TW201821567A - Surface protection film - Google Patents

Abstract

The present invention provides a surface protection film suitable for achieving good hand tearability and high secondary processability while having a polyester-based substrate on one side. The surface protection film X of the present invention has a laminated structure including a substrate 11 as a transparent substrate and an adhesive layer 12. The base material 11 is a uniaxially stretched polyester-based base material having a thickness of 75 μm or more in the width direction of the base material. The Elmendorf tear strength in the width direction of the substrate of the surface protection film X is 0.5 N or less, and the Elmendorf tear strength in the mechanical direction of the substrate of the surface protection film X is 1 N or more.

Description

Surface protection film

The present invention relates to a surface protective film having light transmittance.

In recent years, in various technical fields, surface protection films having high transparency have been used. For example, in the technical field of flat panel displays (FPDs), various optical components assembled into FPDs have surface protection films attached to the surface of the components for the purpose of surface protection during the manufacturing process, inspection steps, and transportation processes. Situation. Such a surface protection film is described in Patent Documents 1 to 3 described below, for example. [Prior Art Literature] [Patent Literature] [Patent Literature 1] Japanese Patent Laid-Open No. 2012-17399 [Patent Literature 2] Japanese Patent Laid-Open No. 2015-157964 [Patent Literature 3] Japanese Patent Laid-Open No. 2016-74899 Bulletin

[Problems to be Solved by the Invention] As a base material of a surface protective film, a polyester-based base material may be used in terms of excellent heat resistance, transparency, and dimensional stability. It is known that, for example, a PET film, which is a light-transmitting polyester-based substrate used as a surface protective film for optical component applications, is usually manufactured by extrusion molding of a raw resin material by a T-die method in a manufacturing process. After being film-shaped, the film is subjected to a biaxial stretching process including an extension in the traveling direction or the machine direction (MD) and an extension in the width direction (TD) of the film. In addition, regarding the surface protective film, in terms of work efficiency and the like, there are cases in which good hand tearability is required. The present invention was conceived based on the above-mentioned circumstances, and an object thereof is to provide a surface protective film suitable for achieving good hand tearability and high secondary processability while having a polyester-based substrate on one side. [Technical means to solve the problem] The surface protection film provided by the present invention has a laminated structure including a transparent substrate and an adhesive layer. The transparent substrate is a uniaxially stretched polyester-based substrate in the width direction of the substrate, and has a thickness of 75 μm or more. The polyester-based substrate refers to a substrate such as a film or a sheet containing a polyester-based resin in a maximum weight ratio among the constituent materials. The so-called uniaxially stretched polyester-based substrate in the width direction of the substrate refers to the direction of travel of the extruded molded body such as a film-like material after the extrusion molding of the raw resin material in the manufacturing process of the polyester-based substrate. Or a uniaxially stretched polyester substrate in the width direction (TD) orthogonal to the machine direction (MD). The adhesive layer contains, for example, at least one selected from the group consisting of an acrylic adhesive, a urethane adhesive, a silicone adhesive, and a rubber adhesive. In this surface protective film, the Elmendorf tear strength in the width direction of the substrate is 0.5 N or less, and the Elmendorf tear strength in the mechanical direction of the substrate is 1 N or more. The transparent substrate included in the surface protection film is a polyester-based substrate as described above. Such a structure is preferable for allowing the surface protective film substrate and even the surface protective film to enjoy various characteristics that are easily exhibited by polyester-based substrates such as heat resistance, transparency, and dimensional stability. The transparent substrate included in the surface protection film is a uniaxially-stretched polyester-based substrate having a thickness of 75 μm or more in the width direction as described above. In the case where the tear strength of the surface protection film such as the tear strength of the Emildorfer is strongly controlled by the mechanical properties of the substrate, this structure is suitable for realizing the surface tear film in the width direction of the substrate. The above-mentioned configuration is 0.5 N or less, and the Emersondorf tear strength of the substrate in the mechanical direction is 1 N or more. In addition, as described above, the surface protection film has an Emmendorf tear strength of 0.5 N or less in the substrate width direction, and an Emmendorf tear strength of 1 N or more in the substrate mechanical direction. Such a structure is suitable for enabling the present surface protective film to achieve good hand tearability in the width direction of the substrate in which the Emmendorf tear strength is relatively significantly lower than 0.5 N. At the same time, the composition of the Emildorf tear strength in the mechanical direction of the substrate is 2 times or more than 1 N in the width direction of the substrate. The structure is to direct the surface protective film to improve the tear in the width direction of the substrate. It ’s better. Therefore, this configuration is preferable for the case where the surface protection film is attached to the adherend, and a peeling force is applied to the mechanical direction of the substrate of the film without tearing. In the case of this film, it is suitably peeled from an adherend. Specifically, it is preferable to apply the peeling force to the film when the surface protection film is attached to the object and then peeled off and then reattached (secondary processing operation). In the mechanical direction of the substrate, the film is appropriately peeled from the adherend without tearing the film. In addition to the width direction of the substrate, the surface protective film that is also easily torn in the mechanical direction of the substrate tends to be easily ruptured upon peeling in a secondary processing operation, and it is difficult to properly peel from the adherend. The cracked surface protective film cannot be used for reattachment. On the other hand, the surface protection film has a substrate with a mechanical strength in the direction of the thickness of the substrate, which is sufficiently larger than that of the substrate in the width direction of the substrate. Therefore, it is suitable for proper peeling from the adherend without tearing during the secondary processing operation. As described above, the surface protective film is suitable for achieving good hand tearability and high secondary workability while having a polyester-based substrate. The thickness of the adhesive layer is preferably 5 μm or more. Such a configuration is preferable in that the surface protective film achieves sufficient adhesion to an adherend. The haze in the thickness direction of the surface protective film is preferably 3% or less. Such a structure is suitable for a surface protection film used for optical components, for example.

FIG. 1 is a partial cross-sectional view of a surface protective film X according to an embodiment of the present invention. The surface protection film X has a laminated structure including a base material 11 and an adhesive layer 12 as a transparent base material. The surface protective film X can be used by bonding to the surface of a component for the purpose of protecting the surface of the optical component in the manufacturing process of various optical components incorporated in a flat panel display, or during inspection steps, transportation, etc., for example. The base material 11 included in the surface protective film X is a part of the surface protective film X that functions as a support, and is a uniaxially stretched polyester-based base material having a light-transmitting substrate width direction. The polyester-based substrate refers to a substrate such as a film or a sheet containing a polyester-based resin in a maximum weight ratio among the constituent materials. Examples of the constituent material of such a substrate 11 include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polyethylene terephthalate-1,4 -Cyclohexane dimethyl ester. The so-called uniaxially stretched polyester-based substrate in the width direction of the substrate refers to the direction in which the raw resin material is extruded during the manufacturing process of the polyester-based substrate and the direction of travel of the extruded molded body such as a film, or Uniaxially stretched polyester-based substrate in the machine direction (MD) orthogonal to the width direction (TD). With regard to such a width direction uniaxially stretched polyester-based substrate 11 in the width direction of the stretch ratio, preferably 2. 5 times or more, more preferably 3 times or more. The stretch ratio is preferably 6 times or less, and more preferably 5. 5 times or less. The thickness of the substrate 11 is 75 μm or more, and preferably 80 μm or more. The thickness of the substrate 11 is preferably 150 μm or less, and more preferably 125 μm or less. The in-plane phase difference of the substrate 11 is preferably 1500 nm or more, more preferably 3000 nm or more, and even more preferably 6000 nm or more. In this embodiment, the in-plane phase difference of the substrate 11 refers to a plane parallel to the principal surface of the substrate 11 related to the birefringence when light with a wavelength of 590 nm passes through the substrate 11 at 23 ° C. Generated between the polarizing component (abnormal light) vibrating in the direction of the retardation axis and the polarizing component (normal light) vibrating in the direction of the advancement axis of the two optical spindles (late phase axis and advanced phase axis) running straight inside Phase difference. The in-plane phase difference is that the refractive index (relatively large) of abnormal light is set to nx, the refractive index (normally small) of normal light is set to ny, and the thickness of the substrate 11 is set to d (nm) In this case, the value is represented by (nx-ny) × d. The surface on the side of the adhesive layer 12 in the base material 11 may also be subjected to a surface treatment for improving the adhesion with the adhesive layer. Examples of such surface treatment include physical treatments such as corona treatment and plasma treatment, and chemical treatments such as primer treatment. The adhesive layer 12 of the surface protective film X contains an adhesive as a main agent and has light transmittance. The so-called base agent refers to a component which contains the largest weight ratio among the contained components. The adhesive layer 12 contains, for example, a composition selected from the group consisting of an acrylic polymer as an acrylic adhesive, a polyurethane as a urethane adhesive, a silicone adhesive, and a rubber-based adhesive. At least one of the group. From the viewpoint of achieving both the degree of adhesion required for the adhesive layer of the surface protective film and high transparency, it is preferable to use an acrylic polymer as the adhesive in the adhesive layer 12. The adhesive layer 12 has an adhesive surface 12a that can be attached to an adherend. When the adhesive layer 12 contains an acrylic polymer as an acrylic adhesive, the acrylic polymer preferably contains an alkyl acrylate derived from a linear or branched alkyl group, and / or The monomer unit of the alkyl methacrylate having a linear or branched alkyl group is used as the most monomer unit by weight ratio. Hereinafter, "(meth) acrylic acid" means "acrylic acid" and / or "methacrylic acid". The (meth) acrylic acid alkyl ester having a linear or branched alkyl group as a monomer unit for forming the acrylic polymer, that is, a monomer component for forming the acrylic polymer Examples of the alkyl (meth) acrylate having a linear or branched alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (methyl) (Isopropyl) acrylate, n-butyl (meth) acrylate, second butyl (meth) acrylate, isobutyl (meth) acrylate, third butyl (meth) acrylate, (meth) acrylic acid Amyl ester, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (formyl) (Isyl) isooctyl acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate Ester, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, (formyl) Base) cetyl acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, isostearyl (meth) acrylate, undecyl (meth) acrylate (Meth) acrylic acid alkyl esters having linear or branched alkyl groups having 1 to 20 carbon atoms, such as esters and eicosyl (meth) acrylate. As the (meth) acrylic acid alkyl ester used in the acrylic polymer, one kind of (meth) acrylic acid alkyl ester may be used, or two or more kinds of (meth) acrylic acid alkyl ester may be used. In this embodiment, as the (meth) acrylic acid alkyl ester used for an acrylic polymer, it is preferred to use a material selected from the group consisting of n-butyl acrylate, 2-ethylhexyl acrylate, and isostearyl acrylate. At least one of the group. The ratio of the monomer unit derived from the (meth) acrylic acid alkyl ester having a linear or branched alkyl group in the acrylic polymer is preferably 50% by weight or more, more preferably 60% by weight or more, It is more preferably 70% by weight or more, more preferably 80% by weight or more, and even more preferably 90% by weight or more. That is, the ratio of the alkyl (meth) acrylate in the monomer component composition of the raw material for forming the acrylic polymer is preferably 50% by weight or more, more preferably 60% by weight or more, and even more preferably 70% by weight. % Or more, more preferably 80% by weight or more, more preferably 90% by weight or more. The acrylic polymer has a monomer unit structure derived from a monomer component composition having such an alkyl (meth) acrylate ratio. This constitution, which is related to the ratio of the alkyl (meth) acrylate having a linear or branched alkyl group, is preferable in that an adhesive layer formed by containing the acrylic polymer is appropriately used. It shows basic properties such as the adhesion of acrylic polymers as acrylic adhesives. The acrylic polymer contained in the adhesive layer 12 may include a monomer unit derived from an alicyclic monomer. The alicyclic monomer as a monomer unit for forming an acrylic polymer, that is, the alicyclic monomer included in the monomer component for forming the acrylic polymer, for example, (meth) acrylic acid Cycloalkyl esters, (meth) acrylates having a bicyclic hydrocarbon ring, and (meth) acrylates having a tricyclic or more hydrocarbon ring. Examples of the cycloalkyl (meth) acrylate include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, and cyclooctyl (meth) acrylate. ester. Examples of the (meth) acrylic acid ester having a bicyclic hydrocarbon ring include (meth) acrylic acid esters and (meth) acrylic acid isopropyl esters. Examples of the (meth) acrylate having a hydrocarbon ring having three or more rings include dicyclopentyl (meth) acrylate, dicyclopentyloxyethyl (meth) acrylate, and tricyclopentyl (meth) acrylate. Esters, 1-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, and 2-ethyl-2-adamantyl (meth) acrylate. As the alicyclic monomer used in the acrylic polymer, one kind of alicyclic monomer may be used, or two or more kinds of alicyclic monomers may be used. In the present embodiment, as the alicyclic monomer used in the acrylic polymer, it is preferable to use a member selected from cyclohexyl acrylate, cyclohexyl methacrylate, isopropyl acrylate, and isopropyl methacrylate. At least one of the group. As for the ratio of the monomer unit derived from an alicyclic monomer in the said acrylic polymer, it is preferable that it is 5 from a viewpoint of achieving moderate softness | flexibility in the adhesive layer which consists of this acrylic polymer. -60% by weight, more preferably 10-50% by weight. The acrylic polymer contained in the adhesive layer 12 may include a monomer unit derived from a hydroxyl-containing monomer. A hydroxyl-containing monosystem is a monomer having at least one hydroxyl group in a monomer unit. When the acrylic polymer in the adhesive layer 12 includes a hydroxyl-containing monomer unit, the adhesive layer 12 easily obtains adhesiveness or a moderate cohesive force. Examples of the hydroxyl group-containing monomer used to form the monomer unit of the acrylic polymer, that is, the hydroxyl group-containing monomer included in the monomer component used to form the acrylic polymer include, for example, hydroxyl group-containing ( (Meth) acrylates, vinyl alcohol, and allyl alcohol. Examples of the hydroxyl-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (methyl) Base) 4-hydroxybutyl acrylate, 6-hydroxyhexyl (meth) acrylate, hydroxyoctyl (meth) acrylate, hydroxydecyl (meth) acrylate, hydroxylauryl (meth) acrylate, and (formyl) (Methyl) (4-hydroxymethylcyclohexyl) acrylate. As the hydroxyl-containing monomer used in the acrylic polymer, one kind of hydroxyl-containing monomer may be used, and two or more kinds of hydroxyl-containing monomers may be used. In this embodiment, as the hydroxyl-containing monomer used in the acrylic polymer, it is preferred to use a monomer selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and At least one of the group consisting of 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, and 4-hydroxybutyl methacrylate. The ratio of monomer units derived from a hydroxyl-containing monomer in the acrylic polymer is preferably 1% by weight or more, more preferably 2% by weight or more, more preferably 3% by weight or more, and even more preferably 5% by weight. The above is more preferably 7% by weight or more, and even more preferably 10% by weight or more. The ratio of the monomer unit derived from the hydroxyl group-containing monomer in the acrylic polymer is preferably 20% by weight or less, and more preferably 18% by weight or less. These constitutions related to the ratio of the hydroxyl-containing monomer are preferable in that the adhesive layer formed by containing the acrylic polymer achieves adhesiveness or moderate cohesion. The acrylic polymer contained in the adhesive layer 12 may include a monomer unit derived from a monomer containing a nitrogen atom. A nitrogen atom-containing monosystem has a monomer having at least one nitrogen atom in a monomer unit. When the acrylic polymer in the adhesive layer 12 includes a monomer unit containing a nitrogen atom, the adhesive layer 12 easily obtains hardness or good adhesion reliability. Examples of the nitrogen atom-containing monomer used to form the monomer unit of the acrylic polymer, that is, the nitrogen atom-containing monomer included in the monomer component used to form the acrylic polymer include, for example, N-ethylene Cyclic amidines and (meth) acrylamides. Examples of the N-vinyl cyclic amidine as a nitrogen atom-containing monomer include N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, and N-vinyl-3 -Linolinone, N-vinyl-2-caprolactam, N-vinyl-1,3-fluoren-2-one, and N-vinyl-3,5-linedione. Examples of the (meth) acrylamide as a nitrogen atom-containing monomer include (meth) acrylamide, N-ethyl (meth) acrylamide, and N-isopropyl (methyl) Acrylamide, N-n-butyl (meth) acrylamide, N-octyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-di Ethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, and N, N-diisopropyl (meth) acrylamide. As the nitrogen atom-containing monomer used in the acrylic polymer, one type of nitrogen atom-containing monomer may be used, or two or more types of nitrogen atom-containing monomers may be used. In the present embodiment, as the nitrogen atom-containing monomer used in the acrylic polymer, N-vinyl-2-pyrrolidone is preferably used. Regarding the ratio of the monomer units derived from the nitrogen atom-containing monomer in the acrylic polymer, the viewpoint of achieving an appropriate hardness, adhesiveness, and transparency of the adhesive layer formed by the acrylic polymer is included. Specifically, it is preferably 1% by weight or more, more preferably 3% by weight or more, and even more preferably 5% by weight or more. In addition, regarding the ratio of the monomer units derived from a monomer containing a nitrogen atom in the acrylic polymer, the viewpoint of achieving sufficient transparency of the adhesive layer formed from the acrylic polymer or suppressing the change is suppressed. From the viewpoint of achieving excellent adhesion and achieving excellent bonding reliability, the weight is preferably 30% by weight or less, and more preferably 25% by weight or less. The acrylic polymer contained in the adhesive layer 12 may include a monomer unit derived from a carboxyl group-containing monomer. A carboxyl-containing monosystem is a monomer having at least one carboxyl group in a monomer unit. When the acrylic polymer in the adhesive layer 12 includes a carboxyl group-containing monomer unit, there are cases where the adhesive layer 12 can obtain good adhesion reliability. Examples of the carboxyl group-containing monomer used to form the monomer unit of the acrylic polymer, that is, the carboxyl group-containing monomer included in the monomer component used to form the acrylic polymer include (meth) Acrylic acid, methylene succinic acid, maleic acid, fumaric acid, butenoic acid, and methacrylic acid. As the carboxyl group-containing monomer used in the acrylic polymer, one kind of carboxyl group-containing monomer may be used, and two or more carboxyl group-containing monomers may be used. In this embodiment, acrylic acid is preferably used as the carboxyl group-containing monomer used in the acrylic polymer. Regarding the ratio of monomer units derived from a carboxyl group-containing monomer in the acrylic polymer described above, the adhesive layer formed by containing the acrylic polymer is obtained when the polar group has a polar group on its surface From the standpoint of the interaction of the polar groups to ensure good bonding reliability, it is preferably 0. 1% by weight or more, more preferably 0. 5% by weight or more. Moreover, regarding the ratio of the monomer unit derived from a carboxyl group-containing monomer in the said acrylic polymer, the point which suppresses the adhesive layer formed by containing this acrylic polymer from becoming too hard and achieves good adhesion reliability is considered. Specifically, it is preferably 20% by weight or less, and more preferably 15% by weight or less. The acrylic polymer contained in the adhesive layer 12 may have a crosslinked structure derived from a polyfunctional (meth) acrylate which is a copolymerizable crosslinking agent. Examples of the polyfunctional (meth) acrylate include 1,6-hexanediol di (meth) acrylate, butanediol di (meth) acrylate, and (poly) ethylene glycol di (meth) ) Acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa ( (Meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, allyl (meth) acrylate, and vinyl (meth) acrylate. As the polyfunctional (meth) acrylate used for the acrylic polymer, one kind of polyfunctional (meth) acrylate may be used, or two or more kinds of polyfunctional (meth) acrylate may be used. In this embodiment, as the polyfunctional (meth) acrylate used in the acrylic polymer, a member selected from the group consisting of 1,6-hexanediol diacrylate, dipentaerythritol hexaacrylate, and trimethylol can be preferably used. At least one of the group consisting of propyl propane triacrylate. The ratio of the monomer units derived from the polyfunctional (meth) acrylate in the acrylic polymer is preferably 0. 01% by weight or more, more preferably 0. 03% by weight or more, more preferably 0. 05% by weight or more. The ratio of the monomer units derived from the polyfunctional (meth) acrylate in the acrylic polymer is preferably 1% by weight or less, more preferably 0. 5% by weight or less. These structures related to the ratio of the polyfunctional (meth) acrylate are preferable in that the adhesive layer formed by containing the acrylic polymer achieves moderate hardness or adhesiveness. When the adhesive layer 12 contains the above-mentioned acrylic polymer as an adhesive, the content rate of the acrylic polymer in the adhesive layer 12 is, for example, 85 to 100% by weight. From the viewpoint of achieving high adhesion at room temperature, the adhesive layer 12 may contain, for example, an acrylic oligomer having a composition of a raw material monomer different from the acrylic polymer described above. When the adhesive layer 12 contains such an acrylic oligomer, the content of the acrylic oligomer in the adhesive layer 12 is, for example, 100 parts by weight of the adhesive or the acrylic polymer in the adhesive layer 12. 0. 1 to 20 parts by weight. The oligomer preferably contains a monomer unit derived from a (meth) acrylate having a cyclic structure (a (meth) acrylate containing a ring), and an alkyl group derived from a linear or branched alkyl group. Polymer of monomer units of alkyl (meth) acrylates. The ring-containing (meth) acrylate as the monomer unit for forming the oligomer, that is, the ring-containing (meth) acrylate included in the monomer component for forming the oligomer, for example, may be Examples are: cycloalkyl (meth) acrylate, (meth) acrylate having a bicyclic hydrocarbon ring, (meth) acrylate having a hydrocarbon ring of three or more rings, and (meth) )Acrylate. Examples of the cycloalkyl (meth) acrylate include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, and cyclooctyl (meth) acrylate. ester. Examples of the (meth) acrylic acid ester having a bicyclic hydrocarbon ring include (meth) acrylic acid esters and (meth) acrylic acid isopropyl esters. Examples of the (meth) acrylate having a hydrocarbon ring having three or more rings include dicyclopentyl (meth) acrylate, dicyclopentyloxyethyl (meth) acrylate, and tricyclic (meth) acrylate Amyl ester, 1-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, and 2-ethyl-2-adamantyl (meth) acrylate. Examples of the (meth) acrylate having an aromatic ring include phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, and benzyl (meth) acrylate. As the ring-containing (meth) acrylate used for the oligomer, one type of ring-containing (meth) acrylate may be used, or two or more types of ring-containing (meth) acrylates may be used. In this embodiment, it is preferable to use at least one selected from the group consisting of dicyclopentyl acrylate and dicyclopentyl methacrylate as the ring-containing (meth) acrylate used in the oligomer. Regarding the ratio of the monomer unit derived from the cyclic-containing (meth) acrylate in the oligomer described above, from the viewpoint of achieving a moderate softness of the adhesive layer 12 including the oligomer, It is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, and even more preferably 35 to 80% by weight. The (meth) acrylic acid alkyl ester having a linear or branched alkyl group as a monomer unit for forming the above oligomer, that is, a monomer having Examples of the (meth) acrylic acid alkyl ester of a chain or branched chain alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (meth) Isopropyl acrylate, n-butyl (meth) acrylate, second butyl (meth) acrylate, isobutyl (meth) acrylate, third butyl (meth) acrylate, amyl (meth) acrylate , Isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) Isooctyl acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, Dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, decyl (meth) acrylate Hexyl Heptadecyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, undecyl (meth) acrylate, and (meth) acrylic acid Alkyl (meth) acrylic acid alkyl esters having linear or branched alkyl groups having 1 to 20 carbon atoms. As the (meth) acrylic acid alkyl ester used in the oligomer, one kind of (meth) acrylic acid alkyl ester may be used, or two or more kinds of (meth) acrylic acid alkyl ester may be used. In this embodiment, as the alkyl (meth) acrylate used for the oligomer, methyl methacrylate is preferably used. Regarding the ratio of the monomer units derived from the (meth) acrylic acid alkyl ester having a linear or branched alkyl group in the above oligomer, a modest degree of the adhesive layer formed by containing the oligomer is achieved. From the viewpoint of the elastic modulus, it is preferably 10 to 90% by weight, more preferably 15 to 80% by weight, and even more preferably 20 to 60% by weight. In addition, the oligomer may include a carboxyl group-containing monomer, or an amino group-containing monomer, an amine group-containing monomer, a cyano group-containing monomer, a sulfonic acid group-containing monomer, or phosphoric acid. Monomer units of monomers, monomers containing isocyanate groups, monomers containing fluorenimine groups. The weight average molecular weight (Mw) of the oligomer is, for example, 1,000 to 30,000, preferably 1,000 to 20,000, and more preferably 1500 to 10,000. The weight average molecular weight of the oligomer is preferably 1,000 or more from the viewpoint of ensuring a good adhesion with the adhesive layer formed by including the oligomer. On the other hand, it is preferable that the weight average molecular weight of this oligomer is 30,000 or less from a viewpoint of ensuring the adhesive force especially the room temperature with the adhesive layer which consists of the said oligomer. The weight average molecular weight of the oligomer can be measured by a gel permeation chromatography (GPC) method. For example, a GPC measurement device (trade name "HLC-8120GPC", manufactured by Tosoh Co., Ltd.) can be used to determine the weight average molecular weight (Mw) in the form of a standard polystyrene conversion value under the following measurement conditions.・ Column: TSKgel Super AWM-H (upstream side, manufactured by Tosoh Co., Ltd.), TSKgel Super AW4000 (manufactured by Tosoh Co., Ltd.), and TSKgel Super AW2500 (downstream side, manufactured by Tosoh Co., Ltd.) Column size: each column is 6. 0 mm f × 150 mm • Column temperature (measurement temperature): 40 ° C • Eluent: Tetrahydrofuran (THF) • Flow rate: 0. 4 mL / min. Sample injection volume: 20 μL. Sample concentration: approx. 2. 0 g / L (tetrahydrofuran solution) • Standard sample: Polystyrene • Detector: Differential refractometer (RI) The adhesive layer 12 may contain a silane coupling agent. Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N- Phenyl-aminopropyltrimethoxysilane. Examples of the silane coupling agent include commercially available products such as the trade name "KBM-403" (manufactured by Shin-Etsu Chemical Industry Co., Ltd.). The silane coupling agent is preferably γ-glycidyloxypropyltrimethoxysilane. In the case where the adhesive layer 12 contains a silane coupling agent, the content of the silane coupling agent in the adhesive layer 12 is preferably 0 relative to 100 parts by weight of the adhesive or acrylic polymer in the adhesive layer 12. 01 parts by weight or more, more preferably 0. 02 parts by weight or more. Also, with respect to 100 parts by weight of the acrylic polymer, the content of the silane coupling agent in the adhesive layer 12 is preferably 1 part by weight or less, more preferably 0. 5 parts by weight or less. The composition related to the content of the silane coupling agent is to make the adhesive layer 12 containing the silane coupling agent achieve a higher adhesiveness under humidified conditions, especially a higher adhesiveness to glass. Speak better. The adhesive layer 12 may contain an ultraviolet absorber. Ultraviolet absorbers are chemical species that can efficiently absorb ultraviolet rays and convert the absorbed energy into heat or infrared rays and release them. Examples of such an ultraviolet absorber include a benzotriazole-based ultraviolet absorber, a hydroxyphenyl three-based ultraviolet absorber, a salicylate-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, and an oxydiamine. A benzophenone-based ultraviolet absorber and a cyanoacrylate-based ultraviolet absorber. The adhesive layer 12 may contain one kind of ultraviolet absorber, or may contain two or more kinds of ultraviolet absorbers. Examples of the benzotriazole-based ultraviolet absorber include 2- (2-hydroxy-5-third butylphenyl) -2H-benzotriazole (trade name "TINUVIN PS", manufactured by BASF Corporation), Phenylpropanoic acid 3- (2H-benzotriazol-2-yl) -5- (1,1-dimethylethyl) -4-hydroxy alkyl ester having 7 to 9 carbon atoms (trade name "TINUVIN 384-2 ", manufactured by BASF Corporation), 3- [3-Third-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] octyl propionate, and 3 -[3-Third-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol-2yl) phenyl] propionic acid 2-ethylhexyl ester mixture (trade name "TINUVIN 109" , Manufactured by BASF), 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol (trade name "TINUVIN 900", BASF Corporation (Manufactured), 2- (2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl ) Phenol (trade name "TINUVIN 928", manufactured by BASF), methyl 3- (3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate, and Reaction product of polyethylene glycol 300 (trade name "TINUVIN 1130", manufactured by BASF), 2- (2H-benzotriazol-2-yl) -p-cresol (trade name "TINUVIN P", BASF company (Manufactured), 2 (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol (trade name "TINUVIN 234", manufactured by BASF), 2 -[5-chloro-2H-benzotriazol-2-yl] -4-methyl-6- (third butyl) phenol (trade name "TINUVIN 326", manufactured by BASF), 2- (2H- Benzotriazol-2-yl) -4,6-di-tert-pentylphenol (trade name "TINUVIN 328", manufactured by BASF), 2- (2H-benzotriazol-2-yl) -4 -(1,1,3,3-tetramethylbutyl) phenol (trade name "TINUVIN 329", manufactured by BASF), 2,2'-methylenebis [6- (2H-benzotriazole- 2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol] (trade name "TINUVIN 360", manufactured by BASF), 2- (2H-benzotriazol-2-yl ) -6-dodecyl-4-methylphenol (trade name "TINUVIN 571", manufactured by BASF), 2- [2-hydroxy-3- (3,4,5,6-tetrahydrophthalate Formamidine-methyl) -5-methylphenyl] benzotriazole (trade name "Sumisorb 250", manufactured by Sumitomo Chemical Co., Ltd.), and 2,2'-methylenebis [6- ( 2H-benzotriazol-2-yl) -4-third octylphenol] (trade name "Adekastab LA-31", manufactured by ADEKA Corporation). Examples of the hydroxyphenyl tri-series ultraviolet absorber include 2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-tri-2-yl) -5-hydroxy Reaction product of phenyl and [(alkoxy group with 10 to 16 carbons) methyl] oxane (trade name "TINUVIN 400", manufactured by BASF), 2- [4,6-bis (2,4 -Dimethylphenyl) -1,3,5-tri-2-yl] -5- [3- (dodecyloxy) -2-hydroxypropoxy] phenol), 2- (2,4 -Dihydroxyphenyl) -4,6-bis- (2,4-dimethylphenyl) -1,3,5-tris with (2-ethylhexyl) -glycidyl ester (commodity Name "TINUVIN 405", manufactured by BASF), 2,4-bis (2-hydroxy-4-butoxyphenyl) -6- (2,4-dibutoxyphenyl) -1,3,5 -Tris (trade name "TINUVIN 460", manufactured by BASF), 2- (4,6-diphenyl-1,3,5-tri-2-yl) -5-[(hexyl) oxy] -phenol (Trade name "TINUVIN 1577", manufactured by BASF Corporation), 2- (4,6-diphenyl-1,3,5-tri-2-yl) -5- [2- (2-ethylhexamethane) Group) ethoxy] -phenol (trade name "Adekastab LAA-46", manufactured by ADEKA Corporation) and 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl)- 4,6-bis (4-phenylphenyl) -1,3,5-tri (trade name "TINUVIN 479 , BASF Corp.). Examples of the salicylate-based ultraviolet absorber include 2-propenyloxybenzoic acid phenyl ester, 2-propenyloxy-3-methylbenzoic acid phenyl ester, and 2-propenyloxybenzoic acid phenyl ester. Phenylmethylbenzoate, 2-propenyloxy-5-methylbenzoate, 2-propenyloxy-3-methoxybenzoate, 2-hydroxybenzoate, 2- Phenyl hydroxy-3-methylbenzoate, phenyl 2-hydroxy-4-methylbenzoate, phenyl 2-hydroxy-5-methylbenzoate, phenyl 2-hydroxy-3-methoxybenzoate And 2,4-di-third-butylphenyl 3,5-di-third-butyl-4-hydroxybenzoate (trade name "TINUVIN 120", manufactured by BASF Corporation). Examples of the benzophenone-based ultraviolet absorber or oxybenzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4 -Benzyloxy-2-hydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone (trade name "KEMISORB 111", manufactured by Chemipro Kasei Co., Ltd.), 2,2 ' , 4,4'-tetrahydroxybenzophenone (trade name "SEESORB 106", manufactured by Shipro Kasei Co., Ltd.), and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone . Examples of the cyanoacrylate-based ultraviolet absorber include an alkyl 2-cyanoacrylate, a cycloalkyl 2-cyanoacrylate, an alkoxyalkyl 2-cyanoacrylate, and 2-cyanoacrylic acid. Alkenyl esters and alkynyl 2-cyanoacrylate. The ultraviolet absorber contained in the adhesive layer 12 is preferably selected from the viewpoint of having a high ultraviolet absorbency and a high light stability, or a viewpoint of easily obtaining an adhesive layer 12 having high transparency. At least one selected from the group consisting of a benzotriazole-based ultraviolet absorber, a hydroxyphenyl tri-based ultraviolet absorber, and a benzophenone-based ultraviolet absorber. The ultraviolet absorber contained in the adhesive layer 12 is more preferably a benzotriazole-based ultraviolet absorber having a hydrocarbon group having 6 or more carbon atoms and a phenyl group having a hydroxyl group as a substituent bonded to a nitrogen atom forming a benzotriazole ring. In the case where the adhesive layer 12 contains an ultraviolet absorber, regarding the content of the ultraviolet absorber in the adhesive layer 12, the transmittance of light with a wavelength of 350 nm of the adhesive layer 12 is controlled to achieve a higher ultraviolet absorbency. From a viewpoint, with respect to 100 parts by weight of the adhesive or acrylic polymer in the adhesive layer 12, preferably 0. 01 parts by weight or more, more preferably 0. 05 parts by weight or more, more preferably 0. 1 part by weight or more. In addition, the content of the ultraviolet absorber in the adhesive layer 12 suppresses the occurrence of yellowing of the adhesive accompanied by the addition of the ultraviolet absorber in the adhesive layer 12 to achieve excellent optical characteristics or high transparency. From the viewpoint of performance, it is preferably 10 parts by weight or less, more preferably 9 parts by weight or less, and still more preferably 8 parts by weight or less based on 100 parts by weight of the adhesive or the acrylic polymer in the adhesive layer 12. The adhesive layer 12 may contain a light stabilizer. When the adhesive layer 12 contains a light stabilizer, it is preferable to include an ultraviolet absorber together. Light stabilizers are chemical species that capture free radicals that may be generated by irradiation with light such as ultraviolet rays. Examples of the light stabilizer include amine-based light stabilizers such as a phenol-based light stabilizer, a phosphorus-based light stabilizer, a thioether-based light stabilizer, and a hindered amine-based stabilizer. The adhesive layer 12 may contain one kind of light stabilizer, and may also contain two or more kinds of light stabilizers. Examples of the phenol-based light stabilizer include 2,6-di-third-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-third-butylphenol, and 2,6- Di-third-butyl-4-ethylphenol, butylated hydroxyanisole, 3- (4-hydroxy-3,5-di-third-butylphenyl) propionic acid n-octadecyl ester, (4-Hydroxy-3-methyl-5-tert-butyl) benzyl malonate distearyl, tocopherol, 2,2'-methylenebis (4-methyl-6-tert-butyl) Phenol), 2,2'-methylenebis (4-ethyl-6-third-butylphenol), 4,4'-methylenebis (2,6-di-third-butylphenol) , 4,4'-butylene bis (6-third-butyl-m-cresol), 4,4'-thiobis (6-third butyl-m-cresol), styrenated phenol, N, N'-hexamethylene bis (3,5-di-third-butyl-4-hydroxyhydrocinnamonamine), bis (3,5-di-third-butyl-4-hydroxybenzylphosphonic acid ethyl) (Ester), calcium, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-third-butyl-4-hydroxybenzyl) benzene, tetrakis [3- (3,5-di-third-butyl-4-hydroxyphenyl) propanyloxymethyl] methane , 1,6-hexanediol-bis [3- (3,5-di-third-butyl-4-hydroxyphenyl) propionate], 2,2'-sub Bis (4-methyl-6-cyclohexylphenol), 2,2'-methylenebis [6- (1-methylcyclohexyl) -p-cresol], 1,3,5-tris (4 -Third-butyl-3-hydroxy-2,6-dimethylbenzyl) isotricyanic acid, 1,3,5-tris (3,5-di-third-butyl-4-hydroxybenzyl) ) Isotricyanic acid, triethylene glycol-bis [3- (3-third-butyl-4-hydroxy-5-methylphenyl) propionate], 2,2'-oxadiamine bis [ Ethyl 3- (3,5-di-third-butyl-4-hydroxyphenyl) propionate], 6- (4-hydroxy-3,5-di-third-butylaniline) -2, 4-dioctylthio-1,3,5-tri, terephthalic acid bis [2-thirdbutyl-4-methyl-6- (2-hydroxy-3-thirdbutyl-5- Methylbenzyl) phenyl] ester, 3,9-bis {2- [3- (3- (third-butyl-4-hydroxy-5-methylphenyl) propanyloxy] -1,1- Dimethylethyl} -2,4,8,10-tetraoxaspiro [5. 5] Undecane and 3,9-bis {2- [3- (3,5-bis-third-butyl-4-hydroxyphenyl) propanyloxy] -1,1-dimethylethyl Radical} -2,4,8,10-tetraoxaspiro [5. 5] Undecane. Examples of the phosphorus-based light stabilizer include tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, and tris [2-tert-butyl phosphite] 4- (3-tert-butyl-4-hydroxy-5-methylphenylthio) -5-methylphenyl] ester, tridecyl phosphite, octyl diphenyl phosphite, Di (decyl) monophenyl phosphate, bis (tridecyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, bis (2, 4-Di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4,6 -Tri-tert-butylphenyl) pentaerythritol diphosphite, tetrakis (tridecyl) isopropylidene diphenol diphosphite, tetrakis (tridecyl) -4,4'-n-butylene Bis (2-third butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (2-methyl-4-hydroxy-5-third Butylphenyl) butane triphosphite, tetra (2,4-di-third-butylphenyl) phenylene diphosphinic acid diester, 9,10-dihydro-9-oxa-10 -Phosphaphenanthrene-10-oxide and tris (2-[(2,4,8,10- - tert-butyl-dibenzo [d, f] [1,3,2] hept-phospholene-dioxa-6-yl) oxy] ethyl) amine. Examples of the thioether-based light stabilizer include dialkyl thiodipropionate such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate. Ester compounds, and β-alkyl mercaptopropionate compounds of polyhydric alcohols such as tetra [methylene (3-dodecylthio) propionate] methane. Examples of the amine-based light stabilizer include a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol (trade name "TINUVIN 622", (Manufactured by BASF), the polymer and N, N ', N'',N'''-tetra- (4,6-bis- (butyl- (N-methyl-2,2,6,6- Tetramethylpiperidin-4-yl) amino) -tri-2-yl) -4,7-diazadecane-1,10-diamine one to one reaction product (trade name "TINUVIN 119" , Manufactured by BASF), poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-tri-2-4-diyl} {2,2,6 , 6-tetramethyl-4-piperidinyl} imino] hexamethylene {(2,2,6,6-tetramethyl-4-piperidinyl) imino} (trade name "TINUVIN 944 ", manufactured by BASF), bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate (trade name" TINUVIN 770 ", manufactured by BASF), sebacic acid bis ( Reaction product of 2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester with 1,1-dimethylethyl hydroperoxide and octane (trade name "TINUVIN 123" manufactured by BASF), [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butylmalonate bis (1,2,2 , 6,6-pentamethyl-4-piperidinyl) ester (trade name "TINUVIN 144", BASF company Made by the company), cyclohexane and N-butyl 2,2,6,6-tetramethyl-4-piperidinamine-2,4,6-trichloro-1,3,5-tris Reaction product of the product with 2-aminoethanol (trade name "TINUVIN 152", manufactured by BASF), bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and Mixture of sebacic acid methyl 1,2,2,6,6-pentamethyl-4-piperidine ester (trade name "TINUVIN 292", manufactured by BASF), and 1,2,3,4-butane Tetracarboxylic acid with 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8 , 10-tetraoxaspira [5. 5] A mixed ester of undecane (trade name "Adekastab LAA-63P", manufactured by ADEKA Corporation). As the amine-based stabilizer, a hindered amine-based stabilizer is particularly preferred. In the case where the adhesive layer 12 contains a light stabilizer, as for the content of the light stabilizer in the adhesive layer 12, from the viewpoint of achieving sufficient light resistance of the adhesive layer 12, compared to the 100 parts by weight of an adhesive or an acrylic polymer, preferably 0. 1 part by weight or more, more preferably 0. 2 parts by weight or more. In addition, the content of the light stabilizer in the adhesive layer 12 is higher than that in the adhesive layer 12 in terms of suppressing the coloration caused by the light stabilizer and achieving high transparency in the adhesive layer 12. 100 parts by weight of an adhesive or an acrylic polymer is preferably 5 parts by weight or less, and more preferably 3 parts by weight or less. The adhesive or acrylic polymer contained in the adhesive layer 12 may be crosslinked by a crosslinking agent other than the above-mentioned copolymerizable crosslinking agent. The gel fraction of the adhesive layer 12 can be adjusted by applying the cross-linking of the adhesive or the acrylic polymer caused by the cross-linking agent. Examples of such a crosslinking agent include an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a melamine-based crosslinking agent, a peroxide-based crosslinking agent, a urea-based crosslinking agent, and a metal alkoxide-based crosslinking agent. Crosslinking agent, metal chelate crosslinking agent, metal salt crosslinking agent, carbodiimide crosslinking agent, oxazoline crosslinking agent, aziridine crosslinking agent, and amine crosslinking Agent. The adhesive layer 12 may contain one kind of the crosslinking agent or two or more kinds of the crosslinking agent. In this embodiment, it is preferable to use an isocyanate-based crosslinking agent and / or an epoxy-based crosslinking agent. Examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates. Examples of the lower aliphatic polyisocyanates include 1,2-ethylidene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate. Examples of the alicyclic polyisocyanates include cyclopentyl diisocyanate, cyclohexyl diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, and hydrogenated xylene diisocyanate. Examples of the aromatic polyisocyanates include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate. Examples of the isocyanate-based crosslinking agent include trimethylolpropane / toluene diisocyanate adduct (trade name "Coronate L", manufactured by Nippon Polyurethane Industry Co., Ltd.), and trimethylolpropane / hexadecane. Methyl diisocyanate adduct (trade name "Coronate HL", manufactured by Nippon Polyurethane Industry Co., Ltd.), trimethylolpropane / xylylene diisocyanate adduct (trade name "Takenate D-110N", Mitsui Chemical Co., Ltd.) and other commercially available products. Examples of the epoxy-based crosslinking agent (multifunctional epoxy compound) include N, N, N ', N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, and 1,3- Bis (N, N-diglycidylaminomethyl) cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol di Glycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol Anhydride polyglycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, triglycidyl isocyanurate , Resorcinol diglycidyl ether, and bisphenol-S-diglycidyl ether. Examples of the epoxy-based crosslinking agent include epoxy-based resins having two or more epoxy groups. In addition, as the epoxy-based crosslinking agent, commercially available products such as the trade name "Tetrad C" (manufactured by Mitsubishi Gas Chemical Co., Ltd.) can also be mentioned. When the adhesive layer 12 contains the above-mentioned cross-linking agent for cross-linking acrylic polymers, the content of the cross-linking agent in the adhesive layer 12 enables the adhesive layer 12 to be coated. From the viewpoint of sufficient adhesion reliability of the body, with respect to 100 parts by weight of the adhesive or acrylic polymer in the adhesive layer 12, preferably 0. 001 parts by weight or more, more preferably 0. 01 parts by weight or more. In addition, regarding the content of the cross-linking agent in the adhesive layer 12, from the viewpoint that the adhesive layer exhibits moderate softness and achieves good adhesion, compared with the adhesive or acrylic acid in the adhesive layer 12 The polymer is 100 parts by weight, preferably 10 parts by weight or less, and more preferably 5 parts by weight or less. The adhesive layer 12 may further contain a coloring agent such as a cross-linking accelerator, a tackifier resin, an anti-aging agent, a filler, a pigment or a dye, an antioxidant, a chain transfer agent, a plasticizer, a softener, a surfactant, and the like, as necessary. And antistatic agents and other additives. Examples of the tackifying resin include rosin derivatives, polyterpene resins, petroleum resins, and oil-soluble phenols. The thickness of the adhesive layer 12 is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint that the surface protective film X achieves sufficient adhesion to the adherend on the adhesive layer 12 side. It is preferably 15 μm or more. From the viewpoint of ease of formation, the thickness of the adhesive layer 12 is preferably 1,000 μm or less, more preferably 900 μm or less, and even more preferably 800 μm or less. For a surface protective film X having a laminated structure including the above-mentioned base material 11 and the adhesive layer 12, the Emmendorf tear strength in the width direction of the base material is 0. 5 N or less, and the Emmydorff tear strength of the substrate in the mechanical direction is 1 N or more. Regarding the surface protection film X in the width direction of the substrate, Amydorff tear strength is preferably 0. 45 N or less, more preferably 0. 4 N or less, more preferably 0. 3 N or less. Regarding the mechanical direction of the surface protective film X, the Emildorf tear strength is preferably 1. Above 1 N, more preferably 1. 3 N or more, more preferably 1. 5 N or more. The Emmendorf tear strength is a value measured in accordance with JIS K 7128-2. Also, regarding the haze in the thickness direction of the optical surface protective film X, it is preferably 3% or less, and more preferably 2. 5% or less, more preferably 2% or less, even more preferably 1. 5% or less, more preferably 1% or less. The haze is a value measured in accordance with JIS K 7136. Regarding the surface protective film X, the total light transmittance in the visible light wavelength range is, for example, 85% or more. The total light transmittance is a value measured in accordance with JIS K 7361-1. The surface protection film X may be provided with a release liner (separation film) so as to cover the adhesive surface 12 a of the adhesive layer 12. The release liner is an element for protecting the adhesive layer 12 of the surface protective film X from being exposed, and is used to peel the surface protective film X from the surface protective film X when the surface protective film X is bonded to an adherend. Examples of the release liner include a substrate having a release-treated layer, a low-adhesive substrate including a fluoropolymer, and a low-adhesive substrate including a non-polar polymer. The surface of the release liner may be subjected to a release treatment, an antifouling treatment, or an antistatic treatment. The thickness of the release liner is, for example, 5 to 200 μm. Specifically, the surface protective film X may be in the form of a sheet with a release liner covering the adhesive surface 12a of the adhesive layer 12, or may be a substrate without the release liner and the surface protective film X The manner in which the material 11 and the adhesive layer 12 are alternately arranged is wound into a roll shape. The surface protective film X having the above-mentioned structure can be produced, for example, by forming the adhesive layer 12 and then bonding the adhesive layer 12 to the substrate 11. The adhesive layer 12 can be formed, for example, by coating an adhesive composition for forming the adhesive layer 12 on a specific release liner to form an adhesive composition layer, and then laminating the adhesive composition layer. The release liner hardens the adhesive composition between the release liners. As the adhesive composition for forming the adhesive layer 12, for example, an adhesive composition that can be hardened by polymerization reaction by irradiation with active energy rays can be used. That is, the adhesive layer 12 is, for example, a cured product of an active energy ray-curable adhesive composition. The active energy ray-curable adhesive composition for forming an acrylic adhesive layer contains at least a monomer, an oligomer, and a photopolymerization initiator for forming an acrylic polymer. The monomers and oligomers in the composition may be provided in the form of so-called partial polymers which are used to form a specific composition of monomer mixtures of acrylic polymers. Moreover, this adhesive composition may contain other components used as needed as a component of the adhesive layer 12 formed. Examples of the active energy rays that are irradiated to the active energy ray-curable adhesive composition to achieve curing of the adhesive layer 12 include ultraviolet rays, alpha rays, beta rays, gamma rays, neutron beams, and electron beams. For the use of ultraviolet rays. For an active energy ray-curable adhesive composition for forming an acrylic adhesive layer that is irradiated with active energy rays, an initial reaction occurs through activation of a photopolymerization initiator, and a polymerization reaction is performed to form an acrylic polymerization. Thing. If an active energy ray irradiation such as ultraviolet irradiation is used as the hardening method of the hardening adhesive composition for forming the adhesive layer, even when the coating film of the adhesive composition is relatively thick, it is easy to obtain appropriate hardening. Adhesive layer. Therefore, it is preferable that the adhesive layer 12 is a hardened product of an active energy ray-curable adhesive composition in terms of achieving an adhesive layer 12 that is sufficiently hardened even if it is relatively thick. Examples of the photopolymerization initiator include benzoin ether-based photopolymerization initiator, acetophenone-based photopolymerization initiator, α-keto alcohol-based photopolymerization initiator, and aromatic sulfonyl chloride-based photopolymerization. Starter, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzophenone-based photopolymerization initiator, benzophenone-based photopolymerization initiator, ketal-based photopolymerization initiator Agent and 9-oxysulfur Department of photopolymerization initiator. Examples of the benzoin ether-based photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and 2,2-dimethoxy-1,2-di Phenylethane-1-one. Examples of the acetophenone-based photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and 1-hydroxycyclohexylbenzene Ketone (α-hydroxycyclohexylphenyl ketone), 4-phenoxydichloroacetophenone, and 4- (third butyl) dichloroacetophenone. Examples of the α-keto alcohol-based photopolymerization initiator include 2-methyl-2-hydroxyphenylacetone and 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropane-1 -ketone. Examples of the aromatic sulfonyl chloride-based photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) -oxime. Examples of the benzoin-based photopolymerization initiator include benzoin. Examples of the benzophenazine-based photopolymerization initiator include benzophenazine. Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzophenobenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, and polyvinyl. Benzophenone. Examples of the ketal-based photopolymerization initiator include benzophenone dimethyl ketal. As 9-oxysulfur Examples of photopolymerization initiators include 9-oxysulfur , 2-chloro9-oxysulfur 2-methyl 9-oxysulfur 2,4-dimethyl 9-oxosulfur Isopropyl 9-oxysulfur 2,4-diisopropyl 9-oxysulfur Dodecyl 9-oxosulfur . The content of the photopolymerization initiator in the active energy ray-curable adhesive composition is, for example, 0.01 to 3% by weight. As the adhesive composition for forming the adhesive layer 12, a solvent-based adhesive composition or an emulsion-type adhesive composition that already contains an acrylic polymer as an adhesive and can be cured by heating and drying, for example, can also be used. . The composition may also contain other ingredients as needed as ingredients of the formed adhesive layer 12. The acrylic polymer in the adhesive composition is obtained by polymerizing a raw material monomer component for forming an acrylic polymer. Examples of the polymerization method include solution polymerization, emulsion polymerization, and block polymerization. When performing the solution polymerization, for example, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, esters, and ketones can be used as a solvent. Examples of the aromatic hydrocarbon solvents include toluene and benzene. Examples of the solvent of the aliphatic hydrocarbon include n-hexane and n-heptane. Examples of the alicyclic hydrocarbon solvent include cyclohexane and methylcyclohexane. Examples of the solvents for the esters include ethyl acetate and n-butyl acetate. Examples of the ketone solvents include methyl ethyl ketone and methyl isobutyl ketone. In the solution polymerization, one kind of solvent may be used, or two or more kinds of solvents may be used. When polymerizing a raw material monomer component in order to obtain an acrylic polymer, a polymerization initiator can be used. Depending on the kind of polymerization reaction, for example, a photopolymerization initiator or a thermal polymerization initiator can be used. In the polymerization, one polymerization initiator may be used, or two or more polymerization initiators may be used. Examples of the photopolymerization initiator include the aforementioned benzoin-based photopolymerization initiator, acetophenone-based photopolymerization initiator, α-ketoalcohol-based photopolymerization initiator, and aromatic sulfonyl chloride-based photopolymerization. Starter, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzophenone-based photopolymerization initiator, benzophenone-based photopolymerization initiator, ketal-based photopolymerization initiator Agent and 9-oxysulfur Department of photopolymerization initiator. The usage-amount of a photoinitiator is 0.01-3 weight part with respect to the total amount (100 weight part) of monomer components, for example. Examples of the thermal polymerization initiator include an azo-based polymerization initiator, a peroxide-based polymerization initiator, and a redox-based polymerization initiator. Examples of the azo-based polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, and 2,2'-azobis ( 2-methylpropanoic acid) dimethyl ester, and 4,4'-azobis-4-cyanovaleric acid. Examples of the peroxide-based polymerization initiator include benzamidine peroxide and tert-butyl maleate peroxide. The usage-amount of a thermal-polymerization initiator is 0.05-0.3 weight part with respect to the total amount (100 weight part) of monomer components, for example. In order to adjust the molecular weight of the acrylic polymer when used to obtain the polymerization of the acrylic polymer, a chain transfer agent may be used. Examples of the chain transfer agent include α-thioglycerol, 2-mercaptoethanol, 2,3-dimercapto-1-propanol, octyl mercaptan, third nonyl mercaptan, and dodecyl mercaptan (lauryl mercaptan). ), Third-dodecyl mercaptan, glycidyl mercaptan, thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate, butyl thioglycolate, third butyl thioglycolate, thioglycolic acid 2- Ethylhexyl, octyl thioglycolate, isooctyl thioglycolate, decyl thioglycolate, and dodecyl thioglycolate. As the chain transfer agent, one kind of chain transfer agent may be used, or two or more kinds of chain transfer agents may be used. In this embodiment, as the chain transfer agent, α-thioglycerin is preferably used. The used amount of the chain transfer agent is, for example, 0.01 to 0.5 parts by weight based on the total amount (100 parts by weight) of the monomer components used to obtain the acrylic polymer. When the adhesive composition for forming an adhesive layer 12 such as an active energy ray-curable adhesive composition, or a solvent-based adhesive composition, an emulsion-type adhesive composition, or the like includes the above-mentioned acrylic oligomer, the An oligomer can be obtained by polymerizing a raw material monomer component of a specific composition. Examples of the polymerization method include solution polymerization, emulsion polymerization, and block polymerization. As the solvent used for the solution polymerization, those described above as the solvent that can be used for the solution polymerization of the acrylic polymer to be obtained can be cited. In this solution polymerization, one kind of solvent may be used, or two or more kinds of solvents may be used. When the raw material monomer component is polymerized in order to obtain the oligomer, a polymerization initiator may be used. As the polymerization initiator, a photopolymerization initiator or a thermal polymerization initiator described above as a polymerization initiator that can be used to obtain a polymerization of an acrylic polymer can be cited. In the polymerization, one polymerization initiator may be used, or two or more polymerization initiators may be used. For example, the base material 11 included in the surface protective film X manufactured as described above is a polyester-based base material as described above. Such a configuration is preferable for allowing the surface protective film base material and even the surface protective film X to enjoy various characteristics that a polyester base material such as heat resistance, transparency, and dimensional stability can easily exhibit. The base material 11 included in the surface protective film X is a uniaxially stretched polyester-based base material in the width direction as described above. The thickness of the substrate 11 is 75 μm or more, and preferably 80 μm or more, as described above. As described above, the thickness of the substrate 11 is preferably 150 μm or less, and more preferably 125 μm or less. The tear strength, such as the tear strength of the surface protection film, is strongly controlled by the mechanical properties of the substrate. These structures are suitable for the surface protection film X to achieve the tear strength of the film in the width direction of the substrate of 0.5 N. Below, the above-mentioned configuration in which the Emersondorf tear strength of the base material is 1 N or more. In addition, the Emmendorf tear strength in the width direction of the substrate of the surface protective film X is 0.5 N or less, preferably 0.45 N or less, more preferably 0.4 N or less, and even more preferably 0.3 N or less as described above. At the same time, the tear strength of the Emersondorf in the mechanical direction of the substrate of the surface protective film X is 1 N or more, preferably 1.1 N or more, more preferably 1.3 N or more, and more preferably 1.5 N or more as described above. These compositions are suitable for enabling the surface protective film X to achieve good hand-tearability in the width direction of the substrate in which the Elmdorf tear strength is relatively significantly lower than 0.5 N. In addition, a configuration in which the tear strength of Emmendorf in the mechanical direction of the substrate is twice or more the substrate width direction is preferable for improving the directivity of the surface protection film X in the substrate width direction. Therefore, this configuration is preferable for the case where the surface protective film X is attached to the adherend, and the peeling force is applied to the mechanical direction of the substrate of the surface protective film X. When the surface protective film X is torn, the surface protective film X is appropriately peeled from the adherend. Specifically, it is preferable to apply a peeling force to the surface protection film when the surface protection film X is attached to the object and then peeled off and then bonded again (secondary processing operation). In the mechanical direction of the substrate of X, the surface protective film X is appropriately peeled from the adherend without tearing the surface protective film X. In addition to the width direction of the substrate, the surface protective film that is also easily torn in the mechanical direction of the substrate tends to be easily broken during peeling in a secondary processing operation, and it is difficult to properly peel from the adherend. The cracked surface protective film cannot be used for reattachment. In contrast, the surface protective film X has a sufficiently large mechanical tearing strength in the mechanical direction of the substrate, compared with the substrate tearing strength in the substrate width direction. It is suitable for proper peeling from the adherend without tearing during the secondary processing operation. As described above, the surface protective film X is suitable for achieving good hand tearability and high secondary workability while having a polyester-based substrate. As described above, the in-plane phase difference of the substrate 11 of the surface protective film X is preferably 1500 nm or more, more preferably 3000 nm or more, and even more preferably 6000 nm or more. Such a configuration is preferable for the case where the surface protective film X is bonded to the surface of the transparent cover which is the foremost part of the display screen of the liquid crystal display device, and the polarized light is prevented from being passed through, for example, polarized sunglasses. The function lens produces a so-called blanking phenomenon when viewing the display screen. In addition, there is a tendency that the larger the in-plane phase difference of the substrate 11 is, and when the surface protective film X is bonded to the surface of the transparent cover that is the foremost part of the display screen of the liquid crystal display device, for example, by polarizing When a lens with a polarizing function, such as sunglasses, sees the display screen, the so-called color unevenness is more suppressed. [Examples] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. [Production example of acrylic oligomer] In a reaction container, α- containing 60 parts by weight of dicyclopentyl methacrylate (DCPMA) and 40 parts by weight of methyl methacrylate (MMA) as a chain transfer agent A mixture of 3.5 parts by weight of thioglycerin and 100 parts by weight of toluene as a polymerization solvent was stirred at 70 ° C for 1 hour under a nitrogen atmosphere. Then, 0.2 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator was added to the mixture in the reaction container to prepare a reaction solution, and the reaction was performed at 70 ° C for 2 hours. Then, reaction was performed at 80 degreeC for 2 hours. Thereafter, the reaction solution in the reaction container was placed under a temperature atmosphere of 130 ° C, and toluene, a chain transfer agent, and unreacted monomers were dried and removed from the reaction solution. Thus, a solid acrylic oligomer was obtained. The weight average molecular weight (Mw) of the acrylic oligomer was 5.1 × 10 ³ . [Preparation Example of Acrylic Adhesive Composition C1] Containing 78 parts by weight of 2-ethylhexyl acrylate (2EHA), 18 parts by weight of N-vinyl-2-pyrrolidone (NVP), and 2-hydroxy acrylate 0.035 parts by weight of a first photopolymerization initiator (trade name "Irgacure 651", manufactured by BASF Corporation) and a second photopolymerization initiator (trade name "Irgacure 184") were added to 4 parts by weight of a monomer mixture of ethyl acetate (HEA). ", Manufactured by BASF) 0.035 parts by weight, the viscosity of the mixture was measured using a viscosity measuring device, and ultraviolet rays were irradiated with an ultraviolet irradiation device until the viscosity of the mixture became approximately 20 Pa · s. In the viscosity measurement, the rotation speed of the rotor of the device was set to 10 rpm, and the measurement temperature was set to 30 ° C. Thereby, a part of the polymer obtained by partially polymerizing a monomer component in the mixture, that is, a prepolymer composition (containing a monomer component that has not been polymerized) is obtained. Then, 100 parts by weight of the prepolymer composition, 11.8 parts by weight of the above-mentioned acrylic oligomer, 17.6 parts by weight of 2-hydroxyethyl acrylate (HEA), and 0.26-hexanediol diacrylate (HDDA) were 0.294. Part by weight and 0.353 part by weight with a silane coupling agent (trade name "KBM-403", manufactured by Shin-Etsu Chemical Industry Co., Ltd.). Thereby, an acrylic adhesive composition (acrylic adhesive composition C1) was obtained. [Preparation Example of Acrylic Adhesive Composition C2] 100 parts by weight of 2-ethylhexyl acrylate (2EHA) was contained in a flask (reaction container) equipped with a loop condenser, a nitrogen introduction tube, a stirrer, and a thermometer. , 4 parts by weight of 2-hydroxyethyl acrylate (HEA), 0.2 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 205 parts by weight of a mixture of ethyl acetate as a polymerization solvent in nitrogen Stir gently in the atmosphere, and perform a reaction at 63 ° C for 4 hours. Thereby, a solution (acrylic polymer solution) containing an acrylic polymer at a concentration of about 35% by weight was obtained. Then, the acrylic polymer solution was diluted with ethyl acetate so that the acrylic polymer concentration became 29% by weight, and 4 parts by weight of the acrylic polymer solution was added to 100 parts by weight of the acrylic polymer. Trimethylolpropane / toluene diisocyanate adduct (trade name "Coronate L", manufactured by Nippon Polyurethane Industry Co., Ltd.), 0.02 parts by weight of dioctyltin dilaurate as a tin-based catalyst (trade name " EMBILIZER OL-1 "(manufactured by Tokyo Fine Chemical Co., Ltd.), and 3 parts by weight of acetamidine and acetone as a cross-linking retarder were mixed at 25 ° C for about 1 minute. Thereby, a solvent-type acrylic adhesive composition (acrylic adhesive composition C2) was obtained. [Example 1] Obtained by performing corona treatment on both sides of a first polyethylene terephthalate film (trade name "COSMOSHINE SRF", with a phase difference of 8400, manufactured by Toyobo Co., Ltd.) with a thickness of 80 μm Film (film F ₁ ) Is applied on the acrylic adhesive composition C1 to form an adhesive composition layer. Next, a polyethylene terephthalate (PET) -based release liner (125 μm thick, manufactured by Nitto Denko Corporation) was laminated on the adhesive composition layer, covered with the adhesive composition layer, and blocked. oxygen. In this way, a layer having a [release liner / adhesive composition layer / film F ₁ ] Laminated body. Then, a black light (manufactured by Toshiba Co., Ltd.) was used to irradiate the laminated body from the side of the release liner with an illumination intensity of 3 mW / cm. ² UV for 300 seconds. Thereby, the adhesive composition layer of the laminated body is hardened to form an adhesive layer. The thickness of the adhesive layer is 100 μm. Film F with [Release liner / Adhesive layer (thickness 100 μm) / Base material produced as above ₁ (Thickness 80 μm)] The surface protective film of Example 1 composed of a laminated layer. [Example 2] A film obtained by corona-treating both sides of a second polyethylene terephthalate film having a thickness of 80 μm (Film F ₂ ) Is applied on top of the acrylic adhesive composition C2 to form an adhesive composition layer. The second polyethylene terephthalate film is from Toyobo, which replaced the easy-adhesive layer of "COSMOSHINE SRF" as the first polyethylene terephthalate film with the easy-adhesive layer for hard coating applications. Film made by a corporation. Next, this adhesive composition layer was heated at 130 ° C for 60 seconds to dry and harden it. ₂ An adhesive layer is formed thereon. The thickness of the adhesive layer is 21 μm. Then, a PET-based release liner (thickness: 25 μm, manufactured by Nitto Denko Corporation) was attached to the surface of the adhesive layer. Film F with [Release liner / Adhesive layer (thickness 21 μm) / Base material produced as above ₂ (Thickness 80 μm)] The surface protective film of Example 2 composed of a laminated layer. [Comparative Example 1] Corona treatment was performed on both sides of a third polyethylene terephthalate film (brand name "XD500P" with a difference of 3,000 in plane and manufactured by Toray Co., Ltd.) with a thickness of 75 μm. Membrane (Film F ₃ ) Instead of membrane F ₁ A surface protection film of Comparative Example 1 was produced in the same manner as in Example 1 except as a base material of the surface protection film. [Comparative Example 2] Using film F ₃ Instead of membrane F ₂ A surface protection film of Comparative Example 2 was produced in the same manner as in Example 2 except as a base material of the surface protection film. <Tear strength of Emily Dove> For each sample piece (60 mm × 75 mm) cut out from the surface protective film of the examples and comparative examples, an Emily Dove tear strength measuring device (trade name "Ely Dom Tear") was used. "Crack Tester", manufactured by TESTER SANGYO Co., Ltd.), to measure the Emmendorf tear strength (N) in the width direction (TD) of the substrate and the Emmendorf tear in the machine direction (MD) of the substrate Cracking strength (N). This measurement is performed in accordance with JIS K 7128-2. A cut-out of 20 mm in length extending from the end portion in the measurement direction (TD or MD) is provided in the sample piece for measurement in advance. In this measurement, the resistance to the tear load imparted to the sample piece by the device in such a way that the slit is further extended is measured. The measurement maximum of the above-mentioned device used in this measurement was 1 N. The results of this measurement are shown in Table 1. <Hand tearability> The hand tearability in the width direction of the substrate was examined for each surface protective film of the examples and comparative examples. Specifically, with respect to the peeled surface protective film of the release liner, a tear by hand in the width direction of the substrate was tried. In this manual inspection, the case where it can be easily torn is evaluated as good hand tearability (性), and the case where it cannot be torn is evaluated as poor hand tearability (×). The results are shown in Table 1. <Haze> For each surface protection film of the examples and comparative examples, a haze meter HM-150 (manufactured by Murakami Color Technology Research Institute Co., Ltd.) was used to measure the haze (%) according to a method prescribed by JIS K 7136. This measurement is performed on a surface protective film in a state where the release liner is peeled off and attached to a glass slide (trade name "Slide S1112", thickness 1.0 to 1.2 mm, manufactured by Matsuba Glass Industrial Co., Ltd.). The results are shown in Table 1. [Evaluation] The surface protective films of Examples 1 and 2 provided with the constitution of the present invention achieved good hand tearability. On the other hand, neither of the surface protective films of Comparative Examples 1 and 2 could be torn in the width direction of the substrate by hand, and good hand tearability was not achieved. [Table 1]

11‧‧‧ Substrate

12‧‧‧ Adhesive layer

12a‧‧‧ Adhesive surface

X‧‧‧ surface protection film

FIG. 1 is a partial cross-sectional view of a surface protective film according to an embodiment of the present invention.

Claims (8)

A surface protection film having a laminated structure including a transparent substrate and an adhesive layer. The transparent substrate is a uniaxially-stretched polyester-based substrate in the width direction of the substrate and has a thickness of 75 μm or more. Elmendorf tear strength is 0.5 N or less, and Elmendorf tear strength of the substrate in the mechanical direction is 1 N or more. The surface protection film according to claim 1, wherein the thickness of the transparent substrate is 150 μm or less. For example, the surface protective film of claim 1, wherein the widthwise extension ratio of the transparent substrate is 2.5 to 6 times. The surface protection film according to claim 1, wherein the thickness of the above-mentioned adhesive layer is 5 μm or more. The surface protection film according to claim 1, wherein the adhesive layer comprises at least one selected from the group consisting of an acrylic adhesive, a urethane adhesive, a polysiloxane adhesive, and a rubber adhesive. One. The surface protection film according to claim 1, wherein the adhesive layer is a hardened product of an active energy ray-curable adhesive composition. If the surface protection film of claim 1 has a haze of 3% or less. The surface protection film according to any one of claims 1 to 7, wherein the transparent substrate has an in-plane phase difference of 1500 nm or more.