JPS60190343A - Incombustible laminated gypsum board and manufacture thereof - 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 The present invention relates to a noncombustible laminated gypsum board and a method for manufacturing the same. For more information, see Irrigation Gypsum Powder.

The gypsum board obtained by laminating and press-forming a green board obtained by paper-making a slurry of a mixture consisting of a fibrous 9-gypsum setting retarder and water before the hydration gypsum in the green board is hydrated. and the manufacturing method.

The conventionally widely known gypsum board has base paper adhered to both sides thereof, and most of its strength depends on the base paper. Therefore, although gypsum board has excellent properties such as nonflammability, sound insulation, and economic efficiency as a construction material, it still has insufficient performance in terms of strength, impact resistance, water resistance, etc.

In order to solve these problems of the well-known gypsum board, a method has been proposed in which a gypsum board containing m fibers is manufactured by a papermaking method from a slurry in which hydrated gypsum and fibers are mixed and dispersed in water. (Special Publication No. 57-413004).

The fiber-filled gypsum board thus obtained (hereinafter referred to as fiber gypsum board) is tough and has improved strength and impact resistance compared to conventional ones.

However, when using the papermaking method, it is difficult to manufacture fiber gypsum boards with a thickness of about 10 mm or more, as will be described in detail later.

Such fiber gypsum board is not only a thin board with a thickness of IOm+a or less, but also a thin board with a thickness of 10Il+mfl'' 100+, for example.
There is a growing demand for plates with a thickness of about 100 yen (AM) from the viewpoint of sound insulation, heat insulation, fire resistance, 1III# impact resistance, etc. Therefore, it is conceivable to manufacture such a fiber gypsum board by a pressure forming method using a mold. However, when a plank is manufactured using a fiber-containing hydrated gypsum composition, the material tends to be non-uniform and the above-mentioned preferred physical properties cannot be maintained. In addition, since the method uses a mold, the time required for manufacturing is significantly longer than that of a thin sheet papermaking method, making it unsuitable for industrial use.

By the way, the thickness is 1OIII11 using the above-mentioned known papermaking method.
1:.

The reason why Fa# gypsum board cannot be manufactured is as follows. That is, in the papermaking method, a slurry whose main components are gypsum and fibers is sent to the chest 1 in the figure, water is added as needed to make a concentration suitable for papermaking, and this slurry is sent to the cylinder vat 2. Subsequently, the solids 4 in the slurry 4 in the cylinder vat 2 are scooped up by the rotating circular mesh cylinder 3 and taken up onto the endless felt 5 to form a thin film. Subsequently, the material is appropriately dehydrated in a vacuum dehydrator 6, and then laminated on a making roll (rotating drum) 7 to a required thickness, cut with a cutter 8, and transferred to a curing and drying process (not shown). The thickness of the thin film mentioned above is about 1 mm, so the required thickness is 10 mm or more.
) The making roll 7 must be rotated about 10 times or more to obtain a green sheet.

During this time, the raw board on the roll stretches and cracks occur on its surface. To prevent this elongation, a vacuum dehydrator 6
When the degree of dehydration in is increased, the raw board on the making roll 7 becomes hard, and when this raw board is cut with the cutter 8 and removed from the making roll 7, the difference in length between the outer circumference and the inner circumference of the raw board becomes hard. is too large, causing cracks to form on the surface of the planar raw board.

For the reasons mentioned above, especially in order to produce a green board with a thickness of about 10 mm or more using the papermaking method, a special device that does not involve mere rotary winding is required. Furthermore, when winding a green board with a thickness of 10 mm or more, it is difficult to obtain a homogeneous product unless the cutting speed is also reduced.

For the above reasons, a fiber gypsum board and a method for manufacturing the same have not yet been proposed.

The present inventors have conducted intensive research on the above technical problems. As a result, the thickness of 6mm was obtained using normal papermaking equipment.
2 or more green boards are laminated before the hydratable gypsum in the green boards is hydrated, and the production rate is 30 to 500 Kg/crn.
When the laminate is pressure-formed at a pressure of 100 lbs. and then cured and dried, the laminate becomes integrated, and the mutual tensile strength of the resulting fiber-laminated gypsum board is:
The present invention was completed based on the knowledge that it is possible to obtain a thick plate with a desired thickness, similar to that of a non-laminated thin plate, and that the papermaking speed can be carried out as efficiently as thin plate manufacturing.

As is clear from the above description, the object of the present invention is to provide thick fiber gypsum boards with fire resistance, sound insulation, heat insulation, impact resistance, and other practical physical properties that cannot be obtained with conventional fiber gypsum boards (thin boards). (noncombustible laminated gypsum board) and an efficient manufacturing method thereof. Another objective is to expand the specific field of application of fiber gypsum board.

The present invention has the following main configurations (1) and (5), and (2)
-(4) and (6)-(Meng) have embodiment configurations.

(1) Two or more green boards obtained by paper-making a mixture of 9 m acidic 9 gypsum gypsum powder and water and water.
- Non-combustible laminated gypsum board made by laminating, pressure forming and curing and drying.

(2) 0.5 to 3 per 100 parts by weight of hydrated gypsum powder
The gypsum board according to item (1) above, which uses 0 parts by weight of fibrous material.

(3) The gypsum board according to item (1) above, which uses 50 to 85 parts by weight of water-use gypsum powder and 50 to 30 parts by weight of industrial water gypsum powder.

(4) The gypsum board according to item (1) above, which uses cellulose, m-fiber, asbestos fiber, or a combination thereof as the ml material.

(5) A mixture slurry obtained by mixing 100 parts by weight of gypsum powder, 0.5 to 30 parts by weight of a fibrous 2-gypsum setting retarder, and water is made into a paper using a circular mesh paper making method, and the paper obtained by this paper making is Two or more green boards are laminated together before the hydratable gypsum in the green boards is hydrated, and the laminate is pressure-formed and integrated at a pressure of 30 to 500 kg/cm, and the laminate is hardened and dried. A method for producing a noncombustible laminated gypsum board, characterized by:

(6) 100 parts by weight of powdered gypsum consisting of 50 to 85 parts by weight of hydrated gypsum powder and 5 to 50 parts by weight of industrial water gypsum, 0
, 5 to 30 parts by weight of fibrous material, a slurry obtained by mixing 0.1 to 2.0 weight % of a gypsum setting retarder and water by external cutting to the above water-based gypsum, using a circular mesh papermaking method. Make paper,
The manufacturing method according to item (5) above, characterized in that a raw board obtained by the papermaking process is used.

(7) The manufacturing method according to item (5) above, wherein cellulose fiber, asbestos fiber, or a combination thereof is used as the fiber.

The structure and effects of the present invention will be explained below.

stomach. Manufacture of green board: In the present invention, a slurry obtained by mixing water-friendly gypsum powder, fibers, and a gypsum setting retarder as essential constituent raw materials with water under the conditions described below is made into a green board. It is also possible to replace less than half of the hydrated gypsum with industrial water gypsum powder, and it is possible to finally produce a noncombustible laminated gypsum board of equivalent quality.

As the hydrated gypsum powder, α-type hemihydrate gypsum, β-type hemihydrate gypsum, soluble anhydrite, or a mixture thereof in any proportion can be used. The powder degree of the hydratable gypsum is preferably 5000 cm''/g or less in Blaine specific surface area value. Examples of industrial gypsum powder include flue gas desulfurization gypsum, phosphate gypsum,
Any of salt gypsum, titanium gypsum, or hydrofluoric acid gypsum can be used. However, the particle size must be less than 500 wells, and preferably less than 5000 cnf/g in Blaine specific surface area value.

Examples of fibers include inorganic fibers such as asbestos or glass fibers, or cellulose fibers.

One or more types of natural or synthetic organic fibers such as vinylon fibers, polypropylene fibers, or polyamide fibers can be used in combination.

Among these, asbestos fibers and cellulose fibers are particularly important for gypsum (
It is preferable to use one or a mixture of these in the fibers used because of their strong adhesion to the cured product).

As the gypsum setting retarder used in the present invention, any known substance such as glycerin, alcohol, phosphate, carboxylic acid, oxycarboxylic acid or their salts, and amino acid derivatives can be used.

In producing the green board according to the present invention, the above raw materials are mixed in the following proportions and water is added to form a slurry that can be made into paper.

First, 0.5 to 30 per 100 parts by weight of hydrated gypsum powder.
Parts by weight of fibrous material and 0.1 to 2.0% by weight of a setting retarder are mixed, and water is added to form a slurry. Irrigation plaster 10
Instead of 0 parts by weight, a total of 100 parts by weight of 50 to 85 parts by weight and 50 to 5 parts by weight of industrial water gypsum can also be used. In this case as well, the mixing ratio of the fibers remains the same, but the setting retarder is maintained at a ratio of 0.1 to 2.0% by weight relative to the water-use gypsum powder.

The slurry obtained as described above is wound up to the required thickness on a making roll (rotating drum) 7 as shown in the figure in the same manner as in the conventional paper making method described above. Fibrous substances or the like can be impregnated by spraying or other methods during the process of winding onto a making roll. The thickness of the tag is 10
It is less than 61 mm, preferably less than 61 mm. The thus wound raw board is cut with a cutter 8 to obtain a raw board 9 of a desired size. This raw board is subjected to the next step of lamination and pressure forming.

Lamination of green plates, pressure forming: A plurality of green plates 9 obtained as described above are stacked on top of a stainless steel plate 10 according to a desired thickness.

The above-mentioned raw boards can be stacked up to 2 or more and about 30 boards, although not limited thereto.

Furthermore, a reinforcing material such as glass fiber or other net-like material is inserted between the green boards in a range that does not inhibit the mutual adhesion between the green boards.

A plurality of stacked stacks of raw laminated plates and stainless steel plates obtained as described above are placed in a pressure molding machine 11 and pressure molded. During this time, it is necessary to adjust the blending of the setting retarder, the manufacturing time of the green board, and the stacking time so that the hydrated gypsum in the green board produced on the making roll does not become hydrated before pressure forming. The time required from the making roll to the pressure forming is usually 10 minutes to 3 hours, preferably less than 1 hour. If the hydration of the water-friendly gypsum in the raw boards begins before the above-mentioned pressure forming, the mutual adhesion between the raw boards and the strength of the obtained laminated gypsum board will be drastically reduced, making it impossible to obtain a product with the highest quality. I can't. The pressure of pressure molding is 30-50
The pressure is maintained at 0 kg/cm' for 1 to 30 minutes at room temperature. There is an appropriate pressure molding time depending on the state of stacking of the raw plates, and it is necessary to dehydrate at an appropriate speed. Rapid dehydration exceeding that rate will cause cracks in the laminate. Furthermore, if pressure is not applied properly and dehydration is insufficient, the water that has leached out will return to the laminate when the pressure is reduced and the raw board will harden without being fully bonded, making it impossible to obtain a laminate of good quality.

C. Curing and drying: 1 The pressure-formed green plate 12 produced as described above is immediately separated from the stainless steel plate using a vacuum carrier 13, stacked on a pallet 14J:, hydrated and cured for a required period of time, and then dried by a known method. The product is made into a product (non-combustible laminated gypsum board).

2. Effects: According to the present invention, by simply stacking and press-forming a plurality of raw boards with a thickness of less than 6 mm, which is the easiest to manufacture homogeneously and efficiently using the paper-making method, according to the desired thickness, the paper-making method can be easily manufactured. It is possible to obtain a noncombustible laminated gypsum board that does not impede productivity and has practical physical properties that could not be achieved with conventional paper-formable intermediate boards.

Conventionally, when a certain thickness was required, it was necessary to construct a plurality of sheets one on top of the other, but with the present invention, a board of the desired thickness can be obtained, so the number of construction steps can be reduced. Regarding the physical properties of the obtained laminate, for example, when looking at the fire resistance performance (JISA13041 hour heating test), a stack of two 12ma+ veneers fails in 55 minutes, while a 24+im laminated board passes in 67 minutes. . In addition, in the case of laminated boards that contain reinforcing materials such as fibers between green boards, surface strength, sound insulation performance, fire resistance, etc. are significantly improved. It will be done.

Therefore, the gypsum board of the present invention can be applied to applications that exceed the performance limits of known gypsum boards as structural materials, such as structural materials such as fire prevention and insulation materials and sound insulation materials. Also in between #
l! In the case of a laminate containing m-quality, bending strength, sound insulation performance, fire resistance performance, etc. are significantly improved, and a thinner structural material with equivalent performance can be obtained.

The present invention will be explained below with reference to Examples.

Examples 1-3. Comparative Example 1 A slurry containing water-use gypsum and fibers as main components and a gypsum setting retardant was made into a paper using a circular mesh paper making machine to a thickness of 6Il.
A green plate of lI was obtained. These 3.6 and 9 pieces of Ikusaka were stacked on a stainless steel plate-1-, pressure-molded at a pressure of 80 kg/cm' and a holding time of 5 minutes, and then the stainless steel plate and the pressure-molded product were immediately separated using a vacuum carrier. . The pressure-formed plate is cured until the water-curing reaction is completed, and then dried by a known method.
An interlayer tensile test was conducted according to II3 to obtain an interlayer adhesion strength value. In addition, as a control example, the following pressure forming, curing drying and tensile tests were conducted on a raw board veneer that was not laminated.

In addition, we also observed the fractured surface of each plaster board and
Changes in state were observed through a 2-hour heating test at °C.

The results are shown in the table.

Table Physical properties of laminated gypsum board 5

[Brief explanation of drawings]

The figure is a flow sheet for manufacturing a circular mesh type gypsum board and a laminate board used in the present invention. In the figure ■...Chest 3...Circle net cylinder 5...Endless felt 7...Making roll 9...Raw board lO...Stainless steel plate 11...Pressure forming machine 12... Pressure molded raw board 13・
...Suction conveyor 14...Pallet or more Patent applicant Onoda Cement Co., Ltd. Asahi Asbestos Industries Co., Ltd. Patent attorney Katsuhiko Nonaka 6 22

Claims (1)

[Claims] (1) Two or more green boards obtained by paper-making a mixture of water-use gypsum powder, a fibrous di-gypsum setting retarder, and water are laminated, pressure-formed, and then hardened and dried. Noncombustible laminated gypsum board. (2) 0.5 to 3 per 100 parts by weight of water-compatible gypsum powder
Claim No. 1 (1) using 0 parts by weight of fibrous material
) Gypsum board as described in section. (3) 50 to 95 parts by weight of hydrated gypsum powder and 50 to 30 parts by weight of trihydrate gypsum powder are used as the fibrous material.
The gypsum board described in item 1). (4) Claim No. 1 in which cellulose fiber, asbestos fiber, or a combination thereof is used as the fiber material.
) Gypsum board as described in section. (5) A mixture slurry obtained by mixing 100 parts by weight of gypsum powder, 0.5 to 30 parts by weight of a fibrous 9 gypsum setting retarder, and water is made into a paper by a circular mesh paper making method, Two or more green boards are laminated together before the hydrated gypsum in the green boards is hydrated, and the laminate is integrated by pressure forming at a pressure of 30 to 500 kg/cm', and the laminate is cured. A method for producing a noncombustible laminated gypsum board, characterized by drying it. (8) 100 parts by weight of powdered gypsum consisting of 50 to 95 parts by weight of water-use gypsum powder and 5 to 50 parts by weight of industrial water gypsum, 0
, a slurry obtained by mixing 5 to 30 parts by weight of fibrous material, 0.1 to 2.0 weight % of a gypsum setting retarder on the outside of the above-mentioned hydrated gypsum, and water using a circular mesh papermaking method. Make paper,
The manufacturing method according to claim (5), characterized in that a raw board obtained by the papermaking process is used. (7) Claim No. 5 in which cellulose #ll fiber, asbestos fiber, or a combination thereof is used as the fiber material.
) The manufacturing method described in section 2.