JP3315523B2 - Dispersant for inorganic hydraulic composition, hydraulic composition and cured product thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispersant excellent in dispersibility and a hydraulic composition containing the same.

[0002]

2. Description of the Related Art Granulated blast furnace slag or converter slag has been conventionally produced in large quantities as an industrial by-product, but is used as a raw material for cement production, or for producing blast furnace cement or aggregate. Many were used for land reclamation without such effective use.

Recently, it has been proposed to add a chemical such as gypsum, quick lime, caustic alkali or the like to granulated blast furnace slag to activate its latent hydraulic property, thereby forming a hydraulic cement itself. However, when blast furnace granulated slag is poured and used for centrifugal molding, etc., the fluidity is poor, and the strength development is insufficient, and the resulting cured product is extremely brittle and cannot withstand use. Not obtained.

[0004]

In recent years, various studies have been made to improve the fluidity of the kneaded composition of the granulated blast furnace slag and the point that the strength of the hardened product is weak. It was inferior to cement mortar and concrete, and the strength was not practical.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks. The present invention is intended to solve the problem by adding ultrafine powdery substances, hardening stimulants, acrylic acid to latent hydraulic substances such as granulated blast furnace slag.・ Maleic acid (or maleic anhydride, fumaric acid)
It has been found that the addition of a copolymer containing as an essential component makes it possible to develop fluidity and strength higher than ordinary Portland cement.

That is, the present inventors have conducted intensive studies on a method for obtaining a composition having no problems as described above, and as a result, have found a composition which can achieve the above object and completed the present invention.

That is, the present invention relates to (1) acrylic acid and a compound selected from the following compound group (a):
Species (a) A dispersant for an inorganic hydraulic composition obtained by copolymerizing maleic acid, maleic anhydride and fumaric acid. (2) A dispersant for an inorganic hydraulic composition obtained by copolymerizing acrylic acid, one selected from the compound group (a) described in (1) above, and another monomer copolymerizable therewith. (3) The copolymerizable monomer is hydroxyethyl (meth)
(2) which is at least one selected from acrylate, N-vinylpyrrolidone, sodium styrene sulfonate, sodium (meth) allyl sulfonate, styrene and vinyl acetate
(4) The dispersant according to (1), (2) or (3), which has a molecular weight of 1,000 to 500,000.

(5) A hydraulic composition comprising a latent hydraulic substance, an ultrafine powdery substance, a hardening stimulant, and the dispersant described in (1), (2), (3) or (4) above. (6) The latent hydraulic material is granulated blast furnace slag, converter slag,
The above (5), which is one or more kinds selected from fly ash
(7) The hydraulic composition according to (7), wherein the ultrafine powdery substance is silica fume.
Or the hydraulic composition according to (6). (8) the curing stimulant is an alkali metal hydroxide or carbonate;
(5) and (6) above which are at least one selected from silicates.
Or (7) the hydraulic composition according to (7), (9) the curing stimulant is at least one selected from the group consisting of caustic soda, sodium carbonate, caustic potash, and sodium silicate, (5), (6), (7) or (8). (10) A cured product obtained by kneading the hydraulic composition according to (5), (6), (7), (8) or (9) with water and then moist curing. About.

Hereinafter, the present invention will be described in detail. Dispersant of the present invention, acrylic acid and maleic acid, maleic anhydride,
Copolymerizing with one kind of monomer selected from fumaric acid,
Alternatively, it can be obtained by copolymerizing a monomer copolymerizable therewith with a monomer. (Hereinafter, one type of monomer selected from maleic acid, maleic anhydride and fumaric acid is referred to as monomer (a) unless otherwise specified.) Both acrylic acid and monomer (a) are used. Specific examples of the polymerizable monomer include hydroxyethyl (meth) acrylate,
N-vinylpyrrolidone, sodium styrenesulfonate, sodium allylsulfonate, sodium methallylsulfonate, styrene, vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, acrylonitrile, methyl methacrylate, methacrylic acid, acrylic amide, Examples include methacrylamide, ethylene, propylene, and isobutylene.

The dispersant of the present invention is described, for example, in US Pat.
No. 915 or the like. The dispersant of the present invention can be used as it is in the form of an acid. However, it is preferable to use the dispersant in the form of a salt after neutralization with, for example, caustic soda. That is, sodium salt of acrylic acid / maleic acid copolymer, sodium salt of acrylic acid / maleic acid / sodium allyl sulfonate copolymer, sodium salt of acrylic acid / maleic anhydride / vinyl acetate copolymer, acrylic acid Preferred examples of the dispersant of the present invention include sodium salts of a maleic anhydride / styrene copolymer and sodium salts of acrylic acid / maleic acid / sodium styrene sulfonate / N-vinylpyrrolidone copolymer.

Next, the hydraulic composition of the present invention will be described in detail. The hydraulic composition of the present invention is a latent hydraulic substance,
It is characterized by containing an ultrafine powdery substance, a curing stimulant and the dispersant of the present invention. The latent hydraulic substance used in the present invention preferably has a Blaine specific surface area of 2,000 cm ² / g or more, particularly preferably 3,000 cm ² / g or more. The latent hydraulic substance is not particularly limited as long as it cures when kneaded with water and a curing stimulant, but blast furnace granulated slag, converter slag, and fly ash are preferred. These latent hydraulic substances can be used alone or in combination of two or more.

As the ultrafine powdery substance used in the present invention, those having an average particle diameter smaller than the average particle diameter of the latent hydraulic substance, preferably one or more smaller than the average particle diameter of the latent hydraulic substance, More preferably, a material smaller than two orders of magnitude is used. The preferred average particle size of the ultrafine powdery substance is 10 μm or less, more preferably 0.01 to 5 μm.
m, and most preferably 0.05 to 1 μm. The average particle size of the ultrafine powdery substance is preferably 1/2 to 1/1000 of the average particle diameter of the latent hydraulic substance.

Specific examples of the ultrafine powdery substance that can be used include, for example, silica fume, fly ash, quartz sand, quartzite powder, clay, talc, kaolin, calcium carbonate, crushed ceramics, crushed blast furnace slag, titania, Zirconia, alumina, aerosil, etc. are listed, but in addition to improving the flowability at the time of casting, and the effect of improving the mechanical strength of the cured body after curing and curing is remarkable, it is possible to use silica fume Particularly preferred. The amount of this ultrafine substance used depends on the size (particle size) and type of latent hydraulic substance,
Depending on the type and amount of other various admixtures to be added as necessary, it is usually preferably 2 to 50 parts by weight, particularly preferably 5 to 50 parts by weight, based on 100 parts by weight of the latent hydraulic substance.
25 parts by weight.

Various alkaline substances can be used as the curing stimulant. Specific examples thereof include, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkali metal carbonates such as sodium carbonate, potassium carbonate, and lithium carbonate; and calcium hydroxide, magnesium hydroxide, and the like. Alkaline earth metal hydroxides, sodium pyrophosphate, potassium pyrophosphate, dipotassium phosphate, tripotassium phosphate, trisodium phosphate, etc., phosphates such as sodium (meth) silicate and potassium (meth) silicate Salts.

Of these curing stimulants, alkali metal hydroxides are preferred, and sodium hydroxide is particularly preferred. These hardening stimulants can be used either in a solid form or in an aqueous solution, but it is preferable to use an aqueous solution so as to be uniformly dispersed in the hydraulic composition during kneading.

The amount of the curing stimulant used depends on its basicity (alkaline strength), the particle size of the latent hydraulic substance, the type and amount of various ultrafine powdery substances to be added, and the amount of water described later. Although it varies depending on the amount, it is generally preferably 0.1 to 20 parts by weight, particularly preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the total of the latent hydraulic substance and the ultrafine powdery substance.

If the amount of the curing stimulant is too small, sufficient strength may not be exhibited or a long time may be required for curing and curing.
Industrially disadvantageous. On the other hand, if the amount is too large, the curing speed becomes too fast, and handling in the kneading step or the molding step may be significantly impaired.

When used in the hydraulic composition of the present invention, the molecular weight of the dispersant of the present invention is preferably from 1,000 to 50.
000, more preferably 3,000 to 100,0
00. Molecular weight of 1,000 or less and 500,
If it is more than 000, the fluidity of the hydraulic composition is poor and the strength of the cured product is low. As the dispersant, those exemplified above can be used alone or in combination of two or more.

In this case, it is preferable that the dispersant is dispersed in the hydraulic composition immediately after kneading the hydraulic composition. Therefore, an aqueous solution of these dispersants or a finely pulverized powder should be used. Is preferred.

The amount of the dispersant varies depending on the required properties of the finally obtained cured product and the like, but is usually 0.1 to 1 with respect to 100 parts by weight of the total amount of the latent hydraulic substance and the ultrafine powdery substance.
0 parts by weight, preferably 0.3 to 6 parts by weight, particularly preferably 0.5 to 3 parts by weight. If the amount of the dispersant is less than 0.1 part by weight, kneading becomes difficult or the fluidity is reduced, depending on the amount of water described below. Further, if the amount of the dispersant is more than 10 parts by weight, it becomes difficult to cure, or even if it is cured, water resistance deteriorates.

In the hydraulic composition of the present invention, various admixtures can be further used, if necessary. Examples of the admixture include, for example, pulverized slow-cooled slag, ferrochrome slag, wollastonite, silica, alumina, talc,
Inorganic fillers such as silica sand, silica powder, clay, kaolin, calcium carbonate, crushed ceramics, titania, zirconia, gravel, etc., fiber materials such as carbon fiber, glass fiber, pulp, nylon fiber, vinylon fiber, polyester fiber and acrylic fiber , A curing retarder such as sugar and glucose, a surface treating agent such as a silane coupling agent, a pigment, and the like.

When these various admixtures are used, they are usually used in an amount of 10 to 300 parts by weight with respect to 100 parts by weight of the latent hydraulic substance in the case of an inorganic filler.
In the case of an admixture such as a surface treating agent or a pigment, it is usually used in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the latent hydraulic substance.

The hydraulic composition of the present invention can be obtained, for example, as follows. That is, a mixture comprising a latent hydraulic substance, an ultrafine powdery substance, a hardening stimulant, a dispersant of the present invention and, if necessary, an admixture is prepared, and a mixture such as an omni mixer (manufactured by Chiyoda Giken Kogyo Co., Ltd.) is prepared. The hydraulic composition of the present invention can be obtained by mixing with a dynamic mixer, a kneader-ruder mixer, a planetary mixer, or the like.

The hydraulic composition of the present invention is kneaded well with water,
After kneading, the cured product of the present invention can be obtained by pouring the mixture into an appropriate mold and further performing wet curing. The amount of water used in this case depends on the type and amount of the latent hydraulic substance and the ultrafine substance used, the type and amount of the hardening stimulant, and the type and amount of other admixtures. Although it is important to determine the kneadability, it is usually 8 to 60 parts by weight, preferably 10 to 45 parts by weight, more preferably 12 to 60 parts by weight based on 100 parts by weight of the total of the latent hydraulic substance and the ultrafine powdery substance. ３５35 parts by weight.

Next, a method of kneading the hydraulic composition of the present invention with water will be described. First, the latent hydraulic substance and the ultrafine powdery substance are mixed, and the dispersant of the present invention finely pulverized and / or dissolved in water, and if necessary, various admixtures are added to the mixer exemplified above. Mix. Next, a predetermined amount of a curing stimulant and a predetermined amount of water or an aqueous solution of the curing stimulant dissolved in water is added to the mixture, and the mixture is further kneaded.

As another method, a latent hydraulic substance, an ultrafine powdery substance and, if necessary, various admixtures are added, and powder is mixed by a mixer. Next, to this mixture, a sodium salt aqueous solution of the dispersant of the present invention, a curing stimulant and a predetermined amount of water, or a predetermined amount of an aqueous solution of the curing stimulant dissolved in water is added, and the mixture is further kneaded to obtain a kneaded material having fluidity obtain.

The wet curing for curing the kneaded material obtained as described above is usually performed at a temperature of 5 to 100 ° C. under a saturated vapor pressure for a period of 2 hours to 1 month.
Autoclave treatment may be performed at a temperature of 00 ° C. or higher for 1 to 20 hours. The higher the wet curing temperature is, the faster the curing tends to be, but generally the temperature is in the above-mentioned range. The wet curing is preferably performed in a high humidity atmosphere in which at least the moisture of the mixture does not evaporate. Generally relative humidity 8
0% or more, preferably 90% or more, more preferably 10% or more.
Performed in an atmosphere of 0%. Alternatively, the molded body in the initial stage of wet curing can be immersed in water and cured in water.

The cured product of the present invention obtained as described above can be used as a building / construction material, such as a structural material for a building utilizing its strength, and a lightweight and high-strength interior / exterior material. Specifically, it can be used as a building material such as a driving form material, a floor slab, a curtain wall, an interior / exterior material, and the like. Further, the dispersant of the present invention, in addition to the hydraulic composition containing a latent hydraulic substance as described above, a hardening stimulant, etc., generally known cement, for hydraulic compositions comprising various admixtures and the like Can also be used as a dispersant.

[0029]

The present invention will be described in more detail with reference to the following examples. The cured product hereinafter refers to a cured product obtained by curing and curing the above-described kneaded material.

The flow values in the examples were measured for the kneaded material or mortar after kneading according to JISR5201.

The compressive strength in the examples was determined by setting the loading rate to 0 using a Tensilon (manufactured by Orientec Co., Ltd.) with a 5 cm diameter and 10 cm height cylinder made of a cured product from a columnar specimen for cement mortar. It is the strength (kgf / cm ² ) at the time of compressing and breaking at 0.2 mm / min.

The bending strength of a 4 × 4 × 16 cm prismatic test piece was measured using Tensilon (manufactured by Orientec Co., Ltd.) at a loading speed of 0.5 mm / min and a span length of 10 cm. Strength at the time (kgf / cm ² ).

The tensile strength is 5 cm in diameter and 1 in length.
Using a Tensilon (manufactured by Orientec Co., Ltd.), a columnar test specimen of 0 cm was subjected to a load from the diametric direction under a loading speed of 0.2 mm / min, and the strength (kgf / cm ² ) when split. ). Further, the present invention is not limited to these examples. In Examples and Comparative Examples, parts and percentages are by weight unless otherwise specified.

Example 1 Maleic anhydride 21 was placed in a separable flask equipped with a reflux tube.
0 parts, 700 parts of deionized water were charged, the temperature was raised to 90 to 100 ° C., and a mixture of 840 parts of acrylic acid, 32 parts of ammonium persulfate, 20 parts of sodium hypophosphite, and 680 parts of water was added dropwise. After reacting for 10 hours, the system was cooled to room temperature, neutralized with 1385 parts of 45% caustic soda, and dried to obtain a sodium salt (water-soluble salt A) of the dispersant of the present invention. The weight average molecular weight of this product was 35,000 (GPC
Method, sodium polystyrene sulfonate conversion).

Examples 2 to 10 The sodium salt of the dispersant of the present invention (water-soluble salts B to J) was prepared in the same manner as in Example 1 except that the types and amounts of the monomers were changed to those shown in Table 1. ) Got. The obtained water-soluble salts B to J
Table 1 shows the polymerization average molecular weight (GPC method, converted to sodium polystyrene sulfonate) of

[0036]

Table 1 Water-soluble salt monomer and its copolymerization ratio Weight average molecular weight (weight ratio) abcdefghB 66 10 24 25,000 C 80 10 10 30,000 D 70 20 10 45,000 E 90 10 42,000 F 60 10 30 37,000 G 80 10 10 29,000 H 70 10 10 10 23,000 I 75 10 10 5 19,000 J 85 10 5 59,000

Note) In Table 1, a: acrylic acid b: maleic anhydride c: fumaric acid d: sodium allylsulfonate e: sodium methallylsulfonate f: vinyl acetate g: styrene h: N-vinylpyrrolidone

Example 11 A Blaine specific surface area of 4000 cm ² / g was added to an omni mixer.
Of blast furnace granulated slag (Nippon Steel Esment Co., Ltd.) and 100 parts of silica fume (average particle size: 0.2 μm, manufactured by Nippon Heavy Industries) were stirred and mixed for 90 seconds. continue,
An aqueous solution consisting of 10 parts of a water-soluble salt A, 20 parts of sodium hydroxide and 220 parts of water as a curing stimulant, and 2 parts of sugar as a curing regulator was added and kneaded for further 6 minutes.

The flow rate of the paste-like kneaded material obtained by these kneading was 250 mm. Next, the kneaded material was placed in a mold for compression, tension and bending tests,
The cured product of the present invention after 1 day of steam curing in an atmosphere of a saturated vapor pressure of 0 ° C. has a compression strength of 1390 kgf / cm ² , a bending strength of 219 kgf / cm ² and a tensile strength of 79 kgf / cm ² .
cm ² .

Examples 12 to 14 The same operation as in Example 11 was repeated for the water-soluble salts B, C, and D, and the test results are shown in Table 2. (However, the amount of the water-soluble salt added was changed as shown in Table 2.)

[0041]

Table 2 Amount of water-soluble salt added Flow value Compressive strength Bending strength Tensile strength Type (parts) mm kgf / cm ² 〃 B 12 210 1280 179 82 C 10 230 1360 188 78 D 10 220 1180 169 69

Example 15 A Blaine specific surface area of 4000 cm ² / g was added to an omni mixer.
900 parts of granulated blast furnace slag (made by Nippon Steel, Esment),
100 parts of silica fume (average particle size: 0.2 μm, manufactured by Nippon Heavy Chemical Industry) and 1000 parts of ferrochrome slag (trade name: NJ Sand 7, manufactured by Nippon Magnetic Separation Co., Ltd.) as fine aggregate were put and mixed for 90 seconds. Subsequently, the water-soluble salt E13
, 20 parts of sodium hydroxide and an aqueous solution composed of 1 part of sugar and 260 parts of water as a curing regulator, kneaded for further 3 minutes, cured as in Example 11, and cured according to the present invention. I got Table 3 shows the results of the same test as in Example 1 performed on the obtained cured product.

Example 16 A water-soluble salt E was replaced by 13 parts of a water-soluble salt F,
In the same manner as in Example 15, a cured product of the present invention was obtained. Table 3 shows the results of the same test as in Example 11 performed on the obtained cured product.

[0044]

Table 3 Water-soluble salt Flow value Compressive strength Bending strength Tensile strength Type mm kgf / cm ² 〃 E 260 1098 237 89 F 220 1189 245 95

Example 17 A concrete mixer having a Blaine specific surface area of 4000 cm
² / g granulated blast furnace slag (Nippon Steel, Esment) 95
0 parts, silica fume (average particle size: 0.2 μm, manufactured by Nippon Heavy Industries) 50 parts, silica sand (Nikko silica sand (manufactured by Kawatetsu Kogyo)) 1
000 parts and 200 parts of wollastonite were added and stirred and mixed for 90 seconds. Subsequently, an alkaline aqueous solution composed of 15 parts of a water-soluble salt G, 20 parts of sodium hydroxide, and 290 parts of water, and 2 parts of sugar as a curing regulator were added, and the mixture was further stirred and kneaded for 5 minutes. These were cured in the same manner as in Example 11 to obtain a cured product of the present invention. Example 11 of the obtained cured product
Table 4 shows the results of the same test.

Example 18 A water-soluble salt G15 was replaced with water-soluble salt H14.
In the same manner as in Example 17, a cured product of the present invention was obtained. Table 4 shows the results of the same test as in Example 11 performed on the obtained cured product.

Example 19 A water-soluble salt G was replaced with 15 parts of a water-soluble salt I.
In the same manner as in Example 17, a cured product of the present invention was obtained. Table 4 shows the results of the same test as in Example 11 performed on the obtained cured product.

Table 4 Water-soluble salt Flow value Compressive strength Bending strength Tensile strength Type mm kgf / cm ² 〃 Ｇ G 220 1079 235 105 H 200 1098 258 85 I 290 1430 245 114

Example 20 A concrete mixer having a Blaine specific surface area of 4000 cm
² / g granulated blast furnace slag (Nippon Steel Esment) 900
Parts, 100 parts of silica fume (average particle size: 0.2 μm, manufactured by Nippon Heavy Industries, Ltd.), 1000 parts of Toyoura sand, sodium polyacrylate (trade name Panakayak-B (Nippon Kayaku Co., Ltd.)
10) and mixed well for 1 minute. Then
10 parts of water-soluble salt J, 20 parts of sodium hydroxide and sugar 3
Of water and 350 parts of water, and the mixture was stirred and kneaded for 5 minutes to obtain a kneaded product. The flow value of the kneaded product obtained by these kneading was 180 mm. Example 1
The compressive strength of the cured product obtained by steam curing in the same manner as in Example 1 is 11
80 kgf / cm ² , flexural strength 258 kgf / cm ² ,
The tensile strength was 109 kgf / cm ² .

Comparative Example 1 Ordinary Portland cement (Asano cement) in a mixing machine
1000 parts and Toyoura sand 1000 parts were charged and mixed well for 2 minutes. Next, 350 parts of water was added and kneaded for another 5 minutes to prepare a mortar. The flow value of this mortar is 130mm
Met. Further, the compressive strength of the cured product of this mortar after curing and curing in the same manner as in Example 11 was 580 kgf
/ Cm ² , bending strength 95 kgf / cm ² , and tensile strength 35 kgf / cm ² .

As shown in Examples 11 to 20 and Tables 2 to 4, the cured product of the kneaded product of the hydraulic composition of the present invention and water has a flow value larger than that of a known mortar, and The cured product has better compression, bending and tensile strength than known cured products.

[0052]

The hydraulic composition containing the dispersant of the present invention comprises:
Since it has excellent fluidity and excellent compressive strength, bending strength, and tensile strength, it can be used in a wide range of fields such as construction, construction, and landscape materials.

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Claims (10)

(57) [Claims] A dispersant for an inorganic hydraulic composition obtained by copolymerizing acrylic acid and one of the following compounds (a): (a) maleic acid, maleic anhydride, and fumaric acid. 2. A dispersant for an inorganic hydraulic composition obtained by copolymerizing acrylic acid, one selected from the compound group (a) according to claim 1, and another monomer copolymerizable therewith. . 3. The copolymerizable monomer is at least one selected from hydroxyethyl (meth) acrylate, N-vinylpyrrolidone, sodium styrenesulfonate, sodium (meth) allylsulfonate, styrene, and vinyl acetate. The dispersant according to claim 2. 4. The dispersant according to claim 1, wherein the dispersant has a molecular weight of 1,000 to 500,000. 5. A hydraulic composition comprising a latent hydraulic substance, an ultrafine powdery substance, a curing stimulant and the dispersant according to claim 1, 2, 3 or 4. 6. The hydraulic composition according to claim 5, wherein the latent hydraulic substance is at least one selected from granulated blast furnace slag, converter slag, and fly ash. 7. The hydraulic composition according to claim 5, wherein the ultrafine substance is silica fume. 8. The curing stimulant is at least one selected from the group consisting of alkali metal hydroxides, carbonates and silicates.
Or the hydraulic composition according to 7. 9. The hydraulic composition according to claim 5, wherein the curing stimulant is at least one member selected from the group consisting of sodium hydroxide, sodium carbonate, potassium hydroxide, and sodium silicate. 10. A cured product obtained by kneading the hydraulic composition according to claim 5, 6, 7, 8 or 9 with water, and then performing wet curing.