JP5244262B1 - Display device front plate bonding adhesive, display device front plate bonding adhesive set, display device manufacturing method, and display device - Google Patents

Abstract

The present invention is excellent in transparency and moisture resistance of a cured product, and can sufficiently bond the front plate and the base material even when the polarity of the front plate and the base material on which the front plate is bonded is greatly different. An object of the present invention is to provide an adhesive for bonding a front plate for a display device. Another object of the present invention is to provide a display device using the adhesive for bonding a front plate for a display device.
The present invention is an adhesive used for bonding a substrate of a display device to a front plate, a monofunctional radical polymerizable compound having a hydrophilic group and a hydrophobic group in the molecule, and the monofunctional radical polymerizable compound An adhesive for bonding a front plate for a display device, comprising a homopolymer of the compound, a polyfunctional radical polymerizable compound, and a photo radical polymerization initiator.

Description

The present invention is excellent in transparency and moisture resistance of a cured product, and can sufficiently bond the front plate and the base material even when the polarity of the front plate and the base material on which the front plate is bonded is greatly different. The present invention relates to an adhesive for bonding a front plate for a display device. The present invention also relates to a display device using the display device front plate bonding adhesive and a method for manufacturing the display device.

In recent years, display devices in which a touch panel or a 3D display function is provided on a flat panel display such as a liquid crystal display, a plasma display, and an organic EL display are widely used. This display device is manufactured by bonding a front panel such as a protective panel, an antireflection panel, a touch panel, a 3D display lens sheet, and a barrier liquid crystal panel to a base material.

Conventionally, front plates such as protective films used in display devices have been attached to substrates with adhesive tape. However, when adhesive tape is used, bubbles and foreign objects can easily enter when the front plate is attached. There has been a problem that the alignment becomes difficult at the time of bonding. Patent Documents 1 and 2 disclose coating-type adhesives that replace adhesive tapes. However, since the adhesive disclosed in Patent Document 1 is composed of a hydrophobic material mainly composed of synthetic rubber, there is a problem that the affinity with a hydrophilic base material such as glass is not good. . In addition, the adhesive disclosed in Patent Document 2 has a problem that the front plate and the base material cannot be sufficiently bonded.

As an adhesive having good affinity with a hydrophilic substrate, for example, Patent Document 3 discloses a resin composition containing an alkyl acrylate and an acrylate having a hydroxyl group. However, since the resin composition disclosed in Patent Document 3 is a mixture of resins having different polarities, there is a problem in compatibility, and the cured product is exposed to light, particularly when exposed to a high humidity environment. There was a problem that it was easily clouded.
Furthermore, the conventional adhesive has a problem that the front plate may be peeled off due to poor adhesion when the polarity of the front plate and the substrate to which the front plate is bonded is greatly different.

JP 2005-015598 A JP 7-134212 A Japanese Patent Laid-Open No. 9-258023

The present invention is excellent in transparency and moisture resistance of a cured product, and can sufficiently bond the front plate and the base material even when the polarity of the front plate and the base material on which the front plate is bonded is greatly different. An object of the present invention is to provide an adhesive for bonding a front plate for a display device. Another object of the present invention is to provide a display device using the adhesive for bonding a front plate for a display device.

The present invention is an adhesive used for bonding a substrate of a display device and a front plate, a monofunctional radical polymerizable compound having a hydrophilic group and a hydrophobic group in the molecule, and the monofunctional radical polymerizable An adhesive for bonding a front plate for a display device, comprising a homopolymer of the compound, a polyfunctional radical polymerizable compound, and a photo radical polymerization initiator.
The present invention is described in detail below.

The inventors use a monofunctional radical polymerizable compound having a hydrophilic group and a hydrophobic group in the molecule, a homopolymer of the monofunctional radical polymerizable compound, and a polyfunctional radical polymerizable compound in combination. The display is excellent in transparency and moisture resistance of the cured product, and can sufficiently bond the front plate and the base material even when the polarity of the front plate and the base material to which the front plate is bonded is greatly different. It has been found that an adhesive for bonding a front plate for a device can be obtained, and the present invention has been completed.

The adhesive for bonding a front plate for a display device of the present invention contains a monofunctional radical polymerizable compound having a hydrophilic group and a hydrophobic group in the molecule (hereinafter also simply referred to as a monofunctional radical polymerizable compound). By using a monofunctional compound as the radical polymerizable compound, a homopolymer having high compatibility with the radical polymerizable compound can be obtained without gelation. In addition, since the monofunctional radically polymerizable compound has a hydrophilic group and a hydrophobic group in the molecule, the front plate to be bonded and the base material are sufficiently different even if the front plate and the base material are made of materials having significantly different polarities. Can be glued. Furthermore, since it has a hydrophilic group, it can suppress that a hardened | cured material becomes cloudy even when exposed to a highly humid environment.

Examples of the hydrophilic group include (poly) ethylene glycol group, (poly) propylene glycol group, (poly) tetramethylene glycol group, (poly) 2-hydroxypropylene glycol group, and the like. Of these, (poly) ethylene glycol groups are preferred because they are highly hydrophilic and the resulting adhesive is excellent in adhesion to highly polar substrates.

Examples of the hydrophobic group include a phenyl group, an alkyl group, an alkylphenyl group, an isobornyl group, a tricyclodecane dimethanol group, and the like. Of these, a phenyl group is preferred because of its good affinity with the resin.

Specific examples of the monofunctional radically polymerizable compound having a hydrophilic group and a hydrophobic group in the molecule include phenoxydiethylene glycol acrylate, 2-ethylhexyl diethylene glycol acrylate, and nonylphenoxy diethylene glycol acrylate. Especially, since the adhesive agent for front plate bonding for display devices obtained becomes the thing excellent in adhesiveness with a base material, the compound represented by following formula (1) is suitable.

In Formula (1), R ¹ represents hydrogen or a methyl group, and R ² represents a linear or branched saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms or a 2-hydroxypropylene group. R ³ represents a substituent represented by the following formula (2-1), (2-2), (2-3), or (2-4), and n is an integer of 1 to 6 Indicates.

In formula (2-1), R ⁴ represents hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms.

In formula (1), R ² may be a linear or branched saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, but is preferably a methylene group, an ethylene group, or a propylene group.

As a monofunctional radically polymerizable compound having a substituent represented by the formula (2-1), for example, phenoxyethyl acrylate (manufactured by Kyoeisha Chemical Co., “Light Acrylate PO-A”, manufactured by Daicel Cytec Co., “EBECRYL110”). ), Phenyldiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate P-200A”), nonylphenol EO adduct acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate NP-4EA”), 2-hydroxy-3-phenoxypropyl acrylate ( Kyoeisha Chemical Co., Ltd., “epoxy ester M-600A”) and the like.
Examples of the monofunctional radically polymerizable compound having a substituent represented by the formula (2-2) include dicyclopentenyloxyethyl acrylate (manufactured by Hitachi Chemical Co., Ltd., “Fancryl FA-512AS”).

Although the acid value of the said monofunctional radically polymerizable compound is not specifically limited, A preferable upper limit is 0.5 mgKOH / g. When the acid value of the monofunctional radical polymerizable compound exceeds 0.5 mgKOH / g, the electrode of the display device to be obtained may be corroded. The upper limit with the more preferable acid value of the said monofunctional radically polymerizable compound is 0.1 mgKOH / g.

The content of the monofunctional radical polymerizable compound is not particularly limited, but the total amount of the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, and the polyfunctional radical polymerizable compound is 100 parts by weight. On the other hand, the preferred lower limit is 5 parts by weight and the preferred upper limit is 90 parts by weight. When the content of the monofunctional radically polymerizable compound is less than 5 parts by weight, the viscosity of the obtained adhesive for bonding a front plate for a display device becomes too high, and coating may be difficult. When the content of the monofunctional radical polymerizable compound exceeds 90 parts by weight, the resulting adhesive for bonding a front plate for a display device is bonded to the front plate and the substrate, resulting in large shrinkage and deformation. Or the viscosity may be too low. The minimum with more preferable content of the said monofunctional radically polymerizable compound is 10 weight part, and a more preferable upper limit is 80 weight part.

The adhesive for bonding a front plate for a display device of the present invention contains a homopolymer of the above monofunctional radically polymerizable compound. By using a homopolymer of the above-mentioned monofunctional radical polymerizable compound as a polymer to be blended in order to reduce cure shrinkage, improve adhesion and dimensional stability, or adjust viscosity, the cured product after light irradiation Can be suppressed from becoming cloudy.

The upper limit with preferable glass transition temperature of the homopolymer of the said monofunctional radically polymerizable compound is 25 degreeC. When the glass transition temperature of the homopolymer of the monofunctional radical polymerizable compound exceeds 25 ° C., the obtained display device may be inferior in impact resistance.

The preferable lower limit of the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) of the homopolymer of the monofunctional radical polymerizable compound is 3000, and the preferable upper limit is 200,000. When the weight average molecular weight of the homopolymer of the monofunctional radically polymerizable compound is less than 3000, the obtained adhesive for bonding a front plate for a display device is inferior in adhesiveness to a front plate or a substrate, The viscosity may be insufficient. When the weight average molecular weight of the homopolymer of the monofunctional radically polymerizable compound exceeds 200,000, the viscosity of the obtained adhesive for bonding a front plate for a display device becomes too high, and coating may be difficult. The minimum with a more preferable weight average molecular weight of the homopolymer of the said monofunctional radically polymerizable compound is 20,000, and a more preferable upper limit is 80,000.
In addition, as a column at the time of measuring the weight average molecular weight by polystyrene conversion by GPC, LF-804 (made by SHOKO) etc. are mentioned, for example.

Although the content of the homopolymer of the monofunctional radical polymerizable compound is not particularly limited, a total of 100 of the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, and the polyfunctional radical polymerizable compound is 100. The preferred lower limit is 10 parts by weight and the preferred upper limit is 80 parts by weight with respect to parts by weight. When the content of the homopolymer of the monofunctional radical polymerizable compound is less than 10 parts by weight, the curing shrinkage is large, and the obtained adhesive for bonding the front plate for a display device is a substrate on which the front plate or the front plate is bonded. It may become inferior in adhesiveness, may be deformed, or may have insufficient viscosity. When the content of the homopolymer of the monofunctional radically polymerizable compound exceeds 80 parts by weight, the viscosity of the obtained adhesive for bonding a front plate for a display device becomes too high, and coating may be difficult. The minimum with more preferable content of the homopolymer of the said monofunctional radically polymerizable compound is 20 weight part, and a more preferable upper limit is 70 weight part.

The adhesive for bonding a front plate for a display device of the present invention contains a polyfunctional radically polymerizable compound. By containing the said polyfunctional radically polymerizable compound, the adhesive agent for front plate bonding for display devices of this invention becomes a crosslinked body after hardening, and a shape maintenance is possible also at high temperature.

Examples of the polyfunctional radical polymerizable compound include polyfunctional epoxy acrylates such as bisphenol A diglycidyl ether diacrylate and polyethylene glycol diglycidyl ether diacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, and pentaerythritol triacrylate. Acrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, polypropylene diacrylate, tricyclo Examples include decane dimethanol diacrylate. These polyfunctional radically polymerizable compounds may be used alone or in combination of two or more.
Of these, tricyclodecane dimethanol diacrylate is preferred because it has a hydrophilic group and a hydrophobic group in the molecule.

The content of the polyfunctional radical polymerizable compound is not particularly limited, but the total amount of the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, and the polyfunctional radical polymerizable compound is 100 parts by weight. On the other hand, the preferred lower limit is 1 part by weight and the preferred upper limit is 30 parts by weight. If the content of the polyfunctional radically polymerizable compound is less than 1 part by weight, crosslinking may be insufficient and deviation may occur at high temperatures. If the content of the polyfunctional radically polymerizable compound exceeds 30 parts by weight, it may become too hard and the impact resistance may be lowered. The minimum with more preferable content of the said polyfunctional radically polymerizable compound is 5 weight part, and a more preferable upper limit is 20 weight part.

The adhesive for bonding a front plate for a display device of the present invention contains a radical photopolymerization initiator.
The radical photopolymerization initiator is not particularly limited, and examples thereof include benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, and thioxanthone.

Examples of commercially available photo radical polymerization initiators include Irgacure 184, Irgacure 369, Irgacure 379, Irgacure 651, Irgacure 819, Irgacure 907, Irgacure 2959, Irgacure OXE01, Lucyrin TPO (all of which are BASF Japan). Benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether (all of which are manufactured by Tokyo Chemical Industry Co., Ltd.) and the like. Among these, Irgacure 651, Irgacure 907, benzoin isopropyl ether, and Lucillin TPO are preferable because of their wide absorption wavelength range. These radical photopolymerization initiators may be used alone or in combination of two or more.

The content of the photo radical polymerization initiator is not particularly limited, but is 100 parts by weight in total of the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, and the polyfunctional radical polymerizable compound. The preferred lower limit is 0.5 parts by weight, and the preferred upper limit is 10 parts by weight. When the content of the photo radical polymerization initiator is less than 0.5 parts by weight, the polymerization does not proceed sufficiently, or the curing reaction of the obtained adhesive for bonding the front plate for a display device is too slow. Sometimes. When the content of the radical photopolymerization initiator exceeds 10 parts by weight, the curing reaction of the obtained adhesive for bonding a front plate for a display device becomes too fast, resulting in a decrease in workability or an obtained display device. The adhesive for bonding the front plate may become a non-uniform cured product. The minimum with more preferable content of the said radical photopolymerization initiator is 1 weight part, and a more preferable upper limit is 5 weight part.

The adhesive for bonding a front plate for a display device of the present invention preferably contains a thermal radical polymerization initiator.
Any thermal radical polymerization initiator may be used as long as it decomposes at a temperature of 100 ° C. or lower to generate radicals, and is selected in consideration of the film forming temperature, the crosslinking temperature, the storage stability, and the like. Can be used. Among these, those having a decomposition temperature of 70 ° C. or less with a half-life of 10 hours are preferably used because of low temperature curability.
Examples of the thermal radical polymerization initiator include azo compounds and organic peroxides. Of these, organic peroxides are preferable.

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-butylperoxy) Isopropyl) 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 peroxyacetate, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, methyl ethyl ketone peroxide, t-butyl hydro Peroxide, p-menthane hydroperoxide, hydroxyheptyl peroxide, chlorohexanone peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, cumyl peroxy octoate, cumyl peroxy neodecanate, succinic agit Peroxide, acetyl peroxide, t-butylperoxy (2-ethylhexanoate), m-toluoyl peroxide, benzoyl peroxide, t-butylperoxyisobutylene DOO, 2,4-dichlorobenzoyl peroxide, t-hexyl peroxypivalate, and the like. These thermal radical polymerization initiators may be used alone or in combination of two or more.

The content of the thermal radical polymerization initiator is not particularly limited, but with respect to a total of 100 parts by weight of the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, and the polyfunctional radical polymerizable compound. The preferred lower limit is 0.1 parts by weight, and the preferred upper limit is 10 parts by weight. When the content of the thermal radical polymerization initiator is less than 0.1 parts by weight, the polymerization does not proceed sufficiently, or the curing reaction of the obtained adhesive for bonding a front plate for a display device is too slow. Sometimes. If the content of the thermal radical polymerization initiator exceeds 10 parts by weight, foaming may occur at the time of curing, or the storage stability of the obtained adhesive for bonding a front plate for a display device may be poor and the viscosity may increase. is there. The minimum with more preferable content of the said thermal radical polymerization initiator is 1 weight part.

The adhesive for bonding a front plate for a display device of the present invention may contain a silane coupling agent as an adhesion promoter as long as the object of the present invention is not impaired.
Specific examples of the silane coupling agent include vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, and γ-glycidoxypropyltrimethoxy. Silane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyl Examples include triethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, and the like. These silane coupling agents may be used alone or in combination of two or more.

The content of the silane coupling agent is not particularly limited, but is 100 parts by weight in total of the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, and the polyfunctional radical polymerizable compound. The preferred lower limit is 0.01 parts by weight and the preferred upper limit is 5 parts by weight. When the content of the silane coupling agent is less than 0.01 part by weight, the effect of improving the adhesiveness of the obtained adhesive for bonding a front plate for a display device may not be sufficiently obtained. When content of the said silane coupling agent exceeds 5 weight part, an excess silane coupling agent may bleed out. The minimum with more preferable content of the said silane coupling agent is 0.5 weight part.

The adhesive for bonding a front plate for a display device of the present invention may contain a filler as long as the object of the present invention is not impaired.
The said filler is not specifically limited, For example, an inorganic filler, an organic filler, etc. are mentioned.
The inorganic filler is not particularly limited. For example, talc, silica, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, diatomaceous earth, magnesium oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, glass beads, barium sulfate. , Gypsum, calcium silicate, sericite activated clay and the like.
The organic filler is not particularly limited, and examples thereof include polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, and acrylic polymer fine particles.
These fillers may be used independently and may use 2 or more types together.

The method for producing the adhesive for bonding a front plate for a display device of the present invention is not particularly limited. For example, using a mixer such as a homodisper, a homomixer, a universal mixer, a planetarium mixer, a kneader, or a three roll, The monofunctional radical polymerizable compound, a homopolymer of the monofunctional radical polymerizable compound, the polyfunctional radical polymerizable compound, the photo radical polymerization initiator, the thermal radical polymerization initiator, and the silane coupling agent The method of mixing with additives, such as these, is mentioned.

The viscosity of the adhesive for bonding a front plate for a display device of the present invention is not particularly limited, but a preferable lower limit of the viscosity measured at 25 ° C. and 2.5 rpm using an E-type viscometer is preferably 20 mPa · s. The upper limit is 500,000 mPa · s. When the viscosity is less than 20 mPa · s, the adhesive for bonding a front plate for a display device may flow out during coating. When the viscosity of the adhesive for laminating a front plate for a display device exceeds 500,000 mPa · s, coating may be difficult. The more preferable lower limit of the viscosity of the adhesive for bonding a front plate for a display device is 50 mPa · s, and the more preferable upper limit is 200,000 mPa · s.

A manufacturing method of a display device in which a base material and a front plate are bonded using an adhesive for bonding a front plate for a display device, wherein at least one of the base material and the front plate is used for the display device of the present invention. A step of applying an adhesive for laminating a face plate; and a step of laminating the adhesive for laminating a front plate for a display device by laminating the base material and the front plate and irradiating light. A method for manufacturing a display device is also one aspect of the present invention.

In the step of applying the display device front plate bonding adhesive of the present invention to at least one of the base material and the front plate, the display device front plate bonding adhesive of the present invention is applied to the front plate. Alternatively, it may be applied to a base material to which the front plate is bonded. Although the thickness of the adhesion layer by the adhesive agent for front plate bonding for display devices of this invention after coating is suitably determined by a material, a use, etc., it is about 1-200 micrometers normally.

Examples of the front plate include a protective panel made of glass, polycarbonate, acrylic, or the like, a resistive or capacitive touch panel, a lenticular lens for 3D display, a barrier liquid crystal panel called a parallax barrier, and the like. .
Examples of the substrate on which the front plate is bonded include a liquid crystal panel module, an organic EL panel module, a plasma display, and electronic paper.
Furthermore, the front plate bonding adhesive for display devices of the present invention can also be used for bonding different front plates.

The method for applying the adhesive for bonding a front plate for a display device of the present invention is not particularly limited, and for example, it can be performed using a coating machine such as a roll coater or a die coater. In particular, in order to apply uniformly, it is preferable to apply to the substrate while heating with a die coater or the like.

In the step of bonding the base material and the front plate, and curing the front plate bonding adhesive for display device by irradiating light, the front plate bonding adhesive for display device of the present invention is After the coating, it can be cured by irradiating light having a wavelength of 300 nm to 400 nm and an integrated light amount of 300 to 3000 mJ / cm ² .

The light source for irradiating light for curing the adhesive for bonding a front plate for a display device of the present invention is not particularly limited. , Black light lamps, microwave-excited mercury lamps, metal halide lamps, sodium lamps, halogen lamps, xenon lamps, fluorescent lamps, sunlight, electron beam irradiation devices, and the like. These light sources may be used independently and 2 or more types may be used together. In selecting these light sources, they are appropriately selected in accordance with the absorption wavelength of the photo radical polymerization initiator.

Examples of the irradiation procedure of the light source to the adhesive for bonding the front plate for a display device of the present invention include simultaneous irradiation of various light sources, sequential irradiation with a time difference, combined irradiation of simultaneous irradiation and sequential irradiation, etc. Any irradiation means may be used.

The lower limit of the transmittance of light having a wavelength of 405 nm when the thickness of the cured product of the adhesive for bonding a front plate for a display device of the present invention is 300 μm is 90%. When the transmittance is less than 90%, the obtained display device may be inferior in optical characteristics.
The cured product of the adhesive for bonding a front plate for a display element of the present invention preferably has a haze value of 2 or less when the thickness is 300 μm. When the fog value exceeds 2, the resulting display element may become cloudy. The haze value is more preferably 1 or less.

Examples of the method for producing a display device using the adhesive for bonding a front plate for a display device of the present invention include, for example, the front plate or the entire surface of a substrate to which the front plate is bonded before the display device of the present invention. Examples include a method in which a base plate bonding adhesive is applied, the base material and the front plate are bonded via the front device bonding adhesive for display device of the present invention, and ultraviolet rays are irradiated.

FIG. 1 is a cross-sectional view showing an example of a display device using the adhesive for bonding a front plate for a display device of the present invention. In the display device shown in FIG. 1, a front plate 1 and a base material 2 are bonded together via a display device front plate bonding adhesive 3. Further, the front plate 1 has a light blocking portion 4 and a light transmitting portion 5, and the portion of the display device front plate bonding adhesive 3 located under the light blocking portion 4 is incident from the front plate side. It is difficult for the light to reach.
As in the display device shown in FIG. 1, when a light-shielding portion such as an opaque electrode or a black matrix is formed on a base material or a front plate, the display positioned at the light-shielding portion is irradiated with light and heated. The adhesive for bonding the front plate for a device can be cured.
In the case where the adhesive for bonding a front plate for a display device is cured by irradiating light and heating, the adhesive for bonding a front plate for a display device of the present invention contains the thermal radical polymerization initiator. It is preferable.

Further, the adhesive for bonding a front plate for a display device of the present invention may be used as an adhesive set combining two or more kinds, and has a viscosity composed of the adhesive for bonding a front plate for a display device of the present invention. A high peripheral adhesive (dam agent) and a filling adhesive (fill agent) made of the adhesive for bonding a front plate for a display device of the present invention having a lower viscosity than the peripheral adhesive to fill the inside. You may seal by sticking a front board and a base material under atmospheric pressure or pressure reduction using the adhesive set for front plate bonding for display devices.
An adhesive used for bonding a base material and a front plate of a display device, the dam agent bonding the base material and the front plate at the periphery of the display device, and the base material and the front plate inside the dam agent The dam agent and the fill agent are adhesives for laminating a front plate for a display device of the present invention, each having the same monofunctional radical polymerizable compound and the monofunctional radical polymerization. A homopolymer of a functional compound, a polyfunctional radical polymerizable compound, and a photo radical polymerization initiator, and the dam agent has a higher content of the homopolymer of the monofunctional radical polymerizable compound than the filler, and E The viscosity of the dam agent measured under the conditions of 25 ° C. and 2.5 rpm using a mold viscometer is the viscosity of the fill agent measured under the conditions of 25 ° C. and 2.5 rpm using an E type viscometer. The adhesive set for bonding the front plate for a display device is 3-10000 times also constitutes the present invention.
In the present specification, the “peripheral portion of the display device” means a so-called “frame” portion between the display pixel portion and the end portion of the display device in the display device.

The dam agent that adheres the base material and the front plate in the peripheral part of the display device, and the fill agent that adheres the base material and the front plate inside the dam agent, containing the same material, Adhesion for bonding the front plate for display devices that can suppress the protrusion of the adhesive when the base material and the front plate are bonded together and the distortion of the image of the display device by adjusting the viscosity with the fill agent to a specific ratio An agent can be obtained. In the method using a simple adhesive set consisting of a dam agent and a fill agent, the base material and the front plate are obtained by coating a dam agent having a high viscosity on the outside of the fill agent having a low viscosity and excellent coatability. Although the dam agent prevents the filling agent from sticking out, the transparent material is used for both the dam agent and the filling agent. Device image may be distorted.

In the adhesive set for bonding a front plate for a display device of the present invention, the dam agent and the filling agent are the adhesive for bonding a front plate for a display device of the present invention. That is, the dam agent and the fill agent include a monofunctional radical polymerizable compound having a hydrophilic group and a hydrophobic group in a molecule, a homopolymer of the monofunctional radical polymerizable compound, a polyfunctional radical polymerizable compound, And a radical photopolymerization initiator.
Further, the dam agent and the fill agent contain the same monofunctional radical polymerizable compound and a homopolymer of the monofunctional radical polymerizable compound, and the dam agent is more monofunctional radical polymerizable than the fill agent. High content of compound homopolymer.

Although the content of the monofunctional radical polymerizable compound in the dam agent is not particularly limited, the total amount of the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, and the polyfunctional radical polymerizable compound is 100 parts by weight. On the other hand, the preferred lower limit is 3 parts by weight and the preferred upper limit is 50 parts by weight. When the content of the monofunctional radically polymerizable compound in the dam agent is less than 3 parts by weight, the viscosity of the obtained dam agent becomes too high and coating may be difficult. When the content of the monofunctional radical polymerizable compound in the dam agent exceeds 50 parts by weight, the viscosity of the dam agent obtained becomes too low, and the dam agent or the fill agent protrudes when the base material and the front plate are bonded together. Or the dam agent may become deformed due to increased shrinkage of the dam agent. The minimum with more preferable content of the monofunctional radically polymerizable compound in the said dam agent is 5 weight part, and a more preferable upper limit is 30 weight part.

The content of the monofunctional radical polymerizable compound in the filling agent is not particularly limited, but the total of the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, and the polyfunctional radical polymerizable compound is 100 parts by weight. On the other hand, the preferred lower limit is 10 parts by weight and the preferred upper limit is 95 parts by weight. When the content of the monofunctional radically polymerizable compound in the filling agent is less than 10 parts by weight, the viscosity of the resulting filling agent becomes too high and coating may be difficult. When the content of the monofunctional radically polymerizable compound in the filler exceeds 95 parts by weight, the curing shrinkage of the filler may be increased and deformed. The minimum with more preferable content of the monofunctional radically polymerizable compound in the said fill agent is 30 weight part, and a more preferable upper limit is 90 weight part.

The dam agent has a higher content of the homopolymer of the monofunctional radical polymerizable compound than the fill agent.
The content of the homopolymer of the monofunctional radical polymerizable compound in the dam agent is not particularly limited as long as the content ratio is higher than that of the fill agent, but the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, And a preferable minimum is 30 weight part and a preferable upper limit is 95 weight part with respect to a total of 100 weight part of a polyfunctional radically polymerizable compound. When the content of the homopolymer of the monofunctional radically polymerizable compound in the dam agent is less than 30 parts by weight, the curing shrinkage is large, and the resulting dam agent has an adhesive property with the front plate and the substrate to which the front plate is bonded. The dam agent may be inferior, deformed, or the viscosity of the dam agent may be insufficient, and the dam agent or the fill agent may protrude when the base material and the front plate are bonded to each other. When the content of the homopolymer of the monofunctional radically polymerizable compound in the dam agent exceeds 95 parts by weight, the viscosity of the dam agent becomes too high and coating may be difficult. The more preferable lower limit of the content of the homopolymer of the monofunctional radical polymerizable compound in the dam agent is 50 parts by weight, and the more preferable upper limit is 90 parts by weight.

The content of the homopolymer of the monofunctional radical polymerizable compound in the filling agent is not particularly limited as long as the content ratio is lower than that of the dam agent, but the monofunctional radical polymerizable compound, the homopolymer of the monofunctional radical polymerizable compound, And a preferable minimum is 1 weight part and a preferable upper limit is 70 weight part with respect to a total of 100 weight part of a polyfunctional radically polymerizable compound. When the content of the homopolymer of the monofunctional radically polymerizable compound in the filler is less than 1 part by weight, the curing shrinkage is large, and the resulting filler is adhesive to the front plate and the substrate to which the front plate is bonded. May be inferior or deformed. When the content of the homopolymer of the monofunctional radically polymerizable compound in the filler exceeds 70 parts by weight, the viscosity of the resulting filler may become too high, and coating may be difficult. The more preferable lower limit of the content of the homopolymer of the monofunctional radical polymerizable compound in the filling agent is 5 parts by weight, and the more preferable upper limit is 50 parts by weight.

Viscosity of the above dam agent measured at 25 ° C. and 2.5 rpm using an E type viscometer with respect to the viscosity of the above filling agent measured at 25 ° C. and 2.5 rpm using an E type viscometer The lower limit of the ratio is three times and the upper limit is 10,000 times. When the viscosity of the dam agent is less than 3 times the viscosity of the fill agent, the dam agent or the fill agent may protrude when the substrate and the front plate are bonded together. When the viscosity of the dam agent exceeds 10,000 times the viscosity of the fill agent, it may be difficult to apply the dam agent, or the base material may be distorted due to a difference in curing shrinkage rate. The preferable lower limit of the ratio of the viscosity of the dam agent to the viscosity of the filler is 5 times, the preferable upper limit is 5000 times, the more preferable lower limit is 10 times, and the more preferable upper limit is 1000 times.

The dam agent has a preferred lower limit of 3000 mPa · s and a preferred upper limit of 500,000 mPa · s, measured using an E-type viscometer at 25 ° C. and 2.5 rpm. If the viscosity of the dam agent is less than 3000 mPa · s, the dam agent or the fill agent may flow out during coating or when the substrate and the front plate are bonded together. When the viscosity of the dam agent exceeds 500,000 mPa · s, it may be difficult to apply the dam agent. The minimum with more preferable viscosity of the said dam agent is 5000 mPa * s, and a more preferable upper limit is 300,000 mPa * s.

The above filling agent has a preferable lower limit of 10 mPa · s and a preferable upper limit of 30,000 mPa · s, as measured with an E-type viscometer under the conditions of 25 ° C. and 2.5 rpm. When the viscosity of the filling agent is less than 10 mPa · s, curing shrinkage may be large and distortion may occur. When the viscosity of the filler exceeds 30,000 mPa · s, it may be difficult to apply the filler. The more preferable lower limit of the viscosity of the adhesive for bonding a front plate for a display device is 100 mPa · s, and the more preferable upper limit is 10,000 mPa · s.

A method for manufacturing a display device in which a base material and a front plate are bonded using an adhesive for bonding a front plate for a display device, wherein a dam agent is formed in a frame shape on at least one peripheral portion of the base material and the front plate The step of applying, the step of applying a fill agent in the frame of the applied dam agent, the substrate and the front plate are bonded together via the dam agent and the fill agent, light The step of curing the dam agent and the fill agent by irradiating the dam agent and the fill agent, the dam agent and the fill agent are the dam agent and the fill of the adhesive set for laminating a front plate for a display device of the present invention. The manufacturing method of the display device which is an agent is also one of this invention.

In the step of applying the dam agent to the peripheral part of at least one of the base material and the front plate in a frame shape, the dam agent may be applied to the front plate or applied to the base material to which the front plate is bonded. You may work. Although the thickness of the adhesion layer by the dam agent after coating is suitably determined by a material, a use, etc., it is about 1-200 micrometers normally.

In the step of applying the dam agent in a frame shape to at least one peripheral part of the base material and the front plate, the method of applying the dam agent is not particularly limited, for example, a method using dispensing, screen printing or the like. Can be mentioned.
Further, in the step of applying the fill agent in the frame of the applied dam agent, the method of applying the fill agent is not particularly limited, and examples thereof include methods using dispensing, screen printing, ink jet, and the like. .
The dam agent and the fill agent are preferably applied while heating in order to apply uniformly.

In the step of curing the dam agent and the fill agent by bonding the base material and the front plate through the dam agent and the fill agent and irradiating light, the dam agent and the fill agent are used. The light irradiated for curing the agent is preferably light having a wavelength of 300 nm to 400 nm and an integrated light amount of 300 to 3000 mJ / cm ² .

The light source for irradiating the dam agent and the light for curing the fill agent is not particularly limited. Examples include a wave excitation mercury lamp, a metal halide lamp, a sodium lamp, a halogen lamp, a xenon lamp, a fluorescent lamp, sunlight, and an electron beam irradiation device. These light sources may be used independently and 2 or more types may be used together. In selecting these light sources, they are appropriately selected in accordance with the absorption wavelength of the photo radical polymerization initiator.

Examples of the light irradiation procedure from the light source include simultaneous irradiation of various light sources, sequential irradiation with a time lag, combined irradiation of simultaneous irradiation and sequential irradiation, and any irradiation means may be used. .

In the cured product of the dam agent and the fill agent, a preferable lower limit of the transmittance of light having a wavelength of 405 nm when the thickness is 300 μm is 90%. When the transmittance is less than 90%, the obtained display device may be inferior in optical characteristics.

When using the adhesive set for laminating a front plate for a display device of the present invention, a light shielding portion such as an opaque electrode or a black matrix is formed on a base material or a front plate as in the display device shown in FIG. In this case, the dam agent and the fill agent located in the light shielding portion can be cured by irradiating light and heating.
When the dam agent and the fill agent are cured by irradiating light and heating, the dam agent and the fill agent preferably contain the thermal radical polymerization initiator.

The adhesive for bonding a front plate for a display device of the present invention and the adhesive set for bonding a front plate for a display device of the present invention can be suitably used for a display device. The display device using the adhesive for bonding a front plate for a display device of the present invention or the adhesive set for bonding a front plate for a display device of the present invention is also one aspect of the present invention.

According to the present invention, the front plate and the base material are sufficiently bonded even when the transparency and the moisture resistance of the cured product are excellent and the polarity of the front plate and the base material to which the front plate is bonded is greatly different. An adhesive for bonding a front plate for a display device can be provided. Moreover, according to this invention, the display device which uses this adhesive agent for front plate bonding for a display device can be provided.

FIG. 1 is a cross-sectional view showing an example of a display device using the adhesive for bonding a front plate for a display device of the present invention.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
40 parts by weight of a phenoxydiethylene glycol acrylate (manufactured by Daicel Cytec Co., Ltd., “EBECRYL110”) as a monofunctional radical polymerizable compound, 50 parts by weight of a homopolymer of phenoxydiethylene glycol acrylate (glass transition temperature—15 ° C., weight average molecular weight 30,000), 10 parts by weight of tricyclodecane dimethanol diacrylate (manufactured by Daicel Cytec, “IRR-214K”) as a polyfunctional radical polymerizable compound, and 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Japan, as a photo radical polymerization initiator, "Irgacure 184") 1 part by weight, 2 parts by weight of benzoyl peroxide (manufactured by NOF Corporation, "NIPER BW") as a thermal radical polymerization initiator, and γ-glycidoxypropylmedium as a silane coupling agent 1 part by weight of rudiethoxysilane (manufactured by Shin-Etsu Silicone, “KBM-403”) is uniformly stirred and mixed at a stirring speed of 3000 rpm using a homodisper-type stirring mixer (“Primix”, “Homodisper L-type”). Thus, an adhesive for bonding a front plate for a display device was obtained.

(Example 2)
As a monofunctional radical polymerizable compound, 40 parts by weight of nonylphenyltetraethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate NP-4EA”) is blended instead of phenoxydiethylene glycol acrylate, and nonyl instead of a homopolymer of phenoxydiethylene glycol acrylate An adhesive for bonding a front plate for a display device was prepared in the same manner as in Example 1 except that 50 parts by weight of a homopolymer of phenyltetraethylene glycol acrylate (glass transition temperature-25 ° C., weight average molecular weight 50,000) was blended. Obtained.

(Example 3)
As a monofunctional radical polymerizable compound, 40 parts by weight of 2-ethylhexyl diethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light Acrylate EHDG-A”) is blended instead of phenoxydiethylene glycol acrylate, and instead of a homopolymer of phenoxydiethylene glycol acrylate, 2- An adhesive for bonding a front plate for a display device was obtained in the same manner as in Example 1 except that 50 parts by weight of a homopolymer of ethylhexyl diethylene glycol acrylate (glass transition temperature-30 ° C., weight average molecular weight 70,000) was blended. .

Example 4
Adhesion for bonding a front plate for a display device in the same manner as in Example 1 except that the blending amount of phenoxydiethylene glycol acrylate was changed to 90 parts by weight and the blending amount of the homopolymer of phenoxydiethylene glycol acrylate was changed to 5 parts by weight. An agent was obtained.

(Example 5)
Adhesion for bonding a front plate for a display device in the same manner as in Example 1 except that the blending amount of phenoxydiethylene glycol acrylate was changed to 5 parts by weight and the blending amount of the homopolymer of phenoxydiethylene glycol acrylate was changed to 90 parts by weight. An agent was obtained.

(Example 6)
The same as in Example 1 except that the amount of phenoxydiethylene glycol acrylate was changed to 49.5 parts by weight and the amount of tricyclodecane dimethanol diacrylate was changed to 0.5 parts by weight. An adhesive for laminating the face plates was obtained.

(Example 7)
For pasting front plate for display device in the same manner as in Example 1 except that the blending amount of phenoxydiethylene glycol acrylate was changed to 10 parts by weight and the blending amount of tricyclodecane dimethanol diacrylate was changed to 40 parts by weight. An adhesive was obtained.

(Example 8)
A display device front plate bonding adhesive was obtained in the same manner as in Example 1 except that benzoyl peroxide was not blended.

Example 9
As a monofunctional radical polymerizable compound, 40 parts by weight of 2-hydroxy-3-phenoxypropyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name “epoxy ester M-600A”) is blended in place of phenoxydiethylene glycol acrylate, and homopolymer of phenoxydiethylene glycol acrylate Prior to display device use in the same manner as in Example 1 except that 50 parts by weight of a 2-hydroxy-3-phenoxypropyl acrylate homopolymer (glass transition temperature 15 ° C., weight average molecular weight 50,000) was blended in place of the polymer. An adhesive for laminating the face plates was obtained.

(Example 10)
Instead of phenoxydiethylene glycol acrylate as a monofunctional radical polymerizable compound, dicyclopentenyloxyethyl acrylate (Hitachi Chemical Co., Ltd., “Fan Fan”, which is a monofunctional radical polymerizable compound having a substituent represented by the formula (2-2). Kuryl FA-512AS ") 40 parts by weight, and instead of phenoxydiethylene glycol acrylate homopolymer, 50 parts by weight of dicyclopentenyloxyethyl acrylate homopolymer (glass transition temperature 10 ° C, weight average molecular weight 80,000) Except having done, it carried out similarly to Example 1, and obtained the adhesive agent for front plate bonding for display devices.

(Comparative Example 1)
An adhesive for bonding a front plate for a display device was obtained in the same manner as in Example 1 except that phenoxydiethylene glycol acrylate was not blended and the blending amount of tricyclodecane dimethanol diacrylate was changed to 50 parts by weight.

(Comparative Example 2)
As a monofunctional radical polymerizable compound, 40 parts by weight of methoxy-triethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., “Light Acrylate MTG-A”) is blended instead of phenoxydiethylene glycol acrylate, and methoxy instead of phenoxydiethylene glycol acrylate homopolymer. -Adhesive for bonding a front plate for a display device in the same manner as in Example 1 except that 50 parts by weight of a homopolymer of triethylene glycol acrylate (glass transition temperature-50 ° C, weight average molecular weight 40,000) was blended. Obtained.

(Comparative Example 3)
As a monofunctional radical polymerizable compound, 40 parts by weight of 2-ethylhexyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) is blended instead of phenoxydiethylene glycol acrylate, and a homopolymer of 2-ethylhexyl acrylate (glass transition temperature) instead of a homopolymer of phenoxydiethylene glycol acrylate (-50 degreeC) Except having mix | blended 50 weight part, it carried out similarly to Example 1, and obtained the adhesive agent for front plate bonding for display devices.

(Comparative Example 4)
An adhesive for bonding a front plate for a display device was obtained in the same manner as in Example 1 except that the homopolymer of phenoxydiethylene glycol acrylate was not blended and the blending amount of phenoxydiethylene glycol acrylate was changed to 90 parts by weight.

(Comparative Example 5)
As in Example 1, except that 40 parts by weight of methoxy-triethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., “Light Acrylate MTG-A”) was added as a monofunctional radical polymerizable compound instead of phenoxydiethylene glycol acrylate. An adhesive for bonding a front plate for a display device was obtained.

(Comparative Example 6)
An adhesive for bonding a front plate for a display device was obtained in the same manner as in Example 1 except that 50 parts by weight of a polyester resin (“Byron 500” manufactured by Toyobo Co., Ltd.) was used instead of the homopolymer of phenoxydiethylene glycol acrylate. It was.

(Comparative Example 7)
An adhesive for attaching a front plate for a display device was obtained in the same manner as in Example 1 except that tricyclodecane dimethanol diacrylate was not blended and the blending amount of phenoxydiethylene glycol acrylate was changed to 50 parts by weight.

<Evaluation>
The following evaluation was performed about the adhesive agent for front plate bonding for display devices obtained in Examples 1-10 and Comparative Examples 1-7. The results are shown in Tables 1 and 2.

(1) Viscosity of the adhesive for bonding a front plate for display devices obtained in Examples 1 to 10 and Comparative Examples 1 to 7 under the conditions of 25 ° C. and 2.5 rpm using an E-type viscometer. It was measured.

(2) Compatibility The adhesive for bonding the front plate for display devices obtained in Examples 1 to 10 and Comparative Examples 1 to 7 was visually observed. The compatibility between the monomer component and the polymer component was evaluated.

(3) Transparency of cured product A film having a thickness of 300 μm is obtained by irradiating 3000 mJ / cm ² of ultraviolet rays to the adhesive for bonding the front plate for display device obtained in Examples 1 to 10 and Comparative Examples 1 to 7. The transparency was evaluated with “◯” when the transmittance of light having a wavelength of 405 nm was 90% or more and “X” when the transmittance was less than 90%.

(4) Moisture resistance of cured product A film having a thickness of 300 μm is obtained by irradiating 3000 mJ / cm ² of ultraviolet rays to the adhesive for bonding the front plate for display device obtained in Examples 1 to 10 and Comparative Examples 1 to 7. The prepared film was allowed to stand in a constant temperature bath at 85 ° C. and 85% RH for 500 hours. After removing the film from the thermostatic chamber, it is visually confirmed. When the film is transparent and transparent, “◯” is indicated. When the film is slightly observed, “△” is indicated. The moisture resistance of the cured product was evaluated as “x”.
In addition, when the adhesive for a display device front plate bonding obtained in Comparative Example 1 was used, the moisture resistance could not be evaluated.

(5) Adhesiveness 1 (after photocuring)
Using the wire bar, the adhesive for bonding the front plate for display devices obtained in Examples 1 to 10 and Comparative Examples 1 to 7 was applied onto ITO vapor-deposited PET (manufactured by Teijin Ltd.), and glass was formed thereon. Were pasted together. Next, using a metal halide lamp, the adhesive was cured by irradiating with 3000 mJ / cm ² of ultraviolet rays to prepare a polarizing plate for evaluation.
The 180 ° peel strength of the obtained polarizing plate for evaluation was measured using a universal testing machine (manufactured by Shimadzu Corporation, “EZ Graph”) under the condition of a peel rate of 5 mm / min. The case where the peel strength was 50 N / 25 mm or more was evaluated as “◯”, the case where it was 20 N / 25 mm or more and less than 50 N / 25 mm as “Δ”, and the case where it was less than 20 N / 25 mm as “X”. did.

(6) Adhesiveness 2 (after thermosetting)
Using the wire bar, the adhesive for bonding the front plate for display devices obtained in Examples 1 to 10 and Comparative Examples 1 to 7 was applied onto ITO vapor-deposited PET (manufactured by Teijin Ltd.), and glass was formed thereon. Were pasted together. The adhesive was cured by heating at 80 ° C. for 1 hour without irradiating with ultraviolet rays, and a polarizing plate for evaluation was produced.
The 180 ° peel strength of the obtained polarizing plate for evaluation was measured using a universal testing machine (manufactured by Shimadzu Corporation, “EZ Graph”) under the condition of a peel rate of 5 mm / min. The case where the peel strength was 50 N / 25 mm or more was evaluated as “◯”, the case where it was 20 N / 25 mm or more and less than 50 N / 25 mm as “Δ”, and the case where it was less than 20 N / 25 mm as “X”. did.
In addition, about the adhesive agent for front plate bonding for display devices obtained in Example 8, since the thermal radical polymerization initiator was not used, evaluation of adhesiveness 2 was not performed.

(Production Example 1)
(Preparation of dam agent A)
As monofunctional radically polymerizable compounds, 5 parts by weight of phenoxydiethylene glycol acrylate (manufactured by Daicel Cytec, "EBECRYL110"), 90 parts by weight of phenoxydiethylene glycol acrylate homopolymer (glass transition temperature -15 ° C, weight average molecular weight 30,000), 5 parts by weight of tricyclodecane dimethanol diacrylate (manufactured by Daicel Cytec, “IRR-214K”) as a polyfunctional radical polymerizable compound, and 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Japan, as a photo radical polymerization initiator, "Irgacure 184") 1 part by weight, 2 parts by weight of benzoyl peroxide (manufactured by NOF Corporation, "NIPER BW") as a thermal radical polymerization initiator, and γ-glycidoxypropylmethyl as a silane coupling agent 1 part by weight of ethoxysilane (manufactured by Shin-Etsu Silicone, “KBE-402”) is uniformly stirred and mixed at a stirring speed of 3000 rpm using a homodisper-type stirring mixer (manufactured by Primics, “Homodisper L-type”). Thus, dam agent A was obtained.

(Production Example 2)
(Preparation of dam agent B)
Dam agent B was obtained in the same manner as in Production Example 1 except that the blending amount of phenoxydiethylene glycol acrylate was changed to 30 parts by weight and the blending amount of the homopolymer of phenoxydiethylene glycol acrylate was changed to 65 parts by weight.

(Production Example 3)
(Preparation of dam agent C)
In place of phenoxydiethylene glycol acrylate, 5 parts by weight of nonylphenyl tetraethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate NP-4EA”) is blended, and the homopolymer of nonylphenyl tetraethylene glycol acrylate is used instead of the homopolymer of phenoxydiethylene glycol acrylate. Dam agent C was obtained in the same manner as in Production Example 1 except that 90 parts by weight of a polymer (glass transition temperature -25 ° C, weight average molecular weight 50,000) was blended.

(Production Example 4)
(Preparation of dam agent D)
Instead of phenoxydiethylene glycol acrylate, 5 parts by weight of 2-ethylhexyl diethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate EHDG-A”) is blended, and instead of the homopolymer of phenoxydiethylene glycol acrylate, a homopolymer of 2-ethylhexyl diethylene glycol acrylate ( A dam agent D was obtained in the same manner as in Production Example 1 except that 90 parts by weight of glass transition temperature -30 ° C, weight average molecular weight 70,000) was blended.

(Production Example 5)
(Preparation of dam agent E)
Dam agent E was obtained in the same manner as in Production Example 1 except that the amount of phenoxydiethylene glycol acrylate was changed to 1 part by weight and the amount of the homopolymer of phenoxydiethylene glycol acrylate was changed to 94 parts by weight.

(Production Example 6)
(Preparation of Fill Agent A)
As a monofunctional radical polymerizable compound, 45 parts by weight of phenoxydiethylene glycol acrylate (manufactured by Daicel Cytec, "EBECRYL110"), 50 parts by weight of a homopolymer of phenoxydiethylene glycol acrylate (glass transition temperature -15 ° C, weight average molecular weight 30,000), 5 parts by weight of tricyclodecane dimethanol diacrylate (manufactured by Daicel Cytec, “IRR-214K”) as a polyfunctional radical polymerizable compound, and 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Japan, as a photo radical polymerization initiator, "Irgacure 184") 1 part by weight, 2 parts by weight of benzoyl peroxide (manufactured by NOF Corporation, "NIPER BW") as a thermal radical polymerization initiator, and γ-glycidoxypropylmethyl as a silane coupling agent 1 part by weight of diethoxysilane (manufactured by Shin-Etsu Silicone, “KBE-402”) is uniformly stirred and mixed at a stirring speed of 3000 rpm using a homodisper type stirring mixer (manufactured by Primics, “homodisper L type”). Thus, a filling agent A was obtained.

(Production Example 7)
(Preparation of Fill Agent B)
Fill agent B was obtained in the same manner as in Production Example 6 except that the blending amount of phenoxydiethylene glycol acrylate was changed to 90 parts by weight and the blending amount of the homopolymer of phenoxydiethylene glycol acrylate was changed to 5 parts by weight.

(Production Example 8)
(Preparation of fill agent C)
In place of phenoxydiethylene glycol acrylate, 45 parts by weight of nonylphenyl tetraethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate NP-4EA”) is blended, and in place of the homopolymer of phenoxydiethylene glycol acrylate, the homopolymer of nonylphenyl tetraethylene glycol acrylate Fill agent C was obtained in the same manner as in Production Example 6 except that 50 parts by weight of a polymer (glass transition temperature-25 ° C, weight average molecular weight 50,000) was blended.

(Production Example 9)
(Preparation of fill agent D)
Instead of phenoxydiethylene glycol acrylate, 45 parts by weight of 2-ethylhexyl diethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate EHDG-A”) is blended, and instead of the homopolymer of phenoxydiethylene glycol acrylate, a homopolymer of 2-ethylhexyl diethylene glycol acrylate ( Fill agent D was obtained in the same manner as in Production Example 6 except that 50 parts by weight of glass transition temperature -30 ° C, weight average molecular weight 70,000) was blended.

(Production Example 10)
(Preparation of fill agent E)
Fill agent E was obtained in the same manner as in Production Example 6 except that the blending amount of phenoxydiethylene glycol acrylate was changed to 35 parts by weight and the blending amount of the homopolymer of phenoxydiethylene glycol acrylate was changed to 60 parts by weight.

<Evaluation>
The following evaluation was performed about the dam agents A to E and the fill agents A to E obtained in Production Examples 1 to 10. The results are shown in Table 3.

(1) Viscosity Using the E-type viscometer, the viscosity of the dam agents A to E and the fill agents A to E was measured under the conditions of 25 ° C. and 2.5 rpm.

(2) The compatibility of the monomer component and the polymer component was evaluated by visually observing the compatible dam agents A to E and the filler agents A to E, with “O” when transparent and “X” when opaque. .

(3) Transparency of cured products Dams A to E and Fill agents A to E are irradiated with 3000 mJ / cm ² of ultraviolet rays to produce a film having a thickness of 300 μm, and the transmittance of light with a wavelength of 405 nm is 90% or more. Transparency was evaluated with “◯” as the case of “x” and “x” as the case of less than 90%.

(4) Moisture resistant dams A to E and cured agents A to E of the cured product are irradiated with 3000 mJ / cm ² of ultraviolet rays to produce a film having a thickness of 300 μm, and the resulting film is 85 ° C. and 85% RH. For 500 hours. After removing the film from the thermostatic chamber, it is visually confirmed. When the film is transparent and transparent, “◯” is indicated. When the film is slightly observed, “△” is indicated. The moisture resistance of the cured product was evaluated as “x”.

(5) Adhesive dam agents A to E and fill agents A to E were applied onto ITO vapor-deposited PET (manufactured by Teijin Ltd.) using a wire bar, and glass was laminated thereon. Next, using a metal halide lamp, the adhesive was cured by irradiating with 3000 mJ / cm ² of ultraviolet rays to prepare a polarizing plate for evaluation.
The 180 ° peel strength of the obtained polarizing plate for evaluation was measured using a universal testing machine (manufactured by Shimadzu Corporation, “EZ Graph”) under the condition of a peel rate of 5 mm / min. The case where the peel strength was 50 N / 25 mm or more was evaluated as “◯”, the case where it was 20 N / 25 mm or more and less than 50 N / 25 mm as “Δ”, and the case where it was less than 20 N / 25 mm as “X”. did.

(Example 11)
The dam agent A was applied in a frame shape to the periphery of the liquid crystal panel using a dispenser (manufactured by Musashi Engineering, “Shot Master 3”). Next, the fill agent A was applied in the frame of the dam agent A of the liquid crystal panel using a dispenser. A glass plate (non-alkali glass, thickness 0.7 mm) is bonded to the liquid crystal panel coated with the dam agent A and the fill agent A as a front plate and irradiated with 3000 mJ / cm ² ultraviolet rays using a metal halide lamp. Agent A and Fill agent A were cured to produce a display device.
When the obtained display device was confirmed visually, the dam agent and the fill agent did not protrude or flow out, and the boundary line between the dam agent and the fill agent could not be seen.

(Example 12)
A display device was produced in the same manner as in Example 11 except that the filler B was used instead of the filler A.
When the obtained display device was confirmed visually, the dam agent and the fill agent did not protrude or flow out, and the boundary line between the dam agent and the fill agent could not be seen.

(Example 13)
A display device was produced in the same manner as in Example 11 except that the dam agent B was used instead of the dam agent A.
When the obtained display device was confirmed visually, the dam agent and the fill agent did not protrude or flow out, and the boundary line between the dam agent and the fill agent could not be seen.

(Example 14)
A display device was produced in the same manner as in Example 11 except that the filler B was used instead of the filler A and the dam agent B was used instead of the dam agent A.
When the obtained display device was confirmed visually, the dam agent and the fill agent did not protrude or flow out, and the boundary line between the dam agent and the fill agent could not be seen.

(Example 15)
A display device was produced in the same manner as in Example 11 except that the fill agent C was used instead of the fill agent A, and the dam agent C was used instead of the dam agent A.
When the obtained display device was confirmed visually, the dam agent and the fill agent did not protrude or flow out, and the boundary line between the dam agent and the fill agent could not be seen.

(Example 16)
A display device was produced in the same manner as in Example 11 except that the fill agent D was used instead of the fill agent A, and the dam agent D was used instead of the dam agent A.
When the obtained display device was confirmed visually, the dam agent and the fill agent did not protrude or flow out, and the boundary line between the dam agent and the fill agent could not be seen.

(Example 17)
The dam agent A was applied in a frame shape to the periphery of the liquid crystal panel using a dispenser (manufactured by Musashi Engineering, “Shot Master 3”). Next, the fill agent A was applied in the frame of the dam agent A of the liquid crystal panel using a dispenser. A liquid crystal panel coated with the dam agent A and the fill agent A is bonded to a glass plate (non-alkali glass, thickness 0.7 mm) provided with a light-shielding portion that does not transmit light as a front plate, and a metal halide lamp is used. The dam agent A and the fill agent A were cured by irradiating ultraviolet rays of 3000 mJ / cm ² . Next, by heating at 60 ° C. for 1 hour, the portion of the dam agent A and the fill agent A that were shielded by the light shielding portion were cured, and a display device was produced.
When the obtained display device was confirmed visually, the dam agent and the fill agent did not protrude or flow out, and the boundary line between the dam agent and the fill agent could not be seen.

(Reference Example 1)
A display device was produced in the same manner as in Example 11 except that the dam agent A was not used and the fill agent A was applied to the entire portion where the front plate of the liquid crystal panel was bonded using a dispenser.
When the obtained display device was confirmed visually, the protrusion of the fill agent A was confirmed between the liquid crystal panel and the front plate.

(Reference Example 2)
A display device was produced in the same manner as in Example 11 except that the dam agent B was used instead of the dam agent A and the fill agent E was used instead of the fill agent A.
When the obtained display device was confirmed with the naked eye, the dam agent was broken and the protrusion of the fill agent was confirmed.

(Reference Example 3)
A display device was produced in the same manner as in Example 11 except that the dam agent E was used instead of the dam agent A, and the fill agent B was used instead of the fill agent A.
When the obtained display device was visually confirmed, the dam agent and the fill agent did not protrude or flow out, but the distortion of the glass was confirmed at the boundary line between the dam agent and the fill agent.

(Reference Example 4)
A display device was produced in the same manner as in Example 11 except that the dam agent C was used instead of the dam agent A.
When the obtained display device was visually confirmed, the dam agent and the fill agent did not protrude or flow out, but the boundary line between the dam agent and the fill agent could be confirmed.

According to the present invention, the front plate and the base material are sufficiently bonded even when the transparency and the moisture resistance of the cured product are excellent and the polarity of the front plate and the base material to which the front plate is bonded is greatly different. An adhesive for bonding a front plate for a display device can be provided. Moreover, according to this invention, the display device which uses this adhesive agent for front plate bonding for a display device can be provided.

DESCRIPTION OF SYMBOLS 1 Front plate 2 Base material 3 Adhesive for bonding a front plate for display device 4 Light shielding portion 5 Light transmitting portion

Claims (8)

An adhesive used for bonding the base material of the display device and the front plate,
A monofunctional radical polymerizable compound having a hydrophilic group and a hydrophobic group in the molecule, a homopolymer of the monofunctional radical polymerizable compound, a polyfunctional radical polymerizable compound, and a photo radical polymerization initiator;
Monofunctional radically polymerizable compound having a hydrophilic group and a hydrophobic group in the molecule, 2-ethylhexyl glycol acrylate, or, the display devices that, comprising a compound represented by the following formula (1) Adhesive for pasting front plates.

In Formula (1), R ¹ represents hydrogen or a methyl group, and R ² represents a linear or branched saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms or a 2-hydroxypropylene group. R ³ represents a substituent represented by the following formula (2-1), (2-2), (2-3), or (2-4), and n is an integer of 1 to 6 Indicates.

In formula (2-1), R ⁴ represents hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms. The adhesive for bonding a front plate for a display device according to claim 1, further comprising a thermal radical polymerization initiator. An adhesive set used for bonding the base material of the display device and the front plate,
It consists of a dam agent that adheres the base material and the front plate at the periphery of the display device, and a fill agent that adheres the base material and the front plate inside the dam agent,
The said dam agent and the said fill agent are the adhesive agents for front plate bonding for display devices of Claim 1 or 2, Comprising: The homopolymer of the same monofunctional radically polymerizable compound, this monofunctional radically polymerizable compound, respectively. Containing a polyfunctional radically polymerizable compound and a photoradical polymerization initiator,
The dam agent has a higher monopolymer radical polymerizable compound homopolymer content than the fill agent,
The viscosity of the dam agent measured under conditions of 25 ° C. and 2.5 rpm using an E-type viscometer is the viscosity of the fill agent measured under conditions of 25 ° C. and 2.5 rpm using an E-type viscometer. The adhesive set for laminating a front plate for a display device, wherein the adhesive set is 3 to 10,000 times the number of A method for producing a display device in which a base material and a front plate are bonded together using an adhesive for bonding a front plate for a display device,
Applying the adhesive for bonding a front plate for a display device according to claim 1 or 2, to at least one of the base material and the front plate;
A method of manufacturing a display device, comprising: bonding the base material to the front plate and irradiating light to cure the display device front plate bonding adhesive. In the process of bonding the base material and the front plate and curing the adhesive for bonding the front plate for display device by irradiating light, the front plate for display device is bonded by irradiating light and heating. The method for manufacturing a display device according to claim 4, wherein the bonding adhesive is cured. A method for producing a display device in which a base material and a front plate are bonded together using an adhesive for bonding a front plate for a display device,
A step of applying a dam agent in a frame shape to at least one peripheral portion of the base material and the front plate; and
Applying a fill agent within the frame of the applied dam agent;
The step of curing the dam agent and the fill agent by irradiating light by laminating the base material and the front plate through the dam agent and the fill agent,
The method for producing a display device, wherein the dam agent and the fill agent are the dam agent and the fill agent of the adhesive set for bonding a front plate for a display device according to claim 3. In the step of laminating the base material and the front plate via a dam agent and a fill agent and irradiating light to cure the dam agent and the fill agent, by irradiating light and heating. The method for manufacturing a display device according to claim 6, wherein the dam agent and the fill agent are cured. A display device comprising the adhesive for bonding a front plate for a display device according to claim 1 or the adhesive set for bonding a front plate for a display device according to claim 3.

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