JPH05148379A - Polyester film for decorative sheet - Google Patents

Abstract

PURPOSE:To improve the adhesion of the subject film to a primer layer as well as to a printing ink for a vinyl chloride resin or to a pressure-sensitive acrylic adhesive by forming two specific primer layers on at least one side of the film. CONSTITUTION:The first primer layer derived from a two-component polyurethane system comprising a polyol and an isocyanate-based curative is formed on at least one side of polyester film, followed by the formation of the second primer layer mainly comprising a vinyl chloride resin on the first layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a polyester film for a decorative sheet, which is provided with two kinds of primer layers on at least one surface thereof, and has excellent adhesion between the polyester film for a decorative sheet and the primer, and further, a vinyl chloride resin. The present invention relates to a polyester film for a decorative sheet, which has excellent adhesion to printing inks and acrylic pressure-sensitive adhesives.

[0002]

2. Description of the Related Art When a decorative sheet is produced from a polyester film for a decorative sheet, particularly a polyethylene phthalate resin film, the adhesion of the ink is not good even if the resin film is printed with an ink for a vinyl chloride resin.
Further, even if an acrylic pressure-sensitive adhesive is transferred and laminated on the resin film, the adhesion is not good. Therefore, there is known a method of using a special reaction type ink in order to improve the adhesion of the ink, but this method has problems such as durability of the ink and loss of residual thickness. Further, the product obtained by coating the resin film with an acrylic pressure-sensitive adhesive has a drawback that the pressure-sensitive adhesive is easily transferred to the substrate side.

[0003]

DISCLOSURE OF THE INVENTION The present invention overcomes the drawbacks of the conventional polyester film for a sheet, has excellent adhesion between the polyester film for a decorative sheet and a primer, and further prints for a vinyl chloride resin. The purpose of the present invention is to provide a polyester film for a decorative sheet, which also has excellent adhesion to ink or an acrylic pressure-sensitive adhesive.

[0004]

The present inventors have conducted various studies to develop a polyester film for a decorative sheet having the above-mentioned preferable characteristics, and as a result, have found that a polyester film for a decorative sheet, particularly a polyethylene phthalate resin film By providing a specific polyurethane-based first primer layer on at least one side, and further by providing a second primer layer mainly composed of vinyl chloride-based resin, it was found that the object can be achieved, the present invention based on this finding It came to completion.

That is, according to the present invention, a two-component reactive polyurethane type first primer layer prepared from a polyol and an isocyanate type curing agent is provided on at least one surface of a polyester film for a decorative sheet, and further on the first primer layer. The present invention provides a polyester film for a decorative sheet, which is provided with a second primer layer mainly composed of vinyl chloride resin.

The polyester film for a decorative sheet, which is a base material in the present invention, is preferably a film composed of a polyester composed of a dicarboxylic acid component unit and a diol component unit. As this dicarboxylic acid component,
Examples thereof include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and aliphatic dicarboxylic acids such as adipic acid and sebacic acid.The diol components include ethylene glycol, diethylene glycol, cyclohexanedimethanol, propylene glycol and neopentyl glycol. The film may contain a small amount of components other than the dicarboxylic acid and diol components as long as the physical properties are not impaired. Among them, the preferred film is composed of a polyethylene terephthalate resin composed of a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing ethylene glycol as a main component.

The thickness of the film is preferably 30 to 10
It is selected in the range of 00 μm. In the present invention, the first primer layer provided on at least one surface of the polyester film for decorative sheet contains a two-component reactive polyurethane prepared from a polyol and an isocyanate curing agent as a coating film forming component, and is a solid The content is preferably 10 to 30% by weight. As the polyol, which is one of the raw materials of the polyurethane, polycondensation from glycols such as ethylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol and dibasic acids such as adipic acid and sebacic acid, or ring-opening such as ε-caprolactone is used. A polyester polyol or a polycarbonate polyol obtained by polymerization is used. Examples thereof include polyethylene adipate, polypropylene adipate, polycaprolactone, and the like.

The isocyanate-based curing agent which is the other raw material is preferably one which is resistant to yellowing, and examples of such agents include hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate and lysine. Examples thereof include diisocyanate. Further, a compounding agent such as a coupling agent for improving adhesiveness, an ultraviolet absorber for preventing deterioration or oxidation, an antioxidant, a heat stabilizer and the like can be added.

Further, the second primer layer composed mainly of vinyl chloride resin provided on the first primer layer contains a vinyl chloride homopolymer or a vinyl chloride-vinyl acetate copolymer as a film forming component. Those having a degree of polymerization of about 600 to 1000 are preferable. In particular, it has good adhesion to the first primer layer and also good adhesion to vinyl chloride resin printing inks and acrylic pressure-sensitive adhesives, and has a glass transition temperature of 65 ° C. or higher,
Moreover, under a predetermined condition, for example, a temperature of 50 ± 2 ° C. and a pressure of 400
Those that do not cause blocking even under the condition of being left under a pressure of g / cm ² for 24 hours are preferable, and those containing an acrylic resin are also used. The solid content of the second primer layer is preferably 10 to 30% by weight.

In order to provide the first primer layer on at least one side of the polyester film for decorative sheet and further provide the second primer layer on the first primer layer, it is preferable to coat each primer coating solution with a coater or a printer. It is preferable to apply the coating so that the thickness of the coating film after drying is 0.5 to 3 μm, and then dry at 80 to 130 ° C.

[0011]

The polyester film for a decorative sheet of the present invention has a predetermined two-layer structure for the primer layer, so that no blocking occurs when the film is wound,
It has high productivity, good adhesion between the polyester film for decorative sheet and primer layer, and excellent peeling resistance, as well as excellent adhesion with printing ink for vinyl chloride resin and acrylic pressure-sensitive adhesive. Has a remarkable effect.

Therefore, since the polyester film for a decorative sheet of the present invention has improved adhesiveness, the range of application to multicolor printed products is expanded in place of the conventional one mainly for single color products, and it is used in a shop window or the like. It is preferably used for decoration of displays, displays, lighting equipment, table tops, window glasses and the like.

[0013]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Example 1 Polypropylene adipate (solid content 60%) was formed on the back surface of a film made of a polyethylene terephthalate resin having a thickness of 50 μm.
%) 100 parts by weight, hexamethylene diisocyanate (solid content 75% by weight) 15 parts by weight, and a diluting solvent (methyl isobutyl ketone or ethyl acetate) 120 parts by weight using a 150 mesh gravure plate roll. It was applied and dried at 120 ° C. to provide a first primer layer having a thickness of about 1 μm.

Then, on this first primer layer, a second layer containing a vinyl chloride-vinyl acetate copolymer resin (degree of polymerization: 800) and a diluting solvent (a mixed solvent of methyl ethyl ketone, toluene and ethyl acetate) having a solid content of 25% by weight. The primer solution was applied using a 150 mesh gravure plate roll and dried at 90 ° C. to form a second primer layer having a thickness of about 1 μm.

Thus, a desired polyethylene terephthalate film for decorative sheet, which strongly adhered to each other, was prepared. This film had good printability in a gravure multicolor printing machine using a printing ink for vinyl chloride resin.

Example 2 A decorative film partially printed on the back surface of a transparent vinyl chloride resin film and a semi-transparent film obtained by vapor-depositing aluminum on one surface of a film made of polyethylene terephthalate resin to have a light transmittance of 45% are used. In the same manner as in Example 1, two kinds of primer layers were provided on the polyethylene terephthalate resin film surface of the 150 μm-thick decorative sheet having the printed surface and the vapor deposition surface bonded with an adhesive.

The obtained films were strongly adhered to each other. Further, this film had good adhesion with the acrylic pressure-sensitive adhesive.

Comparative Example 1 A polyethylene terephthalate film for decorative sheet having only the first primer layer in place of the two kinds of primer layers in Example 1 was prepared in the same manner as in the method for forming the first primer layer in Example 1. The obtained film had blocking properties, and it was difficult to rewind the film.

Comparative Example 2 A polyethylene terephthalate film for decorative sheet having only the second primer layer in place of the two kinds of primer layers in Example 1 was prepared in the same manner as in the method for forming the second primer layer in Example. The obtained film did not have good adhesion, and the primer layer was peeled from the film.

Claims (1)

[Claims] 1. A two-component reactive polyurethane-based first primer layer prepared from a polyol and an isocyanate curing agent is provided on at least one side of a polyester film for a decorative sheet, and a vinyl chloride resin is further provided on the first primer layer. A polyester film for a decorative sheet, which is provided with a second primer layer mainly comprising