JP2022085134A - Cement admixture molded product - Google Patents

Abstract

To provide a cement admixture molded product that can be fluidized after a lapse of a predetermined time, has high self-filling property, and is easy to knead.SOLUTION: The cement admixture molded product satisfies following conditions (A) to (D). Condition (A): cellulose-based carrier A is contained. Condition (B): polycarboxylic acid-based copolymer B is contained. Condition (C): the longest long side L of the cement admixture molded product is 5 cm or more and 15 cm or less. Condition (D): the shortest short side D of the cement admixture molded product is 1 cm or more and 10 cm or less.SELECTED DRAWING: None

Description

The present invention relates to a cement admixture molded product.

In recent years, at concrete construction sites where labor shortages have been touted, concrete with high self-filling ability, which can improve workability by omitting casting work, is desired for the purpose of labor saving.

A thickener is usually added to such highly self-filling concrete. However, in general, thickeners have the property of being poorly soluble in water. Therefore, when a large amount of thickener is used to increase the concentration (viscosity), a powdered thickener and a powder dispersant may be used due to the correction of the concrete composition (for example, patent). See Document 1).

Japanese Patent No. 5623847

At present, powdering dispersants requires advanced techniques. Further, there is a problem that the performance of the powder dispersant that can be mixed is inferior to that of the liquid dispersant, and there is a problem that the types of the powder dispersant are limited. Therefore, when a powder dispersant is used, it may be difficult to transport the base concrete over a long distance (long time), and if the slump loss is large, it may be difficult to maintain sufficient fluidity and high self-filling property for a long time.

Further, Patent Document 1 discloses that a thickener powder or the like is sealed in a soluble bag-like material, and the bag is mixed with a drum-type mixer. However, the soluble bag may not be completely dissolved. Therefore, there is a problem that a part of the soluble bag-like material is wrapped around the mixer and a part of the soluble bag-like material flows into the concrete.

An object of the present invention is to provide a cement admixture molded product which can be fluidized after a lapse of a predetermined time, has high self-filling property, and is easy to knead.

As a result of diligent studies on the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by processing a floc-like cement admixture containing a predetermined component in a cellulosic carrier into a specific molded product. We have found and completed the present invention.

・・・（１）
（前記一般式（１）中、Ｒ^１～Ｒ^３は、それぞれ独立に、水素原子又は炭素原子数１～３のアルキル基を示す。ｐは、０～２の整数を示す。ｑは、０又は１を示す。Ａ^１Ｏは、同一若しくは異なっていてもよい、炭素原子数２～１８のオキシアルキレン基を示す。ｎは、１～３００の整数を示す。Ｒ^４は、水素原子、又は炭素原子数１～３０の炭化水素基を示す。）

・・・（２）
（前記一般式（２）中、Ｒ^５～Ｒ^７は、それぞれ独立に、水素原子、－ＣＨ_３、又は－（ＣＨ_２）_ｒＣＯＯＭ^２を示す。但し、－（ＣＨ_２）_ｒＣＯＯＭ^２は、－ＣＯＯＭ^１又は他の－（ＣＨ_２）_ｒＣＯＯＭ^２と無水物を形成していてもよく、無水物を形成する場合はＭ^１、Ｍ^２は存在しない。Ｍ^１及びＭ^２は、同一若しくは異なっていてもよい、水素原子、アルカリ金属、アルカリ土類金属、アンモニウム基、アルキルアンモニウム基、又は置換アルキルアンモニウム基を示す。ｒは、０～２の整数を示す。） That is, the present inventors provide the following [1] to [5].
[1] A cement admixture molded product characterized by satisfying the following conditions (A) to (D).
Condition (A): The cellulosic carrier A is contained.
Condition (B): Contains the polycarboxylic acid-based copolymer B.
Condition (C): The longest long side L of the cement admixture molded product is 5 cm or more and 15 cm or less.
Condition (D): The shortest short side D of the cement admixture molded product is 1 cm or more and 10 cm or less.
[2] The polycarboxylic acid-based copolymer B becomes a structural unit (I) derived from a monomer represented by the following general formula (1) and a monomer represented by the following general formula (2). It is a copolymer having at least two kinds of structural units selected from the group consisting of the structural unit (II) from which it is derived and the structural unit (III) derived from the monomer represented by the following general formula (3). , [1]. The cement admixture molded product according to [1].

... (1)
(In the above general formula (1), R ¹ to R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. P represents an integer of 0 to 2, and q represents 0. Or 1. A ¹ O indicates an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. N indicates an integer of 1 to 300. R ⁴ is a hydrogen atom or a hydrogen atom. Shows a hydrocarbon group having 1 to 30 carbon atoms.)

... (2)
(In the general formula (2), R ⁵ to R ⁷ independently represent a hydrogen atom, -CH ₃ , or-(CH ₂ ) _r COM ² , where-(CH ₂ ) _r COM ² is used. , -COOM ¹ or other- (CH ₂ ) _r COMM ² may form anhydrate, and when forming an anhydride, M ¹ and M ² do not exist. M ¹ and M ² are the same. Alternatively, it indicates a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an alkylammonium group, or a substituted alkylammonium group, which may be different. R indicates an integer of 0 to 2).

・・・（３）
（前記一般式（３）中、Ｒ^８～Ｒ^１０は、それぞれ独立に、水素原子、又は炭素原子数１～３のアルキル基を示す。Ｒ^１１は、ヘテロ原子を含んでいてもよい炭素原子数１～４の炭化水素基を示す。ｓは、０～２の整数を示す。）
〔３〕前記セルロース系担体Ａ１００重量部に対して、前記ポリカルボン酸系共重合体Ｂを１０～５００重量部の範囲で含むことを特徴とする、〔１〕～〔２〕いずれかに記載のセメント混和剤成形物。
〔４〕増粘剤Ｃをさらに含むことを特徴とする、〔１〕～〔３〕いずれかに記載のセメント混和剤成形物。
〔５〕消泡剤Ｄをさらに含むことを特徴とする、〔１〕～〔４〕いずれかに記載のセメント混和剤成形物。

... (3)
(In the above general formula (3), R ⁸ to R ¹⁰ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ¹¹ is a carbon atom which may contain a hetero atom. It indicates a hydrocarbon group of the number 1 to 4. s indicates an integer of 0 to 2.)
[3] The description according to any one of [1] to [2], wherein the polycarboxylic acid-based copolymer B is contained in the range of 10 to 500 parts by weight with respect to 100 parts by weight of the cellulosic carrier A. Cement admixture molded product.
[4] The cement admixture molded product according to any one of [1] to [3], which further contains a thickener C.
[5] The cement admixture molded product according to any one of [1] to [4], which further contains an antifoaming agent D.

According to the present invention, it is possible to provide a cement admixture molded product which can be fluidized after a lapse of a predetermined time, has high self-filling property, and is easy to knead.

Hereinafter, the present invention will be described in detail according to the preferred embodiment thereof. Unless otherwise specified, the description "AA to BB%" means "AA% or more and BB% or less".

The present invention is a cement admixture molded product characterized in that the following conditions (A) to (D) are satisfied.
Condition (A): The cellulosic carrier A is contained.
Condition (B): Contains the polycarboxylic acid-based copolymer B.
Condition (C): The longest long side L of the cement admixture molded product is 5 cm or more and 15 cm or less.
Condition (D): The shortest short side D of the cement admixture molded product is 1 cm or more and 10 cm or less.

(Cellulose-based carrier A)
The cellulosic carrier A can be used without particular limitation as long as it absorbs water when immersed in water and contains cellulose as a main component, which exhibits water retention. Above all, it is preferable to contain powdered cellulose.

The pulp raw material used to obtain the above-mentioned powdered cellulose is not particularly limited, such as hardwood-derived pulp, softwood-derived pulp, linter-derived pulp, and non-wood-derived pulp. Above all, it is preferable to use pulp derived from coniferous trees. Compared with hardwood-derived pulp, softwood-derived pulp has a longer average fiber length and a wider average fiber width, and is therefore excellent in water absorption, which is preferable.

Examples of pulp derived from coniferous trees include spruce, spruce, spruce, black pine, todomatsu, himekomatsu, ichii, cat, picea polita, spruce, inumaki, fir, sawara, spruce, asunaro, hiba, tsuga, spruce, hinoki, and red pine. , Spruce, Lawson hinoki, Douglas fur, Sitka spruce, Radiata pine, Eastern spruce, Eastern white pine and related tree species thereof. Among these, spruce, larch, larch, black pine, fir, cypress, red pine, douglas fur, and radiata pine are preferable, and spruce, larch, black pine, douglas fur, and radiata pine are more preferable. These softwood-derived pulps may be used alone or in any combination of two or more.

The pulping method (steaming method) is not particularly limited, and examples thereof include a sulfite cooking method, a craft cooking method, a soda / quinone cooking method, and an organosolve cooking method. Among these, the kraft cooking method is preferable from the viewpoint of the environment.

The pulp raw material may be either a wet pulp in the form of a slurry or a dry pulp in which the slurry is dehydrated and dried into a sheet. However, considering the ease of handling, it is preferable to use dry pulp (pulp sheet).

The powdered cellulose can be obtained by pulverizing a pulp obtained by acid-hydrolyzing a pulp raw material with a mineral acid such as hydrochloric acid, sulfuric acid or nitric acid, or by mechanically pulverizing a pulp not subjected to the acid hydrolysis treatment.

The ultimate viscosity of the diluted cellulose solution obtained in this manner according to the method for measuring the number of extreme viscosity (copper ethylenediamine method) specified in JIS P 8215 is preferably 100 to 1800. 100 to 900 is more preferable, and 150 to 600 is even more preferable.

The lower limit of the average degree of polymerization of powdered cellulose is preferably 200 or more. The upper limit is preferably 3000 or less. When the average degree of polymerization of powdered cellulose is 200 or more, water absorption can be exhibited and workability can be improved. On the other hand, when the average degree of polymerization of powdered cellulose is 3000 or less, the water absorption does not become excessively large and the workability can be improved. Therefore, the average degree of polymerization of powdered cellulose is preferably 200 to 3000, more preferably 200 to 1500, and even more preferably 300 to 1000.

The average degree of polymerization of powdered cellulose is a value measured by the following method. Extreme viscosity was measured using a fully automatic viscosity measurement system for pulp and polymer RPV-1 (manufactured by RHEOTEK), and described in "VISCOSITY MEASUREMENTS OF CELLLOUSOSE / SO ₂ -AMINE DIMETHYLSULFOXIDE SOLUTION" (written by Isogai et al., 1998). η] = 0.909 × DP ^0.85 (Equation (2) in the document) can be derived from the equation.

The lower limit of the average particle size of the powdered cellulose is preferably 10 μm or more. The upper limit is preferably 90 μm or less. The larger the average particle size, the larger the amount of water absorption, but if the amount of water absorption is too large, it becomes sticky and the workability deteriorates. On the other hand, if the average particle size is small, the amount of water absorption is low, which is not preferable. Therefore, the average particle size of the powdered cellulose is preferably 10 to 90 μm.

The average particle size is a value measured under the following measurement conditions. A 0.5 g sample was collected in a 100 ml beaker, 60 ml of a 0.5% hexametaphosphate solution was added, and Dr. A measurement sample is prepared by processing with an ultrasonic processing device manufactured by Hielscher GmbH for 2 minutes under the condition of an output of 20%. As a measuring device, a laser diffraction type particle size distribution measuring device (Mastersizer 2000, Spectris Co., Ltd., manufactured by Malvern Business Headquarters) is used to measure the prepared measurement sample. As a measurement principle, a laser scattering method is used, the particle size distribution is expressed as an accumulation distribution, and the value at which the accumulation distribution is 50% is defined as the average particle size.

The lower limit of the apparent specific gravity of the powdered cellulose is preferably 0.1 g / cm ³ or more. The upper limit thereof is preferably 0.6 g / cm ³ or less. When the apparent specific gravity of the powdered cellulose is in the range of 0.1 to 0.6 g / cm ³ , it is suitable for obtaining the effect of having good workability and excellent dispersibility.

The apparent density is a value measured under the following measurement conditions. Put 10 g of the sample into a 100 ml graduated cylinder, tap the bottom of the graduated cylinder, continue until the height of the sample does not decrease, read the scale on the flattened surface, and measure the volume per 10 g of the sample. The apparent specific gravity can be calculated by calculating the weight per unit volume (1 cm ³ ) from the measured volume. The higher this value is, the more compact the powdered cellulose is.

The lower limit of the angle of repose of powdered cellulose is preferably 45 ° or more. The upper limit is preferably 65 ° or less. When the angle of repose of the powdered cellulose is in the range of 45 to 65 °, it is suitable for obtaining the effect of having good workability and excellent expression of dispersibility.

The angle of repose is a value measured under the following measurement conditions. The measurement is performed using a powder tester (PT-N type, manufactured by Hosokawa Micron Co., Ltd.), and the Angle Report value is used as the angle of repose. The value of the angle of repose is an index of powder fluidity, and the smaller this value is, the better the powder fluidity is.

The lower limit of the crystallinity of powdered cellulose is preferably 60% or more, more preferably 65% or more. The upper limit is preferably 90% or less, more preferably 85% or less. The crystallinity of powdered cellulose is mainly influenced by the raw material pulp and the production method. When the crystallinity is 60% or more, the supporting component may be liberated and easily dispersed when added to the kneaded product. On the other hand, when the crystallinity is 90% or less, the amount of water absorption can be secured. Therefore, the crystallinity of powdered cellulose is preferably 60 to 90%.

The crystallinity of powdered cellulose is a value obtained by measuring the X-ray diffraction of the sample. More specifically, the method of Segal et al. (L. Segal, JJ Grely, ether, Text. Res. J., 29, 786, 1959) and the method of Kamide et al. (K. Kamide et al, Polymer). J., 17, 909, 1985), with the diffraction intensity of 2θ = 4 ° to 32 ° in the diffraction diagram obtained from the X-ray diffraction measurement as the baseline, the diffraction intensity of the 002 surface and 2θ = 18 The crystallinity can be calculated by the following equation from the diffraction intensity of the amorphous portion at 5.5 °.

Xc = (I _002C -Ia) / I _002C x 100
Xc: Cellulose crystallinity (%)
I _002C : 2θ = 22.6 °, diffraction intensity of 002 surface Ia: 2θ = 18.5 °, diffraction intensity of amorphous part

The water absorption rate of the cellulosic carrier A before and after immersing the cellulosic carrier A in excess distilled water (hereinafter, also referred to as “hydration treatment”) is preferably 150% or more, more preferably 300% or more, and more preferably 500% or more. More preferred.

The absorption rate is a value calculated as follows. Disperse 1 g of the cellulosic carrier (B) before water treatment (humidity control at a temperature of 25 ° C. and a humidity of 50% for 3 hours) in 20 g of distilled water to obtain a sufficiently stirred slurry. The slurry is naturally filtered for 20 minutes using a 1G1 glass filter (Tokyo glass equipment, maximum pore size 100 to 120 μm) to obtain a cellulosic carrier (B) after water treatment remaining on the filter. The water absorption rate can be calculated by weighing the cellulosic carrier (B) before and after the water treatment and substituting it into the following formula.

Formula: (Weight after water treatment (g) -Weight before water treatment (g)) / Weight before water treatment (g) x 100

When the water absorption rate of the cellulosic carrier A is within the above range, an excellent water retention property is exhibited when impregnated with a supporting component described later, and a stably supported floc cement admixture (F) is prepared. Can be.

The lower limit of the alkali elution rate of powdered cellulose is usually 0.1% or more. The upper limit is preferably 12.0% or less, more preferably 7.0% or less, and even more preferably 5.0% or less. When the alkali elution rate of powdered cellulose exceeds 12.0%, the elution of cellulose decomposition products increases when used in the preparation of cement compositions under alkaline conditions, and dispersion in cement compositions such as fresh concrete. It is not preferable because it causes poor properties and a decrease in the reinforcing effect of the cement structure. Therefore, the alkali elution rate of the powdered cellulose is preferably 0.1 to 12.0%, more preferably 0.1 to 7.0%, and 0.1 to 5.0%. Is even more preferable.

In the present specification, the alkali elution rate is a value calculated by the formula: B / A × 100 (%). That is, the dry weight A of the powdered cellulose and the powdered cellulose were treated with an alkali (immersed in an alkaline solution of pH 13 at a temperature of 50 ° C. for 120 hours) and filtered through a 1G1 glass filter (manufactured by Tokyo Glass Equipment Co., Ltd.) (105 ° C.). It is a value calculated by substituting the dry weight B of the eluate contained in the filtrate (for 3 hours) into the above formula. More specifically, 5 g of powdered cellulose (dry weight A, 105 ° C. for 3 hours) and 100 ml of a sodium hydroxide aqueous solution adjusted to pH 13 are added to a mayonnaise bottle (200 ml) and sufficiently stirred to maintain a constant temperature of 50 ° C. Leave in the tank for 120 hours. Then, the dry weight B (3 hours at 105 ° C.) of the filtrate obtained by filtering with a 1G1 glass filter (manufactured by Tokyo Glass Equipment Co., Ltd.) was measured, and substituted into the formula: B / A × 100 to obtain an alkali elution rate. Calculate (%). The smaller this value is, the better the alkali resistance is.

(Polycarboxylic acid-based copolymer B)
The polycarboxylic acid-based copolymer B is supported on a cellulose-based carrier A and becomes a prototype of the cement admixture molded product of the present invention. Such a polycarboxylic acid-based copolymer B has a structural unit (I) derived from the monomer represented by the general formula (1) and a configuration derived from the monomer represented by the general formula (2). A copolymer having at least two structural units selected from the group consisting of the unit (II) and the structural unit (III) derived from the monomer represented by the general formula (3) is preferable.

(Constituent unit (I))
The structural unit (I) is a structural unit derived from the monomer represented by the general formula (1). In the general formula (1), R ¹ to R ³ independently represent an alkyl group having a hydrogen atom or a carbon atom number of 1 to 3. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group and an isopropyl group. The alkyl group having 1 to 3 carbon atoms may have a substituent (provided that the number of carbon atoms of the substituent is not included in the number of carbon atoms of the alkyl group). R ¹ is preferably a hydrogen atom. ^R2 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group. R ³ is preferably a hydrogen atom.

In the general formula (1), p represents an integer of 0 to 2. In the general formula (1), q represents 0 or 1. In the general formula (1), n represents an integer of 1 to 300.

In the general formula (1), A ¹ O represents an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. Examples of the oxyalkylene group (alkylene glycol unit) include an oxyethylene group (ethylene glycol unit), an oxypropylene group (propylene glycol unit), and an oxybutylene group (butylene glycol unit). Of these, an oxyethylene group and an oxypropylene group are preferable.

The above-mentioned "may be the same or different" means that when a plurality of A ¹ O are contained in the general formula (1) (when n is 2 or more), each A ¹ O is the same oxyalkylene group. It may mean that they may be different (two or more kinds) oxyalkylene groups from each other. As an embodiment in which a plurality of A ¹ O are contained in the general formula (1), an embodiment in which two or more kinds of oxyalkylene groups selected from the group consisting of an oxyethylene group, an oxypropylene group and an oxybutylene group are mixed is used. Can be mentioned. Among them, a mode in which an oxyethylene group and an oxypropylene group are mixed, a mode in which an oxyethylene group and an oxybutylene group are mixed, and a mode in which an oxyethylene group and an oxypropylene group are mixed are preferable. .. In the embodiment in which different oxyalkylene groups are mixed, the addition of two or more kinds of oxyalkylene groups may be block-like addition or random addition.

In the general formula (1), n is the average number of moles of oxyalkylene group added, represents an integer of 1 to 300, and an integer of 1 to 200 is preferable. The average number of moles added means the average value of the number of moles of the oxyalkylene group added to 1 mole of the monomer.

In the general formula (1), R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. ^R4 is preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and even more preferably a hydrogen atom or a methyl group. When the number of carbon atoms of R ⁴ is in this range, the number of carbon atoms does not become too large, so that the kneaded product can be dispersed well.

As a method for producing a monomer represented by the general formula (1), for example, an unsaturated alcohol such as allyl alcohol, methallyl alcohol, 3-methyl-3-butene-1-ol and alkylene oxide are added to 1 to 300. A method of adding moles can be mentioned.

Examples of the monomer produced by this method include (poly) ethylene glycol allyl ether, (poly) ethylene glycol metalyl ether, (poly) ethylene glycol 3-methyl-3-butenyl ether, and (poly) ethylene glycol. (Poly) propylene glycol allyl ether, (poly) ethylene glycol (poly) propylene glycol metallic ether, (poly) ethylene (poly) propylene glycol allyl ether, (poly) ethylene (poly) propylene glycol metallic ether, (poly) ethylene ( Poly) propylene glycol 3-methyl-3-butenyl ether, (poly) ethylene (poly) butylene glycol allyl ether, (poly) ethylene (poly) butylene glycol metallic ether, (poly) ethylene (poly) butylene glycol 3-methyl -3-Butenyl ether, methoxy (poly) ethylene glycol allyl ether, methoxy (poly) ethylene glycol metallicyl ether, methoxy (poly) ethylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) propylene Glycolallyl ether, methoxy (poly) ethylene (poly) propylene glycol metallic ether, methoxy (poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) butylene glycol allyl ether, Examples thereof include methoxy (poly) ethylene (poly) butylene glycol metallic ether and methoxy (poly) ethylene (poly) butylene glycol 3-methyl-3-butenyl ether.

Among these, from the viewpoint of the balance between hydrophilicity and hydrophobicity, (poly) ethylene glycol (meth) allyl ether, (poly) ethylene glycol (poly) propylene glycol (meth) allyl ether, (poly) ethylene (poly) propylene Glycol (meth) allyl ether, (poly) ethylene glycol 3-methyl-3-butenyl ether, and (poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl ether are preferred.

The term "(meth) allyl" as used herein means to include both the concepts of allyl and methallyl.

Other methods for producing the monomer represented by the general formula (1) include unsaturated monocarboxylic acids such as (meth) acrylate, (poly) ethylene glycol, and (poly) ethylene (poly) propylene glycol. , (Poly) ethylene (poly) butylene glycol, methoxy (poly) ethylene glycol, methoxy (poly) ethylene (poly) propylene glycol, methoxy (poly) ethylene (poly) butylene glycol and other (poly) alkylene glycols. There is a method to make it.

Examples of the monomer produced by this method include (poly) ethylene glycol (meth) acrylate, (poly) ethylene (poly) propylene glycol (meth) acrylate, and (poly) ethylene (poly) butylene glycol (meth). (Poly) alkylene glycol (poly) alkylene glycol such as acrylate, methoxy (poly) ethylene glycol (meth) acrylate, methoxy (poly) ethylene (poly) propylene glycol (meth) acrylate, methoxy (poly) ethylene (poly) butylene glycol (meth) acrylate Meta) acrylate can be mentioned.

Among these, (poly) alkylene glycol (meth) acrylate and methoxy (poly) ethylene glycol (meth) acrylate are preferable, and methoxy (poly) ethylene glycol (meth) acrylate is more preferable.

The term "(meth) acrylate" as used herein means to include both the concepts of acrylate and methacrylate.

When the polycarboxylic acid-based copolymer B has a constituent unit (I), it may have only one constituent unit (I), and two or more constituent units derived from different monomers (I). I) may have.

(Constituent unit (II))
The structural unit (II) is a structural unit derived from the monomer represented by the general formula (2). In the general formula (2), R ⁵ to R ⁷ independently represent a hydrogen atom, −CH ₃ or − (CH ₂ ) _r COM ² . In addition, (CH ₂ ) _r COMM ² may form an anhydrate with each other-COOM ¹ or another- (CH ₂ ) _r COMM ² , and in the case of forming an anhydrate, M ¹ and M ² are used. not exist. R ⁵ is preferably a hydrogen atom. R ⁶ is preferably a hydrogen atom, a methyl group or (CH ₂ ) _r COMM ² . R ⁷ is preferably a hydrogen atom.

M ¹ and M ² are hydrogen atoms, alkali metals, alkaline earth metals, ammonium groups, alkylammonium groups or substituted alkylammonium groups, which may be the same or different. It is preferable that M ¹ and M ² are independently hydrogen atoms, alkali metals, and alkaline earth metals, respectively.

r represents an integer of 0 to 2, preferably 0 or 1, more preferably 0.

Examples of the monomer represented by the general formula (2) include an unsaturated monocarboxylic acid-based monomer and an unsaturated dicarboxylic acid-based monomer. Specific examples of the unsaturated monocarboxylic acid-based monomer include acrylic acid, methacrylic acid, crotonic acid and the like, and monovalent metal salts, ammonium salts and organic amine salts thereof. Specific examples of the unsaturated dicarboxylic acid include maleic acid, itaconic acid, citraconic acid, fumaric acid and the like, monovalent metal salts thereof, ammonium salts and organic amine salts and the like, or anhydrides thereof. As the monomer (II), acrylic acid, methacrylic acid, and maleic acid are preferable.

Specific examples of the compound in which (CH ₂ ) _r COM ² forms an anhydrate with −COOM ¹ or another − (CH ₂ ) _r COM ² include maleic anhydride.

When the polycarboxylic acid-based copolymer B has a constituent unit (II), it may have only one constituent unit (II), and two or more constituent units derived from different monomers (II). You may have II).
(Constituent unit (III))
The structural unit (III) is a structural unit derived from the monomer represented by the above general formula (3). In the general formula (3), R ⁸ to R ¹⁰ independently represent an alkyl group having a hydrogen atom or a carbon atom number of 1 to 3, respectively. Examples of alkyl groups having 1 to ³ carbon atoms are the same as those in ^R1 to R3. R ⁸ is preferably a hydrogen atom. R ⁹ is preferably a hydrogen atom. R ¹⁰ is preferably a hydrogen atom.

In the general formula (3), R ¹¹ represents a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom. The number of carbon atoms is preferably 1 to 3, more preferably 2 to 3, and even more preferably 3. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a phosphorus atom, and a silicon atom. Among these, an oxygen atom is preferable. Examples of the hydrocarbon group of R ¹¹ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a butyl group, an isobutyl group and a sec-butyl group. The number of heteroatoms contained in R ¹¹ may be one or two or more. When two or more heteroatoms are contained, each heteroatom may be the same or different from each other.

R ¹¹ is preferably a hydrocarbon group having 1 to 4 carbon atoms including a hetero atom, and more preferably a hydrocarbon group having 1 to 4 carbon atoms including an oxygen atom. Examples of the group include a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 4-hydroxybutyl group, and a glyceryl group. Among these, 2-hydroxyethyl group and 2-hydroxypropyl group are preferable.

In the general formula (3), s represents an integer of 0 to 2, and 0 is preferable.

Examples of the monomer represented by the general formula (3) include monoesters of unsaturated monocarboxylic acids. Examples of the unsaturated monocarboxylic acid monoester include methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. , Glyceryl (meth) acrylate and the like. Among these, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferable.

When the polycarboxylic acid-based copolymer B has a constituent unit (III), it may have only one constituent unit (III), and two or more constituent units derived from different monomers (3 types or more). You may have III).

The polycarboxylic acid-based copolymer B may have the structural unit (IV) shown below in addition to the structural units (I) to (III).

(Constituent unit (IV))
The structural unit (IV) is a structural unit derived from a monomer copolymerizable with the above-mentioned monomers (I) to (III). The monomers copolymerizable with the monomers (I) to (III) are structurally distinguished from the monomers represented by the general formulas (1) to (3). The monomer constituting the structural unit (IV) is not particularly limited, and examples thereof include the following monomers. It should be noted that these monomers can be used alone or in combination of two or more.

Dialyl bisphenol represented by the following general formula (IV-1) such as 3 and 3'-position allyl substitutions such as 4,4'-dihydroxydiphenylpropane, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylsulfone and the like. Kind;

Monoallyl bisphenols represented by the following general formula (IV-2) such as 3-position allyl substitutions such as 4,4'-dihydroxydiphenylpropane, 4,4'-dihydroxydiphenylmethane, and 4,4'-dihydroxydiphenylsulfone;

Allylphenol represented by the following general formula (IV-3);

Half-esters and diesters of unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, and citraconic acid and alcohols having 1 to 30 carbon atoms;

Halfamides and diamides of the unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms;

A half ester of a (poly) oxyalkylene alkyl ether or (poly) oxyalkylene alkyl amine obtained by adding 1 to 500 mol of an alkylene oxide having 2 to 18 carbon atoms to the alcohol or amine and the unsaturated dicarboxylic acids. , Half amides, diesters, diamides;

Half esters and diesters of the unsaturated dicarboxylic acids and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 moles of these glycols added;

Half-amides of maleamic acid and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 moles of these glycols added;

(Poly) ethylene glycol mono (meth) acrylate, (poly) propylene glycol mono (poly) propylene glycol mono (poly) propylene glycol mono (poly) ethylene glycol mono (meth) acrylate to which 1 to 500 mol of alkylene oxide having 2 to 18 carbon atoms is added to unsaturated monocarboxylic acids such as (meth) acrylic acid. Meta) acrylate, (poly) butylene glycol mono (meth) acrylate, etc. (excluding monomers represented by the general formulas (1) to (3));

(Poly) alkylene glycols such as triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate Di (meth) acrylates;

Polyfunctional (meth) acrylates such as hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and trimethylolpropane di (meth) acrylate;

(Poly) alkylene glycol dimalates such as triethylene glycol dimalate and polyethylene glycol dimalate;

Vinyl Sulfonate, (Meta) Allyl Sulfonate, 2- (Meta) Acryloxyethyl Sulfonate, 3- (Meta) Acryloxypropyl Sulfonate, 3- (Meta) Acryloxy-2-Hydroxypropyl Sulfonate, 3- (Meta) Acryloxy-2 -Hydroxypropyl sulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyl oxysulfobenzoate, 4- (meth) acryloxibutyl sulfonate, (meth) acrylamide methyl sulfonic acid, (meth) acrylamide ethyl sulfonic acid, 2- Unsaturated sulfonic acids such as methylpropane sulfonic acid (meth) acrylamide, styrene sulfonic acid, and their monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts;

Amides of unsaturated monocarboxylic acids such as methyl (meth) acrylamide and amines with 1 to 30 carbon atoms;

Vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene;

Alkanediol mono (meth) acrylates such as 1,5-pentanediol mono (meth) acrylate and 1,6-hexanediol mono (meth) acrylate (however, the monomer represented by the general formula (3) is excluded. .);

Dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chlor-1,3-butadiene;

Unsaturated amides such as (meth) acrylamide, (meth) acrylic alkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide;

(Meta) Unsaturated cyanides such as acrylonitrile and α-chloroacrylonitrile;

Unsaturated esters such as vinyl acetate and vinyl propionate;

Unsaturation of (meth) aminoethyl acrylate, (meth) methylaminoethyl acrylate, (meth) dimethylaminoethyl acrylate, (meth) dimethylaminopropyl acrylate, (meth) dibutylaminoethyl acrylate, vinyl pyridine, etc. Amines (excluding monomers represented by the general formula (3));

Divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate;

Allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether;

Vinyl ethers such as methoxypolyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, polyethylene glycol mono (meth) allyl ether, or allyl ethers (however, a single amount represented by the general formula (1)). Excluding the body.);

Polydimethylsiloxane propylaminomaleinamide acid, polydimethylsiloxaneaminopropyleneaminomaleinamide acid, polydimethylsiloxane-bis- (propylaminomaleinamide acid), polydimethylsiloxane-bis- (dipropyleneaminomaleinamide acid), polydimethyl Siloxane- (1-propyl-3-acrylate), polydimethylsiloxane- (1-propyl-3-methacrylate), polydimethylsiloxane-bis- (1-propyl-3-acrylate), polydimethylsiloxane-bis- (1) A siloxane derivative such as -propyl-3-methacrylate) (excluding the monomer represented by the general formula (3)).

The polycarboxylic acid-based copolymer B may have only one structural unit (IV), or may have two or more structural units (IV) derived from different monomers. good.

Each of the structural units (I) to (IV) may be a structural unit composed of one type of monomer, or is a structural unit composed of a combination of two or more types of monomers. May be good.

The polycarboxylic acid-based copolymer B is a copolymer having at least two structural units selected from the group consisting of the structural unit (I), the structural unit (II), and the structural unit (III). , More preferably a copolymer (B1) having a structural unit (I) and a structural unit (II), and a copolymer (B2) having a structural unit (I), a structural unit (II) and a structural unit (III). At least one of.

(Copolymer (B1))
The copolymer (B1) has a structural unit (I) and a structural unit (II). The lower limit of the content ratio of the structural unit (I) is preferably 1 mol% or more, more preferably 5 mol% or more. The upper limit thereof is preferably 99 mol% or less, more preferably 95 mol% or less. The lower limit of the content ratio of the structural unit (II) is preferably 1 mol% or more, more preferably 5 mol% or more. The upper limit thereof is preferably 99 mol% or less, more preferably 95 mol% or less.

That is, the content ratio of the structural unit (I) and the structural unit (II) (constituent unit (I) / structural unit (II)) is preferably 1 mol% to 99 mol / 1 mol% to 99 mol%. More preferably, it is 5 mol% to 95 mol% / 5 mol% to 95 mol%.

(Copolymer (B2))
The copolymer (B2) has a structural unit (I), a structural unit (II) and a structural unit (III). The lower limit of the content ratio of the structural unit (I) is preferably 1 mol% or more, more preferably 4 mol% or more. The upper limit thereof is preferably 98 mol% or less, more preferably 89 mol% or less. The lower limit of the content ratio of the structural unit (II) is preferably 1 mol% or more. The upper limit thereof is preferably 98 mol% or less, more preferably 80 mol% or less. Further, the lower limit of the content ratio of the constituent unit (III) is preferably 1 mol% or more, more preferably 10 mol% or more. The upper limit thereof is preferably 98 mol% or less, more preferably 89 mol% or less.

That is, the content ratio of the structural unit (I), the structural unit (II), and the structural unit (III) (constituent unit (I) / structural unit (II) / structural unit (III)) is 1 mol% to 98 mol%. It is preferably 1 mol% to 98 mol% / 1 mol% to 98 mol%, and more preferably 4 mol% to 89 mol% / 1 mol% to 80 mol% / 10 mol% to 89 mol%. preferable.

As the polycarboxylic acid-based copolymer B, the copolymer (B1) and the copolymer (B2) may be used alone or in combination of two or more. When two or more kinds are used in combination, the copolymer (B1) may be used alone, the copolymer (B2) may be used alone, and the copolymer (B1) and the copolymer (B2) may be used. May be used in combination with each other.

The content ratio is not particularly limited, and when two types are used, it is preferably 1 to 99% by weight / 1 to 99% by weight, and preferably 10 to 90% by weight / 10 to 90% by weight. More preferably, it is 20 to 80% by weight / 20 to 80% by weight.

(Method for Producing Polycarboxylic Acid Copolymer B)
The polycarboxylic acid-based copolymer B can be produced by copolymerizing predetermined monomers by a known method. Examples of the method include polymerization methods such as polymerization in a solvent and bulk polymerization.

Examples of the solvent used for polymerization in the solvent include water; lower alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; aromatic hydrocarbons such as benzene, toluene and xylene; and fats such as cyclohexane and n-hexane. Group hydrocarbons; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone. From the viewpoint of the solubility of the raw material monomer and the obtained copolymer, it is preferable to use at least one solvent of water and a lower alcohol, and it is more preferable to use water.

When the polymerization reaction is carried out in a solvent, each monomer and the polymerization initiator may be continuously added dropwise to the reaction vessel, or a mixture of the monomers and the polymerization initiator may be continuously added dropwise to the reaction vessel. .. Further, the solvent may be charged in the reaction vessel, and the mixture of the monomer and the solvent and the polymerization initiator solution may be continuously dropped into the reaction vessel, respectively, and a part or all of the monomer may be charged in the reaction vessel to start the polymerization. The agent may be continuously dropped.

The polymerization initiator that can be used in the polymerization reaction is not particularly limited.

Examples of the polymerization initiator that can be used when carrying out the polymerization reaction in an aqueous solvent include persulfates such as ammonium persulfate, sodium persulfate and potassium persulfate; and water-soluble such as t-butyl hydroperoxide and hydrogen peroxide. Examples include sex peroxides. At this time, an accelerator such as L-ascorbic acid, sodium bisulfite, or moor salt may be used in combination.

Examples of the polymerization initiator that can be used when carrying out the polymerization reaction in an organic solvent such as a lower alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester or a ketone include benzoyl peroxide and lauryl peroxide. Examples thereof include hydrocarbons; hydrocarbons such as cumene peroxide; and azo compounds such as azobisisobutyronitrile. At this time, an accelerator such as an amine compound may be used in combination.

The polymerization initiator that can be used when the polymerization reaction is carried out in a water-lower alcohol mixed solvent may be appropriately selected from the above-mentioned polymerization initiator or a combination of the polymerization initiator and the accelerator. The polymerization temperature is usually 50 to 120 ° C., although it varies depending on the polymerization conditions such as the solvent used and the type of the polymerization initiator.

In the polymerization reaction, the molecular weight can be adjusted by using a chain transfer agent, if necessary. Examples of the chain transfer agent include known thiol-based agents such as mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thioapple acid, octyl thioglycolate, and 2-mercaptoethanesulfonic acid. Compounds; Sodium bisulfite, hypophosphite, or salts thereof (sodium bisulfite, potassium hypophosphate, etc.), sulfite, hydrogen bisulfite, dithionic acid, metabisulfite, or salts thereof (sodium bisulfite). Examples thereof include lower oxides of sodium, potassium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, sodium bisulfite, potassium bisulfite, sodium metabisulfite, potassium metabisulfite, etc.) or salts thereof. These chain transfer agents may be used alone or in combination of two or more.

In order to adjust the molecular weight of the polycarboxylic acid-based copolymer B, a single amount having high chain transferability other than the monomers constituting the above-mentioned monomers (I) to (III) and the structural unit (IV). The body (V) may be used. Examples of the monomer (V) having high chain transferability include (meth) allylsulfonic acid (salt) -based monomers. The blending ratio of the monomer (V) is usually 20% by weight or less, preferably 10% by weight or less in the entire polycarboxylic acid-based copolymer B. The blending ratio is generally the blending ratio of the monomer represented by the general formula (1) and the blending ratio derived from the monomer represented by the general formula (2) in the production of the copolymer. It is a blending ratio when the sum of the blending ratio of the monomer represented by the formula (3) and the blending ratio of the monomers constituting the constituent unit (IV) is 100% by weight.

When the polymerization reaction is carried out in an aqueous solvent when the polycarboxylic acid-based copolymer B is obtained, the pH at the time of the polymerization reaction is usually strongly acidic due to the influence of the monomer having an unsaturated bond. However, this may be adjusted to an appropriate pH. If it is necessary to adjust the pH during the polymerization reaction, adjust the pH using an acidic substance such as phosphoric acid, sulfuric acid, nitrate, alkylphosphate, alkylsulfuric acid, alkylsulfonic acid, or (alkyl) benzenesulfonic acid. good. Among these acidic substances, it is preferable to use phosphoric acid because it has a pH buffering action and the like. However, in order to eliminate the instability of the ester bond of the ester-based monomer, it is preferable to carry out the polymerization reaction at pH 2 to 7. Further, the alkaline substance that can be used for adjusting the pH is not particularly limited, and an alkaline substance such as NaOH or Ca (OH) ₂ is generally used. The pH adjustment may be performed on the monomer before the polymerization reaction or on the copolymer solution after the polymerization reaction. Further, these are polymerized by adding a part of the alkaline substance before the polymerization reaction, and then the pH is adjusted (for example, pH 3 to 7) with respect to the copolymer solution during the polymerization reaction or after the polymerization reaction. (Adjustment) may be performed.

The lower limit of the solid content concentration in the polycarboxylic acid-based copolymer B is preferably 5% by weight or more, more preferably 15% by weight or more. The upper limit thereof is preferably 70% by weight or less, more preferably 65% by weight or less. Therefore, the solid content concentration in the polycarboxylic acid-based copolymer B is preferably 5 to 70% by weight, more preferably 15 to 65% by weight.

The polycarboxylic acid-based copolymer B may be in a liquid state. An aqueous solvent is exemplified as the solvent in the case of a liquid. Examples of the aqueous solvent include water, alcohols having 1 to 6 carbon atoms (ethyl alcohol, methyl alcohol, ethylene glycol, diethylene glycol, etc.), ketones having 1 to 6 carbon atoms (methylisobutylketone, acetone, etc.) and the like. These aqueous solvents may be used alone or in combination of two or more. Water is preferable as the aqueous solvent.

The polycarboxylic acid-based copolymer B may contain at least one monomer selected from the group consisting of the above general formulas (1) to (3) as a raw material. When the copolymer is obtained, the reaction solvent may be removed, concentrated, purified or the like, if necessary. These treatment methods may be conventionally known methods.

The lower limit of the weight average molecular weight (Mw) of the polycarboxylic acid-based copolymer B is preferably 5000 or more, more preferably 6000 or more. When the weight average molecular weight of the polycarboxylic acid-based copolymer B is in this range, the redispersibility of the base polymer is sufficiently exhibited when it is added to the cement admixture molded product, and the lignin sulfonic acid-based compound or the oxycarboxylic acid-based compound or the oxycarboxylic acid-based compound is sufficiently exhibited. It is possible to obtain a water reduction rate higher than that of an AE water reducing agent such as a compound. Therefore, the fluidity or workability can be improved. The upper limit of the weight average molecular weight is preferably 60,000 or less, more preferably 50,000 or less. When the weight average molecular weight of the polycarboxylic acid-based copolymer B is in this range, the aggregation action of the particles in the base polymer is suppressed, and the workability can be improved. The weight average molecular weight is preferably 5000 to 60000, more preferably 6000 to 50000.

The lower limit of the molecular weight distribution (Mw / Mn) of the polycarboxylic acid-based copolymer B is preferably 1.0 or more, more preferably 1.2 or more. The upper limit is preferably 3.0 or less, more preferably 2.5 or less. The molecular weight distribution is preferably in the range of 1.0 to 3.0, more preferably in the range of 1.2 to 3.0, and even more preferably in the range of 1.2 to 2.5. ..

The above weight average molecular weight and number average molecular weight are values measured by a known method in terms of polyethylene glycol by gel permeation chromatography (GPC). The measurement conditions of GPC are as follows. The weight average molecular weight in the examples in the latter stage is a value measured under this condition.

Measuring device; Column used by Tosoh Co., Ltd .; Shodex Volume OH-pak SB-806HQ, SB-804HQ, SB-802.5HQ
Eluent; 0.05 mM sodium nitrate / acetonitrile 8/2 (v / v)
Standard substance: Polyethylene glycol (manufactured by Tosoh or GL Science)
Detector; differential refractometer (manufactured by Tosoh Corporation)
Calibration curve; polyethylene glycol standard

(Thickener C)
The thickener C may be any thickener used in the art. Examples of such thickeners include cellulose-based thickeners, acrylic-based thickeners, and starch-based thickeners. The thickener C is preferably a thickener that is liquid at 25 ° C. in consideration of being carried on the cellulosic carrier A.

As the thickener C, one kind of thickener may be used, or two or more kinds of thickeners may be used in combination.

Examples of the cellulosic thickener include methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropylmethyl cellulose, and modified products thereof. Further, these cellulosic thickeners may be used alone or in combination of two or more.

As the hydroxyethyl cellulose, a commercially available product can also be used. Examples of commercially available products include "HEC Daicel SP200", "HEC Daicel SP400", "HEC Daicel SP500", "HEC Daicel SP550", "HEC Daicel SP600", "HEC Daicel SP800", "HEC Daicel SP850", and "HEC Daicel SP850". HEC Daicel SP900 "(above, manufactured by Daicel FineChem)," Sun Heck (trademark) HH "," Sun Heck H "," Sun Heck M "," Sun Heck G & L "(above, manufactured by Sansho)," HECSZ-25F "(above, manufactured by Sansho) Sumitomo Seika Co., Ltd.).

As the hydroxypropylmethyl cellulose, a commercially available product can also be used. Examples of commercially available products include "Metro's 90SH-04", "Metro's 90SH-15", "Metro's 90SH-100", "Metro's 90SH-400", "Metro's 90SH-4000", "Metro's 90SH-15000", and "Metro's 90SH-15000". Metrose 90SH-100000 "(above, manufactured by Shin-Etsu Chemical Co., Ltd.)," NEOVISCO-MC HM4000S "," NEOVISCO-MC RM4000S "," NEOVISCO-MC RM15000S "," NEOVISCO-MC RM30000S "," NEOVISCO-MC RM50 , Made by Sanshosha).

Examples of the acrylic thickener include polyacrylamide, sodium polyacrylate, acrylic acid / acrylic acid ester copolymer, sodium acrylate / acrylamide copolymer, and acrylamide / 2-acryloylamino-2-methylpropanesulfonic acid. Examples include sodium copolymers, starch / acrylic acid / sodium acrylate. Further, these acrylic thickeners may be used alone or in combination of two or more.

Examples of the starch-based thickener include modified starches such as starch, pregelatinized starch, etherified starch, esterified starch, and enzyme-modified starch.

(Defoamer D)
The defoaming agent D may be any defoaming agent used in the art. Examples of such defoaming agents include polyether-based defoaming agents, silicone-based defoaming agents, polyalkylene glycol-based defoaming agents, and nonionic surfactant-based defoaming agents. Considering that the defoaming agent D is supported on the cellulosic carrier A, it is preferable that the defoaming agent D is a liquid defoaming agent at 25 ° C.

As the defoaming agent D, one kind of defoaming agent may be used, or two or more kinds of defoaming agents may be used in combination.

(Mixing amount)
The blending amount of each component of the cement admixture molded product is as follows.
The blending amount of the polycarboxylic acid-based copolymer B is preferably 10 to 500 parts by weight, more preferably 50 to 400 parts by weight, and 60 to 300 parts by weight with respect to 100 parts by weight of the cellulose-based carrier A. It is more preferable to be a part. When the blending amount of the polycarboxylic acid-based copolymer B is 10 parts by weight or more, the expected dispersibility can be obtained. On the other hand, when it is 500 parts by weight or less, the stickiness of the cement admixture molded product does not become too large, it is possible to prevent deterioration of workability, and it can be uniformly supported on the cellulose carrier, and uniform dispersibility can be expected.

The blending amount of the thickener C is preferably 0.5 to 40 parts by weight, more preferably 1 to 35 parts by weight, and 1.5 to 30 parts by weight with respect to 100 parts by weight of the cellulosic carrier A. It is even more preferably parts, and even more preferably 1.5 to 10 parts by weight. When the blending amount of the thickener C is 40 parts by weight or less, it is possible to prevent a situation in which a predetermined fluidity after post-addition cannot be obtained due to an excessive amount of the thickening component. On the other hand, when it is 0.5 parts by weight or more, sufficient self-filling property can be ensured.

The blending amount of the defoaming agent D is preferably 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight, and 2 to 10 parts by weight with respect to 100 parts by weight of the cellulosic carrier A. It is more preferable to have. When the blending amount of the defoaming agent D is 20 parts by weight or less, a predetermined amount of air can be secured and the frost damage resistance of the cement can be improved. On the other hand, if it is 0.5 parts by weight or more, it is possible to prevent a situation in which the frost damage resistance of the cement is impaired due to the inability to suppress the entrained air derived from the thickener.

(Preparation method of cement admixture molded product)
The cement admixture molded product can be obtained by supporting the above-mentioned supporting component on the cellulosic carrier A and molding it into a predetermined shape. The supporting method is not particularly limited, and it can be prepared by contact-stirring the cellulosic carrier A and each supporting component and drying them if necessary.

At the time of preparation, other cement dispersants, water-soluble polymers, curing accelerators, thickeners, retarders, polymer emulsions, air entrainers, cement wetting agents, swelling agents, waterproofing agents, flocculants, etc. Any component such as a drying shrinkage reducing agent, a strength enhancer, an antifoaming agent, an AE agent, and a surfactant can also be carried.

These optional components may be used alone or in combination of two or more.

Other cement dispersants include, for example, naphthalene sulfonic acid formaldehyde condensate, melamine sulfonic acid formaldehyde condensate, and lignin sulfonate. These cement dispersants may be used alone or in combination of two or more. The content thereof is preferably 0.01 to 50% by weight with respect to the cellulosic carrier A.

Further, known (co) polymers other than the polycarboxylic acid-based copolymer B can be used. Examples of such known (co) polymers include polymers derived from (poly) alkylene glycol alkenyl ether-based monomers, oxycarboxylic acid-based dispersants, and the like.

Examples of polymers derived from (poly) alkylene glycol alkenyl ether-based monomers include (poly) ethylene glycol allyl ether, (poly) ethylene glycol metalyl ether, and (poly) ethylene glycol 3-methyl-3-butenyl. Ether, (poly) ethylene (poly) propylene glycol allyl ether, (poly) ethylene (poly) propylene glycol metallic ether, (poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl ether, (poly) ethylene ( Poly) Butylene glycol allyl ether, (Poly) ethylene (poly) Butylene glycol metallicyl ether, (Poly) ethylene (poly) Butylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene glycol allyl ether, methoxy (poly) ) Ethylene glycol metharyl ether, methoxy (poly) ethylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) propylene glycol allyl ether, methoxy (poly) ethylene (poly) propylene glycol metharyl ether, methoxy ( Poly) ethylene (poly) propylene glycol 3-methyl-3-butenyl ether, methoxy (poly) ethylene (poly) butylene glycol allyl ether, methoxy (poly) ethylene (poly) butylene glycol metallic ether, methoxy (poly) ethylene ( Poly) Butylene glycol 3-methyl-3-butenyl ether and the like can be mentioned.

The oxycarboxylic acid-based dispersant is preferably an oxycarboxylic acid having 4 to 10 carbon atoms or a salt thereof. Examples of the oxycarboxylic acid-based dispersant include gluconic acid, glucoheptonic acid, alabonic acid, malic acid, citric acid, and inorganic or organic salts such as sodium, potassium, calcium, magnesium, ammonium, and triethanolamine. Can be mentioned.

In the cement admixture molded product of the present invention, it is necessary to support each component on the cellulosic carrier A as described above, and then adjust the molded product into a molded product having a predetermined shape. The predetermined shape can be any shape as long as the effect of the present invention is not impaired, and examples thereof include a spherical shape, a columnar shape, a rectangle, and a cube. The following conditions (C) to (D) are used. It is important to meet.
Condition (C): The longest long side L of the cement admixture molded product is 5 cm or more and 15 cm or less.
Condition (D): The shortest short side D of the cement admixture molded product is 1 cm or more and 10 cm or less.

The longest long side L is determined on each surface of the molded product without considering the diagonal line of the cement admixture molded product of the present invention. Therefore, when the cement admixture molded product of the present invention is on a cylindrical shape, the long side L corresponds to the longest of the height and the diameter of the bottom surface.

When the long side L is 5 cm or more and 15 cm or less, when added to the cement composition, due to contact with the coarse aggregate or fine aggregate in the cement composition, disintegration proceeds moderately and good dispersibility is exhibited. The cement admixture molded product of the present invention preferably has a long side L of 5 to 13 cm, more preferably 6 to 13 cm.

The shortest short side D is determined on each surface of the molded product without considering the diagonal line of the cement admixture molded product of the present invention. Therefore, when the cement admixture molded product of the present invention is on a cylindrical shape, the short side D corresponds to the shortest of the height and the diameter of the bottom surface.

When the short side D is 1 cm or more and 10 cm or less, when added to the cement composition, disintegration proceeds uniformly by the stirring force of a cement mixer or the like usually used, and good dispersibility is exhibited. In such a cement admixture molded product of the present invention, the short side D is more preferably 2 to 8 cm, and more preferably 2 cm or more and less than 6 cm.

Hereinafter, the present invention will be described in detail with reference to Examples. The following examples are for the purpose of suitably explaining the present invention, and do not limit the present invention. Unless otherwise specified, the method for measuring the physical property value or the like is the measurement method described above. Further, the portion means a weight portion unless otherwise specified.

[Measurement of air volume]: The air volume of concrete was evaluated according to JIS A 1128 (2014) "Test method by pressure of air volume of fresh concrete-air chamber pressure method".

[Evaluation of fluidity]: Each slump flow value was measured and evaluated in accordance with JIS A 1150 (2007) “Concrete slump flow test method”.

[Sensory evaluation of ease of kneading]: The base concrete was adjusted to a predetermined slump, and then a floc-like admixture or an admixture in a paper bag was added to start kneading. Then, the presence or absence of undissolved admixture was visually evaluated.

(Production Example 1: Preparation of polycarboxylic acid-based copolymer (B-1))
8000 kg of water was charged into a stainless steel reaction vessel equipped with a thermometer, a stirrer, a reflux device, a nitrogen introduction tube and a dropping device, and the reaction vessel was replaced with nitrogen under stirring. After heating to 100 ° C. under a nitrogen atmosphere, methoxypolyethylene glycol methacrylate (MPEG-MA) (average number of moles of ethylene oxide added 14) 2500 kg (33 mol%), methacrylic acid (MAA) 400 kg (67 mol%). , A monomer aqueous solution containing 2670 kg of water and a stirred mixed solution of 50 kg of sodium persulfate and 500 kg of water were continuously added dropwise to a reaction vessel kept at 100 ° C. for 2 hours each. After the polymerization reaction was carried out for 1 hour while the temperature was maintained at 100 ° C., the polymer was cooled to 65 ° C. with an additional device located at the rear stage of the reaction vessel, neutralized to pH 7 with sodium hydroxide, and at the same time hydrated. , An aqueous solution of the copolymer (B-1) (weight average molecular weight Mw18000, Mw / Mn1.5) having a concentration of 20% was obtained.

(Production Example 2: Preparation of polycarboxylic acid-based copolymer (B-2))
8000 kg of water was charged into a stainless steel reaction vessel equipped with a thermometer, a stirrer, a reflux device, a nitrogen introduction tube and a dropping device, and the reaction vessel was replaced with nitrogen under stirring. After raising the temperature to 100 ° C. in a nitrogen atmosphere, methoxypolyethylene glycol methacrylate (MPEG-MA) (average number of moles of ethylene oxide added 14) 3000 kg (40 mol%), methacrylic acid (MAA) 500 kg (60 mol%) , A monomer aqueous solution containing 2670 kg of water and a stirred mixed solution of 50 kg of sodium persulfate and 500 kg of water were continuously added dropwise to a reaction vessel kept at 100 ° C. for 2 hours each. After the polymerization reaction was carried out for 1 hour while the temperature was maintained at 100 ° C., the polymer was cooled to 65 ° C. with an additional device located at the rear stage of the reaction vessel, neutralized to pH 7 with sodium hydroxide, and at the same time hydrated. , An aqueous solution of the copolymer (B-2) (weight average molecular weight Mw16000, Mw / Mn1.3) having a concentration of 20% was obtained.

(Production Example 3: Preparation of Cellulose-based Carrier A)
A: An average particle size 67 obtained by mechanically pulverizing a bleached wood pulp sheet (coniferous tree-derived pulp NDSP, manufactured by Nippon Paper Industries, Ltd., average degree of polymerization 1600) using a tornado mill (manufactured by Nikkiso Co., Ltd.). Pulp cellulose having an average degree of polymerization of 1479, an apparent specific gravity of 0.24 g / cm ³ , an alkali elution rate of 0.4%, and a water absorption rate of 690%.

(Production Examples 4 to 7: Preparation of cement admixture molded products (E-1) to (E-4))
After thoroughly stirring the cellulosic carrier A, the polycarboxylic acid copolymer B, the thickener C, the defoaming agent D and other dispersants in the blending amounts shown in Table 1, the moldings shown in Table 1 are performed. It was molded into a product to obtain cement admixture molded products (E-1) to (E-4).

As the thickener, a commercially available cellulosic thickener and a commercially available acrylic thickener were used in combination. These combinations were liquid at 25 ° C.

As the defoaming agent, a commercially available nonionic surfactant-based defoaming agent was used, and it was liquid at 25 ° C.

As the other dispersant, a commercially available product is used, which is an oxycarboxylic acid-based dispersant.

(Making base concrete)
At the environmental temperature (20 ° C.), cement, water, fine aggregate and coarse aggregate are added so as to be the blending amounts shown in Table 2, and further, as an initial dispersant, a polycarboxylic acid-based compound manufactured by Floric Co., Ltd. 0.5 part of "SF500S" was added to the cement, and the mixture was mechanically kneaded with a mixer for 60 seconds at low speed and 90 seconds at high speed to obtain the base concrete shown in Table 2. In Table 2, the unit amount of water includes the water content of SF500S.

The details of the symbols in Table 2 are described below.

C: Equivalent mixture of the following three types of cement Ordinary Portland cement (manufactured by Ube-Mitsubishi Cement, specific density 3.16)
Ordinary Portland cement (manufactured by Taiheiyo Cement, specific density 3.16)
Ordinary Portland cement (manufactured by Tokuyama Corporation, specific density 3.16)
W: Tap water S: Land sand from Kakegawa (density 2.58)
G: Crushed stone from Ome (density 2.65)

(Examples 1 to 4)
A cement composition was produced by adding and kneading the cement admixture molded products E1 to E4 to the base concrete obtained above 80 minutes after the start of kneading. The evaluation of the manufactured cement composition is also shown in Table 3.

(Comparative Example 1)
A cement composition was produced in the same manner as in Examples 1 to 4 except that the cement admixture molded product E was not added. The evaluation of the manufactured cement composition is also shown in Table 3.

(Comparative Example 2)
Cement compositions were produced in the same manner as in Examples 1 to 4, except that the fluidizing agent “Leopack G100” manufactured by Lion Co., Ltd. was added in place of the cement admixture molded product E. The evaluation of the manufactured cement composition is also shown in Table 3.

Claims (5)

A cement admixture molded product characterized by satisfying the following conditions (A) to (D).
Condition (A): The cellulosic carrier A is contained.
Condition (B): Contains the polycarboxylic acid-based copolymer B.
Condition (C): The longest long side L of the cement admixture molded product is 5 cm or more and 15 cm or less.
Condition (D): The shortest short side D of the cement admixture molded product is 1 cm or more and 10 cm or less. The polycarboxylic acid-based copolymer B has a structural unit (I) derived from the monomer represented by the following general formula (1) and a configuration derived from the monomer represented by the following general formula (2). Claimed to be a copolymer having at least two structural units selected from the group consisting of the unit (II) and the structural unit (III) derived from the monomer represented by the following general formula (3). The cement admixture molded product according to 1.

... (1)
(In the above general formula (1), R ¹ to R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. P represents an integer of 0 to 2, and q represents 0. Or 1. A ¹ O indicates an oxyalkylene group having 2 to 18 carbon atoms, which may be the same or different. N indicates an integer of 1 to 300. R ⁴ is a hydrogen atom or a hydrogen atom. Shows a hydrocarbon group having 1 to 30 carbon atoms.)

... (2)
(In the general formula (2), R ⁵ to R ⁷ independently represent a hydrogen atom, -CH ₃ , or-(CH ₂ ) _r COM ² , where-(CH ₂ ) _r COM ² is used. , -COOM ¹ or other- (CH ₂ ) _r COMM ² may form anhydrate, and when forming an anhydride, M ¹ and M ² do not exist. M ¹ and M ² are the same. Alternatively, it indicates a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, an alkylammonium group, or a substituted alkylammonium group, which may be different. R indicates an integer of 0 to 2).

... (3)
(In the above general formula (3), R ⁸ to R ¹⁰ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R ¹¹ is a carbon atom which may contain a hetero atom. It indicates a hydrocarbon group of the number 1 to 4. s indicates an integer of 0 to 2.) The cement admixture molding according to any one of claims 1 and 2, wherein the polycarboxylic acid-based copolymer B is contained in the range of 10 to 500 parts by weight with respect to 100 parts by weight of the cellulosic carrier A. thing. The cement admixture molded product according to any one of claims 1 to 3, further comprising a thickener C. The cement admixture molded product according to any one of claims 1 to 4, further comprising an antifoaming agent D.