Surface protective film-attached optical laminate

Abstract

To provide a surface protective film-attached optical laminate that can suppress occurrence of pickup failures.SOLUTION: An optical laminate 10 comprises, in the following order, a release liner 11, an adhesive layer 12, a clear film substrate material 13, an anti-fouling layer 14, and a surface protective film 15. A principal surface 11a on a side opposite the adhesive layer 12 side of the release liner 11 is a first principal surface 10a of the optical laminate 10. A principal surface 15a on a side opposite the anti-fouling layer 14 side of the surface protective film 15 is a second principal surface 10b of the optical laminate 10. Each of a surface resistivity of the first principal surface 10a of the optical laminate 10, and a surface resistivity of the second principal surface 10b of the optical laminate 10 is equal to or less than 1.0*1013 Ω / sq.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an optical laminate with a surface protective film. [Background technology]

[0002] Antireflection films arranged on the outermost surface of image display devices, position detection films for touch panels, window films attached to window panes or show windows, and the like are used in a state where they can be touched from the outside, and are therefore susceptible to contamination by fingerprints, hand marks, dust, etc. For this reason, an antifouling layer is provided for the purpose of preventing contamination from the external environment and facilitating the removal of adhering contaminants.

[0003] A surface protective film is temporarily attached to these optical films (optical laminates) in order to prevent scratches, contamination, and the like before use during processing, transportation, and the like (see, for example, Patent Document 1). Hereinafter, an optical laminate to which a surface protective film is temporarily attached may be referred to as an "optical laminate with a surface protective film" or simply as an "optical laminate".

[0004] In the optical laminate with a surface protective film (laminated plastic film for optical filters) described in Patent Document 1, an adhesive layer and a release film (release liner) are laminated in this order on the side opposite to the surface protective film. The release liner protects the adhesive layer until the optical laminate is bonded to an adherend (e.g., an image display panel, etc.). For this reason, one main surface of the optical laminate described in Patent Document 1 becomes the surface of the surface protective film, and the other main surface becomes the surface of the release liner until it is bonded to an adherend. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-151996 A Summary of the Invention [Problem to be solved by the invention]

[0006] On the other hand, when the optical laminate is attached to an image display panel or the like, a process is provided in which, for example, a suction tool is used to pick up the stacked optical laminates one by one. At this time, the release liner of the first optical laminate and the surface protective film of the second optical laminate tend to adhere to each other due to static electricity. If the adhesion between the release liner and the surface protective film becomes strong, when the first optical laminate is picked up, it may be picked up together with the second optical laminate, or the surface protective film may peel off from the second optical laminate. Hereinafter, the above-mentioned problem during the pick-up process of the optical laminate may be referred to as a "pick-up failure". In particular, in an optical laminate in which an antifouling layer is provided directly under the surface protective film, the adhesion between the antifouling layer and the surface protective film is low due to the nature of the antifouling layer that easily repels moisture and oil, and the surface protective film tends to peel off easily from the antifouling layer. It is difficult to suppress the occurrence of pick-up failures only with the technology described in Patent Document 1.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical laminate with a surface protective film that can suppress the occurrence of pickup defects. [Means for solving the problem]

[0008] <Aspects of the present invention> The present invention includes the following aspects.

[0009] [1] An optical laminate with a surface protective film, comprising a release liner, a pressure-sensitive adhesive layer, a transparent film substrate, an antifouling layer, and a surface protective film in this order, a main surface of the release liner opposite to the pressure-sensitive adhesive layer is a first main surface of the optical laminate with a surface protective film, a main surface of the surface protective film opposite to the antifouling layer side is a second main surface of the optical laminate with the surface protective film, The surface resistivity of the first main surface and the second main surface of the optical laminate with a surface protective film is 1.0×10 13 An optical laminate with a surface protective film having a resistivity of Ω / □ or less.

[0010] [2] The antifouling layer and the surface protective film are in contact with each other, The optical laminate with a surface protective film according to [1] above, wherein the water contact angle of the main surface of the antifouling layer on the surface protective film side is 100° or more.

[0011] [3] The antifouling layer and the surface protective film are in contact with each other, The optical laminate with a surface protective film according to [1] or [2] above, wherein the adhesion strength between the antifouling layer and the surface protective film is 0.07 N / 50 mm or less.

[0012] [4] The surface resistivity of the second main surface of the optical laminate with a surface protective film is 1.0 × 10 8 The optical laminate with a surface protective film according to any one of the above [1] to [3], having a resistivity of Ω / □ or more.

[0013] [5] The transparent film substrate comprises a transparent film and a hard coat layer provided on a first main surface side of the transparent film; The optical laminate with a surface protective film according to any one of the above [1] to [4], wherein the pressure-sensitive adhesive layer is provided on a second main surface side of the transparent film.

[0014] [6] The optical laminate with a surface protective film according to any one of [1] to [5] above, further comprising an antireflection layer provided between the transparent film substrate and the antifouling layer.

[0015] [7] The optical laminate with a surface protective film according to [6], further comprising a primer layer provided between the transparent film substrate and the antireflection layer. Effect of the Invention

[0016] According to the present invention, it is possible to provide an optical laminate with a surface protective film capable of suppressing the occurrence of pickup defects. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view showing an example of an optical laminate with a surface protective film according to the present invention. [Diagram 2] FIG. 2 is a cross-sectional view for explaining a method for evaluating the pick-up property of an optical laminate with a surface protective film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Preferred embodiments of the present invention will be described in detail below, but the present invention is not limited thereto. In addition, all academic and patent documents described in this specification are incorporated herein by reference.

[0019] First, the terms used in this specification will be explained. The "refractive index" is the refractive index for light with a wavelength of 550 nm in an atmosphere at a temperature of 23°C. The "principal surface" of a layered product (more specifically, a release liner, a pressure-sensitive adhesive layer, a transparent film substrate, an antifouling layer, a surface protective film, a transparent film, a hard coat layer, a primer layer, an antireflection layer, a substrate layer, an adhesive layer, an optical laminate with a surface protective film, etc.) refers to a surface perpendicular to the thickness direction of the layered product. The "first principal surface" of a layered product means one of the two principal surfaces of the layered product. The "second principal surface" of a layered product means the principal surface opposite to the first principal surface side of the layered product.

[0020] Unless otherwise specified, the numerical value for the "thickness (film thickness)" of a layered material is the arithmetic average of 10 measured values ​​obtained by observing a cross section of the layered material cut in the thickness direction with an electron microscope, randomly selecting 10 measurement points from the cross-sectional image, and measuring the thickness of the selected 10 measurement points.

[0021] Unless otherwise specified, the number-average primary particle diameter of particles is the number-average value of the circle-equivalent diameters (Heywood diameter: diameter of a circle having the same area as the projected area of ​​a primary particle) of 100 primary particles measured using a scanning electron microscope and image processing software (e.g., "ImageJ" manufactured by the National Institutes of Health, USA).

[0022] Hereinafter, the compound and its derivatives may be collectively referred to by adding "based" after the compound name. In addition, when the compound name is followed by "based" to represent the name of a polymer, it means that the repeating unit of the polymer is derived from the compound or its derivative, unless otherwise specified. In addition, acrylic and methacrylic may be collectively referred to as "(meth)acrylic".

[0023] Unless otherwise specified, the components and functional groups exemplified in this specification may be used alone or in combination of two or more kinds.

[0024] The drawings referred to in the following description are intended to illustrate each component in a schematic manner for ease of understanding, and the size, number, shape, etc. of each component shown in the drawings may differ from the actual size, number, shape, etc., for convenience of drawing. Also, for convenience of explanation, in the drawings described later, the same components as those in the drawings described earlier may be given the same reference numerals, and explanations thereof may be omitted.

[0025] <Optical laminate with surface protection film> The optical laminate with a surface protective film according to this embodiment (hereinafter, may be referred to as "optical laminate A") comprises, in this order, a release liner, a pressure-sensitive adhesive layer, a transparent film substrate, an antifouling layer, and a surface protective film. The main surface of the release liner opposite the pressure-sensitive adhesive layer side is the first main surface of the optical laminate A. The main surface of the surface protective film opposite the antifouling layer side is the second main surface of the optical laminate A. The surface resistivity of the first main surface of the optical laminate A and the surface resistivity of the second main surface of the optical laminate A are both 1.0×10 13 It is less than Ω / □.

[0026] The method for measuring the "surface resistivity" is the same as or a similar method to the measuring method in the examples described below.

[0027] The optical laminate A has the above-mentioned configuration and can therefore suppress the occurrence of pickup failures. The reason for this is presumed to be as follows.

[0028] In the optical laminate A, the surface resistivity of the main surface on the release liner side (first main surface) and the main surface on the surface protective film side (second main surface) are both 1.0 × 10 13 Since the resistance is Ω / □ or less, charging of both main surfaces of the optical laminate A is suppressed. For this reason, in the pick-up process, when the optical laminates A are picked up one by one from the stacked optical laminates A, the adhesion between the optical laminates A (specifically, the release liner of one optical laminate A and the surface protection film of the other optical laminate A) tends to decrease. As a result, when the optical laminates A are picked up one by one, adhesion between the release liner and the surface protection film is suppressed, so that the optical laminate A can suppress the occurrence of pick-up failures.

[0029] In this embodiment, in order to further suppress the occurrence of pickup failure, the surface resistivity of the first main surface of the optical laminate A and the surface resistivity of the second main surface of the optical laminate A are each set to 9.0×10 12 It is preferable that the resistance is Ω / □ or less, and 7.0×10 12 More preferably, it is 5.0×10 12 It is more preferable that the surface resistivity is Ω / □ or less. Note that the surface resistivity of the first main surface of the optical laminate A and the surface resistivity of the second main surface of the optical laminate A may be the same value or different values.

[0030] The lower limit of the surface resistivity of the first main surface (surface of the release liner) of the optical laminate A is not particularly limited, but from the viewpoint of reducing the manufacturing cost of the optical laminate A, it is preferably 1.0×10 7 It is preferable that the resistance is Ω / □ or more, and 1.0×10 8 It is more preferable that the resistance is Ω / □ or more.

[0031] When the optical laminate A is used as an optical film (for example, an anti-reflection film, etc.) to be attached to the surface of an image display panel, the release liner is peeled off from the optical laminate A, and then the exposed pressure-sensitive adhesive layer is attached to the surface of the image display panel. During the manufacture of an image display device, the optical laminate A attached to the surface of the image display panel (specifically, the optical laminate A after the release liner is peeled off) usually has a surface protective film as the outermost layer of the optical laminate A. In this case, when checking the operability of the touch panel in the inspection process of the image display device, the surface of the surface protective film (the second main surface of the optical laminate A) is touched with a finger to check. At this time, if the surface resistivity of the second main surface of the optical laminate A becomes excessively low, it may become difficult to respond even when the screen (specifically, the second main surface of the optical laminate A) is touched with a finger. Hereinafter, when checking the operability of the touch panel, the phenomenon in which the screen does not respond or becomes difficult to respond even when touched with a finger may be referred to as a "touch panel sensor error".

[0032] In order to suppress the occurrence of touch panel sensor errors, the surface resistivity of the second main surface of the optical laminate A is 1.0 × 10 8 It is preferable that the resistance is Ω / □ or more, and 1.0×10 9 More preferably, it is 1.5×10 9 It is more preferable that the resistance is Ω / □ or more.

[0033] The surface resistivity of the first and second principal surfaces of the optical laminate A can be adjusted, for example, by antistatic treatment. Examples of the effective component of the treatment agent used in the antistatic treatment include one or more selected from the group consisting of antistatic agents and conductive polymers.

[0034] When an antistatic agent is used, the antistatic treatment is carried out, for example, by diluting the antistatic agent with a solvent (specifically, an organic solvent, water, etc.) as necessary, applying the antistatic agent to the treated surface (specifically, the surface of the release liner that is the first main surface of the optical laminate A, or the surface of the surface protection film that is the second main surface of the optical laminate A), and drying it. When treating with an antistatic agent, the surface resistivity of the treated surface can be adjusted by changing at least one of the type and amount of the antistatic agent used. Examples of the antistatic agent include quaternary ammonium cation-containing polymers, polyaniline sulfonic acid-based antistatic agents, and phosphate-based antistatic agents, and quaternary ammonium cation-containing polymers are preferred.

[0035] When a conductive polymer is used, the antistatic treatment is performed, for example, by applying a treatment agent containing a conductive polymer to a treated surface (specifically, the surface of the film substrate constituting the release liner or the surface of the film substrate constituting the surface protective film) and drying it. The surface of the conductive polymer-containing layer formed by this antistatic treatment becomes the first or second main surface of the optical laminate A. When treating with a treatment agent containing a conductive polymer, the surface resistivity of the first or second main surface of the optical laminate A can be adjusted by changing at least one of the type and amount of the conductive polymer used. In order to adjust the surface resistivity to the above-mentioned preferred range, the thickness of the conductive polymer-containing layer is preferably 1 nm or more and 100 nm or less, more preferably 3 nm or more and 50 nm or less.

[0036] Examples of the conductive polymer include polythiophene, polyaniline, polypyrrole, polyquinoxaline, polyacetylene, polyphenylenevinylene, polynaphthalene, and derivatives thereof. The conductive polymer is preferably one or more selected from the group consisting of polythiophene, polyaniline, and derivatives thereof, more preferably a polythiophene derivative, even more preferably a poly(3,4-disubstituted thiophene), even more preferably a poly(3,4-alkylenedioxythiophene), and particularly preferably a poly(3,4-ethylenedioxythiophene).

[0037] The conductive polymer may have a hydrophilic functional group, such as a sulfone group, an amino group, an amide group, an imino group, a hydroxyl group, a mercapto group, a hydrazino group, a carboxy group, a sulfate ester group, a phosphate ester group, a quaternary ammonium cation group, or a salt thereof (e.g., a quaternary ammonium base).

[0038] An example of the dopant for the conductive polymer is a polyanion. When the conductive polymer is polythiophene or a derivative thereof, the polyanion can form an ion pair with the polythiophene or a derivative thereof. The polyanion is not particularly limited, and examples thereof include carboxylic acid polymer compounds such as polyacrylic acid, polymaleic acid, and polymethacrylic acid; and sulfonic acid polymer compounds such as polystyrene sulfonic acid, polyvinyl sulfonic acid, and polyisoprene sulfonic acid. The polyanion may be a copolymer of a vinyl carboxylic acid monomer or a vinyl sulfonic acid monomer with another monomer. Examples of the other monomer include (meth)acrylic acid ester compounds and aromatic vinyl compounds (specifically, styrene, vinyl naphthalene, etc.). The polyanion is preferably polystyrene sulfonic acid.

[0039] The conductive polymer-containing treatment agent may contain components (other components) other than the conductive polymer and the dopant, such as a solvent (water, alcohol, etc.), a binder (polyester resin, etc.), a slipping agent (carnauba wax, etc.), a crosslinking agent (melamine-based crosslinking agent, etc.), a leveling agent, an antioxidant, an inorganic filler, an organic filler, etc.

[0040] Hereinafter, the optical laminate A will be described in detail with reference to the drawings as appropriate. Fig. 1 is a cross-sectional view showing an example of the optical laminate A (optical laminate 10).

[0041] The optical laminate 10 shown in Fig. 1 comprises, in this order, a release liner 11, a pressure-sensitive adhesive layer 12, a transparent film substrate 13, an antifouling layer 14, and a surface protective film 15. A main surface 11a of the release liner 11 opposite the pressure-sensitive adhesive layer 12 side is a first main surface 10a of the optical laminate 10. A main surface 15a of the surface protective film 15 opposite the antifouling layer 14 side is a second main surface 10b of the optical laminate 10. The surface resistivity of the first main surface 10a of the optical laminate 10 and the surface resistivity of the second main surface 10b of the optical laminate 10 are both 1.0 x 10 13 It is less than Ω / □.

[0042] The surface protective film 15 has a base material layer 16 and an adhesive layer 17 laminated on the antifouling layer 14 side of the base material layer 16. The surface protective film 15 is peelably attached to the antifouling layer 14 via the adhesive layer 17.

[0043] The transparent film substrate 13 includes a transparent film 18 and a hard coat layer 19 provided on a first main surface 18a side of the transparent film 18. A pressure-sensitive adhesive layer 12 is provided on a second main surface 18b side of the transparent film 18.

[0044] The optical laminate 10 also includes an antireflection layer 20 between the transparent film substrate 13 and the antifouling layer 14. Furthermore, the optical laminate 10 also includes a primer layer 25 between the transparent film substrate 13 and the antireflection layer 20. The optical laminate 10 functions as an antireflection film, for example, by being attached to the surface of an image display panel (not shown).

[0045] The antireflection layer 20 has four layers, namely, a high refractive index layer 21, a low refractive index layer 22, a high refractive index layer 23, and a low refractive index layer 24, in this order from the primer layer 25 side. Details of the high refractive index layer and the low refractive index layer will be described later. The antireflection layer is not limited to a four-layer structure like the antireflection layer 20, and may be a two-layer structure, a three-layer structure, a five-layer structure, or a stacked structure of six or more layers. The antireflection layer is preferably an alternating stack of two or more high refractive index layers and two or more low refractive index layers. In order to reduce reflection at the air interface, it is preferable that the outermost layer of the antireflection layer (the layer farthest from the primer layer) is a low refractive index layer.

[0046] In order to enhance the antifouling performance of the antifouling layer 14 during use of the optical laminate 10 (after peeling off the surface protective film 15 from the antifouling layer 14), the water contact angle of the main surface 14a of the antifouling layer 14 on the surface protective film 15 side is preferably 100° or more, more preferably 105° or more, even more preferably 110° or more, and even more preferably 115° or more, and may be 116° or more, 117° or more, or 118° or more. The method for measuring the water contact angle is the same as or similar to the measuring method in the examples described below. The water contact angle of the main surface 14a of the antifouling layer 14 on the surface protective film 15 side can be adjusted, for example, by changing at least one of the type of material constituting the antifouling layer 14 and the thickness of the antifouling layer 14.

[0047] As shown in FIG. 1, when the antifouling layer 14 and the surface protective film 15 are in contact with each other, if the water contact angle of the main surface 14a of the antifouling layer 14 on the surface protective film 15 side is 100° or more, the adhesion between the antifouling layer 14 and the surface protective film 15 is usually low, and pickup defects tend to occur easily. However, in this embodiment, as described above, the adhesion between the optical laminates tends to decrease, so that the occurrence of pickup defects can be suppressed even if the water contact angle of the main surface 14a of the antifouling layer 14 on the surface protective film 15 side is 100° or more, 105° or more, 110° or more, 115° or more, 116° or more, 117° or more, or 118° or more. In order to further suppress the occurrence of pickup defects, the water contact angle of the main surface 14a of the antifouling layer 14 on the surface protective film 15 side is preferably 125° or less, more preferably 120° or less.

[0048] In addition, as shown in FIG. 1, when the antifouling layer 14 and the surface protective film 15 are in contact with each other, if the adhesion strength between the antifouling layer 14 and the surface protective film 15 is small, pickup failures are likely to occur. However, in this embodiment, as described above, the adhesion between the optical laminates tends to decrease, so that even if the adhesion strength between the antifouling layer 14 and the surface protective film 15 is 0.07 N / 50 mm or less, 0.06 N / 50 mm or less, 0.05 N / 50 mm or less, 0.04 N / 50 mm or less, or 0.03 N / 50 mm or less, the occurrence of pickup failures can be suppressed. In order to further suppress the occurrence of pickup failures, it is preferable that the adhesion strength between the antifouling layer 14 and the surface protective film 15 is 0.01 N / 50 mm or more. The adhesion strength between the antifouling layer 14 and the surface protective film 15 can be adjusted, for example, by changing at least one of the type of material constituting the antifouling layer 14 and the thickness of the antifouling layer 14. The method for measuring the adhesion strength is the same as or a similar method to the measuring method in the examples described below.

[0049] In the example shown in Fig. 1, the transparent film substrate has a hard coat layer, but the transparent film substrate usable in the present invention is not limited to the above example. For example, the transparent film substrate usable in the present invention does not need to have a hard coat layer. When the transparent film substrate does not have a hard coat layer, for example, a transparent film (transparent film 18 in the example shown in Fig. 1) can be used as the transparent film substrate.

[0050] Next, each layer of the optical laminate 10 will be described in detail.

[0051] [Release Liner 11] The release liner 11 protects the surface of the adhesive layer 12 until, for example, the optical laminate 10 is bonded to an adherend (not shown). As a constituent material of the release liner 11, a plastic film formed from acrylic, polyolefin, cyclic polyolefin, polyester, or the like is preferably used. The release liner 11 may be a laminate of two or more layers. When the release liner 11 is a laminate of two or more layers, for example, the release liner 11 may be a laminate having a film substrate and the above-mentioned conductive polymer-containing layer. As a film substrate on which the conductive polymer-containing layer is provided, a plastic film made of the material exemplified as the constituent material of the release liner 11 is preferably used. The thickness of the release liner 11 is, for example, 5 μm or more and 200 μm or less. The main surface of the release liner 11 on the adhesive layer 12 side is preferably subjected to a release treatment. Examples of materials of the release treatment agent used in the release treatment include silicone-based materials, fluorine-based materials, long-chain alkyl-based materials, and fatty acid amide-based materials.

[0052] [Adhesive layer 12] The adhesive (pressure-sensitive adhesive) constituting the adhesive layer 12 is not particularly limited, and can be appropriately selected and used from transparent adhesives whose base polymer is, for example, an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyvinyl ether, a vinyl acetate-vinyl chloride copolymer, a modified polyolefin, an epoxy resin, a fluorine resin, a natural rubber, a synthetic rubber, etc. The thickness of the adhesive layer 12 is not particularly limited, but is preferably 5 μm or more and 100 μm or less from the viewpoint of achieving both a thin layer property and adhesiveness.

[0053] [Transparent film 18] The transparent film 18 is, for example, a transparent resin film having flexibility. Examples of materials constituting the transparent film 18 include polyester resin, polyolefin resin, polystyrene resin, acrylic resin, polycarbonate resin, polyethersulfone resin, polysulfone resin, polyamide resin, polyimide resin, cellulose resin, norbornene resin, polyarylate resin, and polyvinyl alcohol resin. Examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin resins include polyethylene, polypropylene, and cycloolefin polymer (COP). Examples of cellulose resins include triacetyl cellulose (TAC). These materials may be used alone or in combination of two or more. From the viewpoints of transparency and strength, the material of the transparent film 18 is preferably one selected from the group consisting of polyester resin, polyolefin resin, and cellulose resin, more preferably one selected from the group consisting of PET, COP, and TAC, and even more preferably TAC. In other words, as the transparent film 18, a type of film selected from the group consisting of polyester resin film, polyolefin resin film, and cellulose resin film is preferable, a type of film selected from the group consisting of PET film, COP film, and TAC film is more preferable, and a TAC film is even more preferable.

[0054] From the viewpoint of strength, the transparent film 18 has a thickness of preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. From the viewpoint of handleability, the transparent film 18 has a thickness of preferably 300 μm or less, and more preferably 200 μm or less.

[0055] One or both principal surfaces of the transparent film 18 may be subjected to a surface modification treatment. Examples of the surface modification treatment include corona treatment, plasma treatment, ozone treatment, primer treatment, glow treatment, and coupling agent treatment.

[0056] From the viewpoint of improving the transparency of the optical laminate 10, the transparent film 18 has a total light transmittance (JIS K 7375-2008) of preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more and 100% or less.

[0057] [Hard coat layer 19] The hard coat layer 19 is a layer that enhances mechanical properties such as hardness and elastic modulus of the optical laminate 10. The hard coat layer 19 is made of, for example, a cured product of a curable resin composition (composition for forming a hard coat layer). Examples of the curable resin contained in the curable resin composition include polyester resin, acrylic resin, urethane resin, urethane acrylate resin, amide resin, silicone resin, epoxy resin, and melamine resin. These curable resins may be used alone or in combination of two or more kinds. From the viewpoint of enhancing the hardness of the hard coat layer 19, the curable resin is preferably one or more kinds selected from the group consisting of acrylic resin and urethane acrylate resin, and more preferably urethane acrylate resin.

[0058] Examples of the curable resin composition include an ultraviolet-curable resin composition and a thermosetting resin composition. From the viewpoint of improving the productivity of the optical laminate 10, the curable resin composition is preferably an ultraviolet-curable resin composition. The ultraviolet-curable resin composition includes one or more selected from the group consisting of an ultraviolet-curable monomer, an ultraviolet-curable oligomer, and an ultraviolet-curable polymer. A specific example of the ultraviolet-curable resin composition is a composition for forming a hard coat layer described in JP 2016-179686 A.

[0059] The curable resin composition may also contain fine particles. By blending fine particles in the curable resin composition, it is possible to adjust the hardness, surface roughness, refractive index, and antiglare properties of the hard coat layer 19. Examples of the fine particles include metal (or semi-metal) oxide particles, glass particles, and organic particles. Examples of materials for the metal (or semi-metal) oxide particles include silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. Examples of materials for the organic particles include polymethyl methacrylate, polystyrene, polyurethane, acrylic-styrene copolymer, benzoguanamine, melamine, and polycarbonate.

[0060] The curable resin composition may contain particles having a number average primary particle diameter of less than 1.0 μm (hereinafter, may be referred to as "nanoparticles") as the fine particles. That is, the hard coat layer 19 may contain nanoparticles. When the hard coat layer 19 is made of a cured product of a curable resin composition containing nanoparticles, fine irregularities are formed on the surface of the hard coat layer 19, and the adhesion between the hard coat layer 19 and a layer (e.g., primer layer 25) formed thereon tends to be improved.

[0061] From the viewpoint of forming a fine uneven shape that contributes to improving adhesion, the number average primary particle diameter of the nanoparticles is preferably 20 nm or more and 80 nm or less, more preferably 25 nm or more and 70 nm or less, and even more preferably 30 nm or more and 60 nm or less.

[0062] As the material of the nanoparticles, inorganic oxides are preferred. Examples of inorganic oxides include oxides of metals (or semi-metals) such as silicon oxide (silica), titanium oxide, aluminum oxide, zirconium oxide, niobium oxide, zinc oxide, tin oxide, cerium oxide, and magnesium oxide. The inorganic oxide may be a composite oxide of a plurality of (semi-)metals. Among the inorganic oxides exemplified above, silicon oxide is preferred because of its high effect of improving adhesion. In other words, as the nanoparticles, silicon oxide particles (silica particles) are preferred. Functional groups such as acrylic groups and epoxy groups may be introduced to the surfaces of inorganic oxide particles as nanoparticles in order to improve adhesion and affinity with resins.

[0063] The amount of nanoparticles in the hard coat layer 19 is preferably 5 parts by weight or more, and may be 10 parts by weight or more, 20 parts by weight or more, or 30 parts by weight or more, relative to 100 parts by weight of the curable resin. If the amount of nanoparticles is 5 parts by weight or more, the adhesion with the layer formed on the hard coat layer 19 can be further improved. The upper limit of the amount of nanoparticles in the hard coat layer 19 is, for example, 90 parts by weight, preferably 80 parts by weight, and may be 70 parts by weight, relative to 100 parts by weight of the curable resin.

[0064] The thickness of the hard coat layer 19 is preferably 1 μm or more, more preferably 2 μm or more, from the viewpoint of increasing the hardness of the hard coat layer 19. The thickness of the hard coat layer 19 is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 35 μm or less, and even more preferably 30 μm or less, from the viewpoint of ensuring the flexibility of the optical laminate 10.

[0065] The main surface of the hard coat layer 19 opposite to the transparent film 18 side may be subjected to a surface modification treatment. Examples of the surface modification treatment include plasma treatment, corona treatment, ozone treatment, primer treatment, glow treatment, and coupling agent treatment. In order to increase the adhesion between the hard coat layer 19 and a layer (e.g., the primer layer 25 described later) provided on the side opposite to the transparent film 18 side of the hard coat layer 19, it is preferable that the main surface of the hard coat layer 19 opposite to the transparent film 18 side is subjected to plasma treatment.

[0066] (Method of forming hard coat layer 19) The hard coat layer 19 is formed, for example, by applying a curable resin composition (composition for forming a hard coat layer) to one main surface of the transparent film 18, and removing the solvent and curing the resin as necessary. The composition for forming a hard coat layer contains, for example, the above-mentioned curable resin and a polymerization initiator (e.g., a photopolymerization initiator), and contains, as necessary, a solvent capable of dissolving or dispersing these components.

[0067] In addition to the above components, the composition for forming a hard coat layer may contain additives such as nanoparticles, particles having a number-average primary particle diameter of 1.0 μm or more, leveling agents, viscosity modifiers (thixotropic agents, thickeners, etc.), antistatic agents, antiblocking agents, dispersants, dispersion stabilizers, antioxidants, UV absorbers, antifoaming agents, surfactants, and lubricants.

[0068] The coating method of the hard coat layer forming composition may be any suitable method such as bar coating, roll coating, gravure coating, rod coating, slot orifice coating, curtain coating, fountain coating, comma coating, etc. The drying temperature of the coating film after coating may be set to an appropriate temperature depending on the composition of the hard coat layer forming composition, for example, 50°C or higher and 150°C or lower. When the resin component in the hard coat layer forming composition is a thermosetting resin, the coating film is cured by heating. When the resin component in the hard coat layer forming composition is a photocurable resin, the coating film is cured by irradiating it with active energy rays such as ultraviolet rays. The integrated light amount of the irradiated light is preferably 100 mJ / cm. 2 More than 500mJ / cm 2 The following is the result.

[0069] [Primer layer 25] In order to increase the adhesion between the transparent film substrate 13 (hard coat layer 19) and the anti-reflection layer 20, it is preferable to provide a primer layer 25 between the transparent film substrate 13 and the anti-reflection layer 20. Examples of materials for the primer layer 25 include metals (or semi-metals) such as silicon, nickel, chromium, tin, gold, silver, platinum, zinc, titanium, indium, tungsten, aluminum, zirconium, and palladium; alloys of these metals (or semi-metals); and oxides, fluorides, sulfides, or nitrides of these metals (or semi-metals). The oxide constituting the primer layer 25 may be a composite oxide such as indium tin oxide (ITO). Among these, inorganic oxides are preferable as the material for the primer layer 25, silicon oxide, indium oxide, or ITO is more preferable, and SiOx (x<2) is even more preferable.

[0070] In order to ensure the light transmittance of the primer layer 25 while increasing the adhesion between the transparent film substrate 13 and the antireflection layer 20, the thickness of the primer layer 25 is preferably 0.5 nm or more and 20 nm or less, more preferably 0.5 nm or more and 10 nm or less, and even more preferably 1.0 nm or more and 10 nm or less.

[0071] (Method of forming primer layer 25) The method for forming (depositing) the primer layer 25 is not particularly limited, and may be either a wet coating method or a dry coating method. Dry coating methods such as vacuum deposition, CVD, and sputtering are preferred because they can form a thin film with a uniform thickness. From the viewpoint of increasing productivity, the method for depositing the primer layer 25 is preferably a method in which a film is deposited using a roll-to-roll sputtering deposition device (roll-to-roll sputtering method).

[0072] In the roll-to-roll sputtering method, for example, the primer layer 25 and the anti-reflection layer 20 can be continuously formed while transporting a long film (e.g., the transparent film substrate 13) in the longitudinal direction (MD direction). In the sputtering method, the film is formed while introducing an inert gas such as argon, and if necessary, a reactive gas such as oxygen, into the film formation chamber. When forming an oxide layer as the primer layer 25, the oxide layer can be formed by sputtering using either an oxide target or reactive sputtering using a metal (or semi-metal) target.

[0073] Examples of power sources for performing the sputtering method include DC power sources, AC power sources, RF power sources, and MFAC power sources (AC power sources with a frequency band of several kHz to several MHz). The power density when performing the sputtering method is, for example, 0.1 W / cm 2 More than 20W / cm 2 less than or equal to 1 W / cm 2 More than 15W / cm 2 The surface temperature of the film-forming roll when performing the sputtering method is, for example, from −25° C. to 25° C., and preferably from −20° C. to 0° C. The pressure in the film-forming chamber when performing the sputtering method is preferably from 0.01 Pa to 10 Pa, more preferably from 0.05 Pa to 5 Pa, and further preferably from 0.1 Pa to 1 Pa.

[0074] [Anti-reflection layer 20] The antireflection layer 20 is preferably made of two or more thin layers with different refractive indexes. In general, the optical film thickness (product of refractive index and thickness) of the thin film of the antireflection layer is adjusted so that the inverted phases of incident light and reflected light cancel each other out. By making the antireflection layer a multilayer laminate of two or more thin films with different refractive indexes, the reflectance can be reduced in a wide wavelength range of visible light.

[0075] Examples of the thin film material constituting the antireflection layer 20 include metal (or semi-metal) oxides, nitrides, fluorides, etc. The antireflection layer 20 is preferably an alternating laminate of high refractive index layers and low refractive index layers.

[0076] The high refractive index layer has a refractive index of, for example, 1.9 or more, preferably 2.0 or more. Examples of materials for the high refractive index layer include titanium oxide, niobium oxide (Nb2O5, etc.), zirconium oxide, tantalum oxide, zinc oxide, indium oxide, ITO, and antimony-doped tin oxide (ATO). Among these, at least one selected from the group consisting of titanium oxide and niobium oxide is preferred. The low refractive index layer has a refractive index of, for example, 1.6 or less, preferably 1.5 or less. Examples of materials for the low refractive index layer include silicon oxide (SiO2, etc.), titanium nitride, magnesium fluoride, barium fluoride, calcium fluoride, hafnium fluoride, and lanthanum fluoride. Among these, silicon oxide is preferred. In particular, it is preferred to alternately stack a niobium oxide thin film as the high refractive index layer and a silicon oxide thin film as the low refractive index layer. In addition to the low refractive index layer and the high refractive index layer, a medium refractive index layer having a refractive index of more than 1.6 and less than 1.9 may be provided.

[0077] The thickness of the high refractive index layer and the low refractive index layer is preferably 5 nm or more and 200 nm or less, and more preferably 10 nm or more and 150 nm or less. The thickness of each layer may be designed so that the reflectance of visible light is small according to the refractive index and the lamination structure. For example, the lamination structure of the high refractive index layer and the low refractive index layer may be a four-layer structure consisting of a high refractive index layer with an optical thickness of 20 nm or more and 55 nm or less, a low refractive index layer with an optical thickness of 25 nm or more and 55 nm or less, a high refractive index layer with an optical thickness of 80 nm or more and 250 nm or less, and a low refractive index layer with an optical thickness of 100 nm or more and 150 nm or less, from the hard coat layer 19 side.

[0078] When the antireflection layer 20 is a four-layer alternating laminate in which niobium oxide thin films as high refractive index layers and silicon oxide thin films as low refractive index layers are alternately laminated, the antireflection layer 20 can be configured to have, from the hard coat layer 19 side, a niobium oxide thin film with a thickness of 5 nm to 20 nm, a silicon oxide thin film with a thickness of 10 nm to 40 nm, a niobium oxide thin film with a thickness of 65 nm to 120 nm, and a silicon oxide thin film with a thickness of 60 nm to 100 nm, in this order.

[0079] In order to obtain an antireflection layer 20 having excellent bending resistance, the thickness of the antireflection layer 20 is preferably 140 nm or more and 280 nm or less, more preferably 170 nm or more and 280 nm or less, even more preferably 180 nm or more and 260 nm or less, and even more preferably 190 nm or more and 250 nm or less. In this specification, the "thickness of the antireflection layer" refers to the sum of the thicknesses of the layers constituting the antireflection layer (total thickness).

[0080] (Method of forming antireflection layer 20) The antireflection layer 20 is formed (deposited) on, for example, the primer layer 25 by a wet coating method or a dry coating method. Dry coating methods such as vacuum deposition, CVD, and sputtering are preferred because they can form a thin film with a uniform thickness. From the viewpoint of increasing productivity, a roll-to-roll sputtering method is preferred as a method for depositing the antireflection layer 20. When the sputtering method is employed, the deposition conditions can be appropriately set, for example, among the conditions explained above (Method for forming the primer layer 25).

[0081] [Anti-stain layer 14] The antifouling layer 14 is provided for the purpose of preventing contamination from the external environment and facilitating the removal of attached contaminants. In order to suppress a decrease in the antireflection performance of the antireflection layer 20, it is preferable that the antifouling layer 14 has a small difference in refractive index from the outermost layer (e.g., a silicon oxide layer) of the antireflection layer 20. The refractive index of the antifouling layer 14 is preferably 1.6 or less, more preferably 1.55 or less.

[0082] The antifouling layer 14 contains, for example, a fluorine-containing compound having an end structure represented by the chemical formula CF3O- (more specifically, CF3-O-). A fluorine-containing compound having an end structure represented by the chemical formula CF3O- can contribute to a lower refractive index while having excellent antifouling properties. Among them, an alkoxysilane compound containing a perfluoropolyether skeleton is preferred as the fluorine-containing compound because it has excellent water repellency and can exhibit high antifouling properties. Examples of alkoxysilane compounds containing a perfluoropolyether skeleton include compounds represented by the following general formula: CF3-(OCF2) m -(OC2F4) n -O-(CH2)3-Si(OCH3)3

[0083] In the above general formula, m represents an integer of 1 or more and 51 or less, and n represents an integer of 1 or more and 50 or less.

[0084] The fluorine-containing compound having a terminal structure represented by the chemical formula CFO- may be used alone or in combination of two or more. When the alkoxysilane compound is used as the fluorine-containing compound, the alkoxysilane compound may be present in the antifouling layer 14 in a state in which the terminal alkoxy group is reacted (crosslinked).

[0085] The thickness of the antifouling layer 14 is, for example, 2 nm or more and 50 nm or less. The thicker the antifouling layer 14, the more improved the antifouling properties tend to be. The thickness of the antifouling layer 14 is preferably 5 nm or more, more preferably 6 nm or more, and even more preferably 7 nm or more. On the other hand, in order to further suppress the reflection of external light, the thickness of the antifouling layer 14 is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 15 nm or less.

[0086] (Method of forming antifouling layer 14) The antifouling layer 14 is formed, for example, on the antireflection layer 20 by a wet coating method or a dry coating method. When a fluorine-containing compound is used as a material, in order to form a uniform film of the fluorine-containing compound, it is preferable to form the antifouling layer 14 by a dry coating method. Examples of the dry coating method include a vacuum deposition method, a sputtering method, and a CVD method, and the vacuum deposition method is preferable.

[0087] [Base material layer 16] The substrate layer 16 is formed of, for example, any suitable film. Examples of the constituent material of the film include polyester resins such as polyethylene terephthalate resins, polycycloolefin resins such as polynorbornene resins, polyolefin resins such as polypropylene, polyamide resins, polycarbonate resins, and copolymer resins thereof. In order to increase the hardness of the substrate layer 16, polyester resins are preferred as the constituent material of the substrate layer 16. The thickness of the substrate layer 16 is, for example, 10 μm or more and 200 μm or less, and preferably 20 μm or more and 150 μm or less. The substrate layer 16 may be a laminate of two or more layers. When the substrate layer 16 is a laminate of two or more layers, for example, the substrate layer 16 may be a laminate having a film substrate and the above-mentioned conductive polymer-containing layer. As the film substrate on which the conductive polymer-containing layer is provided, a film made of the material exemplified as the constituent material of the substrate layer 16 is preferably used.

[0088] [Adhesive layer 17] The adhesive layer 17 is formed of, for example, any appropriate adhesive. Examples of the adhesive include (meth)acrylic adhesives, urethane adhesives, silicone adhesives, etc. The thickness of the adhesive layer 17 is, for example, 1 μm or more and 40 μm or less, and preferably 2 μm or more and 30 μm or less.

[0089] In order to improve the transportability of the optical laminate 10, the total thickness of the base layer 16 and the adhesive layer 17 (the thickness of the surface protective film 15) is preferably 15 μm or more and 150 μm or less, and more preferably 20 μm or more and 100 μm or less.

[0090] [Preferable embodiment of optical laminate A] In this embodiment, in order to reduce production costs while suppressing the occurrence of pickup failures and touch panel sensor errors, it is preferable that the optical laminate A satisfies the following condition 1. Furthermore, in this embodiment, in order to reduce production costs while suppressing the occurrence of pickup failures and touch panel sensor errors and to enhance the antifouling performance of the antifouling layer, it is preferable that the optical laminate A satisfies the following condition 2, and more preferably satisfies the following condition 3. Condition 1: The surface resistivity of the first main surface of the optical laminate A is 1.0 × 10 7 Ω / □ or more 1.0×10 13 Ω / □ or less, and the surface resistivity of the second main surface of the optical laminate A is 1.0×10 8 Ω / □ or more 1.0×10 13 It is less than Ω / □. Condition 2: The above condition 1 is satisfied, and the antifouling layer and the surface protective film are in contact with each other, and the water contact angle of the main surface of the antifouling layer facing the surface protective film is 100° or more. Requirement 3: The above Requirement 2 is satisfied, and the water contact angle of the main surface of the antifouling layer on the surface protection film side is 125° or less.

[0091] [Other embodiments] Although the optical laminate with a surface protective film according to the present embodiment has been described above, the present invention is not limited to the above-mentioned embodiment. For example, the optical laminate with a surface protective film according to the present invention may not include a primer layer and an antireflection layer. In addition, the optical laminate with a surface protective film according to the present invention may include an optical functional layer different from the layer included in the above-mentioned configuration.

[0092] In the optical laminate with a surface protective film according to the present invention, the surface protective film may be composed of only one layer (base layer). The surface protective film composed of only the base layer has, for example, one main surface having adhesiveness. EXAMPLES

[0093] Examples of the present invention will be described below, but the present invention is not limited to the following examples.

[0094] <Preparation of optical laminate of Example 1> Hereinafter, there will be described a method for producing the optical laminate of Example 1. First, a method for producing the antireflection film will be described.

[0095] [Preparation of anti-reflective film] (Hard coat layer forming process) A photopolymerization initiator (IGM Resins' "Omnirad907") and a leveling agent (DIC's "GRANDIC PC4100") were added to a butyl acetate solution of ultraviolet-curable urethane acrylate (DIC's "Luxidia 17-806", solid content concentration: 80% by weight). The amounts of the photopolymerization initiator and the leveling agent added were 2.4 parts by weight and 0.1 parts by weight, respectively, relative to 100 parts by weight of the solid content in the butyl acetate solution of the urethane acrylate. The resulting mixture was diluted with a 1-methoxy-2-propanol / cyclopentanone mixed solvent (weight ratio 65 / 35) to obtain a hard coat layer forming composition H1 with a solid content concentration of 36% by weight. Next, the hard coat layer forming composition H1 was applied to one main surface of a TAC film (Konica Minolta's "KC8UA", thickness: 80 μm) as a transparent film using a Comma Coater (registered trademark) to form a coating film. Next, the coating film was dried by heating at a temperature of 80° C. for 60 seconds, and then cured by ultraviolet irradiation. When irradiating with ultraviolet light, a high-pressure mercury lamp was used as the light source, ultraviolet light with a wavelength of 365 nm was used, and the cumulative light amount was 300 mJ / cm 2 . 2 This resulted in a transparent film substrate having a TAC film and a hard coat layer (thickness: 6 μm).

[0096] (Surface modification process of hard coat layer) Next, the surface of the hard coat layer was plasma-treated using a roll-to-roll plasma treatment device while transporting the TAC film (transparent film substrate) on which the hard coat layer was formed, in a vacuum atmosphere of 0.5 Pa. During the plasma treatment, argon gas was used as the inert gas, and the effective power density was 0.02 W·min / cm. 2·m. As a result, a laminate (hereinafter, sometimes referred to as "optical film F1") including a TAC film and a plasma-treated hard coat layer was obtained. The effective power density is the power density of the plasma output (W / cm 2 ) divided by the film transport speed (m / min) when using the roll-to-roll method.

[0097] Next, the primer layer forming process and the anti-reflection layer forming process will be described. In the primer layer forming process and the anti-reflection layer forming process, when forming the oxide film, the film was formed while introducing argon gas and oxygen gas into the film forming chamber. When forming the oxide film, the pressure was kept constant by adjusting the amount of argon gas introduced and exhausted, and the amount of oxygen gas introduced was adjusted by plasma emission monitoring (PEM) control so that the film formation mode was maintained in the transition region.

[0098] (Primer layer formation process) The optical film F1 obtained by the above procedure was introduced into a roll-to-roll sputtering deposition apparatus, and the deposition chamber was filled with 1×10 -4 The pressure was reduced to 1 Pa. Next, while conveying the optical film F1, the surface temperature of the film-forming roll was set to -8°C, and a SiOx layer (x<2) having a thickness of 3 nm was formed (deposited) as a primer layer on one main surface of the hard coat layer by a reactive sputtering method. A Si target was used as the target material for forming the primer layer.

[0099] (Anti-reflection layer formation process) Following the formation of the primer layer, a roll-to-roll sputtering deposition apparatus was used to transport the optical film F1 after the formation of the primer layer, while a reactive sputtering method was used to deposit the following layers on one main surface of the primer layer in this order: a first layer: a niobium oxide layer having a thickness of 10.1 nm (refractive index: 2.33), a second layer: a silicon oxide layer having a thickness of 27.5 nm (refractive index: 1.46), a third layer: a niobium oxide layer having a thickness of 105.0 nm, and a fourth layer: a silicon oxide layer having a thickness of 83.5 nm. As a result, an antireflection layer having a four-layer structure (a four-layer structure consisting of a first layer, a second layer, a third layer, and a fourth layer) was formed on one main surface of the primer layer.

[0100] (Anti-stain layer formation process) A coating agent ("SHIN-ETSU SUBELYN KY1903-1" manufactured by Shin-Etsu Chemical Co., Ltd., active ingredient: alkoxysilane compound containing a perfluoropolyether skeleton) was dried and solidified and used as a deposition source, and an antifouling layer having a thickness of 8 nm was formed on the antireflection layer by vacuum deposition at a heating temperature of the deposition source of 260° C. This resulted in an antireflection film AR1 having a TAC film, a hard coat layer, a primer layer, an antireflection layer, and an antifouling layer in this order.

[0101] [Preparation of surface protection film] (Preparation process of conductive polymer-containing treatment agent) First, an aqueous solution containing 0.5% by weight of poly(3,4-ethylenedioxythiophene) as a conductive polymer and 0.8% by weight of polystyrene sulfonic acid (number average molecular weight: 150,000) ("Clevios P" manufactured by Heraeus, hereinafter referred to as "conductive polymer aqueous solution CA1") was prepared. In addition, an aqueous dispersion containing 25% by weight of saturated copolymer polyester resin as a binder ("Binalol MD-1480" manufactured by Toyobo, hereinafter referred to as "binder dispersion BD1") was prepared. In addition, an aqueous dispersion containing 8.0% by weight of carnauba wax as a slipping agent (hereinafter referred to as "slipping agent dispersion SD1") was prepared. Then, 100 parts by weight of the binder dispersion BD1 in terms of solid content, 40 parts by weight of the slippage-imparting agent dispersion SD1 in terms of solid content, 50 parts by weight of the conductive polymer aqueous solution CA1 in terms of solid content, and 10 parts by weight of a melamine-based crosslinking agent were added to a mixed solvent containing water and ethanol in a volume ratio of 1:1, and the mixture was stirred for 20 minutes to prepare a conductive polymer-containing treatment agent CP1 with a solid content concentration of 0.3% by weight.

[0102] (Base layer forming process) Conductive polymer-containing treatment agent CP1 was applied to one side of a 38 μm-thick PET film using a bar coater, and the conductive polymer-containing treatment agent CP1 was dried by heating for 30 seconds at a temperature of 130° C. As a result, a conductive polymer-containing layer with a thickness of 40 nm was formed on one side of the PET film, and a two-layered substrate layer was obtained in which the conductive polymer-containing layer was laminated on the PET film.

[0103] (Adhesive layer forming process) First, a pressure-sensitive adhesive composition PS1 was prepared. In detail, 96 parts by weight of 2-ethylhexyl acrylate, 4 parts by weight of hydroxyethyl acrylate, 0.2 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 150 parts by weight of ethyl acetate were placed in a reaction vessel equipped with a thermometer, a stirrer, a cooler, and a nitrogen gas inlet tube, and nitrogen substitution was performed by introducing nitrogen gas while stirring the contents of the vessel while maintaining the temperature at 23°C. Thereafter, a polymerization reaction was performed for 6 hours while maintaining the temperature of the contents of the vessel at 65°C, to obtain an acrylic polymer solution (concentration: 40% by weight). To 250 parts by weight of the obtained acrylic polymer solution, 73 parts by weight of toluene and 10 parts by weight of acetylacetone were added, and further 5.3 parts by weight of an ethyl acetate solution containing 75% by weight of a tolylene diisocyanate trimer adduct of trimethylolpropane ("Coronate L" manufactured by Tosoh Corporation) and 4 parts by weight of a solution containing 0.5% by weight of a dioctyltin dilaurate catalyst ("Envirizer OL-1" manufactured by Tokyo Fine Chemical Co., Ltd.) were added and stirred to obtain adhesive composition PS1.

[0104] Next, the adhesive composition PS1 was applied to one side of the PET film of the above-mentioned base layer (specifically, the main surface of the PET film opposite to the conductive polymer-containing layer side), and the adhesive composition PS1 was dried by heating at a temperature of 130° C. for 2 minutes. As a result, an adhesive layer having a thickness of 23 μm was formed on one side of the PET film, and a surface protection film SP1 was obtained. Then, in order to protect the adhesive layer, a release-treated surface of a release-treated film having a thickness of 38 μm ("MRF38" manufactured by Mitsubishi Chemical Corporation, a PET film with one side release-treated) was attached to the exposed surface of the adhesive layer.

[0105] [Preparation of release liner] (Conductive polymer-containing layer forming step) The conductive polymer-containing treatment agent CP1 was applied to one side of a PET film having a thickness of 75 μm using a bar coater, and the conductive polymer-containing treatment agent CP1 was dried by heating for 30 seconds at a temperature of 130° C. As a result, a conductive polymer-containing layer having a thickness of 45 nm was formed on one side of the PET film, and a laminate L1 in which the conductive polymer-containing layer was laminated on the PET film was obtained.

[0106] (Release treatment process) First, release treatment agent RP1 was prepared. In detail, 30 parts by weight of a non-fluorine-based addition type silicone composition containing a polyorganosiloxane having a hexenyl group ("LTC761" manufactured by DuPont-Toray Specialty Materials Co., Ltd.), 0.9 parts by weight of a silicone dispersion ("BY 24-850" manufactured by DuPont-Toray Specialty Materials Co., Ltd.), and 2 parts by weight of a platinum catalyst for silicone curing ("SRX 212" manufactured by DuPont-Toray Specialty Materials Co., Ltd.) were diluted with a mixed solvent containing toluene and hexane in a volume ratio of 1:1 to prepare release treatment agent RP1 with a silicone concentration of 1% by weight.

[0107] Next, a release treatment agent RP1 was applied to the main surface of the laminate L1 opposite to the conductive polymer-containing layer side with a bar coater, and the release treatment agent RP1 was dried by heating at a temperature of 130° C. for 1 minute. In this way, one main surface of the laminate L1 was release-treated, and a release liner RL1 was obtained.

[0108] [Preparation of release liner with adhesive layer] (Preparation process of pressure-sensitive adhesive composition) A monomer mixture of 60 parts by weight of butyl acrylate, 6 parts by weight of cyclohexyl acrylate, 26 parts by weight of 4-hydroxybutyl acrylate, and 8 parts by weight of hydroxyethyl acrylate was added to a four-neck flask, and then 0.09 parts by weight of 2,2-dimethoxy-2-phenylacetophenone (IGM Resins' "Omnirad651") and 0.09 parts by weight of 1-hydroxycyclohexyl-phenyl ketone (IGM Resins' "Omnirad184") were added to the four-neck flask. The contents of the flask were irradiated with ultraviolet light under a nitrogen atmosphere to partially photopolymerize, thereby obtaining a partially polymerized product (monomer syrup) with a polymerization rate of 10%. To 100 parts by weight of this partial polymer, 0.12 parts by weight of dipentaerythritol hexaacrylate ("KAYARAD DPHA" manufactured by Nippon Kayaku Co., Ltd.) as a multifunctional polymerizable compound and 0.3 parts by weight of 3-glycidoxypropyltrimethoxysilane ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) were added and mixed to obtain adhesive composition PS2.

[0109] (Step of forming adhesive layer) The release-treated surface of the release liner RL1 was coated with the pressure-sensitive adhesive composition PS2 to form a coating layer made of the pressure-sensitive adhesive composition PS2, and then the release-treated surface of a 38 μm-thick release-treated film ("MRF38" manufactured by Mitsubishi Chemical Corporation) was attached to the coating layer. Then, the coating layer was irradiated with a black light at an irradiation intensity of 5 mW / cm. 2 And the cumulative light intensity is 3600mJ / cm 2 By irradiating ultraviolet rays under the conditions above, a release liner with an adhesive layer PRL1 having a release liner RL1, an adhesive layer, and a release treated film in this order was obtained. The thickness of the adhesive layer in the release liner with an adhesive layer PRL1 was 25 μm.

[0110] [Lamination of surface protection film and release liner] After peeling off the release-treated film ("Mitsubishi Chemical Corporation's MRF38") from the surface protective film SP1, the adhesive layer of the surface protective film SP1 was attached to the antifouling layer surface of the antireflection film AR1 using a roll laminator. Next, after peeling off the release-treated film ("Mitsubishi Chemical Corporation's MRF38") from the adhesive layer of the release liner PRL1 with adhesive layer, the exposed surface of the adhesive layer was attached to the main surface (main surface of the TAC film) of the antireflection film AR1 opposite to the surface protective film SP1 side using a roll laminator, to obtain the optical laminate of Example 1.

[0111] <Preparation of optical laminate of Example 2> Except for using release liner RL2 instead of release liner RL1, an optical laminate of Example 2 was obtained in the same manner as in Example 1. Release liner RL2 was prepared in the same manner as release liner RL1, except for changing the thickness of the conductive polymer-containing layer to 10 nm.

[0112] <Preparation of optical laminate of Example 3> The optical laminate of Example 3 was obtained in the same manner as in Example 1, except that the surface protective film SP2 was used instead of the surface protective film SP1. The surface protective film SP2 was prepared in the same manner as the surface protective film SP1, except that the conductive polymer-containing treatment agent CP2 was used instead of the conductive polymer-containing treatment agent CP1, and the thickness of the conductive polymer-containing layer was changed to 30 nm. The conductive polymer-containing treatment agent CP2 was prepared in the same manner as the conductive polymer-containing treatment agent CP1, except that the amount of the conductive polymer aqueous solution CA1 added was changed to 80 parts by weight in terms of solid content.

[0113] <Preparation of optical laminate of Example 4> Except for using the surface protective film SP3 instead of the surface protective film SP1, the optical laminate of Example 4 was obtained in the same manner as in Example 1. The surface protective film SP3 was produced in the same manner as the surface protective film SP1, except for changing the thickness of the conductive polymer-containing layer to 10 nm.

[0114] <Preparation of Optical Laminate of Comparative Example 1> Except for using release liner RL3 instead of release liner RL1, an optical laminate of Comparative Example 1 was obtained in the same manner as in Example 1. Release liner RL3 was prepared in the same manner as release liner RL1, except that the conductive polymer-containing layer was not provided.

[0115] <Preparation of Optical Laminate of Comparative Example 2> Except for using release liner RL4 instead of release liner RL1, an optical laminate of Comparative Example 2 was obtained in the same manner as in Example 1. Release liner RL4 was prepared in the same manner as release liner RL1, except for changing the thickness of the conductive polymer-containing layer to 5 nm.

[0116] <Preparation of Optical Laminate of Reference Example 1> An optical laminate of Reference Example 1 was obtained in the same manner as in Example 1, except that the primer layer, antireflection layer, and antifouling layer were not formed, and a surface protective film SP1 was attached to the hard coat layer side of the optical film F1.

[0117] <Measurement and evaluation methods> The methods for measuring and evaluating the physical properties of each optical laminate will be described below. In the following description of Reference Example 1, the term "antifouling layer" will be read as "hard coat layer."

[0118] [Water contact angle] First, 5.0 μL of water was dropped onto the surface of the antifouling layer (the main surface to which the surface protective film was to be attached) of each optical laminate before laminating the surface protective film using a contact angle measuring device ("DMo-701" manufactured by Kyowa Interface Science Co., Ltd.) Then, 2 seconds after the dropping, the angle between the antifouling layer surface and the tangent line of the droplet end was measured.

[0119] [Adhesion strength] Each optical laminate was cut to a width of 50 mm and a length of 100 mm, and left to stand for 30 minutes under standard conditions, after which the release liner was peeled off and the exposed adhesive layer was attached to an acrylic plate to obtain a measurement sample. Next, the surface protection film at one end of the measurement sample in the longitudinal direction was peeled off and a peel test was performed under conditions of a peel angle of 180° and a tensile speed of 0.3 m / min, and the obtained peel strength was taken as the adhesion strength (unit: N / 50 mm).

[0120] [Surface resistivity] Under standard conditions, a resistivity meter ("Hiresta UP MCP-HT450" manufactured by Nitto Seiko Analytech Co., Ltd.) was used to measure the surface resistivity by contacting the measuring terminal with the surface of the release liner or surface protection film of each optical laminate (the first or second main surface of the optical laminate) under conditions of an applied voltage of 10 V and a voltage application time of 30 seconds. If measurement was not possible with an applied voltage of 10 V, the applied voltage was changed to 100 V and the surface resistivity was measured.

[0121] [Pickup ability] First, for each of the optical laminates of Examples 1 to 4, Comparative Example 1, Comparative Example 2, and Reference Example 1, two samples cut to 15 cm x 30 cm were prepared. Next, two samples (specifically, any of the optical laminates of Examples 1 to 4, Comparative Example 1, Comparative Example 2, and Reference Example 1) were stacked as shown in FIG. 2. Hereinafter, in FIG. 2, the optical laminate located at the top is referred to as "optical laminate A1", and the optical laminate located at the bottom is referred to as "optical laminate A2". When the optical laminate A1 and the optical laminate A2 were stacked, the first main surface A1a of the optical laminate A1 and the first main surface A2a of the optical laminate A2 were stacked so that they were both surfaces of the release liner. Therefore, the second main surface A1b of the optical laminate A1 and the second main surface A2b of the optical laminate A2 were both surfaces of the surface protection film.

[0122] Next, double-sided tape (not shown) was attached to the index fingers of both hands, and the exposed surfaces of the double-sided tape were then attached to both ends of the optical laminate A1. Next, the pickup properties when both ends of the optical laminate A1 were lifted up were evaluated according to the following criteria.

[0123] (Criteria for judging pick-up ability) A: The adhesion between the release liner of the optical laminate A1 and the surface protective film of the optical laminate A2 is low, and only the optical laminate A1 can be lifted up. B: Both the optical laminate A1 and the optical laminate A2 are lifted, or the surface protective film is peeled off from the antifouling layer of the optical laminate A2.

[0124] When the evaluation result of the pickup property was A, it was evaluated as "excellent pickup property, and pickup failure occurrence could be suppressed." On the other hand, when the evaluation result of the pickup property was B, it was evaluated as "not excellent pickup property, and pickup failure occurrence could not be suppressed."

[0125] [Touch operability] After peeling off the release liner from each optical laminate, the exposed pressure-sensitive adhesive layer was attached to the screen of an "iPad (registered trademark) Air" manufactured by Apple Inc. to obtain an evaluation sample. Next, the surface of the surface protection film of the evaluation sample was touched to evaluate the touch operability according to the following criteria.

[0126] (Touch operability criteria) A: Touch operation is smooth. B: Touch operations are not detected (touch operations are not possible).

[0127] When the evaluation result for touch operability was A, it was evaluated as "excellent touch operability, and the occurrence of touch panel sensor errors was suppressed." On the other hand, when the evaluation result for touch operability was B, it was evaluated as "not excellent touch operability, and the occurrence of touch panel sensor errors was not suppressed."

[0128] <Result> Table 1 shows the water contact angle, adhesion strength, details of the release liner used, details of the surface protection film used, evaluation results of the pick-up property, and evaluation results of the touch operability for the optical laminates of Examples 1 to 4, Comparative Example 1, Comparative Example 2, and Reference Example 1. In Table 1, "-" indicates that the surface resistivity is 1.00×10 14This means that it exceeds Ω / □.

[0129] [Table 1]

[0130] As shown in Table 1, in Examples 1 to 4, the surface resistivity of the first and second main surfaces of the optical laminate was 1.0×10 13 The pickup performance was rated as A in Examples 1 to 4. Therefore, the optical laminates of Examples 1 to 4 were excellent in pickup performance and were able to suppress the occurrence of pickup failure.

[0131] As shown in Table 1, in Comparative Examples 1 and 2, the surface resistivity of the first main surface of the optical laminate was 1.0×10 13 The pickup property was evaluated as B in Comparative Examples 1 and 2. Thus, the optical laminates in Comparative Examples 1 and 2 did not have excellent pickup property, and the occurrence of pickup failures could not be suppressed.

[0132] The above results demonstrate that the present invention can provide an optical laminate with a surface protective film capable of suppressing the occurrence of pickup defects. [Explanation of symbols]

[0133] 10: Optical laminate 11: Release liner 12: Adhesive layer 13: Transparent film base 14: Antifouling layer 15: Surface protection film 18: Transparent film 19: Hard coat layer 20: Anti-reflection layer 25: Primer layer

Claims

1. An optical laminate with a surface protective film, comprising a release liner, a pressure-sensitive adhesive layer, a transparent film substrate, an antifouling layer, and a surface protective film in this order, a main surface of the release liner opposite to the pressure-sensitive adhesive layer is a first main surface of the optical laminate with a surface protective film, a main surface of the surface protective film opposite to the antifouling layer side is a second main surface of the optical laminate with the surface protective film, The surface resistivity of the first main surface and the second main surface of the optical laminate with a surface protective film is 1.0×10 １３ An optical laminate with a surface protective film having a surface resistivity of Ω / □ or less.

2. the antifouling layer and the surface protective film are in contact with each other, 2. The optical laminate with a surface protective film according to claim 1, wherein a water contact angle of the main surface of the antifouling layer on the surface protective film side is 100° or more.

3. the antifouling layer and the surface protective film are in contact with each other, 2. The optical laminate with a surface protective film according to claim 1, wherein the adhesion strength between the antifouling layer and the surface protective film is 0.07 N / 50 mm or less.

4. The surface resistivity of the second main surface of the optical laminate with a surface protective film is 1.0×10 ８ The optical laminate with a surface protective film according to claim 1 , wherein the surface resistivity is Ω / □ or more.

5. The transparent film substrate includes a transparent film and a hard coat layer provided on a first main surface side of the transparent film, The optical laminate with a surface protective film according to claim 1 , wherein the pressure-sensitive adhesive layer is provided on a second main surface side of the transparent film.

6. The optical laminate with a surface protective film according to claim 1 , further comprising an antireflection layer provided between the transparent film substrate and the antifouling layer.

7. The optical laminate with a surface protective film according to claim 6 , further comprising a primer layer provided between the transparent film substrate and the antireflection layer.

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