JP2001181007A - Product of hydraulic material formed by papermaking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a product of a hydraulic material formed by papermaking, excellent in strength and toughness, and further to provide a slurry of the hydraulic material and a method for efficiently producing the product of the hydraulic material formed by the papermaking. SOLUTION: This product of the hydraulic material formed by the papermaking contains 1-10 wt.% reinforcing fiber having 7-30 dtex size, 6-20 mm fiber length, >=100 cN strength and 5-10% elongation, and 1-10 wt.% pulp having 70-130 CSF based on the formed product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article of a hydraulic material, a method for producing the molded article, and a slurry for the molded article.

[0002]

2. Description of the Related Art Conventionally, a molded article formed by molding a hydraulic material by a papermaking method has been widely used as a roof tile, a sizing material, and the like. Such a molded article is a hydraulic material,
It is manufactured by making a slurry containing reinforcing material etc. into a round net type, long net type, flow-on type etc.
Since it is a continuous industrial production method, there is an advantage that a product of uniform and stable quality can be produced. Asbestos has been widely used as a reinforcing material, but in recent years, organic fibers have been increasingly used in place of asbestos to protect health. Has sufficient performance as a tile or a sizing material.

[0003]

Although the molded article has sufficient performance as a tile or a sizing material, it requires a higher degree of impact resistance when used for construction and civil engineering. Therefore, further improvements in various performances have been desired. However, increasing the amount of reinforcing fiber added to enhance the mechanical performance of the paper-formed body has the problem of reducing the water dispersibility of the fiber and the production efficiency of the paper-formed body, and in recent years, from the viewpoint of earthquake resistance, There is a demand for a tough paper body. The object of the present invention is not only a tile and a sizing material, but also a hydraulic material sheeting molded product and a hydraulic material slurry suitable for buildings, civil engineering structures and repair materials thereof,
It is still another object of the present invention to provide a method for efficiently producing the molded article.

[0004]

According to the present invention, there are provided (1) a reinforcing fiber having a fineness of 7 to 30 dtex, a fiber length of 6 to 20 mm, a strength of 100 cN or more, and an elongation of 5 to 10% by 1 to 10% by mass / compact; Hydraulic material sheet molding containing 1 to 10% by mass / mold of pulp of CSF 70 to 130, (2) Fineness 7 to
30dtex, fiber length 6-20mm, strength 100cN or more,
1 to 10% by mass / solid content of reinforcing fibers having an elongation of 5 to 10%,
A hydraulic material slurry for papermaking molding containing 1 to 10% by mass / solid content of pulp of CSF 70 to 130, (3) Maximum strength P (MP) of a standard specimen obtained by a standard papermaking method
a) and the deflection δ (cm) when exhibiting the maximum strength P is 3.5 or more, the hydraulic material slurry for papermaking molding according to (2), (4) fineness 7 to 30 dtex, fiber length 6 ~ 2
Hydraulic material slurry containing 0 mm, strength of 100 cN or more, reinforcing fiber having elongation of 5 to 10%, 1 to 10% by mass / solid, and pulp of CSF 70 to 130, 1 to 10% by mass / solid, is formed by a papermaking method. And a method for producing a sheet-formed molded article.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has been found that a molded article excellent in various properties such as toughness can be obtained by using a specific fiber as a reinforcing material. More specifically, the reinforcing fibers have a fineness of 7 to 30 dtex and a fiber length of 6 to 20.
mm, an organic fiber having a strength of 100 cN or more and an elongation of 5 to 10% is used. Conventionally, relatively small-diameter fibers having a fineness of 5 dtex or less have been used as reinforcing fibers for a molded article, but a great deal of cost is required to increase the fiber strength in order to increase the mechanical performance of the molded article. In addition, when the amount of addition is increased, fiber balls or the like are generated due to low water dispersibility of the fiber, so that various performances of the formed paper product are not so much improved and the production efficiency is lowered.

From the above, the present invention provides a fineness of 7 to 30.
A dtex fiber having a strength of 100 cN or more is used. Even if the strength per decitex is almost the same, it is possible to increase the burden load per fiber by increasing the fineness, and by increasing the diameter, the water dispersibility of the fiber is improved and reinforced. Since the amount of added fiber can be increased, the strength and toughness of the papermaking body can be increased. When the load that can be borne per fiber is small, when an external stress is applied, the crack expands and breaks before the stress is transmitted to other fibers.
If the load that can be borne per book is large, it is possible to expand the crack while receiving the external stress, and as the crack expands, more fibers bear the external stress, so each fiber shares the external stress. It is possible to bear. Therefore, the strength and toughness of the papermaking molded article are improved.

[0007] The fineness of the reinforcing fibers must be 7 dtex or more. If the fineness is too small, the strength of the fiber itself cannot be increased so much even if the strength per unit decitex is high, and the effect of the present invention cannot be obtained because the water dispersibility becomes insufficient. More preferably, the fineness is 10 dtex or more. On the other hand, if the fineness is too large, the adhesiveness to the matrix is greatly reduced, so that "dropout" is likely to occur, and the bridging effect and the reinforcing effect cannot be sufficiently obtained. Therefore 30
dtex or less, particularly preferably 20 dtex or less. In the case of the papermaking method, the fibers are easily oriented in a two-dimensional direction, and the fibers are less likely to be bent or bent as compared with kneading molding.
Is more likely to occur. Therefore, it is preferable to use fibers having a small diameter as compared with the case where the kneading molding method is employed.

[0008] From the viewpoint of ensuring a burden load per fiber, the breaking strength of the fiber is 100 cN or more, preferably 15 cN or more.
It must be 0 cN or more, more preferably 170 cN or more. If the breaking strength of the fiber is too small, when an external stress is applied, the cracks are expanded and the fiber is broken before the stress is transmitted to other fibers, so that the effect of the present invention cannot be obtained.
From the viewpoint of securing the applied load per fiber, the strength of the fiber per decitex is preferably at least 10 cN / dtex, particularly preferably at least 12 cN / dtex. The smaller the fineness, the higher the strength per decitex. Is desirable.

However, the desired effect cannot be obtained simply by using fibers having a specific fineness and strength. That is, the fiber used in the present invention has a larger diameter than the conventionally widely used fiber, has a small adhesive force with the matrix, and is easy to “peel off”, and the papermaking method in which the fiber is two-dimensionally oriented. This tendency is remarkable because of the adoption of.
Furthermore, not only does the entanglement between the fiber and the matrix become too small during the papermaking process, the papermaking properties are reduced and the production efficiency becomes insufficient, but also the hydraulic material particles held by the fiber are reduced and the molded product is reduced. , The mechanical performance tends to be reduced. From the above, it is necessary to make the fiber length of the reinforcing fiber relatively long, that is, 6 to 20 mm, and to make the fiber elongation 5 to 10%.

[0010] That is, by increasing the fiber length of the reinforcing fiber, "pull-out" is less likely to occur, a sufficient bridging effect can be obtained, and stress dispersion to other fibers becomes possible. Are appropriately entangled with each other, so that the machinability is improved, and the effect of holding the fibers of the hydraulic material particles is enhanced, so that the production efficiency and the performance of the obtained molded article are improved. The fiber length is 6 mm or more, particularly 7 mm or more, and more preferably 10 m, from the viewpoint of suppressing fiber detachment and improving the papermaking property.
m or more, and from the viewpoint of ensuring the water dispersibility of the fiber, it is 20 mm or less, particularly 18 mm or less, and more preferably 15 mm or less.
mm or less.

[0011] The elongation of the fiber also needs to be in a specific range. In other words, if the elongation is too high, the degree of freedom of the fiber increases and "pull-out" tends to occur, and the crack width increases, so that the load applied to the bridging fiber increases, causing stress concentration and dispersion of external stress. Becomes difficult.
Therefore, the elongation is preferably 10% or less, particularly 8% or less, and more preferably 7% or less. However, if the elongation is too small, it will easily break at the crack opening when an external load is applied, making it difficult to sufficiently bear external stress and to transmit stress to other fibers. Therefore, the breaking elongation is preferably 5% or more, particularly preferably 6% or more.

[0012] Such reinforcing fibers are lightweight and easy to handle.
It is preferable to use organic fibers because of their excellent mechanical performance. Specifically, polyolefin fibers (polypropylene fibers, polyethylene fibers, etc.), polyamide fibers (including aramid fibers), and polyvinyl alcohol fibers And acrylic fibers, polybenzoxazole fibers, polyester fibers, polyamide fibers (including aramid fibers), rayon fibers (polynosic rayon fibers, solvent-spun rayon fibers, etc.).
Of course, a plurality of types of fibers may be used in combination. Among them, mechanical performance, alkali resistance, polyolefin fiber and or polyvinyl alcohol fiber excellent in weather resistance,
In particular, it is preferable to use at least polyvinyl alcohol-based fibers. The blending amount of the fibers is preferably 1 to 10% by mass / molded article. If the amount of the fiber is too small, the effect of the present invention cannot be sufficiently obtained. Conversely, if the amount is too large, the water dispersibility becomes insufficient. From the viewpoint of the mechanical performance of the molded article, the blending amount is preferably 2.5% by mass or more / the molded article, particularly preferably 3.5% by mass or more / the molded article. From the viewpoint of uniform dispersibility, 6% by mass or less. / A molded article is more preferable.

The present invention is characterized in that the above-mentioned specific reinforcing fiber is compounded. However, other reinforcing fibers may be compounded as long as the effects of the present invention are not impaired. . In particular, it is preferable to mix other reinforcing fibers in an amount of 3% by mass or less / molded body, particularly 1% by mass or less / molded body, and more preferably 0 to 0.5% by mass / molded body.

It is only necessary to mix such a reinforcing fiber with a hydraulic material to obtain a molded article as a slurry, but a desired molded article cannot be obtained simply by using a specific reinforcing fiber. That is, when the diameter of the reinforcing fiber is large, the machinability at the time of papermaking is reduced and the production efficiency is reduced, and the effect of retaining the hydraulic material particles is reduced as compared with the case where the fine fiber is used. And the mechanical performance tends to decrease. From the above, in the present invention, it is necessary to mix a specific pulp, specifically, CSF70-130
Pulp must be blended. By incorporating such fine pulp, hydraulic material particles can be sufficiently captured,
Since the sheet thickness can be increased, not only the production efficiency is improved and the machine can be operated for a long time, but also a molded article having a high density and excellent strength and toughness can be obtained. Generally CSF150
Although pulp of ~ 300 is widely used, in the present invention, when such coarse pulp is used, the desired effect cannot be obtained. In terms of the hydraulic material trapping effect, CSF
It is preferably 125 or less, particularly preferably CSF 115 or less. Conversely, if the CSF is too small, the papermaking properties will decrease.
SF is preferably 70 or more, particularly preferably 80 or more.

The pulp is preferably natural pulp or natural pulp to which various treatments have been added. Among them, wood pulp,
In particular, coniferous wood pulp is more preferable from the viewpoints of paper making property, hydraulic material particle trapping property and the like. Pulp addition amount is 1 ~
It is necessary to be 10% by mass / molded article. When the added amount of pulp is small, the effect of capturing the hydraulic material particles is insufficient, and conversely, even when the added amount of pulp is too large, the formability of the molded article is increased. And the mechanical performance is reduced.
From the viewpoint of obtaining the effects of the present invention more efficiently, it is preferable that the blending amount of pulp is 3% by mass or more / molded product, and 6% by mass or less / molded product. As the CSF of the pulp is smaller, a sufficient effect of capturing the hydraulic material particles can be obtained even if the amount of the pulp is smaller, and the amount of the pulp can be reduced.

The hydraulic material used in the present invention is not particularly limited, and preferred examples include gypsum, gypsum slag, and magnesia. Among them, cement can be suitably used,
Portland cement is a typical example, but blast furnace cement, fly ash cement, alumina cement, or the like may be used, or these may be used in combination. In the present invention, it is preferable that the blending amount of the hydraulic material is 75% by mass or more / molded body, particularly 80% by mass or more / molded body. In other words, in the present invention, fibers having relatively large diameters that easily cause “peeling” are used, and the fibers are two-dimensionally oriented and formed by a papermaking method that is likely to cause “peeling”. Needs to be secured. However, for example, when a large amount of aggregate or the like is added, a sufficient adhesive force cannot be obtained at a contact portion between the fiber and the aggregate, so that the reinforcing effect of the reinforcing fiber is significantly reduced. From the above, in the present invention, it is preferable to mix a large amount of hydraulic material.

[0017] Other additives may be added as long as the effects of the present invention are not impaired. For example, fine particles such as silica fume, silica flour, sodium bentonite, sepiolite, fly ash, blast furnace slag, ball clay, aluminum hydroxide, mica and the like may be added as long as the effects of the present invention are not impaired. By blending the inorganic fine particles, papermaking properties and the like can be improved. From the viewpoint of sufficiently obtaining the effects of the present invention, it is preferable that the blending amount of the inorganic fine particles other than the hydraulic material is 20% by mass or less / compact, particularly 15% by mass or less / compact.

A slurry may be prepared using such a material, and a sheet-formed article may be manufactured using the slurry. For example, a hydraulic material slurry containing 1 to 10% by mass / solid content of a specific reinforcing fiber and 1 to 5% by mass / solid content of pulp may be prepared, and the compounding ratio of the hydraulic material is 75% by mass or more /
Preferably, it is solid. The slurry concentration may be appropriately set, but from the viewpoint of papermaking properties and molded article performance, it is preferable to use a slurry containing 200 to 2,000 parts by weight of water with respect to 100 parts by weight of the solid material. In particular, it is preferable to use 500 to 2,000 parts by weight of water for the round net method and the long net method, and 400 parts by weight or less for the flow-on method. If the amount of water is too large, the papermaking efficiency will be poor, and if too small, the uniform dispersibility of the solid material will be insufficient.

The method for preparing the slurry is not particularly limited, but from the viewpoint of obtaining a slurry in which the solid components are uniformly dispersed, the pulp is put into a stirrer filled with water and stirred, and then the reinforcing fibers, hydraulic material, It is preferable to sequentially add other additives (such as inorganic substances). The forming method is not particularly limited as long as it is a papermaking method. For example, a round net type, a long net type, a flow-on type, or the like may be employed. For example, a method of filtering a slurry on a mesh such as a wire net and transferring it immediately to a felt (round net type, long net type) or a method of casting at a time in a mesh shape (flow-on type) is used. What is necessary is just to shape | mold. Subsequently, if the water is squeezed and cured by a press, a desired paper body can be obtained. In addition, several sheets obtained may be laminated, and if necessary, may be pressed and cured. The press for the simple substance and the laminate may be performed at a pressure of 2 to 10 MPa for a maximum of about 10 minutes,
Pressing increases plate density and improves strength.

The molded article obtained by the present invention is excellent in strength and toughness, and the specific performance greatly differs depending on the papermaking method, the composition, etc., for example, the standard test is carried out by the standard papermaking method using the slurry of the present invention. When the body is manufactured, when the maximum strength is P (MPa) and the deflection at the time of achieving the maximum strength is δ (cm), P × δ is 3.5 or more, particularly 10 or more, a molded article excellent in toughness. Is obtained. Further, the maximum bending strength of such a standard specimen is 20 MPa or more, especially 35 MPa.
It is preferably at least MPs, more preferably at least 38 MPa, and the deflection δ is at least 0.15 cm, particularly preferably at least 0.20 cm, more preferably at least 0.26 cm. From the viewpoints of mechanical performance, durability and the like, the density of the molded body is preferably about 1.4 to 1.8 g / cm ³ .

[0021] The form of the papermaking molded article is not particularly limited.
For example, it can be used in various applications by forming it into a plate shape. ADVANTAGE OF THE INVENTION According to this invention, the intensity | strength and toughness of a papermaking molded object are improved significantly, and the molded object with very large deflection can be provided. This molded article is useful for reinforcing an earthquake-resistant structure and improving and improving the impact resistance of a structure due to its excellent toughness. The molded article of the present invention can be any product, and can be widely used as, for example, roof tiles, sizing materials, water tanks, pipes, and the like. Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to the examples.

[0022]

[Example] [Fineness dtex] The apparent fineness was measured at n = 5 or more by measuring the weight of a given test length of the obtained fibrous material.
The average was determined. In addition, the fineness could not be measured by measuring the weight of a certain yarn length (fine denier fiber) was measured by a vibroscope.

[Fiber strength cN, strength cN / dtex, elongation%] The fibers are allowed to stand in an atmosphere of a temperature of 20 ° C. and a relative humidity of 65% for 24 hours to adjust the humidity.
The fiber strength was measured with an Instron tester “Autograph manufactured by Shimadzu Corporation” at 0 cm and a tensile speed of 5 cm / min.
The strength was obtained by dividing the strength by fineness. The elongation was calculated by elongation at break of single fiber (cm) / gripping length (cm) × 100. If the fiber length is shorter than 10 cm, the maximum length of the sample within the possible range is measured as the grip length.

[CSF (freeness) ml] Freeness test method of pulp Measured according to the Canadian standard type of JIS P8121-1976, and the average value corrected to a slurry concentration of 0.4% by mass and a temperature of 20 ° C. It was evaluated as CSF.

[Deflection (δ) cm showing maximum bending strength (P) MPa and maximum bending strength P] A standard molded body was manufactured from the hydraulic material slurry by the following standard papermaking method.
Eight days later, the test specimen was subjected to a bending test by a central loading method under the following conditions, and the bending stress when a maximum load was generated was evaluated as the maximum bending strength, and the deflection showing the maximum bending strength in the load-deflection curve was evaluated as δ. Standard papermaking method: Formed by a round mesh papermaking method by HACHEK, 14 papermaking sheets are wound around a making roller, pressed and squeezed at a pressure of 5 MPa, and cured at 50 ° C. under a saturated humidity condition for 24 hours. Cured under the conditions of ° C. and saturated humidity to obtain a molded article of hydraulic material. Bending test: Apparatus Shimadzu Autograph AG5000-B Sample Cut out to a size of 25 mm in width, 4 mm in thickness, and 10 cm in length.
A sample of 5 mm is used as a specimen without cutting out. Test speed 0.2mm / min 3-point bending span 5cm

Examples 1 to 5 and Comparative Examples 1 to 8 500 liters of water was put into a pre-stirrer to stir the stirrer, and 1.5 kg of softwood pulp (CSF 120 ml) was added. Reinforcing fibers, further cement, kaolin, and silica fume were added sequentially in the following amounts, and after sufficient stirring, the obtained slurry having a concentration of 40% by mass was transferred to another feed tank. Next, the slurry was supplied from the feed tank to the round net portion, and papermaking was performed by Hatschek. Then, the obtained 14 sheets are wound around a making roller, pressed and squeezed at a pressure of 5 MPa, cured for 24 hours at 50 ° C. and saturated humidity, and further cured at 20 ° C. and saturated humidity. A material molded article was obtained. The obtained molded body has a thickness of 3.95 to 4.25.
mm, density 1.68-1.72 g. It is a slate plate of cm ³ , and the performance of such a molded product is shown in Table 1.

The ordinary cement (ordinary Portland cement manufactured by Chichibu Onoda), kaolin used "Bintan Kaolin" manufactured by Fine Matex Co., Ltd., and silica fume used "EFACO SILICA" manufactured by Union Kasei Co., Ltd. Is as follows. Reinforcing fiber As shown in Table 1, kaolin 5 mass% silica fume 5 mass% pulp 3 mass% ordinary cement balance

[0028]

[Table 1]

[Examples 6 to 11] Moldings were produced in the same manner as in Example 1 except that the composition was changed as follows. Table 2 shows the results
Shown in In addition, ordinary cement (ordinary Portland cement manufactured by Chichibu Onoda), pulp is softwood pulp (CSF)
110ml), silica fume is "EFACO SILICA" manufactured by Union Kasei Co., Ltd., wollastonite is Union Kasei
The compounding amount is as follows using "H-60FF" manufactured by Corporation. Reinforcing fiber 4% by mass Pulp 4% by mass Silica fume 4% by mass Wollastonite 4% by mass Ordinary cement 84% by mass

[0030]

[Table 2]

[Examples 12 to 15, Comparative Examples 9 to 11] C
A molded product was produced in the same manner as in Example 6 except that pulp having a different SF was used, and the thickness was 4 mm ± 0.15 mm and the density was 1.
A molded article of 70 ± 0.02 g / cm ³ was obtained. Table 3 shows the results
Shown in

[0032]

[Table 3]

Examples 16 to 18 and Comparative Example 12 500 liters of water was put into a preliminary stirrer and the stirrer was stirred.
1.5 kg of softwood pulp (CSF 120 ml) was added, and then the reinforcing fibers shown in Table 4 and further cement and pearlite were added in order to obtain the following blending amounts, and after sufficient stirring, the concentration obtained was 40% by mass. Was transferred to another feed tank. Next, the slurry was supplied from the feed tank to a TAPPI papermaking machine, and papermaking was performed by a TAPPI method different from the standard papermaking method. Note that TAPP
Formula I is a method in which a slurry is poured into a box-shaped container having a mesh bottom and then suctioned from the bottom to produce a solid content.
This is a papermaking method similar to the flow-on method. Next, the obtained 14 sheets are wound around a making roller and 5MP.
Press and squeeze under the pressure of a.
Cured for 4 hours, and further cured at 20 ° C. under a saturated humidity condition to obtain a molded article of hydraulic material. The obtained molded body had a thickness of 0.39 to 0.42 mm and a density of 1.48 to 1.51 g.
a slate plate of cm ^3, Table 4 the performance of such compacts
Shown in

The ordinary cement (ordinary Portland cement manufactured by Chichibu Onoda) and the pearlite are Ube Industries, Ltd.
Using "Ube Perlite I" manufactured by Kobe Steel, the compounding amount is as follows. Reinforcement fiber 4% by weight Pearlite 3% by weight Pulp 5% by weight Ordinary cement 88% by weight

[0035]

[Table 4]

Claims (4)

[Claims] 1. Fineness: 7-30 dtex, fiber length: 6-20 m
m, a molded article of a hydraulic material containing 1 to 10% by mass of a reinforcing fiber having a strength of 100 cN or more and an elongation of 5 to 10%, and 1 to 10% by mass of a pulp having a CSF of 70 to 130 / molded body. 2. Fineness: 7-30 dtex, fiber length: 6-20 m
m, a hydraulic material slurry for papermaking molding containing 1 to 10% by mass / solid content of reinforcing fibers having a strength of 100 cN or more and an elongation of 5 to 10%, and 1 to 10% by mass / solid content of pulp of CSF 70 to 130. 3. The product according to claim 2, wherein the product of the maximum strength P (MPa) of the standard specimen obtained by the standard papermaking method and the deflection δ (cm) when indicating the maximum strength P is 3.5 or more. Hydraulic material slurry for papermaking molding. 4. Fineness: 7-30 dtex, fiber length: 6-20 m
m, a hydraulic material slurry containing 1 to 10% by mass / solid content of reinforcing fiber having a strength of 100 cN or more and elongation of 5 to 10%, and 1 to 10% by mass / solid content of pulp of CSF 70 to 130 by a papermaking method. The method for producing a sheet-formed molded article.