JP3048253B2 - Reflector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light reflector comprising a plastic film as a base material and a metal film having a high reflectance laminated thereon.

The application of the reflector according to the present invention is a reflector such as a mirror which is easily manufactured. The reflector can be easily attached to a glass plate such as a window, a door, or a windshield, or a plastic plate, a metal plate, or the like by using an adhesive, an adhesive, or a double-sided tape.

[0003] The present invention is a reflector which has remarkably improved durability, and is used for a reflector plate (lamp house) of a fluorescent lamp as a backlight of a liquid crystal display panel of a word processor or a computer having high reflectivity and high reliability. I can do it. Further, it is useful for energy saving of office lighting as a reflector plate of a fluorescent lamp utilizing high reflectance.

[0004]

2. Description of the Related Art Light-reflective films based on plastic films are lighter, have better impact resistance and are more flexible than glass-based mirrors. To a copier, a solar heat collector,
The use thereof has been widespread as a light reflection plate for a plant factory, a high light reflection plate for a fluorescent lamp, and a backlight reflection plate for a liquid crystal display device.

Conventionally, these reflectors are made by polishing an aluminum plate or a stainless steel plate, by forming a resin coating on these plates, or by laminating a thin film of a metal such as silver or aluminum on a plastic film. Things are used.

However, coatings made of aluminum-deposited products, stainless steel plates, resins, and the like have low reflectivities, which are completely insufficient to meet such demands. A light reflector having a silver thin film layer formed on a plastic film has high reflectivity when manufactured, but the reflectivity of the reflector is significantly reduced due to environmental factors such as heat, gas, and light. It was found that there was a technical problem that the function as a light reflector was not satisfied.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reflector having excellent durability and high reflectance.

[0008]

Means for Solving the Problems The present inventors have improved the durability without lowering the reflectance of a reflector by laminating a thin film of silver and a metal different from silver as the reflector. And completed the present invention.

That is, the present invention is a reflector characterized in that a silver thin film layer and a dissimilar metal thin film layer are alternately laminated on at least one surface of a plastic film.

FIGS. 1 to 3 are schematic views showing the layer structure of the reflector of the present invention.

As a material of the plastic film (1 in the figure) used in the present invention, a hydrophobic resin is desirable, and preferable resins are exemplified by polyester, polyether, polyarylate, acrylic resin, methacrylic resin, polyolefin and polyolefin. Homopolymers or copolymers such as vinyl chloride and polyethersulfone, and the like, more preferably polyester, acrylic resin,
Polyethersulfone is used.

This film can be used as desired, any of which is colorless and transparent, colored and transparent, and opaque.

The thickness of the plastic film is 5 μm
The thickness is preferably 25 μm or more and 250 μm or less from the viewpoint of productivity and handling.

In a preferred embodiment of the present invention, a silver thin film layer (2 in the figure) and Au, A
1, Cu, In, Ir, Mg, Ti, Sn, Si, C
r, Co, Ni, Mo, Ta, Mn, Zn, Zr, P
It is formed by laminating different metal thin film layers (3 in the figure) containing at least one metal selected from the group consisting of t, Pd, V, W, and Pb.
Vacuum evaporation, sputtering, ion plating, ionization evaporation, ion cluster beam evaporation, or the like can be used.

The thickness of the silver thin film layer is preferably 10 to 500 °, more preferably 10 to 200 °. More preferably 10 to
100 mm is desirable.

The thickness of the dissimilar metal thin film layer is also preferably from 10 to 500 °, more preferably from 20 to 200 °, even more preferably from 20 to 100 °.

The total thickness of the laminate is preferably from 500 to 5000 °, more preferably from 1000 to 2000 °.

In the thin film reflector, the silver layer may contain trace amounts of metals and metal compounds other than silver in such a degree that the object of the present invention is not impaired. Further, a metal layer (5 in the figure) having anticorrosion properties can be formed on the outermost layer of the laminate.

In the reflector of the present invention, a transparent protective layer may be provided on the plastic film on the opposite side of the laminate. With such a protective layer, the influence of external environmental factors such as surface hardness, light resistance, gas resistance, and water resistance of the reflector can be suppressed.

Examples of substances that can be used for forming such a protective layer include, for example, acrylic resins such as polymethyl methacrylate, polyacrylonitrile resins, polymethacrylonitrile resins, and silicon resins such as polymers obtained from ethyl silicate. In addition to organic substances such as polyester resin and fluororesin, inorganic substances such as silicon oxide are useful.

Examples of the method for forming the transparent protective layer include existing methods such as coating and laminating a film. Further, these film thicknesses need to be within a range in which a protective effect is exhibited without deteriorating the light reflecting ability, which is the object of the present invention, and is appropriately selected and used according to the material and application. Hereinafter, the present invention will be described in more detail with reference to examples.

[0022]

【Example】

Example 1 On a biaxially stretched polyethylene terephthalate film having a thickness of 50 μm, silver (100 mm) / Ti (100 mm) / silver (100 mm) / T
A thin film layer composed of i (100 °) / silver (100 °) / Ti (100 °) was formed to obtain a light reflector. The reflector layer was formed by DC magnetron sputtering. The light reflector was subjected to an ultraviolet ray deterioration promotion test, and the time until the light (600 nm) reflectance reached 80% of the initial value was measured as the deterioration time.
Table 1 shows the results and the light reflectance before the test for accelerating UV degradation. As can be seen, the deterioration time was 5000 hours or more, and the durability was excellent, with almost no decrease in light reflectance.

Comparative Example 1 On the same film as in Example 1, in the same manner as in Example 1,
A 1000 mm thick silver thin film was formed. It was found that this reflector formed of only silver changed its color to reddish purple upon irradiation with ultraviolet rays, had a low reflectance, and had extremely poor durability against ultraviolet rays.

Example 2 Copper (50 °) / silver (200 °) / copper (100 °) / silver (200 °) was coated on a 50 μm-thick film containing methyl methacrylate as a main component.
A thin film layer composed of Å) / copper (100 Å) / silver (200 Å) was formed to obtain a light reflector. The thin film forming method and the deterioration promotion test were performed in the same manner as in Example 1. Table 1 shows the results. As in Example 1, it had excellent light reflectance and durability.

Example 3 On the same film as in Example 1, Pd (20 °) / silver (50
Å) / Pd (20Å) / Silver (50Å) / Pd (20Å) / Silver (50Å) / Pd (20Å) / Silver (50Å) / Pd (20Å) /
Silver (50Å) / Pd (20Å) / Silver (50Å) / Pd (20Å)
/ Silver (50 °) / Pd (20 °) / Silver (50 °), and a Ni (80) -Cr (20) alloy layer is formed on the silver thin layer as a protective film to a thickness of 100 °. I got a body. Evaluation was performed in the same manner as in Example 1, and the results are shown in Table 1. As in Example 1, it had excellent light reflectance and durability.

[0026]

[Table 1]

[0027]

The reflector using the reflector of the present invention is lightweight, has excellent impact resistance, is flexible, and can be used as a mirror, as well as a light reflector for power saving in a plant factory. It is also used for plates, energy-saving type high-reflection fluorescent lamps, and high-luminance reflectors for backlights for liquid crystal display panels. In addition, the durability as a reflector is improved due to the improved durability against light, heat, and the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a layer configuration of a reflector in which silver thin films and dissimilar metal thin films are alternately laminated on a plastic film.

FIG. 2 is a view showing a layer structure of a reflector in which thin films of different metals and silver thin films are alternately laminated on a plastic film.

FIG. 3 is a diagram showing a configuration of a reflector in which a second dissimilar metal layer is formed as a protective film on a laminate of a silver thin film and a dissimilar metal thin film formed on a plastic film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plastic film 2 Silver thin film 3 Dissimilar metal thin film 4 Repeated layers 2 and 3 5 Corrosion-proof metal layer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 G02B 5/08

Claims (4)

(57) [Claims] 1. A plastic film comprising one or both surfaces of a thin film containing silver as a main component and a thin film containing a metal thin film different from silver as a main component.
A reflector that is alternately stacked eight times. 2. A silver thin film layer having a thickness of 20
2. The reflector according to claim 1, wherein the angle is about 200 [deg.]. 3. The reflector according to claim 1, wherein the thickness of one thin film of the dissimilar metal is 20 to 200 °. 4. The reflector according to claim 1, wherein the thin film of the dissimilar metal contains at least one metal selected from the group consisting of Ti, Cu, and Pd.