JPS6032758B2 - Method for manufacturing decorative sheets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin foam laminate for decorative and cushioning purposes.

The present invention can be used for interior materials of automobiles and cases, interior decoration materials of wall materials and furniture, surface decoration materials such as cushion materials and albums, decoration materials of bags and bags, etc. The present invention provides a material that has excellent strength and texture, and is aesthetically and practically useful.

Traditionally, materials used for this type of purpose include cloth, PVC leather, and synthetic leather, but these are just surface materials, and when making cushioning materials, these materials are sewn into a bag shape, and the inside of the material is sewn into a bag shape. In many cases, cotton or polyurethane foam is inserted as a cushioning material into the wheel, and PVC leather is not applied directly as a wheel interior material, but is applied in layers with polyurethane foam or the like.

The disadvantages of these materials are that it takes a lot of time to sew and is difficult to work with, and if you only use materials such as leather, if a decorative uneven pattern is required on the surface, additional work such as button tying is required. Furthermore, since a product such as leather that integrates a fabric and a resin layer is used in combination with polyurethane foam as a cushioning material, it ends up being expensive.

With the aim of developing a skinned polyurethane foam laminate, the present inventors initially studied a method of transferring a polyurethane film layer on a releasable support provided with a squeeze pattern to a polyurethane foam. However, crests using this transfer method had the disadvantage that the types of crests were limited and it was difficult to create uniqueness. In addition, in this polyurethane foam laminate with a skin, a plastic film is formed directly on the polyurethane foam layer, so when this laminate is adhered to a wall or the ceiling of a car, the solvent contained in the adhesive applied is There was a problem that it passed through the polyurethane foam layer and directly affected the plastic film, and in severe cases, the plastic film swelled and spoiled its appearance. Furthermore, there was a strong demand for the development of decorative sheets that could be embossed using an embossing device. In view of the above, the inventors of the present invention have conducted extensive research in order to obtain a decorative sheet that is not easily affected by adhesives and that provides a stable concave-convex pattern using an embossing device.
It was discovered that this object could be achieved by using a film layer made of a specific synthetic resin, and the present invention was completed.

That is, the present invention has a dielectric loss factor of 0.5 to 10 layers.
A composite sheet is made by laminating and integrating a polyurethane adhesive layer, a polyurethane foam layer with a large dielectric loss factor, and a polyurethane film layer on the surface of a crosslinked synthetic resin foam, and is subjected to high-frequency embossing processing to have an uneven drawing pattern on the surface. In the method for obtaining a decorative sheet, the surface polyurethane film layer and foam layer having a large dielectric loss factor are softened by heat generation through the high-frequency embossing.
The present invention relates to a method for producing a decorative sheet, characterized in that the synthetic resin crosslinked foam is compressed and fixed to form an uneven drawing pattern, and the synthetic resin crosslinked foam is restored almost to its state before high frequency embossing.

The present invention will be explained in detail below.

The crosslinked synthetic resin foam used in the present invention needs to have a lower dielectric loss factor and a lower compression set than the polyurethane foam layer and film layer.

For example, crosslinked elastomers such as polyurethane, natural rubber and styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, neoprene, etc. are used;
Among them, polyurethane foam is common. The polyurethane resin forming the polyurethane film layer and the polyurethane foam layer is prepared by reacting, for example, polytetramethylene glycol, polypropylene glycol, polycarbonate polyester, a hydroxyl compound such as ethylene glycol 1.4 butanediol, etc. with a dibasic acid such as adipic acid. Using polyester or caprolactone-based polyester etc. obtained by
It is formed from polyether or polyester polyurethane obtained by reacting with isocyanates such as diphenylmethane diisocyanate and tolylene diisocyanate, and low molecular weight glycols or diamines. In the present invention, the polyurethane film and the polyurethane foam layer must be adjusted so that the dielectric loss factor is greater than that of the synthetic resin crosslinked foam to be laminated.

If the dielectric loss factor is small, the amount of heat generated during high-frequency embossing is small,
Therefore, since the degree of softening of the polyurethane film layer and the polyurethane foam layer is small, it becomes difficult to clearly form a concavo-convex drawing pattern, which is not preferable. Further, the polyurethane foam layer preferably has a softening point of 100° C. or higher, and the polyurethane film layer is formed of polyurethane having a softening point higher than that of the polyurethane foam layer, and the synthetic resin crosslinked foam also has a softening point higher than that of the polyurethane foam layer. It is preferable to use a synthetic resin having a high melting point or decomposition point. By creating a difference in the softening point of each resin layer in this way, the amount of heat generated during high-frequency embossing first softens and melts the polyurethane foam layer, which then compresses and fixes it, thereby increasing the dielectric loss factor of each resin layer. Due to the synergistic effect of the difference between

As mentioned above, the polyurethane foam layer has a softening point of 100
It is necessary to make it q○ or more, and 130 to 250°C is preferable. If it is less than 100 qo, it is not preferable because it softens significantly during high-frequency embossing, resulting in destruction of the foam layer or adhesion of resin to the mold.

If the temperature exceeds 250°C, it is necessary to lengthen the high-frequency embossing time, which is unsuitable and undesirable for economically forming a concavo-convex pattern in a short period of time.

The polyurethane resin forming the polyurethane adhesive layer is a polyether polyol such as polytetramethylene glycol or polypropylene glycol, or a polycarbonate-based polyether, or a hydroxyl compound such as ethylene glycol, 1,4-butanediol, etc. and a dibasic acid. For example, a polyurethane ester obtained by reacting with adibic acid or a go-caprolactone polyester is used as a polyol component, and is reacted with isocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate, and low molecular weight glycols or diamines. It is made of polyether-based or polyester-based polyurethane obtained by

For the polyurethane adhesive layer, either one-component type or two-component type polyurethane resin can be used. By forming a polyurethane adhesive layer, the influence of the solvent contained in the adhesive on the polyurethane film layer when adhering the decorative sheet to a wall or the ceiling of a car can be reduced by forming a polyurethane foam layer on the synthetic resin crosslinked foam. Combined with solvent resistance, it is significantly reduced.

Furthermore, the method of the present invention is superior in surface smoothness compared to the case where a polyurethane foam layer is adhered to a synthetic resin crosslinked foam without using an adhesive. Although the decorative sheet of the present invention can be used for various purposes, it is particularly suitable for use as an interior material for automobiles and cases, an interior decoration material for walls and furniture, and a surface decoration material for albums, etc. A decorative sheet with a stable concavo-convex pattern can be easily obtained.

Furthermore, a synthetic resin layer such as amino acid, nylon, or acrylic may be further provided on the polyurethane film layer within a range that does not impair high-frequency embossing properties.

An embodiment of the present invention will be shown below based on the drawings, but the present invention is not limited to this embodiment.

As shown in Figure 1, a polyester-based polyurethane resin solution is applied to the surface of a flat silicone paper (mold release support) to a dry thickness of 25 cm, and this is heated and dried to form a polyurethane film. 2 was formed.

The coating of this layer had a 100% modulus of 80k9, a softening point of 17,000, and a dielectric loss factor of 0.30.On this polyurethane coating layer 2, a 1.4-butanediol-adipate-based polyester-based isocyanate-terminated polyurethane prepolymer was used. A foamable urethane elastomer compound mainly composed of
Heat in a humidified 500° heating machine for 3 minutes to foam and harden the product, which has a thickness of 450° and a density of 0.43°/lump softening point of 1450.
A polyurethane foam layer 3 having a dielectric loss factor of 0.0 and a dielectric loss factor of 0.35 was obtained.
Next, on the polyurethane foam layer 3, a polypropylene glycol two-component polyurethane adhesive 4 is applied with a basis weight of 110 mm/kg.
After coating, a soft polyurethane foam (synthetic resin foam) 5 with a density of 15k9/W, a thickness of 3 willow, a softening point of 200qo, and a dielectric loss factor of 0.15 was laminated.
After heating for 10 minutes to reaction-cure the adhesive 4, the silicone paper (release support) 1 was peeled off to obtain a composite sheet for high-frequency embossing. This composite sheet was subjected to high-frequency embossing to obtain a decorative sheet suitable for wall materials, as shown in FIG. 2, in which a diamond-patterned concavo-convex pattern was clearly expressed. As a method for evaluating high frequency workability, the dielectric loss factor was measured using a mutual induction bridge type device under conditions of a temperature of 2500 and a frequency of 1 pi C/S.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the decorative sheet of the present invention.
FIG. 2 is a sectional view showing an embodiment in which a concave-convex pattern is applied to a synthetic resin laminate. DESCRIPTION OF SYMBOLS 1... Release support, 2... Polyurethane film layer, 3... Polyurethane foam layer, 4...
...Polyurethane adhesive layer, 5...Synthetic resin foam. Figure 1 Figure 2

Claims (1)

[Claims] 1. A composite sheet consisting of a polyurethane adhesive layer, a polyurethane foam layer with a high dielectric loss factor, and a polyurethane film layer are laminated and integrated in sequence on the surface of a synthetic resin crosslinked foam with a low dielectric loss factor of 0.5 to 100 mm in thickness, and is subjected to high-frequency processing. In the method of pressing to obtain a decorative sheet having an uneven drawing pattern on the surface, the surface polyurethane film layer and the foam layer having a large dielectric loss factor are heated and softened by the high-frequency embossing, and are compressed and fixed to form the uneven drawing pattern. A method for producing a decorative sheet, characterized in that, when the synthetic resin crosslinked foam is formed and released from compression, the synthetic resin crosslinked foam is almost restored to its state before high frequency embossing.