JP2934305B2 - Surface protection film or sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention makes it possible for an adhesive to easily follow an adherend having a large surface roughness, and to easily peel off without leaving a glue mark even after a long period of time. It relates to a possible surface protection film or sheet.

[Problems to be solved by the prior art and the invention]

In recent years, demand for so-called pre-coated (polyester, urethane, acrylic, etc.) steel sheets, PVC laminated steel sheets, melamine decorative plywood, etc., with embossed surfaces, as interior or exterior materials with enhanced decorative effects in order to give a sense of quality. is increasing.

Such an adherend having a large surface roughness is difficult to adhere to because the adhesive of the surface protective film or sheet is difficult to follow, so that the adherence to the adherend is poor.

Further, there is a problem that even if the lamination pressure is increased at normal temperature, the lamination pressure is increased and the thermoplastic resin is spring-backed, so that the lamination is not performed as a protective film or sheet because the thermoplastic resin is separated from the adherend surface.

Furthermore, in order to improve the adhesiveness, or to add a tackifier or the like to the adhesive, if the thickness of the adhesive layer is increased,
It is conceivable that peeling becomes difficult due to over-adhesion with the adherend or that glue marks remain when peeled from the adherend after a long period of time.

Thus, the present invention provides a surface protective film or an adhesive which easily follows an adherend having a large surface roughness such as emboss, and can be easily peeled off without leaving a glue mark even after a long period of time. Its purpose is to provide a sheet.

[Means for solving the problem]

The present invention is intended to solve the above-mentioned problems, and a layer made of a high melting point resin having a melting point of 130 ° C. or more (hereinafter, referred to as “first
Also referred to as "layer." ), A layer made of a low melting point resin having a melting point of 110 ° C. or less and having a self-supporting property at room temperature (hereinafter, “second layer”)
Also called. ) And a pressure-sensitive adhesive layer, which are sequentially laminated, and are a surface protective film or sheet to be adhered to an adherend by heating in the range of 70 ° C to 130 ° C.

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The drawings show cross-sectional views of the surface protective film or sheet of the present invention, wherein (1) is a first layer, (2) is a second layer,
(3) shows an adhesive layer, respectively.

In the present invention, the melting point of the first layer (1) is 130.
As the high melting point resin having a melting point of not less than 130 ° C. (preferably not less than 130 ° C. and not more than 250 ° C.), a homopolymer such as polyester, vinyl chloride, high-density polyethylene (density: 0.941 to 0.965), polypropylene or a copolymer containing these as a main component And the like, and the thickness of the first layer (1) is 5 to 60 μm, preferably 10 to 60 μm.
40μ.

Further, low-melting point resin having a melting point of 110 ° C. or less (preferably 70 ° C. or more and 110 ° C. or less) constituting the second layer (2) and having self-supporting properties at room temperature include low-density polyethylene (density). : 0.910 to 0.925), an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, and the like. The thickness of the second layer (2) is 5 to 120 µ, preferably 10 to 100 µ.

Further, as an adhesive constituting the adhesive layer (3),
Those generally used for a surface protective film are preferably used. For example, natural rubber, acrylic, polyisobutylene, styrene-isobutylene-styrene copolymer, styrene-butylene-styrene copolymer, styrene-ethylene- A pressure-sensitive adhesive such as a butylene-styrene copolymer is exemplified, and the pressure-sensitive adhesive layer (3) has a thickness of 1 to 30 μm, preferably 2 to 30 μm.
~ 20μ. The reason is that the thickness of the adhesive layer (3) is 30
If it exceeds μ, peeling may be difficult due to over-adhesion to the adherend, or glue may remain when peeled.

The first layer (1) and the second layer (2) constituting the support of the surface protective film or sheet of the present invention are generally formed by coextrusion, dry lamination, wet lamination,
It can be manufactured by an extrusion lamination method or a method combining these methods. As a means for improving the adhesion between the first layer (1) and the second layer (2), an adhesive layer is provided in the middle. Is also good.

In order to adhere the surface protective film or sheet of the present invention to an adherend having a large surface roughness (Rz: 100 to 100 μm) such as embossed, after superimposing the adherend on the adherend, the melting point of the second layer Above the melting point of the first layer (130 ° C), preferably 130 ° C
The heating and laminating may be performed at a temperature within a range of from 70 to 70 ° C, more preferably from 120 to 80 ° C.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

〔Example〕

Example 1 25 μm polyester film (melting point: 235 ° C.)
The second layer was laminated with 50 μm of an ethylene-vinyl acetate copolymer (vinyl acetate content: 14%, melting point: 80 ° C.) [second layer] as a support, and the second layer was coated with 5 μm of an acrylic pressure-sensitive adhesive.
It was applied so as to be thick to produce a surface protective film or sheet.

Example 2 A polypropylene layer (melting point 165 ° C.) [first layer] was 30 μm,
Low density polyethylene (density: 0.92, melting point 105 ° C) [No.
Layer) is 30μ, and the co-extruded material is used as a support,
The same pressure-sensitive adhesive as in Example 1 was applied to the second layer to a thickness of 10 μm to produce a surface protective film or sheet.

Comparative Example 1 A 60 μm polypropylene (melting point 165 ° C.) was used as a support.
The same adhesive as in Example 1 was applied to a thickness of 10 μm,
A surface protection film or sheet was manufactured.

Comparative Example 2 80μ low density polyethylene (density: 0.92, melting point 105 ° C)
Was used as a support, and the same pressure-sensitive adhesive as in Example 1 was applied to a thickness of 50 μm to produce a surface protective film or sheet.

Test Example 1 Adhesion of the surface protective film or sheet obtained in Examples 1 and 2 and Comparative Examples 1 and 2 to an adherend at room temperature and 120 ° C., and change in adhesive force when peeled over time. Was examined.
The results are shown in Table 1.

[Function / Effect] Since the surface protective film or sheet of the present invention is provided with a low-melting resin layer in the second layer, when heated and pressed at a temperature higher than that temperature, the second layer is melted to form an adherend. Follows embossed shape. At this time, since the melting point of the first layer is higher than the melting point of the second layer, the self-supporting property of the first layer is not lost. Thereby, even a very thin layer of pressure-sensitive adhesive can adhere to the rough surface. Further, the second layer is hardened at room temperature, and does not hinder peeling.

Therefore, it can be easily bonded to an adherend having a large surface roughness, and the increase in adhesive strength after bonding can be suppressed to a very small value.

[Brief description of the drawings]

The drawing is a sectional view of the surface protective film or sheet of the present invention. (1) First layer (2) Second layer (3) Adhesive layer

Claims (1)

(57) [Claims] 1. A first layer made of a high melting point resin having a melting point of 130 ° C. or more, a second layer made of a low melting point resin having a melting point of 110 ° C. or less and having self-supporting properties at room temperature, and an adhesive layer are sequentially laminated. A surface protective film or sheet which is heated within a temperature range from the melting point of the second layer to less than the melting point of the first layer to adhere to an adherend.