Surface protection film

Abstract

Provided is a surface protection film which exerts appropriate adhesive properties even to an adherend having a rough surface and which exhibits excellent back surface slidability, blocking resistance, and reeling properties. Specifically, disclosed is a surface protection film which has a laminate structure comprising at least an adhesive layer and a back surface layer, wherein: the adhesive layer is mainly formed from a styrene-based elastomer; the back surface layer is mainly formed from a propylene-based resin containing 0.5 weight% to 10 weight% of a fluorine-containing compound having a polyfluoro-hydrocarbon group and a polyoxyethylene group, and has a 10-point average surface roughness (Rz) of 3[mu]m or more; and the surface protection film has an initial adhesion strength of 1N / 25mm or more in relation to a SUS304 plate, which was subjected to a #320 hair-line processing treatment, and has a reeling strength of 0.5N / 25mm or less when the rolled-up film is being reeled.

Description

technical field [0001] The present invention relates to a surface protection film used to prevent adhesion of stains or scratches on the surface of an adherend. More specifically, it relates to a surface protection film which is effective even for adherends whose surfaces are rough, such as diffusion plates, diffusion films, or prism sheets used in the field of optics. Appropriate adhesive properties, excellent sliding properties on the back side, and excellent handling properties such as blocking resistance and unwinding properties. Background technique [0002] When processing and transporting synthetic resin sheets, metal sheets, coated steel sheets, and various signs, etc., surface protection films are used to prevent stains from adhering to or scratching the surfaces of these products. [0003] In particular, in recent years, ultra-thin displays such as liquid crystal displays are often used as display devices for personal computers, ultra-thin televisions, and the lik...

AI Technical Summary

Problems solved by technology

[0005] In addition, these surface protection films are usually rolled into a roll to form a roll, and these rolls have a problem that the films are easily blocked because the base layer and the adhesive layer are pressed together by a strong adhesive force. , when the surface protective film is unrolled during use, it is difficult to perform operations such as peeling off

As such a release treatment, the method of previously applying a release agent to the back layer has been used conventionally. However, it is difficult to achieve a strong bond between the release agent and the back layer and to make it easy to separate from the adhesive layer. Therefore, using A method of undercoating a special release agent, or corona-treating the back layer before applying a release agent

However, there are problems in that the coating process of such release treatment becomes complicated, and the yield decreases and the cost increases.

However, in such a method, a part of the silicon-based fine particles is captured by the adhesive layer due to the adhesive properties of the adhesive layer, and there is a problem of causing contamination of the adherend or lowering of the adhesive force.

[0010] In addition, for the method of forming the substrate layer and the adhesive layer by the co-extrusion method and laminating them at the same time, many proposals have been proposed, represented by the above-mentioned patent documents. Among them, a laminated film has also been proposed. The composite film is constituted as an adhesive layer that has suitable adhesiveness for sticking to the surface of the adherend, is easy to peel off when peeled off, and does not pollute the surface of the adherend, and is composed of styrene and diene hydrocarbons. Random copolymers are formed (Patent Document 4, Patent Document 5), but it is difficult to avoid the above-mentioned problem of sticking during unwinding that leads to difficult unwinding, and there are common problems that need to be solved with the above-mentioned

[0011] In order to solve such problems in the prior art, the present applicant has proposed a plan for roughening both surfaces of the adhesive layer and the back layer (Patent Document 6), but when desiring to obtain higher adhesive force, sometimes Insufficient effect

[0012] In addition, it is also proposed that the back layer is composed of fluorine-based resin or silicon-based resin and polyolefin (Patent Document 7), but sufficient effect cannot be obtained only by using fluorine-based resin or the like. During storage, etc., the adhesive layer and the back layer may easily stick together

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