Method for manufacturing laminate

Abstract

To provide a method for manufacturing a laminate capable of suppressing liquid dripping when a photocurable resin composition is applied.SOLUTION: This manufacturing method comprises a step (A) for forming a temporarily cured resin layer 13, obtained by temporarily curing a photocurable resin composition 6, on the surface of a light transmissive member 3, a step (B) for laminating the light transmissive member 3 and an image display member 2 to each other via the temporarily cured resin layer 13, and a step (C) for irradiating the temporarily cured resin layer 13 with light to completely cure it. The step (A) comprises a step (A1) for applying the photocurable resin composition 6 on the surface of the light transmissive member 3 and further irradiating the photocurable resin composition 6 with light to prevent deformation of the applied photocurable resin composition 6, and a step (A2) for performing further light irradiation so that the photocurable resin composition 6 irradiated with light in the step (A1) has a predetermined reaction rate.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present technology relates to a method for manufacturing a laminate.

Background Art

[0002] An image display device used in an information terminal such as a smartphone or a tablet PC is manufactured, for example, by the following method (see, for example, Patent Document 1).

[0003] First, as shown in FIG. 9, a liquid photocurable resin composition 6 is applied from a nozzle 101A of a coating portion 101 onto the surface of a light transmissive member (first member) 3 having a light shielding layer 5 formed on its peripheral portion. Next, as shown in FIGS. 10 and 11, the photocurable resin composition 6 applied to the surface of the light transmissive member 3 is irradiated with light from a light irradiation portion 102 to form a temporarily cured resin layer 103. Next, as shown in FIG. 11, the light transmissive member 3 and an image display member (second member) 2 are bonded via the temporarily cured resin layer 103. Next, the temporarily cured resin layer 103 is irradiated with light to fully cure the temporarily cured resin layer 103 and form a cured resin layer. Thereby, an image display device is obtained.

[0004] Thus, in the manufacturing method shown in FIGS. 9 to 11, since temporary curing is performed after applying the photocurable resin composition 6, it is possible to perform bonding while maintaining the coating shape of the photocurable resin composition 6.

[0005] Also, as another manufacturing method, there is a method of bonding without temporarily curing the applied photocurable resin composition. In this method, for example, as shown in FIG. 12(A), the photocurable resin composition 6 is applied onto the surface of the light transmissive member 3, and as shown in FIGS. 12(B) and (C), the light transmissive member 3 and the image display member 2 are bonded via the photocurable resin composition 6. Then, the photocurable resin composition 6 is fully cured.

[0006] Furthermore, as another manufacturing method, instead of using a liquid photocurable resin composition, a method using an optical clear adhesive sheet (OCA) can also be mentioned. In this method, as shown in FIG. 13(A) for example, an optically transparent adhesive sheet 104 is attached to the surface of the light transmissive member 3, and as shown in FIGS. 13(B) and (C), the light transmissive member 3 and the image display member 2 are bonded through the transparent adhesive sheet 104. Then, the transparent adhesive sheet 104 is fully cured.

[0007] By the way, in the method of bonding after temporarily curing the photocurable resin composition as described above, when the photocurable resin composition 6 is applied to the surface of the light transmissive member 3 as shown in FIG. 14(A), there is a tendency for liquid dripping to easily occur at the edges of the applied photocurable resin composition. This liquid dripping causes an unbonded region R as shown in FIG. 14(B) to occur when the light transmissive member 3 and the image display member 2 are bonded through the temporarily cured resin layer 103. When the unbonded region R occurs, for example, it becomes difficult to secure a bonding region in a narrow bezel liquid crystal display panel. In addition, in the method of bonding in the liquid state without temporarily curing the photocurable resin composition as shown in FIGS. 12(A) to (C), and in the method using the optical adhesive sheet 104 as shown in FIGS. 13(A) to (C), it is considered that liquid dripping hardly occurs and the problem of the unbonded region R is small.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present technology has been proposed in view of such a conventional situation, and provides a method for manufacturing a laminate capable of suppressing liquid dripping when a photocurable resin composition is applied.

Means for Solving the Problems

[0010] The method for manufacturing a laminate according to the present technology includes a step (A) of forming a temporarily cured resin layer by temporarily curing a photocurable resin composition on the surface of a first member, a step (B) of bonding the first member and a second member via the temporarily cured resin layer, and a step (C) of irradiating the temporarily cured resin layer with light to perform full curing. The step (A) includes a step (A1) of applying the photocurable resin composition to the surface of the first member and irradiating the photocurable resin composition with light to prevent deformation of the applied photocurable resin composition, and a step (A2) of further irradiating the photocurable resin composition irradiated with light in the step (A1) so as to have a predetermined reaction rate.

Effect of the Invention

[0011] According to the present technology, since the step of forming the temporarily cured resin layer includes irradiating the photocurable resin composition with light to prevent deformation of the applied photocurable resin composition, it is possible to suppress dripping of the photocurable resin composition when it is applied.

Brief Description of the Drawings

[0012]

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DETAILED DESCRIPTION OF THE INVENTION

[0013] <Laminated body> In the method for manufacturing a laminate according to this embodiment, for example, as shown in FIG. 1, a light-transmissive member 3 (first member) having a light-shielding layer 5 formed on its peripheral portion and an image display member 2 (second member) are laminated via a cured resin layer 4 to obtain an image display device 1 (laminate).

[0014] Examples of the image display member 2 include a liquid crystal display panel, an organic EL display panel, a plasma display panel, a touch panel, and the like. Here, the touch panel means an image display / input panel that combines a display element such as a liquid crystal display panel and a position input device such as a touch pad.

[0015] The light-transmissive member 3 may have any light-transmitting property as long as the image formed on the image display member 2 can be visually recognized. For example, plate-like materials or sheet-like materials such as glass, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, and polycarbonate can be mentioned. These materials may be subjected to a hard coat treatment, an antireflection treatment, or the like on at least one surface. Physical properties such as the thickness and elastic modulus of the light-transmissive member 3 can be appropriately determined according to the purpose of use. In addition, the light-transmissive member 3 includes not only relatively simple members as described above but also those in which various sheets or film materials such as a touch panel module are laminated.

[0016] The light-shielding layer 5 is provided to improve the contrast of the image. For example, it can be formed by applying a paint colored in black or the like by a screen printing method or the like and drying and curing it. The thickness of the light-shielding layer 5 is usually 5 to 100 μm.

[0017] The refractive index of the cured resin layer 4 is preferably approximately equal to the refractive indices of the image display member 2 and the light transmissive member 3, and is preferably, for example, 1.45 or more and 1.55 or less. Thereby, the luminance and contrast of the video light from the image display member 2 can be enhanced, and the visibility can be improved. Further, the transmittance of the cured resin layer 4 is preferably more than 90%. Thereby, the visibility of the image formed on the image display member 2 can be made better. The thickness of the cured resin layer 4 is preferably, for example, 50 to 150 μm.

[0018] The cured resin layer 4 can be formed using a liquid photocurable resin composition 6 that is transparent and curable with ultraviolet rays or visible light. The photocurable resin composition 6 may be in any state such as liquid or gel state, and a liquid state is preferred. Here, when the photocurable resin composition 6 is in a liquid state, it is preferably shown that the viscosity at 25°C measured with a B-type viscometer is 0.01 to 100 Pa·s. In the method for manufacturing the laminate according to the present embodiment, even when a photocurable resin composition having a viscosity in the range of 1000 to 60000 mPa·s at 25°C is used, it is possible to suppress the dripping of the liquid when the photocurable resin composition is applied.

[0019] An example of the photocurable resin composition 6 that can be used in this manufacturing method will be described. The photocurable resin composition 6 contains, for example, a (meth)acrylate oligomer, a (meth)acrylate monomer, a photopolymerization initiator, and a softener. Note that the photocurable resin composition 6 may further contain other components other than these components as long as the effects of the present technology are not impaired. In the present specification, (meth)acrylate includes both acrylate and methacrylate.

[0020] (Meth)acrylate oligomers are used as the base material of the photocurable resin composition 6. As the (meth)acrylate oligomers, for example, (meth)acrylate oligomers having a skeleton such as polyurethane, polyisoprene, polybutadiene, etc. can be used. Specific examples of the (meth)acrylate oligomers having a polyurethane skeleton include aliphatic urethane acrylate (EBECRYL 230, manufactured by Daicel Ornex Co., Ltd.). Further, specific examples of the (meth)acrylate oligomers having a polyisoprene skeleton include an esterified product of an adduct of maleic anhydride and a polyisoprene polymer with 2-hydroxyethyl methacrylate (UC102, manufactured by Kuraray Co., Ltd.).

[0021] (Meth)acrylate monomers are used as reactive diluents for imparting sufficient reactivity, coatability, etc. to the photocurable resin composition 6. Examples of the (meth)acrylate monomers include 2-hydroxypropyl (meth)acrylate, benzyl acrylate, dicyclopentenyl oxyethyl (meth)acrylate, isobornyl (meth)acrylate, octyl (meth)acrylate, etc.

[0022] As the photopolymerization initiator, known photopolymerization initiators can be used. For example, 1-hydroxy-cyclohexyl phenyl ketone (Irgacure 184, manufactured by BASF), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)benzyl]phenyl}-2-methyl-1-propan-1-one (Irgacure 127, manufactured by BASF), benzophenone, acetophenone, etc. can be mentioned.

[0023] The softener consists of at least one of a liquid plasticizer and a tackifier. The liquid plasticizer does not undergo photocuring by itself upon ultraviolet irradiation, imparts flexibility to the cured resin layer or the temporarily cured resin layer after photocuring, and reduces the curing shrinkage rate of the cured resin layer or the temporarily cured resin layer. Examples of the liquid plasticizer include polybutadiene-based plasticizers, polyisoprene-based plasticizers, phthalate-based plasticizers, adipate-based plasticizers, etc.

[0024] The tackifier imparts flexibility to the cured resin layer or the semi-cured resin layer after photocuring, and improves the initial adhesion strength (so-called tackiness) of the cured resin layer or the semi-cured resin layer. Examples of the tackifier include terpene resins such as terpene resin, terpene phenol resin, and hydrogenated terpene resin, rosin resins such as natural rosin, polymerized rosin, rosin ester, and hydrogenated rosin, and petroleum resins such as polybutadiene and polyisoprene.

[0025] The photocurable resin composition can be prepared by uniformly mixing the above-described components according to a known mixing method. Examples of commercially available products of the photocurable resin composition include those with trade names "LCR1000-DM", "HSVR600", "HSVR330" (manufactured by Dexerials Corporation, etc.).

[0026] <Method for manufacturing a laminate> This manufacturing method has the following steps (A) to (C). Step (A): A semi-cured resin layer obtained by semi-curing a photocurable resin composition is formed on the surface of the first member. Step (B): The first member and the second member are bonded via the semi-cured resin layer. Step (C): The semi-cured resin layer is irradiated with light for full curing.

[0027] Further, step (A) has the following steps (A1) and (A2). Step (A1): A photocurable resin composition is applied to the surface of the first member, and the photocurable resin composition is irradiated with light to prevent deformation of the applied photocurable resin composition. Step (A2): The photocurable resin composition irradiated with light in step (A1) is further irradiated with light so as to have a predetermined reaction rate.

[0028] Thus, in this manufacturing method, step (A) of forming a temporary cured resin layer includes irradiating the photocurable resin composition with light in order to prevent deformation of the applied photocurable resin composition (at least deformation of the end portion of the applied photocurable resin composition). Thereby, it is possible to suppress dripping of the photocurable resin composition when it is applied. In particular, in this manufacturing method, dripping can be suppressed even when a photocurable resin composition having a relatively low viscosity is used. This manufacturing method is suitable, for example, when using a liquid crystal display panel with a narrow frame (for example, a width of 1 mm or less).

[0029] FIG. 2 is a graph showing the measurement results of the height of the coating surface of the photocurable resin composition according to the elapsed time from when the photocurable resin composition is applied until light irradiation. Further, FIG. 3 is a graph showing the measurement results of the height of the coating surface of the photocurable resin composition according to the coating thickness of the photocurable resin composition. The vertical axis in FIGS. 2 and 3 represents the coating thickness (mm) of the photocurable resin composition. Also, the horizontal axis in FIGS. 2 and 3 represents the distance (mm) from one end in the longitudinal direction of the light transmissive member on which the photocurable resin composition is applied. Here, the coating thickness of the photocurable resin composition can be measured, for example, using a known displacement sensor that measures the height by irradiating the coating surface of the photocurable resin composition with a laser, ultrasonic waves, etc.

[0030] From the results shown in FIG. 2, it can be seen that the shorter the elapsed time from when the photocurable resin composition is applied to the surface of the light transmissive member until light irradiation, such as 15 seconds, 10 seconds, and 5 seconds, the less likely there is dripping. Also, from the results shown in FIG. 3, it can be seen that the thinner the coating thickness of the photocurable resin composition, such as 250 μm, 175 μm, and 100 μm, the more the dripping is suppressed.

[0031] From the above results, for example, it is considered possible to suppress dripping by adopting a method of applying the photocurable resin composition at a very high speed and then immediately performing temporary curing. However, this method has many restrictions in terms of equipment, such as the need for an area-type light irradiator and the need for a coating device (robot) capable of high-speed and high-precision driving, and the equipment cost becomes very high.

[0032] Also, from the above results, it is considered ideal to arrange a light irradiation unit (for example, an ultraviolet irradiator) near the coating part (nozzle) for applying the photocurable resin composition, and perform light irradiation (pre-curing) while applying the photocurable resin composition. However, this method is not always effective for all photocurable resin compositions. For example, when using a photocurable resin composition with a relatively slow curing reaction, if the application rate of the photocurable resin composition is not extremely reduced, there is a risk that the optimal pre-curing conditions will not be achieved.

[0033] In addition, the optimal light irradiation amount varies depending on the type of the photocurable resin composition. This is because the state of pre-curing affects the strength of the photocurable resin composition after main curing, the presence or absence of unevenness, etc.

[0034] In consideration of the above circumstances, in this manufacturing method, the step of forming the pre-cured resin layer is performed at least twice. First, in the first pre-curing (step (A1)), in order to prevent deformation of the photocurable resin composition, the photocurable resin composition is irradiated with light. That is, it is pre-cured to such an extent that the applied shape of the photocurable resin composition can be maintained. Thereby, dripping of the applied photocurable resin composition is suppressed. Then, in the second pre-curing (step (A2)), the pre-cured resin layer obtained in the first pre-curing is further irradiated with light so that it has a predetermined reaction rate. Thereby, a pre-cured resin layer is obtained which is pre-cured to such an extent that bonding can be performed while maintaining the applied shape of the photocurable resin composition.

[0035] According to this manufacturing method, when applying the photocurable resin composition, without using an area type light irradiator or a coating device capable of high-speed and high-precision driving, it is possible to suppress the occurrence of dripping at the end of the applied photocurable resin composition. Therefore, it is possible to suppress dripping when applying the photocurable resin composition without increasing the restrictions on equipment.

[0036] Next, the details of each step of this manufacturing method, that is, step (A1), step (A2), step (B), and step (C), will be described.

[0037] [Step (A1)] The application of the photocurable resin composition in step (A1) can be carried out by various commonly used application methods. In step (A1), for example, as shown in FIG. 4, a coating apparatus including a coating part 7, a light irradiation part 8, and a control part 9 can be used.

[0038] The coating part 7 includes, for example, a storage part (not shown) for storing the photocurable resin composition 6, a slit-shaped nozzle 7A (see FIGS. 5 and 6) for discharging the photocurable resin composition 6, and a pump (not shown) for extruding the photocurable resin composition 6 stored in the storage part into the nozzle 7A. As shown in FIG. 9, for example, the width of the nozzle 7A of the coating part 7 is wider than the width of the region 3S surrounded by the light shielding layer 5 on the surface of the light transmissive member 3. That is, the nozzle 7A has a width that straddles each light shielding layer 5 and the region 3S formed at both ends in the width direction of the light transmissive member 3. Thereby, the coating part 7 can apply the photocurable resin composition 6 across each light shielding layer 5 and the region 3S formed at both ends in the width direction of the light transmissive member 3.

[0039] The light irradiation part 8 is preferably disposed in the vicinity of the coating part 7 and at a position where the nozzle 7A of the coating part 7 is not irradiated with light. By arranging it in such a manner, it is possible to prevent the tip portion of the nozzle 7A from being solidified by the cured product of the photocurable resin composition 6. As the light irradiation part 8, for example, an ultraviolet irradiator can be used.

[0040] The control part 9 relatively moves the coating part 7 and the light irradiation part 8 and the light transmissive member 3. Thereby, the photocurable resin composition 6 is applied from one end side to the other end side of the surface of the light transmissive member 3, and the applied photocurable resin composition 6 is irradiated with light.

[0041] As a specific example of step (A1), as shown in FIGS. 5(A) to 5(C), the stage on which the light-transmissive member 3 is placed is moved in the direction of the arrow, and while the photocurable resin composition 6 is being applied from the coating unit 7 across one end side 3A to the other end side 3B of the surface of the light-transmissive member 3, it is preferable to irradiate the applied photocurable resin composition 6 with light from the light irradiation unit 8. Thereby, it is possible to more effectively suppress the dripping of the photocurable resin composition when it is applied. In step (A1), without moving the stage on which the light-transmissive member 3 is placed, while applying the photocurable resin composition 6 across one end side 3A to the other end side 3B of the surface of the light-transmissive member 3, the coating unit 7 and the light irradiation unit 8 may be moved so as to irradiate the applied photocurable resin composition 6 with light.

[0042] In step (A1), the elapsed time from when the photocurable resin composition 6 is applied to the surface of the light-transmissive member 3 until it is irradiated with light (hereinafter, also referred to as "the time from application to light irradiation") is preferably as short as possible from the viewpoint of suppressing the dripping of the photocurable resin composition 6. For example, the time from application to light irradiation is preferably within 5 seconds.

[0043] When the light-shielding layer 5 is formed on the peripheral portion of the surface of the light-transmissive member 3, the coating thickness of the photocurable resin composition 6 is preferably applied thicker than the thickness of the light-shielding layer 5. Specifically, it is preferable to apply it with a thickness of 1.2 to 50 times (more preferably 2 to 30 times) the thickness of the light-shielding layer 5 over the entire surface of the light-transmissive member 3 on the light-shielding layer formation side including the surface of the light-shielding layer 5. As a more specific coating thickness, 25 to 350 μm is preferable, and 50 to 150 μm is more preferable.

[0044] The light irradiation conditions in step (A1) are preferably set such that, for example, the curing rate of the temporarily cured resin layer 12 obtained after light irradiation in step (A1) is 40 to 50%. Here, the curing rate is a numerical value defined as the ratio (consumption ratio) of the amount of (meth)acryloyl groups present after light irradiation to the amount of (meth)acryloyl groups present in the photocurable resin composition before light irradiation. The larger this curing rate value, the more the curing has progressed. Specifically, the curing rate can be calculated by substituting the absorption peak height (X) at 1640 - 1620 cm -1 from the baseline in the FT-IR measurement chart of the photocurable resin composition 6 before light irradiation and the absorption peak height (Y) at 1640 - 1620 cm -1 from the baseline in the FT-IR measurement chart of the photocurable resin composition (temporarily cured resin layer 12) after light irradiation into the following formula. Curing rate (%) = [(X - Y) / X] × 100

[0045] The light irradiation conditions are not particularly limited as long as the curing rate of the temporarily cured resin layer 12 is preferably 40 to 50%. Such conditions include the type of light source, output, illuminance, integrated light quantity, etc.

[0046] [Step (A2)] In step (A2), for example, by relatively moving the light irradiation unit 8 and the light transmissive member 3, the temporarily cured resin layer is irradiated with light from one end side to the other end side of the surface of the light transmissive member 3. As a specific example of step (A2), as shown in FIGS. 6(A) - (C), a method of moving the stage on which the light transmissive member 3 is placed in the arrow direction and irradiating the temporarily cured resin layer 12 with light from the light irradiation unit 8 from one end side 3A to the other end side 3B of the surface of the light transmissive member 3 can be mentioned. As another method, in step (A2), without moving the stage on which the light transmissive member 3 is placed, the light irradiation unit 8 may be moved so as to irradiate the temporarily cured resin layer 12 with light from one end side 3A to the other end side 3B of the surface of the light transmissive member 3.

[0047] The light irradiation conditions in step (A2) are preferably carried out such that, for example, the curing rate of the temporarily cured resin layer 13 obtained after light irradiation in step (A2) is 90% or less. Here, the curing rate has the same meaning as the above-described curing rate. The light irradiation conditions are not particularly limited as long as the curing rate of the temporarily cured resin layer 13 is preferably 90% or less, such as the type of light source, output, illuminance, integrated light quantity, etc.

[0048] [Step (B)] In step (B), for example, as shown in FIGS. 14(A) and (B), the image display member 2 and the light transmissive member 3 are bonded via the temporarily cured resin layer 13. The bonding can be carried out, for example, by applying pressure at 10 to 80 °C using a known pressure bonding device. From the viewpoint of ease of pressing when bonding the image display member 2 and the light transmissive member 3, it is preferable that the angle of the convex portion at the surface end of the temporarily cured resin layer 13 shown in FIG. 14(A), for example, is an acute angle.

[0049] [Step (C)] In step (C), light irradiation is performed on the temporarily cured resin layer 13 to fully cure the temporarily cured resin layer 13. Thereby, the cured resin layer 4 (see FIG. 1) is formed and the laminate 1 is obtained.

[0050] The light irradiation in step (C) is preferably carried out such that the curing rate of the cured resin layer 4 is 90% or more, and more preferably 95% or more. Here, the curing rate has the same meaning as the above-described curing rate. The light irradiation conditions are not particularly limited as long as the curing rate of the cured resin layer 4 is preferably 90% or more, such as the type of light source, output, illuminance, integrated light quantity, etc.

[0051] This manufacturing method may further have other steps other than the above-described steps as long as the effect of suppressing dripping of the photocurable resin composition when applied is not impaired. For example, after step (C), a step of further irradiating light from the side surface of the laminate 1 may be included.

[0052] In this manufacturing method, the light-transmissive member 3 with the light-shielding layer 5 formed thereon is used, but it is not limited to this example. For example, a light-transmissive member 3 without the light-shielding layer 5 may be used. Thus, even when the photocurable resin composition is applied to the surface of the light-transmissive member without the light-shielding layer, dripping can be suppressed.

[0053] Also, in this manufacturing method, the photocurable resin composition 6 is applied to the surface of the light-transmissive member 3 on the side where the light-shielding layer 5 is formed, but it is not limited to this. For example, the photocurable resin composition 6 may be applied to the surface of the image display member 2.

Example

[0054] Hereinafter, examples of the present technology will be described. In this experimental example, a temporary curing resin layer was formed on the surface of the light-transmissive member, and the light-transmissive member and the image display member were bonded together via the temporary curing resin layer. The amount of dripping at the end of the temporary curing resin layer after bonding was evaluated. The present technology is not limited to these examples.

[0055] [Experimental Example 1] As the photocurable resin composition, a liquid photocurable resin composition (product name: HSVR600, viscosity: 4700 mPa·s, manufactured by DIC Corporation) was used. As the light-transmissive member, a glass plate with a light-shielding layer formed on its peripheral portion was used. This glass plate was obtained by applying a 4-mm-wide light-shielding layer with a dry thickness of 40 μm over the entire peripheral portion of a glass plate with a size of 45 (w) × 80 (l) × 0.4 (t) mm using a screen printing method with a thermosetting type black ink (MRX Ink, manufactured by Teikoku Ink Manufacturing Co., Ltd.) and drying it. Also, as the image display member, a liquid crystal display panel was used.

[0056] As shown in FIG. 9, the photocurable resin composition 6 was applied from the coating portion 101 across from one end side to the other end side of the surface of the light-transmissive member 3, and then, as shown in FIG. 10, the applied photocurable resin composition 6 was irradiated with light from the light irradiation portion 102.

[0057] The coating thickness of the photocurable resin composition was set to 150 μm. Also, the time from when the photocurable resin composition was applied to the surface of the light transmissive member until light irradiation was set to 30 seconds. The reaction rate of the temporarily cured resin layer after light irradiation was 70 - 90%.

[0058] Next, as shown in FIGS. 14(A) and (B), the light transmissive member 3 and the image display member 2 were bonded via the temporarily cured resin layer 13. Then, as shown in FIG. 14(B), the distance of the unbonded region R after bonding was measured, and this distance was evaluated as the amount of liquid leakage. Note that the distance of the unbonded region R was measured as the distance between the double lines visible at the end of the temporarily cured resin layer 13 after the light transmissive member 3 and the image display member 2 were bonded. These double lines are caused by liquid leakage. Also, the distance between the double lines is proportional to the amount of liquid leakage. The amount of liquid leakage in Experimental Example 1 was about 0.8 mm.

[0059] [Experimental Example 2] In Experimental Example 2, the same photocurable resin composition, light transmissive member, and image display member as in Experimental Example 1 were used. In Experimental Example 2, as shown in FIGS. 5(A) to (C), by moving the stage on which the light transmissive member 3 was placed in the direction of the arrow, the photocurable resin composition 6 was applied from the application unit 7 across one end side 3A to the other end side 3B of the surface of the light transmissive member 3, and the applied photocurable resin composition 4 was irradiated with light from the light irradiation unit 8 (Step (A1)).

[0060] The coating thickness of the photocurable resin composition was set to 150 μm. Also, the moving speed of the stage was set so that the time from when the photocurable resin composition was applied to the surface of the light transmissive member until light irradiation was 4 seconds. The reaction rate of the temporarily cured resin layer 12 after light irradiation was 40 - 50%.

[0061] Next, the stage was moved so that the positional relationship among the coating portion 7, the light irradiation portion 8, and the light transmissive member 3 became the state shown in FIG. 6(A). Next, as shown in FIGS. 6(A) to 6(C), the stage on which the light transmissive member 3 was placed was moved in the direction of the arrow at a speed of 10 mm / second, and light was irradiated onto the temporarily cured resin layer 12 from one end side 3A to the other end side 3B of the surface of the light transmissive member 3 (step (A2)). The reaction rate of the temporarily cured resin layer 13 after the light irradiation was 70 to 90%.

[0062] Next, as shown in FIGS. 14(A) and 14(B), the light transmissive member 3 and the image display member 2 were bonded via the temporarily cured resin layer 13, and the amount of liquid dripping was evaluated. The amount of liquid dripping in Experimental Example 2 was about 0.5 mm.

[0063] [Experimental Example 3] In step (A1) of Experimental Example 2, evaluation was performed in the same manner as in Experimental Example 2 except that the time from coating to light irradiation was set to 2 seconds. The amount of liquid dripping in Experimental Example 3 was about 0.4 mm.

[0064] [Experimental Example 4] In step (A1) of Experimental Example 2, evaluation was performed in the same manner as in Experimental Example 2 except that the coating thickness of the photocurable resin composition was set to 100 μm. The amount of liquid dripping in Experimental Example 4 was about 0.4 mm.

[0065] [Experimental Example 5] In step (A1) of Experimental Example 2, evaluation was performed in the same manner as in Experimental Example 2 except that the coating thickness of the photocurable resin composition was set to 50 μm. The amount of liquid dripping in Experimental Example 5 was about 0.15 mm.

[0066] [Experimental Example 6] Evaluation was performed in the same manner as in Experimental Example 1 except that a photocurable resin composition having a viscosity of 1400 mPa·s was used as the photocurable resin composition and the coating thickness of the photocurable resin composition was set to 100 μm. The amount of liquid dripping in Experimental Example 6 was about 0.9 mm.

[0067] [Experimental Example 7] As a photocurable resin composition, evaluation was carried out in the same manner as in Experimental Example 4 except that a photocurable resin composition having a viscosity of 1400 mPa·s was used. The amount of dripping in Experimental Example 7 was about 0.6 mm.

[0068] [Experimental Example 8] As a photocurable resin composition, evaluation was carried out in the same manner as in Experimental Example 6 except that a photocurable resin composition having a viscosity of 4700 mPa·s was used. The amount of dripping in Experimental Example 8 was about 0.75 mm.

[0069] [Experimental Example 9] As a photocurable resin composition, evaluation was carried out in the same manner as in Experimental Example 6 except that a photocurable resin composition having a viscosity of 8800 mPa·s was used. The amount of dripping in Experimental Example 9 was about 0.4 mm.

[0070] [Experimental Example 10] As a photocurable resin composition, evaluation was carried out in the same manner as in Experimental Example 4 except that a photocurable resin composition having a viscosity of 8800 mPa·s was used. The amount of dripping in Experimental Example 10 was about 0.25 mm.

[0071] [Experimental Example 11] As a photocurable resin composition, evaluation was carried out in the same manner as in Experimental Example 6 except that a photocurable resin composition having a viscosity of 50000 mPa·s was used. The amount of dripping in Experimental Example 11 was about 0.2 mm.

[0072] [Experimental Example 12] As a photocurable resin composition, evaluation was carried out in the same manner as in Experimental Example 4 except that a photocurable resin composition having a viscosity of 50000 mPa·s was used. The amount of dripping in Experimental Example 12 was about 0.15 mm.

[0073] The results of Experimental Examples 1 to 5 are shown in Fig. 7. The horizontal axis in Fig. 7 represents the coating thickness of the photocurable resin composition in each experimental example and the time (seconds) from coating to light irradiation. Also, the vertical axis in Fig. 7 represents the amount of dripping (mm).

[0074] From the results shown in Fig. 7, it was found that the shorter the time from coating to light irradiation, the more the dripping of the liquid was suppressed. Specifically, it was found that the time from coating to light irradiation is preferably within 5 seconds.

[0075] Also, it was found that the thinner the coating thickness of the photocurable resin composition, the more the dripping of the liquid was suppressed. Specifically, it was found that the coating thickness of the photocurable resin composition is preferably 50 to 150 μm.

[0076] The results of Experimental Examples 4, 6 to 12 are shown in Fig. 8. The horizontal axis in Fig. 8 represents the viscosity (mPa·s) of the photocurable resin composition in each experimental example. Also, the vertical axis in Fig. 8 represents the amount of liquid dripping (mm). From the results shown in Fig. 8, it was found that the lower the viscosity of the photocurable resin composition, the greater the effect of suppressing liquid dripping by performing two-stage curing (Steps (A1) and (A2)) in the step of forming the temporarily cured resin layer, as in Experimental Examples 4, 7, 10, and 12. In addition, even when a photocurable resin composition with a high viscosity was used as in Experimental Examples 11 and 12, it was found that the liquid dripping was more suppressed in Experimental Example 12 where two-stage curing was performed than in Experimental Example 11 where two-stage curing was not performed.

Explanation of Reference Numerals

[0077] 1 Image display device, 2 Image display member, 3 Light-transmissive member, 4 Cured resin layer, 5 Light-shielding layer, 6 Photocurable resin composition, 7 Coating unit, 7A Nozzle, 8 Light irradiation unit, 9 Control unit, 10 Coating device, 11 Stage, 12 Temporarily cured resin layer, 13 Temporarily cured resin layer, 101 Coating unit, 101A Nozzle, 102 Light irradiation unit, 103 Temporarily cured resin layer, 104 Optically transparent adhesive sheet

Claims

1. A step (A) of forming a temporarily cured resin layer by temporarily curing a photocurable resin composition on the surface of a first member; A step (B) of bonding the first member and a second member via the temporarily cured resin layer; A step (C) of irradiating the temporarily cured resin layer with light to fully cure it, The first member is a light-transmissive member having a light-shielding layer formed on its peripheral portion and no dam-like portion formed thereon, The step (A) is A step (A1) of irradiating the photocurable resin composition with light to prevent deformation of the applied photocurable resin composition while applying the photocurable resin composition to the surface of the light-transmissive member including the light-shielding portion; A method for manufacturing a laminate, comprising a step (A2) of further irradiating the photocurable resin composition irradiated with light in the step (A1) so that it has a predetermined reaction rate.

2. The method for manufacturing a laminate according to Claim 1, wherein in the step (A1), the time from when the photocurable resin composition is applied to the surface of the first member until it is irradiated with light is within 5 seconds.

3. The method for manufacturing a laminate according to Claim 1 or 2, wherein in the step (A1), the photocurable resin composition is applied so that the coating thickness is 50 to 150 μm.

4. The method for manufacturing a laminate according to any one of Claims 1 to 3, wherein in the step (A1), a photocurable resin composition having a viscosity of 1000 to 60000 mPa·s is applied.

5. The method for manufacturing a laminate according to any one of Claims 1 to 4, wherein in the step (A1), the temporarily cured resin layer obtained in the step (A1) is irradiated with light so that the curing rate is 40 to 50%.

6. The method for manufacturing a laminate according to any one of Claims 1 to 5, wherein in the step (A2), the temporarily cured resin layer obtained in the step (A2) is irradiated with light so that the curing rate is less than 90%.

7. The second member is an image display member, The laminate is an image display device, and the method for manufacturing a laminate according to any one of Claims 1 to 6.

8. The method for manufacturing a laminate according to Claim 1, wherein in the step (A1), the step (A2), and the step (B), the first member is not turned upside down.

9. A coating device used in the method for manufacturing a laminate according to any one of Claims 1 to 8, A coating portion for applying the photocurable resin composition; A light irradiation portion disposed near the coating portion; And a control unit. The above control unit controls the relative movement of the above coating unit and the above light irradiation unit and the above first member, and while controlling the coating unit to apply a photocurable resin composition to the surface of the above first member from one end side to the other end side of the surface of the above first member, controls the light irradiation unit to irradiate light to the photocurable resin composition in order to prevent deformation of the applied photocurable resin composition. A coating apparatus.

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