Laminated film, method for manufacturing same, and display device

Abstract

The present invention addresses the problem of providing: a laminated film which is less susceptible to thermal shrinkage, is capable of suppressing optical unevenness, and is capable of suppressing a decrease in definition; a method for producing the same; and a display device. This laminated film is provided with a carrier film, a first adhesive layer, a base film, a second adhesive layer, and a plurality of cured layers in this order, and is characterized in that the first adhesive layer and the second adhesive layer contain at least inorganic particles and a polyolefin resin, and the cured layers are bonded to each other. Comprising the first adhesive layer, the base material film, and the second adhesive layer, the thermal shrinkage rate X in the longitudinal direction and the thermal shrinkage rate Y in the width direction under the conditions of 130 DEG C and 90 minutes satisfy the following formulae (1) and (2), the base material film contains a cycloolefin resin, beads are contained between the plurality of cured layers, and the cured layers are bonded to the base material film. The plurality of cured layers have a refractive index difference, formula (1): Ylt; x [%], formula (2): 0.004 lt; {(X + Y) / 2} lt; 0.16 [%].

Description

Technical Field

[0001] This invention relates to laminated films, methods for manufacturing the same, and display devices. More specifically, it relates to laminated films that are resistant to thermal shrinkage, suppress optical non-uniformity, and suppress resolution degradation. Background Technology

[0002] In recent years, organic light-emitting diodes (OLEDs) utilizing organic EL (Electro Luminescence) have been used in various fields. Furthermore, these OLEDs are used, for example, in display devices. As a new component aimed at further improving the functionality of these OLEDs, such as enhancing image quality and reducing power consumption, a light extraction film, for example, is disclosed in Patent Document 1, thus attempting a technology to improve light extraction techniques.

[0003] Furthermore, in the components used in organic EL as described above, from the viewpoint of reducing functionality and environmental impact, thin-film processing is required. However, this can easily lead to thermal shrinkage, resulting in optical non-uniformity, reduced clarity, and poor appearance.

[0004] Here, "clarity" refers to a parameter related to the occurrence of focus shift when visually observing a displayed pattern. For example, when confirming a pattern through a laminate, if the pattern is clearly visible, it means that no focus shift has occurred, which is a state of high clarity (transparency). If the pattern is blurry, it means that a focus shift has occurred, which is a state of low clarity (transparency). This reduction in clarity (transparency) is a performance that occurs when light passing through the laminate is scattered within a narrow angular range, and this uniformity is an important indicator that directly affects the image quality of the display.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2017-84821 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] The present invention was made in view of the above-mentioned problems and conditions, and its solution is to provide a laminated film that is not prone to thermal shrinkage, can suppress optical non-uniformity, and can suppress the reduction of sharpness, a method for manufacturing the same, and a display device thereof.

[0010] Solution for solving the problem

[0011] In order to solve the above-mentioned problems, the inventors studied the causes of the problems and found that by controlling the thermal shrinkage rate in the length and width directions of a certain laminate portion of the laminated film within a certain range, the above-mentioned problems can be solved, thus completing the present invention.

[0012] That is, the above-mentioned problems of the present invention are solved by the following solution.

[0013] 1. A laminated film, comprising sequentially a carrier film, a first adhesive layer, a substrate film, a second adhesive layer, and a plurality of curing layers, characterized in that the first adhesive layer and the second adhesive layer contain at least inorganic particles and polyolefin resin, and

[0014] For the laminate portion comprising the first adhesive layer, the substrate film and the second adhesive layer, the heat shrinkage rate is measured at 130°C for 90 minutes. When the heat shrinkage rates in the length direction and the width direction are set as X and Y respectively, X and Y satisfy the following equations (1) and (2).

[0015] Formula (1): Y <X [%]

[0016] Formula (2): 0.004<{(X+Y) / 2}<0.16[%],

[0017] Furthermore, the substrate film contains a cyclic olefin resin, contains beads between the plurality of cured layers, and the plurality of cured layers have a refractive index difference.

[0018] 2. The laminated film according to claim 1, characterized in that the carrier film contains at least polyethylene terephthalate, and the peel adhesion of the carrier film to the first adhesive layer is in the range of 0.1 to 0.4 [N / 25mm].

[0019] 3. The laminated film according to claim 1, characterized in that the first adhesive layer and the second adhesive layer contain the same compound and have the same thickness.

[0020] 4. The laminated film according to claim 1, characterized in that the refractive index of the plurality of cured layers gradually increases from the substrate side to the outermost layer side.

[0021] 5. A method for manufacturing a laminated film, comprising the method for manufacturing a laminated film according to any one of claims 1 to 4, characterized in that it includes the following steps: for a laminated portion comprising a first adhesive layer, the substrate film and the second adhesive layer, measuring the heat shrinkage rate at 130°C for 90 minutes, and setting the heat shrinkage rates in the length direction and the width direction as X and Y respectively, adjusting X and Y in such a way that X and Y satisfy the following equations (1) and (2).

[0022] Formula (1): Y <X [%];

[0023] Formula (2): 0.004<{(X+Y) / 2}<0.16[%].

[0024] 6. A display device having an optical film, characterized in that it comprises a portion of a laminated film from any one of items 1 to 4, wherein the carrier film has been removed, as an optical film.

[0025] The effects of the invention

[0026] Through the above-described means of the present invention, it is possible to provide a laminated film that is not prone to thermal shrinkage, can suppress optical non-uniformity, and can suppress the reduction of sharpness, as well as a method for manufacturing the same and a display device.

[0027] Although the mechanism of action or manifestation of the effects of the present invention is not yet clear, it is speculated as follows.

[0028] The laminated film of the present invention is a laminated film comprising a carrier film, a first adhesive layer, a substrate film, a second adhesive layer and a plurality of curing layers in sequence. The first adhesive layer and the second adhesive layer contain at least inorganic particles and polyolefin resin. For the laminated portion comprising the first adhesive layer, the substrate film and the second adhesive layer, the heat shrinkage rate is measured at 130°C for 90 minutes. When the heat shrinkage rates in the length direction and the width direction are set as X and Y, respectively, X and Y satisfy the following formulas (1) and (2).

[0029] Formula (1): Y <X [%];

[0030] Formula (2): 0.004<{(X+Y) / 2}<0.16[%],

[0031] Furthermore, the substrate film contains a cyclic olefin resin, contains beads between the plurality of cured layers, and the plurality of cured layers have a refractive index difference.

[0032] As mentioned above, in the prior art, if a thin laminate is used, thermal shrinkage is likely to occur, resulting in problems such as optical inhomogeneity, reduced clarity, and poor appearance caused by this thermal shrinkage.

[0033] In particular, the aforementioned problems are more pronounced when the film is processed in a roll-to-roll manner. The reasons are as follows.

[0034] If the membrane is processed in a roll-to-roll manner, tension control in the length direction is relatively easy, but tension control in the width direction is difficult. Moreover, if heat is applied to the membrane, dimensional changes occur, particularly from the outer side of the membrane in the width direction, resulting in uneven processing.

[0035] In this invention, the thermal shrinkage rate of the laminate portion comprising the first adhesive layer, the substrate film, and the second adhesive layer is controlled to satisfy the relationship described in equation (2). Furthermore, considering the balance between thermal shrinkage rates in the length and width directions, equation (1) is intentionally satisfied, meaning the thermal shrinkage rate in the length direction is set to be greater than the thermal shrinkage rate in the width direction. It is presumed that this can suppress optical unevenness, reduced clarity, and poor appearance caused by this thermal shrinkage.

[0036] Furthermore, since the first adhesive layer and the second adhesive layer are present, and both adhesive layers contain at least inorganic particles and contain polyolefin resin with excellent flexibility, transparency can be ensured, and appropriate adhesion can be maintained while appropriately maintaining the anti-adhesion (resistance to the phenomenon of films sticking to each other) between the substrate film and the carrier film, or between the substrate film and the cured layer (functional layer).

[0037] Furthermore, since the substrate film contains cyclic olefin resin, its moisture permeability is reduced. Moreover, it is speculated that the different refractive indices created by the beads contained between the multiple cured layers improve light extraction performance. Attached Figure Description

[0038] Figure 1A This is an example of a schematic structural diagram of a laminated film when the curing layer has a two-layer structure.

[0039] Figure 1B This is an example of a schematic structural diagram of a laminated film when the curing layer has a two-layer structure.

[0040] Figure 1C This is an example of a schematic structural diagram of a laminated film when the curing layer has a two-layer structure.

[0041] Figure 2A This is an example of a schematic structural diagram of a laminated film when the curing layer has a three-layer structure.

[0042] Figure 2B This is an example of a schematic structural diagram of a laminated film when the curing layer has a three-layer structure.

[0043] Figure 2C This is an example of a schematic structural diagram of a laminated film when the curing layer has a three-layer structure.

[0044] Figure 2D This is an example of a schematic structural diagram of a laminated film when the curing layer has a three-layer structure.

[0045] Figure 3 A flowchart illustrating the fabrication process of the laminated film of the present invention.

[0046] Figure 4 This is a flowchart illustrating the process of fabricating a substrate film using a solution casting method.

[0047] Figure 5 A schematic diagram of an apparatus for fabricating a substrate film using a solution casting method.

[0048] Figure 6 A top view illustrating the internal structure of the tensioning device.

[0049] Figure 7 This is a side view of three areas within the tensioning device.

[0050] Figure 8 This is a top view of the three areas within the tensioning device.

[0051] Figure 9 A schematic diagram of the nozzle and heater arrangement when viewed from the front of the three areas inside the tensioning device.

[0052] Figure 10 This is a flowchart illustrating the process of fabricating a substrate film using the melt casting method.

[0053] Figure 11 A schematic diagram of an apparatus for producing a substrate film by melt casting.

[0054] Figure 12A This is one specific example of how the portion of the carrier film removed from the laminated film of the present invention can be applied to a self-luminous source.

[0055] Figure 12B This is one specific example of how the laminated film of the present invention, excluding the portion without the carrier film, can be applied to a self-luminous source. Detailed Implementation

[0056] The laminated film of the present invention comprises a carrier film, a first adhesive layer, a substrate film, a second adhesive layer and a plurality of curing layers in sequence. The first adhesive layer and the second adhesive layer contain at least inorganic particles and polyolefin resin. For the laminated portion containing the first adhesive layer, the substrate film and the second adhesive layer, the heat shrinkage rate is measured at 130°C for 90 minutes. When the heat shrinkage rates in the length direction and the width direction are set as X and Y respectively, X and Y satisfy the following formulas (1) and (2). Furthermore, the substrate film contains cyclic olefin resin, the plurality of curing layers contain beads, and the plurality of curing layers have a refractive index difference.

[0057] Formula (1): Y <X [%]

[0058] Formula (2): 0.004<{(X+Y) / 2}<0.16[%]

[0059] This feature is a common or corresponding technical feature of the following implementation methods (solutions).

[0060] As an embodiment of the present invention, from the viewpoint of suppressing the degradation of sharpness and suppressing optical unevenness, it is preferable that the carrier film contains at least polyethylene terephthalate, and that the peel adhesion of the carrier film to the first adhesive layer is in the range of 0.1 to 0.4 [N / 25mm], more preferably in the range of 0.2 to 0.3 [N / 25mm].

[0061] From the viewpoint of suppressing the degradation of sharpness, it is preferable that the first adhesive layer and the second adhesive layer contain the same compound and have the same thickness. Furthermore, in this invention, "having the same thickness" means that as long as it is within a range of approximately ±2%, it is considered to have the same thickness in practical terms.

[0062] From the viewpoint of improving light extraction performance, it is preferable that the refractive index of the plurality of cured layers gradually increases from the substrate side to the outermost layer side.

[0063] The method for manufacturing the laminated film of the present invention is suitable for manufacturing the laminated film of the present invention.

[0064] The display device of the present invention is suitable for use by having a portion of the carrier film removed from the laminated film of the present invention as an optical film.

[0065] The present invention, its constituent elements, and the methods and solutions for implementing the present invention will be described in detail below. Furthermore, in this application, "~" is used to indicate that the values ​​recorded before and after it are lower and upper limits.

[0066] I. Laminated film

[0067] The laminated film of the present invention comprises a carrier film, a first adhesive layer, a substrate film, a second adhesive layer and a plurality of curing layers in sequence. The first adhesive layer and the second adhesive layer contain at least inorganic particles and polyolefin resin. For the laminated portion including the first adhesive layer, the substrate film and the second adhesive layer, the heat shrinkage rate is measured at 130°C for 90 minutes. When the heat shrinkage rates in the length direction and the width direction are set as X and Y respectively, X and Y satisfy the following formulas (1) and (2). Furthermore, the substrate film contains cyclic olefin resin, the plurality of curing layers contain beads, and the plurality of curing layers have a refractive index difference.

[0068] Formula (1): Y <X [%]

[0069] Formula (2): 0.004<{(X+Y) / 2}<0.16[%]

[0070] Figure 1 is a schematic structural diagram of the laminated film of the present invention when the cured layer has a two-layer structure. For example, the following can be listed: Figure 1A , Figure 1B and Figure 1C That kind of structure.

[0071] The laminated film F1 of the present invention, when the curing layer is a two-layer structure, sequentially includes a carrier film CF, a first adhesive layer AL1, a substrate film SF, a second adhesive layer AL2, a curing layer L1, and a curing layer L2. Furthermore, the first adhesive layer AL1 and the second adhesive layer AL2 contain inorganic particles Ip, and beads Op are present between the curing layer L1 and the curing layer L2.

[0072] At this time, the cured layer L1 and the cured layer L2 have a refractive index difference. From the viewpoint of improving light extraction performance, it is preferable that the cured layer L1 is a low refractive index layer LL and the cured layer L2 is a high refractive index layer LH.

[0073] In addition, preferably, such as Figure 1C In this way, the beads Op are uniformly dispersed at a high density between the cured layers L1 and L2. It should be noted that the density and uniformity of these beads Op can be evaluated by measuring the clarity of the laminate.

[0074] To clarify, the terms "low refractive index layer" and "high refractive index layer" were used above. However, these terms are distinguished by their relative relationship, not by a specific numerical boundary. For convenience, in this specification, "low refractive index" refers to a refractive index of 1.49 or lower, and "low refractive index layer" refers to a cured layer with a refractive index of 1.49 or lower. Similarly, "high refractive index" refers to a refractive index greater than 1.49, and "high refractive index layer" refers to a cured layer with a refractive index greater than 1.49.

[0075] The structure of the laminated film of the present invention is not limited to that shown. Figure 1A , Figure 1B and Figure 1C Such a structure can also be a structure with multiple curing layers.

[0076] Figure 2 is a schematic structural diagram of a laminated film of the present invention with a three-layer structure of multiple cured layers. For example, the following can be listed: Figure 2A , Figure 2B , Figure 2C and Figure 2D That kind of structure.

[0077] The laminated film F2 of the present invention, when the curing layer is a three-layer structure, sequentially includes a carrier film CF, a first adhesive layer AL1, a substrate film SF, a second adhesive layer AL2, a curing layer L1, a curing layer L2, and a curing layer L3. Furthermore, the first adhesive layer AL1 and the second adhesive layer AL2 contain inorganic particles Ip, and beads Op are present between the curing layers L1 and L2.

[0078] In this structure, from the viewpoint of improving light extraction performance, it is preferable that the curing layer L1 has a low refractive index and the curing layer L3 has a high refractive index. Note that the curing layer L2 can be either low or high refractive index, but from the viewpoint of improving light extraction performance, it is preferable that the refractive index of the curing layers gradually increases in the order of curing layer L1, curing layer L2, and curing layer L3.

[0079] In addition, the bead Op can be like Figure 2B In that way, it is evenly dispersed between cured layer L1 and cured layer L3. Additionally, as... Figure 2A In that case, it can also be uniformly dispersed only between cured layers L1 and L2, such as Figure 2C In that case, it is also possible to include the beads across the cured layer L2 within the cured layers. Furthermore, it is preferable that the beads Op... Figure 2D In this way, they are uniformly dispersed at a high density between the cured layers L1 and L2.

[0080] 1. Carrier membrane

[0081] The laminated film of the present invention includes a carrier film bonded to a substrate film via a first adhesive layer. Furthermore, the carrier film is peelably bonded to the surface of the first adhesive layer. Additionally, the first adhesive layer contains inorganic particles, thereby ensuring transparency and improving anti-adhesion (resistance to the phenomenon of films sticking together). Moreover, the presence of a polyolefin resin improves flexibility, thus enabling the proper maintenance of adhesion while suppressing adhesion to the substrate film.

[0082] Furthermore, when the laminated film of the present invention is stored in the form of a film roll, the carrier film serves to inhibit the adhesion of the substrate film to other components and prevent damage to the substrate film.

[0083] The carrier film of the present invention can be composed of a resin substrate and an adhesive layer disposed on one side of the resin substrate. Alternatively, a carrier film without the aforementioned adhesive layer can also be used; a self-adhesive resin film can be employed as such a carrier film.

[0084] (1.1) Resin constituting the carrier membrane

[0085] The resin constituting the aforementioned carrier film is not particularly limited, and examples include cyclic olefin resins, polyester resins, polycarbonate resins, and polyamide resins. From the viewpoint of suppressing curling, a polyester resin is preferred. Furthermore, from the viewpoint of transparency and water resistance, polyethylene terephthalate (PET) is preferred.

[0086] (1.2) Thickness of the carrier membrane

[0087] The thickness of the carrier film involved in this invention is preferably in the range of 25 to 100 μm. If the thickness is 25 μm or more, the protective function of preventing damage to the substrate film can be fully utilized. Furthermore, if the thickness is 100 μm or less, the increase in film roll diameter during storage of the laminated film of this invention can be suppressed, and peeling of the carrier film from the substrate film during transport of the laminated film can be suppressed. Moreover, it is preferable that the thickness is in the range of 30 to 70 μm, as this can suppress bending of the carrier film during transport of the laminated film and suppress the increase in roll diameter.

[0088] (Measurement Method)

[0089] The method for measuring the thickness of the carrier film of the present invention can be, for example, using the method described in JIS B 7502 for a micrometer. Specifically, the thickness of a portion of the film or layer is randomly measured at 10 locations. Then, the arithmetic mean of the measurements at the 10 locations is calculated, and this arithmetic mean is taken as the thickness of the film or layer.

[0090] (1.3) Peel adhesion to the first adhesive layer

[0091] Regarding the peel adhesion force of the carrier film to the first adhesive layer according to the present invention, from the viewpoint of suppressing the degradation of sharpness and the suppression of optical unevenness, it is preferably in the range of 0.1 to 0.4 [N / 25mm]. When the adhesion force is higher than 0.1 [N / 25mm], it is less likely for the carrier film to lift during the formation of the cured layer, thereby enabling the cured layer to be formed uniformly without degradation of sharpness. In addition, when it is less than 0.4 [N / 25mm], it is less likely for wrinkles to form in the cured layer when the carrier film is removed from the laminated film, and optical unevenness is less likely to occur. It is more preferably in the range of 0.2 to 0.3 [N / 25mm]. In addition, generally, the adhesive layer sometimes changes over time, so it is preferable to evaluate it under uniform storage, humidity, and other conditions.

[0092] (Measurement Method)

[0093] The peel adhesion force [N / 25mm] of the carrier film to the first adhesive layer of the present invention can be measured, for example, by using the 180-degree peel test method specified in JIS Z 0237:2009 (Test method for adhesive tapes and adhesive sheets).

[0094] Furthermore, in this embodiment and comparative example, the laminated film was cut to a size of 25 mm in width and 100 mm in length, and after being placed at 25°C and 50%RH for 2 hours, the peel adhesion force [N / 25 mm] of the carrier film to the first adhesive layer was measured at a speed of 2.3 m / min.

[0095] (1.4) Other

[0096] As commercially available carrier films according to the present invention, SAT series and PAC series surface protective films manufactured by Sansei Chemicals Co., Ltd. of Japan are preferred, for example. Additionally, ZACROS series surface protective films manufactured by Fujimori Industries Co., Ltd. are also preferred.

[0097] 2. Laminated body portion

[0098] The laminate portion of the present invention comprises a first adhesive layer, a substrate film, and a second adhesive layer. This laminate portion is, for example, composed of the above-described... Figure 1A The laminated film F1 consists of the first adhesive layer AL1, the substrate film SF, and the second adhesive layer AL2.

[0099] (2.1) Thermal shrinkage rate

[0100] The thermal shrinkage rate of the laminate portion consisting of a first adhesive layer, a substrate film, and a second adhesive layer, as per the present invention, is calculated under conditions of 130°C and 90 minutes. The thermal shrinkage rate in the length direction of this laminate portion is defined as X, and the thermal shrinkage rate in the width direction is defined as Y. By ensuring that X and Y satisfy the following equations (1) and (2), optical non-uniformity can be suppressed, and sharpness can be ensured.

[0101] Formula (1) Y <X [%]

[0102] Formula (2) 0.004< {(X+Y) / 2} <0.16 [%]

[0103] Regarding the laminate portion of the present invention, thermal shrinkage is prone to occur because the thickness is set to be thin. In particular, when processing the film in a roll-to-roll manner, tension control in the length direction is relatively easy, but tension control in the width direction is difficult. Therefore, when heat is applied to the film, the dimensions of the outer side of the film in the width direction change, resulting in uneven processing.

[0104] The main means of controlling the heat shrinkage rate involved in this invention is the stretching method in the two-stage stretching process (S9) described later.

[0105] One of the features of the present invention is the control of the thermal shrinkage rate of the above-mentioned laminate portion, which is mainly achieved by controlling the thermal shrinkage rate of the substrate film in the above-mentioned laminate portion.

[0106] The main means of controlling heat shrinkage rate is to control the residual stress of the polymer constituting the film. Methods for controlling this include adjusting the stretching temperature, stretching speed, stretching ratio, heating holding time, cooling rate, residual solvent content, and post-stretching cooling rate.

[0107] Methods to reduce heat shrinkage include reducing the stretching speed, increasing the stretching temperature, extending the heating holding time, and slowing down the cooling rate. Additionally, methods such as adding a process after stretching that reduces the stretch ratio by a few percent, and extending the temperature holding time after stretching at a temperature above the polymer's glass transition temperature (Tg) can be cited.

[0108] Regarding the heating temperature, it is important to set the stretching temperature above the glass transition temperature (Tg) of the polymer constituting the film. Furthermore, regarding the amount of residual solvent, the lower the amount of residual solvent, the more effective it is in further enhancing the aforementioned effects.

[0109] As a means of reducing the thermal shrinkage rate in the width (TD) direction, it is effective to perform a film shrinkage process of about a few percent after stretching, in a state with the held ends in an environment at a temperature above the glass transition temperature (Tg).

[0110] In this invention, the thermal shrinkage rate of the laminate portion consisting of the first adhesive layer, the substrate film, and the second adhesive layer of the laminated film is controlled to satisfy the relationship of the above formula (2). In addition, considering the balance of thermal shrinkage rates in the length direction and the width direction, it is intentionally set to satisfy formula (1). That is, the thermal shrinkage rate in the length direction is set to be greater than the thermal shrinkage rate in the width direction. As a result, optical unevenness, reduced clarity, and poor appearance caused by thermal shrinkage can be suppressed. Furthermore, in this invention, as long as the above formulas (1) and (2) are satisfied, there is no particular limitation on the thermal shrinkage rates X and Y, but as for the absolute value of the thermal shrinkage rate, if the effect shrinkage of the cured layer after coating is also considered, it is preferably in the range of 0.0 to 1.0%, more preferably in the range of 0.002 to 0.2%, and even more preferably in the range of 0.004 to 0.1%.

[0111] (Measurement and calculation methods)

[0112] The calculation of the thermal shrinkage rate of the above-mentioned laminated body portion in the length direction (MD direction) and width direction (TD direction) of the present invention can be performed, for example, as described below.

[0113] First, the laminated body was cut into pieces 100mm wide and 100mm long to create a test piece. Cross-shaped scratches were made at the four corners of the test piece (hereinafter, these scratches will also be referred to as "cross-shaped scratches"). Then, using a CNC three-dimensional measuring machine (product name "LEGEX774") manufactured by Mitutoyo Corporation of Japan, the length in the length direction (MD direction) and the width in the width direction (TD direction) of the four points at the center of the cross-shaped scratches before heating were measured [mm].

[0114] Subsequently, the laminated portion was placed in an oven and heated at 130°C for 90 minutes, and then cooled at room temperature for 1 hour. Then, the length [mm] of the above-mentioned four points in the length direction (MD direction) and width direction (TD direction) was measured again using the above-mentioned CNC three-dimensional measuring machine.

[0115] Substitute the measured lengths [mm] in the length direction (MD direction) and width direction (TD direction) of the four points before heating and after heating into the following formula to calculate the thermal shrinkage rate of each direction in the length direction (MD direction) and width direction (TD direction).

[0116] Heat shrinkage rate [%] = {(Length before heating [mm] - Length after heating [mm]) / Length before heating [mm]} × 100

[0117] (2.2) First adhesive layer and second adhesive layer

[0118] The first and second adhesive layers of the present invention comprise at least inorganic particles and a polyolefin resin. Other resins may also be included. These resins are preferably crosslinked with a crosslinking agent, and may also contain other components as needed. That is, the first and second adhesive layers comprise a composition containing inorganic particles and a resin (a composition for the first adhesive layer or a composition for the second adhesive layer) or a crosslink thereof, and may further contain other components as needed.

[0119] The first and second adhesive layers possess anti-blocking properties by containing inorganic particles. Furthermore, due to the excellent flexibility derived from the inclusion of polyolefin resin, it is possible to maintain appropriate anti-blocking properties between the substrate film and the carrier film, or between the substrate film and the cured layer (functional layer), while simultaneously maintaining adequate adhesion.

[0120] By ensuring that the first and second adhesive layers contain the same compound and have the same thickness, a balance of thermal shrinkage in the thickness direction of the film can be maintained, facilitating the uniform formation of the cured layer. Therefore, from the viewpoint of suppressing the degradation of clarity, it is preferable that the first and second adhesive layers contain the same compound and have the same thickness.

[0121] (2.2.1) Particles contained in the adhesive layer

[0122] (Inorganic particles)

[0123] The first and second adhesive layers of the present invention contain at least inorganic particles. Additionally, other organic particles may be included as needed. By including inorganic particles, anti-adhesion properties can be imparted.

[0124] The first and second adhesive layers of the present invention contain the aforementioned inorganic or organic particles, thereby forming irregularities on the surface of the membrane, which can impart sliding and anti-adhesion properties.

[0125] Examples of inorganic particles include silica, titanium dioxide, aluminum oxide, zirconium oxide, and calcium carbonate. Specifically, silica particles (such as those manufactured by Nippon Shokubai Co., Ltd., "SEAHOSTAR series" KE-P20, KE-P30, etc.) are preferred.

[0126] The average particle size of the aforementioned inorganic particles can be in the range of 20 to 500 nm, preferably in the range of 50 to 400 nm. If it is within the above range, both transparency and anti-blocking properties can be achieved.

[0127] (Organic particles)

[0128] Examples of organic particles include acrylic resin particles, styrene resin particles, polyester resin particles, polyurethane resin particles, polycarbonate resin particles, polyamide resin particles, silicone resin particles, and fluorine resin particles. Additionally, copolymer resin particles containing two or more monomers used in the synthesis of these resins can also be listed.

[0129] The average particle size of the organic particles can be in the range of 20 to 500 nm, preferably in the range of 30 to 300 nm. If it is within the above range, both transparency and anti-blocking properties can be achieved.

[0130] (2.2.2) The resin contained in the adhesive layer

[0131] (Polyolefin resin)

[0132] The olefin can be an olefin with 2 to 6 carbon atoms, such as ethylene or propylene. The polyolefin involved in this invention is preferably an acid-modified polyolefin. This acid-modified polyolefin is an olefin polymer containing structural units derived from unsaturated carboxylic acids. This olefin polymer can be a random copolymer or a graft copolymer. Furthermore, the olefin polymer may further contain structural units derived from other copolymer components such as (meth)acrylates.

[0133] Examples of acid-modified polyolefins include ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid-maleic anhydride copolymer, acid-modified polyethylene, acid-modified polypropylene, acid-modified ethylene-propylene resin, acid-modified ethylene-butene resin, acid-modified propylene-butene resin, and acid-modified ethylene-propylene-butene resin.

[0134] Examples of unsaturated carboxylic acids include (meth)acrylic acid, maleic acid, maleic anhydride, itaconic acid, and itaconic anhydride. The content of structural units derived from unsaturated carboxylic acids is, relative to all structural units, in the range of 0.1 to 25% by mass, preferably in the range of 0.5 to 15% by mass.

[0135] Commercially available polyolefin products include, for example, "ACRYDIC52-666" manufactured by DIC Corporation; "Arrowbase Series" products SB-1200, SE-1010, SE-1013N, SE-1030N, SD-1010, TC-4010, and TD-4010 manufactured by Uniqlo Co., Ltd.; and "Hightech Series" products S3148 and S3121 manufactured by Toho Chemical Co., Ltd. S8512, P-5060N, P-9018; S-120, S-75N, V100, H-200, H-300, EV210H (trade name: UNISTOLE series) manufactured by Mitsui Chemicals Co., Ltd.; XHP-400 (trade name: CHEMIPEARL series) manufactured by Mitsui Chemicals Co., Ltd.; ZAIKTHENE A and ZAIKTHENE L (trade name: ZAIKTHENE series) manufactured by Sumitomo Seika Co., Ltd.; NZ-1004, NZ-1005, NZ-1022 (trade name: HARDLEN series) manufactured by Toyobo Co., Ltd.

[0136] 〔content〕

[0137] Regarding the polyolefin content, for example, it is preferably 40% by mass or more relative to the resin contained in the resin-containing composition (the composition for the first adhesive layer). More preferably, it is 50% by mass or more, and even more preferably 60% by mass or more.

[0138] When the resin contained in the resin-containing composition (the composition for the first adhesive layer) comprises polyolefin and urethane resin, their mass ratio may be, for example, 90 / 10 to 40 / 60. Alternatively, a mass ratio of 90 / 10 to 50 / 50 is preferred.

[0139] (Other resins)

[0140] Examples of resins other than polyolefins included in the first and second adhesive layers of this invention include polyurethane, polyester, polyvinyl chloride, acrylic polymers, modified silicone polymers, and styrene-butadiene rubber. These resins can be used alone or in combination. For example, a combination of polyolefin and polyurethane can be used as a combination of two or more resins.

[0141] [Polyurethane]

[0142] Polyurethane is, for example, a polymer obtained by reacting a polyol compound with a polyisocyanate compound. The polyol component constituting the polyurethane includes polyether polyols. More preferably, polytetramethylene glycol is a polyether polyol.

[0143] Commercially available polyurethane products include, for example, AP-201, AP-40F, HW-140SF, and WLS-202 from the "HYDRAN series" manufactured by DIC Corporation; SF-210, SF460, SF870, SF420, and SF-420NS from the "Superflex series" manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.; and "TAK" from Mitsui Chemicals Co., Ltd. The ELAC series includes models such as W-615, W6010, W-6020, W-6061, W-405, W-5030, W-5661, W-512A-6, W-635, WPB-6601, WS-6021, WS-5000, WS-5100, WS-4000, WSA-5920, WF-764, and ADEKA Corporation's development product "SPX-0882".

[0144] [Polyester]

[0145] Commercially available polyester products include, for example, those manufactured by Toyobo Co., Ltd. under the trade name "VYLONAL Series" such as MD1400, MD1480, MD1245, and MD1500, and those manufactured by Koyo Chemical Industry Co., Ltd. under the trade name "PLAS COAT Series" such as Z-221, Z-561, Z-730, RZ-142, and Z-687.

[0146] Polyvinyl chloride

[0147] Commercially available polyvinyl chloride products include, for example, L509, manufactured by Asahi Kasei Corporation under the trade name "SARAN LATEX series".

[0148] [Acrylic polymers]

[0149] Commercially available acrylic polymers include, for example, WS-700 from Nippon Shokubai Co., Ltd., marketed under the trade name "EPOCROSS WS series", and NUKOTE series from Shin-Nakamura Chemical Co., Ltd.

[0150] [Modified Organosilicon Polymers]

[0151] Commercially available modified organosilicon polymers include, for example, WSA1060 and WSA1070 manufactured by DIC Corporation under the trade name "CERANATE series", and H7620, H7630, and H7650 manufactured by Asahi Kasei Chemicals Co., Ltd.

[0152] [Styrene-butadiene rubber]

[0153] Commercially available styrene-butadiene rubber products include, for example, NIPOL LX415, NIPOL LX407, NIPOL V1004, NIPOL MH8101, and SX1105 manufactured by ZEON Corporation of Japan.

[0154] (2.2.3) Crosslinking agent

[0155] The resin described above is preferably crosslinked using a crosslinking agent. Examples of crosslinking agents include oxazoline compounds, carbodiimide compounds, isocyanate compounds, and epoxy compounds. When the resin is a polyolefin, the crosslinked product of the polyolefin is more preferably a crosslinked product of an acid-modified polyolefin. "Acid-modified polyolefin crosslinked product" refers to a crosslinked product comprising an acid-modified polyolefin and a crosslinking agent.

[0156] (Oxazoline compounds)

[0157] Oxazoline compounds can be compounds having two or more oxazoline groups within their molecules. Commercially available oxazoline compounds include, for example, the EPOCROSS (registered trademark) series, such as WS-700 manufactured by Nippon Shokubai Co., Ltd.

[0158] (Carbodiimide compound)

[0159] Carbodiimide compounds can be compounds having two or more carbodiimide groups within their molecules. Examples of carbodiimide compounds include V-02, V-02-L2, SV-02, V-04, and E-02, manufactured by Nisshinbo Chemical Co., Ltd. and marketed under the "CARBODILITE series".

[0160] (Isocyanate compounds)

[0161] An isocyanate compound is a compound containing two or more isocyanate groups in one molecule, and can be any of aliphatic isocyanates, aromatic isocyanates, or alicyclic isocyanates. Examples of isocyanate compounds include hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, and phenylenediamine diisocyanate. Furthermore, an isocyanate compound can be a compound that has been end-capped with a capping agent.

[0162] (Epoxy compounds)

[0163] As an epoxy compound, a compound having one or more epoxy groups in its molecule is used. Alternatively, when using a polymer (epoxy resin) having two or more epoxy groups in its molecule, a compound having two or more functional groups that react with epoxy groups in its molecule may also be used.

[0164] Here, "functional groups that react with epoxy groups" can be exemplified by, for example, carboxyl groups, phenolic hydroxyl groups, mercapto groups, and primary or secondary aromatic amino groups. From the viewpoint of three-dimensional curability, it is particularly preferable to have two or more of these functional groups in one molecule. Examples of polymers having one or more epoxy groups within the molecule include epoxy resins.

[0165] [Epoxy Resin]

[0166] Examples of epoxy resins include bisphenol A type epoxy resins derived from bisphenol A and epichlorohydrin, bisphenol F type epoxy resins derived from bisphenol F and epichlorohydrin, bisphenol S type epoxy resins, phenolic varnish type epoxy resins, cresol phenolic varnish type epoxy resins, bisphenol A phenolic varnish type epoxy resins, bisphenol F phenolic varnish type epoxy resins, alicyclic epoxy resins, diphenyl ether type epoxy resins, hydroquinone type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, fluorene type epoxy resins, trifunctional epoxy resins, tetrafunctional epoxy resins, and other multifunctional epoxy resins, glycidyl ester type epoxy resins, glycidylamine type epoxy resins, hydantoin type epoxy resins, isocyanurate type epoxy resins, and aliphatic chain epoxy resins. Furthermore, these epoxy resins can be halogenated or hydrogenated.

[0167] Commercially available epoxy resins include, but are not limited to, the following examples. Furthermore, two or more epoxy resins can be used in combination.

[0168] Commercially available products manufactured by Japan Epoxy Resin Co., Ltd. include JER Co., Ltd., 828, 1001, 801N, 806, 807, 152, 604, 630, 871, YX8000, YX8034, and YX4000.

[0169] Commercially available products manufactured by DIC Corporation include the EPICLON 830, EXA835LV, HP4032D, and HP820.

[0170] As commercially available products manufactured by ADEKA Co., Ltd., the EP4100 series, EP4000 series, and EPU series can be listed.

[0171] Commercially available products manufactured by Dai-Cellulose Chemical Co., Ltd. include the CELLOXIDE series (2021, 2021P, 2083, 2085, 3000, etc.), the EPOLEAD series, and the EHPE series.

[0172] Commercially available products manufactured by Nippon Steel Chemical Co., Ltd. include the YD series, YDF series, YDCN series, YDB series, and phenoxy resins. Among these, phenoxy resins include polyhydroxy polyethers synthesized from bisphenols and epichlorohydrins, which have epoxy groups at both ends (YP series), etc.

[0173] Commercially available products manufactured by Nagase Chemtex include the DENACOL series, among others.

[0174] As commercially available products manufactured by Kyoeisha Chemical Co., Ltd., examples include the Epolite series.

[0175] (2.2.4) Other components

[0176] With regard to the first and second adhesive layers of the present invention, other components besides those described above may be included as needed. Examples of other components include leveling agents, polymerization initiators, polymerization accelerators, viscosity modifiers, slip agents, dispersants, plasticizers, heat stabilizers, light stabilizers, lubricants, antioxidants, flame retardants, colorants, antistatic agents, compatibilizers, etc.

[0177] (2.2.5) Thickness of the adhesive layer

[0178] There are no particular limitations on the thickness of the first and second adhesive layers involved in this invention. Preferably, it is in the range of 10 to 1000 nm, more preferably in the range of 20 to 500 nm, and even more preferably in the range of 50 to 400 nm. Furthermore, the thickness of the adhesive layer involved in this invention can be measured using the same method as that used for the carrier film described above.

[0179] (2.2.6) Method for forming adhesive layer

[0180] The present invention relates to a first adhesive layer formed on one side of a substrate film, and then a second adhesive layer formed on the other side of the substrate film. The two adhesive layers can be formed by applying (coating) the adhesive layers with a composition to the surface of the substrate film and then drying or heating.

[0181] The adhesive layer composition can be a solution formed by dispersing or dissolving the aforementioned inorganic particles, organic particles, resin, crosslinking agent, and other components in a solvent (e.g., water). The total solids concentration of the adhesive layer composition can be set according to the type of component, solubility, coating viscosity, wettability, and coating thickness. To obtain an adhesive layer with high surface uniformity, the total solids concentration is preferably in the range of 1 to 100 parts by weight relative to 100 parts by weight of solvent, and more preferably in the range of 1 to 50 parts by weight.

[0182] The viscosity of the composition for the adhesive layer can be any suitable viscosity within the coatable range. As for this viscosity, the value measured at a shear rate of 1000 [1 / s] at 23°C is preferably in the range of 1 to 50 [mPa·sec], more preferably in the range of 2 to 10 [mPa·sec]. If it is within such a range, an adhesive layer with excellent surface uniformity can be formed.

[0183] The adhesive layer composition can be prepared by any method. For example, it can be used with commercially available solutions or dispersions, or with the addition of solvents to commercially available solutions or dispersions, or with solid components dissolved or dispersed in various solvents.

[0184] As a method for applying (coating) the adhesive layer composition, any method can be used, such as a method using a gravure printing machine or a die-coating machine. When applying the adhesive layer to the substrate film, as a pretreatment to improve wettability, solvent modification treatment, corona treatment, plasma treatment, etc., can be performed on the surface of the substrate film.

[0185] (2.3) Substrate film

[0186] The substrate film of the present invention contains a thermoplastic resin, and as this thermoplastic resin, it contains at least a cyclic olefin resin. By containing a cyclic olefin resin in the substrate film, stretchability and crystallinity are easily controlled, ensuring good adhesion. Furthermore, the substrate film can also undergo surface modification treatment after manufacturing. Additionally, the substrate film may contain other thermoplastic resins besides cyclic olefin resins as the resin, and may also contain plasticizers and any other components as additives.

[0187] The phase difference value of the substrate film of the present invention is in the range of 0~10 nm. Here, in this specification, "phase difference value" refers to the in-plane retardation value. The "in-plane retardation value" is an index that represents the degree of birefringence in the in-plane direction of a refractive index anisotropic body. It is the value expressed by the following formula when the refractive index in the slow axis direction with the largest refractive index in the in-plane direction is set as Nx, the refractive index in the fast axis direction orthogonal to the slow axis direction is set as Ny, and the thickness in the direction perpendicular to the in-plane direction of the refractive index anisotropic body is set as d.

[0188] Re[nm] = (Nx - Ny) × d[nm]

[0189] The in-plane retardation value (Re value) can be measured, for example, using the KOBRA-WR manufactured by Oji Measurement Instruments Co., Ltd., employing the parallel Nicol rotation method. Alternatively, the in-plane retardation value for small regions can be measured using the AxoScan manufactured by AXOMETRICS (USA) employing the Mueller matrix. Furthermore, unless otherwise specified in this specification, the in-plane retardation value refers to the value at a wavelength of 550 nm.

[0190] (2.3.1) Resin contained in the substrate film

[0191] (Cyclic olefin resins)

[0192] Examples of cyclic olefin resins (hereinafter also referred to as "COP") include the following cyclic olefin resins.

[0193] Cycloolefin resins are preferably polymers of cycloolefin monomers or copolymers of cycloolefin monomers and other comonomers.

[0194] [Structure: General Formula (A-1) and General Formula (A-2)]

[0195] As a cyclic olefin monomer, a cyclic olefin monomer having a norbornene skeleton is preferred, and a cyclic olefin monomer having the structure shown in the following general formula (A-1) or (A-2) is more preferred.

[0196] [Chemistry 1]

[0197] General formula (A-1)

[0198]

[0199] In general formula (A-1), R 1 ~R 4 Each can independently represent a hydrogen atom, a hydrocarbon group with 1 to 30 carbon atoms, or a polar group. p represents an integer from 0 to 2. Where R... 1 ~R 4 The case where all atoms simultaneously represent hydrogen atoms, R 1 and R 2 Simultaneously representing the case of hydrogen atoms, and R 3 and R 4 Except for cases where hydrogen atoms are also represented.

[0200] R 1 ~R 4 》

[0201] As in general formula (A-1) R 1 ~R 4The hydrocarbon group representing 1 to 30 carbon atoms is preferably a hydrocarbon group representing 1 to 10 carbon atoms, and more preferably a hydrocarbon group representing 1 to 5 carbon atoms. The hydrocarbon group representing 1 to 30 carbon atoms may further have a linking group comprising a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, or a silicon atom. Examples of such linking groups include divalent polar groups such as carbonyl, imino, ether, silyl ether, and thioether. Examples of hydrocarbon groups representing 1 to 30 carbon atoms include methyl, ethyl, propyl, and butyl.

[0202] As in general formula (A-1) R 1 ~R 4 Examples of polar groups include carboxyl, hydroxyl, alkoxy, alkoxycarbonyl, aryloxycarbonyl, amino, amide, and cyano. Among these, carboxyl, hydroxyl, alkoxycarbonyl, and aryloxycarbonyl are preferred, and from the viewpoint of ensuring solubility during solution film formation, alkoxycarbonyl and aryloxycarbonyl are preferred.

[0203] p

[0204] In general formula (A-1), from the viewpoint of improving the heat resistance of the film, p is preferably 1 or 2. When p is 1 or 2, the resulting polymer has a large volume, and the glass transition temperature is easily increased.

[0205] [Chemistry 2]

[0206] General formula (A-2)

[0207]

[0208] In general formula (A-2), R 5 R represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having 1 to 5 carbon atoms. 6 This indicates a carboxyl, hydroxyl, alkoxycarbonyl, aryloxycarbonyl, amino, amide, cyano, or halogen atom (fluorine, chlorine, bromine, or iodine). p represents an integer from 0 to 2.

[0209] R 5 and R 6 》

[0210] R in general formula (A-2) 5 Preferably, it represents a hydrocarbon group having 1 to 5 carbon atoms; more preferably, it represents a hydrocarbon group having 1 to 3 carbon atoms. R in general formula (A-2) 6 Preferably, the radicals are carboxyl, hydroxyl, alkoxycarbonyl, and aryloxycarbonyl. From the viewpoint of ensuring solubility during solution film formation, alkoxycarbonyl and aryloxycarbonyl are more preferred.

[0211] p

[0212] The p in general formula (A-2) is the same as the p in general formula (A-1).

[0213] For cycloolefin monomers having a structure represented by general formula (A-2), it is preferable to improve their solubility in organic solvents. Generally, organic compounds reduce crystallinity by disrupting symmetry, thus increasing their solubility in organic solvents. R in general formula (A-2) 5 and R 6 The ring-forming carbon atoms are substituted only on one side of the molecular axis of symmetry, resulting in low molecular symmetry. This means that the cycloolefin monomers with the structure represented by the general formula (A-2) have high solubility, making them suitable for manufacturing the substrate film of the present invention using a solution casting method.

[0214] Regarding the proportion of cyclic olefin monomers having the structure represented by general formula (A-2) in the polymer of cyclic olefin monomers, relative to the total amount of all cyclic olefin monomers constituting the cyclic olefin resin, it can be, for example, 70 mol% or more, preferably 80 mol% or more, and more preferably 100 mol%. If a certain amount or more of cyclic olefin monomers having the structure represented by general formula (A-2) is included, the orientation of the resin is improved, and therefore the phase difference (retardation) value tends to increase.

[0215] Hereinafter, specific examples of cyclic olefin monomers having a structure represented by general formula (A-1) are shown in Examples 1 to 14, and specific examples of cyclic olefin monomers having a structure represented by general formula (A-2) are shown in Examples 15 to 34.

[0216] [Chemistry 3]

[0217]

[0218] Examples of comonomers that can copolymerize with cyclic olefin monomers include comonomers that can undergo ring-opening copolymerization with cyclic olefin monomers and comonomers that can undergo addition copolymerization with cyclic olefin monomers.

[0219] Examples of comonomers that can undergo ring-opening copolymerization include cyclic olefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene.

[0220] Examples of addition copolymerizable comonomers include compounds containing unsaturated double bonds, vinyl cyclic hydrocarbon monomers, and (meth)acrylates. Examples of compounds containing unsaturated double bonds include olefinic compounds with 2 to 12 carbon atoms (preferably 2 to 8), such as ethylene, propylene, and butene. Examples of vinyl cyclic hydrocarbon monomers include vinylcyclopentene monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene. Examples of (meth)acrylates include alkyl (meth)acrylates with 1 to 20 carbon atoms, such as meth(meth)acrylate, 2-ethylhexyl(meth)acrylate, and cyclohexyl(meth)acrylate.

[0221] Regarding the content ratio of cyclic olefin monomers in the copolymer of cyclic olefin monomers and copolymeric monomers, relative to the total of all monomers constituting the copolymer, it can be in the range of 20 to 80 mol%, preferably in the range of 30 to 70 mol%.

[0222] As mentioned above, cyclic olefin resins are polymers obtained by polymerizing or copolymerizing cyclic olefin monomers having a norbornene skeleton, preferably cyclic olefin monomers having a structure represented by general formula (A-1) or (A-2), and examples include the following polymers (1) to (7).

[0223] (1) Ring-opening polymers of cyclic olefin monomers,

[0224] (2) Ring-opening copolymers of cyclic olefin monomers and comonomers that can undergo ring-opening copolymerization with them,

[0225] (3) The hydride of the ring-opening (co)polymer of (1) or (2) above,

[0226] (4) A (co)polymer with added hydrogen after cyclization of the ring-opening (co)polymer of (1) or (2) above via Friedel-Crafts reaction.

[0227] (5) Saturated copolymers of cyclic olefin monomers and compounds containing unsaturated double bonds,

[0228] (6) Addition copolymers of cyclic olefin monomers and vinyl cyclic hydrocarbon monomers and their hydrides,

[0229] (7) Alternating copolymers of cyclic olefin monomers and (meth)acrylates.

[0230] The polymers mentioned in (1) to (7) can all be obtained by known methods, such as those described in Japanese Patent Application Publication No. 2008-107534 and Japanese Patent Application Publication No. 2005-227606.

[0231] The catalyst and solvent used in the ring-opening copolymerization in (2) above can be, for example, those described in paragraphs 0019 to 0024 of Japanese Patent Application Publication No. 2008-107534. The catalyst used in the hydrides in (3) and (6) above above can be, for example, those described in paragraphs 0025 to 0028 of Japanese Patent Application Publication No. 2008-107534. The acidic compound used in the Friedel-Crafts reaction in (4) above above can be, for example, that described in paragraph 0029 of Japanese Patent Application Publication No. 2008-107534. The catalyst used in the addition polymerization in (5) to (7) above above can be, for example, those described in paragraphs 0058 to 0063 of Japanese Patent Application Publication No. 2005-227606. The alternating copolymerization reaction described in (7) above can be carried out according to the method described in paragraphs 0071 and 0072 of, for example, Japanese Patent Application Publication No. 2005-227606.

[0232] Preferably, the polymers (1) to (3) and (5) above are used, and more preferably the polymers (3) and (5) above are used.

[0233] [Structure: General Formula (B-1) and General Formula (B-2)]

[0234] That is, for cycloolefin resins, from the viewpoint of increasing the glass transition temperature and improving light transmittance, it is preferable to include at least one of the structural units represented by the following general formula (B-1) and the following general formula (B-2). Moreover, it is more preferable to include only the structural unit represented by the following general formula (B-2), or to include both the structural units represented by the following general formula (B-1) and the structural units represented by the following general formula (B-2).

[0235] The structural unit represented in general formula (B-1) is a structural unit derived from the cyclic olefin monomer represented in general formula (A-1) above, and the structural unit represented in general formula (B-2) is a structural unit derived from the cyclic olefin monomer represented in general formula (A-2) above.

[0236] [Chemistry 4]

[0237] General formula (B-1)

[0238]

[0239] In general formula (B-1), X represents -CH=CH- or -CH2CH2-. 1 ~R 4 And p are respectively related to R in general formula (A-1) 1 ~R 4 Same as p.

[0240] [Chemistry 5]

[0241] General formula (B-2)

[0242]

[0243] In general formula (B-2), X represents -CH=CH- or -CH2CH2-. 5 ~R 6 And p are respectively related to R in general formula (A-2) 5 ~R 6 Same as p.

[0244] 〔content〕

[0245] Regarding the content of cyclic olefin resin, it is preferably 70% by mass or more, and more preferably 80% by mass or more, relative to the substrate film of the present invention.

[0246] 〔other〕

[0247] The cyclic olefin resins of the present invention can be commercially available. Examples of commercially available cyclic olefin resins include Arton G (e.g., G7810), Arton F, Arton R (e.g., R4500, R4900, and R5000), and Arton RX manufactured by JSR Corporation.

[0248] The intrinsic viscosity [η]inh of cycloolefin resins, measured at 30°C, is preferably between 0.2 and 5 cm⁻¹. 3 Within the range of / g, more preferably within 0.3~3cm 3 Within the range of / g, it is further preferred to be 0.4~1.5cm. 3 Within the range of / g.

[0249] The number average molecular weight (Mn) of the cyclic olefin resin is preferably in the range of 8,000 to 100,000, more preferably in the range of 10,000 to 80,000, and even more preferably in the range of 12,000 to 50,000.

[0250] The weight-average molecular weight (Mw) of the cyclic olefin resin is preferably in the range of 20,000 to 300,000, more preferably in the range of 30,000 to 250,000, and even more preferably in the range of 40,000 to 200,000.

[0251] The number-average molecular weight and weight-average molecular weight of cyclic olefin resins can be determined by gel permeation chromatography (GPC) converted to polystyrene.

[0252] Gel permeation chromatography

[0253] Solvent: dichloromethane

[0254] Columns: Shodex K806, K805, K803G (three columns manufactured by Showa Denko Co., Ltd. are used for connection)

[0255] Column temperature: 25℃

[0256] Sample concentration: 0.1% by mass

[0257] Detector: RI Model 504 (manufactured by GL Science)

[0258] Pump: L6000 (manufactured by Hitachi, Ltd.)

[0259] Flow rate: 1.0 ml / min

[0260] Calibration curves: Calibration curves were obtained using 13 samples of standard polystyrene (STK standard polystyrene manufactured by Tosoh Corporation) with a Mw range of 500 to 2,800,000. The 13 samples were preferably used at approximately equal intervals.

[0261] When the intrinsic viscosity [η]inh, number-average molecular weight, and weight-average molecular weight are within the above ranges, the heat resistance, water resistance, chemical resistance, mechanical properties, and processability as a film of cyclic olefin resins become good.

[0262] The glass transition temperature (Tg) of cycloolefin resins is typically above 110°C, preferably in the range of 110~350°C, more preferably in the range of 120~250°C, and even more preferably in the range of 120~220°C. When the glass transition temperature (Tg) is above 110°C, deformation under high-temperature conditions is easily suppressed. On the other hand, when the glass transition temperature (Tg) is below 350°C, molding and processing become easier, and heat-induced resin degradation during molding and processing is also easily suppressed. A range of 140~200°C is more preferred.

[0263] (Other thermoplastic resins)

[0264] As thermoplastic resins other than cyclic olefin resins (cyclic olefin resins) as described in this invention, cellulose ester resins, polypropylene resins, acrylic resins, and polyester resins can be used, for example. Examples of cellulose ester resins include triacetyl cellulose (TAC), cellulose acetate propionate (CAP), and diacetyl cellulose (DAC). Examples of polypropylene resins include polypropylene (PP). Examples of acrylic resins include polymethyl methacrylate (PMMA). Examples of polyester resins include polyethylene terephthalate (PET).

[0265] (2.3.2) Plasticizers

[0266] With regard to the substrate film of the present invention, for example, for the purpose of imparting processability, it is preferable to contain at least one plasticizer. The plasticizer is preferably used alone or in combination of two or more. From the viewpoint of effectively controlling moisture permeability and compatibility with substrate resins such as cellulose esters, it is preferable to contain at least one plasticizer selected from sugar esters, polyesters, and styrene-based compounds.

[0267] The molecular weight of this plasticizer is preferably 15,000 or less, and more preferably 10,000 or less. From the viewpoint of balancing improved resistance to damp heat and compatibility with base resins such as cellulose esters, the molecular weight of this plasticizer is preferably 10,000 or less. When the compound with a molecular weight of 10,000 or less is a polymer, a weight-average molecular weight (Mw) of 10,000 or less is preferred. The preferred range of weight-average molecular weight (Mw) is 100 to 10,000, more preferably 400 to 8,000. In particular, the compound with a molecular weight of 1,500 or less is preferably contained in the range of 6 to 40 parts by weight relative to 100 parts by weight of the base resin, more preferably in the range of 10 to 20 parts by weight. By containing it within such a range, it is preferable to balance effective control of moisture permeability and compatibility with the base resin.

[0268] (glycoesters)

[0269] In the substrate film of the present invention, a sugar ester compound may be contained for the purpose of preventing hydrolysis. Specifically, as the sugar ester compound, a sugar ester having at least one of a pyranose structure or a furanose structure in the range of 1 to 12, and having all or part of the OH groups of the structure esterified, may be used.

[0270] (Polyester)

[0271] The substrate film involved in this invention may also contain polyester. There is no particular limitation on the polyester. For example, a polymer with terminal hydroxyl groups (polyester polyol) obtained by the condensation reaction of a dicarboxylic acid or its ester-forming derivative with a diol can be used. Alternatively, a polymer whose terminal hydroxyl groups are blocked with a monocarboxylic acid can be used (terminated polyester). Furthermore, the ester-forming derivatives referred to herein are esterified dicarboxylic acids, dicarboxylic acid acyl chlorides, and dicarboxylic acid anhydrides.

[0272] (Styrene compounds)

[0273] In the substrate film involved in this invention, styrene compounds may be used in addition to or in place of the aforementioned sugar esters and polyesters to improve water resistance.

[0274] Styrene compounds can be homopolymers of styrene monomers or copolymers of styrene monomers with other comonomers. To achieve a certain volume in the molecular structure, the content of constituent units derived from styrene monomers in the styrene compound is preferably in the range of 30-100 mol%, more preferably in the range of 50-100 mol%.

[0275] Examples of styrene monomers include styrene; alkyl-substituted styrene such as α-methylstyrene, β-methylstyrene, and p-methylstyrene; halogen-substituted styrene such as 4-chlorostyrene and 4-bromostyrene; hydroxystyrene such as p-hydroxystyrene, α-methyl-p-hydroxystyrene, 2-methyl-4-hydroxystyrene, and 3,4-dihydroxystyrene; vinylbenzyl alcohols; alkoxy-substituted styrene such as p-methoxystyrene, p-tert-butoxystyrene, and m-tert-butoxystyrene; 3-vinylbenzoic acid, ... Vinylbenzoic acid and other vinylbenzoic acids; 4-vinylbenzyl acetate; 4-acetoxystyrene; amidestyrene such as 2-butyramidestyrene, 4-formamidestyrene, and p-sulfonamidestyrene; aminostyrene such as 3-aminostyrene, 4-aminostyrene, 2-isopropenylaniline, and vinylbenzyldimethylamine; nitrostyrene such as 3-nitrostyrene and 4-nitrostyrene; cyanostylstyrene such as 3-cyanostylstyrene and 4-cyanostylstyrene; vinylphenylacetonitrile; arylstyrene such as styrene; indene, etc. Furthermore, styrene monomers can be one type or a combination of two or more.

[0276] (2.3.3) Optional ingredients

[0277] The substrate film of this invention may, as needed, contain other optional components such as antioxidants, colorants, ultraviolet absorbers, and microparticles. These components may be added in the range of 0.01 to 20 parts by weight relative to 100 parts by weight of the substrate resin.

[0278] (Antioxidants)

[0279] In the substrate film according to the present invention, commonly known antioxidants can be used as antioxidants. In particular, various compounds of the lactone, sulfur, phenol, double bond, hindered amine, and phosphorus types are preferred. These antioxidants are added in the range of 0.05 to 20% by mass, preferably in the range of 0.1 to 1% by mass, relative to the main raw material of the substrate film, namely the resin. Synergistic effects can be obtained by using these antioxidants in combination with compounds of various different systems. For example, the combination of lactone, phosphorus, phenol, and double bond compounds is preferred.

[0280] (Coloring agent)

[0281] In the substrate film of this invention, a colorant is preferably included to adjust the hue without compromising the effectiveness of the invention. The term "colorant" refers to dyes or pigments; in this invention, it refers to a colorant that has the effect of making the hue of the liquid crystal display blue, adjusting the yellow index, or reducing haze. Various dyes and pigments can be used as colorants, but anthraquinone dyes, azo dyes, and phthalocyanine pigments are effective.

[0282] (UV absorber)

[0283] In the substrate film of the present invention, an ultraviolet absorber may be included to impart ultraviolet absorption functionality. There are no particular limitations on the ultraviolet absorber; examples include benzotriazole-based, 2-hydroxybenzophenone-based, or phenyl salicylate-based ultraviolet absorbers. Examples include triazoles such as 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, and 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole; and benzophenones such as 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, and 2,2'-dihydroxy-4-methoxybenzophenone. The above-mentioned ultraviolet absorbers may be used alone or in combination of two or more. The amount of ultraviolet absorber used varies depending on the type of ultraviolet absorber and the conditions of use. Generally, it is added in the range of 0.05% to 10% by mass, preferably in the range of 0.1% to 5% by mass, relative to the base resin.

[0284] (particle)

[0285] In the substrate film of the present invention, it is preferable to add microparticles that impart slip properties. Adding microparticles is effective, particularly from the viewpoints of improving the slip properties of the substrate film surface, improving slip properties during winding, preventing scratches, and preventing adhesion. As microparticles, they can be either inorganic or organic, but inorganic microparticles are more preferred, as long as they do not impair the transparency of the resulting substrate film and possess heat resistance during melting. These microparticles can be used alone or in combination of two or more. By combining particles with different particle sizes or shapes (e.g., needle-like and spherical), both transparency and slip properties can be achieved.

[0286] Among the compounds constituting the above-mentioned particles, silica is particularly preferred because its refractive index is close to that of the cyclic olefin resins, acrylic resins, and cellulose ester resins, thus exhibiting excellent transparency (anti-fogging properties). As specific examples of silica, commercially available products with trade names such as AEROSIL (registered trademark) 200V, AEROSIL (registered trademark) R972V, AEROSIL (registered trademark) R972, R974, R812, 200, 300, R202, OX50, TT600, NAX50 (all manufactured by AEROSIL Corporation of Japan), SEAHOSTER (registered trademark) KEP-10, SEAHOSTER (registered trademark) KEP-30, SEAHOSTER (registered trademark) KEP-50 (all manufactured by Nippon Shokubai Corporation), Sylophobic (registered trademark) 100 (manufactured by Fuji Silicon Chemicals Co., Ltd.), Nipsil (registered trademark) E220A (manufactured by Nippon Silicate Industry Co., Ltd.), and Admafine (registered trademark) SO (manufactured by Admatechs Co., Ltd.) are preferred.

[0287] The shape of the particles can be irregular, needle-like, flat, spherical, etc., without particular restrictions, but spherical particles are particularly preferred, thereby improving the transparency of the resulting substrate film. If the particle size is close to the wavelength of visible light, light will be scattered, and transparency will deteriorate. Therefore, it is preferable to have a particle size smaller than the wavelength of visible light, more preferably less than half the wavelength of visible light. If the particle size is too small, the slip properties may not be improved. Therefore, a size in the range of 80 to 180 nm is particularly preferred. Furthermore, the particle size refers to the size of the aggregate when the particles are an aggregate of primary particles. Additionally, when the particles are not spherical, it refers to the diameter of a circle equivalent to the projected area.

[0288] The microparticles are preferably added in the range of 0.05 to 10% by mass relative to the base resin, and more preferably in the range of 0.1 to 5% by mass.

[0289] (2.3.4) Thickness of the substrate film

[0290] The thickness of the substrate film of the present invention is in the range of 5 to 29 μm. If the thickness of the substrate film is 5 μm or more, the rigidity is increased, and it is easy to maintain the shape. In addition, if the thickness of the substrate film is 29 μm or less, the mass is not increased excessively, and it is easy to produce long strip substrate films. Furthermore, the thickness of the substrate film of the present invention can be measured using the same method as that used for the carrier film described above. More preferably, it is in the range of 10 to 20 μm.

[0291] 3. Curing layer

[0292] The laminated film of the present invention has multiple cured layers, with beads between these cured layers, and the multiple cured layers have a refractive index difference. Furthermore, each cured layer may contain an adhesive resin and particles for increasing the refractive index. Moreover, other additives can be included without hindering these functions. Additionally, the refractive index of the multiple cured layers gradually increases from the substrate side towards the outermost layer side, which is preferable from the viewpoint of improving light extraction performance. Furthermore, the "outermost layer" among the multiple cured layers refers to the outermost cured layer located on the side opposite to the substrate film when viewed from the multiple cured layers.

[0293] As previously stated, Figure 2 is a schematic structural diagram of a laminated film in which the cured layer of the laminated film of the present invention has a three-layer structure. Furthermore, in the case where beads are present between the plurality of cured layers, including as... Figure 2A , Figure 2B , Figure 2C and Figure 2D In this case, the bead is contained between multiple cured layers, i.e., at the interfaces of each cured layer. Furthermore, when the bead is contained between the cured layers, it does not protrude from cured layer L3, but is embedded within the multiple cured layers.

[0294] (3.1) Refractive index of the cured layer

[0295] The laminated film of the present invention comprises a plurality of cured layers having a refractive index difference. In this case, the refractive index difference of the plurality of cured layers is preferably 0.02 or more, more preferably 0.05 or more. Furthermore, either the refractive index of the adhesive resin or the refractive index of the beads can be high, but from the viewpoint of improving light extraction efficiency, the absolute value of the difference between the two refractive indices is preferably in the range of 0.01 to 0.05.

[0296] Combinations where the absolute value of the refractive index difference between the adhesive resin and the beads falls within the aforementioned range include, for example, the following combinations. Furthermore, the values ​​in parentheses below represent the refractive index of the material.

[0297] "Adhesive resin: acrylic resin (1.50)" and "Beads: acrylic resin particles (1.49)", "Adhesive resin: acrylic resin (1.50)" and "Beads: nylon resin particles (1.53)" and "Adhesive resin: epoxy resin (1.55)" and "Beads: polyethylene resin particles (1.53)".

[0298] (Measurement Method)

[0299] The refractive index of the cured layer of the present invention can be measured, for example, by forming the cured layer separately using an Abbe refractometer (NAR-4T manufactured by Aitek Inc., Japan) or an ellipsometer.

[0300] Furthermore, the refractive index of the cured layer can be measured even after it has been laminated into a film containing the cured layer. For example, the Becker method according to JIS K 7142:2008 Method B (for transparent materials in powder or granular form) can be used. The measurement using the Becker method can be performed as follows.

[0301] The cured layers in the laminated film containing the cured layers described above are scraped off with a knife or similar tool to prepare powdered samples, which are then placed on a glass slide. The samples are then immersed in a Cargill reagent with a known refractive index and observed under a microscope to determine their condition.

[0302] Here, because the refractive index of this sample differs from that of the aforementioned Cargill reagent, bright lines (Becker lines) are produced along the sample outline. Utilizing this, the refractive index of the reagent that is not visible to the naked eye along these bright lines (Becker lines) is determined and used as the refractive index of the sample, i.e., the refractive index of the cured layer.

[0303] (3.2) Beads contained in the cured layer

[0304] As previously stated, the "beads" in this invention refer to particulate fillers contained to improve the light diffusion, transparency, etc., of the molded body of the cured layer. The particles can have any geometric shape, such as spherical, cylindrical, or blocky, and do not necessarily have to be open-cell spherical particles. In this invention, resin particles are particularly preferred.

[0305] When resin particles (organic particles) are used as beads in this invention, they have higher light transmittance and less light absorption caused by the particles compared to inorganic particles. Therefore, by including these beads between multiple cured layers, the overall light utilization efficiency of the multiple cured layers is improved.

[0306] Examples of beads used in this invention include silicone resin particles, acrylic resin particles, nylon resin particles, styrene resin particles, styrene-acrylic resin particles, polyethylene particles, benzoguanamine resin particles, urethane resin particles, and melamine resin particles.

[0307] As commercially available products, examples such as the following can be cited.

[0308] Acrylic ester-styrene copolymer, refractive index: 1.53, number average particle size: 8μm (AICA industrial product, trade name Ganzpearl GM-0853S)

[0309] Acrylic ester-styrene copolymer, refractive index: 1.55, number average particle size: 8μm (AICA industrial product, trade name Ganzpearl GM-0855S)

[0310] Polymethylsilsesquioxane, refractive index: 1.41, number average particle size: 4 μm (manufactured by AICA, trade name GanzpearlSI-045)

[0311] Polyacrylate, refractive index: 1.49, number average particle size: 8 μm (manufactured by AICA, trade name Ganzpearl GM-0855S)

[0312] Polystyrene, refractive index: 1.59, number average particle size: 11 μm (AICA industrial product, trade name Ganzpearl GS-1105)

[0313] (Average particle size of beads)

[0314] The average particle size of the beads in this invention is preferably a relatively small value, specifically, preferably in the range of 3 to 6 μm. This results in the surface of the cured layer having a finely textured protrusion shape on the order of several μm, which improves view-dependency. Furthermore, in this specification, "average particle size" refers to a value calculated using the Coulter counting method.

[0315] (Bead content)

[0316] The content of beads in the cured layer of the present invention is preferably 100 parts by weight or more, more preferably 120 parts by weight or more, relative to 100 parts by weight of the adhesive resin. By adjusting the content of beads relative to the adhesive resin in this way, viewing angle dependence can be improved. In addition, the number of beads is preferably 160 parts by weight or less relative to 100 parts by weight of the adhesive resin, thereby suppressing the reduction of light extraction efficiency.

[0317] (3.3) Particles used to increase the refractive index of the cured layer

[0318] In the case of the cured layer of the present invention, in addition to the beads, it may also contain particles for increasing the refractive index (hereinafter also referred to as "high refractive index microparticles"). Furthermore, this allows the cured layer to have a refractive index greater than 1.49, thus becoming a high refractive index layer. Moreover, as mentioned above, for convenience in this specification, cured layers with a refractive index greater than 1.49 are designated as high refractive index layers, and cured layers with a refractive index less than 1.49 are designated as low refractive index layers.

[0319] High refractive index particles are used, for example, inorganic particles. Examples of such inorganic particles include metal oxide particles. Specific examples of such metal oxide particles include particles as described below. Furthermore, the values ​​in parentheses below represent the refractive index of the material.

[0320] Titanium oxide: TiO2 (2.3~2.7), niobium oxide: Nb2O5 (2.33), zirconium oxide: ZrO2 (2.10), antimony oxide: Sb2O5 (2.04), tin oxide: SnO2 (2.00), tin-doped indium oxide: ITO (1.95~2.00), cerium oxide: CeO2 (1.95), aluminum-doped zinc oxide: AZO (1.90~2.00), gallium-doped zinc oxide: GZO (1.90~2.00), zinc antimonate: ZnSb2O6 (1.90~2.00), zinc oxide: ZnO (1.90), yttrium oxide: Y2O3 (1.87), antimony-doped tin oxide: ATO (1.75~1.85), and lithium-doped tin oxide: PTO (1.75~1.85), etc.

[0321] Among the aforementioned metal oxide particles, zirconium oxide: ZrO2 (2.10) is preferred from the viewpoints of high refractive index and cost.

[0322] (Average particle size)

[0323] The average particle size of the high refractive index microparticles is preferably in the range of 5 to 50 nm.

[0324] (content)

[0325] The content of high refractive index particles is preferably in the range of 20 to 95% by mass.

[0326] (3.4) Adhesive resin for cured layer

[0327] There are no particular limitations on the type of adhesive resin; for example, thermoplastic resins, thermosetting resins, and photocurable resins can be listed.

[0328] From the viewpoint of improving surface hardness, the adhesive resin is preferably a polymer or copolymer of a thermopolymerizable monomer or a photopolymerizable monomer. Among these, a polymer of a photopolymerizable monomer is more preferred.

[0329] (Thermoplastic resin)

[0330] As thermoplastic resins, cellulose ester resins such as triacetylcellulose, cellulose acetate propionate, and diacetylcellulose can be used. Additionally, cyclic olefin resins such as cyclic olefin resins, polypropylene resins such as polypropylene, acrylic resins such as polymethyl methacrylate, and polyester resins such as polyethylene terephthalate can be used.

[0331] (Thermosetting resin)

[0332] Examples of thermosetting resins include acrylic resins, urethane resins, phenolic resins, urea-formaldehyde melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins. Furthermore, besides curing with heat, thermosetting resins can also be cured using a curing agent.

[0333] (Light-cured resin)

[0334] There are no particular limitations on the compounds constituting photopolymerizable resins; photopolymerizable monomers, oligomers, and polymers can be used. Examples of monofunctional photopolymerizable monomers include ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene, methylstyrene, and N-vinylpyrrolidone. Examples of difunctional or higher photopolymerizable monomers include polymethylpropane tri(meth)acrylate, hexanediol (meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and compounds modified with ethylene oxide, polyethylene oxide, etc.

[0335] In addition, these compounds can also be modified by introducing aromatic rings, halogen atoms other than fluorine, sulfur, nitrogen, phosphorus atoms, etc., to increase the refractive index.

[0336] Furthermore, in addition to the compounds mentioned above, resins composed of monomers with relatively low molecular weight and unsaturated double bonds can also be used. Examples of such resins include polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, and polythiol polyene resins.

[0337] Polymerization initiators can also be used when polymerizing (crosslinking) photopolymerizable monomers. Polymerization initiators are components that decompose upon light irradiation, generating free radicals that initiate or promote the polymerization (crosslinking) of photopolymerizable compounds.

[0338] (3.5) Other additives, etc.

[0339] Regarding the cured layer of the present invention, in addition to the aforementioned beads, particles for increasing the refractive index (high refractive index microparticles), and adhesive resin, other additives may be included within a range that does not impair these functions. Examples of such other additives include, for instance, conventionally known dispersants, surfactants, antistatic agents, silane coupling agents, tackifiers, anti-discoloration agents, colorants (pigments, dyes), defoamers, leveling agents, flame retardants, ultraviolet absorbers, adhesion promoters, polymerization inhibitors, antioxidants, surface modifiers, and slip agents.

[0340] (3.6) Thickness of the cured layer

[0341] Regarding the thickness of the cured layer according to the present invention, from the viewpoint that a thickness in which the beads do not protrude beyond the outermost layer is preferred, it is preferably in the range of 3 to 30 μm. Furthermore, from the viewpoint that it is easy to prevent curling, it is preferably in the range of 3 to 15 μm. In addition, the thickness of the cured layer according to the present invention can be measured using the same method as that used for the carrier film described above.

[0342] (3.7) Method for forming the cured layer

[0343] The cured layer according to the present invention can be formed by, for example, the following method. First, a coating liquid for a cured layer is prepared by dissolving a photopolymerizable compound containing the aforementioned beads, particles for increasing the refractive index (high refractive index microparticles), adhesive resin and other additives in a suitable solvent.

[0344] Then, the above-mentioned coating solution is applied and dried to form a film. Afterwards, the cured film is irradiated with ultraviolet light or the same coating solution to cause the photopolymerizable compounds to polymerize (crosslink), forming a cured layer. Furthermore, the content of the aforementioned beads and particles used to increase the refractive index (high refractive index microparticles) in the above-mentioned coating solution is adjusted as needed.

[0345] The method of using a coating liquid as a composition for coating and curing can employ known coating methods. Examples of known coating methods include spin coating, dip coating, spray coating, glide coating, bar coating, roller coating, gravure coating, and die coating.

[0346] There are no particular limitations on the light used to cure the composition of the curing layer; examples include ultraviolet light and electron beams. When using ultraviolet light, ultraviolet light emitted by ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, xenon arc lamps, metal halide lamps, etc., can be used. Furthermore, the wavelength of the ultraviolet light can be in the range of 190 to 380 nm. Specific examples of electron beam sources include various electron beam accelerators such as Cockcroft-Walton type, Van de Graaff type, resonant transformer type, insulated core transformer type, linear type, Dynamitron type, and high-frequency type.

[0347] Furthermore, a polymerization initiator may be added to the coating liquid of the above-mentioned curing layer composition as needed. Additionally, other additives may be included to improve the hardness of the cured layer, suppress curing shrinkage, and control the refractive index.

[0348] (Polymerization initiator)

[0349] As a polymerization initiator, there are no particular limitations as long as it can release a substance that initiates free radical polymerization upon light irradiation; known substances can be used. Specific examples of known substances include acetophenones, benzophenones, Michler benzoyl benzoate, α-Amidoxime esters, thioxanones, acetones, benzoin, benzoin derivatives, and phosphine oxides. Furthermore, it is preferable to use the polymerization initiator in combination with a photosensitizer; specifically, examples include n-butylamine, triethylamine, and poly-n-butylphosphine. When the adhesive resin contained in the cured layer is a resin system with unsaturated groups capable of free radical polymerization, acetophenones, benzophenones, thioxanones, benzoin, and benzoin methyl ether are preferably used as the above-mentioned polymerization initiator, either alone or in combination.

[0350] [II. Manufacturing method of laminated films]

[0351] The method for manufacturing the laminated film of the present invention is characterized by having the following steps: for a laminated part consisting of the first adhesive layer, the substrate film and the second adhesive layer, the heat shrinkage rate is measured at 130°C for 90 minutes, and the heat shrinkage rates in the length direction and the width direction are set as X and Y respectively, and X and Y are adjusted in such a way that they satisfy the following formulas (1) and (2).

[0352] Formula (1): Y <X [%]

[0353] Formula (2): 0.004<{(X+Y) / 2}<0.16[%]

[0354] As a sequence of the process for manufacturing the laminated film of the present invention, firstly, a laminated body portion is initially formed by forming a plurality of curing layers on the laminated body portion. Moreover, as a sequence of forming the laminated body portion, a substrate film is initially fabricated by forming a second adhesive layer and a first adhesive layer on the substrate film.

[0355] Figure 3 A flowchart illustrating the fabrication process of the laminated film of the present invention is provided. Furthermore, the carrier film involved in the present invention... Figure 3 In the first adhesive layer forming process, the first adhesive layer is adhered to the first adhesive layer after it is formed.

[0356] 4. Fabrication of the substrate film

[0357] The substrate film involved in this invention is a substrate film containing a cyclic olefin resin. Furthermore, this substrate film can be manufactured, for example, by solution casting or melt casting, and its manufacturing process includes a process for manufacturing the original roll film and a process for processing the original roll film. Hereinafter, the process of manufacturing the substrate film by solution casting will first be described, and then the process of manufacturing the substrate film by melt casting will be described.

[0358] (4.1) Solution casting film production method

[0359] "Solution casting film-forming method" refers to the following film-forming method. First, a coating solution is cast onto a traveling support to form a cast film (web), which is then dried to a peelable consistency. Next, the film is peeled off from the support while being transported by a conveyor roller, and dried or stretched to form a long strip of resin film.

[0360] In the manufacturing process of the substrate film produced by solution casting film production method involved in this invention, the manufacturing process of the original roll film includes at least the following three processes (A), (B) and (C).

[0361] (A) The process of casting a coating liquid onto a support to form a web.

[0362] (B) The first stage of stretching process

[0363] (C) The process of winding the film formed by drying the web material.

[0364] In addition, the processing steps of the original roll film include conveying the wound original roll film and performing a second-stage stretching process.

[0365] Regarding the wound film, in the second stage stretching process, the amount of residual solvent before the second stage stretching is in the range of 0.1 to 0.5% by mass, relative to the winding width.

[0366] Figure 4 A flowchart illustrating the process of fabricating a substrate film using a solution casting method is provided. Figure 5 A schematic diagram of an apparatus for fabricating a substrate film using a solution casting method.

[0367] (4.1.1) Preparation of the original roll film

[0368] The manufacturing process of the original roll film includes at least (A) a process of casting a coating liquid onto a support to form a web, (B) a process of performing a first-stage stretching, and (C) a process of winding the film formed by drying the web.

[0369] (A) The process of casting a coating liquid onto a support to form a web.

[0370] The process of casting a coating liquid onto a support to form a web includes at least a coating liquid preparation process (S1), a casting process (S2), and a peeling process (S3).

[0371] (A-1) Coating solution preparation process (S1)

[0372] In the coating liquid preparation process (S1) (also known as the "stirring and preparation process"), at least the resin and solvent are stirred in the stirring tank 1a of the stirring device 1 to prepare the coating liquid to be cast on the support 3 (annular belt) (see reference). Figure 5 Furthermore, in the production of the substrate film according to the present invention, a cycloolefin resin (hereinafter also referred to as "COP") is used as the above-mentioned resin.

[0373] This process involves dissolving COP in a solvent, primarily a good solvent, in a dissolving vessel while stirring to form a coating solution. Alternatively, depending on the circumstances, the COP may be mixed with other compounds in the dissolving vessel to prepare a coating solution that serves as the main solvent.

[0374] <COP concentration>

[0375] From the viewpoint of reducing the drying load after the coating solution is cast onto the support, a higher concentration of COP in the coating solution is preferred. However, if the concentration is too high, the load during filtration increases, and the accuracy deteriorates. Therefore, from the viewpoint of balancing the reduction of drying load with the decrease in accuracy caused by the increase in filtration load, the concentration of COP in the coating solution is preferably in the range of 10 to 35% by mass, and more preferably in the range of 15 to 30% by mass.

[0376] <Solvent>

[0377] The aforementioned solvents can be used alone or in combination of two or more. However, from the viewpoint of production efficiency, it is preferable to use a mixture of good and bad solvents for COP. From the viewpoint of COP solubility, a higher proportion of good solvent is preferred. Furthermore, it is preferable that the coating solution contains water, with a content in the range of 0.01 to 2.00% by mass. The preferred mixing ratio of good to bad solvent is 70 to 98% by mass for good solvent and 2 to 30% by mass for bad solvent.

[0378] In this specification, the solvent that dissolves COP is defined as a "good solvent." Conversely, the solvent that causes it to swell or remain insoluble is defined as a "bad solvent." Therefore, whether a solvent is good or bad depends on the type and number of substituents in the COP. There are no particular limitations on the good solvents mentioned above; examples include organohalides such as dichloromethane, dioxolane compounds, acetone, methyl acetate, and methyl acetoacetate. Dichloromethane or methyl acetate is particularly preferred. There are no particular limitations on the bad solvents mentioned above; methanol, ethanol, n-butanol, cyclohexane, and cyclohexanone are preferred.

[0379] As the solvent mentioned above, the solvent removed from the substrate film by drying during the substrate film manufacturing process can be recovered and reused. Sometimes the recovered solvent contains trace amounts of additives such as plasticizers, ultraviolet absorbers, polymers, and monomer components; even if these additives are present, reuse is preferred. Alternatively, it can be refined and reused if necessary.

[0380] <Dissolution Method>

[0381] As a method for dissolving COP during coating solution preparation, general methods can be used. Specifically, methods performed at atmospheric pressure, methods performed below the boiling point of the main solvent, and methods performed under pressure above the boiling point of the main solvent are preferred. Furthermore, by combining heating and pressure, heating above the boiling point at atmospheric pressure can be performed. Cooling dissolution is also preferred, thereby allowing COP to dissolve in solvents such as methyl acetate.

[0382] Furthermore, it is preferable to dissolve the solvent by heating and stirring at a temperature above its boiling point under normal pressure and within a range where the solvent will not boil under pressure. This prevents the formation of gels and lumpy undissolved substances. Additionally, it is preferable to wet or swell the COP with a poor solvent before adding a good solvent to dissolve it.

[0383] Pressurization can be achieved by injecting inert gases such as nitrogen or by increasing the vapor pressure of the solvent through heating. The pressure is adjusted to prevent the solvent from boiling at a set temperature. Heating is preferably performed externally; for example, jacketed heating is easier to control and is therefore preferred. From the viewpoint of COP solubility, a higher heating temperature for adding the solvent is preferable, but if the heating temperature is too high, the required pressure increases, and productivity decreases. Therefore, the heating temperature is preferably in the range of 30–120°C, more preferably in the range of 60–110°C, and even more preferably in the range of 70–105°C.

[0384] <Filtering>

[0385] While conventional methods can be used to filter the coating solution, from the viewpoint of minimizing the increase in the pressure difference before and after filtration (called pressure differential), a method of filtration while heating is preferred, where the temperature is above the boiling point of the solvent at atmospheric pressure and within a range where the solvent does not boil under pressure. The preferred temperature range is 30–120°C, more preferably 45–70°C, and even more preferably 45–55°C. Lower filtration pressure is more preferred. Specifically, the filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and even more preferably 1.0 MPa or less.

[0386] It is preferable to use a suitable filter material such as filter paper to filter the coating solution during or after dissolution. Hereinafter, the "coating solution during or after dissolution" will be simply referred to as "COP solution". From the viewpoint of removing insoluble matter, it is preferable to use a filter material with a low absolute filtration precision. However, if the filter material has too low an absolute filtration precision, it is prone to clogging during filtration. Therefore, the absolute filtration precision of the filter material is preferably 0.008 mm or less, more preferably in the range of 0.001 to 0.008 mm, and even more preferably in the range of 0.003 to 0.006 mm.

[0387] There are no particular limitations on the material of the filter material mentioned above. Common filter materials can be used. From the viewpoint of no fiber shedding, filter materials made of plastics such as polypropylene and Teflon (registered trademark) or metals such as stainless steel are preferred.

[0388] Filtration is preferred to remove or reduce impurities, especially bright spot foreign matter, contained in the COP of the raw material. "Bright spot foreign matter" refers to a point (foreign matter) visible when light is shone from one polarizer side and observed from the other polarizer side, for example, by arranging two polarizers in a cross-Nicolas configuration with a film placed between them, and observing from the opposite side. The diameter of bright spot foreign matter is preferably 0.01 mm or more, and it is even more preferable to have fewer bright spots with a diameter less than 0.01 mm.

[0389] The optimal number of bright spots is 200 / cm.2 The following is a preferred ratio of 100 bright spots / cm. 2 The following is a further preferred value: 50 pieces / cm 2 The following is a further preferred option: 0~10 pieces / cm 2 the following.

[0390] (A-2) Casting process (S2)

[0391] In the casting process (S2), the web 5, formed by casting the coating liquid onto the support 3 at a conveying speed V1, is heated on the support 3. This causes the solvent to evaporate from the support 3 until the web 5 can be peeled off the support 3 by the peeling roller 4, controlling the amount of residual solvent before the first stage of stretching (see reference). Figure 5 ).

[0392] <Support Body>

[0393] The support body 3 is preferably a support body with a mirror-polished surface, and more preferably a roller whose surface is finely plated by a stainless steel strip or casting. The support body 3 is, for example, made of stainless steel strip and held by a pair of rollers 3a and 3b and a plurality of rollers located between them. One or both of rollers 3a and 3b are provided with a drive device to apply tension to the support body 3, thereby using the support body 3 in a taut state under applied tension. Alternatively, the support body 3 can also be a roller.

[0394] From the viewpoint that the drying speed of the web can be increased, a higher surface temperature is preferred for the support 3, for example, a temperature in the range of -50°C to the boiling point of the solvent. More preferably, the surface temperature of the support is in the range of 0 to 55°C, and even more preferably in the range of 22 to 50°C.

[0395] There are no particular limitations on the method for controlling the surface temperature of the support 3, and methods such as blowing hot or cold air and contacting the back side of the support with hot water are examples. Among these, the method of contacting the back side of the support with hot water is preferred because it has high heat transfer efficiency and the time it takes for the temperature of the support to become constant is short. Furthermore, when using the method of blowing hot air, sometimes air with a temperature higher than the target temperature is used.

[0396] <Cast die>

[0397] In the casting process (S2), the coating liquid prepared in the coating liquid preparation process (S1) is fed to the casting die 2 through a conduit via a pressurized quantitative gear pump or the like. Then, the coating liquid is cast from the casting die 2 to the casting position on the support body 3, which is made of a continuously moving rotating stainless steel annular belt.

[0398] As casting dies, coat hanger dies, T-die dies, etc., are all preferred. To increase the film-forming speed of the original roll film, two or more of the above-mentioned casting dies can be set on the support to divide and overlap the coating liquid volume. In addition, it is preferable to use a co-casting method that simultaneously casts multiple coating liquids to obtain a laminated original roll film.

[0399] The casting die is equipped with a mechanism for adjusting the width of the slit through which the coating liquid is discharged (or, in the case of molten resin extrusion). The discharge direction of the coating liquid from the casting die 2 to the support 3 is adjusted by the inclination of the casting die 2. At this time, the inclination of the casting die 2 only needs to be appropriately set so that the angle relative to the normal of the surface of the support 3 (the surface on which the coating liquid is cast) is within the range of 0 to 90°.

[0400] Here, the part from which the coating liquid exits the slit of the casting die is called the lip. The shape of the slit of the lip can be adjusted, and a casting die that makes it easy to make the coating liquid have a uniform thickness when it is discharged is preferred. Furthermore, in the casting process (S2), "web material" refers to the coating liquid film cast from the lip.

[0401] Preferably, the gap in the width direction of the slit for discharging the coating liquid is adjusted by using the hot bolt of the casting die to ensure that the thickness deviation of the film after extrusion is within the range of 1.0 to 5.0% relative to the overall cast film (web), thereby controlling the initial discharge film thickness of the cast film (web).

[0402] From the viewpoint of improving productivity, a casting width (also known as "casting width") of 1.3 m or more is preferred, and more preferably within the range of 1.3 to 4.0 m. If the casting width does not exceed 4.0 m, no streaks are generated during the manufacturing process, and the stability in subsequent conveying processes is improved. Furthermore, from the viewpoint of conveyability and productivity, a casting width within the range of 1.3 to 3.0 m is preferred.

[0403] (A-3) Stripping process (S3)

[0404] In the peeling process (S3), the solvent is evaporated until the web 5 on the support 3 achieves peelable film strength as in the casting process (S2). After drying and curing or cooling and solidifying, the web is peeled from the support 3 before the original roll of film wraps around the support 3 once. That is, this process involves peeling the web, which has been evaporated to achieve peelable film strength on the support 3, from the support 3 by the peeling roller 4 in a self-supporting state. Furthermore, the roller that assists in peeling the web from the support is called the peeling roller.

[0405] From the viewpoints of surface quality, moisture permeability, and peelability, the peeling time is preferably in the range of 30 to 600 seconds. The temperature at the peeling location on the support is preferably in the range of -50 to 40°C, more preferably in the range of 10 to 40°C, and particularly preferably in the range of 15 to 30°C.

[0406] <Residual solvent content>

[0407] The amount of residual solvent before the first stage of stretching is appropriately adjusted according to the strength of the drying conditions and the length of the support 3. As a method for controlling this amount of residual solvent, the evaporation is preferably carried out in an atmosphere within the range of 5 to 75°C. Methods for evaporating the solvent include, for example, contacting hot air with the upper surface of the web, using liquid heat transfer from the back of the support 3, and using radiant heat to transfer heat from both the surface and back. From the viewpoint of improving drying efficiency, the method of using radiant heat to transfer heat from both the surface and back is preferred. Furthermore, a combination of these methods is also preferred.

[0408] While it also depends on the thickness of the web, if there is too much residual solvent at the peel point (the location where the web is peeled from the support), the web may sometimes be too soft to peel. This can sometimes impair flatness, resulting in transverse streaks, adhesion, or longitudinal streaks caused by peeling tension. Conversely, if the amount of residual solvent is too little, sometimes only a portion of the web may peel off midway. To ensure good flatness of the web, from the viewpoint of balancing economy, speed, and quality, a residual solvent content of 1 to 50% by mass is preferred, and more preferably, 1 to 15% by mass.

[0409] If a gel casting method (gel casting) is used for peeling while maintaining a high amount of residual solvent in the web, the film formation rate can be increased. Therefore, by gelling the web on the support and reinforcing the film, peeling can be accelerated, thus increasing the film formation speed. Examples include adding a poor solvent like COP to the coating solution, gelling the web after casting, gelling the web by cooling the support and peeling it while maintaining a high amount of residual solvent, and adding a metal salt to the coating solution.

[0410] Furthermore, the amount of residual solvent is defined by the following formula.

[0411] Residual solvent content (mass%) = {(MN) / N} × 100

[0412] In the above formula, M is the mass of the sample collected at any time point during or after the manufacturing of the web or substrate film, and N is the mass of M after heating it at 115°C for 1 hour.

[0413] The residual solvent content can be determined using headspace gas chromatography. This method involves sealing the sample in a container, heating it to fill the container with volatile components, and then rapidly injecting the gas from the container into a gas chromatograph for mass analysis. This allows for both compound identification and quantification of volatile components. Furthermore, by using gas chromatography, all peaks of volatile components can be observed, and by employing analytical methods utilizing electromagnetic interactions, the quantification of volatile substances and monomers can be performed simultaneously with high precision.

[0414] <Peeling Tension>

[0415] The peel tension when peeling the support and the web is preferably 300 N / m or less. More preferably, it is in the range of 196 to 245 N / m, but if wrinkling is likely to occur during peeling, it is preferable to peel with a tension of 190 N / m or less.

[0416] (B) The first stage of stretching process (S4)

[0417] The first-stage stretching process (S4) is a process of stretching the width of the web after it has been cast. In this process (S4), the web, after being peeled from the support, is stretched in the conveying direction (Machine Direction, hereinafter also referred to as the "MD direction"). In this case, the web shrinks in the web surface in the width direction (Traverse Direction, hereinafter also referred to as the "TD direction"), which is orthogonal to the MD direction.

[0418] Methods for shrinking the web include (1) performing high-temperature treatment without maintaining the width of the web to increase the density of the web; (2) applying tension to the web in the conveying direction (MD direction) to shrink the web in the width direction (TD direction); and (3) drastically reducing the amount of residual solvent in the web.

[0419] Stretching can be performed according to the required optical properties, preferably in at least one direction, but it can also be performed in two mutually orthogonal directions. For example, biaxial stretching can be performed in the width direction (TD direction) and the transport direction (MD direction) orthogonal to it. In the case of biaxial stretching, for each of the TD and MD directions, the stretching ratio is preferably set to the range of 1.1 to 2.0 times. Furthermore, the stretching ratio is defined as (stretching direction dimension of the film after stretching) / (stretching direction dimension of the film before stretching).

[0420] <Residual Solvent Amount>

[0421] In this invention, the amount of residual solvent before the first stage of stretching is synonymous with the amount of residual solvent at the peeling point in the peeling process (S3) described above. From the viewpoint of improving the adhesion of the film and suppressing the deterioration of the film strength, it is preferable that the amount of residual solvent before the first stage of stretching is in the range of 1 to 15% by mass, and the stretching ratio is in the range of 1.1 to 2.0 times.

[0422] By performing the stretching process (S4) in the first stage, entanglement between polymer molecules (matrix molecules) in the thickness direction of the web is promoted. As a result, for example, during the fabrication of the laminated film of the present invention, even when the substrate film is bonded via a carrier film and an adhesive layer, the adhesive can easily penetrate into the interior of the substrate film through the entangled portion (crosslinked portion) between matrix molecules.

[0423] As a result, the substrate film can be firmly fixed to the polarizing layer (also known as "polarizing film", "polarizing membrane" or "polarizing thin film") via an adhesive, and the peel strength of the substrate film to the polarizing layer can be improved. That is, the adhesion between the substrate film and the polarizing layer is improved, which can ensure the function of inhibiting the deterioration of film strength.

[0424] (C) The process of winding the film formed by drying the web material.

[0425] The process of winding the film formed by drying the web includes a drying process (S5), a first cutting process (S6), and a first winding process (S7). Furthermore, the conveying speed V1 of the coating liquid in the coating liquid preparation process (S1) and the winding speed in the first winding process (S7) are the same. Additionally, "the same speed" for the conveying speed and the winding speed means, strictly speaking, that they are the same within a range of ±10%.

[0426] (C-1) Drying process (S5)

[0427] The drying process (S5) involves heating the web on a support and causing the solvent to evaporate. Figure 5 In the drying device 7, multiple conveying rollers arranged in a staggered manner when viewed from the side are used to convey the web material, thereby drying the web material.

[0428] There are no particular limitations on the drying method used in drying device 7. Hot air, infrared radiation, heated rollers, microwaves, etc., are commonly used to dry the web material. However, from a simplicity perspective, hot air drying is preferred. Furthermore, combinations of these methods are also preferred. Additionally, the drying process (S5) can be performed as needed.

[0429] If the film is thin, it dries quickly, but excessively rapid drying can damage the flatness of the finished film.

[0430] When performing high-temperature drying, the amount of residual solvent needs to be considered. If the amount of residual solvent is not excessive, problems caused by solvent foaming can be prevented. Drying is generally carried out within a range of approximately 30 to 250°C. Drying within the range of 35 to 200°C is particularly preferred, and it is preferable to increase the drying temperature in stages. The temperature of the support can be uniform throughout or vary depending on its location.

[0431] In the drying process of web fabric, roller drying is generally used, that is, the web fabric is alternately passed between multiple rollers arranged vertically and horizontally for drying, or the web fabric is conveyed and dried simultaneously using a tenter frame. When a tenter frame is used for drying the web fabric, it is preferable to use a device in the stretching process described later that allows independent control of the holding length (distance from the start to the end of holding) of the web fabric using the left and right holding mechanisms of the tenter frame. In addition, it is preferable to provide a neutral zone between different temperature zones where there is no interference between the zones.

[0432] (C-2) First cutting process (S6)

[0433] In the first cutting step (S6), the cutting section 8, which is composed of a slitter, cuts both ends of the film F in the width direction, which has been stretched in the first stage stretching step (S4) and then dried in the drying step (S5). The remaining portion of the film F after cutting constitutes the product portion that becomes a film article. On the other hand, the portion cut from the film F is recycled and can be reused as part of the raw material for the production of a substrate film.

[0434] (C-3) First winding process (S7)

[0435] In the first winding process (S7), the film F is wound by the winding device 9 at a conveying speed V1 (winding speed V1), and the original film production process is completed. The preferred range for the initial tension when winding the film F in the winding process is 20~300 N / m.

[0436] (4.1.2) Processing steps of the original film roll

[0437] The processing steps for the original film roll are a process of conveying the wound film and performing a second-stage stretching. Furthermore, the processing steps for the original film roll include (D) an unwinding step, (E) a second-stage stretching step, and (F) a winding step of the stretched film. Specifically, the processing steps involve unwinding the wound film from its rollers (S8), conveying it at a conveying speed V2 as described in equation (1), and performing a second-stage stretching step. It includes at least an unwinding step (S8), a second-stage stretching step (S9), a second cutting step (S10), and a second winding step (S11).

[0438] In the second stage stretching process, for the wound film, the amount of residual solvent relative to the winding width before the second stage stretching is in the range of 0.1 to 0.5% by mass.

[0439] (D) Unwinding process of the original film roll (S8)

[0440] In the unwinding process (S8) of the original film roll, the wound film is unwound from its rollers and conveyed at a conveying speed V2.

[0441] <Residual solvent content>

[0442] Then, the film undergoes a second stage of stretching. At this time, just before the second stage of stretching, the residual solvent content is in the range of 0.1% to 0.5% by mass.

[0443] (E) The second stage of stretching process (S9)

[0444] In the second-stage stretching process (S9), the film F, conveyed at a conveying speed V2, is stretched by the stretching device 10. Furthermore, the main means of controlling the heat shrinkage rate according to the present invention is the stretching method in this second-stage stretching process (S9).

[0445] One feature of this invention is the control of the thermal shrinkage rate of the laminated portion, but the effect of this invention is mainly achieved by controlling the thermal shrinkage rate of the substrate film in the laminated portion. The main methods for controlling the thermal shrinkage rate are as described above.

[0446] As a stretching method, in order to improve the performance, productivity, flatness or dimensional stability of the film, it is preferable to use a stretching method that sets the circumferential speed difference of the rollers to stretch in the conveying direction (the long side direction of the film; the film forming direction; the casting direction; the MD direction), or a stretching method that fixes the two sides of the film with clamps or the like and stretches in the width direction (the orthogonal direction in the film surface; the TD direction).

[0447] Furthermore, in the case of the so-called tenter frame method, if a linear drive is used to drive the clamping part, smooth stretching can be achieved, reducing the risk of breakage, and is therefore preferred. Preferably, these width maintenance or lateral stretching in the film-making process are performed by a tenter frame, which can be a pin tenter frame or a clamp tenter frame. Moreover, in addition to stretching, drying can also be performed within the stretching machine 10.

[0448] The second-stage stretching process (S9) can be a process that stretches the film only in the MD direction within the film surface, a process that stretches only in the TD direction, a process that stretches in both the MD and TD directions, or a process that stretches in an inclined direction. Furthermore, there is no limitation on the stretching direction; from the viewpoint of obtaining a wide film, it is preferable to include at least a stretching process encompassing the width direction. Such stretching can be performed using a stretching machine 10.

[0449] To ensure high phase difference, wide width, and promote adhesive penetration during bonding with the carrier film or cured layer, it is preferable to stretch the film at a high ratio during the second-stage stretching process. However, if the stretching ratio is too high, cracks may sometimes form within the film due to tensile stress, causing the entanglement between matrix molecules that maintain film strength to disintegrate and the film to become embrittled. Therefore, from the viewpoint of realizing the effects of the present invention, it is more preferable that the stretching ratio in the second-stage stretching process is in the range of 1.1 to 2.0 times. On the other hand, since high-ratio stretching can result in excessive thinness and poses a risk of breakage during production, it is more preferable that the stretching ratio is in the range of 1.3 to 1.8 times.

[0450] Furthermore, as in this invention, when stretching is performed multiple times, such as stretching after the peeling process and stretching during the second-stage stretching process, it is preferable to perform the stretching at the maximum ratio, which carries the highest risk of matrix molecule dissociation during the multiple stretching processes, in the final stretch. Therefore, in this invention, it is preferable to perform the maximum ratio stretching during the second-stage stretching process. In this case, the matrix molecules can be firmly entangled until the maximum ratio stretching is performed. Therefore, even when performing the maximum ratio stretching, the dissociation of matrix molecule entanglement can be suppressed, and aggregation failure can be suppressed.

[0451] <Residual solvent content>

[0452] Preferably, the residual solvent content in the film during stretching is 20% by mass or less, and more preferably, the stretching is 15% by mass or less.

[0453] (Staffing machine)

[0454] A tenter frame is a device that stretches a film by holding both ends of the film in the width direction with clamps, and widening the gap as the clamps and film move together. Tensioner frames are typically divided into multiple zones, such as... Figure 6 As shown, the device includes a preheating zone for the heating film, a transverse stretching zone for stretching the film laterally, a heat-fixing zone for crystallizing the film, and a stress-relieving zone for eliminating thermal stress in the film.

[0455] Furthermore, in this embodiment, stretching can be performed not only laterally using the tenter frame 40, but also simultaneously in the longitudinal direction. In this case, the spacing between the clamps 42 (the distance between the clamps 42 in the conveying direction) can be changed as the clamps 42 move. For example, a linkage mechanism or a linear guide mechanism can be used as the mechanism for changing the spacing between the clamps 42.

[0456] Methods for stretching a membrane include stretching in the longitudinal direction (length direction) (longitudinal stretching), stretching in the transverse direction (width direction) (transverse stretching), stretching longitudinally and transversely sequentially (sequential biaxial stretching), and stretching longitudinally and transversely simultaneously (simultaneous biaxial stretching). In transverse stretching and simultaneous biaxial stretching (including inclined stretching), a stretching machine is used.

[0457] The following is for reference Figure 6 , Figure 7 , Figure 8 and Figure 9 This describes the device used as a tenter frame stretching machine.

[0458] Figure 6 The top view illustrating the internal structure of the tenter frame is a schematic diagram, while the cross-sectional view is a plane perpendicular to the film surface, viewed from above. Additionally, Figure 6 The image shows the state with the cover removed, indicated by a double-dotted line.

[0459] The tenter frame 40 includes multiple clamps 42 that hold the two ends of the film F in the width direction. The clamps 42 are mounted on an annular chain 48 at certain intervals. The annular chain 48 is positioned on both sides while holding the film F, and is respectively mounted between a drive sprocket 50 on the inlet side and a driven sprocket 52 on the outlet side. The drive sprocket 50 is connected to a motor (not shown), and the drive sprocket 50 is rotated by driving the motor. As a result, the annular chain 48 travels around between the drive sprocket 50 and the driven sprocket 52, and therefore, the clamps 42 mounted on the annular chain 48 also travel around it.

[0460] Between the driving sprocket 50 and the driven sprocket 52, a track 54 is provided for guiding the annular chain 48 (or clamp 42). The track 54 is arranged on both sides, clamping the membrane F, and the spacing between the tracks 54 is configured such that the downstream side of the membrane F is wider than the upstream side in the conveying direction. As a result, when the clamp 42 travels around, the spacing between the clamps 42 increases, thus enabling lateral stretching of the membrane F held by the clamp 42 in the width direction.

[0461] Opening components 56 are installed on the driving sprocket 50 and the driven sprocket 52 respectively. The opening component 56 is a device that moves the baffle (not shown) of the clamp 42 (described later) from the holding position to the open position. Through the opening component 56, the holding and opening actions of the membrane F are performed automatically.

[0462] In addition, the interior of the tenter frame 40, such as Figure 6 As shown, the membrane includes a preheating zone, a (transverse) stretching zone, and a heat-setting zone. These zones are separated by air curtains (not shown). Furthermore, within each zone, hot air is supplied to the membrane F from above, below, or both. With each zone maintained at a predetermined temperature, the hot air is uniformly blown out along the width of the membrane F. Thus, the interior of each zone is controlled to the desired temperature. Each zone will be described below.

[0463] The preheating zone is the area where the membrane F is preheated without increasing the spacing of the clamps 42. The preheated membrane F moves towards the transverse stretching zone within the preheating zone.

[0464] The transverse stretching zone is the area in which the film F is stretched laterally in the width direction by widening the spacing of the clamps 42. The stretching ratio in this transverse stretching process is preferably in the range of 1.0 to 2.5 times, more preferably in the range of 1.05 to 2.3 times, and even more preferably in the range of 1.1 to 2 times. The film F, stretched laterally in the transverse stretching zone, moves towards the heat-fixing zone.

[0465] To clarify, in this embodiment, the interior of the tenter frame 40 is divided into a preheating zone, a (transverse) stretching zone, and a heat-setting zone. However, the types and configurations of these zones are not limited to these. For example, a cooling zone for cooling the film F can be provided after the transverse stretching zone. Additionally, a heat-relieving zone can be provided within the heat-setting zone.

[0466] [Furnace temperature]

[0467] Typically, the furnace temperature is preferably in the range of 120~300℃, more preferably in the range of 180~250℃. Here, "furnace temperature" in this invention refers to the temperature measured in the stretching zone of the tenter frame at a position 100mm above the center of the film before stretching (see reference). Figure 7 The temperature is calculated by measuring the temperature values ​​per minute for one hour and then averaging them. Typically, the furnace temperature is preferably in the range of 120~300°C, more preferably in the range of 180~250°C. Here, when setting a temperature gradient along the length direction in multiple zones, the zone undergoing heat treatment is considered. Furthermore, in this invention, the furnace temperature differs depending on whether heat treatment is performed in the stretching zone or not; when heat treatment is performed in the stretching zone, this furnace temperature refers to the furnace temperature in the stretching zone before heat treatment.

[0468] Figure 8 This is a top view of the three zones inside the tenter frame. Figure 9 A schematic diagram showing the nozzle and heater setup for the three time zones inside the tenter frame, viewed from the front.

[0469] There are no particular restrictions on the heating method used within the tenter frame; similar to the first drying process (S5), hot air, infrared radiation, heated rollers, and microwaves can generally be used. When using an infrared (IR) heater, such as... Figure 9 As shown, it is positioned only above the nozzle so that the membrane does not come into contact with the infrared (IR) heater in the event of membrane rupture. Furthermore, since bringing the infrared (IR) heater close to the membrane allows the radiation energy generated by the infrared (IR) heater to be concentrated over a narrower range, the infrared (IR) heater can be brought as close to the membrane as possible without hindering the width release operation performed by the clamp.

[0470] exist Figure 9 The heat treatment shown in this embodiment is mainly performed by the central nozzle. Heat treatment by the end nozzles is not performed in this embodiment, but they can be used together in this embodiment.

[0471] In tensioning devices, such as Figure 7 As shown, when the infrared (IR) heater extends from the nozzle gap, radiant energy can be transferred to the membrane without waste. Figure 8 As shown, infrared (IR) heaters are arranged in rows to heat the entire width of the film before stretching. It should be noted that the heaters can be staggered along the length.

[0472] (other)

[0473] In the second-stage stretching process (S9), the film F can be dried in the same manner as in the first drying process (S5), as needed. There are no particular restrictions on the drying method at this stage; hot air, infrared radiation, heated rollers, and microwaves are generally acceptable. For simplicity, drying the film F with hot air is preferred.

[0474] (F) The process of winding the stretched film

[0475] The process of winding the stretched film includes a second cutting process and a second winding process.

[0476] (F-1) Second cutting process (S10)

[0477] In the second cutting step (S10), the cutting section 11, which is composed of an edge trimmer, cuts both ends of the film F in the width direction, which has been stretched by the second-stage stretching step (S9). The remaining portion of the film F after cutting constitutes the product portion that becomes a film product. On the other hand, the portion cut from the film F can be recycled and reused again as part of the raw material in the film making process.

[0478] (F-2) Second winding process (S11)

[0479] In the second winding process (S11), the film F is wound using the winding device 12 at a conveying speed V2. At this time, it is preferable to wind while simultaneously attaching the protective film. The film thickness is preferably in the range of 5 to 100 μm, more preferably in the range of 5 to 80 μm, and even more preferably in the range of 5 to 40 μm. The preferred range for the initial tension during winding the film F in the second winding process (S11) is 20 to 300 N / m.

[0480] The winding method for membrane F can be any commonly used winding machine. There are various tension control methods, such as constant torque method, constant tension method, taper tension method, and programmed tension control method with constant internal stress, which can be used respectively.

[0481] Before winding, the ends can be cut to the width of the product and trimmed off. To prevent adhesion and scratches during winding, surface modification treatment can also be applied to both ends of the film.

[0482] <Residual Solvent Amount>

[0483] The residual solvent content in the film during the second winding process is 2% by mass or less. Furthermore, from the viewpoint of obtaining a film with good dimensional stability, it is preferable to set the residual solvent content at this time to 0.4% by mass or less, and more preferably to be in the range of 0.00 to 0.20% by mass.

[0484] (4.2) Melt casting film production method

[0485] "Melted film casting" refers to a method in which a composition containing thermoplastic resin and additives is heated and melted until it exhibits fluidity, and then the molten thermoplastic resin containing the fluidity is cast. As a heating and melting molding method, it can be further classified into melt extrusion molding, compression molding, blow molding, injection molding, blow molding, stretch molding, etc. Among these molding methods, melt extrusion is preferred from the viewpoint of mechanical strength and surface finish.

[0486] In the process of manufacturing a substrate film using the melt casting method of the present invention, the process of manufacturing the original roll film includes at least the following three processes (A), (B) and (C).

[0487] (A) The process of casting molten resin or granules onto a support to form a web.

[0488] (B) The first stage of stretching process

[0489] (C) The process of winding the film formed by drying the web material.

[0490] In addition, the processing step of the original film roll is to transport the wound original film roll and perform a second-stage stretching process.

[0491] In the second stage stretching process, for the wound film, the amount of residual solvent before the second stage stretching is in the range of 0.1 to 0.5% by mass relative to the winding width.

[0492] Figure 10 This is a flowchart illustrating the fabrication process of a substrate film using the melt casting method. Additionally, Figure 11 This is a schematic diagram of an apparatus for manufacturing a substrate film using a melt casting method. Hereinafter, in the melt casting method, refer to... Figure 10 and Figure 11 Please provide an explanation.

[0493] like Figure 10 As shown, the manufacturing process of the substrate film using the melt casting method includes an extrusion process (M1), a casting process (M2), a first-stage stretching process (M3), a drying process (M4), a first cutting process (M5), a first winding process (M6), an unwinding process (M7), a second-stage stretching process (M8), a second cutting process (M9), and a second winding process (M10).

[0494] (4.2.1) Preparation of the original roll film

[0495] The manufacturing process of the original roll film using the melt casting method includes at least (G) a process of casting molten resin / particles onto a support to form a web, (H) a process of performing a first-stage stretching, and (I) a process of winding the film formed by drying the web.

[0496] (G) The process of casting molten resin / particles onto a support to form a web.

[0497] The process of casting molten resin / particles onto a support to form a web includes at least an extrusion process (M1) and a casting process (M2).

[0498] (G-1) Extrusion process (M1)

[0499] In the extrusion process (M1), the resin is melted and extruded using the extruder 14 and formed on the die roller 16. Details regarding the resins that can be used in this invention will be described later. It is preferable to pre-mix and granulate the resin, which can be done using known methods. A known method, for example, is to feed dried resin, plasticizer, and other additives into the extruder using a feeder, mix them using a single-shaft or twin-shaft extruder, extrude them from a casting die into strips, water-cool or air-cool them, and cut them to achieve granulation.

[0500] The additives can be mixed with the resin before being fed to the extruder, or the additives and resin can be fed to the extruder separately using separate feeders. Furthermore, for uniform mixing, it is preferable to mix a small amount of additives, such as particles and antioxidants, with the resin beforehand.

[0501] When feeding granules from the feed hopper into the extruder, it is preferable to operate under dry, vacuum, or reduced pressure conditions, or in an inert gas atmosphere to prevent oxidative decomposition. The extruder is preferably designed to suppress shear forces, granulate to prevent resin degradation (molecular weight reduction, coloring, gel formation, etc.), and process at the lowest possible temperature. For example, in the case of a twin-screw extruder, it is preferable to use a deep-groove type screw that rotates in the same direction. For the sake of uniform mixing, an interlocking type screw is preferred. When the resin / granules are melted, it is preferable to filter them using a vane-type filter or similar device to remove impurities.

[0502] The granules obtained as described above are used to form webs. Of course, it is also possible to directly form webs by feeding the raw resin (powder, etc.) directly into the extruder using a feeder without granulation.

[0503] (G-2) Casting process (M2)

[0504] In the casting process (M2), the molten resin / particles from the extrusion process are cast in a film form through a conduit via a pressurized quantitative gear pump or the like. Then, the molten resin / particles are cast from the casting die 15 to a casting position on a continuously conveying, rotating, stainless steel annular casting cylinder 16. Finally, the cast molten resin / particles are molded onto the casting cylinder 16 to form a web.

[0505] The inclination of the casting die 15, i.e. the discharge direction of the molten resin / particles from the casting die 15 to the support 16, can be appropriately set to an angle of 0 to 90° relative to the normal of the surface of the casting roller 16 (the surface where the molten resin / particles are cast).

[0506] The touch roller 16a and the cooling roller 17 of the auxiliary molding roller 16 can be used individually or in combination to form the film F (hereinafter, the dried "web" will also be referred to as "film F").

[0507] (H) The first stage of stretching process (M3)

[0508] In the first-stage stretching process (M3), the film F is stretched using the stretching device 18. The stretching method at this time is the same as that in the first-stage stretching process (S4) when the substrate film is made using the solution casting method.

[0509] (I) The process of winding the web formed by drying the web.

[0510] The process of drying the web material to form a film and then winding it includes a drying process (M4), a first cutting process (M5), and a first winding process (M6). Furthermore, the web material conveying speed V1 in the extrusion process (M1) is the same as the winding speed in the first winding process (M6). Additionally, "the same speed" for both the conveying speed and the winding speed means, strictly speaking, that they are the same within a range of ±10%.

[0511] The drying process (M4), the first cutting process (M5), and the first winding process (M6) are the same as the drying process (S5), the first cutting process (S6), and the first winding process (S7) when the substrate film is made by solution casting.

[0512] (4.2.2) Processing steps of the original film roll

[0513] The processing steps for the original roll film when producing a substrate film using the melt casting method include conveying the wound film and performing a second-stage stretching process. Furthermore, this original roll film processing step includes (J) an unwinding process, (K) a second-stage stretching process, and (L) a winding process of the stretched film. Specifically, the processing steps involve conveying the wound film at a conveying speed V2 via an unwinding process (M7) from its rollers, and performing a second-stage stretching process. It also includes at least a feeding process (M7), a second-stage stretching stroke (M8), a second cutting process (M9), and a second winding process (M10).

[0514] In the second stage stretching process, for the wound film, the amount of residual solvent before the second stage stretching is in the range of 0.1 to 0.5% by mass, relative to the winding width.

[0515] (J) Unwinding process (M7)

[0516] In the unwinding process (M7), the wound film is unwound from its rollers and conveyed at a conveying speed V2.

[0517] <Residual Solvent Amount>

[0518] Then, the membrane undergoes a second stage of stretching. At this point, the amount of residual solvent before the second stage of stretching is in the range of 0.1% to 0.5% by mass.

[0519] (K) The second stage of stretching process (M8)

[0520] In the second-stage stretching process (M8), the film F, which is conveyed at a conveying speed V2, is stretched by the stretching device 21. The stretching method at this time is the same as the second-stage stretching process (S9) when preparing the substrate film using the solution casting method described above.

[0521] <Residual Solvent Amount>

[0522] Preferably, the residual solvent content in the film during stretching is 20% by mass or less, and more preferably, the stretching is 15% by mass or less.

[0523] (Staffing machine)

[0524] The tenter frame can be the same tenter frame used in solution casting film production.

[0525] (other)

[0526] In the second-stage stretching process (M8), the film F can be dried in the same way as in the drying process (M4), depending on the needs. There are no particular limitations on the drying method at this time; hot air, infrared radiation, heated rollers, and microwaves can generally be used. However, from a simplicity perspective, drying the film F with hot air is preferred.

[0527] (L) The process of winding the stretched film

[0528] The process of winding the stretched film includes a second cutting process (M9) and a second winding process (M10).

[0529] (L-1) Second cutting process (M9)

[0530] In the second cutting step (M9), the two ends of the film F, which has been stretched in the second stage stretching step (M8), are cut in the width direction using a cutting section 22 consisting of an edge trimmer. The remaining portion of the film F after cutting constitutes the product portion that becomes the film article. Alternatively, the portion cut from the film F can be recycled and reused again as part of the raw material in the film manufacturing process.

[0531] (L-2) Second winding process (M10)

[0532] In the second winding process (M10), the film F is wound using the winding device 23 at a conveying speed V2. Preferably, the protective film is applied while winding is being performed. The film thickness is preferably in the range of 5 to 100 μm, more preferably in the range of 5 to 80 μm, and even more preferably in the range of 5 to 40 μm. The initial tension during winding of the film F in the second winding process (M10) is preferably in the range of 20 to 300 N / m.

[0533] The winding method for membrane F can be any commonly used winding machine. There are various tension control methods, such as constant torque method, constant tension method, taper tension method, and programmed tension control method with constant internal stress, which can be used respectively.

[0534] Before winding, to prevent sticking and scratches during winding, the ends can be cut to the width of the finished product and trimmed, and the surfaces of both ends of the film can be modified.

[0535] <Residual Solvent Amount>

[0536] The residual solvent content in the film during the second winding process is 2% by mass or less. Furthermore, from the viewpoint of obtaining a film with good dimensional stability, it is preferable to set the residual solvent content to 0.4% by mass or less, and more preferably, the residual solvent content is in the range of 0.00 to 0.20% by mass.

[0537] 5. Formation process of the second adhesive layer (S12)

[0538] In the second adhesive layer formation step (S12), the wound substrate film is unwound, and the aforementioned second adhesive layer composition is applied (coated) to the surface of the substrate film. If a protective film is attached, it is peeled off. Then, the substrate film is dried or heated to form a second adhesive layer on one side, and the protective film is adhered to this second adhesive layer and the film is wound. Preferably, the protective film is adhered to the side opposite to the second adhesive layer. Hereinafter, the substrate film with a protective film produced by the second adhesive layer formation step (S12) will be designated as substrate film F. S12 To clarify, the "substrate film F" mentioned on the left... S12 The "S12" in the text refers to the process of forming the second adhesive layer (S12). There are no particular limitations on the winding method, and conventionally known methods can be used.

[0539] 6. Formation process of the first adhesive layer (S13)

[0540] In the first adhesive layer formation process (S13), the wound substrate film F is...S12 Unwind the film F that is adhered to the substrate. S12 After the protective film is peeled off, the first adhesive layer is applied (coated) with the composition to the other surface of the substrate film where the second adhesive layer has not been formed. Then, by drying or heating, the first adhesive layer is formed on the other side of the substrate film, the carrier film is adhered to the first adhesive layer, and the film is wound up. Hereinafter, the substrate film with the carrier film adhered to it, produced by the first adhesive layer formation step (S13), will be referred to as substrate film F. S13 Furthermore, the "substrate film F" mentioned on the left... S13 The "S13" in the text refers to the process of forming the first adhesive layer (S13). There are no particular limitations on the winding method, and conventionally known methods can be used.

[0541] 7. Formation process of multiple curing layers

[0542] The present invention relates to multiple cured layers, which can be three or more layers; however, as an example of multiple cured layers, the case of forming only two layers will be described here. A first adhesive layer is formed on one side of the substrate film, and a second adhesive layer is formed on the other side, and then the film is wound. That is, the laminate portion of the present invention is formed and wound.

[0543] (7.1) First curing layer formation process (S14)

[0544] In the first curing layer formation process (S14), the wound substrate film F is... S13 Unwinding, and applying the curing layer corresponding to the purpose to the coating liquid of the composition onto the substrate film F. S13 The second adhesive layer side surface. Hereinafter, the coating liquid of the curing layer composition applied when the first curing layer is formed will be referred to as "coating liquid of curing layer composition [1]". Here, if it is desired to form a low refractive index layer on the second adhesive layer, it is preferable to prepare the above-mentioned coating liquid of curing layer composition [1] as the coating liquid of low refractive index layer composition. Then, the coating liquid of curing layer composition [1] is cured, dried, and wound.

[0545] In this invention, since the cured layer formed on the second adhesive layer is a low refractive index layer, the coating liquid of the composition for the low refractive index layer may contain an ultraviolet-curable resin composition and beads (organic resin particles) with a diameter of about 8 μm.

[0546] There are no particular limitations on the curing and drying of the coating liquid [1] of the above-mentioned curing layer composition. For example, curing based on ultraviolet light or hot air curing can be performed. The state of the coating liquid [1] of the curing layer composition after curing and drying is a coating film, which will be referred to as "curing layer [1]" below.

[0547] In this invention, when the curing layer [1] is formed by curing and drying the coating liquid of the low refractive index layer composition, for example, the beads (organic resin particles) with a diameter of about 8 μm can be in a state where about 1 / 3 of the diameter protrudes.

[0548] Furthermore, the carrier film on the first adhesive layer side, where the cured layer [1] has not yet formed, remains adhered. Hereinafter, the substrate film formed after the cured layer is produced through the first cured layer forming process (S14) will be referred to as substrate film F. S14 Furthermore, the "substrate film F" mentioned on the left... S14 The “S14” in the text refers to the process of forming the first curing layer (S14).

[0549] (7.2) Second curing layer formation process (S15)

[0550] In the second curing layer formation process (S15), the wound substrate film F is... S14 Unwinding is performed on the substrate film F S14 A coating liquid [2] of the curing layer composition is applied to the side of the cured layer [1]. Here, if it is desired to form a high refractive index layer on the first cured layer, that is, to make the second cured layer a high refractive index layer, it is preferable to prepare the coating liquid [2] of the curing layer composition as a coating liquid for the high refractive index layer composition. Then, the coating liquid [2] of the curing layer composition is cured, dried, and wound.

[0551] In this case, when the second curing layer is set as a high refractive index layer, the coating liquid [2] of the curing layer composition may contain, for example, an ultraviolet curable resin composition and zirconium oxide (ZrO2, refractive index: 2.10) particles.

[0552] There are no particular limitations on the curing and drying of the coating liquid [2] of the above-mentioned curing layer composition. For example, curing based on ultraviolet light or hot air curing can be performed. The state of the coating liquid [2] of the curing layer composition after curing and drying is defined as the coating film, which is referred to as "curing layer [2]" below.

[0553] In this invention, the curing layer [2] can be a curing layer obtained by curing and drying the coating liquid of the low refractive index layer composition, or it can be a curing layer obtained by curing and drying the coating liquid of the high refractive index layer composition. Moreover, when the curing layer [2] is a curing layer obtained by curing and drying the coating liquid of the high refractive index layer composition, it can be a state in which there is no protrusion of the aforementioned beads (organic resin particles) from the outermost layer and it is completely embedded in the curing layer.

[0554] Furthermore, the carrier film on the side where the first adhesive layer [2] has not been formed remains adhered. Hereinafter, the substrate film formed after the curing layer is produced by the second curing layer forming process (S15) will be referred to as substrate film F. S15 Furthermore, the "substrate film F" mentioned on the left... S15 The “S15” in the text refers to the process of forming a second curing layer (S15).

[0555] As can be seen from the above, the laminated film of the present invention and the aforementioned substrate film F S15 Synonyms.

[0556] [III. Display Device]

[0557] The display device of the present invention is a display device having an optical film, characterized in that it has a portion of the carrier film removed from the laminated film of the present invention as an optical film.

[0558] For example, Figure 12 shows a specific example of how the portion of the carrier film removed from the laminated film of the present invention can be applied to a self-emissive source. Furthermore, it is possible to have... Figure 12A and Figure 12B Such applications are examples. Furthermore, it is conceivable that the aforementioned methods could be used as laminated films. Figure 1A The situation.

[0559] Examples of self-emissive sources include surface-emitting OLEDs and other preferred self-emissive light sources. Furthermore, the self-emissive source is manufactured separately from the laminated film, thereby creating a display device with enhanced light-emitting optics. For ease of explanation, a surface-emitting OLED is shown in a simplified manner.

[0560] To provide enhanced optical performance for the OLED, the laminated film of the present invention is applied to the light-emitting surface Sb of the OLED. Prior to application, the carrier film CF is removed from the laminated film F1, exposing the surface Sa. In some cases, the light-coupled surface of the laminated film of the present invention can be directly configured relative to the light-emitting surface Sb of the OLED.

[0561] The direct contact between the surface Sa (optically coupled surface) of the laminated film of the present invention, in which the carrier film portion has been removed, and the light-emitting surface Sb of the OLED, is sufficient to create a film bond between the two constituent elements without a significant air gap between them.

[0562] Thus, the combination of the portion of the laminated film from which the carrier film has been removed with the OLED can be implemented using a wide variety of known OLEDs, including non-pixelated OLEDs commonly used in lighting applications. However, they are particularly useful when used with generally usable pixelated OLEDs commonly used in electronic displays for generating images.

[0563] Example

[0564] The present invention will be specifically described below with reference to specific embodiments, but the present invention is not limited thereto. Furthermore, the use of the terms "parts" or "%" in the embodiments, unless otherwise specified, indicates "parts by mass" or "% by mass".

[0565] [Fabrication of laminated film [1]]

[0566] [1] Preparation of protective film and carrier film

[0567] When fabricating a laminated membrane [1], firstly, as a protective membrane, the following protective membrane [1] and carrier membrane [A] are prepared.

[0568] Protective film [1]: Polyester film "TORETEC 7832C"

[0569] (30μm thickness, manufactured by Toray Film Processing Co., Ltd.)

[0570] Carrier membrane [A]: Polyethylene terephthalate membrane "SAT-EBF01"

[0571] (38μm thick acrylic adhesive layer manufactured by Sansei Chemical Research Institute; 10μm thick acrylic adhesive layer)

[0572] [2] Fabrication of substrate film

[0573] In the fabrication of the substrate film, the solution casting method is used.

[0574] [2-1] Coating solution preparation process (S1)

[0575] 100 parts by mass of purified toluene and 100 parts by mass of norbornene methyl carboxylate were added to a stirred apparatus. Next, 25 mmol% (relative to monomer mass) of nickel ethylhexanoate dissolved in toluene, 0.225 mol% (relative to monomer mass) of tris(pentafluorophenyl)boron, and 0.25 mol% (relative to monomer mass) of triethylaluminum dissolved in toluene were added to the stirred apparatus. The mixture was then reacted at room temperature with stirring for 18 hours. After the reaction was complete, the reaction mixture was added to excess ethanol to form a polymer precipitate. The precipitate was purified, and the resulting cyclic polyolefin polymer (P-1) was dried under vacuum at 65°C for 24 hours.

[0576] Next, the following composition [1] containing cyclic polyolefin polymer (P-1) prepared by the above method is added to a mixing tank, stirred to dissolve the components, and then filtered with filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm to prepare a coating liquid (D-1).

[0577] <Composition [1]>

[0578] Cyclic polyolefin polymer (P-1) 150 parts by weight

[0579] 380 parts by weight of dichloromethane

[0580] 70 parts by weight of ethanol

[0581] Next, the following composition [2] containing coating liquid (D-1) prepared by the above method is fed into a disperser to prepare a particulate dispersion (M-1) as an additive.

[0582] <Composition [2]>

[0583] Microparticle "AEROSIL R812" (manufactured by AEROSIL Corporation of Japan) First-order average particle size: 7nm, apparent specific gravity 50g / L) 4 parts by mass

[0584] 76 parts by weight of dichloromethane

[0585] 10 parts by weight of ethanol

[0586] Coating liquid (D-1) 10 parts by weight

[0587] 100 parts by mass of the above cyclic polyolefin solution (coating solution (D-1)) and 0.75 parts by mass of the particulate dispersion (M-1) were mixed to prepare a coating solution (COP1) for film formation containing cyclic olefin resin as a resin composition.

[0588] [2-2] Casting process (S2)

[0589] The coating solution (COP1) is fed into the casting die head via a pressurized quantitative gear pump and a conduit. Furthermore, at the casting position on a support body constructed of an infinitely shifting rotating stainless steel annular belt, the coating solution (COP1) is cast from the casting die head on the film production line with a width of 1300 mm. At this time, the coating solution (COP1) is heated on the support body until it becomes self-supporting, causing the solvent to evaporate until the coating solution can be peeled off from the support body using a peeling roller, thereby drying and forming a film. At this time, the delivery speed V1 of the coating solution (COP1) is 55 m / min.

[0590] [2-3] Stripping process (S3)

[0591] In the casting process (S2), after the web is formed, it is peeled off from the support with a peeling roller to make it self-supporting.

[0592] [2-4] The first stage of stretching process (S4)

[0593] The aforementioned fabric was subjected to high-temperature treatment without maintaining its width to increase its density. This caused the fabric to shrink in width relative to its width direction immediately after casting, while simultaneously undergoing the first stage of stretching. At this point, the amount of residual solvent before the first stage of stretching was measured, and the result was 12% by mass. Furthermore, the stretching ratio was 1.50.

[0594] [2-5] Drying process (S5)

[0595] Then, the web is heated on the support, and the solvent evaporates from the web.

[0596] [2-6] First cutting process (S6)

[0597] Cut the two ends of the above-mentioned web material in the width direction after the solvent has evaporated to make the original roll film.

[0598] [2-7] First winding process (S7)

[0599] The original roll film is conveyed at a conveying speed V1 (V1=55m / min) while being wound onto the core using a winding device. The initial tension is 50N, the taper is 70%, and the corner angle is 25%.

[0600] [2-8] Unwinding process of the original film roll (S8)

[0601] The original wound film is unwound at a conveying speed of V2 (10m / min).

[0602] [2-9] The second stage of stretching process (S9)

[0603] While the unwound original roll of film is conveyed in the stretching device at a conveying speed V2 (10 m / min), the second stage of stretching is carried out. At this time, the residual solvent content before the second stage of stretching is measured, and the result is 0.30% by mass. In addition, it is carried out at a stretching ratio of 1.40.

[0604] [2-10] Second cutting process (S10)

[0605] Similar to the first cutting process, a substrate film is produced by cutting both ends of the stretched original roll film in the width direction. Hereinafter, this substrate film will be referred to as "substrate film [A]".

[0606] [2-11] Second winding process (S11)

[0607] While attaching the protective film [1] to the substrate film [A], the substrate film [A] is wound. The initial tension is 50 N, the taper is 70%, and the corner angle is 25%.

[0608] The substrate film [A] is produced through the above processes. Furthermore, the thickness of the substrate film [A] produced through the above processes is 15 μm.

[0609] [3] Formation process of the second adhesive layer (S12)

[0610] [3-1] Preparation of the composition for the second adhesive layer

[0611] The following components were diluted with a diluent (water: 2588 parts by mass / methanol: 1464 parts by mass) to prepare a composition for the second adhesive layer [1]. Furthermore, the silica microparticle dispersion [1] in the following components is a methanol dispersion of "SEAHOSTER KE-30" manufactured by Nippon Shokubai Co., Ltd., which disperses silica microparticles with an average particle size of 300 nm, and the solid content is 5%.

[0612] <Ingredients>

[0613] "Arrowbase SE-1030E" (acid-modified polyolefin resin) 680 parts by weight

[0614] Epocross WS-700 (Oxazoline-based acrylic resin) 30 parts by weight

[0615] Silica microparticle dispersion [1] (content as described above)

[0616] Furthermore, among the aforementioned ingredients, "Arrowbase SE-1030E" (polyolefin resin) is manufactured by Uniqlo Co., Ltd., with a solid content of 22.0%. "Epocross WS-700" (oxazoline acrylic resin) is manufactured by Nippon Shokubai Co., Ltd., with a solid content of 25%.

[0617] [3-2] Application, drying and curing of the composition for the second adhesive layer

[0618] After the protective film [1] is peeled off from the substrate film [A] with the protective film [1] wound in the second winding process (S11), it is unwound at a conveying speed of 20 m / min. At this time, the second adhesive layer composition [1] is applied to the substrate film [A] using a depressurized extrusion die coater, and dried and cured in an atmosphere of 120°C to form a second adhesive layer with a thickness of 320 nm. In addition, while conveying at the same conveying speed of 20 m / min as described above, the protective film [1] is adhered to the second adhesive layer and wound. Hereinafter, the adhesive layer formed in the same process as the second adhesive layer, with the same type of resin, type of inorganic particles, average particle size, and thickness as the adhesive layer, will be referred to as "adhesive layer [A]".

[0619] [4] Formation process of the first adhesive layer (S13)

[0620] [4-1] Preparation of the composition for the first adhesive layer

[0621] The first adhesive layer composition is prepared in the same manner as the second adhesive layer composition. Hereinafter, this first adhesive layer composition will be referred to as "first adhesive layer composition [1]".

[0622] [4-2] Application, drying and curing of the composition for the first adhesive layer

[0623] After the protective film [1] is peeled off from the substrate film [A] with the protective film [1] wound in the second adhesive layer formation step (S12), it is unwound at a conveying speed of 20 m / min. At this time, the first adhesive layer composition [1] is applied to the other surface of the substrate film [A] where the second adhesive layer has not been formed using a depressurized extrusion die coater, and dried and cured in an atmosphere of 120°C to form a first adhesive layer with a thickness of 320 nm. Meanwhile, while conveying at the same conveying speed of 20 m / min as described above, the carrier film [A] is adhered to the first adhesive layer and wound.

[0624] Furthermore, the first adhesive layer and the second adhesive layer are formed through the same process. The types of resin, types of inorganic particles, average particle size, and thickness of the adhesive layer are all the same, therefore it is an adhesive layer [A].

[0625] [5] Formation process of multiple curing layers

[0626] In the fabrication of the laminated film [1], two curing layers are formed as multiple curing layers.

[0627] [5-1] The process of forming the first cured layer (S14)

[0628] [5-1-1] Preparation of the coating liquid for the composition used in the curing layer

[0629] A coating solution for a curing layer composition is prepared by mixing and stirring the following components. This coating solution for a curing layer composition is designated as "coating solution for a curing layer composition [1]". Furthermore, the content of beads in the following components is adjusted such that when the total mass of the coating solution for a curing layer composition [1] is 100 parts by mass, the content of beads in the following components is 70 parts by mass.

[0630] <Ingredients: Formula A1>

[0631] KAYARAD PET-30 (adhesive resin) 30 parts by weight

[0632] Irgacure 184 (polymerization initiator) 1.5 parts by weight

[0633] SEIKABEAM10-28 (Silicone Leveling Agent) 0.05 parts by weight

[0634] Methyl isobutyl ketone (solvent) 70 parts by weight

[0635] Beads: "GM-0806S" (content has been recorded above)

[0636] Furthermore, "KAYARAD PET-30" in the above ingredients is pentaerythritol triacrylate manufactured by Nippon Kayaku Co., Ltd. Additionally, "Irgacure 184" is a polymerization initiator manufactured by BASF Japan, and "SEIKABEAM10-28" is a silicone leveling agent manufactured by Dainisei Chemical Co., Ltd., with a solid content of 10%.

[0637] The beads “GM-0806S” in the above components are polyacrylate manufactured by AICA Industries, Ltd., with a refractive index of 1.49 and a number-average particle size of 8μm.

[0638] [5-1-2] Application, curing, and drying of the composition for the cured layer

[0639] The substrate film [A] with carrier film [A], which was wound in the first adhesive layer formation step (S13), is unwound at a conveying speed of 20 m / min. A coating liquid [1] of the curing layer composition is applied to the surface of the second adhesive layer side, dried, UV cured, and then wound.

[0640] [5-2] Formation process of the second cured layer (S15)

[0641] [5-2-1] Preparation of the coating liquid for the composition used in the curing layer

[0642] A coating solution for a curing layer composition is prepared by mixing and stirring the following components. This coating solution for a curing layer composition is designated as "coating solution for a curing layer composition [2]".

[0643] <Ingredients: Formula A3>

[0644] "KAYARAD PET-30" (adhesive resin) 19.4 parts by weight

[0645] Irgacure 184 (polymerization initiator) 0.6 parts by weight

[0646] SEIKABEAM10-28 (Silicone Leveling Agent) 0.03 parts by weight

[0647] Methyl isobutyl ketone (solvent) 1129.6 parts by weight

[0648] Particulate dispersion “MZ-230X” 51.0 parts by weight

[0649] Furthermore, "KAYARAD PET-30" in the above ingredients is pentaerythritol triacrylate manufactured by Nippon Kayaku Co., Ltd. Additionally, "Irgacure 184" is a polymerization initiator manufactured by BASF Japan, and "SEIKABEAM10-28" is a silicone leveling agent manufactured by Dainisei Chemical Co., Ltd., with a solid content of 10%.

[0650] The particulate dispersion “MZ-230X” in the above composition is a methyl ethyl ketone dispersion of high refractive index ZrO2 particles manufactured by Sumitomo Osaka Cement Co., Ltd., with a solid content of 32.5% by mass.

[0651] [5-2-2] Application, curing, and drying of the composition for the cured layer

[0652] The substrate film [A] with the carrier film [A] formed in the first curing layer formation step (S14) is unwound at a conveying speed of 20 m / min. A coating liquid [2] of the curing layer composition is applied to the surface of the first curing layer side, dried, UV cured, and then wound. A laminated film [1] is produced through the above steps.

[0653] [Fabrication of laminated film [2]]

[0654] [1], [2] Preparation of protective film, carrier film and substrate film

[0655] As a protective film and a carrier film, the same protective film [1] and carrier film [A] as the laminated film [1] are prepared. In addition, instead of making a substrate film, a commercially available polyester film "Lumirror #16" (resin type: polyethylene terephthalate, thickness 16μm) manufactured by Toray Industries, Inc. is prepared. Hereinafter, this substrate film will be referred to as "substrate film [B]".

[0656] [3]~[5] The process of forming the second and first adhesive layers ~ The process of forming multiple curing layers

[0657] For the second adhesive layer, the adhesive layer [A] is formed using the same method as for the laminated film [1], the protective film [1] is adhered, and then the film is wound. Similarly, for the first adhesive layer, the adhesive layer [A] is formed using the same method as for the laminated film [1], the carrier film [A] is adhered, and then the film is wound.

[0658] The first cured layer is formed by preparing a coating liquid of the curing layer composition using the same formulation A1 as the laminated film [1], applying it, drying it, UV curing it, and then winding it. Similarly, the second cured layer is formed by preparing a coating liquid of the curing layer composition using the same formulation A3 as the laminated film [1], applying it, drying it, UV curing it, and then winding it.

[0659] [Fabrication of laminated film [3]]

[0660] [1] Preparation of protective film and carrier film

[0661] As a protective film and a carrier film, a protective film [1] and a carrier film [A] similar to those of the laminated film [1] are prepared.

[0662] [2] Fabrication of substrate film

[0663] The coating solution preparation process (S1) to the unwinding process of the original film (S8) are performed in the same manner as in the laminated film [1]. Regarding the second-stage stretching process (S9), the unwound original film is conveyed in the stretching device at a conveying speed V2 (8 m / min) while the second-stage stretching is performed. At this time, the amount of residual solvent before the second-stage stretching is measured, and the result is 0.30% by mass. Furthermore, the stretching ratio is 1.1 times.

[0664] For the second cutting and second winding processes (S10 and S11), the substrate film is produced by cutting both ends of the stretched original roll film in the width direction, similar to the first cutting process. Hereinafter, this substrate film will be referred to as "substrate film [C]". Furthermore, the aforementioned protective film [1] is adhered to the substrate film [C] while the substrate film [C] is wound. The process is carried out with an initial tension of 50 N, a taper of 70%, and a corner angle of 25%.

[0665] The substrate film [C] is produced through the above processes. Furthermore, the thickness of the substrate film [C] produced through the above processes is 20 μm.

[0666] [3]~[5] The process of forming the second and first adhesive layers ~ The process of forming multiple curing layers

[0667] For the second adhesive layer, the adhesive layer [A] is formed using the same method as for the laminated film [1], the protective film [1] is adhered, and the film is wound. Similarly, for the first adhesive layer, the adhesive layer [A] is formed using the same method as for the laminated film [1], the carrier film [A] is adhered, and the film is wound.

[0668] The first cured layer is formed by applying a coating liquid of the curing layer composition prepared with the same components as the laminated film [1] in formulation A1, curing and drying the coating liquid, and then winding the film. Similarly, the second cured layer is formed by applying a coating liquid of the curing layer composition prepared with the same components as the laminated film [1] in formulation A3, curing and drying the coating liquid, and then winding the film.

[0669] [Fabrication of laminated film [4]]

[0670] [1], [2] Preparation of protective film and carrier film and fabrication of substrate film

[0671] As protective film and carrier film, the same protective film [1] and carrier film [A] as those in the laminated film [1] are prepared. Furthermore, except that the heat shrinkage rate of the laminated portion is appropriately adjusted to the value shown in Table V during the second-stage stretching process, the same substrate film [A] as those used in the fabrication of the laminated film [1] is manufactured. Moreover, the heat shrinkage rate is adjusted as described above by appropriately adjusting the stretching temperature, stretching speed, stretching ratio, heating holding time, cooling rate, residual solvent amount, and post-stretching cooling rate. The following describes a method for appropriately adjusting the heat shrinkage rate of the laminated portion.

[0672] [3]~[5] The process of forming the second and first adhesive layers ~ The process of forming multiple curing layers

[0673] For the second adhesive layer, except that "SEAHOSTER KE-30" (silica microparticles) is not included in the composition of the second adhesive layer, the second adhesive layer is formed using the same method as the laminated film [1], the protective film [1] is adhered, and the film is wound. Hereinafter, this adhesive layer will be referred to as "adhesive layer [B]". In addition, for the first adhesive layer, except that "SEAHOSTER KE-30" (silica microparticles) is not included in the composition of the first adhesive layer, the adhesive layer [B] is formed using the same method as the laminated film [1], the carrier film [A] is adhered, and the film is wound.

[0674] For the first cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A1 as the laminated film [1], applied, cured, and dried to form the first cured layer, and then wound. Similarly, for the second cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A3 as the laminated film [1], applied, cured, and dried to form the second cured layer, and then wound.

[0675] [Fabrication of laminated film [5]]

[0676] [1], [2] Preparation of protective film and carrier film and fabrication of substrate film

[0677] As a protective film and a carrier film, a protective film [1] and a carrier film [A] identical to those in the laminated film [1] are prepared. In addition, except that the heat shrinkage rate of the laminated portion is appropriately adjusted to the value of Table V during the second-stage stretching process, a substrate film identical to the substrate film [A] used in the fabrication of the laminated film [1] is made.

[0678] [3] The process of forming the second adhesive layer

[0679] In the preparation of the composition for the second adhesive layer, the following components were diluted with 912 parts by mass of a diluent (water / methanol = 50 / 50 (mass%)) to prepare the composition for the second adhesive layer [2]. Furthermore, the silica microparticle dispersion [2] in the following components was prepared by mixing "SEAHOSTER KE-30" manufactured by Nippon Shokubai Co., Ltd., which disperses silica microparticles with an average particle size of 300 nm, in a manner where the solid component was 8% relative to the other components.

[0680] <Ingredients>

[0681] Acrydic 52-666 (acrylic resin) 124.0 parts by weight

[0682] "Takenate D110N" (isocyanate curing agent) 63.3 parts by weight

[0683] Silica microparticle dispersion [2] (content as described above)

[0684] Furthermore, among the above ingredients, "Acrydic 52-666" (acrylic resin) is manufactured by DIC Corporation, with a solid content of 50%. "Takenate D110N" (isocyanate curing agent) is manufactured by Mitsui Chemicals, with a solid content of 60%.

[0685] After peeling the protective film [1] from the substrate film [A] wound in the second winding process (S11), the film is unwound at a conveying speed of 20 m / min. At this time, the second adhesive layer composition [2] is applied to the substrate film [A] using a depressurized extrusion die coater, and dried and cured at 120°C to form a second adhesive layer with a thickness of 320 nm. Meanwhile, the protective film [1] is attached to the second adhesive layer while conveying at the same conveying speed of 20 m / min as described above, and the film is wound. Hereinafter, the adhesive layer formed by the same process as the second adhesive layer, and having the same resin type, inorganic particle type, average particle size, and thickness, will be referred to as "adhesive layer [C]".

[0686] [4] The process of forming the first adhesive layer

[0687] The first adhesive layer composition is prepared in the same manner as the second adhesive layer composition. Hereinafter, this first adhesive layer composition will be referred to as "first adhesive layer composition [2]".

[0688] After peeling off the protective film [1] from the substrate film [A] with the protective film [1] wound in the second adhesive layer formation step (S12), it is unwound at a conveying speed of 20 m / min. At this time, using a depressurized extrusion die coater, the first adhesive layer composition [2] is applied to the other surface of the substrate film [A] where the second adhesive layer has not been formed, and dried and cured in an atmosphere of 120°C to form a first adhesive layer with a thickness of 320 nm. Meanwhile, while conveying at the same conveying speed of 20 m / min as described above, a carrier film [A] is attached to the first adhesive layer and wound up.

[0689] Furthermore, the first adhesive layer is formed by the same process as the second adhesive layer, and the types of resin, types of inorganic particles, average particle size, and thickness of the adhesive layer are all the same, therefore it is an adhesive layer [C].

[0690] [5] Formation process of multiple curing layers

[0691] For the first cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A1 as the laminated film [1], applied, dried, and UV cured to form the first layer, which is then wound. Similarly, for the second cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A3 as the laminated film [1], applied, dried, and UV cured to form the second layer, which is then wound.

[0692] [Fabrication of laminated films [6]]

[0693] [1], [2] Preparation of protective film and carrier film and fabrication of substrate film

[0694] As a protective film and a carrier film, a protective film [1] and a carrier film [A] identical to those in the laminated film [1] are prepared. In addition, except that the heat shrinkage rate of the laminated portion is appropriately adjusted to the value of Table V during the second-stage stretching process, a substrate film identical to the substrate film [A] used in the fabrication of the laminated film [1] is prepared.

[0695] [3], [4] Formation process of the second adhesive layer and the first adhesive layer

[0696] No second adhesive layer or first adhesive layer was formed.

[0697] [5] Formation process of multiple curing layers

[0698] For the first cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A1 as the laminated film [1], applied, dried, and UV cured to form the first layer, which is then wound. Similarly, for the second cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A3 as the laminated film [1], applied, dried, and UV cured to form the second layer, which is then wound.

[0699] [Fabrication of laminated films [7]]

[0700] [1], [2] Preparation of protective film and carrier film and fabrication of substrate film

[0701] Prepare the protective film [1] and carrier film [B] as described below. In addition, except that the heat shrinkage rate of the laminate portion is appropriately adjusted to the value in Table VI during the second stage stretching process, the same substrate film [A] as the substrate film [A] used in the fabrication of the laminate film [1] is prepared.

[0702] Protective film [1]: Polyester film "Toretec 7832C"

[0703] (30μm thickness, manufactured by Toray Film Processing Co., Ltd.)

[0704] Carrier membrane [B]: Polyethylene terephthalate membrane "NSA22T"

[0705] (Manufactured by Sansei Chemical Research Institute, 25μm thickness)

[0706] [3] The process of forming the second adhesive layer

[0707] In the second adhesive layer, except that the thickness of the second adhesive layer is set to 50 μm, the second adhesive layer is formed using the same method as the laminated film [1], the protective film [1] is attached, and then it is wound. Hereinafter, this adhesive layer will be referred to as adhesive layer [D].

[0708] [4] The process of forming the first adhesive layer

[0709] The first adhesive layer is formed using the same method as the laminated film [1] (adhesive layer [A]), the carrier film [B] is attached, and then wound.

[0710] [5] Formation process of multiple curing layers

[0711] For the first cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A1 as the laminated film [1], applied, dried, and UV cured to form the first layer, which is then wound. Similarly, for the second cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A3 as the laminated film [1], applied, dried, and UV cured to form the second layer, which is then wound.

[0712] [Fabrication of laminated films [8]]

[0713] [1], [2] Preparation of protective film and carrier film and fabrication of substrate film

[0714] Prepare the protective film [1] and carrier film [C] as described below. In addition, except that the heat shrinkage rate of the laminate portion is appropriately adjusted to the value in Table VI during the second stage stretching process, the same substrate film [A] as the substrate film [A] used in the fabrication of the laminate film [1] is prepared.

[0715] Protective film [1]: Polyester film "Toretec 7832C"

[0716] (30μm thickness, manufactured by Toray Film Processing Co., Ltd.)

[0717] Carrier membrane [C]: Polyethylene terephthalate membrane "NSA22T"

[0718] (Manufactured by Sansei Chemical Research Institute, 38μm thickness)

[0719] [3] The process of forming the second adhesive layer

[0720] In the second adhesive layer, except that the thickness of the second adhesive layer is set to 500 μm, the second adhesive layer is formed using the same method as the laminated film [1], the protective film [1] is attached, and then it is wound. Hereinafter, this adhesive layer will be referred to as adhesive layer [E].

[0721] [4] The process of forming the first adhesive layer

[0722] The first adhesive layer is formed using the same method as the laminated film [1] (adhesive layer [A]), the carrier film [C] is attached, and then wound.

[0723] [5] Formation process of multiple curing layers

[0724] For the first cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A1 as the laminated film [1], applied, dried, and UV cured to form the first layer, which is then wound. Similarly, for the second cured layer, a coating liquid for the curing layer composition is prepared using the same formulation A3 as the laminated film [1], applied, dried, and UV cured to form the second layer, which is then wound.

[0725] [Fabrication of laminated films [9],

[10] and

[11] ]

[0726] Except that the thermal shrinkage rate of the laminate portion is appropriately adjusted to the value shown in Table VI during the second-stage stretching process, laminates [9],

[10] and

[11] are made in the same manner as laminate [1].

[0727] [Fabrication of laminated films

[12] ]

[0728] [1]~[4] Preparation of protective film and carrier film, fabrication of substrate film, formation of second adhesive layer and first adhesive layer

[0729] The processes for preparing the protective film and carrier film, fabricating the substrate film, and forming the second adhesive layer and the first adhesive layer are carried out in the same manner as for the laminated film [1], except that the thermal shrinkage rate of the laminated portion is appropriately adjusted to the value shown in Table VI during the second-stage stretching process. Then, the substrate film with the protective film [1] and the carrier film [A] is wound.

[0730] [5] Formation process of multiple curing layers

[0731] In the fabrication of the laminated film

[12] , two curing layers are formed as multiple curing layers.

[0732] [5-1] The process of forming the first cured layer

[0733] [5-1-1] Preparation of the coating liquid for the composition used in the curing layer

[0734] A coating solution for a curing layer composition is prepared by mixing and stirring the following components. This coating solution for a curing layer composition is designated as "coating solution for a curing layer composition [3]". Furthermore, the content of beads in the following components is such that when the total mass of the coating solution for a curing layer composition [3] is 100 parts by mass, the mass of the beads in the following components is 70 parts by mass.

[0735] <Ingredients: Formula B1>

[0736] "KAYARAD PET-30" (adhesive resin) 19.4 parts by weight

[0737] Irgacure 184 (polymerization initiator) 0.6 parts by weight

[0738] SEIKABEAM10-28 (Silicone Leveling Agent) 0.03 parts by weight

[0739] Methyl isobutyl ketone (solvent) 1129.6 parts by weight

[0740] Beads: "GM-0806S" (content already recorded above)

[0741] Particulate dispersion “MZ-230X” 51.0 parts by weight

[0742] Furthermore, "KAYARAD PET-30" in the above ingredients is pentaerythritol triacrylate manufactured by Nippon Kayaku Co., Ltd. Additionally, "Irgacure 184" is a polymerization initiator manufactured by BASF Japan, and "SEIKABEAM10-28" is a silicone leveling agent manufactured by Dainisei Chemical Co., Ltd., with a solid content of 10%.

[0743] The beads “GM-0806S” in the above components are polyacrylate with a refractive index of 1.49 and a number-average particle size of 8μm.

[0744] The particulate dispersion “MZ-230X” in the above composition is a methyl ethyl ketone dispersion of high refractive index ZrO2 particles manufactured by Sumitomo Osaka Cement Co., Ltd., with a solid content of 32.5% by mass.

[0745] [5-1-2] Application, curing, and drying of the composition for the cured layer

[0746] After peeling the protective film [1] from the substrate film [A] with the protective film [1] and the carrier film [A] that was wound in the second adhesive layer formation process (S13), the film is unwound at a conveying speed of 20 m / min. The protective film [1] that is adhered to the second adhesive layer side of the substrate film [A] is peeled off, and a coating liquid [3] of the curing layer composition is applied to the surface of the second adhesive layer side. The film is then dried, UV cured, and wound.

[0747] [5-2] The process of forming the second curing layer

[0748] [5-2-1] Preparation of the coating liquid for the composition used in the curing layer

[0749] A coating solution for a curing layer composition is prepared by mixing and stirring the following components. This coating solution for a curing layer composition is designated as "coating solution for a curing layer composition [4]".

[0750] <Ingredients: Formula B2>

[0751] "KAYARAD PET-30" (adhesive resin) 19.4 parts by weight

[0752] Irgacure 184 (polymerization initiator) 0.6 parts by weight

[0753] SEIKABEAM10-28 (Silicone Leveling Agent) 0.03 parts by weight

[0754] Methyl isobutyl ketone (solvent) 1129.6 parts by weight

[0755] Particulate dispersion “MZ-230X” 51.0 parts by weight

[0756] Furthermore, "KAYARAD PET-30" in the above ingredients is pentaerythritol triacrylate manufactured by Nippon Kayaku Co., Ltd. Additionally, "Irgacure 184" is a polymerization initiator manufactured by BASF Japan, and "SEIKABEAM10-28" is a silicone leveling agent manufactured by Dainishi Chemical Co., Ltd., with a solid content of 10%.

[0757] The particulate dispersion “MZ-230X” in the above components is a methyl ethyl ketone dispersion of high refractive index ZrO2 particles manufactured by Sumitomo Osaka Cement Co., Ltd., with a solid content of 32.5% by mass.

[0758] [5-2-2] Application, curing, and drying of the composition for the cured layer

[0759] The substrate film [A] with the carrier film [A] formed in the first curing layer formation process is unwound at a conveying speed of 20 m / min. A coating liquid [4] of the curing layer composition is applied to the surface of the first curing layer side, dried, UV cured, and then wound. A laminated film

[12] is produced through the above process.

[0760] [Fabrication of laminated films

[13] ]

[0761] [1]~[4] Preparation of protective film and carrier film, fabrication of substrate film, formation of second adhesive layer and first adhesive layer

[0762] The preparation of the protective film and carrier film, the fabrication of the substrate film, and the formation of the second adhesive layer and the first adhesive layer are carried out in the same manner as for the laminated film [1], except that the heat shrinkage rate of the laminated portion is appropriately adjusted to the value in Table VII during the second stage stretching process. Then, the substrate film with the protective film [1] and the carrier film [A] is wound.

[0763] [5] Formation process of multiple curing layers

[0764] In the fabrication of the laminated film

[13] , three curing layers are formed as multiple curing layers.

[0765] [5-1] Formation process of the first curing layer

[0766] The first curing layer uses the same formulation A1 as the laminated film [1], and a coating liquid of the curing layer composition is prepared, coated, dried, UV cured, and wound.

[0767] [5-2] Formation process of the second curing layer

[0768] [5-2-1] Preparation of the coating liquid for the composition used in the curing layer

[0769] Mix and stir the following ingredients to prepare a coating solution for the curing layer composition. This coating solution for the curing layer composition is designated as "coating solution for the curing layer composition [5]".

[0770] <Ingredients: Formula A2>

[0771] "KAYARAD PET-30" (adhesive resin) 23.8 parts by weight

[0772] Irgacure 184 (polymerization initiator) 0.6 parts by weight

[0773] SEIKABEAM10-28 (Silicone Leveling Agent) 0.03 parts by weight

[0774] Methyl isobutyl ketone (solvent) 1138.6 parts by weight

[0775] Particulate dispersion “MZ-230X” 37.7 parts by weight

[0776] Furthermore, "KAYARAD PET-30" in the above ingredients is pentaerythritol triacrylate manufactured by Nippon Kayaku Co., Ltd. Additionally, "Irgacure 184" is a polymerization initiator manufactured by BASF Japan, and "SEIKABEAM10-28" is a silicone leveling agent manufactured by Dainishi Chemical Co., Ltd., with a solid content of 10%.

[0777] The particulate dispersion “MZ-230X” in the above components is a methyl ethyl ketone dispersion of high refractive index ZrO2 particles manufactured by Sumitomo Osaka Cement Co., Ltd., with a solid content of 32.5% by mass.

[0778] [5-2-2] Application, curing, and drying of the composition for the cured layer

[0779] The substrate film [A] with the carrier film [A] formed in the first curing layer formation process is unwound at a conveying speed of 20 m / min. A coating liquid [5] of the curing layer composition is applied to the surface of the first curing layer side, dried, UV cured, and then wound.

[0780] [5-3] The process of forming the third curing layer

[0781] [5-3-1] Preparation of the coating solution for the composition used in the curing layer

[0782] The components of the aforementioned formulation A3 are mixed and stirred to prepare a coating solution for the curing layer. This coating solution for the curing layer is designated as "coating solution for the curing layer [6]".

[0783] [5-3-2] Coating, curing, and drying of the composition used for the curing layer

[0784] The substrate film [A], which has been wound with a carrier film [A] and has formed the first and second cured layers during the second cured layer formation process, is unwound at a conveying speed of 20 m / min. A coating liquid [6] of the composition for the cured layer is applied to the side of the second cured layer, dried, UV cured, and then wound.

[0785] [Fabrication of laminated films

[14] and

[15] ]

[0786] [1]~[4] Preparation of protective film and carrier film, fabrication of substrate film, formation of second adhesive layer and first adhesive layer

[0787] The preparation of the protective film and carrier film, the fabrication of the substrate film, and the formation of the second adhesive layer and the first adhesive layer are carried out in the same manner as for the laminated film [1], except that the heat shrinkage rate of the laminated portion is appropriately adjusted to the value in Table VII during the stretching process in the second stage. Then, the substrate film with the protective film [1] and the carrier film [A] is wound.

[0788] [5] Formation process of multiple curing layers

[0789] In the fabrication of the laminated films

[14] and

[15] , two curing layers are formed as multiple curing layers. For the first curing layer, the laminated films

[14] and

[15] are formed by applying a coating solution of the curing layer composition prepared with the same components as those in the laminated film [1] using formulation A1, curing, drying, and then winding. For the second curing layer, for the laminated film

[14] , a coating solution of the curing layer composition prepared with the components of formulation A4 is used; for the laminated film

[15] , a coating solution of the curing layer composition prepared with the components of the aforementioned formulation B2 is used; both are applied, dried, UV cured, and then wound.

[0790] <Ingredients: Formula A4>

[0791] "KAYARAD PET-30" (adhesive resin) 23.8 parts by weight

[0792] Irgacure 184 (polymerization initiator) 0.6 parts by weight

[0793] SEIKABEAM10-28 (Silicone Leveling Agent) 0.03 parts by weight

[0794] Methyl isobutyl ketone (solvent) 1138.6 parts by weight

[0795] Beads: "GM-0806S" (content is listed above)

[0796] Particulate dispersion “MZ-230X” 20.0 parts by weight

[0797] Furthermore, "KAYARAD PET-30" in the above ingredients is pentaerythritol triacrylate manufactured by Nippon Kayaku Co., Ltd. Additionally, "Irgacure 184" is a polymerization initiator manufactured by BASF Japan, and "SEIKABEAM10-28" is a silicone leveling agent manufactured by Dainisei Chemical Co., Ltd., with a solid content of 10%.

[0798] The beads “GM-0806S” in the above composition are polyacrylate with a refractive index of 1.49 and an average particle size of 8μm.

[0799] The particulate dispersion “MZ-230X” in the above-mentioned components is a methyl ethyl ketone dispersion of high refractive index ZrO2 particles manufactured by Sumitomo Osaka Cement Co., Ltd., with a solid content of 32.5% by mass.

[0800] [A summary of materials, types of layers, and formulations related to the fabrication of laminated films]

[0801] The formulations of the carrier film, substrate film, adhesive layer, and coating liquid composition of the curing layer used in the above processes are shown in Tables I to IV below.

[0802] [Table 1]

[0803]

[0804] [Table 2]

[0805]

[0806] [Table 3]

[0807]

[0808] [Table 4]

[0809]

[0810] [Various measurements]

[0811] The thickness of each adhesive layer, substrate film, and curing layer of the laminated film produced through the above processes is measured according to the method described in the micrometer of JIS B 7502. Specifically, the thickness of a portion of the film or layer is randomly measured at 10 points, and the arithmetic mean of the measured values ​​at the 10 points is calculated. This arithmetic mean is taken as the thickness of the film or layer.

[0812] In addition, the refractive index of the cured layer of the laminated film was determined using the Beck method according to the above-mentioned JIS K 7142:2008 B method (for transparent materials in powder or granular form).

[0813] The peel adhesion force [N / 25mm] of the carrier film to the first adhesive layer was determined according to the 180-degree peel test method specified in JIS Z 0237:2009 (Test Methods for Adhesive Tapes and Sheets). Specifically, the laminated film was cut into dimensions of 25mm in width and 100mm in length, placed at 25°C and 50%RH for 2 hours, and then the peel adhesion force [N / 25mm] of the carrier film to the first adhesive layer was measured at a speed of 2.3m / min.

[0814] The determination and calculation of the thermal shrinkage rates in the length direction (MD direction) and width direction (TD direction) of the laminated body are as follows.

[0815] First, the laminated body was cut into 100mm wide and 100mm long sections to create a test piece. Cross-shaped scratches were made at the four corners of the test piece. Then, using a Mitutoyo CNC 3D measuring machine (product name "LEGE X774"), the length (MD direction) and width (TD direction) of the four points at the center of the cross-shaped scratches before heating were measured [mm].

[0816] Next, the laminated portion was placed in an oven and heated at 130°C for 90 minutes, then cooled at room temperature for 1 hour. Then, the length [mm] of the four points after heating was measured again using the aforementioned CNC 3D measuring machine in the length direction (MD direction) and width direction (TD direction).

[0817] Substitute the measured lengths [mm] and lengths [mm] of the four points in the length direction (MD direction) and width direction (TD direction) before heating into the following formula to calculate the heat shrinkage rate of each direction in the length direction (MD direction) and width direction (TD direction).

[0818] Heat shrinkage rate [%] = {(Length before heating [mm] - Length after heating [mm]) / Length before heating [mm]} × 100

[0819] [evaluate]

[0820] For the laminated films prepared as described above, the results shown in Tables V to VII are obtained, and based on these results, optical inhomogeneity and sharpness are evaluated.

[0821] <Optical Inhomogeneity>

[0822] [Evaluation Method]

[0823] The laminated film was left to stand for 30 minutes in an indoor environment at 25°C and 65% humidity. A fluorescent lamp was projected onto the film surface at a 45° angle from a position 1 m away from the surface where the number of continuous optical non-uniformities along the length direction was counted. The number of optical non-uniformities was then visually counted from a position 0.5 m away from the surface where the optical non-uniformities were counted at a 45° angle below. It should be noted that, for optical non-uniformities, a non-uniformity that is convex along the length direction of the film relative to the observation surface is considered as one non-uniformity, and the number of wrinkles along the width direction of the film was counted.

[0824] [Evaluation Criteria]

[0825] A: The number of optical non-uniformity roots is in the range of 0 to 5 roots / m.

[0826] B: The number of optical non-uniformity roots is in the range of 6 to 10 roots / m.

[0827] C: The number of optical non-uniformity roots is in the range of 11 to 19 roots / m.

[0828] D: The number of optical non-uniformity roots is 20 or more per meter.

[0829] <Clarity>

[0830] [Evaluation Method]

[0831] Using the BYK Haze Guard i as specified in ASTM D1003, the sharpness of the laminated film was measured in 20 equal divisions along the TD direction, excluding the end 20mm. The difference between the maximum and minimum values ​​was used to evaluate the sharpness.

[0832] [Evaluation Criteria]

[0833] A: The difference between the maximum and minimum values ​​is less than 0.5.

[0834] B: The difference between the maximum and minimum values ​​is greater than 0.5 but less than 1.0.

[0835] C: The difference between the maximum and minimum values ​​is greater than 1.0 but less than 1.5.

[0836] D: The difference between the maximum and minimum values ​​is greater than 1.5 but less than 2.0.

[0837] E: The difference between the maximum and minimum values ​​is 2.0 or more.

[0838] [Manufacturing and Performance Verification of the Display Device]

[0839] The carrier film [A] was peeled off from the laminated film [1] and attached to the surface of an existing OLED device. The results confirmed that the brightness of the OLED device with the laminated film [1] attached was increased more uniformly than that of the OLED device without the laminated film.

[0840] <Overall Review>

[0841] As is evident from Tables V to VII, the laminated film of the present invention is less prone to thermal shrinkage compared to the comparative example, and can suppress optical non-uniformity and reduce sharpness.

[0842] [Table 5]

[0843]

[0844] [Table 6]

[0845]

[0846] [Table 7]

[0847]

[0848] Industrial availability

[0849] It can provide laminated films that are not prone to thermal shrinkage, can suppress optical non-uniformity, and can suppress the reduction of transparency, as well as their manufacturing methods and display devices.

[0850] Explanation of reference numerals in the attached figures

[0851] 1.1a Agitator (Agitator Tank)

[0852] 2 Casting die

[0853] 3. Support body (annular belt, roller)

[0854] Rollers 3a and 3b

[0855] 4. Peeling rollers

[0856] 5 webs (cast film)

[0857] 6. Tensioning devices (tenting machine, inclined tensioning device)

[0858] 7. Drying device

[0859] 8. Cutting section

[0860] 9. Winding device

[0861] 10. Tensioning device

[0862] 11 Cutting section

[0863] 12. Winding device

[0864] 14 Extruder

[0865] 15 Casting die head

[0866] 16. Casting mold roller and support body

[0867] 16a Touch Roller

[0868] 17 Cooling rollers

[0869] 18. Tensioning device (stenter stretching machine)

[0870] 19 Cutting section

[0871] 20 Winding device

[0872] 21. Tensioning device (stenter stretching machine)

[0873] 22 Cutting section

[0874] 23 Winding device

[0875] 40 Tensioning device (stenter stretching machine)

[0876] 42 Fixtures

[0877] 46 masks

[0878] 48. Ring chain

[0879] 50 drive sprocket

[0880] 52 Driven sprocket

[0881] 54 orbits

[0882] 56 Open Components

[0883] 80 Temperature Distribution Sensor

[0884] 101 Nozzle fixing part

[0885] 102 Nozzle

[0886] 103 web (cast film)

[0887] 104 End nozzle

[0888] 105 Central Nozzle

[0889] 106 Clamp Cover

[0890] F membrane

[0891] F1 and F2 laminated films

[0892] SF substrate film

[0893] CF carrier membrane

[0894] AL1 First Adhesive Layer

[0895] AL2 Second Adhesive Layer

[0896] L1, L2, L3 Curing Layers

[0897] LL low refractive index layer

[0898] LH high refractive index layer

[0899] Ip Inorganic particles

[0900] Op beads

Claims

1. A laminated film, comprising sequentially a carrier film, a first adhesive layer, a substrate film, a second adhesive layer, and a plurality of curing layers, characterized in that, The first adhesive layer and the second adhesive layer contain at least inorganic particles and polyolefin resin, and, For the laminate portion including the first adhesive layer, the substrate film and the second adhesive layer, the heat shrinkage rate is measured at 130°C for 90 minutes. When the heat shrinkage rates in the length direction and the width direction are set as X and Y respectively, X and Y satisfy the following equations (1) and (2). Formula (1): Y <X [%] Formula (2): 0.004<{(X+Y) / 2}<0.16[%] Furthermore, the substrate film contains a cyclic olefin resin. The plurality of cured layers contain beads, and the plurality of cured layers have a difference in refractive index.

2. The laminated film according to claim 1, characterized in that, The carrier film contains at least polyethylene terephthalate, and the peel adhesion of the carrier film to the first adhesive layer is in the range of 0.1 to 0.4 [N / 25mm].

3. The laminated film according to claim 1, characterized in that, The first adhesive layer and the second adhesive layer contain the same compound and have the same thickness.

4. The laminated film according to claim 1, characterized in that, The refractive index of the plurality of cured layers gradually increases from the substrate side to the outermost layer side.

5. The method for manufacturing a laminated film according to any one of claims 1 to 4, characterized in that, The process includes the following steps: for the laminate portion comprising the first adhesive layer, the substrate film, and the second adhesive layer, the heat shrinkage rate is measured at 130°C for 90 minutes; the heat shrinkage rates in the length direction and the width direction are set as X and Y, respectively, and adjusted so that X and Y satisfy the following equations (1) and (2). Formula (1): Y <X [%] Formula (2): 0.004<{(X+Y) / 2}<0.16[%].

6. A display device, which is a display device having an optical film, characterized in that, The display device comprises an optical film consisting of a portion of the laminated film according to any one of claims 1 to 4, with the carrier film removed.

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