Harden resin layer

Abstract

To achieve both high viscosity of a dam material and low viscosity of a fill material and improve adhesion between the members, even when a resin composition having the same component is used as the dam material and the fill material.SOLUTION: A production method includes: a step (A) of forming a coating region 7 of a second resin composition 8 on a surface of a first member using a first resin composition; a step (B) of coating the second resin composition 8 onto the coating region 7; a step (C) of bonding the first member and the second member through the second resin composition 8, and filling the coating region 7 with the second resin composition 8; and a step (D) of irradiating the second resin composition 8 with light, and forming a curable resin layer 1. The step (C) includes heating the second resin composition 8. The second resin composition 8 contains a monofunctional monomer having a heating residue after having been heated at 60°C for 30 minutes of 95.0% or more. The second resin composition 8 has a heating residue after having been heated at 80°C for 3 hours of 95.0% or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This technology is cured resin layer Regarding. [Background technology]

[0002] Conventionally, a technique is known in which members are bonded together with a photocurable resin composition and fixed with a light-transmitting resin layer. For example, Patent Document 1 describes a method in which a photocurable resin composition is disposed between an image display member and a light-transmitting member to form a resin composition layer, and the resin composition layer is irradiated with light to form a cured resin layer. Here, it is desirable that the light-transmitting member and the image display member in the image display device have good adhesion.

[0003] Also, from the viewpoint of suppressing the overflow of the photocurable resin composition from the coated object (light-transmitting member or image display member), a so-called dam-fill process may be adopted. In the dam-fill process, for example, a first resin composition (dam material) is used to form a coating area for a second resin composition (fill material) on the surface of an image display member. Next, the second resin composition is coated on the formed coating area, and the image display member and the light-transmitting member are bonded together via the second resin composition. Then, the second resin composition is irradiated with light to form a cured resin layer.

[0004] In the dam-fill process, the dam material is preferably high-viscosity from the viewpoint of preventing dripping. On the other hand, the fill material is preferably low-viscosity from the viewpoint of preventing air bubbles and laminating in a short tact time. Here, in order to improve the visibility of the boundary between the dam material and the fill material, that is, to make the boundary line between the dam material and the fill material less noticeable, a resin composition of the same component may be used for the dam material and the fill material. However, when a resin composition of the same component is used for the dam material and the fill material, there is a concern that the high viscosity of the dam material or the low viscosity of the fill material may be sacrificed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-222350 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present technology has been proposed in consideration of the conventional situation, and provides a photocurable resin composition that can achieve both the high viscosity of the dam material and the low viscosity of the fill material, even when a resin composition of the same components is used for the dam material and the fill material, thereby achieving good adhesion between the components. [Means for solving the problem]

[0007] This technology is a cured resin layer used in a laminate in which a first member and a second member are laminated with a cured resin layer therebetween, the cured resin layer being formed by photocuring a first resin composition and a second resin composition, the first resin composition and the second resin composition having a viscosity at 25°C in the range of 10000 to 50000 mPa·s, the second resin composition being disposed in a liquid stopping portion formed from the first resin composition, and the second resin composition being Monofunctional Monomers 5 to 60 mass%; (Meth)acrylate resin 10 to 60 mass%; Plasticizer The monofunctional monomer contains 10 to 70 mass % of Residue after heating at 60℃ for 30 minutes is 95.0% or more The second resin composition is Residue after heating at 80℃ for 3 hours is 95.0% or more It is. Effect of the Invention

[0008] According to the present technology, even when resin compositions of the same components are used for the first resin composition (dam material) and the second resin composition (fill material), it is possible to achieve both the high viscosity of the dam material and the low viscosity of the fill material, thereby achieving good adhesion between the components. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an example of an image display device. [Diagram 2] FIG. 2A is a front view showing an example of an image display member, and FIG. 2B is a cross-sectional view taken along line AA' shown in FIG. 2A. [Diagram 3] Figure 3(A) is a front view illustrating an example of a method for forming a coating area of ​​a second resin composition on the surface of an image display member using a first resin composition, and Figure 3(B) is a cross-sectional view taken along A-A' in Figure 3(A). [Figure 4] FIG. 4 is a cross-sectional view illustrating an example of a method for forming a coating region of a second resin composition on the surface of an image display member by using a first resin composition. [Diagram 5] FIG. 5(A) is a front view illustrating an example of a method for applying the second resin composition, and FIG. 5(B) is a cross-sectional view taken along line AA' shown in FIG. 5(A). [Figure 6] Figure 6(A) is a front view illustrating an example of a method for bonding an image display member and a light-transmitting member via a second resin composition, and Figure 6(B) is a cross-sectional view taken along line A-A' in Figure 6(A). [Figure 7] FIG. 7 is a cross-sectional view illustrating an example of a method for forming a cured resin layer by irradiating the second resin composition with light. [Figure 8] FIG. 8 is a diagram for explaining a method for measuring the heating residue of a monofunctional monomer. [Figure 9] FIG. 9 is a diagram for explaining a method for measuring the heating residue of a photocurable resin composition. [Figure 10] FIG. 10 is a perspective view for explaining a measurement method in an adhesive strength test. [Figure 11] FIG. 11 is a cross-sectional view taken along line AA' in FIG. [Figure 12] FIG. 12 is a perspective view for explaining a measurement method in an adhesive strength test. [Figure 13] FIG. 13 is a cross-sectional view taken along line AA' in FIG. [Figure 14] FIG. 14 is a perspective view for explaining a measurement method in an adhesive strength test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Method of manufacturing laminate] The method for producing a laminate according to the present embodiment includes the following steps (A) to (D), and step (C) includes heating the second resin composition. The second resin composition used in this production method contains a monofunctional monomer having a heating residue of 95.0% or more after heating at 60°C for 30 minutes, and has a heating residue of 95.0% or more after heating at 80°C for 3 hours, as described in detail later.

[0011] Step (A): A first resin composition is used to form a coating region of a photocurable second resin composition on the surface of a first member. Step (B): A second resin composition is applied to the application area. Step (C): The first member and the second member are bonded together with the second resin composition interposed therebetween, and the second resin composition is allowed to fill the application area. Step (D): The second resin composition is irradiated with light to form a cured resin layer.

[0012] According to this manufacturing method, the viscosity of the second resin composition can be reduced by heating the second resin composition in step (C). Therefore, even when resin compositions of the same components are used as the first resin composition and the second resin composition, it is possible to achieve both a high viscosity of the first resin composition and a low viscosity of the second resin composition. In addition, in this manufacturing method, by using a second resin composition having a heating residue of 95.0% or more after heating at 80°C for 3 hours, it is possible to suppress the volatilization of the components in the second resin composition when the second resin composition is heated, and therefore it is possible to improve the adhesion between the first member and the second member.

[0013] The second resin composition used in this manufacturing method has a heating residue of 95.0% or more after heating at 80°C for 3 hours, preferably 97.0% or more, more preferably 98.0% or more, and even more preferably 99.0% or more. A larger heating residue can more effectively suppress the volatilization of the components in the second resin composition when the second resin composition is heated. In addition, the upper limit of the heating residue of the second resin composition is not particularly limited. Here, the heating residue of the second resin composition refers to a value obtained by measuring the mass before and after heating 10 mg of the resin composition at 80°C for 3 hours using a calorimeter measuring device (device name: Q50, manufactured by TA Instruments). Details of the second resin composition will be described later.

[0014] Each step will be described in detail below with reference to the drawings. In this manufacturing method, as shown in Fig. 1, for example, an image display device 5 (laminate) is obtained in which an image display member 2 (first member) and a light-transmitting member 3 (second member) having a light-shielding layer 4 formed on its peripheral portion are laminated via a cured resin layer 1.

[0015] The cured resin layer 1 is formed from a first resin composition 6 and a second resin composition 8, which will be described later. The refractive index of the cured resin layer 1 is preferably approximately equal to the refractive index of the image display member 2 and the light-transmitting member 3, and is preferably, for example, 1.45 or more and 1.55 or less. This can increase the brightness and contrast of the image light from the image display member 2, and improve visibility. In addition, the transmittance of the cured resin layer 1 is preferably more than 90%. This can further improve the visibility of the image formed on the image display member 2. The thickness of the cured resin layer 1 is preferably, for example, 50 to 200 μm.

[0016] Examples of the image display member 2 include a liquid crystal display panel, a touch panel, etc. Here, the touch panel means 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 touch pad.

[0017] The light-transmitting member 3 may have light transmittance such that the image formed on the image display member 2 is visible. Examples of the light-transmitting member 3 include plate-like or sheet-like materials such as glass, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, and polycarbonate. At least one surface of these materials may be subjected to a hard coat treatment, an anti-reflection treatment, or the like. The physical properties such as the thickness and elastic modulus of the light-transmitting member 3 may be appropriately determined depending on the purpose of use.

[0018] The light-shielding layer 4 is provided to improve the contrast of an image, and can be formed, for example, by applying a paint colored black or the like by screen printing or the like, followed by drying and curing. The thickness of the light-shielding layer 4 is usually 5 to 100 μm.

[0019] [Process (A)] In step (A), as shown in Figures 2 and 3, for example, a coating region 7 of a second resin composition 8 is formed on the surface of an image display member 2 using a first resin composition 6. The coating region 7 is a region surrounded by a frame-shaped liquid stopping portion (dam) 11 formed from the first resin composition 6 in the display region of the image display member 2, as shown in Figures 3 and 4, for example.

[0020] The first resin composition 6 is a material for preventing dripping of the second resin composition 8 to be applied to the application area 7 in step (B). For example, a thermosetting resin composition, a photocurable (e.g., ultraviolet curable) resin composition, etc. can be used as the first resin composition 6. When the first resin composition 6 is a photocurable resin composition, in step (A), for example, as shown in FIG. 4, the first resin composition 6 is irradiated with ultraviolet light 10 from an ultraviolet irradiator 9 to cure the first resin composition 6, and a liquid stopping portion 11 is formed, thereby defining the application area 7.

[0021] In order to prevent dripping, the first resin composition 6 preferably has a high viscosity. For example, the first resin composition 6 preferably has a viscosity at 25° C. of 10,000 to 50,000 mPa·s.

[0022] Various coating methods can be used for coating the first resin composition 6, including, for example, a method using a dispenser, a method using a coater, a method using a spray, etc. In particular, a method using a dispenser is preferred from the viewpoint of suppressing dripping. The coating thickness of the first resin composition 6 can be, for example, equal to or less than the thickness of the second resin composition 8 coated on the coating region 7 in step (B) of the present manufacturing method.

[0023] [Process (B)] In step (B), the second resin composition 8 is applied to the application region 7, for example, as shown in Fig. 5. Various application methods can be used to apply the second resin composition 8, and examples of such methods include the application method for the first resin composition 6 described above. The amount of the second resin composition 8 applied is preferably an amount that can be filled into the application region 7 during lamination in step (C).

[0024] It is preferable that the second resin composition 8 is made such that the boundary line between the liquid stopping portion 11 formed from the first resin composition 6 and the second resin composition 8 is not visually noticeable when cured in step (D). Therefore, it is preferable that the second resin composition 8 is substantially the same component as the first resin composition 6. The same component means that at least the first resin composition 6 and the second resin composition 8 have the same optical properties, for example, the light transmittance and the refractive index are substantially equal. When the optical properties of the first resin composition 6 and the second resin composition 8 are substantially equal, for example, even if the viscosities of the first resin composition 6 and the second resin composition 8 are different, they are considered to be included in the same component.

[0025] From the viewpoints of preventing air bubbles and performing lamination in a short tact time, the second resin composition 8 preferably has a low viscosity during lamination in step (C). For example, the viscosity of the second resin composition 8 at the lamination temperature is preferably 3000 mPa s or less, and more preferably 1000 to 3000 mPa s.

[0026] In this manufacturing method, the viscosity of the second resin composition 8 can be adjusted to a low viscosity (for example, 3000 mPa s or less) by heating (warming) the second resin composition 8 in the following step (C). Therefore, even when the first resin composition 6 and the second resin composition 8 are made of resin compositions of the same components, it is possible to achieve both a high viscosity of the first resin composition 6 and a low viscosity of the second resin composition 8.

[0027] In addition, in this production method, by using the second resin composition 8 having a heating residue of 95.0% or more after heating at 80°C for 3 hours, it is possible to suppress volatilization of components in the second resin composition 8 (for example, a monofunctional monomer described later) when the second resin composition 8 is heated in the following step (C), and therefore it is possible to improve the adhesion between the light-transmitting member 3 and the image display member 2.

[0028] [Process (C)] In step (C), for example, as shown in Fig. 6, the image display member 2 and the light transmitting member 3 are bonded together via the second resin composition 8, and the second resin composition 8 is filled into the application region 7. The image display member 2 and the light transmitting member 3 can be bonded together using, for example, a known pressure bonding device.

[0029] Moreover, the step (C) includes heating the second resin composition 8 as described above. By heating the second resin composition 8, the second resin composition 8 is filled in the application region 7 in a reduced viscosity state. This prevents air bubbles in the second resin composition 8, and enables lamination in a short takt time. The heating conditions are preferably set so that the viscosity of the second resin composition 8 is adjusted to a low viscosity (for example, 3000 mPa·s or less). For example, the heating temperature is preferably 80° C. or less, more preferably 60 to 80° C., taking into consideration the influence of heat on the image display member 2 and the light-transmitting member 3. The heating time can be, for example, about 30 minutes to 3 hours. The timing of heating may be before laminating the image display member 2 and the light-transmitting member 3, during lamination, or after lamination. Examples of the heating method include a method using a heater or the like.

[0030] [Process (D)] In step (D), for example, as shown in Fig. 7, the second resin composition 8 is irradiated with ultraviolet light 10 from an ultraviolet irradiator 9 to form a cured resin layer 1 (see Fig. 1). The light irradiation in step (D) is preferably performed after the second resin composition 8 heated in step (C) is allowed to dissipate heat.

[0031] Here, when the second resin composition 8 is substantially the same as the first resin composition 6, the second resin composition 8 after light irradiation is integrated with the liquid stopping portion 11 to become a single cured resin layer 1 having the same optical properties. This can improve the visibility of the boundary between the liquid stopping portion 11 and the cured second resin composition 8.

[0032] As described above, according to the present manufacturing method, the viscosity of the second resin composition 8 is reduced by heating the second resin composition 8 in step (C). Therefore, even when the first resin composition 6 and the second resin composition 8 are made of the same resin composition, the high viscosity of the first resin composition 6 and the low viscosity of the second resin composition 8 can be achieved at the same time. In addition, in the present manufacturing method, a photocurable resin composition is used as the second resin composition 8, which contains a monofunctional monomer having a heating residue of 95.0% or more after heating at 60°C for 30 minutes and has a heating residue of 95.0% or more after heating at 80°C for 3 hours. This suppresses the volatilization of the components in the second resin composition 8 when the second resin composition 8 is heated, and improves the adhesion between the light-transmitting member 3 and the image display member 2.

[0033] In the above-mentioned manufacturing method, the first resin composition 6 and the second resin composition 8 are applied to the surface of the image display member 2, but the method is not limited to this method. For example, the first resin composition 6 and the second resin composition 8 may be applied to the surface of the light-transmitting member 3. In addition, in the above-mentioned manufacturing method, the light-transmitting member 3 on which the light-shielding layer 4 is formed is used, but the method is not limited to this example. For example, a light-transmitting member on which no light-shielding layer is formed may be used.

[0034] In the above-mentioned step (A), the photocurable resin composition 6 is cured by light irradiation to form the liquid stopping portion 11, but the present invention is not limited to this method. For example, in the step (A), a thermosetting first resin composition 6 may be used, and the first resin composition 6 may be heated and cured to form the liquid stopping portion 11. In addition, when the viscosity of the first resin composition 6 is high enough to prevent the second resin composition 8 from dripping, the first resin composition 6 does not need to be cured by heat or light.

[0035] [Photocurable resin composition] The photocurable resin composition according to the present embodiment contains a monofunctional monomer having a heating residue of 95.0% or more after heating at 60°C for 30 minutes, a (meth)acrylate resin, a photopolymerization initiator, and a plasticizer, and has a heating residue of 95.0% or more after heating at 80°C for 3 hours. Here, (meth)acrylate includes both methacrylate and acrylate. The photocurable resin composition is preferably used as the first resin composition 6 and the second resin composition 8 described above.

[0036] [Monofunctional monomer] The monofunctional monomer preferably has a heating residue after heating at 60° C. for 30 minutes of 95.0% or more, more preferably 97.0% or more, even more preferably 98.0% or more, and particularly preferably 99.50% or more.

[0037] Here, the heating residue of the monofunctional monomer refers to a value obtained by measuring the mass before and after heating 10 mg of the monofunctional monomer at 60° C. for 30 minutes using a calorimeter (device name: Q50, manufactured by TA Instruments).

[0038] By including the monofunctional monomer in the photocurable resin composition, the volatilization of the monofunctional monomer can be more effectively suppressed when the second resin composition is heated in the above-mentioned step (C), and therefore the adhesion between the light-transmitting member 3 and the image display member 2 can be improved.

[0039] Specifically, the monofunctional monomer is preferably a monofunctional (meth)acrylate, and for example, is preferably at least one of a compound represented by formula (A) and a compound represented by formula (B). [ka]

[0040] In formula (A), R 1 R represents a hydrogen atom or a methyl group. 2 R represents an alkylene group having 2 or 3 carbon atoms. 3 R represents a hydrocarbon group, which may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. 3 When R is an aliphatic hydrocarbon group, it is preferably an aliphatic hydrocarbon group having 5 to 10 carbon atoms. 3 When R is an aromatic hydrocarbon group, it is preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably an aromatic hydrocarbon group having 6 to 8 carbon atoms. 3 When R is an aromatic hydrocarbon group, 3 may have a substituent. Examples of the substituent include a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, and an aromatic hydrocarbon group having 6 to 12 carbon atoms. n represents an integer of 1 to 15, and preferably an integer of 1 to 10.

[0041] In formula (B), R 4 R represents a hydrogen atom or a methyl group. 5 R has 11 to 20 carbon atoms, and preferably 15 to 20 carbon atoms. 5 may be any one of a linear, branched, or cyclic alkyl group, is preferably a linear or branched alkyl group, and is more preferably a branched alkyl group.

[0042] Specific examples of monofunctional monomers include isostearyl (meth)acrylate, nonylphenol EO-modified (meth)acrylate, nonylphenol PO-modified (meth)acrylate, 2-ethylhexyl EO-modified (meth)acrylate, phenol EO-modified (meth)acrylate, o-phenylphenol EO-modified acrylate, para-cumylphenol EO-modified acrylate, N-acryloyloxyethylhexahydrophthalimide, and 2-hydroxy-3-phenoxypropyl acrylate.

[0043] In the photocurable resin composition, the content of the monofunctional monomer is preferably 5 to 60 mass%, more preferably 5 to 40 mass%, and further preferably 10 to 30 mass%. The monofunctional monomer may be used alone or in combination of two or more. When two or more types of monofunctional monomers are used in combination, it is preferable that the content thereof satisfies the above content range.

[0044] [(Meth)acrylate resin] The (meth)acrylate resin is, for example, a photocurable (meth)acrylate resin, and may be a polymer or an oligomer. The (meth)acrylate resin is preferably, for example, at least one of polyurethane (meth)acrylate oligomer, polyisoprene (meth)acrylate oligomer, polybutadiene (meth)acrylate oligomer, and polyether (meth)acrylate oligomer. Specific examples of the (meth)acrylate resin include UC-203 (manufactured by Kuraray Co., Ltd.) and UV3700B (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).

[0045] In the photocurable resin composition, the content of the (meth)acrylate resin is preferably 5 to 80 mass%, more preferably 10 to 70 mass%, further preferably 10 to 60 mass%, and particularly preferably 30 to 50 mass%. The (meth)acrylate resin may be used alone or in combination of two or more. When two or more (meth)acrylate resins are used in combination, it is preferable that the content thereof satisfies the above content range.

[0046] [Photopolymerization initiator] The photopolymerization initiator is preferably a photoradical polymerization initiator, and more preferably contains at least one of an alkylphenone-based photopolymerization initiator and an acylphosphine oxide-based photopolymerization initiator. As the alkylphenone-based photopolymerization initiator, 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by BASF), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propylonyl)benzyl]phenyl}-2-methyl-1-propan-1-one (Irgacure 127, manufactured by BASF), etc. can be used. As the acylphosphine oxide-based photopolymerization initiator, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (TPO, manufactured by BASF), etc. can be used. As the other photopolymerization initiator, benzophenone, acetophenone, etc. can also be used.

[0047] In the photocurable resin composition, the content of the photopolymerization initiator is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, based on 100 parts by mass of the total of the monofunctional monomer and the (meth)acrylate resin. By setting the content within such a range, it is possible to more effectively prevent insufficient curing during light irradiation and to more effectively prevent an increase in outgassing due to cleavage. The photopolymerization initiator may be used alone or in combination of two or more types. When two or more types of photopolymerization initiators are used in combination, it is preferable that the total amount thereof satisfies the above range.

[0048] [Plasticizer] The plasticizer does not itself undergo photocuring by irradiation with light, but gives flexibility to the cured resin layer after photocuring. For example, polyisoprene-based plasticizers, polyether-based plasticizers, polybutadiene-based plasticizers, phthalate-based plasticizers, adipate-based plasticizers, etc. can be used. Specific examples of polyisoprene-based plasticizers include LIR-30 and LIR-50 (all manufactured by Kuraray Co., Ltd.), EPOL (manufactured by Idemitsu Kosan Co., Ltd.), etc. Specific examples of polyether-based plasticizers include P-3000 (manufactured by ADEKA Co., Ltd.), etc. Specific examples of polybutadiene-based plasticizers include HLBH-P2000, HLBH-P3000, LBH-P2000, LBHP3000, LBH-P5000 (all manufactured by Cray Valley Co., Ltd.), etc.

[0049] In the photocurable resin composition, the content of the plasticizer is preferably 5 to 70% by mass, more preferably 10 to 70% by mass, and further preferably 15 to 50% by mass. The plasticizer may be used alone or in combination of two or more kinds. When two or more kinds of plasticizers are used in combination, it is preferable that the total amount thereof satisfies the above range.

[0050] [Other ingredients] The photocurable resin composition may further contain other components in addition to the above-mentioned components, as long as the effects of the present technology are not impaired. For example, inorganic fine particles, a tackifier, etc. may be included.

[0051] The photocurable resin composition may contain inorganic fine particles for the purpose of adjusting the refractive index of at least one of the first resin composition 6 and the second resin composition 8. For example, the inorganic fine particles may be silica particles whose surfaces are modified with alkylsilyl groups. As the alkylsilyl group, a monoalkylsilyl group, a dialkylsilyl group, or a trialkylsilyl group may be used. The shape of the inorganic fine particles may be, for example, spherical, elliptical, flat, rod-like, or fibrous. The average particle diameter of the inorganic fine particles is preferably, for example, 1 to 1000 nm, taking into consideration dispersibility in the photocurable resin composition. The specific surface area of ​​the inorganic fine particles (BET adsorption method) may be, for example, 50 to 400 m. 2 / g.

[0052] The tackifier imparts flexibility to the cured resin layer formed from the photocurable resin composition, and further improves the initial adhesive strength (so-called tackiness) of the cured resin layer. Examples of the tackifier that can be used include terpene resins such as terpene resins, terpene phenol resins, and hydrogenated terpene resins; rosin resins such as natural rosin, polymerized rosin, rosin ester, and hydrogenated rosin; and petroleum resins such as polybutadiene and polyisoprene.

[0053] The photocurable resin composition preferably has a transmittance of more than 90%, which can improve the visibility of the image formed on the image display member 2 when the cured resin layer 1 is formed.

[0054] The refractive index of the photocurable resin composition is preferably approximately equal to the refractive index of the image display member 2 and the light-transmitting member 3, and is preferably, for example, from 1.45 to 1.55. This can increase the brightness and contrast of the image light from the image display member 2, thereby improving visibility.

[0055] The photocurable resin composition can be prepared by uniformly mixing the above-mentioned components according to a known mixing method. EXAMPLES

[0056] An embodiment of the present technology will be described below.

[0057] [(Meth)acrylate resin] UC-203: Isoprene oligomer, manufactured by Kuraray UV3700B: Urethane acrylate oligomer, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.

[0058] [Monofunctional monomer] ISTA: Isostearyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. M-111: Nonylphenol EO modified acrylate, manufactured by Toagosei Co., Ltd. M-113: Nonylphenol EO modified acrylate, manufactured by Toagosei Co., Ltd. M-117: Nonylphenol PO modified acrylate, manufactured by Toagosei Co., Ltd. M-120: 2-Ethylhexyl EO modified acrylate, manufactured by Toagosei Co., Ltd. M-101A: Phenol EO modified acrylate, manufactured by Toagosei Co., Ltd. M-102: Phenol EO modified acrylate, manufactured by Toagosei Co., Ltd. M-106: o-Phenylphenol EO modified acrylate, manufactured by Toagosei Co., Ltd. M-110: Paracumylphenol EO modified acrylate, manufactured by Toagosei Co., Ltd. M-140: N-acryloyloxyethylhexahydrophthalimide, manufactured by Toagosei Co., Ltd. M-5700: 2-hydroxy-3-phenoxypropyl acrylate, manufactured by Toagosei Co., Ltd. IBXA: Isobornyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. HPA: Hydroxypropyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd.

[0059] [Plasticizer] LIR-30: Isoprene polymer, manufactured by Kuraray P-3000: Polyether polyol, manufactured by ADEKA

[0060] [Polymerization initiator] Irg184: 1-hydroxycyclohexyl phenyl ketone, manufactured by BASF

[0061] [Heat residue of monofunctional monomer] The heating residue (%) of each monofunctional monomer was determined using a calorimeter (device name: Q50, manufactured by TA Instruments). Specifically, as shown in Fig. 8, 10 mg of monofunctional monomer 13 was placed in a container 12, and the mass of the monofunctional monomer 13 was measured before and after heating at 60°C for 30 minutes.

[0062] [Preparation of Photocurable Resin Composition] The components were uniformly mixed in the amounts (parts by mass) shown in Table 1 to prepare photocurable resin compositions.

[0063] [Viscosity of photocurable resin composition] The viscosity of the photocurable resin composition at 25° C. or 80° C. was measured using a rheometer (RS600, manufactured by HAAKE, cone angle C35 / 2°).

[0064] [Refractive index of photocurable resin composition] The refractive index of each photocurable resin composition after heating at 80° C. for 3 hours and the refractive index before heating were measured using an Abbe refractometer (sodium D line (585 nm), 25° C.).

[0065] [Heating Residue of Photocurable Resin Composition] The heating residue (%) of each photocurable resin composition was determined using a calorimeter (device name: Q50, manufactured by TA Instruments). Specifically, as shown in Fig. 9, 10 mg of the photocurable resin composition 15 was placed in a container 14, and the photocurable resin composition 15 was heated at 80°C for 3 hours, and the mass was measured before and after the measurement.

[0066] [Adhesion strength when photocurable resin composition is not heated] 10 and 11, a photocurable resin composition was dropped onto the center of a 1.1 mm thick glass plate 16, and a 1.1 mm thick glass plate 17 was placed perpendicularly to the glass plate 16 via a 0.15 mm spacer 19. In this way, a glass joined body 20 was obtained in which a resin composition layer 18 having a diameter of 6 mm and a thickness of 0.15 mm was formed between the glass plates 16 and 17.

[0067] As shown in FIG. 12 and FIG. 13, an ultraviolet irradiator 9 was used to irradiate the light with an integrated light amount of 5000 mJ / cm 2 2 The resin composition layer 18 was cured by irradiating it with ultraviolet light 10 from the glass plate 17 side so as to form a cured resin layer 21.

[0068] 14, the glass plates 16 and 17 of the glass bonded body 20 were fixed by jigs 22A and 22B, and were pressed vertically from the jig 22B side at a speed of 5 mm / min, and the bonding state was evaluated according to the following criteria. A load tester (JSV-1000, manufactured by Japan Measurement Systems Co., Ltd.) was used to measure the bonding strength. The bonding strength was calculated by measuring the stress required for the glass plates 16 and 17 to separate at 25°C and dividing the stress by the unit area of ​​the cured resin layer 21.

[0069] [Adhesion strength when photocurable resin composition is heated] The adhesive strength was measured in the same manner as in the case where the photocurable resin composition described above was not heated, except that the photocurable resin composition dropped onto the glass plate 16 was one that had been heated at 80°C for 3 hours.

[0070] [Transmittance] A UV-visible spectrophotometer (Shimadzu Corporation, UV-2450) was used to measure the transmittance in the visible light region of the cured resin layer 21 in the glass bonded body 20. For practical purposes, the transmittance of the cured resin layer 21 is preferably 90% or more.

[0071] [Table 1]

[0072] The photocurable resin composition of the embodiment has a lower viscosity when heated. Therefore, even when the dam material (first resin composition) and the fill material (second resin composition) are made of resin compositions of the same components in a dam-fill process, the dam material can have a high viscosity and the fill material can have a low viscosity.

[0073] In addition, the photocurable resin composition of the embodiment contains a monofunctional monomer that has a heating residue of 95.0% or more after heating at 60°C for 30 minutes, and has a heating residue of 95.0% or more after heating at 80°C for 3 hours. Therefore, it was found that the adhesive strength is good even when the curable resin composition is heated in advance. This makes it possible to suppress the volatilization of the components in the fill material when heating the fill material in, for example, a dam fill process, and to improve the adhesion between the members.

[0074] On the other hand, in Comparative Examples 1 and 2, which used a resin composition with a heating residue of less than 95.0% after heating at 80°C for 3 hours, it was found that the adhesive strength was not good when the resin composition was heated in advance. Therefore, for example, in a dam fill process, when the fill material is heated, the volatilization of the components in the fill material cannot be suppressed, and it is difficult to improve the adhesion between the components. In addition, in Comparative Examples 3 and 4, a resin composition containing no monofunctional monomer and with a heating residue of 95.0% or more after heating at 60°C for 30 minutes was used as the resin composition, so it was found that the adhesive strength was not good. [Explanation of symbols]

[0075] REFERENCE SIGNS LIST 1 cured resin layer, 2 image display member, 3 light-transmitting member, 4 light-shielding layer, 5 image display device, 6 first resin composition, 7 coating area of ​​second resin composition, 8 second resin composition, 9 ultraviolet irradiator, 10 ultraviolet light, 11 liquid stopper (dam), 12 container, 13 monofunctional monomer, 14 container, 15 photocurable resin composition, 16 glass plate, 17 glass plate, 18 resin composition layer, 19 spacer, 20 glass bonded body, 21 cured resin layer, 22A, 22B jig

Claims

1. A cured resin layer used in a laminate in which a first member and a second member are laminated via a cured resin layer, The cured resin layer is formed by photocuring a first resin composition and a second resin composition, The first resin composition and the second resin composition have a viscosity at 25°C in the range of 10,000 to 50,000 mPa·s, The second resin composition is disposed on a liquid stopping portion formed from the first resin composition, The second resin composition contains 5 to 60% by mass of a monofunctional monomer, 30 to 50% by mass of a (meth)acrylate resin, and 15 to 50% by mass of a plasticizer, The monofunctional monomer has a heating residue of 95.0% or more after heating at 60° C. for 30 minutes, The second resin composition has a heating residue of 95.0% or more after heating at 80° C. for 3 hours, The cured resin layer, wherein the monofunctional monomer is at least one of a compound represented by formula (A) and a compound represented by formula (B). 【Chemistry 1】 (In formula (A), R 1 represents a hydrogen atom or a methyl group, R 2 represents an alkylene group having 2 or 3 carbon atoms, R 3 represents a hydrocarbon group, and n represents an integer of 1 to 15. In formula (B), R 4 represents a hydrogen atom or a methyl group, and R 5 represents an alkyl group having 11 to 20 carbon atoms.)

2. The cured resin layer according to claim 1 , wherein the second resin composition further contains a photopolymerization initiator.

3. The cured resin layer according to claim 1 or 2, wherein the second resin composition has a heating residue of 97.0% or more after heating at 80° C. for 3 hours.

4. The cured resin layer according to any one of claims 1 to 3, wherein the second resin composition further contains inorganic fine particles.

5. A cured resin layer used in a laminate in which a first member and a second member are laminated via a cured resin layer, The cured resin layer is formed by photocuring a first resin composition and a second resin composition, The first resin composition and the second resin composition have a viscosity at 25°C in the range of 10,000 to 50,000 mPa·s, The second resin composition is disposed on a liquid stopping portion formed from the first resin composition, The second resin composition contains 5 to 60% by mass of a monofunctional monomer, 30 to 50% by mass of a (meth)acrylate resin, and 15 to 50% by mass of a plasticizer, The monofunctional monomer has a heating residue of 95.0% or more after heating at 60° C. for 30 minutes, The second resin composition has a heating residue of 95.0% or more after heating at 80° C. for 3 hours, The monofunctional monomer is at least one of isostearyl (meth)acrylate, nonylphenol EO-modified (meth)acrylate, nonylphenol PO-modified (meth)acrylate, 2-ethylhexyl EO-modified (meth)acrylate, phenol EO-modified (meth)acrylate, o-phenylphenol EO-modified acrylate, para-cumylphenol EO-modified acrylate, N-acryloyloxyethylhexahydrophthalimide, and 2-hydroxy-3-phenoxypropyl acrylate.

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