JPH05197323A - Transparent reflection layer forming method and production of hologram forming body - Google Patents

Abstract

PURPOSE:To provide a method which forms a transparent reflection layer made of a metal compound on the surface of a resin without damaging the resin itself and a method which produces a hologram forming body having the transparent reflection layer, which has the high adhesion to the resin and has a good reflection property or the like, without affecting on the fine rugged pattern of a hologram on the surface. CONSTITUTION:A base material 8 provided with the fine ruggedness 10 on the surface and made of the resin is set in a prescribed position in a vapor deposition vessel 1, and the pressure in the vapor deposition vessel 1 is reduced to control the degree of vacuum to 10<-5> to 10<-6>Torr, thereafter, gaseous oxygen is introduced from a gas introducing tube 7, and metallic titanium 2 of a heat evaporation source 3 is heated at an arbitrary temperature and evaporated to perform vapor-deposition for a prescribed time, thereby forming a transparent reflection film 9 made of a titanium oxide 2 on the surface of the resin layer. The transparent reflection layer 9 is formed on the base material, where the relief of a hologram is provided on the fine ruggedness 10, by the forming method to produce a hologram forming body 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a transparent reflective layer of a metal compound on the surface of a resin, and a method for producing a hologram forming body using the method.

[0002]

2. Description of the Related Art In recent years, transparent hologram layers have been used as an example of a transparent reflection layer, and the features such as a watermark effect due to their excellent design and transparency can be used to prevent forgery of security products. It is used for displays and decorations. The hologram forming body is formed so as to exhibit a hologram effect by providing fine unevenness on the surface of the base material by duplicating the interference fringe pattern of the hologram, but since it is easy to process and inexpensive, etc. A hologram forming body using a resin as a base material has been put into practical use as a mass-produced product. As the hologram forming body, for example, a thermoplastic resin is used as a base resin, and after the fine unevenness of the hologram is provided on the surface of the thermoplastic resin by means of heating embossing or the like, a metal compound is used as a hologram effect thin film on the surface of the fine unevenness. There is known a structure in which the transparent reflection layer of 1 is provided.

As a transparent reflective layer of a conventional hologram-formed body, one which exhibits a hologram effect in combination with the above-mentioned base resin and does not hide the lower layer is used, and a high refractive index thin film such as a metal oxide or a metal sulfide is used. It is well known that, in the case of a metal compound as a method for forming the transparent reflective layer, general thin film forming methods such as vacuum deposition, sputtering, reactive sputtering, ion plating, and electroplating are used. (For example, JP-A-61-272772.
No.

[0004]

When a transparent reflective layer made of a metal compound such as a metal oxide or a metal nitride is attempted to be formed on a resin surface surely and efficiently, energy such as sputtering or ion plating is actually required. It is necessary to use big means of. However, when the material of the base material itself is a resin, if the energy during the formation of the transparent reflective layer is large, the damage given to the resin itself is large, and especially when the transparent reflective layer is formed after forming fine irregularities on the surface. Since the fine unevenness is formed by heating embossing or the like, there is a defect that the fine unevenness on the surface disappears or the shape of the fine unevenness changes during the formation of the transparent reflective layer,
Further, even when the fine concavo-convex is formed after forming the transparent reflective layer on the fine concavo-convex, there is a problem that the reproducibility of the program image is poor because the deterioration of the resin itself cannot be avoided.

Therefore, from the viewpoint of reproducibility of the hologram image, the transparent reflection layer is limited to one which can be formed on the resin surface under mild conditions (without affecting the hologram image). Therefore, in the actual production of the hologram forming body, a transparent reflecting layer is formed on the surface of the resin base material by a sublimation method using a material having a sublimation property such as zinc sulfide (ZnS).

However, ZnS formed by the sublimation method
The transparent reflective layer of has lower adhesion to the resin layer than the transparent reflective layer formed by other means such as vapor deposition, sputtering, or ion plating, and the hologram-formed body is easily peeled off by heat such as post-processing. In addition, there is a problem that the transparent reflection layer itself becomes white due to thermal deterioration, and there is a problem that heat resistance and durability are low.

Further, not only the transparent reflection layer of such a transparent hologram forming body, but in general, when a transparent reflection layer is formed on the surface of a resin, transparent reflection layers of various metal compounds can be formed without damaging the resin itself. As a forming method, no industrially practical method has hitherto been proposed.

The present invention is intended to solve the above-mentioned drawbacks of the prior art, and provides a method for forming a transparent reflection layer of a metal compound on the surface of a resin without damaging the resin itself, and to provide the method on the surface. An object of the present invention is to provide a method for producing a hologram-formed body having a transparent reflection layer having excellent physical properties such as adhesion to resin, reflectivity and the like, heat resistance and durability without affecting the fine irregularities of the provided hologram. And

[0009]

The method for forming a transparent reflective layer of the present invention is a method for forming a transparent reflective layer and fine irregularities on a surface of a base resin, wherein the base resin is exposed to a vacuum in an oxygen or / and nitrogen atmosphere. In this state, a metal is used as an evaporation source to perform vapor deposition on the surface of the resin, and a transparent reflective layer of a metal compound composed of an oxide or / and a nitride of the metal is formed on the surface of the resin before forming the transparent reflective layer. Alternatively, it is characterized by providing fine irregularities on the resin surface after formation.

Further, the method for producing a hologram-formed body of the present invention comprises forming a hologram having at least fine irregularities of the hologram provided on the surface of the base resin and a transparent reflection layer made of a metal compound formed on the surface of the fine irregularities. In the method for manufacturing a body, the transparent reflection layer is formed by using the above-described forming method.

In the above-mentioned method for producing a hologram forming body, it is preferable that titanium is used as a metal and the atmosphere is oxygen atmosphere to perform vapor deposition on the surface of the base resin to form a transparent reflection layer of titanium oxide on the surface of the resin. ..

[0012]

The method of the present invention does not directly heat a metal compound such as a metal oxide or / and a nitride, but deposits the metal as an evaporation source. Therefore, the metal is heated at a relatively low heating temperature as compared with the metal compound. It is possible to evaporate. Then, the evaporated metal becomes a nitride or an oxide before it reaches the base material resin of the adherend by reacting with oxygen or nitrogen in the atmosphere, and the surface of the base material is not a metal film but a metal oxide or a nitride or It is formed as a film of a mixture of oxide and nitride.

As described above, since the vapor deposition temperature is low and the transparent reflection layer can be formed with low energy, the thermal damage to the resin is small, and the fine irregularities formed on the surface of the resin disappear or are deformed. The transparent reflective layer can be formed without any trouble. Therefore, the range of materials that can be used as the material of the transparent reflection layer is widened, and since the vapor deposition film is firmly attached to the surface of the resin layer, the adhesion is good and there is no risk of the transparent reflection layer peeling off. Further, when the method for forming the transparent reflection layer is used for forming the transparent reflection layer of the hologram forming body, it has excellent hologram image reproducibility without deteriorating the fine relief of the hologram relief and the base resin itself. A hologram former is obtained. Further, due to the heat resistance of the transparent reflection layer, the heat resistance of the fine irregularities of the hologram is also improved, and the transparent reflection layer protects the fine irregularities from post-processing to which heat is applied, long-term heating, etc., and prevents deterioration of the image due to heat. In particular, when titanium is used as the metal and the transparent reflective layer of the hologram forming body is formed by vapor deposition in oxygen atmosphere, the titanium oxide film has good optical characteristics such as refractive index, transmittance and reflectance. Therefore, it is possible to obtain a hologram forming body having excellent image reproducibility, optical characteristics, and heat resistance and durability.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a schematic diagram for explaining an example of the method for forming a transparent reflective layer of the present invention. In this embodiment, a case where a transparent reflection layer is formed on a transparent hologram forming body will be described as an example.

As a device used in the method for forming a transparent reflective layer of the present invention, for example, a device as shown in FIG. 1 can be used. In this apparatus, a metal 2 serving as a vapor deposition source is provided in a vapor deposition container 1.
Has a heating / evaporating section 3 for evaporating the metal 2. The heating / evaporating section 3 is provided with an electron beam (EB) heating device as a heating means or the like for allowing the metal 2 to evaporate. Exhaust pipes 4 and 5 for evacuating the inside of the container 1 are provided, the exhaust pipes 4 and 5 are connected to an exhaust device 6 such as an exhaust pump, and the vapor deposition container 1 has an atmosphere such as oxygen or nitrogen. A gas introduction pipe 7 for introducing gas is provided. Further, the vapor deposition device is provided with a device for supplying and winding a roll-shaped resin sheet, and is configured to perform vapor deposition continuously.
The inside of the vapor deposition container is divided into a vapor deposition chamber and a winding chamber, and the respective chambers are formed so as to have different normal pressure reduction states.

FIG. 2 is a longitudinal sectional view showing a hologram forming body manufactured by the method for forming a transparent reflecting layer of the present invention. As shown in FIG. 2, the method of the present invention is a method of forming the fine irregularities 10 and the transparent reflection layer 9 on the surface of the base resin 8, and in order to form this transparent reflection layer 9 on the base resin 8, First, Fig. 1
As shown in, a base resin 8 having fine relief relief patterns 10 on the surface thereof is set at a predetermined position inside the vapor deposition container 1. Next, after depressurizing the inside of the vapor deposition container 1 to adjust the degree of vacuum to 10 ⁻⁵ to 10 ⁻⁶ Torr, an atmosphere gas of oxygen and / or nitrogen gas is introduced from the gas introduction pipe 7 to introduce the metal of the heating / evaporating unit 3. When heated to an arbitrary temperature to evaporate and perform vapor deposition for a predetermined time, the evaporated metal reacts with the gas in the atmosphere to become a metal compound composed of a metal oxide or / and a nitride, and is deposited on the surface of the base resin 8. The metal compound film is formed by condensation and precipitation, the transparent reflection layer 10 is formed, and the hologram forming body 11 is obtained.

In the method of the present invention, the vapor deposition atmosphere is appropriately selected from oxygen, nitrogen, or a mixed gas thereof depending on the target metal compound. In the method of the present invention, it is important to introduce oxygen or / and nitrogen gas in vacuum as described above, not just vacuum deposition, thereby forming a transparent reflective layer of metal oxide and / or nitride under mild conditions. can do.

Although the amount of the atmospheric gas introduced is arbitrary, it is preferable to supply an excessive amount of gas. This is because, for example, when an excess oxygen gas is supplied and vapor deposition is performed using titanium as a metal, the transparent reflective layer actually formed is a mixture of TiO and TiO ₂ , and comparing the optical characteristics of both (Table 1) Since TiO ₂ has a high refractive index and excellent characteristics, it is preferable to increase the degree of oxidation. When vapor deposition is performed by supplying excess oxygen, dissociation of oxygen is prevented and the proportion of TiO ₂ is It is possible to form a transparent reflective layer having many excellent optical characteristics.

In the method of the present invention, the degree of vacuum inside the evaporation container 1 varies depending on the type of the metal 2 serving as an evaporation source, but the metal is heated and evaporated at a temperature at which the base resin 8 is not damaged by heat. Such conditions may be used. For example, when titanium is used as the metal, it is usually preferable to set it to about 10 ^-5 to 10 ^-6 Torr.

The metal 2 serving as the evaporation source may be heated by any means, but it is particularly preferable to heat it using an EB heating device. This is because the atmosphere gas is excited by the electron beam to be in a weak plasma state, the reactivity with the metal is improved, and the formation of the oxide becomes better. It should be noted that this level of plasma gas does not damage the base material unlike plasma such as ion plating.

In the method of the present invention, it is preferable that the substrate resin 8 to be the vapor-deposited body is cooled by a means such as winding it around a cooling drum through which a refrigerant is passed to further reduce the damage due to heat. Further, it is preferable that the degree of vacuum of the vapor deposition container is increased on the side of the vapor deposition section and the degree of vacuum on the winding side is reduced, from the viewpoint of preventing contamination.

The metal 2 forming the transparent reflection layer 9 used as an evaporation source may be any metal as long as an oxide or a nitride of the metal 2 can be formed as the transparent reflection layer, depending on the use of the transparent reflection layer. Any one can be used. Specific metals include, for example, Be, Mg, Ca, Cr, M
n, Cu, Ag, Al, Sn, In, Te, Fe, C
o, Zn, Ge, Pb, Cd, Bi, Se, Ga, R
b, Sb, Pb, Ni, Sr, Ba, La, Ce, Au
Etc. The transparent reflective layer of the method of the present invention has a transparency that does not cover the lower layer, and also has a reflective property, and the transparent reflective layer includes translucent if the lower layer is visible. .. Further, the transparent reflection layer in this case is not limited to being transparent in the visible region, and may be transparent in the infrared or ultraviolet region, for example.

Table 1 shows the refractive index (n) of metal oxides capable of forming a transparent reflective layer in the visible region. For example, when the transparent reflective layer 9 is a hologram forming body, the refractive index (n) is shown in Table 1. Metals that form the metal compounds as shown can be used. The thickness of the transparent reflective layer can be adjusted by increasing or decreasing the film speed or heating temperature while monitoring the film thickness information with a crystal oscillator type film thickness monitor or a spectral reflection transmittance monitor. In the case of a body, the thickness of the transparent reflective layer is usually formed to be about 10 to 10000Å,
It is preferably 100 to 5000Å.

[0024]

[Table 1]

The base resin 8 forming the transparent reflection layer 9 may be any resin as long as it can form the fine irregularities 10 on its surface, and any resin can be used. For example, unsaturated polyester resin, acrylic urethane resin, epoxy modified acrylic resin, epoxy modified unsaturated polyester resin, alkyd resin, phenol resin and the like, and as the thermoplastic resin, acrylic ester resin, acrylamide resin, Examples thereof include nitrocellulose resin and polystyrene resin. These resins may be used alone or in combination of two or more, various isocyanate resins, cobalt naphthenate,
Metal soap such as zinc naphthenate, benzoyl peroxide, peroxide such as methyl ethyl ketone peroxide, benzophenone, acetophenone, anthraquinone, naphthoquinone, azobisisobutyronitrile, diphenyl sulfide, etc. Good. Further, as the ionizing radiation curable resin, epoxy acrylate, urethane acrylate, acrylic modified polyester and the like are used as an oligomer, and a crosslinked structure,
For the purpose of adjusting the viscosity, neopentyl glycol acrylate, a mixture of monomers such as trimethylolpropane triacrylate, etc. may be mentioned as appropriate. Films made of these resins or polyesters such as polyethylene terephthalate, polycarbonate, polyvinyl chloride, etc. It is used in a form in which the resin for forming unevenness is provided on a substrate film having good transparency. . In the case of a hologram forming body, the thickness of the base resin is usually preferably about 10 μm to 200 μm.

Fine irregularities 1 formed on the surface of the base resin 8
0 can be formed using any means,
In the case of the hologram forming body, any means can be used depending on the type of the base resin 10. For example, when a thermoplastic resin is used as the base resin, a mold having an unevenness obtained by copying a relief pattern of interference fringes of a hologram is used,
A method of applying the mold to the surface of a thermoplastic resin by heat embossing, and in the case of a curable resin such as an ultraviolet curable resin or an unsaturated polyester resin, a shaping mold or the like having the unevenness of the hologram information is used. The method of filling the surface of the shaping mold with the resin and then irradiating it with ultraviolet rays to cure the resin can be used.

In the method of the present invention, the time for providing the fine irregularities 10 on the surface is not particularly limited, and after the transparent reflection layer 9 is formed on the base resin 8, or the transparent reflection layer 9 is formed on the base resin 8. Any one before doing For example, when the above thermoplastic resin is used, both before and after are possible. However, in the case of a curable resin such as an ultraviolet curable resin, it is difficult to give fine irregularities after forming the transparent reflective layer, and the fine irregularities are formed before forming the transparent reflective layer.

The transparent reflective layer forming method of the present invention is not limited to the hologram forming body described above. That is, as long as the fine concavo-convex 10 other than the relief of the hologram and the transparent reflective layer 9 provided on the fine concavo-convex are formed on the base resin 8, the transparent reflective layer is formed by using the method of the present invention. It is possible to As described above, the method of forming the transparent reflective layer of the present invention can be applied to a wide range of optical discs such as compact discs, decorative materials such as hairline sheets, and optical elements such as solar reflectors.

The present invention will be described in more detail by showing specific examples of the present invention. Example 1 A substrate resin having a surface of a polyvinyl chloride resin sheet having a thickness of 100 μm and provided with fine irregularities of hologram by embossing was placed in a vapor deposition container, and the interior of the container was evacuated to a vacuum degree of 2 × 10 ^−. after the ⁶ Torr, maintaining a deposition vessel interior while introducing oxygen gas into the state of ^{1 × 10 -6 ~5 × 10 -6} Torr, the applied voltage of the electron beam the metal using a metal titanium as evaporation sources -10kV At 1300 to 1500 ° C., it was evaporated and vapor deposition was carried out for 10 seconds to form a transparent reflection layer of titanium oxide to obtain a hologram sheet. It was confirmed that a transparent reflection layer composed of a thin film of TiO ₂ having a refractive index of 2.2 and a high degree of oxidation was formed on the surface of the obtained hologram sheet.
The reflective layer has a thickness of 450Å and a reflectance of 30% (550
nm, incident angle 5 °, absolute reflection) A transparent reflection film having a transmittance of 60%. In addition, the relief shape of the hologram on the surface of the resin layer does not change, and the hologram sheet is set to 120 ° × 3.
There was no change in the hologram image after heating for 0 minutes.

Comparative Example 1 For comparison, a hologram sheet was formed and evaluated according to Example 1 except that a transparent reflection layer was formed by a sputtering method using titanium oxide as a target. The evaluation results are shown in Table 2.

Comparative Example 2 For comparison, a hologram sheet was formed and evaluated according to the hologram forming body of Example 1 except that the transparent reflecting layer was formed by the conventional zinc sulfide sublimation method. The evaluation results are shown in Table 2.

[0032]

[Table 2]

[0033]

As described above, the transparent reflection layer forming method of the present invention has the following effects by adopting the above-mentioned structure. Compared with the conventional method of depositing a metal compound in a high energy state such as ion plating or sputtering, a transparent reflective layer made of a metal compound can be formed under mild conditions because metal is used as an evaporation source for vapor deposition. is there. Therefore, it is made of a metal oxide and / or a metal nitride to the resin without causing damage to the substrate resin, fear of disappearing fine irregularities on the surface of the substrate resin, or degrading or deforming the resin itself. It became possible to form a transparent reflection layer.

Further, compared with the method of directly heating and depositing a metal oxide or the like, there is no possibility that oxygen is dissociated and the degree of oxidation of the deposited film is lowered, and a stable metal oxide / or metal nitride is obtained. Can form a film.

In the method for manufacturing the hologram forming body of the present invention, the transparent reflecting layer forming method as described above is used for forming the transparent reflecting layer, and therefore the base resin is less damaged so that the shape retention of the fine irregularities of the hologram is good. As a result, a hologram-formed body excellent in reproducibility of the hologram image can be obtained.
In addition, since it is possible to form a transparent reflective layer of a metal compound which cannot be used due to severe forming conditions, it is possible to obtain a transparent reflective layer having good optical characteristics such as a refractive index.

In the hologram forming body obtained by the method of the present invention as compared with the conventional hologram forming body having the transparent reflecting layer formed by sublimation of ZnS, the transparent reflecting layer is formed as a ceramic film of a metal compound. Therefore, the adhesion to the substrate, the shape retention of fine irregularities, etc. are good, and the heat resistance is good, so that peeling or whitening of the transparent reflective layer does not occur for a long period of time, and excellent image durability etc. A hologram forming body is obtained.

In particular, when titanium is used as a metal and oxygen gas is supplied as an atmosphere, a hologram having a high refractive index and a high reflectance can be formed, and a hologram having excellent heat resistance, durability and optical characteristics can be formed. The body is obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a method for forming a transparent reflective layer of the present invention.

FIG. 2 is a vertical sectional view showing an example of a hologram forming body.

[Explanation of symbols]

 1: Vapor deposition container 2: Metal 3: Heating / evaporating part 4: Exhaust pipe 5: Exhaust pipe 6: Exhaust device 7: Gas introduction pipe 8: Base resin 9: Transparent reflective layer 10: Fine irregularities 11: Hologram former

Claims (3)

[Claims] 1. A method of forming a transparent reflection layer and fine irregularities on a surface of a base resin, wherein a metal is used as an evaporation source while the base resin is in a vacuum and in an atmosphere of oxygen and / or nitrogen. Characteristic is that vapor deposition is performed to form a transparent reflection layer of a metal compound consisting of the oxide or / and nitride of the above metal on the resin surface, and fine irregularities are provided on the resin surface before or after the formation of the transparent reflection layer. And a method for forming a transparent reflective layer. 2. A method for producing a hologram-formed body, comprising at least a fine irregularity of a hologram provided on a surface of a base resin, and a transparent reflective layer made of a metal compound formed on the surface of the fine irregularity. A method for manufacturing a hologram-formed body, comprising: forming a hologram using the method according to claim 1. 3. The method for producing a hologram-formed body according to claim 2, wherein titanium is used as a metal and the atmosphere is an oxygen atmosphere to perform vapor deposition on the surface of the base resin to form a transparent reflection layer of titanium oxide on the surface of the resin. ..