Optical member bonding adhesive sheet with release film, method for producing laminate for image display device, and image display device

Abstract

The present invention provides an optical member bonding adhesive sheet with a release film in which, even if a renewable raw material is used, haze is further suppressed as compared to a single petrochemical raw material and which has excellent recyclability.　Provided is an optical member bonding adhesive sheet with a release film comprising: a release film (Y1) which is laminated on a first surface of an adhesive sheet that has an adhesive layer (X); and a release film (Y2) which is laminated on a second surface of the adhesive sheet, wherein the release film (Y1) and the release film (Y2) are each a polyester film which has a release layer, and the polyester film has a haze of 2% or less and contains a renewable raw material.

Description

Adhesive sheet for bonding optical components with release film, method for manufacturing a laminate for an image display device, and image display device

[0001] The present invention relates to an adhesive sheet for bonding optical components with a release film, a method for manufacturing a laminate for an image display device, and an image display device.

[0002] Polyester films offer excellent transparency, dimensional stability, mechanical properties, heat resistance, and electrical properties. For example, release films made from biaxially oriented polyester film with a release layer primarily composed of silicone resin are used in many fields.

[0003] Common applications of release films include, for example, the bonding of a release film to an adhesive layer, such as an adhesive film formed by laminating an adhesive layer onto a substrate, or to an adhesive layer without a substrate, in order to protect the adhesive layer.

[0004] For example, Patent Document 1 describes an adhesive sheet in which an adhesive composition is applied to a release film to form an adhesive layer, and then a release film is laminated to the surface of the other adhesive layer, in order to obtain an adhesive sheet with excellent reworkability, step absorption, and corrosion resistance. When using the adhesive sheet, the release film is usually peeled off. Therefore, since the release film is often discarded after peeling, there is a need for the reuse of the release film from the viewpoint of reducing the environmental burden. Accordingly, Patent Document 2 discloses a polyester film made from recycled materials.

[0005] Japanese Patent Publication No. 2013-173912 Japanese Patent Publication No. 2024-129245

[0006] According to the inventors' research, the technology disclosed in Patent Document 2 above can reduce environmental impact by using recycled materials. However, polyester film scraps and waste materials are generally coated with various functional coatings, and it has been found that the polyester film containing recycled materials has high haze and a yellowish color due to the functional coating components.

[0007] Therefore, against this background, the present invention provides an adhesive sheet for laminating optical components with a release film that suppresses haze more effectively than petrochemical raw material-only systems, even when using recycled raw materials, and exhibits superior recyclability.

[0008] However, in view of these circumstances, the inventors have conducted extensive research and have found that by including a polyester film in the release film of an adhesive sheet for laminating optical components with a release film, which has a haze value below a specific value and contains recycled raw materials, the haze can be suppressed compared to a petrochemical raw material-only system, resulting in an adhesive sheet for laminating optical components with a release film that is highly recyclable.

[0009] In other words, the present invention has the following embodiments: [1] An adhesive sheet for laminating optical members with a release film, comprising a release film (Y1) laminated on a first surface of an adhesive sheet having an adhesive layer (X), and a release film (Y2) laminated on a second surface of the adhesive sheet, wherein the release film (Y1) and the release film (Y2) are each polyester films having a release layer, and the polyester film is a polyester film with a haze of 2% or less and containing recycled raw materials. [2] The adhesive sheet for laminating optical members with a release film according to [1], wherein the peeling force (F1) when peeling the release film (Y1) from the adhesive sheet and the peeling force (F2) when peeling the release film (Y2) from the adhesive sheet have the relationship of the following formula (1). F1 < F2 ... (1) [3] The adhesive sheet for bonding optical members with a release film according to [1] or [2], wherein the average surface roughness (Sa1) of the surface of the adhesive sheet after peeling off the release film (Y1) and the average surface roughness (Sa2) of the surface of the adhesive sheet after peeling off the release film (Y2) are related by the following formula (2). Sa1 > Sa2 ... (2) [4] The adhesive sheet for bonding optical members with a release film according to any one of [1] to [3], wherein the haze (h1) of the polyester film (y1) constituting the release film (Y1) and the haze (h2) of the polyester film (y2) constituting the release film (Y2) are related by the following formula (3). h1 > h2 ... (3) [5] The adhesive sheet for bonding optical components with a release film as described in [4], wherein the color (y value) of the polyester films (y1) and (y2) measured by the method described below is 0.330 or less. <Measurement method: Color (y value (reflection method))> The color (y value) of the polyester films (y1) and (y2) is determined using a spectrophotometer as follows. The polyester films (y1) and (y2) are punched out with a round holder blade of approximately φ60 mm and sampled. The number of test sheets is the number of sheets that is closest to a stack thickness (total thickness at the time of measurement) of 500 μm. For example, in the case of a 25 μm film, 20 films should be stacked, and in the case of a 38 μm film, 13 films should be stacked.The measurement conditions shall be reflective conditions. The color (y value) shall be measured in an environment of 23°C. [6] The GHG emission coefficient of the polyester films (y1) and (y2) shall be 7 kg_CO. ２Adhesive sheet for laminating optical components with a release film according to [4] or [5], wherein the polyester film (y1) and (y2) comprises recycled raw materials obtained from the steps of: crushing a polyester film having a functional layer into chips using a crusher; putting the chips into a container of a chip washing device, adding hot water and an alkaline agent, and washing them while stirring to adjust to a desired internal temperature and washing time; and after the washing process, draining the liquid, rinsing with water, and then dewatering / drying the removed chips. Adhesive sheet for laminating optical components with a release film according to any one of [4] to [6], wherein the haze of the adhesive sheet for laminating optical components with a release film, as measured by the following measurement method, is 3% or less. <Measurement method> Measured using a haze meter in accordance with JIS K 7136:2000. [9] The adhesive sheet for laminating optical components with a release film according to any one of [1] to [8], wherein the color (y value) of the adhesive sheet for laminating optical components with a release film, as measured by the measurement method described below, is 0.350 or less. <Measurement method: y value (transmission method)> The color (y value) of the adhesive sheet for laminating optical components with a release film is measured using a spectrophotometer, with the measurement conditions being transmission conditions at an environment of 23°C.

[10] A method for manufacturing a laminate for an image display device, comprising the steps of peeling off the release film from the adhesive sheet for laminating optical components with a release film according to any one of [1] to [9], and laminating an image display device component via the adhesive sheet for laminating optical components.

[11] An image display device comprising an image display device laminate obtained by the manufacturing method described in

[10] .

[12] An adhesive sheet for laminating optical members with a release film on one side, wherein the release film (Y1) is peeled off from an adhesive sheet for laminating optical members with a release film according to any one of [1] to [9], and the adhesive sheet having the adhesive layer (X) and the release film (Y2) are laminated together, wherein the haze of the release film (Y2) is 2.0% or less and the sheet contains 80% by mass or more of recycled raw materials.

[0010] The adhesive sheet for bonding optical components with a release film of the present invention suppresses haze more effectively than petrochemical raw material-only systems, even when using recycled materials, and exhibits superior recyclability. Furthermore, because the adhesive sheet for bonding optical components with a release film of the present invention suppresses haze, it can improve the inspection accuracy of foreign matter and other contaminants in the user's automated in-process inspection machine.

[0011] The present invention will be described below based on examples of embodiments for carrying out the present invention. However, the present invention is not limited to the embodiments described below.

[0012] In this specification, "x and / or y (where x and y are any combination)" means at least one of x and y, and can mean x only, y only, or x and y. When expressed as "X to Y" (where X and Y are any numbers), unless otherwise specified, it includes the meaning of "greater than or equal to X and less than or equal to Y," as well as "preferably greater than X" or "preferably less than Y." When expressed as "greater than or equal to X" (where X is any number) or "less than or equal to Y" (where Y is any number), it also includes the meaning of "preferably greater than X" or "preferably less than Y." In this specification, for numerical ranges described in stages, the upper or lower limit of a numerical range in one stage can be arbitrarily combined with the upper or lower limit of a numerical range in another stage. Also, in numerical ranges described in this specification, the upper or lower limit of that numerical range can be replaced with the values ​​shown in the examples. In this specification, a preferred combination of embodiments is a more preferred embodiment. In this specification, the term "layer" includes not only thick layers but also relatively thin layers such as "film," "tape," and "sheet."

[0013] In this specification, "(meth)acrylic" means acrylic or methacrylic, "(meth)acryloyl" means acryloyl or methacryloyl, and "(meth)acrylate" means acrylate or methacrylate. Also, "acrylic resin" is a resin obtained by polymerizing a copolymer component containing at least one (meth)acrylate monomer. In this specification, "main component" means a component that greatly affects the properties of the object, and the content of the component is usually 50% by mass or more in the object, preferably 55% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and may be 100% by mass. When describing measurement methods etc. based on standards in this specification, unless otherwise specified, it shall be based on the standard as of the filing date of this application (or the priority date if there is a priority date). If the standard has been abolished at that time, it shall be based on the standard at the time of its abolition.

[0014] <<Adhesive Sheet for Laminating Optical Components with Release Film>> An adhesive sheet for laminating optical components with a release film according to one embodiment of the present invention (hereinafter sometimes referred to as "this adhesive sheet for laminating optical components with a release film") comprises a release film (Y1) laminated on a first surface of an adhesive sheet having an adhesive layer (X), and a release film (Y2) laminated on a second surface of the adhesive sheet, wherein the release film (Y1) and the release film (Y2) are polyester films having a release layer, and the polyester film includes a polyester film with a haze of 2% or less and containing recycled raw materials. The following describes each component.

[0015] <Release Films (Y1) and (Y2)> The release films (Y1) and (Y2) used in this adhesive sheet for bonding optical components with release films each have a release layer on at least one surface of a polyester film (hereinafter referred to as "polyester film (y1)" and "polyester film (y2)" respectively) as a base material.

[0016] The release film (Y1) is laminated onto the first surface of an adhesive sheet having an adhesive layer (X), and the release film (Y2) is laminated onto the second surface of the adhesive sheet. Here, the "first surface" and "second surface" of the adhesive sheet refer to two main surfaces that face each other in the thickness direction of the adhesive sheet. Specifically, the surface on one side of the adhesive sheet is called the first surface, and the surface on the opposite side is called the second surface.

[0017] [Polyester films (y1) and (y2)] The polyester films (y1) and (y2) are polyester films with a haze of 2% or less and containing recycled raw materials.

[0018] The polyester films (y1) and (y2) preferably have polyester as their main component resin. Furthermore, if the polyester films (y1) and (y2) have a laminated structure, it is preferable that the main component resin of each layer is polyester.

[0019] The polyester, which is the main component resin of the polyester films (y1) and (y2), refers to a polymer compound having ester bonds continuously in its main chain, and may be either a homopolyester or a copolymerized polyester. Specifically, examples include polyesters obtained by polycondensation reaction of a dicarboxylic acid component and a diol component. Furthermore, it is preferable to use a polyester that contains more than 50 mol% of aromatic dicarboxylic acid or aliphatic dicarboxylic acid when the dicarboxylic acid component is 100 mol%.

[0020] Examples of the dicarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, and 4,4'-diphenylsulfondicarboxylic acid, as well as aliphatic dicarboxylic acids such as adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedionic acid, cyclohexanedicarboxylic acid, and their ester derivatives.

[0021] Examples of the diol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-hexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis(4-hydroxyethoxyphenyl)propane, isosorbate, and spiroglycol.

[0022] When the above polyester is a homopolyester, it is preferable to obtain one obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic diol. Preferred aromatic dicarboxylic acids include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and preferred aliphatic diols include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Representative homopolyesters include polyethylene terephthalate (PET) and polyethylene-2,6-naphthalenedicarboxylate (PEN), with polyethylene terephthalate being the most preferred.

[0023] On the other hand, the copolymerized polyester is preferably a polycondensation polymer of a dicarboxylic acid component and an aliphatic diol. The dicarboxylic acid component is preferably one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acids (e.g., p-oxybenzoic acid). The aliphatic diol is preferably one or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, and neopentyl glycol. The copolymerized polyester preferably contains terephthalic acid as the dicarboxylic acid component and ethylene glycol as the aliphatic diol.

[0024] The content of terephthalic acid in the total dicarboxylic acid components constituting polyester films (y1) and (y2) is preferably 50 mol% or more, more preferably 70 mol% or more, and even more preferably 90 mol% or more. Furthermore, the content of ethylene glycol in the total diol components constituting polyester films (y1) and (y2) is preferably 50 mol% or more, more preferably 70 mol% or more, and even more preferably 90 mol% or more. The upper limit for the content of terephthalic acid and ethylene glycol is 100 mol%.

[0025] Furthermore, the polyester films (y1) and (y2) contain recycled materials. Recycled materials refer to polyester film recovered from used polyester film products and / or processes for manufacturing polyester film, which can be used as raw materials for new polyester film products.

[0026] Furthermore, the recycled raw material may be made from polyester film without functional coatings, or from polyester film having a functional layer with functional coatings (hereinafter referred to as "coated polyester film"), but in this embodiment, recycled raw materials made from coated polyester film tend to particularly benefit from the effects of the present invention. Generally, recycled raw materials made from coated polyester film tend to be easily discolored, so it is common technical knowledge for those skilled in the art to avoid using recycled raw materials made from coated polyester film. However, contrary to this common technical knowledge, the present invention has found that by processing recycled raw materials made from coated polyester film in the process described below, even when using recycled raw materials, haze can be suppressed more effectively than in petrochemical raw material-only systems, and an adhesive sheet for laminating optical components with a release film and excellent recyclability can be obtained.

[0027] Preferably, the recycled raw material is obtained by the steps of: crushing the coated polyester film with a pulverizer to make chips; putting the chips into a container of a chip washing device, adding hot water and an alkaline agent, and washing them while stirring to adjust the desired internal temperature and washing time; and after the washing process, draining the liquid, rinsing with water, and then dehydrating / drying the removed chips. The manufacturing process for such recycled raw material may be carried out in accordance with the method described in Japanese Patent Application Publication No. 2004-27072.

[0028] The content of the recycled raw material in the polyester films (y1) and (y2) is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. The upper limit is usually 100% by mass.

[0029] The intrinsic viscosity of the polyester in the polyester films (y1) and (y2) is preferably 0.50 dL / g or more, more preferably 0.52 dL / g or more, and even more preferably 0.54 dL / g or more, while preferably 1.00 dL / g or less, more preferably 0.80 dL / g or less, and even more preferably 0.60 dL / g or less, from the viewpoint of film-forming properties and productivity.

[0030] Furthermore, particles can be incorporated into the polyester in the polyester films (y1) and (y2). By incorporating particles, the polyester film is given slipperiness and prevents damage during each process, resulting in improved handling.

[0031] The types of particles to be included in the polyester are not particularly limited as long as they can impart slipperiness. Specific examples include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, calcium oxalate, kaolin, aluminum oxide, and titanium oxide, as well as cross-linked polymers such as cross-linked silicone resin particles, cross-linked acrylic resin particles, cross-linked styrene-acrylic resin particles, and cross-linked polyester particles, and organic particles such as ion exchange resins. Among these, silica is preferred from the viewpoint of transparency. Furthermore, precipitated particles obtained by precipitating and finely dispersing a portion of a metal compound such as a catalyst during the polyester manufacturing process can also be used.

[0032] There are no particular restrictions on the shape of the particles used; spherical, lumpy, rod-shaped, flattened, etc., may be used. Furthermore, there are no particular restrictions on their hardness, specific gravity, color, etc. Two or more types of these particles may be used in combination as needed.

[0033] Furthermore, the average particle size of the particles used is typically in the range of 0.01 to 5 μm, preferably 0.03 to 4 μm, and more preferably 0.05 to 3 μm. Within this range of average particle size, both the handling properties and transparency of the polyester films (y1) and (y2) can be achieved. In the case of powder particles, the average particle size can be determined by the particle size (d50) at which the cumulative volume fraction of 50% of the equivalent spherical distribution is measured using a centrifugal sedimentation particle size distribution analyzer (for example, Shimadzu Corporation's "SA-CP3" model). The average particle size of particles in a film, layer, or resin can be determined by observing 10 or more particles with a scanning electron microscope (SEM), measuring the diameter of each particle, and taking the average value. In the case of non-spherical particles, the average of the longest and shortest diameters can be measured as the diameter of each particle.

[0034] Further, when the polyester films (y1) and (y2) described below have a laminated structure, it is preferable to provide a surface layer and an intermediate layer, and allow the surface layer to contain particles. In addition, when different designs are adopted for the front and back surfaces by a structure such as a three-type three-layer structure, it is also possible to allow particles to be contained in only at least one surface layer. Therefore, it is preferable that particles are contained in at least one of the surface layers, and as described above, silica is more preferably used as the particles.

[0035] The content of the particles depends on the average particle diameter, but in the layer containing the particles, it is preferably 0.0003% by mass or more and 5% by mass or less, more preferably 0.01% by mass or more and 3% by mass or less, and still more preferably 0.01% by mass or more and 0.5% by mass or less. Within this range, good slippage and transparency of the polyester films (y1) and (y2) can be achieved.

[0036] (Other) In addition to the above-mentioned particles, conventionally known UV absorbers, antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments and the like can be added to the polyester films (y1) and (y2) as necessary. In the polyester films (y1) and (y2), the content of the other components is usually 10 mol% or less.

[0037] The polyester films (y1) and (y2) may have a single-layer structure or a laminated (multi-layer) structure. When the polyester films (y1) and (y2) have a laminated structure, they may have a two-layer structure, a three-layer structure or the like, and may have four or more layers as long as they do not deviate from the gist of the present invention. Among these, when the polyester films (y1) and (y2) have a laminated structure, a two-type three-layer structure and a three-type three-layer structure are preferable, and a two-type three-layer structure is more preferable.

[0038] More specifically, it is preferably a laminated structure composed of at least three layers having a surface layer, an intermediate layer, and a surface layer in this order. Among these, it is more preferable that the laminated structure is composed of three layers having a surface layer, an intermediate layer, and a surface layer in this order.

[0039] The thickness of at least one of the surface layers is preferably 4.5 μm or less, more preferably 4.0 μm or less, and even more preferably 3.5 μm or less. On the other hand, the lower limit of the surface layer thickness is preferably 1.0 μm or more, more preferably 1.5 μm or more, and even more preferably 2.0 μm or more. If the surface layer thickness is below the upper limit, the transparency of the polyester films (y1) and (y2) can be improved when particles are included in the surface layer, making it suitable for inspection in a state where it is bonded to an adhesive layer. On the other hand, if the surface layer thickness is above the lower limit, the polyester films (y1) and (y2) can be made more manageable when particles are included in the surface layer, and there is a tendency for particle shedding to be suppressed.

[0040] From a similar viewpoint, the ratio of the sum of the thicknesses of the surface layers to the sum of the thicknesses of the intermediate layers is preferably 1:3 to 1:18, more preferably 2:7 to 1:12, and even more preferably 1:4 to 1:8. Here, "intermediate layer" refers to layers other than the two surface layers.

[0041] When the polyester films (y1) and (y2) have a laminated structure consisting of three layers in the order of a surface layer, an intermediate layer, and another surface layer, it is preferable that at least the intermediate layer contains the above-mentioned recycled material, and it is more preferable that all layers contain the above-mentioned recycled material. By adopting such a laminated structure, the recycled material content can be increased while setting the y-value and haze of the polyester films (y1) and (y2) to desired values.

[0042] The layer structure and thickness of each layer of polyester films (y1) and (y2) are determined by observing the cross-section obtained by cryogenic fracture using an ultramicrotome, magnifying it 3,000 to 200,000 times using a transmission electron microscope, and taking cross-sectional photographs.

[0043] The total thickness of the polyester films (y1) and (y2) is not particularly limited as long as it is within the range in which a film can be formed, but from the viewpoint of mechanical strength, handling and productivity, it is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, particularly preferably 20 μm or more, and preferably 200 μm or less, more preferably 150 μm or less, even more preferably 125 μm or less, particularly preferably 100 μm or less.

[0044] [Method for Manufacturing Polyester Films (y1) and (y2)] Next, examples of manufacturing polyester films (y1) and (y2) will be specifically described, but the method is not limited to the following examples. For example, when manufacturing a biaxially oriented film, it is preferable to extrude the dried pellets of the polyester raw material (including recycled raw material) mentioned above as a molten sheet from a die using a melt extrusion device such as an extruder, and then cool and solidify them with a cooling roll such as a rotating cooling drum to obtain an unstretched sheet. Here, cooling is preferably carried out to a temperature below the glass transition point of the polymer, for example, to obtain a substantially amorphous unoriented sheet (unstretched sheet). In addition, it is preferable to improve the adhesion between the sheet and the cooling roll in order to improve the flatness of the sheet, and electrostatic application adhesion and / or liquid coating adhesion methods are preferably employed.

[0045] Next, the obtained unstretched sheet is stretched in two axial directions. In this case, first, the unstretched sheet is stretched in one direction using a roll or tenter type stretcher. The stretching temperature is usually 70 to 120°C, preferably 80 to 110°C, and the stretching ratio is usually 2.5 to 7.0 times, preferably 3.0 to 6.0 times.

[0046] Next, the material is stretched in a direction perpendicular to the stretching direction of the first stage. In this case, the stretching temperature is usually 70 to 170°C, and the stretching ratio is usually 3.0 to 7.0 times, preferably 3.5 to 6.0 times.

[0047] Next, a heat treatment is performed at a temperature of usually 180 to 270°C, under tension or under relaxation of 30% or less, to obtain a biaxially oriented film. This heat treatment is also called the heat setting process. The heat treatment may be carried out in two or more stages at different temperatures. Cooling may also be performed in a cooling zone after the heat treatment. The cooling temperature is preferably higher than the glass transition temperature (Tg) of the polyester constituting the film, and more specifically, it is preferably in the range of 100 to 160°C. This cooling may also be carried out in two or more stages at different temperatures. In the above stretching, a method of performing unidirectional stretching in two or more stages can also be employed. In that case, it is preferable that the final stretching ratios in both directions are within the above ranges.

[0048] Furthermore, a simultaneous biaxial stretching method can also be used in the production of polyester films (y1) and (y2). The simultaneous biaxial stretching method is a method of simultaneously stretching and oriented the aforementioned unstretched sheet in the machine direction (longitudinal direction) and width direction (transverse direction) under temperature control, usually at 70 to 120°C, preferably 80 to 110°C, with the stretching ratio being preferably 4 to 50 times, more preferably 7 to 35 times, and even more preferably 10 to 25 times in area ratio. Subsequently, heat treatment is performed at a temperature of usually 170 to 250°C under tension or under relaxation of 30% or less to obtain a stretched and oriented film. Regarding the simultaneous biaxial stretching apparatus employing the above stretching method, conventionally known stretching methods such as screw type, pantograph type, and linear drive type can be used.

[0049] The longitudinal direction (MD) of the film refers to the direction in which the film progresses during the film manufacturing process, i.e., the winding direction of the film roll, and is also called the machine direction or vertical direction. The width direction (TD) of the film refers to the direction parallel to the film surface and perpendicular to the longitudinal direction, i.e., the direction parallel to the central axis of the roll when the film is in a roll form, and is also called the transverse direction.

[0050] Furthermore, the haze of the polyester films (y1) and (y2) is 2.0% or less, preferably 1.8% or less, and more preferably 1.5% or less. The lower limit is not particularly limited, and is about 0.01%. The haze of such polyester films (y1) and (y2) can be measured, for example, by the method described in the following examples.

[0051] Furthermore, it is preferable that the adhesive sheet for bonding optical components with a release film has the following relationship between the haze (h1) of the polyester film (y1) and the haze (h2) of the polyester film (y2): (Equation) h1 > h2 ... (3)

[0052] Furthermore, the color (y value) of the polyester films (y1) and (y2) is preferably 0.330 or less, more preferably 0.325 or less, and even more preferably 0.322 or less. The lower limit is usually 0.300. The color (y value) of such polyester films (y1) and (y2) can be measured, for example, by the method described in the following examples.

[0053] Furthermore, the GHG emission factors of the polyester films (y1) and (y2) are preferably 7 kg CO2 / 1 kg polyester film or less, more preferably 5 kg CO2 / 1 kg polyester film or less, even more preferably 3 kg CO2 / 1 kg polyester film or less, and particularly preferably 2 kg CO2 / 1 kg polyester film or less. Such GHG emission factors can be measured, for example, by the method described in the following examples.

[0054] [Release Layer] The release layer used in the polyester films (y1) and (y2) is a layer provided to impart release properties to the polyester film, and is mainly composed of a release agent. There are no particular restrictions on the raw materials of the release agent, and conventionally known materials can be used. Examples include those mainly composed of curable silicone resin, or modified silicone resins produced by graft polymerization with urethane resin, epoxy resin, etc., long-chain alkyl group-containing compounds, fluorine compounds, hydrocarbon waxes, etc.

[0055] The method for forming the release layer is not particularly limited, and conventionally known coating methods such as reverse gravure coating, direct gravure coating, roll coating, die coating, bar coating, and curtain coating can be used. Examples of coating methods can be found in "Coating Methods," published by Maki Shoten, authored by Yuji Harasaki, in 1979.

[0056] Furthermore, methods for forming the release layer include in-line coating and off-line coating. The drying and curing conditions are not particularly limited; for example, when providing a release layer by off-line coating, it is generally recommended to perform heat treatment at 80 to 200°C for 3 to 40 seconds, preferably at 120 to 180°C for 3 to 40 seconds. On the other hand, when providing a release layer by in-line coating, it is generally recommended to perform heat treatment at 70 to 280°C for 3 to 200 seconds.

[0057] Furthermore, regardless of whether it is offline coating or in-line coating, heat treatment and active energy ray irradiation such as ultraviolet irradiation may be used in combination as needed.

[0058] Furthermore, the polyester films (y1) and (y2) may be subjected to surface treatments such as corona treatment or plasma treatment beforehand.

[0059] Furthermore, it is preferable that the release films (Y1) and (Y2) include an undercoat layer between the polyester films (y1) and (y2) and the release layer.

[0060] The undercoat layer is used not only to improve the adhesion between the polyester films (y1) and (y2) and the release layer, but also to impart various functions to the release films (Y1) and (Y2). Examples of undercoat layers include antistatic properties to suppress peeling charge during the process of peeling off functional layers such as the adhesive layer (X) provided on the release layer, thereby preventing the adhesion of foreign matter, and oligomer sealing properties to seal the precipitation of oligomers from the polyester films (y1) and (y2) when heat treatment is performed at high temperatures for a long time. In the release films (Y1) and (Y2) of this embodiment, it is preferable that the undercoat layer has antistatic properties. The undercoat layer may be a single layer or a configuration of two or more layers.

[0061] While there are no specific requirements for the antistatic agent, for example, polymers can be used that are doped with other anionic compounds, polymers that have anionic groups in the compound consisting of thiophene or a thiophene derivative and are self-doped, or polymers that contain a monomer with an alkyl sulfonate ion as a counterion. Among these, it is more preferable to include a compound consisting of thiophene or a thiophene derivative from the viewpoint of obtaining excellent antistatic performance.

[0062] The haze of the polyester film having a release layer (release films (Y1) and (Y2)) is 2.0% or less, preferably 1.8% or less, and more preferably 1.5% or less. The lower limit is not particularly limited, and is about 0.01%. Such haze can be measured, for example, by the method described in the following examples.

[0063] Furthermore, it is preferable that the adhesive sheet for bonding optical components with a release film has the following relationship between the haze (H1) of the release film (Y1) and the haze (H2) of the release film (Y2): (Equation) H1 > H2 ... (4)

[0064] As mentioned above, the release films (Y1) and (Y2) also contain recycled materials, since the polyester films (y1) and (y2) contain recycled materials. The recycled material content in the release films (Y1) and (Y2) is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. The upper limit is usually 100% by mass.

[0065] Furthermore, the color (y value) of the release films (Y1) and (Y2) is preferably 0.345 or less, more preferably 0.340 or less, and even more preferably 0.335 or less. The lower limit is usually 0.300. Such color (y value) can be measured, for example, by the method described in the following examples.

[0066] <Adhesive Sheet> The adhesive sheet used in this laminate has an adhesive layer (X). The adhesive layer (X) contains an adhesive composition and may be an acrylic adhesive composition mainly composed of acrylic resin, a rubber adhesive composition mainly composed of rubber, a urethane adhesive composition mainly composed of urethane resin, or a silicone adhesive composition mainly composed of silicone resin. In particular, from the viewpoint of adhesiveness, transparency and weather resistance, it is preferable to use a (meth)acrylic acid ester polymer (meaning including copolymers, hereinafter referred to as "acrylic acid ester (co)polymer") as the main component resin.

[0067] Acrylic acid ester-based (co)polymers, which serve as the main component resin, can be prepared by appropriately selecting the type and composition ratio of acrylic monomers and methacrylic monomers used for polymerization, as well as the polymerization conditions, thereby appropriately adjusting physical properties such as glass transition temperature (Tg) and molecular weight.

[0068] Examples of acrylic monomers and methacrylic monomers used for polymerizing acrylic acid ester (co)polymers include 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, n-butyl acrylate, ethyl acrylate, methyl methacrylate, and methyl acrylate. In addition to these, vinyl acetate, hydroxyethyl acrylate, acrylic acid, glycidyl acrylate, acrylamide, acrylonitrile, methacrylonitrile, fluorine acrylate, and silicone acrylate, which have hydrophilic groups or organic functional groups, can also be used. These can be used individually or in combination of two or more.

[0069] As the polymerization treatment using the monomer, known polymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization can be employed, and an acrylic acid ester (co)polymer can be obtained by using polymerization initiators such as thermal polymerization initiators and photopolymerization initiators depending on the polymerization method.

[0070] The mass-average molecular weight (Mw) of the acrylic acid ester (co)polymer is preferably 100,000 to 700,000, more preferably 200,000 to 600,000, and even more preferably 250,000 to 500,000. When the molecular weight of the main component resin is above the lower limit, it tends to exhibit adhesive strength when pre-cured, becoming moderately soft and having excellent handling properties. On the other hand, when it is below the upper limit, it tends to become moderately hard when pre-cured, and tends to easily conform to irregularities and foreign matter on the surface of the adherend.

[0071] Furthermore, the number-average molecular weight (Mn) of the acrylic acid ester (co)polymer is preferably 1 to 500,000, more preferably 20 to 400,000, and even more preferably 50 to 200,000.

[0072] Furthermore, the mass-average molecular weight (Mw) / number-average molecular weight (Mn) is preferably 5 to 10, and more preferably 6 to 9. A large mass-average molecular weight (Mw) / number-average molecular weight (Mn) means that the molecular weight distribution is broad. When this value is large, around 5 to 10, both the low-molecular-weight and high-molecular-weight components contribute to molecular-weight-appropriate performance such as fluidity, wettability, and cohesiveness. As a result, the processability and adhesive performance tend to be better than that of materials with a narrow (uniform) molecular weight distribution.

[0073] Among acrylic ester (co)polymers, it is preferable to use acrylic ester random copolymers, and it is even more preferable to use acrylic ester random copolymers that contain two types of monomers with a large difference in the glass transition temperature (Tg) of each monomer component constituting the random copolymer, that is, the glass transition temperature (Tg) of each monomer component constituting the acrylic ester random copolymer compared to polymers polymerized with only a single monomer.

[0074] In this case, the difference in glass transition temperatures (Tg) of the two monomer components is preferably 25 to 300°C, more preferably 40 to 200°C, even more preferably 60 to 180°C, and particularly preferably 100 to 180°C.

[0075] Specifically, the glass transition temperature (Tg) of one monomer component is typically -100 to 0°C, preferably -80 to -20°C, and the glass transition temperature (Tg) of the other monomer component is typically 0 to 250°C, preferably 20 to 180°C.

[0076] For monomer components with a low glass transition temperature (Tg), such as monomer components with a Tg of -100 to 0°C, it is preferable to use acrylic acid esters with a side chain having 2 or more carbon atoms, preferably 4 or more. On the other hand, for monomer components with a high glass transition temperature (Tg), such as monomer components with a Tg of 0 to 250°C, it is preferable to use vinyl monomers or (meth)acrylic monomers having a side chain with a hydrocarbon having 2 or fewer carbon atoms, as well as ring structures such as alicyclic structures, heterocyclic structures, aromatic structures, or functional groups such as carboxyl groups, hydroxyl groups, amino groups, amide groups, glycidyl groups, acetyl groups, and isocyanate groups.

[0077] (Crosslinking agent) The adhesive composition preferably contains a crosslinking agent from the viewpoint of promoting the crosslinking reaction. This allows the adhesive composition to efficiently form a crosslinked structure. Furthermore, when a crosslinked structure is formed in an adhesive sheet using the adhesive composition, an adhesive sheet with improved shape stability can be obtained, improving storage and handling properties, and preventing the adhesive sheet from protruding from the edges during bonding. In addition, good tackiness and cohesiveness can be obtained in the adhesive sheet when a crosslinked structure is formed.

[0078] Examples of the crosslinking agents include acrylic crosslinking agents, isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, aldehyde crosslinking agents, amine crosslinking agents, and metal chelate crosslinking agents. Among these, isocyanate crosslinking agents are preferred because they exhibit excellent reactivity with acrylic polymers. On the other hand, acrylic crosslinking agents are preferred from the viewpoint of ease of reaction control and the ability to be cured by active energy rays, and among these, polyfunctional (meth)acrylates are preferred.

[0079] Examples of the polyfunctional (meth)acrylate include polyfunctional (meth)acrylic monomers and polyfunctional (meth)acrylic oligomers having two or more (meth)acryloyl groups. These may be used individually or in combination of two or more.

[0080] Examples of the polyfunctional (meth)acrylic monomers include pentanediol di(meth)acrylate, hexadiol di(meth)acrylate, heptanediol di(meth)acrylate, octanediool di(meth)acrylate, nonanediol di(meth)acrylate, decanediool di(meth)acrylate, undecanediol di(meth)acrylate, dodecanediol di(meth)acrylate, 1,4-Butanediol di(meth)acrylate, glycerin di(meth)acrylate, neopentyl glycol di(meth)acrylate, glycerin glycidyl ether di(meth)acrylate, tricyclodecane dimethacrylate, tricyclodecane dimethanol di(meth)acrylate, bisphenol A polyethoxy di(meth)acrylate, bisphenol A polypropoxy di(meth)acrylate, bisphenol F polyethoxy di(meth)acrylate, ethylene glycol di(meth)acrylate, trimethylolpropane trioxyethyl (meth)acrylate, ε-caprolactone modified tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propoxylated pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, propoxylated pentaerythritol Examples include pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, tris(acryloxyethyl) isocyanurate, dipentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol penta(meth)acrylate, neopentyl glycol hydroxybivalate di(meth)acrylate, di(meth)acrylate of the ε-caprolactone adduct of neopentyl glycol hydroxybivalate, trimethylolpropane tri(meth)acrylate, trimethylolpropane polyethoxytri(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate.

[0081] Examples of the polyfunctional (meth)acrylic oligomers include polyester (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, urethane (meth)acrylate oligomers, and polyether (meth)acrylate oligomers.

[0082] Among these crosslinking agents, polyfunctional (meth)acrylate monomers and oligomers having a glycol structure are preferred from the viewpoint of imparting appropriate flexibility to the cured product. Furthermore, from the viewpoint of imparting cohesive force, acrylic acid adducts of pentaerythritol and dipentaerythritol, or alkoxy compounds thereof, are preferred.

[0083] Regarding the amount of crosslinking agent, if the amount of crosslinking agent is too large, the reaction proceeds rapidly and it becomes difficult to control the reaction. Therefore, it is preferable to adjust the amount of crosslinking agent so that the crosslinking can be stopped at any time. From this viewpoint, the amount of crosslinking agent is preferably 0 to 30 parts by mass, more preferably 5 to 28 parts by mass, and even more preferably 10 to 25 parts by mass, per 100 parts by mass of the main component resin.

[0084] (Polymerization Initiator) The adhesive composition preferably contains a polymerization initiator. In this specification, a polymerization initiator is a general term for compounds that are activated by stimuli such as heat or light and produce anions, cations, radicals, etc. that trigger polymerization initiation reactions. The polymerization initiator is preferably a compound that produces radicals (radical generator, radical polymerization initiator).

[0085] The polymerization initiator can be, for example, a thermal polymerization initiator that is activated by heat, or a photopolymerization initiator that is activated by light irradiation. The adhesive sheet is a cured product obtained by partially curing (pre-curing) the adhesive composition, and in one embodiment of the use of the invention, it is assumed that it will be further cured after being bonded to other members. In this case, as a method for appropriately controlling the degree of curing in the pre-curing, for example, a method in which a thermal polymerization initiator and a photopolymerization initiator are used in combination, and an adhesive sheet is manufactured by pre-curing with one curing means and then imparted with the property that it can be cured after bonding using the other means, and a method in which only a thermal polymerization initiator or a photopolymerization initiator is used to control the degree of curing in the pre-curing. In the latter case, it is preferable to use a photopolymerization initiator from the viewpoint that the degree of polymerization can be controlled to some extent by the amount of light irradiation.

[0086] Among the polymerization initiators, photopolymerization initiators are preferred. In a particularly preferred embodiment, the polymerization initiator is a polymerization initiator that generates radicals upon exposure to light (photoradical polymerization initiator).

[0087] The following describes in detail an example of an embodiment in which a photoradical polymerization initiator is used, but the polymerization initiator may be changed and / or combined within the above range, as long as the effects of the present invention are obtained.

[0088] The aforementioned photoradical polymerization initiators can be broadly classified into two types based on their radical generation mechanism. More specifically, they can be broadly divided into cleavage-type radical polymerization initiators, which can generate radicals by cleaving and decomposing the single bonds of the photoradical polymerization initiator itself, and hydrogen abstraction-type radical polymerization initiators, which can generate radicals by the excited initiator abstracting hydrogen from a hydrogen donor in the system. These may be used individually or in combination of two or more types.

[0089] Examples of the hydrogen abstraction-type radical polymerization initiators include benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 2-methylbenzobenzoate, 4-[(4-methylphenyl)thio]benzophenone, 4-acryloyloxybenzophenone, 4-acryloyloxyethoxybenzophenone, 4-acryloyloxy-4'-methoxybenzophenone, 4-acryloyloxyethoxy-4'-methoxybenzophenone, 4-acryloyloxy-4'-bromobenzophenone, 4-acryloyloxyethoxy-4'-bromobenzophenone, and 4-methacrylo Examples include intermolecular hydrogen abstraction radical polymerization initiators such as yloxybenzophenone, 4-methacryloyloxyethoxybenzophenone, 4-methacryloyloxy-4'-methoxybenzophenone, 4-methacryloyloxyethoxy-4'-methoxybenzophenone, 4-methacryloyloxy-4'-bromobenzophenone, and 4-methacryloyloxyethoxy-4'-bromobenzophenone; and intramolecular hydrogen abstraction radical polymerization initiators such as methylbenzoyl formate, methyl benzoyl formate, oxyphenylacetic acid-2-(2-oxo-2-phenylacetoxyethoxy)ethyl ester, and oxyphenylacetic acid-2-(2-hydroxyethoxy)ethyl ester. These may be used individually or in combination of two or more.

[0090] Among the intermolecular hydrogen abstraction type radical polymerization initiators, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, and polymerization initiators having a radical polymerizable functional group with a carbon-carbon double bond in the molecule, such as 4-acryloyloxybenzophenone, 4-methacryloyloxybenzophenone, 4-acryloyloxyethoxybenzophenone, 4-acryloyloxy-4'-methoxybenzophenone, 4-acryloyloxyethoxy-4'-methoxybenzophenone, and 4-methacryloyloxybenzophenone are preferred, and 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, and 4-methacryloyloxybenzophenone are more preferred. Polymerization initiators having a radical polymerizable functional group with a carbon-carbon double bond in the molecule tend to suppress the bleed-out of the polymerization initiator and improve the cohesive force of the adhesive sheet by being incorporated into the polymerization structure after the photoreaction. Furthermore, intramolecular hydrogen abstraction type radical polymerization initiators are preferred because they can serve as the starting point for radical generation not only as hydrogen donors in the system but also as radicals themselves, with methylbenzoyl formate being more preferred.

[0091] Examples of the cleavage-type radical polymerization initiators include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methyl-propan-1-one, oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), and 2-benzyl-2-dimethylamino-1-(4-mol). Examples include folinophenyl)butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)2,4,4-trimethylpentylphosphine oxide, and their derivatives.

[0092] (Other Components) The adhesive composition may optionally contain various additives as "other components," such as silane coupling agents, ultraviolet absorbers, plasticizers, tackifiers, antioxidants, light stabilizers, metal deactivators, anti-aging agents, hygroscopic agents, rust inhibitors, and inorganic particles, as long as they do not impair the effects of the present invention. Furthermore, reaction catalysts such as tertiary amine compounds, quaternary ammonium compounds, and tin laurate compounds may be optionally included. These can be used individually or in combination of two or more.

[0093] An adhesive sheet containing an adhesive layer (X) may be a single-layer adhesive sheet consisting only of an adhesive layer (X) formed from an adhesive composition, or it may be a multilayer adhesive sheet in which multiple adhesive layers, including the adhesive layer (X) formed from the adhesive composition and other adhesive layers, are laminated together. In particular, the layer structure of the adhesive sheet is preferably at least two layers, more preferably at least three layers including an outermost layer, an innermost layer, and an intermediate layer, and it is especially preferable that the outermost layer, innermost layer, and intermediate layer are at least three layers formed from the adhesive composition. By having such a layer structure, it is possible to make an adhesive sheet that is less likely to leave indentations or dents even when localized pressure is applied.

[0094] The thickness of the adhesive sheet is preferably 50 μm or more, more preferably 60 μm or more, particularly preferably 70 μm or more, preferably 1000 μm or less, more preferably 500 μm or less, and particularly preferably 300 μm or less.

[0095] Furthermore, the adhesive sheet may be embossed or subjected to various surface treatments (such as conical, pyramidal, or hemispherical shapes) as needed. In addition, various surface treatments such as corona treatment, plasma treatment, and primer treatment may be applied to the surface in order to improve adhesion to various components.

[0096] <<Method for manufacturing an adhesive sheet for bonding optical components with a release film>> This adhesive sheet for bonding optical components with a release film can be manufactured by laminating release films (Y1) and (Y2) on both sides of an adhesive sheet having an adhesive layer (X). In this case, the release film (Y1) is laminated such that its own release layer is in contact with the first surface of the adhesive sheet of the adhesive layer (X), and similarly, the release film (Y2) is laminated such that its own release layer is in contact with the second surface of the adhesive sheet of the adhesive layer (X).

[0097] The adhesive sheet having the adhesive layer (X) can be manufactured by preparing an adhesive composition containing the main component resin, a crosslinking agent, a polymerization initiator, and other components as needed, molding the adhesive composition into a sheet, curing it by crosslinking, i.e., polymerization, and then processing it as necessary.

[0098] The adhesive composition can be prepared by kneading each of the raw materials using a temperature-controlled kneader (e.g., a single-screw extruder, a twin-screw extruder, a planetary mixer, a twin-screw mixer, a pressure kneader, etc.). When kneading the various raw materials, various additives such as silane coupling agents and antioxidants may be blended with the resin beforehand and then supplied to the kneader, or all materials may be melted and mixed beforehand and then supplied, or a masterbatch may be prepared in which only the additives are concentrated in the resin and then supplied.

[0099] As a method for forming the adhesive composition into a sheet, known methods such as wet lamination, dry lamination, extrusion casting using a T-die, extrusion lamination, calendering, inflation, injection molding, and liquid curing can be employed. Among these, wet lamination, extrusion casting, and extrusion lamination are preferred when manufacturing sheets.

[0100] Furthermore, as another embodiment for forming the adhesive composition into a sheet, the adhesive composition can be dissolved in a suitable solvent and carried out using various coating methods. When using a coating method, in addition to the pre-curing by active energy ray irradiation described above, an adhesive sheet can also be obtained by pre-curing with heat. Also, when using a coating method, the thickness of the adhesive sheet can be adjusted by the coating thickness and the solid content concentration of the coating liquid.

[0101] The aforementioned coating method can be carried out by conventional methods such as roll coating, die coating, gravure coating, comma coating, screen printing, and bar coating.

[0102] Furthermore, the adhesive composition can be cured by irradiation with active energy rays to produce an adhesive sheet. In addition to irradiation with active energy rays, further curing can also be achieved by heating.

[0103] Examples of the active energy ray in the active energy ray irradiation include light rays such as far-ultraviolet rays, ultraviolet rays, near-ultraviolet rays, infrared rays, and visible light rays, and ionizing radiations such as X-rays, α-rays, β-rays, γ-rays, electron beams, proton beams, and neutron beams. Among these, ultraviolet rays are preferable from the viewpoint of suppressing damage to components constituting an optical device and controlling reaction. Ultraviolet rays are also preferable from the viewpoints of curing speed, easy availability of an irradiation device, cost, and the like.

[0104] Examples of light sources for ultraviolet irradiation include high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, chemical lamps, electrodeless discharge lamps, and LED lamps that emit light in a wavelength range of 150 to 450 nm. Among these, it is preferable to use a high-pressure mercury lamp, a metal halide lamp, or an LED lamp.

[0105] From the viewpoint of curing, the irradiation dose (integrated light intensity) of active energy ray is preferably 100 mJ / cm ２ or more, more preferably 200 mJ / cm ２ or more, still more preferably 300 mJ / cm ２ or more, particularly preferably 400 mJ / cm ２ or more, and most preferably 500 mJ / cm ２ or more. Further, the irradiation dose is preferably 10000 mJ / cm ２ or less, more preferably 5000 mJ / cm ２ or less, still more preferably 4000 mJ / cm ２ or less, particularly preferably 3000 mJ / cm ２ or less, and most preferably 2000 mJ / cm ２ or less.

[0106] It is preferable to pre-cur the adhesive sheet for bonding optical components with a release film by irradiating it with active energy rays so that it has potential active energy ray curability, in other words, so that it retains active energy ray reactivity. When pre-curing by irradiation with active energy rays, it is possible to adjust the degree of active energy ray crosslinking (gel fraction) by controlling the amount of active energy rays irradiated, or it is also possible to adjust the degree of active energy ray crosslinking (gel fraction) by partially blocking the active energy rays using a filter or the like.

[0107] The haze of the adhesive sheet for bonding optical components with release film obtained in this way is preferably 3% or less, more preferably 2.5% or less, and even more preferably 2.0% or less. The haze of such an adhesive sheet for bonding optical components with release film can be measured by the method described in the following examples.

[0108] Furthermore, the color (y value) of the adhesive sheet for bonding optical components with release film is preferably 0.350 or less, more preferably 0.340 or less, and even more preferably 0.335 or less. The color (y value) of such an adhesive sheet for bonding optical components with release film can be measured by the method described in the following examples.

[0109] In this adhesive sheet for bonding optical components with a release film, the peeling force (F1) when peeling the release film (Y1) from the adhesive sheet having the adhesive layer (X) is preferably less than 0.050 N / 50 mm, more preferably 0.045 N / 50 mm or less, and even more preferably 0.040 N / 50 mm or less. Furthermore, the peeling force (F2) when peeling the release film (Y2) from the adhesive sheet having the adhesive layer (X) is preferably 0.050 N / 50 mm or more, more preferably 0.055 N / 50 mm or more, and even more preferably 0.060 N / 50 mm or more. Such peeling forces can be measured by the method described in the following examples.

[0110] Furthermore, it is preferable that the peeling force (F1) when peeling the release film (Y1) from the adhesive sheet having the adhesive layer (X) and the peeling force (F2) when peeling the release film (Y2) from the adhesive sheet having the adhesive layer (X) have the following relationship: (Equation) F1 < F2 ... (1)

[0111] Preferably, the average surface roughness (Sa1) of the surface of the adhesive sheet having the adhesive layer (X) after peeling off the release film (Y1) and the average surface roughness (Sa2) of the surface of the adhesive sheet having the adhesive layer (X) after peeling off the release film (Y2) have the following relationship: (Equation) Sa1 > Sa2 ... (2)

[0112] The average surface roughness (Sa) mentioned above is one of the surface roughness parameters (ISO 25178), and is an extension of the two-dimensional Ra to three dimensions. It is calculated by dividing the volume of the area enclosed by the surface shape curve and the average surface by the measured area, and can be obtained from the following equation (i). When the surface is the XY plane and the height direction is the Z axis, if A is the defined area (the entire image) and Z(x,y) is the height of the image point (x,y) from the plane with height 0, then it can be expressed as shown in the following equation (i).

[0113]

[0114] In the present invention, if it is difficult to directly determine the surface roughness of the adhesive layer, the relationship between Sa1 and Sa2 in formula (2) shall represent the relative surface roughness of the release films (Y1) and (Y2) that covered the surface of the adhesive layer on the side where they were bonded to the adhesive layer.

[0115] <Preferred Uses of the Adhesive Sheet for Laminating Optical Components with Release Film> In one embodiment, this adhesive sheet for laminating optical components with release film is suitably used for laminating optical components. Specifically, it is suitably used for laminating components that constitute a display, in particular components used to manufacture a display, and is suitably used as an adhesive sheet for laminating an image display panel and image display device components such as a protective panel or touch panel placed on its front side (viewing side), or for laminating components that constitute the image display device components. Note that the same image display device components as those described later can be used.

[0116] Furthermore, this adhesive sheet for bonding optical components with a release film is usually used in a state where, after the release film (Y1) has been peeled off, the surface of the exposed adhesive layer (X) is bonded to an optical component such as a polarizing plate (adhesive sheet for bonding optical components with a release film on one side). In this adhesive sheet for bonding optical components with a release film on one side (optical component / adhesive layer (X) / release film (Y2)), it is preferable that the haze of the release film (Y2) is 2.0% or less and that it contains 80% by mass or more of recycled raw materials.

[0117] According to the configuration of the adhesive sheet for bonding optical components with a single-sided release film, high-precision inspection can be performed through the release film (Y2) while the surface of the adhesive layer (X) exposed by peeling off the release film (Y1) is bonded to an optical component such as a polarizing plate. Specifically, the polyester film (y2) constituting the release film (Y2) contains recycled raw materials at a high concentration of 80% by mass or more, yet its haze is controlled to a low level of 2.0% or less. This suppresses noise such as scattering of inspection light by the release film (Y2) and adhesive layer (X) after bonding to a polarizing plate or the like.

[0118] <<Laminate for Image Display Device>> An example of an embodiment of the present invention (hereinafter sometimes referred to as "this laminate for image display device") is a laminate for image display device manufactured by bonding two image display device components together using this adhesive sheet for bonding optical components with a release film. More specifically, this laminate for image display device can be manufactured by first peeling off one side of the adhesive sheet for bonding optical components with a release film, exposing one side of the sheet, bonding it to an image display device component (referred to as the first component), and then peeling off the other side of the adhesive sheet (referred to as the second component) to bond an image display device component (referred to as the second component) to the other side of the exposed adhesive sheet.

[0119] Of the components of the laminate for this image display device, the adhesive sheet for bonding the optical component with release film is as described above, and the other components will be explained below.

[0120] <Image Display Device Components> Examples of image display device components that constitute the laminate for this image display device include flat panel image display device components, image display device components having curved portions, and flexible image display device components. Examples of such image display device components include liquid crystal displays and organic electroluminescent (EL) displays, surface protection panels (surface protection films), polarizing plates, polarizing elements, phase difference films, color filters, barrier films, viewing angle compensation films, brightness enhancement films, contrast enhancement films, diffusion films, semi-transparent reflective films, electrode films, transparent conductive films, metal mesh films, and touch sensor films. Any one or two of these can be used in combination. For example, a combination of a surface protection panel and other image display device components, or a combination of other image display device components, can be used.

[0121] Preferably, one of the two image display device components is a surface protection panel, and the other is a component consisting of one or more types from the group consisting of a touch sensor film, an image display panel, a color filter, a polarizing element, and a phase difference film. It is even more preferable that the surface protection panel has a frame-shaped concealing portion at its periphery, and that the frame width is 3 mm or less. With this configuration, the effects of the present invention can be particularly enjoyed.

[0122] <<Image Display Device>> An image display device according to an example of an embodiment of the present invention (hereinafter sometimes referred to as "this image display device") is an image display device that incorporates a laminate for an image display device having a configuration in which two image display device components are bonded together via an adhesive sheet for bonding optical components with a release film. For example, an image display device can be given that has a structure in which a laminate for an image display device having a configuration in which two image display device components are bonded together via an adhesive sheet is combined with other image display device components.

[0123] In this context, "other image display device components" can refer to, for example, FPC cables, reflective sheets, light guide plates and light sources, diffusion films, prism sheets, liquid crystal panels, organic EL panels, anti-reflective films, color filters, polarizing plates, phase difference plates, glass substrates, surface protection films, and composites of these components.

[0124] Specific examples of this image display device include, for example, liquid crystal displays, organic EL displays, inorganic EL displays, electronic paper, plasma displays, and microelectromechanical systems (MEMS) displays used in personal computers, mobile devices, game consoles, televisions (TVs), car navigation systems, touch panels, pen tablets, etc.

[0125] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. In the examples, "parts" and "%" refer to mass. Prior to the examples, the following components were prepared.

[0126] (Washed recycled raw material) Coated polyester film was crushed into chips using a pulverizer and placed into a container of a chip washing device. Hot water, polyoxyethylene derivative, and liquid caustic soda were added, and the internal temperature was raised to 90°C while stirring. After the internal temperature reached 90°C, the washing process was maintained at that temperature for 30 minutes until the washing process was complete. After draining, the liquid was removed and the chips were rinsed with shower water. After rinsing, the water was thoroughly drained and the washed chips were removed. These chips were then dehydrated and dried to obtain washed recycled raw material.

[0127] (Raw resins for polyester film) ・Petrification raw material A: Homopolyethylene terephthalate (intrinsic viscosity = 0.63 dL / g) ・Petrification raw material B: Solid-phase polymerized homopolyethylene terephthalate (intrinsic viscosity = 0.85 dL / g) ・Petrification raw material C: Masterbatch of homopolyethylene terephthalate blended with 0.3% silica particles with an average particle size of 2.7 μm (intrinsic viscosity = 0.59 dL / g) ・Petrification raw material D: Masterbatch of homopolyethylene terephthalate blended with 0.6% silica particles with an average particle size of 2.7 μm (intrinsic viscosity = 0.59 dL / g) ・Recycled raw material E: Recycled homopolyethylene terephthalate containing the above-mentioned washed recycled raw material particles, which is obtained by stripping and washing a polyester film having a coating layer (intrinsic viscosity = 0.58 dL / g) Raw materials A to D are virgin raw materials derived from petrification, and raw material E is a washed recycled raw material.

[0128] (Release agent 1) - Addition-curing silicone resin (LTC856, manufactured by Toray Dow Corning): 20 parts - Addition-curing platinum catalyst (SRX212, manufactured by Toray Dow Corning): 0.2 parts - MEK / toluene / n-heptane mixed solvent (mixing ratio 1:1:1)

[0129] (Release agent 2) - Addition-type curing silicone resin (X62-5039, manufactured by Shin-Etsu Chemical Co., Ltd.): 17 parts (a mixture of curing silicone resin containing vinyl groups and curing silicone resin containing SiH groups) - Organopolysiloxane resin (KS-3800, manufactured by Shin-Etsu Chemical Co., Ltd.): 3 parts - Addition-type platinum catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.): 0.5 parts - MEK / toluene / n-heptane mixed solvent (mixing ratio 1:1:1)

[0130] (Intermediate Adhesive Composition) An acrylic acid ester copolymer (Mw = 500,000, Mn = 62,000, Mw / Mn = 8, theoretical Tg -50°C) was prepared by random copolymerizing 75 parts of 2-ethylhexyl acrylate (homopolymer Tg: -70°C), 20 parts of vinyl acetate (homopolymer Tg: 32°C), and 5 parts of acrylic acid (homopolymer Tg: 106°C). To 1 kg of the acrylic acid ester copolymer, 150 g of UV-curable resin propoxylated pentaerythritol triacrylate (ATM-4PL, manufactured by Shin-Nakamura Chemical Co., Ltd.) as a crosslinking agent and 7 g of 4-methylbenzophenone as a photopolymerization initiator were mixed to prepare an intermediate adhesive layer composition.

[0131] (Composition for surface adhesive) A surface adhesive composition was prepared by adding and mixing 20 g of 4-methylbenzophenone as a photopolymerization initiator to 1 kg of the acrylic ester copolymer.

[0132] [Preparation of Polyester Film for Example (y1-1)] A mixed raw material prepared by mixing petrochemical raw materials B and C in proportions of 68% and 32%, respectively, was used as the raw material for the front and back layers, and a mixed raw material prepared by mixing petrochemical raw material B and recycled raw material E in proportions of 5% and 95%, respectively, was used as the raw material for the intermediate layer. Each of the raw materials for the front and back layers and the intermediate layer was supplied to two extruders, melted at 280°C, and then co-extruded and cooled and solidified on a cooling roll set at 25°C in a two-type, three-layer structure to obtain an unstretched sheet. Next, the obtained unstretched sheet was stretched 3.0 times in the longitudinal direction (MD) at 90°C using a roll stretcher. Furthermore, after preheating at 100°C in a tenter, it was stretched 4.0 times in the width direction (TD) at 120°C. Finally, a heat treatment was performed at 230°C to obtain a polyester film for the example (y1-1) with a thickness of 38 μm (front and back layers: 1.5 μm, intermediate layer: 35.0 μm).

[0133] [Preparation of Polyester Film for Example (y2-1)] A mixed raw material prepared by mixing petrochemical raw materials B and C in proportions of 92% and 8%, respectively, was used as the raw material for the front and back layers, and a mixed raw material prepared by mixing petrochemical raw material B and recycled raw material E in proportions of 5% and 95%, respectively, was used as the raw material for the intermediate layer. Each of the raw materials for the front and back layers and the intermediate layer was supplied to two extruders, melted at 280°C, and then co-extruded on a cooling roll set at 25°C in a 2-type, 3-layer structure, and cooled and solidified to obtain an unstretched sheet. Next, the obtained unstretched sheet was stretched 3.0 times in the longitudinal direction (MD) at 90°C using a roll stretcher. Furthermore, after preheating at 100°C in a tenter, it was stretched 4.0 times in the width direction (TD) at 120°C. Finally, a heat treatment was performed at 230°C to obtain a polyester film for the example (y2-1) with a thickness of 100 μm (front and back layers: 2.5 μm, intermediate layer: 95.0 μm).

[0134] [Preparation of Comparative Example Polyester Film (y'1-1)] A mixed raw material prepared by mixing petrochemical raw materials B and D in proportions of 70% and 30%, respectively, was used as the raw material for the front and back layers, and 100% petrochemical raw material A was used as the raw material for the intermediate layer. Each of the raw materials for the front and back layers and the intermediate layer was supplied to two extruders, melted at 280°C, and then co-extruded on a cooling roll set at 25°C in a 2-type, 3-layer structure, and cooled and solidified to obtain an unstretched sheet. Next, the obtained unstretched sheet was stretched 3.0 times in the longitudinal direction (MD) at 90°C using a roll stretcher. Furthermore, after preheating at 100°C in a tenter, it was stretched 4.0 times in the width direction (TD) at 120°C. Finally, it was heat-treated at 230°C to obtain a comparative example polyester film (y'1-1) with a thickness of 38 μm (front and back layers: 1.5 μm, intermediate layer: 35.0 μm).

[0135] [Preparation of Comparative Example Polyester Film (y'2-1)] A mixed raw material prepared by mixing petrochemical raw materials B and D in proportions of 70% and 30%, respectively, was used as the raw material for the front and back layers, and 100% petrochemical raw material A was used as the raw material for the intermediate layer. Each of the raw materials for the front and back layers and the intermediate layer was supplied to two extruders, melted at 280°C, and then co-extruded on a cooling roll set at 25°C in a 2-type, 3-layer structure, and cooled and solidified to obtain an unstretched sheet. Next, the obtained unstretched sheet was stretched 3.0 times in the longitudinal direction (MD) at 90°C using a roll stretcher. Furthermore, after preheating at 100°C in a tenter, it was stretched 4.0 times in the width direction (TD) at 120°C. Finally, it was heat-treated at 230°C to obtain a comparative example polyester film (y'2-1) with a thickness of 100 μm (front and back layers: 2.5 μm, intermediate layer: 95.0 μm).

[0136] The following measurements were performed using the polyester films for the above-mentioned examples and comparative examples. The results are shown in Table 1 below.

[0137] [Haze] Measured using a haze meter (HM-150, manufactured by Murakami Color Technology Research Institute Co., Ltd.) in accordance with JIS K 7136:2000.

[0138] [Color (y-value (reflection method))] The color (y-value) of the polyester films used for the examples and comparative examples was determined using a Konica Minolta Japan spectrophotometer "CM-3700d" as follows. The polyester film was sampled by punching it out with a round holder blade of approximately φ60 mm. The number of test sheets was set to the number of sheets that resulted in a stack thickness (total thickness at the time of measurement) closest to 500 μm. For example, for a 25 μm film, 20 films should be stacked, and for a 38 μm film, 13 films should be stacked. The measurement conditions were reflection conditions. The color (y-value) was measured in an environment of 23°C.

[0139] [Recycled Material Content] The recycled material content is the percentage of polyester made from recycled materials out of the total polyester raw materials used when manufacturing the polyester film.

[0140] [GHG Emission Factor] The GHG emission factor for polyester film using petrochemical raw materials, calculated by referring to ISO 14040, 14044, and ISO 14067, and the amount of CO2 reduction for polyester film that reuses recycled raw materials after being manufactured once were estimated and used as an indicator of reduced environmental impact.

[0141]

[0142] [Preparation of release film for example (Y1-1)] The above polyester film for example (y1-1) was coated with a release agent 1 by offline application at a rate (after drying) of 0.1 g / m². 2 The film was applied using a reverse gravure coating method, and after heat treatment at 180°C for 10 seconds, a release film for the example (Y1-1) was obtained.

[0143] [Preparation of release film for example (Y2-1)] The above polyester film for example (y2-1) was coated with a release agent 2 by offline application at a rate (after drying) of 0.1 g / m². 2 The film was applied using a reverse gravure coating method, and after heat treatment at 180°C for 10 seconds, a release film for the example (Y2-1) was obtained.

[0144] [Comparative Example Release Film (Y'1-1)] The above comparative example polyester film (y'1-1) was coated with a release agent 1 by offline application at a rate (after drying) of 0.1 g / m². 2 The film was applied using a reverse gravure coating method, and after heat treatment at 180°C for 10 seconds, a comparative release film (Y'1-1) was obtained.

[0145] [Comparative Example Release Film (Y'2-1)] The above comparative example polyester film (y'2-1) was coated with a release agent 2 by offline application at a rate (after drying) of 0.1 g / m². 2 The film was applied using a reverse gravure coating method, and after heat treatment at 180°C for 10 seconds, a comparative release film (Y'2-1) was obtained.

[0146] The following measurements were performed using the release films for the above-mentioned examples and comparative examples. The results are shown in Table 2 below.

[0147] [Haze] Measured using a haze meter (HM-150, manufactured by Murakami Color Technology Research Institute Co., Ltd.) in accordance with JIS K 7136:2000.

[0148] [Color (y-value (reflection method))] The color (y-value) of the release films for the examples and comparative examples was determined using a Konica Minolta Japan spectrophotometer "CM-3700d" as follows. The release films were punched out with a round holder blade of approximately φ60 mm and sampled. The number of test sheets was set to the number of sheets that resulted in a stack thickness (total thickness at the time of measurement) closest to 500 μm. For example, for a 25 μm film, 20 films should be stacked, and for a 38 μm film, 13 films should be stacked. The measurement conditions were reflection conditions. The color (y-value) was measured in an environment of 23°C.

[0149]

[0150] <Example 1> The intermediate adhesive layer composition was coated onto the example release film (Y1-1) in a sheet form to a thickness of 130 μm and then molded. The sheet was then covered with a release film that was easier to peel than the example release film (Y1-1). High-pressure mercury lamps were applied to both the front and back sides of the release film at a rate of 1000 mJ / cm². 2 The intermediate adhesive layer composition was crosslinked by irradiating it with ultraviolet light to produce an intermediate adhesive layer (S) with a thickness of 130 μm.

[0151] The surface adhesive composition was coated onto the example release film (Y2-1) in a sheet form to a thickness of 35 μm and molded, and then covered with a release film that was easier to peel than the example release film (Y2-1). High-pressure mercury lamps were applied to both the front and back sides through the release film at a rate of 1000 mJ / cm². 2 The surface adhesive composition was crosslinked by irradiation with ultraviolet light to produce a surface adhesive layer (H-1) with a thickness of 35 μm.

[0152] Next, a release film that was easier to peel off than the example release film (Y1-1) of the intermediate adhesive layer (S) was peeled off to expose the adhesive surface, and then the adhesive surface that was easier to peel off than the example release film (Y2-1) of the surface adhesive layer (H-1) was peeled off to expose the adhesive surface, and a two-layer adhesive sheet with two types of release films for bonding optical components was produced.

[0153] Next, the surface adhesive composition was coated onto the example release film (Y1-1) in a sheet shape to a thickness of 35 μm and formed, and then covered with a release film that was easier to peel than the example release film (Y1-1). High-pressure mercury lamps were applied to both the front and back sides through the release film at a rate of 1000 mJ / cm². 2 The surface adhesive composition was crosslinked by irradiation with ultraviolet light to produce a second surface adhesive layer (H-2) with a thickness of 35 μm.

[0154] Next, the release film (Y1-1) for the example of the adhesive sheet for bonding optical components with two types and two layers was peeled off to expose the adhesive surface, and the adhesive surface of the second surface adhesive layer (H-2), which has a release film that peels more easily than the release film (Y1-1) for the example was peeled off to expose the adhesive surface, and the adhesive surface was laminated with a laminator to produce an adhesive sheet for bonding optical components with two types and three layers of release film (adhesive layer thickness 200 μm) (H-1 / S / H-2 = 35 / 130 / 35).

[0155] <Comparative Example 1> The comparative example release film (Y'1-1) was coated with the intermediate adhesive layer composition to a thickness of 130 μm in a sheet form and then molded. The sheet was then covered with a release film that was easier to peel than the comparative example release film (Y'1-1). High-pressure mercury lamps were applied to both the front and back sides of the release film at a rate of 1000 mJ / cm². 2 The intermediate adhesive layer composition was crosslinked by irradiating it with ultraviolet light to produce an intermediate adhesive layer (S') with a thickness of 130 μm.

[0156] The surface adhesive composition was prepared and coated onto the comparative release film (Y'2-1) in a sheet shape with a thickness of 35 μm, and then molded and covered with a release film that was easier to peel than the comparative release film (Y'2-1). High-pressure mercury lamps were applied to both the front and back sides through the release film at a rate of 1000 mJ / cm².2 The surface adhesive composition was crosslinked by irradiation with ultraviolet light to produce a surface adhesive layer (H'-1) with a thickness of 35 μm.

[0157] Next, a release film that was easier to peel off than the comparative example release film (Y'1-1) of the intermediate adhesive layer (S') was peeled off to expose the adhesive surface, and then the adhesive surface that was easier to peel off than the comparative example release film (Y'2-1) of the surface adhesive layer (H'-1) was peeled off to expose the adhesive surface, and a two-layer adhesive sheet with two types of release films for bonding optical components was produced.

[0158] Next, the surface adhesive composition was coated onto the comparative example release film (Y'1-1) in a sheet shape to a thickness of 35 μm and molded, and then covered with a release film that was easier to peel than the comparative example release film (Y'1-1). High-pressure mercury lamps were applied to both the front and back sides through the release film at a rate of 1000 mJ / cm². 2 The surface adhesive composition was crosslinked by irradiation with ultraviolet light to produce a second surface adhesive layer (H'-2) with a thickness of 35 μm.

[0159] Next, the comparative example release film (Y'1-1) of the two-layer adhesive sheet for bonding optical components with two types of release films was peeled off to expose the adhesive surface, and the adhesive surface of the second surface adhesive layer (H'-2), which had a release film that peeled off more easily than the comparative example release film (Y'1-1), was laminated with a laminator to produce a two-layer adhesive sheet for bonding optical components with two types of release films (thickness 200 μm) (H'-1 / S' / H'-2 = 35 / 130 / 35).

[0160] The following measurements were performed using the adhesive sheets for bonding optical components with release films from Example 1 and Comparative Example 1. The results are shown in Table 3 below.

[0161] [Haze] Haze was measured using a haze meter (NDH-5000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7136:2000.

[0162] [Color (y-value (transmission method))] The color (y-value) of the adhesive sheets for bonding optical components with release films of Example 1 and Comparative Example 1 was measured using a spectrophotometer "SC-P" manufactured by Suga Test Instruments Co., Ltd., under transmission conditions at an environment of 23°C.

[0163] [Peeling Force] A sheet piece measuring 50 mm in width and 150 mm in length was cut from the adhesive sheet for bonding optical components with release film of Example 1 and Comparative Example 1. For peeling force (1) (light peeling force: peeling force of release film (Y1-1) in Example 1, and release film (Y'1-1) in Comparative Example 1), the sheet piece was used as a measurement sample. For peeling force (2) (heavy peeling force: peeling force of release film (Y2-1) in Example 1, and release film (Y'2-1) in Comparative Example 1), the release film on the light peeling side of the sheet piece was peeled off, and a PET film with a thickness of 50 μm was attached to the exposed adhesive surface as a backing, and this was used as a measurement sample. For each sample, the side opposite to the side where the peel force was measured was attached to a bakelite plate with double-sided tape and fixed to a base. Using a tensile testing machine, a 180° peel test was performed in accordance with JIS Z0237, and the adhesive force [N / 50mm] when peeled 180° from the surface of the adhesive layer of the release film was measured. This was defined as the "peel force of the release film." The measurements were performed under the conditions of 23℃±2℃, 50%±5%RH atmosphere, peel angle of 180°, tensile speed of 10000 mm / min, and tensile speed of 300 mm / min. Three tests (n) were performed, and the average value was calculated.

[0164]

[0165] As shown in Table 1, the polyester films for the examples (y1-1) and (y2-1) have a haze of 2% or less, and their y values ​​are close to those of the comparative example polyester films (y'1-1) and (y'2-1) that use petrochemical raw materials, thus uniquely achieving both haze and color as optical properties. Furthermore, since the polyester films for the examples (y1-1) and (y2-1) are recycled raw materials after being subjected to specific processing on a coated polyester film that has been manufactured once, they have a significantly lower environmental impact compared to the comparative example polyester films (y'1-1) and (y'2-1). In addition, the adhesive sheet for laminating optical components with a release film in Example 1 also has a haze of 3% or less and has a y value equivalent to that of the adhesive sheet for laminating optical components with a release film in Comparative Example 1. Based on the results above, this adhesive sheet for bonding optical components with a release film exhibits less haze than adhesive sheets for bonding optical components with a release film made solely from petrochemical raw materials. Therefore, it contributes to improved inspection accuracy in the user's automated in-process inspection machine and is an industrially beneficial invention with a significantly lower environmental impact.

[0166] While the above embodiments illustrate specific forms of the present invention, these embodiments are merely illustrative and should not be interpreted restrictively. Various modifications that are obvious to those skilled in the art are intended to fall within the scope of the present invention.

[0167] This adhesive sheet with release film for bonding optical components can be suitably used as an adhesive sheet for laminates for image display devices, image display devices, and component parts of image display devices.

Claims

1. An adhesive sheet for laminating optical components with a release film, comprising a release film (Y1) laminated on a first surface of an adhesive sheet having an adhesive layer (X), and a release film (Y2) laminated on a second surface of the adhesive sheet, wherein the release film (Y1) and the release film (Y2) are each polyester films having a release layer, and the polyester film is a polyester film with a haze of 2% or less and containing recycled materials.

2. The adhesive sheet for bonding optical members with a release film according to claim 1, wherein the peeling force (F1) when peeling the release film (Y1) from the adhesive sheet and the peeling force (F2) when peeling the release film (Y2) from the adhesive sheet have the following relationship: F1 < F2 ... (1) 3. The adhesive sheet for bonding optical members with a release film according to claim 1, wherein the average surface roughness (Sa1) of the surface of the adhesive sheet after peeling off the release film (Y1) and the average surface roughness (Sa2) of the surface of the adhesive sheet after peeling off the release film (Y2) have the following relationship: Sa1 > Sa2 ... (2) 4. The adhesive sheet for bonding optical members with a release film according to claim 1, wherein the haze (h1) of the polyester film (y1) constituting the release film (Y1) and the haze (h2) of the polyester film (y2) constituting the release film (Y2) have the following relationship: h1 > h2 ... (3) 5. The adhesive sheet for bonding optical members with a release film according to claim 4, wherein the color (y value) of the polyester films (y1) and (y2) measured by the method described below is 0.330 or less. <Measurement method: Color (y value (reflection method))> The color (y value) of the polyester films (y1) and (y2) is determined using a spectrophotometer as follows. The polyester films (y1) and (y2) are punched out with a round holder blade of approximately φ60 mm and sampled. The number of test sheets is the number of sheets that is closest to a stack thickness (total thickness at the time of measurement) of 500 μm. For example, for a 25 μm film, 20 films should be stacked, and for a 38 μm film, 13 films should be stacked. The measurement conditions are reflection conditions. The color (y value) measurement is performed in an environment of 23°C.

6. The GHG emission factors of the polyester films (y1) and (y2) are 7 kg_CO2. ２ The adhesive sheet for bonding optical components with a release film according to claim 4, wherein the weight is less than or equal to 1 kg of polyester film.

7. The adhesive sheet for bonding optical members with a release film according to claim 4, wherein the polyester films (y1) and (y2) include recycled raw materials obtained from the steps of: crushing a polyester film having a functional layer into chips using a pulverizer; putting the chips into a container of a chip washing device, adding hot water and an alkaline agent, and washing them while stirring to adjust to a desired internal temperature and washing time; and after the washing process, draining the liquid, rinsing with water, and then dehydrating / drying the removed chips.

8. The adhesive sheet for bonding optical components with a release film according to claim 1 or 2, wherein the haze of the adhesive sheet for bonding optical components with a release film, as measured by the following measurement method, is 3% or less. <Measurement method> Measured using a haze meter in accordance with JIS K 7136:2000.

9. The adhesive sheet for laminating optical components with a release film according to claim 1 or 2, wherein the color (y value) of the adhesive sheet for laminating optical components with a release film, measured by the measurement method described below, is 0.350 or less. <Measurement method: y value (transmission method)> The color (y value) of the adhesive sheet for laminating optical components with a release film is measured using a spectrophotometer under transmission conditions at an environment of 23°C.

10. A method for manufacturing a laminate for an image display device, comprising the steps of: peeling off a release film from an adhesive sheet for laminating optical members with a release film according to claim 1 or 2; and laminating an image display device component via the adhesive sheet for laminating optical members.

11. An image display device comprising a laminate for an image display device obtained by the manufacturing method described in claim 10.

12. An adhesive sheet for laminating optical members with a release film on one side, wherein the release film (Y1) is peeled off from the adhesive sheet for laminating optical members with a release film according to claim 1, and the adhesive sheet having the adhesive layer (X) and the release film (Y2) are laminated together, wherein the haze of the release film (Y2) is 2.0% or less and the sheet contains 80% by mass or more of recycled raw materials.

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