JPH05254959A - Production of hydraulic inorganic composition and production of formed body - Google Patents

Abstract

PURPOSE:To form even with a material obtained by adding fine particles to a composition acquired by adding water to a hydraulic inorg. substance as stoichiometrically as possible without deteriorating its flowability, to produce a hydraulic inorg. composition in which a water-soluble high molecular substance is uniformly dispersed and having high strength and excellent durability and to produce its formed body. CONSTITUTION:A frother is dissolved in 15-65 pts.wt. of water so that the frother concn. is controlled to 5-20wt.% and agitated to froth the water, 0.3-1 pts.wt. of a water-soluble high molecular substance is added and mixed, then 100 pts.wt. of a hydraulic inorg. substance is added and mixed, and a hydraulic inorg. composition and its formed body are obtained.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a hydraulic inorganic composition in which a water-soluble polymer substance is uniformly dispersed, and a method for producing a molded article from the composition.

[0002]

2. Description of the Related Art Molded articles using a hydraulic inorganic substance such as cement, mortar or gypsum have been used for various structural materials since ancient times. In the process of producing these hydraulic inorganic substance molded bodies, the hydraulic inorganic substance and water are uniformly kneaded, and in order to ensure good fluidity, water of a stoichiometric amount or more in the hydration reaction of cement is used. Has been added. Therefore, there is a problem that voids due to excess water are formed in the molded product after curing, and strength, durability, etc. are reduced as compared with a molded product cured with an amount of water close to stoichiometry.
That is, when the amount of water is small, there is a drawback in that even if a small amount of a water-soluble polymer substance is added in order to improve fluidity, insufficient dispersion occurs and sufficient strength cannot be obtained.

Therefore, as a method for obtaining a high-strength hydraulic inorganic molding, as described in JP-A-54-126228, JP-B-3-21324, etc.,
A method is known in which a large amount of a water-soluble polymer substance is added to increase the fluidity of a mixture, and the mixture is uniformly dispersed with a small amount of water to increase the strength.

[0004]

However, in the above method, when the water-soluble polymer substance in the molded product finally obtained by curing is eluted by water or the like and is used in a high humidity environment, etc. However, there was a problem that the long-term durability was lowered.

The object of the present invention is to solve the above problems, and even a composition obtained by adding water to a hydraulic inorganic substance in an amount as close as possible to the stoichiometry can be molded without impairing the fluidity, It is an object of the present invention to provide a method for producing a hydraulic inorganic composition and a method for producing a molded body, in which a water-soluble polymer substance is uniformly dispersed and which has high strength and excellent durability.

[0006]

The hydraulic inorganic substance used in the present invention is not particularly limited as long as it is an inorganic substance which exhibits a hardening property when kneaded with water, and examples thereof include ordinary Portland cement, special Portland cement, and alumina cement. Examples include plain cements such as roman cement, acid-resistant cements, fire-resistant cements, special cements such as water glass cements, and air-hardening cements such as gypsum, lime and magnesia cements. Especially, in terms of strength and water resistance, Portland cement Alumina cement is preferably used.

If the amount of water used in the production method of the present invention is too small, the hardening of the hydraulic inorganic substance will not proceed sufficiently, and the dispersibility of the hydraulic inorganic substance will decrease. Since the mechanical strength of the obtained cured product decreases,
It is limited to 15 to 65 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance.

The water-soluble polymer substance used in the production method of the present invention dissolves in water to impart viscosity, enhances dispersibility of the hydraulic inorganic substance, enhances fluidity of the mixture, and improves shapeability. Moreover, it is not particularly limited as long as it is a polymer substance that can be a binder that absorbs excess water in the cured body and fills the voids in the cured body, for example, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, hydroxy. Examples thereof include cellulose ethers such as propylmethyl cellulose, polyvinyl alcohol, polyacrylic acid and the like.

If the amount of the water-soluble polymer substance added is too small, the fluidity of the composition is poor even in the production method of the present invention.
If the amount is too large, the water resistance of the resulting molded article will decrease, so the amount is limited to 0.3 to 1 part by weight per 100 parts by weight of the hydraulic inorganic substance.

The foaming agent used in the production method of the present invention remarkably exerts the action of all the constituent materials used in the production method of the present invention among materials which generate bubbles by being dissolved in water and stirred. It is not particularly limited as long as it does not inhibit, but those generally used as a surfactant can be preferably used, and among these, aromatic sulfonic acid derivatives such as sodium p-dodecylbenzenesulfonate, lauryl sulfate, etc. Anionic surfactant, cationic surfactant such as triethanolamine halogenate, polyoxyethylene lauryl ether sulfate, polymethylsiloxane type surfactant, molecular weight consisting of protein hydrolyzate 5,
Examples include protein-based foaming agents such as 000 to 15,000 polypeptides. These may be used alone or in combination of two or more kinds. Examples of such a foaming agent include Takenaka Yushi Co., Ltd., trade name; Airset, San Orient Chemical Co., Ltd., trade name: Glufoam, and the like.

If necessary, a water-soluble polymer such as polyethylene oxide or polyvinyl alcohol, or a foam stabilizer such as stearate or aluminate may be added to these foaming agents.

In the present invention, reinforcing fibers may be further used if necessary. As the reinforcing fiber, any can be used depending on the performance desired to be imparted to the molded body, for example,
Synthetic fibers such as vinylon, polyamide, polyester and polypropylene, glass fibers, pulp fibers and the like can be used. In particular, when synthetic fibers are used, it is possible to impart flexibility that cannot be obtained by conventional hydraulic inorganic molded articles. Further, if the thickness of the reinforcing fiber is too thin, it is re-aggregated during mixing and fiber balls are easily formed by entanglement, and the strength of the obtained molded body is not further improved. The thickness is 0.1-40 because the effect is poor and the dispersibility and orientation of the fibers are reduced.
Denier is preferred. If the length of the reinforcing fiber is too short, the reinforcing effect is small, and if it is too long, the dispersibility of the fiber decreases, so that the length is preferably 1 to 15 mm. If the addition amount of the reinforcing fiber is too large, the dispersion of the fiber becomes poor at the time of mixing, so that the content is preferably 20% or less in the total volume of the composition.

In the present invention, an inorganic filler may be used 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,
Aggregate for cement mortar such as river sand, fly ash, silica flower, silica fume, bentonite, mixed cement admixture such as blast furnace slag, natural minerals such as sepiolite, wollastonite, calcium carbonate, mica, silica balloon, perlite, fly Ash balloon,
Examples include shirasu balloons, glass balloons, and inorganic natural foams such as foamed clay. These may be used alone or in combination of two or more kinds.

If the inorganic filler is too small, it tends to absorb water in the composition and is difficult to manufacture, and if it is too large, the particles of the inorganic filler are difficult to disperse.
Since the surface condition of the finally obtained molded body deteriorates,
0.03 to 500 μm is preferable.

If the amount of the inorganic filler added is too large, the strength of the resulting molded article decreases, so the hydraulic inorganic substance 100 is used.
It is preferably 200 parts by weight or less with respect to parts by weight. In the present invention, an organic filler may be used if necessary. The material of the organic filler is not particularly limited as long as it does not dissolve in water and does not inhibit the hardening reaction of the hydraulic inorganic substance, and examples thereof include organic synthetic resin powder, styrene beads, urethane foam, and vinylidene chloride. An organic synthetic resin foam such as a balloon can be used. If the amount of the organic filler added is too large, the strength of the resulting molded article will be reduced, so 200 parts by weight or less is preferable for 100 parts by weight of the hydraulic inorganic substance.

In the method for producing a hydraulic inorganic composition of the present invention 1, first, in the first step, the foaming agent is dissolved in 15 to 65 parts by weight of the water and stirred to foam. The amount of the foaming agent, when the foaming agent concentration to water is too low, after adding the water-soluble polymer substance to the foaming agent solution and mixing, when the hydraulic inorganic substance is added to the resulting mixture. Dispersion of the hydraulic inorganic substance becomes poor, the fluidity of the composition is insufficient with the amount of the water-soluble polymer substance used in the present invention, the strength of the obtained molded article is lowered, and if it is too high, Since the foaming agent is segregated and the strength of the obtained molded article is reduced,
Limited to 0% by weight.

Next, in the second step, the water-soluble polymer substance is added to and mixed with the mixture obtained in the first step. The mixing method used in the second step is not particularly limited, and any conventionally known mixer can be used.

Next, in the third step, 100 parts by weight of the hydraulic inorganic substance and, if necessary, the mixture of the water-soluble polymer substance, which is obtained in the second step, is dissolved in water or is being dissolved. Accordingly, reinforcing fibers, inorganic fillers, organic fillers, etc. are added and mixed. The mixing method used in the third step is not particularly limited, and any conventionally known mixer can be used.

Since the inorganic filler may be added to the liquid in which the water-soluble polymer substance is being dissolved in water, a material excellent in water solubility as the water-soluble polymer substance,
For example, when using hydroxypropylmethyl cellulose or the like, the inorganic filler may be mixed with water at the same time as the water-soluble polymer substance.

The method for producing a hydraulic inorganic molding of the present invention 2 is characterized in that a kneaded product comprising the composition obtained by the production method of the present invention 1 is subjected to vibration pressure molding. Invention 2
The vibration pressure molding in the above means that the composition obtained by the production method of the present invention is supplied into a pressure mold and pressure molding is performed while vibrating the mold.

The pressing die used in the manufacturing method of the present invention 2 is a conventionally known pressing die to which a conventionally known vibrator is attached. The pressing die and the mixture supplied into the pressing die are used. In order to give a slight vibration, and to give thixotropic properties to the kneaded product effectively, it is preferable to give the pressing die a frequency of 100 to 10,000 Hz with an amplitude of 1 to 500 μm. The direction of vibration may be one direction or may be a three-dimensional direction. An example of a device that can be used for the above-mentioned vibration pressure molding is a vibration press molding machine described in the Aichi Tokoname Ceramics Technology Center-Research Results Report in 1988.

In the method for producing a hydraulic inorganic molded article of the present invention 3, the composition obtained by the production method of the present invention 1 is extrusion-molded and then formed into a molded article having a desired shape by press molding. Characterize. As the extruder used in the present invention, any conventionally known one can be used, and the continuous molded body obtained by this is cut into a required size and supplied to a pressing mold, which is pressed. By doing so, a molded article having a desired shape can be formed.

The hydraulic inorganic moldings obtained by the methods of the present inventions 2 and 3 can be used during molding, for example, during press molding, if a hydraulic inorganic material having a high curing rate such as gypsum is used. It can be cured at the same time as it is formed by heating it to a desired temperature, and the resulting molded product may be naturally cured over time, but a slow curing reaction, such as a hydraulic inorganic material such as Portland cement. When using a substance, heat the molded body, humidify, etc.
Needless to say, the curing reaction can be promoted and the mechanical properties can be improved by carrying out curing by a conventionally known method.

[0024]

EXAMPLES Details of the present invention will be described with reference to examples. Examples 1 to 3 and Comparative Example 3 First step: A foaming agent in a predetermined amount of water shown in Table 1 (manufactured by Takenaka Oil & Fat Co., trade name; Airset, or manufactured by San Orient Chemical Co., trade name; Gulu The foam) was added and dissolved, and the solution was stirred with a whisk to generate bubbles.

Second step: The mixture obtained in the first step was put into a mixer of 10 liters, and a predetermined amount of hydroxypropylmethyl cellulose shown in Table 1 (viscosity of a 2% aqueous solution at 20 ° C. 30,000 cps) or polyvinyl alcohol (Shin-Etsu Chemical Co., Ltd., trade name; PA-
18S) was added and mixed for 2 minutes.

Third step: The mixture obtained in the second step was mixed with a predetermined amount of ordinary Portland cement shown in Table 1.
Fly ash with an average particle size of 100 μm (JIS A 6
Equivalent to 201; manufactured by Kanden Kako Co., Ltd., true specific gravity 2.3, bulk specific gravity 0.6), thickness 2 denier, and length 5 mm polypropylene fiber were added and mixed for 3 minutes to obtain a hydraulic inorganic composition. .. The obtained composition was further kneaded with a clay kneader to obtain an integrated kneaded product, which was further extruded with a vacuum extrusion molding machine to form a plate-shaped continuous molding having a width of 400 mm and a thickness of 5 mm.

Example 4 The composition obtained in the same manner as in Example 1 was further kneaded with a clay kneader to obtain an integrated kneaded product. The obtained kneaded product was pressed with a vibration press molding machine at a pressing pressure of 20 kg / cm ² , frequency 1,000 Hz, amplitude in three-dimensional directions 10 μm each
Molded for 5 seconds, 400mm x 400mm, thickness 5mm
A plate-shaped molded body of was obtained.

Comparative Examples 1 and 2 A mixture was obtained in the same manner as in Example 1 and kneaded with a clay kneader, but they were not integrated and a kneaded product having a moldable viscosity could not be obtained.

The molded bodies of Examples 1 to 4 and Comparative Example 3 obtained above were aged at 60 ° C. and 90% RH for 6 hours to be cured, and the cured bodies were cut to obtain test pieces. I went to

Evaluation of physical properties Moldability: A mark is given for a product that can be easily molded, and a Δ is given for a product that can be molded but has a problem in molding such as an increase in back pressure. Bending Strength The bending strength of the obtained test piece was measured according to the method of JIS A 1408.

The above results are shown in Table 2.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

As described above, the method for producing a hydraulic inorganic composition of the present invention 1 comprises dissolving a foaming agent having a specific concentration in water,
A first step of stirring and foaming; a second step of adding a specific amount of a water-soluble polymer substance to the mixture obtained in the first step and mixing; and a second step The third step of adding a hydraulic inorganic substance and, if necessary, reinforcing fibers, an inorganic filler, an organic filler, etc. to the mixed mixture and mixing them, is appropriately performed by the first step. Addition in the third step helps to disperse the water-soluble polymer substance added in the second step in the foamed aqueous solution and has sufficient viscosity even if the water-soluble polymer substance is in a small amount. Helps disperse the hydraulic inorganic material.

The method for producing a hydraulic inorganic molded body of the present invention 2 is to subject the composition obtained by the method of the present invention 1 to vibration pressure molding, and it is possible to impart sufficient fluidity to the kneaded product by fine vibration. Molding is possible even with a small amount of water, and a molded product having high strength and high moisture resistance can be obtained.

The method for producing a hydraulic inorganic molded article of the present invention 3 is characterized in that the composition obtained by the method of the present invention 1 is extrusion-molded and then shaped into a molded article having a desired shape by press molding. Therefore, even if the composition contains a small amount of water, such as a kneaded product comprising the composition of the present invention 1, a high-strength hydraulic inorganic molded product can be obtained while maintaining the dispersibility of the hydraulic inorganic substance. be able to.

Therefore, according to the production method of the present invention, the hydraulic material can be uniformly dispersed even when water is mixed in a relatively small amount, so that the strength is uniform and the moldability and durability are excellent. It is possible to obtain a molded body having

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area // (C04B 28/00 24:20 B 2102-4G 24:26 Z 2102-4G 16:06 Z 2102-4G 18:08) B 2102-4G

Claims (3)

[Claims] 1. A foaming agent concentration of 5 to 15 to 65 parts by weight of water.
The first step in which the foaming agent is dissolved so as to be 20% by weight, and the mixture is stirred to foam, and the mixture obtained in the first step is mixed with the water-soluble polymer substance 0.
The second step of adding 3 to 1 part by weight and mixing, and the mixture obtained in the second step, the hydraulic inorganic material 100
A method for producing a hydraulic inorganic composition, which comprises the third step of adding and mixing parts by weight. 2. A method for producing a hydraulic inorganic molding, which comprises subjecting the composition obtained by the method according to claim 1 to vibration pressure molding. 3. A method for producing a hydraulic inorganic molded body, which comprises subjecting the composition obtained by the manufacturing method according to claim 1 to extrusion molding and then shaping the composition into a molded body having a desired shape by press molding. ..