JP3293294B2 - Additive for cement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a novel cement additive, and more particularly, to a cement additive which is uniform in an aqueous solution state, has low air entrainment, and has high water reducing property and high slump loss preventing property. It relates to the agent.

[0002]

2. Description of the Related Art Conventionally, as additives for cement compounds such as concrete and mortar, water-reducing agents such as naphthalene sulfonic acid formaldehyde condensate, melamine sulfonic acid formaldehyde condensate, lignin sulfonate and polycarboxylic acid compounds have been used. It is used as In recent years, there has been an increasing demand for high strength concrete, and it has become necessary to reduce the amount of water in the concrete composition.
Although the above-mentioned water reducing agent has an effect of reducing water in the concrete composition, it has a drawback that a decrease in the fluidity of the concrete composition which occurs with time, that is, a so-called slump loss cannot be avoided. In order to solve this drawback, a copolymer having an excellent effect of preventing slump loss and having a large water-reducing property has been disclosed (JP-A-63-285140). However, when this compound is used, there is a disadvantage that the amount of entrained air is too large. In general, in the above water reducing agent, a polycarboxylic acid compound is often used.However, when a polycarboxylic acid compound is used as a water reducing agent, air entrainment is large, and in most cases, a combined use of an antifoaming agent is required. Becomes
Water-soluble or water-dispersible defoaming agents generally have poor defoaming properties, and those having a defoaming effect tend to separate in water. When a polycarboxylic acid compound is used as a water reducing agent, it is almost used as an aqueous solution in terms of workability.
Therefore, when an antifoaming agent is added to an aqueous solution of a polycarboxylic acid compound, there is a problem that separation occurs with time and it is difficult to add an initial target amount. Also, too many air bubbles in a concrete molded product cause deterioration in appearance quality. Therefore, as a method for improvement, a method using a terminal esterified product of a defoamable polyoxyalkylene block polymer has been disclosed (Japanese Patent Application Laid-Open No. H10-163,086). No. 61-111950). However, although this method has the effect of improving appearance deterioration due to large bubbles and the like, it has a drawback in that all of them cannot be sufficiently satisfied with respect to air entrainment, water reduction and slump loss prevention.

[0003]

SUMMARY OF THE INVENTION Under such circumstances, the present invention is uniform in an aqueous solution state, has low air entrainment during use, and has both high water reduction and high slump loss prevention. The purpose of the present invention is to provide an additive for cement.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to develop a cement additive having the above-mentioned preferable properties, and as a result, have found that a copolymer of a specific polyoxyalkylene derivative and maleic anhydride can be obtained. When a specific polyoxyalkylene derivative having an antifoaming effect is reacted at a predetermined ratio to the coalesced product, it is uniform when it is used as an aqueous solution, and has low air entrainment during operation, high water reduction and high slump loss. The inventors have found that the present invention has both preventive properties, and have completed the present invention based on this finding.

That is, the present invention relates to (A) (a) a general formula [1] R ¹ O (A ¹ O) _m R ² ... [1] wherein R ¹ is an alkenyl group having 2 to 5 carbon atoms , A ¹ O has 2 carbon atoms in which at least 50 mol% is an oxyethylene group.
An oxyalkylene group of 1 to 4, R ² is a hydrocarbon group having 1 to 18 carbon atoms, and m is an integer of 1 to 200]. to 100 parts by weight of the copolymer to, (B) the general formula ^{[2] R 3 O (C} 2 H 4 O) x (a 2 O) y (C 2 H 4 O) z H ... [2] [ In the formula, R ³ is a hydrocarbon group or an acyl group having 1 to 22 carbon atoms, A ² O is an oxyalkylene group having 3 or 4 carbon atoms, x
Is an integer of 0 or 1 to 20, y is an integer of 10 to 100, z
Is an integer of 0 or an integer of 1 to 20, and satisfies a relationship of y ≧ x + z ≧ 1, and the (C ₂ H ₄ O) chain and the (A ² O) chain are block-shaped adducts. An object of the present invention is to provide an additive for cement containing, as a main component, a product obtained by reacting 0.01 to 5 parts by weight of an oxyalkylene derivative.

Hereinafter, the present invention will be described in detail. In the additive for cement of the present invention, a copolymer of the component (A) used as a raw material of a reactant used as a main component includes:
(A) The polyoxyalkylene derivative represented by the general formula [1] R ¹ O (A ¹ O) _m R ² ... [1] and (b) maleic anhydride are essential monomers. In the general formula [1], R ¹ is an alkenyl group having 2 to 5 carbon atoms, and specific examples thereof include a vinyl group, an allyl group, a methallyl group, a 3-butenyl group, a 4-pentenyl group, and a 3-methyl-
And a 3-butenyl group. A ¹ O has 2 to 2 carbon atoms.
The oxyalkylene group of No. 4 is, for example, an oxyethylene group, an oxypropylene group, an oxybutylene group, an oxytetramethylene group or the like, and it is necessary that at least 50 mol% is an oxyethylene group. When this oxyethylene group is less than 50 mol%, the water solubility is insufficient and the water reduction is poor. Further, m is an integer of 1 to 200. When m is larger than 200, the viscosity becomes high, and the production becomes difficult. Further, R ² is a hydrocarbon group having 1 to 18 carbon atoms, and specific examples include a methyl group, an ethyl group,
Propyl, isopropyl, butyl, isobutyl, tert-butyl, amyl, isoamyl, hexyl, heptyl, 2-ethylhexyl, octyl,
Nonyl, decyl, undecyl, dodecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, oleyl, phenyl, benzyl, cresyl, butylphenyl, octylphenyl, nonylphenyl, naphthyl Such as a saturated hydrocarbon group, an unsaturated hydrocarbon group, an aromatic group, and a substituted aromatic group.

The copolymer of the component (A) comprises, as essential monomers, the polyoxyalkylene derivative represented by the general formula [1] of the component (A) and the maleic anhydride of the component (B). These can be easily obtained by copolymerizing them with an organic peroxide initiator such as benzoyl peroxide or an azo initiator such as azobisisobutyronitrile. At the time of this copolymerization, a solvent such as benzene, toluene, or xylene can be used, if necessary, or a copolymerizable monomer such as styrene or vinyl acetate can be added. Further, the polyoxyalkylene derivative represented by the general formula [1] of the component (A) and (B)
The ratio of the components used to maleic anhydride was 3: 7 in molar ratio.
To 7: 3, preferably 1: 1. The copolymer of the component (A) thus obtained was 1
Species may be used, or two or more may be used in combination.

In the present invention, the copolymer of the component (A) is compared with the general formula [2] of the component (B) R ³ O (C ₂ H ₄ O) _x (A ² O) _y (C ₂ H ₄ O) _z H A polyoxyalkylene derivative represented by [2] is reacted.
In the above general formula [2], R ³ is a hydrocarbon group having 1 to 22 carbon atoms or an acyl group, and the hydrocarbon group includes:
For example, methyl group, ethyl group, propyl group, isopropyl group, 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, dodecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, oleyl,
Examples include saturated hydrocarbon groups such as behenyl group, phenyl group, benzyl group, cresyl group, butylphenyl group, octylphenyl group, nonylphenyl group, and naphthyl group, unsaturated hydrocarbon groups, aromatic groups, substituted aromatic groups, and the like. Can be Also,
Examples of the acyl group include acetic acid, propionic acid, butyric acid, isobutyric acid, caproic acid, caprylic acid, 2-ethylhexanoic acid, capric acid, undecylenic acid, lauric acid,
Saturated acyl groups derived from myristic acid, palmitic acid, margaric acid, stearic acid, arachiic acid, behenic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, isopalmitic acid, isostearic acid, benzoic acid, etc. Examples include an unsaturated acyl group and an aromatic acyl group.

A ² O is an oxyalkylene group having 3 or 4 carbon atoms, and specific examples thereof include an oxypropylene group, an oxybutylene group and an oxytetramethylene group. x and z are each 0 or an integer of 1 to 20, and when it is larger than 20, the water solubility increases and the defoaming effect becomes insufficient. y is an integer of 10 to 100;
Outside of this range, the defoaming effect becomes insufficient. x, y
And z need to satisfy the relationship y ≧ x + z,
The (C ₂ H ₄ O) chain and the (A ² O) chain are block-shaped adducts. As the polyoxyalkylene derivative of the component (B), one type may be used, or two or more types may be used in combination.

The polyoxyalkylene derivative of the component (B) is used in an amount of 100 parts by weight of the copolymer of the component (A).
It is necessary to react at a rate of 0.01 to 5 parts by weight. When the amount is less than 0.01 part by weight, the defoaming property is insufficient, and when it exceeds 5 parts by weight, the effect of improving the defoaming property is not so much seen for the amount. The reaction product of the copolymer of the component (A) and the polyoxyalkylene derivative of the component (B) includes alkali metal compounds such as sodium hydroxide, potassium hydroxide, and sodium methylate; calcium hydroxide, magnesium hydroxide, and the like. An alkaline earth metal compound of the formula: can be easily obtained by mixing in the presence of amines such as ammonia, monoethanolamine, diethanolamine, triethanolamine and the like, or by mixing and heating. It can also be obtained by mixing and heating without a catalyst.

The additives for cement of the present invention may include, if desired, alkali metal compounds such as sodium hydroxide and potassium hydroxide; alkaline earth metal compounds such as calcium hydroxide and magnesium hydroxide; ammonia, monoethanolamine, diethanolamine. And amines such as triethanolamine. The cement additive of the present invention is usually added at a ratio of 0.01 to 3% by weight, preferably 0.04 to 1% by weight, based on the cement. When the amount is less than 0.01% by weight, the effects of the present invention, such as low air entrainment, high water reduction and low slump loss, are not sufficiently exhibited. When the amount exceeds 3% by weight, the effects of the present invention are exhibited. However, it is not preferable because workability such as setting delay is deteriorated. Additives for cement of the present invention, to the extent that the performance is not impaired, naphthalenesulfonic acid formalin condensate salt, melaminesulfonic acid formaldehyde condensate salt, other additives such as polycarboxylic acid compounds, or air entrainer, It may be used in combination with a rust inhibitor, a setting accelerator, a setting retarder and the like.

[0012]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. Production Example 1 In a four-necked flask equipped with a stirrer, a nitrogen blowing tube, a thermometer, and a reflux tube, a molar ratio of polyoxyethylene (average number of moles added: 11) monoallyl monomethyl ether to maleic anhydride of 1: 1. Of a copolymer of oleyl alcohol, 2.5 g of a block adduct of propylene oxide (30 mol) of oleyl alcohol and ethylene oxide (8 mol), and 0.5 g of sodium methylate.
The reaction was carried out at 5 to 105 ° C for 2 hours to obtain the desired product. When a 20 wt% aqueous solution of this reaction product was prepared, it was a homogeneous liquid. Production Examples 2 to 10 A polyoxyalkylene derivative of the general formula (1) shown in Table 1, maleic anhydride, and another monomer were copolymerized in a molar ratio shown in Table 1 to obtain a copolymer. Obtained. Use this,
As shown in Table 1, the reaction was carried out in the same manner as in Production Example 1 except that the polyoxyalkylene derivative represented by the general formula (2) was used in the amount shown in Table 1, thereby obtaining an intended product. When 20 wt% aqueous solutions of these reactants were prepared, they were all homogeneous liquids.

[0013]

[Table 1]

[0014]

[Table 2]

[Notes] 1) {} indicates that the product is a random addition product. 2) C ₄ H ₈ O represents an oxybutylene group. Production Example 11 250 g of the reaction product obtained in Production Example 3 and 250 g of sodium salt of a naphthalenesulfonic acid formaldehyde condensate were mixed. When a 20 wt% aqueous solution of these mixtures was prepared, it was a homogeneous liquid. Production Example 12 250 g of the reaction product obtained in Production Example 3 and 250 g of a copolymer of polyoxyethylene (average addition mole number: 33) monoallyl monomethyl ether and maleic anhydride in a molar ratio of 1: 1 were mixed. When a 20 wt% aqueous solution of these mixtures was prepared, it was a homogeneous liquid.

Examples 1 to 12 20% by weight of the reactants and the mixture obtained in Production Examples 1 to 12
A test with a mortar was performed using an aqueous solution. The composition and test conditions are shown below. Composition (g) Water 180 Cement 360 Sand 1080 Additives Types and amounts shown in Table 2 Water / cement ratio 50.0% Take the above components in a mortar mixer, mix for 3 minutes, take out, flow value and air The amount was measured. Further, after 30 minutes and 60 minutes, the flow value and the air amount were measured. Table 2 shows the results.

Comparative Examples 1 to 5 The same tests as in Examples 1 to 12 were carried out using the following compounds as comparative examples. Table 2 shows the results. Comparative Example 1 Naphthalenesulfonic acid formalin condensate sodium salt Comparative Example 2 Copolymer of polyoxyethylene (11 mol) monoallyl monomethyl ether and maleic anhydride Comparative Example 3 Polyoxyethylene (33 mol) monoallyl monomethyl ether and anhydrous Copolymer with maleic acid Comparative Example 4 500 g of a 20 wt% aqueous solution of the compound of Comparative Example 3
And a block adduct of oleyl alcohol with propylene oxide (30 mol) and ethylene oxide (3 mol).
5 g of the mixture was added. The mixture separated after 2 days. Comparative Example 5 No additive. However, only Comparative Example 5 had the following composition. Composition (g) Water 225 Cement 360 Sand 1080 Water / cement ratio 62.5%

[0018]

[Table 3]

From the above results, it can be seen that Examples 1 to 12 have higher water reduction and higher anti-slump loss properties than Comparative Example 1 of the sodium salt of the formalin condensate of naphthalenesulfonic acid. In addition, it can be seen from Comparative Examples 2 and 3, which do not contain the defoaming group of the general formula [2], that the examples of the present invention have low air entrainment. The performance of Comparative Example 4 in which only an alkylene oxide block adduct was simply added was substantially the same as that of Example 3, but the aqueous mixture solution of Comparative Example 4 was separated over time, which is not practically preferable. In Comparative Example 5 having no additive, a predetermined flow value cannot be obtained unless the amount of water is increased.

[0020]

The cement additive of the present invention can be used as an aqueous solution by using as a main component a reaction product of a specific polyoxyalkylene derivative and a copolymer of maleic anhydride and a specific polyoxyalkylene derivative. When used for mortar, concrete, etc., the composition has low air entrainment, high water reduction and high slump loss prevention performance.

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Claims (1)

(57) [Claims] 1. A (A) (i) the general formula ^{[1] R 1 O (A} 1 O) m R 2 ... [1] [R 1 in the formula is an alkenyl group having 2 to 5 carbon atoms, A ¹ O Has 2 carbon atoms in which at least 50 mol% is an oxyethylene group.
Oxyalkylene group of 1 to 4, R ² is a hydrocarbon group having 1 to 18 carbon atoms, m is an integer of 1 to 200 ] , and (ii) maleic anhydride are essential monomers to 100 parts by weight of the copolymer to, (B) the general formula ^{[2] R 3 O (C} 2 H 4 O) x (a 2 O) y (C 2 H 4 O) z H ... [2] [ In the formula, R ³ is a hydrocarbon group or an acyl group having 1 to 22 carbon atoms, A ² O is an oxyalkylene group having 3 or 4 carbon atoms, x
Is an integer of 0 or 1 to 20, y is an integer of 10 to 100, z
Is an integer of 0 or an integer of 1 to 20 and satisfies a relationship of y ≧ x + z ≧ 1 , and the (C ₂ H ₄ O) chain and the (A ² O) chain are block-shaped adducts. An additive for cement containing, as a main component, a product obtained by reacting 0.01 to 5 parts by weight of an oxyalkylene derivative.