JP3140820B2 - Hologram transfer foil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer foil (hologram transfer foil) for providing a hologram on a hardly adherent material such as a prepaid card.

[0002]

2. Description of the Related Art In a conventional hologram transfer foil, a thermoformable resin layer is provided on the surface of a mold having releasability, and a hologram plate is heated and pressed against the surface of the thermoformable resin layer to emboss fine irregularities of the hologram. A configuration is known in which a hologram-forming layer is formed by applying the hologram-forming layer, a reflective thin-film layer or the like is provided on the embossed surface of the hologram-forming layer, and a heat-sensitive adhesive layer is formed on the outermost surface of the transfer foil.

[0003] In particular, a hologram transfer foil requires a resin layer on the hologram forming layer to provide hologram irregularities to a certain thickness, so that the transfer layer is thicker than a normal transfer foil. However, when the thickness of the transfer layer is increased, the step difference from the surface of the transferred object becomes large after the transfer, and the transfer layer is easily peeled off. Therefore, the thickness of the adhesive layer is made thinner so that the thickness of the entire transfer layer does not become unnecessarily thick. Must be
Also, the adhesive layer is formed thin for the purpose of improving the foil breakage during the transfer.

[0004]

In recent years, in prepaid cards such as telephone cards, it has been required to partially form a hologram on the surface of the card for the purpose of preventing forgery. However, when a hologram is transferred and formed on a telephone card or the like using a conventional hologram transfer foil, the telephone card has a surface protective layer such as an OP varnish made of an ultraviolet-curable resin in order to prevent the surface from being damaged. Since the surface of the protective layer is non-polarized and contains wax, the adhesiveness is extremely poor, and the hologram layer as a transfer layer cannot have sufficient adhesion, and is particularly resistant to moisture. Also, there has been a problem that the transfer layer containing the hologram is easily peeled off due to poor heat resistance and the like.

[0005] It is easy to improve the adhesiveness by forming a thick adhesive layer of the hologram transfer foil. However, when the adhesive layer is thickened, the cutting of the foil usually deteriorates as described above, and the workability deteriorates. In addition, the step between the transfer layer and the surface of the transfer-receiving member becomes large, and it is easy to peel off with a nail or the like, which is not preferable.
Therefore, by simply forming the conventional transfer foil with a thick adhesive layer, it was not possible to obtain a hologram transfer foil that can be transferred to a poorly adhesive material, has good adhesion, and has good workability during transfer. .

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and is capable of transferring onto a poorly adhesive material, having good adhesion of a transfer layer after transfer, and improving workability during transfer. An object is to provide an excellent hologram transfer foil.

[0007]

The present invention provides (1) releasability.
At least hologram as a transfer layer on the surface of the base film
Hologram roll, in which a film forming layer and an adhesive layer are sequentially laminated.
In the photo foil, the hologram forming layer has the effect of the hologram.
The irregularities that appear are formed, and the adhesive layer is porous.
Made of heat-sensitive adhesive with matte surface
Hologram transfer foil, characterized in that (2) the adhesive layer
(1) wherein the thickness is 2 to 20 μm.
The hologram transfer foil according to any one of the preceding claims.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of the hologram transfer foil of the present invention. The hologram transfer foil 1 of the present invention shown in FIG. 1 is a hologram in which a release layer 4, a hologram forming layer 5, a reflective layer 6, and an adhesive layer 7 are sequentially laminated as a transfer layer 3 on the surface of a base film 2 having releasability. The transfer foil 1 is made of a heat-sensitive adhesive in which the inside of the adhesive layer 7 is porous and the surface is formed in a mat shape. Note that the transfer foil 1 of the present invention does not necessarily have all of the above-described configuration, and it is sufficient that at least the hologram forming layer 5 and the adhesive layer 7 made of a porous and mat-shaped heat-sensitive adhesive are provided.

The adhesive layer 5 used in the hologram transfer foil 1 of the present invention has a porous inside and a mat-like surface with irregularities. The inside of the adhesive layer 5 is preferably in a state where air bubbles having a degree of porosity of 0.05 to 2.5 μm are dispersed, and the degree of matting of the surface is preferably an Ra value of about 0.05 to 1 μm. or,
Although the thickness of the adhesive layer 7 varies depending on the type of the material having poor adhesion, it is preferably 2 to 20 μm, more preferably 3 to 20 μm.
７7 μm. If the thickness of the adhesive layer is less than 2 μm, it will not penetrate into the fine irregularities (1 to 2 μm in the case of an OP varnish made of an ultraviolet curable resin) of the transferred material, and the adhesive strength will be reduced, and the irregularities of about 2,000 mm will usually occur. If the adhesive layer cannot absorb the heat pressure applied during transfer to the relief pattern exhibiting the hologram effect, the damage cannot be prevented, and if the thickness of the adhesive layer exceeds 20 μm, the transferred object will not be transferred after the transfer. The step with the surface becomes large, and the transfer layer is easily peeled off.

The means for forming the inside of the adhesive layer 7 to be porous and the surface thereof to be mat-like is not particularly limited.
For example, the following means can be used. A heat-sensitive adhesive resin forming an adhesive layer is a solvent obtained by mixing a solvent having a good compatibility with a solvent having a low compatibility with the resin, and a solvent having a good compatibility with the solvent is more preferable. It is dissolved in a mixed solvent that is a highly volatile solvent, applied to the surface side of the hologram forming layer 5 (the surface of the reflective thin film layer 6), and the solvent is volatilized and evaporated. When a solvent for the resin is selected in this way, the heat-sensitive adhesive resin is dissolved in a compatible solvent in the early stage of drying, but if the compatible solvent volatilizes quickly, the compatibility is poor. As the amount of solvent increases, the inside of the resin layer undergoes layer separation between the poorly compatible solvent and the resin, and when the adhesive layer is completely dried, the poorly compatible solvent becomes a void and the entire resin layer becomes It is formed porous and the surface is also formed in a mat shape. After applying a coating material in which a heat-sensitive adhesive resin for forming an adhesive layer is dissolved in a solvent, the solvent is rapidly evaporated from the coated product at a high ambient temperature. In the case of such rapid drying, when the solvent evaporates, the heat of vaporization absorbs moisture inside the adhesive layer, and the water inside the adhesive layer becomes a void after drying, and the inside of the adhesive layer becomes porous. To form a mat-like surface.

As the heat-sensitive adhesive resin for forming the above-mentioned adhesive layer 7, a known resin can be used. For example, rubbers such as polyisoprene rubber, polyisobutylene rubber, styrene butadiene rubber, poly (meth) acrylate, poly (meth) acrylate, poly (meth) acrylate, butyl (meth) acrylate, poly (meth) acrylate (Meth) acrylates such as 2-ethylhexyl acrylate, polyvinyl ethers such as polyisobutyl ether, polyvinyl acetates such as polyvinyl acetate and vinyl chloride-vinyl acetate copolymer, polyacrylamide, polymethylol acrylamide, etc. Polyamide, vinyl chloride such as polyvinyl chloride, polystyrene, polyester, polychlorinated olefin, polyvinyl butyral, and others, vinyl acetate / octyl acrylate, vinyl acetate / butyl acrylate, vinylidene chloride / butyl acrylate, and the like. It is.

The solvent of the heat-sensitive adhesive used in the above-mentioned method is slightly different depending on the kind of the resin, but is generally a solvent having good compatibility with the adhesive resin (good solvent). , Methyl ethyl ketone, diisopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, methyl propyl ketone, diethyl ketone, diacetone alcohol, methyl cyclohexanone, methyl acetate, ethyl acetate butyl acetate, methylene chloride, ethyl ether, tetrahydrofuran, benzene, toluene, xylene, etc. On the other hand, as a poorly compatible solvent (poor solvent), n-butanol, isopropanol, n-propanol, n-pentanol, ethylene glycol and the like are used. The mixing ratio of these solvents may be appropriately selected so as to form the above-mentioned adhesive layer according to the type of the resin and the like. Further, rosin adhesive layer, ester gum, terpene resins, C ₅ petroleum resins, C ₉ petroleum resins, PCPD petroleum resins, styrene resins, alkylphenol resins, fillers terpene phenol, antioxidant Can be added for the purpose of a tackifier.

An example of a specific composition of a resin-coated heat-sensitive adhesive for forming the adhesive layer 7 of the hologram transfer foil of the present invention is shown below. [Composition of heat-sensitive adhesive resin coating] Concentration Composition Resin (Tg) (% by weight) Solvent (parts by weight) ・ PVC (PVC / PVC = 7/3) 20 * 1 20 ・ MMA-BMA ( (50 ° C) 40 * 2 14 · MMA (70 ° C) 40 * 3 10 The solvent in which the above resins are dissolved is * 1: toluene /
Ethyl acetate, * 2: Toluene / isopropanol, *
3: Toluene.

The above-mentioned adhesive composition is preferably diluted with a solvent described below, applied using a Clavia reverse coater, and then dried by blowing at room temperature to form an adhesive layer. Room temperature blast drying forms a mat-like surface,
More effective than heat drying. [Diluent solvent composition] (parts by weight) Toluene 10 Tolsac 21 n-butanol 20 Ethylene glycol 5

In the hologram transfer foil 1 of the present invention, as a means for forming a mat-like surface, for example, a composition obtained by dissolving an adhesive resin in a solvent may be applied, and then steam may be sprayed at a place where the composition is dried. When the adhesive layer is dried in this way, since the water vapor has low compatibility with the resin, the surface of the adhesive layer 7 is matted.

The base film 2 used in the transfer foil of the present invention
Any material may be used as long as it has releasability from the transfer layer 3. For example, a biaxially stretched polyethylene terephthalate film is most preferable in terms of dimensional stability, heat resistance, toughness, and the like. Films, polypropylene films, polyethylene films, polycarbonate films, cellophane, "Vinylon" (trademark) film, acetate films, nylon films, synthetic films such as polyvinyl alcohol films, polyamide films, polyamide imide films, and papers such as condenser paper are used. And the thickness is 6 to 12 μm
Is preferred.

The release layer 4 is a layer which is transferred to the surface of the transfer object after the transfer foil is transferred and becomes the outermost surface side. The release layer 4 is provided for the purpose of improving the release property and the foil cut property of the transfer layer. Various known materials can be used depending on the type of the base film 2. Examples of the material of the release layer 4 include polymethacrylate resin, polyvinyl chloride resin, cellulose resin, silicone resin, waxes mainly composed of hydrocarbons, polystyrene resin, chlorinated rubber, casein, various surfactants, and metal oxides. Among them, one type or a mixture of two or more types is used. In particular, the release layer 4 is preferably formed by appropriately selecting the material and the like so that the release force between the base film 2 and the transfer layer 3 is 1 to 5 g / inch (90 ° release). The release layer 4 can be formed on the surface of the base film 2 by a known method such as inking and coating.
A range of 1 to 1.0 μm is desirable.

A hologram is formed on the surface of the release layer 4. When the hologram is a reflection type relief hologram, as shown in FIG. 1, a hologram forming layer 5 for forming irregularities of a normal hologram, hologram irregularities 8 formed on the hologram forming layer 5, and a reflective thin film layer 6 are formed. And formed from In the hologram transfer foil 1 of the present invention, the hologram-forming layer is not particularly limited to the above-mentioned reflection-type relief hologram, but may be a diffraction grating or the like. The hologram-forming layer 5 can be selected from various resin materials such as a thermoplastic resin, a thermosetting resin, and an ionizing radiation-curable resin, and has a surface formed with concavities and convexities 8 on which hologram information is cast.

Examples of the thermosetting resin used for the hologram forming layer 5 of the reflection type relief hologram include unsaturated polyester resin, acrylic urethane resin, epoxy-modified acrylic resin, epoxy-modified unsaturated polyester resin,
Alkyd resin, phenolic resin, and the like, and
Examples of the thermoplastic resin include an acrylate resin, an acrylamide resin, a nitrocellulose resin, a polystyrene resin, and the like. These resins may be used alone or in combination of two or more of various isocyanate resins, metal soaps such as cobalt naphthenate and zinc naphthenate, peroxides such as benzoyl peroxide and methyl ethyl ketone peroxide, benzophenone, acetophenone, anthraquinone, naphthoquinone and azo. A heat or ultraviolet curing agent such as bisisobutyronitrile and diphenyl sulfide may be blended. Examples of the ionizing radiation-curable resin include oligomers of epoxy acrylate, urethane acrylate, and modified acrylic polyester, and monomers such as neopentyl glycol acrylate and trimethylolpropane triacrylate for the purpose of adjusting the crosslinking structure and viscosity. Are appropriately mixed. In the case of a reflection type relief hologram, the hologram forming layer 5 is preferably formed to have a thickness of about 0.5 to 20 μm.

The hologram-forming layer 5 can be formed by ink-coating on the surface of the above-mentioned release layer (in the case where no release layer is formed, directly on the surface of the substrate fill) by a known method. The hologram unevenness 8 varies depending on the type of resin of the hologram forming layer, but is provided on the hologram forming layer by a known means such as embossing. For example, in the case of using the ionizing radiation-curable resin, the coated resin is brought into close contact with the resin layer having the unevenness of the hologram in an uncured state, and is irradiated with ionizing radiation in the state and cured. I just need. The time when the unevenness 8 is provided on the hologram forming layer may be before or after the reflective thin film layer is formed. It is desirable that the hologram forming layer 5 has a resin Tg higher than the temperature at the time of thermal transfer.
Specifically, Tg is set to be between 100 and 200 ° C.

When the hologram of the transfer foil is formed as a reflection type, a metal thin film which reflects light is used as the reflective thin film layer 6 provided on the unevenness 8 of the hologram. A hologram effect thin film that expresses a hologram in combination with a hologram forming layer and does not conceal the lower layer is used, and can be appropriately selected and used according to the purpose and the like. As the metal thin film used in the case of the reflection hologram, specifically, Cr, T
i, Fe, Co, Ni, Cu, Ag, Au, Ge, A
1, Mg, Sb, Pb, Pd, Cd, Bi, Sn, S
It is a thin film formed by using a metal such as e, In, Ga, Rb and its oxides, nitrides, etc. alone or in combination of two or more kinds. Among the above metal thin films, Al, Cr,
Ni, Ag, Au and the like are particularly preferable, and the film thickness is 10 to 10.
It is in the range of 10,000, preferably 200 to 2,000.

The hologram effect thin film used in the case of a transparent hologram can be made of any material as long as it is a light-transmitting material capable of exhibiting a hologram effect. For example, there is a transparent material having a different refractive index from the resin of the hologram forming layer 5. The refractive index in this case may be larger or smaller than the resin of the hologram formation layer, but the difference in the refractive index is preferably 0.1 or more, more preferably 0.5 or more.
And 1.0 or more is optimal. In addition to the above, there is a reflective metal thin film of 200 ° or less. For example, the following materials can be used as such a hologram effect thin film.

A transparent continuous thin film having a higher refractive index than the hologram-forming layer is classified into a transparent one in the visible region shown in Table 1 and a transparent one in the infrared or ultraviolet region shown in Table 2. In the table, n indicates a refractive index.

[Table 1]

[0024]

[Table 2]

Table 3 shows a transparent ferroelectric substance having a higher refractive index than the hologram forming layer.

[Table 3]

Table 4 shows a transparent continuous thin film having a smaller refractive index than the hologram forming layer.

[Table 4]

Reflective metal film having a thickness of 200 ° or less The reflective metal thin film has a complex refractive index, and the complex refractive index: n
= N-iK. n indicates a refractive index, and K indicates an absorption coefficient. The material of the reflective metal thin film used in the present invention is shown in Table 5, and the above n and K are shown together with the table.

[Table 5] As other materials, Sn, In, Te, Fe, Co,
Zn, Ge, Pb, Cd, Bi, Se, Ga, Rb and the like can be used. Also, oxides of the above-listed metals,
Nitride and the like can be used alone or in combination of two or more.

Resin having a different refractive index from the hologram forming layer The resin having a higher or lower refractive index than the resin of the hologram forming layer may be used. Table 6 shows these examples.

[Table 6] In addition to the above, a general synthetic resin can be used, but a resin having a large refractive index difference from the hologram forming layer 5 is particularly preferable.

Laminated body obtained by appropriately combining the above-mentioned materials The combination of the above-mentioned materials is arbitrary, and the vertical relationship of each layer in the layer structure is arbitrarily selected. Of the above-mentioned thin film layers, the thickness of the thin film layer is 20
Although it is 0 ° or less, the thickness of the thin film layers of and may be a transparent region of a material forming the thin film, and is generally preferably 10 to 10000 °, more preferably 1 to 10000 °.
It is 00 to 5000 °. In order to provide the reflective thin film layer 6 on the hologram forming layer 5, the thin film layer
In the case of a material of the general formula (I), a general method such as vacuum evaporation, sputtering, reactive sputtering, ion plating, and electroplating is used. When the thin film is made of the above material, a general coating method is used.

FIG. 2 is an explanatory view showing a transfer example using the hologram transfer foil of the present invention. When the transfer is performed using the hologram transfer foil of the present invention, as shown in FIG. 2, the hologram transfer foil 1 of the present invention is applied to the surface of the transfer object 9 to which the design of the hologram is to be imparted by the adhesive layer 7 of the transfer foil. The portions of the transfer foil 1 where the design of the hologram is to be imparted (the base film side) are heated and pressed with a pressing plate 10 or the like to melt and bond the desired portion of the adhesive layer. Thereafter, when the transfer foil is peeled off, only the desired portion of the transfer layer is transferred, and the hologram design can be imparted to the surface of the transfer object.

The hologram transfer foil of the present invention can be transferred to a wide range of objects to be transferred, and the object to be transferred is not particularly limited, but a printed material having a surface coated with UVOP varnish (for example, a prepaid card such as a telephone card) and the like. It can be optimally used as a transfer foil for the purpose of providing a hologram design. This is because when trying to transfer a hologram to a surface of a printed material coated with an OP varnish such as an ultraviolet-curable resin, the surface of the printed material coated with the ultraviolet-curable resin is actually fine irregularities. Since the adhesive layer of the transfer foil of the present invention is inserted into the irregularities and the inside of the adhesive layer is formed porous, the inside of the adhesive layer is Is easily melted, and the adhesive resin is uniformly filled into the irregularities on the surface of the transfer object having fine irregularities, so that the adhesiveness after transfer is very good.

The present invention will be described in more detail with reference to specific examples of the present invention. Examples 1 and 2 A hologram transfer foil on which an adhesive layer shown in Table 7 below was formed was prepared, and the foil cut property and adhesion of the transfer foil were evaluated.
Table 7 shows the obtained results. Comparative Example For comparison, the same resin as in Example 2 was used, an adhesive layer was formed using only a good solvent as a solvent, and a hologram transfer foil was prepared in the same manner as in the example to evaluate the foil cutting property and adhesion. did. Table 7 shows the obtained results.

[0033]

[Table 7] * 1: Evaluation of adhesion ○ ・ ・ ・ No cell tape peeling (90 ° peeling), no hologram image disorder × ・ ・ ・ Poor cell tape peeling (90 ° peeling), hologram image disorder due to poor adhesion

[0034]

As described above, the hologram transfer foil of the present invention uses a porous heat-sensitive adhesive having a mat-like surface for the adhesive layer. Even when the adhesive layer is formed thick, the foil is cut easily and the workability is not reduced, so that the adhesive layer can be formed thick and the adhesive strength can be improved. Since the unevenness of the surface of the adhesive layer formed in a mat shape is cut into the fine unevenness of the surface of the transfer receiving body and melted, a sufficient adhesive force is obtained between the transfer layer and the transfer receiving body. In this case, since the inside of the adhesive layer is formed to be porous, the volume of the adhesive layer after transfer (after heating and pressing) is reduced, and the thickness of the transfer layer may become unnecessarily thick. Therefore, it has an effect of preventing the transfer layer from being easily peeled off by a nail or the like.

Further, since the adhesive layer of the hologram transfer foil of the present invention is porous, the adhesive layer absorbs the pressure caused by the heating and pressurizing during the transfer, so that the unevenness of the hologram caused by the pressure is reduced. Since damage is prevented, the hologram effect is not reduced. Further, since the surface of the transfer layer is formed uniformly, an excellent hologram effect can be obtained. The hologram transfer foil of the present invention has good internal air escape during transfer due to the unevenness of the adhesive layer surface,
It has various effects, such as being able to perform good transfer without foaming or air bubble accumulation by air.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one example of a hologram transfer foil of the present invention.

FIG. 2 is an explanatory diagram in a case where transfer is performed using a hologram transfer foil of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hologram transfer foil 2 Base film 3 Transfer layer 5 Hologram formation layer 7 Adhesive layer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B44C 1/17 G03H 1/18

Claims (2)

(57) [Claims] 1. A hologram transfer foil comprising at least a hologram forming layer and an adhesive layer sequentially laminated as a transfer layer on the surface of a releasing base material film, wherein the hologram forming layer is
The hologram has irregularities that exhibit the effect.
A hologram transfer foil , wherein the adhesive layer is made of a heat-sensitive adhesive having a porous surface and a mat-like surface. 2. The hologram transfer foil according to claim 1, wherein the thickness of the adhesive layer is 2 to 20 μm.