JPS647562B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for manufacturing an inorganic substrate by a papermaking method, in which the inside of a papermaking machine A is sequentially divided into an initial papermaking zone 7a, a first retention zone 7b, and a second retention zone 7c. Then, using the paper-making belt 3, first the inorganic-containing slurry 1 is extracted in the initial paper-making zone 7a to form a cake layer 5a, and then the colored slurry 8 is extracted in the first retention zone 7b and placed on the cake layer 5a. A colored cake layer 5b is formed, and a second layer is formed.
This method of manufacturing an inorganic substrate is characterized in that a resin-containing slurry 9 is extracted by a retention zone 7c to form a resin layer 5c, and its purpose is to add resin only to the surface layer of the inorganic substrate to form a surface layer. An object of the present invention is to provide a method for producing an inorganic substrate that has improved hardness (strength) and water permeability, and is lightweight overall.

Inorganic substrates are porous if they have a low density, and even if they are coated with paint, they have poor adhesion, and pinholes are likely to form (requires 2 to 3 painting processes). If the density of the material is increased, it becomes heavier and has poor workability. Furthermore, if only the surface layer is made separately and bonded, it is likely to peel off from the interface. Further, in conventional examples in which resins and the like are added, they are added to the entire slurry to form paper, so the resin is dispersed throughout the slurry, resulting in high costs.

The present invention aims to eliminate such conventional drawbacks, and will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an example of a papermaking machine A used in the present invention, in which an initial papermaking zone 7a and a first and second retention zone 7 are sequentially formed by first and second shielding plates 6a and 6b.
It is divided into three zones: b and 7c. These zones are somewhat in communication with each other through passages below the lower ends of the first and second shielding plates 6a and 6b, and the supply pipe 1
It is filled with slurry 1 containing inorganic material fed from 0. First, the slurry 1 supplied to the initial papermaking zone 7a through the supply pipe 10 is homogenized by the igner roll 2, and is then drawn onto the endless felt-like papermaking belt 3 which is driven downward in the direction of the arrow. A cake layer 5a is formed. 4 is a suction device that sucks the slurry 1 and forms it onto the papermaking belt 3. Next, a colored slurry 8 containing pigments is fed into the first retention zone 7b from a colorant supply device 12 and dispersed in the slurry 1 by an impeller 13, and a colored cake layer 5b is formed on the cake layer 5a. It can be raised. Further, resin is introduced from the distributor 14 into the second retention zone 7c immediately before the completion of papermaking and mixed with the slurry 1, and a resin-containing slurry 9 is produced as a resin layer 5c on the colored cake layer 5b. Reference numeral 11 denotes a sliding device for smoothing the surface condition of the paper sheet. In addition, when introducing aggregate, the second shielding plate 6b and this sliding device 1
1 and may be appropriately supplied and dispersed into the slurry 1 from a supply device.

In the present invention, the first shielding plate 6a allows the colored slurry 8 added to the first retention zone 7b to
This is to prevent it from being dispersed throughout the
The second shielding plate 6b is for preventing the fibers and binder, especially the fibers, in the slurry 1 from flowing into the second retention zone 7c, that is, the sheaker section. In this case, be careful not to place the first and second shielding plates 6a, 6b too close to the rolled-up surfaces of the cake layer 5a and colored cake layer 5b, as this will roughen the surface of the rolled-up green sheet 5. There is a need.

Green sheet 5 extracted in this way
As shown in FIG. 2, a colored cake layer 5b is formed on a normal cake layer 5a, and a resin layer 5 is further formed on top of the colored cake layer 5b.
The resin layer 5c is formed into an inseparable sheet, and after being pressed and cured, only the surface resin layer 5c is subjected to heat treatment in the drying process. The temperature and time of this heat treatment vary depending on the resin used, but irradiation with infrared rays (IR) or far infrared rays, which can heat only the surface area, is preferred as a method. The resin may be either thermosetting or thermoplastic as long as it can be used in the method of the present invention.

Since the present invention is as described above,
A resin treatment layer can be formed only on the surface layer, and the inorganic substrate can be given high hardness (strength) on the surface without impairing its lightness, and it is also possible to improve water permeability and the like. Further, since a resin layer is also formed in the papermaking process, there is an advantage that a coating process is not necessary and a resin layer of considerable thickness can be formed without repeating coating. Moreover, since the resin layer is integrally formed as the surface layer of the green sheet itself, there is no possibility of interfacial peeling.

The present invention will be specifically described below based on examples.

Example The composition of the substrate was a mixture of blast furnace cement type C, MSH (calcium aluminum monosulfate hydrate), and gypsum, with the addition of glass fiber and pulp as reinforcing fibers, and a 6% slurry was used as a whole for the papermaking machine. The machine was operated under conditions that allowed it to digest 100 kg per minute. The paper-making conditions for the colored layer and resin layer were as follows.

(1) A 5% concentration tea raw material slurry was added to the first retention zone at a rate of 10 kg/min.

In the second retention zone, add novolac phenol and hexamethylenetetraamine as a hardener at 10% of the resin, add CaCO ₃ as a filler in the same amount as the resin + hardener, and add tea pigment to 5% of the total.
% was mixed before addition and added at a rate of 1 kg/min.

After pressing and curing, the surface is treated with IR during the drying process.
The temperature was maintained at 150°C and irradiated for 5 minutes to cure. The resin layer of the obtained substrate was 1 mm thick for a board thickness of 12 mm. It was then cooled down. the hardness of the surface of the object,
As a result of measuring the water permeability resistance, it was improved compared to the one without a resin layer on the surface.

(2) Add the same pigment slurry as (1) to the first retention zone.
Added at 10Kg/min.

Water-soluble resol was added to the second retention zone at 2 Kg/min.

After pressing and curing, the surface is treated with IR during the drying process.
It was kept at 200°C and irradiated for 5 minutes to cure. The resin layer was 1.5 mm thick for a board thickness of 12 mm. It was then cooled down. As a result of measuring the hardness and water permeability of the surface of the product, it was found to be better than those without a resin layer on the surface.

(3) A 3% concentration reddish-brown pigment slurry was added to the first retention zone at a rate of 10 Kg/min.

A mixture of PVC (polyvinyl chloride) powder, CaCO ₃ and red-brown pigment (8:1:1) was added to the second retention zone at 1.5 Kg/min.

After pressing and curing, the drying process is performed using IR at 180℃.
It was irradiated for 5 minutes and melted. The resin layer was 1.6 mm thick compared to the board thickness of 12 mm. It was then cooled down. As a result of measuring the surface physical properties (hardness, water permeability, etc.) of the material itself, it was found to be better than those without resin on the surface.

(4) Pigment slurry was added to the first retention zone in the same manner as in (3).

The second retention zone is made of polyamide resin (mp150
°C) and reddish brown pigment (9:1).
Added at 1.0Kg/min.

After pressing and curing, the drying process is performed at IR at 180℃, 5
Irradiate for a minute to melt. The resin layer was 0.9 mm thick compared to the board thickness of 12 mm. It was then cooled down. As a result of measuring the surface physical properties (hardness, water permeability, etc.) of the material itself, it was found to be better than those without resin on the surface.

(5) Pigment slurry with a concentration of 5% is placed in the first retention zone.
Added at 10Kg/min.

In the second retention zone (blast furnace cement + MSH +
Gypsum) and polyamide resin (mp150℃) 5:
5, and 2% of 1/4 inch glass fiber was added as fiber at 2 kg/min.

After pressing and curing, the surface is treated with IR during the drying process.
It was irradiated at 200°C for 10 minutes to melt it. The resin layer was 1.8 mm thick compared to the board thickness of 12 mm. It was then cooled down.
The surface properties (hardness, water permeability, etc.) were measured and found to be better than those without a resin layer.

[Brief explanation of the drawing]

FIG. 1 is a schematic process explanatory diagram of an embodiment of the present invention;
FIG. 2 is a partially omitted cross-sectional view of a green sheet obtained by the above method. In the figure, A is a paper making machine, 1 is a slurry, 3 is a paper making belt, 5a is a cake layer, 5b is a colored cake layer, 5c
7a is a resin layer, 7a is an initial papermaking zone, 7b is a first retention zone, 7c is a second retention zone, 8 is a colored slurry, and 9 is a resin-containing slurry.

Claims (1)

[Claims] 1 The inside of the papermaking machine is divided into an initial papermaking zone, a first retention zone, and a second retention zone, and a papermaking belt first extracts an inorganic-containing slurry in the initial papermaking zone to form a cake layer. A method for producing an inorganic substrate, comprising the steps of: collecting a colored slurry in a retention zone to form a colored cake layer on the cake layer; and further collecting a resin-containing slurry in a second retention zone to form a resin layer.