JP2012153038A - Fingerprint-resistant decorative film and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fingerprint-resistant decorative film decorating a display face of a portable information terminal without spoiling a function of a fingerprint-resistance-processed layer and a method of manufacturing the same.SOLUTION: In the fingerprint-resistant decorative film, the fingerprint-resistance-processed layer is formed on one surface of a transparent resin film and a mirror finished surface layer is formed on the other surface. In the method of manufacturing the fingerprint-resistant decorative film, the mirror finished surface layer is formed on the surface of the transparent resin film with the fingerprint-resistance-processed layer formed on one surface, on which the fingerprint-resistance-processed layer is not formed.

Description

  The present invention relates to a fingerprint-proof decorative film and a method for manufacturing the fingerprint-proof decorative film for preventing a fingerprint from adhering to a display surface of a portable information terminal such as a mobile phone and decorating the display surface.

Patent Document 1 discloses a protective sheet provided with an anti-fingerprint treatment layer (hard coat layer) in order to prevent fingerprints from adhering to an information display surface of a portable information terminal.
On the other hand, there is a user's need to decorate the information display surface of a portable information terminal like a mirror.
However, if a mirror surface layer is provided on the anti-fingerprint processing layer, there is a problem that the function of the anti-fingerprint processing cannot be obtained.

JP 2010-64423 A

  Then, an object of this invention is to provide the anti-fingerprint decoration film which can decorate the display surface of a portable information terminal, and its manufacturing method, without impairing the function of a fingerprint-proof process layer.

In order to solve the above problems, the present inventors have found the following means for solving the problems as a result of intensive studies.
That is, the anti-fingerprint decorative film of the present invention is characterized in that, as described in claim 1, the anti-fingerprint treatment layer is provided on one side of the transparent resin film and the mirror layer is provided on the other side.
The invention according to claim 2 is characterized in that, in the invention according to claim 1, the average reflectance of visible light band light 380 nm to 780 nm from the fingerprint-proofing layer side is 5% to 40%.
According to a third aspect of the present invention, in the first or second aspect of the present invention, the transparent resin film is made of a polyethylene-based or polyolefin-based resin having a thickness of 50 μm-200 μm, and the anti-fingerprint treatment layer has a thickness of It is 0.5 μm to 10 μm, and the mirror layer has a thickness of 50 nm to 800 nm.
The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the mirror layer is formed by alternately stacking silicon dioxide layers and niobium pentoxide layers. .
Moreover, the manufacturing method of the anti-fingerprint decorative film of the present invention is the surface where the anti-fingerprint treatment layer is not provided with respect to the transparent resin film provided with the anti-fingerprint treatment layer on one side, as described in claim 5. A mirror surface layer is provided on the surface.
The invention according to claim 6 is the invention according to claim 5, wherein the mirror layer is formed by laminating dielectric layers, and each dielectric layer is formed on the transparent resin film by sputtering metal atoms. A metal atomic layer having a thickness of 5 nm to 200 nm is formed and then oxidized to form a dielectric layer, and the dielectric layer is repeatedly formed to form the mirror layer by laminating the dielectric layer.
Invention of claim 7, wherein, in the invention of claim 6, wherein the outermost layer of the dielectric layer and SiO ₂ layer, the SiO ₂ layer on the acrylic pressure-sensitive adhesive layer, a resin sheet of polyethylene or polyolefin A layer, a silicone resin layer, and a polyethylene-based or polyolefin-based release sheet layer are provided in this order.

  According to the anti-fingerprint decorative film of the present invention, the anti-fingerprint function by the anti-fingerprint processing layer and the decorative function by the mirror layer can be given to the display surface of the portable information terminal. Moreover, according to the manufacturing method of this invention, it becomes possible to provide the decoration layer which can adjust color and brightness | luminance widely as desired with respect to the resin film with a commercially available fingerprint-proof process layer.

Device sectional view for explaining the production method of the present invention Sectional view of the anti-fingerprint decorative film of the present invention Partial enlarged sectional view of the anti-fingerprint decorative film of the present invention The graph which shows the measurement result of the reflectance of the comparative example 1 The graph which shows the measurement result of the reflectance of Example 1 The graph which shows the measurement result of the reflectance of Example 2 The graph which shows the measurement result of the reflectance of Example 3 The graph which shows the measurement result of the reflectance of Example 4

The anti-fingerprint decorative film of the present invention uses a known anti-fingerprint-treated film, and, as shown in FIG. 2, a mirror surface layer 17 is provided on the surface opposite to the anti-fingerprint treatment layer 21 of the anti-fingerprint film. It is provided.
This mirror surface layer 17 has an average reflectance of visible light band light 380 nm to 780 nm as viewed from the fingerprint-proofing layer 21 side through the transparent resin film 2 to 5% to 40%. It is because it can be set as the mirror surface layer 17 in the state which is easy to see a display surface by setting it as this range.
The mirror surface layer 17 of this anti-fingerprint decorative film is formed by laminating a plurality of dielectric layers (see 17a-17c in FIG. 3) having different refractive indexes.
Each dielectric layer 17a-17c is formed by sputtering of metal atoms and oxidation of the sputtered atoms, so that the thickness of the entire mirror layer is 50 nm-800 nm. This is because if the thickness is less than 50 nm, the adhesion to the display surface is insufficient and peeling occurs, and if the thickness exceeds 800 nm, cracks are likely to occur due to the influence of film stress.

  The material of the transparent resin film 2 is not particularly limited as long as it is transparent or translucent, and is difficult to expand and contract by heat when the mirror surface layer 17 is formed. For example, polyvinyl chloride, amorphous or low crystal May be composed of a resin such as a polyester-based or polypropylene-based, polybutylene terephthalate-based, unstretched or low-stretched ethylene vinyl alcohol, and among these, from the viewpoint of optical properties, an ethylene-based or polyolefin-based resin It is preferable to do. Moreover, there is no restriction | limiting in particular also about the thickness, However, It is preferable to set it as about 50 micrometers-200 micrometers. This is because workability such as handling work is difficult when the thickness is less than 50 μm, and when the thickness exceeds 200 μm, a step is formed when used as a display surface of a portable information terminal, and the design is impaired.

The dielectric layers 17a-17c can be selected from metal oxides that provide a desired reflection angle, chromaticity, and the like. For example, when the low refractive index layer and the high refractive index layer are alternately laminated, a silicon compound such as SiO ₂ having a refractive index of 1.5 or less is used as the low refractive index layer, and the refractive index is used as the high refractive index layer. A Nb ₂ O ₅ niobium oxide of 2.0 or more, a titanium compound of TiO ₂ or the like can be used. Among these metal oxides, it is preferable to select SiO ₂ and Nb ₂ O ₅ . This is because the material has a high crystal transition temperature and low photoresponsiveness.
The thickness of each dielectric layer 17a-17c is not particularly limited as long as the thickness of the entire dielectric layer is in the range of 50 nm to 800 nm as described above, but the thickness of each dielectric layer is not limited. Is preferably 5 nm to 200 nm. This is because when the thickness is less than 5 nm, it is difficult to optically control each dielectric layer, and when it exceeds 200 nm, the cost is increased for industrial production.
As shown in FIG. 3, a release sheet 19 is provided on the outermost layer 17 a of the dielectric layer via an adhesive layer 18. The release sheet 19 is configured by laminating a polyethylene or polyolefin resin sheet layer 19a, an adhesive layer (silicone resin layer) 19b, and a polyethylene or polyolefin release sheet layer 19c in this order. Since the adhesive strength of the adhesive layer 18 needs to be strong in relation to the adhesive strength between the adhesive layer 19b and the adhesive layer 18, the outermost layer 17a of the dielectric layer is an SiO ₂ layer, and the acrylic adhesive as the adhesive layer 18 It is preferable to provide the release sheet 19 using This is because the acrylic pressure-sensitive adhesive has strong adhesive strength with the SiO ₂ layer 17a. The adhesive layer 18 may be formed of a pressure-sensitive adhesive having stronger adhesive force than the pressure-sensitive adhesive layer (silicone resin layer) 19b, or may be formed of a so-called adhesive that solidifies and adheres.

  The anti-fingerprint layer 21 is also called a hard coat layer, and is usually provided with a thickness of about 0.5 μm to 10 μm. This is because when the film thickness is less than 0.5 μm, the protection of the surface of the transparent resin film 2 is insufficient, and when it exceeds 10 μm, curing by heating or radiation is not sufficiently obtained and blocking is likely to occur. Further, as the material of the hard coat layer 21, for example, a silane-based material or a radiation curable material can be used, but a radiation curable material is preferable, and an ultraviolet curable material is preferable among them.

Next, the manufacturing method of the anti-fingerprint decorative film of this invention is demonstrated with reference to FIG.
In the film forming apparatus whose cross section is shown in FIG. 1, a cylindrical rotating body 3 for supporting a base material 2 is arranged at the center in a cylindrical vacuum chamber 1, and the first rotating along the inner periphery of the chamber 1. The sputtering region 4, the ion gun 5, the second sputtering region 6, and the third sputtering region 7 are arranged in this order. Although not shown, a vacuum pump is connected to the vacuum chamber 1 so that the inside of the chamber 1 can be evacuated.

The first to third sputtering regions 4, 6, and 7 are formed by sputtering a film material on the base material 2. In each of the regions 4, 6, and 7, a sputtering gas is formed in the vicinity of the base material 2. A gas inlet (not shown) for introduction is provided. Each region 4, 6, 7 is provided with a cathode 11-13 to which a target 8-10 is attached so as to face the cylindrical rotating body 3. These cathodes 11-13 are connected to a direct current or an alternating current power source (not shown) to supply power to the target 8-10.
Further, a shutter 14-16 is provided on each of the regions 4, 6 and 7 on the substrate 2 side, and the shutter 14-16 is selectively opened at the time of film formation in each of the regions 4, 6 and 7. It has become.

  The ion gun 5 is used to oxidize metal atoms formed in the respective regions 4, 6, and 7. An oxygen introduction port is provided to introduce oxygen into the region, and a magnetic circuit is provided. Yes. In order to generate microwave excitation plasma from this magnetic circuit, a waveguide outside the vacuum chamber 1 and a microwave antenna inside the vacuum chamber 1 are connected via a microwave introduction window.

With the above configuration, the first metal is formed on the base material 2 with a film thickness of about a monoatomic layer by the first sputtering region 4, and the cylindrical rotating body 3 is rotated and oxidized by the ion gun 5 to be oxidized. 1 metal oxide film (first dielectric layer), and further rotating the cylindrical rotating body 3 to form a second metal with a film thickness of about a monoatomic layer by the second sputtering region 6; The cylindrical rotating body 3 is rotated and oxidized by the ion gun 5 to form a second metal oxide film (second dielectric layer). These are alternately repeated, and a plurality of dielectric layers are laminated on the substrate 2. A mirror layer is formed. In the case of sputtering three kinds of metal atoms, sputtering by the third film formation region 7 and oxidation by the ion gun 5 are performed as in the first film formation region 4 and the second film formation region 6. Good. The term “monoatomic layer” refers to a thickness range of 5 nm to 200 nm.
According to the said method, it becomes possible to provide a desired color and brightness | luminance to a mirror surface layer.

  Moreover, in the said method, the pressure at the time of sputtering and oxidation of a metal material is 0.5 Pa-1.0 Pa.

In the above method, when silicon atoms and niobium atoms are used as metal atoms, the sputtering temperature is set to 80 ° C. or lower (the lower limit is the temperature at which plasma is generated in the subsequent oxidation). It is preferable. This is because a uniform film having a thickness of about a single atom can be formed at high speed. In this case, the film formation rate can be arbitrarily adjusted. For example, in the case of Nb ₂ O ₅ , 1.0-2.5 Å / s, and in the case of SiO ₂ , 1.0-3. It can be set to 0 ｓ / s or the like.

Next, the anti-fingerprint decorative film of the example of the present invention will be described.
In the following examples, film formation is performed under the following conditions unless otherwise described.
(1) Base material (transparent resin film 2)
A transparent resin film 2 made of polyethylene having a thickness of 100 μm, a width of 500 mm, and a length of 1000 mm was provided with a fingerprint-proof treatment layer (lipophilic hard coat layer) 21 having a thickness of 1 μm on one side.
(2) Film formation conditions of mirror surface layer 17 In this example, SiO ₂ and Nb ₂ O ₅ were formed as dielectric layers.
a) SiO ₂ film forming conditions Target: Si
Power source: DC power source Oxidation source: Ion gun Deposition temperature: Room temperature Cathode input power: 6 w / cm ²
Ar flow rate: 500 sccm
O ₂ flow rate: 100 sccm
b) Nb ₂ O ₅
Target: Si
Power source: DC power source Oxidation source: Ion gun Deposition temperature: Room temperature Cathode input power: 5 w / cm ²
Ar flow rate: 500 sccm
O ₂ flow rate: 300 sccm

Using the apparatus described in the above embodiment, each dielectric layer constituting the mirror surface layer 17 was formed as follows.
a) Nb ₂ O ₅ film In the state where the vacuum chamber 1 of the same apparatus is depressurized to 8.0 × 10 ⁻⁴ Pa and Ar is introduced into the first sputtering region 4, power is applied to the cathode 11, A process of forming an Nb film on one surface of the substrate 2 by sputtering and a process of rotating the cylindrical rotating body 3 to oxidize the Nb film by the ion gun 5 are repeated to obtain an Nb ₂ O ₅ film (dielectric layer) did.
b) SiO ₂ film The inside of the vacuum chamber 1 was adjusted to 8.0 × 10 ⁻⁴ Pa, Ar was introduced into the sputtering region 6, and power was supplied to the cathode 12 to form a Si film by sputtering. Subsequently, the cylindrical rotating body 3 was rotated, and the Si film was oxidized by the ion gun 5 to obtain a SiO ₂ film (dielectric layer).

By the said method, the comparative example 1 and Example 1-4 of the layer structure shown in the following Table 1 were produced.
The layer structure in Table 1 is described in order from the transparent resin film 2 side. Further, after the mirror surface layer 17 was formed, the release sheet 19 was bonded to the adhesive layer (acrylic pressure-sensitive adhesive) 18 to form an anti-fingerprint decorative film.
The results of measuring the reflectance for each example are attached to FIGS.
The “average reflectance” in Table 1 is the average reflectance (%) at a visible light region wavelength of 380 nm to 780 nm, and the “maximum reflectance” is the maximum reflectance (% at a visible light region wavelength of 380 nm to 780 nm). ). The reflectance was measured according to JIS Z 8722.
Further, the evaluation of “anti-fingerprint” in Table 1 is evaluated in two stages of ○ and Δ on the ease of conspicuous pressing a fingerprint against the fingerprint-proofing layer 21 side of the transparent resin film 2.
The evaluation of “decorativeness” is evaluated as “◯” when the presence or absence of the specular layer 17 can be confirmed by viewing angle, and “X” when it is not.

Comparative Example 1 and Examples 1 and 2 have an average reflectance of 4% to 18% and a maximum reflectance of 4% to 21%, and the attached fingerprint does not stand out even if there is reflection by the mirror surface layer. It was found that it does not harm the anti-fingerprint function. Further, in Example 3, since the average reflectance 43% and the maximum reflectance 56% were both high values, the attached fingerprint was conspicuous, and it was found that the fingerprint resistance was impaired. In Example 4, although the average reflectance was relatively low at 25%, the maximum reflectance was as high as 79%, so that fingerprint adhesion was slightly noticeable.
Moreover, since the comparative example 1 is a low value with both average reflectance 4% and maximum reflectance 4%, it turned out that the display of the decoration function by a mirror surface layer is not enough. In Example 1-4, the average reflectance was 10% to 43% and the maximum reflectance was 11% to 79%, and it was found that the effect of the mirror surface layer, that is, the decorative function could be exhibited.
From the above, both Comparative Example 1 and Example 1-4 are anti-fingerprint decorative films in which a mirror layer can be provided on a transparent resin film provided with an anti-fingerprint treatment layer. From the viewpoint of decorativeness, it was found that Examples 2 and 3 having a visibility reflectance (maximum reflectance) of more than 4% and less than 56% are preferable. Moreover, it turned out that it is preferable to make an average reflectance into the range of 10% -18%.

DESCRIPTION OF SYMBOLS 1 Cylindrical vacuum chamber 2 Base material 3 Cylindrical rotary body 4, 6, 7 1st-3rd sputtering area | region 5 Ion gun 8-10 Target 11-13 Cathode 14-16 Shutter 17 Dielectric layer 18 Adhesion layer 19 Release sheet 21 Anti-fingerprint treatment layer (hard coat layer)

Claims (7)

  An anti-fingerprint decorative film comprising a transparent resin film provided with a fingerprint-proof layer on one side and a mirror layer on the other side.   2. The anti-fingerprint decorative film according to claim 1, wherein an average reflectance of visible light band light 380 nm to 780 nm from the fingerprint-proof processing layer side is 5% to 40%.   The transparent resin film is made of a polyethylene or polyolefin resin having a thickness of 50 μm to 200 μm, the anti-fingerprint treatment layer is 0.5 μm to 10 μm, and the mirror layer is 50 nm to 800 nm. The anti-fingerprint decorative film according to claim 1 or 2, wherein the anti-fingerprint decorative film is provided.   The anti-fingerprint decorative film according to any one of claims 1 to 3, wherein the mirror surface layer is formed by alternately laminating a silicon dioxide layer and a niobium pentoxide layer.   A method for producing an anti-fingerprint decorative film, comprising: providing a mirror surface layer on a surface not provided with the anti-fingerprint treatment layer with respect to a transparent resin film provided with an anti-fingerprint treatment layer on one side.   The mirror surface layer is formed by laminating dielectric layers, and each dielectric layer is formed by sputtering metal atoms to form a metal atom layer having a thickness of 5 nm to 200 nm on the transparent resin film, and then oxidizing the dielectric layer to form a dielectric layer. 6. The method of manufacturing an anti-fingerprint decorative film according to claim 5, wherein the body layer is formed and the dielectric layer is repeatedly formed to form the mirror surface layer. The outermost layer of the dielectric layer is an SiO ₂ layer, and on the SiO ₂ layer, an acrylic pressure-sensitive adhesive, a polyethylene-based or polyolefin-based resin sheet layer, a silicone resin layer, and a polyethylene-based or polyolefin-based release sheet layer are arranged in this order. The method for producing a fingerprint-proof decorative film according to claim 6, wherein the film is provided.