JPH0152355B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lightweight mineral fiberboard that is useful as a building material, particularly as a ceiling material, and which passes semi-flammable standards.

(Conventional structure and its problems) Fiberboards made by bonding mineral fibers such as rock wool and slag wool by adding an appropriate binder have traditionally had excellent heat insulation, fireproofing, and sound absorption properties. Therefore, it is widely used in construction materials such as ceiling panels.

These mineral fiberboards are made by mixing pulp into the fiber material to meet quasi-noncombustible standards in order to improve strength, reduce weight, and improve workability and processability. In order to further reduce the weight and improve heat insulation and sound absorption properties, a lightweight inorganic foam such as perlite is added in place of a portion of the fiber material.

However, since lightweight inorganic foams such as pearlite are lightweight, when obtaining fiberboard by wet papermaking, mineral fibers have poor dispersibility in slurry and float up to the surface layer, making the surface rough.
Only 10 parts by weight or less can be added to 100 parts by weight, so the resulting mineral fiberboard has a specific gravity of
It was not possible to lower it below 0.3.

This is because lightweight inorganic foams such as perlite are closed foams with air bubbles inside, so during papermaking, they do not disperse uniformly in the slurry but float to the top of the slurry, forming a plate with a uniform composition. This is because it becomes difficult to obtain water, and if such a closed foam is forced to absorb water, it becomes difficult to remove the water that has entered the inside.

(Object of the invention) The present invention solves these problems,
To provide a lightweight mineral fiberboard with excellent heat insulation and sound absorption properties that can be easily produced using conventional manufacturing equipment without using conventional closed foams such as perlite or shirasu balloons.

Another object of the present invention is to provide a mineral fiberboard that increases the bending strength, which is slightly reduced due to weight reduction, by forming a surface layer, and has excellent surface smoothness and paintability. It is something.

(Structure of the Invention) In order to achieve the above object, the mineral fiberboard of the present invention is based on 100 parts by weight of mineral fibers in a fiberboard mainly composed of mineral fibers such as rock wool.
20 to 100 parts by weight of open lightweight inorganic foam is mixed therein, and the mineral fiberboard is used as a substrate, and on the surface of the substrate, per 100 parts by weight of mineral fibers such as rock wool. A surface layer is provided in which an organic component consisting of pulp and a binder such as starch or synthetic resin is mixed in a proportion of 20 parts by weight or less.

(Description of Embodiments) Embodiments of the present invention will be explained with reference to the drawings.
is a mineral fiber board, which is mainly made of mineral fibers such as rock wool or slag wool, and is a so-called open type in which air bubbles are exposed to the outside by rapidly heating and firing raw materials such as crushed raw stone and whitebait. It is made by uniformly mixing a large number of foams 3.

This mineral fiber board 1 is made by mixing an open foam 3 with 100 parts by weight of mineral fibers 2 such as rock wool.
It is obtained by mixing 20 to 100 parts by weight with an organic component consisting of pulp and a suitable binder in a proportion of 20 parts by weight or less of the total, and then forming the mixture into a paper. In this case, the open foam has good dispersibility in the slurry and can form a fiberboard with a uniform composition.

Open-type foams generally have an expansion ratio 2 to 3 times that of closed-type foams, and their apparent specific gravity is 1/2 to 1/3 of that of closed-type foams, with the cells exposed to the outside. can easily penetrate inside the foam,
Therefore, as mentioned above, the proportion of surfacing is small,
Good dispersibility in slurry and water, and
Since the moisture inside the foam can be easily evaporated from the exposed portions of the bubbles by heating, it is possible to add a large amount of the foam to the mineral fiberboard.

The strength of mineral fiberboard is obtained from the entanglement of the fibers and the binder, but in order to achieve fire resistance that satisfies the standards for semi-noncombustible materials, the organic content must be 20 parts by weight or less of the total amount. Therefore, in order to achieve strength and weight reduction, it is sufficient to add a large amount of pulp and binder, which make the fibers flexible and tangle well, but there is a limit in terms of fire resistance.

On the other hand, open foam is added to replace some of the mineral fibers, but adding too much will reduce the strength, so it is necessary to maintain a certain level of strength while reducing weight compared to conventional fiberboard. Mineral fiber to achieve
It is added at a ratio of 20 to 100 parts by weight per 100 parts by weight.

When adding a large amount of such open-type foam to mineral fibers, it is advantageous to use a small particle size from the viewpoint of formation, and in the present invention, a particle size of 200 to 600μ is advantageous.
are used.

By adding a large amount of such lightweight foam, the specific gravity remains strong enough to be used as a ceiling material.
This makes it possible to reduce the weight to about 0.2.

However, when strength is required, such as in the case of large ceiling materials, or when surface hardness is required due to patterning, mineral fiberboard 1 with the above composition is used, as shown in Figure 2. is used as a substrate, and on the surface of this substrate, an organic component consisting of a binder such as pulp, starch, or synthetic resin is added to the surface of the substrate at a ratio of 25 parts by weight or less, based on 100 parts by weight of mineral fibers such as rock wool, that is, only in the surface layer. Paid ratio is 20% of the total
This is a mineral fiberboard integrally provided with a surface layer 4 having a composition of less than or equal to %.

In this case, a high-density surface layer can be formed by using short fibers whose fiber length is adjusted to 100 to 2000 microns as the mineral fibers of the surface layer 4.

In other words, if it is a short fiber with a length of 100 to 2000μ,
Because the fiber length is extremely short, it easily flows due to the pressure during wet papermaking and the movement of moisture during dehydration in the overlapping part with the wet sheet that becomes the substrate 1, and the normal mineral fibers and foam that make up the substrate 1 tend to flow. The bonding points between the two are significantly increased by biting into the gap between the two, and by applying a binder to the bonding points, the bonding points are firmly fixed and peeling of the dense surface layer 4 is prevented. .

By providing the high-density surface layer 4 on the substrate 1 in this way, the bending strength of the mineral fiberboard is improved and the surface hardness is increased, so that patterns can be beautifully and easily formed by pressing or the like.

Next, specific examples of the present invention will be shown.

After adjusting the particle size of spherical crushed stone, shirasu, etc. containing 4 to 5% bound water to a particle size of 50 to 300μ, the apparent A lightweight inorganic foam with a specific gravity of 0.07 was obtained.

Approximately 80% of this inorganic foam is open foam, and its water absorption rate is twice that of commercially available perlite.
It showed a water absorption rate of 200%.

Next, the open inorganic foam, mineral fibers, pulp, and starch were mixed in water with the following composition to form a slurry, and a plate with a thickness of 12 m/m was formed using a circular paper machine. did.

Mineral fiber 100 parts by weight Inorganic foam 100 〃 Pulp 35 〃 Starch 10 〃 Next, by drying this plate-like material, a specific gravity of 0.20, a bending breaking load of 16 kg/f, a hardness of 25 kg (radius
(Load when pushing a 14-inch steel ball 2m/m)
of mineral fiberboard was obtained.

In addition, when manufacturing mineral fiberboard with the above composition, 0.5% of a high concentration slurry having the following composition was used as the surface layer.
Provided by means of coating on the wet mat of the mineral fiberboard so as to form a layer with a thickness of m/m,
An integrally layered mineral fiberboard was obtained using a roll press.

Mineral fiber 100 parts by weight (fiber length 100-1000μ) Pulp 10 parts by weight Starch 5 Synthetic resin binder 10 The thickness of the fiberboard made of the upper and lower layers thus obtained was 12 m/m (surface layer: 0.5 m/m) m, board: 11.5
m/m), the overall specific gravity is 0.25, the bending breaking load is 21 kg/f, and the hardness is 31 kg, and by providing a high-density layer only on the surface layer, both hardness and hardness can be greatly improved. be.

Note that this surface layer portion may be formed by laminating the wet mat and wet sheet obtained by paper making, and furthermore, by applying an appropriate bonding agent to the interface between the substrate and the surface layer, the bond between the two may be bonded. It can also increase adhesion.

In addition, the length of the mineral fibers in the surface layer is 100 to 2000μ,
Preferably, by using short fibers of 100 to 1000μ and increasing the proportion of binder compared to the substrate layer, a dense and hard surface layer can be formed, and the bending strength can be greatly improved and the surface smoothness, paintability and Improves workability of travertine patterns, pin hole patterns, etc.

(Effects of the invention) As described above, according to the mineral fiberboard of the present invention,
Since lightweight inorganic foam, mainly open-type lightweight inorganic foam, is mixed into the mineral fibers, the amount of foam added to the slurry during manufacturing can be greatly increased compared to conventional products. It can be easily produced using ordinary manufacturing equipment, and can be significantly reduced in weight. Therefore, it has excellent handling properties, workability, heat insulation properties, and sound absorption properties.

In addition, by using such a mineral fiberboard as a substrate and providing a high density mainly composed of mineral fibers on the surface, it is possible to eliminate the decrease in bending strength due to weight reduction, and to improve surface smoothness, paintability, workability, etc. This is a huge improvement.

[Brief explanation of drawings]

The drawings show examples of the present invention; FIG. 1 is a sectional view of Example 1, and FIG. 2 is a sectional view of Example 2. 1...Mineral fiberboard, 2...Mineral fiber, 3...
...Open foam, 4...Surface layer.

Claims (1)

[Claims] 1. In a mineral fiberboard mainly made of mineral fibers such as rock wool, 20 to 100 parts by weight of open lightweight inorganic foam is mixed with 100 parts by weight of mineral fibers. A mineral fiberboard featuring: 2. The mineral fiberboard according to claim 1, wherein the lightweight inorganic foam has an apparent specific gravity of 0.1 or less. 3 In a mineral fiberboard mainly composed of mineral fibers such as rock wool, a fiberboard made by mixing 20 to 100 parts by weight of an open lightweight inorganic foam to 100 parts by weight of mineral fibers is used as a substrate, and this A surface layer is provided on the surface of the substrate, which is made by mixing 100 parts by weight of mineral fibers such as rock wool with an organic component consisting of pulp, starch, a binder such as synthetic resin, etc. at a ratio of 25 parts by weight or less. Features mineral fiber fibers. 4 The mineral fibers forming the surface layer have a fiber length of
The mineral fiberboard according to claim 3, characterized in that the mineral fiberboard mainly has a particle diameter of 100 to 2000μ.