JPH10128937A - Decorative laminated sheet of melamine resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the wear resistance of a surface without deteriorating smooth nailing properties and an outward appearance when this decorative laminated sheet is used as the top sheet for a pachinko machine by blending water-soluble melamine resin varnish with which a decorative paper is impregnated with glass powder of a specific particulate diameter with the surface treated by a silane coupling agent. SOLUTION: A melamine resin decorative laminated sheet best suited for the top plate of a pachinko machine is formed by blending a water-soluble melamine resin varnish with which a decorative paper is impregnated, with glass powder of a particulate diameter of 5-15μm with the surface treated by a silane coupling agent. The melamine resin decorative laminated sheet for the top sheet of the pachinko machine requires surface luster finish. For this purpose, glass powder is best suited for obtaining a transparent appearance compared to a translucent filler such as alumina. To realize the transparency and the feeling of a printed paper, however, the most appropriate blending amount of the glass powder is 1.0-5.0 pts.wt. a good example of the silane coupling agent is epoxy silane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative melamine resin plate which is suitably used for a top plate of a pachinko machine, and more particularly to a decorative plate having significantly improved abrasion resistance of the top plate. It is.

[0002]

2. Description of the Related Art Melamine resin decorative boards are often used for pachinko machines because of their excellent surface hardness and durability. Printed decorative paper used for ordinary decorative boards is made by gravure printing, and is suitable as a building material, but it is difficult to obtain clear colors and lacks realism of the image of the pattern for pachinko machines was there.

[0003] Decorative paper for pachinko tops applied to improve the image of printing paper that cannot be expressed by such gravure printing is mainly composed of black, indigo, red, blue,
It is manufactured by offset printing using five pink UV inks.

[0004] Then, in order to bring out the subtle color contrast of the pachinko table top plate and to express colors other than the five colors, five colors are overcoated. When impregnating decorative paper with melamine resin varnish,
In the case where the resin does not sufficiently penetrate and the decorative panel is manufactured and then attached to the substrate to form a pachinko top panel, nailing properties, which are the most important practical panel characteristics, are reduced. In particular, when nailing, many cracks occur in the overcoated portion.

[0005] On the other hand, there is a method of improving the impact resistance by modifying and plasticizing the melamine resin varnish in order to improve such an inconvenience. There is a disadvantage that wearability is significantly reduced. In any case, the curing of the melamine resin has not been sufficiently promoted in order to avoid a decrease in crack resistance. Therefore, the surface hardness was not sufficiently developed. In order to improve such a problem, it is effective to add a small amount of alumina to the varnish of the melamine resin meaning.
It is not practical because the surface of the US plate is damaged and the surface must be polished every time. Although the addition of finely divided silica is also effective, a large amount of silica needs to be added, which has the disadvantage of impairing the transparency.

[0006] The decorative melamine resin plate is composed of a decorative melamine resin layer, a shielding layer, and a phenol resin core layer in this order. The decorative layer of melamine resin is a decorative paper on which printing is applied or an impregnated paper obtained by impregnating and drying a predetermined amount of melamine resin into paper into which a pigment is incorporated. The phenol resin core layer is an impregnated paper obtained by impregnating kraft paper with a phenol resin and drying. The shielding layer can be omitted.

[0007]

As described above, the present invention has been completed for a melamine resin decorative board suitable for use in a pachinko machine top plate, in order to achieve both crack resistance and abrasion resistance. It is.

[0008]

According to the present invention, a water-soluble melamine resin varnish impregnated in decorative paper has a particle size of 5 to 15 μm.
The present invention relates to a melamine resin decorative board characterized by containing glass powder surface-treated with a silane coupling agent.

The melamine resin decorative plate for pachinko top plate of the present invention will be described below. In the present invention, a predetermined amount of melamine is reacted with formalin to obtain a water-soluble melamine resin varnish. After obtaining the melamine resin varnish, the particle size is 5
A glass powder having a thickness of about 15 μm and surface-treated with a silane coupling agent is added, and a latent curing catalyst (for example, Catanit A) is added to prepare a resin varnish for coating. In addition, when impregnating this varnish, undercoating is generally performed, but it is not necessary to add glass powder to the undercoating varnish. As the silane coupling agent for treating the surface of the glass powder, any of epoxy silane and amino silane may be used, but epoxy silane is preferable in order to obtain better light resistance when a decorative plate is formed.

If the glass powder used is 5 μm or less, it is difficult to obtain and it becomes more expensive. If the particle size is 15 μm or more, it will settle in the coating varnish and it will be difficult to obtain an impregnated paper having stable properties. When glass powder that has not been treated with a silane coupling agent is used, the glass powder does not fit well into the melamine resin, so that cracking resistance during nailing decreases. Further, in order to improve the crack resistance, the use of a glass short fiber was also studied. However, a fiber having a fiber length of 15 μm or less was hardly obtained, and the wear resistance was not improved.

A melamine resin decorative plate for a pachinko top plate requires a glossy finish on its surface. As described above, when glass powder is used, a translucent filler such as alumina is used. However, in order to obtain a realistic appearance of a printing paper, the amount of glass powder to be added is preferably 1.0 to 5.0 parts by weight in order to obtain a realistic appearance of printed paper.

[0012]

【Example】

Example 1 Melamine and formalin were blended so that the molar ratio was 1.7, and the water miscibility at a reaction temperature of 95 ° C. was 12 to 12.
The reaction was carried out until a 24 ml / 5 ml varnish was obtained to obtain a melamine resin varnish. To 100 parts by weight of the melamine resin varnish, 2 parts by weight of cellulose powder was added as a thixotropic agent, and 3 parts by weight of glass powder having an average particle diameter of 8 μm, which was surface-treated with glycidoxypropyltrimethoxysilane, was added. Was prepared. This varnish was applied to a decorative paper for a pachinko top plate by a conventional method to obtain a decorative layer. Combine this with a phenolic resin impregnated paper as the core layer,
By heating and pressing, a decorative plate for a pachinko machine top plate was obtained.

Comparative Example 1 In Example 1, 2 parts by weight of cellulose powder as a thixotropy-imparting agent was added to 100 parts by weight of a melamine resin varnish, and 0.7 part by weight of alumina (average particle size: 8 μm) was added. A coating varnish was prepared. In the same manner as in Example 1, a decorative plate for a pachinko machine top plate was obtained.

Comparative Example 2 In Example 1, 2 parts by weight of cellulose powder was added as a thixotropy-imparting agent to 100 parts by weight of a melamine resin varnish, and 4 parts by weight of crystalline silica (average particle size: 1-2 μm) was added. The varnish was added to prepare a coating varnish. This was carried out in the same manner as in Example 1 to obtain a decorative panel for a pachinko machine top plate.

Comparative Example 3 In Example 1, 100 parts by weight of melamine resin varnish was added with 2 parts by weight of cellulose powder as a thixotropy-imparting agent, and then 8 parts by weight of crystalline silica (average particle diameter of 1-2 μm) was added. The varnish was added to prepare a coating varnish. This was carried out in the same manner as in Example 1 to obtain a decorative panel for a pachinko machine top plate.

Comparative Example 4 In Example 1, 2 parts by weight of cellulose powder as a thixotropy-imparting agent was added to 100 parts by weight of a melamine resin varnish, and then glass powder having an average particle diameter of 20 μm, which was surface-treated with epoxysilane, was added.
A part by weight was added to prepare a coating varnish. This was performed in the same manner as in the example to obtain a decorative plate for a pachinko machine top plate.

With respect to the obtained decorative plate, abrasion resistance test according to JIS, nailing test, observation of the situation where a mirror plate used in the case of heating and pressing was damaged and appearance were evaluated, and the results were evaluated. It is shown in FIG.

[0018]

[Table 1]

The decorative panel for a pachinko top plate obtained according to the present invention has improved surface abrasion resistance without impairing nailing properties and appearance, and is practically used because it does not damage the mirror surface plate. It is also useful as an excellent decorative board for pachinko tops.

Claims (3)

[Claims] 1. A melamine resin decorative board, wherein a water-soluble melamine resin varnish impregnated in decorative paper contains glass powder having a particle diameter of 5 to 15 μm, which is surface-treated with a silane coupling agent. Resin decorative board. 2. The decorative melamine resin board according to claim 1, wherein the amount of the glass powder added to the water-soluble melamine resin varnish is 1.0 to 5.0% by weight. 3. The decorative melamine resin board according to claim 1, wherein the decorative melamine resin board is for a pachinko machine.