JP2577938B2 - High reflection film - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a high-reflection film, and more particularly, to a high-reflectance film such as a fluorescent lamp back reflector, a laser reflector, and a liquid crystal display back reflector. The present invention relates to a high-reflection film used for a used application.

[Prior art] Conventionally, a high-reflection film having a metallic luster of this type includes, for example, a film obtained by depositing a thin film of a metal such as aluminum or silver on the surface of a polyester film, and further forming a protective layer by coating. there were.

However, in the case where the above-mentioned polyester film is provided with an aluminum vapor-deposited layer on the surface, the reflectance is inferior to that in the case where a silver vapor-deposited layer is provided. Further, in the case where a silver vapor deposition layer is provided on the surface of the above polyester film, there is a problem that high reflection cannot be obtained due to reflection from the polyester film surface and haze of the polyester film itself.

[Object of the Invention] The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a high-reflection film having excellent reflectance.

[Constitution of the Invention] The present invention provides a surface layer made of silicon dioxide on the surface of a substrate made of polyethylene terephthalate film,
The present invention relates to a high-reflection film characterized in that a silver deposition layer and a protective layer made of an acrylic resin are sequentially formed on the back surface.

That is, it has been used in a conventional high reflection film having this type of metallic luster. For example, instead of forming a thin film of a metal such as aluminum and silver on the surface of a polyester film by vapor deposition, and further applying and forming a protective layer,
In the present invention, a surface layer made of silicon dioxide is provided on the surface of a base material made of polyethylene terephthalate film, and a silver deposited layer and a protective layer made of acrylic resin are sequentially formed on the back surface. By eliminating all points, a highly reflective film with excellent reflectivity has been completed.

That is, in the present invention, a surface layer (2) made of silicon dioxide is provided on the surface of a substrate (1) made of polyethylene terephthalate film, and a silver deposition layer (3) and a protective layer (4) made of an acrylic resin are provided on the back surface. Are sequentially formed, and if necessary, an adhesive layer (5) and a release sheet (6) are additionally provided.
May be formed on an acrylic resin protective layer. With such a configuration, it is possible to provide a highly reflective film having excellent reflectance.

The thickness of the base material (1) comprising a polyethylene terephthalate film in the high reflection film of the present invention is not particularly limited, but it is preferable to use a base material having a thickness of about 12 to 200 μm, particularly 25 to 100 μm. Thick thing,
It is preferable in terms of transparency, durability, handleability, economy and the like.

The silver deposition layer (3) of the high reflection film of the present invention is, for example, silver deposited by a conventional method. Silver deposition layer (3)
Is usually selected from a range of about 70 to 100 nm. For example, if the thickness is less than 70 nm, the reflectivity of the metal is not sufficient,
On the other hand, when the thickness is 100 nm or more, the reflectivity of the metal is not changed, so that the economic efficiency is inferior and it is not preferable.

The surface layer (2) made of silicon dioxide of the high reflection film of the present invention is, for example, silicon dioxide deposited by a conventional method. The thickness of the surface layer (2) is desirably formed to an optical thickness (nd) λ / 4. Usually 70-120nm range,
More preferably, it is selected from the range of 90 to 100 nm. 7 in thickness
When the thickness is less than 0 nm, the antireflection effect is insufficient and the film surface is insufficient to smooth the surface, and the haze of the polyethylene terephthalate film itself cannot be eliminated to improve the light transmittance, so that the surface layer (2) There is no value in forming the surface layer (2) because the effect of providing
On the other hand, when the thickness exceeds 120 nm, the surface layer (2) is too thick, and the antireflection effect is lost and the transparency is impaired. In addition, the film formation becomes slow, which is inefficient and inferior in economical efficiency.

In the present specification, the term “evaporation” means to form a thin film by a normal metal thin film forming method such as a vacuum evaporation method, a sputtering method, and an ion plating method.

The silver deposition layer includes all silver thin films formed by these metal thin film forming methods.

In the high reflection film of the present invention, the silver deposition layer (3) itself has low mechanical strength and is easily damaged by friction, and is chemically active and easily discolored or corroded by sulfides in the atmosphere. On the surface of the vapor deposition layer (3), a protective layer (4) made of an acrylic resin is provided for the purpose of protecting the silver vapor deposition layer. The thickness of the protective layer (4) is not particularly limited, but is usually 0.1.
It is appropriately selected from the range of 01 to 10 μm.

As the acrylic resin paint for forming the protective layer (4), for example, a paint composed of any of a thermoplastic resin, a thermosetting resin, an electron beam curable resin, and an infrared curable resin is used.

The protective layer (4) is formed by applying a resin coating for forming the protective layer (4) by a usual coating method such as a roll coating method, a gravure coating method, a reverse coating method, a spray coating method, and drying ( In the case of a thermosetting resin, an electron beam curable resin, an ultraviolet curable resin, or the like, curing is performed.

 Next, the present invention will be described with reference to examples.

Example 1 Example 1 A silicon dioxide vapor-deposited layer was formed on a surface of a 50 μm-thick polyethylene terephthalate film by a vacuum vapor deposition method so as to have an optical film thickness (nd) of λ / 4. To form a silver layer on the back surface of the polyethylene terephthalate film by a sputtering method to form a silver vapor-deposited layer having a thickness of 80 nm.
, 19 parts of methyl isobutyl ketone and 10 parts of xylene, were applied and dried to form a protective layer having a thickness of about 50 nm to obtain a high reflection film of the present invention.

Example 2 On the surface of the protective layer of the high-reflection film of the present invention obtained in Example 1, an acrylic pressure-sensitive adhesive resin was applied on the release surface of the release film.
A coating liquid consisting of 100 parts, 4 parts of a curing agent, 20 parts of ethyl acetate, and 10 parts of toluene was applied and dried to form an adhesive layer having a thickness of 18 μm. By laminating, a highly reflective film of the present invention was obtained.

Comparative Example 1 Aluminum was vapor-deposited on the back surface of a 50 μm-thick polyethylene terephthalate film by a vacuum vapor deposition method to a thickness of 80 μm.
nm deposited aluminum layer and acrylic resin
A coating liquid consisting of 10 parts, 19 parts of methyl isobutyl ketone, and 10 parts of xylene was applied and dried to form a protective layer of about 50 nm to obtain a conventional high reflection film.

Comparative Example 2 Thickness was formed by sputtering silver on the back surface of a 50 μm thick polyethylene terephthalate film by a sputtering method.
An 80 nm silver vapor-deposited layer is formed, and a coating liquid consisting of 10 parts of acrylic resin, 10 parts of methyl isobutyl ketone, and 10 parts of xylol is applied and dried to form a protective layer of about 50 nm. Obtained.

[Effects of the Invention] The reflectance of the high reflection films obtained in Examples 1 and 2 and Comparative Examples 1 and 2 was as shown in Table 1.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a basic structure of a high-reflection film of the present invention, and FIG. 2 is a sectional view showing another embodiment of the high-reflection film of the present invention. . (Signs in the drawings) (1): base material (2): surface layer (3): deposited silver layer (4): protective layer (5): adhesive layer (6): peelable film

Claims (1)

(57) [Claims] 1. A surface layer made of silicon dioxide is provided on the surface of a substrate made of polyethylene terephthalate film,
A high-reflection film characterized by sequentially forming a silver deposition layer and an acrylic resin protective layer on the back surface.