JPH06167094A - Base board for free access floor - Google Patents

Abstract

PURPOSE:To provide a base board for a free access floor having light weight and satisfactory workability by laminating a metal plate on a porous composite plate prepared with a vinyl monomer, cement, reinforcing fibers, etc. CONSTITUTION:Reverse emulsion composition including cement having vinyl monomer, water, cement, reverse emulsifier and reinforcing fibers mixed with each other is set to prepare a porous composite plate 2. Then, the apparent specific gravity of the porous composite plate 2 is set to 0.95-1.30 and the porous composite plate 2 is provided in the direction of the thickness with a plurality of thin through holes. Further, the more the thin holes are spaced from the center part and both diagonals of the porous composite plate 2, the closer the thin holes provided to each other. Next, a metal plate 3 having 0.2-0.8mm of thickness is bonded and laminated on the porous composite plate 2. Thus, an incombustible base board 1 for free access floor having high mechanical strength, light weight and satisfactory workability, can be provided.

Description

Detailed Description of the Invention

[0001] The present invention relates to a non-combustible substrate which is lightweight and has good workability and which is used for a free access floor such as OA equipment where underfloor wiring can be easily performed.

[0002]

2. Description of the Related Art A free access floor consisting of a fixed-shaped substrate and a supporting member can be easily used for underfloor wiring of OA equipment, etc., and even if the layout is changed, the wiring can be easily rearranged, so that it has been used recently. Is becoming. As a substrate for such a free access floor, it is conceivable to use wood-based materials, metals, synthetic resins, or ceramic-based materials such as cement, which have been conventionally used as building materials, but conventional materials are used as they are. Each had its drawbacks.

For example, wood-based materials and synthetic resins are light in weight and have good workability, but they are flammable and difficult to prevent fires. Metal materials are excellent in fire resistance but lack in light weight, and they are dimensionally required for construction. There was a problem that it was difficult to cut to match Further, ceramic materials such as cement have the same problems as metal materials. Light-weight cellular concrete is lightweight and non-combustible, but has poor mechanical strength such as bending and compressive strength, and even if it was reinforced with a metal plate, it could not be used as a substrate for a free access floor because of its strength. .

A hardened product of an inverse emulsion composed of vinyl monomer, water, cement and reinforcing fibers is lightweight and has nonflammability, good processability, and mechanical properties superior to those of the above-mentioned lightweight cellular concrete. However, the strength was still insufficient for use as a floor material.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a substrate for a free access floor which is lightweight, nonflammable, has high mechanical strength, and has good workability.

[0006]

According to the present invention, an apparent specific gravity obtained by curing a cement-containing inverse emulsion composition comprising vinyl monomer, water, cement, inverse emulsifier and reinforcing fiber is 0.95 to 1. There is provided a substrate 1 for a free access floor, characterized in that a metal plate 3 having a thickness of 0.2 to 0.8 mm is laminated on 30 porous composite plates 2 and further, the porous composite plate 2 is arranged in the thickness direction. There is provided the above-mentioned substrate 1 for a free access floor, which is characterized by having a large number of through holes 21. Further, the pores 21 are so dense that they are farther from the central part of the porous composite plate 2 and on both diagonal lines. The above-mentioned substrate 1 for a free access floor is provided.

That is, the thickness of the porous composite plate 2 is 0.2
It was found that a free access floor substrate 1 having sufficient lightness, noncombustibility, mechanical strength and workability can be obtained by laminating an extremely thin metal plate 3 having a thickness of about 0.8 mm. It was also found that when the porous composite plate 2 having a large number of pores 21 in the thickness direction is used, the weight can be further reduced without significantly lowering the mechanical strength.

The porous composite plate 2 used in the present invention can be manufactured, for example, as follows. First, a vinyl monomer solution in which an inverse emulsifier is dissolved, water, cement and reinforcing fibers are mixed by stirring to form a cement-containing inverse emulsion, and then the obtained cement-containing inverse emulsion is molded by means such as extrusion molding or press molding. It is obtained by curing and curing. Examples of the vinyl monomer include styrene having a double bond in the molecule and (meth) acrylic acid ester. Examples of the cement include Portland cement, blast furnace slag, fly ash and the like. As the inverse emulsifier, a usual surfactant having an inverse emulsifying property can be used. Examples of the reinforcing fiber include synthetic fiber such as acrylic fiber and polypropylene fiber, glass fiber or carbon fiber.

Since the substrate for the free access floor is lightweight and requires a certain level of mechanical strength, it is necessary to manufacture the porous composite plate 2 so that the apparent specific gravity becomes 0.95 to 1.30. . The apparent specific gravity of the porous composite plate 2 can be adjusted by changing the water: cement ratio.
Apparent specific gravity increases when the amount of cement used for water is increased,
The mechanical strength increases, and conversely, if the amount of cement used is reduced, the apparent specific gravity and mechanical strength decrease. Generally, when the water: cement ratio is in the range of 1: 1.0 to 1.5, the porous composite plate 2 having a balanced apparent specific gravity and mechanical strength can be obtained. The thickness of the porous composite plate 2 is 15 to 40 mm.
A degree is preferable.

Further, it is preferable to use a porous composite plate 2 having a large number of pores 21 formed in the thickness direction, because the obtained free access floor substrate 1 can be further reduced in weight and can be easily constructed. In particular, the pores 21 are formed in the porous composite plate 2
It is preferable to provide the holes so that they become denser as they go farther from the center of the diagonal line, because many pores 21 are provided in a portion where stress is not concentrated, so that the mechanical strength is not lowered so much and the weight can be reduced.

The metal plate 3 has a thickness of 0.2 to 0.8 m.
There is no particular limitation as long as it satisfies the range of m, and examples thereof include a steel plate, a zinc steel plate, a stainless steel plate, an aluminum alloy plate and the like, and a zinc steel plate is particularly preferable in terms of price, strength, rust prevention effect and the like. Although the bending strength of the substrate 1 obtained by increasing the thickness of the metal plate 3 is increased, the reinforcing effect cannot be expected so much because the porous composite plate 2 cannot be bent as much as the metal plate 3 even if it is made too thick. Further, if the metal plate 3 is thick, it becomes difficult to perform post-processing such as cutting when aligning the dimensions at the corners during construction. Also, if it is too thin, there is no reinforcing effect, which is not preferable.

The porous composite plate 2 and the metal plate 3 are bonded and laminated with an adhesive to manufacture the substrate 1 for a free access floor of the present invention. The adhesive may be an ordinary adhesive, and examples thereof include urethane-based, epoxy-based, silicone-based adhesives and emulsion-based adhesives. The support member 4 is attached to the substrate 1 manufactured in this way, and the free access floor 5 is obtained.

[0013]

[Function] Since the porous composite plate 2 obtained by curing the cement-containing inverse emulsion composition is elastic, the metal plate 3 is used.
When laminated with, the free access floor substrate 1 having a large reinforcing effect on the metal plate 3 and high bending strength can be obtained.
Further, since the metal plate 3 is thin, it can be easily cut when it is necessary to cut it for size adjustment.

[0014]

The present invention will be specifically described below with reference to examples. In this example, the free access floor 5 was prepared in which the supporting members were attached to the four corners of the substrate 1 for the free access floor having various lengths of 500 × 500 mm and various thicknesses, and the physical properties were evaluated by the following methods. <1 point load fracture strength at the center of 4 pillars> A load of 2 mm / min is applied to the center of the free access floor 5 at a speed of 2 mm / min with a jig having a radius of curvature of 12.5 mm at the tip. It is expressed by the load when it is broken and when it is broken. <Compressive strength> Cut out a porous composite plate according to JIS A541
It measured based on 6. <Non-flammability> The results measured according to JIS A1321 were evaluated.

Production Example 1 75 parts by weight of a styrene monomer as a vinyl monomer and 25 parts by weight of sorbitan monooleate as an inverse emulsifier,
A vinyl monomer solution obtained by dissolving 0.75 part by weight of a polymerization initiator and 0.45 part by weight of a polymerization accelerator was added at 15.97.
kg / hr, Portland cement as cement 331.6 kg / hr, water 252.6 kg / hr, and acrylonitrile fiber (diameter 16μ, length 5 mm) 6.0 kg / hr as reinforcing fibers continuously in a kneader. It is supplied and stirred to form a cement-containing inverse emulsion composition, which is extruded into a plate shape by an extruder and then at 90 ° C. for 19 hours.
After steam curing for a period of time, a porous composite plate having a commonly known thickness of 25 mm was obtained. The apparent specific gravity of this product was 1.18.

Production Example 2 The same raw materials as in Production Example 1 were used to prepare a vinyl monomer solution at 16.2.
A porous composite plate having a commonly known thickness of 25 mm and 30 mm was obtained in the same manner as in Production Example 1 except that 2 kg / hr, 308.1 kg / hr of cement and 275.7 kg / hr of water were changed. The apparent specific gravity of this product was 1.01.

Production Example 3 The same raw material as in Production Example 1 was used to prepare a vinyl monomer solution at 19.3.
kg / hr, cement 308.4 kg / hr, water 3
A porous composite plate having a commonly known thickness of 30 mm was obtained in the same manner as in Production Example 1 except that the porous composite plate was changed to 45.9 kg / hr. The apparent specific gravity of this product was 0.87.

Example 1 The surface of the porous composite plate obtained in Production Example 1 was polished with a # 240 belt sander, cut into a size of 500 × 500 mm, and a vinyl acetate emulsion adhesive was applied to one side. Insert the porous composite plate coated with the adhesive into the press, stack 0.4 mm thick zinc steel plates and cool for 5 seconds at a pressure of 4 kg / cm2, then remove from the press and press at room temperature for 5
It was deposited and cured for a day to obtain a substrate for a free access floor of the present invention. The properties are shown in Table 1.

Examples 2 and 3 The surface of the porous composite plate having a so-called thickness of 30 mm obtained in Production Example 2 was ground with a # 240 belt sander and then 500.
It was cut to a size of X500 mm, and a silicone adhesive was applied to one surface. Insert the porous composite board coated with the adhesive into the press machine, each of which has a thickness of 0.4 mm, a zinc steel board,
After a steel plate having a thickness of 0.6 mm was stacked and cold pressed at a pressure of 4 kg / cm 2 for 5 seconds, it was taken out from the press machine and deposited at room temperature for 5 days for curing to obtain a substrate for a free access floor of the present invention. The properties are shown in Table 1.

Example 4 The surface of the porous composite plate having a commonly known thickness of 25 mm obtained in Production Example 2 was ground with a # 240 belt sander, and then 500
It was cut to a size of X500 mm, and an epoxy adhesive was applied to one surface. Insert the porous composite board coated with the adhesive into the press, stack the 0.4mm thick zinc steel board, and stack 4kg.
After cooling with a pressure of / cm2 for 5 seconds, the substrate was taken out from the press and deposited at room temperature for 5 days for curing to obtain a substrate for a free access floor of the present invention. The properties are shown in Table 1.

Example 5 The surface of the porous composite plate having a commonly known thickness of 25 mm obtained in Production Example 2 was ground with a # 240 belt sander, and then 500
It was cut to a size of X500 mm, and 360 holes were opened so that the pores having a diameter of 4 mm became denser as the distance from the center of the porous composite plate was increased diagonally, and then an epoxy adhesive was applied to one surface. Insert the porous composite board coated with the adhesive into the press, and stack the zinc steel boards with a thickness of 0.4 mm
After cooling with a pressure of kg / cm 2 for 5 seconds, the substrate was taken out from the press, deposited at room temperature for 5 days and cured to obtain a substrate for a free access floor of the present invention. The properties are shown in Table 1.

[0022]

[Table 1]

Comparative Example 1 A substrate for a free access floor was obtained in the same manner as in Examples 2 and 3 except that a 0.4 mm thick zinc steel plate was stacked on the porous composite plate obtained in Production Example 3. The properties are shown in Table 2.

Comparative Example 2 The surface of the porous composite plate having a so-called thickness of 30 mm obtained in Production Example 2 was ground with a # 240 belt sander, and then 500
It was cut to a size of X500 mm and directly used as a substrate for a free access floor. The properties are shown in Table 2.

Comparative Example 3 A substrate for a free access floor was prepared in the same manner as in Examples 2 and 3 except that a commercially available lightweight cellular concrete plate having an apparent specific gravity of 0.6 and a thickness of 37 mm was laminated with a zinc steel plate having a thickness of 0.4 mm. However, the workability was poor due to the reinforcing wire mesh inside the lightweight cellular concrete plate, and the strength was not sufficient. The properties are shown in Table 2.

[0026]

[Table 2]

[0027]

[Effect] The substrate for a free access floor of the present invention is lightweight, has nonflammability, and has good workability. Moreover, since the porous composite board used in the present invention is more elastic than the conventional cement-based board (especially lightweight cellular concrete board), the reinforcing effect by the metal board is great, and the compressive strength is also excellent for a long time. Even when used for floor materials that are subject to high loads, there is little deformation due to creep. Further, since the metal plate is used in the lower part, it is easy to attach the supporting member.

[Brief description of drawings]

FIG. 1 is a sectional view of a substrate for a free access floor according to the present invention.

FIG. 2 is a perspective view showing an example of a free access floor created using the substrate for a free access floor of the present invention.

FIG. 3 is a perspective view showing another example of a free access floor created using the substrate for a free access floor of the present invention.

[Explanation of symbols]

 1 Free Access Floor Substrate 2 Porous Composite Plate 21 Pore 3 Metal Plate 4 Support Leg

Claims (3)

[Claims] 1. An apparent specific gravity obtained by curing a cement-containing inverse emulsion composition comprising vinyl monomer, water, cement, inverse emulsifier and reinforcing fiber is 0.95 to 1.30.
1. A substrate 1 for a free access floor, which is obtained by laminating a metal plate 3 having a thickness of 0.2 to 0.8 mm on the porous composite plate 2. 2. The substrate for a free access floor according to claim 1, wherein the porous composite plate 2 has a large number of through holes 21 in the thickness direction. 3. The substrate 1 for a free access floor according to claim 2, wherein the pores 21 are denser as they are farther from the center of the porous composite plate 2 and on both diagonal lines.