JP2008006709A - Transfer foil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer foil subjected to low temperature transfer while retaining heat resistance, improved in transfer properties such as foil cutting properties or the like, superior in chemical resistance and environmental stability and enabling the transfer to a medium especially such as an IC card or the like. <P>SOLUTION: The transfer foil 10 has a base material 11, a transfer layer 15 and an adhesive layer 17 and the adhesive layer 17 has a sea-island structure containing a thermal adhesive polyester resin and microsilica. The compounding ratio of the polyester resin and microsilica of the adhesive layer 17 is 90-94:6-10. The particle size of microsilica is 0.4-2 μm and the thickness of the adhesive layer 17 is preferably 0.4-0.8 μm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transfer foil. More specifically, the present invention relates to a transfer foil that can be transferred at a low temperature while having heat resistance, has good transferability such as foil sharpness, and is excellent in chemical resistance and environmental stability.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. “PET” is an abbreviation, functional expression, common name, or industry term for “polyethylene terephthalate”.

  (Main use) The main use of the transfer foil of the present invention is to pay a certain amount such as ID cards such as employee cards, membership cards, student cards, gift certificates, admission cards, pass cards, service points ( It is a medium that proves rights and qualifications (called prepaid). As a transfer layer, a hologram having excellent design properties and security, a protective layer having excellent durability such as abrasion resistance, and the like are transferred onto a part or the entire surface of the medium. It can be applied as an adhesive layer of the transfer foil of the transfer. However, it is not particularly limited as long as it is used for transferring to a medium.

  (Background Art) Conventionally, since vouchers, cards, various certificates, etc. have qualifications and certain economic value and effects, they are constantly counterfeited, altered and illegally used. Thus, in recent years, the use of IC cards has progressed. However, since the IC card has an IC chip, an antenna coil, etc. embedded in the card, some irregularities are inevitable on the surface of the card. When transferring to such an uneven surface, the heat must be higher and the pressure must be stronger, but the IC chip, antenna coil, and their contacts may be deformed by heat or pressure, adversely affecting the function. In particular, when the transfer foil is laminated on the entire surface, the card base material may be deformed. Furthermore, there is a problem that the heat and pressure at the time of transfer cause poor foil sharpness at the time of transfer and transferability is significantly reduced. Therefore, a transfer foil that is transferred to a medium such as an IC card is required to be able to transfer at a low temperature while having heat resistance, to have good transferability such as foil sharpness, and to be excellent in chemical resistance and environmental stability. ing.

  (Prior Art) Conventionally, an adhesive layer of a transfer foil is composed of dimer acid polyamide and microsilica, and a coating amount of a specific amount is known to improve adhesion, blocking property, etc. (for example, , See Patent Document 1). However, it is a wood material transfer foil that prevents molten adhesive from penetrating into the material to be transferred. The transfer temperature range of the adhesive layer of the transfer foil is narrow, and it is agglomerated to further improve adhesion. When an adhesive layer is used for a high-strength base resin, there is a problem that foil breakage is worsened and foil paris is likely to occur. As an improved adhesive layer, an inorganic filler is contained, the adhesive layer is formed by dividing it into two or more layers, and the inorganic additive is reduced as it goes to the transferred-agent-side adhesive layer. What is contained is known (for example, refer to Patent Document 2). However, in order to divide the adhesive layer into two or more layers, there are disadvantages that it takes time for production and is expensive. Furthermore, dimer acid polyamide or a condensate of dimer acid and ethylenediamine is used as the heat-adhesive resin, and there is no description or suggestion about the combination of the resin system of the present invention and microsilica.

Japanese Patent Laid-Open No. 3-9899 JP-A-4-185498

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. Its purpose is to provide a transfer foil that can be transferred at a low temperature while having heat resistance, has good transferability such as foil sharpness, is excellent in chemical resistance and environmental stability, and is especially transferred to a medium such as an IC card. That is.

In order to solve the above problems, a transfer foil according to the invention of claim 1 is a transfer foil having a substrate and at least a transfer layer and an adhesive layer on one surface of the substrate, and the adhesive layer Contains a heat-adhesive polyester resin and microsilica so that the heat-adhesive polyester resin and the microsilica have a sea-island structure.
The transfer foil according to the invention of claim 2 is such that the ratio of the heat-adhesive polyester resin and the microsilica in the adhesive layer is polyester resin: microsilica = 90 to 94: 6 to 10 on a mass basis. , That is.
The transfer foil according to the invention of claim 3 is such that the particle diameter of the microsilica is 0.4-2 μm.
The transfer foil according to the invention of claim 4 is such that the thickness of the adhesive layer is 0.4 to 0.8 μm.
The transfer foil according to the invention of claim 5 has an ultraviolet absorbing layer between the transfer layer and the adhesive layer.

According to the first aspect of the present invention, the heat-adhesive polyester resin and the microsilica have a sea-island structure, so that they have blocking resistance, heat resistance, low temperature transferability, foil breakage, etc. Transferability is good, and by using a polyester resin, there is provided a transfer foil that is excellent in chemical resistance and environmental stability, and that is transferred to a medium such as an IC card.
According to the second to fourth aspects of the present invention, in addition to the effect of the first aspect, by making the particle diameter of the microsilica 0.4 to 2 μm, the coating film surface has irregularities and has blocking resistance. A sea-island structure can be obtained by quantitatively suppressing the amount of microsilica blended to a mass ratio of 6 to 10%. For this reason, when used as an adhesive layer of a transfer foil, the thermal rise of the melting point of the heat-adhesive polyester resin to be heat-sealed is sharp, and a transfer foil with more stable transfer fixability is provided.
According to the fifth aspect of the present invention, in addition to the effects of the first to fourth aspects, there is provided a transfer foil capable of preventing fading of an image printed on an IC card as a transfer target due to ultraviolet rays.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a sectional view of a transfer foil showing one embodiment of the present invention.

  (Adhesive layer composition) The transfer foil 10 of the present invention may have the substrate 11, the transfer layer 15 and the adhesive layer 17 as essential. The adhesive layer 17 of the transfer foil 10 of the present invention contains at least a heat-adhesive polyester resin and microsilica so that the heat-adhesive polyester resin and microsilica have a sea-island structure. Preferably, the ratio of the heat-adhesive polyester resin and the microsilica of the adhesive layer 17 is polyester resin: microsilica = 90 to 94: 6 to 10 on a mass basis, and the microsilica particle diameter is 0.4 to 2 μm. And the thickness of the adhesive layer 17 is 0.4 to 0.8 μm.

  (Transfer Foil) As shown in FIG. 1, the transfer foil 10 of the present invention has a base material 11, a transfer layer 15 and an adhesive layer 17, and a release layer 12 and / or a release layer 13 as necessary. Further, another layer 21 may be provided as necessary. For example, the layer structure of the substrate 11 / release layer 12 (if necessary) / release layer 13 (if necessary) / transfer layer 15 / other layer 21 (if necessary) / adhesive layer 17 Good. In addition, the structure position of the other layer 21 may be arbitrary as long as it is other than the interlayer of the base material 11 / release layer 12 / release layer 13 regardless of the figure.

  (Substrate) As the substrate 11, various materials can be applied depending on the use as long as the substrate 11 has heat resistance, mechanical strength, mechanical strength to withstand manufacturing, solvent resistance, and the like. For example, polyester resins such as polyethylene terephthalate / polybutylene terephthalate / polyethylene naphthalate, polyamide resins, vinyl resins such as polyvinyl chloride, acrylic resins, imide resins, engineering resins such as polyarylate, polycarbonate, cellophane, etc. Cellulosic film. The substrate may be a copolymer resin containing these resins as a main component, a mixture (including an alloy), or a laminate composed of a plurality of layers. Usually, polyester films such as polyethylene terephthalate and polyethylene naphthalate are preferably used because of their good heat resistance and mechanical strength, and polyethylene terephthalate is most suitable.

  The substrate 11 may be a stretched film or an unstretched film, but a film stretched in a uniaxial direction or a biaxial direction is preferable for the purpose of improving the strength. The thickness of the base material is usually about 2.5 to 50 μm, preferably 2.5 to 12 μm, and most preferably 4 to 6 μm. Prior to coating, the substrate 11 is applied to the coated surface by corona discharge treatment, plasma treatment, ozone treatment, flame treatment, primer (also called anchor coat, adhesion promoter, or easy adhesive) coating treatment, pre-heat treatment, dust removal. Easy adhesion treatment such as treatment, vapor deposition treatment, and alkali treatment may be performed. Moreover, you may add additives, such as a filler, a plasticizer, a coloring agent, and an antistatic agent, as needed.

  (Release layer, release layer) In order to improve the releasability at the time of transfer, the release layer 12 and / or the release layer 13 may be provided as necessary, and both the release layer 12 and the release layer 13 are provided. If provided, the time of transfer can be further improved. If it is a base material with low surface energy, it is not necessary to provide.

  (Release Layer) As the release layer 12, a release resin, a resin containing a release agent, a curable resin that is cross-linked by ionizing radiation, and the like can be applied. The releasable resin is, for example, a fluorine resin, silicone, melamine resin, epoxy resin, polyester resin, acrylic resin, or fiber resin. The resin containing the release agent is, for example, an acrylic resin, vinyl resin, polyester resin, or fiber resin obtained by adding or copolymerizing a release agent such as fluorine resin, silicone, or various waxes. is there.

  The release layer 12 is formed by dispersing or dissolving the resin in a solvent and applying it to at least one part by a printing or coating method such as roll coating, gravure coating, bar coating, or die coating, and drying to form a coating film. If necessary, it may be crosslinked by heating at a temperature of 30 ° C. to 120 ° C., aging, or irradiation with ionizing radiation. The thickness of the release layer 12 is usually about 0.01 μm to 5.0 μm, preferably about 0.5 μm to 3.0 μm. The thinner the thickness is, the better. However, when the thickness is 0.1 μm or more, better film formation is obtained and the peeling force is stabilized.

  (Peeling layer) As the peeling layer 13, an acrylic resin, vinyl resin, polyester resin, fiber resin, wax, melamine to which a release agent such as fluorine resin, silicone, or various waxes is added or copolymerized is used. In the case where both the release layer 12 and the release layer 13 are provided, they may be used in appropriate combination. In this case, the release layer 13 also has a function as a protective layer after transfer.

  (Transfer layer) The transfer layer 15 is not particularly limited, and examples thereof include known hologram layers, hard coat layers, protective layers, and the like, provided that a layer having a function corresponding to each application is provided by a known formation method. Good.

  (Other layers) The other layers 21 are not particularly limited, but can be exemplified by known printing layers, decorative layers, adhesion promoting layers, etc., depending on applications and layer structures, and may be applied by known forming methods. Preferably, it is an ultraviolet-absorbing layer, and the ultraviolet-absorbing layer can prevent an image printed on an IC card as a transfer medium from being faded by ultraviolet rays.

  (Adhesive layer) The adhesive layer 17 contains at least a heat-adhesive polyester resin and microsilica, and the heat-adhesive polyester resin and microsilica have a sea-island structure.

  (Thermoadhesive resin) In the prior art JP-A-4-185498, a condensate (polyamide resin) of dimer acid and ethylenediamine having a melting point of 150 to 230 ° C is used. Use polyester resin with excellent chemical and environmental stability. Among these polyester resins, those having a melting point of 80 ° C. to 90 ° C. and a sharp rise in the thermal melting point are preferable.

  (Microsilica) In the prior art Japanese Patent Laid-Open No. 4-185498, silica is exemplified in the specification, but the silica used for the adhesive layer 17 uses microsilica. Preferably, the particle diameter of the crosilica is 0.4 to 2 μm, and the ratio of the adhesive polyester resin and the microsilica is based on the mass of adhesive polyester resin: microsilica = 90 to 94: 6 to 10 By doing so, the adhesive polyester resin and the microsilica can have a sea-island structure. By blending microsilica, the adhesive layer tears and the foil breaks, and the surface has fine irregularities to improve blocking resistance, but the adhesive polyester resin and microsilica have a sea-island structure. Thus, the foil breakage and blocking resistance can be further improved.

  (Sea-island structure) When used as the adhesive layer 17 of the transfer foil 10 of the present invention, the thermal rise of the melting point of the heat-adhesive polyester resin to be heat-sealed at the time of transfer is sharp and rapidly melts at the time of transfer heating. Since it is fixed immediately upon completion of heating, it can be transferred at a low temperature while having heat resistance, and the transfer fixing property can be further stabilized.

  The adhesive layer 17 is formed by printing or coating methods such as roll coating, gravure coating, bar coating, and die coating by dispersing or dissolving a heat-adhesive polyester resin, microsilica, and other additives in a solvent as necessary. Then, it may be applied to at least one part and dried to form a coating film.

  (Thickness) The thickness of the adhesive layer 17 is preferably 0.4 to 0.8 μm, and the total thickness of the two-layer adhesive layer in the prior art Japanese Patent Laid-Open No. 4-185498 is 30 to 40 μm. Even if it compares, the micro silica which comprises the island can be exposed to the surface by making it remarkably thin. Further, by making the thickness of the adhesive layer 17 smaller than the particle diameter of crosilica, it is preferable to expose the microsilica to the surface, and the blocking resistance can be further improved.

  As described above, the adhesive layer 17 has a material, composition, structure, and thickness of the adhesive layer 17, so that it has a blocking resistance and has a heat resistance, but heat-sealing polyester resin that is heat-sealed during transfer heating. The thermal rise of the melting point is sharp, melts rapidly, and quickly fixes with the end of heating, so it has good low-temperature transferability, transferability such as foil breakage, and is also resistant to chemicals by using polyester resin It is excellent in stability and environmental stability. In particular, even when transferring to a medium such as an IC card having surface irregularities, or even with low heat or pressure, the irregular surface can be followed, and transfer can be performed with good transferability such as foil breakage.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this.

(Example 1) A PET film having a thickness of 16 μm was used as the base material 11, and a melamine resin coating solution was applied to one surface of the base material 11 by a gravure coating method so that the dry thickness was 2 μm. Then, the release layer 12 was formed by drying.
The surface of the release layer 12 is coated with the following ionizing radiation curable resin composition with a gravure reverse coater so that the thickness after drying is 2 μm, dried at 100 ° C., and then irradiated with ultraviolet light using a high pressure mercury lamp. Was cured by irradiation to form a release layer 13 (also having a protective layer function).
・ <Procedure for producing ionizing radiation curable resin composition>
First, “ionizing radiation curable resin composition M” was produced by the following procedure. A reactor equipped with a stirrer, reflux condenser, dropping funnel and thermometer was charged with 206.1 g of ethyl acetate and 133.5 g of isophorone diisocyanate trimer (HULS product, VESTANAT T1890, melting point 110 ° C.), 80 The solution was heated to 0 ° C. and dissolved. After air was blown into the solution, 0.38 g of hydroquinone monomethyl ether, 249.3 g of pentaerythritol triacrylate (product of Osaka Organic Chemical Industry Co., Ltd., Biscoat 300) and 0.38 g of dibutyltin dilaurate were charged. After reacting at 80 ° C. for 5 hours, 688.9 g of ethyl acetate was added and cooled.
The “ionizing radiation curable resin composition M”, a film-forming resin (acrylic oligomer), a reactive silicone, a photopolymerization initiator, and a solvent are blended in the following composition to obtain an ionizing radiation curable resin composition. Prepared. In addition, a mass part is the number of parts as solid content, and it is the same after that.
・ <Ionizing radiation curable resin composition of protective layer>
“Ionizing radiation curable resin composition M” 30 parts by mass Methacrylate oligomer (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name: Purple light 6630B) 5 parts by mass Polyethylene wax (average particle size: 5 μm) 0.3 part by mass Photopolymerization initiator (Ciba Company name, Irgacure 907) 0.9 parts by weight Solvent (ethyl acetate: methyl isobutyl ketone = 1: 1) 70 parts by weight After drying the ionizing radiation curable resin composition on the protective layer surface with a gravure reverse coater The film was coated so as to have a thickness of 2 μm and dried at 100 ° C. to form a hologram layer corresponding to the transfer layer 15 of the present invention.
・ <Ionizing radiation curable resin composition of hologram layer>
“Ionizing radiation curable resin composition M” 25 parts by mass Methacrylate oligomer (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name Murasaki 6630B) 5 parts by mass reactive silicone (manufactured by Shin-Etsu Chemical Co., Ltd., trade name X-22-2445) 0. 2 parts by mass Photopolymerization initiator (Ciba, trade name Irgacure 907) 0.9 parts by mass Ethyl acetate 70 parts by mass Next, a quasi-continuous replicated from the diffraction grating by the two-beam interference method to the hologram layer surface by the 2P method A stamper with a pattern was attached to an embossing roller of a duplicating apparatus, and heated and pressed (embossed) with an opposing roller to form a relief having a fine uneven pattern. Immediately after shaping, it was cured by irradiating with ultraviolet rays using a high-pressure mercury lamp.
A reflective layer was formed by forming an aluminum thin film having a thickness of 50 nm on the relief surface of the hologram layer by vacuum deposition.
The following adhesive layer composition was applied to the reflective layer surface with a gravure coater so that the coating amount after drying was 0.5 μm, and dried at 100 ° C. to form an adhesive layer 17. The transfer foil 10 was obtained.
・ <Adhesive layer composition>
Polyester resin P-170 (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name) 20 parts by mass Microsilica (average particle size 0.5 μm) 10 parts by mass Solvent (MEK: toluene = 1: 1) 70 parts by mass

Example 2 A transfer foil 10 was obtained in the same manner as in Example 1 except that the adhesive layer composition was as follows.
・ <Adhesive layer composition>
Polyester resin P-170 (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name) 20 parts by mass Microsilica (average particle size 1.5 μm) 6 parts by mass Solvent (MEK: toluene = 1: 1) 70 parts by mass

  Example 3 A transfer foil 10 was obtained in the same manner as in Example 1 except that the thickness of the adhesive layer was 0.8 μm.

  (Example 4) A reflective layer is formed into a titanium oxide thin film having a thickness of 100 nm by a vacuum deposition method, and UVA (produced by Showa Ink Industry Co., Ltd., trade name of ultraviolet absorbing layer composition) is applied to the reflective layer surface as an ultraviolet absorbing layer composition. Example 1 except that the adhesive layer 17 is formed after forming the ultraviolet absorbing layer 23 by coating and drying at 100 ° C. so that the coating amount after drying with a gravure coater is 1 μm. In the same manner as described above, a transfer foil 10 was obtained.

Comparative Example 1 A transfer foil 10 was obtained in the same manner as in Example 1 except that the adhesive layer composition was as follows.
・ <Adhesive layer composition>
Polyester resin P-170 (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name) 20 parts by mass Microsilica (average particle size 0.5 μm) 4 parts by mass Solvent (MEK: toluene = 1: 1) 70 parts by mass

(Comparative Example 2) A transfer foil 10 was obtained in the same manner as in Example 1 except that the adhesive layer composition was as follows.
・ <Adhesive layer composition>
Polyester resin P-170 (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name) 20 parts by mass Microsilica (average particle size 0.5 μm) 15 parts by mass Solvent (MEK: toluene = 1: 1) 70 parts by mass

  Comparative Example 3 A transfer foil 10 was obtained in the same manner as in Example 1 except that the thickness of the adhesive layer was 1.0 μm.

(Evaluation, Results) Using the transfer foil 10 of the examples and comparative examples, transfer to a surface of a known credit card-sized IC card made of polyvinyl chloride with a known thermal printer, transferability such as foil breakage, The followability to the uneven surface was evaluated. In the IC card transferred using the transfer foil 10 of Examples 1 to 3, the hologram (transfer layer) transferred to the card surface has no transfer defects such as burrs and chips, and the unevenness of the IC chip and the antenna portion. The hologram also followed the surface well, had good transferability, and had excellent design and security. In the IC card transferred using the transfer foil 10 of Comparative Examples 1 and 3, the hologram (transfer layer) transferred to the card surface followed the uneven surface of the IC chip and the antenna portion. Cutting was bad and burr was frequently generated, and transferability was poor. In the IC card transferred using the transfer foil 10 of Comparative Example 2, the hologram (transfer layer) transferred to the card surface cannot follow the concave and convex surfaces of the IC chip and the antenna portion although the foil breakage is good. Foil chipping occurred frequently and was a defective product. In the IC card transferred using the transfer foil 10 of Example 4, the hologram (transfer layer) transferred to the card surface has no transfer defects such as burrs and chips, and is on the uneven surface of the IC chip and the antenna portion. In addition, a transparent hologram with good transferability, good design and security was transferred.
Furthermore, weather resistance was performed using a card in which a face photograph by a sublimation transfer method was printed on the surface of the IC card in advance. According to JIS-B-7753 (Sunshine carbon arc lamp type light resistance and weather resistance tester), the weather resistance test was conducted by visually comparing the color change of the printed material after 100 hours of irradiation with that before irradiation. When evaluated, no significant changes were observed.

It is sectional drawing of the transfer foil which shows one Example of this invention.

Explanation of symbols

11: Base material 13: Release layer 15: Release layer 17: Transfer layer 19: Adhesive layer 21: Other layers

Claims (5)

A transfer foil having at least a transfer layer and an adhesive layer on one surface of the substrate, the adhesive layer containing a heat-adhesive polyester resin and microsilica, and the heat-adhesive polyester A transfer foil, wherein the resin and the microsilica have a sea-island structure. The transfer foil according to claim 1, wherein a ratio of the heat-adhesive polyester resin and the microsilica in the adhesive layer is polyester resin: microsilica = 90 to 94: 6 to 10 on a mass basis. The transfer foil according to claim 1, wherein the microsilica has a particle size of 0.4 to 2 μm. The transfer foil according to claim 1, wherein the adhesive layer has a thickness of 0.4 to 0.8 μm. The transfer foil according to claim 1, further comprising an ultraviolet absorbing layer between the transfer layer and the adhesive layer.

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