Method for manufacturing optical device

Abstract

The invention provides a method for manufacturing an optical device capable of easily removing bubbles in a photocurable resin composition. A method for manufacturing an optical device includes: a step (A) in which a wall portion surrounding a region coated with a photocurable resin composition is formed on an optical member or a transparent panel; a step B in which a photocurable resin composition is applied to the application region; a step C in which a laminate is obtained by bonding the optical member and the transparent panel with the photocurable resin composition in a reduced-pressure atmosphere that is less than atmospheric pressure; and a step D in which bubbles in the photocurable resin composition are removed by pressurizing the laminate. In the step B, the photocurable resin composition is applied such that at least the photocurable resin composition on the wall portion side is higher than the wall portion, and the laminate obtained in the step C has a plurality of divided spaces due to bubbles formed in the thickness direction of the photocurable resin composition.

Description

[0001] This application is a divisional application of the invention patent application with an international filing date of July 22, 2020, application number 202080052531.9 and name “Method for manufacturing an optical device”. Technical Field

[0002] The present technology relates to a method for manufacturing an optical device. This application claims priority based on Japanese Patent Application No. 2019-138981 filed in Japan on July 29, 2019, which is incorporated herein by reference. Background Art

[0003] Conventionally, optical devices such as image display devices used in information terminals such as smartphones and car navigation devices have a light-transmitting cured resin layer provided between an optical member such as a liquid crystal display panel and a transparent panel for protecting the optical member in order to reduce thickness and improve visibility.

[0004] As a method for manufacturing an image display device, for example, the following method can be cited. Fig. 9 A method including the following steps a to f is shown (see Patent Document 1).

[0005] Step a: forming a wall portion (hereinafter also referred to as a barrier) 102 (hereinafter also referred to as a barrier) surrounding a coating region 101 of a photocurable resin composition (hereinafter also referred to as a filler) 103 on a transparent panel 100 (eg, a light-transmitting cover member) Fig. 9 (A) Fig. 9 (B)).

[0006] Step b: Applying the filling material 103 to the coating area 101 ( Fig. 9 (B)).

[0007] Step c: The transparent panel 100 and the optical member 104 (eg, a liquid crystal display panel) are bonded together by vacuum bonding via the filler 103 to obtain a laminate 105 ( Fig. 9 (C)).

[0008] Step d: Using an autoclave 107, the laminate 105 is subjected to a pressure degassing treatment ( Fig. 9 (D)).

[0009] Step e: Irradiating the photocurable resin composition layer 106 sandwiched between the optical member 104 and the transparent panel 100 with ultraviolet rays 108 to form a cured resin layer 109 ( Fig. 9 (E), Fig. 9 (F)).

[0010] exist Fig. 9 In step b of the method shown in the figure, the following method is used: using a slit nozzle 110 ( Fig.10 (A)), multiple nozzles 111 with narrow spacing (e.g. 1 to 2 mm) ( Fig.11 (A)) coating a photocurable resin composition 103 so that the filler 103 is evenly spread over the entire surface of the coating area 101; a method of using a dispenser 112 to apply a low-viscosity filler 103 that wets and spreads in a short time in a rough pattern ( Fig.12 (A)) etc.

[0011] exist Fig. 9 In step c of the method shown in FIG. 1 , the optical member 104 and the spacer 102 are usually first bonded together, thereby suppressing the leakage of the filler 103 to the outside of the spacer 102 ( Fig.13 Then, after the optical member 104 is bonded to the barrier member 102, the barrier member 102 is flattened, and the filler material 103 is bonded to the optical member 104 ( Fig.14 (A) Fig.14 (B)). When the filler 103 and the optical component 104 are bonded, the filler 103 contacts the optical component 104 from a certain portion 113 and bonds. The rarefied air enclosed during bonding is concentrated in the final bonding portion due to the bonding expansion effect of the filler 103, forming air bubbles 114 ( Fig.15 (A) Fig.15 (B)).

[0012] Since the density of the bubbles 114 is increased, they tend to be difficult to disappear even in the pressure degassing treatment using the autoclave 107 in step d ( Fig.16 (A) Fig.16 As a method to easily remove the bubbles 114, for example, it is possible to further increase the vacuum degree during lamination in step c. However, this method is difficult to implement because it is accompanied by problems such as increased equipment cost and longer cycle time. In addition, as another method to easily remove the bubbles 114, it is possible to make the height of the barrier 102 as close as possible to the thickness (volume / area) of the filling material 103 ( Fig.17 However, this method has limitations in terms of the height of the barrier 102 and the plane accuracy of the bonding device, and there is a possibility that the filling material 103 may leak ( Fig.17 (B)). In addition, in this method, when a large panel 104A with a large bonding area is used as the optical member 104 ( Fig.18 (B)), and when using the small panel 104B ( Fig.18 Compared with (A)), the volume of the bubbles 114 is relatively larger, so the bubbles 114 tend to be less likely to disappear.

[0013] Prior art literature

[0014] Patent Literature

[0015] Patent Document 1: Japanese Patent Application Publication No. 2018-128668 Summary of the invention

[0016] Problems to be solved by the invention

[0017] The present technology provides a method for producing an optical device capable of easily removing bubbles in a photocurable resin composition.

[0018] Solutions for solving problems

[0019] The present technology includes: step A, forming a wall portion surrounding a coating area of ​​a photocurable resin composition on an optical component or a transparent panel; step B, coating the photocurable resin composition on the coating area; step C, bonding the optical component and the transparent panel with the photocurable resin composition in a reduced pressure atmosphere lower than atmospheric pressure to obtain a laminate; and step D, removing bubbles in the photocurable resin composition by pressurizing the laminate, wherein in step B, the photocurable resin composition is coated in such a manner that at least the photocurable resin composition on the wall side is higher than the wall, and the laminate obtained in step C has a plurality of cut-off spaces due to bubbles formed in the thickness direction of the photocurable resin composition.

[0020] Effects of the Invention

[0021] According to the present technology, bubbles in a photocurable resin composition can be easily removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 (A) is a diagram for explaining step B of the method for manufacturing an optical device, (A) is a top view, and (B) is a cross-sectional view.

[0023] Figure 2 (A) is a diagram for explaining step C of the method for manufacturing an optical device, (A) is a plan view, and (B) is a cross-sectional view.

[0024] Figure 3 (A) is a diagram for explaining step C of the method for manufacturing an optical device, (A) is a plan view, and (B) is a cross-sectional view.

[0025] Figure 4 (A) is a diagram for explaining step D of the method for manufacturing an optical device, (A) is a top view, and (B) is a cross-sectional view.

[0026] Figure 5(A) is a plan view for explaining step B of Example 1 of the method for manufacturing an optical device, Figure 5 (B) is a top view for explaining step C. Figure 5 (C) is a top view for explaining step D. Figure 5 (D) is a plan view for explaining the obtained laminated body.

[0027] Figure 6 (A) is a plan view for explaining step B of the method for manufacturing an optical device of Example 2 of the method for manufacturing an optical device, Figure 6 (B) is a top view for explaining step C. Figure 6 (C) is a plan view for explaining step D.

[0028] Figure 7 (A) is a plan view for explaining step B of Example 3 of the method for manufacturing an optical device, Figure 7 (B) is a top view for explaining step B. Figure 7 (C) is a top view for explaining step C. Figure 7 (D) is a plan view for explaining step D.

[0029] Fig. 8A (A) is a plan view for explaining step B of Example 4 of the method for manufacturing an optical device, Fig. 8A (B) is Fig. 8A A-A section view in (A).

[0030] Figure 8B (C) to (E) are plan views for explaining step C.

[0031] Figure 8C (F) is a top view for explaining step C. Figure 8C (G) is a plan view for explaining step D.

[0032] Fig. 9(A) is a cross-sectional view for illustrating a conventional method for manufacturing an optical device, wherein (A) is a cross-sectional view showing a process of forming a wall portion surrounding a coating area of ​​a photocurable resin composition on a transparent panel; (B) is a cross-sectional view showing a process of coating the photocurable resin composition on the coating area; (C) is a cross-sectional view showing a process of bonding a transparent panel to an optical component by a vacuum bonding method using the photocurable resin composition to obtain a laminate; (D) is a cross-sectional view showing a process of performing a pressure degassing treatment on the laminate using an autoclave; (E) is a cross-sectional view showing a process of irradiating a photocurable resin composition layer sandwiched between an optical component and a transparent panel with ultraviolet rays to form a cured resin layer; and (F) is a cross-sectional view showing the obtained optical device.

[0033] Fig.10 (A) Fig.10 (B) is a perspective view for explaining a method of applying a photocurable resin composition using a slit nozzle.

[0034] Fig.11 (A) Fig.11 (B) is a perspective view for explaining a method of applying a photocurable resin composition using a multi-nozzle.

[0035] Fig.12 (A) Fig.12 (B) is a perspective view for explaining a method of applying a photocurable resin composition using a dispenser.

[0036] Fig.13 This is a cross-sectional view showing an example of a state in which a transparent panel and an optical member are bonded together by a vacuum bonding method via a photocurable resin composition.

[0037] Fig.14 (A) is a cross-sectional view showing an example of a state in which the optical member and the spacer are bonded together, the spacer is flattened, and the filler and the optical member are bonded together. Fig.14 (B) is a top view.

[0038] Fig.15 This is a cross-sectional view showing an example of a state in which the rarefied air enclosed during bonding is concentrated in the final bonding portion due to the bonding expansion effect of the filling material and becomes bubbles. Fig.15 (B) is a top view.

[0039] Fig.16 (A) is a cross-sectional view showing an example of a state where a laminate is subjected to a pressure degassing treatment using an autoclave, Fig.16 (B) is a top view.

[0040] Fig.17 (A) Fig.17(B) is a cross-sectional view showing an example of a state in which the height of the spacer is made as close as possible to the thickness of the filling material.

[0041] Fig.18 (A) is a plan view showing an example of the state of bubbles in a laminated body when a small panel is used as an optical member. Fig.18 (B) is a plan view showing an example of the state of bubbles in a laminated body when a large panel is used as an optical member. DETAILED DESCRIPTION

[0042] In the manufacturing method of the optical device of the present embodiment (hereinafter also referred to as the present manufacturing method), an optical device 1 is obtained in which a transparent panel 2 and an optical member 3 are laminated via a cured resin layer 4 (see Fig. 9 F).

[0043] [Transparent Panel]

[0044] The transparent panel 2 uses a panel having light transmittance that allows visual recognition of the image formed on the optical member 3. As the transparent panel 2, for example, resin materials such as glass, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, and polycarbonate can be listed. The shape of the transparent panel 2 can be, for example, a plate or a sheet. For the transparent panel 2, a hard coating treatment, an anti-reflection treatment, etc. can be applied to at least one surface. The physical properties of the transparent panel 2, such as the shape, thickness, and elastic modulus, can be appropriately determined according to the purpose of use.

[0045] The transparent panel 2 is formed with a light shielding portion 5 in an area corresponding to the periphery of the display area of ​​the optical member 3. The light shielding portion 5 is provided to improve the contrast of the image. The light shielding portion 5 can be formed by, for example, applying a coating colored in black or the like by screen printing, and drying / curing the coating. The thickness of the light shielding portion 5 can be appropriately changed according to the purpose, and can be, for example, 5 to 100 μm.

[0046] [Optical components]

[0047] Examples of the optical member 3 include a liquid crystal display panel, an organic EL display panel, a plasma display panel, and a touch panel. Here, a touch panel refers to an image display / input panel that combines a display element such as a liquid crystal display panel with a position input device such as a touchpad.

[0048] [Cured resin layer]

[0049] The cured resin layer 4 is formed by a photocurable resin composition 6 described later. The refractive index of the cured resin layer 4 is preferably substantially equal to the refractive index of the transparent panel 2 and the optical component 3, for example, it can be set to be greater than 1.45 and less than 1.55. Thus, the brightness and contrast of the image light from the transparent panel 2 can be improved, so that the visual recognition is good. In addition, the light transmittance of the cured resin layer 4 is preferably greater than 90%. Thus, the visual recognition of the image can be better. The thickness of the cured resin layer 4 can be appropriately changed according to the purpose, for example, it can be set to 50 to 200 μm.

[0050] <Process A>

[0051] In step A, for example, Figure 1 As shown in FIG. 1 , first, a transparent panel 2 having a light shielding portion 5 is prepared, and a wall portion 8 surrounding a coating region 7 of a photocurable resin composition 6 is formed on the surface of the transparent panel 2. The wall portion 8 is used to divide the coating region of the photocurable resin composition 6 constituting the cured resin layer 4 and prevent the photocurable resin composition 6 coated in step B from overflowing to the outside of the wall portion 8. For example, Figure 1 As shown in (A), the wall portion 8 is formed in a substantially frame-like shape along the light shielding portion 5 on the display area side 5A of the light shielding portion 5 formed in a frame shape. In addition, the wall portion 8 is formed in a manner that abuts from the upper surface of the light shielding portion 5 to the inner side when the optical member 3 is attached to the transparent panel 2 in step C of the present manufacturing method. The wall portion 8 can also be formed from the upper surface of the light shielding portion 5 to the coating area 7 side surrounded by the light shielding portion 5.

[0052] The wall portion 8 can be formed, for example, using a curable resin composition that is cured by heat or light. The curable resin composition for the wall portion 8 can be applied, for example, in a roughly frame shape by a dispenser. When a photocurable resin composition is used as the curable resin composition for the wall portion 8, the photocurable resin composition is applied and irradiated with light (e.g., ultraviolet rays) to cure the photocurable resin composition to form the wall portion 8. The wall portion 8 can be formed using a photocurable resin composition having the same components as the photocurable resin composition 6 applied in step B.

[0053] The height of the wall portion 8 can be appropriately changed according to the thickness of the cured resin layer 4 to be formed, and can be set to 50 to 100 μm, for example, in a state where the wall portion 8 is sandwiched between the optical member 3 and the transparent panel 2 .

[0054] <Process B>

[0055] In step B, for example, Figure 1 As shown in FIG. 1 , a photocurable resin composition 6 is applied to a coating region 7 surrounded by a wall portion 8. In step B, for example, Figure 2 , Figure 3As shown in FIG. 1 , the photocurable resin composition 6 is applied so that the laminate 15 obtained in step C has a plurality of cut-off spaces due to the bubbles 13 formed in the thickness direction of the photocurable resin composition 6. That is, in step B, the photocurable resin composition pattern 11 is formed so that many bubbles 13 are dispersed in the surface of the photocurable resin composition 6 during lamination in step C. In addition, in step B, the photocurable resin composition 6 is preferably applied so that the total amount of the applied amount of the photocurable resin composition 6 becomes the target volume (thickness). By such step B, for example, Figure 3 As shown, the bubbles 13 are easily distributed in the photocurable resin composition 6 of the laminated body 15 obtained in the step C. Therefore, in the step D, the bubbles 13 in the photocurable resin composition 6 can be removed more easily.

[0056] A specific example of step B is described below. In step B, for example, Figure 1 As shown in (A), on the coating area 7 surrounded by the wall portion 8 on the surface of the transparent panel 2, the photocurable resin composition 6 is coated into a plurality of lines (strips) from one or more needles 9 to form a photocurable resin composition pattern 11. In addition, in step B, in order to bond in step C ( Figure 2 , Figure 3 ) so that the photocurable resin composition 6 does not overflow to the outside of the wall portion 8, it is preferred to adjust the distance (d1) between the photocurable resin composition patterns 11 and the distance (d2) between the wall portion 8 and the photocurable resin composition pattern 11 closest to the wall portion 8 to an appropriate range. The distance (d1) is preferably set to 2 to 4 mm, for example. The distance (d2) is preferably set to 1 to 3 mm, for example. By setting the distance (d1) and the distance (d2) to an appropriate range, the photocurable resin composition 6 can be more effectively prevented from overflowing to the outside of the wall portion 8 during the bonding of step C. In addition, by setting the distance (d1) and the distance (d2) to an appropriate range, it is easier to distribute the bubbles 13 in the photocurable resin composition 6 of the laminate 15 obtained in step C, and the bubbles 13 in the photocurable resin composition 6 can be more easily removed in step D.

[0057] In addition, in step B, the photocurable resin composition 6 is applied so that the height (h1) of at least the photocurable resin composition pattern 11 on the wall portion 8 side, for example, the photocurable resin composition pattern 11 closest to the wall portion 8 is greater than the height (h2) of the wall portion 8. In this way, in step B, the height (h1) of the photocurable resin composition pattern 11 on the wall portion 8 side can be made as close to the height (h2) of the wall portion 8 as possible, so that the degree of freedom related to the height of the wall portion 8 and the plane accuracy of the bonding device can be improved. It should be noted that the height (h1) of the photocurable resin composition pattern 11 other than the photocurable resin composition pattern 11 closest to the wall portion 8 can be higher than the height (h2) of the wall portion 8, can be set to the same level as the height (h2) of the wall portion 8, or can be lower than the height (h2) of the wall portion 8, but in terms of more effectively obtaining the effect of the present technology, it is preferred that the height (h1) of all the photocurable resin composition patterns 11 be higher than the height (h2) of the wall portion 8. For example, when the height (h2) of the wall portion 8 is set to 0.33 mm, the height (h1) of the entire photocurable resin composition pattern 11 can be set to 0.40 to 0.50 mm.

[0058] In step B, as described above, the photocurable resin composition 6 is applied so that the laminate 15 obtained in step C has a plurality of cut-off spaces due to the bubbles 13 formed in the thickness direction of the photocurable resin composition 6, thereby, for example, Fig.12 As shown, compared with the previous method of using a low-viscosity filling material 103 that wets and spreads in a short time, a filling material with a higher viscosity (for example, about 80,000 mPa·s) or a filling material with thixotropy can be used. Thixotropy refers to the property that the viscosity changes according to the shear stress. For example, when a filling material with thixotropy is ejected from the needle 9, it becomes low-viscosity due to the shear stress, and returns to the original viscosity after ejection (in a state where no shear stress is applied), so it tends to be difficult to deform the shape after ejection. In the present technology, a filling material with a higher viscosity or a filling material with thixotropy can also be used, so the height of the photocurable resin composition pattern 11 can be easily ensured so that the height (h1) of the photocurable resin composition pattern 11 on the wall portion 8 side is greater than the height (h2) of the wall portion 8.

[0059] The application form of the photocurable resin composition 6 in step B is not limited to Figure 1The linear shape shown in (A) may be, for example, a spiral, lattice, pulsating or a combination thereof. The photocurable resin composition 6 applied in step B preferably has a viscosity of 1000 to 10000 mPa·s at 25°C measured by a cone-plate viscometer or has thixotropy. The viscosity of the photocurable resin composition 6 at 25°C is preferably 1000 to 5000 mPa·s, more preferably 2000 to 4500 mPa·s.

[0060] As the photocurable resin composition 6, for example, one containing a base component (component (a)), an acrylate monomer component (component (b)), a plasticizer component (component (c)), and a photopolymerization initiator (component (d)) can be used.

[0061] <Ingredients (a)>

[0062] Component (a) is a film-forming component. As component (a), a component containing at least one of an elastomer and an acrylic oligomer can be used. As the elastomer, for example, an acrylic copolymer containing a copolymer of an acrylic ester, polybutene, polyolefin, etc. can be listed.

[0063] As acrylic oligomers, for example, (meth)acrylate oligomers having polyisoprene, polyurethane, polybutadiene, etc. in the skeleton can be cited. It should be noted that in this specification, (meth)acrylate refers to acrylate and methacrylate. As (meth)acrylate oligomers with a polyisoprene skeleton, esters of maleic anhydride adducts of polyisoprene polymers and 2-hydroxyethyl methacrylate (UC102 (polystyrene-converted molecular weight 17000), UC203 (polystyrene-converted molecular weight 35000), UC-1 (molecular weight of about 25000), all of which are manufactured by Kuraray Co., Ltd.) and the like can be cited. As (meth)acrylic oligomers with a polyurethane skeleton, aliphatic polyurethane acrylates (EBECRYL230 (molecular weight 5000), manufactured by DAICEL-ALLNEX; UA-1, manufactured by Light Chemical Co., Ltd.) and the like can be cited. As the (meth)acrylate oligomer having a polybutadiene skeleton, a known one can be used.

[0064] <Ingredient (b)>

[0065] Component (b) is a substance used as a reactive diluent in order to impart sufficient reactivity and coating properties to the photocurable resin composition. Component (b) includes: (meth)acrylate monomers having a hydroxyl group (e.g., 2-hydroxypropyl methacrylate), (meth)acrylate monomers having an aromatic group (e.g., benzyl acrylate), (meth)acrylate monomers having an alicyclic group (e.g., dicyclopentenyloxyethyl methacrylate), and the like.

[0066] The total content of the component (a) and the component (b) in the photocurable resin composition can be, for example, 25 to 85% by mass. The component (a) and the component (b) may be used alone or in combination of two or more.

[0067] <Ingredient (c)>

[0068] Component (c) is used to give cushioning properties to the cured resin layer and reduce the cure shrinkage of the photocurable resin composition, and does not react with components (a) and (b) under ultraviolet irradiation. As component (c), solid tackifiers and liquid oil components can be used. As solid tackifiers, terpene resins such as terpene resins, terpene phenolic resins, and hydrogenated terpene resins; rosin resins such as natural rosin, polymerized rosin, rosin esters, and hydrogenated rosin, etc. As liquid oil components, polybutadiene oils, polyisoprene oils, etc. can be listed. The content of component (c) in the photocurable resin composition can be set to 10 to 65% by mass, for example. Component (c) can be used alone or in combination of two or more.

[0069] <Ingredient (d)>

[0070] As component (d), a known photoradical polymerization initiator can be used, for example, 1-hydroxy-cyclohexyl phenyl ketone (IRGACURE 184, BASF), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)benzyl]phenyl}-2-methyl-1-propane-1-one (IRGACURE 127, BASF), benzophenone, acetophenone, etc. The content of component (d) can be 0.1 to 5 parts by mass relative to 100 parts by mass of the total of component (a) and component (b).

[0071] The photocurable resin composition may contain general additives such as an adhesion improver such as a silane coupling agent and an antioxidant, as required.

[0072] <Process C>

[0073] In step C, for example, Figure 2 , Figure 3As shown, in a reduced pressure atmosphere lower than atmospheric pressure, the optical component 3 and the transparent panel 2 are bonded together by means of a photocurable resin composition 6 to obtain a laminate 15. That is, in step C, a vacuum bonding method using a vacuum bonding device 12 is used to obtain a laminate 15 in which the transparent panel 2, the photocurable resin composition 6 and the optical component 3 are sequentially bonded.

[0074] The reduced pressure atmosphere below atmospheric pressure refers to, for example, a low vacuum, medium vacuum, high vacuum or ultra-high vacuum state. Specifically, the pressure is preferably 1000 Pa or less, more preferably 100 Pa or less, and further preferably 60 Pa or less. The lower limit of the vacuum degree is not particularly limited, but in order to avoid the increase in the cost of the vacuum bonding device 12 and the increase in the cycle time, it is preferably 0.1 Pa or more, and more preferably 10 Pa or more. The bonding of the optical member 3 and the transparent panel 2 can be performed, for example, using a vacuum bonding device 12 that can form a reduced pressure atmosphere state below atmospheric pressure.

[0075] As described above, the height (h1) of the photocurable resin composition pattern 11 applied in step B is greater than the height (h2) of the wall portion 8. Therefore, in step C, when the optical component 3 and the transparent panel 2 are bonded together in a reduced pressure atmosphere lower than the atmospheric pressure, the optical component 3 and the photocurable resin composition pattern 11 first come into contact. Then, when the optical component 3 and the photocurable resin composition pattern 11 come into contact, the photocurable resin composition is cut into a plurality of ( Figure 2 That is, a plurality of closed spaces S (cut-off spaces) are formed. Then, as the transparent panel 2 and the optical member 3 are bonded together, a plurality of tiny bubbles 13 are dispersed in the surface of the photocurable resin composition 6 ( Figure 3 ). The number of bubbles 13 increases or decreases according to the expansion mode of the photocurable resin composition 6. As an example, Figure 1 As shown, in step B, when four linear photocurable resin composition patterns 11 are formed in parallel at intervals of d1, in step C, the surface of the photocurable resin composition 6 is divided into at least five parts ( Figure 2 ), as the transparent panel 2 and the optical member 3 are bonded together, seven bubbles 13 are dispersed in the surface of the photocurable resin composition 6 ( Figure 3 ).

[0076] Even under normal pressure, some of the tiny bubbles 13 disappear as the bonding of the transparent panel 2 and the optical member 3 proceeds. The size of the bubbles 13 after bonding the optical member 3 and the transparent panel 2 in step C tends to be Figure 3 The photocurable resin composition 6 shown in (A) is smaller in the center than in the peripheral portion. For example, the size of the bubble 13 is Figure 3The central portion of the photocurable resin composition 6 shown in (A) can be set to 0.1 mm or less, and the peripheral portion of the photocurable resin composition 6 can be set to about 0.3 to 1.0 mm. When the size of the bubbles 13 after bonding in step C becomes 1.0 mm or less, it tends to disappear easily as the bonding of the transparent panel 2 and the optical member 3 proceeds. Therefore, with respect to the laminated body 15 obtained in step C, the size of the bubbles 13 in the photocurable resin composition 6 is preferably 1.0 mm or less, and more preferably 0.5 mm or less.

[0077] In this way, the laminate 15 obtained in step C has multiple truncation spaces due to the bubbles 13 formed in the thickness direction of the photocurable resin composition 6, and the bubbles 13 are distributed throughout the surface of the photocurable resin composition 6, so the bubbles 13 in the photocurable resin composition 6 can be more easily removed in step D.

[0078] <Process D>

[0079] In process D, if Figure 4 As shown, the bubbles 13 in the photocurable resin composition 6 are removed by pressurizing the laminate 15 obtained in step C. The pressurization method of the laminate 15 can adopt a known pressurized degassing treatment. For example, in step D, it is preferred to use an autoclave 14 to pressurize the laminate under the conditions of a pressure of 0.2 to 0.8 MPa, a temperature of 25 to 60° C., and a time of 5 to 30 minutes. The number of gas molecules in the bubbles 13 is proportional to the product of the vacuum degree (pressure) and the volume. Therefore, the tiny bubbles 13 dispersed in the surface of the photocurable resin composition 6 in step C can easily disappear in step D.

[0080] <Process E>

[0081] In step E, the photocurable resin composition 6 of the laminate 15 obtained in step D is irradiated with light to cure the photocurable resin composition 6. For example, in step E, the photocurable resin composition 6 sandwiched between the optical member 3 and the transparent panel 2 is irradiated with ultraviolet rays from the transparent panel 2 side using an ultraviolet irradiation device, thereby forming a cured resin layer 4. The light irradiation in step E is performed so that the curing rate (gel fraction) of the cured resin layer 4 is preferably 90% or more, more preferably 95% or more.

[0082] As described above, according to the present manufacturing method, in step B, the photocurable resin composition 6 is applied so that the height of the photocurable resin composition pattern 11 on at least the wall portion 8 side is greater than the height of the wall portion 8, and the laminated body 15 obtained in step C has a plurality of cut-off spaces due to the bubbles 13 formed in the thickness direction of the photocurable resin composition 6. As a result, the laminated body 15 obtained in step C has a plurality of cut-off spaces due to the bubbles 13 formed in the thickness direction of the photocurable resin composition 6, and the bubbles 13 are easily distributed in the surface of the photocurable resin composition 6. Therefore, in the present manufacturing method, in step C, the bubbles 13 in the photocurable resin composition 6 can be easily removed.

[0083] In the present manufacturing method, bubbles can be easily removed even for large panels and special-shaped panels that are difficult to remove bubbles using conventional manufacturing methods. Therefore, a liquid photocurable resin composition having high printing height difference followability and high bonding strength can be used, thereby improving the quality of the optical device and improving the productivity of the optical device. In addition, in the present manufacturing method, in step B, the photocurable resin composition 6 is applied in such a manner that the laminate 15 obtained in step C has a plurality of cut-off spaces due to the bubbles 13 formed in the thickness direction of the photocurable resin composition 6, so that, for example, Fig.12 As shown, the time from application of the photocurable resin composition 6 (filler) to lamination in step C can be shortened compared to the conventional method using a low-viscosity filler 103 that wets and spreads in a short time.

[0084] Example

[0085] Hereinafter, examples of the present technology will be described. It should be noted that the present technology is not limited to the following examples.

[0086] [Example 1]

[0087] <Process A>

[0088] In Example 1, Figure 5 As shown in (A), a cover glass 17 (130 mm × 300 mm, thickness 0.3 mm) with a special shape having a shading portion 5 formed in an area corresponding to the periphery of the display area of ​​the liquid crystal display panel 16 is prepared in such a manner as to surround the coating area of ​​the photocurable resin composition. The photocurable resin composition is coated on the display area side of the shading portion 5 of the cover glass 17 to form a wall portion 8A with a height of 0.3 mm and a width of 1 mm. As the photocurable resin composition, a photocurable resin composition with a viscosity of 3700 mPa·s at 25°C was used. A dispensing device (manufactured by Musashi Engineering Co., Ltd., model 350PC) was used for coating the photocurable resin composition.

[0089] <Process B>

[0090] A plurality of lines of photocurable resin composition 6 are applied in parallel in a linear manner to the coating region 7A surrounded by the wall portion 8A to form a photocurable resin composition pattern 11A. Specifically, the photocurable resin composition 6 ( d1 ) is applied so that the distance (d2) between the curable resin composition patterns 11A is 3 mm and the distance (d1) between the curable resin composition pattern 11A closest to the wall portion 8A and the wall portion 8A is 4 mm. Figure 5 (A)). In addition, all curable resin composition patterns 11A are made higher than the wall portion 8A.

[0091] <Process C>

[0092] Using a vacuum laminating apparatus (manufactured by Takatori Co., Ltd.), under the conditions of a vacuum degree of 50 Pa, a laminating pressure of 0.01 MPa, a laminating time of 10 seconds, and a temperature of 25° C., a cover glass 17 and a liquid crystal display panel 16 were laminated via a photocurable resin composition 6 to obtain a laminate 15 ( Figure 5 (B)). In the laminate 15, bubbles 13 are distributed throughout the photocurable resin composition 6.

[0093] <Process D>

[0094] The laminate 15 was pressurized using an autoclave 14 (product name: TBR600, manufactured by Chiyoda Electric Co., Ltd.) at a pressure of 0.5 MPa and room temperature for 20 minutes ( Figure 5 (C)). With respect to the laminated body 18A after pressurization, it was confirmed that the bubbles 13 in the photocurable resin composition 6 were removed ( Figure 5 (D)).

[0095] <Process E>

[0096] The photocurable resin composition 6 of the laminated body 18A after pressurization is irradiated with ultraviolet rays to cure the photocurable resin composition 6. Thus, an optical device in which the cover glass 17 and the liquid crystal display panel 16 are bonded together via the cured resin layer 4 is obtained.

[0097] [Example 2]

[0098] In Example 2, in step A, Figure 6 As shown in (A), a cover glass 19 (130 mm×300 mm, thickness 0.3 mm) is prepared in which a light shielding portion 5 is formed in an area corresponding to the periphery of the display area of ​​the liquid crystal display panel 16. In step B, Figure 6As shown in (A), the optical device is obtained in the same manner as in Example 1 except that the photocurable resin composition 6 is applied in a spiral shape in the coating area 7B to form a photocurable resin composition pattern 11B. Specifically, in Example 2, when the photocurable resin composition 6 is applied in a spiral shape, the distance (d1) between the photocurable resin composition patterns 11B is set to 4 mm, and the distance (d2) between the photocurable resin composition pattern 11B closest to the wall portion 8B and the wall portion 8B is set to 3 mm. In Example 2, as in Example 1, it is confirmed that the bubbles 13 in the photocurable resin composition 6 are removed ( Figure 6 (B) Figure 6 (C)).

[0099] [Example 3]

[0100] In Example 3, in step A, Figure 7 As shown in (A), a cover glass 19 (130 mm×300 mm, thickness 0.3 mm) is prepared in which a light shielding portion 5 is formed in an area corresponding to the periphery of the display area of ​​the liquid crystal display panel 16. In step B, Figure 7 An optical device was obtained in the same manner as in Example 1 except that the photocurable resin composition was applied in a lattice shape (cross shape) to the application area 7C to form a photocurable resin composition pattern 11C.

[0101] Specifically, in Example 3, in step B, first, Figure 7 As shown in (A), when six lines of photocurable resin composition 6 are applied in parallel in a linear manner, the distance (d1) between the photocurable resin composition patterns 11C is set to 4 mm, and the distance (d2) between the photocurable resin composition pattern 11C closest to the wall portion 8C and the wall portion 8C is set to 3 mm. Figure 7 As shown in (B), three lines of photocurable resin composition are applied in parallel in a linear manner orthogonal to the photocurable resin composition pattern 11C on the six lines of photocurable resin composition pattern 11C, and a photocurable resin composition pattern 11C is further formed. In this way, in Example 3, the inner side of the photocurable resin composition pattern 11C is divided into 10 parts, and a space ( Figure 7 Then, as the cover glass 19 and the liquid crystal display panel 16 are bonded together, a total of 14 bubbles 13 (10 in the central part and 4 in the peripheral part) are distributed throughout the surface of the photocurable resin composition 6 ( Figure 7 (C)).

[0102] It can be seen that: in Example 3, Figure 7 As shown in (C), after vacuum bonding, the number of bubbles 13 before pressurization in the autoclave 14 is reduced compared with the cases of Examples 1 and 2. In addition, it is known that in Example 3, the bubbles 13 can be removed more easily in the autoclave than in the cases of Examples 1 and 2. This is considered to be because in Example 3, the number of cutoff spaces formed in the surface of the photocurable resin composition is further increased by increasing the number of photocurable resin composition patterns compared with Example 1, and as a result, the bubbles are further subdivided.

[0103] [Example 4]

[0104] In Example 4, in step A, Fig. 8A As shown in (A), a cover glass 20 (60 mm×110 mm, thickness 0.1 mm) is prepared in which a light shielding portion 5 is formed in an area corresponding to the periphery of the display area of ​​the liquid crystal display panel 16. In step B, Fig. 8A (A) Fig. 8A An optical device was obtained in the same manner as in Example 1 except that the photocurable resin composition 6 was applied in a pattern consisting of a combination of linear and pulsating shapes to form a photocurable resin composition pattern 11D.

[0105] Specifically, in process B, if Fig. 8A As shown in (A), the distance (d1) between the photocurable resin composition patterns 11D is 4 mm, and the distance (d2) between the photocurable resin composition pattern 11D closest to the wall 8D and the wall 8D is 3 mm. Fig. 8A As shown in (B), by increasing the ejection amount of the photocurable resin composition 6 or reducing the speed of the dispenser 21 at the portion to be divided, a convex portion 22 with increased height and width of the photocurable resin composition pattern 11D is locally formed. Thus, a total of 13 rows of photocurable resin composition patterns 11D are formed, namely Fig. 8A In (A), a linear photocurable resin composition pattern 11Da is formed at each end, and a total of 11 columns of discontinuous and uneven photocurable resin composition patterns 11Db are formed between the photocurable resin composition patterns 11Da. Each photocurable resin composition pattern 11Db is Fig. 8A There are six protrusions 22 in the longitudinal direction in (A).

[0106] In process C, if Figure 8B As shown in (C) to (E) of FIG. 1 , as the cover glass 20 and the liquid crystal display panel 16 are bonded together, the photocurable resin composition pattern 11D spreads unevenly (pulsatingly) between the cover glass 20 and the liquid crystal display panel 16, forming a plurality of closed spaces 23 ( Figure 8B (E)). Figure 8B In the state shown in (E), the in-plane of the photocurable resin composition 6 is divided into approximately 98 parts, and the formed plurality of closed spaces 23 are further subdivided compared to the cases of Examples 1 to 3.

[0107] It can be seen that: in such embodiment 4, Figure 8C As shown in (F), after vacuum bonding, the bubbles 13 before pressurization in the autoclave 14 are reduced compared to the cases of Examples 1 and 2. In addition, it can be seen that in Example 4, the cycle time is not increased compared to the cases of Examples 1 and 2, and the bubbles 13 can be removed more easily in the autoclave 14 than in the cases of Examples 1 and 2.

[0108] Description of Reference Numerals

[0109] 1: optical device; 2: transparent panel; 3: optical member; 4: cured resin layer; 5: light shielding portion; 6: photocurable resin composition; 7, 7A, 7B, 7C: coating area; 8, 8A, 8B, 8C, 8D: wall; 9: needle; 11, 11A, 11B, 11C, 11D: photocurable resin composition pattern; 12: vacuum laminating device; 13: air bubble; 14: autoclave; 15: laminate; 16: liquid crystal display panel; 17: cover glass; 18, 18A, 18B, 18C, 18D: pressurized laminate; 19: cover glass 1: glass; 20: cover glass; 21: dispenser; 22: convex portion; 23: enclosed space; 100: transparent panel; 100A: shading portion; 101: coating area; 102: wall portion (partition); 103: photocurable resin composition (filling material); 104: optical component; 105: laminate; 106: photocurable resin composition layer; 107: autoclave; 108: ultraviolet rays; 109: cured resin layer; 110: slit nozzle; 111: multi-nozzle; 112: dispenser; 113: part; 114: bubble; 115: optical device.

Claims

1. A method for manufacturing an optical device, comprising: Step A, forming a wall portion surrounding a region where a photocurable resin composition is applied on an optical member or a transparent panel; Step B, coating the coating area with a photocurable resin composition; Step C, in a reduced pressure atmosphere lower than atmospheric pressure, laminating the optical member and the transparent panel via the photocurable resin composition to obtain a laminated body; as well as Step D, subjecting the laminate to a pressure degassing treatment, In the step B, the photocurable resin composition is applied in such a manner that the height of the photocurable resin composition on at least the wall side is greater than the height of the wall, and the laminate obtained in the step C has a plurality of cut-off spaces due to bubbles formed in the thickness direction of the photocurable resin composition.

2. The method for manufacturing an optical device according to claim 1, wherein: In the step B, the photocurable resin composition is applied so that the bubbles are distributed throughout the photocurable resin composition of the laminate obtained in the step C.

3. The method for manufacturing an optical device according to claim 1 or 2, wherein: The reduced pressure atmosphere in the step C is 100 Pa or less.

4. The method for manufacturing an optical device according to any one of claims 1 to 3, wherein: In the step B, the photocurable resin composition is applied in at least one pattern selected from the group consisting of a linear pattern, a spiral pattern, a lattice pattern, and a pulsating pattern.

5. The method for manufacturing an optical device according to any one of claims 1 to 3, wherein: In the step B, the photocurable resin composition is applied in a pattern consisting of a combination of a linear pattern and a pulsating pattern or a lattice pattern.

6. The method for manufacturing an optical device according to any one of claims 1 to 5, wherein: In the step B, a photocurable resin composition having a viscosity of 1000 to 10000 mPa·s at 25° C. or a photocurable resin composition having thixotropy is applied.

7. The method for manufacturing an optical device according to any one of claims 1 to 6, wherein: The transparent panel has a light shielding portion formed in a region corresponding to a periphery of a display region of the optical member, and the wall portion is formed on the display region side of the light shielding portion.

8. The method for manufacturing an optical device according to any one of claims 1 to 7, wherein: The method further includes a step E of irradiating the photocurable resin composition of the laminate obtained in the step D with light to form the cured resin layer.

9. The method for manufacturing an optical device according to any one of claims 1 to 8, wherein: The wall portion is formed of a photocurable resin composition having the same components as the photocurable resin composition.

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