)>
In addition, the monomer (a) represented by the general formula (B) constituting the above (II-2) includes, for example, methoxypolyethylene glycol, methoxypolypropylene glycol, ethoxypolyethylenepolypropyleneglycol, etc., one-end alkyl group-capped polyalkylene An esterified product of glycol and (meth) acrylic acid, or an EO or PO adduct to (meth) acrylic acid is preferably used. The additional form may be single, random, block, or alternating. An esterified product of methoxypolyethylene glycol and (meth) acrylic acid is more preferable, and an esterified product of methoxypolyethylene glycol and methacrylic acid having an EO average addition mole number of 2 or more and less than 100 is particularly preferable. Moreover, when placing importance on the dispersibility and initial strength development of the hydraulic composition, it is preferable to use the monomer (a) in which n2 in the general formula (B) is 110 to 300. When emphasizing the viscosity in the fresh state, it is preferable to use the monomer (a) in which n2 in the general formula (B) is 1 to 50.

  Further, the monomer represented by the general formula (C) constituting the above (II-2) includes unsaturated monocarboxylic acid monomers such as (meth) acrylic acid and crotonic acid, maleic anhydride, maleic acid Unsaturated dicarboxylic acid monomers such as acid, itaconic anhydride, itaconic acid, fumaric acid, or their alkali metal salts, alkaline earth metal salts, ammonium salts, mono-, di-, optionally substituted with hydroxyl groups A trialkylammonium salt is preferable, more preferably (meth) acrylic acid or an alkali metal salt thereof, and particularly preferably methacrylic acid or an alkali metal salt thereof.

  Further, as the monomer represented by the general formula (D) constituting the above (II-2), allyl sulfonic acid, methallyl sulfonic acid, or an alkali metal salt, alkaline earth metal salt, ammonium salt thereof, Mono-, di-, and trialkylammonium salts that may be substituted with hydroxyl groups are used.

  JP-A-2002-187755 can be referred to for the production method and preferred range of the above compounds (II-1) and (II-2).

<(II-3) Copolymer mixture (A)>
Examples of the monomer (A1) represented by the general formula (a1) used for the production of the copolymer mixture (A) of (II-3) include methoxypolyethylene glycol, methoxypolypropylene glycol, methoxypolybutylene. One-terminal alkyl-blocked polyalkylene glycols such as glycol, methoxypolystyrene glycol, ethoxypolyethylenepolypropylene glycol, and (half) esterified products of (meth) acrylic acid and maleic acid, etherified products of (meth) allyl alcohol, and (meta ) Adducts of ethylene oxide and propylene oxide to acrylic acid, maleic acid and (meth) allyl alcohol are preferably used, R ¹³ is preferably a hydrogen atom, p is 1 and m11 is preferably 0. More preferred is an esterified product of alkoxy, particularly methoxypolyethylene glycol and methacrylic acid.

  For the copolymer mixture (II-3), when it is necessary to have both initial strength development and viscosity reduction, it is preferable to copolymerize those having a large n11 and those having a small n11, particularly the monomer (A1) It is preferable to use a monomer (A1-1) represented by the following general formula (a1-1) and a monomer (A1-2) represented by the following general formula (a1-2) together .

(Where
R ′: hydrogen atom or methyl group
AO: oxyalkylene group having 2 to 4 carbon atoms or oxystyrene group, preferably oxyalkylene group having 2 to 3 carbon atoms
s: Number from 12 to 300
X ^{11 represents a} hydrogen atom or an alkyl group having 1 to 18 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. )

(Where
R ″: hydrogen atom or methyl group
AO: oxyalkylene group having 2 to 4 carbon atoms or oxystyrene group, preferably oxyalkylene group having 2 to 3 carbon atoms
t: Number of 2 to 290 (however, the relationship with s in the general formula (a1-1) is s> t and (s−t) ≧ 10, preferably ≧ 30, more preferably ≧ 50). )
X ^{12 represents a} hydrogen atom or an alkyl group having 1 to 18 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. )

  In this case, the average weight ratio of the two is preferably (A1-1) / (A1-2) = 0.1 to 8, more preferably 0.2 to 2.5, and particularly preferably 0.4 to 2. In addition, this average weight ratio is an average of the weight ratio of all the monomers used for reaction.

  The reaction molar ratio [(A1-1) + (A1-2)] / (A2) of the monomers (A1-1), (A1-2) and (A2) is preferably before and after the change. Is at least one of the molar ratios of 0.02 to 4, more preferably 0.05 to 2.5, and particularly preferably 0.1 to 2. Most preferably, the molar ratios before and after the change are both in these ranges.

  Further, as the monomer (A2) represented by the general formula (a2) used for the production of the copolymer mixture (A), monocarboxylic acid monomers such as (meth) acrylic acid and crotonic acid, Dicarboxylic acid monomers such as maleic acid, itaconic acid, fumaric acid, etc., or anhydrides or salts thereof, such as alkali metal salts, alkaline earth metal salts, ammonium salts, mono- and di-substituted with hydroxyl groups , Trialkyl (2 to 8 carbon atoms) ammonium salt is preferable, (meth) acrylic acid, maleic acid, maleic anhydride, more preferably (meth) acrylic acid or alkali metal salts thereof, particularly preferable. Is methacrylic acid or an alkali metal salt thereof.

  The copolymer mixture (A) is a copolymer obtained by reacting the monomers (A1) and (A2) with a molar ratio preferably in the range of (A1) / (A2) = 0.02-4. The coalescence mixture (A) is contained, but the molar ratio (A1) / (A2) is changed at least once during the reaction.

  JP-A-2002-3259 can be referred to for the detailed production method and preferred range of the copolymer mixture (A) of (II-3). In (II-3), those having monomer units (A), (B), and (C) shall be handled as the copolymer (I) of the present invention. It is excluded from the polymer mixture (A).

<Copolymer (II-4)>
Examples of the monomer (a) represented by the general formula (4A) include esterified products of one-end alkyl-blocked polyalkylene glycol such as methoxypolyethylene glycol and acrylic acid or methacrylic acid, acrylic acid or methacrylic acid. Examples thereof include ethylene oxide and propylene oxide adducts. When AO in general formula (4A) contains ethylene oxide and propylene oxide, any of random addition, block addition, alternating addition, etc. may be sufficient. In addition, from the viewpoint of not causing concrete hardening delay, the added mole number n ′ in the general formula (4A) is preferably 50 or more, and more preferably 110 or more.

Examples of the monomer (b) represented by the general formula (4B) include linear or branched alkyl (meth) acrylates having 1 to 18 carbon atoms, and particularly preferably R ^43. This is the case for hydrogen atoms. Here, as R ⁴⁴ in the above general formula (4B), those having 1 to 4 carbon atoms are particularly preferable in view of good solubility of the resulting polymer in water. The form is not particularly limited.

  The ratio of the monomer (a) unit and the monomer (b) unit constituting the copolymer (II-4) is simple from the viewpoint that fluidity is not lowered and excellent fluidity can be obtained. The range of monomer (a) 0.1-50 mol% and monomer (b) 50-99.9 mol%, especially monomer (a) 1-40 mol% and monomer (b) 60-99 mol% preferable.

  The copolymer (II-4) can further have units derived from the monomer (c) represented by the general formula (4C).

(Where
M ⁴¹ : hydrogen atom, alkali metal, alkaline earth metal, ammonium group, alkylammonium group or substituted alkylammonium group
R ^{45 to} R ⁴⁷ : hydrogen atom, methyl group or (CH ₂ ) _m41 COOM ⁴² , respectively, but M ⁴² is the same as M ⁴¹
m41: 0 or 1)

  As the monomer (c), acrylic acid, methacrylic acid, crotonic acid, or alkali metal salts, ammonium salts, amine salts and substituted amine salts thereof can be used as monocarboxylic acid monomers. As the unsaturated dicarboxylic acid monomer, maleic acid, itaconic acid, citraconic acid, fumaric acid, or alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, substituted amine salts thereof can be used. Other examples of the monomer that may be contained include acrylamide, vinyl acetate, styrene, vinyl chloride, and the like.

  When the monomer (c) is contained, the ratio of the monomer (a) unit, the monomer (b) unit and the monomer (c) unit constituting the copolymer (II-4) is as follows. The range of the monomer (a) 0.1 to 50 mol%, the monomer (b) 50 to 90 mol% and the monomer (c) 0.1 to 50 mol% is excellent in fluidity retention, particularly the monomer (a) In the range of 5 to 40 mol%, monomer (b) 50 to 90 mol% and monomer (c) 5 to 40 mol%, there is almost no decrease in fluidity, and initial fluidity and fluidity retention. The balance is good, and as a result, it is extremely excellent in that the amount of the dispersant used for the concrete can be reduced.

  Among these compounds (II-1) to (II-4), those having a maximum value of AO addition mole number of 5 to 110 are more preferable from the viewpoint of dispersibility and viscosity, more preferably 5 to 90, and further 5 To 75, more preferably 5 to 50, and particularly preferably 10 to 50.

  The weight ratio of the copolymer (I) and the copolymer (II) is preferably copolymer (I) / copolymer (II) = 5/95 to 95/5, and the copolymer (I) / copolymer The polymer (II) = 15/85 to 85/15 is more preferable, and the copolymer (I) / copolymer (II) = 25/75 to 75/25 is more preferable.

  The weight average molecular weight of the copolymer (II) is preferably in the range of 5000 to 500000 from the viewpoint of fluidity, and in the range of 20000 to 100000, and further in the range of 30000 to 85000 is particularly excellent in fluidity. The weight average molecular weight is determined by gel permeation chromatography (converted to standard substance polyethylene glycol).

  In addition, other copolymerizable monomers can be used together as a raw material for the copolymer (II). Specifically, acrylonitrile, alkyl (meth) acrylate (C1-12) ester, (meth) acrylamide, styrene And styrene sulfonic acid.

  In the dispersant for a hydraulic composition of the present invention, the dispersant for a total hydraulic composition containing the copolymer (I) is 0.02 to 3.0% by weight, preferably 0.0. It is added so as to be 1 to 2.5% by weight.

  Moreover, even if the dispersing agent for hydraulic compositions containing the copolymer (I) of the present invention is added after mixing all components in advance to the concrete, the copolymer (I) and other components are added separately. Alternatively, it may be used after first diluted with kneading water.

The dispersant for a hydraulic composition of the present invention is suitable for the production of concrete for vibration molded products for concrete products, concrete for centrifugal molded products molded by compaction with a vibrator or centrifugal force, and ready-mixed concrete for on-site construction.
Furthermore, it can also be used for high-fluidity concrete that has a self-filling property without using a vibrator and exhibits a fluidity of a slump flow of 500 mm or more. Especially preferably, it is 500-800 mm.

  The hydraulic composition in which the dispersant of the present invention functions well is mortar or concrete containing water, cement, aggregate. Examples of the cement include ordinary Portland cement, early-strength Portland cement, and ultra-early-strength Portland cement. Even if the W / P of the hydraulic composition is 20 to 45% by weight, more preferably 25 to 40% by weight, and particularly 25 to 35% by weight, the effects of the present invention can be sufficiently obtained.

  Of the aggregates, fine aggregates are preferably mountain sand, land sand, river sand and crushed sand, and coarse aggregates are preferably mountain gravel, land gravel, river gravel and crushed stone. Depending on the application, lightweight aggregates may be used. The term “aggregate” is based on the “concrete overview” (published on June 10, 1998, published by Technical Shoin).

  Concrete to be added is mainly composed of cement, fine aggregate, coarse aggregate, etc., but various types of blast furnace slag, fine limestone powder, fly ash, silica sand, silica fume and the like can be used.

  Further, it can be used in combination with known additives, for example, AE agent, AE water reducing agent, high performance water reducing agent, retarder, early strengthening agent, accelerator, foaming agent, foaming agent, antifoaming agent, thickening agent. , Waterproofing agents, antifoaming agents and the like.

《Concrete material》
Concrete was produced according to the formulation shown in Table 1 using the following concrete materials.
W: Tap water mixed with cement dispersant C: Ordinary Portland cement [Pacific Cement Co., Ltd.], surface dry specific gravity = 3.16
LS: Limestone fine powder (Shimizu Kogyo, brain value 5200), surface dry specific gravity = 2.70
S: Fine aggregate, mountain sand from Kimitsu, Chiba Prefecture, surface dry specific gravity = 2.63
G: Coarse aggregate, Wakayama crushed stone G2013, surface dry specific gravity = 2.62
W / P: [W / (C + LS)] × 100 (% by weight)
s / a: [S / (S + G)] × 100 (volume%)
Air volume: 2%

<Cement dispersant>
Half-esterification with the monomer (b), monomer (b) in Table 2 and the carboxylic acid in Table 2 and the compound of the general formula (2) in advance [with respect to 1 equivalent of an acid anhydride group of maleic acid, Copolymers shown in Table 2 were produced using the monomer (c) in which the hydroxyl group of the general formula (2) was bonded at a ratio of 1 equivalent] and used as a cement dispersant. Moreover, the cement dispersing agent of Table 5 was obtained using the copolymer of Table 3 or a copolymer as arbitrary copolymers. Using the obtained cement dispersant, concrete was produced under the following conditions, and the performance in each formulation was evaluated. The results are shown in Tables 4-8.

* Mw is a weight average molecular weight (the same applies hereinafter). The copolymerization mol% is a ratio in the sum of the monomers (A), (B), and (C). [N] and [m] are average added mole numbers.

《Concrete production conditions》
The kneading amount was 40 liters. Concrete materials other than water mixed with the cement dispersant are put into a 60-liter forced biaxial mixer, kneaded for 10 seconds, water mixed with the cement dispersant is added, kneaded for 90 seconds, and then discharged.

《Dispersibility》
(1) In the case of compounding W / P = 27 The dispersibility of the concrete is 65 ± 1 cm in the slump flow value (concrete library 93: high fluid concrete construction guidelines, pp160-161, Japan Society of Civil Engineers) immediately after mixing the concrete. The solid content addition ratio with respect to the weight of the hydraulic powder (P) of the dispersant required at times was used as a scale. The smaller the value, the better the dispersibility. At this time, the initial air volume was adjusted to 2% or less with a foaming agent (Mighty AE-03: manufactured by Kao Corporation) and an antifoaming agent (Antifoam E-20: manufactured by Kao Corporation). .

(2) In the case of blend W / P = 40 The dispersibility of the concrete is the weight of the hydraulic powder (P) of the dispersant required when the slump value (JIS A1101) immediately after kneading the concrete is 18.0 to 18.5 cm. The solid content addition rate relative to was taken as a scale. The smaller the value, the better the dispersibility. At this time, the initial air volume was adjusted to 2% or less with a foaming agent (Mighty AE-03: manufactured by Kao Corporation) and an antifoaming agent (Antifoam E-20: manufactured by Kao Corporation). .

<Dispersion retention>
The slump flow value (W / P = 27) or slump value (W / P = 40) after 15 minutes, 30 minutes and 45 minutes immediately after kneading was used as a measure of dispersion retention. It is good for the concrete according to the present invention that the numerical value is about the same up to about 15 minutes and the numerical value after 30 minutes is small compared to the numerical value immediately after kneading.

  In particular, in relation to filling stability, in the above concrete blending, after 30 minutes from immediately after kneading, if the slump flow is 650 mm or the slump value exceeds 18 cm, the coarse aggregate separates from the mortar or hardens when vibration is applied. If a slump flow is 550 mm or less or a slump value is 10 cm or less 30 minutes after the kneading, coarse bubbles remain on the concrete surface after curing, which is not preferable.

  Also, in relation to the finish of the trowel, if the above-mentioned concrete blend is 45 minutes after kneading and the slump flow exceeds 650 mm or the slump value exceeds 18 cm, the finish of the trowel is required twice, which is not preferable.

"viscosity"
Mortar was obtained by separating and removing the aggregate from the concrete after 10 minutes from kneading with a sieve having an opening of 5 mm. This mortar is filled in the device of the shape shown in Fig. 1 made by processing stainless steel (SUS304), with the lower discharge opening closed, and then scraped off at the surface of the upper input opening, and then the lower discharge opening is opened. The mortar was allowed to flow down naturally, and the time (flow time) until pores were confirmed in at least a part of the mortar when visually observed from the upper charging opening was used as a measure of viscosity. The shorter the flow-down time, the lower the viscosity of the mortar.

<Evaluation method of filling stability>
With a hand scoop so that charging is completed in 30 seconds while applying vibration to the mold of length x width x height = 100 mm x 200 mm x 500 mm immediately after kneading and after 30 minutes. Fill the concrete and observe the surface of the cured body after curing. Formwork vibration is 0.5 mm amplitude at W / P = 27, 1800 vpm vibration frequency (1800 vibrations per minute), 60 seconds vibration time, 0.5 mm amplitude at W / P = 40, 2200 vpm vibration frequency (2200 vpm) The vibration frequency per minute was 2200 times) and the vibration time was 30 seconds. Three cured bodies were produced and evaluated according to the following criteria.
X: A water channel was generated on the surface of all the cured bodies, or a large number of coarse pores remained on the entire surface of all the cured bodies.
(Triangle | delta): The water channel generate | occur | produced on the surface in one hardening body, or the coarse pore remained in a part of surface in one hardening body.
◯: There were no water channels on the surface of all the cured products, and almost no coarse pores were observed in all of the cured products.

《Needle finish》
Immediately after kneading, concrete was filled in a mold of length × width × height = 200 mm × 500 mm × 100 mm without vibration, and after 30 minutes immediately after kneading, the surface was smoothed once with a trowel. The finished surface after curing was observed and evaluated according to the following criteria.
X: A thin layer of dried mortar is formed on the surface and peels easily.
Δ: A thin layer of dried mortar is partially formed on the surface, and the surface is not smooth.
◯: There is no thin mortar layer on the surface, and the surface is finished smoothly.

* Temperature is the temperature of concrete, and the addition rate is solid powder (P) solid content weight% (hereinafter the same).

Schematic showing the equipment used to measure the flow down time for viscosity evaluation in the examples

Explanation of symbols

1 ... Upper inlet opening 2 ... Lower outlet opening

Claims (6)

(A) an alkylene glycol ether monomer unit represented by the general formula (1),
(B) one or more carboxylic acid monomer units selected from maleic anhydride, maleic acid, maleate, and (c) one or more carboxylic acids selected from maleic anhydride, maleic acid, maleate. And the alkylene glycol compound represented by the general formula (2) has a half ester monomer unit, and the ratio of (C) in the total of 100 mol% of (A), (B) and (C) is 1 mol%. The dispersing agent for hydraulic compositions containing the copolymer (I) which is super 45 mol% or less.
R ¹ —O— (R ² O) _n R ³ (1)
[Where,
R ¹ : Alkenyl group R ² O: One kind or a mixture of two or more kinds of oxyalkylene groups having 2 to 4 carbon atoms. In the case of two kinds or more, they may be added in a block form or a random form.
R ^3: a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, a phenyl group, or alkylphenyl group n: an average value [n] is an integer of 1 or more which is a 15 to 100. ]
R ⁴ —O— (R ⁵ O) _m H (2)
[Where,
R ⁴ : Alkenyl group R ⁵ O: One type or a mixture of two or more types of oxyalkylene groups having 2 to 4 carbon atoms, and in the case of two or more types, they may be added in block or random form.
m: An integer of 1 or more with an average value [m] of 15 to 100. ] The dispersant for hydraulic composition according to claim 1, which is used for high fluidity concrete. The dispersant for hydraulic composition according to claim 1, which is used for concrete for vibration products. The dispersing agent for hydraulic compositions according to claim 1, which is used for concrete for centrifugal products. The hydraulic composition containing the dispersing agent for hydraulic compositions of any one of Claims 1-4. Molded hydraulic composition MonoNaru form the claim 5 the hydraulic composition.

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