JP3233775B2 - Metal core double-sided decorative board - Google Patents

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 plate used for interior parts of vehicles and the like, and more particularly to a metal core double-sided decorative plate suitably used for applications involving bending, which has been difficult in the past. It is about a board.

[0002]

2. Description of the Related Art In addition to excellent heat resistance, a melamine resin metal core decorative board has been used as an interior material having both the surface performance of a melamine decorative board and a high mechanical strength characteristic by being combined with a metal sheet. Used in As shown in FIG. 1, a conventional melamine metal decorative board has a surface layer 1,
It is composed of a melamine resin decorative layer 2, a shielding layer 3, a phenol resin core layer 4, an adhesive layer 5, and a metal plate 6. The surface layer 1 is made of thin translucent paper impregnated with melamine resin impregnated and dried, and becomes transparent after molding, and is required to have good wear resistance. The melamine resin decorative layer 2 is an impregnated paper obtained by impregnating and drying a predetermined amount of melamine resin on a decorative paper or a printed paper with pigment. The phenolic resin core layer 4 is an impregnated paper obtained by impregnating kraft paper with a phenolic resin and drying. Between the decorative melamine resin layer 2 and the phenolic resin core layer 4, a shielding layer 3 made of a paper impregnated with a phenolic resin or a melamine resin and impregnated with a phenolic resin or a melamine resin is usually provided.

As the metal plate 6, an aluminum plate is generally used, but a rust-proof iron plate is also used. Each impregnated paper is set on a metal plate 6 provided with an adhesive layer 5 made of a resin-impregnated paper as shown in FIG. 1 and heated and pressed by a conventional method to obtain a melamine decorative metal plate. The thickness of the layer excluding the metal plate is generally in the range of 0.5 to 0.7 mm. Approximately 0.3mm for thin melamine decorative metal plate
It is. Such a melamine metal decorative board has a structure shown in FIG. 2 and has a resin layer only on one side and a metal surface is exposed on the other side. In the case of such an asymmetric configuration, there is a drawback that the decorative board is warped due to contraction stress at the time of molding of a resin layer (particularly, a melamine resin layer) on only one side and expansion / contraction stress generated by a change in temperature and humidity of an atmosphere during use. Yes,
Also, depending on the use site, dew condensation may occur on the back 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 only on one side, and has disclosed a metal core double-sided decorative plate having resin layers on both sides of a metal plate. No. 253403. Although this double-sided decorative board significantly reduces the defects of warpage and corrosion of the conventional single-sided metal decorative board, it has a disadvantage that the internal bending workability of the single-sided metal decorative board is greatly reduced. . The minimum radius that can be bent differs depending on the basis weight, ash content, type of melamine resin, etc. of the paper used for the decorative layer, but in bending with a bender roll at room temperature, a single-sided metal decorative board is usually used. In the vertical direction,
２００200 mmR and 80-120 mmR in the horizontal direction are possible, while the double-sided metal decorative board is 5 mm in the vertical direction.
Inward bending can be performed only up to 200 mmR in the horizontal direction.

[0005] The reason for this is that in the double-sided metal decorative board, when the decorative surface side is inwardly bent, an external bending stress acts on the back side resin layer. In order to follow this bending stress, the backside resin layer must have good elongation characteristics, but the resin layer made of melamine resin impregnated paper based on decorative base paper, which has been conventionally used, can follow this. This is because the elongation property cannot be obtained enough to cause breakage.

On the other hand, the present inventor has proposed that, as a means for imparting elongation characteristics to the backside resin layer, the resin which is another element constituting the resin-impregnated base material (resin layer) is used instead of the base material. In order to plasticize, modification and change of the type of resin were examined, but it was difficult to simultaneously satisfy both characteristics of improvement in bending workability and prevention of warpage of the decorative board.

[0007]

As described above, the present invention has the disadvantages 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 problem. At the same time.

[0008]

According to the present invention, a fiber substrate impregnated with a thermosetting resin is laminated on both surfaces of a metal plate, and a fiber substrate impregnated with a melamine resin is further laminated on each surface.
The present invention relates to a metal core double-sided decorative panel obtained by heating and pressing, wherein an organic or inorganic fiber nonwoven fabric is used as one or both of the melamine resin-impregnated fiber base material on both surfaces. It is. That is, a resin-impregnated fiber base material layer is provided on both sides of a metal plate as a center, the structure of the resin-impregnated fiber base material is symmetrical about the metal plate, and a non-woven fabric is used as a 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 sectional views of a double-sided metal core decorative plate of the present invention. FIG. 3 shows a metal plate 21 having thermosetting resin-impregnated substrates 22 and 23 laminated on both sides thereof, and a melamine resin. The impregnated nonwoven fabrics 24 and 25 are laminated, and the whole is integrated by heat and pressure molding. In FIG. 4, thermosetting resin-impregnated substrates 22 and 23 are laminated on both sides of a metal plate 21, a melamine resin-impregnated nonwoven fabric 24 is laminated on one side, and a 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 hardly generates rust. Its thickness is usually about 0.8 to 1.6 mm. The surface is usually roughened for good adhesion.

The thermosetting resin-impregnated substrate to be superimposed on both surfaces of the metal plate acts as an adhesive between the metal plate and the decorative layer. It is impregnated and dried with a curable resin. The thermosetting resin is preferably a phenol resin and / or an epoxy resin having good adhesion to a metal plate and excellent in impregnation into a substrate. Usually, a phenol resin or a mixture of a phenol resin and an epoxy resin is used to make the decorative board nonflammable. Phenolic resins are preferably used because they are water-soluble because of their particularly good impregnation into the substrate. The substrate may be any substrate as long as such a thermosetting resin varnish is well impregnated, but usually a kraft paper of 30 to 150 g / m ² is used. In order to further improve the nonflammability of the decorative board, it is preferable to use thin kraft paper having a basis weight of 30 to 40 g / m ² , but the cost increases. When a plurality of thermosetting resin-impregnated substrates are used, the outermost layer may be a shielding layer made of a substrate impregnated with a pigment and impregnated with a phenol resin or a melamine resin. Further, in order to improve the bending property, the nonwoven fabric described below can be used at least outside the bending process.

In the present invention, an organic or inorganic nonwoven fabric is used as a base material for impregnating the melamine resin of the decorative layer. Although the nonwoven fabric is easy to bend due to its structure, this feature is effectively maintained even after being impregnated with resin and molded. As such nonwoven fabric, polyester fiber nonwoven fabric, polyamide fiber nonwoven fabric, organic fiber nonwoven fabric such as polyethylene fiber nonwoven fabric, or glass fiber nonwoven fabric,
Although there is an inorganic fiber nonwoven fabric such as a carbon fiber nonwoven fabric, a highly flexible organic fiber nonwoven fabric, particularly a polyester fiber nonwoven fabric, is preferable in order to improve bending workability. This base material contains titanium oxide or a coloring pigment as necessary, and a pattern is appropriately printed on the surface. Basis weight is 25 ~
100 g / m ² is appropriate, but a smaller 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 may be used, and in order to eliminate the shielding layer below the base material, the content is increased. Better.

The melamine resin to be impregnated into the substrate may be the one used for a normal melamine resin decorative board, but when bending with a small curvature, a flexible type is preferred. Examples of the flexible melamine resin include p-toluenesulfonamide, guanamines, glyogizole, denaturation with sucrose, etc., polyacrylonitrile, polymethyl acrylate, polyvinyl butyral, denaturation or blending with a thermoplastic resin such as polyamide, and formaldehyde to melamine. There is a resin having a reduced molar ratio.

It is preferable to incorporate alumina in the melamine resin varnish in order to eliminate the surface layer of the decorative plate, from the viewpoint of improving abrasion resistance. The amount of alumina is suitably 2 to 5% by weight based on the solid resin content of the melamine resin varnish. In the case where only one side of both decorative layers is used as the interior material surface in actual use, the other decorative layer may be formed of a base material without color pigment blending or pattern printing. There is no need to mix alumina.

Further, when only one side becomes the surface of the interior material in actual use and the surface of the inner layer material is bent inward, the melamine resin as described above is applied only to the outer surface (back surface). An impregnated nonwoven fabric may be used, and the inner layer material surface side may have the same configuration as a conventional decorative plate or a decorative plate described in Japanese Patent Application No. 5-253403 (FIG. 2). Conversely, when the inner layer material surface is externally bent, the melamine resin impregnated nonwoven fabric is used only on the inner layer material surface side, and the back side is described in a conventional decorative plate or Japanese Patent Application No. 5-253403. The same configuration as the decorative board can be adopted.

The content of the melamine resin or the thermosetting resin impregnated in the above-mentioned base material (nonwoven fabric or paper) is usually about 40 to 65% by weight based on the whole resin-impregnated base material.
When the nonwoven fabric is used only on one side, the nonwoven fabric has a low anti-stretching force. Therefore, in order to prevent warpage, it is necessary to increase the resin content and balance the stretching stress with the other surface not using the nonwoven fabric. Therefore, in this case, the resin content of 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-faced decorative sheet of the present invention, the above-mentioned 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 and heated in a conventional manner. Pressing may be performed.

In the present invention, the total thickness of the decorative board is 2.
0 mm or less, usually 1.2 mm to 2.0 mm. Since the thickness of the metal plate is generally 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, 100 basis weight
g / m ² of kraft paper was impregnated with a water-soluble phenolic resin and dried, and one sheet of impregnated paper having a resin content of 50% was obtained. Furthermore, the both surfaces of the basis weight 50 g / m ² polyester fiber nonwoven fabric melamine resin impregnated dry-obtained resin content of 75% melamine resin-impregnated nonwoven fabric superposed one each, 160 ° C., of 100 kg / cm ² It was heated and pressed under the conditions to obtain a 1.6 mm-thick aluminum core double-sided decorative board. (Fig. 3)

Example 2 Both surfaces of an aluminum plate having a thickness of 1.0 mm were roughened by sandig. On one side of the kraft paper having a basis weight of 100 g / m ² , one sheet of impregnated paper having a resin content of 50% obtained by impregnating and drying a water-soluble phenol resin is overlapped, and a polyester fiber having a basis weight of 50 g / m ² is placed on the surface. The nonwoven fabric impregnated with the melamine resin having a resin content of 75% obtained by impregnating and drying the nonwoven fabric with the melamine resin was overlaid. On the other side, two sheets of impregnated paper having a resin content of 50% obtained by impregnating and drying a water-soluble phenol resin on kraft paper having a basis weight of 100 g / m ² are superimposed, and contain 20% of titanium oxide 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.
Subsequently, it was heated and pressed under the conditions of 160 ° C. and 100 kg / cm ² to obtain a 1.6 mm-thick aluminum core double-sided decorative board. (FIG. 4)

Comparative Example 1 Two sheets of the same phenolic resin-impregnated paper having the same structure as the other surfaces in the above-mentioned Example 2 and two sheets of the melamine resin-impregnated paper as the decorative layer were superposed on both surfaces of the same aluminum plate as in the above-mentioned Example, respectively. It was heated and pressed under the same conditions as in the example to obtain a 1.6 mm-thick aluminum core double-sided decorative board. (Fig. 2)

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

With respect to each of the decorative boards thus obtained, bending workability (bending resistance), dew condensation, and warpage were measured, and the results shown in Table 1 were obtained. The results of the nonflammability test according to the regulations of the Ministry of Transport were acceptable for any of the decorative panels.

The measuring method of each characteristic is as follows. 1. Flex resistance: according to JIS K6902. In Example 2, bending was performed with the nonwoven fabric side facing outward, and in Comparative Example 2, with the side where the metal plate was exposed facing outward. 2. Dew condensation property: The presence or absence of dew condensation was tested under the same conditions as in an actual vehicle cooled in 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 determined, and the value obtained by subtracting the decorative plate thickness from this was defined as warpage.

Table 1 Example 1 Example 2 Example 2 Comparative Example 1 Comparative Example 2 屈曲 Bending resistance Length 25 25 100 30 (Minimum curvature, mm) Side 20 20 50 20 Dew condensation No dew condensation No dew condensation No dew condensation Large, dew drops on vertical surface. Warp (mm) 0 to 10 to 10 to 10 １０〜 ──────────────────────

[0024]

Industrial Applicability The metal core double-sided decorative board of the present invention maintains and improves the bending characteristics of the conventional melamine resin single-sided metal decorative board, and has no dew condensation on the back surface and no warp. Which is suitable as an inner layer material for vehicles and the like.

[Brief description of the drawings]

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

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

FIG. 3 is a schematic cross-sectional view of one example of a metal core double-faced decorative plate of the present invention.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface layer 2 Decorative layer 3 Shielding layer 4 Core material 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 impregnated Paper 24, 25 Melamine resin impregnated nonwoven fabric 26 Melamine resin impregnated decorative paper

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-84680 (JP, A) JP-A-1-319541 (JP, A) JP-A-54-6071 (JP, A) JP-A-53-1981 33284 (JP, A) JP-A-4-59249 (JP, A) JP-A-7-108647 (JP, A) JP-A-4-197748 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 15/08

Claims (5)

(57) [Claims] 1. A metal substrate formed by laminating a fibrous base material impregnated with a thermosetting resin on both surfaces of a metal plate, and further laminating a fibrous base material impregnated with a melamine resin on each surface, and heating and pressing. In a decorative board, an organic or inorganic fiber nonwoven fabric is used as one or both of the melamine resin-impregnated fiber base materials on both surfaces of the decorative board. 2. The metal core double-sided decorative board according to claim 1, wherein one or both of the nonwoven fabrics has a pattern provided on a surface thereof. 3. The metal core double-sided decorative board according to claim 1, wherein the nonwoven 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 thickness of the decorative board is 2.0 mm or less.