CN103254819A - Surface protection sheet - Google Patents

Abstract

The present invention provides a surface protection sheet including a base material layer and an adhesive layer, wherein even if a foreign matter is embedded on the outermost surface of the base material layer, the appearance and touch are not impaired. The surface protection sheet of the present invention comprises a substrate layer and an adhesive layer, the substrate layer and the adhesive layer are formed integrally by co-extrusion, and the surface roughness Ra of the outermost surface of the substrate layer is 0.10 μm to 0.60 μm, and the 60-degree glossiness of the outermost surface of the substrate layer is 20.0 to 71.5.

Description

surface protection sheet

technical field

The present invention relates to a surface protection sheet. Specifically, the present invention relates to a surface protection sheet including a base material layer and an adhesive layer. The surface protection sheet of the present invention is used, for example, in transporting, processing or maintaining metal plates, painted plates, aluminum alloy frames, resin plates, decorative steel plates, vinyl chloride laminated steel plates, glass plates and other components, polarizing films, optical components such as liquid crystal panels, For electronic components, etc., it can be used for the purpose of sticking to the surface of these and protecting them.

Background technique

The surface protection sheet is usually provided with an adhesive layer on one side of the substrate layer. As a method of producing such a surface protection sheet including a base material layer and an adhesive layer, a method of integrating the base material layer and the adhesive layer by coextrusion molding has been proposed (for example, refer to Patent Document 1).

Generally, the outermost surface of the base material layer in the surface protection sheet may have many foreign substances embedded therein. Therefore, in the conventional surface protection sheet, when the outermost surface of the base material layer is smoothed, there is a problem that the external appearance and touch are impaired due to internal foreign matter.

prior art literature

Patent document: Japanese Patent Application Laid-Open No. 61-103975

Contents of the invention

The problem to be solved by the invention

An object of the present invention is to provide a surface protection sheet including a base material layer and an adhesive layer, wherein even if a foreign substance is embedded on the outermost surface of the base material layer, the appearance and touch are not impaired. means to solve the problem

The surface protection sheet of the present invention comprises a substrate layer and an adhesive layer, wherein,

The substrate layer and the adhesive layer are integrally formed by co-extrusion,

The surface roughness Ra of the outermost surface of the substrate layer is 0.10 μm to 0.60 μm,

The 60 degree glossiness of the outermost surface of this base material layer is 20.0-71.5.

In a preferred embodiment, the surface roughness Ra is 0.20 μm˜0.60 μm, and the 60 degree gloss is 20.0˜65.0.

In a preferred embodiment, the base material layer contains a polyolefin-based resin as a main component.

In a preferred embodiment, the base material layer includes a white-colored layer.

In a preferred embodiment, the white-colored layer contains a polyethylene-based resin as a main component.

In a preferred embodiment, the polyethylene-based resin contains autoclave polyethylene as a main component.

In a preferred embodiment, the white-colored layer further contains a resin different from the polyethylene-based resin.

In a preferred embodiment, the resin different from the polyethylene-based resin is at least one selected from polypropylene-based resins and ethylene-vinyl acetate copolymers.

In a preferred embodiment, the white-colored layer contains particles.

In a preferred embodiment, the base material layer includes a black color layer.

In preferable embodiment, the said black-colored layer contains polyethylene-type resin as a main component.

In a preferred embodiment, the adhesive layer comprises a styrenic thermoplastic elastomer.

Invention effect

According to the present invention, it is possible to provide a surface protection sheet including a base material layer and an adhesive layer, wherein even if foreign matter is embedded on the outermost surface of the base material layer, the appearance and feel are not impaired.

Description of drawings

FIG. 1 is a cross-sectional view schematically showing an example of the structure of the surface protection sheet of the present invention.

Symbol Description

100 surface protection sheets

10 adhesive layers

20 substrate layers

21 white layer

22 black layer

Detailed ways

The surface protection sheet of the present invention comprises a substrate and an adhesive layer. The surface protection sheet of this invention may contain arbitrary appropriate other layers in the range which does not impair the effect of this invention.

The thickness of the substrate layer is preferably 20 μm to 300 μm, more preferably 30 μm to 250 μm, even more preferably 40 μm to 200 μm, particularly preferably 45 μm to 150 μm, most preferably 50 μm to 100 μm. As long as the thickness of the base layer is within the above range, when the surface protection sheet of the present invention is attached to an adherend and then peeled off, the base layer is less likely to be damaged or cracked, and the hardness of the base layer can be suppressed. Therefore, after sticking the surface protection sheet of the present invention to an adherend, it is difficult to cause floating or the like.

The thickness of the adhesive layer is preferably 1 μm to 50 μm, more preferably 2 μm to 40 μm, even more preferably 3 μm to 30 μm, particularly preferably 4 μm to 20 μm, most preferably 5 μm to 10 μm. By setting the thickness of the adhesive layer within the above range, it is easy to control the layer configuration when producing the surface protection sheet of the present invention by coextrusion molding, and a surface protection sheet having sufficient mechanical strength can be obtained.

The overall thickness of the surface protection sheet of the present invention is preferably 30 μm to 150 μm, more preferably 35 μm to 140 μm, still more preferably 40 μm to 130 μm, particularly preferably 45 μm to 120 μm, and most preferably 50 μm to 110 μm. By keeping the overall thickness of the surface protection sheet of the present invention within the above range, a surface protection sheet having excellent handling properties and sufficient mechanical strength can be obtained.

The display protection sheet of the present invention is formed by co-extruding the base material layer and the adhesive layer into one body. As the coextrusion molding, any appropriate coextrusion molding generally used in the production of films, sheets, etc. can be adopted. As coextrusion molding, blow molding method, coextrusion T-die method, etc. can be used, for example. These coextrusion moldings are preferable from the viewpoints of cost and productivity.

In the surface protection sheet of the present invention, the surface roughness Ra of the outermost surface of the substrate layer is 0.10 μm to 0.60 μm, preferably 0.20 μm to 0.60 μm, more preferably 0.25 μm to 0.60 μm, even more preferably 0.30 μm ~0.60 μm, particularly preferably 0.35 μm to 0.60 μm, most preferably 0.40 μm to 0.60 μm. By keeping the surface roughness Ra of the outermost surface of the base layer within the above-mentioned range, the outermost surface of the base layer can be effectively roughened, and even on the outermost surface of the base layer, for example, internally A surface protection sheet that does not impair the appearance and feel of foreign matter. In addition, the details of the method of measuring the surface roughness Ra will be described later.

For the surface protection sheet of the present invention, the 60-degree glossiness of the outermost surface of the substrate layer is 20.0 to 71.5, preferably 20.0 to 65.0, more preferably 20.0 to 63.0, still more preferably 20.0 to 60.0, particularly preferably 20.0 ~55.0, most preferably between 20.0 and 50.0. By keeping the 60-degree glossiness of the outermost surface of the base layer within the above-mentioned range, the outermost surface of the base layer can be effectively matted, and even if there are foreign substances on the outermost surface of the base layer, for example, internal , and will not damage the appearance and touch of the surface protection sheet. In addition, the detail of the measuring method of 60 degree glossiness is mentioned later.

In the surface protection sheet of the present invention, it is preferable that both the surface roughness Ra of the outermost surface of the substrate layer and the 60-degree glossiness of the outermost surface of the substrate layer fall within the above ranges. For example, the surface protection sheet of the present invention preferably has a surface roughness Ra of 0.10 μm to 0.60 μm on the outermost surface of the substrate layer, and preferably has a 60-degree glossiness of 20.0 to 71.5 on the outermost surface of the substrate layer, more preferably the surface The roughness Ra is 0.20 μm to 0.60 μm, and more preferably the 60 degree gloss is 20.0 to 65.0. By keeping the surface roughness Ra of the outermost surface of the base layer and the 60-degree glossiness of the outermost surface of the base layer within the above-mentioned ranges, the outermost surface of the base layer can be effectively roughened and matted. The treatment is effective in providing a surface protection sheet that does not impair the appearance and touch even if foreign matter is embedded on the outermost surface of the base material layer, for example.

The base material layer preferably contains a polyolefin-based resin as a main component. When the base material layer contains polyolefin-based resin as a main component, it can have heat resistance, solvent resistance, and flexibility, and can be easily wound up into a roll shape. The polyolefin-based resin contained in the base material layer may be only one kind, or may be two or more kinds.

The substrate layer may be a single layer or a multilayer.

Here, in the present invention, the "main component" is preferably 50% by weight or more, more preferably 60% by weight or more, still more preferably 70% by weight or more, particularly preferably 80% by weight or more, most preferably 90% by weight %above.

Examples of polyolefin-based resins include polyethylene-based resins, polypropylene-based resins, ethylene·α-olefin copolymers, and the like.

Specific examples of polyolefin-based resins include polyethylene-based resins such as high-density polyethylene (HDPE), medium-density polyethylene, low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE). Resin; polypropylene-based resins such as homopolypropylene, block polypropylene, and random polypropylene; poly(1-butene), poly(4-methyl-1-pentene), ethylene-propylene copolymer, ethylene- 1-butene copolymer, ethylene·1-hexene copolymer, ethylene·4-methyl-1-pentene copolymer, ethylene·1-octene copolymer, ethylene·methyl acrylate copolymer, ethylene·formaldehyde Ethylene-α-olefin copolymers such as methyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl alcohol copolymer, etc.

When the base material layer is composed of two or more layers, it is preferable to select, as the resin components constituting them, those that can form strong bonds with each other by melt coextrusion.

The base material layer may also contain a white color layer. When the base layer contains a white-colored layer, a surface protection sheet excellent in weather resistance can be obtained.

The base layer may also contain a black color layer. When the base material layer contains a black color layer, it can be set as a surface protection sheet excellent in weather resistance.

Preferably, the substrate layer includes at least two layers, a white-based layer and a black-based layer. When the base material layer includes at least two layers of a white-based layer and a black-based layer, a surface protection sheet with excellent weather resistance can be produced.

When the substrate layer includes at least two layers of a white-based layer and a black-based layer, as the laminated structure of the surface protection sheet of the present invention, as long as the effect of the present invention is not impaired, for example, "white-based layer/black-based layer/ Adhesive layer", "black-colored layer/white-colored layer/adhesive layer" and other arbitrary appropriate laminated structures. Fig. 1 is a cross-sectional view schematically showing an example of a structure in which the surface protection sheet 100 of the present invention has a laminated structure of "white-colored layer 21/black-colored layer 22/adhesive layer 10". The white-color layer 21 and the black-color layer 22 become the base material layer 20 .

The white layer is a layer showing a white color tone. For example, the whiteness specified in JIS-L-1015 is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, particularly preferably 85% or more. The white-based layer preferably contains a white pigment. Any appropriate white pigment can be used as the white pigment. As such a white pigment, titanium oxide is mentioned, for example. When the white-colored layer contains a white pigment, its content is preferably 0.1% by weight to 50% by weight, more preferably 1% by weight to 40% by weight, and still more preferably 2% by weight, based on the resin component forming the white-colored layer. ~30% by weight. By making the content ratio of the white pigment to the resin component forming the white-colored layer within the above-mentioned range, a surface protection sheet excellent in weather resistance can be obtained, and moldability such as extrudability is also excellent.

The white-colored layer preferably contains a polyolefin-based resin as a main component. Examples of the polyolefin-based resin that can be included in the white-colored layer include polyethylene-based resins, polypropylene-based resins, ethylene·α-olefin copolymers, and the like. The polyolefin-type resin which can be contained in a white-colored layer may use only 1 type, and may use 2 or more types.

Specific examples of polyolefin-based resins that may be included in the white-colored layer include high-density polyethylene (HDPE), medium-density polyethylene, low-density polyethylene (LDPE), and linear low-density polyethylene. (LLDPE) and other polyethylene resins; homopolypropylene, block polypropylene, random polypropylene and other polypropylene resins; poly(1-butene), poly(4-methyl-1-pentene), ethylene Propylene copolymer, ethylene 1-butene copolymer, ethylene 1-hexene copolymer, ethylene 4-methyl-1-pentene copolymer, ethylene 1-octene copolymer, ethylene methacrylate Ethylene/α-olefin copolymers such as ester copolymers, ethylene/methyl methacrylate copolymers, ethylene/vinyl acetate copolymers, ethylene/ethyl acrylate copolymers, ethylene/vinyl alcohol copolymers, etc.

The content of the polyolefin-based resin in the white-colored layer is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, most preferably 90% by weight or more .

The white-colored layer preferably contains a polyethylene-based resin as a main component. By containing the polyethylene-based resin as a main component in the white-colored layer, the base material layer can have heat resistance, solvent resistance, and flexibility, and the surface protection sheet of the present invention can be easily wound into a roll.

When the white-colored layer contains polyethylene-based resin as a main component, the polyethylene-based resin preferably contains low-density polyethylene as a main component. When the polyethylene-based resin contains low-density polyethylene as a main component, the base material layer can have sufficient heat resistance, solvent resistance, and flexibility, and the surface protection sheet of the present invention can be wound into a roll more easily. .

Examples of the polyethylene-based resin that can be contained in the white-colored layer include autoclave-processed polyethylene and tubular-processed polyethylene.

Compared with tubular polyethylene, autoclave polyethylene has a wider molecular weight distribution, and there are many high molecular weight components. Therefore, when autoclaved polyethylene is used as the main component of the polyethylene-based resin that can be contained in the white-colored layer, the outermost surface of the white-colored layer can be effectively matted. In addition, the long chain branch of autoclave polyethylene causes a swelling phenomenon called a charge swelling phenomenon accompanied by a pressure loss during extrusion molding. Therefore, when autoclaved polyethylene is used as the main component of the polyethylene-based resin that can be contained in the white-colored layer, the outermost surface of the white-colored layer can be effectively roughened. As the polyethylene-based resin contained in the white-colored layer, autoclave-processed polyethylene and pipe-processed polyethylene may be used in combination.

The density of the polyethylene-based resin that can be included in the white-colored layer is preferably 0.880 g/cm ³ to 0.940 g/cm ³ , more preferably 0.880 g/cm ³ to 0.923 g/cm ³ , and even more preferably 0.880 g/cm ³ ~0.915 g/cm ³ . By making the density of the polyethylene-type resin which can be contained in a white-colored layer into the said range, the roughening and matte processing of the outermost surface of a white-colored layer can be effectively performed.

The MFR of the polyethylene-based resin that can be contained in the white-colored layer is preferably 0.1 g/10 min to 10 g/10 min, more preferably 0.3 g/10 min to 5 g/10 min, and still more preferably 0.3 g/10 min to 3 g/10 min. By making MFR of the polyethylene-type resin which can be contained in a white-colored layer into the said range, the outermost surface of a white-colored layer can be roughened and matte-processed effectively.

When the white-colored layer contains a polyethylene-based resin as a main component, the white-colored layer may further contain a resin different from the polyethylene-based resin (this may be referred to as a "different resin"). When the white-colored layer contains a different type of resin, the outermost surface of the white-colored layer can be effectively roughened and matted in combination with the polyethylene-based resin. As such a different type of resin, any appropriate resin can be employed within the range not impairing the effect of the present invention. As such a different kind of resin, for example, at least one selected from polypropylene-based resins and ethylene-vinyl acetate copolymers may be mentioned. When the white-colored layer contains such a different resin, the content of the different resin in the white-colored layer is preferably 5% by weight to 70% by weight, more preferably 10% by weight to 50% by weight, and even more preferably 10% by weight. % by weight to 40% by weight, particularly preferably 10% by weight to 30% by weight. By making the content ratio of such a different resin in the white-colored layer within the above-mentioned range, the outermost surface of the white-colored layer can be roughened and matted more effectively by combining with the polyethylene-based resin.

The white layer can also contain particles. By containing particles in the white-colored layer, roughening and matting can be effectively performed on the outermost surface of the white-colored layer. As such particles, any appropriate particles can be employed within the range not impairing the effect of the present invention. Examples of such particles include organic particles, inorganic particles, and the like. Examples of organic particles include acrylic beads made of PMMA and the like. Examples of the inorganic particles include silica, zeolite, and the like. When the white-colored layer contains such particles, the content of such particles in the white-colored layer is preferably 0.3% by weight to 10% by weight, more preferably 0.5% by weight to 7% by weight, and even more preferably 0.5% by weight. ~5% by weight, particularly preferably 0.5% by weight to 3% by weight. By making the content ratio of such particles in the white-colored layer within the above range, the outermost surface of the white-colored layer can be more effectively roughened and matted.

As the thickness of the white-colored layer, any appropriate thickness can be adopted according to the purpose. Such a thickness is preferably 2 μm to 100 μm, more preferably 3 μm to 80 μm, still more preferably 4 μm to 60 μm, particularly preferably 5 μm to 50 μm.

The black-based layer is a layer showing a black-based color tone. Preferably, the black-colored layer contains a black pigment. Any appropriate black pigment can be used as the black pigment. As such a black pigment, carbon black is mentioned, for example. When the black-colored layer contains a black pigment, its content is preferably 0.01% by weight to 10% by weight, more preferably 0.1% by weight to 5% by weight, and still more preferably 0.5% by weight, based on the resin component forming the black-colored layer. ~3% by weight. By setting the content ratio of the black pigment to the resin component forming the black-colored layer within the above-mentioned range, a surface protection sheet excellent in weather resistance can be obtained, and moldability such as extrudability is also excellent.

The black-colored layer preferably contains a polyolefin-based resin as a main component. Examples of the polyolefin-based resin that can be included in the black-colored layer include polyethylene-based resins, polypropylene-based resins, ethylene·α-olefin copolymers, and the like. The polyolefin-type resin which can be contained in a black-colored layer may use only 1 type, and may use 2 or more types.

Examples of polyolefin-based resins that can be included in the black-colored layer include high-density polyethylene (HDPE), medium-density polyethylene, low-density polyethylene (LDPE), and linear low-density polyethylene. (LLDPE) and other polyethylene resins; homopolypropylene, block polypropylene, random polypropylene and other polypropylene resins; poly(1-butene), poly(4-methyl-1-pentene), ethylene Propylene copolymer, ethylene 1-butene copolymer, ethylene 1-hexene copolymer, ethylene 4-methyl-1-pentene copolymer, ethylene 1-octene copolymer, ethylene methacrylate Ethylene/α-olefin copolymers such as ester copolymers, ethylene/methyl methacrylate copolymers, ethylene/vinyl acetate copolymers, ethylene/ethyl acrylate copolymers, ethylene/vinyl alcohol copolymers, etc.

The content of the polyolefin resin in the black-colored layer is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, most preferably 90% by weight or more .

The black-colored layer preferably contains a polyethylene-based resin as a main component. By containing the polyethylene-based resin as a main component in the black-colored layer, the base material layer can have heat resistance, solvent resistance, and flexibility, and the surface protection sheet of the present invention can be easily wound into a roll.

When the black-colored layer contains a polyethylene-based resin as a main component, it is preferable that the polyethylene-based resin contains at least one selected from low-density polyethylene and linear low-density polyethylene. When the above-mentioned polyethylene-based resin contains at least one selected from low-density polyethylene and linear low-density polyethylene, the base layer can sufficiently have heat resistance, solvent resistance, and flexibility, and can be further easily The surface protection sheet of the present invention is wound into a roll.

The density of the polyethylene-based resin that can be included in the black-colored layer is preferably 0.880 g/cm ³ to 0.940 g/cm ³ , more preferably 0.880 g/cm ³ to 0.924 g/cm ³ , and still more preferably 0.880 g/cm ³ ~0.915 g/cm ³ . By making the density of the polyethylene-based resin that can be contained in the black-colored layer fall within the above-mentioned range, the base material layer can have sufficient heat resistance, solvent resistance, and flexibility, and the surface protection of the present invention can be further easily protected. The sheet is wound into a roll shape.

The MFR of the polyethylene-based resin that can be contained in the black-colored layer is preferably 1 g/10 min to 10 g/10 min, more preferably 1 g/10 min to 5 g/10 min, and even more preferably 2 g/10 min to 4 g/10 min. By making the MFR of the polyethylene-based resin that can be included in the black-colored layer fall within the above-mentioned range, the base layer can have sufficient heat resistance, solvent resistance, and flexibility, and the surface protection of the present invention can be further easily protected. The sheet is wound into a roll shape.

As for the thickness of the black color layer, any appropriate thickness can be adopted according to the purpose. Such a thickness is preferably 2 μm to 100 μm, more preferably 3 μm to 80 μm, still more preferably 4 μm to 60 μm, particularly preferably 5 μm to 50 μm.

The base material layer may contain arbitrary appropriate additives. Such additives include, for example, antioxidants, ultraviolet absorbers, antiaging agents, light stabilizers, antistatic agents, surface lubricants, leveling agents, plasticizers, low molecular polymers, preservatives, Polymerization agent, silane coupling agent, inorganic and organic fillers (such as calcium oxide, magnesium oxide, silicon dioxide, zinc oxide, titanium oxide, etc.), metal powder, colorant, pigment, heat-resistant stabilizer, anti-deposition Anti-adhesive agent (目ヤニ preventive agent), lubricant, anti-blocking agent, etc.

Back treatment may also be performed on the outermost layer on the side opposite to the adhesive layer of the base material layer. As a method of backside treatment, any appropriate method can be employed within the range not impairing the effect of the present invention. Examples of methods for such back treatment include surface treatment such as embossing and uneven treatment, methods including a long-chain alkyl-based back treatment agent or a fatty acid derivative, and the like. Such a long-chain alkyl-based back-treating agent or fatty acid derivative may be only one kind, or two or more kinds thereof.

When the substrate layer contains a fatty acid derivative, the content ratio of the fatty acid derivative in the substrate layer is preferably 0.05% by weight to 1.00% by weight, more preferably 0.10% by weight to 1.00% by weight, based on the resin component in the substrate layer. 0.90% by weight, more preferably 0.30% by weight to 0.80% by weight. By setting the content ratio of the fatty acid derivative in the base layer to the resin component in the base layer within the above-mentioned range, the roll-shaped surface protection sheet of the present invention can be easily unwound, and can sufficiently express release effect, and at the same time, the pollution caused by the oozing out of the fatty acid derivative can be sufficiently suppressed.

The fatty acid derivative refers to a compound including a fatty acid derivative structure in its molecular structure.

Examples of fatty acid derivatives include saturated fatty acid bisamides, unsaturated fatty acid bisamides, aromatic bisamides, substituted ureas, and fatty acid metal salts. Examples of fatty acid derivatives include, for example, methylenebisstearic acid amide, ethylenebisstearic acid amide, ethylenebisoleic acid amide, N,N-dioleyl hexadiene acid amide, N-stearyl-N'-stearyl urea, etc., N-stearyl-N'-stearic acid amide, zinc stearate, etc.

As a fatty acid derivative, preferably a fatty acid amide, more preferably at least one selected from methylenebisstearic acid amide, ethylenebisstearic acid amide, N-stearyl-N'-stearic acid amide kind.

The fatty acid derivative preferably has a melting point of 100°C or higher. Fatty acid derivatives having a melting point of less than 100° C. transfer significantly to the surface of the adhesive layer, which may easily cause a decrease in adhesive force.

It is preferable that the adhesive layer contains a thermoplastic resin as a main component. The thermoplastic resin contained in the adhesive layer may be only one kind, or may be two or more kinds.

Any appropriate thermoplastic resin can be adopted as the thermoplastic resin. Examples of such thermoplastic resins include olefin-based resins, aromatic group-containing olefin/diene copolymers, styrene-based resins, and ester-based resins. Among these thermoplastic resins, styrene-based resins are preferred, and styrene-based thermoplastic elastomers are more preferred.

As a styrene-type thermoplastic elastomer, Preferably, a styrene-type block copolymer or its hydrogenated substance is mentioned.

Examples of styrene-based block copolymers include styrene-butadiene-styrene copolymers (SBS), styrene-isoprene-styrene copolymers (SIS), and other styrene-based ABA types. Block copolymers (tri-block copolymers); styrene-butadiene-styrene-butadiene copolymer (SBSB), styrene-isoprene-styrene-isoprene copolymer (SISI ) and other styrene-based ABAB block copolymers (tetrablock copolymers); styrene butadiene styrene butadiene styrene copolymer (SBSBS), styrene isoprene benzene Styrenic ABABA-type block copolymers (pentablock copolymers) such as ethylene-isoprene-styrene copolymer (SISIS); styrenic block copolymers having more than one AB repeating unit; and the like.

Examples of hydrogenated products of styrene-based block copolymers include: styrene-ethylene-butylene copolymer-styrene copolymer (SEBS), styrene-ethylene-propylene copolymer-styrene copolymer (SEPS) ), styrene·ethylene-butylene copolymer·styrene·ethylene-butylene copolymer (SEBSEB), etc.

The styrene-based thermoplastic elastomer may be used alone or two or more kinds may be used.

When the styrene-based thermoplastic elastomer is a styrene-based block copolymer or a hydrogenated product thereof, the styrene block content in the styrene-based thermoplastic elastomer is preferably 5% by weight to 40% by weight, more preferably 7% by weight to 30% by weight, more preferably 9% by weight to 20% by weight. When the above-mentioned styrene block content is reduced, there is a possibility that adhesive residue due to insufficient cohesion of the adhesive layer may easily occur. When the above-mentioned styrene block content increases, the adhesive layer may become hard, and there is a possibility that favorable adhesiveness to a rough surface may not be obtained.

As the styrene-based thermoplastic elastomer, a styrene-based block copolymer having a repeating structure (ABA type, ABAB type, ABABA type, etc.) of a triblock copolymer or more composed of styrene (A) and butadiene (B) is preferable Hydrides of segment copolymers (SEBS, SEBSEB, SEBSEBS, etc.). By adopting such a styrene-based thermoplastic elastomer, the adhesive force in the state of sticking to the adherend can be further moderately and sufficiently improved, and on the other hand, the adhesive force when peeling off after sticking to the adherend It is a more moderate size, so it can be peeled off from the adherend more easily with a slight force, and further, it can further suppress the increase in the adhesive force under the environmental load of long-term storage at a relatively high temperature .

The styrene-based thermoplastic elastomer is a styrene-based block having a repeating structure (ABA type, ABAB type, ABABA type, etc.) of a triblock copolymer composed of styrene (A) and butadiene (B). In the case of a hydrogenated copolymer (SEBS, SEBSEB, SEBSEBS, etc.), the proportion of the butene structure in the ethylene-butene copolymer block is preferably 60% by weight or more, more preferably 70% by weight or more, and furthermore Preferably it is 75% by weight or more. By keeping the ratio of the butene structure in the ethylene-butene copolymer block within the above range, the adhesive force in the state of sticking to an adherend can be further moderately and sufficiently improved. On the other hand, The adhesive force at the time of peeling off after sticking to the adherend is further moderate, so it can be peeled off from the adherend more easily with a slight force, and further, exposure to higher temperatures can be further suppressed. The increase of the adhesive force in the case of long-term storage in the case of environmental load. In addition, the proportion of the butene structure in the ethylene-butene copolymer block is preferably 90% by weight or less.

The adhesive layer may contain other styrene-based thermoplastic elastomers within a range that does not impair the object of the present invention for the purpose of adjusting the adhesiveness.

Other styrene-based thermoplastic elastomers include: styrene-based block copolymers other than the above; styrene-butadiene copolymer (SB), styrene-isoprene copolymer (SI), Styrene-ethylene-butylene copolymer (SEB), styrene-ethylene-propylene copolymer (SEP) and other AB block polymers; styrene-butadiene rubber (SBR) and other benzene Ethylene-based random copolymers; A-B-C type styrene-olefin crystalline block polymers such as styrene-ethylene-butylene copolymer-olefin crystalline copolymers (SEBC); hydrogenated products of these, etc.

When forming the adhesive layer, for the purpose of controlling adhesive properties, etc., for example, polyolefin-based resins, silicone-based polymers, Liquid acrylic copolymers, phosphate ester compounds, anti-aging agents, light stabilizers, UV absorbers, surface lubricants, leveling agents, plasticizers, low molecular polymers, antioxidants, preservatives, polymerization inhibitors , silane coupling agent, inorganic and organic fillers (such as calcium oxide, magnesium oxide, silicon dioxide, zinc oxide, titanium oxide, etc.), metal powder, colorant, pigment, heat-resistant stabilizer and other additives.

Surface treatment such as corona discharge treatment, ultraviolet irradiation treatment, flame treatment, plasma treatment, sputter etching treatment and the like may be performed on the surface of the adhesive layer as necessary for the purpose of controlling the adhesion or sticking workability.

Compounding of a tackifier is effective for improving the adhesive force. However, in order to avoid the problem of adhesive residue caused by the reduction of the cohesive force, the compounding amount of the tackifier is appropriately determined according to the adherend to which the surface protection sheet is applied. The blending amount of the tackifier is preferably 80% by weight or less, more preferably 40% by weight or less, and still more preferably 20% by weight or less, based on the base polymer of the adhesive layer. In addition, when the adherend to which the surface protection sheet is applied is a metal plate, it is preferable not to add a tackifier when forming the adhesive layer.

As the tackifier, for example, petroleum-based resins such as aliphatic copolymers, aromatic copolymers, aliphatic-aromatic copolymers, or alicyclic copolymers can be used without particular limitation; coumarone-indene Rosin-based resins, terpene-based resins, terpene-phenolic resins, polymerized rosin and other rosin-based resins; (alkyl) phenolic-based resins, xylene-based resins, and their hydrogenated products are generally used as tackifiers for adhesives. One kind of thickener may be used, or two or more kinds may be used. Among these tackifiers, hydrogenated tackifiers are preferable from the viewpoint of peelability, weather resistance, and the like. Moreover, the tackifier commercially available as a blend with an olefin resin can also be used for a tackifier.

The addition of a softener is effective for improving the adhesive force. Examples of softeners include low molecular weight diene polymers, polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene, derivatives thereof, and the like. Such derivatives include, for example, derivatives having OH groups or COOH groups at one or both terminals, specifically, hydrogenated polybutadiene diol, hydrogenated polybutadiene monoalcohol, hydrogenated polybutadiene monoalcohol, hydrogenated Polyisoprene diol, hydrogenated polyisoprene monoalcohol, etc. In particular, a hydrogenated product of a diene polymer such as hydrogenated polybutadiene or hydrogenated polyisoprene, or an olefin-based softener is preferable for the purpose of suppressing an increase in adhesiveness to an adherend. As such a softener, the brand name "KurapreneLIR-200" etc. of the Kuraray company make are specifically, available. These softeners may be used alone or in combination of two or more.

The molecular weight of the softener can be appropriately set to any appropriate amount. However, when the molecular weight becomes smaller, it may cause migration of substances from the adhesive layer to the adherend or re-peeling. On the other hand, when the molecular weight becomes larger, , the improvement effect of the adhesive force tends to be insufficient, so the number average molecular weight of the softener is preferably 5,000 to 100,000, and more preferably 10,000 to 50,000.

In the case of using a softener, its addition amount can be appropriately set to any appropriate amount, but when the addition amount increases, the residual adhesive tends to increase when exposed to high temperature or outdoors, so it is preferable to The base polymer content is 100% by weight or less, more preferably 60% by weight or less, even more preferably 40% by weight or less. In addition, when the adherend to which the surface protection sheet is applied is a metal plate, it is preferable not to add a softener when forming the adhesive layer.

A polyolefin-based resin may be added to the adhesive layer for the purpose of suppressing an increase in the adhesive force or the like. As the polyolefin-based resin, the same resins as those used for the formation of the base material layer can be exemplified. This polyolefin resin may be only one kind, and may be two or more kinds. The compounding quantity of this polyolefin resin is preferably 50 weight% or less with respect to the base polymer of an adhesive layer, More preferably, it is 30 weight% or less, More preferably, it is 20 weight% or less.

In the adhesive layer, if necessary, a separator or the like may be temporarily adhered for protection until it is used in practical use.

It is preferable that the manufacturing method of the surface protection sheet of this invention integrates a base material layer and an adhesive layer by coextrusion molding, and manufactures it. Thereby, a surface protection sheet having a laminated structure having a predetermined thickness can be efficiently and inexpensively produced. As the coextrusion molding, any appropriate coextrusion molding generally used in the production of films, sheets, etc. can be adopted. As coextrusion molding, blow molding method, coextrusion T-die method, etc. can be used, for example.

According to co-extrusion molding, the outermost surface of the opposite side of the adhesive layer of the base material layer and the adhesive layer are not in contact with the molten heating state, therefore, the outermost surface of the opposite side of the adhesive layer of the base material layer is not formed. By-products due to thermal deterioration and the by-products did not migrate to the adhesive layer, excellent unwinding properties were exhibited, and contamination of the adhesive layer surface was suppressed.

Example

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.

(measurement of density)

The density (g/cm ³ ) of the resin is a value measured in accordance with ISO1183.

(Measurement of surface roughness Ra)

The surface protection sheet was pasted back and forth on the SUS430BA board with a 2 kg roll. According to JISB0601 (2001), the surface roughness Ra (μm) of the white layer side of the attached surface protection sheet was measured with a stylus tip diameter of 2 μm, a measurement length of 4 mm, and a cutoff value of 0.8 mm.

(Determination of 60 degree gloss)

The 60° angle reflectance was measured using a miniature three-angle gloss meter manufactured by Gardner.

(appearance evaluation)

The surface protection sheet was pasted back and forth with a 2 kg roll on the SUS430BA board, and visually observed from the white layer side of the pasted surface protection sheet.

The case where air bubbles or foreign matter were conspicuously seen during sticking was made x, and the case where air bubbles or foreign matter were hardly seen due to roughening or low gloss of the surface was made 0.

(Co-extrusion molding conditions)

In Examples and Comparative Examples, molding was performed by blow molding under the following melting temperature conditions.

Substrate layer: 165°C

Adhesive layer: 165°C

Co-extrusion temperature: 165°C

[Example 1]

Low-density polyethylene (manufactured by Japan Polyethylene, trade name: NovatecLD LF440C, density = 0.923g/cm ³ , MFR = 2.8g/10min, autoclave polyethylene) 82% by weight, white pigment (titanium oxide, manufactured by Dupont) , trade name: Ti-PureR103) 18% by weight to obtain a white layer-forming material.

Next, a mixture of 95% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density = 0.924 g/cm ³ ) and carbon black MB (manufactured by Sumika Color, trade name: Black SPEMB-865, carbon content 20 %) of 5% by weight to obtain a black layer-forming material.

Furthermore, 82% by weight of SEBS (hydrogenated SEBS, styrene content = 15% by weight, manufactured by JSR, trade name: Dynaron 8600P) and a tackifier (C5 series hydrogenated aromatic petroleum resin, manufactured by Idemitsu Kosan, trade name: Aimerb P140) 18% by weight to obtain an adhesive layer forming material.

Using the white-type layer-forming material, black-type layer-forming material, and adhesive layer-forming material obtained above, a three-layer structure (white-type layer/black-type layer/adhesive layer ) surface protection sheet (1) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 1.

[Example 2]

As a white layer forming material, 82% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 172, density=0.920g/cm ³ , MFR=0.3g/10min, autoclave method polyethylene) and white pigment were used. (Titanium oxide, manufactured by Dupont, trade name=Ti-Pure R103) 18% by weight of the white-colored layer-forming material obtained, except that, proceed in the same manner as in Example 1 to obtain a three-layer structure (white-colored layer/black-colored layer) layer/adhesive layer) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 1.

[Example 3]

As a white layer forming material, 73% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene), long-chain alkanes Base-based back treatment agent (manufactured by Ashio Sangyo Co., Ltd., ASHIO RESINRA95HS (completely saponified polyvinyl octadecyl carbamate-based release agent)) 9% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103) 18% by weight of the white-colored layer-forming material obtained, except that, it was carried out in the same manner as in Example 1 to obtain a surface protection sheet with a three-layer structure (white-colored layer/black-colored layer/adhesive layer) (3) (thickness: white-color layer/black-color layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 1.

[Example 4]

As a white layer forming material, 47% by weight of low-density polyethylene (manufactured by Japan Polyethylene, trade name: NovatecLD LC720, density=0.922g/cm ³ , MFR=9.4g/10min, autoclave method polyethylene) was used, Low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 172, density=0.920g/cm ³ , MFR=0.3g/10min, autoclave polyethylene) 35% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name : Ti-Pure R103) 18% by weight of the white-colored layer-forming material obtained, except that, in the same manner as in Example 1, the surface protection of the three-layer structure (white-colored layer/black-colored layer/adhesive layer) was obtained. Sheet (4) (thickness: white-colored layer/black-colored layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 1.

[Example 5]

As a material for forming the white layer, 32% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene), low-density polyethylene Ethylene (manufactured by Tosoh, trade name: Petrothene 172, density=0.920g/cm ³ , MFR=0.3g/10min, autoclave polyethylene) 50% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti- Pure R103) 18% by weight of the white-colored layer-forming material obtained, except that, it was carried out in the same manner as in Example 1, and a surface protection sheet (5 ) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 1.

[Example 6]

Low-density polyethylene (manufactured by Japan Polyethylene, trade name: NovatecLD LF440C, density = 0.923g/cm ³ , MFR = 2.8g/10min, autoclave polyethylene) 47% by weight, low-density polyethylene (Tosoh Manufactured, trade name: Petrothene 172, density = 0.920 g/cm ³ , MFR = 0.3 g/10 min, autoclave polyethylene) 35% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103) 18 % by weight of the resulting white-colored layer-forming material, except that it was carried out in the same manner as in Example 1 to obtain a surface protection sheet (6) (thickness: White-colored layer/black-colored layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 1.

[Example 7]

As a white-colored layer-forming material, 77% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene), acrylic beads, and acrylic beads were used. MB (manufactured by Sumika Color, trade name: Kino Plus EMB-Y-1231, acrylic bead concentration 5%) 5% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-PureR103) 18% by weight The white-colored layer-forming material, except that, was carried out in the same manner as in Example 1 to obtain a surface protection sheet (7) (thickness: white-colored layer/black-colored layer/adhesive layer) with a three-layer structure Black color layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 2.

[Example 8]

As a white layer forming material, 72% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene) and acrylic beads were used. MB (manufactured by Sumika Color, trade name: Kino Plus EMB-Y-1231, acrylic bead concentration 5%) 10% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103) 18% by weight and The obtained white-colored layer-forming material was carried out in the same manner as in Example 1 except that, to obtain a surface protection sheet (8) (thickness: white-colored layer /black color layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 2.

[Example 9]

As a white layer forming material, 77% by weight of low-density polyethylene (manufactured by Japan Polyethylene, trade name: NovatecLD LF440C, density=0.923g/cm ³ , MFR=2.8g/10min, autoclave method polyethylene) was used, Acrylic beads MB (manufactured by Sumika Color, trade name: Kino PlusEMB-Y-1231, acrylic bead concentration 5%) 5% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103) 18% by weight % of the obtained white-colored layer-forming material, except that, it was carried out in the same manner as in Example 1 to obtain a surface protection sheet (9) (thickness: white-colored layer/black-colored layer/adhesive layer) of a three-layer structure. series layer/black series layer/adhesive layer=20μm/35μm/5μm).

The results are shown in Table 2.

[Example 10]

As a material for forming the white layer, 72% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene), polypropylene ( A white-colored layer-forming material obtained by 10% by weight of Japan Polypropylene, NovatecPP EG8B) and 18% by weight of a white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103), was the same as in Example 1 except that To obtain a surface protection sheet (10) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm) of a three-layer structure (white layer/black layer/adhesive layer).

The results are shown in Table 2.

[Example 11]

As a material for forming the white layer, 62% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene), polypropylene ( A white-colored layer-forming material obtained by 20% by weight of NovatecPP EG8B manufactured by Japan Polypropylene, and 18% by weight of a white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103), was the same as in Example 1 except that Carry out in a timely manner to obtain a surface protection sheet (11) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm) of a three-layer structure (white layer/black layer/adhesive layer).

The results are shown in Table 2.

[Example 12]

As a white-colored layer-forming material, 62% by weight of low-density polyethylene (manufactured by Japan Polyethylene, trade name: NovatecLD LC720, density=0.922g/cm ³ , MFR=9.4g/10min, autoclave method polyethylene), Ethylene-vinyl acetate copolymer (manufactured by Mitsui Dupont Polychemicals, trade name: Evaflex EV360RC) 20% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103) 18% by weight Formation of a white-colored layer Material, except that, carry out similarly with embodiment 1, obtain the surface protection sheet (12) of three-layer structure (white color layer/black color layer/adhesive layer) (thickness: white color layer/black layer/adhesive layer) Composite layer = 20 μm/35 μm/5 μm).

The results are shown in Table 2.

[Comparative example 1]

As a white layer forming material, 82% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene), white pigment ( Titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103) 18% by weight of the white-colored layer-forming material obtained, except that, carry out in the same manner as in Example 1, and obtain a three-layer structure (white-colored layer/black-colored layer /adhesive layer) surface protection sheet (C1) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 3.

[Comparative example 2]

As a material for forming the white-colored layer, 72% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene), low-density polyethylene Ethylene (manufactured by Tosoh, trade name: Petrothene 172, density=0.920g/cm ³ , MFR=0.3g/10min, autoclave polyethylene) 10% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti- Pure R103) 18% by weight of the white-colored layer-forming material obtained, except that, it was carried out in the same manner as in Example 1 to obtain a surface protection sheet (C2 ) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 3.

[Comparative example 3]

As a material for forming the white layer, 62% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene), low-density polyethylene Ethylene (manufactured by Tosoh, trade name: Petrothene 172, density=0.920g/cm ³ , MFR=0.3g/10min, autoclave polyethylene) 20% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti- Pure R103) 18% by weight of the white-colored layer-forming material obtained, except that, it was carried out in the same manner as in Example 1 to obtain a surface protection sheet (C3 ) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 3.

[Comparative example 4]

As a material for forming the white layer, 72% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene), metallocene poly Propylene (manufactured by Japan Polypropylene, trade name: Wintech WFX6) 10% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103) 18% by weight of the white layer forming material obtained, in addition, Carry out in the same manner as in Example 1 to obtain a surface protection sheet (C4) (thickness: white-based layer/black-based layer/adhesive layer=20 μm/35 μm) of a three-layer structure (white-based layer/black-based layer/adhesive layer) /5μm).

The results are shown in Table 3.

[Comparative Example 5]

As a white layer forming material, 72% by weight of low-density polyethylene (manufactured by Tosoh, trade name: Petrothene 186R, density=0.924g/cm ³ , MFR=3.0g/10min, tubular polyethylene) mixed with ethylene·acetic acid was used. Vinyl ester copolymer (manufactured by Mitsui Dupont Polychemicals, trade name: Evaflex EV360RC) 10% by weight, white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-PureR103) 18% by weight of the white layer forming material obtained, except Otherwise, proceed in the same manner as in Example 1 to obtain a surface protection sheet (C5) (thickness: white layer/black layer/adhesive layer=20 μm) with a three-layer structure (white layer/black layer/adhesive layer). /35μm/5μm).

The results are shown in Table 3.

【Table 1】

【Table 2】

【table 3】

As can be seen from Table 1, Table 2, and Table 3, the surface protection sheet of the present invention is a surface protection sheet comprising a substrate layer and an adhesive layer, and the outermost surface of the substrate layer is effectively roughened and matted. Even if, for example, there are foreign substances inside, the appearance and feel will not be damaged. Industrial availability

The surface protection sheet of the present invention is used, for example, in transporting, processing or maintaining metal plates, painted plates, aluminum alloy frames, resin plates, decorative steel plates, vinyl chloride laminated steel plates, glass plates and other components, polarizing films, optical components such as liquid crystal panels, For electronic components, etc., it can be used for the purpose of sticking to the surface of these and protecting them.

Claims (12)

1. A surface protection sheet, wherein, comprising a substrate layer and an adhesive layer, The substrate layer and the adhesive layer are integrally formed by co-extrusion, The surface roughness Ra of the outermost surface of the substrate layer is 0.10 μm to 0.60 μm, The 60 degree glossiness of the outermost surface of this base material layer is 20.0-71.5. 2. The surface protection sheet according to claim 1, wherein, The surface roughness Ra is 0.20 μm˜0.60 μm, and the 60 degree gloss is 20.0˜65.0. 3. The surface protection sheet according to claim 1, wherein, The base material layer contains a polyolefin-based resin as a main component. 4. The surface protection sheet according to claim 1, wherein, The base material layer includes a white color layer. 5. The surface protection sheet according to claim 4, wherein, The white-colored layer contains polyethylene-based resin as a main component. 6. The surface protection sheet according to claim 5, wherein, The polyethylene-based resin contains autoclave polyethylene as a main component. 7. The surface protection sheet according to claim 5, wherein, The white-colored layer further contains a resin different from the polyethylene-based resin. 8. The surface protection sheet according to claim 7, wherein, The resin different from the polyethylene-based resin is at least one selected from polypropylene-based resins and ethylene-vinyl acetate copolymers. 9. The surface protection sheet according to claim 4, wherein, The white layer contains particles. 10. The surface protection sheet according to claim 1, wherein, The base material layer includes a black color layer. 11. The surface protection sheet according to claim 10, wherein, The black-colored layer contains polyethylene-based resin as a main component. 12. The surface protection sheet according to claim 1, wherein, The adhesive layer includes a styrenic thermoplastic elastomer.

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