JPS6061210A - Manufacture of inorganic cured body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for producing an inorganic cured product using a fourdrinier paper machine.

[Background technology]

There are two typical methods for mass-producing ate-free bodies (particularly inorganic yarn boards): a circular net method and a fourdrinier method. Conventionally, the circular net type is more often used than the fourdrinier type. In the circular mesh papermaking method, a Hachinik papermaking machine (circular mesh papermaking machine) is used to create a slurry containing cement, reinforcing fibers, etc., and the resulting inorganic thin f@ (thickness approximately 1 to 2 mII) A cured inorganic body is obtained by stacking a plurality of sheets and molding them, and performing pressing or the like. However, this method has a problem in that since the inorganic cured product obtained has poor freeze damage resistance and is likely to cause delamination, since a thin layer of 1@ is applied in many layers in the thickness direction.

Therefore, for several years now, the Fourdrinier papermaking method, which involves forming paper in one layer, has been widely used. In the Fourdrinier papermaking method using a long-length papermaking machine, the resulting inorganic hardened material has better resistance to frost damage than the circular wire papermaking method in which multiple sheets are formed. Fourdrinier papermaking speed, which has the advantage of high production speed, is generally about 8 to 12 m/min. On the other hand, the papermaking speed of the round net method is generally about 40 to 60 m/min, but it is usually about 5 m/min.
Since ~6 sheets of MT@ are rolled, the papermaking speed after stacking is approximately 6 to 10 m/min.

However, the long-form papermaking method also had problems. That is, since a slurry obtained by mixing raw materials and a large amount of water is continuously filtered using felt or the like, solid/liquid separation of the slurry is likely to occur during papermaking. Therefore, the side facing the felt etc. of the resulting paper product (
On the lower surface Wi), there is more matrix such as cement, and on the opposite side (upper surface r@), there are many relatively light materials such as reinforcing fibers, and the compositions of both layers are not the same but different. The problem is that it often becomes a problem. Such a situation adversely affects the physical properties, quality, etc. of the obtained inorganic cured product. In order to prevent the above-mentioned layer separation, measures have been taken such as increasing the slurry concentration and using fine particles and fine fibers as raw materials, but these measures slow down the papermaking speed. (The filtration speed decreases).

[Purpose of the invention]

This invention was made in view of the above circumstances, and is a method for producing inorganic cured products using a fourdrinier paper making machine, which can speed up the production speed and obtain homogeneous inorganic cured products as a whole. The purpose is to provide a manufacturing method.

[Disclosure of the invention]

In order to achieve the above-mentioned object, the present invention involves forming a single-layer molded product by using a fourdrinier paper machine to form a slurry containing cement and reinforcing fibers, and then curing and hardening this to form an inorganic material. An inorganic hardened body characterized in that, in producing the hardened body, pulp whose Schopper freeness is adjusted to 30 to 60°SR is used as a reinforcing fiber in an amount of 1 to 7% by volume based on the solid content of the blended material. The gist is the manufacturing method. The present invention will be explained in detail below.

Here, cement refers to ordinary Portland cement I-
Refers to general cements used in the production of inorganic hardened bodies, such as blast furnace cement, fly ash cement, and alumina cement.

As the reinforcing fibers, pulp that has been adjusted to have a Schopper freeness of 30 to 60°SR by fibrillation or the like is used. Since such pulp has many fibers with a small diameter and is bulky (has a large volume), it is made into paper using a fourdrinier paper making machine.

When solid/liquid separation of the slurry occurs (pulp.

This greatly reduces the risk of cement and water separating from each other.

As described later, in this invention, the amount of pulp used is 1 to 7% by weight based on the solid content of the blended raw materials, but the amount of pulp used with a Schopper freeness of less than 30° SR is 7% by weight.
If it is less than that, solid/liquid separation of the slurry is likely to occur. If a pulp with a Schopper freeness exceeding 60°SR is used, there is no risk of solid/liquid separation of the slurry, but the freeness of the slurry will be extremely poor and the papermaking speed will be reduced.

Pulp with a Schottspar freeness adjusted to 30 to 60"SR is not limited to pulp that falls within this range of Schottspar freeness, but can also be a mixture of multiple pulps with different Schottspar freenesses. This also includes combinations of multiple pulps that fall within the range of Schopper freeness as described above.For example, unbeaten pulp with a Schopper freeness of 20°SR or less, and pulp that has been beaten, etc. Pulp with a Schopper freeness of 60°SR or higher is used in combination, and when the two are mixed, the Schopper freeness is 30 to 60°.
It may be within the range of SR.

Other reinforcing fibers may be used in addition to pulp. Examples of reinforcing fibers used in combination include glass fibers, inorganic fibers such as rock wool and carbon fibers, metal fibers such as steel fibers, and organic fibers such as vinylon, polyethylene, polypropylene, and acrylic fibers.

In the method for producing an inorganic cured product according to the present invention, asbestos fibers may be used as reinforcing fibers, as in the conventional production method, but asbestos fibers are likely to cause pollution, so it is best to avoid using them as much as possible. Asbestos fibers have been widely used in the past because they are very suitable for use as reinforcing fibers in papermaking methods due to their small fiber diameter and good compatibility with cement and water. As mentioned above, there is a high risk of causing pollution. In the papermaking method, fibers such as asbestos fibers, which have a small fiber diameter and are compatible with cement and water, are essential, but in this invention, pulp is used as such fibers, so asbestos fibers are not used at all. It is also good.

In addition to cement and reinforcing fibers, fillers and the like are used as necessary.

An inorganic hydraulic slurry is created by mixing and stirring cement, reinforcing fibers, etc. in the presence of a large amount of water. The valve is
It should be used in an amount of 1 to 7% based on the solid content of the raw materials. This is because if the amount of pulp used exceeds 7% by weight, there is a very high probability that the obtained inorganic cured product will fail the nonflammability test.

When using other organic fibers in addition to the valve, it is preferable that the total usage of the valve and the organic fibers used together is 7% by weight or less based on the solid content of the blended raw materials, 7% by weight. You can get it by exceeding! (This is because there is a high possibility that the machine-cured material will fail the nonflammability test.

Long 11i! The slurry is continuously filtered using an I-pass paper making machine to obtain a molded article consisting of one layer (single layer molding). The fourdrinier papermaking machine referred to here is basically a device that can perform one-layer molding by continuously filtering slurry using a wire mesh net or felt, and is a partially modified version of the generally known fourdrinier papermaking machine. It also includes things that have been done. The obtained molded body is pressed under pressure if necessary, and then cured and cured to obtain an inorganic cured body.

In the method for producing an inorganic cured product according to the present invention, pulp whose Schopper freeness is adjusted to 30 to 60''SR is used as the reinforcing fiber, so there is almost no evidence of solid/liquid separation of the slurry during papermaking. It is possible to obtain an inorganic cured product that is homogeneous throughout.Also, since the slurry filtration speed during papermaking is fast and the papermaking speed is fast, the production speed of the inorganic cured product can be increased.

Next, Example 1 to explain Examples and Comparative Examples
-5 and Comparative Examples 1 to 3, inorganic cured bodies were produced in the following manner. First, with the composition shown in Table 1, 1
Using Kyoto materials, a slurry was made by mixing the raw materials in the presence of a large amount of water (see the margin below).Next, the slurry obtained under the papermaking conditions shown in Table 1 was processed using a fourdrinier method. The paper was made using a paper making machine, and the paper product was pressed at a press pressure of 40 kg/cd to form a molded product having a thickness of about 611 IIn. After this, the molded body was heated at a temperature of 60°C and a humidity of 95%R.
A cured inorganic body (inorganic board) was obtained by heating with moist heat for 2 weeks at FI or above. The appearance and bending strength of the obtained inorganic cured product with a specific gravity of 9 were examined, and a freeze damage test (ASTM ■ method 300 times) was conducted.
I did it. The results are shown in Table 2. In Table 2, in terms of appearance and frost damage test results, ○ means pass, and × means fail.

(Margins below) From Table 2, all of the inorganic cured bodies obtained in Examples 1 to 5 have almost no difference in quality between the front and back surfaces compared to that obtained in Comparative Example 1. It has excellent frost damage resistance, and
It can also be seen that the bending strength is higher when a load is applied from the back side.

Also, in Table 1, when comparing the papermaking speeds of Examples 1 to 5 and Comparative Examples 1 to 3, the papermaking speeds of Comparative Examples 2 and 3 are slower than the others; This is because in Examples 2 and 3, it was not possible to increase the papermaking speed any further. That is, in Examples 1 to 5, it was possible to increase the speed of papermaking of the slurry and increase the production speed of the inorganic cured body compared to Comparative Examples 2 and 3.

〔Effect of the invention〕

In the method for producing an inorganic cured body according to this invention, cement) II
A slurry containing JI and reinforcing fibers is drawn up using a fourdrinier machine to make a single-layer molded product, and then this is cured and cured to create an inorganic hardened product. Since the valve adjusted to 30 to 60° SR is used in an amount of 1 to 7% by weight based on the solid content of the blended raw materials, the production speed can be increased and an inorganic cured product that is homogeneous as a whole can be obtained.

Agent: Patent Attorney Takehiko Matsumoto

Claims (1)

[Claims] (1) A slurry containing cement and reinforcing fibers is made using a Fourdrinier paper machine to make a single-layer molded product, and then this is cured and cured to create an inorganic hardened product. Freeness level 30-60
The pulp adjusted to °SR is 1% based on the solid content of the blended raw materials.
A method for producing an inorganic cured body characterized by using ~7% air volume.