JPH04225000A - Transfer foil and manufacture thereof - Google Patents

Abstract

PURPOSE:To make a relief shape having excellent decorative effect on the surface of a molded piece by a method wherein recesses of a roll intaglio are filled with electromagnetic radiation curing resin, a film base material is contacted to the resin, and the resin is cured by irradiation with ionizing radiation so as to form a relief pattern. CONSTITUTION:A transfer foil 1 is constituted of a mold releasing film 4 made of a film base material 2 having a relief pattern 3 on the surface thereof and a transfer layer 5 layered thereon. The transfer layer 5,contains a picture pattern layer 7 and is formed by a peeling layer 6 and an adhesive layer 8. The relief pattern 3 of the mold releasing film 4 is formed by an ionizing radiation curing resin. When the transfer foil is to be used, the adhesive layer 8 of the transfer foil is layered so as to abut to the surface of a molded piece 9 formed already to which a relief surface is to be made, on which the transfer foil is pressed with pressure so as to stick fast by heating as occasion demands. Thereafter, the mold releasing film 4 is removed so as to make a desired relief shape on the surface of the molded piece formed already.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer foil for imparting an uneven shape with excellent design effects to the surface of various molded articles, and a method for producing the same.

0002

[Prior Art] Conventionally, when forming an uneven pattern such as an embossed pattern on the surface of a molded product, a releasable film having an uneven shape corresponding to the desired uneven pattern on the surface is used, and then A transfer foil is used in which transfer layers such as a release layer, a pattern layer, and an adhesive layer are sequentially laminated. The above transfer foil becomes a release layer whose surface has surface irregularities corresponding to the surface irregularities of the release film, so by transferring the transfer layer to a molded product etc. using this transfer foil, the molded product A desired uneven shape can be imparted to the outermost surface of the substrate.

Conventionally, as a method for imparting an uneven pattern to the releasable film of the transfer foil described above, for example, 1) a thermoplastic resin film is used as a base film, and the surface of the film is formed by a method such as heat embossing. 2) Using ink with a thermosetting resin or ultraviolet curable resin as a vehicle on the surface of the base film, printing in a raised manner using a printing device such as screen printing or gravure printing, and then curing the ink. Methods are known.

0004

[Problems to be Solved by the Invention] However, when using the above-mentioned releasable film in the conventional transfer foil, for example, when the releasable film is used in the method 1), it is difficult to emboss the thermoplastic resin by heating. Therefore, there was a risk that the embossed shape would deform or disappear due to changes over time. Furthermore, when the embossed shape is too fine or the unevenness is too deep, the reproducibility of providing the unevenness is not very good. In addition, when using a releasable film formed by method 2) above, the liquid ink transferred from the plate onto the film substrate flows, and the resin from the raised printing flows and creates unevenness before being irradiated with ultraviolet rays. The shape was distorted, and it was very difficult to form a sharp and fine uneven pattern. In addition, when producing a release film using the printing method described above, the viscoelastic behavior of the ink changes due to variations in ink production lots and changes in printing conditions such as printing temperature, resulting in deformation of the edges of the uneven pattern. Therefore, it is difficult to mass-produce a releasable film having an uneven pattern of the same shape with good reproducibility in a stable manner, and as a result, the quality of the transfer foil becomes unstable.

The present invention has been made in order to eliminate the drawbacks of the above-mentioned prior art, and provides a transfer foil that can reliably form a sharp and fine uneven shape on the surface of a molded product after transfer. It is an object of the present invention to provide a manufacturing method that can reliably and stably manufacture the transfer foil.

[0006]

[Means for Solving the Problems] The present invention provides a transfer foil in which a transfer layer is laminated on a releasable film having at least an uneven pattern on its surface, in which at least the recesses of a rolled intaglio plate are filled with an ionizing radiation-curable resin. At the same time, a film base material is brought into contact with the resin, and while the resin is held between the film base material and a roll intaglio, ionizing radiation is irradiated to cure the resin and form a releasable film with an uneven pattern. This is a transfer foil characterized by having the following characteristics. Further, the manufacturing method of the present invention is a method for manufacturing a transfer foil in which a transfer layer is laminated on a releasable film having at least an uneven pattern on the surface,
At least the recesses of the roll intaglio are filled with an ionizing radiation-curable resin, and a film base is brought into contact with the roll intaglio and the filled ionizing radiation-curable resin, and while the film base is in contact with the intaglio, ionizing radiation is applied. The ionizing radiation curable resin interposed between the intaglio and the film base material is cured by irradiation from the film base material side and/or the inside of the intaglio plate, and the resin and the film base material are brought into close contact with each other. is peeled from the intaglio to form a releasable film by providing an uneven pattern made of ionizing radiation-curable resin on the surface of the film base material, and then a transfer layer is laminated on the surface side of the releasable film to form a transfer foil. This is a method of manufacturing.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. As shown in FIG. 1, the transfer foil 1 of the present invention is formed by laminating a transfer layer 5 on a releasable film 4 having an uneven pattern 3 on the surface of a film base material 2, and the transfer layer 5 has a pattern layer 7 on it. It is formed of at least a release layer 6 and an adhesive layer 8, as necessary, and the uneven pattern 3 of the release film 4 is formed of an ionizing radiation curable resin. The uneven pattern 3 of the release film 4 is a pattern corresponding to a desired shape, and its shape and pattern are not particularly limited. Examples include patterns that reproduce the uneven shape of objects, character symbols, parallel lines, various abstract patterns, various matte surfaces, mirror gloss, etc. Examples of the above-mentioned line patterns include, for example, a group of unevenness or grooves forming parallel straight lines or curves, and a group of parallel lines or straight lines in adjacent patterns that share a closed boundary line that surrounds the group and have different directions. Examples include patterns such as a collection of straight lines or curved lines in a closed area.

[0008] The width W and the height H of the convex portions of the concavo-convex pattern 3 are normally formed to be about 0.1 to 100 μm. Further, the ratio C=H/W of the width W of the protrusion and the height of the protrusion can be set to about 0.1 to 10. A preferable ratio C of the width W of the convex portion to the height of the convex portion is about 0.5 to 1.0. In addition, the shape of the convex portion is an ideal shape 31 (indicated by a dotted line) as shown in FIG. For the film, the reproducibility of the actual convex shape 32 with respect to the convex shape 31 of the original concave-convex pattern is as follows, where W is the width of the ideal convex tip and X is the actual width of the convex tip. It is more preferable to form the uneven pattern 3 by forming X to be 85% or more of W in order to impart a desired shape with good reproducibility. Further, the uneven pattern 3 may be composed of a convex portion 3A and a resin layer 3B serving as the bottom surface of the concave portion, as shown in FIG. 1, or may be composed of only a convex portion 3A, as shown in FIG.

As the ionizing radiation curable resin forming the above-mentioned uneven pattern 3, known ionizing radiation curable resins can be used, such as prepolymers having a polymerizable unsaturated bond or epoxy group in the molecule, There are compositions in which oligomers and/or monomers are appropriately mixed.

The film base material 2 used for the release film 4 of the transfer foil of the present invention includes polyester such as polyethylene terephthalate, polyamide such as nylon, acrylic resin such as polyvinyl chloride, polymethyl methacrylate, polycarbonate, Polystyrene, polyacrylate, fluororesin, polypropylene, cellulose triacetate,
Examples include a plastic film made of cellophane or the like, metal foil of copper, iron, aluminum, etc., paper, etc., and these may be used alone or as a base material in which they are laminated as appropriate. The thickness of the film base material 2 is appropriately selected depending on the application, but is generally 10 to 100 μm, preferably 25 to 50 μm.

The release layer 6 is provided to facilitate the release from the release film 4 and to provide the surface shape of the transfer layer 5 after transfer, and its resin composition has the desired composition as a surface protective layer after transfer. Select to have physical properties. In particular, when surface scratch resistance and stain resistance are required, thermosetting resins or ionizing radiation curable resins are usually used. The thickness of the peeling layer 6 is usually about 0.1 to 10 μm. Examples of the resin forming the releasability 6 include thermoplastic resins such as cellulose derivatives, styrene resins, acrylic resins, and vinyl polymers;
Examples include thermosetting resins such as phenol resins and melamine resins, as well as ionizing radiation-curable resins similar to the resins that form the above-mentioned uneven pattern. Further, the release layer 6 may be colored or a matting agent may be added thereto.

[0012] The pattern layer 7 includes patterns and figures imitating natural objects,
2 to 6 designs of symbols, characters, colored layers, etc. are printed using known printing methods.
It is formed in μm. Further, the pattern layer 7 can also be formed of metal such as aluminum by vacuum evaporation or the like to a thickness of about 40 to 600 Å. The number of these pattern layers is not limited to one layer, but two or more layers can also be provided. In addition, in the transfer foil of the present invention, the pattern layer 7 does not need to be particularly formed.

The adhesive layer 8 is provided to adhere the transfer layer 5 to a molded article, etc., and its material can be the same as that of the adhesive layer normally used in this type of transfer foil. Examples include acrylic resin, styrene resin, vinyl chloride-vinyl acetate copolymer, and the like. Further, the adhesive layer does not need to be particularly formed when the release layer or the pattern layer has sufficient adhesion to the transfer target.

Next, a method for manufacturing the transfer foil 1 of the present invention will be explained. First, a releasable film 4 having a concavo-convex pattern 3 provided on the surface of a film base material 2 is manufactured. As shown in FIG. 4, first, the concave portion 11 of the roll intaglio 10 is filled with ionizing radiation curable resin 12 using the coating device 13, and the resin 12 filled with the film base material 2 is also contacted with the roll intaglio 10. Contact is made using a pressure roll 21. Here, as a method for filling the recesses 11 with the ionizing radiation-curable resin 12, a T-die type nozzle coating device can be used as shown in FIG. In the nozzle coating device, the nozzle is a roll intaglio plate 10.
It is provided like a curtain so as to cover both ends of the roll intaglio in a direction perpendicular to the rotation direction (width direction) with a constant width in the rotation direction, and is equipped with a discharge device for pressurizing and discharging the curable resin. There is. In addition, the nozzle coating device is preferably provided with a cavity 19 in the middle of the nozzle in order to alleviate unevenness in discharge amount and changes over time. In addition to the nozzle coating apparatus described above, a coating apparatus using an appropriate method such as a roll coating method or a knife coating method may be employed as the coating apparatus. The resin 12 is desirably applied to the roll intaglio 10 side in order to prevent air bubbles from entering and to faithfully reproduce the shape of the recesses 11, but it is preferable to apply the resin 12 to the film base material 2 side. is also possible.

Next, the film base material 2 is rolled into an intaglio plate 10.
(specifically, when the roll is in contact with the press roll 21 and the feed roll 22 in the figure), the ionizing radiation irradiation device 17 irradiates the recess 11 of the roll intaglio 10 with ionizing radiation. The curable resin 14 inside is brought into close contact with the film base material 2. That is, while the ionizing radiation-curable resin 12 is held between the base film 2 and the recess 11 of the roll intaglio 10, it is irradiated with ionizing radiation and cured. The degree of curing at this time may be at least as long as it causes the resin 12 to lose its fluidity and to develop adhesion to the film base material 2. After passing through the irradiation device 17, the film base material 2 is peeled off from the rolled intaglio plate 11. As a result, the cured ionizing radiation curable resin 12 is integrated with the film base material 2 and detached from the recesses 11 to obtain a releasable film 2.

Examples of ionizing radiation include ultraviolet rays emitted from light sources such as ultra-high-pressure mercury lamps, high-pressure mercury lamps, low-pressure mercury lamps, carbon arcs, black light lamps, metal halide lamps, etc., Cockroft-Walton type, Van de Graaff type, resonant transformer type, An electron beam emitted from an irradiation source such as an insulated core transformer type, a linear type, a dynamitron type, a high frequency type, etc., can be used. In the present invention, a solvent type ionizing radiation curable resin can be used to control the fluidity to some extent. In that case,
As shown in FIG. 3, a solvent drying device 16 is provided to dry the solvent in the resin before irradiating with ionizing radiation. This drying device 1
6 can use hot air, an infrared heater, or the like. Use of a solvent-based resin expands the range of resin selection and makes it easier to adjust coating properties. Note that when a solvent-free ionizing radiation-curable resin is used, the drying device 16 is not necessary.

In the present invention, as shown in FIG. 3, the ionizing radiation-curable resin that has been cured and detached from the recesses of the roll intaglio is further irradiated with ionizing radiation using an ionizing radiation device 18 to further improve the ionizing radiation-curable resin. The resin can also be cured. In the manufacturing method of the present invention, the roll intaglio 10 and the press roll 21
The thickness of the concave-convex pattern 3 made up of the convex portions 3A and the resin film 3B serving as the bottom surface of the concave portions can be controlled by adjusting the gap and pressure between them. In addition, by removing the resin other than the resin filled in the recess with a doctor blade etc., the convex part 3 as shown in FIG.
A concave-convex pattern 3 of only A can be formed.

The roll intaglio 10 is made of chrome-plated copper,
Using metals such as iron, glass, ceramics such as quartz, and synthetic resins such as silicone resin, the recesses are formed by known methods such as photocorrosion, electroforming, and milling. In addition, in order to prevent heat damage to the base film 2 and coating resin 12 during irradiation with ionizing radiation, or to adjust the viscosity of the coating resin 12, the roll intaglio 11 is made hollow or double-walled, and cold water is placed inside. or by supplying hot water, cold air or hot air to roll intaglio 1
It is preferable to control the temperature of the printing plate No. 1.

In the present invention, ionizing radiation is generally irradiated from the film base material 2 side as shown in the figure, but the roll intaglio plate 10 is formed of a material transparent to ionizing radiation such as quartz or glass, and the inside of the intaglio plate 10 is It is also possible to irradiate from the side (specifically, by an irradiation device installed inside the roll hollow). Alternatively, irradiation may be performed from both sides, including the film substrate side and the inside of the intaglio plate. However, when ionizing radiation is irradiated from the film base material 2 side, the film base material 2 needs to be transparent to ionizing radiation. In the present invention, the shape of the convex portion can be formed with good reproducibility as shown in FIG. 4 by irradiating ionizing radiation while the film base is in contact with an intaglio coated with an ionizing radiation-curable resin. can.

When using the transfer foil of the present invention, for example, as shown in FIG. After laminating them so that they are in contact with each other, pressing the transfer foil and applying heating etc. as necessary to bring them into close contact, the release film 4 is peeled off to impart a desired uneven shape to the surface of the molded product. I can do it. Next, the present invention will be explained in more detail by giving specific examples.

Example 1 The surface of an easily adhesive PET film (manufactured by Teijin: HP-7, thickness 38 μm) was irradiated with ionizing radiation under the following conditions using the following ionizing radiation curable resin and intaglio to form an uneven pattern. A release layer having the following properties was formed.・Ionizing radiation curable resin: UV curable resin (Dainichiseika: Seikabeam EX880926B, viscosity 750 cps)・
Intaglio: A concave pattern consisting of an aggregate of multiple divided areas each having lines with a groove width and depth of 15 μm and a pitch of 30 μm, and divided by changing the direction and angle of the adjacent lines across the sides. Intaglio with. (The angle of the line is 0°,
30°, 60°, 90°)・Ionizing radiation irradiation conditions: 1 ozone-containing high-pressure mercury lamp (160 W/cm), substrate feeding speed 20 m/min

Next, on the surface of the release layer, a release layer forming resin (release varnish 46-7 manufactured by Showa Ink Kogyo Co., Ltd.) was applied using a gravure roll at a coating amount of 3 g/m2 to form a release layer. A picture pattern was formed on this release layer by gravure printing (manufactured by Showa Ink Industries: BCT).
) Furthermore, an adhesive layer-forming resin (manufactured by Showa Ink Industries: HS-AS201) was applied with a gravure roll to the surface on which the pattern layer was provided at a coating amount of 3 g/m2 to form an adhesive layer. It was made into a transfer sheet. When this transfer sheet was transferred to a plastic molded article by hot stamping, a molded article was obtained in which a transferred pattern with a beautiful uneven pattern was formed on the surface.

Effects of the Invention As explained above, the transfer foil of the present invention is produced by filling at least the concave portions of a roll intaglio with an ionizing radiation-curable resin, and bringing a film base material into contact with the resin, so that the resin can bond between the film base material and the roll intaglio plate. A transfer foil in which the uneven pattern of a conventional releasing film is formed by printing, by having a releasing film that is held in between and irradiated with ionizing radiation to harden the resin to form an uneven pattern. Compared to , it has an uneven pattern with sharp edges and good reproducibility, and has an excellent effect on design reproducibility. In the transfer foil of the present invention, even when the height of the convex portion is relatively large compared to the width of the convex portion in the shape of the concavo-convex pattern, the shape of the edge does not collapse and a releasable film with a good surface shape can be obtained. Therefore, it is possible to form an uneven pattern with excellent design on the surface of the release layer that forms the surface of the transfer layer after transfer, and it is possible to form fine and beautiful embossed patterns on the surface of the molded product. An uneven pattern can be easily imparted. Furthermore, since the surface unevenness pattern is formed from an ionizing radiation-curable resin,
Compared to conventional thermoplastic resins formed on the surface by heat embossing or the like, the embossing does not disappear over time and has excellent heat resistance, solvent resistance, etc. Therefore, since the transfer foil of the present invention does not change the uneven shape even when heated during transfer, stable transfer can be performed without changing the uneven shape even if the transfer conditions change. In addition, the method for manufacturing the transfer foil of the present invention includes filling at least the concave portions of a roll intaglio with an ionizing radiation curable resin, and bringing a film base material into contact with the roll intaglio and the filled ionizing radiation curable resin. While in contact with the intaglio, ionizing radiation is irradiated from the film base side and/or the inside of the intaglio to cure the ionizing radiation-curable resin interposed between the intaglio and the film base, thereby bonding the resin and the film base. By adopting a method of forming a releasable film by bringing the materials into close contact with each other, and then peeling the film base material from the intaglio to form an uneven pattern made of an ionizing radiation-curable resin on the surface of the film base material, Compared to the conventional method of forming a releasable film using normal printing, etc., the resin held in the recesses is cured as it is, so it is not affected by changes in the physical properties of the ink or changes in manufacturing conditions. Since the uneven pattern can be formed without any process, it is possible to consistently produce a releasable film with good reproducibility. Therefore, it is possible to reliably produce a transfer foil having an uneven shape of uniform and stable quality.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing an example of the transfer foil of the present invention.

FIG. 2 is a schematic vertical cross-sectional view showing an example of a releasable film used in the transfer foil of the present invention.

FIG. 3 is an explanatory diagram showing an example of the manufacturing method of the present invention.

FIG. 4 is a partially enlarged sectional view of an uneven pattern on the surface of a releasable film.

FIG. 5 is an explanatory diagram when performing transfer using the transfer foil of the present invention.

[Explanation of symbols]

1 Transfer foil 2 Film base material 3. Uneven pattern 4. Release film 5 Transfer layer 10 roll intaglio 11 Recessed part 12 Ionizing radiation curable resin

Claims (2)

[Claims] Claim 1. A transfer foil comprising a transfer layer laminated on a releasable film having at least an uneven pattern on the surface,
Fill at least the recesses of the roll intaglio with an ionizing radiation-curable resin, bring the film base into contact with the resin, and irradiate the resin with ionizing radiation while the resin is held between the film base and the roll intaglio. 1. A transfer foil comprising a releasable film formed by curing a releasable film to form an uneven pattern. 2. A method for producing a transfer foil comprising laminating a transfer layer on a releasable film having at least an uneven pattern on its surface, wherein at least the concave portions of a roll intaglio are filled with an ionizing radiation-curable resin, and the roll intaglio and A film substrate is brought into contact with the filled ionizing radiation curable resin, and while the film substrate is in contact with the intaglio, ionizing radiation is irradiated from the film substrate side and/or the inside of the intaglio to separate the intaglio and film substrate. The ionizing radiation curable resin interposed between them is cured to bring the resin and the film base into close contact, and then the film base is peeled off from the intaglio to form the uneven pattern made of the ionizing radiation curable resin on the film base. 1. A method for manufacturing a transfer foil, which comprises forming a releasable film on the surface of a material, and then laminating a transfer layer on the surface side of the releasable film.