Surface protective film

Abstract

To provide a surface protective film which is attached to the exposed surface of an optical member or an electronic member to prevent scratching of the surface of the optical member or the electronic member during processing, assembly, inspection, transportation or the like in the manufacturing process of the optical member or the electronic member and can exhibit both excellent light peelability and excellent antistatic properties and further to provide an optical member or an electronic member to which such a surface protective film is attached.SOLUTION: There is provided a surface protective film having a base material layer, an antistatic layer and an adhesive layer in this order, wherein the antistatic layer contains a binder resin and a conductive polymer, an adhesive constituting the adhesive layer is formed from an adhesive composition, the adhesive composition comprises a base polymer and a fluorine-based compound and the base polymer is a urethane prepolymer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a surface protective film. [Background technology]

[0002] In the manufacturing process of optical and electronic components, a surface protection film is generally applied to the exposed surface of the optical or electronic component to prevent damage to its surface during processing, assembly, inspection, and transportation. Such a surface protection film is removed from the optical or electronic component when surface protection is no longer needed (Patent Document 1).

[0003] Optical and electronic components are generally expensive and easily damaged. Therefore, surface protective films applied to the exposed surfaces of optical and electronic components require excellent peelability to prevent damage to the components during removal.

[0004] Furthermore, surface protective films, optical components, and electronic components typically have high electrical insulation properties and generate static electricity through friction and peeling. Therefore, static electricity is easily generated when peeling surface protective films from optical components and electronic components. In such cases, for example, applying voltage to the liquid crystal while static electricity remains present could lead to loss of liquid crystal molecule orientation or panel defects. Additionally, the presence of static electricity can attract dust and reduce work efficiency.

[0005] To prevent static electricity, the substrate of surface protective films is subjected to antistatic treatment. For example, in a surface protective film having a release layer, a substrate film layer, and an acrylic adhesive layer in that order, it has been reported that an antistatic layer is formed between the release layer and the substrate film layer, or between the substrate film layer and the acrylic adhesive layer (Patent Document 2). In addition, a removable protective adhesive film has been reported that has an antistatic layer on one side of a transparent resin film, and a removable adhesive layer further on the antistatic layer (Patent Document 3).

[0006] However, the surface protection film described in Patent Document 2 does not possess sufficiently excellent antistatic properties required for surface protection films to be bonded to high-performance optical and electronic components, nor does it have sufficiently good peelability, leaving room for improvement. Similarly, the re-peelable protective adhesive film described in Patent Document 3 does not possess sufficiently excellent antistatic properties required for surface protection films to be bonded to high-performance optical and electronic components.

[0007] To prevent static electricity, a technology has been reported that imparts antistatic properties to the adhesive layer constituting the surface protective film itself. Specifically, a method has been employed in which an ionic compound, such as an alkali metal salt or ionic liquid that functions as an antistatic agent, is incorporated into the adhesive layer and transferred to the adherend (Patent Document 4). However, even with the surface protective film described in Patent Document 4, there is room for improvement in order to achieve sufficiently excellent antistatic properties. Furthermore, in the surface protective film described in Patent Document 4, the degree of antistatic properties largely depends on the amount of antistatic agent in the adhesive layer. Therefore, if the amount of antistatic agent is increased in order to obtain excellent antistatic properties, the adherend may become contaminated, and when another component is newly bonded to the adherend after the surface protective film has been peeled off, there is a risk of process defects such as peeling. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 6613516 [Patent Document 2] Patent No. 4170102 [Patent Document 3] International Publication No. 2013 / 129303 Pamphlet [Patent Document 4] Patent No. 6896927 [Overview of the project] [Problems that the invention aims to solve]

[0009] The object of the present invention is to provide a surface protection film that can exhibit both excellent peelability and excellent antistatic properties, which is applied to the exposed surface of optical components and electronic components to prevent scratches on the surface of such components during the manufacturing process, such as processing, assembly, inspection, and transportation of such components, in the manufacturing process of optical components and electronic components. [Means for solving the problem]

[0010] [1] A surface protective film according to an embodiment of the present invention is a surface protective film having a base layer, an antistatic layer and an adhesive layer in that order, wherein the antistatic layer comprises a binder resin and a conductive polymer, and the adhesive constituting the adhesive layer is formed from an adhesive composition, the adhesive composition comprises a base polymer and a fluorine-based compound, and the base polymer is a urethane prepolymer. [2] In the surface protective film described in [1] above, the adhesive composition may contain a fatty acid ester. [3] In the surface protective film described in [2] above, the molecular weight of the fatty acid ester may be 300 to 400. [4] In the surface protective film described in any of [1] to [3] above, the adhesive composition may contain an ionic compound. [5] In the surface protection film described in any of [1] to [4] above, the amount of residual sulfur on the surface of the acrylic plate after the adhesive layer side of the surface protection film is bonded to the surface of the acrylic plate, left at 23°C for 30 minutes, and then peeled off the surface protection film from the surface of the acrylic plate may be less than 0.1 atomic%. [6] In the surface protective film described in [4] or [5] above, the content ratio of the ionic compound to 100 parts by weight of the base polymer may be 0.4 parts by weight to 3.0 parts by weight. [7] In the surface protective film described in any of [4] to [6] above, the molecular weight of the ionic compound may be 200 to 350. [8] In the surface protection film according to any one of [1] to [7] above, the adhesive composition contains a polyfunctional isocyanate compound, and the equivalent ratio of the NCO group possessed by the polyfunctional isocyanate compound to the Urethane prepolymer OH group possessed by the [compound] may be 1.6 to 2.5 as NCO group / OH group. [9] In the surface protection film according to any one of [1] to [8] above, the surface free energy of the surface of the adhesive layer with respect to diiodomethane is 3.5 mJ / m 2 ~ 7.0 mJ / m 2 and it may be so.

[10] In the surface protection film according to any one of [1] to [9] above, the content ratio of the fluorine-based compound with respect to 100 parts by weight of the base polymer may be 0.1 part by weight to 3.0 parts by weight.

[11] The optical member according to an embodiment of the present invention is one to which the surface protection film according to any one of [1] to

[10] above is adhered.

[12] The electronic member according to an embodiment of the present invention is one to which the surface protection film according to any one of [1] to

[10] above is adhered. [Effect of the Invention]

[0011] According to the present invention, in the manufacturing process of an optical member or an electronic member, a surface protection film adhered to the exposed surface of the optical member or the electronic member for preventing damage to the surface of the optical member or the electronic member during processing, assembly, inspection, transportation, etc., and capable of simultaneously exhibiting excellent peelability and excellent antistatic property can be provided. Further, an optical member and an electronic member to which such a surface protection film is adhered can be provided. [Brief Description of the Drawings]

[0012] [Figure 1] It is a schematic cross-sectional view of a surface protection film according to one embodiment of the present invention. [Mode for Carrying Out the Invention]

[0013] Where the term "weight" appears in this specification, it may be interpreted as "mass," which is the commonly used SI unit for weight.

[0014] In this specification, the expression "(meth)acrylic" means "acrylic and / or methacrylic," the expression "(meth)acrylate" means "acrylate and / or methacrylate," the expression "(meth)allyl" means "allyl and / or methallyl," and the expression "(meth)acrolein" means "acrolein and / or metacrolein." A. Surface protective film The surface protection film according to an embodiment of the present invention has a base layer, an antistatic layer, and an adhesive layer in this order.

[0015] The surface protection film according to an embodiment of the present invention may include any other suitable components or layers, as long as they do not impair the effects of the present invention, provided that they have a base layer, an antistatic layer, and an adhesive layer in that order. Examples of such other components or layers include any other suitable components or layers, as long as they do not impair the effects of the present invention. Examples of such other components or layers include a release liner.

[0016] Figure 1 is a schematic cross-sectional view of a surface protection film according to one embodiment of the present invention. In Figure 1, the surface protection film 10 comprises a base layer 1, an antistatic layer 2, and an adhesive layer 3. In the embodiment shown in Figure 1, the base layer 1, the antistatic layer 2, and the adhesive layer 3 are directly laminated together.

[0017] In Figure 1, the surface of the adhesive layer 3 opposite the antistatic layer 2 may be provided with an appropriate release liner (sometimes called a release sheet or separator) for protection until use (not shown). Examples of release liners include a release liner in which the surface of a substrate (liner substrate) such as paper or plastic film is treated with silicone, and a release liner in which the surface of a substrate (liner substrate) such as paper or plastic film is laminated with a polyolefin resin.

[0018] Examples of plastic films used as liner substrates include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene-vinyl acetate copolymer film.

[0019] The thickness of the release liner is preferably 1 μm to 500 μm, more preferably 3 μm to 450 μm, even more preferably 5 μm to 400 μm, and particularly preferably 10 μm to 300 μm.

[0020] The thickness of the surface protective film according to the embodiment of the present invention is preferably 5 μm to 500 μm, more preferably 10 μm to 450 μm, even more preferably 15 μm to 400 μm, and particularly preferably 20 μm to 300 μm.

[0021] The surface protection film according to the embodiment of the present invention has an adhesive layer side that is bonded to the surface of an acrylic plate, left at a temperature of 23°C for 30 minutes, and then peeled off at a peeling angle of 180 degrees and peeling speed of 300 mm / min at a temperature of 23°C. The peeling force A is preferably 3.0 gf / 25 mm or less, more preferably 2.5 gf / 25 mm or less, even more preferably 2.3 gf / 25 mm or less, even more preferably 2.0 gf / 25 mm or less, particularly preferably 1.8 gf / 25 mm or less, and most preferably 1.6 gf / 25 mm or less. If the above peeling force A is within the above range, the surface protection film according to the embodiment of the present invention can exhibit excellent easy peelability. In order to prevent unintended peeling during the manufacturing process, the lower limit of the above peeling force A is preferably 0.5 gf / 25 mm or more. The method for measuring the above peeling force A will be described later.

[0022] The surface protection film according to the embodiment of the present invention has an adhesive layer side that is bonded to the surface of an acrylic plate, left at a temperature of 50°C for one day, and then peeled off at a temperature of 23°C at a peeling angle of 180 degrees and a peeling speed of 300 mm / min. The peeling force B is preferably 10.0 gf / 25 mm or less, more preferably 8.0 gf / 25 mm or less, even more preferably 6.0 gf / 25 mm or less, even more preferably 5.5 gf / 25 mm or less, particularly preferably 5.0 gf / 25 mm or less, and most preferably 4.5 gf / 25 mm or less. If the above peeling force B is within the above range, the surface protection film according to the embodiment of the present invention can exhibit excellent easy peelability while also exhibiting stability of peeling force over time. In order to prevent unintended peeling during the manufacturing process, the lower limit of the above peeling force B is preferably 0.5 gf / 25 mm or more. The method for measuring the above peeling force B will be described later.

[0023] The surface protection film according to the embodiment of the present invention has a peel force increase rate over time from peel force A to peel force B (peel force increase rate over time (%) = (peel force B / peel force A) × 100 (%)) which is preferably 390% or less, more preferably 350% or less, even more preferably 330% or less, particularly preferably 310% or less, and most preferably 300% or less. The lower limit of the peel force increase rate over time is preferably as small as possible, and preferably 100% or more. If the peel force increase rate over time is within the above range, the surface protection film according to the embodiment of the present invention can exhibit greater stability of peel force over time.

[0024] The surface protection film according to the embodiment of the present invention has an adhesive layer side that is bonded to the surface of an acrylic plate, left at 23°C for 30 minutes, and then peeled off the acrylic plate surface. The residual sulfur content on the acrylic plate surface after this peeling is preferably less than 0.1 atomic%. The lower limit of the residual sulfur content is preferably as small as possible, and preferably 0 atomic% or more. If the residual sulfur content is within the above range, the surface protection film according to the embodiment of the present invention suppresses contamination of the adherend after bonding and peeling, and can suppress process defects such as peeling when bonding another component to the adherend. The residual sulfur content serves as an indicator of the extent to which the adhesive component of the surface protection film is transferred to and contaminates the adherend. A smaller residual sulfur content indicates a surface protection film that does not contaminate the adherend, while a larger residual sulfur content indicates a surface protection film that contaminates the adherend. The method for measuring the residual sulfur content will be described later.

[0025] The surface protection film according to an embodiment of the present invention is bonded to the surface of an acrylic plate with its adhesive layer side attached, left at 23°C for one day, then peeled off from the acrylic plate surface at a peeling angle of 180 degrees and a peeling speed of 300 mm / min. After that, an adhesive tape (19 mm wide, cut to a length of 150 mm, Nitto Denko Corporation's "No. 31B", with a base material thickness of 25 μm) is bonded to the surface of the acrylic plate, left at 23°C for 30 minutes, and then peeled off from the acrylic plate surface at 23°C at a peeling angle of 180 degrees and a peeling speed of 300 mm / min, and the adhesive strength is measured. Let C be the adhesive strength, and D be the adhesive strength when the adhesive tape is attached to the surface of an acrylic plate that has not undergone the above-mentioned peeling treatment, left at a temperature of 23°C for 30 minutes, and then peeled off at a peeling angle of 180 degrees and a peeling speed of 300 mm / min at a temperature of 23°C. Then, the residual adhesive strength against the acrylic plate (%) = (adhesive strength C / adhesive strength D) × 100 (%) is preferably 80% or more, more preferably 85% or more, even more preferably 90% or more, particularly preferably 92% or more, and most preferably 95% or more. The upper limit of the residual adhesive strength against the acrylic plate is preferably as high as possible, and preferably 100% or less. If the residual adhesive strength against the acrylic plate is within the above range, the surface protective film according to the embodiment of the present invention can suppress contamination of the adherend after it has been attached to and peeled off, and can suppress the occurrence of process defects such as peeling when another component is newly attached to the adherend. The above-mentioned residual tackiness to the acrylic sheet serves as an indicator of the extent to which the adhesive components of the surface protection film are transferred to and contaminate the surface of the adherend. A higher value for the residual tackiness to the acrylic sheet indicates that the adherend is not contaminated by the surface protection film, while a lower value indicates that the adherend is contaminated by the surface protection film. The method for measuring the residual tackiness to the acrylic sheet will be described later.

[0026] The surface protection film according to the embodiment of the present invention has a peel-off band voltage to the acrylic plate at a temperature of 23°C and a humidity of 50%RH, preferably 6.0kV or less, more preferably 4.0kV or less, even more preferably 3.0kV or less, even more preferably 2.5kV or less, particularly preferably 2.0kV or less, and most preferably 1.5kV or less. The lower limit of the peel-off band voltage to the acrylic plate is preferable as much as possible, but in reality, it is preferably 0.01kV or more. If the peel-off band voltage to the acrylic plate is within the above range, the surface protection film according to the embodiment of the present invention can exhibit excellent antistatic properties. The method for measuring the peel-off band voltage to the acrylic plate will be described later.

[0027] The surface protective film according to the embodiment of the present invention preferably has a surface resistance value of 1.0 × 10⁻¹ on the adhesive layer side at a temperature of 23°C and a humidity of 50% RH. 10 It is less than or equal to Ω, and more preferably 1.0 × 10⁻⁶. 9 It is less than or equal to Ω, and more preferably 5.0 × 10⁻⁶. 8 It is less than or equal to Ω, and particularly preferably 1.0 × 10⁻⁶. 8 It is less than or equal to Ω, and most preferably 8.0 × 10⁻⁶. 7 It is less than or equal to Ω. While a smaller lower limit for the surface resistance value is preferable, in practice, it is preferably 1.0 × 10⁻⁶. 4 The surface resistance is greater than or equal to Ω. If the above surface resistance value is within the above range, the surface protective film according to the embodiment of the present invention can exhibit excellent antistatic properties. The method for measuring the above surface resistance value will be described later.

[0028] ≪A-1. Base material layer≫ The base layer may be a single layer or two or more layers. The base layer may also be stretched.

[0029] The thickness of the substrate layer is preferably 4 μm to 450 μm, more preferably 8 μm to 400 μm, even more preferably 12 μm to 350 μm, and particularly preferably 16 μm to 250 μm.

[0030] For surfaces of the base layer that do not have an adhesive layer, a release treatment can be performed by adding fatty acid amides, polyethyleneimines, long-chain alkyl additives, etc. to the base layer for purposes such as forming a winding body that is easy to unwind, or a coating layer made of any suitable release agent such as silicone-based, long-chain alkyl-based, or fluorine-based agents can be provided.

[0031] Any suitable material can be used for the base layer depending on the application. Examples include plastics, paper, metal films, and nonwoven fabrics. Preferably, it is plastic. That is, the base layer is preferably a plastic film. The base layer may be composed of one type of material or two or more types of materials. For example, it may be composed of two or more types of plastics.

[0032] Examples of the above-mentioned plastics include polyester resins, polyamide resins, and polyolefin resins. Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin resins include homopolymers of olefin monomers and copolymers of olefin monomers. Specifically, examples of polyolefin resins include homopolypropylene; propylene copolymers such as block, random, and graft types with ethylene as the copolymer component; reactor TPO; ethylene polymers such as low-density, high-density, linear low-density, and ultra-low-density polymers; ethylene copolymers such as ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methacrylic acid copolymer, and ethylene-methyl methacrylate copolymer.

[0033] The base layer may contain any suitable additives as needed. Examples of additives that may be contained in the base layer include antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, fillers, pigments, surfactants, inorganic salts, polyhydric alcohols, and metal compounds. The type, number, and amount of additives that may be contained in the base layer can be appropriately set according to the purpose. Note that a base layer containing an antistatic agent as an additive is different from the antistatic layer in the present invention.

[0034] ≪A-2. Antistatic layer≫ The antistatic layer may be placed at least between the substrate layer and the adhesive layer. The antistatic layer may also be provided on the side of the substrate layer opposite the adhesive layer.

[0035] The antistatic layer may consist of only one layer or two or more layers.

[0036] The thickness of the antistatic layer can be any appropriate thickness depending on the purpose, as long as it does not impair the effects of the present invention. In order to better exhibit the effects of the present invention, the thickness of the antistatic layer is preferably 3 nm to 100 nm, more preferably 5 nm to 80 nm, even more preferably 8 nm to 60 nm, and particularly preferably 10 nm to 50 nm.

[0037] The antistatic layer comprises a binder resin and a conductive polymer. By including a binder resin and a conductive polymer in the antistatic layer placed between the substrate layer and the adhesive layer, the surface protective film according to the embodiment of the present invention can exhibit excellent antistatic properties.

[0038] The binder resin in the antistatic layer may be of one type only, or it may be of two or more types. The conductive polymer in the antistatic layer may be of one type only, or it may be of two or more types.

[0039] The antistatic layer may contain any other suitable components, as long as they do not impair the effects of the present invention.

[0040] The content ratio of the binder resin in the antistatic layer is preferably 50 to 100 parts by weight, more preferably 70 to 100 parts by weight, even more preferably 90 to 100 parts by weight, and particularly preferably 95 to 100 parts by weight, as a solid content ratio.

[0041] The content ratio of the conductive polymer in the antistatic layer is preferably 3 to 40 parts by weight, more preferably 5 to 35 parts by weight, even more preferably 8 to 32 parts by weight, and particularly preferably 10 to 30 parts by weight, per 100 parts by weight of the binder resin, as a solid content ratio.

[0042] The binder resin preferably contains a polyester resin in order to better exhibit the effects of the present invention. The content of the polyester resin in the binder resin is preferably 50% to 100% by weight, more preferably 70% to 100% by weight, even more preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight, and most preferably substantially 100% by weight, as a percentage of solid content.

[0043] The binder resin may contain resins other than polyester resin. Examples of such resins include at least one resin selected from acrylic resin, acrylic urethane resin, acrylic styrene resin, acrylic silicone resin, silicone resin, polysilazane resin, polyurethane resin, fluororesin, and polyolefin resin.

[0044] The antistatic layer is preferably formed by coating a conductive coating liquid containing a binder resin and a conductive polymer onto any suitable substrate layer, in order to better exhibit the effects of the present invention. Specifically, for example, it is an antistatic layer formed by coating a conductive coating liquid containing a binder resin and a conductive polymer onto a substrate layer. After coating, drying is performed as necessary, and curing treatment (heat treatment, ultraviolet treatment, etc.) is performed as necessary. Any suitable coating method can be used as long as it does not impair the effects of the present invention. Examples of such coating methods include the roll coating method, gravure roll coating method, reverse roll coating method, kiss roll coating method, dip roll coating method, bar coating method, roll brush coating method, spray coating method, knife coating method, air knife coating method, comma coating method, direct coating method, and die coating method.

[0045] The conductive coating liquid preferably comprises a binder resin, a conductive polymer, a crosslinking agent, and a solvent, and more preferably comprises a polyester resin, a conductive polymer, a crosslinking agent, and a solvent, in order to better exhibit the effects of the present invention.

[0046] The polyester resin preferably contains polyester as its main component. The polyester content in the polyester resin is preferably more than 50% by weight, more preferably 75% by weight or more, even more preferably 90% by weight or more, and particularly preferably substantially 100% by weight.

[0047] As the polyester, any suitable polyester can be used as long as it does not impair the effects of the present invention. Preferably, such a polyester has a structure in which one or more compounds selected from polycarboxylic acids (e.g., dicarboxylic acid compounds) having two or more carboxyl groups in one molecule and their derivatives (e.g., anhydrides, esters, halides, etc. of polycarboxylic acids) (polycarboxylic acid component) and one or more compounds selected from polyhydric alcohols (e.g., diols) having two or more hydroxyl groups in one molecule (polyhydric alcohol component) are condensed together.

[0048] As the polycarboxylic acid component, any suitable polycarboxylic acid can be used as long as it does not impair the effects of the present invention. Examples of such polycarboxylic acids include oxalic acid, malonic acid, difluoromalonic acid, alkylmalonic acid, succinic acid, tetrafluorosuccinic acid, alkylsuccinic acid, (±)-malic acid, meso-tartaric acid, itaconic acid, maleic acid, methylmaleic acid, fumaric acid, methylfumaric acid, acetylenedicarboxylic acid, glutaric acid, hexafluoroglutaric acid, methylglutaric acid, glutaconic acid, adipic acid, dithioadipic acid, methyladipic acid, dimethyladipic acid, tetramethyladipic acid, methyleneadipic acid, muconic acid, galactaric acid, pimelic acid, suberic acid, Aliphatic dicarboxylic acids such as perfluorosveric acid, 3,3,6,6-tetramethylsveric acid, azelaic acid, sebacic acid, perfluorosebacic acid, brassic acid, dodecyldicarboxylic acid, tridecyldicarboxylic acid, and tetradecyldicarboxylic acid; alicyclic dicarboxylic acids such as cycloalkyldicarboxylic acids (e.g., 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid), 1,4-(2-norbornene)dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid (Hymic acid), adamantanedicarboxylic acid, and spiroheptanedicarboxylic acid;Phthalic acid, isophthalic acid, dithioisophthalic acid, methylisophthalic acid, dimethylisophthalic acid, chloroisophthalic acid, dichloroisophthalic acid, terephthalic acid, methylterephthalic acid, dimethylterephthalic acid, chloroterephthalic acid, bromoterephthalic acid, naphthalenedicarboxylic acid, oxofluorange carboxylic acid, anthracenedicarboxylic acid, biphenyldicarboxylic acid, biphenylenedicarboxylic acid, dimethylbiphenylenedicarboxylic acid, 4,4"-p-terephenylenedicarboxylic acid, 4,4"-p-quarylphenyldicarboxylic acid, bibenzyldicarboxylic acid, azobenzenedicarboxylic acid, homophthalic acid, phenylenediacetic acid, phenyl Aromatic dicarboxylic acids such as dipropionic acid, naphthalenedicarboxylic acid, naphthalenedipropionic acid, biphenyldiacetic acid, biphenyldipropionic acid, 3,3'-[4,4'-(methylenedi-p-biphenylene)]dipropionic acid, 4,4'-bibenzyldiacetic acid, 3,3'(4,4'-bibenzyl)dipropionic acid, and oxydi-p-phenylenediacetic acid; acid anhydrides of any of the above polycarboxylic acids; esters of any of the above polycarboxylic acids (e.g., alkyl esters, monoesters, diesters, etc.); and acid halides corresponding to any of the above polycarboxylic acids (e.g., dicarboxylic acid chlorides).

[0049] Preferred polycarboxylic acid components include aromatic dicarboxylic acids and their acid anhydrides, such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; aliphatic dicarboxylic acids and their acid anhydrides, such as adipic acid, sebacic acid, azelaic acid, succinic acid, fumaric acid, maleic acid, hymic acid, and 1,4-cyclohexanedicarboxylic acid; and lower alkyl esters of these dicarboxylic acids (for example, esters with monoalcohols having 1 to 3 carbon atoms).

[0050] As the polyhydric alcohol component, any suitable polyhydric alcohol can be used as long as it does not impair the effects of the present invention. Examples of such polyhydric alcohols include ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, xylylene glycol, hydrogenated bisphenol A, bisphenol A, and other diols; alkylene oxide adducts of these diols (e.g., ethylene oxide adducts, propylene oxide adducts, etc.).

[0051] The number-average molecular weight of the polyester resin is preferably 3,000 to 100,000, more preferably 6,000 to 50,000, even more preferably 8,000 to 30,000, and particularly preferably 10,000 to 20,000, in order to better exhibit the effects of the present invention.

[0052] The glass transition temperature (Tg) of the polyester resin is preferably 0°C to 120°C, more preferably 5°C to 80°C, even more preferably 10°C to 60°C, and particularly preferably 15°C to 40°C, in order to better exhibit the effects of the present invention.

[0053] As a polyester resin, for example, commercially available products from Toyobo Co., Ltd., such as the "Byronal®" series, can be used.

[0054] As the conductive polymer, any suitable conductive polymer can be used as long as it does not impair the effects of the present invention. Examples of such conductive polymers include conductive polymers in which polyanions are doped into π-conjugated conductive polymers. Examples of π-conjugated conductive polymers include chain-like conductive polymers such as polythiophene, polypyrrole, polyaniline, and polyacetylene. Examples of polyanions include polystyrene sulfonic acid, polyisoprene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyethyl sulfonic acid, and polymethacrylate.

[0055] As the crosslinking agent that may be included in the conductive coating liquid, any suitable crosslinking agent can be used as long as it does not impair the effects of the present invention. There may be only one type of crosslinking agent or two or more types. Preferred examples of such crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, as well as urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, and amine-based crosslinking agents. Among these, melamine-based crosslinking agents are preferred.

[0056] The proportion of crosslinking agent in the conductive coating liquid is preferably 0.5 to 15 parts by weight, more preferably 1 to 12 parts by weight, even more preferably 2 to 9 parts by weight, and particularly preferably 3 to 7 parts by weight, per 100 parts by weight of binder resin, as a solid content ratio.

[0057] Examples of the solvent include organic solvents, water, or a mixed solvent thereof. Examples of the organic solvent include esters such as ethyl acetate; ketones such as methyl ethyl ketone, acetone, and cyclohexanone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, and cyclohexanol; glycol ethers such as alkylene glycol monoalkyl ethers (e.g., ethylene glycol monomethyl ether and ethylene glycol monoethyl ether) and dialkylene glycol monoalkyl ethers. Preferably, the solvent is water or a mixed solvent of water and ethanol.

[0058] The conductive coating liquid may contain any other appropriate components as long as the effects of the present invention are not impaired.

[0059] ≪A-3. Adhesive layer≫ The thickness of the adhesive layer is preferably 5 μm to 150 μm, more preferably 10 μm to 130 μm, still more preferably 30 μm to 120 μm, particularly preferably 50 μm to 100 μm, and most preferably 60 μm to 90 μm in terms of more effectively expressing the effects of the present invention.

[0060] The surface free energy of the adhesive layer with respect to diiodomethane is preferably 3.5 mJ / m 2 ~7.5 mJ / m 2 and more preferably 3.5 mJ / m 2 ~7.0 mJ / m 2 and still more preferably 3.5 mJ / m 2 ~6.5 mJ / m 2 and still more preferably 3.5 mJ / m 2 ~6.0 mJ / m 2 and particularly preferably 3.5 mJ / m 2 ~5.5 mJ / m 2 and most preferably 3.7 mJ / m 2 ~5.0 mJ / m2 If the surface free energy of the adhesive layer with respect to diiodomethane is within the above range, the surface protective film according to the embodiment of the present invention can sufficiently suppress the peeling band voltage and exhibit excellent antistatic properties. If the surface free energy of the adhesive layer with respect to diiodomethane is too low and outside the above range, the peeling band voltage may not be sufficiently suppressed, and excellent antistatic properties may not be exhibited. If the surface free energy of the adhesive layer with respect to diiodomethane is too high and outside the above range, the adherend may be contaminated.

[0061] Furthermore, the surface free energy of the adhesive layer with respect to diiodomethane can be easily measured, as will be described later. By designing the adhesive layer so that this surface free energy falls within the predetermined range described above, the surface protective film according to the embodiment of the present invention can sufficiently suppress the peel voltage and exhibit excellent antistatic properties.

[0062] The adhesive layer is composed of an adhesive. The adhesive is formed from an adhesive composition. That is, the adhesive formed from the adhesive composition forms a layer structure, thereby creating the adhesive layer.

[0063] Adhesives can be defined as those formed from an adhesive composition. This is because adhesives become adhesives when an adhesive composition undergoes a crosslinking reaction due to heating or ultraviolet irradiation, and therefore it is impossible and impractical to directly identify an adhesive by its structure. Thus, the definition "formed from an adhesive composition" appropriately identifies the adhesive as a "thing."

[0064] The adhesive layer can be formed by any suitable method. Such a method includes, for example, applying an adhesive composition onto any suitable substrate, heating and drying as necessary, and curing as necessary to form an adhesive layer on the substrate. Such application methods include, for example, gravure roll coaters, reverse roll coaters, kiss roll coaters, dip roll coaters, bar coaters, knife coaters, air knife coaters, spray coaters, comma coaters, direct coaters, and roll brush coaters.

[0065] The adhesive composition comprises a base polymer and a fluorine-based compound, wherein the base polymer is a urethane prepolymer. Because the adhesive composition comprises a base polymer and a fluorine-based compound, and the base polymer is a urethane prepolymer, the surface protective film according to the embodiment of the present invention can sufficiently suppress the peel voltage and exhibit excellent antistatic properties.

[0066] In the present invention, the effects of the present invention can be achieved by including a fluorine-based compound in the adhesive composition in addition to the base polymer.

[0067] The content of the base polymer in the adhesive composition is preferably 60% to 99.9% by weight, more preferably 65% ​​to 99.9% by weight, even more preferably 70% to 99.9% by weight, particularly preferably 75% to 99.9% by weight, and most preferably 80% to 99.9% by weight, based on solid content. If the content of the base polymer in the adhesive composition is within the above range based on solid content, the surface protective film according to the embodiment of the present invention can more sufficiently suppress the peel voltage and exhibit better antistatic properties.

[0068] The content ratio of the fluorine-based compound to 100 parts by weight of the base polymer is preferably 0.01 to 3.0 parts by weight, more preferably 0.1 to 3.0 parts by weight, even more preferably 0.2 to 2.0 parts by weight, particularly preferably 0.2 to 1.5 parts by weight, and most preferably 0.2 to 1.0 parts by weight. If the content ratio of the fluorine-based compound to 100 parts by weight of the base polymer is within the above range, the surface protective film according to the embodiment of the present invention can more sufficiently suppress the peeling band voltage and exhibit better antistatic properties. If the content ratio of the fluorine-based compound to 100 parts by weight of the base polymer is too low and outside the above range, the peeling band voltage may not be sufficiently suppressed, and excellent antistatic properties may not be exhibited. If the content ratio of the fluorine-based compound to 100 parts by weight of the base polymer is too high and outside the above range, the adherend may be contaminated.

[0069] <A-3-a.ベースポリマー> The urethane prepolymer, which is the base polymer, can react with a polyfunctional isocyanate compound to form a urethane resin. More specifically, a urethane resin is preferably formed from a composition containing a urethane prepolymer and a polyfunctional isocyanate compound, and more specifically, a urethane resin is formed by curing a composition containing a urethane prepolymer and a polyfunctional isocyanate compound. As a method for curing a composition containing a urethane prepolymer and a polyfunctional isocyanate compound to form a urethane resin, any suitable method can be used, such as a urethane formation reaction method using bulk polymerization or solution polymerization, as long as it does not impair the effects of the present invention.

[0070] There are two methods for producing urethane-based resins: the "one-shot method," which involves directly reacting a polyol with a polyfunctional isocyanate to produce a urethane adhesive without using a urethane prepolymer, and the "prepolymer method," which involves reacting a urethane prepolymer with a polyfunctional isocyanate to produce a urethane adhesive. In this invention, the urethane prepolymer as the base polymer refers to the urethane prepolymer that reacts with the polyfunctional isocyanate in the "prepolymer method" described above, and is different from the polyol that reacts with the polyfunctional isocyanate in the "one-shot method" described above.

[0071] The urethane prepolymer may be of one type or two or more types.

[0072] The number-average molecular weight (Mn) of the urethane prepolymer is preferably 3,000 to 1,000,000.

[0073] Urethane prepolymers are typically polymers obtained by reacting polyols with polyfunctional isocyanate compounds, and they have isocyanate groups at the molecular ends.

[0074] The urethane prepolymer is preferably a polyurethane polyol, and more preferably at least one selected from polyester polyol (a1) and polyether polyol (a2), which is reacted with a polyfunctional isocyanate compound in the presence or absence of a catalyst.

[0075] The polyester polyol (a1) may be of one type or two or more types.

[0076] The polyether polyol (a2) may be of one type or two or more types.

[0077] Any suitable polyester polyol (a1) can be used. Examples of such polyester polyols (a1) include polyester polyols obtained by reacting an acid component with a glycol component. Examples of acid components include terephthalic acid, adipic acid, azelaic acid, sebatic acid, phthalic anhydride, isophthalic acid, and trimellitic acid. Examples of glycol components include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, 1,6-hexane glycol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin, trimethylolpropane, and pentaerythritol. Other examples of polyester polyols (a1) include those obtained by ring-opening polymerization of lactones such as polycaprolactone, poly(β-methyl-γ-valerolactone), and polyvalerolactone.

[0078] The molecular weight of polyester polyol (a1) can range from low to high. Preferably, the number average molecular weight (Mn) of polyester polyol (a1) is between 100 and 100,000. If the number average molecular weight (Mn) is less than 100, the reactivity will be high, potentially leading to gelation. If the number average molecular weight (Mn) exceeds 100,000, the reactivity will be low, and the cohesive force of the polyurethane polyol itself may decrease. The amount of polyester polyol (a1) used is preferably between 0 mol% and 90 mol% of the polyol constituting the polyurethane polyol.

[0079] Any suitable polyether polyol (a2) can be used. Examples of such polyether polyols (a2) include those obtained by polymerizing oxirane compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using a low molecular weight polyol such as water, propylene glycol, ethylene glycol, glycerin, or trimethylolpropane as an initiator. Specifically, examples of such polyether polyols (a2) include polyether polyols with two or more functional groups, such as polypropylene glycol, polyethylene glycol, and polytetramethylene glycol.

[0080] The polyether polyol (a2) can be used with a molecular weight ranging from low to high. The number average molecular weight (Mn) of the polyether polyol (a2) is preferably between 100 and 100,000. If the number average molecular weight (Mn) is less than 100, the reactivity may increase, potentially leading to gelation. If the number average molecular weight (Mn) exceeds 100,000, the reactivity may decrease, and furthermore, the cohesive force of the polyurethane polyol itself may weaken. The amount of polyether polyol (a2) used is preferably between 0 mol% and 90 mol% of the polyol constituting the polyurethane polyol.

[0081] Polyether polyol (a2) can be used in combination with glycols such as ethylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin, trimethylolpropane, and pentaerythritol, or polyhydric amines such as ethylenediamine, N-aminoethylethanolamine, isophoronediamine, and xylylenediamine, as needed.

[0082] As the polyether polyol (a2), only a bifunctional polyether polyol may be used, or a polyether polyol having a number average molecular weight Mn of 100 to 100,000 and having at least three hydroxyl groups in one molecule may be used in part or in whole. When a polyether polyol having a number average molecular weight Mn of 100 to 100,000 and having at least three hydroxyl groups in one molecule is used in part or in whole as the polyether polyol (a2), a good balance between adhesiveness and re-peelability can be obtained. In such polyether polyols, if the number average molecular weight Mn is less than 100, the reactivity may increase and gelation may occur easily. Also, in such polyether polyols, if the number average molecular weight Mn exceeds 100,000, the reactivity may decrease, and furthermore, the cohesive force of the polyurethane polyol itself may decrease. The number average molecular weight Mn of such polyether polyols is more preferably 100 to 10,000.

[0083] The polyfunctional isocyanate compound that can be reacted with the polyol to obtain the urethane prepolymer may be one type or two or more types.

[0084] Any suitable polyfunctional isocyanate compound that can be used in the urethane reaction can be employed as the polyfunctional isocyanate compound. Examples of such polyfunctional isocyanate compounds include polyfunctional aliphatic isocyanate compounds, polyfunctional alicyclic isocyanates, polyfunctional aromatic isocyanate compounds, and polyfunctional aromatic aliphatic isocyanate compounds.

[0085] Examples of polyfunctional aliphatic isocyanate compounds include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, 2,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0086] Examples of polyfunctional alicyclic isocyanate compounds include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanate methyl)cyclohexane, 1,4-bis(isocyanate methyl)cyclohexane, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.

[0087] Examples of polyfunctional aromatic diisocyanate compounds include 1,3-phenylenediisocyanate, 1,4-phenylenediisocyanate, 2,4-tolylenediisosoanate, 2,6-tolylenediisocyanate, 2,2'-diphenylmethanediisocyanate, 4,4'-diphenylmethanediisocyanate, 4,4'-toluidinediisocyanate, 2,4,6-triisocyanatetoluene, 1,3,5-triisocyanatebenzene, 4,4'-diphenyletherdiisocyanate, 4,4'-diphenyldiisocyanate, 1,5-naphthalenediisocyanate, 4,4',4"-triphenylmethanetriisocyanate, dianisidinediisocyanate, and xylylenediisocyanate.

[0088] Examples of polyfunctional aromatic aliphatic isocyanate compounds include ω,ω'-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate-1,4-dimethylbenzene, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylenediisocyanate, and 1,3-tetramethylxylylenediisocyanate.

[0089] Examples of polyfunctional isocyanate compounds include the trimethylolpropane adduct derivatives of the various polyfunctional isocyanate compounds mentioned above, the biuret derivatives obtained by reaction with water, and trimers having an isocyanurate ring. These may also be used in combination.

[0090] The isocyanate groups in the polyfunctional isocyanate compound are preferably used in excess of the hydroxyl groups of the polyol in a molar ratio. The equivalent ratio of NCO groups to OH groups in the polyol and polyfunctional isocyanate compound that can be used to obtain a urethane prepolymer is preferably 1.01 to 5.0, more preferably 1.1 to 3.0, even more preferably 1.1 to 2.0, particularly preferably 1.1 to 1.8, and most preferably 1.2 to 1.6 as NCO group / OH group.

[0091] Any suitable catalyst can be used to obtain the urethane prepolymer. Examples of such catalysts include tertiary amine compounds and organometallic compounds.

[0092] Examples of tertiary amine compounds include triethylamine, triethylenediamine, and 1,8-diazabicyclo(5,4,0)-undecene-7(DBU).

[0093] Examples of organometallic compounds include tin compounds and non-tin compounds. Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, and tin 2-ethylhexanoate. Examples of non-tin compounds include titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanate, and butoxytitanium trichloride; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate; iron compounds such as iron 2-ethylhexanoate and iron acetylacetonate; cobalt compounds such as cobalt benzoate and cobalt 2-ethylhexanoate; zinc compounds such as zinc naphthenate and zinc 2-ethylhexanoate; and zirconium compounds such as zirconium naphthenate.

[0094] When a catalyst is used in preparing the urethane prepolymer, the amount of catalyst used is preferably 0.001% to 1.0% by weight, and more preferably 0.005% to 1.0% by weight, relative to the total amount of polyester polyol (a1), polyether polyol (a2), and polyfunctional isocyanate compound.

[0095] When using a catalyst in the preparation of urethane prepolymers, systems containing two types of polyols, polyester polyols and polyether polyols, tend to exhibit problems such as gelation and turbidity of the reaction solution due to their differing reactivity when using a single catalyst. Therefore, using two types of catalysts when obtaining urethane prepolymers makes it easier to control the reaction rate and catalyst selectivity, thereby resolving these issues. Examples of such two-catalyst combinations include tertiary amine compounds / organometallic compounds, tin compounds / non-tin compounds, and tin compounds / tin compounds. Preferably, it is a tin compound / tin compound, and more preferably a combination of dibutyltin dilaurate and tin 2-ethylhexanoate. The weight ratio of tin 2-ethylhexanoate / dibutyltin dilaurate is preferably less than 1, and more preferably 0.2 to 0.6. A ratio of 1 or more may increase the likelihood of gelation due to the balance of catalytic activity.

[0096] When a catalyst is used in preparing a urethane prepolymer, the reaction temperature is preferably less than 100°C, and more preferably between 85°C and 95°C. At temperatures above 100°C, it may become difficult to control the reaction rate and crosslinking structure, potentially making it difficult to obtain a urethane prepolymer with a predetermined molecular weight.

[0097] When preparing urethane prepolymers, a catalyst may not be used. In that case, the reaction temperature is preferably 100°C or higher, and more preferably 110°C or higher. Furthermore, when preparing urethane prepolymers without a catalyst, it is preferable to allow the reaction to proceed for 3 hours or more.

[0098] As a method for preparing a urethane prepolymer, for example, 1) a method of charging a polyol, a catalyst, and a polyfunctional isocyanate compound into a full-volume flask, and 2) a method of charging a polyol and a catalyst into a flask and adding a polyfunctional isocyanate compound dropwise can be mentioned. In the method of 2), after dropping the polyfunctional isocyanate compound, a polyol and a polyfunctional isocyanate compound may be further added. As a method for preparing a urethane prepolymer, the method of 2) is preferable in terms of controlling the reaction.

[0099] When preparing a urethane prepolymer, any suitable solvent can be used. Examples of such solvents include methyl ethyl ketone, ethyl acetate, toluene, xylene, and acetone. Among these solvents, toluene is preferable.

[0100] <A-3-b. Polyfunctional isocyanate compound> The urethane prepolymer as a base polymer reacts with a polyfunctional isocyanate compound to form a urethane resin. Therefore, the adhesive composition preferably contains a polyfunctional isocyanate compound.

[0101] The polyfunctional isocyanate compound may be only one kind or two or more kinds.

[0102] As the polyfunctional isocyanate compound, any suitable polyfunctional isocyanate compound that can be used in the urethanization reaction can be adopted. As such a polyfunctional isocyanate compound, the polyfunctional isocyanate compound described as a polyfunctional isocyanate compound that can react with a polyol to obtain a urethane prepolymer can be adopted. The polyfunctional isocyanate compound that reacts with the urethane prepolymer as a base polymer to form a urethane resin may be the same as or different from the polyfunctional isocyanate compound described as a polyfunctional isocyanate compound that can react with a polyol to obtain a urethane prepolymer.

[0103] The equivalent ratio of the NCO groups of the polyfunctional isocyanate compound to the OH groups of the urethane prepolymer is preferably 1.0 to 2.7, more preferably 1.2 to 2.5, and still more preferably 1.4 to 2.5 is More preferably 1.5 to 2.5, even more preferably 1.6 to 2.5, particularly preferably 1.6 to 2.3, and most preferably 1.6 ~2.2. When the equivalent ratio of NCO groups / OH groups is within the above range, it is difficult to be easily peeled off from the adherend. Typically, during the manufacturing process of optical members and electronic members, peeling hardly occurs after being attached to the exposed surface of the optical member or the electronic member, and when peeling is required, a surface protection film that can be easily peeled off can be provided. Further, when the equivalent ratio of NCO groups / OH groups is within the above range, it becomes possible to reduce haze.

[0104] The content ratio of the polyfunctional isocyanate compound in the adhesive composition is preferably 1.0 to 30 parts by weight, more preferably 1.5 to 27 parts by weight, still more preferably 2.0 to 25 parts by weight, still more preferably 2.3 to 23 parts by weight, still more preferably 2.3 to 18 parts by weight, particularly preferably 2.5 to 18 parts by weight, and most preferably 2.5 to 16 parts by weight with respect to 100 parts by weight of the urethane prepolymer. When the content ratio of the polyfunctional isocyanate compound is within the above range, it is difficult to be easily peeled off from the adherend. Typically, during the manufacturing process of optical members and electronic members, peeling hardly occurs after being attached to the exposed surface of the optical member or the electronic member, and when peeling is required, a surface protection film that can be easily peeled off can be provided. Further, when the content ratio of the polyfunctional isocyanate compound is within the above range, it becomes possible to reduce haze.

[0105] <A-3-c. Fluorine-based compound> As the fluorine-based compound, any appropriate fluorine-based compound can be adopted as long as the effects of the present invention are not impaired. By including a fluorine-based compound in the adhesive composition in addition to the base polymer, the surface protection film according to the embodiment of the present invention can sufficiently suppress the peeling charging voltage and exhibit excellent antistatic properties.

[0106] The fluorine-based compound may be one type or two or more types.

[0107] In terms of being able to better express the effects of the present invention, the fluorine-based compound is preferably a fluorine-based oligomer, more preferably an oligomer having a fluorine-containing group and a hydrophilic group and / or a lipophilic group, and even more preferably an oligomer having a fluorine-containing group, a hydrophilic group and a lipophilic group.

[0108] Examples of fluorine-containing groups include fluorine-containing alkyl groups (e.g., CF3-, etc.) and / or fluorine-containing alkylene groups (e.g., -CF2-CF2-, etc.). A hydrophilic group is a group that has hydrophilic properties, and hydrophilicity is a property generally known to those skilled in the art, meaning "having an affinity for water" (see, for example, the McGraw-Hill Dictionary of Scientific and Technical Terms (3rd revised edition, Nikkan Kogyo Shimbun). A lipophilic group is a group that has lipophilic properties, and lipophilicity is a property generally known to those skilled in the art, meaning "having an affinity for oil" (see, for example, the McGraw-Hill Dictionary of Scientific and Technical Terms (3rd revised edition, Nikkan Kogyo Shimbun).

[0109] In order to better exhibit the effects of the present invention, the fluorine-based compound, when used as a 0.1% toluene solution, preferably has a surface tension (surface tension of toluene is 27.9 mN / m) of 19.0 mN / m to 25.9 mN / m, more preferably 22.0 mN / m to 25.7 mN / m, even more preferably 23.0 mN / m to 25.5 mN / m, particularly preferably 23.5 mN / m to 25.3 mN / m, and most preferably 24.0 mN / m to 25.0 mN / m. By employing such specific fluorine-based compounds as described above, the surface protective film according to the embodiment of the present invention can sufficiently suppress the peeling voltage, exhibit excellent antistatic properties, and the adhesive layer can exhibit excellent anchoring properties.

[0110] A particularly preferred embodiment of the fluorinated compound is an oligomer containing a fluorinated group, a hydrophilic group, and a lipophilic group, and having a surface tension of 19.0 mN / m to 25.9 mN / m when used in a 0.1% toluene solution (the surface tension of toluene is 27.9 mN / m). The above surface tension is preferably 22.0 mN / m to 25.7 mN / m, more preferably 23.0 mN / m to 25.5 mN / m, even more preferably 23.5 mN / m to 25.3 mN / m, and particularly preferably 24.0 mN / m to 25.0 mN / m. By employing such a specific fluorinated compound as the fluorinated compound, the surface protective film according to the embodiment of the present invention can more sufficiently suppress the peeling band voltage, exhibit better antistatic properties, and the adhesive layer can exhibit better anchoring properties.

[0111] An example of an oligomer having a fluorine-containing group and a hydrophilic group and / or a lipophilic group is the "MegaFac series" manufactured by DIC Corporation.

[0112] Among the "MegaFac Series" manufactured by DIC Corporation, examples of oligomers containing fluorine-containing groups, hydrophilic groups, and lipophilic groups include: "Megafac F-477" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 26.4 mN / m), "Megafac F-553" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 26.4 mN / m), "Megafac F-555-A" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 20.4 mN / m), "Megafac F-556" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 27.5 mN / m), "Megafac F-559" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 26.1 mN / m), "Megafac F-562" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 24.8 mN / m), "Megafac F-565" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 27.6 mN / m), "Megafac F-568" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 24.7 mN / m), "Megafac F-571" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 24.8 mN / m), These are some examples.

[0113] Among the "MegaFac series" manufactured by DIC Corporation, fluorine-based compounds with a surface tension of 19.0 mN / m to 25.9 mN / m when used in a 0.1% toluene solution (toluene's surface tension is 27.9 mN / m) include, for example, "Megafac F-251" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 24.9 mN / m), "Megafac F-253" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 21.9 mN / m), "Megafac F-551-A" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 25.6 mN / m), "Megafac F-552" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 24.9 mN / m), "Megafac F-554" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 25.5 mN / m), "Megafac F-555-A" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 20.4 mN / m), "Megafac F-560" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 20.2 mN / m), "Megafac F-561" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 23 mN / m), "Megafac F-562" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 24.8 mN / m), "Megafac F-563" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 20.2 mN / m), "Megafac F-568" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 24.7 mN / m), "Megafac F-569" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 19.7 mN / m), "Megafac F-570" (an oligomer containing fluorine groups, hydrophilic groups, lipophilic groups, and carboxyl groups; surface tension in a 0.1% toluene solution = 22.9 mN / m), "Megafac F-571" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 24.8 mN / m), "Megafac F-576" (fluorine-containing and lipophilic oligomer, surface tension in a 0.1% toluene solution = 24.8 mN / m), These are some examples.

[0114] Among the "MegaFac Series" manufactured by DIC Corporation, an oligomer containing a fluorine-containing group, a hydrophilic group, and a lipophilic group, and having a surface tension of 19.0 mN / m to 25.9 mN / m when used in a 0.1% toluene solution (the surface tension of toluene is 27.9 mN / m), is, for example, a fluorine-based compound. "Megafac F-555-A" (an oligomer containing fluorine, hydrophilic, and lipophilic groups; surface tension in a 0.1% toluene solution = 20.4 mN / m), "Megafac F-562" (an oligomer containing a fluorine group, a hydrophilic group, and a lipophilic group, surface tension = 24.8 mN / m when it is a 0.1% toluene solution), "Megafac F-568" (an oligomer containing a fluorine group, a hydrophilic group, and a lipophilic group, surface tension = 24.7 mN / m when it is a 0.1% toluene solution), "Megafac F-570" (an oligomer containing a fluorine group, a hydrophilic group, a lipophilic group, and a carboxyl group, surface tension = 22.9 mN / m when it is a 0.1% toluene solution), "Megafac F-571" (an oligomer containing a fluorine group, a hydrophilic group, and a lipophilic group, surface tension = 24.8 mN / m when it is a 0.1% toluene solution), may be mentioned.

[0115] <A-3-d. Ionic compound> The adhesive composition may contain an ionic compound. The ionic compound preferably can exhibit an antistatic effect. By using the ionic compound in combination with a fluorine-based compound, it is推测 that due to the interaction with the fluorine-based compound, the ionic compound tends to be unevenly distributed on the surface side (the side bonded to the adherend) of the adhesive layer. The surface protection film according to the embodiment of the present invention can more sufficiently suppress the peeling charging voltage, can exhibit more excellent antistatic properties, and the adhesive layer can exhibit more excellent anchoring properties.

[0116] The ionic compound may be only one kind or two or more kinds.

[0117] The content ratio of the ionic compound to 100 parts by weight of the base polymer is preferably 0.2 parts by weight or more, more preferably 0.3 to 4.0 parts by weight, even more preferably 0.4 to 3.0 parts by weight, even more preferably 0.4 to 2.0 parts by weight, particularly preferably 0.4 to 1.5 parts by weight, and most preferably 0.4 to 1.0 parts by weight. If the content ratio of the ionic compound to 100 parts by weight of the base polymer is within the above range, the surface protective film according to the embodiment of the present invention can suppress the peeling band voltage even more sufficiently and exhibit even better antistatic properties. If the content ratio of the ionic compound to 100 parts by weight of the base polymer is too low and outside the above range, the peeling band voltage may not be sufficiently suppressed, and excellent antistatic properties may not be exhibited. If the content ratio of the ionic compound to 100 parts by weight of the base polymer is too high and outside the above range, the adherend may be contaminated.

[0118] As the ionic compound, any suitable ionic compound can be used as long as it does not impair the effects of the present invention. Preferably, such an ionic compound is an ionic liquid. An ionic liquid refers to a molten salt (ionic compound) that is liquid at 25°C.

[0119] As the ionic liquid, any suitable ionic liquid can be used as long as it does not impair the effects of the present invention. Such an ionic liquid is preferably an ionic liquid containing a fluoroorganic anion, and more preferably an ionic liquid composed of a fluoroorganic anion and an onium cation, in that it can better exhibit the effects of the present invention.

[0120] As the fluoroorganic anion that can constitute the ionic liquid, any suitable fluoroorganic anion can be used, as long as it does not impair the effects of the present invention. Such fluoroorganic anions may be fully fluorinated (perfluorinated) or partially fluorinated.

[0121] Such fluoroorganic anions are preferably perfluoroalkyl sulfonates, bis(fluorosulfonyl)imides, and bis(perfluoroalkanesulfonyl)imides, in that they can better express the effects of the present invention. Specifically, examples include trifluoromethanesulfonate, pentafluoroethanesulfonate, heptafluoropropanesulfonate, nonafluorobutanesulfonate, bis(fluorosulfonyl)imides, and bis(trifluoromethanesulfonyl)imides.

[0122] As the onium cation that can constitute the ionic liquid, any suitable onium cation can be used as long as it does not impair the effects of the present invention. Examples of such onium cations include pyridinium cation, pyrrolidinium cation, piperidinium cation, cation having a pyrroline skeleton, cation having a pyrrole skeleton, imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation, pyrazolium cation, pyrazolinium cation, tetraalkyl (or substituted alkyl)ammonium cation, trialkyl (or substituted alkyl)sulfonium cation, and tetraalkyl (or substituted alkyl)phosphonium cation. Preferably, in terms of being able to better express the effects of the present invention, pyridinium cation, pyrrolidinium cation, piperidinium cation, imidazolium cation, pyrazolium cation, pyrazolinium cation, and tetraalkyl (or substituted alkyl)ammonium cation are used.

[0123] Examples of pyridinium cations include 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1-butyl-3-methylpyridinium cation, and 1-octyl-4-methylpyridinium cation. Examples of pyrrolidinium cations include 1-methyl-1-propylpyrrolidinium cation. Examples of piperidinium cations include 1-methyl-1-propylpiperidinium cation. Examples of imidazolium cations include 1-ethyl-3-methylimidazolium cation and 1-hexyl-3-methylimidazolium cation. Examples of pyrazolium cations include 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation, 1-ethyl-2,3,5-trimethylpyrazolium cation, 1-propyl-2,3,5-trimethylpyrazolium cation, and 1-butyl-2,3,5-trimethylpyrazolium cation. Examples of pyrazolinium cations include 1-ethyl-2,3,5-trimethylpyrazolinium cation, 1-propyl-2,3,5-trimethylpyrazolinium cation, and 1-butyl-2,3,5-trimethylpyrazolinium cation. An example of a tetraalkyl (or substituted alkyl)ammonium cation is trimethylpropylammonium cation.

[0124] Preferably, as an ionic liquid, in terms of being able to better express the effects of the present invention, is 1-hexylpyridinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylpyridinium trifluoromethanesulfonate, 1-ethyl-3-methylpyridinium pentafluoroethanesulfonate, 1-ethyl-3-methylpyridinium heptafluoropropanesulfonate, 1-ethyl-3-methylpyridinium nonafluorobutanesulfonate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide, 1-octyl-4-methylpyridinium bis(fluorosulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(fluorosulfonyl)imide, 1-methyl-1-propylpiperidinium bis(trifluoro Examples include olomethanesulfonyl)imide, 1-methyl-1-propylpiperidinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium heptafluoropropanesulfonate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-hexyl-3-methylimidazolium bis(fluorosulfonyl)imide, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, and lithium bis(fluorosulfonyl)imide, more preferably 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide.

[0125] Ionic liquids may be commercially available ones or synthesized ones. Examples of the method for synthesizing ionic liquids include general synthesis methods using, for example, the halide method, hydroxide method, acid ester method, complex formation method, and neutralization method as described in the literature "Ionic Liquids - The Forefront and Future of Development -" published by CMC Publishing Co., Ltd.

[0126] <A-3-e. Fatty acid ester> The adhesive composition preferably contains a fatty acid ester. The fatty acid ester may be only one kind or two or more kinds. By the adhesive composition containing a fatty acid ester, the surface protection film of the present invention can exhibit excellent light peelability while exhibiting excellent temporal stability of the peel strength.

[0127] The number average molecular weight Mn of the fatty acid ester is preferably 100 to 800, more preferably 150 to 700, still more preferably 200 to 600, still more preferably 250 to 500, particularly preferably 300 to 400, and most preferably 350 to 400. If the number average molecular weight Mn of the fatty acid ester is within the above range, the surface protection film of the present invention can exhibit excellent light peelability while exhibiting more excellent temporal stability of the peel strength.

[0128] As the fatty acid ester, any appropriate fatty acid ester can be adopted as long as the effects of the present invention are not impaired. Examples of such fatty acid esters include polyoxyethylene bisphenol A laurate, butyl stearate, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, behenic acid monoglyceride, cetyl 2-ethylhexanoate, isopropyl myristate, isopropyl palmitate, cholesteryl isostearate, lauryl methacrylate, methyl coconut fatty acid, methyl laurate, methyl oleate, methyl stearate, myristyl myristate, octyldodecyl myristate, pentaerythritol monooleate, pentaerythritol monostearate, pentaerythritol tetrapalmitate, stearyl stearate, isotridecyl stearate, triglyceride 2-ethylhexanoate, butyl laurate, octyl oleate.

[0129] When the adhesive composition contains a fatty acid ester, the content ratio of the fatty acid ester is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 40 parts by weight, still more preferably 0.5 to 30 parts by weight, particularly preferably 1 to 20 parts by weight, and most preferably 5 to 15 parts by weight based on 100 parts by weight of the base polymer. If the content ratio of the fatty acid ester is within the above range with respect to 100 parts by weight of the base polymer, the surface protection film of the present invention can exhibit excellent light peelability and more excellent temporal stability of the peel strength.

[0130] <A-3-f. Other components> The adhesive composition may contain any other suitable components as long as they do not impair the effects of the present invention. Examples of such other components include solvents, catalysts, silicone-based additives such as modified silicone oils, crosslinking accelerators, silane coupling agents, antioxidants, UV absorbers, light stabilizers, resin components, tackifiers, crosslinking retarders, inorganic fillers, organic fillers, metal powders, colorants (such as pigments and dyes), chain transfer agents, plasticizers, softeners, anti-aging agents, conductive agents, foils, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, and lubricants.

[0131] ≪A-4. Manufacturing of surface protective film≫ The surface protective film according to the embodiment of the present invention can be manufactured by any suitable method. Such a manufacturing method is, for example, (1) A method (direct method) in which an adhesive composition is directly applied to a base film as any suitable base layer (for example, the base layer in a surface protective film according to an embodiment of the present invention), and heated and dried as necessary to form an adhesive layer on the base layer. (2) A method (transfer method) in which an adhesive composition is applied to the surface (peel surface) of a release liner, and heated and dried as necessary, and the adhesive layer formed on the surface of the release liner is bonded to a suitable base film (for example, the base film in the surface protection film according to an embodiment of the present invention) and the adhesive layer is transferred onto the base film. (3) A method of forming and coating an adhesive composition by extruding it onto a substrate layer. (4) A method of extruding a substrate layer and an adhesive layer in two or multiple layers, (5) A method of laminating an adhesive layer onto a substrate layer as a single layer, or a method of laminating an adhesive layer together with a laminate layer as a double layer. (6) A method of laminating an adhesive layer and a base material such as a film or laminate layer in two or multiple layers. This can be carried out according to any suitable manufacturing method. From the viewpoint of anchoring properties of the adhesive layer, the direct method of (1) or the transfer method of (2) is preferred, and the direct method of (1) is more preferred.

[0132] As for the coating method, various conventionally known methods such as roll coating, gravure roll coating, reverse roll coating, kiss roll coating, dip roll coating, bar coating, roll brush coating, spray coating, knife coating, air knife coating, comma coating, direct coating, and die coating can be appropriately employed.

[0133] ≪≪B.Applications≫≫ The surface protection film according to the embodiment of the present invention is typically applied to the exposed surface of optical or electronic components during the manufacturing process of such components, such as during processing, assembly, inspection, and transportation, to prevent scratches on the surface of the optical or electronic components. The optical component of the present invention has the surface protection film of the present invention applied to it. The electronic component of the present invention has the surface protection film of the present invention applied to it. [Examples]

[0134] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way to these examples. The test and evaluation methods in the examples are as follows. When "parts" is written, it means "parts by weight" unless otherwise specified, and when "%" is written, it means "percent by weight" unless otherwise specified.

[0135] <Surface free energy of diiodomethane on the surface of the adhesive layer> The surface protective film, from which the release liner had been peeled off, was cut to a size of 50 mm in width and 100 mm in length. With the adhesive layer surface facing upwards, it was fixed to a contact angle meter (Kyowa Interface Science Co., Ltd., model "CA-X"), and 2.0 μL of water was dropped onto the adhesive layer surface to measure the contact angle. Next, using the same procedure, 2.0 μL of diiodomethane was dropped onto the surface and the contact angle was measured. From the contact angle values ​​of these two liquids, the surface free energy of the adhesive layer surface for diiodomethane was calculated using the Owens-Wendt method.

[0136] <Amount of residual sulfur on the surface of the acrylic sheet> The adhesive layer of the surface protection film (10mm x 10mm) from which the release liner had been peeled off was attached to the surface of an acrylic plate (Acrylite, manufactured by Mitsubishi Chemical Corporation) using a 2kg hand roller in one pass-and-go motion. It was then left to stand for 30 minutes at an ambient temperature of 23°C. After removing the surface protective film from an acrylic sheet (Acrylite, manufactured by Mitsubishi Chemical Corporation), narrow-scan measurements were performed on the removed area using ESCA to calculate the elemental ratio (atomic%). The measurement conditions were as follows: Equipment: ULVAC-PHI "Quantera SXM" X-ray source: Monochrome Al Ka X Ray setting:100μmφ[15kV,25W] Photoelectron extraction angle: 45 degrees relative to the sample surface Neutralization conditions: Combined use of a neutralization gun and an Ar ion gun (neutralization mode) Correction of bond energy: The peak originating from the CC bond in the C1s spectrum is corrected to 285.0 eV. Detection limit: 0.1 atomic%

[0137] <Measurement of peeling force A from acrylic sheet (after being left at 23°C for 30 minutes)> The adhesive layer of the surface protection film (25mm wide x 140mm long), from which the release liner had been peeled off, was bonded to the surface of an acrylic plate (Acrylite, manufactured by Mitsubishi Chemical Corporation) using a 2kg hand roller in one pass-and-go motion, and left for 30 minutes at an ambient temperature of 23°C. The evaluation samples obtained as described above were measured using a tensile testing machine. The tensile testing machine used was the "Autograph AG-Xplus HS 6000mm / min high-speed model (AG-50NX plus)" manufactured by Shimadzu Corporation. The evaluation samples were set in the tensile testing machine and the tensile test was started. Specifically, the load when peeling the surface protective film from the acrylic plate was measured, and the average load at that time was defined as the peel force A of the surface protective film from the acrylic plate. The conditions for the tensile test were: test environment temperature: 23℃, peel angle: 180 degrees, peel speed (tensile speed): 300mm / min.

[0138] <Measurement of peeling force B from acrylic sheet (after being left at 50°C for 1 day)> The adhesive layer of the surface protection film (25mm wide x 140mm long), from which the release liner had been peeled off, was bonded to the surface of an acrylic plate (Acrylite, manufactured by Mitsubishi Chemical Corporation) using a 2kg hand roller in one pass-and-go motion, and left for one day at an ambient temperature of 50°C. The evaluation samples obtained as described above were measured using a tensile testing machine. The tensile testing machine used was the "Autograph AG-Xplus HS 6000mm / min high-speed model (AG-50NX plus)" manufactured by Shimadzu Corporation. The evaluation samples were set in the tensile testing machine and the tensile test was started. Specifically, the load when peeling the surface protective film from the acrylic plate was measured, and the average load at that time was defined as the peel force B of the surface protective film from the acrylic plate. The conditions for the tensile test were: test environment temperature: 23℃, peel angle: 180 degrees, peel speed (tensile speed): 300mm / min.

[0139] <Percentage increase in peeling force over time> The rate of increase in peeling force over time from peeling force A to peeling force B was calculated using the following formula. Rate of increase in peeling force over time (%) = (Peeling force B / Peeling force A) × 100 (%)

[0140] <Residual adhesive strength against acrylic sheets> An adhesive layer of surface protection film was applied to the entire surface of an acrylic sheet (Acrylite, manufactured by Mitsubishi Chemical Corporation) using a hand roller. After being stored for 24 hours at an ambient temperature of 23°C, the surface protection film was peeled off at a peeling angle of 180 degrees and a peeling speed (tensile speed) of 300 mm / min. Adhesive tape (19 mm wide, cut to a length of 150 mm, Nitto Denko Corporation "No. 31B", base material thickness = 25 μm) was then applied to the surface of the acrylic sheet after peeling using a 2 kg roller in one pass-and-go manner at an ambient temperature of 23°C. After being left for 30 minutes at an ambient temperature of 23°C, the adhesive strength C was measured using a tensile testing machine (product name "Autograph AG-Xplus HS 6000 mm / min high-speed model (AG-50NX plus)" manufactured by Shimadzu Corporation) at a peeling angle of 180 degrees and a tensile speed of 300 mm / min. On the other hand, for acrylic sheets (Acrylite, manufactured by Mitsubishi Chemical Corporation) that had not undergone the above-mentioned peeling treatment, the adhesive tape was similarly applied to the surface of the acrylic sheet, left at a temperature of 23°C for 30 minutes, and then peeled off at a peeling angle of 180 degrees and a peeling speed of 300 mm / min at a temperature of 23°C, and the adhesive strength D was measured. The residual adhesive strength against the acrylic sheet was calculated using the following formula. Residual adhesive strength against acrylic sheet (%) = (Adhesive strength C / Adhesive strength D) × 100 (%)

[0141] <Potential difference in acrylic sheet delamination> The surface protection film, with the release liner removed, was cut to a size of 70 mm in width and 100 mm in length. It was then pressed onto the surface of an acrylic sheet (Acrylite, manufactured by Mitsubishi Chemical Corporation) using a 2 kg hand roller in one pass-and-go motion, so that one end of the surface protection film in the longitudinal direction extended 30 mm beyond the edge of the acrylic sheet. The sample was left for one day in an environment of 23°C and 50% RH humidity, and then placed in a designated position on a sample fixing stand 20 mm high. The end of the surface protective film, which extended 30 mm beyond the edge of the acrylic plate, was fixed to an automatic winding machine, and peeled off at a peeling angle of 150 degrees and a peeling speed of 30 m / min. The potential of the acrylic plate surface generated at this time was measured using a potential measuring instrument (manufactured by Shishido Electrostatics Co., Ltd., model "STATIRON DZ-4") fixed at a height of 30 mm from the center of the acrylic plate, and the obtained potential was defined as the peeled-off band voltage relative to the acrylic plate. The measurement was performed in an environment of 23°C and 50% RH humidity.

[0142] <Surface resistance value> The surface protective film was cut to a size of 50mm x 50mm, and after peeling off the release liner, the adhesive layer side was measured by pressing the terminals against it with 10V for 10 seconds using Trek Japan Co., Ltd.'s "Model 152P-2P".

[0143] [Manufacturing Example 1]: Preparation of coating material for forming an antistatic layer As a binder resin, 100 parts by weight of a 25% aqueous solution of polyester resin (manufactured by Toyobo Co., Ltd., product name "Vaironal MD-1480"), 20 parts by weight of a conductive polymer, and 5 parts by weight of a melamine-based crosslinking agent (manufactured by Sumitomo Chemical Co., Ltd., product name "Sumimar M-50W") were added to a mixed solvent of water / ethanol (1 / 1 by weight ratio) and stirred for about 20 minutes to mix thoroughly. In this way, a coating material for forming an antistatic layer with a solid content of approximately 0.4% was prepared. As the conductive polymer, an aqueous solution (Bytron P, manufactured by HCStark) containing 0.5% poly(3,4-ethylenedioxythiophene) (PEDOT) and 0.8% polystyrene sulfonate (weight-average molecular weight 150,000) (PSS) was used.

[0144] [Manufacturing Example 2]: Preparation of substrate with antistatic layer (a) A transparent polyethylene terephthalate (PET) film with a thickness of 75 μm (product name "T100-75S", thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) was prepared. The antistatic layer-forming coating material prepared in Manufacturing Example 1 was applied to one side of this PET film using a bar coater and dried by heating at 130°C for 2 minutes. In this way, an antistatic layer-coated substrate (a) having a transparent antistatic layer with a thickness of 30 nm on one surface of the PET film was prepared.

[0145] [Manufacturing Example 3]: Preparation of substrate with antistatic layer (b) A transparent polyethylene terephthalate (PET) film with a thickness of 75 μm (product name "T100-75S", thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) was prepared. The antistatic layer-forming coating material prepared in Manufacturing Example 1 was applied to both sides of this PET film using a bar coater and dried by heating at 130°C for 2 minutes. In this way, an antistatic layer-coated substrate (b) having a transparent antistatic layer with a thickness of 30 nm on both surfaces of the PET film was prepared.

[0146] [Manufacturing Example 4]: Preparation of urethane prepolymer In a polymerization apparatus equipped with a 1L round-bottom separable flask, separable cover, separatory funnel, thermometer, nitrogen inlet tube, Liebig condenser, vacuum seal, stirring rod, and stirring blade, 197g of polypropylene glycol (product name "Sannix PP-2000", manufactured by Sanyo Chemical Industries, Ltd.), 197g of polyester polyol (product name "Kuraray Polyol P-2010", manufactured by Kuraray Co., Ltd.), 110g of toluene (manufactured by Tosoh Corporation) as a solvent, and 0.041g of dibutyltin(IV) dilaurate (manufactured by Wako Pure Chemical Industries, Ltd.) as a catalyst were added, and nitrogen purging was carried out at room temperature for 1 hour while stirring. Subsequently, under nitrogen inflow and while stirring, 33.5 g of hexamethylene diisocyanate (product name "HDI", manufactured by Tosoh Corporation) was added, and the solution temperature in the experimental apparatus was controlled to 90±2°C in a water bath and held for 4 hours. Then, 44 g of polypropylene glycol (product name "GP1000", manufactured by Sanyo Chemical Industries, Ltd.) was added, and the solution temperature in the experimental apparatus was controlled to 90±2°C in a water bath and held for 2 hours. Then, 25.4 g of hexamethylene diisocyanate (product name "HDI", manufactured by Tosoh Corporation) was added, and the solution temperature in the experimental apparatus was controlled to 90±2°C in a water bath and held for 2 hours to obtain a solution of urethane prepolymer A. During polymerization, toluene was added dropwise as needed to control the temperature during polymerization and to prevent a decrease in stirability due to viscosity increase. The total amount of toluene added dropwise was 380 g. The solid content concentration of the urethane prepolymer A solution was 50% by weight.

[0147] [Example 1] A urethane-based adhesive composition was obtained by diluting 100 parts by weight of urethane prepolymer A, 4.0 parts by weight of isocyanate compound (Coronate HX:C / HX, manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent, 0.3 parts by weight of Megafac F-571 (manufactured by DIC Corporation, an oligomer containing fluorine-containing groups, hydrophilic groups, and lipophilic groups, surface tension of 24.8 mN / m when used in a 0.1% toluene solution) as a fluorine-based oligomer, 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, 0.3 parts by weight of Elexel AS110 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as an antistatic agent, and 10 parts by weight of Saracos 913 (isotridecyl isononanoate, molecular weight = 341, manufactured by Nisshin Oillio Group Ltd.) as a fatty acid ester with ethyl acetate so that the total solid content was 50% by weight. The obtained urethane-based adhesive composition was applied to the antistatic layer-equipped substrate (b) obtained in Production Example 3 to a dry thickness of 75 μm, and cured and dried at a drying temperature of 130°C for a drying time of 2 minutes. Next, the silicone-treated side of a release liner (product name "MRF25", thickness 25 μm, manufactured by Mitsubishi Chemical Corporation), made of polyester resin with a thickness of 25 μm and one side of which was silicone-treated, was laminated to the surface of the obtained adhesive layer to obtain a surface protective film (1). Aging was performed at room temperature for 5 days, and evaluation was conducted. The release liner was peeled off immediately before evaluation as needed. The results are shown in Tables 1 and 2.

[0148] [Example 2] As shown in Table 1, a surface protective film (2) was obtained in the same manner as in Example 1, except that the amount of Elexel AS110 used as the ionic compound was changed to 0.5 parts by weight. The results are shown in Tables 1 and 2.

[0149] [Example 3] As shown in Table 1, a surface protective film (3) was obtained in the same manner as in Example 1, except that the amount of Elexel AS110 used as the ionic compound was changed to 1.0 part by weight. The results are shown in Tables 1 and 2.

[0150] [Example 4] As shown in Table 1, a surface protective film (4) was obtained in the same manner as in Example 1, except that 0.3 parts by weight of CIL-312 (manufactured by Nippon Carlit Co., Ltd.) was used as the ionic compound. The results are shown in Tables 1 and 2.

[0151] [Example 5] As shown in Table 1, a surface protective film (5) was obtained by following the same procedure as in Example 4, except that the amount of CIL-312 used as the ionic compound was changed to 0.5 parts by weight. The results are shown in Tables 1 and 2.

[0152] [Example 6] As shown in Table 1, a surface protective film (6) was obtained in the same manner as in Example 4, except that the amount of CIL-312 used as the ionic compound was changed to 1.0 part by weight. The results are shown in Tables 1 and 2.

[0153] [Example 7] As shown in Table 1, a surface protective film (7) was obtained in the same manner as in Example 1, except that the amount of isocyanate compound used as a crosslinking agent was changed to 3.0 parts by weight. The results are shown in Tables 1 and 2.

[0154] [Example 8] As shown in Table 1, a surface protective film (8) was obtained by following the same procedure as in Example 7, except that the amount of Elexel AS110 used as the ionic compound was changed to 1.0 part by weight. The results are shown in Tables 1 and 2.

[0155] [Example 9] As shown in Table 1, a surface protective film (9) was obtained by following the same procedure as in Example 2, except that the amount of Megafac F-571 used as a fluorine-based oligomer was changed to 0.5 parts by weight. The results are shown in Tables 1 and 2.

[0156] [Example 10] As shown in Table 1, a surface protective film (10) was obtained in the same manner as in Example 2, except that the amount of Megafac F-571 used as a fluorine-based oligomer was changed to 0.1 parts by weight. The results are shown in Tables 1 and 2.

[0157] [Example 11] As shown in Table 1, a surface protective film (11) was obtained in the same manner as in Example 2, except that 10.0 parts by weight of Excepal IPP (isopropyl palmitate, molecular weight = 299, manufactured by Kao Corporation) was used as the fatty acid ester. The results are shown in Tables 1 and 2.

[0158] [Example 12] As shown in Table 1, a surface protective film (12) was obtained in the same manner as in Example 2, except that 10.0 parts by weight of Excepal IPM (isopropyl myristate, molecular weight = 270, manufactured by Kao Corporation) was used as the fatty acid ester. The results are shown in Tables 1 and 2.

[0159] [Example 13] As shown in Table 1, a surface protective film (13) was obtained in the same manner as in Example 2, except that fatty acid esters were not used. The results are shown in Tables 1 and 2.

[0160] [Example 14] As shown in Table 1, a surface protective film (14) was obtained in the same manner as in Example 1, except that an ionic compound was not used. The results are shown in Tables 1 and 2.

[0161] [Example 15] As shown in Table 1, a surface protective film (15) was obtained in the same manner as in Example 2, except that the amount of Megafac F-571 used as a fluorine-based oligomer was changed to 1.0 part by weight. The results are shown in Tables 1 and 2.

[0162] [Example 16] As shown in Table 1, a surface protective film (16) was obtained in the same manner as in Example 2, except that 0.3 parts by weight of Megafac F-563 (an oligomer containing fluorine groups and lipophilic groups, with a surface tension of 20.2 mN / m in a 0.1% toluene solution) was used as the fluorine-based oligomer. The results are shown in Tables 1 and 2.

[0163] [Example 17] As shown in Table 1, a surface protective film (17) was obtained in the same manner as in Example 2, except that 0.3 parts by weight of Megafac F-477 (manufactured by DIC Corporation, an oligomer containing fluorine-containing groups, hydrophilic groups, and lipophilic groups, with a surface tension of 26.4 mN / m in a 0.1% toluene solution) was used as the fluorine-based oligomer. The results are shown in Tables 1 and 2.

[0164] [Comparative Example 1] As shown in Table 1, a urethane adhesive composition was prepared without using either an ionic compound or a fluorine-based oligomer. Instead of applying it to the antistatic layer substrate (b) obtained in Production Example 3 to a dry thickness of 75 μm, the composition was applied to the PET film side of the antistatic layer substrate (a) obtained in Production Example 2 to a dry thickness of 75 μm. The process was carried out in the same manner as in Example 1, except that the composition was applied to the PET film side of the antistatic layer substrate (a) obtained in Production Example 2 to a dry thickness of 75 μm. A surface protective film (C1) was obtained. The results are shown in Tables 1 and 2.

[0165] [Comparative Example 2] As shown in Table 1, a urethane adhesive composition was prepared without using a fluorine-based oligomer. Instead of applying it to the antistatic layer substrate (b) obtained in Production Example 3 to a dry thickness of 75 μm, the composition was applied to the PET film side of the antistatic layer substrate (a) obtained in Production Example 2 to a dry thickness of 75 μm. The process was carried out in the same manner as in Example 3, except that the composition was applied to the PET film side of the antistatic layer substrate (a) obtained in Production Example 2 to a dry thickness of 75 μm. A surface protective film (C2) was obtained. The results are shown in Tables 1 and 2.

[0166] [Comparative Example 3] As shown in Table 1, a surface protective film (C3) was obtained in the same manner as in Example 3, except that instead of coating the antistatic layer-coated substrate (b) obtained in Production Example 3 to a dry thickness of 75 μm, the antistatic layer-coated substrate (a) obtained in Production Example 2 was coated to the PET film side to a dry thickness of 75 μm. The results are shown in Tables 1 and 2.

[0167] [Comparative Example 4] As shown in Table 1, a surface protective film (C4) was obtained in the same manner as in Comparative Example 3, except that the amount of Elexel AS110 used as the ionic compound was changed to 3.0 parts by weight. The results are shown in Tables 1 and 2.

[0168] [Table 1]

[0169] [Table 2]

[0170] [Examples 18-34] For each of the surface protective films (1) to (17) obtained in Examples 1 to 17, the separator was peeled off, and the adhesive layer side was attached to a polarizing plate (manufactured by Nitto Denko Corporation, product name "TEG1465DUHC"), which is an optical component, to obtain an optical component with the surface protective film attached.

[0171] [Examples 35-51] For each of the surface protective films (1) to (17) obtained in Examples 1 to 17, the separator was peeled off, and the adhesive layer side was attached to a conductive film (manufactured by Nitto Denko Corporation, product name "Elecrista V270L-TFMP") which is an electronic component, to obtain an electronic component with the surface protective film attached. [Industrial applicability]

[0172] The surface protection film of the present invention can be used in any suitable application. Preferably, the surface protection film of the present invention is used in the fields of optical components and electronic components. [Explanation of Symbols]

[0173] 1 Base material layer 2. Antistatic layer 3. Adhesive layer 10 Surface protective film

Claims

1. A surface protective film having a base layer, an antistatic layer, and an adhesive layer in this order, The antistatic layer comprises a binder resin and a conductive polymer. The adhesive constituting the adhesive layer is formed from an adhesive composition, The adhesive composition comprises a base polymer, a polyfunctional isocyanate compound, a fatty acid ester, and a fluorine-based compound. The base polymer is a urethane prepolymer, and the urethane prepolymer is a polyurethane polyol. Surface protective film.

2. The surface protective film according to claim 1, wherein the molecular weight of the fatty acid ester is 300 to 400.

3. The surface protective film according to claim 1, wherein the adhesive composition contains an ionic compound.

4. The surface protective film according to claim 1, wherein the adhesive layer side of the surface protective film is bonded to the surface of the acrylic plate, left at 23°C for 30 minutes, and then the surface protective film is peeled off the surface of the acrylic plate, and the remaining sulfur content on the surface of the acrylic plate is less than 0.1 atomic%.

5. The surface protective film according to claim 3, wherein the content ratio of the ionic compound to 100 parts by weight of the base polymer is 0.4 parts by weight to 3.0 parts by weight.

6. The surface protective film according to claim 3, wherein the molecular weight of the ionic compound is 200 to 350.

7. The surface protective film according to claim 1, wherein the equivalent ratio of the NCO group of the polyfunctional isocyanate compound to the OH group of the urethane prepolymer is 1.6 to 2.5 as NCO group / OH group.

8. The surface free energy of the adhesive layer for diiodomethane is 3.5 mJ / m². 2 ~7.0 mJ / m 2 The surface protective film according to claim 1.

9. The surface protective film according to claim 1, wherein the content ratio of the fluorine-based compound to 100 parts by weight of the base polymer is 0.1 parts by weight to 3.0 parts by weight.

10. An optical member to which a surface protective film according to any one of claims 1 to 9 is attached.

11. An electronic component to which a surface protective film according to any one of claims 1 to 9 is attached.

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