TW201418400A - Surface protective sheet - Google Patents

Abstract

Provided is a surface protective sheet which comprises a substrate layer and a pressure-sensitive adhesive layer and which exhibits sufficiently and moderately high adhesive force in high-speed peeling even with respect to an adherend having a rough surface and further exhibits sufficiently and moderately high adhesive force even in high-speed peeling at low temperature. This surface protective sheet comprises a substrate layer and a pressure-sensitive adhesive layer, wherein the adhesive force of the sheet with respect to a hairline-processed SUS plate at 23 C is 1.0N/20mm or more and the adhesive force thereof with respect to a hairline-processed SUS plate at 5 C is 1.5N/20mm or more, each adhesive force being determined in 180-degree peeling at a rate of pulling of 10m/min.

Description

Surface protection sheet

The present invention relates to a surface protection sheet. In particular, the present invention relates to a surface protection sheet comprising a substrate layer and an adhesive layer. The surface protection sheet of the present invention can be used, for example, for a metal plate, a coated plate, an aluminum sash, a resin plate, a decorative steel plate, a vinyl chloride laminated steel plate, a glass plate, or the like, a polarizing film, or a liquid crystal panel. When the optical member or the electronic member is transported, processed, or aged, it is attached to the surface and protected. The surface protection sheet of the present invention is particularly useful as a surface protection sheet of a SUS wool screen having a surface treated with a brush surface.

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 protective sheet comprising a base material layer and an adhesive layer, a method of forming a base material layer and an adhesive layer by co-extrusion molding has been proposed (for example, see Patent Document 1).

However, the adhesion strength of the prior surface protection sheet in the state of being attached to the adherend is not high enough. Therefore, when the adherend to which the previous surface protective sheet is attached is processed or the like, there is a problem that a part of the surface protective sheet is peeled off. In particular, for example, even if the adhesion at a low-speed peeling of about 0.3 m/min is high, the adhesion force at a high-speed peeling of about 10 m/min is not high. The reduction in the adhesion force under such high-speed peeling is more apparent in the case of using a surface protective sheet of a synthetic rubber-based adhesive. On the other hand, the adhesion force at the low-speed peeling or the adhesion force at the high-speed peeling is too high, and it becomes difficult to peel off. Therefore, the adhesion force is required to be moderately high.

Moreover, the prior surface protection sheet has a problem that the adhesion to the rough surface is low, for example. In the case of sticking to a SUS wool screen having a surface treated with a brush surface, there is a problem that peeling or breakage during processing or the like does not exhibit sufficient adhesion.

Further, the surface protective sheet of the prior surface has a poor adhesion at high-speed peeling at a low temperature. For example, in a low-temperature environment of about 5 ° C, peeling or breakage occurs during surface processing of the surface protective sheet adhered to the adherend. Can't show the problem of full connectivity.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 61-103975

An object of the present invention is to provide a surface protective sheet which comprises a base material layer and an adhesive layer, and which has a rough surface to the adherend, and has a sufficient adhesion under high-speed peeling, and is moderately high, and at a low temperature. The high-speed peeling can also exhibit sufficient and moderately high adhesion.

The surface protection sheet of the present invention comprises a substrate layer and an adhesive layer, and the adhesion force at 23 ° C of the SUS wool panel is 1.0 N at a tensile speed of 10 m/min. /20 mm or more, the adhesion force at 5 ° C of the SUS wool panel was 1.5 N/20 mm or more at a tensile force of 180° peeling at a tensile speed of 10 m/min.

The surface protection sheet of the present invention comprises a substrate layer and an adhesive layer, and the adhesive layer comprises a styrene-based thermoplastic elastomer and an adhesion-imparting agent, and the styrene-based thermoplastic elastomer has a styrene content of 5% by weight to 13% The % by weight, the softening point of the adhesion-imparting agent is from 90 ° C to 120 ° C.

In a preferred embodiment, the surface protection sheet of the present invention is formed by integrally forming the base material layer and the adhesive layer by co-extrusion molding.

In a preferred embodiment of the present invention, in the surface protection sheet of the present invention, the base material layer contains a polyolefin resin as a main component.

According to the present invention, it is possible to provide a surface protective sheet comprising a substrate layer and an adhesive layer, and the adherend having a rough surface to the surface, the adhesion force under high-speed peeling is also sufficient and moderately high, and at a low temperature The high-speed peeling can also exhibit sufficient and moderately high adhesion.

10‧‧‧Adhesive layer

20‧‧‧Substrate layer

21‧‧‧White layer

22‧‧‧Black layer

100‧‧‧Surface protection sheet

Fig. 1 is a cross-sectional view schematically showing a configuration example of a surface protective sheet of the present invention.

The surface protection sheet of the present invention comprises a surface protection sheet of a substrate layer and an adhesive layer. The surface protective sheet of the present invention may contain any suitable other layer within the scope of the effects of the present invention.

The thickness of the substrate layer is preferably from 20 μm to 300 μm, more preferably from 30 μm to 250 μm, still more preferably from 40 μm to 200 μm, still more preferably from 45 μm to 150 μm, most preferably from 50 μm to 100 μm. By adjusting the thickness of the base material layer to the above range, the base material layer is less likely to be broken or cracked when the surface protective sheet of the present invention is attached to the adherend, and the base layer is prevented from being broken or broken. Since the plasticity of the material layer becomes large, it is less likely to cause bulging or the like after the surface protective sheet of the present invention is attached to the adherend.

The thickness of the adhesive layer is preferably from 1 μm to 50 μm, more preferably from 2 μm to 40 μm, still more preferably from 3 μm to 30 μm, still more preferably from 4 μm to 20 μm, most preferably from 5 μm to 10 μm. By adjusting the thickness of the adhesive layer to the above range, it is easy to control the layer constitution when the surface protective sheet of the present invention is produced by co-extrusion molding, and it is possible to obtain a charge. A surface protection sheet of mechanical strength.

The thickness of the entire surface protective sheet of the present invention is preferably from 30 μm to 150 μm, more preferably from 35 μm to 140 μm, still more preferably from 40 μm to 130 μm, still more preferably from 45 μm to 120 μm, most preferably from 50 μm to 110 μm. By adjusting the thickness of the entire surface protective sheet of the present invention to the above range, a surface protective sheet excellent in handleability and having sufficient mechanical strength can be obtained.

The surface protection sheet of the present invention is preferably formed by integrally forming a base material layer and an adhesive layer by coextrusion molding. As the coextrusion molding, any suitable coextrusion molding which is generally used for the production of a film, a sheet or the like can be employed. As the coextrusion molding, for example, an inflation method, a coextrusion T-die method, or the like can be employed. Such coextrusion molding is preferred in terms of cost or productivity.

The surface protection sheet of the present invention is excellent in the adhesion to the adherend having a rough surface. Examples of the adherend having such a rough surface include a adherend having a rough surface having a surface roughness Ra of 0.210 μm to 0.310 μm. Among such an adherend, the surface protective sheet of the present invention can exhibit excellent effects particularly as a surface protective sheet of a SUS silk panel which is surface-finished by a brush surface. In the present specification, the "SUS wool screen panel" is a SUS plate having a surface treated with a brush surface, and has a rough surface having a surface roughness Ra of 0.210 μm to 0.310 μm. Further, in the present invention, the surface roughness Ra is a contact surface roughness meter (SJ400: manufactured by Mitutoyo Co., Ltd.), and the SUS plate processed by the brush surface is at right angles to the stripe direction of the hair surface. Direction measurement (measurement conditions: measured according to JIS-B-0601: (2001). Specifically, the value is measured at a stylus radius of 2 μm, a cutoff value of 0.8 mm, and a measurement length of 4 mm).

The adhesion strength of the surface protective sheet of the present invention to the SUS wool panel at 23 ° C is preferably 1.0 N/20 mm or more, more preferably 1 N, at a tensile strength of 180 ° at a tensile speed of 10 m/min. /20mm~5N/20mm, further preferably 1N/20mm~4N/20mm, especially preferably 1N/20mm~3N/20mm. If it is at 23 °C for SUS wool panel Then, when the force is within the above range at 180° peeling at a tensile speed of 10 m/min, the surface protective sheet of the present invention exhibits a sufficient and moderately high adhesion force at high speed peeling at room temperature. . Furthermore, the method for measuring various adhesion forces to the SUS wool panel will be described later.

The adhesion of the surface protective sheet of the present invention to the SUS wool panel at 5 ° C is preferably 1.5 N/20 mm or more, more preferably 1.5, at a tensile speed of 10 m/min. N/20mm~5N/20mm, further preferably 1.5N/20mm~4N/20mm, and particularly preferably 1.5N/20mm~3.5N/20mm. When the adhesion force at 5 ° C of the SUS wool panel is within the above range at 180° peeling at a tensile speed of 10 m/min, the surface protective sheet of the present invention is peeled off at a high speed at a low temperature. It can exhibit sufficient and moderately high adhesion. Furthermore, the method for measuring various adhesion forces to the SUS wool panel will be described later.

The adhesion of the surface protective sheet of the present invention to the SUS wool panel at 10 ° C is preferably 1.5 N/20 mm or more, more preferably 1.5, at a tensile speed of 10 m/min. N/20mm~5N/20mm, further preferably 1.5N/20mm~4N/20mm, and particularly preferably 1.5N/20mm~3.5N/20mm. When the adhesion force at 10 ° C of the SUS wool panel is within the above range at 180° peeling at a tensile speed of 10 m/min, the surface protective sheet of the present invention is peeled off at a high speed at a low temperature. It can exhibit sufficient and moderately high adhesion. Furthermore, the method for measuring various adhesion forces to the SUS wool panel will be described later.

The base material layer preferably contains a polyolefin resin as a main component. When the base material layer contains a polyolefin-based resin as a main component, it can have heat resistance, solvent resistance, flexibility, and can be easily wound into a roll shape. The polyolefin resin contained in the base material layer may be used alone or in combination of two or more. The substrate layer may be a single layer or a plurality of layers.

Here, in the present invention, the term "main component" means preferably 50% by weight or more, more preferably 60% by weight or more, still more preferably 70% by weight or more, and particularly preferably 80% by weight. More than %, preferably more than 90% by weight.

Examples of the polyolefin-based resin include a polyethylene resin, propylene, a propylene resin containing a propylene component and an ethylene component, and an ethylene-vinyl acetate copolymer.

Specific examples of the polyolefin-based resin include high density polyethylene (HDPE), medium density polyethylene, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polypropylene, and 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-methyl methacrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene - a vinyl alcohol copolymer or the like.

In the case where the base material layer contains a plurality of layers of two or more layers, it is preferred that each of the adjacent layers be selected as a resin component constituting the same by melt co-extrusion.

The substrate layer may also comprise a white tie layer. By including a white layer on the base material layer, a surface protection sheet excellent in weather resistance can be obtained.

The substrate layer may also comprise a black layer. By including the black layer in the base material layer, a surface protection sheet excellent in weather resistance can be obtained.

The base material layer preferably contains at least two layers of a white layer and a black layer. By including at least two layers of a white layer and a black layer in the base material layer, a surface protection sheet excellent in weather resistance can be obtained.

In the case where the base material layer contains at least two layers of a white layer and a black layer, the laminated structure of the surface protective sheet of the present invention can be, for example, "white layer/black layer" as long as the effect of the present invention is not impaired. / Adhesive layer", "black layer / white layer / adhesive layer" and other suitable laminated layers. 1 is a cross-sectional view schematically showing a configuration example of a case where the surface protection sheet 100 of the present invention has a laminated structure of "white layer 21 / black layer 22 / adhesive layer 10". The white layer 21 and the black layer 22 become the base layer 20.

The white layer is a layer having 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, and particularly preferably 85. %the above. The white tie layer preferably contains a white pigment. As the white pigment, any appropriate white pigment can be employed. As such a white pigment, titanium oxide is mentioned, for example. In the case where the white layer contains a white pigment, the content ratio thereof is preferably from 0.1% by weight to 50% by weight, more preferably from 1% by weight to 40% by weight, even more preferably from 1% by weight to 40% by weight, based on the resin component forming the white layer. 2% by weight to 30% by weight. By setting the content ratio of the white pigment to the resin component forming the white layer in the above range, the surface protective sheet excellent in weather resistance can be obtained, and the moldability such as extrusion property is also excellent.

The resin component forming the white layer is preferably a polyolefin resin, more preferably a propylene polymer or a vinyl polymer. Specific examples of the resin component forming the white layer are: homopolypropylene, block polypropylene, random polypropylene, high density polyethylene (HDPE), medium density polyethylene, and low density polyethylene. (LDPE), linear low density polyethylene (LLDPE). The white layer preferably contains a polyethylene resin as a main component. The density of the polyethylene-based resin 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 , still more preferably 0.880 g/cm ³ to 0.915. g/cm ³ . By including the polyethylene-based layer as a main component, the base material layer can have heat resistance, solvent resistance, and flexibility, and the surface protective sheet of the present invention can be easily wound into a roll shape. When the white layer contains a polyethylene resin as a main component, the polyethylene resin preferably contains a low density polyethylene. By making the polyethylene-based resin contain low-density polyethylene, the base material layer can sufficiently have heat resistance, solvent resistance, and flexibility, and the surface protective sheet of the present invention can be more easily wound into a roll. shape.

The content ratio of the polyolefin resin in the white layer is preferably 60% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more, particularly preferably 85% by weight or more, and most preferably 90% by weight. %the above. These polyolefin-based resins may be used alone or in combination of two or more.

The thickness of the white layer may be any suitable thickness depending on the purpose. The thickness is preferably from 2 μm to 100 μm, more preferably from 3 μm to 80 μm, still more preferably from 4 μm to 60 μm, still more preferably from 5 μm to 50 μm.

The black layer shows a layer of black tones. The black layer preferably contains a black pigment. As the black pigment, any appropriate black pigment can be employed. As such a black pigment, carbon black is mentioned, for example. When the black layer contains a black pigment, the content ratio thereof is preferably 0.01% by weight to 10% by weight, more preferably 0.1% by weight to 5% by weight, based on the resin component forming the black layer. Preferably, it is 0.5% by weight to 3% by weight. When the content ratio of the black pigment to the resin component forming the black layer is within the above range, a surface protective sheet excellent in weather resistance can be obtained, and moldability such as extrusion property is also excellent.

The resin component forming the black layer is preferably a polyolefin resin, more preferably a propylene polymer or a vinyl polymer. Specific examples of the resin component forming the black-based layer include homopolypropylene, block polypropylene, random polypropylene, high-density polyethylene (HDPE), medium-density polyethylene, and low-density polyethylene. (LDPE), linear low density polyethylene (LLDPE). The black layer preferably contains a polyethylene resin as a main component. The density of the polyethylene-based resin 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 , still more preferably 0.880 g/cm ³ to 0.915. g/cm ³ . By including the polyethylene-based layer as a main component, the base layer can have heat resistance, solvent resistance, and flexibility, and the surface protective sheet of the present invention can be easily wound into a roll shape. When the black layer contains a polyethylene resin as a main component, the polyethylene resin preferably contains low density polyethylene and linear low density polyethylene. By including the low-density polyethylene and the linear low-density polyethylene in the polyethylene-based resin, the base material layer can sufficiently have heat resistance, solvent resistance, flexibility, and the surface protective sheet of the present invention can be used. The material is more easily wound into a roll.

The content ratio of the polyolefin resin in the black layer is preferably 60% by weight or more. It is preferably 70% by weight or more, more preferably 80% by weight or more, still more preferably 85% by weight or more, and most preferably 90% by weight or more. These polyolefin-based resins may be used alone or in combination of two or more.

The thickness of the black layer may be any suitable thickness depending on the purpose. The thickness is preferably from 2 μm to 100 μm, more preferably from 3 μm to 80 μm, still more preferably from 4 μm to 60 μm, still more preferably from 5 μm to 50 μm.

The substrate layer may contain any suitable additives. Examples of such an additive include an antioxidant, an ultraviolet absorber, an anti-aging agent, a light stabilizer, an antistatic agent, a surface lubricant, a leveling agent, a plasticizer, a low molecular weight polymer, an anticorrosive agent, and a polymerization inhibition. Agent, decane coupling agent, inorganic and organic filler (such as calcium oxide, magnesium oxide, cerium oxide, zinc oxide, titanium oxide, etc.), metal powder, colorant, pigment, heat stabilizer, anti-cell fat accumulation agent , lubricants, anti-blocking agents, etc.

The substrate layer preferably contains a photostabilizer. By providing the substrate layer with a photostabilizer, sufficient weather resistance can be imparted to the surface protection sheet of the present invention.

As the light stabilizer, any appropriate light stabilizer can be employed without departing from the effects of the present invention. As such a photostabilizer, for example, a hindered amine-based light stabilizer (HALS) is preferably used.

In the case where the base material layer contains a light stabilizer, the content ratio of the light stabilizer is preferably 0.10% by weight or more, and more preferably 0.20% by weight based on the total weight of the surface protective sheet of the present invention. It is preferably 0.60% by weight, more preferably 0.30% by weight to 0.60% by weight, still more preferably 0.34% by weight to 0.55% by weight. When the base material layer contains a light stabilizer, when the content ratio of the light stabilizer is within the above range with respect to the weight of the entire surface protection sheet of the present invention, the surface protection sheet of the present invention can be imparted. More comprehensive weather resistance.

The back side treatment may also be performed on the outermost layer of the substrate layer opposite to the adhesive layer. As a method of the back surface treatment, any appropriate aspect can be employed without departing from the effects of the present invention. law. Examples of the method of the back surface treatment include surface processing such as embossing or uneven processing, and a method of containing a fatty acid derivative. These fatty acid derivatives may be used alone or in combination of two or more.

When the base material layer contains a fatty acid derivative, the content ratio of the fatty acid derivative in the base material layer is preferably 0.05% by weight to 1.00% by weight based on the resin component in the base material layer, and more preferably 0.10% by weight to 0.90% by weight, more preferably 0.30% by weight to 0.80% by weight. When the content ratio of the fatty acid derivative in the base material layer is within the above range with respect to the resin component in the base material layer, the surface protective sheet of the present invention which can be easily rolled into a roll can be sufficiently expressed. The release effect is exhibited, and the contamination caused by the bleeding of the fatty acid derivative can be sufficiently suppressed.

The fatty acid derivative means a compound containing a fatty acid derivative structure in a molecular structure.

Examples of the fatty acid derivative include a saturated fatty acid biguanide, an unsaturated fatty acid biguanide, an aromatic biguanide, a substituted urea, and a fatty acid metal salt. Specific examples of the fatty acid derivative include methylenebisstearylamine, ethylidenebisstearylamine, ethylideneamine, ethylideneamine, and N. N-stearyl-N'-stearylamine such as N-dioleyl hexamethylenediamine or N-stearyl-N'-stearyl urea, zinc stearate, and the like.

As the fatty acid derivative, a fatty decylamine is preferred, and more preferably selected from the group consisting of methylenebisstearylamine, ethylbisstearylamine, ethylidene, N-stearylamine- At least one of N'-stearylamine.

The fatty acid derivative preferably has a melting point of 100 ° C or higher. The fatty acid derivative having a melting point of less than 100 ° C has a marked transfer to the surface of the adhesive layer, and is liable to cause a decrease in adhesion.

The adhesive layer preferably contains a thermoplastic resin as a main component. The thermoplastic resin contained in the adhesive layer may be one type or two or more types.

As the thermoplastic resin, any appropriate thermoplastic resin can be employed. Examples of such a thermoplastic resin include an olefin resin, an aromatic group-containing olefin/diene copolymer, a styrene resin, and an ester resin. Among these thermoplastic resins, a styrene resin is preferred, and a styrene thermoplastic elastomer is more preferred.

The styrene-based thermoplastic elastomer is preferably a hydrogenated styrene-butadiene rubber (HSBR), a styrene block copolymer or a hydrogenated product thereof.

Examples of the styrene-based block copolymer include styrene-based ABA type embedding such as styrene-butadiene-styrene copolymer (SBS) and styrene-isoprene-styrene copolymer (SIS). Segment copolymer (triblock copolymer); styrene-butadiene-styrene-butadiene copolymer (SBSB), styrene-isoprene-styrene-isoprene copolymer (SISI) Styrene-based ABAB type block copolymer (tetrablock copolymer); styrene-butadiene-styrene-butadiene-styrene copolymer (SBSBS), styrene-isoprene-styrene a styrene-based ABABA type block copolymer (penta block copolymer) such as isoprene-styrene copolymer (SISIS); a styrene block copolymer having the above AB repeating unit, and the like.

Examples of the hydride of the styrene block copolymer include styrene, ethylene-butene copolymer, styrene copolymer (SEBS), styrene, ethylene-propylene copolymer, and styrene copolymer (SEPS). , styrene, ethylene-butene copolymer, styrene, ethylene-butene copolymer copolymer (SEBSEB), and the like.

The styrene-based thermoplastic elastomer may be used alone or in combination of two or more.

The styrene content in the styrene-based thermoplastic elastomer (the styrene block content in the case of the styrenic block copolymer) is preferably from 5% by weight to 13% by weight, more preferably from 1% by weight to 20% by weight. % is further preferably 2% by weight to 18% by weight, particularly preferably 3% by weight to 15% by weight. By adjusting the styrene content to the above range, the surface protective sheet of the present invention exhibits a sufficient and moderately high adhesion force at a high temperature peeling, and at a low temperature, at a high temperature. At high speed peeling, a sufficient and moderately high adhesion force can be exhibited. If the styrene content is small, it tends to be condensed by the adhesive layer. The lack of force caused by the residue of the paste. If the styrene content is increased, the adhesive layer becomes hard and the good adhesion to the rough surface cannot be obtained.

As the styrene-based thermoplastic elastomer, a styrene system having a repeating structure (ABA type, ABAB type, ABABA type, or the like) containing a triblock copolymer of styrene (A) and butadiene (B) is preferable. Hydride of block copolymer (SEBS, SEBSEB, SEBSEBS, etc.). By using such a styrene-based thermoplastic elastomer, the adhesion force in the state of being attached to the adherend can be more appropriately improved, and the adhesion at the time of peeling after being attached to the adherend is more appropriate. Since it is small in size, it can be more easily peeled off from the adherend by a slight force, and further, the increase in the adhesion force in the case of the environmental load which is stored for a long period of time at a relatively high temperature can be further suppressed.

The styrene-based thermoplastic elastomer is a styrene block copolymer having a repeating structure (ABA type, ABAB type, ABABA type, etc.) containing a triblock copolymer of styrene (A) and butadiene (B). In the case of a hydride of a substance (SEBS, SEBSEB, SEBSEBS, etc.), the ratio of the butene structure to the ethylene-butene copolymer block is preferably 60% by weight or more, more preferably 70% by weight or more, and further It is preferably 75% by weight or more. By setting the ratio of the above butene structure to the ethylene-butene copolymer block within the above range, the adhesion force in the state of being attached to the adherend can be more appropriately improved, and on the other hand, the attachment is performed. The adhesive force at the time of peeling after being pressed is a more appropriate size, so that it can be more easily peeled off from the adherend by a slight force, and further, the environmental load for long-term storage at a relatively high temperature can be further suppressed. The rise in the force of the situation. Further, the ratio of the above butene structure to the ethylene-butene copolymer block is preferably 90% by weight or less.

The adhesive layer may also contain other styrene-based thermoplastic elastomers for the purpose of adjusting the adhesion and the like without departing from the object of the present invention.

Examples of the other styrene-based thermoplastic elastomer include styrene block copolymers other than the above; styrene-butadiene copolymer (SB), styrene-isoprene copolymer (SI), and styrene. ‧Ethylene-butene copolymer copolymer (SEB), styrene, ethylene-propylene AB type block polymer such as copolymer of copolymer (SEP); styrene-based random copolymer such as styrene-butadiene rubber (SBR); copolymer of styrene, ethylene-butene copolymer and olefin crystal ABC type styrene-olefin crystalline block polymer such as (SEBC); such a hydride or the like.

When the adhesive layer is formed, for example, a softener, an adhesion-imparting agent, a polyolefin-based resin for a substrate layer, a polyoxymethylene-based polymer, or a liquid acrylic resin may be appropriately added for the purpose of controlling adhesion characteristics and the like. Copolymer, phosphate ester compound, anti-aging agent, light stabilizer, ultraviolet absorber, surface lubricant, leveling agent, plasticizer, low molecular weight polymer, antioxidant, anticorrosive agent, polymerization inhibitor, decane Mixtures, inorganic and organic fillers (such as calcium oxide, magnesium oxide, cerium oxide, zinc oxide, titanium oxide, etc.), metal powders, colorants, pigments, heat stabilizers and other additives.

For the surface of the adhesive layer, for example, corona discharge treatment, ultraviolet irradiation treatment, flame treatment, plasma treatment, sputtering etching treatment, or the like may be applied to the surface treatment for adhesion control or adhesion workability.

The adhesion of the adhesion-imparting agent is effective in improving the adhesion. However, in order to avoid the problem of the residue of the paste caused by the decrease in the cohesive force, the amount of the adhesion-imparting agent is appropriately determined depending on the adherend to which the surface protective sheet is applied. The amount of the adhesion-imparting agent 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.

The softening point of the adhesion-imparting agent is preferably from 90 ° C to 120 ° C, more preferably from 70 ° C to 135 ° C, further preferably from 80 ° C to 130 ° C, and particularly preferably from 85 ° C to 125 ° C. By adjusting the softening point of the above-mentioned adhesion-imparting agent to the above range, the surface-protecting sheet of the present invention exhibits a sufficient and moderately high adhesion force at the high-speed peeling of the adherend having a rough surface. A sufficient and moderately high adhesion force can be exhibited at high speed peeling at low temperatures.

As the adhesion-imparting agent, for example, an aliphatic copolymer, an aromatic copolymer, an aliphatic-aromatic copolymer or an alicyclic copolymer can be used without any limitation. Oil-based resin, scented sputum-based resin, terpene-based resin, phenol-based resin, rosin-based resin such as polymerized rosin, (alkyl) phenol-based resin, xylene-based resin, and the like, etc. For the adhesive. The adhesive agent may be used alone or in combination of two or more. Among these adhesion-imparting agents, a hydrogenation-based adhesion-imparting agent is preferable in terms of peelability, weather resistance, and the like, and a C5-based hydrogenated aromatic petroleum resin is particularly preferable. Further, the adhesion-imparting agent can also be used as a blend with an olefin resin.

The adjustment of the softener is effective in improving the adhesion. Examples of the softening agent include a low molecular weight diene polymer, polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene, and the like. Examples of such a derivative include those having an OH group or a COOH group at one terminal or both ends, and specific examples thereof include hydrogenated polybutadiene diol, hydrogenated polybutadiene monool, and hydrogenated polyisoprene. An olefinic diol, a hydrogenated polyisoprene monool, or the like. In particular, for the purpose of suppressing the improvement of the adhesion to the adherend, a hydrogenated product of a diene polymer such as hydrogenated polybutadiene or hydrogenated polyisoprene or an olefin softener or the like is preferable. Specifically, as such a softener, a product name "Kurapren LIR-200" manufactured by Kuraray Co., Ltd., or the like can be obtained. These softeners may be used alone or in combination of two or more.

The molecular weight of the softening agent can be appropriately set to any appropriate amount. However, if the molecular weight is small, the material may be transferred from the adhesive layer to the adherend, or may be peeled off. If it is large, there is a tendency to become less effective in improving the adhesion. Therefore, the number average molecular weight of the softener is preferably from 5,000 to 100,000, more preferably from 10,000 to 50,000.

When the softener is used, the amount thereof may be appropriately set to any appropriate amount. However, if the amount of addition is increased, there is a tendency for the paste residue to increase at a high temperature or outside exposure, and thus the base polymerization is performed with respect to the adhesive layer. The content is preferably 100% by weight or less, more preferably 60% by weight or less, still more preferably 40% by weight or less.

Polyolefin tree can also be added to the adhesive layer for the purpose of suppressing the increase in adhesion fat. The polyolefin-based resin can be exemplified as the same as those used for the formation of the base material layer. The polyolefin resin may be used alone or in combination of two or more. The blending amount of the polyolefin resin is preferably 50% by weight or less, more preferably 30% by weight or less, and still more preferably 20% by weight or less based on the base polymer of the adhesive layer.

For the adhesive layer, it is also possible to temporarily attach the separator to protect it before it is put into practical use.

The method for producing a surface protective sheet of the present invention is preferably produced by integrally forming a base material layer and an adhesive layer by co-extrusion molding. Thereby, the surface protection sheet having the laminated structure of a specific thickness can be manufactured efficiently and inexpensively. As the coextrusion molding, any suitable coextrusion molding which is generally used for the production of a film, a sheet or the like can be employed. As the coextrusion molding, for example, an inflation method, a coextrusion T-die method, or the like can be employed.

By co-extrusion molding, the outermost surface of the opposite side of the adhesive layer of the substrate layer is not in contact with the adhesive layer in the molten state, and therefore there is no outermost surface on the opposite side of the adhesive layer of the substrate layer. The formation of by-products caused by thermal deterioration and the transfer of the by-products to the adhesive layer exhibit excellent rewindability and can suppress contamination of the surface of the adhesive layer.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by the examples.

(Measurement of density)

The density (g/cm ³ ) of the resin was set to a value measured in accordance with ISO 1183.

(Measurement of adhesion force at 23 ° C, 5 ° C, and 10 ° C for SUS wool screen)

The adhesion force at 23 ° C, 5 ° C, and 10 ° C of the SUS wool panel was measured in accordance with JIS-Z-0237 (2000). Specifically, a SUS capillary panel having a surface roughness Ra of 0.210 to 0.310 is used as a adherend, and the surface of the SUS filament panel is washed with toluene, and then a 2 kg roller is reciprocated once. The sample was crimped, and after 30 minutes, an Instron type tensile tester (manufactured by Shimadzu Corporation) was used. Autograph), the stretching speed was set to 10 m/min, and the initial adhesion was measured by 180° peeling. At this time, the measurement environment and the storage environment were carried out at 23 ° C: temperature 23 ° C / humidity 50%, 5 ° C: temperature 5 ° C / humidity 50%, 10 ° C: temperature 10 ° C / humidity 50%.

(co-extrusion molding conditions)

In the examples and comparative examples, they were formed by an inflation method in accordance with the following melting temperature conditions.

Substrate layer: 165 ° C

Adhesive layer: 165 ° C

Coextrusion temperature: 165 ° C

[Example 1]

A white pigment (titanium oxide, manufactured by Dupont, trade name: Ti-Pure R103) was blended in a content ratio of Table 1 with respect to low-density polyethylene (manufactured by Tosoh, trade name: Petrocene 186R, density = 0.924 g/cm ³ ). A hindered amine light stabilizer (HALS, manufactured by BASF, trade name: TINUVIN 783) was obtained to obtain a white layer forming material.

Then, it is made up of low-density polyethylene (manufactured by Tosoh, trade name: Petrocene 186R, density = 0.924 g/cm ³ ), 85 wt%, and linear low-density polyethylene (manufactured by Sumitomo Chemical Co., Ltd., trade name: EXCELLEN FX FX307, Density = 0.890 g/cm ³ ) A resin mixture of 10% by weight was prepared by disposing carbon black MB (manufactured by SUMIKA COLOR, trade name: Black SPEMB-865, carbon content: 20%) at 5% by weight to obtain a black layer forming material.

Further, 82% by weight of HSBR (styrene content = 10% by weight, manufactured by JSR, trade name: Dynaron 1321P) and an adhesion-imparting agent (C5-based hydrogenated aromatic petroleum resin, manufactured by Eastman Chemical, trade name: EASTOTAC C115W, softening point) were prepared. = 115 ° C) 18% by weight to obtain an adhesive layer forming material.

Using the white layer forming material, the black layer forming material, and the adhesive layer forming material obtained above, a three-layer structure (white layer/black layer/adhesive layer) was obtained by co-extrusion molding by an inflation method. Surface protection sheet (1) (thickness: white layer / black layer /Adhesive layer = 20 μm / 35 μm / 5 μm).

The results are shown in Table 1.

[Embodiment 2]

A surface protective sheet (2) having a three-layer structure (white layer/black layer/adhesive layer) was obtained in the same manner as in Example 1 except that the thickness of the black layer was 45 μm. Thickness: white layer/black layer/adhesive layer=20 μm/45 μm/5 μm).

The results are shown in Table 1.

[Example 3]

A three-layer structure (white layer/black) was obtained in the same manner as in Example 1 except that the blending ratio of the HSBR was 80% by weight and the blending ratio of the tackifier was 20% by weight. Surface protection sheet (3) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 1.

[Example 4]

A surface protective sheet (4) having a three-layer structure (white layer/black layer/adhesive layer) was obtained in the same manner as in Example 3 except that the thickness of the black layer was 45 μm. Thickness: white layer/black layer/adhesive layer=20 μm/45 μm/5 μm).

The results are shown in Table 1.

[Example 5]

A three-layer structure (white layer/black) was obtained in the same manner as in Example 1 except that the blending ratio of the HSBR was changed to 85% by weight and the blending ratio of the tackifier was changed to 15% by weight. Surface protection sheet (5) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 1.

[Embodiment 6]

The thickness of the black layer was set to 45 μm, and otherwise the same as in Example 5. The manner was carried out to obtain a surface protective sheet (6) of a three-layer structure (white layer/black layer/adhesive layer) (thickness: white layer/black layer/adhesive layer=20 μm/45 μm/5 μm).

The results are shown in Table 1.

[Comparative Example 1]

SEBS (hydrogenated SEBS, styrene content = 15% by weight, manufactured by JSR, trade name: Dynaron 8600P) 82% by weight and an adhesion-imparting agent (C5-based hydrogenated aromatic petroleum resin, manufactured by Idemitsu Kosan Co., Ltd., trade name: I-MARV) P140, softening point = 140 ° C) 18% by weight, obtained in the same manner as in Example 1 except that the adhesive layer forming material was obtained, and a three-layer structure (white layer/black layer/adhesive layer) was obtained. Surface protection sheet (C1) (thickness: white layer/black layer/adhesive layer=20 μm/35 μm/5 μm).

The results are shown in Table 2.

[Comparative Example 2]

A surface protective sheet (C2) having a three-layer structure (white layer/black layer/adhesive layer) was obtained in the same manner as in Comparative Example 1, except that the thickness of the black layer was 45 μm. Thickness: white layer/black layer/adhesive layer=20 μm/45 μm/5 μm).

The results are shown in Table 2.

[Comparative Example 3]

Preparation of HSBR (styrene content = 10% by weight, manufactured by JSR, trade name: Dynaron 1321P) 82% by weight and adhesion-imparting agent (C5-based hydrogenated aromatic petroleum resin, manufactured by Idemitsu Kosan, trade name: I-MARV P140, softened A surface protective sheet having a three-layer structure (white layer/black layer/adhesive layer) was obtained in the same manner as in Example 1 except that the adhesive layer forming material was obtained at 18% by weight. Material (C3) (thickness: white layer / black layer / adhesive layer = 20 μm / 35 μm / 5 μm).

The results are shown in Table 2.

[Comparative Example 4]

The thickness of the black layer was set to 45 μm, except that it was the same as in Comparative Example 3. In the manner, a surface protective sheet (C4) having a three-layer structure (white layer/black layer/adhesive layer) (thickness: white layer/black layer/adhesive layer=20 μm/45 μm/5 μm) was obtained.

The results are shown in Table 2.

[Comparative Example 5]

SEBS (hydrogenated SEBS, styrene content = 15% by weight, manufactured by JSR, trade name: Dynaron 8600P) 82% by weight and an adhesion-imparting agent (C5-based hydrogenated aromatic petroleum resin, manufactured by Eastman Chemical, trade name: EASTOTAC C115W, softened) A surface protective sheet having a three-layer structure (white layer/black layer/adhesive layer) was obtained in the same manner as in Example 1 except that the adhesive layer forming material was obtained in an amount of 18% by weight. Material (C5) (thickness: white layer / black layer / adhesive layer = 20 μm / 35 μm / 5 μm).

The results are shown in Table 2.

[Comparative Example 6]

A surface protective sheet (C6) having a three-layer structure (white layer/black layer/adhesive layer) was obtained in the same manner as in Comparative Example 5 except that the thickness of the black layer was 45 μm ( Thickness: white layer/black layer/adhesive layer=20 μm/45 μm/5 μm).

The results are shown in Table 2.

[Comparative Example 7]

A three-layer structure (white layer/black layer/adhesive layer) was obtained in the same manner as in Comparative Example 1, except that the thickness of the black layer was 90 μm and the thickness of the adhesive layer was 10 μm. Surface protection sheet (C7) (thickness: white layer / black layer / adhesive layer = 20 μm / 90 μm / 10 μm).

The results are shown in Table 2.

[Comparative Example 8]

A three-layer structure (white layer/black layer/adhesive layer) was obtained in the same manner as in Comparative Example 1, except that the thickness of the black layer was 70 μm and the thickness of the adhesive layer was 10 μm. ) Surface protection sheet (C8) (thickness: white layer / black layer / sticky Layer = 20 μm / 70 μm / 10 μm).

The results are shown in Table 2.

According to Tables 1 and 2, it was found that the surface protective sheet of the present invention has a sufficient adhesion to the adherend having a rough surface, and is sufficiently high and moderate under high-speed peeling, and can exhibit sufficient under high-speed peeling at a low temperature. And moderately high adhesion.

[Industrial availability]

The surface protection sheet of the present invention can be used, for example, for a member such as a metal plate, a coated plate, an aluminum sash, a resin plate, a decorative steel plate, a vinyl chloride laminated steel plate, a glass plate, or the like, a polarizing film, or a liquid crystal panel. When the electronic component or the like is transported, processed, or aged, it is attached to the surface and protected. The surface protection sheet of the present invention is particularly useful as a surface protection sheet of a SUS wool screen having a surface treated with a brush surface.

10‧‧‧Adhesive layer

20‧‧‧Substrate layer

21‧‧‧White layer

22‧‧‧Black layer

100‧‧‧Surface protection sheet

Claims (6)

A surface protection sheet comprising a substrate layer and an adhesive layer, and an adhesion force at 23° C. to a SUS silk panel at a tensile speed of 10 m/min is 1000 N at a peeling force of 1.0 N. /20 mm or more, the adhesion force at 5 ° C of the SUS wool panel was 1.5 N/20 mm or more at a tensile force of 180° peeling at a tensile speed of 10 m/min. A surface protection sheet comprising a substrate layer and an adhesive layer, wherein the adhesive layer comprises a styrene-based thermoplastic elastomer and an adhesion-imparting agent, and the styrene-based thermoplastic elastomer has a styrene content of 5% by weight to 13% The % by weight, the softening point of the adhesion-imparting agent is from 90 ° C to 120 ° C. The surface protection sheet according to claim 1, wherein the base material layer and the adhesive layer are integrally formed by co-extrusion molding. The surface protection sheet according to claim 1, wherein the base material layer contains a polyolefin resin as a main component. The surface protection sheet according to claim 2, wherein the base material layer and the adhesive layer are integrally formed by co-extrusion molding. The surface protection sheet according to claim 2, wherein the base material layer contains a polyolefin resin as a main component.