JPH03216377A - Transfer sheet and transfer method - Google Patents

Abstract

PURPOSE:To enhance releasability by forming a transfer layer to the polyester surface of a base sheet formed by laminating a polyolefin resin layer to a non-stretched polyester film. CONSTITUTION:A base sheet 1 is composed of a laminated material of a non- stretched polyester film 11 and a polyolefin resin 12. The non-stretched polyester film 1 becomes the structural support of a transfer sheet 1 and makes a transfer layer easily releasable. Since it is necessary that the polyester film sufficiently stretches in all of directions and closely comes into contact with the surface of a three-dimensional molded product, the polyester film must be substantially non-stretched. The polyolefin resin 12 prevents the blocking of an adhesive layer 15 when the transfer sheet 1 is taken up. The release layer B easily releasable from the base sheet is provided at the contact position with the polyester film and a function layer 4 and the adhesive layer 15 are formed thereon to desirably set three layers of the release layer 13, the function layer 14 and the adhesive layer 15 to the transfer layer transferred to a material to be transferred.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a transfer sheet and a transfer method. More specifically, the present invention relates to a transfer sheet that can be transferred onto a three-dimensional curved surface of a three-dimensional molded product, and a method for transferring onto such a three-dimensional curved surface. <Conventional technology> Since it is difficult to print a detailed pattern on the surface of a three-dimensional molded product with a three-dimensional curved surface, printing is performed on a flexible plastic sheet to make a transfer sheet, and printing is performed from this transfer sheet. A transfer method in which a pattern is transferred to the surface of a molded product is suitably used.

During transfer, the transfer sheet needs to be in close contact with the surface of the molded product, so it is drawn and formed along the shape of the surface of the molded product. For this reason, the base of the transfer sheet is required to have dimensional stability that allows it to stretch well when heated to a temperature that activates the adhesive, and that does not distort the printed image. In order to meet these requirements, hard polyvinyl chloride sheets have traditionally been used. (Unexamined Japanese Patent Publication No. 63-214424, Unexamined Japanese Patent Publication No. 63-214424,
Publication No. 3-221099, JP-A-63-222
Publication No. 900). In addition, since the only resin that has sufficient releasability for such hard polyvinyl chloride sheets is butyral resin, the transfer layer provided on this base sheet has a function of butyral resin that is in contact with the base sheet. It consisted of a layer, an adhesive layer.

<Problems to be Solved by the Invention> The butyral I4j resin constitutes the surface of a three-dimensional molded product after transfer, but it has poor mechanical properties such as abrasion resistance. Furthermore, since inks that adhere closely to butyral resin are limited to inks that use butyral resin as a binder, inks that use butyral resin as a binder have also been used for the functional layer.

Such inks also lacked abrasion resistance.

Furthermore, when ink is used that uses another resin as a binder, the ink and Petitral resin may peel off and float.

On the other hand, acrylic resin is known as a resin with excellent abrasion resistance, but when this resin was applied to the surface of the above-mentioned hard polyvinyl chloride sheet, the releasability of both was poor and transfer could not be performed.

Means for Solving the Problem> In order to solve this problem, the invention of claim (1) provides a transfer layer on the polyester surface of a base sheet formed by laminating an unstretched polyester film and a polyolefin resin layer. A transfer sheet is provided.

Further, the invention as set forth in claim (2) provides the above transfer sheet, in which the transfer layer includes an acrylic resin layer in contact with the base sheet, and a functional layer and an adhesive layer formed on the resin layer.

Furthermore, the invention as set forth in claim (3) provides a transfer method, characterized in that the transfer sheet is superimposed on the surface of the three-dimensional molded product, and the three-dimensional molded product is brought into close contact with the product by drawing, and then the base sheet is peeled off and removed.

<Specific Description of the Invention> The transfer sheet (1) according to the present invention consists of a base sheet and a transfer layer. After the transfer, the transfer layer remains on the surface of the three-dimensional molded product, which is the object to be transferred, and the base sheet is removed.

In addition, the base sheet was an unstretched polyester film (1
It consists of a laminated material of 1) and polyolefin resin (12). The unstretched polyester film (11) serves as a structural support for the transfer sheet and also facilitates peeling from the transfer layer. During transfer, it is necessary to sufficiently stretch in all directions and adhere tightly to the surface of the three-dimensional molded product, so it is necessary that it is substantially unstretched. On the other hand, a stretched film cannot adhere to the surface of a three-dimensional molded product because of its elongation. This polyester film (11) may have a stretching ratio of 5% or less. Also, 10 to 100μ
A thickness of m is sufficient.

The polyolefin resin (12) prevents the adhesive layer (15) described below from blocking when the transfer sheet (1) is wound up. Polyethylene, polypropylene, etc. can be used. The thickness may be 1 to 200 μm.

The polyester film (11) and the polyolefin resin (12) can be laminated via an adhesive layer. For example, the polyester film (11) and the polyolefin film (12) may be bonded together using an adhesive, or the surface of the polyester film (11) may be coated with an adhesive and then the polyolefin (12) may be melt-extruded and coated. ．． A two-component curing urethane adhesive can be used as the adhesive. Prior to adhesion, the surface of the polyolefin is subjected to surface treatments such as corona discharge treatment and ozone treatment.
It is desirable to activate it.

Since the transfer layer is peeled off from the base sheet after transfer, it is necessary to use a layer that can be easily peeled off from the base sheet. For this purpose, a base sheet and an easy release layer (116) are provided at the position in contact with the polyester, and a functional layer (14) is placed on top of this.
and forming an adhesive layer (I5), this release layer (13),
It is desirable that the three layers, the functional layer (14) and the adhesive layer (15), be used as a transfer layer to be transferred to the object to be transferred.

It is desirable that the release layer (I3) be applied to the entire surface of the base sheet. Since the surface of the three-dimensional molded product is formed after the transfer, an acrylic resin having excellent mechanical properties such as wear resistance is suitable. For example, polymethyl methacrylate.

The functional layer (14) ensures the original purpose of the transfer sheet, and is, for example, a printed pattern layer for decoration. The printed pattern layer can be formed by a well-known printing method such as gravure printing, silk screen printing, offset printing, or letterpress printing. Furthermore, the functional layer may be a metal vapor deposition layer, a retroreflective layer made of glass beads, or the like.

It is desirable that the functional layer (14) fully expands following the base sheet during transfer. For example, it is a printing ink or paint using a chloride of polyvinyl acetate resin or an acrylic resin as a resin binder. When the functional layer (l4) is partially formed, for example, when it is formed in a pattern such as an abstract pattern or a wood grain pattern, it is not necessarily necessary to follow the elongation of the base sheet. This is because the base sheet only needs to stretch in the portion where the functional layer (14) is not present.

The adhesive layer (15) firmly adheres the entire transfer layer to the three-dimensional molded article that is the object to be transferred, and prevents it from peeling off. Various adhesives can be used depending on the type of three-dimensional molded product. For example, heat-activated adhesives. If the three-dimensional molded product is made of acrylonitrile-ptadiene-styrene copolymer, a urethane adhesive can be used. The transfer sheet (1) of the present invention can be transferred onto a flat or curved object. However, when the object to be transferred is a three-dimensional molded product having a three-dimensional curved surface, the characteristics of the transfer sheet of the present invention can be utilized. Transfer begins with the process of overlaying the transfer sheet (1) on the three-dimensional molded product. Although it is not necessary that they be in close contact, if the functional layer (14) of the transfer sheet (1) has a pattern, the functional layer (14) and the curved surface of the three-dimensional molded product should be aligned. The transfer sheet has its adhesive layer (
15) is placed so that it is in contact with the three-dimensional molded product. Next, the transfer sheet (1) is drawn and molded to adhere closely to the three-dimensional molded product. Squeeze molding is possible by heating and softening the transfer sheet and applying fluid pressure from the opposite side of the three-dimensional molded product. The transfer sheet (1) may be heated, for example, by a far-infrared panel heater. Heating is performed to soften the base sheet to allow sufficient elongation and to activate the adhesive. Usually, it is sufficient to heat it to 80°C or higher. Further, since a temperature higher than necessary causes drawdown of the base sheet, it is desirable to heat the base sheet to a temperature of 200°C or less.

Air can be used as the fluid. Atmospheric air or compressed air. For example, by vacuum suction from the three-dimensional molded product side,
The transfer sheet (1) can be drawn and formed at atmospheric pressure. It is also possible to perform drawing molding by applying compressed air from the opposite side of the three-dimensional molded product.

FIG. 2 shows an example of a transfer device. In FIG. 2, the entire apparatus is hermetically sealed and divided into upper and lower chambers (A) and (B) by a transfer sheet (1).

The three-dimensional molded product (2) is placed on a vertically movable table (3) and stored in the lower chamber (A).

For transfer, first open the valves (8) and (9), vacuum the upper and lower chambers (A) and (B) with the vacuum pump (5), and heat and soften the transfer sheet (1) with the panel heater (4). to activate the adhesive.

Next, the valve (8) is closed, the valve (7) is opened, compressed air is blown from the blower pump (6) to the upper chamber (B), and the table (3) is raised to transfer the transfer sheet (1).
) is brought into close contact with the surface of the three-dimensional molded product (2) and drawn at the same time. Note that cooling of the transfer sheet (1) starts as soon as the transfer sheet (1) comes into contact with the three-dimensional molded product (2), and the transfer sheet (
Since 1) may not stretch sufficiently, it is desirable to heat the three-dimensional molded product (2) in advance. Heating is possible by energizing a resistance heating element built into the table (3). The heating temperature may be 50°C or higher. Further, since cooling occurs due to adiabatic expansion at the same time that the compressed air enters the upper chamber (B), cooling of the transfer sheet (1) can be prevented by heating the compressed air. Finally, only the base sheet is peeled off to obtain a three-dimensional molded product on which the transfer layer is formed.

<Example> (1) Base sheet. A polypropylene film (thickness l
00um) laminated material. (2) Transfer layer. The following (a) to (e) were gravure printed on the surface of an unstretched polyethylene terephthalate film in this order. (a) Release layer. Acrylic resin, functional layer.

An ink that uses vinyl chloride acetate resin as a binder. Adhesive layer.

Urethane resin. P! ! Layout 5 g/m” (dr
y) (b) (c) (3) Three-dimensional molded product. A molded product made of acrylonitrile butadiene-styrene copolymer resin with a three-dimensional curved surface.

(4) Apparatus.

The apparatus of FIG.

(5) Transfer method.

As shown in Figure 2, the upper and lower chambers are divided into two by a transfer sheet, and both the upper and lower chambers are heated to 0.5 to
rr. At the same time, the transfer sheet was heated to 150° C. using a panel heater.

Next, compressed air of 3 kg/cm" was blown into the upper chamber, and the table was raised to bring the transfer sheet into close contact with the three-dimensional molded product on the table. At the same time, drawing was performed.Finally, the base sheet was removed, A three-dimensional molded product with the transfer layer transferred was obtained.

(6) Results.

The transfer layer adhered well to the surface shape of the three-dimensional molded product, and the base sheet was easily peeled off. The surface properties such as abrasion resistance were also excellent.

Effects> According to the invention described in claim (1), a transfer sheet can be obtained that can be closely adhered to the surface shape of a three-dimensional molded product and has good releasability from various release layers. According to the invention described in claim (2), in addition to this, a transfer sheet for a three-dimensional molded product having excellent surface properties such as abrasion resistance can be obtained.

According to the invention described in claim (3), it is possible to form a transfer film with excellent surface properties on the surface of a three-dimensional molded product having a complicated three-dimensional shape.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the transfer sheet. FIG. 2 is an explanatory diagram of the transfer device. (1)...Transfer sheet (11)...Unstretched polyester film (12)...
...Polyolefin resin (13) ...Peeling layer (14) ...Functional layer (15) ...Adhesive layer (2) ...Three-dimensional molded product patent applicant Toppan Printing Co., Ltd. Representative Kazuo Suzuki 12 Figure 1 Figure 2

Claims (3)

[Claims] (1) A transfer sheet comprising a transfer layer formed on the polyester surface of a base sheet formed by laminating an unstretched polyester film and a polyolefin resin layer. (2) The transfer sheet according to claim (1), wherein the transfer layer comprises an acrylic resin layer in contact with the base sheet, and a functional layer and an adhesive layer formed on the resin layer. (3) A transfer method, which comprises stacking the transfer sheet according to claim (1) or (2) on the surface of a three-dimensional molded product, drawing it into close contact, and then peeling and removing the base sheet.