JPH0153215B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to shrinkage reducing agents used in cement. Conventionally, one of the serious drawbacks of cement mortar and concrete (hereinafter referred to as cement compositions) is that they are susceptible to dry cracking. This is due to the large drying shrinkage of cement. Therefore, it is desired to reduce drying shrinkage of cement compositions. In order to reduce the drying shrinkage of cement compositions, a method of mixing latex such as acrylic latex or synthetic rubber latex into the cement composition is used, but in this case, a large amount of relatively expensive latex is used. (For example, 20~
(approximately 30% by weight), which is not only economically undesirable, but also causes a fatal defect in that the strength of the cement composition is significantly reduced. Furthermore, the incorporation of a large amount of latex causes a serious drawback in that the nonflammability of the cement composition is impaired. Although inorganic expandable admixtures (for example, calcium sulfoaluminate-based expandable admixtures) have been developed in recent years, they are not sufficient to essentially reduce drying shrinkage. Under such circumstances, the inventors conducted intensive studies on shrinkage reducing agents that can be used in cements that do not have the above-mentioned runner-up properties, and as a result, they arrived at the present invention. That is, the present invention is based on the general formula (1) X[-(AO)nH]m (1) (wherein, residue excluding active hydrogen, A is an alkylene group having 2 to 3 carbon atoms, n is a number from 1 to 10, m is a number from 1 to 2, and n×m is a number from 1 to 10). A shrinkage reducing agent used in cement consisting of a compound represented by general formula (1), and a cement with improved shrinkage reducing effect, which further contains a compound represented by formula (1) and a fluorine-based surfactant or/and a silicone-based surfactant. It is a shrinkage reducing agent used in Examples of aliphatic amines having 1 to 7 carbon atoms serving as the X residue constituting the general formula (1) of the present invention include methylamine, ethylamine, propylamine, isopropylamine, butylamine, pentylamine, hexylamine, 2 -ethylbutylamine, dimethylamine, diethylamine, dipropylamine,
Methylethylamine, methylpropylamine, methylpentylamine, ethylpropylamine, ethylbutylamine, etc. are mentioned, and examples of cycloalkylamines having 4 to 7 carbon atoms that serve as the X residue include cyclobutylamine, cyclopentylamine, cyclohexylamine. , methylcyclohexylamine and the like. Among these various amines, aliphatic amines are preferable in that they can further improve the effect of reducing shrinkage, and primary aliphatic amines having an alkyl group or a cycloalkyl group having 3 to 5 carbon atoms are particularly preferable. Use of an amine having an alkyl group having 8 or more carbon atoms or a cycloalkyl group having 8 or more carbon atoms not only reduces the shrinkage reduction effect but also entrains air into the cement composition, resulting in a decrease in strength, which is not preferable. In the general formula (1) of the present invention, the alkylene oxide constituting (-AO)-n is ethylene oxide,
such as propylene oxide. In addition, in the present invention, the total number of moles of these alkylene oxides n×
m is preferably a number of 1 to 10, and more preferably n×m is within a range of 3 to 6 from the viewpoint of shrinkage reduction effect. When this number exceeds 10, air is entrained in the cement composition, which not only reduces the strength of the composition but also reduces the shrinkage reduction effect, which is not preferable. In addition, from the viewpoint of shrinkage reducing effect, coadducts (especially block-like adducts) in which the molar ratio of ethylene oxide/propylene oxide (C ₂ H ₄ O/C ₃ H ₆ O) is within the range of 0 to 5 are preferred. Among these, those to which only propylene oxide is added are most preferred. In this case, the scope of the present invention also includes those to which oxides such as butylene oxide and styrene oxide are co-added to an extent that does not impede the performance of the cement composition (usually 50% by weight or less based on the total oxyalkylene). . In addition, when the amine compound has a primary amino group, this amino group may act as a monovalent to extend one chain of alkylene oxide, or act as a divalent to extend two chains. Any of these cases may be used. However, from the point of view of the shrinkage-reducing effect, a compound which acts as a divalent amino group and has an alkylene oxide added thereto is particularly preferred, and is a compound where m in the general formula (1) is 2. The method for synthesizing the compound of general formula (1) of the present invention is preferably a method of adding alkylene oxide to the amine compound because it is simple, but is not limited to this method. For example, polyethylene glycol (molecular weight 200 It can also be obtained by chloridizing one hydroxyl group among the terminal groups of a polyalkylene glycol such as phosphorus trichloride, and then reacting this with the amine compound. There are various synthesis methods other than those described above, and the compound of general formula (1) obtained by any method can be used as the shrinkage reducing agent of the present invention. The shrinkage reducing agent of the present invention can obtain an excellent shrinkage reducing effect by using one or a mixture of two or more compounds represented by the general formula (1) as an essential component. When a silicone surfactant and a silicone surfactant are used in combination, the shrinkage reducing effect is further improved due to a synergistic effect, which is very preferable. There are cationic, nonionic, and anionic surfactants to be used in combination with these surfactants, and any of these can be used, but cationic and nonionic surfactants reduce cement shrinkage. It is preferable in terms of effectiveness, and nonionic type is more preferable. As the fluorine-containing surfactant used in the present invention, commonly available commercially available ones can be used. A typical example of a cationic type surfactant has a perfluoroalkyl group having 5 to 18 carbon atoms as a hydrophobic group, and a cationic hydrophilic group (for example, a quaternary ammonium base, etc.). There are compounds. For example, Florado manufactured by Sumitomo 3M Ltd.
FC-134, Megafuc F-150 manufactured by Dainippon Ink Chemical Co., Ltd., Surflon S-121 manufactured by Asahi Glass Co., Ltd., Sturgient 300 manufactured by Neos Co., Ltd., Tohoku Fertilizer ( Eftup EF- manufactured by Co., Ltd.
Examples include 123B and EF-132. A typical example of a nonionic fluorocarbon surfactant is a compound consisting of a perfluoroalkyl group having 5 to 18 carbon atoms as a hydrophobic group and a nonionic hydrophilic group (for example, an ethylene oxide adduct). be. For example, Florado manufactured by Sumitomo 3M Ltd.
FC-170C, Megafuc F-142D, F-144D, F-171, F177 manufactured by Dainippon Ink & Chemicals Co., Ltd., Surflon S-141 manufactured by Asahi Glass Co., Ltd., Sturgient manufactured by Neos Co., Ltd. 200, 251, EF-121, EF-122A, EF-122B, EF manufactured by Tohoku Fertilizer Co., Ltd.
-122C, EF-122A3, etc. Typical examples of anionic type surfactants include:
There are compounds comprising a perfluoroalkyl group having 5 to 18 carbon atoms as a hydrophobic group and an anionic hydrophilic group (for example, a sulfonic acid group, a carboxylic acid group, a phosphoric acid ester group, etc.). These include Florado FC-95, FC-98, manufactured by Sumitomo 3M Ltd.
FC-126, FC-128, Megafuck F-110, F-113, F-120, F- manufactured by Dainippon Ink Chemical Co., Ltd.
812, F-191, Surflon S- manufactured by Asahi Glass Co., Ltd.
111, S-112, S-113, Sturgient 100, 150 manufactured by Neos Co., Ltd., Eftup manufactured by Tohoku Fertilizer Co., Ltd.
EF-102, EF-103, EF-112, EF-123A, EF
-123B etc. In addition to the above,
Cationic, anionic, and nonionic surfactants are available from Daikin Industries, Ltd., Kanto Denka Co., Ltd.
It is also commercially available from DuPont, ICI, Hoechst, and CIBA-GEIGY, and these can also be used as the fluorine-based surfactant of the present invention. In addition, the silicone surfactant used in the present invention refers to a polysiloxane with a hydrophobic group, a cationic hydrophilic group (e.g., quaternary ammonium base), a nonionic hydrophilic group (e.g., an alkylene oxide adduct) ), anionic hydrophilic groups (e.g. sulfate ester salts, phosphate ester salts,
carboxylic acid salts, etc.). In Japan, Toray Silicone Co., Ltd., Shin-Etsu Silicone
Various products are commercially available from companies such as Toshiba Silicone Co., Ltd. and Toshiba Silicone Co., Ltd., and these various products can be used in the present invention. The amount of the shrinkage reducing agent used in the cement of the present invention is determined by the number of carbon atoms in the alkyl group of the compound represented by general formula (1),
Although it varies depending on the number of carbon atoms in the alkylene group, it is usually 0.5 to 10% by weight based on the cement. If the amount used is less than 0.5% by weight, the shrinkage reduction effect will be small;
On the other hand, if it exceeds 10% by weight, the strength of the cement composition will be about 2/3 or less compared to that without additives.
Not enough in terms of practicality. Further, when the compound represented by the general formula (1) is used in combination with a fluorine-based surfactant and/or a silicone-based surfactant, the shrinkage reducing effect increases due to a synergistic effect. When these surfactants are used together, the amount of each compound added is 0.3 to 10% by weight of the compound represented by general formula (1) based on the cement weight, and 50% to 10% of the weight of the cement for the fluorine-based surfactant. 500 ppm, and the silicone surfactant is 0.05 to 1% by weight based on the cement. The means for adding the shrinkage reducing agent used in the cement of the present invention is the same as in the case of cement admixtures generally used, such as mixing an appropriate amount of the shrinkage reducing agent in the mixing water in advance, or It is possible to adopt a method such as adding an appropriate amount of the shrinkage reducing agent during kneading of a mixture consisting of cement, aggregate, and water. The shrinkage reducing agent used in the cement of the present invention is
It can be used in combination with other components (optional). Such optional ingredients include metal chlorides such as calcium chloride and sodium chloride, metal sulfates such as sodium sulfate, known cement hardening accelerators such as organic amines such as triethanolamine, alcohols, sugars, starch, and glycerin. , known cement hardening retardants such as sodium polyphosphate, known reinforcing steel rust preventive agents such as sodium nitrite and calcium nitrite, lignin sulfonic acid,
Known cement dispersants such as oxycarboxylic acid, naphthalene sulfonic acid formalin condensate, and melamine sulfonic acid formalin condensate; known cement pastes such as carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl starch, phosphorylated starch, and sodium alginate; Various agents can be mentioned. The method for constructing mortar or concrete to which the shrinkage reducing agent of the present invention has been added may be the same as conventional methods, such as troweling, filling into formwork, spraying, and injection with a caulking gun.
The curing method may be air dry curing, humid air curing, water curing, heating accelerated curing (steam curing, autoclave curing, etc.), or these methods may be used in combination. When the shrinkage reducing agent used in the cement of the present invention is added to the cement, a significant reduction in drying shrinkage is achieved compared to when no additive is added. In addition, the nonflammability of the cement composition is less likely to be impaired, and furthermore, even when added in a high amount (for example, on the order of several percent), the strength of the cement composition will not be significantly reduced. The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. Example 1 4 moles of ethylene oxide were added to 1 mole of the amine compound shown in Table 1 by a conventional method to obtain a shrinkage reducing agent used in the cement of the present invention. For the cured mortar obtained by adding these shrinkage reducing agents at a pure proportion of 3.5% by weight to ordinary Portland cement, the shrinkage rate was determined by the dial gauge method of JIS A 1129, and the strength was determined by JIS R 5201. The results shown in Table 1 were obtained. In addition, the air content was measured for concrete based on JIS A 1128. In addition, the water/cement ratio of the mortar used to measure shrinkage rate and strength was 65%, and the sand/cement ratio was 200%.
It is. The mixture of concrete whose air content was measured was: unit cement amount 300Kg/m ³ and water/cement ratio.
60%, and the fine aggregate ratio is 44%. Ordinary Portland cement manufactured by Nippon Cement Co., Ltd. was used. Table 1 lists only the amine compounds constituting the X residue of general formula (1), which is the starting material for the cement shrinkage reducing agent. This indicates that the substance was added and tested.

【table】

[Table] Example 2 Using butylamine as a starting material, Example 1 was prepared by changing the number of moles of alkylene oxide added.
Shrinkage reducing agents used in various cements were obtained in the same manner as above. These were added in an amount of 3.5% by weight based on ordinary Portland cement, and the shrinkage rate, air content, and strength were measured using the same method as in Example 1, and the results shown in Table 2 were obtained. In addition, EO in Table 2 refers to ethylene oxide,
PO stands for propylene oxide.

[Table] Example 3 Using the shrinkage reducing agent used in No. 13 of Example 2,
A test was conducted in the same manner as in Example 1 by changing the amount added, and the results shown in Table 3 were obtained.

【table】

[Table] In Example 2, the shrinkage reducing agent No. 13 of the present invention was used at 2.0% by weight based on the cement, Florard FC-170C was used as the futsuo-based surfactant, SH 3746 was used as the silicone-based surfactant, and their addition A test was conducted in the same manner as in Example 1 by changing the amount, and the results shown in Table 5 were obtained.

[Table] Example 5 Shrinkage reducing agent No. 13 of the present invention in Example 2 was used in an amount of 2.0% by weight based on the cement, Florard FC-170C was used as the futsuo-based surfactant, and SH 3746 was used as the silicone-based surfactant. A test was conducted in the same manner as in Example 1 by changing the amount added, and the results shown in Table 5 were obtained.

【table】

Claims (1)

[Scope of Claims] 1 General formula (1) X[-(AO)nH]m (1) (wherein, A residue obtained by removing m active hydrogens from an amine, A is an alkylene group having 2 to 3 carbon atoms, n is a number from 1 to 10, m is a number from 1 to 2, and n×m is a number from 1 to 10. Shrinkage reducing agent used in cement consisting of the compound shown in (number). 2 In general formula (1), X is the first group having 1 to 7 carbon atoms.
The shrinkage reducing agent used in cement according to claim 1, wherein the shrinkage reducing agent is a residue of a class aliphatic amine, and m is 2. 3 In general formula (1), X is the first group having 3 to 5 carbon atoms.
Claim 1 which is a residue of a class aliphatic amine
A shrinkage reducing agent used in the cement according to item 1 or 2. 4 In the general formula (1), (n×m) is a number from 3 to 6 in claim 1, 2, or 3.
A shrinkage reducing agent used in the cement according to any of paragraphs. 5 In the general formula (1), the polyalkylene oxide represented by (-AO)-n is a random or/and block-like adduct with an ethylene oxide/propylene oxide molar ratio of 0 to 5. A shrinkage reducing agent used in the cement according to any one of items 1 to 4. 6 In the general formula (1), the polyalkylene oxide represented by (-AO)-n is a block-like adduct with an ethylene oxide/propylene oxide molar ratio of 0 to 5. Claims 1 to 4 A shrinkage reducing agent used in the cement according to any of paragraphs. 7. A shrinkage reducing agent used in cement, comprising a compound represented by the general formula (1) and a fluorine-based surfactant or/and a silicone-based surfactant. 8. The shrinkage reducing agent for use in cement according to claim 7, wherein the fluorine-based surfactant and/or the silicone-based surfactant are cationic or nonionic surfactants. 9. The shrinkage reducing agent for use in cement according to claim 8, wherein the fluorine-based surfactant and/or the silicone-based surfactant are nonionic surfactants.