JPH08110750A - Hologram layered product - Google Patents

Abstract

PURPOSE: To quickly and stably provide a hologram layered product excellent in chemical resistance, particularly alcohol resistance. CONSTITUTION: In this hologram layered product having a hologram layer 2 and a transparent thin film layer 3 formed on a substrate 1, the transparent thin film layer 3 is made of titanium oxide and zirconium oxide at the mixing mole percentage of 50:50 to 95:5, and the thickness of the thin film is set to 5-200nm in particular.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a wide variety of images used for decoration and forgery prevention on the surfaces of credit cards, cash cards, book covers, record jackets, video cases, etc. And a hologram laminate having a hologram layer and a transparent thin film layer formed on a base material.

[0002]

2. Description of the Related Art As one means for forming a hologram on a card or the like, a transparent hologram for forming a hologram without hiding a pattern on the card or the like is becoming the mainstream among holograms. As a basic technique thereof, a hologram laminated body in which a hologram layer and a transparent thin film layer are formed on a substrate is known from JP-A-61-254975.

The material used as the transparent thin film layer of the hologram laminate is zinc sulfide (ZnS) having a high refractive index.
S), titanium oxide (TiO ₂ ), zinc oxide (ZnO),
Zirconium oxide (ZrO ₂ ) and the like satisfy the required characteristics. Among them, zinc sulfide (ZnS) is industrially and functionally excellent and is preferably used because it has a sublimation property and enables high-speed vapor deposition.

However, zinc sulfide has a drawback that it is inferior in chemical resistance, particularly in alcohol resistance, because it peels off, cracks or whitens when immersed in a chemical.

Since various cards, books, video cases, etc. in which holograms are used are used by humans on a daily basis, they are very often exposed to acids, alkalis, and alcohols, and the holograms themselves are chemically resistant. Must have
Among them, alcohols have the most opportunities on a daily basis, and the alcohol resistance of holograms is one of the most important chemical resistances, which has been a fatal defect when using zinc sulfide as a transparent thin film layer. . Also, the adhesiveness was insufficient.

On the other hand, zinc oxide (ZnO) has a problem in chemical resistance like zinc sulfide, since the thin film is corroded by an acid. Furthermore, when a thin film is formed by vacuum evaporation, the evaporation source becomes hot, so that zinc oxide is easily decomposed. Even when vapor deposition is carried out by re-oxidation using a reactive vapor deposition method or the like, the vapor deposition rate is very slow, so that the productivity is extremely low, and only expensive and non-chemical resistant materials can be produced.

On the other hand, titanium oxide (TiO ₂ ) is a ceramic, although it is stable against chemicals, and is used as an evaporation source in order to obtain a practical evaporation rate when forming a thin film by vacuum evaporation. You must use an electron beam. However, titanium oxide has good thermal conductivity as a ceramic, and evaporates while being entirely melted in the crucible during electron beam irradiation, resulting in a large heat loss at the evaporation source,
Further, a high vapor deposition rate cannot be obtained due to the influence of cooling the crucible. Therefore, the productivity is industrially low and the cost is high.

Like titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ) which is stable to chemicals,
Among ceramics, the melting point is high and the thermal conductivity is low, and only the electron beam irradiation region evaporates in a semi-molten state, so the vapor deposition is unstable. Furthermore, since the vapor pressure is low, a high vapor deposition rate cannot be obtained. In order to force vapor deposition at high speed, the power of the electron beam must be increased and the vapor deposition source must be heated to a high temperature, which often causes splashes and the like, which further deteriorates the vapor deposition characteristics of zirconium oxide that vaporizes in semi-melting. Besides, pinholes may be formed in the base material and the hologram layer formed on the base material, and radiant heat may seriously damage the hologram. Therefore, the productivity is low and the cost is high.

Zirconium oxide has a maximum refractive index of 2.05 and a refractive index of about 1.9 depending on the thin film forming conditions.
0.2 compared to 3 to 2.35 zinc sulfide and titanium oxide
It is smaller than 5 and the difference in refractive index between the layer on which the hologram is formed and the resin film substrate is small, so that it is difficult to recognize the hologram image.

On the other hand, since zirconium oxide has a negative inhomogeneity, in the field of optical multilayer thin films such as optical filters, in order to improve the inhomogeneity of zirconium oxide,
A zirconium oxide-based material obtained by mixing zirconium oxide with titanium oxide showing a positive inhomogeneity in a weight ratio of 9: 1 is used and is commercially available. Since this mixed material is a zirconium oxide-based material, the refractive index thereof is slightly higher than that of zirconium oxide and improved to about 2.10, but it has the same drawbacks as zirconium oxide.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a hologram laminate having excellent chemical resistance, particularly alcohol resistance. It is to provide such a hologram laminated body at high speed and stably.

[0012]

In order to solve this problem, the present invention provides a hologram laminate having a hologram layer and a transparent thin film layer formed on a substrate, wherein the transparent thin film layer comprises:
It is composed of titanium oxide and zirconium oxide having a mixing ratio of 50:50 to 95: 5 in terms of a molar ratio, and particularly has a film thickness of 5 to 2
Provided is a hologram laminate, which is a thin film having a thickness of 00 nm.

The present invention will be described in detail below. As the substrate in the present invention, a thermoplastic resin such as polyvinyl chloride, polyvinyl acetate, acrylic, polystyrene, polycarbonate, polyester, melamine, epoxy, or a polymer thereof, and a thermoforming substance having a radically polymerizable unsaturated group. Etc. can be used, these resins etc. alone,
Alternatively, a mixture, a mixture obtained by laminating and curing, or a laminate may be used.

As a general method, the hologram layer is formed by heating and pressing the surface of the base material using a hologram stamper. Besides, it can be formed by using a technique such as photolithography and is not particularly limited.

The transparent thin film layer in the present invention is a thin film of a metal oxide composed of titanium oxide and zirconium oxide, and the mixing ratio of titanium oxide and zirconium oxide in this thin film is 50:50 to 95: 5 in molar ratio. A thin film is used in the range of.

As a material for obtaining the thin film, a mixture of powders of titanium oxide and zirconium oxide is used as a vapor deposition material. This mixture powder may be previously press-molded and preheated to be sintered into an appropriate shape. The mixing ratio of the vapor deposition material is such that the mixing ratio of titanium oxide and zirconium oxide in the thin film is 50:50 to 9 in molar ratio.
Within the range of 5: 5, there is no particular problem and it can be set arbitrarily.

The method for obtaining the above-mentioned thin film is not particularly limited, but a vacuum vapor deposition method or a vapor deposition method in a gas,
A vapor deposition method in which a vapor deposition material is heated to form a thin film on a substrate, such as an ion plating method, is preferable. An electron beam is preferably used as the vapor deposition material heating means.

The thickness of the transparent thin film layer in the present invention is 20.
It is preferably 0 nm or less. When the film thickness is 200 nm or more, the flexibility of the transparent thin film layer is poor, cracks are generated in the transparent thin film layer, the decorative property is poor, and the reliability of forgery prevention is poor.

[0019]

[Function] The metal oxide thin film composed of titanium oxide and zirconium oxide is composed of titanium oxide and zirconium oxide, which are chemically very stable, and is also chemically stable as a thin film of a mixture. Excellent in performance. When the mixing ratio of titanium oxide and zirconium oxide of the thin film is 50:50 to 95: 5 in terms of molar ratio, the transparent thin film layer has a refractive index of 2.2 to 2.3, which is similar to that of titanium oxide. The hologram image can be easily recognized visually.

As a vapor deposition method, when the mixture powder is heated by a vapor deposition material heating means, particularly by irradiation with an electron beam for heating, it is melted in a wider area than the electron beam irradiation region. However, since zirconium oxide having a low thermal conductivity is mixed, heat is difficult to be transmitted, and the temperature becomes high locally only near the electron beam irradiation region. Therefore, the titanium oxide and the zirconium oxide can be locally evaporated without being entirely melted in the crucible. In this way, since it is evaporated without melting in the crucible as a whole, the heat loss in the evaporation source is small, and since the thermal conductivity is low, it is less affected by the cooling of the crucible. In contrast, high deposition rates are obtained. Further, since vapor deposition is carried out by mixing with titanium oxide having a relatively low melting point, the power of electron beam can be suppressed as compared with vapor deposition of zirconium oxide alone. Therefore,
The influence of radiant heat from the evaporation source and splash can be reduced, and damage to the resin film substrate and the hologram layer formed thereon can be prevented.

[0021]

EXAMPLES The present invention will be described in more detail by way of examples. Regarding the evaluation of the hologram laminate, regarding the chemical resistance, the alcohol resistance that has the most chances to come in contact with each other on a daily basis,
The acid resistance and alkali resistance were evaluated. The conditions for the chemical resistance test are
2 in each aqueous solution of 50% ethanol for alcohol tolerance test, 5% acetic acid for acid / alkali resistance, 1% sodium carbonate
After soaking for 4 hours, visual appearance evaluation was performed. Regarding the adhesiveness, an adhesive tape peeling test was conducted. The mixing ratio of the deposited film is EPMA (Electoron Probe Micro Analize).
r) to measure XPS (X-ray Photoe
The bonding state of titanium oxide and zirconium oxide in the thin film was analyzed by electron spectroscopy. From the results of XPS, it was found that titanium oxide and zirconium oxide were not bonded in the thin film, and the thin film was formed in a mixed form. The refractive index of the thin film was measured by an ellipsometer (photometric wavelength λ = 633 nm). The results of the examples are shown in Table 1.

Example 1 A hologram layer was formed by using a polyester film having a thickness of 25 μm as a base material and using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin in a weight ratio of 5: 2 thereon. Then, a thin film of a metal oxide composed of titanium oxide and zirconium oxide having a mixing ratio of titanium oxide and zirconium oxide of 90:10 was formed as a transparent thin film layer on the relief forming surface of the hologram layer by electron beam heating. It was formed by vapor deposition. FIG. 1 shows a sectional view of the hologram laminate. During the vapor deposition, there was no splash and stable vapor deposition was possible, and there was no damage to the hologram layer due to radiant heat. The thickness of this thin film is 120 nm, and the refractive index is
It was 2.39 to 2.33. With respect to chemical resistance, even when immersed in alcohol, acid, or alkali, the hologram image was clear as it was before immersion.

Example 2 A 25 μm-thick polyester film is used as a substrate, and a hologram layer is formed thereon by using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride vinyl chloride resin in a weight ratio of 5: 2. Then, on the relief forming surface of the hologram layer, as a transparent thin film layer, a thin film of a metal oxide composed of titanium oxide and zirconium oxide having a mixing ratio of titanium oxide and zirconium oxide of 80:20 is formed by electron beam heating. did. During the vapor deposition, there was no splash and stable vapor deposition was possible, and there was no damage to the hologram layer due to radiant heat. The thickness of this thin film was 120 nm, and the refractive index was 2.36 to 2.33. With respect to chemical resistance, even when immersed in alcohol, acid, or alkali, the hologram image was clear as it was before immersion.

Example 3 A hologram film was formed by using a polyester film having a thickness of 25 μm as a base material and using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin in a weight ratio of 5: 2 thereon. Then, on the relief forming surface of the hologram layer, as a transparent thin film layer, a thin film of a metal oxide composed of titanium oxide and zirconium oxide with a mixing ratio of titanium oxide and zirconium oxide of 70:30 was deposited by electron beam heating. Formed. During the vapor deposition, there was no splash and stable vapor deposition was possible, and there was no damage to the hologram layer due to radiant heat. The thickness of this thin film was 120 nm, and the refractive index was 2.32 to 2.28. With respect to chemical resistance, even when immersed in alcohol, acid, or alkali, the hologram image was clear as it was before immersion.

Example 4 A 25 μm-thick polyester film was used as a substrate, and a hologram layer was formed thereon by using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin in a weight ratio of 5: 2. Then, a thin film of a metal oxide composed of titanium oxide and zirconium oxide with a mixing ratio of titanium oxide and zirconium oxide of 60:40 was deposited as a transparent thin film layer on the relief forming surface of the hologram layer by electron beam heating. Formed. During the vapor deposition, there was no splash and stable vapor deposition was possible, and there was no damage to the hologram layer due to radiant heat. The thickness of this thin film was 120 nm, and the refractive index thereof was 2.29 to 2.26. With respect to chemical resistance, even when immersed in alcohol, acid, or alkali, the hologram image was clear as it was before immersion.

Example 5 A hologram film was formed by using a polyester film having a thickness of 25 μm as a base material and using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin in a weight ratio of 5: 2 thereon. Then, a thin film of a metal oxide composed of titanium oxide and zirconium oxide with a mixing ratio of titanium oxide and zirconium oxide of 50:50 was formed as a transparent thin film layer on the relief forming surface of the hologram layer by electron beam heating. It was formed by vapor deposition. During the vapor deposition, there was no splash and stable vapor deposition was possible, and there was no damage to the hologram layer due to radiant heat. The thickness of this thin film was 120 nm, and the refractive index was 2.27 to 2.23. With respect to chemical resistance, even when immersed in alcohol, acid, or alkali, the hologram image was clear as it was before immersion.

<Comparative Example 1> A polyester film having a thickness of 25 μm was used as a base material, and a hologram resin layer was formed thereon with a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin in a weight ratio of 5: 2. On the relief forming surface of the hologram layer, a transparent thin film layer containing titanium oxide and zirconium oxide at a molar ratio (outside the range of the present invention) of 30: 7.
A thin film of a metal oxide of 0 of titanium oxide and zirconium oxide was deposited by electron beam heating. During the vapor deposition, the vapor deposition was stable without splash, but some damage to the hologram layer due to radiant heat was observed. The thickness of this thin film is 120 nm, and the refractive index is 2.10 to 2.05.
Met. However, the hologram image was slightly unclear as compared with the examples. The chemical resistance was the same as before immersion even when immersed in alcohol, acid or alkali.

<Comparative Example 2> A 25 μm-thick polyester film was used as a base material, and a hologram layer was formed thereon by using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin in a weight ratio of 5: 2. A transparent thin film layer is formed on the relief forming surface of the hologram layer, and the mixing ratio of titanium oxide and zirconium oxide is a molar ratio (outside the range of the present invention) of 10:
A thin film of metal oxide 90 consisting of titanium oxide and zirconium oxide was formed by vapor deposition by electron beam heating. Splash was observed during vapor deposition, and damage to the hologram layer due to radiant heat was observed. The thickness of this thin film was 120 nm, and the refractive index was 2.00 to 1.95. But,
The hologram image was unclear as compared with the examples. The chemical resistance was the same as before immersion even when immersed in alcohol, acid or alkali.

Comparative Example 3 A hologram layer was formed by using a polyester film having a thickness of 25 μm as a base material and using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin in a weight ratio of 5: 2 thereon. Then, a thin film of zinc sulfide ZnS was formed as a transparent thin film layer by electron beam heating on the relief forming surface of the hologram layer. There was no splash during vapor deposition, and there was no damage to the hologram layer due to radiant heat. The thickness of this thin film is 120 nm, and the refractive index is
It was 2.30-2.27. Although the hologram image was clear, the chemical resistance was such that after immersion in alcohol, many fine cracks were formed and the transparent thin film layer was whitened.

Comparative Example 4 A hologram film was formed by using a polyester film having a thickness of 25 μm as a base material and using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin in a weight ratio of 5: 2 thereon. Then, a thin film of zinc oxide was vapor-deposited by electron beam heating as a transparent thin film layer on the relief forming surface of the hologram layer. There was no splash during vapor deposition, and there was no damage to the hologram layer due to radiant heat.
The thickness of this thin film is 120 nm, and the refractive index is 1.9.
It was 1-1.85. The holographic image is unclear,
Regarding the chemical resistance, it was found that the transparent thin film layer was obviously immersed in the acid after the immersion.

Comparative Example 5 A hologram layer was formed by using a polyester film having a thickness of 25 μm as a base material and using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin at a weight ratio of 5: 2 thereon. Then, a thin film of a metal oxide made of zirconium oxide was formed as a transparent thin film layer by electron beam heating on the relief forming surface of the hologram layer by vapor deposition. Many splashes were seen during the vapor deposition, and the damage caused by radiant heat as if the hologram layer had been melted was clearly seen. The thickness of this thin film was 120 nm, and the refractive index thereof was 1.95 to 1.88. Compared to the examples,
The hologram image was unclear. The chemical resistance was the same as before immersion even when immersed in alcohol, acid or alkali.

Comparative Example 6 A hologram film was formed by using a polyester film having a thickness of 25 μm as a base material and using a mixed resin prepared by mixing an acrylic resin and a vinyl chloride / vinyl chloride resin at a weight ratio of 5: 2 thereon. Then, on the relief forming surface of the hologram layer, a thin film of a metal oxide made of titanium oxide was formed by vapor deposition by electron beam heating as a transparent thin film layer. However, the vapor deposition rate was about 70% as compared with the example. There was no splash during vapor deposition and no damage to the hologram layer due to radiant heat was observed. The film thickness of this thin film was 120 nm, and the refractive index thereof was 2.35 to 2.30. However, the hologram image was clear as in the example. The chemical resistance was the same as before immersion even when immersed in alcohol, acid or alkali. The above results are summarized in Table 1.

[0033]

[Table 1]

[0034]

As described above, according to the present invention, the transparent thin film layer of the hologram laminated body in which the hologram layer and the transparent thin film layer are formed on at least one surface of the resin film substrate has a mixing ratio of mol. By using a metal oxide thin film composed of titanium oxide and zirconium oxide having a ratio within the range of 50:50 to 95: 5, it has excellent chemical resistance, can withstand daily harsh use environments, and has flexibility. Therefore, it is possible to provide a hologram laminate having excellent decorativeness and reliability at high speed and stably.

Further, according to the present invention, the thickness of the transparent thin film layer made of titanium oxide and zirconium oxide is 5 to 200.
By setting the thickness to nm, it is possible to obtain a hologram laminate which is flexible, has no cracks in the transparent thin film layer, and is excellent in decorativeness and reliability.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a hologram laminate according to the present invention.

[Explanation of symbols]

 1 ... Polyester film 2 ... Hologram layer 3 ... Vapor deposition film (transparent thin film layer)

Claims (2)

[Claims] 1. A hologram laminate comprising a hologram layer and a transparent thin film layer formed on a base material, wherein the transparent thin film layer and titanium oxide are mixed in a molar ratio of 50:50 to 95: 5. A hologram laminate, which is a thin film made of zirconium. 2. The hologram laminate according to claim 1, wherein the transparent thin film layer has a thickness of 5 to 200 nm.