JPH09150493A - Melamine resin decorative laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve nailing properties for a roof of a pinball machine without decreasing definition of color shade of printing paper, an amino silane coupling agent or an epoxy silane coupling agent is contained in water-soluble melamine resin varnish with which decorative paper is impregnated by drying. SOLUTION: A specific amount of melamine is made to react on folmaline to obtain water soluble melamine resin varnish. After obtaining the melamine resin varnish, crystalline silica, alumina, etc., are added to improve abrasion resistance, and application varnish is compounded. In that case, an amino silane coupling agent or an epoxy silane coupling agent is added to compound applicating resin varnish. Though pigment containing metal such as iron (II) ferro cyanide, atrium alumino silicate, etc., is often used as printing ink for decorative paper, the silane coupling agent has a large effect on improving adhesion thereto, and can improve nailing properties without deteriorating definition of the color shade.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melamine resin decorative board suitable for use as a top board of a pachinko machine, and more particularly to a decorative board having a significantly improved nailability of the top board. is there.

[0002]

2. Description of the Related Art A melamine decorative board is often used as a top board of a pachinko machine because of its excellent surface hardness and durability. The printing decorative paper used for ordinary decorative boards is made by gravure printing and has an appropriate color tone as a building material, but it is difficult to obtain a clear color tone, making it a realistic image of the image for pachinko machines. There were poor shortcomings.

[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 made by offset printing using 5 pink inks, but 5 colors are overlaid to reveal the subtle color contrast of the pachinko machine top plate and to express colors other than 5 colors. Therefore, the melamine resin varnish does not penetrate into the overcoated part, and when it is used as a pachinko base top plate after it is laminated to the substrate after making a decorative plate, in the nailing property which is the most important as a practical panel property, In particular, when a nail is hit, a crack defect occurs in the part where the nail is applied.

In order to improve this defect, there are methods such as lowering the viscosity of the melamine resin varnish at the time of application, making the impregnated paper slightly dry, and advancing the impregnation of the resin into the inside of the paper at the time of pressing. However, it is not sufficient for sufficient impregnation, and further improvement has been desired. There is also a method of modifying the melamine resin varnish by plasticizing it to improve impact resistance, but it has drawbacks such as impairing impregnation, surface hardness and impairing transparency.

In printing decorative paper, the smaller the mesh of the plate used for offset printing is, the worse the impregnation of the melamine resin varnish is. Therefore, it is considered that the mesh of the plate is enlarged in order to improve the impregnation of the varnish. But,
In this case, there is a problem that the design and color are not clearly displayed. The melamine resin decorative board is composed of a melamine resin decorative layer and a phenol resin core material layer in that order. The melamine resin decorative layer is an impregnated paper obtained by impregnating and drying a melamine resin on the printing paper obtained by offset printing as described above.

[0006]

The inventor of the present invention has confirmed that the printing ink and the melamine resin layer are peeled from each other by observing the cracked portion of the decorative plate. It is presumed that the occurrence of cracks is due to the weak adhesion between the printing ink and the melamine resin layer, and as a result of intensive studies to improve the adhesion, the present invention has been completed.

It is an object of the present invention to provide a decorative board with improved nailability of a top board for a pachinko machine, without reducing the sharpness of the hue of the printing paper.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a melamine resin decorative board characterized in that a water-soluble melamine resin varnish impregnated into a decorative paper contains an aminosilane coupling agent or an epoxysilane coupling agent. Is.

In the present invention, a predetermined amount of melamine and formalin are reacted to obtain a water-soluble melamine resin varnish. After obtaining a melamine resin varnish, crystalline silica, alumina, etc. are added to improve abrasion resistance and a coating varnish is prepared. At that time, an aminosilane coupling agent or an epoxysilane coupling agent is used. Is added to prepare a coating resin varnish. Although the undercoating is carried out when the varnish is applied and impregnated, the coupling agent may be added to both the undercoating varnish and the main impregnated varnish, or one of them may be added, but the effect is more exerted. Therefore, it is preferable to add it to both varnishes.

In the printing ink for decorative paper, pigments containing a metal such as ferric ferrocyanide and atrium aluminosilicate are often used. In the present invention, the silane coupling agent improves the adhesion with them. The effect of doing this is considered to be great. Furthermore, it is considered that the amino group or epoxy group of the aminosilane coupling agent or the epoxysilane coupling agent reacts with the methylol group of the melamine resin to improve the adhesion between the printing ink and the melamine resin.

The decorative surface for a pachinko base top plate is required to have a glossy finish on the surface, but since it is overcoated, uneven glossiness is likely to occur, and in order to improve this point and the defect of nailing property,
As described above, it is effective to add a coupling agent,
Even if the coupling agent is excessively added, uneven gloss may occur. Therefore, the amount of the coupling agent added should be 0.
A preferred range is 5 to 5.0 parts by weight.

[0012]

【Example】

<< Examples 1 and 2 >> The melamine resin varnish was obtained by blending formalin and melamine in a molar ratio of 1.7 and reacting at a reaction temperature of 95 ° C until the water miscibility becomes 12 to 24 ml / 5 ml. It was After adding 2 parts by weight of cellulose powder as a thixotropic agent and 4 parts by weight of crystalline silica as an abrasion resistance imparting agent to 100 parts by weight of a melamine resin varnish, γ-glycidoxypropyltris as an epoxysilane coupling agent. Methoxysilane (SH-604
0: Toray Silicone) or γ-glycidoxypropylmethylethoxysilane (KBE-402: Shin-Etsu Chemical)
2 parts by weight each was added to prepare a varnish. This varnish was applied to a decorative paper for a pachinko top plate by a conventional method to obtain a decorative layer. This and a phenol resin-impregnated paper as a core layer were combined and heated under pressure to obtain a decorative board for a pachinko base.

<< Examples 3 and 4 >> In the same manner as in Examples 1 and 2, except that the addition amount of the epoxysilane coupling agent was 1.0 part by weight, the makeup for a pachinko base plate was prepared. I got a plate.

Example 5 In Example 1, instead of the epoxysilane coupling agent, γ- (2-aminoethyl) aminopropyltrimethoxysilane (SH-6020: manufactured by Toray Silicone) was used as an aminosilane coupling agent. A decorative board for a pachinko board top plate was obtained in exactly the same manner as in Example 1 except that 2.0 parts by weight of was added.

Comparative Example 1 In Example 1, instead of the epoxysilane coupling agent, vinyltriethoxysilane (A-15) was used as a vinylsilane coupling agent.
A decorative board for a pachinko stand top plate was obtained in exactly the same manner as in Example 1 except that 2 parts by weight of (1: Nippon Unicar) was added.

Comparative Example 2 A varnish containing no coupling agent was obtained in the same manner as in Example 1, and a decorative board for a pachinko board top plate was obtained in the same manner.

With respect to each of the obtained decorative boards, the varnish appearance,
The appearance of the coated paper, the appearance of the decorative plate (all visually observed), and the nailability were evaluated, and the results shown in Table 1 were obtained. As the decorative paper for the pachinko stand top plate, the one coated with the printing ink most difficult to be impregnated with the melamine resin was used.

[0018]

[Table 1]

[0019]

EFFECTS OF THE INVENTION The melamine resin decorative board of the present invention makes the color pattern of the print stand out more clearly without lowering the vividness of the color tone, and the nailability is also improved. It is extremely useful as a top plate.

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Claims (3)

[Claims] 1. A melamine resin decorative board, characterized in that a water-soluble melamine resin varnish impregnated into a decorative paper and dried contains an aminosilane coupling agent or an epoxysilane coupling agent. 2. The melamine resin decorative board according to claim 1, wherein the amount of the silane coupling agent added to the water-soluble melamine resin varnish is 0.5 to 5.0 parts by weight. 3. The melamine resin decorative board according to claim 1, wherein the decorative board is for a pachinko machine.