JPH05201754A - Reinforcing material for hydraulic inorganic molded article and method for producing hydraulic inorganic cured article - Google Patents

Abstract

(57) [Summary] [Purpose] When added to a hydraulic inorganic composition, it has good fluidity, excellent extrusion moldability, and no carcinogenicity. Provided is a method for producing an excellent hydraulic inorganic cured product. [Structure] A reinforcing material for a hydraulic inorganic molded body, characterized in that substantially the entire surface is composed of pulp coated with an antigorite mineral, and after this is dispersed in water in advance and defibrated A method for producing a hydraulic inorganic cured product, which comprises subjecting a composition obtained by kneading a hydraulic inorganic substance to extrusion molding to cure and cure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing material for a hydraulic inorganic molded article and a method for producing a hydraulic inorganic cured article, which can be suitably used for building materials such as interior materials and exterior materials.

[0002]

2. Description of the Related Art Extrusion molding of a hydraulic inorganic composition using a hydraulic inorganic substance such as cement, mortar and gypsum and water,
The hydraulic inorganic cured product obtained by curing and curing is suitably used for building materials such as interior materials and exterior materials. In the process of producing these hydraulic inorganic cured products, a method for obtaining a high-strength hydraulic inorganic cured product by adding asbestos fiber to a hydraulic inorganic composition and extrusion-molding and curing it is also known from the related art. Has been. However, in this method, the problem of carcinogenicity to asbestos fibers is pointed out, and the development of alternative means is desired.

Therefore, 1) a cement admixture for extrusion molding in which cement is mixed with fibers (glass fiber and organic fiber) limited to a predetermined length (JP-A-51-111235), 2) pulp and asbestos A method of mixing and defibrating with a dry state, kneading cement and water and extruding (Japanese Patent Laid-Open No. 54-1584)
No. 30), 3) A method for producing a reinforced fiber cement board for obtaining a harmless and high-strength cured product by using a composition obtained by adding pulp and an antigorite mineral to a hydraulic inorganic composition (JP-A-3- 330
No. 42), etc. have been proposed.

[0004]

However, when extrusion molding is performed using the cement admixture of 1), since the glass fiber is a brittle material, the glass fiber is broken or damaged during molding, and the reinforcing effect is obtained. Almost gone,
Further, when organic fibers are used, the bent fibers of the molded product are exposed on the surface of the molded product due to pressure release immediately after molding, the irregularity of the molded product becomes severe, and the fluidity of the composition is lowered, making molding difficult. There were drawbacks such as.

Further, in the manufacturing methods 2) and 3),
There are drawbacks such that the reinforcing effect of the pulp is small, the fluidity of the composition is lowered, molding is difficult, and the surface roughness of the obtained molded body becomes severe.

The object of the present invention is to solve the above problems, a method for producing a reinforcing material for a hydraulic inorganic molded body which is excellent in extrusion moldability and has no carcinogenicity, and a hydraulic inorganic cured body which is high in strength and excellent in surface property. To provide.

[0007]

Means for Solving the Problems The reinforcing material for a hydraulic inorganic molded body of the present invention 1 comprises pulp whose substantially entire surface is coated with an antigorite mineral powder,
By substantially the entire surface is meant that most of the outer surface of the pulp is coated with antigorite minerals. The pulp used in the present invention 1 refers to an aggregate of the plant raw materials mechanically or chemically treated and the cellulose fibers separated into pieces, and the plant raw materials include conifers, hardwoods, waste paper, hemp, and bamboo. Etc. The mechanically treated ones include groundwood pulp and the like, and the chemically treated ones include sulfate pulp, sulfite pulp, phosphate pulp, soda pulp, nitric acid pulp, chlorine pulp and the like. Further, it may be a bleached pulp obtained by bleaching these during the manufacturing process. The length of the pulp is not particularly limited, but if it is less than 1 mm, the reinforcing effect is small, and if it exceeds 10 mm, the unevenness of the surface of the finally obtained molded body becomes severe, so that it is preferably 1 to 10 mm. The pulp having a diameter of 10 to 50 μm can be preferably used.

The antigorite mineral used in the present invention 1 is a tabular crystal body containing magnesium silicate (MgSii ₂ O ₅ (OH) ₄ ) as a main component, and is a mineral belonging to the metamorphic serpentinite group. The antigorite alone may be used, or the mixed crystal of antigolite and lizardite may be used. The average particle size of the antigolite mineral powder is 10 to 100 μm.
It is preferable that the diameter of the pulp is substantially the same as that of the pulp.

In the present invention 1, the method of coating substantially the entire surface of the pulp with the antigorite mineral powder is not particularly limited, and for example, the pulp is dispersed and defibrated in water to form a slurry. An example is a method in which an antigorite mineral is added to this slurry, stirred, taken out, and dried. Further, at this time, it is preferable to add a coagulant, because the antigorite mineral adheres strongly to the pulp. As the aggregating agent, an organic polymer compound having an action of aggregating and separating fine particles suspended and dispersed in water to clarify water can be preferably used, and examples thereof include polyacrylamide, polyethylene oxide, and urea-formalin resin. Nonionic polymer, anionic sodium acrylate, anionic polyacrylamide, anionic partially sulfomethylated polyacrylamide, anionic poly (2-acrylamide) -2-methylpropane sulfate,
Polymer electrolytes such as cationic polyaminoalkylmethacrylate, cationic polyethyleneimine, and cationic polydiallylammonium halide can be used.

When the concentration of pulp in the above slurry is less than 2% by weight, the pulp is not sufficiently covered with the antigorite mineral powder, and when it exceeds 8% by weight, the fluidity of the slurry decreases, so that 2 to 8% by weight. % Is preferred.

If the amount of the above-mentioned antigolite mineral added is less than 30 parts by weight relative to 100 parts by weight of pulp, substantially the entire surface of the pulp will not be covered with the antigolite mineral, and the final molding will be obtained. There is little improvement in the unevenness of the body surface. 3
If the amount is more than 00 parts by weight, the antigorite mineral powder is not firmly adhered, so 30 to 300 parts by weight is preferable.

The method for obtaining a molded product from the above-mentioned reinforcing material for a hydraulic inorganic molded product is not particularly limited, and a hydraulic inorganic substance and water, and optionally a reinforcing fiber, a water-soluble polymer substance and an inorganic filler. The kneaded product obtained by kneading with the material can be molded by a conventionally known method such as cast molding, press molding, and extrusion molding.

The hydraulic inorganic substance used in the production method of the present invention 2 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,
Examples include plain cement such as Roman cement, acid-resistant cement, fire-resistant cement, special cement such as water glass cement, and air-hardening cement such as gypsum, lime, and magnesia cement. Especially, in terms of strength and water resistance, Portland cement Alumina cement is preferably used.

When the amount of water used in the production method of the present invention 2 is less than 15 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance, the hydraulic inorganic substance is not sufficiently cured,
Further, the dispersibility of the composition fiber decreases, and if it exceeds 50 parts by weight, the mechanical strength of the obtained molded product decreases, so that
The amount is preferably 0 part by weight, more preferably 20 to 30 parts by weight.

The addition amount of the reinforcing material for a hydraulic inorganic molded body of the present invention 1 used in the production method of the present invention 2 varies depending on the amount of the coated antigorite mineral powder, but the hydraulic inorganic substance is 100 wt. If the amount is less than 0.5 parts by weight, the reinforcing effect is small, and if the amount exceeds 30 parts by weight, the surface roughness of the obtained molded article becomes severe, so 0.5 to 30 parts by weight is preferable, and more preferably 5 to 25 parts by weight.

In the present invention, if necessary, an antigorite mineral powder which does not cover the pulp may be added. When the total amount of the above-mentioned antigolite mineral powder added is more than 50 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance, the amount of the antigolite mineral powder is large. Absorbs water,
Since the flowability of the composition is deteriorated and the moldability is lowered, 50
It is preferably less than or equal to parts by weight.

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 synthetic fibers such as vinylon, polyamide, polyester, polypropylene, carbon, aramid, acryl and rayon, glass fibers, potassium titanate, steel and the like. Inorganic fibers can be used. Particularly when synthetic fibers are used, the flexibility is remarkably improved. The thickness of the reinforcing fiber is reaggregated at the time of mixing when it is too thin, fiber balls are easily formed by entanglement, the strength of the obtained molded article is not further improved, and either too thick or too short, the tensile strength. The reinforcing effect such as improvement is small, and if it is too long, the dispersibility and orientation of the fibers are reduced.
-15 mm is preferable. When the amount of the reinforcing fiber added is more than 20 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance, the dispersibility of the fiber decreases, so 20 parts by weight or less is preferable.

In the present invention, a water-soluble polymer substance may be added if necessary. The water-soluble polymer substance is
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 There is no particular limitation as long as it is a polymeric substance that can serve as a binder for filling voids between particles, and examples thereof include cellulose ethers such as methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, polyvinyl alcohol, polyacrylic acid, and the like. Be done. The amount of the water-soluble polymer substance added is preferably 5 parts by weight or less, since the water resistance of the obtained molded article decreases when the amount exceeds 5 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance.

In the present invention, an inorganic filler may be added if necessary. The inorganic filler is not particularly limited as long as it does not dissolve in water, does not inhibit the curing 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, for example, Quartz sand,
Examples include aggregates for cement mortar such as river sand, admixtures for mixed cement such as fly ash, silica flower, silica fume, bentonite and blast furnace slag, natural minerals such as sepiolite, wollastonite and mica, calcium carbonate, diatomaceous earth and the like. For the purpose of further reducing the weight, silica balloon, perlite, fly ash balloon, shirasu balloon, glass balloon, inorganic natural foam such as foamed clay may be used. These may be used alone or in combination of two or more kinds.

The above-mentioned inorganic filler has an average particle size of 0.03.
If it is less than μm, the strength of the obtained molded article decreases, and if it exceeds 500 μm, it becomes difficult to disperse the particles of the inorganic filler, and the impact strength decreases.
00 μm is preferable. When the amount of the inorganic filler added exceeds 200 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance, the strength of the resulting molded article decreases, so 200 parts by weight or less is preferable.

The method for producing a hydraulic inorganic cured product of the present invention 2 is an extrusion molding of a composition prepared by kneading the above-mentioned reinforcing material for a hydraulic inorganic molded product which has been previously dispersed in water and defibrated, and a hydraulic inorganic substance. It is characterized by curing and curing.

In the above defibration method, a pulp dispersed and defibrated in water is coated with an antigorite mineral powder to obtain a reinforcing material for a hydraulic inorganic molded body, which is dehydrated to a predetermined amount of water. Alternatively, the reinforcing material for a hydraulic inorganic molded body may be stirred and dispersed in a predetermined amount of water to be defibrated.

As the extrusion molding method in the present invention 2, a conventionally known extrusion molding method can be used. The method for curing a hydraulic inorganic cured product of the present invention 2 is to heat a molded product obtained by extrusion molding,
Any conventionally known method such as humidifying can be used, or
The molded body thus obtained may be naturally cured over time.

[0024]

EXAMPLES The details of the present invention will be described in more detail with reference to Examples. Examples 1 to 4 Pulp having an average length of 3.5 mm and an average diameter of 30 μm (produced in USA, unbleached softwood sulfate pulp, hereinafter referred to as NUKP
100 parts by weight) was dispersed in water and stirred with a mixer to prepare a slurry having a weight percentage of 5%. There 2
Anionic polyacrylamide-based coagulant (manufactured by Ichikawa Kaori Co., Ltd .; trade name; 150 ppm was added to the pulp. 1 more
After stirring for a minute, the mixture was filtered to obtain 300 parts by weight of the reinforcing material 1 for a hydraulic inorganic molded body. In addition, it was visually confirmed that substantially the entire surface of the pulp was covered with antigorite.

The reinforcing material 1 for a hydraulic inorganic molded body is dispersed in a predetermined amount of water shown in Table 1, stirred and defibrated, and then ordinary Portland cement (manufactured by Onoda Cement Co., Ltd.) and fly ash (JIS A 6201 equivalent). Products; manufactured by Kanden Kako Co., Ltd.,
Polypropylene fiber (manufactured by Daiwa, trade name; PZL2
d), hydroxypropylmethyl cellulose (viscosity of a 2% aqueous solution at 20 ° C. is 15,000 cps), and styrene beads (Sekisui Plastics Co., Ltd., trade name; Eslen beads) are added, and a 10-liter mixer (produced by Erich Co., trade name) is added. ; Erich mixer RV02) and mixed. The obtained mixture is an extruder (manufactured by Miyazaki Iron Works,
Product name: MV-100), thickness 12 mm, width 2
A 50 mm flat plate was molded.

Example 5 An amount of antigorite equivalent to NUKP was fixed in the same manner as in Example 1 to obtain a reinforcing material 2 for a hydraulic inorganic molded body, and a flat plate was molded in the same manner as in Example 1.

Example 6 A hydraulic inorganic molding was carried out in the same manner as in Example 1 except that a pulp having an average length of 1.2 mm and an average diameter of 20 μm (produced in Japan, unbleached hardwood sulfate pulp: hereinafter referred to as LUKP) was used. The body reinforcing material 3 was obtained, and a flat plate was formed in the same manner as in Example 1.

Example 7 The mixture obtained in the same manner as in Example 1 was pressed to form a flat plate having a thickness of 12 mm, a width of 250 mm and a length of 250 mm.

Comparative Examples 1 to 7 Mixtures of the prescribed amounts of ordinary Portland cement, fly ash, pulp, antigorite, polypropylene fibers, hydroxypropylmethyl cellulose, styrene beads and water used in Examples 1 to 7 were mixed. A flat plate was molded in the same manner as in Example 1 except that the mixture was put in and mixed.

Comparative Example 8 The mixture obtained in the same manner as in Comparative Example 1 was pressed to form a flat plate having a thickness of 12 mm, a width of 250 mm and a length of 250 mm.

The molded bodies obtained in Examples 1 to 7 and Comparative Examples 1 to 8 were aged at 90% RH for 10 hours to obtain a cured body, which was then subjected to the following tests. Density The obtained cured product was cut to obtain a test piece, and the weight was measured and divided by the volume. Surface roughness The center line average roughness was measured according to the base material test of JIS B 0601. Bending strength 12 mm x 50 mm x 250 by cutting the obtained cured body
mm test piece was obtained, and bending strength was measured according to JIS A 1408.
The measurement was performed according to the method of.

The above results are also shown in Table 2.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

INDUSTRIAL APPLICABILITY The reinforcing material for a hydraulic inorganic molded body of the present invention 1 has no carcinogenicity because it has a pulp whose substantially entire surface is coated with antigolite mineral powder. It exhibits excellent moldability when added to a hydraulic inorganic substance.

The method for producing a hydraulic inorganic cured product of the present invention 2 is a composition obtained by kneading a reinforcing material for a hydraulic inorganic molded product according to claim 1 which has been previously dispersed in water and defibrated, and a hydraulic inorganic substance. Is extruded and cured by curing, and the fibers of the pulp are excellent in orientation and can be molded with a small amount of water, so that a hydraulic inorganic cured product having high strength and excellent surface smoothness can be obtained.

Therefore, according to the method for producing a lightweight aggregate for hydraulic inorganic molded articles and a hydraulic inorganic cured article of the present invention, a hydraulic inorganic cured article that can be suitably used for building materials such as interior materials and exterior materials is provided. Obtainable.

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Claims (2)

[Claims] 1. A reinforcing material for a hydraulic inorganic molded body, characterized in that substantially the entire surface is made of pulp coated with antigolite mineral powder. 2. The method according to claim 1, wherein the particles have been previously dispersed in water and defibrated.
A method for producing a hydraulic inorganic cured product, which comprises subjecting a composition obtained by kneading the reinforcing material for a hydraulic inorganic molded product described above and a hydraulic inorganic substance to extrusion molding to cure and cure.