JP2015087469A - Display device and method for manufacturing the same - Google Patents

Abstract

An object of the present invention is to improve the adhesion at the interface between a transparent resin and a display panel or a protection panel and prevent reflection at each interface to obtain a display device with high display quality. A display unit that displays an image, a resin unit that is formed on one surface of the display unit and prevents reflection on the surface of the display unit, and a display unit that is formed on the display unit via the resin unit. And a protective part 1 that protects the display part 3, the resin part 2 has two or more types of photoinitiators with different reaction wavelengths, and the type of photoinitiator decreases after the resin part 2 is cured. A display device comprising: [Selection] Figure 1

Description

  The present invention shields light from a step portion of a transparent protective plate that can be used as a constituent member of an image display device such as a personal computer, a mobile terminal (PDA), a game machine, a television (TV), a car navigation system, a touch panel, and a pen tablet. The present invention relates to a display device provided with a section and a method for manufacturing the same.

  In many cases, the display surface of the display panel is covered with a transparent protective plate because of the necessity of protecting the display panel from external impacts or inundation due to rain or the need to improve the design.

  Examples of the display device include a liquid crystal display device and an organic electroluminescence display device.

  When a transparent protective plate is arranged on the display surface of the display panel, if there is an air layer in the gap between the display panel and the transparent protective plate, the external light incident on the display surface is reflected on the front and back surfaces of the transparent protective plate, the display panel The surface may be reflected and the visibility may be reduced. In order to suppress this decrease, a method of arranging a transparent resin in the gap between the display panel and the transparent protective plate to improve the visibility is used (for example, Patent Document 1).

  Thus, when the space between the image display panel and the protective panel or touch panel member is filled with a transparent resin (adhesive), the interface between the image display panel and the transparent resin (adhesive), the protective panel, etc. Defects may exist at the interface with the transparent resin (adhesive). In such a state, it has been pointed out that when exposed to a high-temperature and high-humidity environment or exposed to a rapid temperature change, gas accumulates starting from the defect, and foaming or peeling occurs.

  Therefore, various studies have been made to solve such problems. After the adhesive composition is pre-cured (or thermally cured) to prepare a partially crosslinked adhesive composition (temporary curing stage), the optical functional member, the display panel, Paste together. Thereafter, a method of manufacturing an optical functional member integrated display device has been proposed, in which the adhesive composition is thermally cured (or photocured) by heat treatment (or light irradiation) (main curing stage) (for example, Patent Documents 2 and 3).

Japanese Patent Application Laid-Open No. 2004-077887 (page 7, FIG. 5) Japanese Unexamined Patent Publication No. 2009-109532 (page 7, FIG. 1) Patent No. 4971529 (8th page)

  However, in the conventional display device, since the state of the temporary curing stage is controlled by photocuring (or heat curing), the light irradiation condition changes due to the aging deterioration of the lamp illuminance, the variation of the light source distance, the irradiation time, and the like. For this reason, the physical properties of the resin before bonding are not stable, the curing shrinkage of the photo-curing transparent resin at the temporary curing stage is too small, and the shrinkage at the time of main curing is large, which deforms the display panel and adversely affects the display quality. There was a problem of waking up. Conversely, if the curing shrinkage of the photo-curing transparent resin in the pre-curing stage is excessive, the necessary adhesion cannot be obtained even after the main curing, or the steps of the display device cannot be filled. In particular, there is a problem that bubbles are generated when the display device is exposed to a high temperature.

  The present invention has been made in order to solve the above-described problems, and obtains a display device in which deterioration in display quality is suppressed by improving adhesion at an interface between a transparent resin and a display panel or a protection panel. Is.

  The display device according to the present invention includes a display unit that displays an image, a resin unit that is formed on one surface of the display unit and prevents surface reflection of the display unit, and the display unit via the resin unit. And a protective part that protects the display part. The resin part has two or more types of photoinitiators with different reaction wavelengths before the resin part is cured, and the resin part is cured. Later, at least one of the two or more types of photoinitiators is configured to disappear.

  This invention uses two or more types of photoinitiators that react at different wavelengths in pre-curing and main curing in the transparent resin, so that the type of photoinitiator in the transparent resin disappears from before the curing process to after the curing process. Therefore, it is possible to improve the adhesion at the interface between the transparent resin and the display panel or the protection panel, and to obtain a display device in which the deterioration of display quality is suppressed.

1 is a schematic cross-sectional structure diagram of a display device according to a first embodiment of the present invention. It is a schematic diagram which shows the reaction process of the photocurable resin in the manufacturing process of the display apparatus of Embodiment 1 of this invention. It is a manufacturing flow schematic diagram of the display apparatus of Embodiment 1 of this invention. It is another manufacturing flow schematic diagram of the display apparatus of Embodiment 1 of this invention. It is a related figure of the absorption wavelength and wavelength absorption amount of resin at the time of temporary hardening of the display apparatus of Embodiment 1 of this invention.

Embodiment 1 FIG.
FIG. 1 is a schematic cross-sectional view of a display device according to Embodiment 1 of the present invention. In FIG. 1, a display device 4 includes a transparent protective plate 1 that is a protective part, a photocurable resin 2 that is a resin part, and a display panel 3 that is a display part.

  As the display panel 3, a liquid crystal display panel, an organic electroluminescence panel, or the like is used. As a driving method of these display panels 3, there are a passive driving method and an active driving method.

  The transparent protective plate 1 is on a rectangle. The transparent protective plate 1 has a transparent protective plate main body 1a and a light shielding step portion 1b formed over the outer periphery of the back surface, which is a surface facing the photocurable resin 2 of the transparent protective plate 1. The protection plate main body 1a is a transparent plate that hardly absorbs in the visible region, and a glass plate reinforced using an ion exchange method or an air cooling strengthening method, a laminated glass, or the like can be used.

  Further, the protective plate body 1a may be a transparent resin plate such as an acrylic resin, a polycarbonate resin, or a cycloolefin resin.

  Further, the protective plate main body 1a can be appropriately subjected to anti-glare processing, anti-reflection treatment for improving visibility, and hard coat processing for preventing scratches on the protective plate main body 1a. The protection plate main body 1 a is arranged so as to cover at least a larger area than the display section which is a display area of the display panel 3 and further to cover a larger range than the transparent resin body 2.

  The light shielding step portion 1b is made of a material that almost shields wavelengths in the visible region. For example, an acrylic resin blended with carbon black is used. The light shielding step portion 1b can be formed in accordance with the display area of the display panel 3, but from the viewpoint of design, the clearance between the element for displaying the image on the display panel 3 and the light shielding step portion 1b is made as small as possible. Size is preferred. The light shielding stepped portion 1b only needs to satisfy desired performance such as design and light shielding properties, and the formation method is not particularly limited. For example, the light shielding stepped portion 1b can be formed by applying a resin using a screen printing method. . The coating thickness of the light shielding step portion 1b (corresponding to the step height of the light shielding step portion 1b) varies depending on the intensity of the light source to be shielded, but about 3 to 50 μm is used. When the color of the light-shielding step portion 1b is white, the coating thickness of the light-shielding step portion 1b is large and is about 10 to 50 μm, and when it is black, it is preferably about 3 to 40 μm.

  The photocurable resin 2 is for suppressing the visibility of the display panel 3 from being lowered. When an air layer is interposed in the gap between the display panel 3 and the transparent protective plate 1, external light incident on the surface of the display panel 3 is reflected on the front and back surfaces of the protective plate body 1 a and the surface of the display panel 3. Thus, the visibility of the display panel 3 is reduced. The photo-curable resin 2 is provided for suppressing a reduction in the visibility of the display panel 3.

  The photocurable resin 2 contains (meth) acrylate and a photoinitiator as raw materials as its components.

  Specific examples of (meth) acrylates include polyester (meth) acrylate resins, epoxy (meth) acrylate resins, urethane (meth) acrylate resins, and the like, which are limited to these resins. Instead, any transparent photo-curing resin may be used.

  For example, as the photocurable resin 2 other than the above, a silicone resin and a photoinitiator are included.

  FIG. 2 is a schematic diagram showing a reaction process of the photocurable resin in the manufacturing process of the display device according to the first embodiment of the present invention. FIG. 2A shows a case where a self-cleaving photoinitiator is used. FIG. 2B shows a case where a hydrogen abstraction type photoinitiator is used. In the figure, ◯ and ◎ represent self-cleaving photoinitiators, and ● represents a hydrogen abstraction type photoinitiator. As light irradiation, UV light 5 which is a light source having a first wavelength and UV light 6 which is a light source having a second wavelength are irradiated. In FIG. 2A, when two types of self-cleaving photoinitiators (◯, ◎) having different reaction wavelengths are used, curing treatment is performed using two different wavelengths in temporary curing and main curing. Thus, no photoinitiator remains in the photocurable resin 2. Thereby, the substance change of the photocurable resin 2 resulting from a photoinitiator becomes difficult to occur.

  On the other hand, in FIG. 2B, when a hydrogen abstraction type photoinitiator (●) is used, the photoinitiator (●) remains in the photocurable resin 2 even after temporary curing and main curing. And since an unreacted hydrogen component remains in the photocurable resin 2, a hydrogen abstraction reaction by a photoinitiator occurs even in light irradiation at the time of use, so that there is a possibility that the physical properties of the photocurable resin 2 change. .

  As the photoinitiator, two or more kinds of photoinitiators that generate radicals at different wavelengths can be used in combination. A known photoinitiator can be used as the type. Specific examples of the photoinitiator include, for example, benzoin series such as acetophenone series and benzyldimethyl ketal, benzophenone series, thioxanthone series such as isopropylthioxanthone and 2-4-diethylthioxanthone, and other special ones such as methylphenylglyoxy At least two types of rates can be selected and used.

  As a combination of photoinitiators, a method of combining two types of photoinitiators having a self-cleaving type radical generating mechanism is more preferable (FIG. 2A). Thereby, radical generation due to the photoinitiator can be suppressed under the environment in the field. Moreover, the physical properties of the cured product in the temporary curing stage can be stabilized.

  However, a combination of two or more kinds of photoinitiators having a hydrogen abstraction type radical generation mechanism is not preferable because radicals are generated even in an environment in the field, which may cause changes in physical properties (FIG. 2B). )).

  Further, a combination of photoinitiators having a self-cleavage type and a hydrogen abstraction type radical generating mechanism can be used. As a result, radical generation due to the photoinitiator can be reduced in the field environment, and the physical properties of the cured product in the temporary curing stage can be stabilized. The blending amount of the hydrogen abstraction type photoinitiator is preferably equal to or less than the self-cleavage type photoinitiator. When the blending amount of the hydrogen abstraction type photoinitiator is larger than the blending amount of the self-cleaving type photoinitiator, the amount of radical generation due to the photoinitiator increases in the field environment, so display unevenness and discoloration May cause problems.

  In addition, in the case of the photocurable resin 2 composed only of one type of hydrogen abstraction type photoinitiator, the temporary curing and the main curing have the same wavelength. Since it becomes a factor which produces malfunctions, such as generation | occurrence | production of the bubble by step embedding lack, it is not preferable.

  About the compounding quantity of the said photoinitiator, in this invention, it is preferable to set it as 0.001-10.0 mass parts with respect to 100 mass parts of said raw material polymers, especially 0.005-3 mass parts.

  Examples of the acetophenone photoinitiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenyl. Propan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1- ON, 1- [4- (2-hydroxyethoxy) -phenyl] -2- Dorokishi-2-methyl-1-like phenylglyoxylate butyric acid methyl ester can be used.

  Examples of the benzophenone photoinitiator include benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, and 3,3′-dimethyl-4-methoxy. Benzophenone or the like can be used.

  Further, as tertiary amine photoinitiators, triethanolamine, methyldiethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone, 4,4′-diethylaminobenzophenone, ethyl 2-dimethylaminobenzoate, Ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 or the like can be used.

  Generally, a photoinitiator has an absorption wavelength that is unique to each structure, and there is a wavelength range that absorbs to some extent. For example, in the case of 1-hydroxy-cyclohexyl ruphenyl-ketone, the absorption wavelength has a range of absorption wavelength from about 220 nm to about 220 to 265 nm. On the other hand, in the case of 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, the absorption wavelength has a peak from about 270 to about 360 nm centered at about 320 nm and a peak at about 230 nm. It has a peak with a base to the vicinity of 250 nm on the long wavelength side. When these two types of self-cleaving photoinitiators are used in combination, a light source having a central wavelength at 260 nm is used to cure 1-hydroxy-cyclohexyl ruphenyl-ketone, and 2-benzyl-2-dimethylamino- In order to cure 1- (4-morpholinophenyl) -butanone-1, by using a light source having a central wavelength at 320 nm, a photoinitiator that reacts in temporary curing and main curing can be selectively used. The physical properties of the temporarily cured product can be stabilized, and desired physical properties can be obtained after the main curing. Although the absorption wavelengths of the two types of photoinitiators may overlap, it is only necessary that the absorption efficiencies be different from each other by a certain amount.

  As a suitable example of the combination of two or more kinds of self-cleaving photoinitiators that generate radicals at different wavelengths in the photocurable resin 2, 1-hydroxycyclohexylphenyl-ketone and 2-benzyl-2-dimethyl A combination of amino-1- (4-morpholinophenyl) -butanone-1, 1-hydroxy-cyclohexyl phenyl-ketone and 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1- Combination of ON, 2-hydroxy-2-methyl-1-phenyl-propan-1-one and 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1 -ON combinations and the like. As a suitable example of a combination of a self-cleavage type and a hydrogen abstraction type photoinitiator, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and phenylglyoxylic acid methyl A combination of esters. The combination of a photoinitiator is not limited to these, The combination of the light source and photoinitiator to be used can be selected suitably.

  The photocurable resin 2 may contain an organic peroxide in combination with the photoinitiator. Examples of the organic peroxide include 2,5-dimethylhexane-2,5-dihydroxyperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, di-t. -Butyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, dicumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) ) Benzene; n-butyl-4,4-bis- (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxybenzoate, benzoyl peroxide, t-butyl Tilperoxyacetate, methyl ethyl ketone peroxide, t-butyl hydroperoxide, p-menthane hydroperoxide, hydroxyheptyl peroxide, chlorohexanone peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, cumyl peroxide Octoate, succinic acid peroxide, acetyl peroxide, t-butyl peroxide (2-ethylhexanoate), m-toluoyl peroxide, benzoyl peroxide, t-butyl peroxyisobutyrate, 2,4 -Dichlorobenzoyl peroxide etc. are mentioned, It can mix | blend suitably according to the physical property requested | required.

  As the organic peroxide, one of these can be used alone or in admixture of two or more, and the addition amount is usually 0.01 to 10 parts by mass with respect to 100 parts by mass of the starting polymer. In particular, 0.2 to 2.0 parts by mass is recommended. If the blending amount is small, the cured product may be softened. If the blending amount is large, unreacted products and by-products after curing increase, which may deteriorate the performance.

  In addition to the raw material polymer, photoinitiator, and organic peroxide, the photocurable resin 2 may contain known additives. For example, a silane coupling agent can be added to promote adhesion. Specific examples of the silane coupling agent include vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, and γ-glycidoxypropyltrimethoxysilane. , Γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltri Examples include ethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, and the like. One of these can be used alone, or two or more can be used in combination. The addition amount of these silane coupling agents is usually 0.01 to 5 parts by mass with respect to 100 parts by mass of the base polymer.

  Moreover, an epoxy group-containing compound can also be added for the purpose of improving adhesiveness. Examples of the epoxy group-containing compound include triglycidyl tris (2-hydroxyethyl) isocyanurate, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, acrylic glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, Examples thereof include phenol glycidyl ether, pt-butylphenyl glycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, glycidyl methacrylate, butyl glycidyl ether, and the like. be able to. The addition amount of these epoxy group-containing compounds is usually 0.01 to 20 parts by mass with respect to 100 parts by mass of the base polymer.

  Furthermore, a hydrocarbon resin can be added as another additive for the purpose of improving workability such as workability and bonding. In this case, the added hydrocarbon resin may be either a natural resin type or a synthetic resin type. As the natural resin system, rosin, rosin derivatives, and terpene resins are preferably used. As the rosin, gum resin, tall oil resin, and wood resin can be used. As the rosin derivative, rosin obtained by hydrogenation, heterogeneity, polymerization, esterification, or metal chloride can be used. As the terpene resin, a terpene phenol resin can be used in addition to a terpene resin such as α-pinene and β-pinene.

  In addition, dammar, corbal and shellac may be used as other natural resins. On the other hand, in the synthetic resin system, petroleum resin, phenol resin, and xylene resin are preferably used. As the petroleum resin, aliphatic petroleum resin, aromatic petroleum resin, alicyclic petroleum resin, copolymer petroleum resin, hydrogenated petroleum resin, pure monomer petroleum resin, and coumarone indene resin can be used. As the phenol resin, an alkyl phenol resin or a modified phenol resin can be used. As the xylene-based resin, a xylene resin or a modified xylene resin can be used.

  In order to fill the space between the transparent protective plate 1 and the display panel 3 with no gap, the photo-curing resin 2 has high plasticity from the viewpoint of visibility. It is necessary to have flexibility from the viewpoint of reducing the impact on dropping and pressing in the fully cured state after bonding and in order to satisfy these many requirements, A polymerizable resin composition containing a resin component containing a monomer and an oligomer and a photoinitiator is preferable.

  The mixing ratio (mass ratio) of the raw material polymer and the raw material monomer / oligomer in the photocurable resin 2 is preferably 10/90 to 60/40, more preferably 15/85 to 50/50. If the amount of the raw material polymer is too large, the viscosity becomes too high and not only the workability is lowered, but also the followability is deteriorated, and the surface unevenness of the pre-cured product becomes too large. There is a risk of generating bubbles. On the other hand, when the amount of the raw material polymer is too small, the viscosity becomes too low, and the end rectangularity of the temporarily cured product may be deteriorated, or bleeding may occur and workability may be lowered.

  In addition, it is preferable that the number average molecular weights of a raw material polymer are 20000-300000 normally, More preferably, it is 40000-250,000. Moreover, it is preferable that the viscosity of the said mixture is 0.5-33 Pa.s, More preferably, it is 2.5-20 Pa.s.

  FIG. 3 is a schematic manufacturing flow diagram of the display device according to the first embodiment of the present invention. A method for manufacturing the display device having the above-described structure will be described with reference to FIGS.

  First, as shown to Fig.3 (a), the photocurable resin 2 is apply | coated to the surface of the protection plate main body 1a in the side which has the light-shielding level | step-difference part 1b using a slit coater (resin application process). The application amount of the photocurable resin 2 may be an amount that can be applied to a desired area. Moreover, the coating thickness of the photocurable resin 2 is not less than the thickness for filling the light shielding stepped portion 1b, has shock absorption, can suppress display unevenness, etc., preferably 4 to 1000 μm, more preferably 25 to 25 μm. 750 μm. This coating method is not limited to the slit coater, and it is sufficient that the photocurable resin 2 is uniformly formed on the surface of the protective plate body 1a. For example, a method of coating by dispenser or screen printing may be used. it can.

  Next, as shown in FIG. 3B, the photocurable resin 2 is irradiated with UV light 5 using a predetermined light source that is a light source of the first wavelength, thereby forming a temporarily cured state (first Curing step). The type of the first light source used for temporary curing is not particularly limited as long as the photoinitiator can be selectively photocured, but an LED light source having a sharp output wavelength can be used more suitably. The LED of SETI (Sensor Electronic Technology) can be used as a light source arranged in a straight line. By passing through the resin coating step and the first curing step, the photocurable resin can be formed into a sheet shape, for example.

  Next, as shown in FIG.3 (c), the display panel 3 which is a display part is bonded on the surface of the photocurable resin 2 of a temporary hardening state (display part sticking process). Since the photocurable resin 2 is in a temporarily cured state and has plastic deformability, the photocurable resin 2 can follow some unevenness of the photocurable resin 2 and the unevenness of the panel.

  Next, as shown in FIG. 3D, a temporarily cured photocurable resin 2 bonded to the display panel 3 is passed through a transparent protective plate 1 with a predetermined light source that is a light source of the second wavelength. Using this, UV light 6 is irradiated to perform main curing (second curing step). The type of the second light source used in the main curing is not particularly limited, and may be selected according to the photoinitiator.

  The display device of the present invention can be manufactured through the above steps (FIG. 3E). In addition, the photocurable resin 2 immediately below the light shielding step portion 1b of the transparent protective plate 1 is not sufficiently exposed to the light for main curing, and the temporarily cured state is maintained. When inconveniences such as bubbles and display unevenness occur due to this, light irradiation from the side surface can be avoided. Light irradiation from the side surface can be performed by arranging a light source on the side surface or installing a reflecting mirror.

  FIG. 4 is another schematic manufacturing flow diagram of the display device according to Embodiment 1 of the present invention. FIG. 4A to FIG. 4F show another method for manufacturing the display device of the present invention.

  First, as shown to Fig.4 (a), the photocurable resin 2 is apply | coated to the release sheet 7, such as PET film, using a slit coater (resin application process). This coating method can use the same method as the method shown in FIG.

  Next, as shown in FIG.4 (b), UV light 5 is irradiated to the photocurable resin 2 using a predetermined | prescribed light source, and a temporary hardening state is formed (1st hardening process). As the temporary curing method, the method used in FIG. 3B can be used as it is.

  Next, as shown in FIG.4 (c), the photocurable resin 2 is bonded together to the protection board main body 1a of the side which has the light-shielding level | step-difference part 1b (protection board sticking process).

  Then, as shown in FIG.4 (d), the release sheet 7 is peeled and the display panel 3 is bonded on the surface of the photocurable resin 2 of a temporary hardening state (display part bonding process).

  Next, as shown in FIG. 4 (e), the temporarily cured photocurable resin 2 bonded to the display panel 3 is irradiated with UV light 6 through the transparent protective plate 1 using a predetermined light source. Perform the main curing. This curing method can use the method described in FIG.

  Through the above steps, the display device of the present invention can be manufactured (FIG. 4F). Note that the photo-curing resin immediately below the light-shielding step portion 1b of the transparent protective plate 1 is not sufficiently exposed to the light for main curing, and the temporarily cured state is maintained. When inconveniences such as bubbles and display unevenness occur due to this, light irradiation from the side surface can be avoided. Light irradiation from the side surface can be performed by arranging a light source on the side surface or installing a reflecting mirror.

  In the present invention, the combination of the photoinitiator used and the selection of the light source are very important. That is, if a light source wavelength or a combination of photoinitiators that causes radicals to be generated by any of the photoinitiators used is selected, the properties of the temporarily cured state are not stabilized.

  FIG. 5 is a relationship diagram between the absorption wavelength of the resin and the wavelength absorption amount during temporary curing of the display device according to Embodiment 1 of the present invention. As shown in FIG. 5, it can be seen that the physical property variation of the photocurable resin changes depending on the combination of the absorption wavelength and the wavelength absorption amount of the photoinitiator. As shown in FIG. 5B and FIG. 5C, when the wavelength absorption amounts (a1, a2) of the two types of photoinitiators are a2> a1 / 2, curing occurs in the temporary curing state. If it proceeds too much, it will not be possible to fill the surface unevenness of the photocurable resin or the display panel 3, and bubbles may be generated or display unevenness may occur (FIG. 5 (c)). Otherwise, the rectangular shape at the end of the photocurable resin cannot be maintained, and peripheral bubbles are generated, or display unevenness occurs due to excessive curing shrinkage (FIG. 5B).

  As a result of intensive studies, when the absorption amount at a specific wavelength of the photoinitiator used for temporary curing is 1, the absorption amount at the same wavelength of the photoinitiator used for main curing is ½ or less (a2 ≦ a1 / 2). It has been clarified that it is sufficient if it is preferably 1/5 or less (FIG. 5A). That is, it was found that desired characteristics can be obtained by selecting a photoinitiator and a light source having a certain difference in wavelength absorption.

  For example, when two types of self-cleaving photoinitiators are used, 1-hydroxy-cyclohexyl-phenyl-ketone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 are used. As the first light source used in the case of selection, when the former photoinitiator is used at the time of temporary curing, a light source having a peak top at 260 nm is used, and when the latter photoinitiator is used at the time of temporary curing, a peak top is set at 320 nm. The light source which has can be used preferably.

  As the first light source used when 1-hydroxy-cyclohexyl-phenyl-ketone and 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one are selected, the former is used. When the photoinitiator is used during temporary curing, a light source having a peak top at 260 nm can be used, and when the latter photoinitiator is used during temporary curing, a light source having a peak top at 310 nm can be preferably used.

  Also, 2-hydroxy-2-methyl-1-phenyl-propan-1-one and 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one When the former photoinitiator is used at the time of temporary curing, the light source having a peak top at 240 nm is used as the first light source used when the former is selected, and when the latter photoinitiator is used at the time of temporary curing, the peak top is 280 nm. A light source having the following can be preferably used.

  Furthermore, as an example in the case of using a combination of a self-cleavage type photoinitiator and a hydrogen abstraction type photoinitiator, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and As a first light source used when phenylglyoxylic acid methyl ester is selected, when the former photoinitiator is used during temporary curing, a light source having a peak top at 320 nm is used, and the latter photoinitiator is used during temporary curing. When used, a light source having a peak top at 255 nm can be preferably used. The light source at the time of temporary curing is not particularly limited, and any light source satisfying desired characteristics can be selected as appropriate, and a metal halide lamp, a mercury lamp, a xenon lamp, or the like can be selected. Further, by combining a commercially available optical filter, only a desired wavelength region can be taken out and used as a light source. An LED lamp or an excimer lamp can be preferably used because it can output a specific wavelength sharply.

  The light source at the time of the main curing is not particularly limited and can be appropriately selected as long as the desired characteristics are satisfied. A metal halide lamp, a mercury lamp, a xenon lamp, or the like can be selected.

  In the display device configured as described above, by using a photoinitiator having a reaction wavelength different between temporary curing and main curing, the physical properties of the photocurable resin in the temporary curing state and the main curing state are stabilized. Thereby, the level | step difference of the light-shielding part provided in the transparent protective plate 1 can be filled without gap by the plastic deformation of the photocuring type resin of a temporary hardening state. Furthermore, after setting the transparent protective plate 1 and the display panel 3 to the main cured state, the photocurable resin can be firmly cross-linked. Therefore, for example, the pressure of the outgas generated from the protective plate or the polarizing plate of the display panel 3, and the adhesive force sufficient to counter the gas generated in the thermal cycle test and the warp of the protective plate / display panel 3 It can have cohesive strength. Thereby, the deterioration of display quality can be suppressed.

  Material design that does not cause display unevenness due to curing shrinkage of the photo-curable resin 2 by stabilizing the physical properties of the pre-cured state and the main cured state by using different wavelengths and photoinitiators for the temporary curing and the main curing. Becomes easier.

  For example, even if bubbles are generated due to defective bonding position or undulation of the transparent resin, defective products can be excluded and repaired before the main curing, so that the yield can be improved.

  According to the method for manufacturing a display device according to the present invention, when a self-cleaving initiator is used as a photoinitiator, the amount of radicals generated is defined by the amount of photoinitiator introduced. Even if variations in workpiece height occur, the physical properties in the pre-cured state can be stabilized and the reliability of the final display device can be improved by carrying out light irradiation of a certain amount or more.

[Example]
Example 1
100 parts of Soken Chemical's syrup B as a (meth) acrylic base polymer, 0.1 parts of Kyoei Chemical's TMP-A and 10 parts of Kyoeisha Chemical's HOA as an acrylic monomer / oligomer, the first light 0.4 parts 1-hydroxy-cyclohexyl luphenyl-ketone as initiator and 0-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 as second photoinitiator .6 parts was blended to form the photocurable resin 2 of Example 1. This photocurable resin 2 was applied to the transparent protective plate 1 made of tempered glass having a black frame printing portion with a film thickness of 250 μm by a slit coating method. A dose of 700 mJ is applied to the transparent protective plate 1 coated with the photo-curable resin 2 and equipped with an LED ultraviolet irradiation lamp in which UVTOP 260 made by SETI is arranged in a straight line as a first light source for temporary curing. / Cm < ² > light irradiation was implemented and the temporary hardened | cured material was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 after predetermined alignment, and a dose of 1500 mJ / cm is applied from the transparent protective plate 1 side with a device equipped with a USIO metal halide lamp. ² was performed to complete the main curing, and a display device was obtained.

(Example 2)
100 parts of Soken Chemical Syrup B as (meth) acrylic base polymer, 0.1 part of Kyoeisha Chemical TMP-A and 10 parts of Kyoeisha Chemical HOA as acrylic monomer / oligomer 0.4 part of 1-hydroxycyclohexylphenyl-ketone as an agent and 0 of 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one as a second photoinitiator .6 parts was blended to form the photocurable resin 2 of Example 2. This photocurable resin 2 was applied to the transparent protective plate 1 made of tempered glass having a black frame printing portion with a film thickness of 250 μm by a slit coating method. A dose of 700 mJ is applied to the transparent protective plate 1 coated with the photo-curable resin 2 and equipped with an LED ultraviolet irradiation lamp in which UVTOP 260 made by SETI is arranged in a straight line as a first light source for temporary curing. / Cm < ² > light irradiation was implemented and the temporary hardened | cured material was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 after predetermined alignment, and a dose of 1500 mJ / cm is applied from the transparent protective plate 1 side with a device equipped with a USIO metal halide lamp. ² was performed to complete the main curing, and a display device was obtained.

(Example 3)
100 parts of Soken Chemical Syrup B as (meth) acrylic base polymer, 0.1 part of Kyoeisha Chemical TMP-A and 10 parts of Kyoeisha Chemical HOA as acrylic monomer / oligomer 0.4 parts 2-hydroxy-2-methyl-1-phenyl-propan-1-one as an agent and 1- [4- (2-hydroxyethoxy) -phenyl] -2-2 as a second photoinitiator Photocurable resin 2 of Example 3 was formed by blending 0.6 parts of hydroxy-2-methyl-1-propan-1-one. This photocurable resin 2 was applied to the transparent protective plate 1 made of tempered glass having a black frame printing portion with a film thickness of 250 μm by a slit coating method. An irradiation amount of 300 mJ is applied in an apparatus equipped with an LED ultraviolet irradiation lamp in which UVTOP 240 manufactured by SETI is arranged in three rows as a first light source for temporary curing on the transparent protective plate 1 coated with the photocurable resin 2. / Cm < ² > light irradiation was implemented and the temporary hardened | cured material was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 after predetermined alignment, and a dose of 1500 mJ / cm is applied from the transparent protective plate 1 side with a device equipped with a USIO metal halide lamp. ² was performed to complete the main curing, and a display device was obtained.

Example 4
100 parts of Soken Chemical Syrup B as (meth) acrylic base polymer, 0.1 part of Kyoeisha Chemical TMP-A and 10 parts of Kyoeisha Chemical HOA as acrylic monomer / oligomer 0.6 parts 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 as an agent and 0.4 parts phenylglyoxylic acid methyl ester as a second photoinitiator , And the photocurable resin 2 of Example 4 was formed. This photocurable resin 2 was applied to the transparent protective plate 1 made of tempered glass having a black frame printing portion with a film thickness of 250 μm by a slit coating method. An irradiation amount of 300 mJ is applied in an apparatus equipped with an LED ultraviolet irradiation lamp in which UVTOP 320 made by SETI is arranged in a straight line as a first light source for temporary curing on the transparent protective plate 1 coated with the photocurable resin 2. / Cm < ² > light irradiation was implemented and the temporary hardened | cured material was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 by predetermined alignment, and the irradiation amount is 1500 mJ / in with a device equipped with a USIO low-pressure UV lamp from the transparent protective plate 1 side. The main curing was completed by performing light irradiation of cm ² to obtain a display device.

(Example 5)
100 parts of syrup B made by Soken Chemical as the (meth) acrylic base polymer, 0.1 part of TMP-A made by Kyoeisha Chemical and 5 parts of HOA made by Kyoeisha Chemical and 130A made by Kyoeisha Chemical 5 parts, 0.3 parts 1-hydroxycyclohexylphenyl-ketone as the first photoinitiator and 2-methyl-1- (4- (methylthio) phenyl) -2 as the second photoinitiator -0.7 part of morpholinopropan-1-one was blended to form the photocurable resin 2 of Example 5. This photocurable resin 2 was applied to the transparent protective plate 1 made of tempered glass having a black frame printing portion with a film thickness of 250 μm by a slit coating method. A dose of 700 mJ is applied to the transparent protective plate 1 coated with the photo-curable resin 2 and equipped with an LED ultraviolet irradiation lamp in which UVTOP 260 made by SETI is arranged in a straight line as a first light source for temporary curing. / Cm < ² > light irradiation was implemented and the temporary hardened | cured material was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 after predetermined alignment, and a dose of 1500 mJ / cm is applied from the transparent protective plate 1 side with a device equipped with a USIO metal halide lamp. ² was performed to complete the main curing, and a display device was obtained.

(Example 6)
The photocurable resin 2 obtained in Example 1 was applied at a film thickness of 250 μm by a slit coating method on the transparent protective plate 1 made of tempered glass having a black frame printing portion. A dose of 750 mJ is applied to the transparent protective plate 1 coated with the photo-curable resin 2 and equipped with an LED ultraviolet irradiation lamp in which UVTOP 260 made by SETI is arranged in three rows as a first light source for temporary curing. / Cm < ² > light irradiation was implemented and the temporary hardened | cured material was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 after predetermined alignment, and a dose of 1500 mJ / cm is applied from the transparent protective plate 1 side with a device equipped with a USIO metal halide lamp. ² was performed to complete the main curing, and a display device was obtained.

(Comparative Example 1)
As a (meth) acrylic base polymer, 100 parts of Soken Chemical's syrup B, as an acrylic monomer / oligomer, 0.1 part of Kyoei Chemical's TMP-A and 10 parts of Kyoeisha Chemical's HOA, as a photoinitiator 1 part of 1-hydroxy-cyclohexyl phenyl ketone was blended to form a photocurable resin 2 of Comparative Example 1. This photocurable resin 2 was applied to the transparent protective plate 1 made of tempered glass having a black frame printing portion with a film thickness of 250 μm by a slit coating method. A dose of 700 mJ is applied to the transparent protective plate 1 coated with the photo-curable resin 2 and equipped with an LED ultraviolet irradiation lamp in which UVTOP 260 made by SETI is arranged in a straight line as a first light source for temporary curing. / Cm < ² > light irradiation was implemented and the temporary hardened | cured material was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 after predetermined alignment, and a dose of 1500 mJ / cm is applied from the transparent protective plate 1 side with a device equipped with a USIO metal halide lamp. ² was performed to complete the main curing, and a display device was obtained.

(Comparative Example 2)
100 parts of Soken Chemical Syrup B as (meth) acrylic base polymer, 0.1 part of Kyoeisha Chemical TMP-A and 10 parts of Kyoeisha Chemical HOA as acrylic monomer / oligomer 0.4 part of 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 as an agent and 2-methyl-1- (4- (methylthio) as a second photoinitiator 0.6 parts of phenyl) -2-morpholinopropan-1-one (Irgacure 907) was blended to form a photocurable resin 2 of Comparative Example 2. This photocurable resin 2 was applied to the transparent protective plate 1 made of tempered glass having a black frame printing portion with a film thickness of 250 μm by a slit coating method. A dose of 400 mJ is applied to the transparent protective plate 1 coated with the photo-curable resin 2 with an LED ultraviolet irradiation lamp in which UVTOP 310 manufactured by SETI is arranged in three rows as a first light source for temporary curing. / Cm < ² > light irradiation was implemented and the temporary hardened | cured material was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 by predetermined alignment, and the irradiation amount is 1500 mJ / in with a device equipped with a USIO low-pressure UV lamp from the transparent protective plate 1 side. The main curing was completed by performing light irradiation of cm ² to obtain a display device.

(Comparative Example 3)
The photocurable resin 2 obtained in Example 1 was applied at a film thickness of 250 μm by a slit coating method on the transparent protective plate 1 made of tempered glass having a black frame printing portion. The transparent protective plate 1 coated with the photo-curable resin 2 is irradiated with light having an irradiation amount of 700 mJ / cm ² using a device equipped with a low-pressure mercury lamp manufactured by USIO as a first light source for temporary curing. A cured product was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 after predetermined alignment, and a dose of 1500 mJ / cm is applied from the transparent protective plate 1 side with a device equipped with a USIO metal halide lamp. ² was performed to complete the main curing, and a display device was obtained.

(Comparative Example 4)
100 parts of Soken Chemical's syrup B as the (meth) acrylic base polymer, 0.1 part of Kyoeisha Chemical's TMP-A as the acrylic monomer / oligomer, 10 parts of Kyoeisha Chemical's HOA, and phenyl as the photoinitiator 1 part of glyoxylic acid methyl ester was blended to form a photocurable resin 2 of Comparative Example 4. This photocurable resin 2 was applied to the transparent protective plate 1 made of tempered glass having a black frame printing portion with a film thickness of 250 μm by a slit coating method. The transparent protective plate 1 coated with the photocurable resin 2 is irradiated with light having an irradiation amount of 300 mJ / cm ² using a device equipped with a low-pressure UV lamp manufactured by USIO as a first light source for temporary curing. A cured product was obtained. The transparent protective plate 1 on which the temporarily cured product is formed is bonded to the display panel 3 by predetermined alignment, and the irradiation amount is 1500 mJ / in with a device equipped with a USIO low-pressure UV lamp from the transparent protective plate 1 side. The main curing was completed by performing light irradiation of cm ² to obtain a display device.

  In the reliability test, 10 sets of each of the display devices of Examples 1 to 6 and Comparative Examples 1 to 4 were manufactured, and the following cooling / heating cycle evaluation and weather resistance evaluation were performed to confirm the reliability. The test items for reliability were confirmed by the presence or absence of bubbles, the presence or absence of display unevenness, and the presence or absence of yellowing. In each inspection, “◯” was entered when no problems occurred, “Δ” was entered when problems occurred in 1 to 3 sets, and “X” was entered when problems occurred in 4 or more sets.

  In addition, the thermal cycle test conditions were -50 ° C. × 24 hours and 105 ° C. × 24 hours as one set, and a total of 10 sets were carried out.

The weather resistance test was performed using an ultraviolet fluorescent light weather meter having a peak at a wavelength of 280 to 315 nm (UV-B) in the ultraviolet region, and was exposed for 500 hours at an irradiance of 28 W / m ² and an irradiation distance of 50 mm.

  As a yellowing confirmation method, measurement based on JISZ8729 was carried out, and it was determined that yellowing occurred when the change from the initial value of b *, which is an evaluation index of yellowing, exceeded 1.0.

  In Examples 1 to 3, no problem occurred in the cooling / heating cycle and the weather resistance test. This is considered to be because only the self-cleavage type was used as the photoinitiator in the photocurable resin 2, and the light source wavelength used for temporary curing and main curing was optimally selected. In Example 4, the self-cleavage type and the hydrogen abstraction type were used in combination as the photoinitiator in the photocurable resin 2, but the hydrogen abstraction type photoinitiation was higher than the blending amount of the self-cleavage type photoinitiator. Since the blending amount of the agent was reduced, no bubbles or display unevenness was observed in the weather resistance evaluation. Example 5 is different in the constitution of the acrylic monomer / oligomer of Example 2, but the result of the reliability evaluation was good. Therefore, the photoinitiator of the present invention and the light source used for temporary curing / main curing. It is considered that a display device with an optimal wavelength can be used universally in various material systems. In Example 6, the photocurable resin 2 used is the same as in Example 1, but the amount of pre-curing irradiation is increased. Since the result of the reliability evaluation was also good for this Example 6, the light irradiation amount at the time of temporary curing increased by selecting a photoinitiator and a light source having a certain difference in wavelength absorption amount. However, it was found that the reaction of the photoinitiator used in the main curing can be suppressed, and the elastic modulus, the plastic deformation rate, the adhesive property, and the like of the temporarily cured photocurable resin 2 are not greatly affected.

  In Comparative Example 1, a display device was prepared using one type of self-cleaving photoinitiator, but in the reliability test, one out of 10 bubbles was generated in the thermal cycle evaluation, and 10 in the weather resistance evaluation. Display unevenness occurred in two of the platforms. This is presumably because the physical properties of the pre-cured state changed due to variations in the irradiation amount of the ultraviolet irradiation device. That is, when the irradiation amount at the time of pre-curing is less than a predetermined value, the crosslinking density of the photo-curing resin 2 in the pre-cured state becomes low, and the amount of curing shrinkage at the time of main curing becomes large. Is considered to have occurred. On the other hand, when the irradiation amount at the time of temporary curing is larger than a predetermined value, the crosslinking density of the photocurable resin 2 at the time of temporary curing is increased and the elastic modulus is increased, so that the step embedding property and the adhesive property are lowered, and the cooling cycle. It is considered that bubbles were generated in the evaluation.

  Comparative Example 2 is a display device in which the photocurable resin 2 is composed of a combination of two types of self-cleaving photoinitiators having substantially the same absorption wavelength. The relationship between the photoinitiator and the exposure wavelength is shown in FIG. In the reliability test, 7 out of 10 air bubbles were generated in the reliability test, and 8 out of 10 air bubbles were generated in the weather resistance evaluation. This is because radicals are generated from any photo-initiator during light irradiation at the time of temporary curing, so that the crosslinking density of the photocurable resin 2 at the time of temporary curing is increased and the elastic modulus is increased, so that the step embedding characteristics and It is considered that the adhesive property was lowered and bubbles were generated in the thermal cycle evaluation. Even in the weather resistance evaluation, it is considered that bubbles were generated due to the high elastic modulus at the time of temporary curing and the decrease in the adhesion to various members of the display device.

  In Comparative Example 3, the relationship between the photoinitiator and the exposure wavelength is similar to that in FIG. 5B, but in the reliability test, 6 out of 10 bubbles were generated in the cooling cycle evaluation. In the weather resistance evaluation, bubbles were generated in 9 of 10 units. This is because radicals are generated from any photo-initiator during light irradiation at the time of temporary curing, so that the crosslinking density of the photocurable resin 2 at the time of temporary curing is increased and the elastic modulus is increased, so that the step embedding characteristics and It is considered that the adhesive property was lowered and bubbles were generated in the thermal cycle evaluation. Even in the weather resistance evaluation, it is considered that bubbles were generated due to the high elastic modulus at the time of temporary curing and the decrease in the adhesion to various members of the display device.

  Comparative Example 4 is a display device configured using a photocurable resin 2 configured using only a hydrogen abstraction type photoinitiator as a photoinitiator. Bubbles were generated on the table. This is because the irradiation amount at the time of temporary curing of the ultraviolet irradiation device is larger than a predetermined value, the crosslinking density of the photocurable resin 2 at the time of temporary curing is increased, and the elastic modulus is increased, so that the step embedding characteristic and the adhesive characteristic are lowered. However, it is considered that bubbles were generated in the evaluation of the thermal cycle. Further, in the weather resistance evaluation, display unevenness occurred in 6 of 10 cars, and yellowing also occurred. This is because radicals are generated from the photoinitiator remaining in the photocurable resin 2 after the main curing by ultraviolet irradiation during the weather resistance test, and the physical properties of the photocurable resin 2 change due to the radicals. It is thought that unevenness occurred.

  In Table 1, the reliability evaluation result of Examples 1-6 and Comparative Examples 1-4 is shown. From Table 1, it was found that Examples 1 to 6 were formed to satisfy the specifications as comprehensive evaluation. However, Comparative Examples 1 to 4 could not satisfy the specifications as a comprehensive evaluation.

  As described above, in the display device using the transparent protective plate having the light-shielding portion according to the present invention, it is possible to provide a display device that suppresses deterioration in display quality and a method for manufacturing the display device.

  DESCRIPTION OF SYMBOLS 1 Transparent protective plate, 1a Protective plate main body, 1b Light-shielding level | step-difference part, 2 Photocurable resin, 3 Display panel, 4 Display apparatus, 5,6 UV irradiation light, 7 Release sheet.

Claims (7)

A display for displaying an image;
A resin part formed on one surface of the display part to prevent surface reflection of the display part;
A protective part that is formed to face the display part via the resin part and protects the display part,
The resin portion has two or more types of photoinitiators having different reaction wavelengths before the resin portion is cured, and at least one of the two or more types of photoinitiators after the resin portion is cured. A display device characterized in that the initiator disappears. The display device according to claim 1, wherein the photoinitiator includes a self-cleaving material. The display device according to claim 1, wherein the photoinitiator includes a hydrogen abstraction type material and a self-cleavage type material. The display device according to any one of claims 1 to 3, wherein the display unit includes at least one of a touch panel, an image display panel, a display protection panel, and a polarizing film. A resin application step of applying a resin having two or more types of photoinitiators with different reaction wavelengths on one surface of the protective part;
A first curing step of curing the resin using a light source of a first wavelength;
A display unit pasting step for pasting the display unit to face the protective unit via the resin;
A display device manufacturing method comprising: a second curing step of curing the resin using a light source having a second wavelength via the protection unit. A resin coating step of coating a resin having two or more types of photoinitiators with different reaction wavelengths on one surface of the sheet;
A first curing step of curing the resin using a light source of a first wavelength;
A protective part attaching step for attaching the protective part to the sheet part through the resin;
A display unit pasting step of peeling the sheet and pasting the display unit to face the protective unit through the resin,
A second curing step of curing the resin using a light source of a second wavelength via the protection unit;
The method for manufacturing a display device, wherein the resin has two or more types of photoinitiators having different reaction wavelengths, and the types of the photoinitiators are reduced after the second curing step. The method for manufacturing a display device according to claim 5, wherein the resin is formed into a sheet shape in the resin coating step and the first curing step.