JP2005247591A - Slag-reducing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slag-reducing agent having suitable water-reducing property, allowing concrete to have excellent workability and to develop sufficient strength by ordinary centrifugal compaction, having high slag-reducing effect, and allowing concrete to develop early strength only by low-pressure steam curing. <P>SOLUTION: The slag-reducing agent comprises a copolymer obtained by polymerizing 50 to 99 wt. % (1) specified vinyl monomer with 1 to 50 wt.% (2) specified unsaturated aliphatic dicarboxylic acid monomer or maleic anhydride and 0 to 30 wt.% (3) other copolymerizable monomers and a specified polyether compound having a cloud point of 20°C or lower as measured in a 1% aqueous solution. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a Noro reducing agent.

  Conventionally, concrete products such as concrete piles, poles, and fume pipes have been manufactured by compaction and compaction by centrifugal force. In the centrifugal molding process, the water in the concrete is squeezed out to form a dense structure, but this water is mixed with fine particles in the cement and aggregate, and is discharged as a so-called noro. Since this noro is strongly alkaline, the solid content must be treated as industrial waste after sedimentation and neutralization. For this reason, not only a large amount of money is required, but recently it has become difficult to secure a disposal place for Noro, which is a big problem for the centrifugal molding industry.

On the other hand, in recent years, concrete piles require strength of 90 N / mm ² or more in about one week, so a large amount of high-performance water reducing agent is added, high strength materials, silica sand, silica fume or gypsum are added in large quantities. Addition or after steam curing further high temperature and high pressure steam curing (180 ° C., 10 kg / m ² ) to obtain early strength and cope with this. The method of adding a large amount of these agents or materials can provide the desired strength, but the adverse effect that the viscosity of the concrete is increased and the workability is reduced, the compaction is insufficient, and a large amount of noro is generated. Occurs. Moreover, not only high-temperature and high-pressure steam curing alone can not cope with a high strength of 90 N / mm ² or more, but the equipment cost and running cost become very high.

In order to solve such a problem, various reducing agents have been proposed (for example, Patent Document 1).
On the other hand, in JP-A-9-309755, by mixing a specific copolymer with cement as a cement dispersant, the dispersibility of cement particles can be improved and mortar with high fluidity can be generated. Is described. JP-A-57-118058

  However, when a known noro-reducing agent as described in Patent Document 1 is used for centrifugal molding of concrete, the amount of noro can be reduced, but the desired strength cannot be obtained, the viscosity of the concrete is high, and workability is improved. There was a negative effect such as lowering. Patent Document 2 describes that a specific copolymer is mixed with mortar or concrete as a cement dispersant, but does not describe the influence on mixing of cement fine particles in the waste water during centrifugal molding. . There is also no data showing the possibility of high early strength required for recent high compressive strength concrete products.

  The problem of the present invention is that it has moderate water reduction, excellent workability, shows sufficient strength by compaction with ordinary centrifugal force, has a high reduction effect, and early strength is expressed only by atmospheric steam curing. It is to provide a Noro reducing agent.

That is, the Noro reducing agent according to the present invention includes 50 to 99% by weight of the monomer (A) represented by the following formula (1), the monomer represented by the following formula (2) or maleic anhydride (I) 1 A copolymer obtained by polymerizing ˜50 wt% and other copolymerizable monomer (c) 0-30 wt%, and the cloud point of 1% aqueous solution represented by the following formula (3) It contains a polyether compound having a temperature of 20 ° C. or lower.

^However, R 1, ^{R 2} and ^{R 3} each independently represent a hydrogen atom or a methyl group, ^{R 4} represents a hydrogen atom, ^{A 1} O is one or more kinds of oxyalkylene group having 2 to 3 carbon atoms 50 mol% or more is an oxyalkylene group having 2 carbon atoms, and in the case of 2 or more types, it may be block or random, and p = 21 to 100 and q = 0 to 2.

However, ^{M 1} is a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or organic ammonium, X represents a -OM ² or _{^{-Y- (A 2 O) r R}} 5, Y is an ether group or an imino group M ² represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or organic ammonium, and A ² O is one or two or more of oxyalkylene groups having 2 to 3 carbon atoms, and two or more of them In some cases, it may be block or random, and R ⁵ is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, and r = 1 to 50. )

However, R ⁶ and R ⁷ represent a hydrogen atom or a functional group derived from a hydrocarbon having 1 to 22 carbon atoms, and A ³ O and A ⁵ O are one or two kinds of oxyalkylene groups having 3 to 4 carbon atoms. As mentioned above, in the case of 2 or more types, it may be block or random, and A ⁴ O and A ⁶ O are oxyalkylene groups having 2 carbon atoms, s = 0 to 100, u = 0 to 100, s + u = 10 -100, t = 0-15, v = 0-15, t + v = 0-15.

  The Noro reducing agent of the present invention is excellent in workability and compaction of concrete, can reduce Noro discharge after centrifugal molding, and also exhibits an excellent effect in early strength development. In particular, with the Noro reducing agent of the present invention, it is possible to largely squeeze out water and increase the compressive strength without discharging much of the powder in the concrete. In Patent Document 2, it is described that a specific copolymer is mixed into a mortar as a cement dispersant, but its effect is an improvement in fluidity of the mortar by improving the dispersibility of cement particles in water. The influence on the mixing of cement fine particles in the waste water during centrifugal molding is not described.

  The Noro reducing agent of the present invention comprises 50 to 99% by weight of the monomer (a) represented by the formula (1) and 1 to 50% by weight of the monomer represented by the formula (2) or maleic anhydride (ii). And a copolymer obtained by polymerizing 0 to 30% by weight of another copolymerizable monomer (c).

In the formula ^(1), R 1, ^{R 2} and ^{R 3} is a hydrogen atom or a methyl group, preferably the total number of carbon atoms in ^R 1, ^{R 2} and ^{R 3} 0 to 1.
In the formula (1), A ¹ O is an oxyalkylene group having 2 to 3 carbon atoms, and examples thereof include an oxyethylene group and an oxypropylene group, preferably 50 mol% or more is an oxyethylene group, more preferably 80 More than mol% is an oxyethylene group. A ¹ O may be a ^single type or a mixture of two or more types.
p is the number of added moles of the oxyalkylene group having 2 to 3 carbon atoms, 21 to 100, and preferably 25 to 70. If the value of p exceeds 100, the resulting compound has a high viscosity, which makes it difficult to produce.
q is the number of methylene groups and is 0-2. Preferably it is 1. If the value of q exceeds 2, it is not preferable because production is difficult.

M ¹ and M ^{2 in} the formula (2) are a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or organic ammonium. Examples of the alkali metal include lithium, sodium, potassium, rubidium and the like.
Examples of the alkaline earth metal include magnesium and calcium.
Organic ammonium is an ammonium derived from an organic amine. Examples of the organic amine include alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, and triethylamine. Monoethanolamine, methylamine, ethylamine, diethylamine.
X is —OM ² or —Y— (A ² O) _r R ⁵ . Y is an ether group or imino group, the ether group represents —O—, and the imino group represents —NH—.
A ² O is an oxyalkylene group having 2 to 3 carbon atoms, and examples thereof include an oxyethylene group and an oxypropylene group. Preferably, 50 mol% or more is an oxyethylene group, more preferably 80 mol% or more is oxyethylene. It is a group.
R ⁵ is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. Examples of the hydrocarbon group having 1 to 4 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, There are butyl groups. When the number of carbon atoms of the hydrocarbon group represented by R ⁵ exceeds 4, the resulting copolymer is not sufficiently hydrophilic and tends to foam, such being undesirable.

  When maleic anhydride is used as (i), it is preferable to use ring-opening with sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia or the like, or ring-opening with water. If the anhydrous ring portion is closed, the effect of lowering the viscosity of the concrete is lowered, and the water reduction is also lowered.

  The weight average molecular weight of the copolymer as the main component of the Noro reducing agent of the present invention is 500 to 100,000, preferably 5,000 to 50,000, more preferably 10,000 to 20,000. It is. A compound having a weight average molecular weight exceeding 100,000 is not preferable because it has a low degrading property, water reduction, and a low effect of reducing the viscosity of concrete, and is difficult to produce due to high viscosity.

Moreover, the copolymer used as the main component of the Noro reducing agent of this invention can be obtained by superposing | polymerizing by a well-known method using a polymerization initiator. About this polymerization method, aqueous solution polymerization is preferable. In aqueous solution polymerization, persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate, hydrogen peroxide, and a water-soluble azo initiator can be used. In that case, sodium bisulfite, hydroxylamine hydrochloride, Accelerators such as thiourea and sodium hypophosphite can also be used in combination.
A chain transfer agent such as thioglycolic acid or mercaptoethanol can also be used.

The copolymer that is the main component of the Noro reducing agent of the present invention may be a copolymer that is substantially composed only of the monomers (a) and (b). Or in the range which does not impair the effect of this invention, in addition to the said monomer (a) (b), you may copolymerize the monomer (u) which can be copolymerized.
Examples of the monomer (c) that can be used in combination include acrylonitrile, acrylamide, methacrylamide, vinyl acetate, acrylic acid, methacrylic acid, sodium allyl sulfonate, sodium methallyl sulfonate, and the like.

The ratio of the monomer (a), the monomer (b) and the monomer (c) in the monomer mixture for obtaining the copolymer as the main component of the Noro reducing agent of the present invention is Body (A) / Monomer (A) / Monomer (U) = (50 to 99) / (1 to 50) / (0 to 30) (weight ratio) Properties, excellent viscosity of concrete, monomer (a) / monomer (b)
/ Monomer (U) = (80 to 95) / (5 to 20) / 0 (weight ratio) is particularly excellent.

The Noro reducing agent of this invention contains the polyether compound shown by Formula (3) other than the said copolymer.
R ⁶ and R ^{7 in} the formula (3) are a hydrogen atom or a functional group derived from a hydrocarbon having 1 to 22 carbon atoms, and examples of the functional group derived from a hydrocarbon having 1 to 22 carbon atoms include a methyl group, an ethyl group, Propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group Group, isotridecyl group, tetradecyl group, hexadecyl group, isocetyl group, octadecyl group, isostearyl group and other aliphatic saturated hydrocarbon groups; allyl group, oleyl group and other aliphatic unsaturated hydrocarbon groups; cyclohexyl group, methylcyclohexyl group Alicyclic saturated hydrocarbon group such as cycloaliphatic unsaturated hydrocarbon group such as cyclopentenyl group and cyclohexenyl group; Group, benzyl group, cresyl group, butylphenyl group, dibutylphenyl group, octylphenyl group, nonylphenyl group, dodecylphenyl group, dioctylphenyl group, dinonylphenyl group, α-methylbenzylphenyl group, etc. Or substituted aromatic hydrocarbon group; etc., and these may be used alone or in combination of two or more. Preferably, the sum of carbon numbers of R ⁶ and R ⁷ is 12-40.

A ³ O and A ⁵ O in the formula (3) are oxyalkylene groups having 3 to 4 carbon atoms, and are an oxypropylene group, an oxybutylene group, an oxytrimethylene group, a 1,2-oxybutylene group, 1,3- Examples thereof include an oxybutylene group, a 2,3-oxybutylene group, and an oxytetramethylene group, and one type or two or more types may be bonded together in any block or random manner.
A ⁴ O and A ⁶ O are oxyalkylene groups having 2 carbon atoms, and examples thereof include oxyethylene groups. s and u are the number of added moles of an oxyalkylene group having 3 to 4 carbon atoms, s = 0 to 100, u = 0 to 100, s + u = 10 to 100, and preferably s + u = 10 to 50. If the value of s + u exceeds 100, the resulting compound has a high viscosity, which makes it difficult to produce. t and v are the number of added moles of the oxyalkylene group having 2 carbon atoms, t = 0 to 15, v = 0 to 15, t + v = 0 to 15, and preferably t + v = 0 to 10.

  In the polyether compound represented by the formula (3) of the present invention, the cloud point of a 1% aqueous solution is preferably 20 ° C. or less, and more preferably 10 ° C. or less. When the cloud point of a 1% aqueous solution exceeds 20 ° C., the compatibility with the copolymer of the present invention is good, but the effect of reducing the roughness of the present invention is not exhibited, and the compressive strength is lowered.

  As the Noro reducing agent of the present invention, a solution in which the above copolymer and the polyether compound represented by the formula (3) are mixed is preferably used. The mixing ratio of the copolymer and the polyether compound is preferably a copolymer / polyether compound = 95.00 to 99.99 / 0.01 to 5.00 by weight.

The Noro reducing agent of the present invention is preferably added in an amount of 0.05 to 1.0% by weight, particularly 0.2 to 0.8% by weight, based on the cement weight, as an active ingredient of the Noro reducing agent aqueous solution. If the amount is less than 0.05% by weight, the effect cannot be obtained, which is not preferable. If the amount exceeds 1.0% by weight, a setting delay is caused and early strength cannot be obtained.
The method of use can be used after dissolving in water used for concrete and diluting it, and can be used at the same time as pouring water, or added between pouring and kneading. It can be used, and it can also be used after being added to concrete once kneaded.

  The Noro reducing agent of the present invention can be used in combination with other additives or additives as required, as long as the effect is not impaired. Other additives include, for example, other water reducing agents such as naphthalene sulfonic acid formaldehyde condensate salt, melamine sulfonic acid formaldehyde condensate salt, lignin sulfonic acid salt, aromatic amino sulfonic acid formaldehyde condensate salt, air Entraining agent, separation reducing agent, thickening agent, waterproofing agent, setting retarding agent, setting accelerator, swelling agent, drying shrinkage reducing agent, rust preventive agent, foaming agent, foaming agent, AE agent, surfactants, etc. Can be mentioned. Examples of other additives include high-strength materials, high-strength admixtures, and ultrahigh-strength admixtures.

As the cement used for the high-strength centrifugal molded body according to the present invention, it is usually preferable to use one or more of Portland cement, silica fume cement, or blast furnace cement of early strength or ultra-early strength, and preferably two or more types. There is no particular limitation on the combination in this case. Moreover, the amount of cement in 1 m ^{3 of} concrete is preferably 450 to 600 kg, and if it is less than 450 kg, the amount of cement can be reduced even if the noro reducing agent of the present invention is used at maximum, but this is not preferable because the early strength is lowered, and exceeds 600 kg. This is not preferable because compaction becomes difficult and the effect of reducing rolls decreases. More preferably, it is 450-550 kg. Further, the water cement ratio is preferably 18 to 40% by weight, more preferably 20 to 35% by weight, and particularly preferably 20 to 28% by weight.

The fine aggregate used in the high-strength centrifugal molded body according to the present invention is not limited to the production area, and mountain sand, river sand, sea sand, crushed sand, etc. can be used, and one or more of these are used. May be. The coarse aggregate ratio (FM) of the fine aggregate is preferably 2.30 to 3.10, since the effect of reducing noro of the present invention is sufficiently exhibited, more preferably 2.50 to 3.00. The amount of fine aggregate in 1 m ^{3 of} concrete is preferably 500 to 800 kg, more preferably 550 to 750 kg. The coarse aggregate is not limited to the production area, and crushed stone, river gravel, etc. can be used, and one or more of these may be used. The amount of coarse aggregate in concrete 1 m ³ is preferably 900～1300Kg, more preferably 1000～1200Kg. The fine aggregate ratio is preferably 30 to 50% by volume, more preferably 34 to 46% by volume.

  In addition, the ratio of materials used for the high-strength centrifugal molded body according to the present invention, that is, the ratio of water, cement, fine aggregate, coarse aggregate, and other admixtures is the weight ratio in concrete: water: cement: fine bone Material: Coarse aggregate: Other admixture = 8-24: 45-60: 50-80: 90-130: 0-5, preferably water: cement: fine aggregate: coarse aggregate: other admixture = 9-16: 45-55: 55-75: 100-120: 0-3.

  In order to produce a high-strength centrifugal molded body according to the present invention, first, the above components and other optional components are added and mixed according to a conventional method to prepare concrete, and the concrete is placed in a desired mold and centrifuged. Mold with pressure. The concrete temperature at the time of concrete adjustment is preferably 10 to 40 ° C., and more preferably 20 to 35 ° C., since the effect of reducing the roughness of the present invention is sufficiently exhibited. Centrifugal force conditions can be 3 to 40 G for 5 to 30 minutes. Initially, the centrifugal force is made uniform by applying centrifugal force at a low rotation speed, and then centrifugal force is applied at medium and high speeds. It is preferable to form the concrete by spending time. After such centrifugal molding is completed, the molded body is allowed to stand at room temperature for 2 to 3 hours and then pre-cured, followed by atmospheric steam curing. In normal pressure steam curing, the temperature of the steam is gradually increased at a heating rate of 10 to 30 ° C./hr, held at 60 to 75 ° C. for about 2 to 4 hours, then naturally cooled, and the molded body is demolded. .

  Hereinafter, the present invention will be described with reference to examples. The structural formula of the compound represented by the formula (1), the structural formula of the compound represented by the formula (2), the copolymer composition and the weight average molecular weight are shown in Table 1, and the structure of the compound represented by the formula (3) The formula is shown in Table 2.

(Production Example 1)
After taking 58 g (1.0 mol) of allyl alcohol and 1.0 g of sodium methoxide as a catalyst in a 5 liter pressurized reactor and replacing the air in the system with nitrogen gas, 1320 g (30. 0 mol) and 116 g (2.0 mol) of propylene oxide in advance were gradually injected at a pressure of about 0.05 to 0.5 MPa (gauge pressure) to carry out an addition reaction. It cooled to 60 degreeC after completion | finish of reaction.
Subsequently, 1133 g of water and 166.6 g (1.7 mol) of maleic anhydride were added to the reaction solution kept at 60 ° C., and 38.8 g (0.17 mol) of ammonium persulfate as a polymerization initiator at 35 ° C. After replacing the air in the system with nitrogen gas, the reaction was carried out at 60 ± 2 ° C. for 10 hours. After completion of the polymerization reaction, 283 g of a 48% aqueous sodium hydroxide solution (3.4 mol as sodium hydroxide) was added to neutralize, and 1397 g of water was further added to obtain a 40% aqueous solution of the copolymer.

(Production Example 2)
After taking 58 g (1.0 mol) of allyl alcohol and 1.0 g of sodium methoxide as a catalyst in a 5 liter pressurized reactor, and replacing the air in the system with nitrogen gas, 1452 g (33. 0 mol) was gradually injected at about 0.05 to 0.5 MPa (gauge pressure) to carry out the addition reaction. After completion of the reaction, the reaction solution was cooled to 60 ° C. or lower, and 647 g of water was added to the reaction solution to obtain a 70% aqueous solution of allyl alcohol ethylene oxide adduct. Transfer the entire 70% aqueous solution of allyl alcohol ethylene oxide adduct obtained in a 5 liter pressurized reactor to a 5 liter flask equipped with a stirrer, thermometer, nitrogen gas inlet tube, dropping funnel and reflux condenser. The atmosphere was replaced with nitrogen and heated to 95 ± 5 ° C. in a nitrogen atmosphere. Thereafter, an aqueous solution obtained by dissolving 186.2 g (1.9 mol) of maleic anhydride, 14.4 g (0.1 mol) of sodium allylsulfonate and 45.2 g (0.19 mol) of sodium persulfate in 524 g of water was added for 2 hours. Added at. After completion of the addition, the temperature in the reaction vessel was maintained at 95 ± 5 ° C. for another 2 hours to complete the polymerization reaction. After completion of the polymerization reaction, 507 g of a 30% aqueous sodium hydroxide solution (3.8 mol as sodium hydroxide) was added for neutralization, and 1336 g of water was further added to obtain a 40% aqueous solution of the copolymer.

(Production Examples 3 to 4)
A reaction was carried out in the same manner as in Example 1 except that the compound of formula (1) and the compound of formula (2) were changed as shown in Table 1, to obtain an aqueous solution of a copolymer. However, in Production Example 3, a potassium hydroxide aqueous solution was used instead of the sodium hydroxide aqueous solution.

(Production Example 5)
Into a 5 liter pressure reactor, 268 g (1.0 mol) of oleyl alcohol and 3.0 g of potassium hydroxide as a catalyst were taken, the air in the system was replaced with nitrogen gas, and 2204 g of propylene oxide (38 ° C. at 90 to 110 ° C.) Mole) was gradually injected at about 0.05 to 0.5 MPa (gauge pressure) to carry out the addition reaction. Subsequently, 220 g (5.0 mol) of ethylene oxide was gradually injected at about 0.05 to 0.5 MPa (gauge pressure) at 100 to 120 ° C. to carry out an addition reaction. After completion of the reaction, potassium hydroxide in the system was neutralized with 38% hydrochloric acid to obtain a polyether compound having a 1% aqueous solution cloud point of 5 ° C.

(Production Example 6)
In a 5 liter pressurized reactor, 300 g (1.0 mol) of polyethylene glycol (addition mole of ethylene oxide, about 7 mol) and 1.0 g of potassium hydroxide as a catalyst were taken, and the air in the system was replaced with nitrogen gas. Addition reaction was carried out by gradually injecting 1508 g (26.0 mol) of propylene oxide at about 0.05 to 0.5 MPa (gauge pressure) at ˜110 ° C. After completion of the reaction, the system temperature was lowered to 60 ° C. or lower, and potassium hydroxide was neutralized with 38% hydrochloric acid. After dehydration, 1.0 g of p-toluenesulfonic acid and 568 g (2.0 mol) of stearic acid are added, and dehydration reaction is performed at 140 ° C. for 3 hours, and a 1% aqueous solution cloud point is 0 ° C. or less. Got.

(Production Example 7)
After taking 1740 g (1.0 mol) of polypropylene glycol (addition mole of propylene oxide, about 30 moles) and 1.0 g of potassium hydroxide as a catalyst in a 5 liter pressurized reactor, and replacing the air in the system with nitrogen gas, Addition reaction was carried out by gradually injecting 176 g (4.0 mol) of ethylene oxide at about 0.05 to 0.5 MPa (gauge pressure) at 100 to 120 ° C. After completion of the reaction, the system temperature was lowered to 60 ° C. or lower, and potassium hydroxide was neutralized with 38% hydrochloric acid to obtain a polyether compound having a 1% aqueous solution cloud point of 23 ° C.

(Production Example 8)
Polyoxyethylene (n = 10) monoallyl monomethyl ether 512 g (1 mol) and maleic anhydride 98 g (1 mol) were added to a 2 liter flask equipped with a stirrer, thermometer, nitrogen gas inlet tube, dropping funnel and reflux condenser. ), 10.4 g (0.1 mol) of styrene and 200 g of toluene were weighed. In a nitrogen gas atmosphere, 2.16 g (0.01 mol) of tert-butylperoxy-2-ethylhexanoate as a polymerization initiator dissolved in 86.4 g of toluene was placed in a flask at 85 ± 2 ° C. It was dripped in 3 hours. After completion of dropping, the reaction was further carried out at 85 ± 2 ° C. for 3 hours. When toluene was distilled off under reduced pressure, and the kinematic viscosity of the obtained copolymer was measured, it was 352 mm ² / s at 100 ° C. Thereafter, 940 g of ion-exchanged water was added to obtain a 40% aqueous solution of the target copolymer.

The cloud point of a 1% aqueous solution was measured by the following method.
(Measurement method of cloud point of 1% aqueous solution)
1 g of the test sample was weighed into a 300 ml Erlenmeyer flask, 99 g of ion-exchanged water was added, and the mixture was heated or cooled and stirred to dissolve completely to obtain a uniform solution. Subsequently, a part of the solution was put in a test tube to a height of about 40 mm, and a thermometer was put therein. When the solution is clear at room temperature, heat it up with a thermometer until it is about 2-3 ° C higher than the temperature at which cloudiness occurs. Measured and taken as 1% aqueous solution cloud point. Also, when the solution is cloudy at room temperature, cool with good stirring until the solution becomes clear, gradually warm up to a temperature that causes turbidity while stirring again, and then gradually stir The temperature when cooled and became transparent was measured as the cloud point of 1% aqueous solution.
The components of each production example were blended as shown in Table 3 to obtain blends of the respective blend examples.

(Formulation example 1)
1000 g of a 40% aqueous solution of the copolymer produced in Production Example 1 (400 g as a copolymer) in a 2 liter flask equipped with a stirrer, a thermometer and a nitrogen gas inlet tube, and the polyether compound 8 produced in Production Example 5 .2 g was weighed, stirred and mixed for 30 minutes to obtain an aqueous solution for reducing agent.

(Formulation examples 2 to 6)
In the same manner as in Formulation Example 1, blending was carried out according to the compounds in Table 3 and the weight% to obtain a Noro reducing agent aqueous solution.
(Combination Example 7: Blending of (High Performance) Water Reducing Agent / Metal Salt of Copolymer of α-Olefin and Unsaturated Carboxylic Acid / Coagulation Accelerator Described in JP-A-9-309755)
The blending was carried out with reference to (Invention Example 1-12) of JP-A-9-309755. That is, in a 1 L flask equipped with a stirrer, a thermometer, and a nitrogen gas introduction tube, 720 g of Floric PSR (manufactured by Floric Co., Ltd., lignin sulfonic acid-naphthalene sulfonic acid cocondensate water-soluble salt), isobutylene-maleic acid co-polymer Combined Na salt (α-olefin monomer ratio: 50 mol%, weight average molecular weight: 1.3 million, neutralization degree 0.6) 8.0 g and sodium formate 50 g are weighed, mixed for 30 minutes, and mixed with a Noro reducing agent aqueous solution. Obtained.

(Examples 1-4 and Comparative Examples 1-4)
45 L / batch of concrete raw materials were mixed under the blending conditions shown in Table 4 and kneaded with a forced mixer for 90 seconds, and the slump of the obtained concrete was measured to determine workability. The temperature of the obtained concrete was 25-27 degreeC. In addition, the Noro reducing agent was used as a part of unit water quantity. Moreover, in Table 4, the addition amount of Noro reducing agent shows the ratio with respect to the unit cement amount. Next, as a specimen for strength test, 15.5 kg of the concrete obtained above was filled in a small mold for centrifugal molding having a diameter of 20 cm and a length of 30 cm, and the centrifugal force was 3 G for 2 minutes, 10 G for 2 minutes, Centrifugal molding was carried out at 35 G for 9 minutes. The compaction property of the concrete at that time was judged, and the amount of discharge was measured. Next, pre-cured at room temperature for 3 hours, then heated at a rate of temperature increase of 20 ° C./hr and kept at 75 ° C. for 3 hours for steam curing, natural cooling, and removal after 24 hours. The compressive strength at the time of molding was measured. Thereafter, air curing was performed, and the strength was measured for 7 days. These test results are shown in Table 5. Six test specimens for strength test were prepared, the average discharge amount was 6 and the compressive strength was 3 after 24 hours and 3 after 7 days of age.

＊１ ノロ低減剤添加量は、固形分あたりの添加量を記載。
＊２ ノロ低減剤の替わりにナフタレンスルホン酸系減水剤「マイティ１５０」を使用。
＊３ 比重：２．５８、ＦＭ：２．８６
＊４ 比重：２．６４

* 1 The additive amount of Noro reducing agent is the amount added per solid content.
* 2 Use naphthalene sulfonic acid water reducing agent “Mighty 150” instead of Noro reducing agent.
* 3 Specific gravity: 2.58, FM: 2.86
* 4 Specific gravity: 2.64

In Table 5, in Comparative Example 4, naphthalene sulfonic acid water reducing agent “Mighty 150” was used instead of Noro reducing agent (* 1). The evaluation criteria for “workability and concrete tightening” are as follows (* 2).
“◎”: Low viscosity, good workability, and compacted on average.
“O”: Although compacted on average, the viscosity is slightly high and workability is slightly poor.
Or although viscosity is low and workability | operativity is good, the smoothness of an inner surface or an outer surface is a little bad.
“Δ”: The smoothness of the inner or outer surface is slightly poor, the viscosity is high, and the workability is poor.
“X”: Viscosity is high, workability is difficult, and smoothness of the inner surface or outer surface is poor.

(Examples 5-8 and Comparative Examples 5-7)
As a concrete raw material, the one shown in Table 6 was used, and the amount added was changed to the amount shown in Table 7. Slump, workability, concrete compaction, noro discharge, 24 hours later The compressive strength of 7 days after material age was measured. The temperature of the obtained concrete was 21-23 degreeC. The results are shown in Table 7.

  In Comparative Example 7, naphthalene sulfonic acid water reducing agent “Mighty 150” was used instead of Noro reducing agent (* 1). The evaluation criteria for “workability and concrete tightening” are as described above (* 2).

(Examples 9-12 and Comparative Examples 8-10)
As a concrete raw material, slump, workability, concrete compaction, noro discharge, 24 hours later, except that the materials shown in Table 8 were used and the addition amount was as shown in Table 9. The compressive strength of 7 days after material age was measured. The temperature of the obtained concrete was 30-32 degreeC. The results are shown in Table 9.

  In Comparative Example 10, naphthalenesulfonic acid water reducing agent “Mighty 150” was used instead of Noro reducing agent (* 1). The evaluation criteria for “workability and concrete tightening” are as described above (* 2).

From the above results, the comparison between Examples 1 to 4 and Comparative Examples 1, 3, and 4, the comparison between Examples 5 to 8 and Comparative Examples 5 to 7, and the comparison between Examples 9 to 12 and Comparative Examples 8 to 10 The addition of the Noro reducing agent of the present invention improves workability and concrete tightening, increases the early compressive strength, and reduces Noro emissions. When Example 1 and Comparative Example 3, Example 5 and Comparative Example 6, and Example 9 and Comparative Example 9 are compared, the discharge capacity of Noro is almost the same, but the discharge weight of Noro, that is, the specific gravity of Noro is the present invention. Example 1, Example 5 and Example 9 are smaller. If there is a lot of powder in Noro, the specific gravity of Noro itself will increase, the Noro discharge weight will increase, and if there is a large amount of powder in Noro, the compressive strength of the resulting product will decrease, With the Noro reducing agent of the present invention, the powder content in the concrete is not discharged so much, and water can be mainly squeezed to increase the compressive strength.

Claims (1)

Monomer (a) represented by the following formula (1) 50 to 99% by weight, monomer represented by the following formula (2) or maleic anhydride (ii) 1 to 50% by weight, and other copolymerizable monomers A copolymer obtained by polymerizing 0 to 30% by weight of monomer (c) and a polyether compound represented by the following formula (3) and having a cloud point of 1% aqueous solution of 20 ° C. or less Noro reducing agent characterized by the above.

(However, R ¹ , R ² and R ³ each independently represents a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom, and A ¹ O represents one or two kinds of oxyalkylene groups having 2 to 3 carbon atoms. In the above, 50 mol% or more is an oxyalkylene group having 2 carbon atoms, and in the case of 2 or more types, it may be block or random, and p = 21 to 100 and q = 0 to 2.)

(Wherein, ^{M 1} is represents a hydrogen atom, an alkali metal, alkaline earth metal, ammonium or organic ammonium, X represents a -OM ² or _{^{-Y- (A 2 O) r R}} 5, M 2 represents a hydrogen atom, Represents an alkali metal, an alkaline earth metal, ammonium or organic ammonium, Y represents an ether group or an imino group, and A ² O represents one or more of oxyalkylene groups having 2 to 3 carbon atoms, and two or more thereof. In this case, it may be block or random, and R ⁵ is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, and r = 1 to 50.)

(However, R ⁶ and R ⁷ represent a hydrogen atom or a functional group derived from a hydrocarbon having 1 to 22 carbon atoms, and A ³ O and A ⁵ O are one or two of oxyalkylene groups having 3 to 4 carbon atoms. In the case of two or more species, it may be block or random, and A ⁴ O and A ⁶ O are oxyalkylene groups having 2 carbon atoms, s = 0 to 100, u = 0 to 100, s + u = 10-100, t = 0-15, v = 0-15, t + v = 0-15.)