JP6479589B2 - Manufacturing method of image display device - Google Patents

Description

  The present invention provides an image display by adhering and laminating an image display panel such as a liquid crystal display panel and a light-transmissive transparent substrate such as a transparent protective glass disposed on the surface side of the image display panel via a photo-curable transparent resin layer. The invention relates to a method of manufacturing a device.

  An image display device such as a liquid crystal display panel used in an information terminal such as a smart phone is between an image display panel such as a liquid crystal display panel or an organic EL panel and a transparent substrate such as a transparent protective glass. After the photocurable transparent resin composition is arranged, the composition is produced by irradiating the composition with ultraviolet rays and curing it to form a photocurable transparent resin layer, thereby bonding and laminating the image display panel and the transparent substrate. (Patent Document 1).

  As a method of supplying the photocurable transparent resin composition between the image display panel and the transparent substrate, the photocurable transparent resin composition is applied to the surface of the transparent substrate, and then the transparent substrate is coated on the image display panel. A method of sticking the surface on which the photocurable transparent resin composition is applied is used. Here, when apply | coating a photocurable transparent resin composition to a transparent substrate, it is necessary to apply | coat the photocurable transparent resin composition so that it may become flat on the whole surface of a transparent substrate. This is because if the photocurable transparent resin composition is not applied flatly, bubbles are involved in the subsequent bonding to the image display panel, and the image is distorted after the bonding.

  As a method for supplying the photocurable transparent resin composition between the image display panel and the transparent substrate, for example, there is a method of applying the photocurable transparent resin composition to the transparent substrate using a dispenser. In this method, as shown in FIG. 5, a light-transmitting cover member 20 is prepared, and a liquid photo-curing property using a dispenser 21 is provided on a surface 20 a of the light-transmitting cover member 20 facing the image display device. The transparent resin composition 22 is applied in a predetermined shape. Alternatively, as shown in FIG. 6, the photocurable transparent resin composition 22 is applied to the surface 20 a of the light-transmitting cover member 20 with a squeegee 27 through a screen plate 26 such as a mesh plate or a stencil using screen printing. You may print and apply | coat to a predetermined shape.

  Next, as shown in FIG. 7, the light transmissive cover member 20 is bonded to the image display panel 23 from the surface 20 a side where the photocurable transparent resin composition 22 is applied. Thereby, the photocurable transparent resin composition 22 spreads between the image display panel 23 and the light transmissive cover member 20 and is filled over the entire surface.

  However, in the method using the dispenser 21, it is difficult to control the filling shape of the photocurable transparent resin composition 22 after the light transmissive cover member 20 is bonded to the image display panel 23, and the photocurable transparent resin composition There is a risk that productivity may be reduced, such as the object 22 protruding from between the image display panel 23 and the light-transmitting cover member 20 and requiring cleaning. In addition, a method of applying in advance a resin that becomes a dam to prevent protrusion may be considered, but other problems such as an increase in the number of man-hours and the appearance of a boundary line with the dam part arise.

  Moreover, when a mesh board is used, air cannot be used practically because air is involved when the squeegee slides and voids remain in the photocurable transparent resin layer. When a stencil is used, the photocurable transparent resin composition 22 enters between the light-transmitting cover member 20 and the metal stencil, and cannot be used with a low-viscosity resin or a resin having no thixotropy.

  As a method of supplying a photocurable transparent resin composition between an image display panel and a transparent substrate with respect to a method using such a dispenser or screen printing, a photocurable transparent resin composition using an application head is used. There is also a method of applying to the transparent substrate. In this method, as shown in FIG. 8, the photocurable transparent resin composition 22 is discharged from the tip of the nozzle of the coating head 24 onto the surface 20a of the light transmissive cover member 20 facing the image display panel 23. Thus, as shown in FIG. 9A, a rectangular photo-curing transparent resin layer 25 is formed with a predetermined thickness over the entire surface of the light-transmitting cover member 20.

  Next, as shown in FIG. 9B, the photocurable transparent resin layer 25 formed on the surface 20a of the light transmissive cover member 20 is preliminarily cured by irradiating with ultraviolet rays to be precured. This is because the photocurable transparent resin composition 22 is made not to flow remarkably from the liquid state, so that it does not flow down even if it is turned upside down, thereby improving the handleability.

  Next, as shown in FIG. 9C, the light transmissive cover member 20 is bonded to the image display panel 23 from the side of the light curable transparent resin layer 25, and the light curable transparent resin layer 25 is applied by ultraviolet irradiation. Let it harden.

International Publication No. 2010/027041

  Here, when the liquid photocurable transparent resin composition 22 is applied to the substrate surface such as the light transmissive cover member 20, the outer edge portion of the photocurable transparent resin layer 25 is outward as shown in FIG. 10. When wetting and spreading and bonding to the image display panel 23, the outer edge portion of the photocurable transparent resin layer 25 is insufficient in thickness, and the image display panel 23 and the light transmissive cover member 20 are within the display area of the image display panel. There may be a region where a gap is formed without being completely filled with the photocurable transparent resin composition 22. Then, external light may enter the display area from the outer edge of the photocurable transparent resin layer 25, which may degrade the image quality.

  In addition, as shown in FIG. 11, generally, a transparent substrate such as a light-transmitting cover member 20 is applied to the peripheral portion of the surface facing the image display panel 23 by decorative printing or the like to improve the brightness and contrast of the display image. A light shielding layer 30 is provided. By providing the light shielding layer 30, when a step is formed between the main surface portion 31 and the light shielding layer 30, the photocurable transparent resin layer 25 is disposed above the light shielding layer 30 from above the main surface portion 31. A raised protrusion 32 is also formed. If the convex portion 32 formed on the photocurable transparent resin layer 25 is high, air is mixed between the light display cover member 20 and the image display panel 23 when the light transmission cover member 20 and the image display panel 23 are bonded together. Although there is a possibility of deteriorating quality, it is difficult to control the convex portion 32 with high accuracy.

  Furthermore, when the liquid photocurable transparent resin composition 22 is applied to a transparent substrate such as the light transmissive cover member 20 or the like, as shown in FIG. The resin composition 22 is stored, and the photocurable transparent resin layer 25 cannot be formed to a uniform thickness.

  Accordingly, the present invention provides a method for manufacturing an image display device in which a photocurable resin layer is formed with a uniform thickness between an image display panel and a transparent substrate, and deterioration of image quality due to incidence of external light can be prevented. The purpose is to provide.

  In order to solve the above-described problems, a manufacturing method of an image display device according to the present invention is a bump in which a liquid photocurable transparent resin composition is applied to a releasable sheet material, and the outer edge portion is raised from the main surface portion. Coating step of forming a photocurable transparent resin layer having a portion, a first light irradiation step of performing light irradiation to suppress the flow of the photocurable transparent resin layer, and the surface of the photocurable transparent resin layer A step of adhering to the transparent substrate, a second light irradiation step of performing light irradiation to temporarily cure the photocurable transparent resin layer, and peeling the release sheet material from the photocurable transparent resin layer. And a pasting step of attaching the photocurable transparent resin layer to the image display panel, and a third light irradiation step of performing photoirradiation to fully cure the photocurable transparent resin layer.

  According to the present invention, the photocurable transparent resin layer has a smooth surface that is in contact with the surface of the releasable sheet material as a surface to be attached to the image display panel. In addition, no voids are generated in the outer edge portion by spreading the photocurable transparent resin composition wet. Therefore, the image display device manufactured by this process can prevent image quality from deteriorating due to external light entering a gap formed between the image display panel and the transparent substrate.

FIG. 1 is a cross-sectional view showing an image display device. FIG. 2 is a cross-sectional view showing the production process according to the present invention, wherein (A) is a step of applying a photocurable transparent resin composition to a releasable sheet material and irradiating with ultraviolet light, and (B) is photocuring. (C) is a step of irradiating the photocurable transparent resin layer with ultraviolet light and temporarily curing it, and (D) is a step of removing the release sheet material from the photocurable transparent resin layer. The step of peeling, (E), shows a step of laminating a photocurable transparent resin layer on the image display panel and performing main curing by irradiating with ultraviolet light. FIG. 3 is a perspective view showing a step of applying a photocurable transparent resin composition to a releasable sheet material with a resin dispenser. FIG. 4 is a cross-sectional view showing a state in which a concave portion formed with a releasable sheet material is filled with a photocurable transparent resin composition. FIG. 5 is a perspective view showing a process of applying a liquid photocurable transparent resin composition in a predetermined shape to the surface of the light transmissive cover member using a dispenser. FIG. 6 is a side view showing a step of printing the photocurable transparent resin composition on the surface of the light-transmitting cover member using screen printing. FIG. 7 is a perspective view showing a process of bonding a light-transmitting cover member to the image display panel from the surface side where the photocurable transparent resin composition is applied. FIG. 8 is a perspective view showing a step of forming a photocurable transparent resin layer by discharging the photocurable transparent resin composition from the coating head onto the surface of the light transmissive cover member. FIG. 9A is a cross-sectional view showing a light-transmitting cover member on which a photocurable transparent resin layer is formed, and FIG. 9B shows a process of irradiating the photocurable transparent resin layer with ultraviolet light. FIG. 9C is a cross-sectional view illustrating a state in which a light-transmitting cover member is bonded to the image display panel from the light-curable transparent resin layer side. FIG. 10 shows that the outer edge portion of the photocurable transparent resin layer spreads outward, and an area in which a gap is formed between the image display panel and the light transmissive cover member is generated in the display area of the image display panel. It is sectional drawing which shows a state. FIG. 11 is a cross-sectional view illustrating a state in which a convex portion that is raised above the upper portion of the main surface portion is formed on the upper portion of the light shielding layer of the photocurable transparent resin layer. FIG. 12 is a cross-sectional view showing a state where the photocurable transparent resin composition is stored in the concave portion of the curved transparent substrate and the thickness of the photocurable transparent resin layer is nonuniform.

  Hereinafter, a manufacturing method of an image display device to which the present invention is applied will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention. Further, the drawings are schematic, and the ratio of each dimension may be different from the actual one. Specific dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[Image display device]
As shown in FIG. 1, an image display device 1 manufactured by applying the present invention includes a liquid photocurable transparent resin composition in which an image display panel 2 and a transparent substrate 3 serving as a light-transmitting cover member are in a liquid state. It is laminated via a photocurable transparent resin layer 5 formed from the product 4.

  Examples of the image display panel 2 include a liquid crystal display panel, an organic EL display panel, a plasma display panel, and a touch panel. Here, the touch panel means an image display / input panel in which a display element such as a liquid crystal display panel and a position input device such as a touch pad are combined.

  The transparent substrate 3 only needs to be light transmissive so that an image formed on the image display member can be visually recognized, and is a plate-like material such as glass, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, or sheet-like material. Materials. These materials can be subjected to single-sided or double-sided hard coat treatment, antireflection treatment or the like. The physical properties such as thickness and elasticity of the transparent substrate 3 can be appropriately determined according to the purpose of use.

  In the transparent substrate 3, a light shielding layer 6 formed along the peripheral edge is formed on the surface 3 a laminated with the image display panel 2. The light shielding layer 6 is provided to increase the contrast of an image, and is formed by applying a paint colored black or the like by a screen printing method or the like, and drying and curing. The thickness of the light shielding layer 6 is usually 5 to 100 μm.

[Photocurable transparent resin composition]
As the photocurable transparent resin composition 4 applied to the surface 3a of the transparent substrate 3, the liquid photocurable transparent resin is a liquid photocurable transparent resin that is temporarily cured and permanently cured by irradiating ultraviolet rays as described later. A composition is preferably used. As shown in FIG. 2 (A), the liquid photocurable transparent resin composition 4 is applied to the smooth surface 9a of the releasable sheet material 9 to be described later, so that the photocurable transparent resin is applied to the surface 9a. A resin layer 5 is formed. The photocurable transparent resin layer 5 has an outer edge portion 5a and a main surface portion 5b, and the outer edge portion 5a is formed with a bump portion 10 that is raised from the main surface portion 5b. Here, “liquid” means a cone plate viscometer of 0.01 to 100 Pa.s. It shows the viscosity of s (25 ° C.).

  Such a photocurable transparent resin composition 4 has an acrylate oligomer component (component (I)), an acrylate monomer component (component (b)), and a photopolymerization initiator (component (c)) as main components. What is contained can be illustrated preferably.

  The acrylate oligomer of component (a) is used as a base material for the photocurable transparent resin composition 4. Preferable specific examples include (meth) acrylate oligomers modified with polyisoprene, polyurethane, polybutadiene, etc. (for example, polyisoprene (meth) acrylate oligomers, polyurethane (meth) acrylate oligomers, polybutadiene (meth) acrylate oligomers, etc.) ). In the present specification, the term “(meth) acrylate” includes acrylate and methacrylate.

  Preferable specific examples of the polyisoprene-based (meth) acrylate oligomer include an esterified product of a maleic anhydride adduct of polyisoprene polymer and 2-hydroxyethyl methacrylate (UC102 (polystyrene equivalent molecular weight 17000), Kuraray Co., Ltd .; UC203 (Polystyrene conversion molecular weight 35000), Kuraray Co., Ltd .; UC-1 (molecular weight of about 25000), Kuraray Co., Ltd.) and the like.

  Specific examples of the polyurethane (meth) acrylate oligomer include an aliphatic urethane acrylate oligomer (EBECRYL230 (molecular weight 5000), Daicel Ornex Co., Ltd .; UA-1, Light Chemical Industry Co., Ltd.) and the like. Can do.

  A well-known thing can be employ | adopted as a polybutadiene type (meth) acrylate oligomer.

  The component (b) acrylate monomer component is used as a reactive diluent in the manufacturing process of the image display device in order to impart sufficient reactivity and coating properties to the photocurable transparent resin composition 4. . Examples of such acrylate monomers include 2-hydroxypropyl methacrylate, benzyl acrylate, dicyclopentenyloxyethyl methacrylate, and the like.

  As the photopolymerization initiator of component (c), a known radical photopolymerization initiator can be used. For example, 1-hydroxy-cyclohexyl phenyl ketone (Irgacure 184, BASF Japan Ltd.), 2- Hydroxy-1- {4- [4- (2-monohydroxy-2-methyl-propionyl) benzyl] phenyl} -2-methyl-1-propan-1-one (Irgacure 127, BASF Japan Ltd.), benzophenone, Examples include acetophenone.

  If such a photopolymerization initiator is too small relative to 100 parts by mass of the total of component (a) acrylate oligomer and component (b) acrylate monomer, curing will be insufficient upon irradiation with ultraviolet rays, and if too large, outgassing due to cleavage will increase. Since there exists a tendency of a foaming defect, Preferably it is 0.1-5 mass parts, More preferably, it is 0.2-3 mass parts.

  The photocurable transparent resin composition 4 can further contain a component (d) a plasticizer component. The plasticizer component of component (d) is used for imparting buffering properties to the cured resin layer and for reducing the curing shrinkage of the photocurable transparent resin composition 4, and for the irradiation of ultraviolet rays, It does not react with the acrylate oligomer component and the component (b) acrylate monomer component. Such a plasticizer component contains a solid tackifier (1) and a liquid oil component (2).

  Solid tackifiers (1) include terpene resins such as terpene resins, terpene phenol resins and hydrogenated terpene resins, natural rosins, polymerized rosins, rosin esters, rosin resins such as hydrogenated rosins, and terpene hydrogenated resins. Can be mentioned. In addition, non-reactive oligomers in which the above-mentioned acrylate monomers are preliminarily polymerized can also be used. Specifically, copolymers of butyl acrylate and 2-hexyl acrylate and acrylic acid, and cyclohexyl acrylate and methacrylic acid are used. Examples thereof include an acid copolymer.

  As the liquid oil component (2), polyptadiene oil or polyisoprene oil can be contained.

  Moreover, the photocurable transparent resin composition 4 can contain a chain transfer agent for adjusting the molecular weight. Examples thereof include 2-mercaptoethanol, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-ethylhexyl thioglycolate, 2,3-dimethylcapto-1-propanol, and α-methylstyrene dimer.

  Moreover, the photocurable transparent resin composition 4 can further contain general additives such as an adhesion improving agent such as a silane coupling agent and an antioxidant, if necessary.

  The photocurable transparent resin composition 4 can contain a plasticizer component (component (d)) as long as the effects of the present invention are not impaired. Therefore, the total content of the acrylate oligomer component of component (A) and the acrylate monomer component of component (B) in the photocurable transparent resin composition 4 is preferably 25 to 85% by mass. The content of the plasticizer component in d) is in the range of 0 to 65% by mass.

[Manufacturing Process of Image Display Device 1]
Next, the manufacturing process of the image display device 1 will be described. In the manufacturing process of the image display device 1, a liquid photocurable transparent resin composition is applied to a releasable sheet material, and a photocurable transparent resin layer having bump portions raised from the main surface portion is formed on the outer edge portion. A coating process; a first light irradiation process for performing light irradiation to suppress the flow of the photocurable transparent resin layer; an adhesion process for bringing the surface of the photocurable transparent resin layer into close contact with the transparent substrate; and light irradiation. A second light irradiation step of pre-curing the photocurable transparent resin layer, peeling the release sheet from the photocurable transparent resin layer, and removing the photocurable transparent resin layer from the image display panel. And a third light irradiation step of performing light irradiation and main curing the photocurable transparent resin layer.

[Coating process]
In the coating step, as shown in FIG. 2A, the liquid photocurable transparent resin composition 4 is applied to the releasable sheet material 9, and the bump portion 10 raised from the main surface portion 5b is formed on the outer edge portion 5a. It is a process of forming the photocurable transparent resin layer 5 to have.

  The releasable sheet material 9 supports the photocurable transparent resin layer 5 by applying and curing the liquid photocurable transparent resin composition 4 on the surface, and preferably a flexible material such as silicone rubber. It is formed of a material having properties. The releasable sheet material 9 is peeled off from the photocurable transparent resin layer 5 after the photocurable transparent resin layer 5 is adhered to the transparent substrate 3 and temporarily cured.

  The releasable sheet material 9 has a smooth surface 9a on which the liquid photocurable transparent resin composition 4 is applied. Accordingly, in the photocurable transparent resin layer 5 formed on the smooth surface 9a, the surface in contact with the surface 9a is also smoothed. Then, as will be described later, the photocurable transparent resin layer 5 is interposed between the image display panel 2 and the transparent substrate 3 by bonding the smooth surface of the photocurable transparent resin layer 5 and the image display panel 2 together. It can be formed with a uniform thickness.

  For example, as shown in FIG. 3, the releasable sheet material 9 is coated with the photocurable transparent resin composition 4 on the surface 9 a by a resin dispenser 13. The resin dispenser 13 has a storage part for storing the photocurable transparent resin composition 4 and a discharge port for discharging the photocurable transparent resin composition 4 in the storage part to the surface 9 a of the releasable sheet material 9. . The resin dispenser 13 has a predetermined width corresponding to the width of the photocurable transparent resin layer 5 whose discharge port is transferred to the transparent substrate 3, and the photocurable transparent resin extends over the entire width of the discharge port. The composition 4 is discharged.

  The resin dispenser 13 is moved from one end side to the other end side in the longitudinal direction of the smooth surface 9a of the releasable sheet material 9 while moving in a liquid photocurable transparent resin composition 4 by a pump (not shown). Is applied to the surface 9a of the releasable sheet material 9 so as to be applied at a predetermined thickness. Thereby, the substantially rectangular photocurable transparent resin layer 5 is formed on the smooth surface 9 a of the releasable sheet material 9.

[Bump part]
This photocurable transparent resin layer 5 has an outer edge portion 5a and a main surface portion 5b, and the outer edge portion 5a according to the wettability of the photocurable transparent resin composition 4 to the surface 9a of the releasable sheet material 9. A bump portion 10 is formed so as to rise from the main surface portion 5b. The photocurable transparent resin layer 5 has a bump portion 10 formed along the outer edge portion 5a, thereby suppressing the outward spreading of the photocurable transparent resin composition 4 and releasing the release sheet material 9. It is possible to prevent a gap from being generated without being sufficiently filled with the photocurable transparent resin composition 4 in the thickness direction between the transparent substrate 3 and the transparent substrate 3. Further, even when the bump portion 10 is pressed against the transparent substrate 3 and the photocurable transparent resin composition 4 is spread outward, the releasability is achieved by the photocurable transparent resin composition 4 constituting the bump portion 10. The space between the sheet material 9 and the transparent substrate 3 is filled, and a uniform photocurable transparent resin layer 5 can be formed in the thickness direction.

  In addition, you may form the bump part 10 by controlling the discharge amount and moving speed of the photocurable transparent resin composition 4 with the resin dispenser 13, etc. FIG. For example, the resin dispenser 13 increases the discharge amount at one end and the other end in the movement direction to be higher than the discharge amount therebetween, or lowers the movement speed at the one end and the other end in the movement direction from the movement speed therebetween. Thereby, the bump part 10 can be formed in the both ends of the movement direction of the resin dispenser 13. Moreover, the resin dispenser 13 can form the bump part 10 along the moving direction of the resin dispenser 13 by increasing the discharge amount at both ends of the discharge port more than the discharge amount therebetween. Further, when examining the discharge amount and the moving speed, the distance between the surface 9a of the releasable sheet material 9 and the discharge port can be devised. Alternatively, the bump portion 10 is formed on the surface 9a of the releasable sheet material 9 by forming a convex portion along the outer edge of the application region of the photocurable transparent resin composition 4 according to the convex portion. Can do.

  In addition, the coating method of the photocurable transparent resin composition 4 is not limited to the method using the dispenser 13 for resin, A screen printing and other well-known coating methods can be used suitably. In the case of screen printing, since the adhesiveness between the release sheet material 9 made of a flexible material such as silicone rubber and the stencil increases, the problem that the resin enters the gap between the two can be solved.

[Concave part]
As shown in FIG. 4, the releasable sheet material 9 may be provided with a concave surface portion 9b for holding the photocurable transparent resin composition 4 in a predetermined shape on the surface 9a. By applying the photocurable transparent resin composition 4 to the concave portion 9b, the outward spreading of the photocurable transparent resin composition 4 is suppressed, and the thickness is uniform between the transparent substrate 3 and the transparent substrate 3. The photocurable transparent resin layer 5 can be formed. The shape of the concave portion 9b can be arbitrarily set.

[First light irradiation step]
Following the step of applying the photocurable transparent resin composition 4 to the releasable sheet material 9, as shown in FIG. 2 (A), the photocurable transparent resin layer 5 is irradiated with ultraviolet rays to accelerate the curing reaction. And performing a first light irradiation step for suppressing flow. In the first light irradiation step, the liquid photocurable transparent resin composition 4 is cured to such an extent that wetting and spreading can be suppressed and the shape of the photocurable transparent resin layer 5 can be maintained. For this reason, it is preferable to perform a 1st light irradiation process immediately after application | coating of the photocurable transparent resin composition 4. FIG.

For irradiation with ultraviolet rays, a known ultraviolet light source such as an LED, a mercury lamp, a metal halide lamp, or a xenon lamp can be used. Irradiation conditions vary depending on the type of light curable transparent resin composition 4 and the light source, but can be, for example, LED: 365 nm, 500 mW / cm ² , and 1000 mJ / cm ² .

  At this time, the curing rate of the photocurable transparent resin layer 5 is preferably 60% or more and 97% or less, and more preferably 70% or more and 95% or less. When the curing rate exceeds 97%, the curing reaction proceeds too much, and the adhesion with the transparent substrate 3 may be lowered or air may be involved. Further, if the curing rate is less than 60%, the shape cannot be maintained, and there is a possibility that it cannot be adhered to the transparent substrate 3.

  In addition, although it is preferable that an ultraviolet-ray is irradiated from the photocurable transparent resin layer 5 side, when the releasable sheet material 9 is formed with the material which has translucency, the back surface of the releasable sheet material 9 You may irradiate from the side. Further, the photocurable transparent resin layer 5 is hard to be cured on the surface side exposed to air and the progress of the curing reaction is slow, and the curing reaction is likely to proceed on the surface side in contact with the surface 9a of the releasable sheet material 9. .

[Adhesion process]
Next, as shown in FIG. 2B, an adhesion process is performed in which the surface of the photocurable transparent resin layer 5 is adhered to the transparent substrate 3. Thereby, the bump portion 10 formed on the surface of the photocurable transparent resin layer 5 is crushed by being pressed against the transparent substrate 3, thereby photocuring at the outer edge portion 5 a of the photocurable transparent resin layer 5. Generation of voids due to wetting and spreading of the transparent conductive resin composition 4 is prevented.

  Further, by forming the releasable sheet material 9 from a flexible material such as silicone rubber, the roller 11 is slid onto the back surface of the releasable sheet material 9 and the like, so that a photocurable transparent resin is obtained. The layer 5 can be transferred to the transparent substrate 3. Thereby, the photocurable transparent resin layer 5 can be brought into close contact while crushing the bump portion 10 and extruding air intervening on the contact surface with the transparent substrate 3.

  Even if a step is generated due to the flexible substrate or the like being bonded to the transparent substrate 3 when closely attached to the transparent substrate 3, the release sheet material 9 having flexibility absorbs the step, and the transparent substrate 3 The photocurable transparent resin layer 5 can be adhered to the surface. Therefore, the transparent substrate 3 can improve the freedom degree of arrangement | positioning of components, such as a flexible substrate.

  In addition, since the releasable sheet material 9 is pressed by a roller 11 or the like to closely adhere the photocurable transparent resin layer 5, the bump portion 10 is crushed and formed to have a uniform thickness regardless of the height of the bump portion 10. Therefore, high-precision height control of the bump part 10 is not necessary.

  Further, since the release sheet material 9 having flexibility is rolled by a roller 11 or the like, even if the transparent substrate 3 is curved, the photocurable transparent resin layer 5 follows the undulations on the surface of the transparent substrate 3. The photocurable transparent resin layer 5 can be formed on the surface of the transparent substrate 3 with a uniform thickness.

[Second light irradiation step]
Next, as shown in FIG. 2C, a second light irradiation process is performed in which the photocurable transparent resin layer 5 is irradiated with ultraviolet rays to be temporarily cured. In the second light irradiation step, by accelerating the curing reaction of the photocurable transparent resin layer 5, it is possible to peel from the releasable sheet material 9 while maintaining the shape (for example, a curing rate of 80 to 90%) ) Is temporarily cured. As a result, the photocurable transparent resin layer 5 also has a curing reaction on the surface in contact with the transparent substrate 3 and is firmly adhered to the transparent substrate 3.

[Attaching process]
Next, as shown in FIGS. 2D and 2E, an attaching step of peeling the release sheet material 9 from the photocurable transparent resin layer 5 and bonding the photocurable transparent resin layer 5 to the image display panel 2. I do. Since the photocurable transparent resin layer 5 is temporarily cured by the second light irradiation step, it remains attached to the transparent substrate 3 and only the releasable sheet material 9 is peeled off. Thereby, the smooth surface 5c which was in contact with the surface 9a of the releasable sheet material 9 appears in the photocurable transparent resin layer 5.

  The smooth surface 5 c of the photocurable transparent resin layer 5 is attached to the image display panel 2. Affixing to the image display panel 2 can be performed by pressurizing at 10 ° C. to 80 ° C., for example, using a known pressure bonding device. At this time, since the photocurable transparent resin layer 5 uses the smooth surface 5c that is in contact with the surface 9a of the releasable sheet material 9 as a surface to be attached to the image display panel 2, it does not involve air bubbles and is easy. Can be pasted on. Moreover, since the photocurable transparent resin layer 5 is temporarily cured, the photocurable transparent resin composition 4 does not generate voids even in the outer edge portion 5a due to the wet spreading of the photocurable transparent resin composition 4. Therefore, the image display device 1 manufactured by this process can prevent the image quality from deteriorating due to external light entering the gap formed between the image display panel 2 and the transparent substrate 3. .

  In the case where a liquid crystal display panel is used as the image display panel 2, a polarizing plate is generally disposed in the liquid crystal display unit to which the transparent substrate 3 is attached, so that the photocurable transparent resin supported by the transparent substrate 3. The layer 5 is laminated on a polarizing plate provided in the image display panel 2. Since the image display device 1 manufactured by this process has the smooth surface 5c attached to the polarizing plate, voids are generated even when the photocurable transparent resin layer 5 is thermally contracted by the heat of the polarizing plate. It is possible to suppress the deterioration of image quality due to the incidence of external light.

[Third light irradiation step]
Next, a third light irradiation step is performed in which the photocurable transparent resin layer 5 sandwiched between the image display panel 2 and the transparent substrate 3 is irradiated with light to be fully cured. Thereby, the image display panel 2 and the transparent substrate 3 are laminated via the photocurable transparent resin layer 5 to obtain the image display device 1. The curing rate of the photocurable transparent resin layer 5 in the third light irradiation step is preferably 90% or more, more preferably 95% or more.

  Note that the light transmissive level of the photocurable transparent resin layer 5 may be light transmissive so that an image formed on the image display panel 2 can be visually recognized.

DESCRIPTION OF SYMBOLS 1 Image display apparatus, 2 Image display panel, 3 Transparent substrate, 3a surface, 4 Photocurable transparent resin composition, 5 Photocurable transparent resin layer, 5a Outer edge part, 5b Main surface part, 5c Smooth surface, 9 Release property Sheet material, 9a surface, 9b concave portion, 10 bump portion, 13 resin dispenser

Claims (10)

An application step of applying a liquid photocurable transparent resin composition to the releasable sheet material and forming a photocurable transparent resin layer having a bump portion raised from the main surface portion on the outer edge portion;
A first light irradiation step for performing light irradiation and suppressing flow of the photocurable transparent resin layer;
An adhesion step of closely attaching the surface of the photocurable transparent resin layer to a transparent substrate;
Performing a light irradiation, a second light irradiation step of temporarily curing the photocurable transparent resin layer,
An affixing step of peeling the release sheet material from the photocurable transparent resin layer, and affixing the photocurable transparent resin layer to the image display panel;
A method of manufacturing an image display device, comprising: a third light irradiation step of performing light irradiation and subjecting the photocurable transparent resin layer to main curing.   The method of manufacturing an image display device according to claim 1, wherein in the first light irradiation step, light irradiation is performed from the photocurable transparent resin layer side.   The method for manufacturing an image display device according to claim 1, wherein, in the first light irradiation step, the curing rate of the photocurable transparent resin layer is 60% or more and 97% or less.   In the third light irradiation step, a polarizing plate is disposed on the surface of the image display panel, and the polarizing plate and the photocurable transparent resin layer are laminated. The manufacturing method of the image display apparatus of description. The method for manufacturing an image display device according to claim 1, wherein the releasable sheet material is provided with a concave surface portion that holds the photocurable transparent resin composition in a predetermined shape. The method for manufacturing an image display device according to claim 1, wherein the releasable sheet material has flexibility. The method for manufacturing an image display device according to claim 6, wherein in the adhesion step, the photocurable transparent resin layer is transferred onto the transparent substrate by rolling the release sheet material onto the transparent substrate.   The method for manufacturing an image display device according to claim 1, wherein the transparent substrate is a glass substrate. The manufacturing method of the image display apparatus of any one of Claims 1-8 which apply | coat the said photocurable transparent resin composition to the said mold release sheet | seat material with an application | coating head. The manufacturing method of the image display apparatus of any one of Claims 1-8 which apply | coat the said photocurable transparent resin composition to the said release sheet material by screen printing.

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