JPH1149551A - Production of hydraulic hardened body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hydraulic hardened body having excellent water resistance, frost resistance, toughness, strength and surface properties with good extruding property by adding a cationic alkali-hardening acrylic emulsion to a base material essentially comprising a slag, gypsum and cement, kneading the mixture and extruding to form. SOLUTION: A cationic alkali-hardening acrylic emulsion, preferably 2 to 25 wt.% is added to a base material essentially comprising a slag, preferably a blast furnace granulated slag preferably by 25 to 80 wt.%, gypsum, preferably water gypsum preferably by 5 to 30 wt.%, and cement (e.g. normal portland cement) preferably 2 to 20 wt.%, and if necessary, with addition of fly ash preferably by 2 to 25 wt.%. The mixture is kneaded and formed by extruding. If necessary, further, a fiber (e.g. glass fiber), plasticizer (e.g. methyl cellulose), extrusion assistant (e.g. sepiolite), etc., are added.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a water-cured product, particularly a water-cured product to be extruded.

[0002]

2. Description of the Related Art In recent years, a water-cured body has been extruded to form an outer wall material,
Products using various building materials such as roofing materials have been proposed.
Since the water-cured body by extrusion molding can be formed into an arbitrary shape, it is expected as a corner building material or an angle building material.

[0003] In particular, demand is expected for a water-hardened product mainly composed of slag, gypsum and cement, because of its light weight, and if necessary, light aggregate and fiber are further added thereto and mixed. After kneading by adding water, the mixture is extruded by an extruder, cured, and dried to obtain a product.

[0004] However, such a product has problems that it cannot be cut into a sharp shape when cutting, or that a corner is chipped. So slag, gypsum and cement-based substrate surface, styrene-butadiene rubber,
It has been proposed to impart toughness by coating with a surface material obtained by adding an aqueous dispersion (synthetic resin emulsion) of a polymer such as chlorosulfonated polyethylene, ethylene vinyl acetate, and acrylic emulsion (Japanese Patent Application Laid-Open (JP-A) No. 2002-110630). JP-A-63-25257).

[0005]

However, the strength, toughness and surface properties are improved by coating the surface material obtained by adding the aqueous dispersion of the polymer as described above, but the water resistance,
It is not yet sufficient in terms of the frost damage resistance, and there is a possibility that the surface may peel off or crack due to the freezing and expansion of the intruding water, and the strength may decrease. Therefore, a product having more excellent water resistance and frost damage resistance has been desired.

An object of the present invention is to provide a method for producing a water-cured product by extrusion molding, which is excellent in water resistance and frost damage resistance.

[0007]

According to the method of the present invention for producing a water-cured product, a cationic alkali-curable acrylic emulsion is added to a base material mainly composed of slag, gypsum and cement, kneaded, and then extruded. It is characterized by doing.

[0008] As the slag, granulated blast furnace slag is preferable, and its use amount is preferably 25 to 80% by weight. If the amount used is less than the above range, the workability will decrease. If the amount is more than the above range, carbonation is quick and the freeze-thaw resistance is lowered.

[0009] The gypsum is preferably gypsum dihydrate, which is desalted gypsum, and the amount used is preferably 5 to 30% by weight. If the amount used is less than the above range, the workability will decrease. On the other hand, if the amount is more than the above range, the water resistance is lowered, which is not suitable.

As the cement, ordinary Portland cement, white cement and various kinds of mixed cement can be used. The use amount is preferably 2 to 20% by weight. If the amount used is less than the above range, the shape retention in an uncured state is reduced. On the other hand, if the amount is more than the above range, the workability is reduced.

The mixing ratio of slag, gypsum and cement is preferably, for example, 6: 3: 0.5, whereby sufficient strength can be obtained.

The cationic alkali-curable acrylic emulsion is, for example, an aqueous emulsion of an acrylic resin. The acrylic resin preferably has an epoxy group or a functional group represented by the formula 1 at the terminal. In the formula 1, X is chlorine, bromine or iodine.

[0013]

(Equation 1)

Examples of the acrylic resin include alkyl acrylates and / or alkyl methacrylates having an alkyl group or cycloalkyl group having 1 to 12 carbon atoms, such as methyl acrylate and methyl methacrylate. And an alkali-crosslinkable quaternary ammonium salt monomer.
Examples of the alkali-crosslinkable quaternary ammonium salt monomer include dimethylaminoethyl methacrylate / epichlorohydrin adduct chloride and nitrate. As the surfactant, nonionic, anionic and cationic surfactants can be used.

The use amount of the cationic alkali-curable acrylic emulsion is preferably 2 to 25% by weight as a resin solid content. When the amount is less than the above range, the effects of water resistance and frost damage resistance are reduced, and when the amount is more than the above range, extrudability is reduced.

The cationic acrylic resin particles are well adsorbed to anionic cement particles and aggregates, and the epoxy group at the terminal of the acrylic resin particles or the functional group represented by the formula (1) is used as a cement. A crosslinking reaction is caused by the alkali of the particles to form a tough and water-resistant coating. Therefore, the space between the cement particles and between the aggregates is buried with the coating, and water hardly enters. Also, this acrylic acid-based resin has a low glass transition temperature and the formed film is soft. Further, the cationic alkali-curable acrylic emulsion has a thick colloidal hydrate layer, is chemically stable, is hardly crushed even with a small amount of water, and has good extrusion moldability.

The base material mainly composed of slag, gypsum and cement may be added with a lightweight aggregate, or may be made of a fiber to improve shape retention, impact resistance, nailing and the like during molding. May be added. As the lightweight aggregate, perlite, shirasu balloon and the like are preferably used, and the amount of use is 5 to 25% by weight.
Is preferred. When the amount used is smaller than the above range, the specific gravity increases. If the usage is more than the above range,
Moldability is reduced, and it is damaged by pressure during molding,
This causes a reduction in strength.

As the fibers, alkali-resistant glass fibers, synthetic fibers, pulp fibers and the like are preferably used.
The glass fiber is preferably a chopped strand fiber from the viewpoint of improving the mixing property and the shape retention. 0.5 used
~ 30% by weight is preferred. If the amount is more than the above range, the strength is reduced and the moldability is deteriorated. On the other hand, if the amount is too small, the shape retention during molding deteriorates and molding becomes unstable.

As the synthetic fibers, vinylon fibers and polypropylene fibers are preferred. Addition of these synthetic fibers improves the shape retention during molding. Although the strength cannot be greatly improved, improvement in impact resistance and nailing performance can be expected. The use amount is preferably 0.5 to 5% by weight. If the amount is more than the above range, the surface properties will be poor. On the other hand, if the amount is too small, the shape retention during molding is reduced.

Further, as the pulp fiber, coniferous or hardwood virgin pulp, cardboard waste paper, cardboard core paper, newspaper waste paper and the like can be used. The use amount is preferably 2 to 20% by weight. If the addition amount is larger than the above range, the strength of the water-cured body will not be exhibited. If the amount is too small, the shape retention and strength are reduced.

A plasticizer such as methyl cellulose may be used to improve the fluidity of the water-cured product during extrusion molding. The amount of the plasticizer is preferably 0.5 to 5% by weight. If the addition amount is less than this range, the thickening and curing of the water-cured body is reduced,
Extrusion cannot be performed. If it is more than the above range, the viscosity increases, the load becomes large, and molding becomes impossible.

Further, sepiolite may be added as an extrusion aid. The use amount is preferably from 2 to 20% by weight. If the addition amount is less than the above range, the moldability deteriorates, and if the addition amount is more than the above range, the strength is not exhibited.

When a water dispersion of a polymer such as a cationic alkali-curable acrylic emulsion is added, the extrudability of the water-cured product may be reduced. Therefore, it is preferable to use fly ash as a molding aid. By using fly ash, extrudability can be improved, and weight reduction can be maintained.
The use of fly ash is not limited to the case where a cationic alkali-curable acrylic emulsion is used, but may be the case where another acrylic emulsion is used.

The amount of fly ash to be added is 2 to 2
5% by weight is preferred. If the addition amount is less than this range, the extrusion pressure increases and the extrudability deteriorates. If the amount is more than the above range, the specific gravity increases and the nailing property deteriorates, and the extrusion pressure increases and the extrusion property deteriorates. The fly ash may be replaced with a lightweight aggregate, which makes it possible to reduce the weight while improving the formability. The substitution ratio can be 10 to 100%.

[0025]

EXAMPLES As shown in Table 1 below, water-cured products having the compositions as in Examples 1 and 2 and Comparative Examples 1 and 2 were prepared and kneaded.
Each sample was extruded using a screw type extruder, steam-cured at 80 ° C. for 12 hours, and dried at 105 ° C. for 24 hours to obtain each sample. Using these samples, performance was measured for the items shown in Table 2.

In Table 1, * indicates an acrylic emulsion. All units are% by weight. Granulated blast furnace slag as slag, dihydrate gypsum as gypsum, ordinary Portland cement as cement, methylcellulo as plasticizer
In Examples 1 and 2 as the acrylic emulsion, the acrylic emulsion containing a cationic alkali-curable acrylic emulsion
F-943 (manufactured by NSC Japan) was used. In Comparative Example 1, a sock-free, non-alkali-curable Poncoat 550 (manufactured by Dainippon Ink) as an acrylic emulsion, and in Comparative Example 2, a nonionic, non-alkali-curable GF-1 (acrylic emulsion). Japan NS
C company).

In Table 2, the unit of bending strength, specific strength, Young's modulus and extrusion pressure is kg / cm ² , and the nailing property is the distance from the nailable end and the unit is mm. -The unit of load is ampere.

[0028]

[Table 1]

[0029]

[Table 2]

In Table 2, when Example 1 and Comparative Example 1 are compared, Comparative Example 1 has almost the same physical properties such as strength as Example 1, but has poor extrudability, extrusion pressure and extruder model. −
Data load is large. On the other hand, comparing Example 1 with Comparative Example 2, it can be seen that Comparative Example 2 has lower strength and worse physical properties than Example 1, and also has a large extrusion pressure and a large extruder motor load, resulting in poor extrudability.

In Example 2 in which fly ash was used in which the perlite was halved in Example 1, the physical properties were not so different from those in Example 1, but in Example 2, the extrusion pressure and the extrusion motor were higher than in Example 1. -It can be seen that the extrusion moldability is improved, such as a decrease in the load.

[0032]

According to the present invention, a cationic alkali-curable acrylic emulsion is added to a base material mainly composed of slag, gypsum and cement, kneaded, and then extruded to obtain an excellent water resistance and frost damage resistance. A water-cured body having the following shape can be obtained.

The conventionally used synthetic resin emulsion is chemically unstable when the amount of water is small, and the hydrated layer is destroyed, and the film forming property is remarkably deteriorated due to a shear stress caused by a screw or the like in an extruder. By making the colloidal hydrate layer thicker and chemically stable, extrudability can be improved even in a low-moisture environment. However, in general, the water resistance of an emulsion film having a thicker colloidal hydrate layer is significantly reduced.

In the present invention, since a cationic alkali-curable acrylic emulsion is used for the emulsion, the colloid hydrate layer is thick and good extrudability is maintained.
Crosslinking can form a coating having high water resistance.

Further, by adding fly ash, the extrudability can be further improved while maintaining the lightness.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 22:14 24:26 7:02) (C04B 28/14 7:02 18:14 24:26)

Claims (4)

[Claims] 1. A method for producing a water-cured product, comprising adding a cationic alkali-curable acrylic emulsion to a base material mainly composed of slag, gypsum and cement, kneading the mixture, and extruding the mixture. 2. A cationic alkali-curable acrylic emulsion comprising 2 to 25% by weight of a base containing 25 to 80% by weight of slag, 5 to 30% by weight of gypsum and 2 to 20% by weight of cement.
A method for producing a water-cured product, comprising: extruding after kneading with kneading by weight%. 3. A method for producing a water-cured product, comprising adding an acrylic emulsion and fly ash to a base material mainly composed of slag, gypsum and cement, kneading the mixture, and extruding the mixture. 4. A base containing 25 to 80% by weight of slag, 5 to 30% by weight of gypsum and 2 to 20% by weight of cement is added with 2 to 25% by weight of acrylic emulsion and 2 to 25% by weight of fly ash. And then extruding after kneading.