JPH082608B2 - Composite panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to interior and exterior materials for buildings, such as wall materials and ceiling materials for shops, and as decorative materials for furniture, or for ships and aircraft. The present invention also relates to a composite panel useful as an interior panel or a partition panel of a vehicle, and more particularly to a composite panel improved so as not to warp over a wide temperature range.

(Prior Art) Since stone materials generally have great design value and have excellent heat insulating properties, they have been widely used as interior materials, exterior materials, floor materials, etc. of buildings for a long time.

(Problems to be Solved by the Invention) However, stone materials have drawbacks such as brittleness and heavy weight, and have poor workability. Therefore, it has been extremely difficult to use as a large-sized building material conventionally. In recent years, commercial buildings, especially high-rise buildings, have been popular, and it has been desired to improve the workability so that stone materials can be properly incorporated therein.

Recently, as disclosed in Japanese Patent Laid-Open No. 56-8217, there is a technique for obtaining a thin layer of stone material by pressing a backing material on both sides of a stone slab such as marble and cutting and separating the center of the stone slab in that state. A panel using a thin layer of stone has been proposed and developed in British Patent No. 1,215,501.

The panel according to the present invention has advantages that it is lightweight and can be easily cut, has excellent workability, and has a high design effect. On the other hand, when the panel is used in an atmosphere of a wide temperature range (for example, 0 ° C to 80 ° C), a new problem of "warping" occurs, and it is confirmed that the panel cannot sufficiently withstand the use over time. Was done. The warp tendency of the panel increases as the size increases, especially when the panel exceeds the size of 30 cm in length and 30 cm in width,
The warp becomes noticeable, which is a serious problem in practical use.

An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a composite panel having a thin-layered stone skin that does not warp even if it is used for a long time under various temperature conditions.

(Means for Solving the Problems) The present inventor has conducted extensive studies on a composite panel having a thin-layer stone skin in order to solve the above problems, and has found that the skin has a material satisfying the following formula (1). To be
The present invention has been completed by finding that the occurrence of panel warpage can be effectively suppressed, and the characteristics of lightweight, high strength, and high rigidity generally required for laminated panels can be maintained.

That is, in the composite panel of the present invention, a thin stone skin is pressure-bonded to the skin surface of a laminate of a core and a skin with an adhesive, and the skin satisfies the following formula (1). It is characterized by being.

E × t × α ≦ 0.080 In the formula (1), E, t, and α have the following meanings.

E: Elastic modulus of skin at 25 ° C (kg / mm ² ) t: Thickness of skin (mm) α: Linear expansion coefficient of skin (1 / ° C) The thin-layer stone used in the present invention is a natural stone For example, it includes a thin plate material having a thickness of 0.5 to 10 mm, preferably 1 to 7 mm, which is made of marble, granite, various ceramics, artificial stones, or the like. These stone skins are obtained by the processing technology developed in recent years.

Further, as the laminated body to which the thin-layer stone skin is attached, a conventionally known sandwich structure in which a skin is pressure-bonded to one side or both sides of the core can be used.

As the core, a metal foil such as an aluminum foil or a stainless steel foil, or a core material such as a thin-layer organic sheet or a thin-layer inorganic sheet has a honeycomb structure (of hexagonal cells, pseudo-hexagonal cells or square cells). Molded,
Alternatively, a foamed body of a thermoplastic resin or a thermosetting resin, a lightweight cellular concrete, a lightweight stone material, or a lightweight core material to which shirasu balloon or the like is bonded can be used.
In the case of a honeycomb core, the thickness of the core foil is 5μ or
Cell size (spacing between facing sides) in the range of 100μ 3.1
It can be used in the range of 75 mm to 45.00 mm. Also, regarding the thickness of the entire core, 3 mm to 100 mm
Is used.

On the other hand, as the skin, any thin material of metal, fiber reinforced plastics, and inorganic material can be used, or a combination thereof can be used.

As the metal skin, for example, a thin plate made of aluminum, stainless steel, iron and titanium steel, and alloy steels thereof, or a processed product thereof can be used.

Further, as the skin of the fiber reinforced plastics, thermoplastic resins and thermosetting resins, especially thermosetting resins such as epoxy resins, unsaturated polyester resins, vinyl ester resins, phenol resins, polyimide resins, melamine resins, urea resins, diallyls. A composite plate composed of phthalate resin and the like and reinforcing fibers such as glass fiber, carbon fiber, aramid fiber (Kevlar fiber), boron fiber, silicon carbide fiber and short fibers and long fibers, preferably a laminated plate thereof can be used. . When the length and width of the composite panel are different from each other, it is preferable to dispose the reinforcing fibers so that the density of the reinforcing fibers becomes higher in the longitudinal direction, and particularly, a fabric such as a woven fabric or a knitted fabric is used as the reinforcing fibers. In some cases, it is preferable to orient the woven or knitted fabric in the longitudinal direction.

However, whichever material the skin is used from among materials having an elastic modulus (E), thickness (t) and coefficient of linear expansion (α) that satisfy the following equation (1): It is optionally required to choose alone or in combination.

E × t × α ≦ 0.080 In the formula (1), E, t, and α have the following meanings.

E: Elastic modulus of skin at 25 ° C (kg / mm ² ) t: Thickness of skin (mm) α: Coefficient of linear expansion of skin (1 / ° C) where the elastic modulus E is generally σ = E · ε (Wherein σ represents vertical stress and ε represents vertical strain), which means the longitudinal elastic modulus of the material. In addition, the linear expansion coefficient α
Means a value calculated from α = Δl / l × 1 / ° C. (wherein Δl / l represents the elongation rate of the length of the material).

In consideration of the above formula (1), in the case of the metal skin, the one having the elastic modulus E in the range of 1000 to 25000 kg / mm ² is used, and the one having the thickness t in the range of 0.01 to 1 mm and the wire Those having an expansion coefficient α in the range of 0.05 to 30 × 10 ^-6 / ° C are used. Further, in the case of a fiber reinforced plastic skin, one having an elastic modulus E in the range of 1000 to 12000 kg / mm ² is used, and one having a thickness t in the range of 0.01 to 3 mm and a linear expansion coefficient α of 8 Those in the range of up to 50 × 10 ^-6 / ℃ are selectively used.

The surface of these skins may be flat or uneven, and even if they have holes partially formed, the application of the skin will not be hindered. It doesn't matter.

As the adhesive for pressure-bonding the thin-layer stone skin and the skin, an organic type or an inorganic type can be used. As the organic adhesive, for example, a room temperature curable or thermosetting adhesive, a thermoplastic resin adhesive, and particularly a thermosetting resin structural adhesive that has been conventionally used for exterior of buildings can be applied. For example, epoxy-based, unsaturated polyester-based, polyester-based, polyurethane-based adhesives and the like can be used. The adhesive desirably has a thixotropy index of 2 to 10 (measured at a viscosity of 80,000 cps at 25 ° C).
The adhesive may be transparent or colored, and may have a flame retardant, an inorganic filler, or the like mixed therein. Application of the adhesive may be carried out by a conventional method. The coating amount of the adhesive, it is a range of ^{10g / m 2 ~1000g / m 2} .

Further, as the adhesive used for bonding the core and the skin, a room temperature curable or thermosetting adhesive, particularly a thermosetting resin structural adhesive can be used. For example, epoxy-based, unsaturated polyester-based and polyurethane-based adhesives can be applied, and a flame retardant, an inorganic filler, or the like may be mixed therein, and the amount of the adhesive applied. it is good in the range of ^{10g / m 2 ~1000g / m 2} . When the core has a honeycomb structure, an appropriate amount of the adhesive may be applied so that a fillet is formed in the vicinity of the contact portion between the core and the skin after the adhesive is cured. The core and the skin can be adhered by a commonly used pressing method.

In the composite panel of the present invention, a thixotropic adhesive is preferably applied from the core and the skin to the skin surface of the laminate so that a large number of ridges oriented in one direction are formed, and then the thin stone skin is applied. It can be manufactured by a method of forming a panel by laminating and press-bonding on the adhesive layer while expelling air between the ridges.

The thin-layer stone skin may be crimped on the basis of, for example, the well-known vacuum bag method, air bag method, and flat plate pressing method. In this case, consider bonding the stone skin and the laminated body so that no air remains between them. Required to do. For example, in the case of the vacuum bag method, the inside of the bag is first made to have a strong and low pressure to achieve bonding without air remaining, then deaeration is weakened and the inside of the bag is returned to an appropriate pressure, and then this pressure can be taken out of the product. It is good to carry out the procedure of keeping time. In the case of the air bag method,
It is advisable to pressurize all at once to achieve bonding with no residual air, and then return to an appropriate pressure. Further, since the curing of the adhesive is generally completed in about 8 hours at room temperature and about 3 hours at 60 ° C. heating, the pressure bonding time by the bag method should be set in consideration of this.

(Function) In the composite panel of the present invention, the elastic modulus E, the thickness t, and the linear expansion satisfying the above formula (1) are satisfied by the skin that joins the thin-layer stone surface skin, despite having a laminated structure of different materials. Since it has the coefficient α, it is possible to significantly reduce the warp of the panel with respect to the temperature change while maintaining the characteristics of being lightweight, having high strength and high rigidity. The present inventor has confirmed the above facts as a result of various studies and studies. This is because by satisfying the condition of the formula (1), the degree of thermal expansion of the panel surface material (stone skin) and the member (skin) to be joined to the panel surface material are substantially the same, and the warp change does not occur, and at the same time, as a skin. It is considered that this is because moderate strength and weight are maintained.

(Example) Hereinafter, the Example of this invention is described with reference to drawings.

Examples 1 to 3 The composite panels of these examples are examples in which a metal skin is used, and as shown in FIG. 1 and FIG.
4.5 mm marble thin-layered stone skin 1 is attached to the skin surface of the laminate 2 with an adhesive and pressure-bonded, length 2 m, width 1 m
It is a stone panel with the size of. The laminated body 2 is made of an aluminum foil having a thickness of 76 μ and has a cell size of 6.35 mm and a core thickness of 19 mm, which is made of aluminum foil, which satisfies the above formula (1) and is shown in Table 1 below. It is attached to the upper and lower sides of the. The adhesive layer 5 is formed by curing a room temperature curable or thermosetting resin structural adhesive having a thixotropic index of 2 to 10.

This composite panel is manufactured by the following process.
First, the laminate 2 having a sandwich structure is processed according to a known technique, and then the thixotropic adhesive is applied to the entire skin surface of the laminate 2 so that the ridges are formed in one direction. On the other hand, the thin-layer stone skin 1 is manufactured in advance by the above-mentioned cutting process.

Then, the stone skin 1 and the laminated body 2 are put in a vacuum bag (not shown), and then the inside of the bag is deaerated by operating a vacuum pump. First, in about 5 minutes from the start of degassing, the inside of the bag is reduced to a low pressure of about 400 mmHg, then the degassing is weakened and the inside of the bag is returned to an appropriate pressure of about 700 mmHg within 2 to 3 minutes, and then this pressure is taken out of the product. Keep for 3 to 4 hours until possible. Through this process, the stone skin 1 is stuck on the adhesive layer 5 and pressure-bonded.

Alternatively, the stone skin 1 and the laminated body 2 are housed between an air bag (not shown) and a pressing mold, and then air is forcefully pressed into the air bag, and the stone skin 1 is pressed against the skin surface by pressing the bag. It is stuck on the adhesive layer 5 and pressure-bonded.

Further, as Comparative Examples 1 and 2, composite panels shown in Table 1 below, which did not satisfy the above formula (1), were manufactured by the same method as described above.

Example 4 The composite panel of this example is an example using a fiber-reinforced plastic skin, and as shown in FIG.
A stone panel having a length of 2 m and a width of 1 m is obtained by laminating a thin stone skin 1 of a 4.5 mm-thick marble thin plate on the skin surface of a laminated body 2 with an epoxy adhesive. The laminated body 2 was obtained by air-drying a skin 4 of a glass fiber reinforced plastics plate (thickness 1.0 mm) (which satisfies the above formula (1) and which is shown in Table 2 below) which has been previously thermoset, in a thickness of 19 mm. Specific gravity 0.6
The lightweight cellular concrete 6 as a core made of silica stone, cement, quicklime, and aluminum powder is bonded to both upper and lower surfaces. The panel of this Example 4 was manufactured by the same method as that of the panel of Example 1.

As Comparative Example 3, a composite panel (thickness of skin 4 of 3.0 mm) shown in Table 2 below, which did not satisfy the above formula (1), was manufactured by the same method as in Example 1.

Test Example A warp test was performed on each of the manufactured composite panels of Examples and Comparative Examples.

The test panel is placed in a temperature-controlled room at 0, 20 ° C, and 80 ° C for 24 hours or more, and then the panel is taken out from the temperature-controlled room, and two diagonal lines connecting the four corners of the panel intersect as shown in Fig. 5. The amount of warpage δ at the position A was measured. In particular,
Two metal rulers were placed on a diagonal line connecting the two opposite corners of the panel, and the distance between the intersection of the metal rulers and the panel was measured. Here, as shown in FIG. 4 (a), the case where the thin-layer stone skin 1 warps so as to swell is defined as a positive warp, while the fourth warp
As shown in FIG. 6B, the case where the thin-layered stone skin 1 is warped so as to be recessed is defined as a negative warp, and the amount of positive and negative warpage is calculated.

 The test results are shown in Tables 1 and 2.

From Tables 1 and 2, whether the skin is metal or fiber reinforced plastics, the composite panels of Examples satisfying the formula (1) show that the warpage is significantly small over a wide temperature range. Recognize.

(Effects of the Invention) As described above, the composite panel of the present invention is a panel having a large area, for example, a panel larger than 30 cm × 30 cm, by limiting the skin in contact with the stone skin to the one having specific physical properties. However, the warp of the panel can be made extremely small over a wide temperature range, for example, a range of −15 ° C. to 80 ° C., so that the panel can be installed very easily,
At the same time, the finished appearance is significantly improved. Needless to say, the properties required for the laminated panel, such as light weight, high strength, high rigidity, and design effect peculiar to stone materials, are maintained well.

[Brief description of drawings]

1 is a perspective view showing a composite panel of Examples 1 to 3 of the present invention, FIG. 2 is a sectional view showing the composite panel of FIG. 1, and FIG. 3 is a sectional view showing a composite panel of Example 4. FIGS. 4 (a) and 4 (b) are views showing the direction of warpage of the composite panel. FIG. 4 (a) shows a positive warp and FIG. 4 (b) shows a negative warp. FIG. 5 is a diagram showing a method for measuring the warp amount of the composite panel. In the figure, 1 ... Thin-layered stone skin 2 ... Laminated body 3 ... Honeycomb core 4 ... Skin 5 ... Adhesive layer 6 ... Lightweight cellular concrete 7 ... Composite panel A ... Measuring point δ ... Warpage amount

Claims (1)

[Claims] 1. A thin stone skin is pressure-bonded to a skin surface of a laminate of a core and a skin with an adhesive, and the skin satisfies the following formula (1). And a composite panel. E × t × α ≦ 0.080 In the formula (1), E, t, and α have the following meanings. E: Elastic modulus of skin at 25 ° C (kg / mm ² ) t: Thickness of skin (mm) α: Coefficient of linear expansion of skin (1 / ° C)