JPH07291691A - Dispersing agent for inorganic hydraulic composition, hydraulic composition and cured material thereof - Google Patents

Abstract

PURPOSE:To obtain a dispersing agent for an inorganic hydraulic composition having excellent dispersing performances, by copoymerizing acrylic acid with maleic acid, maleic anhydride or fumaric acid. CONSTITUTION:The dispersing agent for an inorganic hydraulic composition, is obtained by copolymerizing acrylic acid with a monomer (a) selected from maleic acid, maleic anhydride or fumaric acid, or copolymerizing a monomer copolymerizable therewith with the monomers. As the monomers copolymerizable with the monomer (a), hydroxyethyl (meth)acrylate, N-vinylpyrroridone, sodium styrene sulfonic acid, etc., are cited. This hydraulic composition is obtained by blending a latently hydraulic material, a super fine powdery material, a curing stimulator, and the dispersing agent. This hydraulic composition can be used in a wide field such as architecture, construction or scenic material, since it has good fluidity property, and is excellent in compression, bending and stretching strength.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, a large amount of granulated blast furnace slag or converter slag has been produced as an industrial by-product, but its use is as a raw material for cement production, blast furnace cement and aggregate production. Most of them were used for landfill without effective use.

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

[0004]

In order to improve the fluidity of the kneaded composition of the granulated blast furnace slag and the weak strength of the cured product, various studies have been made in recent years. It was inferior to cement mortar and concrete, and its strength could not be put to practical use.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to solve this drawback, and a latent hydraulic substance such as granulated blast furnace slag is added to an ultrafine powder substance, a curing stimulant, and acrylic acid.・ 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 achieve fluidity and strength development more than ordinary Portland cement.

That is, the present inventor has completed the present invention by discovering a composition that can achieve the above-mentioned object as a result of earnest research on a method for obtaining a composition having no problems as described above.

That is, the present invention is (1) 1 selected from acrylic acid and the following compound group (a):
A dispersant for an inorganic hydraulic composition obtained by copolymerizing a seed (a) maleic acid, maleic anhydride, or 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 with these. (3) The copolymerizable monomer is hydroxyethyl (meth)
At least one selected from acrylate, N-vinylpyrrolidone, sodium styrenesulfonate, sodium (meth) allylsulfonate, styrene, vinyl acetate (2)
The dispersant according to (4), the dispersant according to (1), (2) or (3) having a molecular weight of 1000 to 500,000.

(5) A hydraulic composition comprising a latent hydraulic substance, an ultrafine powder substance, a curing 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 at least one selected from fly ash
(7) The above-mentioned (5), wherein the ultrafine powdery substance is silica fume.
Alternatively, the hydraulic composition according to (6). (8) The curing stimulant is an alkali metal hydroxide, carbonate,
(5), (6) above, which is one or more selected from silicates
Alternatively, the hydraulic composition according to (7), (9) the curing stimulant is one or more selected from caustic soda, sodium carbonate, caustic potash, and sodium silicate. (5), (6), (7) or (8) ) Described above, (10) A cured product obtained by kneading the hydraulic composition according to (5), (6), (7), (8) or (9) described above with water and then subjecting to wet curing. Regarding

The present invention will be described in detail below. The dispersant of the present invention is acrylic acid and maleic acid, maleic anhydride,
Copolymerize with one monomer selected from fumaric acid,
Alternatively, it can be obtained by copolymerizing these with a monomer copolymerizable with them. (In the following, one monomer selected from the above maleic acid, maleic anhydride, and fumaric acid is referred to as a monomer (a) unless otherwise specified.) Acrylic acid and a monomer (a) 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, acrylamide, Methacrylic amide, ethylene, propylene, isobutylene and the like can be mentioned.

The dispersant of the present invention is, for example, US Pat. No. 3,635.
It can be produced by a known method described in, for example, No. 915. The dispersant of the present invention can be used in the acid form as it is, but it is preferably neutralized with caustic soda and the like and used in the salt form. 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 salt of a maleic anhydride / styrene copolymer and sodium salt 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 powder, a curing stimulant and the dispersant of the present invention. The latent hydraulic material used in the present invention preferably has a Blaine specific surface area of 2000 cm ² / g or more, and particularly preferably 3000 cm ² / g or more. The latent hydraulic substance is not particularly limited as long as it hardens when kneaded with water and a hardening stimulant, but granulated blast furnace slag, converter slag, and fly ash are preferable. These latent hydraulic substances can be used alone or in admixture of two or more.

The ultrafine powder used in the present invention has an average particle size smaller than that of the latent hydraulic substance, preferably one order smaller than that of the latent hydraulic substance. It is more preferable to use one that is smaller than two orders of magnitude. The preferable average particle size of the ultrafine powder 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 powder substance is preferably 1/2 to 1/1000 of the average particle size of the latent hydraulic substance.

Specific examples of the ultrafine powder that can be used include silica fume, fly ash, silica sand, silica stone powder, clay, talc, kaolin, calcium carbonate, ground ceramics, slowly cooled blast furnace slag ground material, titania, Zirconia, alumina, aerosil, etc. can be mentioned, but in addition to improving the fluidity at the time of cast molding, the effect of improving the mechanical strength of the cured product after curing and curing is remarkable, so it is possible to use silica fume. Particularly preferred. The amount of ultrafine powder used depends on the size (particle size) and type of latent hydraulic substance,
Although it varies 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, and particularly preferably 5 to 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 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 and magnesium hydroxide. Alkaline earth metal hydroxides, sodium pyrophosphate, potassium pyrophosphate, dipotassium phosphate, tripotassium phosphate, trisodium phosphate and other phosphates, sodium (meth) silicate, potassium (meth) silicate and other silicic acids Examples include salt.

Of these curing stimulants, alkali metal hydroxides are preferable, and sodium hydroxide is particularly preferable. Although these curing stimulants can be used as solids or aqueous solutions, it is preferable to use an aqueous solution so that they are uniformly dispersed in the hydraulic composition during kneading.

The amount of the hardening stimulant to be used is its basicity (alkaline strength), the particle size of the latent hydraulic substance, the type and amount of various ultrafine powder substances to be added, and the water described later. Although it depends on the amount, it is preferably 0.1 to 20 parts by weight, and particularly preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the total amount 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 curing may take a long time.
It is an industrial disadvantage. On the other hand, if the amount is too large, the curing speed will be too fast, and handling in the kneading step or molding step may be significantly hindered.

When used in the hydraulic composition of the present invention, the molecular weight of the dispersant of the present invention is preferably 1,000 to 50.
30,000, more preferably 3,000 to 100,0
00. The molecular weight is 1,000 or less and 500,
If it is 000 or more, the fluidity of the hydraulic composition is poor, and the strength of the cured product is weak. Further, as the dispersant, those exemplified above can be used alone or in combination of two or more kinds.

In this case, it is preferable that the dispersant is rapidly dispersed in the composition when the hydraulic composition is kneaded. Therefore, an aqueous solution of these dispersants or a finely ground powder is used. Is preferred.

The amount of the dispersant used varies depending on the required properties of the finally obtained cured product, etc., but is usually 0.1 to 1 per 100 parts by weight of the total amount of the latent hydraulic substance and ultrafine powder substance.
It is 0 part 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 used is less than 0.1 part by weight, kneading may be difficult or the fluidity may decrease, depending on the amount of water to be described later. Further, if the amount of the dispersant used is more than 10 parts by weight, it will be difficult to cure, or even if it is cured, there will be problems such as poor water resistance.

If desired, various admixtures may be used in the hydraulic composition of the present invention. Examples of admixtures include, for example, crushed slowly cooled slag, ferrochrome slag, wollastonite, silica, alumina, talc,
Inorganic filler such as silica sand, silica powder, clay, kaolin, calcium carbonate, crushed ceramics, titania, zirconia, gravel, carbon fiber, glass fiber, pulp, nylon fiber, vinylon fiber, polyester fiber, acrylic fiber and other fiber materials , A setting retarder such as sugar and glucose, a surface treating agent such as a silane coupling agent, and a pigment.

In the case of using these various admixtures, the amount used is usually 10 to 300 parts by weight with respect to 100 parts by weight of the latent hydraulic substance in the case of the inorganic filler, and a curing retarder,
In the case of an admixture such as a surface treatment agent or a pigment, it is usually used in an amount of 0.1 to 20 parts by weight with respect to 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 of a latent hydraulic substance, an ultrafine powder substance, a hardening stimulant, the dispersant of the present invention and, if necessary, an admixture is prepared and shaken with an omnimixer (Chiyoda Giken Kogyo Co., Ltd.). 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 thoroughly kneaded with water,
After the kneaded product, it is poured into an appropriate mold, and the product is wet-cured to obtain the cured product of the present invention. The amount of water used in this case depends on the type and amount of the latent hydraulic substance and ultrafine powder substance used, the type and amount of the hardening stimulant, and the type and amount of other admixtures, and the kneaded product is good. It is important to decide so as to show kneadability, but usually 8 to 60 parts by weight, preferably 10 to 45 parts by weight, more preferably 12 parts by weight based on 100 parts by weight of the total of the latent hydraulic substance and the ultrafine powdery substance. ~ 35 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 powder substance are mixed, and the dispersant of the present invention finely ground and / or dissolved in water and, if necessary, various admixtures are put in the mixer exemplified above. And mix. Next, a predetermined amount of a hardening stimulant and a predetermined amount of water or an aqueous solution of the hardening stimulant dissolved in water is added to this mixture, and kneading is further performed.

As another method, a latent hydraulic substance, an ultrafine powdery substance and, if necessary, various admixtures are added, and the powder is mixed by a mixer. Then, 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 in which the curing stimulant is dissolved in water is added, and further kneaded to obtain a fluid kneaded product. obtain.

The wet curing for curing the kneaded product obtained as described above is usually carried out at a temperature of 5 to 100 ° C. under a saturated vapor pressure for 2 hours to 1 month.
The autoclave treatment may be performed at a temperature of 00 ° C or higher for 1 to 20 hours. The higher the moisture curing temperature, the faster the curing tends to be, but generally, the temperature is within the above range. The wet curing is preferably performed in a high humidity atmosphere in which at least the water content of the mixture does not evaporate. Generally a relative humidity of 8
0% or more, preferably 90% or more, more preferably 10
Perform in an atmosphere of 0%. It is also possible to carry out curing in water by immersing the molded body in the early stage of wet curing 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 construction that takes advantage of 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, and an interior / exterior material. Further, the dispersant of the present invention is used for a hydraulic composition comprising a generally known cement, various admixtures, etc., in addition to a hydraulic composition containing a latent hydraulic substance, a curing stimulant, etc. as described above. It can also be used as a dispersant.

[0029]

EXAMPLES The present invention will now be described in more detail by way of examples. The term "cured product" hereinafter refers to a cured product obtained by curing and curing the kneaded product described above.

The flow value in the examples was measured according to JIS R5201 for the kneaded product or mortar after kneading.

Further, the compressive strength in the examples is obtained by using Tensilon (manufactured by Orientec Co., Ltd.) for a cylinder having a diameter of 5 cm and a height of 10 cm, which is a hardened material made of a cylindrical test specimen for cement mortar, and a loading speed of 0. It is the strength (kgf / cm ² ) when it is compressed and broken at 0.2 mm / min.

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

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

Example 1 Maleic anhydride 21 was placed in a separable flask equipped with a reflux tube.
0 parts and 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 is 35,000 (GPC
Method, converted to sodium polystyrene sulfonate).

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 kinds and amounts of the monomers were changed to those shown in Table 1. ) Got. Obtained water-soluble salts B to J
Table 1 shows the polymerization average molecular weight (GPC method, converted into sodium polystyrene sulfonate).

[0036]

Table 1 Table 1 Water-soluble salts Monomers and their copolymerization ratio Weight average molecular weight (weight ratio) a b c def g h B 66 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 30 7,000 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 allyl sulfonate e: sodium methallyl sulfonate f: vinyl acetate g: styrene h: N-vinyl pyrrolidone

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

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

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

[0041]

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

Example 15 Blaine specific surface area 4000 cm ² / g in an omni mixer
900 parts of granulated blast furnace slag (made by Nippon Steel, Essent)
100 parts of silica fume (average particle diameter 0.2 μm, manufactured by Nippon Heavy Chemical Industry Co., Ltd.) and 1000 parts of ferrochrome slag (trade name NJ Sand No. 7, manufactured by Nippon Magnetic Co., Ltd.) were added as fine aggregate and stirred and mixed for 90 seconds. Then, water-soluble salt E13
Part, 20 parts of sodium hydroxide and an aqueous solution consisting of 1 part of sugar and 260 parts of water as a hardening regulator are added, and the mixture is kneaded for a further 3 minutes and then cured in the same manner as in Example 11 to give a cured product of the present invention. Got Table 3 shows the results of the same tests as in Example 1 performed on the obtained cured product.

Example 16 Except that 13 parts of the water-soluble salt E was changed to 10 parts of the water-soluble salt F,
A cured product of the present invention was obtained in the same manner as in Example 15. The results of the same test as in Example 11 on the obtained cured product are shown in Table 3.

[0044]

[Table 3] Table 3 Flow rate of water-soluble salt Compressive strength Bending strength Tensile strength Type mm kgf / cm ² 〃 〃 E 260 1098 237 89 F 220 220 1189 245 95

Example 17 Brane specific surface area 4000 cm in a concrete mixer
² / g granulated blast furnace slag (Nippon Steel, Essent) 95
0 parts, silica fume (average particle size 0.2 μm, made by Nippon Heavy Chemical Industry Co., Ltd.) 50 parts, silica sand (Nikko silica sand (made 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 consisting of 15 parts of water-soluble salt G, 20 parts of sodium hydroxide, and 290 parts of water, and 2 parts of sugar as a curing modifier 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 the cured product of the present invention. Example 11 of the obtained cured product
The results of the same test as in Table 4 are shown in Table 4.

Example 18 Except that 15 parts of the water-soluble salt G was changed to 14 parts of the water-soluble salt H,
A cured product of the present invention was obtained in the same manner as in Example 17. The results of the same test as in Example 11 on the obtained cured product are shown in Table 4.

Example 19 Except that 15 parts of water-soluble salt G was changed to 10 parts of water-soluble salt I,
A cured product of the present invention was obtained in the same manner as in Example 17. The results of the same test as in Example 11 on the obtained cured product are shown in Table 4.

Table 4 Water-soluble salt flow value Compressive strength Bending strength Tensile strength Type mm kgf / cm ² 〃 〃 G 220 2079 235 105 105 H 200 1098 258 85 I 290 1430 245 114

Example 20 Brane specific surface area 4000 cm in a concrete mixer
² / g granulated blast furnace slag (Nippon Steel Essent) 900
Parts, silica fume (average particle size 0.2 μm, manufactured by Nippon Heavy Chemical Industry Co., Ltd.) 100 parts, Toyoura sand 1000 parts, sodium polyacrylate (trade name Panakayak-B (Nippon Kayaku Co., Ltd.)
(Manufactured)) was charged and mixed well for 1 minute. Then
Water-soluble salt J 10 parts, sodium hydroxide 20 parts and sugar 3
Part, and 350 parts of water were added, 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. This is Example 1
The compressive strength of the cured product obtained by steam curing in the same manner as in 1 was 11
80 kgf / cm ² , flexural strength 258 kgf / cm ² ,
The tensile strength was 109 kgf / cm ² .

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

As shown in the above 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 known mortar, and The cured product is superior in compression, bending and tensile strength to known cured products.

[0052]

The hydraulic composition containing the dispersant of the present invention is
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.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area // (C04B 28/08 22:06 A 24:26 E H Z 22:06 Z 24:38) Z 103: 40

Claims (10)

[Claims] 1. A dispersant for an inorganic hydraulic composition, which is obtained by copolymerizing acrylic acid and one kind selected from the following compound group (a) (a) maleic acid, maleic anhydride, and fumaric acid. 2. A dispersant for an inorganic hydraulic composition, which is obtained by copolymerizing acrylic acid, one kind selected from the compound group (a) according to claim 1 and another monomer copolymerizable therewith. . 3. The copolymerizable monomer is one or more 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, 2 or 3 having 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 one or more selected from granulated blast furnace slag, converter slag and fly ash. 7. The hydraulic composition according to claim 5, wherein the ultrafine powdery substance is silica fume. 8. The curing stimulant is one or more selected from hydroxides, carbonates and silicates of alkali metals.
Alternatively, the hydraulic composition according to item 7. 9. The hydraulic composition according to claim 5, 6, 7 or 8, wherein the curing stimulant is at least one selected from caustic soda, sodium carbonate, caustic potash 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 subjecting it to wet curing.