JPH11130503A - Cement admixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cement admixture hardly causing retardation of hardening, manifesting excellent dispersing activities and slump-maintaining activities, and having extreme separating resistance of a material by subjecting a polyoxyalkylene (derivative) to a cocondensation with a monomer the formaldehyde addition-condensation of which can be carried out with the polyoxyalkylene, a compound forming sulfone group and the formaldehyde. SOLUTION: This cement admixture is obtained by subjecting a polyoxyalkylene (derivative) of formula I R1 is a 1-5C alkyl; Z1 is a 1-5C alkoxy, NH2 or NH-Z2 [Z2 is formula II (R2 to R5 are each H, a 1-5C alkyl, a 1-5C alkoxy or an aromatic compound)]; AO and BO are each a block or random 2-5C oxyalkylene; (m) and (n) are each 0-300 [300>=(m)+(n)>=2] to a cocondensation with a monomer a formaldehyde addition-condensation of which can be carried out with the polyoxyalkylene, a compound forming sulfone group and the formaldehyde. Melamine, phenol, urea, aminobenzenesulfonic acid, etc., are cited as the monomer the formaldehyde addition-condensation of which can be carried out. A sulfonating agent is used as the compound forming sulfone group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an admixture for a cement or a cement composition, and more particularly, to the addition of a hydraulic cement composition such as a cement paste, mortar, concrete or the like when kneading to improve the workability. The present invention relates to a cement admixture to be improved.

[0002]

2. Description of the Related Art
Various types of organic compounds added to cement, particularly as a cement water reducing agent, are known. Representative examples include salts of highly condensed β-naphthalene sulfonic acid formaldehyde, salts of melamine sulfonic acid formaldehyde condensate, lignin sulfonic acid salts, salts of amino sulfonic acid condensates, and oxycarboxylic acids. . When these compounds are added to a kneaded product composed of cement, water and aggregate, sufficient workability can be obtained even if the amount of water during kneading is reduced. Therefore, there is an advantage that workability is improved, and since the water-cement ratio can be reduced, it is useful for enhancing the strength of a hydraulic cement composition such as cement paste, mortar, and concrete.

[0003] However, in general, cement paste,
Mortar, hydraulic cement composition such as concrete,
With the passage of time after kneading, the fluidity is lost. This phenomenon occurs when the organic compound added as the cement water reducing agent is used, and particularly, β-
This is remarkable when a salt of a highly condensed naphthalenesulfonic acid formaldehyde or the like is used, and depending on the composition of the concrete, a phenomenon in which the slump is reduced to half or less within 30 minutes after kneading is observed. Due to the phenomenon that the slump loss is large, the following problems occur. In other words, the concrete composition may be pumped by pumping concrete, but if the pumping is temporarily interrupted due to a break time or various troubles at that time, the pumping pressure may suddenly increase when resuming, And piping may be blocked. Also, due to reduced fluidity, the compact may not be sufficiently compacted in the mold and a defective portion may be generated.

Therefore, various water reducing agents have been developed in the past in order to suppress slump loss. For example, a substance in which the functional group is dissociated by an alkali in concrete, a so-called sustained-release high-performance water reducing agent (Japanese Patent Publication No. 63-5346) is known. Further, a water-soluble vinyl copolymer (Japanese Patent Publication No. 6-60042) is known, in which a new functional group appears by being hydrolyzed in an alkali and suppresses slump loss. Further, for the purpose of maintaining a slump due to steric hindrance of a molecular chain, a polyalkylene glycol monoester monomer having an unsaturated bond and a (meth) acrylic acid monomer and / or an unsaturated dicarboxylic acid monomer And copolymers thereof (JP-B-59-18338,
Japanese Patent Publication No. 2-7897, Japanese Patent Publication No. 2-7898, Japanese Patent Publication No. 2-7901, Japanese Patent Publication No. 2-8983, Japanese Patent Publication No. 2-11542, Japanese Patent Publication No. 5-110
No. 57, Japanese Patent Publication No. Hei 6-88817) and the like, and water-soluble vinyl copolymers (these are collectively referred to as polycarboxylic acid type). Furthermore, a condensate in which a polyalkylene glycol chain has been introduced into an aromatic compound (JP-A-6-340559) has recently been developed.

[0005] However, while these compounds exhibit excellent flow effects, they have various problems. First,
In the case of sustained-release high-performance water reducing agents that work with alkali in concrete and water-soluble vinyl copolymers that are alkali-hydrolyzed to replenish functional groups and suppress slump loss, carboxyl groups are contained in the compound. Appears over time. This carboxyl group has a large bonding force with calcium ions. Therefore, these compounds trap calcium ions in the cement, and when the amount of addition is large, there is a problem that the setting delay becomes large and the process cannot proceed to the next operation.

Furthermore, a polycarboxylic acid having an oxyalkylene chain in the molecule has high air entrainment, and it is difficult to control the amount of air in concrete. In reality, the amount of air is controlled using an antifoaming agent, but the amount of air fluctuates greatly depending on the kneading conditions in the concrete mixer, the agitator conditions of the mixer truck, and the transport time,
There is a problem that it is difficult to use. Furthermore, (meta)
Since copolymerization is carried out using acrylic acid-based monomers and / or unsaturated dicarboxylic acid-based monomers, these compounds have a carboxyl group in the molecule. However, there is a problem that is increased. That is, the initial strength of the cement mortar or concrete decreases. In addition, when a large slump is used, that is, when soft mortar or concrete is used, material separation may occur, which is a problem.

Further, a condensate in which a polyalkylene glycol chain is introduced into an aromatic compound has a problem that a flow effect similar to that of a polycarboxylic acid having an oxyalkylene chain in a molecule cannot be recognized.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve these problems, and as a result, it has been found that a compound having a specific molecular structure does not cause remarkable curing delay and has an excellent dispersion effect. The present inventors have found that they exhibit a slump holding effect and have a remarkable resistance to material separation, and have accomplished the present invention.

That is, the present invention relates to a polyoxyalkylene or its derivative (A) represented by the following general formula (I), a polyoxyalkylene or its derivative (A), and a monomer (B) capable of formaldehyde addition condensation, and a sulfone. The present invention relates to a cement admixture comprising a co-condensate of a compound (C) which forms a group and formaldehyde. General formula (I) Here, R ₁ : an alkyl group having 1 to 5 carbon atoms Z ₁ : an alkoxy group having 1 to 5 carbon atoms, —NH ₂ , and —NH
-Z ₂ Z _2: R _{2 to} R ₅ are each independently H, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an aromatic compound AO, BO: an oxyalkylene group having 2 to 5 carbon atoms AO and BO are blocks Or random m, n: an integer of 0 to 300, where 300 ≧ m + n ≧ 2

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. In the present invention, the following general formula (I) polyoxyalkylene or its derivative (A) is used. General formula (I) Here, R ₁ : an alkyl group having 1 to 5 carbon atoms Z ₁ : an alkoxy group having 1 to 5 carbon atoms, —NH ₂ , and —NH
-Z ₂ Z _2: R _{2 to} R ₅ are each independently H, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an aromatic compound AO, BO: an oxyalkylene group having 2 to 5 carbon atoms AO and BO are blocks Or random m, n: an integer of 0 to 300, where 300 ≧ m + n ≧ 2

The polyoxyalkylene represented by the general formula (I) or its derivative (A) is, for example,
The compound can be easily obtained by reacting an unsaturated nitrile compound such as acrylonitrile with the amino terminal of the compound obtained by the method disclosed in JP-A No. 8 and further performing a hydrogenation reaction. Examples of the unsaturated nitrile compound used for the synthesis of the polyoxyalkylene represented by the general formula (I) or the derivative (A) thereof include acrylonitrile, crotonnitrile,
Nitric acid cinnamate, 4-chlorocinnamic acid nitrile, 4-methoxycinnamic acid nitrile, 4-ethoxyacrylonitrile,
2-furan acrylonitrile, 2-pentenenitrile and the like.

The compound represented by the general formula (I) is 1
It can be used in combination of more than one species. Furthermore,
The addition amount is preferably from 0.001 to 0.5 mol, more preferably from 0.1 to 0.5 mol, per 1 mol of the monomer (B) capable of formaldehyde addition condensation with the polyoxyalkylene or its derivative (A). 005-0.35 mol is preferred.

The monomer (B) capable of undergoing formaldehyde addition condensation with polyoxyalkylene or its derivative (A) is represented by the general formula (II) Here, X _{1 to} X ₆ : independently, H, CH ₂ OH or CH ₂ SO ₃ Y Y: alkali metal, alkaline earth metal, ammonium,
Compounds represented by amines and substituted amines, that is, melamine, melamine containing a methylol group, melamine containing a sulfomethyl group, and the like can be used. In the case of sulphomethyl group-containing melamine, salts thereof can also be used. As the salts, inorganic salts, that is, alkali metal salts or alkaline earth metal salts such as potassium, sodium, and magnesium, and organic salts, that is, ammonium salts, monoethanolamine salts, diethanolamine salts, and the like can also be used.

In addition, other than the above, general formula (III) Here, X ₇ : H, CH ₂ OH or CH ₂ SO ₃ Y,
Sulfone group or its alkali metal salt, alkaline earth metal salt, ammonium salt, amine, substituted amine Y: alkali metal, alkaline earth metal, ammonium,
Amine, substituted amine R ₆ : a compound represented by H or an alkyl group having 1 to 6 carbon atoms, that is, phenol, cresol, p
Alkyl phenols such as -t-butyl phenol and pt-amyl phenol, sulfonic acids or sulfonic acid salts thereof, methylol group-containing phenols, sulfomethyl group-containing phenols, and salts thereof can also be used. As the salts, similarly to the general formula (II), inorganic salts and organic salts thereof can be used. Among them, phenol, phenol containing a methylol group, phenol containing a sulfomethyl group, or phenolsulfonic acid and salts thereof are preferable in terms of economy and reactivity.

Further, the compound represented by the general formula (IV) Here, X _{8 to} X ₁₁ : each independently H, CH ₂ OH
Alternatively, CH ₂ SO ₃ YY: a compound represented by an alkali metal, an alkaline earth metal, ammonium, an amine, or a substituted amine, that is, urea, a urea containing a methylol group, or a urea containing a sulfomethyl group can also be used. In the case of a sulfomethyl group-containing urea, inorganic salts and organic salts thereof can be used as in the case of the general formula (II).

Furthermore, the general formula (V) Here, X ₁₂ : H, an alkali metal, an alkaline earth metal, ammonium, an amine, a substituted amine R ₇ : a compound represented by H or an alkyl group having 1 to 6 carbon atoms, that is, sulfanilic acid, metanic acid, ortanic acid, etc. Aminobenzenesulfonic acids,
Alternatively, salts thereof can be used. As the salts,
As in the general formula (IV), inorganic salts and organic salts thereof can be used. Among them, sulfanilic acid, metanic acid and salts thereof are preferable from the viewpoint of economy and reactivity.

In the present invention, general formula (II):
One or more monomers of the general formula (III), the general formula (IV) and the general formula (V) can be used in combination. Is also preferred.

Known sulfonating agents such as sodium sulfite, sodium bisulfite, sodium pyrosulfite, sulfur dioxide, fuming sulfuric acid and the like can be used as the compound forming a sulfone group.

These sulfonating agents have the general formula (I)
I) may be used when introducing a sulfone group or a sulfomethyl group into the raw materials corresponding to general formulas (III) and (IV), or may be used after synthesizing a co-condensate with formaldehyde, A sulfone group or a sulfomethyl group may be directly introduced into the cocondensate.

For example, a method for introducing a sulfomethyl group into melamine of the general formula (II) can be carried out by a known method. That is, the compound can be introduced by addition condensation of melamine with formaldehyde to obtain methylol melamine, followed by a sulfonating agent and replacement with a hydroxyl group. It is known that 6 mol of formaldehyde is addition-condensed as methylol group to 1 mol of melamine. In the present invention, since it is highly possible that 2 moles of methylol groups are used for cocondensation, sulfomethyl groups can be introduced into the remaining 4 moles of methylol groups at the maximum. In consideration of the economic aspect and the flow effect of the obtained co-condensate, the amount of sulfomethyl group introduced is from 0.3 to 4
Moles are preferred, with 0.5 to 2 moles being more preferred. The same applies to the case where a sulfomethyl group is introduced into the phenol of the general formula (III). The introduction amount is preferably from 0.3 to 2 mol, more preferably from 0.5 to 1.5 mol, per mol of phenol. is there. The same applies when a sulfomethyl group is introduced into the urea of the general formula (IV),
An introduction amount of 0.3 to 2 mol per mol of urea is preferable,
More preferably, the amount is 0.5 to 1.5 mol.

The formaldehyde used for synthesizing these formaldehyde cocondensates is usually 3
It is preferable to use one having a concentration of 0 to 60% by weight. Further, if necessary, paraform can be used in combination. The formaldehyde is preferably used in an amount of 1 to 6 times the total number of moles of the polyoxyalkylene or its derivative (A) and the monomer (B) capable of formaldehyde addition condensation. In consideration of economy, ease of the condensation reaction, and the like, it is more preferable to use 1.5 to 4 moles.

The formaldehyde co-condensation reaction is carried out at pH 4-1.
The method is carried out by a usual method in the range of 2, ie, from a weakly acidic region to a basic region. If the pH is less than 4, it is difficult to control the reaction, for example, the condensation reaction may rapidly proceed and gel. In addition, the formaldehyde may be added in advance in the reaction apparatus, or may be reacted by dropping formalin during the reaction.

The composition of the compound constituting the admixture in the present invention is important. That is, polyoxyalkylene or its derivative (A): polyoxyalkylene or its derivative (A) and a monomer capable of formaldehyde addition condensation (B): compound that generates a sulfone group (C): formaldehyde (D) The molar ratio of the co-condensate is (0.0
01: 0.5): 1: (0.3-4) :( 1-6), more preferably (0.005-0.5)
0.35): 1: (0.5-2) :( 1.5-4) is preferred.

Next, a specific example of the method for producing the cement admixture of the present invention will be described below, but the present invention is not limited thereto. Example 1 Formaldehyde (D) and water were charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a dropping funnel, and a monomer capable of addition condensation with polyoxyalkylene or its derivative (A) ( B) is added. Reactor temperature is 60-9
After raising the temperature to 0 ° C., the reaction is carried out under basic conditions for 0.5 to 2 hours. Next, polyoxyalkylene or its derivative (A) is charged, and further reacted at 60 to 90 ° C. for 0.5 to 2 hours. Further, a compound (C) that generates a sulfone group is added, and the mixture is reacted at 60 to 90 ° C. for 0.5 to 3 hours. Further, the inside of the system is made weakly acidic, and the reaction proceeds at 50 to 80 ° C. until the viscosity of the solution reaches a predetermined value. When the viscosity of the solution reaches a predetermined value, the reaction is stopped by neutralization. The predetermined viscosity for stopping the reaction varies depending on the nonvolatile content of the solution. When the nonvolatile content is 35%, the value measured by a B-type viscometer is preferably 10 to 500 cp / 25 ° C.
5 to 300 cp / 25 ° C is more preferable.

Specific Example 2 Formaldehyde (D), water, a monomer (B) capable of addition condensation with polyoxyalkylene or its derivative (A), a compound (C) capable of forming a sulfone group, and polyoxyalkylene or The derivative (A) was charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a dropping funnel, and the internal temperature of the reactor was raised to 60 to 90 ° C. Let react for hours. Further, the inside of the system is made weakly acidic, and the reaction proceeds at 50 to 80 ° C. until the viscosity of the solution reaches a predetermined value. When the viscosity of the solution reaches a certain value,
Neutralize to stop the reaction. The predetermined viscosity at which the reaction is stopped is the same as in Example 1. The compound represented by the polyoxyalkylene or its derivative (A) can be added in all steps in the reaction process for producing the cement admixture of the present invention. It is preferable to add it to the step after charging the monomer (B) capable of performing an addition reaction. That is, the compound represented by the monomer (B) capable of undergoing an addition reaction with the polyoxyalkylene or its derivative (A) may be added and the temperature may be raised, or during or after the reaction under basic conditions, It may be added before or after the preparation of the compound (C) that generates a sulfone group, or may be added immediately before and immediately after adjusting the pH to a weakly acidic region. Further, for the purpose of cooling, the charged water may be divided into the respective steps, or the addition of each compound may be divided and added. Further, the order of adding each compound may be changed.

The cement admixture of the present invention can be used in combination with other conventionally known water reducing agents, AE water reducing agents, high performance water reducing agents, high performance AE water reducing agents, and fluidizing agents. That is, β-naphthalene sulfonic acid formaldehyde high condensate salt, melamine sulfonic acid formaldehyde condensate salt, amino sulfonic acid condensate salt, lignin sulfonic acid salt, oxycarboxylic acid, polycarboxylic acid type water reducing agent, alkali hydrolysis It can be used in combination with a type water reducing agent, a sustained release high performance water reducing agent, and the like.

With respect to the method of using the admixture of the present invention, other known cement admixtures such as an air entraining agent, an antifoaming agent, a setting accelerator, a setting retarder, a rust inhibitor, a preservative, a waterproofing agent, and a strength accelerator It can be used in combination with an agent or the like. In addition, the method of use is usually mixed in kneading water and added to the cement composition.However, the method of adding the cement composition at once or adding it separately at the time of preparing the cement composition, the method of adding the cement composition after kneading, Any method such as the method of adding may be used. The admixture according to the present invention varies depending on the formulation and the use of the cement composition, but is usually 0.01 to 0.01 in terms of solid content relative to cement.
It is used in a proportion of 5.0% by weight, preferably 0.05 to 3.0% by weight. If the amount used is less than 0.01% by weight,
This is not preferred because the dispersion fluidity tends to decrease and the effect of preventing slump loss tends to decrease. On the other hand, if the content exceeds 5.0% by weight, it tends to cause material separation, making it difficult to obtain a homogeneous cured product, and is disadvantageous economically, which is not preferable.

The cement admixture according to the present invention can be applied to concrete and mortar prepared using various portland cements, fly ash cements, blast furnace cements, silica cements, various types of mixed cements and the like. Furthermore, the present invention can be applied to concrete containing silica fume, blast furnace slag, limestone fine powder and the like.

The reason why the cement admixture of the present invention exhibits an excellent flow effect, a slump loss suppressing effect and a material separation resistance without showing a setting delay is not clear, but is presumed as follows. That is, since the admixture of the present invention has a sulfone group in the molecule similarly to the conventional high-performance water reducing agent,
The electric repulsion enhances the dispersibility of the cement particles. Moreover, when the admixture of the present invention is adsorbed on the cement particles, it is considered that the polyoxyalkylene chain in the molecule extends to the outside of the cement particles. A hydration layer is formed around the polyoxyalkylene chain extending to the outside, and the steric hindrance effect accompanying this seems to maintain the dispersibility of the cement particles for a long time and suppress slump loss. Furthermore, as in the conventional sustained-release high-performance water reducing agent, polycarboxylic acid-based water reducing agent, and alkali hydrolysis-type water reducing agent, C is contained in the molecule.
Since it does not have an a ion and a carboxyl group having a high chelating ability, it is not expected to exhibit a setting retardation property. therefore,
The admixture of the present invention has excellent dispersion performance, slump loss suppressing effect, and material separation resistance.

The admixture of the present invention will be described in more detail in the following Examples, but the present invention is not limited thereto. In addition, all percentages or parts described below as units of numerical values are% by weight or parts by weight unless otherwise specified. The polyoxyalkylene represented by the general formula (I) or its derivative (A) is described in JP-B 1-4004.
No. 8 can easily be obtained by reacting an unsaturated nitrile compound (b) such as acrylonitrile with the amino terminal of the compound (a) obtained by the method disclosed in JP-A No. 8 (1996), and further performing a hydrogenation reaction. The compound (a) used as a raw material of the polyoxyalkylene or its derivative (A) used in the present invention was manufactured by JEFFAMI of San Techno Chemical Co., Ltd.
In the NEM series, acrylonitrile and cinnamate nitrile were used as unsaturated nitrile compounds (b). Table 1 shows polyoxyalkylene or its derivative (A) obtained from each raw material.

[0031]

[Table 1]

[0032]

【Example】

Production Example 1 0.50 mol (63.1 parts) of melamine, 1.9 mol (154.1 parts) of 37% formalin, and 474.0 parts of water were mixed with a stirrer, a thermometer, a reflux tube, and a dropping funnel. The mixture was charged into a neck flask and mixed with stirring. After the temperature was raised to 65 ° C., the pH was adjusted to 11.5 with a 25% aqueous sodium hydroxide solution.
The reaction was performed at 65 ° C. for 1 hour. 0.05 mol of urea (3.0 moles)
Parts) and 0.30 mol (52.0 parts) of sulfanilic acid, and the mixture was further reacted at 70 ° C. for 1 hour. Then water 10
After charging 0.0 parts and cooling to 45 ° C. at the same time, 0.15 mol (14.1 parts) of phenol was charged over 30 minutes using a dropping funnel. After completion of the charging, the reaction was carried out at 60 ° C. for 1 hour. Subsequently, 0.10 mol of derivative A-1 (1
00.0 parts), 0.70 mol of sodium bisulfite (7
2.9 parts) and reacted at 80 ° C. for 1 hour. 60
After cooling to 40 ° C., the pH was adjusted to 6.0 with 40% sulfuric acid,
C., and the reaction solution was allowed to react at a viscosity of 18 cp / 2.
When the temperature reached 5 ° C., the reaction was stopped by neutralizing with a 25% aqueous sodium hydroxide solution, and the obtained product was treated with co-condensate 1
And Table 2 shows the composition and physical properties.

Production Example 2 477.0 parts of water, 3.2 mol of 37% formalin (25 mol
9.5 parts) was charged into a four-necked flask equipped with a stirrer, a thermometer, and a reflux tube, followed by stirring and mixing. 1.0 mol (126.1 parts) of melamine, 0.8 mol (83.3 parts) of sodium bisulfite, 0.1 mol of sodium pyrosulfite in this flask.
Two moles (38.0 parts) were added under stirring. This was heated up to 75 ° C., and after confirming that it became a transparent liquid, 0.01 mol (2.0 parts) of derivative A-2 was added.
PH 11 with 25% aqueous sodium hydroxide solution, 75 ° C
For 2 hours. After confirming that free sulfite ions had disappeared, the mixture was cooled to 60 ° C. Then 40%
The pH was adjusted to 6.0 with sulfuric acid, and the reaction was allowed to proceed at 60 ° C. When the viscosity of the reaction solution reached 28 cp / 25 ° C, the reaction was stopped by neutralization with a 25% aqueous sodium hydroxide solution, and the resulting product was obtained. Was designated as cocondensate 2. Table 2 shows the composition and physical properties.

Production Examples 3 to 6 Co-condensation was attempted in the same manner as in Production Example 1, except that the composition of the compound was changed as shown in Table 2. As a result, co-condensates 3 to
6 was obtained.

Production Example 7 Co-condensation was attempted using the same composition and method as in Production Example 1, except that the derivative (A) was not added. As a result, a co-condensate 7 was obtained.

Production Example 8 Co-condensation was attempted using the same composition and method as in Production Example 1, except that the derivative (A) and the monomer (B) capable of formaldehyde addition condensation were not added. As a result, co-condensate 8
I got

Production Example 9 Co-condensation was attempted using the same composition and method as in Production Example 1, except that the compound (C) that produces a sulfone group was not added. As a result, a co-condensate 9 was obtained.

Production Example 10 Co-condensation was attempted using the same composition and method as in Production Example 1, except that no formaldehyde (D) was added. As a result, a co-condensate 10 was obtained.

[0039]

[Table 2]

Example 1 Using a 50-liter forced biaxial concrete mixer, based on the composition shown in Table 3, the cement, coarse aggregate, and the mixture obtained in Production Example 1 were adjusted to a kneading amount of 40 liters. Condensate 1 and water were charged, kneaded and mixed for 90 seconds, coarse aggregate was further charged, and kneaded for 3 minutes. A high fluidity concrete having a slump flow of 60 ± 2 cm and an air volume of 3 ± 1% was prepared. To achieve the target air volume, use the air entrainer Vinsol manufactured by Yamamune Chemical Co., Ltd. if the entrained air volume is insufficient, and use Hokukon Sangyo Co., Ltd. as an antifoaming agent if the air volume is too high. It was adjusted by using Delkrite 850 manufactured by KK. After kneading, slump and slump flow with time were measured every 30 minutes until 90 minutes later. In addition, the compressive strength was measured in 1 day, 7 days, and 28 days by preparing a cylindrical specimen having a diameter of 10 cm and a height of 20 cm. Regarding the material separation resistance, the degree of movement of the aggregate during slump flow measurement was visually observed, and relative evaluations of ◎, 、, Δ, and × were made. In addition, the method of measuring the slump, the amount of air, the setting time and the compressive strength, and the method of preparing the specimen for compressive strength were all based on Japanese Industrial Standards (JIS-A6204). Table 4 shows the results.

[0041]

[Table 3] Formulation for concrete test W / C: water / cement (% by weight) s / a: fine aggregate / (fine aggregate + coarse aggregate) (volume%) C: cement S: fine aggregate G: coarse aggregate

Material for Concrete Kneading Cement: Three kinds of ordinary Portland cement (Mitsubishi Materials Corporation, Chichibu Onoda Corporation, Tokuyama Corporation)
Specific gravity = 3.16 Fine aggregate: Weathered granite sand from Irino, Kawachi-cho, Kamo-gun, Hiroshima Prefecture
Specific gravity = 2.57 Coarse aggregate: Hard sandstone crushed stone from ishiishi-shaped wall stone in Shimonoseki-shi, Yamaguchi Prefecture Crushed stone 5: Crushed stone 6 = 1: 1: 1 Specific gravity = 2.69

Examples 2 to 6 The same operation as in Example 1 was performed except that cocondensates 2 to 6 were used. Table 4 shows the results.

Comparative Examples 1 to 4 The same operation as in Example 1 was performed except that condensates 7 to 10 were used. Table 4 shows the results.

Comparative Examples 5 to 9 As a water reducing agent for comparison, Melflow 40 (Mitsui Toatsu Chemical Co., Ltd .: melamine) which is a commercially available high-performance water reducing agent,
Mighty 150 (Kao Corporation: naphthalene type), Palic FP200U (Fujisawa Pharmaceutical Co., Ltd .: aminosulfonic acid type), sustained release type Mighty 2000WH which is a high performance AE water reducing agent (Kao Corporation: naphthalene type + The same operation as in Example 1 was performed using Tupole HP-8 (Takemoto Oil & Fats Co., Ltd .: polycarboxylic acid system). Table 4 shows the results.

[0046]

[Table 4]

[0047]

As is clear from the examples and comparative examples, the cement admixture obtained according to the present invention shows a high flow effect at a low addition amount and a residual flow as compared with the existing cement water reducing agent. It has the characteristics of high rate and excellent daily strength. That is, it has high initial fluidity and excellent slump holding properties without causing hardening delay for cement compositions such as mortar and concrete. Furthermore, it has excellent material separation resistance. Therefore, when the cement admixture obtained by the present invention is used for civil engineering and construction-related works, workability can be significantly improved.

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[Procedure amendment]

[Submission date] January 20, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

Production Example 2 477.0 parts of water and 3.2 mol (259.5 parts) of 37% formalin were charged into a four-necked flask equipped with a stirrer, a thermometer, and a reflux tube, followed by stirring and mixing. 1.0 mol of melamine (126.1 parts) in this flask,
0.8 mol (83.3 parts) of sodium bisulfite and 0.2 mol (38.0 parts) of sodium pyrosulfite were added under stirring. This was heated to 75 ° C., and after it was confirmed that a transparent liquid was obtained, 0.001 mol (2.0 parts) of derivative A-2 was added, and then the solution was adjusted to pH 11 with a 25% aqueous sodium hydroxide solution to adjust the pH to 75. The reaction was carried out at 2 ° C. for 2 hours. After confirming that free sulfite ions had disappeared, the mixture was cooled to 60 ° C. Next, the pH was adjusted to 6.0 with 40% sulfuric acid, the reaction was allowed to proceed at 60 ° C., and when the viscosity of the reaction solution reached 32 cp / 25 ° C., the reaction was stopped by neutralizing with a 25% aqueous sodium hydroxide solution. The obtained product was designated as cocondensate 2. Table 2 shows the composition and physical properties.

Continued on the front page (72) Inventor Yoshihiko Tomita 7-1-1, Hikoshimasako-cho, Shimonoseki-shi, Yamaguchi Prefecture Inside Mitsui Chemicals, Inc.

Claims (7)

[Claims] 1. A polyoxyalkylene or its derivative (A) represented by the following general formula (I), a polyoxyalkylene or its derivative (A) and a monomer (B) capable of formaldehyde addition condensation and a sulfone group: A cement admixture comprising a co-condensate of the resulting compound (C) and formaldehyde (D). General formula (I) Here, R ₁ : an alkyl group having 1 to 5 carbon atoms Z ₁ : an alkoxy group having 1 to 5 carbon atoms, —NH ₂ , and —NH
-Z ₂ Z _2: R _{2 to} R ₅ are each independently H, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an aromatic compound AO, BO: an oxyalkylene group having 2 to 5 carbon atoms AO and BO are blocks Or random m, n: an integer of 0 to 300, where 300 ≧ m + n ≧ 2 2. A polyoxyalkylene or its derivative (A) and a monomer (B) capable of formaldehyde addition condensation are melamine or its derivative, phenol or its derivative, urea or its derivative, aminobenzenesulfonic acid or its derivative The cement admixture according to claim 1, wherein the cement admixture is one or more compounds selected from the group consisting of a derivative, and alkylaminobenzenesulfonic acid or a derivative thereof. 3. A compound (C) which forms a sulfone group
The cement admixture according to claim 1, wherein the admixture comprises one or more compounds selected from the group consisting of sodium sulfite, sodium bisulfite, sodium pyrosulfite, fuming sulfuric acid, and sulfur dioxide. 4. The cement admixture according to claim 2, wherein the melamine or a derivative thereof is represented by the following general formula (II). General formula (II) Here, X _{1 to} X ₆ : independently, H, CH ₂ OH or CH ₂ SO ₃ Y Y: alkali metal, alkaline earth metal, ammonium,
Amine, substituted amine 5. The cement admixture according to claim 2, wherein the phenol or a derivative thereof is represented by the following general formula (III). General formula (III) Here, X ₇ : H, CH ₂ OH or CH ₂ SO ₃ Y,
Sulfone group or its alkali metal salt, alkaline earth metal salt, ammonium salt, amine, substituted amine Y: alkali metal, alkaline earth metal, ammonium,
Amine, substituted amine R ₆ : H or alkyl group having 1 to 6 carbon atoms 6. The cement admixture according to claim 2, wherein the urea or a derivative thereof is represented by the following general formula (IV). General formula (IV) Here, X _{8 to} X ₁₁ : each independently H, CH ₂ OH
Or CH ₂ SO ₃ Y Y: an alkali metal, an alkaline earth metal, ammonium,
Amine, substituted amine 7. An aminobenzenesulfonic acid or a derivative thereof, or an alkylaminobenzenesulfonic acid or a derivative thereof, represented by the following general formula (V):
The cement admixture according to the above. General formula (V) Here, X ₁₂ : H, alkali metal, alkaline earth metal, ammonium, amine, substituted amine R ₇ : H or an alkyl group having 1 to 6 carbon atoms