JPH0726223A - Highly transparent and slightly sticky antistatic protective film - Google Patents

Abstract

PURPOSE:To prepare a highly transparent antistatic protective film which can be applied to various displays, esp. a liq. crystal display, hardly causes reflection of light due to the difference in refractive index of light at the interface of the film and a polarizing plate stuck to the film. CONSTITUTION:This highly transparent and slightly sticky protective film is obtd. by forming an antistatic layer 2 on one side of a substrate film 1 made of a monoaxially oriented polyethylene terephthalate film and forming an acrylic self-adhesive layer 3 on the other side of the substrate film 1. The protective film may comprise the substrate film 1, an antistatic layer 2 formed on one side of the substrate film 1, and an acrylic self-adhesive layer 3 formed on the surface of the antistatic layer 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent film attached for the purpose of surface protection of various displays such as word processors, computers and televisions, and in particular, it has antistatic property and has a slight adhesive property. The present invention relates to a highly transparent protective film.

[0002]

2. Description of the Related Art A transparent protective film such as polyethylene or polypropylene is laminated on the surface of various displays such as word processors, computers and televisions for the purpose of surface protection. These protective films are often removed by peeling after the liquid crystal display or the like is assembled, but there is a problem that static electricity is generated during the peeling and surrounding dust is caught.

On the other hand, the conventional transparent protective films, such as polyethylene and polypropylene, are inferior in transparency, and are inferior in transparency when the product is inspected for defects after the display is assembled. Therefore, it is difficult to perform the defect inspection with high accuracy.

[0004]

In order to increase the transparency of the above-mentioned conventional transparent protective film, a highly transparent polyethylene terephthalate film (PET film).
The PET film is usually biaxially stretched, and its refractive index is 1.66. By the way, when this biaxially stretched PET film is attached to protect the polarizing plate on the surface of the liquid crystal display, the triacetylcellulose material as the material of the polarizing plate surface has a refractive index of 1.49 and the biaxially stretched PET film. Has a high refractive index of 1.66, so that reflection occurs at the interface between the two and there is a problem that it is difficult to find the mixed foreign matter in the defect inspection of the manufactured display product.

Therefore, the present invention can be applied to various displays, and a highly transparent protective film in which reflection due to a difference in the refractive index of light is unlikely to occur at the interface with the attached polarizing plate and static electricity is prevented from occurring. The purpose is to provide.

[0006]

FIG. 1 is a sectional view showing the layer structure of a protective film of the present invention. In FIG. 1, 1 is a base film, 2 is an antistatic layer, and 3 is an acrylic adhesive layer. is there. In order to solve the above-mentioned problem, the present invention uses a uniaxially stretched polyethylene terephthalate film as a base film 1, forms an antistatic layer 2 on one surface of the base film 1, and forms the antistatic layer 2 on the other side of the base film. The acrylic adhesive layer 3 is provided on the surface to provide a slightly adhesive and highly transparent protective film.

FIG. 2 is a cross-sectional view showing another layer structure of the protective film of the present invention, and the material of each layer in FIG. 2 is given the same number as in FIG. In order to solve the above-mentioned problems, the present invention uses a uniaxially stretched polyethylene terephthalate film as a base film 1, forms an antistatic layer 2 on one surface of the base film 1, and further forms the antistatic layer 2 The acrylic adhesive layer 3 is provided on the surface of the protective film, which is a slightly adhesive and highly transparent protective film.

Since the protective film of the present invention uses a uniaxially stretched polyethylene terephthalate film as the base film, it has high transparency and its refractive index is about 1.50. When the protective film of the present invention is attached to a polarizing plate arranged on the surface of the liquid crystal of a liquid crystal display, the refractive index of the polarizing plate is about 1.49 when the polarizing plate is triacetyl cellulose. So
There is virtually no difference in the refractive index between the two. Therefore, reflection is unlikely to occur at the interface between the two, and the foreign matter mixed in can be easily found in the defect inspection.

The antistatic layer in the present invention is formed by applying an antistatic resin composition. Examples of the antistatic agent contained in this antistatic resin composition include various cationic antistatic agents having a cationic group such as quaternary ammonium salt, pyridinium salt, and primary to tertiary amino groups, and sulfonic acid. Anionic antistatic agents having anionic groups such as bases, sulfate ester bases, phosphate ester bases and phosphonate bases, amphoteric antistatic agents such as amino acid series and aminosulfate series, amino alcohol series, glycerin series, polyethylene glycol Examples include various surface active agent type antistatic agents such as nonionic antistatic agents, and polymer type antistatic agents obtained by polymerizing the above antistatic agents into a high molecular weight. Group or quaternary ammonium group, monomers and oligomers that are polymerizable by ionizing radiation, such as N, N-dialkylaminoalkyl (meth) Chestnut rates monomers, also polymerizable antistatic agents such as those quaternary compounds can be used.

As described above, the protective film produced by applying the resin composition containing the antistatic agent does not generate static electricity. Therefore, when this protective film is attached to the polarizing plate, static electricity is not generated when the protective film is peeled off, and dust is not attached. Also, when incorporated into a liquid crystal display or the like, there is no external electrostatic damage.

Since the protective film of the present invention has the slightly adhesive layer formed thereon, it has an advantage that it can be reattached cleanly even if it fails when it is attached. In the present invention, slight adhesion means
Using a Tensilon tester, the peel strength measured at 180 ° C. and a peeling speed of 300 mm / min was 1 to 5
0 g / inch, preferably 3 to 15 g / inch. Examples of the slight pressure-sensitive adhesive forming the slight pressure-sensitive adhesive layer include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, and urethane pressure-sensitive adhesives.

[0012]

【Example】

[Example 1] A uniaxially stretched polyethylene terephthalate film (manufactured by Toyobo Co., Ltd.) was prepared as a base film, and the ultraviolet curable antistatic resin composition EXG40-13 (AS-1) [trade name] was provided on the base film. : Manufactured by Dainichi Seika Kogyo Co., Ltd.] was applied so as to have a thickness of 5 μm / dry, and was irradiated with ultraviolet rays to be cured to form an antistatic layer on the substrate film.

Next, as the acrylic adhesive, a slight adhesive having the following composition was prepared. To 100 parts by weight of the ultraviolet curable resin composition SK Dyne 1496-D (trade name: Soken Chemical Co., Ltd., containing 35% of ultraviolet curable resin), an isocyanate curing agent L-45 (trade name) was used as a curing agent. 5 parts by weight was added to obtain a slight adhesive. This slight pressure-sensitive adhesive is applied to the other surface of the base film on which the antistatic layer is not formed by the comma coat method in an amount of 10 to 15 μm / dry.
And was dried at 80 ° C. for 1 to 2 minutes to form an acrylic pressure-sensitive adhesive layer. The obtained laminated film is a highly transparent, highly transparent protective film having high transparency and antistatic properties, which is composed of three layers having a base film as an inner layer.

[Example 2] In Example 2, the same materials as those in Example 1 were used as the materials for forming the base film, the antistatic layer and the acrylic adhesive layer.

On one side of a uniaxially stretched polyethylene terephthalate film (manufactured by Toyobo Co., Ltd.), an ultraviolet curable antistatic resin composition EXG40-13 (AS-1) [trade name: manufactured by Dainichiseika Kogyo Co., Ltd.] was used at 5 μm / dry. And was cured by irradiation with ultraviolet rays to form an antistatic layer on the substrate film.

Then, on this antistatic layer, the same slight adhesive as in Example 1 was used in a comma coat method in an amount of 10 to 15 μm.
It was applied so as to be m / dry and dried at 80 ° C. for 1 to 2 minutes to form an acrylic pressure-sensitive adhesive layer. The obtained laminated film is a highly transparent, slightly adhesive and highly transparent protective film having an antistatic layer and an acrylic adhesive layer formed on one surface of a substrate film and having high transparency.

[0017]

The protective film provided with the antistatic property of the present invention uses a uniaxially stretched polyethylene terephthalate film as a base film, and therefore has a difference substantially from the refractive index of the triacetyl cellulose film used for the polarizing plate. Absent. Therefore, the antistatic protective film of the present invention can prevent light reflection from occurring at the interface between the protective film and the polarizing plate, and has high transparency.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a layer structure of a protective film of the present invention.

FIG. 2 is a cross-sectional view showing another layer structure of the protective film of the present invention.

[Explanation of symbols]

 1 Base Film 2 Antistatic Layer 3 Acrylic Adhesive Layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B32B 27/36 7421-4F C08J 7/04 CFD D G02B 5/30 9018-2K G02F 1/1335 510 7408-2K // B32B 7/02 104 7148-4F 7/10 7148-4F G02B 1/10

Claims (2)

[Claims] 1. An antistatic layer is formed on one surface of a base film made of a uniaxially stretched polyethylene terephthalate film, and an acrylic adhesive layer is provided on the other surface of the base film. A slightly adhesive and highly transparent protective film with antistatic properties. 2. A charging characterized in that an antistatic layer is formed on one surface of a base film made of a uniaxially stretched polyethylene terephthalate film, and an acrylic adhesive layer is further provided on the surface of the antistatic layer. Slightly adhesive and highly transparent protective film with preventive properties.