JPH0456760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a transfer painting method for effectively transferring images onto the surface of a transfer target substrate having an irregular cross section using a transfer paper and a mold.

(Prior Art) Various attempts have been made to apply decorations to the surfaces of three-dimensional molded products, and many decorations have also been made to extrusion molded products having irregular cross sections. Typical examples of painting on extrusion molded products include inserting a printed film or transfer paper into an extrusion die, or laminating printed films or transferring using transfer paper using the residual heat of the molded product at the exit of the extrusion die. etc., and have been put into practical use. However, when inserting a printed film into an extrusion die, a heat-resistant film must be used as the film. For example, a composite film containing a polyethylene terephthalate resin film is often used, but the adhesion between the layers of the composite film is insufficient. Moreover, when inserting the transfer paper into the extrusion die, a heat-resistant film is used as the base, so it is not necessary to adjust the gloss of the final finished surface by adjusting the peeling gloss of the heat-resistant film in advance. There are limitations due to the difficulty of embossing heat-resistant films. Alternatively, in a method of laminating using the residual heat of a molded product, there is a risk that the transfer target substrate may be deformed by the residual heat, and in transfer using residual heat, there are also restrictions on the surface shape of the transfer target substrate.

In addition to the above-mentioned method of painting at the same time as or immediately after extrusion, there is also a method of painting the extruded material once it has been molded. For example, there is a method in which a large number of small laminate rolls are arranged according to the surface shape of the base material, and the printed film is pasted while being gradually bent as it progresses. However, although this method is suitable for prismatic columns and shallow grooves, it is problematic in terms of ensuring laminate strength through uniform pressurization for those with continuous curved surfaces, relatively deep square grooves, and grooves with an arcuate cross section. Therefore, shrinkage of the film after application tends to cause blistering, peeling, or warping of the molded product.

In order to ensure uniform pressure during lamination, a mold with the opposite shape to the substrate to be transferred is prepared, the printed film is sucked into this mold, and then the mold is used as a pressure bonding means to bond it together. A method is also known (Japanese Patent Application Laid-open No. 58-28350). According to this method, most of the drawbacks of the conventional technology described above are solved, but the diameter of the extrusion die must be made small in consideration of pasting the film, and the film is made of thermoplastic material. As a result, the physical properties of the surface of the resulting product are inadequate, and warpage due to the difference in shrinkage between the film and the base material still remains.

As a result of careful consideration of the above-mentioned conventional techniques, the present inventors have attempted to perform transfer printing using a mold on the transfer substrate instead of laminating using a mold, thereby improving the use of film. The defects have been resolved, and the problems caused by the thickness of the film have been resolved by changing the shape of the mold in consideration of the thickness of the film, making it possible to use exactly the same extrusion die for those with and without decoration. The present invention was achieved by discovering that it can be manufactured using the following methods.

(Structure of the Invention) The present invention is a method of applying a transfer pattern to a transfer substrate using a mold, and the mold has a cross-sectional shape on the exit side that is opposite to the cross-sectional shape of the transfer surface of the transfer substrate. The cross-sectional shape on the inlet side is similar to the cross-sectional shape on the outlet side, and is larger than the outlet side.
And, the cross-sectional shape continuously changes from the inlet side to the outlet side, and the transfer paper is a transfer paper base material with a releasable surface and at least a transfer pattern layer. First, apply the transfer paper from the entrance side of the mold so that the transfer paper base is in contact with the mold surface, and send the transfer paper to the exit side while drawing suction from the mold surface. The transfer is performed by closely moving the mold and the substrate to be transferred along the cross-sectional shape, and moving the mold and the substrate to be transferred relatively while pressing the mold and the substrate to be transferred through the transfer paper on the exit side, The gist of this method is a method of transferring a painting onto the surface of a substrate having an irregular cross section, which is characterized in that the transfer paper substrate is then removed.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a conceptual diagram showing the outline of the method of the present invention, in which the transfer paper 10 is sent to the mold surface from the entrance 2A side of the mold 2, and similarly the transfer substrate 3 is also fed to the mold surface from the entrance 2A side of the mold 2.
is sent to the mold surface from the inlet 2A side. Inside the mold 2, the transfer paper is sucked by the mold as it advances and passes through the exit 2B.
It is shown that the mold 2 is bent into almost the same shape as the transfer target base material 3 in the vicinity, and transfer is performed by applying pressure between the mold 2 and the transfer target base material 3 at the outlet 2B. After that, the base material of the transfer paper is peeled off.

FIG. 2 is a perspective view showing an example of the shape of the transfer substrate 3, in which the surfaces other than the lower surface 4, the end 5, and the end 5' are decorated surfaces.

FIG. 3 is a perspective view of the mold 2 used when transferring to the transfer substrate shown in FIG. The shape has been enlarged in the width direction of the mold and the degree of unevenness has been made gentler. Also, the cross-sectional shape on the exit 2B side is the reverse mold shape of the transfer substrate, making it more accurate. In this case, it is preferable to increase the thickness by taking into consideration the thickness of the transfer paper when transferring to the transfer target substrate.

The mold 2 is also provided with a large number of fine suction holes 6 at necessary locations on the mold surface, and although not shown, the suction holes are connected to each other by appropriate means and connected to a suction pump or a vacuum pump. As a result, the transfer paper is sucked, and this suction causes the transfer paper to be conveyed and brought into close contact with the mold surface, so that the transfer paper can be shaped into the same shape as the surface of the transfer target base material near the mold exit. When the mold is composed of split molds, vacuum suction may be applied from the gap between each split mold.

Incidentally, in order to absorb the dimensional error of the transfer target substrate, the mold 2 may be formed into two or more pieces and connected to each other with a spring.

FIG. 4 is a cross-sectional view showing an example of the transfer paper 10 used in the present invention.
are laminated, and a transfer pattern layer 15 consisting of a printed pattern layer 13 and an adhesive layer 14 is further laminated. As the transfer paper, any known transfer paper can be used, and in principle, what is commonly called hot stamping foil can be used. In addition to those shown in the fourth figure, there are also cases in which the releasable base material itself is used and the releasable layer 12 is omitted, cases in which a protective layer is provided to protect the printed pattern layer after transfer, and cases in which the printed pattern layer itself is adhesive. It is possible to use one in which the adhesive layer is omitted, or one in which the transfer paper base material is provided with matte portions or convex portions to produce matte portions or concave portions on the surface after transfer.

Each layer of the transfer paper will be further explained using the layer shown in the fourth figure as an example.

Various plastic films such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, polycarbonate, nylon (polyamide), polystyrene, ABS, ethylene/vinyl acetate copolymer,
Plastic films of ethylene/vinyl alcohol copolymer, ionomer, cellulose acetate, polysulfone, polyimide, etc., composite laminate sheets of these plastic films, or laminates of these plastic layers with paper, nonwoven fabric, etc. can be used.

If the shape of the transfer surface of the transfer base material is complex, use of polyvinyl chloride (preferably produced by the cast method) or nylon film will improve the ability of the transfer paper to follow the mold. This is preferable because it improves the performance. Further, when a water-soluble film such as polyvinyl alcohol film is used, it can be peeled off by applying water to dissolve and remove the film after transfer.

The appropriate thickness of the transfer paper base material is about 20 to 200 μm.

The releasable layer has releasability to the transfer paper base material,
Any material may be used as long as it does not prevent the transfer paper from following the mold surface, such as polyvinyl chloride resin, cyclized rubber, chlorinated rubber, thermoplastic acrylic resin, cellulose resin, polyolefin resin, etc. It can be configured using The releasable layer is provided by gravure coating, roll coating, offset printing, or extrusion coating.

The printed pattern layer can be formed using an ink using an appropriate synthetic resin as a vehicle, as long as it does not prevent the transfer paper from following the mold. As the vehicle, resins such as polyester, polyvinyl chloride, polyamide, cellulose, polyurethane, and acrylic may be used.

The adhesive layer is made of, for example, thermoplastic acrylic resin, polyvinyl chloride resin, polyolefin resin, chlorinated rubber, NBR, etc. in order to ensure adhesion to the transfer substrate and followability of the transfer paper to the mold surface. , provided by various types of printing or coating.

In order to adjust the base color of the transfer substrate during transfer, polyvinyl chloride resin, polyolefin resin,
It is preferable to use a colored paint or ink using a cyclized rubber, thermoplastic acrylic resin, cellulose resin, polyvinyl alcohol resin, polyethylene terephthalate resin, or polyamide resin as a vehicle and provide it between the above-described printed pattern layer and the adhesive layer. .

In addition, a protective layer may be provided between the releasable layer and the printed pattern layer in order to improve the surface physical performance after transfer. Examples of the synthetic resin constituting the protective layer include polyurethane resin, acrylic resin, and fluorine-based resin. The material may be resin, polysulfone resin, polyimide resin, polycarbonate resin, polyethylene terephthalate resin, polyamide resin, etc., and may be provided by printing, coating, extrusion coating, or lamination. Of course, the protective layer can also be provided by a spray method or the like in a separate process after transferring the pattern.

In order to perform the transfer using the above-mentioned transfer paper and mold, an appropriate method as exemplified below can be adopted depending on the structure of the transfer paper and the material of the transfer target substrate.

A method that uses an adhesive between the transfer paper and the transfer substrate. The adhesive may be present on the transfer paper, on the transfer substrate, or on both. When the adhesive is a heat-sensitive adhesive, the mold is heated to perform pressure and heating simultaneously during transfer. It is also effective to preheat the transfer target substrate.

A method in which either or both of the transfer paper and the substrate to be transferred are activated with an activation composition that activates the adhesive surface, and then the transfer is performed. According to this method, the generation of air bubbles at the adhesive interface is reduced.

In either method, it is effective to heat the transfer base material in advance, and after pressure is applied for transfer, additional pressure may be applied using a roller or the like.

Further, after applying pressure, the adhesive force may be improved by leaving the transfer paper base material for a long time before peeling it off, or by heating it.

Furthermore, reducing the pressure of the surrounding atmosphere during transfer has the effect of reducing entrapment of air bubbles.

As described above, the method of the present invention uses a mold to press the transfer paper and the substrate to be transferred, so it is suitable for complex cross-sectional shapes. When the shape is complicated, the method of the present invention may be applied only to the complex-shaped part, and the conventional method may be applied to the other parts. For example, the method of the present invention is used for sharp inner right angles and inner radius parts, and roll pressure bonding is used for general quadratic curved surfaces and flat surfaces.

(Effects of the Invention) According to the present invention, it is possible to transfer the printed pattern of the transfer paper by applying uniform pressure to the transfer base material having a complicated cross-sectional shape, so there is very little occurrence of transfer unevenness. Compared to the layer obtained by laminating printed films using a mold, the transferred printed pattern layer is much thinner, so there is less warpage on the product. Since there is practically no difference in dimensions between products subjected to this process and products not subjected to this process, it has the advantage that the transfer substrate can be manufactured using the same extrusion die.

(Example) Examples for showing the present invention more specifically are listed below.

Example 1 A releasable layer,
A wood grain pattern layer and an adhesive layer were provided.

Ink for release layer (“Release Varnish B” manufactured by Showa Ink) Polyvinyl chloride resin 15 parts Toluene 35 parts Methyl ethyl ketone 50 parts Ink for pattern layer (“VMC” manufactured by Morohoshi Ink) Polyvinyl chloride resin 12 parts Pigment 6 parts Toluene 30 Methyl ethyl ketone 50 parts Adhesive layer ink (Showa Ink "ALT") Acrylic resin 30 parts Toluene 20 parts Methyl ethyl ketone 30 parts The obtained transfer paper was sucked into a heated mold and the cross section of the PVC sash material to be transferred was drawn. Bend it to the same shape as the shape, feed the PVC sash material between the heated mold and the roller, press it and transfer it, then
When the nylon film was peeled off, a PVC satsuri material with a wood grain pattern was obtained.

Example 2 A releasable layer (the ink used in Example 1 was used) was provided on a polyethylene terephthalate film with a thickness of 10 μm, and then a protective layer and a pattern layer were both formed by gravure printing using an ink with the following composition. Established.

Ink for protective layer Acrylic resin 40 parts Ultraviolet absorber (manufactured by Ciba Geigy, Tinuvin P) 0.1 part Ethyl acetate 40 parts Ink for pattern layer Acrylic resin 30 parts Pigment 20 parts Toluene 25 parts Ethyl acetate 40 parts Irregular shape for transfer substrate Using a molded aluminum sash material, an adhesive composition containing acrylic resin/polyvinyl chloride resin/chlorinated rubber = 40/5/10 was spray-coated on the surface in advance, and the other conditions were the same as in Example 1. I went to

In Example 2, the same transfer as in Example 1 could be carried out, and since the obtained product had a protective layer, it passed a 3000 hour weather resistance test on a weatherometer.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram showing an overview of the method of the present invention, Fig. 2 is a perspective view showing an example of a transfer substrate, Fig. 3 is a perspective view of a mold, and Fig. 4 is a diagram showing the laminated structure of transfer paper. It is a sectional view showing an example. 2...Mold, 2A...Inlet, 2B...Outlet, 3
...Transfer base material, 4...Bottom surface, 5,5'...Kibutsu,
6... Suction hole, 10... Transfer paper, 11... Transfer paper base material, 12... Peelable layer, 13... Print pattern layer,
14...Adhesive layer, 15...Transfer pattern layer.

Claims (1)

[Scope of Claims] 1. A method of applying a transfer pattern to a transfer base material using a mold, in which the cross-sectional shape of the exit side of the mold is an inverse shape of the cross-sectional shape of the transfer surface of the transfer base material. The cross-sectional shape of the inlet side is similar to the cross-sectional shape of the outlet side and larger than that of the outlet side, and the cross-sectional shape changes continuously from the inlet side. uses a transfer paper base material with a releasable surface and at least a transfer pattern layer,
First, apply the transfer paper from the entrance side of the mold so that the transfer paper base is in contact with the mold surface, and send the transfer paper to the exit side while drawing suction from the mold surface. The transfer is performed by closely moving the mold and the substrate to be transferred along the cross-sectional shape, and moving the mold and the substrate to be transferred relatively while pressing the mold and the substrate to be transferred through the transfer paper on the exit side, A method of transfer painting onto the surface of a base material having an irregular cross section, the method comprising: thereafter removing the transfer paper base material. 2. The transfer painting method according to claim 1, wherein thermal transfer is performed by heating a mold. 3. The transfer painting method according to claim 1, wherein pressure transfer is performed by interposing an adhesive between the transfer paper and the transfer target substrate. 4. The transfer painting method according to claim 1, characterized in that an activation composition for activating the adhesive surface is interposed in advance between the transfer paper and the transfer target substrate. 5. The transfer painting method according to any one of claims 1 to 4, characterized in that the substrate to be transferred is heated prior to the transfer. 6. The transfer painting method according to any one of claims 1 to 5, characterized in that the transfer is performed under reduced pressure.