JPS6324469B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a decorative sheet and a method for producing the same, and more specifically to a decorative sheet that has excellent heat resistance, cold resistance, weather resistance, and processability, and the production thereof. It is about law.

As conventional decorative sheets, those made by appropriately processing paper, woven fabric, non-woven fabric, metal foil, plastic film, synthetic leather, natural leather, etc. by printing, embossing, sewing, laminating, etc. are known. These decorative sheets are selected based on their performance depending on the application, but especially when applied to mass-produced products such as automobiles and electrical products, strict performance is required, especially surface scratch resistance. There are strict requirements regarding strength, heat resistance, cold resistance, and weather resistance, and it must also have excellent workability and be suitable for mass production.

In particular, as decorative materials used in the above-mentioned automobiles, electrical products, etc., plastics have been widely used in these fields in recent years, so plastics have been used extensively in recent years, such as in-die extension molding, reaction in-die extension molding (RIM), vacuum molding,
There is a demand for a decorative sheet that has processability suitable for application to processing methods such as vacuum-pressure forming.

Currently, decorative sheets with processability as described above are made by coloring or printing a film or sheet of polyvinyl chloride, ABS, polystyrene, acrylic, etc., and providing a protective resin layer of a normal thermoplastic resin as necessary. When using a decorative sheet, apply an adhesive, especially a heat-sensitive adhesive, etc. to the back side and attach it to the surface of an appropriate molded product, or use a vacuum forming method to attach it, or use a decorative sheet. The decorative sheet is formed in advance, placed in a mold, and then injected from the back side of the decorative sheet to integrate it.

However, while the above-mentioned conventional decorative sheets have excellent processability such as molding, they are insufficient in properties such as heat resistance, cold resistance, weather resistance, and strength such as surface scratch resistance.

The present inventors have been involved in the production of decorative sheets for some time, and have attempted to improve the drawbacks of such conventional decorative sheets. It has excellent heat resistance and cold resistance without impairing the formability of the decorative sheet, and also has ultraviolet shielding properties created by irradiating the polyarylate resin layer with ultraviolet rays and making part of the resin have an o-oxyketone structure. The present invention was completed based on the discovery that weather resistance, particularly ultraviolet ray resistance, can be imparted by using this method.

That is, the first aspect of the present invention relates to a decorative sheet consisting of a base material, a printed layer, and a polyarylate resin layer at least a part of which has an o-oxyketone structure; A method for producing a decorative sheet, which comprises forming a printed layer on a material using ordinary ink, then forming a polyarylate resin layer over the printed layer, and then irradiating the polyarylate resin layer with ultraviolet rays. It is something.

The present invention will be explained in detail below.

As the base material in the present invention, paper, metal foil or metal plate, plastic film or sheet, wood base material, etc. can be used. Examples of paper include tissue paper, bleached kraft paper, titanium paper, art paper,
Coated paper, gypsum board paper, paperboard, etc., metal foils or metal plates include iron, aluminum, copper, tin,
Plastic films or sheets made of gold, silver, etc. or their alloys include polyethylene film, polypropylene film,
Polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, polyethylene terephthalate film, polycarbonate film, nylon film, polystyrene film, ethylene vinyl acetate copolymer film,
Ethylene vinyl alcohol copolymer film, ionomer film or sheet, wooden base material such as so-called veneer made of thinly processed precious wood, etc.
In addition, woven fabrics, non-woven fabrics, synthetic leathers, natural leathers, etc. can also be used, and are selected and used in consideration of appearance, performance, and workability depending on the purpose.

Next, a printing layer can be provided on the base material as described above by printing using ordinary ink, and an appropriate vehicle is used as the ink, and in addition to the vehicle, pigments or coloring agents are added. ,
A product obtained by kneading plasticizers, stabilizers, dispersants, solvents, diluents, etc. is used, and the vehicles include cellulose derivatives such as ethyl cellulose, ethyl hydroxyethyl cellulose, cellulose acetate propionate, and cellulose acetate, polystyrene, and polyα. Styrene resins and styrene copolymer resins such as methylstyrene, acrylic or methacrylic resins alone or copolymer resins such as polyethyl methacrylate, polyethyl acrylate, and polybutyl acrylate, rosin, rosin-modified maleic acid resin, rosin-modified resin Rosin ester resins such as phenol resins and polymerized rosins, polyvinyl acetate resins, coumaron resins, vinyl toluene resins, vinyl chloride resins, polyester resins, polyurethane resins, butyral resins, and even mixtures of several of these resins are used. Also, known methods of printing using the above inks include gravure printing, offset gravure printing, offset printing, silk screen printing, letterpress printing, electrostatic printing, jet printing, etc. The printing method may be used.

After providing the printing layer on the above-described base material as described above, a polyarylate resin layer is provided on the printing layer.

The polyarylate resin constituting the polyarylate resin layer is a copolymer resin composed of terephthalic acid, isophthalic acid, and a divalent phenolic compound such as bisphenol, and preferably has a molecular weight of 30,000 to 30,000.
For example, U Polymer (trade name) manufactured by Unitika Co., Ltd. is used.

The above polyarylate resin layer is formed by an extrusion method such as extrusion coating, with a melting temperature of 320°C to 350°C and a resin temperature of 200°C to 250°C when touching the printed layer provided on the base material.
It is preferable that the polyarylate resin layer is laminated simultaneously with extrusion, and the thickness of the polyarylate resin layer is preferably 50 μm to 100 μm. The polyarylate resin may contain a colorant in advance, or a primer layer may be provided on the printing layer prior to providing the polyarylate resin layer.

Next, the polyarylate resin layer provided as described above is irradiated with ultraviolet rays. As ultraviolet light,
Using a light source such as an ultra-high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, metal halide lamp, carbon arc, xenon arc, etc., the intensity of ultraviolet rays on the irradiated surface is 600 to 800 W/cm, and the irradiation time is 10 to 100 seconds, preferably 30 to 60 seconds. This will be carried out under the following conditions.

By irradiating the polyarylate resin layer with ultraviolet rays as described above, ultraviolet shielding properties are imparted to the polyarylate resin layer. The reason why the ultraviolet shielding property occurs is that some ester groups of the polyarylate resin constituting the polyarylate resin layer become o-oxyketone structure due to Fries transition due to ultraviolet irradiation, and this o-oxyketone structure plays the role of ultraviolet absorption. be. Also, due to the o-oxyketone structure, the polyarylate resin layer exhibits a slight yellow color, but
There is no problem in actual use with most decorative sheets except white.

Note that the above polyarylate resin layer may be subjected to a known embossing process.

The present invention has the above configuration, and since the decorative sheet of the first aspect of the present invention has a polyarylate resin layer on the surface, it does not impair the moldability of the base material and has excellent heat resistance and scratch resistance. It has a surface strength of Further, since a part of the polyarylate resin layer has an o-oxyketone structure, it blocks ultraviolet rays and prevents the printing layer and the base material from deteriorating due to ultraviolet rays.

Moreover, the second aspect of the present invention is that the decorative sheet of the first aspect can be easily manufactured.

The decorative sheet obtained by the present invention as described above is
It is suitable for various decorative sheet applications, particularly for mass-produced products such as automobiles and electrical products.

Claims (1)

[Claims] 1. A decorative sheet comprising a base material, a printed layer, and a polyarylate resin layer at least partially having an o-oxyketone structure. 2. Production of a decorative sheet characterized by forming a printed layer on a base material using ordinary ink, then forming a polyarylate resin layer over the printed layer, and then irradiating the polyarylate resin layer with ultraviolet rays. Law.