JPH07266497A - Metal core double-faced decorative plate - Google Patents

Abstract

PURPOSE:To obtain an incombustible decorative plate having improved bending property, having no dew condensation to be caused on the rear face nor warp by using organic or inorganic fiber unwoven cloth for one or both of melamine resin-impregnated fiber base materials on both surfaces, in a metal core double- faced decorative plate. CONSTITUTION:On both faces of a metallic plate 21, thermosetting resin- impregnated base materials 22 and 23 are layered and melamine resin- impregnated unwoven clothes 24 and 25 are further layered so as to integrate the whole of them by heat press molding. For the metallic plate 21, an aluminum plate which is light in weight and does not gather rust easily is preferable. Its thickness is about 0.8-1.6mm. The surface is roughened so as to obtain excellent adhesion. For the unwoven cloth, an organic fiber unwoven cloth such as polyester fiber unwoven cloth etc., or an inorganic fiber unwoven cloth such as carbon fiber unwoven cloth etc., can be named. However, a polyester fiber unwoven cloth having high flexibility is preferable in order to obtain excellent bending property.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melamine resin metal core double-sided decorative sheet used for interiors of vehicles and the like, and in particular, a metal core double-sided decorative sheet suitable for use in a bending process which has hitherto been difficult. It is about boards.

[0002]

2. Description of the Related Art A melamine resin metal core decorative plate has been used for a long time as an interior material having excellent heat resistance as well as the surface performance of a melamine decorative plate and high mechanical strength due to the combination with a metal plate. Is used for. As shown in FIG. 1, the conventional melamine decorative metal sheet has a surface layer 1,
It comprises a melamine resin decorative layer 2, a shielding layer 3, a phenol resin core material layer 4, an adhesive layer 5, and a metal plate 6. The surface layer 1 is an impregnated paper obtained by impregnating and drying a thin semitransparent paper with a melamine resin, and becomes transparent after molding, and it is required to have good abrasion resistance. The melamine resin decorative layer 2 is a printed decorative paper or an impregnated paper obtained by impregnating and drying a predetermined amount of melamine resin on a pigment-containing paper. The phenol resin core agent layer 4 is impregnated paper obtained by impregnating and drying kraft paper with a phenol resin. Between the melamine resin decorative layer 2 and the phenolic resin core material layer 4, there is usually provided a shielding layer 3 made of a shielding impregnated paper obtained by impregnating a pigment-containing paper with a phenolic resin or a melamine resin.

An aluminum plate is generally used as the metal plate 6, but a rustproof iron plate is also used. A melamine decorative metal plate is obtained by setting each impregnated paper on a metal plate 6 provided with an adhesive layer 5 made of resin-impregnated paper as shown in FIG. 1 and applying heat and pressure by a conventional method. The thickness of the layers excluding the metal plate is approximately 0.5 to 0.7 mm. About 0.3 mm for thin melamine decorative metal plate
Is. Such a melamine metal decorative plate has a structure shown in FIG. 2, and has a resin layer on only one side and has a metal surface exposed on the other side. In the case of such an asymmetrical structure, there is a drawback in that the decorative sheet is warped due to the contraction stress at the time of molding the resin layer on only one side (particularly the melamine resin layer) and the expansion and contraction stress generated by the temperature and humidity changes of the atmosphere during use. Yes,
Further, depending on the part to be used, dew condensation may occur on the backside metal surface having high thermal conductivity, which may cause corrosion of this surface or other metal parts such as structural materials.

The present applicant has studied to improve the drawbacks of a melamine resin metal decorative plate having a resin layer on only one side, and has proposed a metal core double-sided decorative plate having a resin layer on both sides of the metal plate in Japanese Patent Application No. Filed as No. 253403. This double-sided decorative sheet greatly improves the warpage and corrosion defects of the conventional single-sided metal decorative plate, but on the other hand, there is a drawback that the internal bending workability of the single-sided metal decorative plate is greatly reduced. . The minimum radius that can be bent differs depending on the basis weight and ash content of the paper used for the decorative layer, the type of melamine resin, etc.However, when bending with a bender roll at room temperature, it is usually a single-sided metal decorative plate. In the case of, in the vertical direction, 150
~ 200 mmR, 80 ~ 120 mmR in the horizontal direction, while in the case of double-sided metal decorative plate, 5 in the vertical direction
Inner bending can be performed only up to 00 mmR and 200 mmR even in the lateral direction.

The reason for this is that in the double-sided metal decorative plate, when the decorative surface side is internally bent, external bending stress acts on the back surface side resin layer. In order to follow this bending stress, the backside resin layer must have good elongation properties, but the resin layer made of melamine resin-impregnated paper, which has been used as a base material for decorative base paper, has been required to follow this. This is because the elongation property just enough to obtain is not obtained and the material breaks.

On the other hand, the present inventor, as a means for imparting elongation characteristics to the backside resin layer, does not use the resin, which is another element that constitutes the resin-impregnated base material (resin layer), rather than the base material. For plasticizing, modification and change of resin type were studied, but it was difficult to satisfy both properties of improving bending workability and preventing warpage of the decorative sheet at the same time.

[0007]

As described above, the present invention has the drawbacks of warpage and corrosion caused by the conventional single-sided metal decorative plate and the defect of poor bending workability of the double-sided metal decorative plate invented to improve the problems. Are to be solved at the same time.

[0008]

According to the present invention, a thermosetting resin-impregnated fiber base material is overlaid on both surfaces of a metal plate, and a melamine resin-impregnated fiber base material is overlaid on each surface.
A metal core double-sided decorative board, characterized by using an organic or inorganic fiber non-woven fabric as one or both of the melamine resin-impregnated fiber base materials on the both surfaces of the metal core double-sided decorative board formed by heat and pressure molding. Is. That is, with a metal plate as the center, resin-impregnated fiber base material layers are provided on both sides of the metal plate, the composition of the resin-impregnated fiber base material is made symmetrical with respect to the metal plate, and a nonwoven fabric is used as the melamine resin-impregnated base material on the surface. By doing so, the bending workability is improved.
(Hereinafter, "fiber base material" is simply referred to as "base material")

FIGS. 3 and 4 are schematic cross-sectional views of a metal core double-sided decorative sheet of the present invention. FIG. 3 shows thermosetting resin-impregnated base materials 22 and 23 laminated on both sides of a metal plate 21, and a melamine resin. The impregnated non-woven fabrics 24 and 25 are laminated and integrated as a whole by heat and pressure molding. In FIG. 4, the thermosetting resin-impregnated base materials 22 and 23 are laminated on both sides of the metal plate 21, the melamine resin-impregnated non-woven fabric 24 is further laminated on one side, and the melamine resin-impregnated decorative paper 26 is laminated on the other side. It is integrated by pressure molding. In the present invention, the metal plate is preferably an aluminum plate because it is lightweight and does not easily generate rust. Its thickness is usually about 0.8 to 1.6 mm. The surface is usually roughened for good adhesion.

The thermosetting resin-impregnated base material laminated on both surfaces of the metal plate acts as an adhesive between the metal plate and the decorative layer, and heats a base material such as kraft paper which is usually used. The curable resin is impregnated and dried. The thermosetting resin is preferably a phenol resin and / or an epoxy resin, which has good adhesiveness to a metal plate and excellent impregnation property into a base material. Usually, a phenolic resin or a mixture of a phenolic resin and an epoxy resin is used for making the decorative board nonflammable. A water-soluble phenolic resin is preferably used because it has a particularly excellent impregnation property into the substrate. The base material may be any as long as it is well impregnated with such a thermosetting resin varnish, but kraft paper of 30 to 150 g / m ² is usually used. In order to further improve the nonflammability of the decorative board, it is preferable to use a thin kraft paper having a basis weight of 30 to 40 g / m ² , but this increases the cost. When there are a plurality of thermosetting resin-impregnated base materials, the outermost layer may be a shielding layer composed of a shielding-impregnated base material obtained by impregnating a pigment-containing base material with a phenol resin or a melamine resin. Further, in order to improve the bending workability of the base material, a nonwoven fabric described below can be used at least outside the bending work.

In the present invention, an organic or inorganic non-woven fabric is used as a base material for impregnating the melamine resin of the decorative layer. A nonwoven fabric is easy to bend due to its structure, but this feature is effectively maintained even after being resin-impregnated and molded. Examples of such non-woven fabric include polyester fiber non-woven fabric, polyamide fiber non-woven fabric, organic fiber non-woven fabric such as polyethylene fiber non-woven fabric, or glass fiber non-woven fabric,
Although there are inorganic fiber non-woven fabrics such as carbon fiber non-woven fabrics, organic fiber non-woven fabrics having high flexibility, particularly polyester fiber non-woven fabrics are preferable in order to improve bending workability. This base material optionally contains titanium oxide or a color pigment, and a pattern is appropriately printed on the surface. Basis weight is 25 ~
100 g / m ² is suitable, but a lower basis weight is better for improving nonflammability. When titanium oxide is contained, its content is usually 5 to 50% by weight, but when a coloring pigment is used, a relatively small amount is sufficient, and it is increased to eliminate the shielding layer under the substrate. Better.

The melamine resin with which the base material is impregnated may be the one used in a usual melamine resin decorative board, but a flexible type is preferable in the case of bending with a small curvature. Examples of the flexible melamine resin include p-toluenesulfonamide, guanamines, glyogizole, sucrose and the like modified, polyacrylonitrile, polymethyl acrylate, polyvinyl butyral, modified or blended with a thermoplastic resin such as polyamide, and formaldehyde to melamine. Some resins have a reduced molar ratio.

Alumina is preferably blended in the melamine resin varnish in order to omit the surface layer of the decorative plate from the viewpoint of improving abrasion resistance. A proper amount of alumina is 2 to 5% by weight based on the resin solid content in the melamine resin varnish. In the case where only one side of both decorative layers is the interior material surface in actual use, the other decorative layer may be a base material having no color pigment blending or pattern printing, and may be used in the melamine resin varnish. It is not necessary to mix alumina.

Further, in the case where only one side is the surface of the interior material in actual use, and when the surface of the inner layer material is internally bent, the above melamine resin is applied only to the outer surface (back surface). An impregnated non-woven fabric may be used and the surface side of the inner layer material may have the same structure as the conventional decorative plate or the decorative plate described in Japanese Patent Application No. 5-253403 (Fig. 2). On the contrary, when the surface of the inner layer material is subjected to outward bending, the above melamine resin-impregnated nonwoven fabric is used only on the surface side of the inner layer material, and the back surface side is described in the conventional decorative board or Japanese Patent Application No. 5-253403. The same configuration as that of the decorative plate can be used.

The content of the melamine resin or thermosetting resin impregnated in the above-mentioned substrate (nonwoven fabric, paper, etc.) is usually about 40 to 65% by weight based on the whole resin-impregnated substrate.
When the non-woven fabric is used only on one side, the non-woven fabric has a weak anti-stretching force. Therefore, in order to prevent warpage, it is necessary to increase the resin content to balance the stretching stress with the other face where the non-woven fabric is not used. Therefore, in this case, the resin content in the resin-impregnated nonwoven fabric is preferably 65 to 85% by weight, which is considerably higher than usual. In order to obtain the metal core double-sided decorative sheet of the present invention, the thermosetting resin-impregnated base material and the melamine resin-impregnated base material (nonwoven fabric or paper) are sequentially laminated on both sides of the metal plate and heated by a conventional method. It may be pressure molded.

In the present invention, the total thickness of the decorative board is 2.
It is 0 mm or less, usually 1.2 mm to 2.0 mm. Since the thickness of the metal plate is usually 0.8 to 1.6 mm, the thickness of the resin-impregnated base material on one side is about 0.2 to 0.3 mm.

[0017]

【Example】

<Example 1> Both surfaces of an aluminum plate having a thickness of 1.0 mm were roughened by sandig. On both sides, basis weight 100
Kraft paper of g / m ² was impregnated with a water-soluble phenolic resin and dried, and one impregnated paper having a resin content of 50% was laminated on each. Further, a melamine resin-impregnated non-woven fabric having a resin content of 75% obtained by impregnating and drying a melamine resin on a polyester fiber non-woven fabric having a basis weight of 50 g / m ² is laminated on both surfaces, and the melamine resin-impregnated non-woven fabric of 160 ° C. and 100 kg / cm ² is laminated. Heat-press molding was carried out under the conditions to obtain an aluminum core double-sided decorative plate having a thickness of 1.6 mm. (Figure 3)

Example 2 Both surfaces of an aluminum plate having a thickness of 1.0 mm were roughened by sandig. On one surface thereof, superimposed one resin content of 50% impregnated paper a water-soluble phenolic resin obtained by impregnating dried kraft paper having a basis weight of 100 g / m ^2, the basis weight 50 g / m ² on its surface polyester fibers A non-woven fabric was impregnated with a melamine resin and dried, and a non-woven fabric impregnated with a melamine resin having a resin content of 75% was laminated. On the other side, two pieces of impregnated paper having a resin content of 50% obtained by impregnating and drying a kraft paper having a basis weight of 100 g / m ^{2 with} a water-soluble phenol resin are contained, and 20% of titanium oxide is contained as a decorative layer. A decorative paper having a basis weight of 100 g / m ² was impregnated with a melamine resin and dried, and an impregnated paper having a resin content of 50% was overlaid.
Then, it was heated and pressed under the conditions of 160 ° C. and 100 kg / cm ² to obtain an aluminum core double-sided decorative plate having a thickness of 1.6 mm. (Figure 4)

Comparative Example 1 Two sheets of the same phenolic resin-impregnated paper having the same structure as the other side of Example 2 and a melamine resin-impregnated paper as a decorative layer were laminated on both sides of the same aluminum plate as in the above Example, The aluminum core double-sided decorative sheet having a thickness of 1.6 mm was obtained by heat-press molding under the same conditions as in the examples. (Fig. 2)

Comparative Example 2 (Conventional Example) Two phenolic resin-impregnated papers having the same constitution as the other surface in Example 2 only on one side of the same aluminum plate as in the above-mentioned Example, and melamine resin-impregnated paper as a decorative layer. Were laminated and heat-pressed under the same conditions as in Example to obtain a single-sided decorative plate having a thickness of 1.3 mm. (Fig. 1)

Bending workability (bending resistance), dew condensation property, and warpage were measured for each of the obtained decorative boards, and the results shown in Table 1 were obtained. The results of the nonflammability test according to the Ministry of Transport were acceptable for all of the above decorative boards.

The measuring method of each characteristic is as follows. 1. Flex resistance: According to JIS K 6902. In Example 2, the non-woven fabric side was outside, and in Comparative Example 2, the side where the metal plate was exposed was outside, and bending was performed. 2. Condensation property: The presence or absence of dew condensation was tested under the same conditions as an actual vehicle cooled in the summer. 3. Warp: A decorative plate of 1230 × 2460 mm was placed on a flat plate, left at 20 ° C. for 10 days, the maximum height from the flat plate was obtained, and the value obtained by subtracting the thickness of the decorative plate was taken as the warp.

Table 1 ────────────────────────────────── Example 1 Example 2 Comparative Example 1 Comparative Example 1 2 ────────────────────────────────── Flexing resistance Vertical 25 25 100 30 30 (Minimum curvature, mm) Horizontal 20 20 50 20 Condensation non-condensation non-condensation non-condensation Large condensation, water drops flowing down on vertical surfaces (mm) 0-10 10-10-1 10-20 ───────────── ──────────────────────

[0024]

EFFECTS OF THE INVENTION The metal core double-sided decorative sheet of the present invention maintains and improves the bending characteristics of the conventional melamine resin single-sided metal decorative sheet, has no dew condensation on the back surface, and does not warp. Therefore, it is suitable as an inner layer material for vehicles and the like.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a conventional melamine resin single-sided metal decorative plate.

FIG. 2 is a schematic cross-sectional view of a metal core double-sided decorative board using a paper base material.

FIG. 3 is a schematic sectional view of an example of a metal core double-sided decorative plate of the present invention.

FIG. 4 is a schematic cross-sectional view of another example of the metal core double-sided decorative plate of the present invention.

[Explanation of symbols]

 1 Surface Layer 2 Decorative Layer 3 Shielding Layer 4 Core Layer 5 Adhesive 6 Metal Plate 11 Metal Plate 12, 13 Thermosetting Resin Impregnated Paper 14, 15 Melamine Resin Impregnated Decorative Paper 21 Metal Plate 22, 23 Thermosetting Resin Impregnation Paper 24,25 Melamine resin impregnated non-woven fabric 26 Melamine resin impregnated decorative paper

Claims (5)

[Claims] 1. A metal core both sides obtained by stacking a fibrous base material impregnated with a thermosetting resin on both surfaces of a metal plate, further stacking a fibrous base material impregnated with a melamine resin on each surface, and heating and pressing. In the decorative board, a metal core double-sided decorative board characterized in that an organic or inorganic fiber nonwoven fabric is used as one or both of the melamine resin-impregnated fiber base materials on both surfaces. 2. The metal core double-sided decorative sheet according to claim 1, wherein one or both of the non-woven fabrics has a pattern on its surface. 3. The metal core double-sided decorative board according to claim 1, wherein the non-woven fabric is made of polyester fiber. 4. The metal core double-sided decorative board according to claim 1, wherein the resin content in the melamine resin-impregnated nonwoven fabric is 65 to 85% by weight. 5. The decorative board according to claim 1, wherein the decorative board has a thickness of 2.0 mm or less.