TW200930783A - Surface protective film - Google Patents

Abstract

The present invention relates a surface-protective film which is useful for protecting the surface of various resin sheet, glass plate, metal sheet and the like used in the fields of building materials, electrical appliances and electronic components when adhered onto their surface to prevent the adherend from scratches, contamination and the like during storage, transportation and post-processing. In particular, the present invention provides a surface-protective film having extremely minor contamination to the surface of adherend and also exhibiting excellent secondary processing suitability. The resins for the adhesive layer used in the said surface-protective film are obtained by mixing a specific ratio of amorphous α -olefinic polymer and straight-chain low density polyethylene, or mixing a specific ratio of amorphous α -olefinic polymer, straight-chain low density polyethylene and crystalline ethylene-α -olefinic copolymer as the main component.

Description

200930783 IX. Description of the Invention: [Technical Field] The present invention relates to a method for protecting the surface of various resin plates, glass plates, metal plates, and the like used in construction materials, electrical appliances, electronics, and the like. On the surface thereof, a surface protective film which prevents scratches, contamination, etc. of the adherends during storage, transportation, and post-processing. In particular, it relates to a surface protective film which does not float or peel off from the adherend after attaching the surface protective film to the adherend, and which has little contamination of the paste residue on the surface of the adherend after the film is peeled off. [Prior Art] The basic properties required for the surface protective film include: it is necessary to have excellent adhesion workability to various adhesive bodies as described above, which can be uniformly attached without wrinkles or air. It must have a moderate adhesion that does not cause floating or peeling during storage, transportation, etc. of the adherend, and the change in the adhesion caused by environmental changes or post-processing of the adherent must be small, and It can be easily peeled off, and it will not contaminate the surface of the 〇v of the adherend after peeling. In the surface protective film of the prior art, a film made of a polyvinyl chloride resin, a polyethylene resin, a polypropylene resin or the like is used as a substrate, and a urethane-based or acrylic acid is applied to one surface thereof. Adhesives such as systems and rubber systems. However, such a surface protective film has a poor adhesion between the film as a substrate and an adhesive, or a low cohesive force of the adhesive itself, and one of the adhesives to be peeled off from the adhesive. Some of the problems will remain on the surface of the adherend. In addition, the surface-protected 200930783 protective film produced by applying an adhesive on a film has a problem of increasing manufacturing cost because it requires at least two steps of a manufacturing step of a film as a substrate and a coating step of an adhesive. And, in the coating step of the adhesive, there is a problem that a large amount of solvent needs to be removed to cause an increase in environmental load and the like. In order to improve the above-mentioned problems, a self-adhesive surface protective film obtained by simultaneously extruding and laminating a film layer of a substrate and an adhesive layer by a co-extrusion lamination method has been proposed. Such a surface protective film is, for example, a resin composition for an adhesive layer, which contains an amorphous terpene olefin copolymer, a crystalline olefin copolymer, and a thermoplastic elastomer, and has specific properties. a mixture (see, for example, Patent Document 1); or a mixture obtained by mixing an amorphous olefin copolymer, a crystalline olefin-based polymer, and a block copolymer having a crystalline olefin block at a specific ratio ( See, for example, Patent Document 2) to provide a multilayer film having excellent adhesion strength and peeling stability without peeling off the paste residue. In addition, the inventors of the present invention have provided a surface-protecting film® which has a small adhesiveness and heat resistance and which is less contaminated on the surface of the adherend after peeling, and provides a crystalline propylene-based polymer as a main component. a surface protective film obtained by laminating a base layer and an adhesive layer obtained by mixing an amorphous α-olefin polymer and a crystalline propylene polymer as a main component at a specific ratio ( For example, Patent Document 3 discloses a surface protective film provided by the above-mentioned Patent Document 1 or 2, which is adhered to an acrylic plate or the like, and is adhered due to high initial adhesion. The situation in which the body is difficult to peel off. In addition, depending on the use, it is necessary to apply secondary processing such as printing to the surface of a resin plate or the like as an adherend after the protective film is peeled off. However, the surface protective film composed of the co-extruded laminated film provided by the above-mentioned Patent Document 1 or 2 has a slight amount of residue such as paste residue on the surface of the adherend after the film is peeled off. As a result, there is a problem that an important factor of poor printing is formed in the secondary processing as described above. Further, when the styrene-based elastomer is mixed in the adhesive layer, when it is wound up in a roll shape and then unrolled, the adhesive layer and the base material layer may be adhered to each other and the winding may be difficult. The problem is the so-called "blocking" situation. Further, in the surface protective film provided in Patent Document 3, although the surface of the adherend after peeling does not cause contamination sufficiently large enough to be visually confirmed, it may cause a change in the surface properties of the adherend, particularly When secondary processing such as coating and printing is applied after peeling, it may cause adverse effects. (Patent Document 1) Japanese Laid-Open Patent Publication No. 2006-1 88646 (Patent Document 2) Japanese Laid-Open Patent Publication No. 2006-25 7247 (Invention Patent Document 3) Japanese Laid-Open Patent Publication No. 2007-130872 [Technical Problem] The technical problem of the present invention is to provide a surface protective film which has moderate adhesion and adhesion stability, and is visually confirmed to be residue on the surface of the adherent after peeling, of course, It is said that it is impossible to confirm trace contamination, and the secondary processing of printing and the like is good, and after being wound into a roll, there is no sticking when it is re-rolled. 200930783 [Technical means for solving the problem] The inventors of the present invention have found that the resin used as the adhesive layer of the surface protective film is mixed in a specific ratio in order to solve the technical problem as described above. A resin obtained by a linear α-olefin polymer and a linear low-density polyethylene, or a mixture of amorphous 〇:-olefin polymer, linear low-density polyethylene, and crystalline ethylene at a specific ratio The resin obtained by the ct-olefin copolymer is used as a main component, whereby the contamination on the surface of the adherend is extremely small, and the secondary processing suitability can be improved, and the present invention has finally been attained. That is, the present invention provides a surface protective film which is obtained by the laminated adhesive layer (A) and the substrate layer (B), and the adhesive layer (A) is 5 to 50% by weight. Crystalline α-olefin polymer. (A 1 ) and a density of 50 to 95% by weight is 0. 8 80 to 0. 93 8 g / cm 3 of linear low-density polyethylene (A2) mixed resin, or 5 to 50% by weight of amorphous α-olefin polymer (Α1), 40 to 90% by weight of 0. 880 to 0. A linear resin of 938 g/cm3 of a low-density polyethylene (A2) and a mixed resin of 5 to 50% by weight of a crystalline ethylene-α-olefin copolymer (A3) are mainly contained. In addition, the term "specific resin as a main component in each layer" as used in the present invention means that the resin composition used in the layer (including various additives or other resins used as needed) Among them, 65% by weight or more of the resin or mixed resin specified in the present invention is contained. [Effects of the Invention] The surface protective film of the present invention is attached to various resin sheets, glass sheets, metal sheets, and the like, and is not visually observed on the surface of the adhered body after peeling even after being exposed to a high temperature environment for a long period of time. The residue of the paste is confirmed, and the residue that can be visually confirmed by 200930783 is also extremely small. Therefore, the surface protective film of the present invention can be used as a film for protecting the surface of various resin sheets, glass sheets, metal sheets, etc., and is particularly suitable for secondary processing in which printing or the like is applied after peeling off the protective film. Further, the surface protective film of the present invention also has excellent blocking resistance because it does not adhere when it is taken up in a roll shape and then unwound. Further, in particular, in the surface protective film of the present invention obtained by using a vinyl-based polymer as a substrate layer, in addition to the properties as described above, further enthalpy is also observed in the state in which the adhesive body is attached to the surface protective film. When the adhesive body is processed, the surface protective film can be perfectly cut, and does not cause excellent properties such as poor appearance such as drawing and raising, and thus it is widely used. [Embodiment] [Best Mode for Carrying Out the Invention] Hereinafter, the present invention will be described in detail. The surface protective film of the present invention is a coextruded laminated film obtained by forming an adhesive layer (A) and a substrate layer (B) by co-extrusion lamination. The amorphous α-olefin polymer (Α1) used in the adhesive layer (A) of the surface protective film of the present invention is a polymer or copolymer containing a monomer unit based on an olefin having 3 to 20 carbon atoms. Further, in the measurement range of -100 to 200 °C of the differential scanning calorimeter (DSC: Differential Scanning Calorimeter), the melting peak of the melting heat of the crystal of 1 J/g or more and the heat of crystallization were not observed. (crystallization heat) is a polymer of any one of crystallized peaks of 1 J/g or more, and these may be used alone or in addition to -10-200930783, or two or more kinds thereof may be used. The "olefin having 3 to 20 carbon atoms" as described above may be either linear or branched, and includes, for example, propylene, butene, pentene-1, hexene. -1,heptene-1,octene-1'nonene_丨,nonene_丨, undecene-1, dodecene-1,tridecene-丨,tetradecene·丨'pentene _ i, hexadecene i, heptadecene-1, octadecene-1 'nonadecanes-1, hexadecene, etc. linear 0: - olefin; 3-methylbutene-1, Branched α- 3-methylpentene-1, 4-methylpentene-1, 2-ethyl-1-hexene, 2,2,4-trimethylpentene-1, etc. Olefins. Further, the "amorphous α-olefin-based polymer (A 1 )" as described above is preferably a copolymer having two or more such α-olefin-based monomer units; industrially easy It is more preferable to obtain the compatibility, the compatibility with the linear low-density polyethylene (Α2) or the crystalline ethylene-α-olefin copolymer (A3) described later, and the co-extrusion moldability. a copolymer having more than one propylene-based monomer unit and a monomer unit based on an α-olefin having 4 to 20 carbon atoms; especially an amorphous propylene-butene-1 copolymer, amorphous A propylene-ethylene-butylene-1 copolymer. Further, the amorphous α-olefin-based polymerization product (Α1) may have a monomer unit other than the α-olefin as described above. Such monomer units include, for example, monomer units based on ethylene, a polyene compound, a cyclic olefin, a vinyl aromatic compound, and the like. The content of the propylene-based monomer unit in the "amorphous propylene-butene-1 copolymer" as described above is considered from the viewpoint of improving the heat resistance of the obtained surface protective film. When the total monomer unit of the amorphous propylene-butene-1 copolymer is 100% by weight, it is preferably 7% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight. the above. -11 - 200930783 The content of the propylene-based monomer unit in the "amorphous propylene-ethylene-butylene-ι copolymer" as described above can improve the heat resistance of the prepared surface protective film. When the total monomer unit of the amorphous propylene-ethylene-butene-1 copolymer is 100% by weight, it is preferably 50% by weight or more, and more preferably 60% by weight or more. Further, the content of the ethylene-based monomer unit in the "amorphous propylene-ethylene-butene-1 copolymer" is assumed to be the same as the monomer of the amorphous propylene-ethylene-butene-1 copolymer. When the unit is 100% by weight, it is preferably 1% by weight or more, more preferably 20% by weight or more. If the content of the monomer unit based on styrene is in this range, since the adhesive layer (B) as described above will become relatively soft, even if there is unevenness on the surface of the adherend,  It is also possible to adhere to the unevenness of the film so that sufficient adhesion can be obtained. Further, as described above, "the ultimate viscosity of the amorphous α-olefin polymer (A 1 ) [7?]" is higher. Good for 0. 1 to 10. 0dl/g, more preferably 0. 7 to 7. 0dl/g. Further, the molecular weight distribution (Mw/Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (?η) is preferably more than 1 and is 4 © or less, more preferably 2 to 3. When the ultimate viscosity and molecular weight distribution of the amorphous α-dilute hydrocarbon polymer (A1) are in this range, heat resistance, transparency, and adhesion can be improved, and even if the surface protective film is attached for a long period of time Adhesion of the adherend or exposure to a high temperature environment can also reduce the contamination of the adherend caused by the transfer of the low molecular weight component in the amorphous α-olefin polymer (Α1) to the surface of the adherend. In addition, since the amorphous α-olefin polymer (α ι ) is an olefin polymer, there is no case where an ethylene-vinyl acetate copolymer is used as a resin for an adhesive layer, and deacetic acid or the like is used. The resin becomes -12-200930783. The aging-induced adhesion increases the long-term continuous maintenance of stable adhesion. The method for producing the amorphous α-olefin polymer (A1) as described above is not particularly limited, and for example, a gas phase polymerization method, a solution polymerization method, a slurry polymerization method, a bulk polymerization method, or the like can be used, and A metallocene is a method in which a catalyst is subjected to polymerization or the like. A more preferable production method is a production method described in Japanese Laid-Open Patent Publication No. 2002-34841. The resin system used in the adhesive layer (A) of the surface protective film of the present invention is obtained by mixing the amorphous α-olefin polymer (A 1 ) and the linear low density polyethylene (A2) as described above. The obtained resin, or by mixing the amorphous α-olefin polymer (A1), the linear low-density polyethylene (A2), and the crystalline ethylene-α-olefin copolymer (A3) as described above The resin obtained. By mixing the linear low-density polyethylene (A2) and the crystalline ethylene-α-olefin copolymer (A3) in the amorphous α-olefin polymer (A 1 ) as described above, the energy can be modulated. Corresponding to the adhesive force according to the surface state of the adhesive body, the material of the adhesive body, and the use characteristics, and the influence of the adhesive strength, the contamination on the surface of the adhesive body after peeling can be reduced. The density of the linear low-density polyethylene (Α2) as described above is 0. 8 80 to 0. In the range of 938 g/cm3, the density is better as 0. 898 to 0. 925 g/cm3. In addition, its MeltFlow Rate (MFR: according to JISK7210 (1 9 99) guidelines, at 19 0 °C, 2 1. The enthalpy measured at 18 N. ) preferably 0. 5 to 30. 0 g/10 min, more preferably 2. 0 to 15. 0 g/10 min. When the density and MFR of the linear low-density polyethylene (A2) are in this range, compatibility with the amorphous α-olefin polymer (A 1 ) as described above is preferable, and • 13 - 200930783 It also improves the film formation of laminated films. The crystalline ethylene-α-olefin copolymer (A3) as described above, although it includes an ethylene-propylene copolymer, an ethylene-butene-1 copolymer, etc., is industrially easy to obtain and can be easily adjusted. From the viewpoint of the adhesion of the surface protective film, an ethylene-butene-1 copolymer is preferred. The crystalline ethylene-α-olefin copolymer (A3) is preferably MFR (at 19 (TC, 21. 18 値 measured under the armpit. ) is 0. 5 to 30. 0 g/10 min, and the density is 0. 870 to 0. For 905 g/cm3, it is better that the MFR is 2. 0 to 15. 0 g/10 min, and the density is 0. 880 © to 0. 900 g/cm3. When the MFR and density of the crystalline ethylene-α-olefin copolymer (A3) are in this range, compatibility with the amorphous α-olefin polymer (Α1) as described above is preferable, and The film formation property of the laminated film can be improved. Further, from the viewpoint of the effect of preventing contamination on the surface of the adherend, these resins are more preferably a metallocene catalyst system having a low molecular weight component as described later. In addition, the term "crystallinity" means that the heat of fusion of crystals is 1 J/g or more in the measurement range of -100 to 20,000 °C of a differential scanning calorimeter (DSC). The melting peak and the heat of crystallization are those of the crystallization peaks of 1 J/g or more. When the adhesive layer (A) is a mixture of a non-crystalline α-olefin polymer (A1) and a linear low-density polyethylene (Α2) as a main component, the mixing ratio is amorphous α - The olefin-based polymer (Α1) is 5 to 50% by weight, the linear low-density polyethylene (Α2) is 50 to 95% by weight, and more preferably the component (Α1) is 5 to 40% by weight, and the composition (Α2) ) is obtained by mixing 60 to 95% by weight. When the mixing ratio of the amorphous α-olefin polymer (A 1 ) is less than 5% by weight, sufficient adhesion cannot be obtained, and if it exceeds 50 -14 to 200930783% by weight, the adhesion is too strong. The problem of the usability of the film is encountered. Further, by adjusting the mixing ratio of the component (A1) and the component (A2) in the range as described above, it can be easily adjusted to about 所 according to the required adhesive force. 〇5 to 5. ON/2 5 mm adhesion. Further, when the adhesive layer (A) is used, a mixture of an amorphous α-olefin polymer (A1), a linear low-density polyethylene (Α2), and a crystalline ethylene-α-olefin copolymer (A3) is used. When the obtained resin is used as a main component, the mixing ratio is 5 to 50% by weight of the amorphous α-olefin polymer (A 1 ), and the density 〇 is 0. 880 to 0. The linear low-density polyethylene (A2) of 938 g/cm3 is 40 to 90% by weight, the crystalline ethylene·α-olefin copolymer (A3) is 5 to 50% by weight, and more preferably the component (A 1 ) It is 5 to 30% by weight, the component (Α2) is 40 to 85 wt%/〇, and the component (A3) is 10 to 45 wt%. By adjusting the mixing ratio of the component (A1), the component (A2), and the component (A3) to the range as described above, it can be easily adjusted to about 0 according to the required adhesive force. 1 to 7·0 N/25 mm adhesion. In the present invention, the resin used for the adhesive layer (A) is mainly composed of the above-mentioned ® mixed resin, but other resins can be used without impairing the efficacy of the present invention. In this case, other resins which can be used include, for example, 'propylene homopolymer, propylene-butene-1 copolymer, propylene-butene-1-ethylene terpolymer, butene-1 homopolymer, benzene. Ethylene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (sis), styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-ethylene - propylene-styrene copolymer (SEPS), styrene-butadiene copolymer (SB), styrene-isoprene copolymer (SI), styrene-ethylene-butene copolymer (SEB), - 15-200930783 Styrene-butadiene rubber (SBR), styrene-ethylene-butylene-ethylene copolymer (SEBC), and further such hydrides. Further, the preparation method of the mixed resin used in the adhesive layer (A) of the present invention is not particularly limited, but it is difficult to use the amorphous α-olefin polymer (Α1) at normal temperature. It is preferable to melt-knead the amorphous α-olefin polymer (Α1) and the linear low-density polyethylene (Α2) or other crystalline polymer in advance to form an easy-to-use pellet, so that it can be more The co-extrusion lamination method is easily applied. In addition, as described above, in the present invention, the term "specific resin in each layer as a main component" is a resin composition used in the layer (including various additives or other materials used as necessary). In the case where the resin or the mixed resin specified in the present invention is contained in an amount of 65% by weight or more, it is preferably 75% by weight or more, and particularly preferably, from the viewpoint that the effect of the present invention can be easily exhibited. 8 5 wt% or more. The resin used for the substrate layer of the surface protective film of the present invention is not particularly limited as long as it is a thermoplastic resin and can be co-extruded with the adhesive layer. When the affinity of the adhesive layer is good, it is preferable to use an olefin polymer as a main component, and particularly preferably a vinyl polymer (Β1) or a crystalline propylene polymer (Β2). Main ingredient. The "vinyl polymer (Β 1 )" as described above includes, for example, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, and the like. These systems can be used individually or separately. Among these, since the heat resistance is good, it is preferably a linear low-density polyethylene, a medium-density polyethylene, or a mixed resin of low-density polyethylene and high-density polyethylene, which is mainly composed of -16-200930783. When the vinyl polymer (B1) as described above is used as the base material layer (B), in addition to the main purpose of the present invention, the effect of preventing contamination of the surface of the adherend after peeling is further improved. When the adhesive body is cut and processed in a state in which the surface protective film is attached to the adhesive body, the surface protective film can be perfectly cut without causing excellent cuttability such as poor appearance such as drawing and raising. In addition, these ethylene-based polymers (B1), if their MFR (at 190 O °C, 21. The enthalpy measured at 18 N is 0. 5 to 30. 0 g/10 min, it is preferable because extrusion molding can be easily performed, and it is more preferable that the MFR is 2. 0 to 15. 0 g/10 minutes. In addition, when the melting point of the ethylene-based polymer (B1) is 90 to 135 ° C, the film is exposed to a high-temperature environment even if it is dried, heated, or the like after being attached to the adherend. Since it is small, it is preferable to suppress floating or peeling from the adherend, warpage of the adherend, etc., and it is more preferable that it has a melting point of 105 to 130 °C. When the surface protective film of the present invention is required to have better heat resistance, it is preferred to use the crystalline propylene polymer (B2) as the resin used for the substrate layer (B). The crystalline propylene polymer (B2) includes, for example, a propylene homopolymer, an ethylene-propylene copolymer, a propylene-butene-1 copolymer, an acrylonitrile-butene-1 copolymer, and the like. These may be used alone or in combination of two or more. Further, 'MFR of these crystalline polypropylene-based polymers (B2) is preferred (at 23 ° C, 21. The enthalpy measured at 18 N is 〇·5 to 3 〇 gram/1 〇 minute, and the melting point is 120 to 165 ° C, and more preferably MFR is 2. 0 to 15. 0 g/10 min. And the melting point is 125 to 162 °C. When the MFR and the melting point are in the range of -17 to 200930783, since the shrinkage of the film exposed to the high-temperature environment is small due to drying, heat molding, or the like after being attached to the adherend, there is no floating or peeling, and it is not caused. This causes warpage of the adherend and also improves the film formation of the laminated film. In addition, the term "crystallinity" means that the melting heat of J crystal is 1 J/g or more in the measurement range of -100 to 200 °C of a differential scanning calorimeter (DSC). The polymer having a melting peak and a crystallization heat of any one of crystallized peaks of 1 J/g or more. Further, among the crystalline propylene-based fluorene polymer (B2) used in the substrate layer (B) as described above, a crystalline propylene-based polymer obtained by using a metallocene catalyst is preferred (also It is called "metallocene catalyst polypropylene".). The metallocene catalyst polypropylene is used to replace the traditional Ziegler-Nat. (Ziegler-Natta) is a catalyst, and is a polypropylene obtained by polymerization using a metallocene catalyst. The metallocene-based catalyst includes, for example, a dimetallocene compound containing a metallocene compound and a methyl aluminoxane, and a metallocene compound supported on the particulate carrier. The obtained metallocene metal is supported by a catalyst or the like. The ferrocene-loaded catalyst ❹ is disclosed in Japanese Laid-Open Patent Publication No. 5-155531, Japanese Patent Laid-Open No. Hei 8-104 691, Japanese Patent Application Laid-Open No. 8-157515, and Japanese Kaiping No. 8-231621 and the like. Since the metallocene catalyst-based polypropylene has a high molecular weight distribution and composition distribution and a low content of a low molecular weight component, by using a metallocene catalyst-based polypropylene in the substrate layer (B) of the present invention, Contamination of the surface of the adherend due to exudation of low molecular weight components can be easily prevented. Further, the metallocene catalyst-based polypropylene may be a propylene homopolymer or a copolymer of propylene and other α-olefins, and an example of the copolymerization of propylene with other α-olefins -18 - 200930783 includes: ethylene - Propylene copolymer and the like. When the base layer (B) as described above is a crystalline propylene-based polymer (B2) as described above, it can also be used as described in the adhesive layer (A) as described above. The same amorphous α-olefin-based polymer (B3) is described. By using the amorphous α-olefin polymer (Β 3 ), the softness of the obtained surface protective film can be increased to improve the followability of the film to the surface of the adherent when attached, and It can be peeled off smoothly when peeling off. In addition, the amorphous α-olefin polymer (Β 3 ) used at this time may be an amorphous α-olefin polymer which is used in an adhesive layer (Α) as described above. (Α1) is the same copolymer or may be a different copolymer. When the amorphous-abnormal hydrocarbon-based polymer (Β 3 ) is mixed in the base material layer (Β), the crystalline propylene-based polymer (Β2) and the amorphous α-olefin-based polymer (Β3) are The mixing ratio is preferably [crystalline propylene-based polymer (Β 2 )]: [amorphous α-olefin-based polymer (Β 3 )] = 70 to 95: 30 to 5 by weight. More preferably, the ratio is as described above in the range of go to 95:20 to 5. When the mixing ratio of the crystalline propylene-based polymer (β 2 ) and the amorphous α ® -olefin-based polymer (Β3 ) is in this range, sufficient flexibility can be imparted to the obtained surface protective film. Maintain heat resistance. Further, the flexibility of the obtained surface protective film can also be adjusted by using the vinyl polymer (Β1) and the crystalline propylene polymer (Β2) as the substrate layer (Β) as described above. . Further, the flexibility of the obtained film can also be adjusted by using an ethylene-methyl methacrylate copolymer (hereinafter referred to as "EMM A"). EMMA is preferably MFR (at 190. (:, measured at 21 U N) is 〇. 5 to 30. 0g/10 minutes, more preferably Mfr -19- 200930783 is 2. 0 to 15. 0 g/10 minutes. In the EMMA, the content of the monomer unit based on methyl methacrylate (hereinafter referred to as "MMA") is preferably from 3 to 30% by weight. More preferably, it is 8 to 25% by weight. When the content of MFR and MMA as described above is in this range, sufficient flexibility can be imparted to the obtained surface protective film, and the film formability of the laminated film can be improved. When the amorphous olefin-based polymer (B2) is mixed with the amorphous α-olefin-based polymer (B3) and the vinyl-based polymer (B1) and/or EMMA, the crystalline propylene (B) is crystalline propylene. Polymer (Β2), amorphous 〇: - olefinic 0 polymer (Β3), ethylene polymer (Β1) and/or EMMA mixing ratio 'by weight, [crystalline propylene polymer ( B2)]: [Amorphous α-olefin polymer (B3)]: [Ethylene polymer (Β1) and/or EMMA] is preferably in the range of 7〇 to 95: 4 to 29: 1 to 12. More preferably, the ratio is as described above in the range of 80 to 95: 4 to 19: 1 to 5. When the mixing ratio is in this range, sufficient flexibility can be imparted to the surface protective film obtained, and heat resistance can be maintained. Although the surface protective film of the present invention has a configuration in which the two layers of the adhesive layer (A 〇) and the substrate layer (B) as described above are necessary, it is also possible to further laminate the substrate layer (B). A surface layer (C) is provided on the opposite side of the face of the adhesive layer (a). The resin used for the surface layer (C) is not particularly limited, but is considered to be an olefin polymer from the viewpoint of having a good affinity with the substrate layer (B) as described above. As the main component, it is more preferable to use a vinyl polymer (C1) or a crystalline propylene polymer (C2). Specifically, the main component of the substrate layer (B) is ethylene. In the case of the polymer (B1), it is more preferred that the ethylene-based polymer (C1) is mainly composed of -20 to 200930783 parts; and if the main component of the substrate layer (B) is a crystalline propylene-based polymer (B2), More preferably, the crystalline propylene-based polymer (C2) is mainly composed. The ethylene-based polymer (C1) suitable for use as the main component of the surface layer (C) is the same as the ethylene-based polymer (B1) used as the main component of the substrate layer (B) as described above. Further, by selecting the vinyl polymer (C1) as the main component of the surface layer (C), it is possible to use the same as in the case of using the vinyl polymer (B1) as the main component of the substrate layer (B). The resulting surface protective film will exhibit high cutting properties. In addition, the ethylene-based polymer (B1) used in the substrate layer Ο (B) and the vinyl-based polymer (C1) used in the surface layer (C) can be used in the same manner. Resin, but can also be used. The same resin. In the ethylene-based polymer (C1) used as the main component of the surface layer (C) as described above, when the low-density polyethylene is used, the surface of the surface layer (C) can be easily modified. It is satin-shaped. By forming the surface of the surface layer (C) into a satin-like surface, even if the adhesive force of the adhesive layer (A) is designed to be strong, the adhesion can be alleviated. In addition, when high-density polyethylene is used together with the low-density polyethylene, the rigidity of the surface protective film to be produced can be improved, and workability such as attachment and peeling tends to be good. The mixed resin of the ethylene-based polymer (C1) and the ethylene-propylene copolymer may be used as the main component of the surface layer (C) to modify the surface of the surface layer (C) into a satin surface. The ethylene-propylene copolymer is as long as it is a resin obtained by copolymerizing ethylene and propylene, for example, including polymerization of ethylene by the presence of a propylene homopolymer or '-21-200930783 ethylene And an ethylene-propylene block copolymer obtained by polymerization of propylene. Among these, since the surface can be easily formed into a satin surface, it is preferably an ethylene-propylene block copolymer having a content of ethylene derived from 8 to 20% by weight, more preferably used. The ethylene-propylene block copolymer having a content of ethylene derived from 10 to 15% by weight. Further, from the viewpoint of easy extrusion processing, the MFR of the ethylene-propylene copolymer (at 230 ° C, 21. The enthalpy measured at 18 N is preferably in the range of 4 to 12 g/10 minutes, more preferably in the range of 6 to 10 g/10 minutes. Similarly, from the viewpoint of easy extrusion processing, the density of the copolymer is preferably 0. 890 to 0. The range of 910 g/cm3 is more preferably from 0.895 to 0. 90 5 g/cm3 range. In addition, even if the ethylene-propylene copolymer as described above is used as the main component of the surface layer (C) alone, the surface of the surface layer (C) can be modified into a satin surface, and thus it is preferred. It is suitably selected and used according to the affinity with the kind of the resin used for the base material layer (B). The crystalline propylene-based polymer (C2) suitable for use as a main component of the surface layer (C) includes a crystalline propylene-based polymer which is used as a main component of the substrate layer (b) as described above. (B2) the same. Further, by selecting the crystalline C-type polymer (C2) as the main component of the surface layer (C), it is possible to use the crystalline propylene-based polymer (B2) as the main component of the substrate layer (B). In the same manner, the surface protective film finally obtained can exhibit high heat resistance and the main component of the 'surface layer (C), if it is considered from the viewpoint of the adhesion level or the required transparency, etc. The crystalline propylene-based polymer (C2) and the acetylene-propylene copolymer as described in ij are mixed to appropriately adjust the strength of the satin surface-22-200930783. The surface protective film of the present invention is preferably such that its total film thickness is from 20 to 120 #m. When the thickness of the total film is within this range, the workability of the adhesive, such as the protective property, the adhesiveness, and the attachment and peeling, tends to be good. Further, the thickness of the adhesive layer (A) is preferably from 3 to 30 / zm, more preferably from 5 to 25 #m. If the thickness of the adhesive layer (A) is in this range, the adhesiveness and the film formability of the laminated film tend to be good. Further, when the surface protective layer of the present invention is provided with the surface layer (C) as described above, the thickness of the surface layer (C) is preferably from 3 to 30 / zm, more preferably from 5 to 2 Å. When the thickness of the surface layer (C) is in this range, the heat resistance and the film formability of the laminated film tend to be good. The method for producing the surface protective film of the present invention is not particularly limited as long as it is a co-extrusion lamination method, and for example, a resin for melting each resin layer may be used by using two or more extruders. A co-extrusion method such as a co-extrusion dies method or a feed block method is carried out in a molten state, and then an inflation method, a T-die, and a chiller are used. A method of processing into a film shape by a method such as a T-die-chill roll method ® . In the case of using the T-die/cold roll method, it is also possible to cool the film by melt-stacking between a rubber contact roll, a steel belt, or the like and a chill roll. Further, the surface protective film of the present invention can also be extended at least in a uniaxial direction. The stretching method may be a conventional method such as uniaxial stretching in the longitudinal direction or in the transverse direction, sequential biaxial stretching, simultaneous biaxial stretching, or tubular biaxial stretching. Further, the 'extension step' can be on the production line or also on the production line. The method of extending the uniaxial extension may be a near roll extension method or a calendering method. -23- 200930783 The extension ratio of uniaxial extension is preferably extended longitudinally or laterally. 1 to 80 times, more preferably 3 to 30 times. On the other hand, the stretching ratio of the biaxial stretching is preferably 1. 2 to 70 times, more preferably 4 to 6 times in the longitudinal direction, 5 to 9 times in the lateral direction, and 20 to 54 times in the area ratio. In addition, the longitudinal or lateral extension step is not limited to one-stage extension, but may also be a multi-stage extension. In particular, in the longitudinal and uniaxial extension of the longitudinal uniaxial roll extension, the longitudinal uniaxial rolling extension, and the like, which are successively biaxially stretched, it is preferable to adopt a multi-stage extension from the viewpoints of thickness and uniformity of physical properties. . Further, in terms of the extension of the proximal roller, although it may be either a planar method or an intersection method, it is more preferable to reduce the multi-section proximal cross extension of the reduced width. In the case of uniaxial extension, the extension temperature of either extension method.  Preferably, the system is preferably from 80 ° C to 160 ° C, and is preferably from 90 to 165 ° C if the tenter is extended by uniaxial stretching. In addition, the preferred extension temperatures are 110 to 1551: 120 to 160 °C, respectively. On the other hand, in the case of biaxial stretching, either method is preferably the same extended temperature range as in the case of uniaxial stretching. Further, it is also possible to appropriately set the preheating portion before the extending step and to provide the heat fixing portion after the extending step. At this time, the temperature of the preheating portion is preferably from 60 to 140 °C, and the temperature of the heat fixing portion is preferably in the range of from 90 to 160 °C. The surface protective film of the present invention can be stabilized by at least a uniaxial direction and stabilized by a heat-fixing desired structure, whereby the alignment crystallization can be obtained by the resin used for the substrate layer (B) and the surface layer (C). Further, it is preferable to further improve the heat resistance, and it is possible to reduce the change over time of the adhesive force. In particular, when a crystalline propylene-based polymer is used as the substrate layer (B) and/or the surface layer (C), -24- 200930783 High efficiency. In addition, a lubricant, an anti-blocking agent, an ultraviolet absorber, a light stabilizer, an antistatic agent, an antifogging agent, a coloring agent, etc. may be appropriately added without impairing the efficacy range of the present invention, and the added object may be added. The resin layer can be added to any layer depending on the purpose. These additives are preferably various additives for use in the olefin-based polymer. EXAMPLES Hereinafter, the present invention will be specifically described by way of illustrative examples and comparative examples [Synthesis Example 1] (Amorphous α-olefin) Synthesis of a polymer (amorphous propylene-butene-1 copolymer)) In a 100 liter stainless steel polymerization vessel equipped with a stirrer, hydrogen is used as a molecular weight regulator to continuously carry propylene and butene-1 together. Polymerization was carried out to obtain an amorphous propylene-butene-1 copolymer as an amorphous ?-olefin polymer. Specifically, hexane was continuously supplied as a polymerization solvent at a supply rate of 1 Torr/hr from the lower portion of the polymerization reactor. 00 kg / hour supply of propylene, to 1. The butene-1 was supplied at 81 kg/hr, and the reaction mixture was continuously withdrawn from the upper portion of the polymerization reactor so that the reaction mixture in the polymerization reactor was maintained at 100 liters. In addition, from the lower part of the polymerization reactor, it is continuously supplied separately: the supply speed is 0. 00 5 g / h of dimethyl decyl (tetramethylcyclopentadienyl) (3-tris-butyl-5-methyl-2-phenoxy) titanium dichloride, supply rate of 0 . 298 g/hr of triphenylmethylphosphonium (pentafluorophenyl)borate, and a supply rate of 2. 315 g / h of triisobutyl aluminum, etc. as a catalyst into -25- 200930783 parts. The copolymerization reaction was carried out at 45 ° C by circulating cooling water to a water jacket installed outside the polymerization reactor. After a small amount of ethanol is added to the reaction mixture continuously extracted from the upper portion of the polymerization reactor to stop the polymerization reaction, amorphous propylene-butene is obtained through a monomer removal, water washing, and solvent removal steps. -1 copolymer. Next, the obtained copolymer was dried under reduced pressure at 80 ° C for 24 hours. As a result, the content of the propylene monomer unit in the amorphous propylene-butene-1 copolymer was 94. The content of 5% by weight of the butene-1 monomer unit is 5. 5% by weight (each monomer unit was measured by a nuclear magnetic resonance apparatus JMN-LA300 manufactured by JEOL 〇 Ltd.). In addition, the copolymer did not observe a melting peak in DSC (EXSTAR 6 000 manufactured by Seiko Instruments Inc.), in addition, Its ultimate viscosity [7?] is 2. 3 dl / g, molecular weight distribution (Mw / Mn) is 2. 2 (Molecular weight distribution was analyzed by a gel permeation chromatograph manufactured by TOSCH Corporation, HLC-8020). [Synthesis Example 2] (Synthesis of amorphous α-olefin polymer (amorphous propylene-ethylene-butene-1 copolymer oxime)) A stirrer, a thermometer, a dropping funnel, and a reflux cooling tube were provided. After a 2 liter separable flask reactor was depressurized and replaced with nitrogen, 1 liter of dry toluene was introduced as a polymerization solvent. The mixture was continuously supplied with 2 x 10 · 6 cm 3 /min of ethylene, 4 x l -6 cm 3 /min of propylene, and 1 x 10 6 cm 3 /min of butene-1 at a normal pressure, and the solvent temperature was set to 30 °C. Will be 0. 75 millimoles of isobutylaluminum (hereinafter referred to as "TIBA") is added to the polymerization tank and will be 0. 0015 millimoles of dimethyl decyl (tetramethylcyclopentadienyl) (3- -26- 200930783 tert-butyl-5-methyl-2-phenoxy) titanium dichloride added Aggregation tank. After 15 seconds, it will be 0. 0075 mmol of triphenylmethylphosphonium (pentafluorophenyl)boronic acid vinegar was added to the polymerization tank to carry out polymerization for 1 minute. As a result, an amorphous propylene-butene-ethylene copolymer can be obtained. The content of the propylene monomer unit in the amorphous propylene-ethylene-butylene-ruthenium copolymer is 61. 5 wt%, the content of ethylene monomer unit is 21. The content of 0% by weight of the butene d monomer unit was 175% by weight. Further, the copolymer did not observe a melting peak in DSC, and further, its ultimate viscosity [77] was 1. 69 dl / g, molecular weight distribution (Mw / Mn) is 2. 0 © [Modulation Example 1] (by containing non. Preparation of pellets composed of the composition (1) of the crystalline-olefin-based polymer) Amorphous propylene-butene·1 copolymer and crystalline propylene obtained according to Synthesis Example 1 as described above Butene-1 copolymer [density is 0. 900 g/cm3, MFR (at 230 °C, 21. The enthalpy measured at 18 N is 10. 0 g/10 min, the maximum melting peak at DSC is 126 ° C] mixed into amorphous propylene-butene®-1 copolymer/crystalline propylene-butene-1 copolymer = 60/40 (weight ratio) And, respectively, 2,000 ppm of aromatic phosphite-based antioxidants (Ciba Specialty Chemicals Co., Ltd.) "Irgafos 168" manufactured by the company, and ergonomic phenolic antioxidant [Irganox 1010" manufactured by Ciba Specialty Chemicals Co., Ltd.) and a twin-screw extruder (PCM30, 30 ιηιηφ screw manufactured by IKEGAI) The melt-kneading was carried out at 230 ° C, and then the pellets of the composition (1) containing the amorphous α-olefin polymer were obtained by a granulator (CK 2 manufactured by Nakatani Machinery Co., Ltd.). -27-200930783 [Preparation Example 2] (Preparation of pellets composed of the composition (2) containing an amorphous olefin polymer), except that it is mixed into an amorphous propylene-butene copolymer; In the same manner as in the adjustment example 1, except that the crystalline propylene-butene-1 copolymer ==95/5 (weight ratio), the composition (2) containing the amorphous α-olefin polymer was obtained. Cut the pellets. [Preparation Example 3] 〇 (Preparation of dicing composed of a composition (3) containing an amorphous "-olefin-based polymer").  In the adjustment example 1, except that the amorphous α-olefin-based polymer to be used was changed to the amorphous propylene-ethylene-butene-1 copolymer obtained according to Synthesis Example 2, the rest was prepared and modulated. In the same manner as in Example 1, the pellets of the composition (3) containing the amorphous α-olefin polymer were obtained. [Preparation Example 4] (Preparation of dicing particles composed of the composition (4) containing an amorphous-olefin-based polymer), except for mixing into amorphous propylene-ethylene-butene-1 copolymer/crystallization The granules of the composition (4) containing the amorphous α-olefin polymer were obtained in the same manner as in the adjustment example 3 except that the propylene-butene-1 copolymer was 95/5 (weight ratio). . [Preparation Example 5] (Preparation of pellets composed of the composition (5) containing the amorphous α-olefin polymer) -28- 200930783 Except that the non-synthesis example 1 described above was prepared Crystalline propylene-butene-1 copolymer and linear low density polyethylene [density of 0. 935 g/cm3, MFR (at 190 ° C, 21. The enthalpy measured at 18 N is 3. 5 g/10 min] was mixed into amorphous propylene-butene-1 copolymer/linear low-density polyethylene = 9 5/5 (weight ratio), and the rest was prepared in the same manner as in Preparation Example 1. A pellet of the composition (5) containing an amorphous α-olefin polymer is obtained. [Example 1] The "resin for surface layer" used 80 parts by weight of a propylene homopolymer (closeness: 0. 900 g/cm3, MFR (at 230 ° C, 21. 18 Ν measured 値): 8. 0 g/10 min; in the following, it is called "HOPP". ], 20 parts by weight of ethylene-propylene block copolymer [density: 0. 900 g/cm3, MFR (at 23 0 °C, 21. The resin used for the measurement of 18 Å) is used as the mixed resin of 8 g/10 min. The resin for the base material layer is HOPP, and the resin for the adhesive layer is 30 parts by weight, which is prepared as described above. The composition (1) containing an amorphous α-olefin polymer and 70 parts by weight of a linear low-density polyethylene [density: 0. 902 g/cm3, MFR (at 190 ° C, 21. 値 measured by 1 8 N) ® : 3_0 g/10 min; in the following, it is called "LLDPE (1)". a mixture of the surface layer and an extruder (caliber of 50 mm) for the substrate layer and an extruder (caliber of 40 mm) for the adhesive layer, respectively. The co-extrusion method has a thickness of 12 2 /zm extruded from the T-die at a pressing temperature of 250 ° C, a thickness of the substrate layer of 3 8 /zm, and a thickness of the adhesive layer of l〇// m, then cooled by a 4 (TC water-cooled metal cooling roll and then rolled up into a roll shape, whereby a surface protective film can be obtained. The obtained film is stabilized at 35 ° C for physical properties. It is aged for 48 -29 to 200930783 hours in the aging chamber. [Example 2] In addition to the "resin for the surface layer", the ethylene-propylene block copolymer is used, and the "resin for the adhesive layer" is replaced by 50 parts by weight. A surface protective film was obtained in the same manner as in Example 1 except that the composition (1) of the amorphous α-olefin polymer and 50 parts by weight of LLDPE (1) were used. [Example 3] The same composition of Example 2 was supplied to the surface layer extruder (with a diameter of 50 mm) and the substrate layer was extruded. The machine (caliber 50 mm) and the adhesive layer extruder (caliber 40 mm), and the thickness of the surface layer extruded from the Τ-die at a pressing temperature of 250 ° C by co-extrusion method is 4 〇 Em, substrate layer.  The thickness is 120/zm, the thickness of the adhesive layer is 40/zm, and then cooled by cooling the metal cooling roller with water of 40 ° C, and then extending 4 times in the longitudinal direction at 40 ° C by the close roller extension method, and Heat setting was applied at 145 ° C to obtain a uniaxially stretched surface protective film. The obtained film was aged for 48 hours in a curing chamber where the physical properties were stabilized at 35 °C. Further, the thickness of each layer of Example 3® in Table 1 is the thickness after uniaxial stretching. [Example 4] The "adhesive layer resin" was replaced by a mixture of 40 parts by weight of the amorphous α-olefin polymer-containing composition (2) and 60 parts by weight of LLDPE (1). A surface protective film was obtained in the same manner as in Example 2. [Example 5] In addition to the "resin for adhesive layer", 40 parts by weight of the composition (4) containing amorphous α -30-200930783 - olefin polymer and 60 parts by weight of linear low density polyethylene were used. [density: 0. 920 g/cm3, MFR (at 190 ° C, 21. 値 measured under 18 N): 4. 0 g/10 min; in the following, it is called "LLDPE (2)". A surface protective film was obtained in the same manner as in Example 2 except for the mixture. [Example 6] Except that 20 parts by weight of the composition (5) containing the amorphous α-olefin polymer and 80 parts by weight of the LLDPE (2) mixture were used, the "resin for the adhesive layer" was used. A surface protective film was obtained in the same manner as in Example 2. [Example 7].  In the case of "the surface layer resin j is used, the "base material layer resin" is the same one, and the "adhesive layer resin" is a composition containing 10 parts by weight of the amorphous ?-olefin polymer ( 2) a mixed resin of 90 parts by mass of LLDPE (2), which is supplied to an extruder for surface layer (caliber of 50 mm), an extruder for substrate layer (caliber of 50 mm), and a layer for adhering β layer Extruder (caliber 40 mm), and the thickness of the surface layer is 14#m from the Τ-die at a extrusion temperature of 205 ° C, and the thickness of the substrate layer is 42 A surface protective film was obtained in the same manner as in Example 1 except that the thickness of the adhesive layer was 14 #m. [Example 8] "Resin for base material layer" was a metallocene catalyst-based ethylene-propylene random copolymer [density: 0. 900 g/cm3, MFR (at 230 °C, 21. 测定 measured under 18 N): 7. 0 g/10 min, the content of ethylene monomer unit: 3. 5 weight -31 - 200930783%; hereinafter, it is called "metallocene catalyst system COPP". The "adhesive for the adhesive layer" is a mixture of 50 parts by weight of the composition (3) containing the amorphous α-olefin polymer and 50 parts by weight of the LLDPE (2); and is supplied to the substrate layer separately. Extrusion machine (caliber 50 mm) and adhesive layer extruder (caliber 40 mm), and extruded from the T-die to the thickness of the substrate layer by co-extrusion at an extrusion temperature of 250 ° C It is 50 μm, the thickness of the adhesive layer is 10 μm, and then cooled by cooling the metal cooling roll with water of 40 ° C, and then wound into a roll shape, whereby a surface protective film can be obtained. The resulting film was aged for 48 hours in a ripening chamber at 35 ° C for stabilization of its physical properties. [Example 9] In addition to the "metallocene layer resin", the "metallocene resin" was used, and the "adhesive layer resin" was used. A surface protective film was obtained in the same manner as in Example 2 except that 0 part by weight of the composition of the amorphous α-olefin-based polymer (2) and 94 parts by weight of LLDPE (2) were mixed. [Example 1 〇] In addition to the "resin for the base layer", the metallocene catalyst COPP was used, and the "resin for the adhesive layer" was used. 0 parts by weight of the composition (2) containing the amorphous α-olefin-based polymer, 84 parts by weight of LLDPE (2) and 10 parts by weight of the ethylene·butene-1 copolymer [density: 0. 895 g/cm3, MFR (at 190 ° C, 2 1. 1 measured under 1 8 N): 3. 0 g / 1 0 minutes; in the following, it is called "EBR". A surface protective film was obtained in the same manner as in Example 2 except for the mixture. [Example 1 1] In the "resin for substrate layer", a metallocene catalyst copp was used, and "-32-200930783 resin for an adhesive layer" was used in an amount of 30 parts by weight of a composition containing an amorphous olefin polymer. A surface protective film was obtained in the same manner as in Example 2 except that a mixture of the object (2), 50 parts by weight of LLDPE (2) and 20 parts by weight of EBR was used. [Example 1 2] In the "resin for the base layer", the metallocene catalyst-based COPP was used, and the "resin for the adhesive layer" was a composition containing 20 parts by weight of the amorphous α-olefin-based polymer ( A surface protective film was obtained in the same manner as in Example 2 except that a mixture of 40 parts by weight of LLDPE (2) and 40 parts by weight of EBR was used. [Example 1 3].  "Resin for base material layer" is 50 parts by weight of high density polyethylene [density: 0. 96 0 g/cm3, MFR (at 190 ° C, 21. 18Ν measured by 18Ν): 13g/10 minutes; hereinafter, it is called “HDPE”. ] and 50 parts by weight of low density polyethylene [density: 0. 902 g/cm3, MFR (at 190 ° C, 21. The enthalpy measured at 18 N): 4 g/10 min; in the following, it is called "LDPE ® ". The mixed resin, "resin for adhesive layer" is 30 parts by weight of the composition (1) containing the amorphous α-olefin polymer prepared by the above, and 70 parts by weight of LLDPE (1). Mixed resin; and separately supplied to the substrate layer extruder (caliber 50 mm) and the adhesive layer extruder (caliber 40 mm), and the coextrusion method at the extrusion temperature of 250 ° C The thickness of the substrate layer extruded from the T-die is 56 / / m, the thickness of the adhesive layer is 14; / rn, and then cooled by a metal cooling roller cooled at 40 ° C, and then wound into a roll, Thereby, a surface protective film can be obtained. The film produced was made to stabilize its physical properties -33- 200930783. (Example 1 4) In the "adhesive layer resin", 50 parts by weight of the composition (1) and 50 parts by weight of the amorphous α-olefin-based polymer were used. A surface protective film was obtained in the same manner as in Example 13 except that the mixed resin of LLDPE (1) was used. [Example 1 5] 40 parts by weight of the resin used in the "adhesive layer" was used. The surface protection was obtained in the same manner as in Example 13 except that the composition of the α 〇-olefin polymer (2) and the mixed resin of 60 parts by weight of LLDPE (1) were used. Protective film. [Example 1 6] The "adhesive layer resin" was prepared by using 40 parts by weight of the composition (4) containing the amorphous ?-olefin polymer and 60 parts by weight of the mixed resin of LLDPE (1). Then, a surface protective film was obtained in the same manner as in Example 13. © [Example 1 7] In addition to the "resin for adhesive layer", 40 parts by weight of the composition (2) containing the amorphous α-olefin polymer, 40 parts by weight of LLDPE (1) and 2 parts by weight are used. A surface protective film was obtained in the same manner as in Example 13 except for the mixed resin of EBR. [Example 1 8] In addition to the "resin for adhesive layer", 15 parts by weight of the composition (2) containing the amorphous α-olefin polymer and 85 parts by weight of the LLDPE (2)-34-200930783 were used. A surface protective film was obtained in the same manner as in Example 13 except for the resin. [Example 19] In addition to the "resin for surface layer", a mixed resin of 95 parts by weight of LDPE and 5 parts by weight of an ethylene-propylene block copolymer was used, and "resin for substrate layer" used 50 parts by weight of HDPE and 50 parts by weight of the LDPE mixed resin, "adhesive layer resin" is a mixed resin containing 1 part by weight of the amorphous α-olefin polymer-containing composition (2) and 90 parts by weight of LLDPE (2). 〇 and separately supplied to the surface layer extruder (caliber 50 mm), the substrate layer extruder (caliber 50 mm) and the adhesive layer extruder (caliber 40 mm), and coextrusion The pressing method is extruded from a Τ-die to a thickness of 14 Am at a pressing temperature of 250 ° C, a thickness of the substrate layer of 42 / / m, a thickness of the adhesive layer of 14 4 am, and the rest is Example 1 3 A surface protective film was obtained in the same manner. [Example 20] A surface was obtained in the same manner as in Example 19 except that the resin for the surface layer was a mixture of 85 parts by weight of HOPP and 15 parts by weight of the ethylene-propylene block copolymer. Protective film. [Example 2 1] In the "resin for surface layer", 95 parts by weight of a mixed resin of LLDPE (1) and 5 parts by weight of an ethylene-propylene block copolymer was used, and "resin for a base layer" was LLDPE ( A surface protective film was obtained in the same manner as in Example 19 except for 1). [Example 22] -35- 200930783 In addition to the "resin for surface layer", a mixed resin of 95 parts by weight of LLDPE (2) and 5 parts by weight of an ethylene-propylene block copolymer was used, and "resin for substrate layer" was used. A surface protective film was obtained in the same manner as in Example 19 except that LLDPE (2) was used. [Example 23] In addition to the "resin for surface layer", 95 parts by weight of a linear low-density polyethylene was used [density: 0. 940 g/cm3 ' MFR (at 190 ° C, 21. 测定 measured under 18 N): 4. 0 g/10 min; in the following, it is called "LLDPE (3 〇 )". And a surface-protective film obtained in the same manner as in Example 19 except that LLDPE (3) was used as the mixed resin of the ethylene-propylene block copolymer, and the resin for the base material layer was used. [Example 24] A surface protective film was obtained in the same manner as in Example 18 except that LDPE was used as the "resin for base material layer". [Example 25] In the case of "resin for base material layer", LDPE was used, and "resin for adhesive layer" was used. The composition (2) and 90 parts by weight of the amorphous α-olefin polymer containing 10 parts by weight were used. A surface protective film was obtained in the same manner as in Example 13 except for the mixed resin of LLDPE (2). [Example 26] Except that 20 parts by weight of the composition containing the amorphous α-olefin polymer (5) and 80 parts by weight of the LLDPE (2) were used as the "resin for the adhesive layer", A surface protective film was obtained in the same manner as in Example 19. -36- 200930783 [Comparative Example 1] In addition to the "resin for adhesive layer", 3·16 parts by weight of the composition (2) and the composition containing the amorphous α-olefin polymer were used. A surface protection film for comparison was prepared in the same manner as in Example 2 except for a mixture of 84 parts by weight of LLDPE (2). [Comparative Example 2] The "adhesive layer resin" was prepared by using 30 parts by weight of the composition (1) containing the amorphous ?-olefin polymer and 70 parts by weight of the LLDPE (3) mixture. A surface protective film for comparison was obtained in the same manner as in Example 2. [Comparative Example 3].  In the "adhesive layer resin", 52 parts by weight of the composition (2) containing the amorphous α-olefin polymer was used, and 8 parts by weight of the same crystalline propylene-butene as that of the user of Preparation Example 1 was used. -1 copolymer and 40 parts by weight of styrene-ethylene-propylene-styrene block copolymer ("SEPTON 2063" manufactured by Kurar ay; hereinafter referred to as "SEPS"). A surface protection film for comparison was prepared in the same manner as in Example 2 except for the mixture. [Comparative Example 4] In addition to the "resin for adhesive layer", 50 parts by weight of a mixture of the amorphous α-olefin polymer-containing composition (1) and 50 parts by weight of ruthenium was used. 2 A surface protection film for comparison was prepared in the same manner. [Comparative Example 5] -37- 200930783 In addition to the "resin for adhesive layer", 50 parts by weight of the composition (1) containing the amorphous α-olefin polymer, 30 parts by weight of LLDPE (2) and 20 parts by weight were used. A surface protection film for comparison was prepared in the same manner as in Example 2 except for the mixture of EBR. [Comparative Example 6] In addition to the "resin for adhesive layer", 30 parts by weight of the composition (2) containing the amorphous ?-olefin polymer, 20 parts by weight of LLDPE (2), and 5 parts by weight of EBR were used. A surface protection film for comparison was prepared in the same manner as in Example 2 except for the mixture. [Comparative Example 7] In addition to the "resin for the adhesive layer". Use 3 . 16 parts by weight of the composition (2) and 96 containing the amorphous α-olefin polymer. A surface protective film for comparison was prepared in the same manner as in Example 13 except that 84 parts by weight of the mixed resin of LLDPE (2) was used. [Comparative Example 8] Except that 30 parts by weight of the composition (1) containing the amorphous α-olefin-based polymer and 70 parts by weight of the mixed resin of LLDPE (3) were used, the resin for the adhesive layer was used. Then, a surface protective film for comparison was obtained in the same manner as in Example 13. [Comparative Example 9] In the "adhesive layer resin", 52 parts by weight of the amorphous-olefin-based polymer-containing composition (2) and 8 parts by weight were used, and the same crystallinity as in the user of Preparation Example 1 was used. A surface protective film of Comparative -38 to 200930783 was obtained in the same manner as in Example 13 except that a propylene-butene-1 copolymer and 40 parts by weight of a mixed resin of SEPS were used. [Comparative Example 1 0] In addition to the "resin for the adhesive layer", 50 parts by weight of the composition (1) containing the amorphous α-olefin polymer and 50 parts by weight of the mixed resin of the ruthenium were used. Example 1 3 A comparative surface protective film was obtained in the same manner. [Comparative Example 1 1] In addition to the "resin for adhesive layer", 50 parts by weight of the composition (1) containing the amorphous α/olefin polymer, 30 parts by weight of LLDPE (2) and 2 parts by weight were used. The other than the mixed resin of EBR, the others were prepared in the same manner as in Example 13. A more suitable surface protection film. Using the surface protective films prepared in Examples 1 to 26 and Comparative Examples 1 to 1 described above, the measurement and evaluation as described below were carried out. (1) Measurement of adhesion force The surface protection thin film which was prepared as described above was attached to the thermostatic chamber at 23 ° C and 50% RH according to the adhesion evaluation method according to JIS Z0 237:2000. Acrylic sheet with a thickness of 2 mm (mirror finish, Mitsubishi Rayon Co.) ,Ltd.  ) "ACRYLITE" manufactured). The film-attached acrylic resin sheet was allowed to stand in a constant temperature room at 23 ° C for 24 hours, and then peeled off at a speed of 300 mm/min toward the 180° direction using a tensile tester (manufactured by A&D Co., Ltd.). To determine the initial adhesion. Further, after the film-attached acrylic resin sheet was allowed to stand in a dryer at 5 ° C for 1 day, the adhesion was measured in the same manner. (2) Evaluation of Adhesive-39-200930783 It was visually confirmed that the surface protective film was attached to the acrylic resin sheet when the surface protective film was attached to the acrylic resin sheet for the measurement of the adhesive force as described above, and Adhesion evaluation was performed on the following basis: 〇: A uniform adherent was maintained on the surface of the acrylic sheet; X: Uniform adhesion was not maintained, and a part of the float occurred. (3) Evaluation of paste residual property In a constant temperature room of 23 ° C and 50% RH, the surface protective film was attached to a propylene phthalate resin plate having a length of 15 cm and a width of 5 cm according to the method of JIS Z0237: 2000. (Mirror finish, "ACRYLITE" manufactured by Mitsubishi Rayon Co., Ltd.). Apply the film to the acrylic resin sheet at 60. After standing for 3 days in a dryer at °C, it was cooled in a constant temperature room at 23 ° C for 1 hour. The film was peeled off from the cooled test piece by hand at a high speed in the direction of 180°, and then the contamination state of the surface of the acrylic plate was visually confirmed, and the evaluation of the residualness of the paste was performed on the following basis: 〇: No on the surface of the acrylic plate Contamination of blurred, white fringe, foreign matter, etc.; 〇X: Any contamination of the surface of the acrylic plate with ambiguity, white streaks, foreign matter, and the like. (4) Measurement of Wet Tension of Surface of Acrylic Resin Plate Using the test piece for evaluating the peeled film as described in (3) above, the wet tension of the surface of the acrylic resin plate was measured according to the method of JIS K6768 (1999) (wet Tension). (5) Evaluation of printability after peeling of the protective film The wet tension was measured from the blank of the wet tension of the wet tension of -40 to 200930783 obtained by the measurement of (4) as described above (washing with alcohol) The surface of the acrylic tree with the film before the film was dried and the reduction in wet tension measured by the same method: 40 mN/m) was evaluated as a substitute for the printability after peeling of the protective film. The evaluation criteria are as follows: 〇: The reduction in wet tension relative to the blank sheet is 2 mN/m or less; X: The reduction in wet tension relative to the billet is more than 2 mN/m. (6) Evaluation of blocking resistance The surface protective film thus obtained was cut out to an A4 size (longitudinal 297 mm X 横 transverse 210 mm). At this time, the extrusion direction (MD direction) of the cut film at the time of film formation can be made to coincide with the longitudinal direction of A4. Then, after laminating the cut film 10 pieces, a vinyl chloride plate having a thickness of 3 mm of A4 size was placed on the upper and lower sides, and a weight of 5 kg was placed and placed in a dryer at 40 ° C. After storage for 14 days, it was stored in a constant temperature room at 23 ° C and 50% RH for 1 hour. Next, the film was cut out in the MD direction at a width of 25 mm, and then peeled toward the 180° direction at a speed of 300 mm/min using a tensile tester (manufactured by A&D Co., Ltd.) to determine the adhesion. (blocking force). From the adhesion obtained from ©, the adhesion resistance was evaluated on the following basis: 〇: The adhesion was less than 0. 8 N/25 mm ; X : The adhesion force is 0. 8 N/25 mm or more. (7) Evaluation of the cutting property The surface protective film prepared as described above was attached to the thickness in a constant temperature chamber of 23 ° C and 50% RH according to the adhesion evaluation method of JIS Z0237: 2000. It is a two-sided acrylic resin plate (mirror-polished, "ACRYLITE" manufactured by Mitsubishi Rayon Co., Ltd.). Then, the cut-off end face of the film which was cut with a high-speed slicer was visually observed by attaching a film of -41-200930783 to the film, and the cuttability was evaluated by the following criteria: 〇: No observation was made on the cut end face of the film. Difficult appearance to the drawing, raising, cracking, etc.; △: A poor appearance such as drawing, raising, cracking, or the like was observed slightly on the cut end surface of the film; X: A poor appearance such as drawing, raising, cracking, or the like was observed on the cut end surface of the film.评估 The evaluation results obtained by the layer constitution of the surface protective film prepared as described above and using the surface protective film are shown in Tables 1 to 6. In addition to this, the embodiment in which the surface layer is not provided • The comparative example empties the column into a blank white bar. The composition containing the amorphous ?-olefin polymer used in the adhesive layer is labeled according to each component. -42- 200930783

Table 1 Example 1 2 3 4 5 6 7 Layer of surface protective film constituting surface layer Resin composition (% by weight) HOPP 80 Ethylene/propylene block copolymer 20 100 100 100 100 100 100 Thickness of surface layer ("m) 12 12 10 12 12 12 14 Base material layer resin composition (% by weight) HOPP 100 100 100 100 100 100 100 Thickness of substrate layer ("m) 38 38 30 38 38 38 42 Adhesive layer resin composition (% by weight) Amorphous Propylene-butene-1 copolymer 18 30 30 38 19 9.5 Amorphous propylene-ethylene-butene-1 copolymer 38 Crystalline propylene-butene-1 copolymer 12 20 20 2 2 0.5 LLDPE (1) ( Density: 0.902 g/cm3) 70 50 50 60 LLDPE (2) (density: 〇·920 g/cm3) 60 80 90 LLDPE (density: 〇_935 g/cm3) 1 Thickness of the adhesive layer (μm) 10 10 10 10 10 10 14 Thickness of total film Um) 60 60 50 60 60 60 70 Uniaxial extension of film Μ /\\s ^rrr /ηΛ Μ te /\w M ^\\s M /w\ Evaluation result Adhesion Force (N/25 mm) Initial 0.60 0.35 0.20 1.80 0.10 0.21 0.08 50°CX After 1 day 1.20 1.00 0.50 3.00 0.40 0.32 0.20 Adhesive 〇〇 Paste residual dampness tension (mN/m) 38 38 38 38 38 38 38 Wet tension reduction (mN/m) 2 2 2 2 2 2 2 Printing after peeling of protective film Adhesive adhesion (N/25mm) 0.05 0.10 0.10 0.30 0.20 0.05 0.60 Anti-blocking 〇〇〇〇〇〇〇-43- 200930783

Table 2 Example 8 9 10 11 12 Layer of surface protective film constituting surface layer Resin composition (% by weight) Ethylene-propylene block copolymer 100 100 100 100 Thickness of surface layer (//m) 12 10 12 12 Substrate layer Resin composition (% by weight) Metallocene catalyst system COPP 100 100 100 100 100 Thickness of substrate layer ("m) 50 38 30 38 38 Adhesive layer resin composition (weight 〇/〇) Amorphous propylene-butene -1 copolymer 5.7 5.7 28.5 19 Amorphous propylene-ethylene-butene-1 copolymer 30 Crystalline propylene-butene-1 copolymer 20 0.3 0.3 1.5 1 LLDPE (2) (density: 0.920 g/cm3) 50 94 84 50 40 EBR 10 20 40 Thickness of adhesive layer (ym) 10 10 10 10 10 Thickness of total film (,) 60 60 50 60 60 Uniaxial extension of film without jw\ te Μ Μ. /»\s Evaluation results Adhesion (N/25 mm) Initial 0.60 0.10 0.12 0.40 2.00 50°CX After 1 day 1.10 0.20 0.20 1.00 3.30 Adhesive paste residual moisture tension (mN/m) 38 39 38 39 38 Wet tension reduction (mN/m) 2 1 2 1 2 Printing after peeling of protective film Sexual adhesion (N/25mm) 0.40 0.02 0.02 0.30 0.50 Anti-blocking 〇〇〇〇〇-44- 200930783 Table 3 Example 13 14 15 16 17 18 Substrate layer HDPE 50 50 50 50 50 50 Resin composition (% by weight) LDPE 50 50 50 50 50 50 Thickness of surface substrate layer ((iv)) 56 56 56 56 56 56 Amorphous propylene-butene-1 copolymer 18 30 38 38 14.2 5 Protection of amorphous The propylene-ethylene-butene-1 copolymer 38 film layer constitutes the adhesive layer resin composition crystalline propylene-butene-1 copolymer 12 20 2 2 2 0.75 (weight 0 / 〇) LLDPE (1) (density: 0.902 g/cm3) 70 50 60 60 40 LLDPE (2) (density: 0.920 g/cm3) 85 EBR 20 Thickness of adhesive layer (iUtn) 14 14 14 14 14 14 Thickness of total film ("m) 70 70 70 70 70 70 Adhesive initial 0.72 0.40 2.00 0.14 2.20 0.13 (N/25 mm) 5〇°C xl days later 1.80 1.40 3.50 0.50 4.20 0.30 Adhesiveness evaluation residual residue evaluation wet tension (mN/m) 38 38 38 38 38 38 Wet tension reduction (mN/m) 2 2 2 2 2 2 Printability and adhesion after peeling off the protective film (N/25mm) 0.10 0.15 0.40 0.20 0.45 0.05 Anti-adhesion 〇〇〇〇〇〇 Cut-off 〇〇〇〇〇〇-45 - 200930783

Table 4 Example 19 20 21 22 23 24 25 26 Surface protection film 'layer constituting surface layer Resin composition (% by weight) LDPE 95 95 LLDPE (1) (density: 0.902 e/cm3) 95 LLDPE (2) (density: 0·920 g/cm3) 95 LLDPE (3) (density: 0.940 g/cm3) 95 HOPP 85 Ethylene/propylene block copolymer 5 15 5 5 5 5 Thickness of surface layer (Aim) 14 14 14 14 14 - 14 Substrate layer Resin composition (% by weight) HDPE 50 50 50 LLDPE (1) (density: 0.902 g/cm3) 100 100 LLDPE (2) (density: 0.920 R/cm3) LLDPE (3) (density: 0.940 g/cm3 100 LDPE 50 50 100 100 50 Thickness of a certain layer (am) 42 42 42 42 42 56 56 42 Adhesive layer resin composition (% by weight) Amorphous propylene-butene-1 copolymer 9.5 9.5 9.5 9.5 9.5 14.25 9.5 19 Crystalline propylene-butene-1 copolymer 0.5 0.5 0.5 0.5 0.5 0.75 0.5 LLDPE (2) (density: 0.920 g/cm3) 90 90 90 90 90 85 90 90 LLDPE (3) (density: 0.935 g/cm3) 1 S occupies the thickness of the layer ("m) 14 14 14 14 14 14 14 14 Total film thickness (wm) 70 70 7 0 70 70 70 70 70 Evaluation results Adhesion (N/25 mm) Initial 0.10 0.09 0.12 0.11 0.08 0.13 0.10 0.15 5〇°CX After 1 day 0.20 0.21 0.32 0.25 0.19 0.30 0.30 0.35 Adhesive 〇〇〇〇〇〇〇〇 Paste residual dampness tension (mN/m) 38 38 38 38 38 38 38 38 Wet tension drop side (mN/m) 2 2 2 2 2 2 2 2 Printing after peeling of protective film Piece of Adhesive Force (N/25mm) 0.10 0.10 0.40 0.25 0.10 0.05 0.10 0.20 Anti-adhesion 〇〇〇〇〇〇〇〇Scissibility 〇〇〇〇〇〇〇〇-46 - 200930783

Table 5 Comparative Example 1 2 3 4 5 6 Layer of surface protective film constituting surface layer Resin composition (% by weight) Ethylene-propylene block copolymer 100 100 100 100 100 100 Thickness of surface layer (/t/m) 12 12 10 12 12 12 Base layer resin composition (weight HOPP 100 100 100 100 100 100 Thickness of base material layer (//m) 38 38 30 38 38 38 Adhesive layer resin composition (weight 0 / 〇) Amorphous propylene - butene -1 copolymer 3 18 49.4 30 30 28.5 Crystalline propylene-butene-1 copolymer 0.16 12 10.6 20 20 1.5 SEPS 40 HOPP 50 LLDPE (2) (density: 0.920 g/cm3) 96.8 4 30 20 LLDPE (3) (density: 0.940 g/cm3) 70 EBR 20 50 Thickness of the adhesive layer Urn) 10 10 10 10 10 10 Thickness of the total film Um) 60 60 60 60 60 60 Evaluation result Adhesion (N/25 mm) Initial 0.05 0.03 4.50 0.05 0.60 3.50 50°CX After 1 day 0.08 0.04 6.30 0.10 1.50 5.50 Adhesion XX Residual residue XXX 〇 Wet tension (mN/m) 38 38 34 36 38 38 Wet tension reduction (mN/m) 2 2 6 4 2 2 Printability after peeling of protective film 〇〇 XX 〇〇 Adhesion (N/25mm) 0.02 0.05 1.10 0.30 0.70 0.90 Anti-blocking 〇〇X 〇〇X -47- 200930783 Table 6 Comparative Example 7 $ 9 10 11 Layer of surface protective film composed of mum resin composition (weight HDPE 50 50 50 50 50 LDPE 50 50 50 50 50 Thickness of surface layer ("m) 56 56 56 56 56 Adhesive layer resin composition (% by weight) Amorphous propylene-butene-1 copolymer 3 18 49.4 30 20 Crystallinity Propylene-butene-1 copolymer 0.16 12 10.6 20 20 SEPS 40 HOPP 50 LLDPE (2) (density: 0.920 g/cm3) 96.84 LLDPE (3) (density: 〇_940g/cm3) 70 30 EBR 20 Adhesive layer Thickness Urn) 14 14 14 14 14 Thickness of total film (//m) 70 70 70 70 70 Evaluation result Adhesion (N/25mm) Initial 0.05 0.03 5.50 0.06 0.80 5〇°CX After 1 day 0.10 0.04 8.50 0.17 1.80 Adhesive Sex XX Residual residual 〇〇 XXX Wet tension (mN/m) 38 38 34 36 38 Wet tension reduction (mN/m) 2 2 6 4 2 Printing after peeling of protective film Suitable for 14 〇〇 XX 〇 Adhesion Force (N/25mm) 0.02 0.05 1.10 0.30 0.70 Anti-blocking 〇〇X 〇〇 According to the results of Examples 1 to 26, it is understood that the surface protective film of the present invention has an adhesion to an acrylic resin plate of about 0.1 to 2.2 N/2 5 mm, and has surface protection. The film is best suited for a wide range of adhesions from microadhesive to moderately adherent. Further, it has been found that the adhesive film does not float, peel, or the like after being attached to the acrylic resin sheet, and has good adhesion as a surface protective film. In particular, when the film of the thin -48-200930783 film is peeled off from the attached acrylic resin sheet, there is no ambiguity, streaks, foreign matter, or the like which can be visually confirmed, and the surface of the acrylic resin sheet after the surface protective film is peeled off Since the reduction in the wet tension is also extremely small, it has been found to be suitable for use in a secondary processing such as printing after peeling off the surface protective film. Further, it has been found that by further using the ethylene-based polymer in the base material layer, it is possible to obtain a surface protective film which is excellent when the adhesive body is cut and processed in a state in which the surface-protective film is attached to the adhesive body. A surface protection film which is cut and does not cause a poor cut-out appearance such as drawing or raising. Ο Comparative Example 1 is an example of a surface protective film obtained by setting the amount of the linear low-density polyethylene to be more than 95% by weight of the predetermined upper limit and about 97% by weight. According to the results, it can be seen that the protective film of the watch of Comparative Example 1 has an adhesive force of only about 〇.5 N/25 tnm in its initial enthalpy, and floats, peels, etc. when it is gently washed. Therefore, the adhesion is not enough. Comparative Example 2 is an example of a surface protective film obtained by setting the density of the linear low-density polyethylene to 0.93 8 g/cm 3 which exceeds the upper limit of 0.93 g/cm 3 . According to the results, it was found that the surface protective ruthenium film of Comparative Example 2 had an adhesive force of only about 0.03 N/25 mm in its initial state, and floated, peeled off, etc. immediately after the film was attached. If the density of the mixed linear low-density polyethylene is too high, the adhesion will be insufficient. Comparative Example 3 was an example in which the adhesive layer was replaced with a styrene-ethylene-propylene-styrene block copolymer (SEPS) without using a linear low-density polyethylene. According to the results, it was found that the surface protective film of Comparative Example 3 was subjected to paste residue, and the surface of the acrylic resin sheet after peeling off the surface protective film was also reduced in wet tension, and the adhesion force was large, -49-200930783 Anti-blocking properties are also poor. Comparative Example 4 is an example in which the adhesive layer is not a linear low-density polyethylene, but a propylene homopolymer is used instead of the obtained surface protective film. According to the results, it was found that the surface protective film of Comparative Example 4 had a paste residue, and the wet tension of the surface of the acrylic resin sheet after peeling off the surface protective film was also large. Comparative Example 5 is an example of a surface-protected thin film obtained by setting the blending amount of the linear low-density polyethylene to a predetermined lower limit of less than 40% by weight to 37.5% by weight. From the results, it was found that the surface protective film of Comparative Example 5 had a problem of paste residue. Comparative Example 6 is an example of a surface protective film obtained by setting the amount of the ethylene-α-olefin copolymer (EBR) to be more than 40% by weight of the predetermined upper limit and about 50.8% by weight. According to the results, it was found that the surface protective film of Comparative Example 6 had a large adhesion force and was inferior in blocking resistance. In Comparative Example 7, the mixing ratio of the amorphous propylene-butene-1 copolymer of the adhesive layer and the linear low-density polyethylene was set to be less than 5% by weight of the lower limit and Ο was about 3% by weight. An example of a surface protective film. According to the results, it can be seen that the surface protective film of Comparative Example 7 has an adhesive force of only about 〇.〇5 N/25 mm in its initial state, and floats and peels off when gently rubbed. Therefore, the adhesion is not enough. Comparative Example 8 is an example of a surface protective film prepared by setting the density of the linear low-density polyethylene used in the adhesive layer to a predetermined upper limit of 938.938 g/cm3 and 0.940 g/cm3. . According to the results, it can be seen that the surface protective film of Comparative Example 8 has an adhesive force of only about 〇.03 -50 - 200930783 N/25 nun in its initial state, and the film floats immediately after attachment. , peeling, etc., and if the density of the mixed linear low-density polyethylene is too high, the adhesion will be insufficient. Comparative Example 9 was an example in which the adhesive layer was replaced with a styrene-ethylene-propylene-styrene block copolymer (SEPS) without using a linear low-density polyethylene. According to the results, it was found that the surface protective film of Comparative Example 9 was subjected to paste residue, and the surface of the acrylic resin sheet after peeling off the surface protective film was also reduced in wet tension, and the adhesion force was large, and the adhesion resistance was high. Sex is also poor. In Comparative Example 10, an adhesive layer was not used, and a propylene homopolymer was used instead of the obtained surface protective film. According to the results, it was found that the surface protective film of the comparative example had a paste residue. The decrease in the wet tension of the surface of the acrylic resin sheet after peeling off the surface protective film was also large. Comparative Example 1 1 is a surface protective film in which the mixing ratio of the amorphous propylene-butene-1 copolymer of the adhesive layer and the linear low-density polyethylene is set to be more than 4% by weight based on the upper limit and 50% by weight. An example. From the results, it was found that the surface protective film of Comparative Example 11 had a problem of paste residue. [Simple description of the diagram] None" [Main component symbol description] None. -51-

Claims (1)

200930783 X. Patent application scope: 1. A surface protection film characterized by a laminated adhesive layer (A) and a substrate layer (B), and the adhesive layer (A) is mainly composed of the following components: 5 50% by weight of the amorphous α-olefin-based polymer (a 1 ) and 50 to 90% by weight of a linear low-density polyethylene (A2) having a density of 0.88 to 0.93 8 g/cm 3 Mixed resin, or 5 to 50% by weight of the amorphous α-olefin polymer (A1), 40 to 90% by weight of a linear low-density polyethylene (A2) having a density of 0.880 to 0.93 8 g/cm 3 And a mixed resin of 5 to 50% by weight of the crystalline ethylene-α-olefin copolymer (A3). 2. The surface protection film of claim 1, wherein the substrate layer (Β) is mainly composed of a vinyl polymer (Β1) or a crystalline propylene polymer (Β2). 3. The surface protective film according to claim 1 or 2, wherein the amorphous α-olefin polymer (Α1) is an amorphous propylene-butene-1 copolymer, or amorphous propylene-ethylene- Butene-1 copolymer. The surface protective film according to any one of claims 1 to 3, wherein the ethylene-α-olefin copolymer (A3) is an ethylene-butene-1 copolymer. 5. The surface protective film according to any one of claims 1 to 4, which is characterized in that an olefin-based polymer is mainly provided on the opposite side of the surface of the base layer (Α) of the adhesive layer (Α). Surface layer (C). 6. The surface protection film of any one of claims 1 to 5, which extends at least in a uniaxial direction. -52- 200930783 VII. Designated representative map: (1) The representative representative of the case is: None. (2) A brief description of the symbol of the representative figure: 〇 八 8. If there is a chemical formula in this case, please disclose the chemical formula that best shows the characteristics of the invention: