JP2696242B2 - Fiber-reinforced cement molded article and inorganic cosmetic cement molded article using the molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fiber-reinforced cement molded article in which a filler is added to an inorganic substance in a cement molded article and reinforced, and an inorganic and excellent heat and chemical resistance. And a non-combustible decorative cement molding.

[Prior art and its problems] Since molded products of cement are strong in compression but weak in bending strength due to the inherent fragility of the cement mixture, they are generally formed by mixing fibers in a cement matrix and molding. The molding is reinforced with fibers. When heat resistance is required in addition to mechanical strength, asbestos fiber has been used so far.

Asbestos fibers have excellent heat-resistant properties in which the fiber strength does not decrease until the asbestos crystallization water discharge temperature reaches about 350 ° C. However, there is a risk of causing asbestos pollution such as harming silicosis in manufacturing or using the cement molding.
Continuing to use asbestos fiber from now on is a problem in protecting the social environment.

Even when synthetic organic fibers having excellent heat resistance, such as polyamide, polyester, and vinylon, are used as the reinforcing fibers, there is a problem in affinity, dispersibility, etc. with the matrix cement and the water wetting agent. The strength of the final molded product was not satisfactory due to the inability to carry out the treatment effectively and the adhesion to the cement was not sufficient. As a result, there is a drawback that the device cannot be used, so that the range of use is naturally limited and the cost is increased.

In view of the circumstances described above, the inventors of the present invention have both strong flexural strength and impact resistance at normal temperature, and have been used for insulation materials where asbestos cement molded products have been used due to their excellent heat resistance properties. When considering sepiolite as a filler material in the cement matrix with the task of obtaining a cement molded product that can be used for a wide range of applications, the mechanical properties of the cement molded product in relation to the fiber length and fiber width were examined. Have been found to be able to significantly improve the dispersibility of the filler material and to further improve the performance by contributing to the improvement of the dispersibility of the filler material.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention relates to a fiber-reinforced cement molded product, which comprises 90-60% by weight of hydraulic cement.
It is configured to mix natural sepiolite with 10-40% by weight of sepiolite fiber processed to have an average length of 0.5-5000 μm and an average width of 0.2-5 μm.

In the case of fiber-reinforced cement moldings, 90-60% by weight of hydraulic cement and natural sepiolite have an average length of 0.5-5%.
9 to 30% by weight of sepiolite fiber processed to an average width of 0.2 to 5 μm at 000 μm and 1 to 10% by weight of a glass fiber chopped strand having an average length of 5 to 50 mm. The glass fiber chopped strand may be dispersed in the cement matrix in a strand state, or may be dispersed in the cement matrix by being defibrated into filaments.

In fiber-reinforced cement molded products, the average length of hydraulic cement 90 to 60% by weight and natural sepiolite is 0.5 to 5%.
The composition was such that 5 to 20% by weight of sepiolite fibers processed to have an average width of 0.2 to 5 [mu] m and 5 to 20% by weight of wollastonite were mixed.

In fiber-reinforced cement molded products, the average length of hydraulic cement 90 to 60% by weight and natural sepiolite is 0.5 to 5%.
4 to 10% by weight of sepiolite fiber processed to an average width of 0.2 to 5 [mu] m at 000 [mu] m, 1 to 10% by weight of glass fiber chopped stunand having an average fiber length of 5 to 50 mm, and 5 to 20% by weight of the wollastonite It was configured to mix

In addition, in order to obtain an inorganic cosmetic cement molded product having excellent mechanical strength, heat resistance, nonflammability and chemical resistance, a baking coating film is formed on a fiber-reinforced cement molded plate having such a configuration by using an inorganic paint. It is composed.

In addition, as the inorganic coating used for the inorganic cosmetic cement molded article, those having excellent heat resistance and chemical resistance are desired,
It contains potassium silicate and lithium silicate as main components, zinc oxide as a hardening agent, and other inorganic fillers and pigments as appropriate. Inorganic paints need to be baked at 200-250 ° C in order to fully exhibit coating film properties. The inorganic cement molded article prepared by using the fiber reinforced cement composition of the present invention has excellent heat resistance without cracks or the like under these processing conditions.

[Action] The sepiolite fiber used in the present invention is obtained by crushing and cutting natural sepiolite and having an average length of 0.5 to 5000 μm and an average width of 0.2 to
It was processed into a fibrous shape in the range of 5 μm.

The sepiolite fiber having such a size range can maintain mechanical strength substantially equal to that of natural sepiolite. In addition, when stirring with water, it contains 100% or more of water and also acts as a thickener, which facilitates uniform mixing in the cement matrix. The average fiber length of sepiolite fiber is 5000
If it exceeds μm, the effect as a thickener is weakened, flocculation is liable to occur, and uneven mixing is caused. When the average fiber length is 0.5 μm or less, the effect of thickening is large, but the mechanical strength of the cement molded product decreases.

When the mixing ratio of sepiolite fiber is used alone, the reinforcing effect on the mechanical strength is remarkable in the range of 10 to 40% by weight, and 4% by weight when used in combination with glass fiber chopped strand and / or wollastonite particles. As described above, the reinforcing effect on the mechanical strength is remarkable.

[Example 1] Natural sepiolite as pulverulent fiber was pulverized and cut, and 60 parts of a group having an average fiber length of about 500 µm and an average fiber width of about 1.8 µm in a low tap sieve particle size distribution, and an average fiber length of 60 parts. About 170
A mixture prepared so as to contain 40 parts of a group having 0 μm and an average fiber width of about 2.6 μm is prepared, and Portland cement is prepared as cement.

First, Portland cement 73% by weight, sepiolite fiber 27
Weigh the weight%, add an appropriate amount of water and stir for about 15 minutes.
The sepiolite fibers absorb more than 100% of the added water and become viscous and mix evenly in Portland cement.

Next, it is poured into a mold and press-molded. In press molding, pressurization is performed at 100 kgf / cm ² for 30 seconds, and further pressurized to 150 kgf / cm ² and held for 60 seconds. Thereafter, the pressure was released and the press-formed product was water-cured for 2 days, followed by natural curing for 7 days.
A plate-like fiber-reinforced cement molding was obtained.

[Example 2] The same sepiolite fiber as that used in Example 1 was prepared as sepiolite fiber, and a monofilament having an average fiber diameter of 13.5 µm was bundled as a chopped strand made of glass fiber to a length of 13 mm. Prepare the cut pieces.

First, Portland cement 73% by weight, sepiolite fiber 24
The weight% and the glass fiber chopped strand 3% by weight are weighed, and an appropriate amount of water is added thereto and stirred for about 15 minutes.
The sepiolite fiber absorbs the added water to 100% or more to generate viscosity, and chopped strands made of sepiolite fiber and glass fiber are uniformly mixed in Portland cement.

Next, this was subjected to plus molding and curing under the same conditions as in Example 1 to obtain a plate-like fiber-reinforced cement molded product.

[Example 3] As the sepiolite fiber, the same blended particulate sepiolite fiber as that used in Example 1 above was prepared, and the same glass fiber as that used in Example 2 was prepared as the glass fiber. The wollastonite particles pass through a 400-mesh screen selected from natural wollastonite and prepare fibrous particles with an aspect ratio of 30 to 40.

First, 70% by weight of Portland cement, 17% by weight of sepiolite fiber, 3% by weight of glass fiber chopped strand, and 10% by weight of wollastonite are weighed and mixed, and an appropriate amount of water is added and stirred for about 15 minutes. The sepiolite fiber absorbs more than 100% of the added water and produces a viscosity, and the sepiolite fiber, glass fiber chopped strand, and wollastonite are uniformly mixed in the Portland cement. Next, this was subjected to plus molding and curing under the same conditions as in Example 1 to obtain a plate-like fiber-reinforced cement molded product.

Example 4 A fiber-reinforced cement molded plate based on any of the specifications of Examples 1 to 3, for example, the specification of Example 1, is prepared. Using a spray gun on the surface of this fiber-reinforced cement molded plate, an inorganic paint composed of 40 parts by weight of lithium silicate, 25 parts by weight of zinc oxide, 25 parts by weight of chromium oxide, and 10 parts by weight of silica with respect to 100 parts by weight of potassium silicate. Spray painting, 230
When baked and cured at a temperature of ~ 250 ° C for 2 hours, a baked coating of inorganic paint is formed.

In this state, there was no crack on the fiber-reinforced cement molded plate and its coating film surface, and it exhibited excellent properties of heat resistance and chemical resistance as a top plate for a laboratory bench.

In addition, it is possible to obtain a desired color of the baked coating film by appropriately adding an inorganic pigment to the above-mentioned inorganic paint as needed, and to add a hardened metal to a certain degree of hardness of the baked coating film surface. It can also be adjusted.

Comparative Example 1 73% by weight of Portland cement and 27% by weight of natural sepiolite are mixed, an appropriate amount of water is added, and the mixture is stirred for about 15 minutes. Next, this was taken out and subjected to press molding and curing under the same conditions as in Example 1 to obtain a plate-shaped sepiolite cement molded product.

Table 1 shows the bending strength and the Charpy impact value of Examples 1 to 3 and Comparative Example 1.

From Table 1, the bending strength at room temperature is 90 kgf / cm ² for the sepiolite cement molded product mixed with the natural sepiolite of Comparative Example 1, whereas the molded products of Examples 1 to 3 are Both are 255kgf
It can be seen that the strength has been increased to a value of / cm ² or more. The Charpy impact value of the sepiolite cement molded product of Comparative Example 1 was 0.1.
8 kgf-cm / cm ² , whereas the molded article of Example 1
gf-cm / cm ² , compared to the molded article of Example 1,
The molded product of Example 2 in which particulate sepiolite fiber and glass fiber were mixed was improved to 3.3 kgf-cm / cm ² , and the mixture in which particulate sepiolite fiber, glass fiber and wollastonite particles were mixed. It can be seen that the molded product of Example 3 has been improved to 3.0 kgf-cm / cm ² .

Further, the results of the accelerated thermal degradation test on the bending strength of the fiber-reinforced cement molded products of Examples 1 to 3 were improved by about 2.7 times or more respectively from those of Comparative Example 1 from FIG.
℃ × 3 hours, 300 ℃ × 3 hours, and 500 ℃
It can be seen that the bending strength after the treatment for 3 hours has been improved to about 150 kgf / cm ² as compared with Comparative Example 1.

The bending strength of the fiber-reinforced cement molded products of Examples 2 and 3 in which glass fibers were mixed was 200 ° C. × 3 hours, and then 300 ° C.
In the heat deterioration promotion test after the treatment at 500 ° C. for 3 hours after the treatment for 3 hours, it is understood that the improvement was made as compared with that of Example 1 in which the glass fiber was not mixed.

Further, the bending strength of the fiber-reinforced cement molded product of Example 3 in which wollastonite particles were mixed was 200 ° C. × 3 hours, and then 300 ° C. ×
In the heat deterioration promotion test after the treatment for 3 hours and after the treatment at 500 ° C. for 3 hours, it can be seen that the results are improved as compared with those of Examples 1 and 2 in which wollastonite particles are not mixed.

[Effect of the Invention] A natural sepiolite is pulverized and cut to have an average length of 0.5.
When used as a cement filler material in the form of particulate sepiolite fibers of up to 5000 μm and a diameter of 0.2 to 5 μm, it also acts as a thickener, facilitates uniform mixing, and contains 10 to 67 parts by weight. In addition, the reinforcing effect on the fiber-reinforced cement molding is remarkably exhibited, and the bending strength and the Charpy impact value are remarkably improved.

Further, when 1 to 12 parts by weight of glass fiber having a fiber length of 5 to 50 mm and a fiber diameter of 9 to 18 μm is mixed, the Charpy impact value of the fiber-reinforced cement molded product is further improved.

Further, when 5-25 parts by weight of wollastonite particles are further mixed, there is an effect that the temperature characteristics of the bending strength of the fiber-reinforced cement molded product are improved.

By forming an inorganic vitreous baked coating film on the surface of the fiber-reinforced cement molded product, the surface can be decorated, and an inorganic cosmetic cement molded product having excellent heat resistance and excellent chemical resistance can be obtained.

As described above, the fiber-reinforced cement molded article is excellent in mechanical strength and heat resistance, so that it is useful as a building material, and particularly useful where heat resistance is required. Also,
Inorganic cosmetic cement moldings are made of fiber-reinforced cement moldings with excellent mechanical strength and heat resistance with a baking coating of inorganic paint formed on the surface, so they have excellent mechanical strength and heat resistance, and also have chemical resistance Because it is non-flammable, it is useful not only as a building material but also as a top plate for a laboratory bench.

[Brief description of the drawings]

FIG. 1 shows a bending strength characteristic diagram after a heat deterioration promotion test by treatment at 200 ° C. × 3 hours, treatment at 300 ° C. × 3 hours, and treatment at 500 ° C. × 3 hours. FIG. 2 shows a perspective view of an inorganic cosmetic cement molded product. 1 ... fiber-reinforced cement molded plate, 2 ... baking coating film,
3 ... Inorganic cosmetic cement molded product.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C04B 14:38) 111: 12

Claims (5)

(57) [Claims] (1) In a fiber-reinforced cement molded product, 90-60% by weight of hydraulic cement and natural sepiolite have an average length of 0.5%.
A fiber-reinforced cement molded product, which is mixed with 10 to 40% by weight of sepiolite fiber processed to 5 to 5000 µm and having an average width of 0.2 to 5 µm. 2. A fiber-reinforced cement molded product comprising 90-60% by weight of hydraulic cement and natural sepiolite having an average length of 0.5%.
A mixture of 9 to 30% by weight of sepiolite fiber processed to 5 to 5000 μm and having an average width of 0.2 to 5 μm and 1 to 10% by weight of glass fiber chopped stunand having an average length of 5 to 50 mm. Fiber reinforced cement moldings. 3. A fiber-reinforced cement molded article comprising 90-60% by weight of hydraulic cement and natural sepiolite having an average length of 0.5%.
A fiber-reinforced cement molded product comprising 5 to 20% by weight of sepiolite fiber and 5 to 20% by weight of wollastonite processed to 5 to 5000 m and having an average width of 0.2 to 5 m. 4. A fiber-reinforced cement molded article comprising 90-60% by weight of hydraulic cement and natural sepiolite having an average length of 0.5%.
4 to 10% by weight of sepiolite fiber processed to 5 to 5000 μm and average width of 0.2 to 5 μm, 1 to 10% by weight of glass fiber chopped stonenoid having an average length of 5 to 50 mm, and 5 to 20% by weight of wollastonite
A fiber-reinforced cement molded product characterized by mixing: 5. An inorganic decorative cement, characterized in that a baked coating film of an inorganic paint is formed on the surface of the fiber-reinforced cement molded product according to any one of claims (1) to (4). Molding.