JPH0733492A - Hydraulic inorganic composition - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to shape even a small amount of water, the structure of the molded product is densified, and a cured product with high strength and excellent water resistance can be obtained. An excellent hydraulic inorganic composition is provided. A hydraulic inorganic composition comprising 100 parts by weight of a hydraulic inorganic substance, 1 to 100 parts by weight of a layered clay compound capable of adsorbing water between layers and having an average particle size of 0.2 to 100 μm, and water. .

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a hydraulic inorganic composition.

[0002]

2. Description of the Related Art A molded product using water and a hydraulic inorganic substance such as cement, mortar and gypsum is preferably used as a structural material such as construction and civil engineering materials. It has been used for various structural materials since ancient times. Since a fluidity of the composition is required when producing these hydraulic inorganic molded articles, a large amount of water has been added to secure the fluidity. A cured product obtained by curing such a hydraulic inorganic molded product is a cured product obtained by molding and curing with a water amount in which voids are formed by excess water and strength, water resistance, etc. are close to the stoichiometric amount. There was a problem that it was lower than the body.

Therefore, in order to obtain a high-strength cured product, 1) a method in which a water-soluble nonionic cellulose ether is mixed with cement and fine aggregate, and the mixture is molded by roll or extrusion molding (Japanese Patent Publication No. 3-21324). 2) A method in which water is absorbed in a clathrate-containing resin and then frozen, and the powder is mixed with a hydraulic inorganic substance, and water is released from the resin by pressing force (JP-A-1-264803), etc. Is proposed.

[0004]

However, in the method 1), it is necessary to add a large amount of water-soluble nonionic cellulose ether in order to impart good moldability, and as a result, the material cost becomes high. However, there was a problem that the water resistance was lowered. Further, in the method 2), since the composition has a poor fluidity at the time of molding, a high molding pressure is required, and it is impossible to mold atypically shaped products and large-sized molded products.

The object of the present invention is to solve the above-mentioned problems, to obtain a cured product which can be shaped even with a small amount of water, the structure of the molded product is densified, and which has high strength and excellent water resistance. Another object of the present invention is to provide a hydraulic inorganic composition which can be formed and has excellent moldability.

[0006]

The hydraulic inorganic substance used in the present invention is not particularly limited as long as it is an inorganic substance which shows a hardening property when kneaded with water. For example, ordinary Portland cement, special Portland cement, alumina cement, Simple cement such as Roman cement, acid-resistant cement, fire-resistant cement, special cement such as water glass cement, gypsum, lime, air-hardening cement such as magnesia cement, etc., especially strength, water resistance, Portland cement, Alumina cement is preferably used.
These may be used alone or in combination of two or more.

The layered clay compound used in the present invention is a phyllosilicate compound in which Si-O tetrahedra are bonded to each other to form a layer, which is capable of adsorbing water between layers. It is preferable that one absorbs 1 to 20 parts by weight of water with respect to 100 parts by weight of the layered clay compound. Examples of the layered clay compound include montmorillonite stones such as montmorillonite, magnesia montmorillonite, and synthetic smectite; mica groups such as shirounmo, quinunmo, and synthetic unmo; kaolin groups such as kaolinite and technite. When the average particle size of the layered clay compound is small, the layered clay compounds aggregate with each other, and when the average particle size is large, the dispersibility in the composition is deteriorated, and therefore, it is limited to 0.2 to 100 μm. When the amount of the layered clay compound is small, it cannot absorb the water in the added composition, and when it is large, it is difficult to release the water during molding. Therefore, it is limited to 0.1 to 100 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance. It

In the present invention, a water-soluble polymer substance may be added if necessary. The water-soluble polymer substance,
It dissolves in water to give viscosity, enhances the fluidity of the composition obtained from the hydraulic inorganic substance and water to improve the shapeability, and absorbs excess water in the cement hardened product to cement. Polymeric substances that can serve as a binder for filling voids between particles are preferable, and examples thereof include cellulose ethers such as methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, polyvinyl alcohol, polyacrylic acid, and lignin sulfonate. can give. When the amount of the water-soluble polymer substance added decreases, the fluidity of the composition decreases, and when the amount of the water-soluble polymer substance increases, the water resistance of the finally obtained cured product decreases, so 1 part by weight relative to 100 parts by weight of the hydraulic inorganic substance is added. The following are preferred.

In the present invention, an inorganic filler may be added if necessary. The inorganic filler is preferably one that does not dissolve in water, does not inhibit the hardening reaction of the hydraulic inorganic substance, and does not significantly inhibit the action of any constituent material used in the production method of the present invention, such as silica sand and river sand. Cement mortar aggregates, fly ash, silica flour, silica fume, bentonite, blast furnace slag, and other mixed cement admixtures, sepiolite, wollastonite, natural minerals such as mica, calcium carbonate, and diatomaceous earth. For the purpose of further reducing the weight, inorganic natural foams such as silica balloons, perlite, fly ash balloons, shirasu balloons, glass balloons and foamed and baked clay may be added. These may be added alone or in combination of two or more.

When the average particle size of the above-mentioned inorganic filler is small, the strength of the finally obtained cured product is lowered, and when it is large, the particles of the inorganic filler are difficult to disperse, and the impact strength is lowered. 0.03 to 500 μm is preferable. The amount of the above-mentioned inorganic filler is preferably 200 parts by weight or less with respect to 100 parts by weight of the hydraulic inorganic substance, because the strength of the finally obtained cured product decreases as the added amount increases.

In the present invention, reinforcing fibers may be further added if necessary. As the reinforcing fiber, any one can be used according to the performance desired to be imparted to the molded product, and examples thereof include vinylon fiber, polyamide fiber, polyester fiber, polypropylene fiber, carbon fiber, aramid fiber, glass fiber, potassium titanate fiber, and steel fiber. Can be used.
The fiber diameter of the reinforcing fiber is reaggregated at the time of mixing when it becomes thin, fiber balls are easily formed by entanglement, the strength of the finally obtained cured product is not further improved, and when it becomes thick or short, the tensile strength is increased. Since the reinforcing effect such as improvement is small and the dispersibility and orientation of the fiber are reduced when it is long, the fiber diameter is preferably 0.3 to 40 denier and the fiber length is 1 to 15 mm. Since the dispersibility of the fibers decreases as the amount of the reinforcing fibers added increases, the hydraulic inorganic substance 1
20 parts by weight or less is preferable with respect to 00 parts by weight.

The hydraulic inorganic composition of the present invention comprises the above-mentioned hydraulic inorganic substance, a layered clay compound and water, and optionally reinforcing fibers, a water-soluble polymer substance and an inorganic filler.
The method for obtaining a molded article from the hydraulic inorganic composition of the present invention is not particularly limited, and any conventionally known method can be used, for example, a pressure molding method such as a vibration pressure molding method and a dehydration pressure molding method, extrusion. A molding method, a cast molding method and the like are used, and in order to effectively release water from the layered clay compound, the vibration pressure molding method and the extrusion molding are particularly preferable. As the vibration pressure molding method, the method described in JP-A-5-64807 is used.

When the amount of water used in the present invention is small, the hydraulic inorganic substance is not sufficiently cured, and
Since the dispersibility of the composition decreases and the strength of the finally obtained cured product decreases when the dispersibility increases, it is preferably 15 to 100 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance. When used, it is more preferably 20 to 50 parts by weight. When the extrusion method is used, it is more preferably 15 to 65 parts by weight.

The molded product obtained in the present invention may be further cut into a required size if necessary, and supplied to a pressing mold to be shaped into a desired shape. By pressing the metal mold while slightly vibrating it in the three-dimensional direction, it may be shaped into a molded product having a complicated shape.

The hydraulic inorganic molded article obtained from the composition of the present invention is heated during molding, for example, during press molding, if a hydraulic inorganic material having a high curing rate such as gypsum is used. As a result, it can be cured at the same time as molding. The obtained cured product may be naturally cured over time, but when a hydraulic inorganic substance having a slow curing reaction, such as Portland cement, is used, the molded product is heated and humidified. By performing curing by a conventionally known method such as autoclave curing, the curing reaction can be promoted and the mechanical properties can be improved.

[0016]

EXAMPLES The present invention will be described in more detail by way of examples. Examples 1-4, Comparative Examples 1-4

The predetermined amounts of ordinary Portland cement (manufactured by Onoda Cement Co., Ltd.) and fly ash (average particle size 100 μm, true specific gravity 2.3, bulk specific gravity 0.6; J) shown in Table 1
According to ISA 6201), synthetic smectite (manufactured by Coop Chemical Co., trade name; SWN, capable of adsorbing 7.4 parts by weight of water between layers, average particle size 5 μm), synthetic ummo (Coop Chemical Co., trade name; ME100, Water between the layers 5.3
Part by weight can be adsorbed, average particle size 5 μm) is dry-blended and mixed with a predetermined amount of water shown in Table 1 by a mixer, and the kneaded product is kneaded to obtain a vibration press molding machine (Asahi Engineering Co., Ltd.). Manufactured by model SA-50) at a predetermined pressure shown in Table 1 and a vibration frequency of 1000H in the three-dimensional direction.
z, vibration with an amplitude of 10 μm was applied, and molding was performed for 5 seconds. The cross-sectional shape shown in FIG.
width 5 having a semicircular part 2 of mm and a central straight part 3 of 80 mm
A molded body having a length of 00 mm, a length of 500 mm and a thickness of 10 mm was obtained.

Comparative Examples 5 and 6 Synthetic smectites having the average particle size shown in Table 1 obtained by classifying the synthetic smectites used in Example 1 (each capable of adsorbing 7.4 parts by weight of water between layers) were used. A molded body was obtained in the same manner as in Example 1 except that it was used.

The molded bodies obtained in Examples 1 to 4 and Comparative Examples 1 to 6 were cured by curing at 90% RH for 6 hours to obtain a cured body, which was subjected to the following tests.

Physical property evaluation Formability The shape of the semi-circular part of the obtained cured product was visually judged, and ○ when no defective molding such as cracks occurred, and no defective filling, but cracks in the semi-circular part. △,
A mark X was given to those in which poor filling occurred. Bending strength A test piece was obtained by cutting the linear parts 1 at both ends of the obtained cured body.
Bending strength was measured according to the method of JIS A1408,
The bending strength of the material. The above results are shown in Table 1.

[0021]

[Table 1]

Examples 5 to 8 and Comparative Examples 7 to 10 A predetermined amount of ordinary Portland cement (manufactured by Onoda Cement Co., Ltd.) and fly ash (average particle size 100) shown in Table 2 were used.
μm, true specific gravity 2.3, bulk specific gravity 0.6; JISA 62
01), synthetic smectite (manufactured by Coop Chemical Co., trade name; SWN, capable of adsorbing 7.4 parts by weight of water between layers, average particle size 5 μm), synthetic ummo (Coop Chemical Co., trade name; ME100, interlayer) Can adsorb 5.3 parts by weight of water, average particle size 5 μm, and hydroxypropylmethyl cellulose (viscosity of 2% aqueous solution at 20 ° C. is 30,0).
(00 cps), dry blend it with a mixer,
After mixing with the predetermined amount of water shown in Table 2, the kneaded product obtained by kneading is extrusion-molded with an extruder having a screw diameter of 200 mm in which a mold having a parallel portion of 100 mm in the extrusion direction is installed. A molded body having a width of 300 mm and a thickness of 5 mm was obtained. The molding pressure during extrusion was measured with a pressure gauge and is shown in Table 2.

Comparative Examples 11 and 12 Synthetic smectites having the average particle size shown in Table 2 obtained by classifying the synthetic smectites used in Example 7 (each capable of adsorbing 7.4 parts by weight of water between layers) were used. A molded product was obtained in the same manner as in Example 7 except that the used product was used.

The obtained molded body was cured by curing at 90% RH for 6 hours to obtain a cured body, which was subjected to the following tests.

Dry / wet repeated test The obtained cured product was cut to obtain a test piece, and a dry / wet repeated test was conducted according to the method of ISO / DIS9125.
A sample was taken out for each cycle, the bending strength was measured in the same manner as the above method, and the number of cycles in which the strength was maintained at 90% was noted.

Bending Strength The obtained cured product was cut to obtain a test piece, and the bending strength was measured by JI.
The bending strength of the material was measured according to the method of SA 1408. The above results are shown in Table 2.

[0027]

[Table 2]

[0028]

EFFECT OF THE INVENTION The hydraulic inorganic composition of the present invention comprises 100 parts by weight of a hydraulic inorganic substance and a layered clay compound 1 capable of adsorbing water between layers and having an average particle size of 0.1 to 100 μm.
Since it is composed of 100 parts by weight and water, it can be shaped even with a small amount of water, has excellent moldability, can obtain a molded product having a fine structure, and can obtain a cured product having high strength and excellent water resistance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a molded body of Example 1 of the present invention.

[Explanation of symbols]

 1 Straight line on both ends 2 Half circle 3 Central straight line

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Claims (1)

[Claims] 1. A water-soluble inorganic substance, 100 parts by weight, 1 to 100 parts by weight of a layered clay compound capable of adsorbing water between layers and having an average particle size of 0.2 to 100 μm, and water. And a hydraulic inorganic composition.