JP2015069178A - Image display device and image display device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device manufacturing method capable of exhibiting a sufficient bonding force and reliability and simplifying manufacturing processes by active energy ray irradiation in a step before bonding a light transmission cover member to an image display member when an image display device is manufactured by stacking the image display member and the light transmission cover member arranged on a surface side of the image display member via a curable resin layer of a photocurable resin composition.SOLUTION: An image display device manufacturing method includes: a step (I) of forming a liquid photocurable resin composition containing a compound (A) having photopolymerizable functional groups, a photoinitiator (B) at a 4 to 10 mass% of the entire photocurable resin composition, and a plasticizer (C), on a light-shield-layer formation-side surface of a light transmission cover member or a light-shield-layer-side surface of an image display member; a step (II) of forming a curable resin layer by irradiating the formed photocurable resin composition with an active energy ray to cure the photocurable resin composition; and a step (III) of bonding the image display member to the light transmission cover member so that a light shield layer and the curable resin layer are interposed between the image display member and the light transmission cover member, thereby obtaining an image display device, the photocurable resin composition being irradiated with the active energy ray and cured so that a hardening rate of the curable resin layer becomes 80% or more in the step (II).

Description

  The present invention relates to an image display device and a method for manufacturing the image display device.

  An image display device such as a liquid crystal display panel used for an information terminal such as a smart phone has a photocurable resin composition between an image display member such as a liquid crystal display panel or an organic EL panel and a light transmissive cover member. After the product is disposed, the composition is produced by irradiating the composition with ultraviolet rays and curing it to form a light-transmitting cured resin layer, thereby bonding and laminating the image display member and the light-transmitting cover member ( Patent Document 1).

  By the way, since a light shielding layer is provided on the periphery of the surface of the light transmissive cover member on the image display portion side in order to improve the brightness and contrast of the display image, the space between the light shielding layer and the image display member is not provided. Curing of the photocurable resin composition sandwiched between the layers does not proceed sufficiently, so that sufficient adhesive force cannot be obtained, peeling between the light-transmitting cover member and the image display member, and moisture in the gap There is a concern that degradation of image quality and the like may occur due to the intrusion.

  Therefore, a thermal polymerization initiator is blended with the photocurable resin composition to obtain a heat and photocurable resin composition, and the heat and photocurable resin composition is formed on the surface of the light transmissive cover member on which the light shielding layer is formed. After applying the product, the coated surface is overlapped on the image display member, and after being cured by irradiating with ultraviolet rays, the entire structure is heated to heat and light curable sandwiched between the light shielding layer and the image display member. It has been proposed to thermally cure a resin composition (Patent Document 2).

  In addition, after applying a liquid photocurable resin composition containing no thermal polymerization initiator to the surface of the light-transmitting cover member including the light-shielding layer or the surface of the image display member, ultraviolet rays are irradiated in that state. A method of forming a light-transmitting cured resin layer by laminating an image display member and a light-transmitting cover member through a temporarily-cured resin layer that has been pre-cured and then irradiating with ultraviolet rays to perform main curing is proposed. (Patent Document 3).

International Publication No. 2010/027041 International Publication No. 2008/126860 Japanese Patent No. 5138820

However, according to the technology of Patent Document 2, it can be expected that the problem concerned in Patent Document 1 will be solved, but the thermal polymerization initiator is used in combination with the photopolymerization initiator, and the thermal polymerization process is performed in addition to the photopolymerization process. Since it must be carried out, there has been a problem that the burden of equipment investment for the thermal polymerization process is increased, and there is a problem that the storage stability of the heat and the photocurable resin composition is lowered.
Further, according to the technique of Patent Document 3, it can be expected that the problem concerned in Patent Document 2 is solved, but the photocurable resin composition sandwiched between the light shielding layer and the image display member is subjected to a temporary curing step. In order to perform pasting in a semi-cured state after passing through, the generation of bubbles from between the light shielding layer and the surface of the light-transmitting cover member, delamination of the light-transmitting cover and the resin, and the semi-curing resin are pasted together, the main curing Until the process is carried out, there is a concern about the displacement of the light-transmitting cover and the photocurable resin composition due to liquid floating from the photocurable resin composition. In addition, after the light-transmitting cover member and the image display member are bonded together, light curing by further ultraviolet irradiation is performed for adhesion, which increases the tact time and increases the capital investment for the main curing process. There's a problem.
In addition, in the comparative example of Patent Document 3, a composition containing 1% by mass of a photopolymerization initiator in a photocurable resin composition was temporarily cured to a curing rate of 90% on a glass plate with a light-shielding layer. Although an example in which a glass plate and a liquid crystal display element are bonded together and further cured and bonded by irradiating ultraviolet rays from the surface of the glass plate is disclosed, a good bonding state is not obtained.

  Accordingly, an object of the present invention is to solve the above-described problems of the conventional technique, and fills a space between a light-transmitting cover member such as a protective panel in the image display device and the image display member. Therefore, the active energy ray irradiation in the process before bonding the light-transmitting cover member and the image display member can provide sufficient adhesiveness and excellent reliability, and simplify the manufacturing process. An image display device manufacturing method that can be used, and an image display device.

  In order to solve the above-mentioned problems, the present inventors have conducted various studies, and as a result, a photocurable resin composition in which the content of the photopolymerization initiator is adjusted to be in a specific range, is obtained as a light containing a light shielding layer. After being formed on the surface of the transmissive cover member or the surface of the image display member, the image display member and the light transmissive cover are passed through the cured resin layer after being irradiated with ultraviolet rays and cured to a curing rate of 80% or more. By laminating the members, the photocurable resin composition between the light shielding layer and the image display member can be sufficiently cured so as to follow the step on the light-transmitting cover member or the step on the image display member. As a result, the present invention has been completed.

That is, the present invention provides the following [1] to [8].
[1] An image display member and a light-transmitting cover member having a light-shielding layer formed on the peripheral edge thereof are 4 to 10 based on the total amount of (A) the compound having a photopolymerizable functional group and the photocurable resin composition. The light-shielding layer-forming surface of the light-transmitting cover member is interposed through a light-transmitting cured resin layer formed of a photocurable resin composition containing (B) a photopolymerization initiator and (C) a plasticizer. A manufacturing method of an image display device laminated so as to be disposed on the image display member side, the manufacturing method having the following steps (I) to (III), and in step (II), a cured resin layer A method for producing an image display device, wherein the photocurable resin composition is irradiated with an active energy ray to be cured so that the curing rate is 80% or more.
Process (I): The process of forming a photocurable resin composition in the light shielding layer formation side surface of a light-transmitting cover member, or the light shielding layer side surface of an image display member.
Step (II): A step of forming a cured resin layer by irradiating the cured photocurable resin composition with an active energy ray and curing it.
Step (III): The image display member and the light transmissive cover member are bonded together so that the light shielding layer and the cured resin layer are interposed between the image display member and the light transmissive cover member. Obtaining a device;
[2] In step (I), the photocurable resin composition is applied to the entire surface of the light-shielding layer forming side surface of the light-transmitting cover member or the light-shielding layer forming side surface of the image display member, including the surface of the light-shielding layer. The method for producing an image display device according to [1], wherein the curable resin composition is formed to be flat.
[3] The method for manufacturing an image display device according to [1] or [2], wherein in the step (I), the photocurable resin composition is formed so as to embed a light shielding layer.
[4] The image according to any one of [1] to [3], wherein in the step (I), the layer of the photocurable resin composition is formed with a thickness of ⁶ μm to 1.5 × 10 ³ μm. A method for manufacturing a display device.
[5] The image display device according to any one of [1] to [4], wherein the image display member is a liquid crystal display panel, an organic EL display panel, a plasma display panel, a touch panel, or a parallax barrier panel. Production method.
[6] The image display device according to any one of [1] to [5], wherein (A) the compound having a photopolymerizable functional group contains a photoradically polymerizable poly (meth) acrylate as a main component. Production method.
[7] The method for producing an image display device according to any one of [1] to [6], wherein the photocurable resin composition contains a liquid rubber-based (meth) acrylate.
[8] An image display device manufactured by the manufacturing method according to any one of [1] to [7].

  According to the manufacturing method of the present invention, the light-transmitting cover member and the image display member are suitable for filling a space between the light-transmitting cover member such as a protective panel in the image display device and the image display member. Manufacturing method of an image display device and an image display device capable of exhibiting sufficient adhesiveness and excellent reliability and simplifying the manufacturing process by irradiation with active energy rays in the process before bonding Can be provided.

It is a figure explaining one example of process (I) of the manufacturing method of the apparatus for image displays of this invention. It is a figure explaining one example of process (I) of the manufacturing method of the apparatus for image displays of this invention. It is a figure explaining one example of process (II) of the manufacturing method of the apparatus for image displays of this invention. It is a figure explaining one example of process (III) of the manufacturing method of the apparatus for image displays of this invention. It is a figure explaining one example of process (I) of the manufacturing method of the apparatus for image displays of this invention. It is a figure explaining one example of process (II) of the manufacturing method of the apparatus for image displays of this invention. It is a figure explaining one example of process (III) of the manufacturing method of the apparatus for image displays of this invention. It is explanatory drawing of the adhesive force test of a light transmissive cured resin layer.

Hereinafter, the manufacturing method of the image display device of the present invention will be described in detail by embodiments. In addition, this invention is not limited by this embodiment.
In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

[Photocurable resin composition]
The photocurable resin composition (hereinafter, also simply referred to as “resin composition”) used in the present invention includes (A) a compound having a photopolymerizable functional group, (B) a photopolymerization initiator, and (C) a plasticizer. And the content of the component (B) is 4 to 10% by mass.

<(A) Compound having a photopolymerizable functional group>
The compound (A) having a photopolymerizable functional group used in the present invention (hereinafter sometimes referred to as “component (A)”) is not particularly limited as long as it is photocurable, and (meth) acryloyl. A compound having an ethylenically unsaturated bond that can be cured by a photopolymerization initiator that generates radicals, such as a group, a vinyl group, or an allyl group; cured by a photoacid generator that generates an acid, such as an epoxy group or an oxetane group A compound containing a possible cyclic ether group is preferred, but from the viewpoint of curability, transparency and reliability, a compound containing an ethylenically unsaturated bond is preferred, and a compound containing a (meth) acryloyl group is more preferred. Moreover, although it is preferable that (A) component contains radically photopolymerizable poly (meth) acrylate as a main component, it is not restricted to this.
In the present specification, “(meth) acrylate” means “acrylate” and “methacrylate” corresponding thereto. Similarly, “(meth) acryl” means “acryl” and “methacryl” corresponding thereto, and “(meth) acryloyl” means “acryloyl” and corresponding “methacryloyl”.

(Compound containing (meth) acryloyl group)
Examples of the compound containing a (meth) acryloyl group include a polymer having a (meth) acryloyl group in the molecule (hereinafter also referred to as “component (A1)”), and a single molecule having one (meth) acryloyl group in the molecule. (Hereinafter also referred to as “component (A2)”), from the viewpoint of adjusting the viscosity of the resin composition, reducing the shrinkage of curing and increasing the tackiness and improving the adhesion, the component (A1) and It is preferable to use the component (A2) in combination. Compared to the case where only the component (A1) is used, it is considered that the adhesiveness can be improved by using the component (A2) together, and the component (A1) compared to the case where only the component (A2) is used. It is considered that the curing shrinkage rate of the resin composition can be reduced by using together.
Further, as the (meth) acryloyl component, components other than the components (A1) and (A2) may be used in combination, but it is preferable to use only the components (A1) and (A2).
Hereinafter, the component (A1) and the component (A2) will be described.

[(A1) component: a polymer having a (meth) acryloyl group in the molecule]
Examples of the polymer having a (meth) acryloyl group in the molecule as the component (A1) include a polyester oligomer having a (meth) acryloyl group, a urethane polymer having a (meth) acryloyl group, and a polyethylene glycol mono (meth). Acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol mono (meth) acrylate, polypropylene glycol di (meth) acrylate, butadiene polymer having (meth) acryloyl group, isoprene polymer having (meth) acryloyl group, etc. It is done.
Among these, an isoprene polymer having a (meth) acryloyl group is preferable from the viewpoint of transparency, yellowing resistance, and balance of various properties.

  As the isoprene polymer having a (meth) acryloyl group, for example, a compound represented by the following general formula (1) is preferable.

In the general formula (1), m represents a number of 50 to 1000, n is a number of 1 to 5, R ¹ represents a hydrogen atom or a methyl group.
m is 50 to 1000, preferably 100 to 800, more preferably 150 to 700, and still more preferably 200 to 600.
Although n is 1-5, Preferably it is 1.5-4.0, More preferably, it is 2.0-3.5, More preferably, it is 2.0-3.0.
Commercially available products of the compound represented by the general formula (1) include UC-102 and UC-203 (both product names) which are esterified products of a polyisoprene polymer maleic anhydride adduct and 2-hydroxyethyl methacrylate. , Manufactured by Kuraray Co., Ltd.).

The average number of functional groups in the component (A1) is preferably 1.5 or more, more preferably 2.0 or more, and preferably 4.0 from the viewpoint of further reducing the curing shrinkage and elastic modulus of the resin composition. Hereinafter, more preferably 3.5 or less, and still more preferably 3.0 or less.
The “functional group number” indicates the number of functional groups ((meth) acryloyl group) in one molecule of the component (A1), and the “average functional group number” indicates the number of functional groups per molecule in the entire component (A1). The average value is shown.

The number average molecular weight (Mn) of the component (A1) is preferably 1.0 × 10 ⁴ or more, more preferably 1.25, from the viewpoints of viscosity after blending, workability, toughness of the cured product, and elastic modulus. × 10 ⁴ or more, more preferably 1.5 × 10 ⁴ or more, and preferably 1.0 × 10 ⁵ or less, more preferably 5.0 × 10 ⁴ or less, still more preferably 4.0 × 10 ^4. Hereinafter, it is particularly preferably 3.0 × 10 ⁴ or less, and very preferably 2.0 × 10 ⁴ or less.

In the present specification, the molecular weight is a value measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve, specifically a value measured by the method described below. .
<Molecular weight measurement>
The number average molecular weight (Mn) is measured based on the following method.
The determination is carried out using gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and a calibration curve is prepared using polystyrene as a standard substance.
In preparing the calibration curve, 5 sample sets (PStQuickMP-H, PStQuick B [trade name, manufactured by Tosoh Corporation]) are used as standard polystyrene.
Apparatus: High-speed GPC apparatus HCL-8320GPC (detector: differential refractometer or UV)
(Product name, manufactured by Tosoh Corporation)
Solvent: Tetrahydrofuran (THF)
Column: Column TSKGEL SuperMultipore HZ-H
(Product name, manufactured by Tosoh Corporation)
Column size: Column length is 15 cm, column inner diameter is 4.6 mm
Measurement temperature: 40 ° C
Flow rate: 0.35 ml / min Sample concentration: 10 mg / THF 5 ml
Injection volume: 20 μl
Further, the number average molecular weight, the weight average molecular weight, and the degree of dispersion are defined as follows.
(A) Number average molecular weight (Mn)
Mn = Σ (N _i M _i ) / ΣN _i = ΣX _i M _i
(X _i = Mole fraction of molecules with molecular weight M _i = N _i / ΣN _i )
(B) Weight average molecular weight (Mw)
Mw = Σ (N _i M _i ² ) / ΣN _i M _i = ΣW _i M _i
(W _i = weight fraction of molecules of molecular weight M _i = N _i M _i / ΣN _i M _i )
(C) Molecular weight distribution (dispersion degree)
Dispersity = Mw / Mn

The content of the component (A1) in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably, based on the total amount of the resin composition, from the viewpoint of reliability and curability. From the viewpoint of curing shrinkage and elastic modulus, it is preferably 55% by mass or less, more preferably 40% by mass or less, and further preferably 25% by mass or less.
If content of (A1) component is 5 mass% or more, while being able to improve the sclerosis | hardenability of a resin composition, the adhesiveness and reliability of hardened | cured material can be made favorable. On the other hand, when the content of the component (A1) is 55% by mass or less, the curing shrinkage rate is good and the elastic modulus of the cured product is not excessively increased, which is preferable.

[(A2) component: a monomer having one (meth) acryloyl group in the molecule]
The monomer having one (meth) acryloyl group in the molecule as the component (A2) is preferably liquid at room temperature (25 ° C.) and is represented by the following general formula (2) (meta ) More preferably an acrylate, more preferably a compound having either a dicyclopentanyl group, a dicyclopentenyl group or an isobornyl group in the molecule, and a compound having a dicyclopentenyl group or an isobornyl group in the molecule. Is particularly preferable, and a compound having a dicyclopentenyl group in the molecule is very preferable. These plural types of compounds may be used alone or in combination.

In the general formula (2), R ² represents a hydrogen atom or a methyl group, and R ³ represents an alkyl group having 4 to 20 carbon atoms. From the viewpoint of imparting more flexibility, R ³ is preferably an alkyl group having 6 to 18 carbon atoms, more preferably an alkyl group having 8 to 16 carbon atoms.

Examples of the (meth) acrylate represented by the general formula (2) include n-butyl (meth) acrylate, tert-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, n -Octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, n-hexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) ) Alkyl (meth) acrylates such as acrylate; 2-hydroxyethyl (meth) acrylate, 1-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate Hydroxyl groups such as 1-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 1-hydroxybutyl (meth) acrylate, etc. (Meth) acrylates; (meth) acrylamides such as dimethyl (meth) acrylamide, isopropyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide; hydroxyl-containing (meth) acrylamides such as hydroxyethyl (meth) acrylamide; diethylene glycol and triethylene Polyethylene glycol mono (meth) acrylates such as glycol; polypropylene glycol mono (meth) acrylates such as dipropylene glycol and tripropylene glycol; Polybutylene glycol mono (meth) acrylates such as butylene glycol and tributylene glycol; morpholine group-containing (meth) acrylates such as acryloylmorpholine; dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate And dicyclopentenyloxyethyl methacrylate, isobornyl (meth) acrylate, and the like.
These compounds may be used alone or in combination of two or more.
Among these, from the viewpoint of optical properties, liquid floating, adhesive strength, wet heat resistance and tackiness after curing, (meth) acrylate having a dicyclopentanyl group, a dicyclopentenyl group, or an isobornyl group is preferable. A (meth) acrylate having a dicyclopentenyl group or an isobornyl group is more preferable, and a (meth) acrylate having a dicyclopentenyl group is still more preferable. These plural types of compounds may be used alone or in combination.

The content of the component (A2) in the resin composition is the total amount of the resin composition from the viewpoint of obtaining a resin composition having an appropriate viscosity, the viewpoint of adjusting the curing shrinkage rate, and the transparency of the cured product. On the other hand, it is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more, and the total amount of the resin composition from the viewpoint of adjustment of the curing shrinkage rate and the elastic modulus of the cured product. Is preferably 40% by mass or less, more preferably 35% by mass or less, and still more preferably 30% by mass or less.
When the content of the component (A2) is 10% by mass or more, a resin composition having an appropriate viscosity can be obtained, workability such as coating can be improved, and the curing shrinkage rate is lowered. be able to. Moreover, transparency of hardened | cured material can be improved.
If the content of the component (A2) is 40% by mass or less, the curing shrinkage rate and the elastic modulus can be prevented from becoming too high, and when used in an image display device, display unevenness and module warpage are suppressed. Occurrence can be suppressed.
The ratio of the component (A1) to the component (A2) is preferably at least 0.1, more preferably at least 0.2, even more preferably at least 0.3, particularly preferably at a mass ratio (A1) / (A2). 0.4 or more, very preferably 0.5 or more, and preferably 5.5 or less, more preferably 4.0 or less, still more preferably 3.0 or less, particularly preferably 2.0 or less, very preferably Is 1.0 or less.

  The content of the component (A) is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, and particularly preferably 40% by mass or more with respect to the total amount of the resin composition. And, it is preferably 90% by mass or less, more preferably 70% by mass or less, still more preferably 60% by mass or less, and particularly preferably 50% by mass or less.

(Compounds having a vinyl group and compounds having an allyl group)
Examples of the compound having a vinyl group and the compound having an allyl group include styrene, divinylbenzene, vinylpyrrolidone, triallyl isocyanurate, 1,2-polybutadiene, and the like. These may be used alone or in combination of two or more.

(Compound containing cyclic ether group)
Examples of the compound containing a cyclic ether group include compounds containing a cyclic ether group that can be cured with a photoacid generator that generates an acid, such as an epoxy group or an oxetane group. For example, as a compound containing an epoxy group, bifunctional or polyfunctional aromatic glycidyl ether such as bisphenol A type epoxy resin, bifunctional or polyfunctional aliphatic glycidyl ether such as polyethylene glycol type epoxy resin, hydrogenated bisphenol A type epoxy resin 2 such as bifunctional alicyclic glycidyl ether such as phthalic acid, difunctional glycidyl ester such as diglycidyl phthalate, bifunctional alicyclic glycidyl ester such as tetrahydrophthalic acid diglycidyl ester, N, N-diglycidyl aniline, etc. Bifunctional alicyclic epoxy resins such as functional or polyfunctional aromatic glycidyl amines and alicyclic diepoxycarboxylates, bifunctional heterocyclic epoxy resins, polyfunctional heterocyclic epoxy resins, bifunctional or polyfunctional silicon-containing epoxies Resin etc. are mentioned. Examples of oxetane resins include 2-ethylhexyl oxetane, xylylene bisoxetane, 3-hydroxymethyl oxetane, 3-ethyl-3-hydroxymethyl oxetane (oxetane alcohol), 3-ethyl-3 {[((3-ethyl Oxetane-3-yl) methoxy] methyl} oxetane and the like. These may be used alone or in combination of two or more.

<(B) Photopolymerization initiator>
The photocurable resin composition of the present invention contains (B) a photopolymerization initiator (hereinafter sometimes referred to as “component (B)”).
There are no particular limitations on the photopolymerization initiator, and known materials such as benzophenone-based, anthraquinone-based, benzoyl-based, sulfonium salts, diazonium salts, and onium salts can be used.

  Examples of photopolymerization initiators that generate radicals by irradiation with active energy rays such as ultraviolet rays, electron beams, α rays, β rays, and γ rays to accelerate the curing reaction of the resin composition include, for example, benzophenone, N, N ′ -Tetramethyl-4,4'-diaminobenzophenone (Michler ketone), N, N-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4,4'-dimethylaminobenzophenone, α-hydroxyisobutylphenone, 2- Ethyl anthraquinone, tert-butylanthraquinone, 1,4-dimethylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 1,2-benzoanthraquinone, 2-phenylanthraquinone, 1, 4-naphthoquinone, 9,10-phenanthraquino Aromatic ketone compounds such as thioxanthone, 2-chlorothioxanthone, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 2,2-diethoxyacetophenone; benzoin compounds such as benzoin, methylbenzoin, and ethylbenzoin Benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether and benzoin phenyl ether; benzyl compounds such as benzyl and benzyldimethyl ketal; ester compounds such as β- (acridin-9-yl) (meth) acrylic acid; Acridine compounds such as 9-phenylacridine, 9-pyridylacridine, 1,7-diacridinoheptane; 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophene); Nyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5 -Diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) 5-phenylimidazole dimer, 2- (2, 2,4,5-triarylimidazole dimers such as 4-dimethoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methylmercaptophenyl) -4,5-diphenylimidazole dimer; 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpho Alkyl-1-phenone compounds such as 1-propane; 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl ] -2-Hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl -Α-hydroxyalkylphenone compounds such as propan-1-one and oligo {2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone}; phenylglyoxylic acid methyl ester; Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybe Nzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and other phosphine oxide compounds. Of these, aromatic ketone compounds, phenylglyoxylic acid methyl esters or α-hydroxyalkylphenone compounds are preferred, and phosphine oxide compounds are more preferred from the viewpoints of curability and reactivity.

In addition, when a compound containing a cyclic ether group such as an epoxy group or an oxetane group is used, examples of the photopolymerization initiator (also referred to as a photoacid generator) that generate an acid upon irradiation with active energy rays include, for example, aryldiazonium salts , Diaryliodonium salts, triarylsulfonium salts, triarylselenonium salts, dialkylphenazylsulfonium salts, dialkyl-4-hydroxyphenylsulfonium salts, sulfonic acid esters and the like.
These (B) photopolymerization initiators can be used alone or in combination of two or more.

In this invention, content of (B) component is 4-10 mass% with respect to the total amount of a resin composition. When the content of the component (B) is less than 4% by mass, the curing reaction cannot be sufficiently promoted on the surface of the coating film in the presence of oxygen, and a cured product may not be obtained. On the other hand, when the content of the component (B) exceeds 10% by mass, the tackiness tends to decrease, which is not preferable.
The content of the component (B) is 4% by mass or more and 10% by mass or less with respect to the total amount of the resin composition. From the above viewpoint, it is preferably 4.5% by mass or more, more preferably 5% by mass or more. More preferably 5.2% by mass or more, particularly preferably 5.4% by mass or more, very preferably 5.5% by mass or more, and preferably 9% by mass or less, more preferably 8% by mass or less, More preferably, it is 7.5 mass% or less, Most preferably, it is 7 mass% or less, Most preferably, it is 6.5 mass% or less.
The ratio of the component (A) to the component (B) is preferably at least 0.05, more preferably at least 0.07, even more preferably at least 0.08, and even more preferably at a mass ratio (B) / (A). 0.09 or more, particularly preferably 0.1 or more, very preferably 0.12 or more, and preferably 0.9 or less, more preferably 0.5 or less, still more preferably 0.3 or less, and even more It is preferably 0.25 or less, particularly preferably 0.2 or less, and very preferably 0.14 or less.

<(C) component: plasticizer>
The plasticizer used as the component (C) in the present invention has substantially no (meth) acryloyl group. Moreover, it is preferable that it is a liquid component at 25 degreeC from a viewpoint which suppresses precipitation of the plasticizer by workability | operativity at the time of photocurable resin composition preparation, recrystallization, etc.

Examples of the component (C) include butadiene rubber, isoprene rubber, silicon rubber, styrene butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, ethylene propylene rubber, urethane rubber, acrylic rubber, chlorosulfonated polyethylene rubber, fluorine rubber, hydrogen Liquefied nitrile rubber, epichlorohydrin rubber liquid; poly α-olefin such as polybutene; hydrogenated α-olefin oligomer such as hydrogenated polybutene; polyvinyl oligomer such as atactic polypropylene; aromatic oligomer such as biphenyl and triphenyl;
Hydrogenated polyene oligomers such as hydrogenated liquid polybutadiene; Paraffin oligomers such as paraffin oil and chlorinated paraffin oil; Cycloparaffin oligomers such as naphthene oil;
Dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di- (2-ethylhexyl) phthalate, di-n-octyl phthalate, diisobutyl phthalate, diheptyl phthalate, diphenyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, di (heptyl, Nonyl, undecyl) phthalate, benzyl phthalate, butyl benzyl phthalate, dinonyl phthalate, dicyclohexyl phthalate, and other phthalic acid derivatives; dimethyl isophthalate, di- (2-ethylhexyl) isophthalate, diisooctyl isophthalate, and other isophthalic acid derivatives; Di- (2-ethylhexyl) tetrahydrophthalate, di-n-octyltetrahydrophthalate, diisodecyltetrahydrophthalate Adipic acid derivatives such as di-n-butyl adipate, di (2-ethylhexyl) adipate, diisodecyl adipate, diisononyl adipate; di- (2-ethylhexyl) azelate, diisooctyl azelate, di-n -Azelaic acid derivatives such as hexyl azelate;
Sebacic acid derivatives such as di-n-butyl sebacate and di- (2-ethylhexyl) sebacate; maleic acid derivatives such as di-n-butyl malate, dimethyl malate, diethyl maleate and di- (2-ethylhexyl) malate; Fumaric acid derivatives such as n-butyl fumarate and di- (2-ethylhexyl) fumarate; tri- (2-ethylhexyl) trimellitate, tri-n-octyl trimellitate, triisodecyl trimellitate, triisooctyl trimellitate Trimellitic acid derivatives such as tate, tri-n-hexyl trimellitate, triisononyl trimellitate; pyromellitic acid derivatives such as tetra- (2-ethylhexyl) pyromellitate, tetra-n-octyl pyromellitate; triethylcyto Rate, tri-n-butyl citrate, Citric acid derivatives such as cetyltriethyl citrate and acetyl tri- (2-ethylhexyl) citrate; monomethyl itaconate, monobutyl itaconate, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, di- (2-ethylhexyl) itaconate, etc. Itaconic acid derivatives; oleic acid derivatives such as butyl oleate, glyceryl monooleate, diethylene glycol monooleate; ricinoleic acid derivatives such as methyl acetyl ricinolate, butyl acetyl ricinolate, glyceryl mono ricinolate, diethylene glycol mono ricinolate; n-butyl stearate Stearic acid derivatives such as glycerol monostearate, diethylene glycol distearate; diethylene glycol monolaurate, diethylene glycol Other fatty acid derivatives such as coledipelargonate, pentaerythritol fatty acid ester; triethyl phosphate, tributyl phosphate, tri- (2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate, Phosphoric acid derivatives such as trixylenyl phosphate, tris (chloroethyl) phosphate; diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, triethylene glycol di- (2-ethylbutyrate), triethylene glycol di- (2-ethylhexoate), glycol derivatives such as dibutylmethylenebisthioglycolate; glycerol monoacetate Examples thereof include glycerin derivatives such as tate, glycerol triacetate, and glycerol tributyrate, and epoxy derivatives such as epoxidized soybean oil, epoxyisohydrophthalate diisodecyl, epoxy triglyceride, epoxidized octyl oleate, and epoxidized oleate decyl.
These compounds can be used alone or in combination of two or more.

  Among these, when an isoprene polymer containing a (meth) acryloyl group is used as the component (A1), butadiene rubber and isoprene rubber are used from the viewpoints of volatility, viscosity, workability, yellowing resistance, compatibility and heat resistance. , Poly α-olefin, hydrogenated α-olefin oligomer and di- (2-ethylhexyl) sebacate are preferred, and butadiene rubber and butadiene rubber having a hydroxyl group at the terminal are more preferred.

The number average molecular weight of the component (C) is preferably 3.5 × 10 ² or more, more preferably 4.0 × 10, from the viewpoint of adjusting the optical properties and viscosity of the plasticizer and adjusting the viscosity of the resin composition. ² or more, more preferably 5.0 × 10 ² or more, particularly preferably 8.0 × 10 ² or more, and preferably 3.0 from the viewpoint of the volatility of the plasticizer and the viscosity adjustment of the resin composition. × 10 ⁴ or less, more preferably 1.0 × 10 ⁴ or less, still more preferably 5.0 × 10 ³ or less, and particularly preferably 3.5 × 10 ³ or less.
If the number average molecular weight of (C) component is 3.5 * 10 < ² > or more, volatilization of a plasticizer can be suppressed. And if the number average molecular weight of (C) component is 3.0 * 10 < ⁴ > or less, it can suppress that the viscosity of a plasticizer becomes high too much and the cloudiness of a plasticizer.

The content of the component (C) is preferably 20% by mass or more, more preferably 30% by mass or more, and still more preferably with respect to the total amount of the resin composition from the viewpoint of adjusting the elastic force of the cured product to an appropriate range. Is 35% by mass or more, particularly preferably 40% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, still more preferably 65% by mass or less, particularly preferably 60% by mass or less. .
If content of (C) component is 20 mass% or more, generation | occurrence | production of the curvature by an elastic modulus becoming high too much can be suppressed. And if content of (C) component is 80 mass% or less, the fall of the adhesive force and reliability by an elasticity modulus becoming too low can be suppressed.

<Other additives>
The resin composition of the present invention can further contain other additives as long as the effects of the present invention are not impaired.
Other additives include general adhesion improvers such as silane coupling agents, thermal polymerization initiators, moisture curing agents, antioxidants, thixotropic agents, chain transfer agents, stabilizers, and photosensitizers. Additives can be included.

(D component: antioxidant)
Among these, the antioxidant (D component) can be used for the resin composition of this invention from a viewpoint which can suppress liquid floating and yellowing. Preferable embodiments of the antioxidant include (D1) compounds having a hindered phenol structure, amine-based, phosphorus-based, sulfur-based, hydrazine-based, and amide-based compounds. Among these, (D1) a compound having a hindered phenol structure is more preferable from the viewpoint of suppressing bleed-out, and among the compounds having a hindered phenol structure from the viewpoint of suppressing yellowing (D1 ′ ) Use of a hindered phenol compound having a thioether structure (hindered phenol-thioether compound) is preferable, or a compound having a hindered phenol structure and a sulfur compound are more preferably used in combination. As the sulfur compound used in combination, it is more preferable to use a compound (D2) having a thioether structure described later.

[(D1) component: a compound having a hindered phenol structure)]
(D1) As the compound having a hindered phenol structure, a compound represented by the following general formula (3) is preferably used. From the viewpoint of further suppressing yellowing, among the components (D1), a hindered phenol compound (hindered phenol-thioether compound) having a (D1 ′) thioether structure represented by the following general formula (4): It is preferable to use it.

In General Formula (3), R ⁵ represents a tert-butyl group or —CH ₂ —S—R ^a , R ⁴ represents an alkyl group having 1 to 5 carbon atoms or —CH ₂ —S—R ^a , R ^A plurality of ⁴ may be present as independent substituents. Moreover, n shows the integer of 1-4. A represents an n-valent organic group. Further, the R ^a represents an alkyl group having 1 to 20 carbon atoms.

In General Formula (4), R ⁶ represents an alkyl group having 1 to 5 carbon atoms, and R ⁷ and R ⁸ each independently represents an alkyl group having 1 to 20 carbon atoms.

  Examples of the compound having the (D1) hindered phenol structure include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-hydroxyphenyl) propionate] (IRGANOX 1010 manufactured by BASF Japan Ltd.), thiodiethylene. Bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (IRGANOX1035 manufactured by BASF Japan Ltd.), octadecyl-3- (3,5-di-tert-butyl-4-hydroxy Phenyl) propionate (IRGANOX1076 manufactured by BASF Japan Ltd.), N, N′-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionamide] (BASF Japan) IRGAN made by X1098), benzenepropanoic acid, 3,5-bis (1,1-dimethylethyl) -4-hydroxy, C7-C9 side chain alkyl ester (IRGANOX1135 manufactured by BASF Japan Ltd.), 2,4-dimethyl-6 (1-methylpentadecyl) phenol (IRGANOX1141 manufactured by BASF Japan K.K.), diethyl [{3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl} methyl] phosphonate (manufactured by BASF Japan K.K.) IRGANOX1222), 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ″-(mesitylene-2,4,6-triyl) tri-p-cresol ( BASF Japan Co., Ltd. IRGANOX 1330), calcium diethylbis [[[3,5-bis (1,1- (Methylethyl) -4-hydroxyphenyl] methyl] phosphonate] and polyethylene wax (IRGANOX1425WL manufactured by BASF Japan Ltd.), 4,6-bis (octylthiomethyl) -o-cresol (IRGANOX1520L manufactured by BASF Japan Ltd.) ), Ethylenebis (oxyethylene) bis [3- (tert-butyl-4-hydroxy-m-tolyl) propionate] (IRGANOX245 manufactured by BASF Japan Ltd.), 1,6-hexanediol-bis [3 (3 5-Di-tert-butyl-4-hydroxyphenyl) propionate] (IRGANOX259 manufactured by BASF Japan Ltd.), 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanuric acid (BASF Japan IRGANOX 3114), 1,3,5-tris [(4-tert-butyl-3-hydroxy-2,6-xylyl) methyl] -1,3,5-triazine-2,4,6 1H, 3H, 5H) -trione (IRGANOX3790 manufactured by BASF Japan Ltd.), reaction product of N-phenylbenzenamine and 2,4,4-trimethylpentene (IRGANOX5057 manufactured by BASF Japan Ltd.), 6- ( 4-hydroxy-3-5-di-tert-butylanilino) -2,4-bisoctylthio-1,3,5-triazine (IRGANOX565 manufactured by BASF Japan Ltd.), 1,3,5-tris (3 5-di-tert-butyl-4-hydroxybenzyl) isocyanuric acid (ADEKA STAB AO-20 manufactured by ADEKA Corporation), 1,1, -Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane (ADEKA STAB AO-30 manufactured by ADEKA Corporation), 4,4'-butylidenebis (6-tert-butyl-3-methylphenol) ( (Adeka Adeka Stub AO-40), 3- (4′-hydroxy-3 ′, 5′-di-tert-butylphenyl) propionic acid-n-octadecyl (Adeka Adeka Stub AO-50), Pentaerythritol tetrakis [3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] (ADEKA STAB AO-60 manufactured by ADEKA Corporation), triethylene glycol bis [3- (3-tert -Butyl-4-hydroxy-5-methylphenyl) propionate] (ADEKA) ADK STAB AO-70), 3,9-bis [1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenylpropionyloxy] ethyl] 2,4,8,10 -Tetraoxaspiro [5,5] -undecane (ADEKA STAB AO-80 manufactured by ADEKA Corporation), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4 -Hydroxybenzyl) benzene (ADEKA STAB AO-330 manufactured by ADEKA Corporation), 2,2-oxamidobis- [ethyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (manufactured by Chemtura) Naugard XL-1), 1,1,3-tris {2-methyl-4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) pro Pionyloxy] -5-tert-butylphenyl} butane (GSY-242 manufactured by API Corporation) and the like. Among these, from the viewpoint of suppressing bleed out, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and 4,6-bis (octylthiomethyl) -o -Cresol is preferable, 4,6-bis (octylthiomethyl) -o-cresol having a thioether structure in the molecule is more preferable because it can suppress yellowing as well as bleed out, and is used in a wide range. Is a benzenepropanoic acid, 3,5-bis (1,1-dimethylethyl) -4-hydroxy, C7-C9 side chain alkyl ester that can suppress bleed-out, has low odor, and is liquid from the viewpoint of operability Is more preferable.

[(D2) component: a compound having a thioether structure]]
(D2) As the compound having a thioether structure, a compound represented by the following general formula (5) is preferably used.

In general formula (5), R ⁹ represents an alkyl group having 1 to 20 carbon atoms.

(D2) Examples of the compound having a thioether structure include didodecyl thiodipropionate (SEENOX DL manufactured by Sipro Kasei Co., Ltd., IRGANOX PS 800 FL manufactured by BASF Japan Co., Ltd., and Sumizer TPL-R manufactured by Sumitomo Chemical Co., Ltd.). ), Ditridecyl 3,3′-thiodipropionate (AO-503 manufactured by ADEKA Corporation), ditetradecylthiodipropionate (Sumitizer TPM manufactured by Sumitomo Chemical Co., Ltd.), distearyl thiodipropionate (Sumitomo Chemical) (Sumilizer TPD manufactured by Co., Ltd.).
The content in the case of containing the component (D) is preferably 0.5% by mass or more, more preferably 0.6% by mass or more, with respect to the total amount of the resin composition, from the viewpoint of further suppressing bleeding out. More preferably, it is 0.7 mass% or more, and preferably 3.0 mass% or less, More preferably, 2.7 mass% or less, More preferably, 2.5 mass% or less.
If content of (D) component is 0.5 mass% or more, yellowing of a resin composition and bleed-out can be suppressed. And if content of (D) component is 3.0 mass% or less, the fall of sclerosis | hardenability and a sensitivity can be suppressed.
In the case where the component (D1) and the component (D2) are used in combination, the ratio of the component (D1) to the component (D2) is a mass ratio (D1) / (D2), preferably 0.25 or more, more preferably. Is 0.3 or more, more preferably 0.5 or more, and is preferably 4 or less, more preferably 3 or less, still more preferably 2 or less.

(Chain transfer agent and stabilizer)
In addition, the photocurable resin composition used in the present invention can contain a stabilizer such as a chain transfer agent or triphenyl phosphite in order to adjust the molecular weight and prevent oxygen inhibition during photocuring.
Examples of the chain transfer agent include 2-mercaptoethanol, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-ethylhexyl thioglycolate, 2,3-dimethylcapto-1-propanol, α-methylstyrene dimer, 1,4- Bis (3-mercaptobutyryloxy) butane, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, Examples include thiol compounds such as pentaerythritol tetrakis (3-mercaptobutyrate).

(Organic solvent)
In addition, it is preferable that the resin composition of this invention does not contain an organic solvent (solvent) substantially from a viewpoint of suppressing heat-and-moisture resistance and the bubble generation in hardened | cured material.
In the present invention, the “organic solvent” means an organic compound that does not have a (meth) acryloyl group, is liquid at 25 ° C., and has a boiling point of 250 ° C. or less at atmospheric pressure.
Here, “substantially does not contain an organic solvent” means that an organic solvent is not intentionally added, and it is a trace amount as long as it does not significantly deteriorate the characteristics after photocuring of the resin composition of the present invention. The organic solvent may be present.
Specifically, the content of the organic solvent in the resin composition may be 1.0 × 10 ³ ppm or less, preferably 5.0 × 10 ² ppm or less, based on the total amount of the resin composition. More preferably, it is 1.0 × 10 ² ppm or less, and it is preferable that no organic solvent is contained.

<Viscosity of photocurable resin composition>
The viscosity at 25 ° C. of the resin composition of the present invention is preferably 10 mPa · s or more, more preferably 4.0 × 10 ² mPa · s or more, and further preferably 5.0 × 10 ² mPa from the viewpoint of workability. S or more, more preferably 1.0 × 10 ³ mPa · s or more, particularly preferably 2.0 × 10 ³ mPa · s or more, very preferably 3.0 × 10 ³ mPa · s or more, and , Preferably 1.0 × 10 ⁵ mPa · s or less, more preferably 5.0 × 10 ⁴ mPa · s or less, still more preferably 2.0 × 10 ⁴ mPa · s or less, and even more preferably 1.5 ×. It is 10 ⁴ mPa · s or less, particularly preferably 1.25 × 10 ⁴ mPa · s or less, and very preferably 1.0 × 10 ⁴ mPa · s or less.
In addition, the viscosity at 25 degreeC here is the value measured based on JISZ8803, and specifically, it measures with a B-type viscosity meter (Toki Sangyo Co., Ltd. product, BL2). The calibration of the viscometer can be performed based on JIS Z 8809-JS14000.
Moreover, the case where it has a viscosity of 10 mPa * s-1.5 * 10 < ⁶ > mPa * s is called liquid state.

<Curing shrinkage of photocurable resin composition>
The curing shrinkage rate of the resin composition of the present invention is preferably 4.0 from the viewpoint of further suppressing the warpage of a substrate such as a protective panel or an image display unit when used as a constituent member of an image display device. %, More preferably less than 3.5%. The curing shrinkage is more preferably less than 3.0%, and in this case, the warpage of the substrate can be sufficiently suppressed.

The cure shrinkage referred to here can be calculated from the following formula.
Curing shrinkage (%) = ((1 / liquid specific gravity) − (1 / cured product specific gravity)) / (1 / liquid specific gravity)
(Liquid specific gravity)
Using a Herbert specific gravity bottle, measure according to JIS K0061.
(Cured product specific gravity)
The resin composition prepared in each Example and each Comparative Example was dropped on a PET film whose surface was release-treated, and another sheet of PET so that the film thickness after curing of the resin composition was 1 mm. Affix the film. Then, from the one PET film side, the resin composition is cured by irradiating with an ultraviolet ray having an exposure amount of 1.0 × 10 ⁴ mJ / cm ² using the above-described ultraviolet irradiation device to produce a cured product.
Next, the PET film was peeled off, and the specific gravity measured at 25 ° C. was measured using a specific gravity meter (product name “SD-200L” manufactured by Alpha Mirage Co., Ltd.) for the test piece obtained by separating the cured product into 10 mm × 10 mm. The specific gravity of the cured product.

<Elastic modulus of cured product of photocurable resin composition>
The elastic modulus of the cured product of the resin composition of the present invention is, when used as a constituent member of an image display device, from the viewpoint of suppressing the occurrence of display unevenness by suppressing the application of local stress to the image display unit or the like. The pressure is preferably 2.0 × 10 ⁵ Pa or less, more preferably 1.5 × 10 ⁵ Pa or less, and still more preferably 1.0 × 10 ⁵ Pa or less. If the elastic modulus is 2.0 × 10 ⁵ Pa or less, it is possible to suppress the application of local stress to the image display unit that may cause display unevenness.
Further, the elastic modulus of the cured product of the resin composition of the present invention is not limited to the lower limit of the elastic modulus as long as the liquid material is not separated from the cured product or does not sag when heated, but is preferably Is 1.0 × 10 ⁴ Pa or more.
In the present invention, the cured product of the resin composition has a modulus of elasticity of a cured product having a thickness of t = 1 mm and a width of 10 mm with an autograph (product name “EZ Test, manufactured by Shimadzu Corporation) at a distance of 25 mm between chucks. )) Means the value of the tensile modulus obtained by measuring at 25 ° C.

[Method for Manufacturing Image Display Device]
The method for manufacturing an image display device according to the present invention is a method for manufacturing an image display device laminated so that a light-shielding layer is disposed between the light-transmitting cover member and the image display member, and includes the following step (I): To (III), and in step (II), the photocurable resin composition used in the present invention is irradiated with active energy rays so that the curing rate of the cured resin layer is 80% or more. This is a method for manufacturing an image display device that is cured.

  Process (I): The process of forming a photocurable resin composition in the light shielding layer formation side surface of a light-transmitting cover member, or the light shielding layer side surface of an image display member.

  Step (II): A step of forming a cured resin layer by irradiating the cured photocurable resin composition with an active energy ray and curing it.

Step (III): The image display member and the light transmissive cover member are bonded together so that the light shielding layer and the cured resin layer are interposed between the image display member and the light transmissive cover member. Obtaining a device;
Hereinafter, a preferred example of a method for manufacturing an image display device of the present invention will be described in detail for each step with reference to the drawings.

<Step (I) (resin layer forming step)>
First, as shown in FIG. 1, a light-transmitting cover member 2 having a light shielding layer 1 formed on the peripheral edge of one side is prepared, and as shown in FIG. 2, on the surface 2 a of the light-transmitting cover member 2, The photocurable resin composition 3 is formed.
Specifically, light including the surface of the light shielding layer 1 including the surface of the light shielding layer 1 is thicker than the thickness of the light shielding layer 1 so as to fill the step 4 formed by the light shielding layer 1 and the light shielding layer forming surface 2a of the light transmissive cover member 2. The photocurable resin composition 3 is formed on the entire surface of the light shielding layer forming side surface 2a of the transmissive cover member 2. The photocurable resin composition 3 is not necessarily formed so as to be flat, and includes a case where the surface of the formed resin composition 3 is not flat and is formed so as to embed a light shielding layer. Therefore, the thickness of the resin layer after the photocurable resin composition 3 is cured by irradiating active energy rays such as ultraviolet rays is preferably 6 μm or more, more preferably 15 μm or more, still more preferably 20 μm or more, particularly Preferably it is 50 μm or more, very preferably 1.0 × 10 ² μm or more, and preferably 1.5 × 10 ³ μm or less, more preferably 1.0 × 10 ³ μm or less, still more preferably 5.0. × 10 ² μm or less.

  Examples of the method for forming the photocurable resin composition 3 include screen printing, metal mask printing, general coating by a slit coater, bar coater, etc., and multi-nozzles (in which a number of nozzles of a dispenser are arranged in a row). Dispense etc. are mentioned. A cured film may be formed using one or more of these methods so as to obtain a required thickness.

The light transmissive cover member 2 only needs to be light transmissive so that an image formed on the image display member can be visually recognized, and plate-like materials such as glass, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, and polycarbonate. And sheet-like 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 light-transmitting cover member 2 can be appropriately determined according to the purpose of use. Further, the light transmissive cover member 2 may include a touch sensor layer, a parallax barrier layer for the naked eye 3D, and the like.

The light shielding layer 1 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 1 is usually 5 μm to 1.0 × 10 ² μm, and this thickness corresponds to the step 4.

<Process (II) (curing process)>
Next, as shown in FIG. 3, the light curable resin layer 5 is formed by irradiating the photocurable resin composition 3 formed in the step (I) with an active energy ray such as ultraviolet rays and curing the composition. To do.
Specifically, the curing rate (gel fraction) of the light-transmitting cured resin layer 5 is a value measured by the method shown in the examples described later, preferably 80% or more, more preferably 90% or more, 95 % Or more is more preferable.

  As long as it can be cured so that the curing rate (gel fraction) is 80% or more with respect to irradiation of active energy rays such as ultraviolet rays, there are no particular limitations on the type of light source, output, accumulated light amount, etc. The photo radical polymerization process conditions of (meth) acrylate by irradiation of active energy rays such as can be employed.

  In addition, as a waiting time for shifting from the step (I) (resin layer forming step) to the step (II) (curing step), the interval from the completion of the resin layer formation to the exposure is preferably within 60 seconds, more preferably within 30 seconds. It is preferably within 10 seconds, more preferably within 5 seconds. If the interval from application to exposure is within 60 seconds, it is possible to prevent the coated end portion of the photocurable resin composition from becoming thick due to surface tension and resulting in no smoothness.

<Process (III) (bonding process)>
Next, as shown in FIG. 4, the light-transmitting cover member 2 is bonded to the image display member 6 from the light-transmitting cured resin layer 5 side. Bonding can be performed by applying pressure at a temperature of 10 ° C. to 80 ° C. using a known pressure bonding apparatus.

  Examples of the image display member 6 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 and 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.

  Note that the light transmissive level of the light transmissive cured resin layer 5 may be light transmissive so that an image formed on the image display member 6 can be visually recognized.

As mentioned above, although FIGS. 1-4 demonstrated the example which formed the photocurable resin composition in the light shielding layer side formation surface of a light-transmitting cover member, in the following FIGS. The example which formed the photocurable resin composition is demonstrated. 1 to 4 and FIGS. 5 to 7, the same reference numerals represent the same components.
In addition, a method of forming the image display member on the surface side is also included in the step (I), but in the following description representing one example, the steps (Ir) to (IIIr) are distinguished from the above description. Describe.

<Process (Ir) (resin layer forming process)>
First, as shown in FIG. 5, the photocurable resin composition 3 is formed on the surface of the image display member 6. In this case, the thickness of the resin layer to be formed is preferably 6 μm or more, more preferably 15 μm or more, further preferably 20 μm or more, particularly preferably 50 μm or more, and most preferably 1.0 × 10 ² μm or more, and The thickness is preferably 1.5 × 10 ³ μm or less, more preferably 1.0 × 10 ³ μm or less, and still more preferably 5.0 × 10 ² μm or less.

  In addition, you may perform formation of this photocurable resin composition 3 in multiple times so that required thickness may be obtained.

<Process (IIr) (curing process)>
Next, as shown in FIG. 6, the light curable cured resin layer 5 is formed by irradiating and curing the photocurable resin composition 3 formed in the step (Ir) with ultraviolet rays.
The curing rate (gel fraction) of the light transmissive cured resin layer 5 is preferably 80% or more, more preferably 90% or more, and still more preferably 95% or more.

<Process (IIIr) (bonding process)>
Next, as shown in FIG. 7, the light transmissive cover member 2 is bonded to the light transmissive cured resin layer 5 of the image display member 6 from the light shielding layer 1 side. Bonding can be performed by applying pressure at 10 to 80 ° C. using a known pressure bonding apparatus.

  Examples of the image display member 6 include a liquid crystal display panel, an organic EL display panel, a plasma display panel, a touch panel, and a parallax barrier panel.

  Note that the light transmissive level of the light transmissive cured resin layer 5 may be light transmissive so that an image formed on the image display member 6 can be visually recognized.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited to the following example. In Examples and Comparative Examples, the photocurable resin composition and the properties of the cured product were measured and evaluated by the following methods.
Hereinafter, the present invention will be specifically described by way of examples.

[Production Example 1]
As a compound having a photopolymerizable functional group of the component (A) in mass% with respect to the total amount of the photocurable resin composition, the compound represented by the above general formula (1) is used as the component (A1), and R ¹ is 19.8% by mass of UC-102 (manufactured by Kuraray Co., Ltd.) with methyl group, n = 2 (methacryloyl group = 2), (A2) as component, dicyclopentanyl acrylate (FA-513AS, Hitachi) As a photopolymerization initiator of 12.9% by mass of Kasei Chemical Co., Ltd.) and 12.9% by mass of dicyclopentenyloxyethyl methacrylate (FA-512M, manufactured by Hitachi Chemical Co., Ltd.), component (B) , 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (LUCIRIN TPO, manufactured by BASF Japan Ltd.) 5.9 mass%, polybutadiene (G-1000, Blended present Soda Ltd. Co.) 48.5 wt%, heated and stirred for 30 minutes at 90 ° C., to prepare a photocurable resin composition was uniformly mixed.

[Examples 1 to 6 and Comparative Examples 1 to 4]
Steps (I) to (III) or (IV) were performed under the conditions shown in Table 1 and evaluated.

<Step (I) (resin layer forming step)>
First, a glass plate having a size of 55 (W) mm × 85 (L) mm × 0.7 (T) mm and having a light-shielding layer with a thickness of 30 μm and a width of 5 mm over the entire periphery was prepared.

The photocurable resin composition prepared in Production Example 1 was discharged over the entire surface of the light shielding layer-forming surface of the glass plate with the light shielding layer using a coater to form a photocurable resin composition film.
This photocurable resin composition film was formed so as to straddle almost the entire area of the light shielding layer as shown in FIG.

<Process (II) (curing process)>
Next, with respect to this photocurable resin composition film, the photocurable resin composition film was cured using an ultraviolet irradiation device to form a cured resin layer.

<Process (III) (bonding process)>
Next, the glass plate obtained in the step (II) is placed on the surface on which the polarizing plate of the liquid crystal display element having a size of 55 (W) × 85 (L) mm is laminated so that the cured resin layer side is the polarizing plate side. The glass plate was attached by pressing with a rubber roller from the glass plate side at room temperature (25 ° C.).
When the liquid crystal display element was visually observed from the glass plate side in the attached state, no bubbles were observed around the light shielding layer.
Thereby, the liquid crystal display device by which the glass plate as a light transmissive cover member was laminated | stacked on the liquid crystal display element through the light transmissive cured resin layer was obtained.

<Process (IV) (Additional curing process)>
The cured resin layer was further cured by irradiating the obtained liquid crystal display element with ultraviolet rays from the glass plate side to form a light transmissive cured resin layer.

[Evaluation method]
<Hardening rate of photocurable resin composition>
The curing rate (gel fraction) in the present invention is the ratio of the abundance of (meth) acryloyl groups after ultraviolet irradiation to the abundance of (meth) acryloyl groups in the photocurable resin composition 3 before ultraviolet irradiation ( Consumption ratio) is defined as a numerical value, and the larger this value, the harder the curing.

Incidentally, curing rate (gel fraction), the absorption peak of 800cm ^-1 ~820cm ^-1 from baseline in FT-IR measurement chart of the ultraviolet radiation before the resin composition layer height as (X), any irradiation absorption peak height of the 800cm ^-1 ~820cm ^-1 from baseline in FT-IR measurement chart of the resin composition layer after the ultraviolet irradiation in an amount ^{(Y), 2.0 × 10 4} mJ / cm 2 after the ultraviolet irradiation the absorption peak height of the 800cm ^-1 ~820cm ^-1 from baseline in FT-IR measurement chart of the resin composition layer and (Z), was calculated by substituting the equation (1) below.
Curing rate (%) = {(X−Y) / (X−Z)} × 100 (1)

<Reliability evaluation>
The obtained test piece was put into a test bath at 85 ° C. for 500 hours, visually evaluated for bleed out, peeling, bubbles, and occurrence of yellowing, and evaluated according to the following criteria.
A: No change.
F: Bleed out, peeling, bubbles, yellowing were confirmed.

<Adhesive strength evaluation>
As shown in FIG. 8, a glass base 7 of 26 (W) mm × 76 (L) mm × 0.2 mm T is used, and the glass base 7 is 26 (W) mm × 76 (L) mm × 0. The photocurable resin composition 3 was applied on a glass base 8 having a thickness of 2 mmT, and ultraviolet light was irradiated at 4.0 × 10 ³ mJ / cm ² using an ultraviolet irradiation device, whereby the photocurable resin composition 3 was obtained. The glass base 8 on which the light-transmitting cured resin layer 5 is formed is cured so that the short sides of the glass base 7 and the glass base 8 are parallel to each other. A glass joined body was obtained by bonding to the glass base 7 from the resin layer 5 side. The area of the bonding portion was 26 mm × 20 mm (or 520 mm ² ), and the thickness of the bonding layer was 0.2 mm.
And the glass base 7 was fixed perpendicularly | vertically with respect to the ground, the load of 500g was applied to the glass base 8 perpendicularly | vertically downward, the shape change after 24 hours was observed, and the following reference | standard evaluated.
A: No change.
F: The position shift of the glass base 7 and the glass base 8 was confirmed.

  From Table 1, the photocurable resin composition which consists of a manufacturing method of Examples 1-6 makes additional ultraviolet irradiation in (IV) process by making the hardening rate after process (II) 80% or more especially. It turns out that the adhesiveness of the glass member bonded together through the resin cured material and reliability are favorable, without requiring. In Comparative Examples 3 and 4, the curing rate in the (II) step was 50%, and post-curing was performed in the (IV) step, but the reliability was inferior compared to the examples. .

According to the method for manufacturing an image display device of the present invention, an image display device is laminated with a light-transmitting cover member disposed on the surface side through a cured resin layer of a photocurable resin composition. When manufacturing the material, the active energy ray irradiation in the process before the light-transmitting cover member and the image display member are bonded together can exhibit sufficient adhesive force and reliability and simplify the manufacturing process. .
Therefore, the manufacturing method of the present invention is useful for industrial manufacture of information terminals such as touch panels, smart phones and touch pads with a naked-eye 3D parallax barrier, personal computers, and televisions.

DESCRIPTION OF SYMBOLS 1 Light shielding layer 2 Light transmissive cover member 2a Light shielding layer formation side surface of light transmissive cover member 3 Photocurable resin composition 4 Level difference 5 Light transmissive cured resin layer 6 Image display member 7 Glass base 8 Glass base

Claims (8)

4 to 10% by mass of the image display member and the light-transmitting cover member having a light-shielding layer formed on the peripheral portion with respect to the total amount of (A) the compound having a photopolymerizable functional group and the photocurable resin composition The light-shielding layer-forming surface of the light-transmitting cover member is an image display member through a light-transmitting cured resin layer formed of a photocurable resin composition containing (B) a photopolymerization initiator and (C) a plasticizer. A method for manufacturing an image display device laminated so as to be disposed on the side, the method including the following steps (I) to (III), wherein in step (II), the curing rate of the cured resin layer The manufacturing method of the apparatus for image displays which cures a photocurable resin composition by irradiating an active energy ray so that it may become 80% or more.
Process (I): The process of forming a photocurable resin composition in the light shielding layer formation side surface of a light-transmitting cover member, or the light shielding layer side surface of an image display member.
Step (II): A step of forming a cured resin layer by irradiating the cured photocurable resin composition with an active energy ray and curing it.
Step (III): The image display member and the light transmissive cover member are bonded together so that the light shielding layer and the cured resin layer are interposed between the image display member and the light transmissive cover member. Obtaining a device;   In the step (I), the photocurable resin composition is formed on the entire surface of the light-shielding layer forming side surface of the light-transmitting cover member or the light-shielding layer forming side surface of the image display member, including the surface of the light-shielding layer. The method for producing an image display device according to claim 1, wherein the composition is formed to be flat.   The method for manufacturing an image display device according to claim 1, wherein in the step (I), the photocurable resin composition is formed so as to embed the light shielding layer. The process for producing an image display device according to any one of claims 1 to 3, wherein in the step (I), the layer of the photocurable resin composition is formed with a thickness of ⁶ µm to 1.5 × 10 ³ µm. Method.   The manufacturing method of the apparatus for image displays in any one of Claims 1-4 whose image display member is a liquid crystal display panel, an organic electroluminescence display panel, a plasma display panel, a touch panel, or a parallax barrier panel.   (A) The manufacturing method of the apparatus for image displays in any one of Claims 1-5 in which the compound which has a photopolymerizable functional group contains radical photopolymerizable poly (meth) acrylate as a main component.   The manufacturing method of the apparatus for image displays in any one of Claims 1-6 in which a photocurable resin composition contains liquid rubber type | system | group (meth) acrylate.   The image display apparatus manufactured by the manufacturing method in any one of Claims 1-7.

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