JP4843902B2 - Additive for cement - Google Patents

Description

  The present invention relates to a cement additive containing a specific polyether compound and a cement composition containing the cement additive. Furthermore, the present invention relates to a cement additive containing a specific polyether compound, a cement additive containing a specific polyether compound and a polycarboxylic acid compound, and a cement composition.

Cement compositions represented by concrete and the like have been used in large quantities as building materials because they are excellent in workability, strength, and durability, and are inexpensive and can be produced in large quantities. In most cases, cement additives such as air entraining agents and water reducing agents are used for cement compositions from the viewpoint of workability, durability, quality, and the like. In particular, demands for higher strength and higher durability for cement compositions in recent years, especially concrete, are increasing, and the opportunity to use a water reducing agent for the purpose of reducing the amount of kneaded water is increasing.
Conventionally, naphthalene sulfonic acid formaldehyde condensate salt, melamine sulfonic acid formaldehyde condensate salt, lignin sulfonic acid salt, etc. have been used as water reducing agents, but these water reducing agents are used in mortar and concrete compositions. Although there is an effect of reducing the amount of water, it does not satisfy various requirements, for example, there is a problem that the setting time of the cement composition is delayed.
In order to solve these problems, a polycarboxylic acid-based water reducing agent such as a polyoxyethylene monoallyl ether-maleic acid copolymer is used (for example, see Patent Document 1). However, the effect of reducing the amount of water used in the mortar or concrete composition is great, but it is still insufficient and the slump retention effect is low. Further, a polycarboxylic acid-based water reducing agent, that is, a polyoxyethylene monoalkenyl monoalkyl ether-maleic anhydride copolymer (see, for example, Patent Document 2), a polycarboxylic acid-based water reducing agent, and a nitrogen-containing polyoxyalkylene compound, A mixture (for example, see Patent Document 3), a copolymer in which a nitrogen-containing compound is introduced into a polycarboxylic acid-based copolymer (for example, see Patent Document 4), a polycarboxylic acid-based copolymer, and The combined use with a nitrogen-containing polyether compound (see, for example, Patent Document 5) has a large effect of reducing the amount of water used in the mortar and concrete composition and a high slump retention effect.
However, when a polycarboxylic acid-based water reducing agent that has a large effect on reducing the amount of water used in the cement composition and has a high slump retention effect is used, the cement composition decreases as the mixing water used in the cement composition decreases. There is a problem that the viscosity when constructing a material is high (workability is poor). The term “viscosity” as used herein refers to performance that cannot be discriminated by the slump value that has been used as an index of workability. When this “viscosity” is high, the cement composition is poured by pumping, and is cast into the mold. It has been pointed out that workability in processes that rely on human hands, such as installation and surface finishing, has been pointed out.

JP-A-57-118058 (pages 1 to 8) JP 63-285140 A (pages 1 to 5) JP-A-7-232945 (pages 1 to 8) JP 7-33496 A (pages 1 to 5) JP 2000-109357 A (pages 1 to 5)

  The problem to be solved by the present invention is to provide an additive composition for cement that is excellent in workability by reducing the viscosity of a cement composition such as produced concrete.

That is, the present invention is as follows.
(1) Formula (1) or Formula (2)

(Wherein, Z is a residue of a compound having 5 or more and less than 40 active hydrogens bonded to a nitrogen atom and having 3 or more nitrogen atoms, A ¹ O is an oxyethylene group , a is a a = 1 to 20 with an average addition number of moles is indicated by a ¹ O Luo carboxymethyl ethylene group, in ^{a 2} O is an oxyalkylene group having 3 or 4 carbon atoms, carbon atoms b is represented by ^{a 2} O The average number of moles added of 3 or 4 oxyalkylene groups is b = 1 to 20, the relationship between a and b is 0.5 <a / b <5, and 5 ≦ (a + b) ≦ 20 , R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and n is 5 or more and less than 40.)
A cement additive comprising 1 to 95% by weight of a polyether compound (A) represented by formula (5) and 5 to 99% by weight of a polycarboxylic acid compound (PC).
(2) The structural unit (a) based on the polyalkylene glycol ether represented by the formula (3) in which the polycarboxylic acid compound (PC) is 50 to 99% by weight, the dicarboxylic acid or maleic anhydride represented by the formula (4) 1 to 50% by weight of the structural unit (a) based on the acid and the structural unit (c) based on the other copolymerizable monomer with respect to the sum of the weights of the structural unit (a) and the structural unit (a) The above-mentioned additive for cement, which is a copolymer having 0 to 30% by weight.

(However, R ² , R ³ and R ⁴ each independently represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 1 to 4 carbon atoms, and R ⁶ represents a hydrogen atom or a carbon atom having 1 to 22 carbon atoms. A hydrogen group and AO are 1 type or 2 types or more of a C2-C4 oxyalkylene group, and when it is 2 or more types, it may be a block form or a random form, p is an average of a C2-C4 oxyalkylene group (The number of moles added is p = 1 to 150.)

(Where X represents —OM ² or —Y— (AO) _r R ⁷ [formula (5)], and M ¹ and M ² each independently represent a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or organic. Y represents an ether group or an imino group, R ⁷ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, AO represents one or more of an oxyalkylene group having 2 to 4 carbon atoms, In the case of 2 or more types, it may be a block shape or a random shape, and r is an average added mole number of an oxyalkylene group having 2 to 4 carbon atoms, and r = 1 to 150.)
( 3 ) The structural unit based on the monocarboxylic acid represented by the structural unit (d) in which the polycarboxylic acid compound (PC) is based on the polyalkylene glycol ester represented by the formula (6) (e) 50 to 99% by weight. (E) The structural unit (c) based on 1 to 50% by weight and another copolymerizable monomer is 0 to 30% based on the sum of the weights of the structural unit (e) and the structural unit (e) % Of the above-mentioned cement additive,

(However, R ⁸ represents a hydrogen atom or a methyl group, R ⁹ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, and AO is one or more kinds of oxyalkylene groups having 2 to 4 carbon atoms. In the case of two or more types, it may be block or random, and s is the average number of moles of oxyalkylene groups having 2 to 4 carbon atoms, and s = 1 to 150.)

(However, R ¹⁰ represents a hydrogen atom or a methyl group, and M ³ represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or organic ammonium.)
( 4 ) A cement composition comprising the above-mentioned cement additive, aggregate, water and cement.
( 5 ) The said cement composition characterized by the ratio of the water with respect to a cement being 45% or less by weight ratio.

  Even when there is no difference in slump value and slump flow value, which has been used as an index of conventional concrete workability, the cement composition using the cement additive of the present invention has reduced viscosity and is handled. Since easy-to-use concrete can be obtained, it is advantageous for pumping and the like, and the workability can be improved and speeded up.

The additive for cement of the present invention contains the polyether compound (A) represented by the formula (1) or the formula (2).
In the polyether compound (A) represented by the formula (1) or (2), Z is a compound having 5 or more and less than 40 active hydrogens bonded to a nitrogen atom and having 3 or more nitrogen atoms. Is the residue. Examples of the compound having 5 or more and less than 40 active hydrogen bonded to a nitrogen atom and having 3 or more nitrogen atoms include, for example, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine. And polyalkylene polyamines such as tripropylenetetramine; polyallylamine, polyethyleneimine and the like. When the number of active hydrogens in a compound having 5 or more and less than 40 active hydrogens bonded to nitrogen atoms and having 3 or more nitrogen atoms is 40 or more, formula (1) or The molecular weight of the polyether compound (A) represented by the formula (2) becomes large, and the effect of the present invention is hardly obtained.

As a compound having 5 or more and less than 40 active hydrogens bonded to a nitrogen atom and having 3 or more nitrogen atoms, preferably diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine , Tripropylenetetramine, polyethyleneimine having a number average molecular weight of 300 (approximately 7 active hydrogen atoms) to 1,700 (approximately 40 active hydrogen atoms). More preferably, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and polyethyleneimine having a number average molecular weight of 300 to 1,700, most preferably having a number average molecular weight of 300 to 1,200 (approximately 28 active hydrogen atoms). ) Polyethyleneimine. The organic amine used may be a single compound or two or more.
In the polyether compound (A) represented by the formula (1) or the formula (2), A ¹ O is one kind of an oxyalkylene group having 2 to 4 carbon atoms in which 80 mol% or more thereof is an oxyethylene group or 2 or more, and in the case of 2 or more, it may be random or block. Examples of the oxyalkylene group having 2 to 4 carbon atoms include an oxyethylene group, an oxypropylene group, and an oxybutylene group. Is preferably a 1,2-oxypropylene group, and the oxybutylene group is preferably a 1,2-oxybutylene group. A 1 to ^O 80 mol% or more is limited oxyethylene groups, with the viscosity reduction effect which is a feature of the polyether compound of the present invention is outside this range (A) is lowered, A ¹ O More preferably, is composed of only oxyethylene groups.
A ² O is one or two or more of C 2-4 oxyalkylene groups in which 80 mol% or more thereof is a oxyalkylene group having 3 or 4 carbon atoms. The oxyalkylene group having 2 to 4 carbon atoms includes an oxyethylene group, an oxypropylene group, and an oxybutylene group, and the oxypropylene group is preferably a 1,2-oxypropylene group, and an oxybutylene group Is preferably a 1,2-oxybutylene group. The fact that 80 mol% or more of A ² O is limited to an oxyalkylene group having 3 or 4 carbon atoms is less than this range, the viscosity reducing effect that is characteristic of the polyether compound (A) of the present invention is low. Therefore, it is more preferable that A ² O is an oxyalkylene group having 3 or 4 carbon atoms.

a and b are the average addition mole number of the oxyalkylene group having 2 to 4 carbon atoms represented by ^{A 1} O and ^{A 2} O each, from 1 to 20, respectively, and preferably 2 to 15. When a and b are out of the above ranges, the viscosity reducing effect that is a feature of the polyether compound (A) of the present invention is lowered.
The average addition mole number a of the oxyalkylene group having 2 to 4 carbon atoms represented by A ¹ O and the average addition mole number b of the oxyalkylene group having 2 to 4 carbon atoms represented by A ² O are: 5 <a / b <5 and 5 ≦ (a + b) ≦ 40 are preferably satisfied, and a / b is a highly hydrophilic portion of the polyether chain A ¹ O in the polyether compound (A). And a weakly hydrophilic portion A ² O, and if it is out of this range, the viscosity reducing effect that is a feature of the polyether compound (A) of the present invention is lowered, which is not preferable. Preferably, a / b satisfies the relationship 0.7 ≦ a / b ≦ 4.
Further, (a + b) means the chain length of the polyoxyalkylene moiety per equivalent of active hydrogen bonded to the nitrogen atom, and 5 ≦ (a + b) ≦ 40. When (a + b) is out of this range, the viscosity reducing effect that is characteristic of the polyether compound (A) of the present invention is lowered, which is not preferable. (A + b) preferably satisfies the relationship of 5 ≦ (a + b) ≦ 20.
(A ¹ O) a and (A ² O) b are bonded in a block form, but have 5 or more and less than 40 active hydrogens bonded to a nitrogen atom, and a compound having 3 or more nitrogen atoms Either side may be bonded first, and any of the compounds represented by the formulas (1) and (2) may be used.

R ¹ in Formula (1) or Formula (2) is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. Examples of the hydrocarbon group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, allyl group, butyl group, isobutyl group, t-butyl group, amyl group, isoamyl group, hexyl group, A heptyl group, an octyl group, 2-ethylhexyl group, a phenyl group, a benzyl group, a cresyl group, etc. are mentioned, These may be 1 type or 2 types or more. Preferably, it is a C1-C4 hydrocarbon group such as a hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, allyl group, butyl group, and more preferably a hydrogen atom or a methyl group. If the number of carbon atoms of the hydrocarbon group represented by R ¹ exceeds 8, it is not preferable because it is difficult to produce.

The weight average molecular weight of the polyether compound (A) represented by the formula (1) or the formula (2) is 350 to 100,000, preferably 1,000 to 50,000, and more preferably. It is 2,000 to 20,000, and particularly preferably 2,000 to 12,000.
The polyether compound (A) represented by the formula (1) or the formula (2) has 5 or more and less than 40 active hydrogens bonded to the nitrogen atom derived from Z in the formula (1) or (2). And it can manufacture by adding an alkylene oxide to the compound which has a 3 or more nitrogen atom.
In the addition reaction of alkylene oxide, a catalyst may be used, and in some cases, the catalyst may not be used. Examples of the catalyst for the addition reaction of alkylene oxide include sodium hydroxide, alkali hydroxide such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and magnesium hydroxide and hydroxide of alkaline earth metal, sodium, potassium, sodium hydride, Alkali metal compounds such as sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, alkylamines such as triethylamine, and alkanolamines such as triethanolamine can be used. In addition to the above alkali catalyst, a Lewis acid catalyst such as boron trifluoride or tin tetrachloride may be used.
The addition reaction of alkylene oxide is carried out, for example, in the presence of a catalyst if necessary for a compound having a nitrogen atom as a raw material at 50 to 200 ° C. and 0.02 MPa to 1.0 MPa in an inert gas atmosphere such as argon or nitrogen gas. The alkylene oxide can be produced by continuously adding pressure under pressure.
The polyether-terminated hydroxyl group produced by the above method can be alkyl etherified by a known method, for example, by reacting a halogenated hydrocarbon in the presence of sodium hydroxide.

  Examples of the polycarboxylic acid compound (PC) used in the present invention include maleic acid or a derivative thereof, and a copolymer having acrylic acid, methacrylic acid or a derivative thereof as a constituent monomer. -Styrene sulfonate copolymer or salt thereof, maleic anhydride-styrene copolymer, hydrolyzate thereof or salt thereof, maleic anhydride-olefin copolymer, hydrolyzate thereof or salt thereof, polyoxyalkylene Monoalkyl ether (meth) acrylate- (meth) acrylic acid copolymer or salt thereof, polyoxyalkylene mono (meth) allyl ether-maleic acid copolymer or salt thereof, polyoxyalkylene monoalkyl mono (meth) allyl ether -Maleic anhydride copolymer, its hydrolyzate or its salt, etc. It is. These may be used alone or in combination of two or more.

Among these, Preferably, the following copolymers are mentioned.
1) 50 to 99% by weight of the structural unit (a) based on the polyalkylene glycol ether represented by the formula (3) and 1 to 50 based on the dicarboxylic acid or maleic anhydride represented by the formula (4) The copolymer which has 0-30 weight% with respect to the sum total of the weight of a structural unit (a) and a structural unit (I) based on the weight% and the other monomer which can be copolymerized.
2) The structural unit (e) based on the polyalkylene glycol ester represented by the formula (6) (50 to 99% by weight), the structural unit (e) based on the monocarboxylic acid represented by the formula (7) and 1 to 50% by weight The copolymer which has 0-30 weight% of structural units (u) based on the other monomer which can superpose | polymerize with respect to the sum total of the weight of a structural unit (d) and a structural unit (e).
In 1), the structural unit (a) based on the polyalkylene glycol ether represented by the formula (3) and the structural unit (a) based on the dicarboxylic acid or maleic anhydride represented by the formula (4) are composed of% by weight. The ratio of unit (a): structural unit (b) = 50 to 99: 1 to 50 is not preferable because the water reduction performance and slump loss prevention performance of the cement composition are deteriorated if the ratio is outside this range. Preferably, it is the ratio of structural unit (A): structural unit (A) = 75 to 99: 1 to 25 in% by weight. In addition, the structural unit (c) based on another copolymerizable monomer is 0 to 30% by weight, preferably 10%, based on the total weight of the structural unit (a) and the structural unit (a). % By weight or less.
In 2), the structural unit (e) based on the polyalkylene glycol ester represented by the formula (6) and the structural unit (e) based on the monocarboxylic acid represented by the formula (7) ): Structural unit (e) = 50 to 99: 1 to 50, and if it is out of this range, the water reduction performance and slump loss prevention performance of the cement composition are unfavorable. Preferably, the ratio of structural unit (e): structural unit (e) = 65 to 99: 1 to 35 in% by weight. In addition, the structural unit (c) based on another copolymerizable monomer is 0 to 30% by weight, preferably 10%, based on the sum of the weights of the structural unit (d) and the structural unit (e). % By weight or less.
In 1) or 2), the other monomer copolymerizable as the structural unit (c) may or may not be present.

  Examples of other monomers copolymerizable as the structural unit (c) include ethylene, propylene, butadiene, isoprene, 2-methyl-1-butene, 1-hexene, isobutylene, diisobutylene, 1-dodecene, styrene, Examples include p-methylstyrene, isopropyl vinyl ether, butyl vinyl ether, isopropenyl methyl ether, vinyl acetate, acrylamide, (meth) acrylic acid and its salts, alkyl esters of (meth) acrylic acid, and the like. The above may be used simultaneously, and the ratio is 30% by weight or less of the structural units of the entire copolymer. Exceeding this range is not preferred because the polycarboxylic acid compound (PC) may hinder the performance that should be exhibited originally.

In the formula (3), R ² , R ³ and R ⁴ are each independently a hydrogen atom or a methyl group.
In the formula (3), formula (5) and formula (6), AO is an oxyalkylene group having 2 to 4 carbon atoms, and examples thereof include an oxyethylene group, an oxypropylene group and an oxybutylene group, preferably an oxyethylene group. And an oxypropylene group, more preferably an oxyethylene group.
R ⁵ is an alkylene group having 1 to 4 carbon atoms, and includes a methylene group, an ethylene group, a propylene group, and a butylene group. The propylene group is preferably a 1,2-propylene group, and the butylene group is 1 , 2-butylene group and 2,3-butylene group are preferred. If the number of carbon atoms in R ⁵ exceeds 4, it is not preferable because production is difficult.
p is the number of added moles of an oxyalkylene group having 2 to 4 carbon atoms, and is 1 to 150, preferably 10 to 100.

M ¹ , M ² and M ³ in formula (4) and formula (7) 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.
The organic ammonium is an ammonium derived from an organic amine, and examples of the organic amine include alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine, methylamine, dimethylamine, triethylamine, ethylamine, diethylamine, and triethylamine. Preferably, they are monoethanolamine, methylamine, ethylamine, and diethylamine.

X is -OM ² or -Y- (AO) _r R ⁷ [(5)]. Y is an ether group or imino group, the ether group represents —O—, and the imino group represents —NH—.
R ⁶ , R ⁷ and R ⁹ are a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, and examples of the hydrocarbon group having 1 to 22 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. , Isobutyl group, tert-butyl group, amyl group, isoamyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, isotridecyl group, tetradecyl group, hexadecyl group, Examples include octadecyl group, oleyl group, docosyl group, phenyl group, benzyl group, cresyl group, butylphenyl group, octylphenyl group, nonylphenyl group, and naphthyl group. When the number of carbon atoms of the hydrocarbon group represented by R ⁶ , R ⁷ and R ⁹ exceeds 22, the hydrophilicity of the compound represented by (2) is not preferable.
In the formula (6), R ⁸ is a hydrogen atom or a methyl group.
In the formula (5), r is an average added mole number of an oxyalkylene group having 2 to 4 carbon atoms, preferably 1 to 150, and preferably 3 to 100.
In the formula (6), s is an average added mole number of an oxyalkylene group having 2 to 4 carbon atoms, preferably 1 to 150, and preferably 3 to 100.

The polycarboxylic acid compound used in the cement additive composition of the present invention can be obtained by polymerization using a polymerization initiator by a known method. The polymerization method may be bulk polymerization or solution polymerization. When water is used as a solvent in solution polymerization, persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate, hydrogen peroxide, and water-soluble azo initiators can be used. Accelerators such as sodium, hydroxylamine hydrochloride, thiourea and sodium hypophosphite can be used in combination.
Also, in solution polymerization, lower alcohols such as methanol, ethanol and isopropanol, aliphatic hydrocarbons such as n-hexane, 2-ethylhexane and cyclohexane, aromatic hydrocarbons such as toluene and xylene, acetone, methyl ethyl ketone, ethyl acetate, etc. In the case of polymerization using an organic solvent or bulk polymerization, organic peroxides such as benzoyl peroxide, di-t-butyl peroxide and t-butylperoxyisobutyrate, and azo compounds such as azoisobutyronitrile Etc. can be used. In this case, a chain transfer agent such as thioglycolic acid or mercaptoethanol can also be used.

The cement additive composed of the polyether compound (A) represented by the formula (1) or the formula (2) of the present invention may be used alone, but is particularly used in combination with the polycarboxylic acid compound (PC). The effect can be exhibited more.
When the polyether compound (A) and the polycarboxylic acid compound (PC) are used in combination as an additive for cement, the polyether compound (A) represented by the formula (1) or the formula (2) and the polycarboxylic acid are used. The composition ratio of the acid compound (PC) is 1 to 80% by weight of the polyether compound (A) and 20 to 99% by weight of the polycarboxylic acid compound (PC), preferably the polyether compound (A) 5 To 50% by weight and polycarboxylic acid compound (PC) 50 to 95% by weight, more preferably 10 to 30% by weight polyether compound (A) and 70 to 90% by weight polycarboxylic acid compound (PC). It is. If the amount of the polyether compound (A) is less than 1% by weight with respect to the polycarboxylic acid compound (PC), the effect of reducing the viscosity of the cement composition is not seen, so a large amount of addition is necessary. This is not preferable because of delay in curing of hydraulic materials such as cement and cement. When the amount of the polyether compound (A) is more than 50% by weight with respect to the polycarboxylic acid compound (PC), a large amount of addition is required to increase the water reduction of the cement composition. From this point of view, excessive addition is required, and even if excessive addition is carried out, a viscosity reducing effect corresponding to the addition is not seen, which is not preferable in terms of economy.

The cement additive of the present invention can be used as it is, but it can also be diluted with water. When diluted with water, it can be used by diluting and dissolving in the kneading water for the cement composition. It can also be added and used simultaneously with the pouring of the kneading water. It can also be added and used, and it can also be used after being added to the cement composition once kneaded.
The cement composition of the present invention contains at least water, cement, and the additive of the present invention, and may be blended with aggregates such as sand and gravel, and other extenders such as clay, if necessary. Examples of cement include Portland cements such as normal, early strength, medium-ripening, and belite, and various mixed cements and gypsums that are blended with mineral powders such as blast furnace slag, silica fume, fly ash, and limestone. Can be mentioned. Further, various types of mineral powders such as blast furnace slag, silica fume, fly ash, and limestone may be blended with the various cements. There are no particular restrictions on the aggregate, and river sand, mountain sand, land sand, crushed sand, river gravel, crushed stone, artificial aggregate, concrete recycled aggregate, etc. can be used, its type, The mixing ratio can be appropriately selected and used.

The additive used for the cement composition is the additive for cement of the present invention, and the cement additive is 0.01 to 10% by weight, preferably 0.02 to 10% by weight based on the powder of cement or the like in the cement composition. 3% by weight, and 0.01% by weight is not preferable because the effect cannot be obtained, and the use of more than 10% by weight does not improve the effect.
In addition, the water ratio of the cement composition is 15 to 300% by weight with respect to the powder such as cement. However, when the ratio of water in the cement composition is low, viscosity becomes a problem. Therefore, water is preferably 15 to 50% by weight, more preferably 20 to 45% by weight, as a range in which the effects of the present invention are easily exhibited.
The cement additive used in the cement composition is 0.01 to 5% by weight, preferably 0.02 to 3% by weight, based on the weight of cement and other hydraulic materials in the cement composition, An amount of 0.01% by weight is not preferable because a sufficient dispersion effect cannot be obtained.
The cement additive of the present invention can be used in combination with other additives as required, as long as the effect is not impaired. As other additives, the main component is naphthalene sulfonic acid formaldehyde condensate salt, melamine sulfonic acid formaldehyde condensate salt, aromatic sulfonic acid formaldehyde condensate salt, lignin sulfonic acid salt, modified lignin sulfonic acid salt , Other water reducing agents for cement, such as polyoxyalkylene aryl ether derivatives, oxycarboxylic acid salts, air entrainers, swelling agents, waterproofing agents, curing retarders, curing accelerators, quick setting agents, drying shrinkage reducing agents, A foaming agent, a rust preventive agent, etc. are mentioned.

Synthesis Example 1 [Synthesis of Polyether Compound (a)]
To a stainless steel 5 liter pressure resistant reactor equipped with a stirrer, pressure gauge, thermometer, safety valve, burst valve, gas blowing pipe, exhaust pipe, cooling coil, steam jacket,
146 g of triethylenetetramine (manufactured by Tosoh Corporation, active hydrogen bonded to nitrogen atom per mole: 6 equivalents) was charged, and the system was replaced with nitrogen gas. Under agitation, the temperature was raised to 80 ° C., and then, 792 g of ethylene oxide (3 per equivalent of active hydrogen bonded to nitrogen atom) from a pressure vessel prepared separately at 80 to 100 ° C. and 0.05 to 0.5 MPa (gauge pressure). Mol) was added under pressure by a nitrogen gas pressure from a gas blowing tube. After the addition, the reaction was continued under the same conditions until the internal pressure became constant. While blowing nitrogen gas, the treatment was carried out at 70 to 80 ° C. and 13 kPa or less for 0.5 hour to remove unreacted ethylene oxide from the system. After cooling to 40 ° C., 2 g of sodium hydroxide was added and the system was replaced with nitrogen gas. After heating up to 80 ° C. with stirring, 1,392 g of propylene lenoxide (4 moles per equivalent of active hydrogen bonded to nitrogen atoms) was conducted from 80 to 100 ° C. and 0.05 to 0.5 MPa from a gas blowing tube. Pressurized with nitrogen gas. After completion of the addition, the reaction was carried out for 3 hours under the same conditions. The treatment was performed at 70 to 80 ° C. and 13 kPa or less for 0.5 hour while blowing nitrogen gas. After returning to normal pressure with nitrogen gas and cooling to 30 ° C., the reaction product was taken out from the pressure-resistant reactor to obtain a brown polyether compound (a).

Synthesis Example 2 [Synthesis of Polyether Compound (b)]
In the same apparatus as that used in Synthesis Example 1, 109.5 g of triethylenetetramine (manufactured by Tosoh Corporation) and 1.5 g of KOH were charged, and the system was replaced with nitrogen gas. After heating up to 80 ° C. with stirring, 783 g of propylene oxide (3 mol per equivalent of active hydrogen bonded to nitrogen atom) under the conditions of 80 to 100 ° C. and 0.05 to 0.5 MPa was supplied from a gas blowing tube to nitrogen gas. Pressurized by pressure. After the addition, the reaction was continued under the same conditions until the internal pressure became constant. While nitrogen gas was blown in, treatment was performed at 70 to 80 ° C. and 13 kPa or less for 1.0 hour, and unreacted propylene oxide was excluded from the system. Nitrogen gas was used to set the internal pressure to 0.05 MPa, and under conditions of 80 to 100 ° C. and 0.05 to 0.5 MPa, 1,386 g of ethylene oxide (7 mol per equivalent of active hydrogen bonded to nitrogen atoms) was introduced into the nitrogen from the gas blowing tube. Pressurized with gas. After completion of the addition, the mixture was reacted for 2 hours under the same conditions, and then treated at 70 to 80 ° C. and 13 kPa or less for 0.5 hour while blowing nitrogen gas. After returning to normal pressure with nitrogen gas and cooling to 30 ° C., 303 g of KOH was charged, and the system was replaced with nitrogen gas. After the temperature was raised to 80 ° C., 45 g of methyl chloride was added under pressure from a gas blowing tube by nitrogen gas pressure at 80 to 100 ° C. After the addition, the reaction was continued under the same conditions until the internal pressure became constant. While blowing nitrogen gas, treatment was performed at 70 to 80 ° C. and 13 kPa or less for 1 hour to remove unreacted methyl chloride from the system. After cooling the internal pressure to 0.05 MPa with nitrogen gas and cooling to 60 ° C., the reaction product was taken out into a 5 liter beaker, and 1 liter of ion exchange water at 60 ° C. was gradually added while stirring with a crow bar. After completion of the addition of ion-exchanged water, the mixture was sufficiently stirred with a glass rod and allowed to stand in a thermostatic chamber adjusted to 70 ° C. in a sealed state for about 2 hours. After standing, the upper polyether layer and the aqueous layer were separated, the polyether layer was taken in a 5 L eggplant flask, and dehydrated at 90 to 100 ° C. under 13 kPa in a nitrogen gas atmosphere. After dehydration, 40 g of adsorbent KYOWARD 700 (manufactured by Kyowa Chemical Industry Co., Ltd.) is added, treated in a nitrogen gas atmosphere at 90-100 ° C. and 13 kPa, and the resulting salt and adsorbent are separated by filtration. An ether compound (b) was obtained.

Synthesis Example 3 [Synthesis of Polyether Compound (f)]
150 g of polyethyleneimine (manufactured by Wako Pure Chemical Industries, Ltd., average molecular weight of about 600, active hydrogen bonded to nitrogen atom per mole: about 14 equivalents) and KOH of 2 g are charged in the same apparatus as used in Synthesis Example 1. The inside of the system was replaced with nitrogen gas. After heating up to 80 ° C. under stirring, 1,232 g of ethylene oxide (8 moles per equivalent of active hydrogen bonded to nitrogen atoms) was supplied from a gas blowing tube under conditions of 80 to 100 ° C. and 0.05 to 0.5 MPa. Pressurized by pressure. After the addition, the reaction was continued under the same conditions until the internal pressure became constant. While blowing nitrogen gas, the treatment was carried out at 70 to 80 ° C. and 13 kPa or less for 0.5 hour to remove unreacted ethylene oxide from the system. After increasing the internal pressure to 0.05 MPa with nitrogen gas, 504 g of 1,2-butylene oxide (2 moles per equivalent of active hydrogen bonded to nitrogen atoms) at 80 to 100 ° C. and 0.05 to 0.5 MPa. ) Was added under pressure by a nitrogen gas pressure from a gas blowing tube. After the addition, the reaction was continued under the same conditions until the internal pressure became constant. While blowing nitrogen gas, the treatment was carried out at 70 to 80 ° C. and 13 kPa or less for 0.5 hour to remove unreacted butylene oxide from the system. After pressurizing the internal pressure to 0.05 MPa, 812 g of propylene oxide (2 mol per equivalent of active hydrogen bonded to a nitrogen atom) was added from a gas blowing tube under conditions of 80 to 100 ° C. and 0.05 to 0.5 MPa. Pressurized with gas. After completion of the addition, the reaction was carried out for 3 hours under the same conditions. The treatment was performed at 70 to 80 ° C. and 13 kPa or less for 0.5 hour while blowing nitrogen gas. The pressure was returned to normal pressure with nitrogen gas, and after cooling to 30 ° C., the reaction product was taken out from the pressure resistant reactor to obtain a brown polyether compound (f).
Table 1 shows the polyether compounds obtained in the above synthesis examples.
Thereafter, the polyether compounds (c), (d), (e) and (g) to (l) shown in Table 1 were synthesized in the same manner.

Synthesis Example 4 [Synthesis of Polycarboxylic Acid Compound (I)]
Into a 2 liter four-necked flask equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet tube, 916 g (0.5 mol) of polyoxyethylene (average number of moles added 40) allyl methyl ether, 49 g of maleic anhydride ( 0.5 mol) and 200 g of toluene were weighed and heated to 50 to 55 ° C. in a nitrogen gas atmosphere to be uniformly dissolved. Subsequently, 5.0 g of benzoyl peroxide was added and reacted at 80 to 85 ° C. for 8 hours. Subsequently, toluene was removed under a reduced pressure of 13 kPa or less while blowing nitrogen gas in the range of 80 to 90 ° C. After cooling the reaction product to 60 ° C., 1,455 g of ion-exchanged water was added to obtain an aqueous solution containing the polycarboxylic acid compound (I). The water content of the aqueous solution obtained by weight change after standing for 2 hours in a thermostat adjusted to 120 ± 2 ° C. of 10 g of the aqueous solution was 39.8% by weight, and the weight average molecular weight of the copolymer obtained by GPC was 22,600. (Converted using polyethylene glycol as a standard).

Synthesis Example 5 [Synthesis of polycarboxylic acid compound (b)]
520 g of ion-exchanged water was weighed in a 3 liter four-necked flask equipped with a stirrer, two dropping funnels, a cooling tube, a thermometer, and a nitrogen gas introduction tube, and heated to 65 to 70 ° C. in a nitrogen gas atmosphere. . Separately prepared polyoxyethylene (average number of moles 23) methyl ether methacrylate 734 g, methacrylic acid 93.7 g, mercaptoethanol 5.8 g dissolved in ion-exchanged water 560 g and ammonium persulfate 11.0 g ion-exchanged The initiator solution dissolved in 180 g of water was weighed in a separate dropping funnel and dropped at 65 to 70 ° C. over 5 hours. After completion of the dropwise addition, the mixture was further stirred for 2 hours to obtain an aqueous solution containing the polycarboxylic acid compound (b). The water content of the aqueous solution was 40.1% by weight, and the weight average molecular weight determined by GPC was 25,800, as determined by the change in weight after leaving 10 g of the aqueous solution at 120 ± 2 ° C. for 2 hours.

Synthesis Example 6 [Synthesis of polycarboxylic acid compound (C)]
Into a 3-liter four-necked flask equipped with a stirrer, dropping funnel, condenser, thermometer and nitrogen gas inlet tube, 762 g of polyoxyethylene (average number of moles of 25) allyl methyl ether, 73.3 g of maleic anhydride and ions 1,070 g of exchange water was weighed and heated to 60 to 65 ° C. in a nitrogen gas atmosphere to be uniformly dissolved. Subsequently, a solution prepared by dissolving 12.0 g of ammonium persulfate in 200 g of ion-exchanged water was dropped at 60 to 65 ° C. over 6 hours. After completion of the dropwise addition, the mixture was further stirred for 3 hours to obtain an aqueous solution containing the polycarboxylic acid compound (C). The water content of the aqueous solution was 40.0% by weight, and the weight average molecular weight determined by GPC was 23,800, as determined by the weight change after standing for 2 hours in a thermostat adjusted to 120 ± 2 ° C.

Example 1
25 g of the polyether compound (a) obtained in Synthesis Example 1 shown in Table 1 and 251.2 g of the aqueous solution containing the polycarboxylic acid compound (I) obtained in Synthesis Example 2 were weighed in a 2-liter beaker, and ions were added thereto. The exchange water 222.8g was added and it stirred for 15 minutes. Subsequently, 1 g of commercially available Dis Home CC-118 (manufactured by Nippon Oil & Fats Co., Ltd.) was added as an antifoaming agent with stirring, and dispersed uniformly to prepare a cement additive (1).
Using the above-prepared cement additive (1) and air-entraining agent 6.0 g [Floric AE (manufactured by Floric Co., Ltd.) diluted 10 times (by weight) with water] as follows: A concrete test was conducted.
Table 2 shows the composition of the additive for cement.

"Concrete test"
The concrete test was conducted in a test room adjusted to a temperature of 20 ± 3 ° C. and a humidity of 50% to 70%.
"Adjustment of concrete"
50L forced biaxial mixer, normal portland cement (made by Taiheiyo Cement Co., Ltd.) 14.6kg, coarse aggregate (crushed stone from Torigatayama, Kochi Prefecture, 27.2kg), fine aggregate (Kimitsu hill sand from Chiba Prefecture) Then, 7.3 kg of surface water ratio (0.8%) and 17.0 kg (crushed sand produced in Tanuma, Tochigi Prefecture, surface water ratio 0.1%) were added and air-kneaded for 15 seconds. After completion of empty kneading, 5.0 kg of kneaded water in which a predetermined amount of cement additive and air entraining agent are mixed and dispersed in clean water is added, kneaded for 120 seconds, and concrete is discharged into an 80 L type resin container. It was adjusted.

"Measurement method of concrete properties"
・ Slump flow The concrete is filled in the slump cone described in JISA1101 placed in the center part of the 90cm x 90cm steel bottom plate, only the cone is pulled upward, and the maximum diameter of the concrete when the concrete spread is stationary and the direction perpendicular thereto. The diameter is measured and an average value is obtained in units of 0.5 cm to obtain a slump flow value.
-Air quantity It measured based on JISA1128 using the Washington type air meter (made by Tesco Co., Ltd.).
・ Inclined flow test Cement and concrete papers No. Measurement was performed at an inclination angle of 23.0 degrees using an inclined flow tester (manufactured by New Tech Co., Ltd.) described in 56 (2002) (issued by Cement Association). The measurement is carried out by pushing a slump measuring stick 10 times per layer into a 10-L loading portion at the top of the tester, and throwing it into three layers in total, making the upper surface uniform with a scissors. After the concrete has been charged, the gate is opened quickly, and the speed at which the spilled concrete passes between the sensors 25 cm and 30 cm from the gate (V1) and the speed at which the concrete passes between the sensors 30 cm and 35 cm from the gate (V2) Is measured, and the average of V1 and V2 is determined as the gradient flow velocity. The time required for the concrete to reach a distance of 60 cm after opening the gate was also measured.
The slump flow measurement and the inclined flow test were performed almost simultaneously after the concrete was adjusted.
The results are shown in Table 3.

Example 2
Instead of the polyether compound (a) in Example 1, the polyether compound (b) shown in Table 1 and the polycarboxylic acid compound (ii) instead of the polycarboxylic acid compound (I) in Example 1 were used. Use and adjust the cement additive (2) in the same manner as in Example 1 except that the content ratio was adjusted to the weight ratio shown in Table 2, and the cement additive (2) and the air entraining agent were used. Concrete tests were conducted using the ratios in Table 3. The results are shown in Table 3.
Examples 3-8
Concrete tests were conducted in the same manner as in Example 1 except that the cement additives (3) to (8) shown in Table 2 using the polyether compounds shown in Table 1 were used. The results are shown in Table 3.

Comparative Example 1
Instead of the polyether compound (b) in Example 2, using the cement additive (9) prepared in the same manner as in Example 1 except that the compound (i) shown in Table 1 was used, A concrete test was conducted using cement additive (9) and air entraining agent in the proportions shown in Table 3. The results are shown in Table 3.
Comparative Examples 2-4
Cement additive (10) prepared in the same manner as in Example 1 except that the compounds (j) to (l) shown in Table 1 were used instead of the polyether compound (i) in Comparative Example 1. Concrete tests were carried out using (12) and air entraining agents in the proportions shown in Table 3. The results are shown in Table 3.
Comparative Example 5
Instead of the cement additive (9) in Comparative Example 1, a concrete high-performance AE water reducing agent (SEICAMENT 1100NT, manufactured by Nihon Sika Co., Ltd.) and an air entraining agent were used in the proportions shown in Table 3, respectively. It was. The results are shown in Table 3.

From the results of Table 3, in the examples using the cement additive of the present invention, the concrete adjusted so that the slump flow and the air amount are within the specified ranges have a high inclined flow rate in the inclined flow test, and the final The flow arrival time is also fast, and it is judged that the viscosity is low and easy to handle. On the other hand, the concrete of the comparative example has a slump flow and air amount within the specified range similar to the example, but the inclined flow speed is slower and the final flow arrival time is slower than the example, so that it is difficult to handle and has a high viscosity. To be judged. In Comparative Example 2, the polyether compound (j), which is an additive component for cement, has a single polyether chain composition of only oxyethylene groups, and the chain length is too long. It can be judged. In Comparative Example 1 and Example 5, although the oxyalkylene unit of the polyether chain is the same, the flow test result of Example 5 bonded in a block form is larger than that of Comparative Example 1 bonded in a random form. It can be judged that it is good and has a viscosity reducing effect. Further, in Comparative Example 3 and Comparative Example 4 having the same block-like polyether composition, since the balance of the block composition of the polyether portion is not preferable in Comparative Example 3, it can be determined from the test results that the viscosity is high. Since the polyether chain length is short, it can be judged from the test results that the viscosity is high.
Furthermore, the case of the comparative example 5 using a commercial item is the same as that of another comparative example, and compared with the example, the inclined flow speed is slower than the example and the final flow arrival time is also slower.

Claims (5)

Formula (1) or Formula (2)

(Wherein, Z is a residue of a compound having 5 or more and less than 40 active hydrogens bonded to a nitrogen atom and having 3 or more nitrogen atoms, A ¹ O is an oxyethylene group , a is a a = 1 to 20 with an average addition number of moles is indicated by a ¹ O Luo carboxymethyl ethylene group, in ^{a 2} O is an oxyalkylene group having 3 or 4 carbon atoms, carbon atoms b is represented by ^{a 2} O The average number of moles added of 3 or 4 oxyalkylene groups is b = 1 to 20, the relationship between a and b is 0.5 <a / b <5, and 5 ≦ (a + b) ≦ 20 , R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and n is 5 or more and less than 40.)
A cement additive comprising 1 to 95% by weight of a polyether compound (A) represented by formula (5) and 5 to 99% by weight of a polycarboxylic acid compound (PC). The structural unit (a) based on the polyalkylene glycol ether represented by the formula (3) is 50 to 99% by weight of the polycarboxylic acid compound (PC), based on the dicarboxylic acid or maleic anhydride represented by the formula (4) 1 to 50% by weight of the structural unit (a) and the structural unit (c) based on the other copolymerizable monomer is 0 to 0% of the sum of the weights of the structural unit (a) and the structural unit (a). cement additive according to claim 1 Symbol mounting a copolymer having 30 wt%.

(However, R ² , R ³ and R ⁴ each independently represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 1 to 4 carbon atoms, and R ⁶ represents a hydrogen atom or a carbon atom having 1 to 22 carbon atoms. A hydrogen group and AO are 1 type or 2 types or more of a C2-C4 oxyalkylene group, and when it is 2 or more types, it may be a block form or a random form, p is an average of a C2-C4 oxyalkylene group (The number of moles added is p = 1 to 150.)

(Where X represents —OM ² or —Y— (AO) _r R ⁷ [formula (5)], and M ¹ and M ² each independently represent a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or organic. Y represents an ether group or an imino group, R ⁷ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, AO represents one or more of an oxyalkylene group having 2 to 4 carbon atoms, In the case of 2 or more types, it may be a block shape or a random shape, and r is an average added mole number of an oxyalkylene group having 2 to 4 carbon atoms, and r = 1 to 150.) The structural unit (e) based on the monocarboxylic acid represented by the formula (7) in which the polycarboxylic acid-based compound (PC) is 50 to 99% by weight based on the polyalkylene glycol ester represented by the formula (6) A copolymer having 1 to 50% by weight and 0 to 30% by weight of the structural unit (c) based on another monomer copolymerizable with respect to the sum of the weights of the structural unit (d) and the structural unit (e) cement additive according to claim 1 Symbol placement is a polymer.

(However, R ⁸ represents a hydrogen atom or a methyl group, R ⁹ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, and AO is one or more kinds of oxyalkylene groups having 2 to 4 carbon atoms. In the case of two or more types, it may be block or random, and s is the average number of moles of oxyalkylene groups having 2 to 4 carbon atoms, and s = 1 to 150.)

(However, R ¹⁰ represents a hydrogen atom or a methyl group, and M ³ represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, or organic ammonium.) A cement composition comprising the additive for cement according to any one of claims 1 to 3 , an aggregate, water, and cement. 5. The cement composition according to claim 4 , wherein the ratio of water to cement is 45% or less by weight.