KR20170102063A - Curable resin composition, laminate comprising same, and process for production of the laminate - Google Patents

Abstract

A curable resin composition capable of sufficiently fixing the face materials between the face materials when the face materials are laminated and integrated via the resin layer made of the cured product of the curable resin composition and reducing the stress due to shrinkage upon curing of the resin layer, And a laminate obtained by laminating face plates using the curable resin composition.
As a curable resin composition that is at least used for the laminated body formed by curing by sandwiching a curable resin composition of uncured between either the face plate of transparent 1 pair, the storage shear modulus of the dynamic viscoelasticity measurement of the cured 5 × 10 ² ~ 1 x 10 < ⁵ > Pa, and the loss tangent is 1.4 or less.

Description

TECHNICAL FIELD [0001] The present invention relates to a curable resin composition, and a laminate using the same and a method of manufacturing the same. BACKGROUND ART [0002]

The present invention relates to a curable resin composition suitable for bonding face materials, a laminate obtained by laminating face plates using the curable resin composition, and a method for producing the laminate.

In a display device in which a protective plate is laminated on a display device with a bonding resin layer interposed therebetween, a stress generated by contraction of the bonding resin layer when the bonding resin layer is cured may affect the display device. If stress is applied to the display device, the following problems may occur.

The display-forming material (hereinafter, referred to as display material) in the display device is affected by the stress, and the uniformity of display may be impaired. For example, in the case of a liquid crystal display device, the arrangement of liquid crystal enclosed in a display device may be disturbed by external stress and may be visually recognized as display unevenness.

When an optical film for improving the display quality such as a viewing angle is formed on the substrate surface on the display surface side of the display device, the optical characteristics of the optical film are locally changed by the stress, .

Further, since the bonded resin layer is formed on the viewer side of the display device, the following problems may occur if bubbles are present in the cured resin resin layer.

The outgoing light or the reflected light from the display device is disturbed by the bubbles, and there is a possibility that the image quality of the display image is greatly damaged.

When the display device is not displaying an image, the bubbles remaining in the bonding resin layer are easily visually recognized through the protective plate, and thus there is a possibility that the quality of the product is greatly impaired.

The interfacial adhesion between the resin layer and the display device or the interfacial adhesion between the resin layer and the protective plate is reduced.

The following method is known as a method of manufacturing a display device having a laminated structure in which a transparent face material is laminated on a display device.

(1) After a liquid raw material is injected onto a protective plate made of a resin and cured to form a bonding resin, or a bonding resin on a roll sheet is pasted on a resin protective plate in a deaerated state, In a deaerated state while being pressed against the laminate. A silicone gel is preferably used as a raw material of the bonding resin (Patent Document 1).

(2) A method in which a display panel is positioned and fixed with a fixing member at a predetermined position of a glass protection plate, and then a liquid resin material is injected into a space formed between the protection plate and the display panel and cured. As a liquid resin material, a silicone resin is preferably used (Patent Document 2).

Japanese Patent Application Laid-Open No. 7-209635 Japanese Laid-Open Patent Publication No. 2006-58753

According to the knowledge of the present inventors, the polarity and the molecular weight of the resin forming the bonding resin layer can be decreased to lower the elastic modulus of the bonding resin layer. When the elastic modulus of the bonding resin layer interposed between the display device and the transparent face material is reduced, the stress generated at the time of shrinkage of the curing is reduced, and the influence on the display quality can be suppressed.

However, simply by lowering the elastic modulus of the bonding resin layer, the force for fixing the display device and the transparent face material may be insufficient. For example, when the display device is vertically installed and used, There is a fear that it may deviate with time or may be desorbed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a curable resin composition which is capable of sufficiently fixing the face plates together when the face plates are laminated and integrated via the resin layer comprising the cured product of the curable resin composition, And a laminate obtained by laminating a face plate using the curable resin composition.

In addition, the present invention can sufficiently fix the face plates to each other when the face plates are laminated and integrated via the resin layer made of the cured product of the curable resin composition, and can reduce stress due to shrinkage upon curing of the resin layer, It is another object of the present invention to provide a method for producing a laminate which can sufficiently suppress the generation of bubbles in the resin layer.

The curable resin composition of the present invention is a curable resin composition for use in a laminate formed by sandwiching and curing an uncured curable resin composition between a pair of face materials at least one of which is transparent, A shear modulus of 5 10 ² to 1 10 ⁵ Pa, and a loss tangent of 1.4 or less.

It is preferable to contain the following curing compound (II) and the following non-curable oligomer (D).

The curable compound (II) is composed of at least one kind of curable compound which undergoes a curing reaction at the time of curing of the curable resin composition, and at least one kind of the curable compound has a hydroxyl group which does not react upon curing of the curable resin composition.

(D): an oligomer which does not react with the curing compound (II) during the curing of the curing resin composition and which has 0.8 to 3 hydroxyl groups per molecule.

It is preferable that the curable compound (II) contains a monomer having a curable group and having a hydroxyl group.

Wherein the curable compound (II) comprises an oligomer (A ') having a curable group and a molecular weight of 1000 to 100000 and a monomer (B') having a curable group and having a molecular weight of 125 to 600, And a monomer (B3) having a hydroxyl group.

It is preferable that the noncurable oligomer (D) is a polyoxyalkylene polyol, and the oligomer (A ') is a urethane oligomer synthesized using a polyoxyalkylene polyol and a polyisocyanate as raw materials.

It is preferable that the oligomer (A ') has an acryl group and at least a part of the monomer (B') has a methacryl group.

It is preferable that the monomer (B3) contains hydroxyl methacrylate having 1 to 2 hydroxyl groups and 3 to 8 carbon atoms and a hydroxyalkyl group.

It is preferable that the monomer (B ') contains a monomer (B4) selected from the group consisting of alkyl methacrylates having an alkyl group having 8 to 22 carbon atoms.

It is preferable that the composition contains no chain transfer agent or contains a chain transfer agent and its content is 1 part by mass or less based on 100 parts by mass of the curable compound (II).

It is preferable that the curable resin composition is a photo-curable resin composition.

The present invention provides a laminate in which a pair of face plates are laminated and integrated through a resin layer made of a cured product of the curable resin composition of the present invention.

It is preferable that at least one of the pair of face plates is a transparent face plate.

One of the pair of face plates is a transparent face plate and the other is a display device.

It is preferable that the display device is a liquid crystal display device.

A method for producing a laminate of the present invention is a method for producing a laminate having a first face material and a second face material, a resin layer sandwiched between the first face material and the second face material, and a sealing portion surrounding the periphery of the resin layer , And the following steps (a) to (d).

(a) a step of applying a liquid curable resin composition for forming a seal portion containing a curable compound (I) and a polymerization initiator to the periphery of the surface of the first face plate to form a non-cured seal portion.

(b) A step of supplying a curable resin composition for forming a resin layer made of the curable resin composition of the present invention to a region surrounded by a seal portion of uncured.

(c) The second face material is superimposed on the curable resin composition for forming a resin layer under a reduced pressure of not more than 100 Pa, and the cured resin composition for forming a resin layer is sealed with the first face material, the second face material, A process for obtaining a laminated precursor.

(d) A step of curing the uncured sealing portion and the curable resin composition for forming a resin layer in a state in which the lamination precursor is kept under a pressure of 50 kPa or more.

At least one of the first face material and the second face material is preferably a transparent face material.

It is preferable that one of the first face material and the second face material is a transparent face material and the other is a display device.

Wherein the curable compound (I) is a photocurable compound, the curable resin composition for forming a seal part contains a photopolymerization initiator (C1), the curable resin composition for forming a resin layer is a curable resin composition which is photo- In the step (d), it is preferable to irradiate light to the uncured portion and the curable resin composition for forming a resin layer.

According to the curable resin composition of the present invention, by sandwiching and curing the face material between the face materials, a pair of face materials can be sufficiently fixed and the stress due to shrinkage upon curing can be reduced.

According to the laminate of the present invention, the face material and the face material are sufficiently fixed via the resin layer, and the stress due to shrinkage upon curing of the resin layer is reduced.

According to the method for producing a laminate of the present invention, it is possible to sufficiently fix a pair of face plates through a resin layer made of a cured product of the curable resin composition of the present invention, and the stress due to shrinkage upon curing of the resin layer And the laminate can be produced while sufficiently suppressing the generation of bubbles in the resin layer.

According to the manufacturing method of the present invention, the occurrence of bubbles in the resin layer between the display device and the protection plate is sufficiently suppressed, and the display device and the protection plate interpose the resin layer therebetween And the stress at the time of curing shrinkage is reduced so that the display device is prevented from deteriorating in display quality due to the stress.

1 is a cross-sectional view showing an example of a display device in which a display device is protected by a transparent face material.
2 is a plan view of the display device of Fig.
3 is a plan view showing an example of the shape of the step (a).
4 is a cross-sectional view showing an example of a state of the step (a).
5 is a plan view showing an example of a state of the step (b).
6 is a cross-sectional view showing an example of a state of the step (b).
7 is a cross-sectional view showing an example of a state of the step (c).
8 is a cross-sectional view showing an example of a state of the step (d).

In the present invention, it is defined as follows.

In a display device, a transparent face material to be a protective plate of a display device is referred to as a " surface material " and a display device is referred to as a " backing material ".

Surface material and backing material are collectively referred to as " face material ".

Among the face materials, in the production method of the present invention, the face material on which the sealing portion is formed on the periphery and the liquid curable resin composition is supplied to the region surrounded by the seal portion is referred to as " first face material " Is referred to as " second face material ".

The face material having light transmittance is referred to as " transparent face material ".

The transparent face material made of glass is called a " glass plate ".

Hereinafter, as a preferred embodiment of the present invention, a laminate according to the present invention is a display device, a pair of face plates is a surface material (a transparent face material to be a protective plate) and a backing material (display device) An embodiment in which the curable resin composition for resin layer formation is a photo-curable resin composition will be described.

<Display device>

1 is a cross-sectional view showing an example of a display device of the present embodiment, and Fig. 2 is a plan view.

The display device 1 includes a transparent face material 10 (a second face material (or a first face material)) as a surface material, a display device 50 (a first face material (or a second face material)) as a backing material, 10 and the display device 50 and a sealing portion 42 surrounding the resin layer 40 and a display device 50 connected to the display device 50 are operated A flexible printed wiring board 54 (FPC) on which a driving IC is mounted, and a light shielding printing portion 55 (light shielding portion) formed on the periphery of the transparent face material 10.

In the display device 1, the shielding printing portion 55 is formed on the periphery of the transparent face material 10 and the area of the light projecting portion 56 surrounded by the shielding printing portion 55 is surrounded by the sealing portion 42 The area of the transparent face material 10 is larger than the area of the display device 50 and the total area of the resin layer 40 and the seal portion 42 is smaller than the area of the transparent face material 10 and the display device 50, respectively.

[Surface material]

The surface material is a transparent face material (protective plate) that transmits a display image of a display device.

Examples of the transparent face material include a glass plate and a transparent resin plate. The transparent face plate is excellent in transparency to the outgoing light or reflected light from the display device, and is excellent in light resistance, low birefringence, high flatness, Glass plate is most preferable even in view of its high strength and high mechanical strength. A glass plate is preferable from the viewpoint of sufficiently transmitting light for curing the photocurable resin composition.

As a material of the glass plate, a glass material such as soda lime glass can be mentioned, and a highly transparent glass (white plate glass) having a lower iron content and a lower blue color is more preferable. Tempered glass may be used as the surface material to enhance safety.

As a material of the transparent resin plate, a resin material having high transparency (polycarbonate, polymethyl methacrylate, etc.) can be mentioned.

The transparent face material may be subjected to surface treatment in order to improve interfacial adhesion with the resin layer. Examples of the surface treatment method include a method of treating the surface of the transparent face material with a silane coupling agent and a method of forming a thin film of silicon oxide through an oxide salt by a frame burner. In order to increase the contrast of a display image, an anti-reflection layer may be formed on the back surface of the bonding surface with the resin layer. The antireflection layer can be formed by a method of directly forming an inorganic thin film on the surface of the transparent face material, or a method of bonding a transparent resin film with an antireflection layer to the transparent face material.

In addition, depending on the purpose of image display, a part or the whole of the transparent face material may be colored or scattering light in the form of an opaque glass, or refracting or reflecting light at the time of transmission through fine irregularities on the surface It can be. It is also possible to use an optical film, optical film or the like, which exhibits the above-described embodiment, optically modulated such as a polarizing film, or the like, which is obtained by blending a transparent face material with a transparent face material.

The thickness of the transparent face material is usually from 0.5 to 25 mm in the case of a glass plate in terms of mechanical strength and transparency. In applications such as a television receiver used indoors and a display for a PC, it is preferable that the display apparatus is 0.7 to 6 mm from the viewpoint of lightening the weight of the display device, and 3 to 20 mm is preferable for a public display application installed outdoors. Tempered glass may be used as the transparent face material, and when the transparent face material is thin, chemically tempered glass can be used. In the case of a transparent resin plate, 2 to 10 mm is preferable.

[Substrate]

The back side is a display device.

The display device 50 shown in the drawing is a liquid crystal display device having a configuration in which a transparent face plate 52 on which a color filter is formed and a transparent face plate 53 on which TFTs are formed are sandwiched by a pair of polarizing plates 51, However, the display device in the present embodiment is not limited to the example shown in the drawings.

The display device is a display device sandwiched between a pair of electrodes, at least one of which is a transparent electrode, and a display material whose optical mode is changed by an external electrical signal. There are a liquid crystal display device, an EL display device, a plasma display device, and an electronic ink display device depending on the kind of the display material. Further, the display device has a structure in which at least one of the face members is a transparent face member, and the transparent face member is disposed in contact with the resin layer. At this time, in some display devices, an optical film such as a polarizing plate and a retardation plate may be provided on the outermost layer side of the transparent face plate on the side in contact with the resin layer. In this case, the resin layer is an aspect of bonding the optical film and the surface material on the display device.

The surface of the display device to be bonded to the resin layer may be subjected to a surface treatment in order to improve the interfacial adhesion with the seal portion. The surface treatment may be only the periphery, or may be the entire surface of the face material. As a method of the surface treatment, a method of treating with a bonding primer capable of low-temperature processing or the like can be given.

The thickness of the display device is usually 0.4 to 4 mm in the case of a liquid crystal display device operated by a TFT, and 0.2 to 3 mm in the case of an EL display device.

[Resin Layer]

The resin layer is a layer formed by curing the curable resin composition of the present invention (hereinafter sometimes referred to as a photo-curable resin composition for forming a resin layer).

The curable resin composition of the present invention (the photo-curable resin composition for forming a resin layer of the present embodiment) can reduce the modulus of elasticity after curing and reduce the stress generated at the time of curing. Therefore, adverse effects on the display performance of the display device due to such stress can be suppressed. In addition, since the viscosity of the curable resin composition at the time of uncured is low, the supply of the curable resin composition to the surface of the face material can be performed in a short time, so that it is easy to prevent the bubbles from remaining after lamination of the surface material and the back material.

The thickness of the resin layer is preferably 0.03 to 2 mm, more preferably 0.1 to 0.8 mm, and particularly preferably 0.2 to 0.6 mm. When the thickness of the resin layer is 0.03 mm or more, the resin layer effectively cushions impact due to external force from the side of the transparent face material, thereby protecting the display device. Particularly, when the display device is sensitive to an external force and the display quality is likely to be affected, it is preferable that the thickness is 0.2 mm or more. In addition, in the manufacturing method of the present embodiment, even if foreign substances exceeding the thickness of the resin layer are mixed between the transparent face plate and the display device, the thickness of the resin layer is not largely changed, and the influence on the light transmission performance is small. When the thickness of the resin layer is 2 mm or less, bubbles do not remain in the resin layer, and the total thickness of the display device is not unnecessarily increased. When the elastic modulus of the resin layer is small, it is preferable that the thickness of the resin layer is 0.6 mm or less in order to suppress displacement of the junction position of the display device over time.

As a method of adjusting the thickness of the resin layer, there is a method of regulating the thickness of the seal portion, which will be described later, and controlling the supply amount of the liquid photo-curing resin composition for forming the resin layer to be supplied to the first face plate.

[Seal part]

The seal portion is formed by applying a liquid photo-curing resin composition for forming a seal portion, which will be described later, and curing it. Since the area outside the image display area of the display device is relatively narrow, the width of the seal part is preferably narrow. The width of the seal portion is preferably 0.5 to 2 mm, more preferably 0.8 to 1.6 mm.

[Shading printing section]

If necessary, the light shielding printing portion can be formed on the periphery of the transparent face material. The shading printing unit makes it impossible to visually recognize the image display area other than the image display area of the display device from the side of the transparent face material, thereby concealing wiring members and the like connected to the display device. The light shielding printing portion can be formed on the bonding surface of the transparent face material with the resin layer or on the back surface thereof and is provided on the bonding surface of the transparent face material with the resin layer in terms of reducing parallax between the light shielding printing portion and the image display region . When the transparent face material is a glass plate, it is preferable to use ceramic printing including a black pigment in the light-shielding printing portion because the light shielding property is high. The light shielding printing portion may be formed by bonding a transparent film having a light shielding printing portion formed on its surface or back surface thereof to a transparent face material. A transparent face material without a shading printing section may be used.

[shape]

The shape of the display device is typically rectangular.

The size of the display device is not particularly limited, but it is 0.3 m x 0.18 m in the case of a PC monitor using a liquid crystal display device in view of the manufacturing method of the present embodiment being particularly suitable for manufacturing a relatively large-area display device, , 0.4 m x 0.3 m or more is suitable, and 0.7 m x 0.4 m or more is particularly preferable. The upper limit of the size of the display device is often determined by the size of the display device. In addition, an overly large display device tends to be difficult to handle in installation or the like. The upper limit of the size of the display device is usually about 2.5 m x 1.5 m due to these restrictions. In the case of a small display, 0.14 m x 0.08 m or more is preferable.

The dimensions of the transparent face material to be a protective plate and the display device may be almost the same. However, in many cases, the transparent face material becomes larger than the display device due to the relationship with the other case in which the display device is housed. Conversely, depending on the structure of the other case, the transparent face material may be made slightly smaller than the display device.

<Manufacturing Method of Display Device>

The manufacturing method of the display device of the present embodiment is a method having the following steps (a) to (d).

(a) A liquid phase sealing resin composition for forming a sealing portion containing a curing compound (I) and a photopolymerization initiator (C1) is applied to the periphery of the surface of the first face sheet (the back face material (When the first face plate is a display device, a sealing portion is formed on the surface of the image display side).

(b) A step of supplying a liquid photo-curing resin composition for forming a resin layer containing a curing compound (II) and a photopolymerization initiator (C2) in a region surrounded by a seal portion of uncured.

(c) a second face material (a front face material (or a back face material)) is superimposed on the photo-curable resin composition for forming a resin layer under a reduced pressure of not more than 100 Pa to form a resin layer with a first face material, In the case where an antireflection film is formed on the surface of the second face plate, the surface of the back face side is in contact with the photocurable resin composition for forming a resin layer When the second face material is a display device, the image display side is superimposed on the photo-curable resin composition for forming a resin layer.

(d) A step of irradiating light to the uncured sealing portion and the resin layer-forming photocurable resin composition in a state in which the lamination precursor is left under a pressure of 50 kPa or more.

When no shielding portion is formed on the transparent face material, light is irradiated from the side of the transparent face material of the lamination precursor through the light transmitting portion to the seal portion and the photo-curing resin composition for forming the resin layer.

When the light shielding portion is formed on the periphery of the transparent face material, the area of the light transmitting portion surrounded by the light shielding portion becomes smaller than the area of the resin layer surrounded by the seal portion, and the photopolymerization initiator C2 Has an absorption wavelength lambda 2 existing on the longer wavelength side than the absorption wavelength lambda 1 of the photopolymerization initiator (C1) contained in the photo-curable resin composition for forming the seal portion, and in the step (d) So that the light radiated from the side of the absorption wavelength band? 1 includes the light of the wavelength within the absorption wavelength range? 1 and the light within the absorption wavelength range? 2.

The manufacturing method of the present embodiment is a method for forming a resin layer for forming a resin layer sealed in a high pressure atmosphere such as an atmospheric pressure atmosphere by filling a liquid phase resin for forming a resin layer for forming a resin layer between a first face material and a second face material under a reduced- And a method of curing the photo-curing resin composition to form a resin layer (a vacuum lamination method). The encapsulation of the photo-curing resin composition for forming a resin layer under reduced pressure is not a method of injecting a photo-curing resin for forming a resin layer into a narrow space between the first face material and the second face material, Curable resin composition for forming a resin layer is supplied to the surface of the first face material and the second face material is superimposed thereon to enclose the photo-curable resin composition for forming a resin layer between the first face material and the second face material.

There is known an example of a process for producing a transparent laminate by encapsulating a liquid photo-curable resin composition for forming a resin layer under reduced pressure and curing the photo-curable resin composition for forming a resin layer under atmospheric pressure. For example, in a pamphlet of International Publication No. 2008/81838 and International Publication No. 2009/16943, a method for producing a transparent laminate and a photo-curing resin composition for use in the production method are described and are hereby incorporated.

[Step (a)]

First, an uncured sealing portion is formed along the periphery of one surface of the first face plate. The backing material or the surface material may be used as the first face material.

When the first face plate is a transparent face plate serving as a protective plate of a display device, the face forming the uncured seal portion is any one of the two surfaces. In the case where the two surfaces have different properties, one of the necessary surfaces is selected. For example, when a surface treatment for improving the interfacial adhesion with the resin layer is performed on one surface, an uncured sealing portion is formed on the surface. When an antireflection layer is formed on one surface, an uncured sealing portion is formed on the back surface of the antireflection layer.

When the first face plate is a display device, the face forming the uncured portion of the sealant is the surface of the image display side.

The unhardened sealing portion is a portion of the uncured cured resin in the step (c) to be described later, from the interface between the uncured sealing portion and the first face material, and the interface between the uncured sealing portion and the second face material, It is important to have an interfacial adhesive force at least not to leak, and a rigidity enough to hold the shape. Therefore, it is preferable that the sealing portion of uncured state is formed by coating a photo-curing resin composition for forming a sealing portion having a high viscosity by printing, dispensing, or the like.

In order to keep the distance between the first face material and the second face material, spacer particles having a predetermined particle diameter may be added to the photo-curing resin composition for forming a seal portion. Immediately after applying the photo-curing resin composition for forming a seal part, the shape of the seal part can be maintained for a longer time by partially curing the seal part by irradiating light for curing the seal part.

[Photo-curable resin composition for forming a seal part]

The photo-curable resin composition for forming a seal part (hereinafter also referred to as seal material) is a liquid composition containing a photo-curable curable compound (I) and a photo polymerization initiator (C1).

The viscosity of the photo-curable resin composition for forming a seal part is preferably 500 to 3000 Pa s, more preferably 800 to 2500 Pa s, and still more preferably 1000 to 2000 Pa s. If the viscosity is 500 Pa s or more, the shape of the uncured portion of the seal can be maintained for a relatively long time, and the height of the seal portion can be sufficiently maintained. When the viscosity is 3000 Pas 占 퐏 or less, the sealing portion can be formed by a coating method.

The viscosity of the photo-curable resin composition for forming a seal part is measured at 25 캜 by using an E-type viscometer.

(Curable compound (I))

The curable compound (I) is preferably a mixture of at least one oligomer (A) having a curable group and having a number average molecular weight of 30,000 to 100,000, and at least one oligomer (A) having a number average molecular weight of from 30,000 to 100,000 in view of easily adjusting the viscosity of the photo- (B) having a curable group and a molecular weight of 125 to 600. The monomer (B)

Examples of the curable group of the oligomer (A) or the monomer (B) include an addition polymerizable unsaturated group (acryloyloxy group, methacryloyloxy group, etc.), a combination of an unsaturated group and a thiol group, And a group selected from the group consisting of an acryloyloxy group and a methacryloyloxy group is preferable in that a sealing part with high transparency is obtained.

The curable group in the oligomer (A) and the curable group in the monomer (B) may be the same or different. Since the curing group in the relatively high molecular weight oligomer (A) tends to have lower reactivity than the curing group in the relatively low molecular weight monomer (B), the curing of the monomer (B) first proceeds and the viscosity And the curing reaction may become heterogeneous. It is preferable that the curing group of the oligomer (A) is an acryloyloxy group having a relatively high reactivity and the curable group of the monomer (B) is a methacryloyl group having a relatively low reactivity in order to reduce the difference in reactivity between the curing groups of the two and to obtain a homogeneous seal portion. More preferably, a silane period.

The number average molecular weight of the oligomer (A) is 30,000 to 100,000, preferably 40,000 to 80,000, and more preferably 50,000 to 65,000. When the number average molecular weight of the oligomer (A) is within this range, the viscosity of the photo-curable resin composition for forming the seal portion can be easily adjusted to the above range.

The number average molecular weight of the oligomer (A) is the number average molecular weight in terms of polystyrene obtained by GPC measurement. When a peak of an unreacted low-molecular-weight component (such as a monomer) appears in the GPC measurement, the number average molecular weight is obtained except for the peak.

The molecular weight of the monomer (B) is from 125 to 600, preferably from 140 to 400, more preferably from 150 to 350. When the molecular weight of the monomer (B) is 125 or more, the volatilization of the monomer (B) when the display device is produced by the vacuum lamination method described later is suppressed. When the molecular weight of the monomer (B) is 600 or less, the solubility of the monomer (B) to the oligomer (A) having a high molecular weight can be enhanced and viscosity adjustment as a photo-curable resin composition for forming a seal portion can be preferably performed.

(Oligomer (A))

It is preferable that the oligomer (A) has an average of from 1.8 to 4 curable groups per molecule in view of the curability of the photo-curing resin composition for forming the seal portion and the mechanical properties of the seal portion.

Examples of the oligomer (A) include a urethane oligomer having a urethane bond, a poly (meth) acrylate of a polyoxyalkylene polyol, and a poly (meth) acrylate of a polyester polyol.

Urethane oligomers synthesized by using a polyol and a polyisocyanate as raw materials are preferable from the viewpoint that the mechanical properties of the resin after curing by the molecular design of the urethane chain or the like and the adhesiveness with the face material can be widely adjusted. ) Is more preferable. The polyol is more preferably a polyoxyalkylene polyol.

(Urethane oligomer (A1))

The urethane oligomer (A1) having a number average molecular weight in the range of from 30000 to 100000 has a high viscosity, so that it is difficult to synthesize by a usual method, and even if it can be synthesized, it is difficult to mix with the monomer (B).

Therefore, the urethane oligomer (A1) is synthesized by a synthesis method using the monomer (B) (the monomers (B1) and (B2) shown below), and the obtained product is directly used as a photo- Or the obtained product is again diluted with the monomer (B) (monomer (B1), monomer (B3), etc.) to be used as the photo-curable resin composition for forming the seal part.

- Monomer (B1): a monomer having a curable group in the monomer (B) and not having a group capable of reacting with an isocyanate group.

- Monomer (B2): A monomer having a group capable of reacting with an isocyanate group and having a curable group in the monomer (B).

- Monomer (B3): Of monomers (B), monomers having a curable group and also having a hydroxyl group.

Synthesis method of urethane oligomer (A1):

Reacting the polyol with a polyisocyanate in the presence of the monomer (B1) as a diluent to obtain a prepolymer having an isocyanate group, and then reacting the monomer (B2) with the isocyanate group of the prepolymer.

Examples of the polyol and the polyisocyanate include a known compound such as a polyol (i), a diisocyanate (ii), and the like, which are described as raw materials for the urethane oligomer (a) described in the pamphlet of International Publication No. 2009/016943 , Which are incorporated herein by reference.

Examples of the polyol (i) include polyoxyalkylene polyols such as polyoxyethylene glycol and polyoxypropylene diol, polyester polyols and polycarbonate polyols. Among these, a polyoxyalkylene polyol is preferable, and a polyoxypropylene polyol is particularly preferable. Further, substitution of a part of the oxypropylene group of the polyoxypropylene polyol with an oxyethylene group is more preferable because compatibility with other components of the resin composition for forming a resin layer can be enhanced.

Here, the substitution of a part of the oxypropylene group with an oxyethylene group means that a part of the oxypropylene structure constituting the polyoxypropylene polyol molecule is a molecular structure substituted with an oxyethylene structure. The same reference is applied to the following description. The oxyethylene structure may be present randomly or in a block in the polyoxypropylene polyol molecule. The oxyethylene structure may be either inside the polyoxypropylene polyol molecule or immediately before the terminal hydroxyl group. When the oxyethylene structure is immediately before the terminal hydroxyl group, it can be obtained by adding ethylene oxide to the polyoxypropylene polyol.

As the diisocyanate (ii), a diisocyanate selected from aliphatic diisocyanate, alicyclic diisocyanate and non-sulfur-modified aromatic diisocyanate is preferable. Among them, examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, 2,4,4-trimethyl-hexamethylene diisocyanate and the like. Examples of the alicyclic polyisocyanate include isophorone diisocyanate and methylene bis (4-cyclohexyl isocyanate). Examples of the non-sulfur-modified aromatic diisocyanate include xylylene diisocyanate and the like. These may be used singly or in combination of two or more kinds.

Examples of the monomer (B1) include alkyl (meth) acrylates having an alkyl group having 8 to 22 carbon atoms (n-dodecyl (meth) acrylate, n-octadecyl (meth) acrylate, Etc.), (meth) acrylates having an alicyclic hydrocarbon group (isobornyl (meth) acrylate, adamantyl (meth) acrylate, etc.).

Examples of the monomer (B2) include monomers having active hydrogen (hydroxyl group, amino group, etc.) and a curable group. Specific examples thereof include hydroxyalkyl (meth) acrylates having 2 to 6 carbon atoms (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate and 4-hydroxybutyl Hydroxyalkyl acrylates having a hydroxyalkyl group of 4 are preferred.

(Monomer (B))

It is preferable that the monomer (B) has 1 to 3 curable groups per molecule in view of the curability of the photo-curable resin composition for forming the seal portion and the mechanical properties of the seal portion.

The photo-curable resin composition for forming a seal part may contain the monomer (B1) used as a diluent in the method for synthesizing the urethane oligomer (A1) described above as the monomer (B). The monomer (B) may contain the unreacted monomer (B2) used in the above-described method for synthesizing the urethane oligomer (A1).

The monomer (B) preferably contains a monomer (B3) having a hydroxyl group in terms of adhesion between the face material and the seal portion and solubility of various additives to be described later.

Examples of the monomer (B3) having a hydroxyl group include hydroxyl methacrylate having a hydroxyl group number of 1 to 2 and a hydroxyalkyl group of 3 to 8 carbon atoms (2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl methacrylate, glycerol monomethacrylate and the like), and 2-hydroxybutyl methacrylate is particularly preferable.

The content of the monomer (B) in the photo-curable resin composition for forming the seal part is preferably 100% by mass or more (100% by mass) Is preferably from 15 to 50 mass%, more preferably from 20 to 45 mass%, and still more preferably from 25 to 40 mass%. When the proportion of the monomer (B) is 15 mass% or more, the curability of the photo-curing resin composition for forming the seal portion and the adhesion between the face plate and the seal portion are improved. When the proportion of the monomer (B) is 50 mass% or less, the viscosity of the photo-curing resin composition for forming the seal portion can be easily adjusted to 500 Pa · s or more.

In the synthesis of the urethane oligomer (A1), the monomer (B2) reacted with the isocyanate group of the prepolymer is present as a part of the oligomer (A). Therefore, the monomer ). &Lt; / RTI &gt; On the other hand, in the synthesis of the urethane oligomer (A1), the monomer (B) added after synthesizing the monomer (B1) used as the diluent and the urethane oligomer (A1) B).

(Photopolymerization initiator (C1))

Examples of the photopolymerization initiator (C1) contained in the photo-curing resin composition for forming a seal part include a photopolymerization initiator (C1), a photopolymerization initiator (C1), an acetophenone based polymer, a ketal based polymer, a benzoin or benzoin ether based polymer, a phosphine oxide based polymer, a benzophenone based polymer, , And photopolymerization initiators based on acetophenone, ketal, and benzoin ethers are preferred. In the case of curing by visible light having a short wavelength, a phosphine oxide-based photopolymerization initiator is more preferable in terms of the absorption wavelength side. By using two or more kinds of photopolymerization initiators (C1) having different absorption wavelength regions in combination, it is possible to further accelerate the curing time or increase the surface hardening property at the sealing portion. When the uncured portion for sealing and the photo-curing resin composition for forming a resin layer, which are held by the light-shielding printing portion by light irradiation from the side face of the face material, are formed on the transparent face material, A photopolymerization initiator (C2) described below may be used in combination within a range that does not inhibit the curing of the photocurable resin composition for forming the resin layer adjacent to the portion. The content ratio of the polymerization initiator (C1) and the polymerization initiator (C2) is preferably from 50: 1 to 5: 1 by mass ratio of (C1) :( C2) from the standpoint that the curing can be efficiently and effectively carried out, 1 is preferable. In order to cure the photo-curing resin composition for forming a resin layer sandwiched by the light-shielding printing portion in a short time by the light irradiated from the side face of the face material through the uncured sealing material, the photo- (C2) is not contained.

(The total amount of (C1) and (C2) when the photopolymerization initiator (C1) is contained in the photopolymerizable resin composition for forming a seal part (when the photopolymerization initiator (C2) is contained) is preferably the total amount of the curable compound Is preferably from 0.01 to 10 parts by mass, more preferably from 0.1 to 5 parts by mass, per 100 parts by mass of the total amount of the oligomer (A) and the monomer (B).

(additive)

The photo-curable resin composition for forming a seal part may contain a polymerization inhibitor, a photo-curing accelerator, a chain transfer agent, a light stabilizer (ultraviolet absorber, radical trapping agent, etc.), an antioxidant, Etc.), pigments, dyes and the like, and preferably contains a polymerization inhibitor and a light stabilizer. In particular, the stability of the photo-curable resin composition for forming a seal portion can be improved and the molecular weight of the resin layer after curing can be adjusted by containing a polymerization inhibitor in an amount smaller than that of the polymerization initiator. When the sealing material is cured by the light emitted from the side face of the face plate, the polymerization inhibitor, the chain transfer agent, the light stabilizer, the pigment or the dye which has the effect of delaying the curing reaction is not used as much as possible, .

Examples of the polymerization inhibitor include a polymerization inhibitor such as a hydroquinone system (2,5-di-t-butylhydroquinone and the like), a catechol system (pt-butylcatechol, etc.), an anthraquinone system, a phenothiazine system and a hydroxytoluene system And so on.

Examples of the light stabilizer include ultraviolet absorbers (benzotriazole-based, benzophenone-based, salicylate-based), radical trapping agents (hindered amine-based), and the like.

Examples of the antioxidant include phosphorus and sulfur compounds.

The total amount of these additives is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, based on 100 parts by mass of the total of the curing compound (I), i.e., the oligomer (A) and the monomer (B).

[Process (b)]

After the step (a), a liquid photo-curing resin composition for forming a resin layer is supplied to an area surrounded by a seal portion of uncured.

The supply amount of the photo-curable resin composition for forming a resin layer is such that the space formed by the seal portion, the first face material and the second face material is filled with the photo-curable resin composition for forming the resin layer, and the space between the first face material and the second face material (That is, the resin layer has a predetermined thickness) at a predetermined interval. At this time, it is preferable to consider the decrease in volume by the curing shrinkage of the photo-curing resin composition for forming the resin layer in advance. Therefore, the amount is preferably such that the thickness of the photo-curing resin composition for resin layer formation becomes slightly thicker than the predetermined thickness of the resin layer. When the curing shrinkage is small, the predetermined thickness of the resin layer and the thickness of the photocurable resin composition for forming the resin layer may be substantially the same.

As the feeding method, there can be mentioned a method in which the first face sheet is placed horizontally and fed in a passe, a line or a plane by a feeding means such as a dispenser or a die coater.

[Photocurable resin composition for resin layer formation]

The photo-curable resin composition for forming a resin layer is a liquid photo-curable resin composition having a storage shearing modulus in a dynamic viscoelasticity measurement after curing of 5 10 ² to 1 10 ⁵ Pa and a loss tangent (tan?) Of 1.4 or less .

The storage shear modulus and the loss tangent are measured by irradiating light while applying dynamic shear strain to a photo-curable resin composition for forming an uncured resin layer using a dynamic viscoelasticity measuring apparatus, as described in detail below, The composition is cured.

When the shear modulus after curing is 5 x 10 &lt; ⁵ &gt; Pa or less, the stress caused by the shrinkage of the resin at the time of curing can be sufficiently reduced, and the influence on the display quality of the display panel can be suppressed. When the shear modulus of elasticity is 5 x 10 &lt; ² &gt; Pa or more, the resin layer is hardly deformed elastically, and displacement between the display device and the transparent face material can be easily prevented. When the loss tangent is 1.4 or less, the display device is sufficiently fixed on the transparent face material even when the display device is installed vertically, and the resin layer is plastically deformed by the self weight of the display device, It is possible to satisfactorily prevent displacement of the position

The storage shear modulus is preferably 8 × 10 ² to 5 × 10 ⁴ Pa, more preferably 1 × 10 ³ to 3 × 10 ⁴ Pa. The loss tangent is preferably 1.0 or less, more preferably 0.5 or less.

Such as a liquid crystal display device of the IPS type, which will be described later, the number of places using a susceptible display device affect the display performance due to stress caused by shrinkage during curing of the resin layer, the storage shear modulus 5 × 10 ² ~ 5 after curing X 10 &lt; ³ &gt; Pa, and a loss tangent (tan delta) of less than 0.2. By setting the shear modulus to 5 x 10 &lt; ³ &gt; Pa or less, the stress caused by the shrinkage of the resin at the time of curing can be suppressed to a sufficiently small value and the loss tangent (tan? , It is possible to suppress plastic deformation over time of the resin layer due to its own weight of the display device. In this case, it is more preferable that the loss tangent (tan?) Is 0.1 or less.

The lower limit of the loss tangent is not particularly limited and may be within a range that can be taken into production. In the case of a relatively flexible resin layer, it is usually 0.01 or more.

The viscosity of the photo-curing resin composition for forming a resin layer is preferably from 0.05 to 50 Pa s, more preferably from 1 to 20 Pa s. When the viscosity is 0.05 Pa · s or more, the ratio of the monomer (B ') which will be described later can be suppressed and deterioration of the physical properties of the resin layer can be suppressed. Further, since the component of the low boiling point is reduced, it is suitable for the vacuum lamination method described later. When the viscosity is 50 Pa 占 퐏 or less, bubbles do not remain in the resin layer.

The viscosity of the photo-curable resin composition for forming a resin layer is measured at 25 캜 using an E-type viscometer.

The photo-curable resin composition for forming a resin layer is preferably a liquid composition containing a photo-curable curable compound (II), a photo polymerization initiator (C2), and a non-curable oligomer (D). The non-curable oligomer (D) is an oligomer having 0.8 to 3 hydroxyl groups per molecule which does not react with the curable compound (II) in the composition during curing of the photo-curable resin composition for forming a resin layer.

By including the non-curable oligomer (D) in the photo-curable resin composition for forming a resin layer, the storage shear modulus can be lowered while suppressing an increase in the loss tangent (tan?) Of the resin layer after curing, The storage shear modulus of elasticity and the loss tangent (tan delta) can be achieved at the same time.

Further, by containing a small amount of chain transfer agent, the storage modulus of the resin layer can be reduced by adjusting the molecular weight of the resin layer after curing, but the curing rate is often slowed down.

In the photo-curable resin composition for forming a resin layer containing a relatively large amount of the non-curable oligomer (D) of the present invention, since the modulus of elasticity can be adjusted by the content of the oligomer (D), the content of the chain transfer agent . Specifically, the addition amount of the chain transfer agent is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, based on 100 parts by mass of the total of the curable compound (II), i.e., the oligomer (A ') and the monomer (B' More preferable. The chain transfer agent includes n-dodecyl mercaptan.

(Curable compound (II))

The curable compound (II) in the photo-curable resin composition for forming a resin layer is composed of at least one kind of curable compound which undergoes a curing reaction at the time of curing the photo-curable resin composition for forming the resin layer, and at least one kind of the curable compound , And the compound (IIa) having a hydroxyl group which does not react upon curing of the photo-curable resin composition for forming the resin layer.

When the curable compound (II) contains the compound (IIa), a hydroxyl group is present in the cured product obtained by the curing reaction of the curable compound (II) alone. The presence of such a hydroxyl group contributes to the stabilization of the uncurable oligomer in the photo-curable resin composition for forming a resin layer.

Therefore, the compound (IIa) having a hydroxyl group which does not react upon curing may be one which has an unreacted hydroxyl group after the curing reaction. For example, even if a part of the hydroxyl groups of the compound (IIa) It may be left unreacted without reacting.

The compound (IIa) having a hydroxyl group which does not react upon curing may have a curing group which contributes to the curing reaction, and may have a hydroxyl group. The compound (IIa) may be a monomer or an oligomer having a repeating unit. In order to make it easier to adjust the viscosity of the photo-curing composition at the time of uncured curing, it is preferable to use a monomer having a curable group and also having a hydroxyl group as the compound (IIa). Specific examples of the compound (IIa) which is a monomer having a hydroxyl group include hydroxy (meth) acrylate having a hydroxyl group number of 1 to 2 and a hydroxyalkyl group having 3 to 8 carbon atoms (2-hydroxypropyl (meth) Hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate and the like are preferable, and 2-hydroxy (meth) acrylate Particularly preferred is butyl methacrylate.

As the curable compound (II), at least one oligomer (A ') having a curable group and having a number average molecular weight of 1000 to 100000 and a curable group and having a molecular weight of 125 (B ') having a number-average molecular weight (Mw) of at most 600.

In this case, as at least a part of the monomer (B '), it is preferable to use a monomer (B3) having a hardening group and a hydroxyl group and having a molecular weight of 125 to 600.

Examples of the curing group of the oligomer (A ') or the monomer (B') include an addition polymerizable unsaturated group (acryloyloxy group, methacryloyloxy group, etc.), a combination of an unsaturated group and a thiol group, A group selected from the group consisting of an acryloyloxy group and a methacryloyloxy group is preferable in that a resin layer having a high transparency and a high transparency can be obtained.

The curable group in the oligomer (A ') and the curable group in the monomer (B') may be the same or different. Since the curing group in the relatively high molecular weight oligomer (A ') tends to have lower reactivity than the curing group in the relatively low molecular weight monomer (B'), the curing of the monomer (B ' There is a fear that the whole viscosity becomes high and the curing reaction becomes heterogeneous. It is preferable that the curing group of the oligomer (A ') is an acryloyloxy group having a relatively high reactivity and the curable group of the monomer (B') is relatively reactive, in order to reduce the difference in reactivity between the curing groups of the two and to obtain a homogeneous resin layer And it is more preferable to use a lower methacryloyloxy group.

(Oligomer (A '))

The number average molecular weight of the oligomer (A ') is preferably from 1,000 to 100,000, more preferably from 10,000 to 700,000. When the number average molecular weight of the oligomer (A ') is within this range, the viscosity of the photo-curable resin composition for forming a resin layer can be easily adjusted to the above range.

The number average molecular weight of the oligomer (A ') is the number average molecular weight in terms of polystyrene obtained by GPC measurement. When a peak of an unreacted low-molecular-weight component (such as a monomer) appears in the GPC measurement, the number average molecular weight is obtained except for the peak.

The oligomer (A ') preferably has an average of from 1.8 to 4 curable groups per molecule in view of the curability of the photo-curable resin composition for forming a resin layer and the mechanical properties of the resin layer.

Examples of the oligomer (A ') include a urethane oligomer having a urethane bond, a poly (meth) acrylate of a polyoxyalkylene polyol, and a poly (meth) acrylate of a polyester polyol. The urethane oligomer (A2) is preferable because it can widely adjust the mechanical properties of the resin after curing and the adhesion with the face material.

The urethane oligomer (A2) is preferably synthesized by reacting a polyol and a polyisocyanate to obtain a prepolymer having an isocyanate group, and then reacting the monomer (B2) with an isocyanate group of the prepolymer.

Examples of the polyol and the polyisocyanate include a known compound such as a polyol (i), a diisocyanate (ii), and the like, which are described as raw materials for the urethane oligomer (a) described in the pamphlet of International Publication No. 2009/016943 , Which are incorporated herein by reference.

As the urethane oligomer (A2), a commercially available product may be used. For example, EB230 (manufactured by Daicel-Cytec Corporation, number of functional groups 2, polypropylene glycol / IPDI / 2-hydroxyethyl acrylate is regarded as a reaction product ), U-200AX (manufactured by Shin-Nakamura Chemical Co., Ltd., functional group number 2, aliphatic polyester polyol / aliphatic or alicyclic polyisocyanate / 2-hydroxyethyl acrylate).

The content of the oligomer (A ') is preferably from 20 to 90% by mass based on the total (100% by mass) of the curable compound (II), that is, the sum of the oligomers (A') and the monomers (B ' , More preferably from 30 to 80 mass%. When the proportion of the oligomer (A ') is 20 mass% or more, the heat resistance of the resin layer becomes good. When the proportion of the oligomer (A ') is 90% by mass or less, the curability of the photocurable resin composition for forming a resin layer and the adhesion between the face material and the resin layer are improved. Since the oligomer (A ') has a large molecular weight per one curable group, it is more preferable that the proportion of the oligomer (A') is 70 to 90 mass% in order to specifically suppress shrinkage upon curing.

(Monomer (B '))

The molecular weight of the monomer (B ') is preferably from 125 to 600, more preferably from 140 to 400. When the molecular weight of the monomer (B ') is 125 or more, the volatilization of the monomer when the display device is manufactured by the vacuum lamination method described later is suppressed. If the molecular weight of the monomer (B ') is 600 or less, the adhesion between the face plate and the resin layer becomes good.

The monomer (B ') preferably has 1 to 3 curable groups per molecule in view of the curability of the photo-curable resin composition for forming a resin layer and the mechanical properties of the resin layer.

The content of the monomer (B ') is preferably 10 to 80% by mass in the total (100% by mass) of the curable compound (II), that is, the sum of the oligomers (A') and the monomers (B ' , More preferably from 20 to 70 mass%.

The monomer (B ') preferably contains a monomer (B3) having a curable group and also having a hydroxyl group. The monomer (B3) contributes to the stabilization of the noncurable oligomer (D). Also, when the monomer (B3) is contained, excellent adhesion between the face plate and the resin layer is easily obtained. The number of hydroxyl groups in one molecule of the monomer (B3) can be arbitrarily selected from the number capable of stabilizing the noncurable oligomer (D), but it is preferably 1 to 2 in one molecule from the viewpoint of availability.

The monomer (B3) having a hydroxyl group may be the same as the monomer (B3) in the photo-curable resin composition for forming a seal portion, and 2-hydroxybutyl methacrylate is particularly preferable.

The content of the monomer (B3) is preferably 10 to 60% by mass in the total (100% by mass) of the curable compound (II), i.e., the sum of the oligomers (A ') and the monomers (B') By mass, and more preferably from 20 to 50% by mass. If the content of the monomer (B3) is 10% by mass or more, the effect of improving the stability of the photocurable resin composition for forming a resin layer and improving the adhesion of the face material and the resin layer tends to be sufficiently obtained. When the content of the monomer (B3) is 60% by mass or less, the hardness of the cured product of the resin composition for forming a resin layer is not excessively high, which is preferable.

The monomer (B ') preferably contains the following monomer (B4) in view of the mechanical properties of the resin layer. The monomer (B4) lowers the glass transition temperature (Tg) of the resin layer after curing, thereby contributing to lowering of the elastic modulus of the resin layer after curing, thereby improving the flexibility of the resin layer.

However, in some cases, it is preferable that the content of the monomer (B4) is reduced or not, for example, when the curing property of the photo-curable resin composition for forming a resin layer is increased to shorten the time required for curing.

Monomer (B4): At least one member selected from the group consisting of alkyl methacrylates having an alkyl group having from 8 to 22 carbon atoms. When the number of carbon atoms is 8 or more, the glass transition temperature of the cured product can be lowered, and when the number of carbon atoms is 22 or less, alcohol as a raw material can be easily obtained as a light oil.

Examples of the monomer (B4) include n-dodecyl methacrylate, n-octadecyl methacrylate and n-behenyl methacrylate, and n-dodecyl methacrylate or n-octadecyl methacrylate The rate is preferred.

The content of the monomer (B4) is preferably 5 to 50 mass% in the total (100 mass%) of the curable compound (II), that is, the total amount (100 mass%) of the oligomer (A ') and the monomer , More preferably 15 to 40 mass%. If the content of the monomer (B4) is 5 mass% or more, a sufficient addition effect of the monomer (B4) tends to be obtained easily.

(Photopolymerization initiator (C2))

Examples of the photopolymerization initiator (C2) contained in the photocurable resin composition for forming a resin layer include a photopolymerization initiator (C2), such as an acetophenone based, ketal based, benzoin or benzoin ether based, phosphine oxide based, benzophenone based, thioxanthone based, , A photopolymerization initiator of a phosphine oxide type or a thioxanone type is preferable, and a phosphine oxide type is particularly preferable in terms of suppressing coloration after a photopolymerization reaction.

The content of the photopolymerization initiator (C2) in the photocurable resin composition for forming a resin layer is preferably 0.01 to 5 parts by mass based on 100 parts by mass of the total of the curing compound (II), i.e., the oligomer (A ') and the monomer (B' 10 parts by mass is more preferable, and 0.1 parts by mass to 5 parts by mass is more preferable.

When a part of the photo-curing resin composition for forming a resin layer adjacent to the sealing material is cured by the light irradiated from the side of the face material, the photo-polymerization initiator (C2) 2) which is located on the longer wavelength side than the wavelength? 2. The photopolymerization initiator C2 may have only the absorption wavelength lambda 2 or may have the absorption wavelength lambda 1 'and absorption wavelength lambda 2 overlapping with the absorption wavelength lambda 1.

(Non-curable oligomer (D))

The non-curable oligomer (D) is preferably used in the photo-curable resin composition for forming a resin layer and does not contribute to curing, so that the stress due to shrinkage upon curing of the resin layer can be reduced without impairing transparency and homogeneity .

The non-curable oligomer (D) is an oligomer having 0.8 to 3 hydroxyl groups per molecule which does not react with the curable compound (II) in the composition during curing of the photo-curable resin composition for forming a resin layer. The number of hydroxyl groups per molecule is more preferably 2 to 3. When the number of hydroxyl groups per one molecule is 0.8 or more, it is preferable that the noncurable oligomer can stably be maintained between the noncurable oligomers or the cured product obtained from the noncurable oligomer and the curable compound (II) , And when the number of hydroxyl groups per one molecule is 3 or less, the non-curable oligomer is preferable because it can be preferably used in the resin composition for forming a resin layer.

The number average molecular weight (Mn) per hydroxyl group of the noncurable oligomer (D) is preferably 400 to 8000. If the number-average molecular weight per hydroxyl group is 400 or more, the polarity of the non-curable oligomer (D) is not excessively increased, and good compatibility with the curable compound (II) in the resin composition for forming a resin layer is likely to be obtained. When the number average molecular weight per hydroxyl group is 8000 or less, the noncurable oligomer (D) is stabilized in the resin layer after curing by the interaction between the hydroxyl groups derived from the curable compound (II) and the hydroxyl groups of the non-curable oligomer (D) It is easy to obtain the effect of making This interaction is presumed to involve hydrogen bonding.

The noncurable oligomer (D) may be used singly or in combination of two or more.

Examples of the noncurable oligomer (D) containing a hydroxyl group include a high molecular weight polyol and the like, and a polyoxyalkylene polyol, a polyester polyol and a polycarbonate polyol are preferable.

Examples of the polyoxyalkylene polyol include polyoxyalkylene monool, polyoxyalkylene diol or polyoxyalkylene tereol having repeating units of oxyalkylene having 2 to 4 carbon atoms. Specific examples include polyoxyethylene glycol, polyoxypropylene diol (hereinafter also referred to as polypropylene glycol), polyoxypropylene triol, and polyoxytetramethylene glycol.

The number average molecular weight (Mn) of the polyoxyalkylene polyol per hydroxyl group is preferably from 400 to 8000, more preferably from 600 to 5,000.

Examples of the polyester polyol include aliphatic polyesters having residues of aliphatic diols such as ethylene glycol, propylene glycol, and 1,4-butanediol and residues of aliphatic dicarboxylic acids such as glutaric acid, adipic acid and sebacic acid Diols.

Examples of the polycarbonate polyol include an aliphatic polycarbonate diol such as an aliphatic polycarbonate diol having a diol residue such as 1,6-hexanediol, and a ring-opening polymer of an aliphatic cyclic carbonate.

The number average molecular weight (Mn) of the polyester polyol or polycarbonate polyol per hydroxyl group is preferably 400 to 8000, and more preferably 800 to 6000.

The number average molecular weight of the non-curable oligomer (D) in the present specification is preferably in the range of from 1 to 100 parts by weight per 100 parts by weight of the hydroxyl group (A) (KOH mg / g) measured in accordance with JIS K 1557-1 Is the value calculated from the number B of hydroxyl groups by the following formula (1).

Molecular weight of the non-curable oligomer (D) = 56.1 x B x 1000 / A (One)

It is preferable to use a polyoxyalkylene polyol as the non-curable oligomer (D), particularly, a polyoxypropylene polyol because the elasticity of the resin layer after curing tends to be lower. As described later, a part of the oxypropylene group of the polyoxypropylene polyol may be substituted with an oxyethylene group in order to control the polarity of the non-curable oligomer (D). The same as the description of the polyol (i) described above in which a part of the oxypropylene group may be substituted with an oxyethylene group.

For example, the oligomer (A ') is a urethane oligomer synthesized using a polyoxyalkylene polyol and a polyisocyanate as raw materials, and the noncurable oligomer (D) is a polyoxyalkylene polyol in view of compatibility .

In the present invention, in order to stabilize the photo-curable resin composition for forming a resin layer in the uncured state and to prevent the uncured oligomer (D) from being separated from the resin layer after curing, the oligomer (A ') and the non- (D) have molecular chains of the same structure or similar structure.

Specifically, a compound having a hydroxyl group such as a polyol (hereinafter sometimes referred to as a hydroxyl group-containing compound) is used as a raw material in synthesizing the oligomer (A ') in the photo-curable resin composition for forming a resin layer , It is preferable to use the same hydroxyl group-containing compound as the non-curable oligomer (D).

For example, when the oligomer (A ') is a urethane oligomer synthesized using a polyoxyalkylene polyol and a polyisocyanate as raw materials, the polyoxyalkylene polyol is preferably used as the non-curable oligomer (D).

Alternatively, when the hydroxyl group-containing compound as the raw material of the oligomer (A ') and the hydroxyl group-containing compound used as the non-curable oligomer (D) are not the same, the molecular chains of both of them have a common repeating unit Structure, and it is preferable that the polarities of both are the same. Methods for adjusting the polarity include, for example, a method of increasing the polarity by introducing a polar group, a method of increasing polarity by substituting a part of the oxypropylene group with an oxyethylene group, and a method of increasing the polarity by decreasing the molecular weight per hydroxyl group have. These methods may be combined.

For example, when the oligomer (A ') is a polyoxypropylene polyol (a') in which a part of the oxypropylene group is substituted with an oxyethylene group and a urethane oligomer synthesized by using a polyisocyanate as a raw material, As the oxypropylene polyol, it is preferable to use a polyoxypropylene polyol having a molecular weight per one hydroxyl group smaller than that of the polyol (a ') as the non-curable oligomer (D).

As an example of the most preferable photo-curable resin composition for forming a resin layer, a prepolymer having an isocyanate group is obtained by reacting a polyoxypropylene diol substituted with an oxyethylene group with a part of an oxypropylene group and a polyisocyanate compound, (A2) obtained by reacting a urethane oligomer (A2) obtained by reacting a polyoxypropylene diol having an oxyethylene group substituted with an oxyethylene group as a raw material of the urethane oligomer (A2) with a noncurable oligomer ( D) as a monomer (B '), and a monomer (B3) having a hydroxyl group as a monomer (B').

As such, if the oligomer (A ') partially has the same molecular structure as the non-curable oligomer (D), the compatibility of the uncurable oligomer (D) in the composition becomes higher and the monomer (B') has a hydroxyl group , It is considered that the noncurable oligomer (D) can be stably present in the cured product due to the interaction of the hydroxyl groups in the molecular structure of the uncured oligomer (D) in the molecular structure of the curable compound (II) after curing.

As another example, a urethane oligomer (A2) obtained by reacting a polyoxypropylene diol having a part of an oxypropylene group substituted with an oxyethylene group and a polyisocyanate compound to obtain a prepolymer having an isocyanate group and then reacting with the monomer (B2) As the oligomer (A '), the polyoxypropylene diol not substituted with an oxyethylene group, the polyoxypropylene diol having a smaller molecular weight than the polyoxypropylene diol as the raw material of the urethane oligomer (A2), as the uncured oligomer (D) Also in the case of a composition containing a monomer (B3) having a hydroxyl group as the monomer (B '), good compatibility of the non-curable oligomer (D) in the composition can be obtained and stable curing of the uncurable oligomer (D) Can exist.

The content of the non-curable oligomer (D) in the photo-curing resin composition for forming a resin layer is preferably from 10 to 90% by mass. When the content of the non-curable oligomer is 10 mass% or more, the effect of reducing the stress caused by the shrinkage of the resin at the time of curing tends to be sufficiently obtained. When the content is 90% by mass or less, the face members are easily fixed to each other, and the positional displacement with time after the bonding of the face material and the back material is easily prevented well. The content of the non-curable oligomer (D) is preferably set so as to obtain a storage shear modulus and a desirable value of loss tangent depending on the composition of the curable compound (II). A more preferred range is 30 to 80 mass%.

(additive)

The photo-curing resin composition for forming a resin layer may contain a polymerization inhibitor, a photo-curing accelerator, a chain transfer agent, a light stabilizer (ultraviolet absorber, radical capturing agent, etc.), an antioxidant, Etc.), pigments, dyes, and the like, and preferably contains a polymerization inhibitor or a light stabilizer. In particular, by containing a polymerization inhibitor in an amount smaller than that of the polymerization initiator, the stability of the photo-curable resin composition for forming a resin layer can be improved and the molecular weight of the resin layer after curing can also be adjusted.

[Step (c)]

After step (b), the first face plate to which the photo-curable resin composition for forming a resin layer is fed is placed in a decompression apparatus, and the first face plate is placed horizontally on the fixed support board in the decompression apparatus so that the face of the curable resin composition is located .

A movable support mechanism capable of moving in the vertical direction is formed in the upper portion of the decompression apparatus, and a second face plate is attached to the movement support mechanism. When the second face plate is a display device, the surface of the side on which the image is displayed faces downward. When the antireflection layer is formed on the surface of the second face plate, the surface on the side where the antireflection layer is not formed faces downward.

The second face sheet is placed at a position above the first face sheet and in contact with the photo-curable resin composition for forming a resin layer. That is, the photocurable resin composition for forming the resin layer on the first face material and the second face material are opposed to each other without contact.

Further, a movable support mechanism capable of moving in the up and down direction may be formed in the lower portion of the decompression apparatus, and a first face plate to which the curable resin composition is supplied may be provided on the movable support mechanism. In this case, the second face plate is mounted on a fixed support plate formed at the upper portion in the pressure-reducing device to face the first face plate and the second face plate.

Further, both of the first face material and the second face material may be supported by a movement supporting mechanism formed above and below the inside of the pressure reducing device.

After arranging the first face plate and the second face plate at predetermined positions, the interior of the pressure-reducing device is reduced in pressure to obtain a predetermined reduced-pressure atmosphere. If possible, the first face plate and the second face plate may be positioned at predetermined positions in the pressure reducing apparatus during the pressure reducing operation or after the pressure reducing atmosphere is set to a predetermined reduced pressure atmosphere.

After the inside of the decompression apparatus becomes a predetermined reduced pressure atmosphere, the second face plate supported by the movement supporting mechanism is moved downward, and the second face plate is superimposed on the photo-curable resin composition for forming the resin layer on the first face plate.

By superposition, the surface of the first face material (the surface on the image display side in the case of the display device), the surface of the second face material (in the case of the display device, the surface on the image display side) A photo-curing resin composition for forming a resin layer is sealed in the enclosed space.

 The photo-curable resin composition for forming a resin layer is pushed out by the self weight of the second face plate, the pressing force from the movement support mechanism, etc., so that the photo-curable resin composition for resin layer formation is filled in the space, (d), a layer of a photo-curable resin composition for forming a resin layer with little or no bubbles is formed when exposed to a high pressure atmosphere.

The reduced-pressure atmosphere at the time of superposition is 100 Pa or less, preferably 10 Pa or more. If the reduced pressure is too low, the components (curing compound, photopolymerization initiator, polymerization inhibitor, light stabilizer, etc.) contained in the resin composition for forming a resin layer may be adversely affected. For example, when the reduced pressure atmosphere is excessively low, each component may be vaporized, and it may take time to provide a reduced pressure atmosphere. The pressure of the reduced-pressure atmosphere is more preferably from 15 to 40 Pa.

The time from the time when the first face material and the second face material are superposed to when the decompressed atmosphere is released is not particularly limited and the pressure reducing atmosphere may be immediately released after the sealing of the photo-curable resin composition for forming a resin layer, After the sealing of the photo-curing resin composition for forming, the reduced pressure state may be maintained for a predetermined time. By maintaining the reduced pressure state for a predetermined time, the resin composition for forming a resin layer flows in the closed space to make the distance between the first face material and the second face material uniform, and it becomes easy to maintain the sealed state even if the atmosphere pressure is increased. The time for maintaining the reduced pressure state may be a long time of several hours or more, but is preferably within 1 hour and more preferably within 10 minutes from the viewpoint of production efficiency.

In the production method of the present embodiment, in the case of forming the uncured sealing portion by coating the photo-curing resin composition for forming the seal portion having a high viscosity, the photo-curing resin for forming the resin layer in the lamination precursor obtained in the step (c) The thickness of the composition can be relatively increased to 10 탆 to 3 탆.

[Process (d)]

After releasing the reduced pressure atmosphere in the step (c), the lamination precursor is placed under a pressure atmosphere having an atmosphere pressure of 50 kPa or more.

When the laminated precursor is left in a pressure atmosphere of 50 kPa or more, the pressure is applied in the direction in which the first face plate and the second face plate are brought into close contact with each other by the elevated pressure, so that if bubbles are present in the closed space in the lamination precursor, The resin composition flows and the entire sealed space is uniformly filled with the photo-curing resin composition for forming a resin layer.

The pressure atmosphere is usually 80 to 120 deg. The pressure atmosphere may be an atmospheric pressure atmosphere or a higher pressure. An atmospheric pressure atmosphere is most preferable in that the operation such as curing of the photo-curing resin composition for forming a resin layer can be carried out without requiring special facilities.

There is no particular limitation on the time from when the laminated precursor is placed under a pressure of 50 kPa or more to when curing of the photo-curable resin composition for forming a resin layer is started (hereinafter referred to as a high-pressure holding time). When the lamination precursor is taken out of the decompression apparatus and moved to the curing apparatus and the process up to the initiation of curing is carried out in an atmospheric pressure atmosphere, the time required for the process becomes the high pressure holding time. Therefore, when the bubbles are not present in the closed space of the lamination precursor at the time of leaving the atmospheric pressure atmosphere, or when the bubbles are lost during the process, the photo-curable resin composition for forming the resin layer can be immediately cured. When it takes time for the bubbles to disappear, the lamination precursor is kept under an atmosphere of a pressure of 50 kPa or more until the bubbles disappear. In addition, since the normal trouble does not occur even if the high-pressure holding time is prolonged, the high-pressure holding time may be elongated from other necessities in the process. The high-pressure holding time may be a long period of one day or more, but it is particularly preferable to be within 10 minutes from the viewpoint of production efficiency, preferably within 6 hours, more preferably within 1 hour, and further increase production efficiency.

Subsequently, the photo-curable resin composition for forming a resin layer is cured in a state in which the lamination precursor is kept under a pressure of 50 kPa or more to form a resin layer joining the display device and the protective plate to produce a display device.

The photo-curable resin composition for forming a resin layer and the photo-curable resin composition for forming a seal part are cured by irradiation of light. For example, ultraviolet light or short-wavelength visible light is irradiated from a light source (ultraviolet lamp, high-pressure mercury lamp, black light, chemical lamp, UV-LED, etc.) to cure the photo-curable resin composition.

At this time, the unhardened sealing portion formed from the photo-curable resin composition for forming the seal portion may be cured simultaneously with the curing of the photo-curable resin composition for forming the resin layer, or may be cured prior to curing of the photo- It may be cured. When a shielding printing portion is formed on a part of the transparent face material and a sealing portion is sandwiched by the shielding printing portion, the light shielding portion is used for curing the photo-curing resin composition for forming a resin layer, It is difficult to cure the seal portion, so that the seal portion may be cured after curing of the photo-curing resin composition for forming a resin layer.

For example, light is irradiated from the light-transmitting side of the first face material and the second face material of the lamination precursor to the photo-curable resin composition for forming a resin layer, and light emitted from the side of the lamination precursor and sandwiched between the light- Light is applied to the sealant portion of the curing and the photo-curable resin composition for forming the resin layer.

Among the first face plate and the second face plate, the display device does not have light transmittance in a state in which it is not operated, and therefore, light is irradiated from the side of the transparent face plate as a protective plate through the light transmitting portion.

If there is an uncured sealing portion or a photo-curable resin composition for forming a resin layer in a region sandwiched between the shielding printing portion and the display device, the light shielding printing portion is formed in the peripheral portion of the transparent face material. It can not be sufficiently cured by light alone. Therefore, light is irradiated from the side of the display device.

As light, ultraviolet light or visible light of 450 nm or less is preferable. In particular, when a transparent resin film on which an antireflection layer is formed on an antireflection layer or an antireflection layer or an antireflection film formed between the antireflection film and a transparent face layer does not transmit ultraviolet rays, It becomes necessary.

As a light source for light irradiation from the side, a light source used for light irradiation from the side of the transparent face material may be used, but it is preferable to use an ultraviolet light or an LED that emits visible light of 450 nm or less, Which is preferable in view of efficient light irradiation.

The light irradiation step may be light irradiation from the side after the light irradiation from the side of the transparent face material, or light irradiation may be performed in the opposite direction or at the same time, but the light- In order to further promote the photo-curing of the composition, it is preferable to first irradiate light from the side or light irradiation from the side of the transparent face side simultaneously with the side. When curing of the photocurable resin composition for the resin layer is required to take a long time after the irradiation with light, the curing of the photocurable resin composition for forming the resin layer may be accelerated The sealing portion may be hardened by light irradiation from the side.

[Specific Example]

In the manufacturing method of the present embodiment, the backing material or the surface material may be used as the first face plate. Therefore, the display device can be manufactured by the following two methods according to the selection of the first face material.

(α-1) A method of using a display device (backing material) as a first face material and a transparent face material (surface material) serving as a protection plate as a second face material.

(α-2) A method of using a transparent face material (surface material) to be a protective plate as a first face material and a display device (back material) as a second face material.

Hereinafter, a method of manufacturing the display device of Fig. 1 will be described in detail with reference to the case of the method (? -1).

(Step (a))

3 and 4, a photo-curing resin composition for forming a seal portion is applied along the periphery of the display device 50 (first face material) by a dispenser (schematically shown) or the like to form an uncured seal portion 12, .

A wiring member such as an FPC for transmitting an electric signal for operating the display device may be provided on the outer peripheral portion of the display device. In the manufacturing method of the present embodiment, it is preferable to dispose the display device as the first face plate at the lower side in order to facilitate arrangement of the wiring members when holding the face plates.

(Step (b))

Next, as shown in Figs. 5 and 6, the photo-curable resin composition 14 for forming a resin layer is supplied to the rectangular region 13 surrounded by the uncured sealing portion 12 of the display device 50. Next, as shown in Fig. The supply amount of the photo-curable resin composition 14 for forming the resin layer is set such that the space sealed by the uncured sealing portion 12, the display device 50 and the transparent face material 10 (see Fig. 7) Curable resin composition 14 is filled in advance.

5 and 6, the supply of the photo-curable resin composition 14 for forming the resin layer is performed by placing the display device 50 horizontally on the lower surface of the lower plate 18 and moving the dispenser 20 moving in the horizontal direction, Curable resin composition 14 for forming a resin layer in a line, a stripe, or a dot shape.

The dispenser 20 is horizontally moved in the entire range of the area 13 by a known horizontal moving mechanism composed of a pair of feed screws 22 and a feed screw 24 orthogonal to the feed screw 22, It is possible. In place of the dispenser 20, a die coater may be used.

(Step (c))

Next, as shown in Fig. 7, the display device 50 and the transparent face material 10 (second face material) are carried into the decompression device 26. Then, as shown in Fig. In the upper portion of the decompression device 26, an upper half 30 having a plurality of suction pads 32 is disposed, and a lower half 31 is formed in a lower portion. The assumed chamber 30 is movable up and down by the air cylinder 34. As shown in Fig.

The transparent face material 10 is mounted on the adsorption pad 32. The display device 50 is fixed on the lower surface of the lower plate 31 with the surface to which the photo-curing resin composition 14 for forming a resin layer is supplied.

Subsequently, the air in the decompression device 26 is sucked by the vacuum pump 28. After the atmosphere pressure in the decompression device 26 reaches a reduced pressure atmosphere of, for example, 15 to 40 Pa, the transparent face plate 10 is held by suction on the adsorption pad 32 of the inhalation bath 30, The air cylinder 34 is operated to descend toward the display device 50 which is waiting on the display device 50. Then, the display device 50 and the transparent face plate 10 are superposed on each other via the uncured sealing portion 12 to form a lamination precursor, and the lamination precursor is held for a predetermined time under a reduced-pressure atmosphere.

The mounting position of the display device 50 with respect to the lower flat panel 31, the number of the suction pads 32, the mounting position of the transparent face plate 10 with respect to the upper half 30, The size of the transparent face material 10, the shape, and the like. By using the electrostatic chuck as the adsorption pad and adopting the electrostatic chuck holding method described in the specification (accepted in this specification) attached to Japanese Patent Application No. 2008-206124, it is possible to stably maintain the glass substrate in a reduced-pressure atmosphere have.

(Step (d))

Subsequently, the interior of the decompression device 26 is set at, for example, atmospheric pressure, and then the lamination precursor is removed from the decompression device 26. The surface of the laminate precursor on the display device 50 side and the surface on the side of the transparent face material 10 are pressed by the atmospheric pressure so that the photo-curing resin composition 14 for forming the resin layer in the closed space Is pressed by the display device (50) and the transparent face plate (10). By this pressure, the photo-curable resin composition 14 for forming a resin layer in the closed space flows and the entire closed space is uniformly filled with the photo-curable resin composition 14 for forming a resin layer.

Next, in the case where a light-shielding printing portion is formed on the transparent face plate and the uncured sealing portion sandwiched by the light-shielding printing portion and the photo-curable resin composition for resin layer formation are first cured, as shown in Fig. 8, from the side of the lamination precursor The light (ultraviolet ray or visible light of 450 nm or less) is irradiated onto the uncured sealing portion 12 and the photo-curing resin composition 14 for resin layer which are sandwiched between the shielding printing portion 55 and the display device 50, (Ultraviolet ray or 450 nm or less visible light) is irradiated from the side of the transparent face plate 10 through the light transmitting portion 56 to the photo-curing resin composition 14 for resin layer formation, Curing the sealing portion 12 and the photo-curing resin composition 14 for forming a resin layer are cured, whereby the display device 1 is manufactured.

In the case where the transparent face plate is not provided with the light shielding printing portion, light is irradiated to the entire surface of the lamination precursor from the side of the transparent face plate 10 to form the uncured sealing portion 12 in the lamination precursor and the photo- 14 are cured, whereby the display device 1 is manufactured.

The manufacturing method of the display device of the present embodiment has been described above in detail by taking the case of the method (α-1) as an example. However, the display device of the other method (α-2) can be similarly manufactured.

[Function and effect: Manufacturing method of display device]

According to the manufacturing method of the display device of the present embodiment described above, it is possible to manufacture a relatively large-area display device without generating bubbles in the resin layer. Even if air bubbles remain in the resin composition for forming a resin layer sealed under a reduced pressure, the pressure is applied to the photo-curable resin composition for forming a sealed resin layer under a high pressure atmosphere before curing, and the volume of the air bubble decreases, The bubbles are easily lost. For example, it is considered that the volume of gas in the bubbles in the photo-curable resin composition for forming a resin layer sealed under 100 Pa is 1/1000 under 100.. Since the gas is dissolved in the photo-curable resin composition for forming the resin layer, the gas in the minute volume of the air bubbles dissolves quickly in the photo-curable resin composition for forming the resin layer and disappears.

Even when a pressure such as atmospheric pressure is applied to the photo-curable resin composition for forming a resin layer after sealing, since the liquid photo-curing resin composition for forming a resin layer is a fluid composition, the pressure is uniformly distributed And no further stress is applied to a part of the surface of the display device in contact with the photo-curable resin composition for forming a resin layer, so there is little risk of damage to the display device.

The interfacial adhesion between the resin layer and the display device or the transparent face material due to the curing of the photo-curable resin composition for forming a resin layer is higher than the interfacial adhesion by heat fusion. Further, since the photo-curing resin composition for forming a resin layer for fluidity is pressed and adhered to the surface of the display device or the transparent face material and is cured in this state, a higher interfacial adhesion can be obtained and the surface of the display device or the transparent face material Uniform adhesion can be obtained, and the interfacial adhesion force is not partially lowered.

Therefore, there is less concern that peeling will occur on the surface of the resin layer, and there is less possibility that moisture or corrosive gas intrudes into the portion where the interface adhesion force is insufficient.

Compared with a method (injection method) of injecting a flowable resin layer composition for forming a resin layer into a space having a narrow and wide area between two face materials, generation of air bubbles is small and the photo-curable resin composition for forming a resin layer The resin composition can be filled. In addition, since the viscosity of the photocurable resin composition for forming a resin layer is less restricted, the photocurable resin composition for forming a resin layer having a high viscosity can be easily filled. Therefore, a photo-curable resin composition for forming a resin layer having a high viscosity and containing a relatively high molecular weight curable compound capable of enhancing the strength of the resin layer can be used.

The photopolymerization initiator (C2) of the photocurable resin composition for forming a resin layer is preferably a photopolymerization initiator (C2) having an absorption wavelength lambda 2 existing on the longer wavelength side than the absorption wavelength region (lambda 1) of the uncured, By using both the initiator C2 and the light within the absorption wavelength range lambda 1 and the light within the absorption wavelength range lambda 2 as the light irradiated from the side of the lamination precursor, The light of the wavelength within the absorption wavelength range 2 that is not absorbed by the negative photopolymerization initiator C1 sufficiently reaches the photocurable resin composition for forming the resin layer sandwiched by the display device in the light shielding portion, , The photopolymerizable resin composition for forming a resin layer can be sufficiently cured.

[Function and effect: Curable resin composition]

In the bonding of the display device and the transparent face plate (protective plate), by reducing the shrinkage rate at the time of curing of the curable resin or by reducing the elastic modulus of the resin layer after curing, the stress on the display device is reduced, Can be effectively prevented. On the other hand, if the modulus of elasticity of the resin layer is too low, there is a possibility that positional shift between the display device and the transparent face material may occur due to the elastic deformation of the resin layer. Further, according to the knowledge of the present inventors, even if the modulus of elasticity of the resin layer is sufficiently high, if the self weight of the display device, such as when the display device is vertically disposed, is applied to the resin layer for a long period of time, There is a possibility that the accuracy of the bonding position of the display device is lowered.

On the other hand, in the curable resin composition of the present invention, the storage shear modulus in the dynamic viscoelasticity measurement after curing is 5 × 10 ² to 1 × 10 ⁵ Pa and the loss tangent is 1.4 or less, the elastic deformation of the resin layer It is possible to reduce the stress caused by the curing shrinkage of the resin layer while preventing the positional displacement between the face plates (the display device and the shielding plate) caused by the face members (the display device and the shield plate) caused by plastic deformation of the resin layer with time, Can be effectively prevented.

Particularly, in the case of a TN (Twisted Nematic) type liquid crystal display device in which a display device is a liquid crystal display device and an IPS (In-plane Switching) type or an optical film for visual improvement is attached to a display surface, It is preferable that the bonding resin layer has a low elastic modulus because the low stress is liable to adversely affect the display quality.

Therefore, as a display device in a display device to which the curable resin composition of the present invention is applied, a liquid crystal display device is preferable, and IPS type liquid crystal display device or TN type liquid crystal display device is more preferable.

The photo-curable resin composition for forming a resin layer contains an uncurable oligomer having 0.8 to 3 hydroxyl groups per molecule as an uncurable component that does not undergo curing reaction with the curable compound (II) at the time of curing, The presence of a hydroxyl group that does not react upon curing in the compound (II) can reduce the storage shear modulus while suppressing an increase in the loss tangent (tan?) Of the resin layer after curing, and at the same time, The stability of the photo-curing resin composition for forming a negative electrode can be good, the viscosity can be made low, and the uniformity of the curing reaction at the time of curing can be obtained.

If the stability at the time of uncured is good and the uniformity of the curing reaction at the time of curing is good, a resin layer having good transparency tends to be obtained. When the viscosity of the photocurable resin composition for forming a resin layer at the time of uncured is low, generation of bubbles is easily suppressed sufficiently, and good interface bonding force between the face plate and the resin layer is easily obtained.

Further, the curable resin composition of the present invention is not limited to a display device, but can be applied to a laminate obtained by laminating a pair of face plates through a resin layer, and the same effect can be obtained.

Further, the curable resin composition of the present invention may be a thermosetting resin composition, and in this case, a thermosetting group known as a curable group of the curable compound is used. If necessary, a known thermal polymerization initiator is contained. In the above embodiment, when the curable resin composition for forming a resin layer is thermosetting, it is preferable that the curable resin composition for forming a seal portion is also thermosetting.

In particular, the photo-curable resin composition is preferable because it does not require a high temperature at the time of curing, and there is little fear of adverse effects on the face material due to high temperature.

The photopolymerization initiator and the thermopolymerization initiator may be used in combination to perform photo-curing and thermosetting simultaneously or individually to increase the curability.

The method of producing a laminate using the curable resin composition of the present invention is not limited to the method of the above embodiment, and a known method can be appropriately used.

Example

Hereinafter, examples for confirming the effectiveness of the present invention will be described. Examples 1 to 4, 8 and 9 are examples, and Examples 5 to 7 are comparative examples.

(Storage shear modulus, and method of measuring loss tangent thereof)

The storage shear modulus and the loss tangent (tan delta) of the resin layer after curing were measured by using a rheometer (Physica MCR301, manufactured by Antonfarza Co., Ltd.) as the curing resin composition for forming an uncured resin layer on a stage of soda lime glass (FL15BL, manufactured by Nippon Company, Ltd.) sandwiched in a gap of 0.4 mm between a measuring spindle (D-PP20 / AL / S07 manufactured by Anton Farsa) and 35 deg. By applying a 1% dynamic shear strain while irradiating light of 2 mW / cm &lt; 2 &gt; for 30 minutes, thereby curing the photocurable resin composition for forming a resin layer. The position of the spindle was automatically controlled so as not to generate stress in the normal direction of the spindle during curing of the photo-curable resin composition for forming a resin layer.

The irradiation intensity was measured on a stage on which a photocurable resin composition for forming a resin layer was provided using an illuminometer (Uni-meter UIT-101 manufactured by Ushio Inc.).

(Number average molecular weight)

The number average molecular weight of the oligomer was determined using a GPC apparatus (HLC-8020, manufactured by TOSOH Corporation).

(Viscosity)

The viscosity of the photo-curable resin composition was measured with an E-type viscometer (RE-85U, manufactured by Toray Industries, Inc.).

(Hayeschi)

The haze value was determined by measurement according to ASTM D1003 using Haze Guard II manufactured by Toyobo Co., Ltd.

[Example 1]

(Display device)

A liquid crystal display device was taken out from a commercially available 17-inch liquid crystal monitor (V137b, manufactured by Acer). The display mode of the liquid crystal display device was a TN (Twisted Nematic) type, and the size of the display portion was 338 mm in length and 270 mm in width. On both sides of the liquid crystal display device, a polarizing plate was stuck, and six driving FPCs were bonded on one side of the long side and three side driving FPCs on one side of the short side, and a printed wiring board was bonded to the end of the long side FPC . The liquid crystal display device was used as the display device A.

(Glass plate)

A light-shielding printed portion was formed on a frame by ceramic printing including a black pigment so that the translucent portion had a length of 340 mm and a width of 272 mm on the periphery of one surface of soda lime glass having a length of 355 mm, a width of 290 mm and a thickness of 2.8 mm To prepare a glass plate B serving as a protective plate.

(Photo-curable resin composition for forming a seal part)

A bifunctional polypropylene glycol having a number average molecular weight of 4000 and a content of ethylene oxide in the polypropylene glycol molecule of 24% by mass) having two hydroxyl groups in one molecule to which ethylene oxide was added at the molecular end and hexa Methylene diisocyanate was mixed at a molar ratio of 6 to 7 and then diluted with isobornyl acrylate (IBXA, manufactured by Osaka Organic Chemical Industry Co., Ltd.), and reacted at 70 캜 in the presence of a tin compound catalyst to obtain a prepolymer And 2-hydroxyethyl acrylate were added in a molar ratio of approximately 1: 2, and 0.03 parts by mass of 2,5-di-t-butylhydroquinone (polymerization inhibitor) was added and reacted at 70 占 폚 to give 30 parts by mass % Solution of urethane acrylate oligomer (hereinafter referred to as UC-1) diluted with isobornyl acrylate. The number of curable radicals of UC-1 was 2, and the number average molecular weight was about 55,000. The viscosity of the UC-1 solution at 60 占 폚 was about 580 Pa 占 퐏.

90 parts by mass of the UC-1 solution and 10 parts by mass of 2-hydroxybutyl methacrylate (Light Ester HOB manufactured by Kyowa Chemical Industry Co., Ltd.) were uniformly mixed to obtain a mixture. 100 parts by mass of the mixture and 3 parts by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, IRGACURE 184, manufactured by Chiba Specialty Chemicals) were uniformly mixed to obtain a photo- C was obtained.

The photo-curable resin composition C for forming a seal part was placed in a container and placed in a decompression apparatus in an open state. The inside of the decompression apparatus was decompressed to about 20 Pa and maintained for 10 minutes to perform defoaming treatment. The viscosity of the photo-curable resin composition C for forming a seal part at 25 캜 was measured and found to be about 1300 Pa · s.

(Photo-curing resin composition for forming a resin layer)

A bifunctional polypropylene glycol having a number average molecular weight of 4000 and an ethylene oxide content of 24% by mass in the polypropylene glycol molecule) having two hydroxyl groups in one molecule to which ethylene oxide is added at the molecular end, Is mixed at a molar ratio of 4 to 5 and reacted at 70 DEG C in the presence of a tin compound in the presence of a catalyst to obtain a prepolymer. 2-hydroxyethyl acrylate is added in a molar ratio of about 1: 2, And 0.03 parts by mass of 2,5-di-t-butylhydroquinone (polymerization inhibitor) were added and reacted at 70 ° C to obtain a urethane acrylate oligomer (hereinafter referred to as UA-2). The number of curable groups of UA-2 was 2, the number average molecular weight was about 24000, and the viscosity at 25 캜 was about 830 Pa 占 퐏.

40 parts by mass of UA-2, 30 parts by mass of 2-hydroxybutyl methacrylate (Light Ester HOB manufactured by Kyowa Chemical Industry Co., Ltd.) and 30 parts by mass of n-dodecyl methacrylate were uniformly mixed, , 0.5 part by mass of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (photopolymerization initiator, IRGACURE 819, manufactured by Ciba Specialty Chemicals Inc.), 100 parts by mass of n-dodecyl mercaptan 0.5 part by mass of a photo-curable resin composition PD, manufactured by Kao Corporation, thiocarco 20) was uniformly dissolved.

Subsequently, 60 parts by mass of PD and a bifunctional polypropylene glycol having two hydroxyl groups in one molecule modified with ethylene oxide at the molecular end, which were the same as those used in the synthesis of UA-2 Number average molecular weight: 4,000, content of ethylene oxide in polypropylene glycol molecule: 24 mass%) were uniformly dissolved to obtain a photo-curable resin composition D for forming a resin layer.

The photo-curable resin composition D for forming a resin layer was placed in a container and placed in a decompression apparatus in an open state. The inside of the decompression apparatus was decompressed to about 20 Pa and held for 10 minutes to perform defoaming treatment. The viscosity of the photo-curing resin composition D for forming a resin layer at 25 캜 was measured and found to be 1.7 Pa · s.

The photopolymerization initiator (IRGACURE 819) used in the photo-curable resin composition D for forming a resin layer had an absorption wavelength region (about 380 nm or less) of the photopolymerization initiator (IRGACURE 184) used for the photo- (About 440 nm or less) on the longer wavelength side.

Next, the photo-curable resin composition D for forming a resin layer for a resin layer was measured for its viscoelastic properties after curing using a rheometer. As a result, the storage shear modulus was 1.0 × 10 ⁴ Pa and the loss tangent (tan δ) thereof was 0.83.

(Step (a))

The photo-curing resin composition C for forming a seal portion was coated with a dispenser so as to have a width of about 1 mm and a coating thickness of about 0.6 mm over an entire periphery of a position of about 4 mm outside the image display area of the display device A, Respectively.

(Step (b))

Curable resin composition D for forming a resin layer was supplied to a plurality of points at a total mass of 38 g by using a dispenser in an inner region of an uncured sealing portion applied to the outer periphery of the image display region of the display device A.

During the supply of the photo-curing resin composition D for forming the resin layer, the shape of the uncured cured portion was maintained.

(Step (c))

The display device A was horizontally placed on the upper surface of the lower half of the lower portion of the decompression apparatus provided with the pair of base plate elevating devices so that the surface of the photo-curable resin composition D for forming the resin layer was located above.

When the glass plate B is viewed from above using an electrostatic chuck at the lower surface of the upper half of the elevation device in the pressure reduction device so that the surface of the glass plate B on which the light shield printing portion is formed faces the display device A, The image display area of the display device A was kept at the same position with a margin of about 1 mm so that the distance from the display device A in the vertical direction was 30 mm.

The decompression device was sealed and evacuated until the pressure in the decompressor reached about 10 Pa. The upper and lower platens were brought close to each other with the elevating device in the decompression apparatus, and the display device A and the glass plate B were pressed together with a pressure of 2 psi through the photo-curing resin composition D for forming a resin layer and held for 1 minute. The electrostatic chuck was removed to remove the glass plate B from the supposing plate, and the pressure inside the decompression apparatus was returned to atmospheric pressure in about 15 seconds, and the photo-curable resin composition D for forming the resin layer was sealed with the display device A, the glass plate B, To obtain a layered precursor E.

The shape of the uncured sealing portion in the layered precursor E remained almost the initial state.

(Step (d))

An ultraviolet light source (manufactured by Spectrum Illumination Co., Ltd.) in which ultraviolet LEDs were arranged in a line was placed in a non-cured seal portion (photo-curable resin composition C for seal portion formation) formed on the periphery of the display device A of the lamination precursor E from the side of the display device A LL146-395) was used to irradiate light over the entire circumference of the uncured seal portion for about 10 minutes to cure the seal portion. The intensity of the irradiated light was measured with an illuminometer (UV-M02, manufactured by Orkmanufacturing Co., Ltd., receiving unit UV-42) and found to be about 1 mW / cm2. After the seal was cured, the laminate precursor E was held horizontally and stopped for about 10 minutes.

Ultraviolet rays from black light and visible light of 450 nm or less were uniformly irradiated from the surface of the laminate precursor E on the glass plate B side for 30 minutes to cure the resin composition layer for forming a resin layer D to form a resin layer, Device F was obtained. The display device F does not require defoaming such as air bubbles remaining in the resin layer, although it is unnecessary to carry out a bubble removing process required in manufacturing by the conventional injection method. In addition, defects such as leakage of the photo-curing resin composition for forming a resin layer from the seal portion were not confirmed. The thickness of the resin layer was a target thickness (about 0.4 mm).

A transparent laminate was manufactured in the same manner using a glass plate of substantially the same size instead of the display device A, and the haze value at the portion without the printing light-shielding portion was measured to be 1% or less.

The display device F was returned to the case of the liquid crystal display in which the liquid crystal display device was taken out and the liquid crystal monitor was installed so that the display device A bonded to the glass plate B became vertical after the wiring was reconnected. As a result of turning on the power after stopping for 5 days, the display image was homogeneous and good over the entire surface of the display screen, and the display contrast was high from the beginning. The image is not disturbed even when the image display surface is strongly pressed with the finger, and the glass plate B effectively protects the display device A.

Subsequently, the display device F was installed in the same manner, and the position of the display device was confirmed one month later. However, there was no positional deviation, and the display device was preferably held on the glass plate.

[Example 2]

(Photo-curing resin composition for forming a resin layer)

40 parts by mass of UA-2 used in Example 1, 30 parts by mass of 2-hydroxybutyl methacrylate (Light Ester HOB manufactured by Kyowa Chemical Industry Co., Ltd.) and 30 parts by mass of n-dodecyl methacrylate were uniformly mixed And 0.5 parts by mass of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (photopolymerization initiator, IRGACURE 819, manufactured by Ciba Specialty Chemicals) was uniformly dissolved in 100 parts by mass of the mixture, A photo-curing resin composition PG was obtained.

Next, 40 parts by mass of PG and a bifunctional polypropylene glycol having two hydroxyl groups in one molecule modified with ethylene oxide at the molecular end, which were the same as those used in the synthesis of UA-2 Number average molecular weight: 4,000, ethylene oxide content in polypropylene glycol molecules: 24 mass%) were uniformly dissolved to obtain a resin composition G for forming a resin layer.

The photo-curing resin composition G for forming a resin layer was placed in a container and placed in a decompression apparatus in an open state. The inside of the decompression apparatus was decompressed to about 20 Pa and held for 10 minutes to perform defoaming treatment. The viscosity of the photo-curing resin composition G for forming a resin layer at 25 캜 was measured and found to be 1.3 Pa s.

Next, the photo-curable resin composition G for forming a resin layer for a resin layer was measured for its viscoelasticity after curing using a rheometer. As a result, the storage shear modulus was 3.7 × 10 ³ Pa and the loss tangent (tan δ) thereof was 0.61.

A display device H was obtained in the same manner as in Example 1 except that the composition C was used as the photo-curable resin composition for forming the seal portion and the composition G was used as the photo-curable resin composition for forming the resin layer.

The display device H was returned to the case of the liquid crystal display in which the liquid crystal display device was taken out and the liquid crystal monitor was provided so that the display device A connected to the glass plate B was perpendicular after the wiring was reconnected. As a result of turning on the power after stopping for 5 days, the display image was homogeneous and good over the entire surface of the display screen, and the display contrast was high from the beginning. The image is not disturbed even when the image display surface is strongly pressed with the finger, and the glass plate B effectively protects the display device A.

Subsequently, the display device H was installed in the same manner, and the position of the display device was confirmed one month later. However, no positional deviation was observed, and the display device H was well maintained on the glass plate.

[Example 3]

(Photo-curing resin composition for forming a resin layer)

A bifunctional polypropylene glycol having a number average molecular weight of 4000 and an ethylene oxide content of 24% by mass in the polypropylene glycol molecule) having two hydroxyl groups in one molecule to which ethylene oxide is added at the molecular end, The prepolymer obtained by mixing perone diisocyanate at a molar ratio of 3 to 4 and reacting at 70 DEG C in the presence of a tin compound in the presence of a catalyst is added at a molar ratio of 2-hydroxyethyl acrylate to the amount of 2-hydroxyethyl acrylate, 0.03 parts by mass of 2,5-di-t-butylhydroquinone (polymerization inhibitor) was added and reacted at 70 占 폚 to obtain a urethane acrylate oligomer (hereinafter referred to as UA-3). The number of curable groups of UA-3 was 2, the number average molecular weight was about 21,000, and the viscosity at 25 占 폚 was about 350 Pa 占 퐏.

80 parts by mass of UA-3 and 20 parts by mass of 2-hydroxybutyl methacrylate (Light Ester HOB, manufactured by Kyowa Chemical Industry Co., Ltd.) were added to 100 parts by mass of the mixture, -Trimethylbenzoyl) -phenylphosphine oxide (photopolymerization initiator, IRGACURE 819, manufactured by Chiba Specialty Chemicals Co., Ltd.) was uniformly dissolved to obtain a photocurable resin composition PI.

Next, 30 parts by mass of PI and 70 parts by mass of a bifunctional polypropylene glycol (number average molecular weight calculated from hydroxyl value: 2000, EO content in polypropylene glycol: 0 mass%) having two hydroxyl groups in one molecule Was uniformly dissolved to obtain a photo-curing resin composition I for forming a resin layer.

The photo-curing resin composition I for forming a resin layer was placed in a container and placed in a decompression apparatus in an open state. The inside of the decompression apparatus was decompressed to about 20 Pa and held for 10 minutes to perform defoaming treatment. The viscosity of the photo-curable resin composition I for forming a resin layer at 25 캜 was measured and found to be 2.0 Pa s.

Next, the photo-curable resin composition I for the resin layer formation for the resin layer formation was measured by using a rheometer to measure the viscoelastic characteristics after curing. As a result, the storage shear modulus was 2.5 × 10 ⁴ Pa and the loss tangent (tan δ) was 0.06.

A display device J was obtained in the same manner as in Example 1 except that the composition C was used as the photo-curable resin composition for forming the seal portion and the composition I was used as the photo-curable resin composition for resin layer formation.

The display device J was returned to the case of the liquid crystal display from which the liquid crystal display device was taken out and the liquid crystal monitor was provided so that the display device A bonded to the glass plate B was perpendicular after the wiring was reconnected. As a result of turning on the power after stopping for 5 days, the display image was homogeneous and good over the entire surface of the display screen, and the display contrast was high from the beginning. The image is not disturbed even when the image display surface is strongly pressed with the finger, and the glass plate B effectively protects the display device A.

Subsequently, the display apparatus J was installed in the same manner, and after 1 month, the bonding positions of the display devices were confirmed, but the positions were not misaligned and were well maintained on the glass plate.

[Example 4]

(Photo-curing resin composition for forming a resin layer)

20 parts by mass of the PI used in Example 3 and 80 parts by mass of a bifunctional polypropylene glycol having two hydroxyl groups in one molecule (number average molecular weight calculated from hydroxyl value: 2000, EO content in polypropylene glycol: 0% by mass) Mass part was uniformly dissolved to obtain a photo-curing resin composition I2 for forming a resin layer.

The photo-curable resin composition I2 for forming a resin layer was placed in a container and placed in a decompression apparatus in an open state. The inside of the decompression apparatus was decompressed to about 20 Pa and maintained for 10 minutes to perform defoaming treatment. The viscosity of the photo-curing resin composition I2 for forming a resin layer at 25 占 폚 was measured and found to be 1.0 Pa 占 퐏.

Next, the photo-curable resin composition I2 for forming a resin layer using a rheometer was measured for its viscoelastic properties after curing. As a result, the storage shear modulus was 4.0 × 10 ³ Pa and the loss tangent (tan δ) was 0.07.

A display device J2 was obtained in the same manner as in Example 1 except that the composition C was used as the photo-curable resin composition for forming the seal portion and the composition I2 was used as the photo-curable resin composition for forming the resin layer.

The display device J2 was returned to the case of the liquid crystal display in which the liquid crystal display device was taken out and the liquid crystal monitor was provided so that the display device A bonded to the glass plate B became vertical after the wiring was reconnected. As a result of turning on the power after stopping for 5 days, the display image was homogeneous and good over the entire surface of the display screen, and the display contrast was high from the beginning. The image is not disturbed even when the image display surface is strongly pressed with the finger, and the glass plate B effectively protects the display device A.

Subsequently, the display device J2 was installed in the same manner, and the junction position of the display device was confirmed one month later. However, there was no positional deviation, and it was well maintained on the glass plate.

[Example 5]

(Photo-curing resin composition for forming a resin layer)

40 parts by mass of UA-2 used in Example 1, 20 parts by mass of 2-hydroxybutyl methacrylate (Light Ester HOB manufactured by Kyowa Chemical Industry Co., Ltd.) and 40 parts by mass of n-dodecyl methacrylate were uniformly mixed , 0.3 parts by mass of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (photopolymerization initiator, IRGACURE 819, manufactured by Chiba Specialty Chemicals Co., Ltd.), and 2.5 parts by mass of 2,5- 0.04 parts by mass of di-t-butylhydroquinone (polymerization inhibitor), 0.5 parts by mass of n-dodecylmercaptan (chain transfer agent, ThioCarol 20, manufactured by Kao Corp.), 0.5 parts by mass of ultraviolet absorber (Chiba Specialty 0.3 parts by mass of TINUVIN 109 manufactured by Chemicals Corporation) was uniformly dissolved to obtain a photo-curable resin composition K for resin layer formation.

The photo-curing resin composition K for forming a resin layer was placed in a container and placed in a decompression apparatus in an open state. The inside of the decompression apparatus was decompressed to about 20 Pa and maintained for 10 minutes to perform defoaming treatment. The viscosity of the photo-curing resin composition K for forming a resin layer at 25 캜 was measured and found to be 2.0 Pa s.

Next, the photo-curable resin composition K for forming a resin layer for a resin layer was measured for its viscoelastic properties after curing using a rheometer. As a result, the storage shear modulus was 1.6 × 10 ⁵ Pa and the loss tangent (tan δ) thereof was 0.44.

A display device L was obtained in the same manner as in Example 1 except that the composition C was used as the photo-curable resin composition for forming the seal portion and the composition K was used as the photo-curable resin composition for resin layer formation.

The display device L was returned to the case of the liquid crystal display from which the liquid crystal display device was taken out and the liquid crystal monitor was provided so that the display device A bonded to the glass plate B became vertical after the wiring was reconnected. As a result of turning on the power after temporarily stopping for five days, display irregularities occurred in a part of the display screen, and in particular, the periphery of the display screen in the intermediate display was visually recognized. In a portion where there is no display unevenness, an image with higher contrast than the initial one was obtained.

Subsequently, the display device L was installed in the same manner, and the position of bonding of the display device was confirmed one month later. However, no positional deviation was observed, and it was maintained on the glass plate well.

[Example 6]

(Photo-curing resin composition for forming a resin layer)

The photo-curable resin composition PG used in Example 2 was used as a photo-curable resin composition M for forming a resin layer.

The photo-curable resin composition M for forming a resin layer was placed in a container and placed in a decompression apparatus in an open state. The inside of the decompression apparatus was decompressed to about 20 Pa and maintained for 10 minutes to perform defoaming treatment. The viscosity of the photo-curing resin composition M for forming a resin layer at 25 캜 was measured and found to be 2.2 Pa s.

Next, the photo-curable resin composition M for forming a resin layer for a resin layer was measured for its viscoelasticity after curing using a rheometer. As a result, the storage shear modulus was 3.1 × 10 ⁵ Pa and the loss tangent (tan δ) was 0.32.

A display device N was obtained in the same manner as in Example 1 except that the composition C was used as the photo-curable resin composition for forming the seal portion and the composition M was used as the photo-curable resin composition for forming the resin layer.

The display device N was returned to the case of the liquid crystal display from which the liquid crystal display device was taken out and the liquid crystal monitor was installed so that the display device A bonded to the glass plate B was perpendicular after the wiring was reconnected. As a result of turning on the power after stopping for 5 days, the display was unevenly displayed on a part of the display screen. Particularly, it was visibly marked on the periphery of the display screen in the half-tone display. In a portion where there is no display unevenness, an image with higher contrast than the initial one was obtained.

Subsequently, the display device N was installed in the same manner, and the position of the display device was confirmed one month later. However, there was no positional deviation, and it was maintained on the glass plate well.

[Example 7]

(Photo-curing resin composition for forming a resin layer)

40 parts by mass of UA-2 used in Example 1, 20 parts by mass of 2-hydroxybutyl methacrylate (Light Ester HOB manufactured by Kyowa Chemical Industry Co., Ltd.) and 40 parts by mass of n-dodecyl methacrylate were uniformly mixed , 0.3 parts by mass of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (photopolymerization initiator, IRGACURE 819, manufactured by Chiba Specialty Chemicals Co., Ltd.), 100 parts by mass of n-dodecyl And 1.5 parts of mercaptan (chain transfer agent, Thiocarco 20 manufactured by Kao Corporation) were uniformly dissolved to obtain a photo-curable resin composition O for resin layer formation.

The photo-curable resin composition O for forming a resin layer was placed in a container and placed in a decompression apparatus in an open state. The inside of the decompression apparatus was decompressed to about 20 Pa and maintained for 10 minutes to perform defoaming treatment. The viscosity of the photo-curable resin composition O for resin layer formation at 25 캜 was measured and found to be 1.9 Pa 占 퐏.

Next, the photo-curable resin composition O for photocurable resin composition for forming a resin layer was measured for its viscoelastic properties after curing using a rheometer. As a result, the storage shear modulus was 7.5 × 10 ³ Pa and the loss tangent (tan δ) was 1.8.

A display device P was obtained in the same manner as in Example 1 except that the composition C was used as the photo-curable resin composition for forming the seal portion and the composition O was used as the photo-curable resin composition for resin layer formation.

The display device P was returned to the case of the liquid crystal display in which the liquid crystal display device was taken out and the liquid crystal monitor was provided so that the display device A bonded to the glass plate B was vertical after the wiring was reconnected. After confirming the bonding position of the display device after about one hour, the display device was separated from the glass plate by about several millimeters, and the display device could not be maintained on the glass plate well.

Thus, as a result of installing the display device P so that the display device A bonded to the glass plate B is horizontal, turning the power source after stopping for 5 days, A display image was obtained, and the display contrast was high from the beginning. The image is not disturbed even when the image display surface is strongly pressed with the finger, and the glass plate B effectively protects the display device A.

[Example 8]

In Example 1, in the synthesis of UA-2, instead of the bifunctional polypropylene glycol obtained by adding ethylene oxide to the terminal of the molecule, a bifunctional polypropylene glycol having two hydroxyl groups in one molecule not adding ethylene oxide to the terminal of the molecule A mixture containing approximately equal amounts of polypropylene glycol (number-average molecular weight of 5500 as calculated by hydroxyl value) and 2,2,4-trimethylhexamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate, (UA-4) was synthesized in the same manner as in Example 1, except that the monomer mixture was blended at a molar ratio of 1: 2. The number of curable groups of UA-4 was 2, the number average molecular weight was about 16000, and the viscosity at 25 占 폚 was about 39 Pa 占 퐏.

In Example 1, a photo-curable resin composition PQ for forming a resin layer was obtained in the same manner as in Example 1 except that UA-4 was used instead of UA-2. 40 parts by mass of PQ and a bifunctional polypropylene glycol having two hydroxyl groups in one molecule which does not add ethylene oxide to the molecular end and which is the same as that used for the synthesis of UA-4 Molecular weight 5500) is used to obtain a photo-curing resin composition Q for forming a resin layer. The viscosity of the photo-curable resin composition Q for resin layer formation at 25 占 폚 was 0.8 Pa 占 퐏.

The photo-curable resin composition Q for forming a resin layer by a rheometer had a storage shear modulus of 2.4 × 10 ⁴ Pa and a loss tangent (tan δ) of 0.13 after the photo-curing.

A display device R was obtained in the same manner as in Example 1 except that the composition C was used as the photo-curable resin composition for forming the seal portion and the composition Q was used as the photo-curable resin composition for resin layer formation.

The display device R was returned to the case of the liquid crystal display in which the liquid crystal display device was taken out and the liquid crystal monitor was provided so that the display device A bonded to the glass plate B was perpendicular after the wiring was reconnected. As a result of turning on the power after stopping for 5 days, the display image was homogeneous and good over the entire surface of the display screen, and the display contrast was high from the beginning. The image is not disturbed even when the image display surface is strongly pressed with the finger, and the glass plate B effectively protects the display device A.

Subsequently, the display device R was installed in the same manner, and the position of the display device was confirmed one month later. However, the position was not deviated, and the display device was well maintained on the glass plate.

[Example 9]

A bifunctional polypropylene glycol (number-average molecular weight 2000 calculated by hydroxyl value) having two hydroxyl groups in one molecule not adding ethylene oxide to the molecular end and isophorone diisocyanate in a molar ratio of 5: 6 (UA-5) was synthesized in the same manner as in Example 1, The number of curable groups of UA-5 was 2, the number average molecular weight was about 18000, and the viscosity at 25 占 폚 was about 620 Pa 占 퐏.

In Example 1, a photo-curing resin composition PS for forming a resin layer was obtained in the same manner as in Example 1 except that UA-5 was used in place of UA-2. 40 parts by mass of PS and a bifunctional polypropylene glycol having two hydroxyl groups in one molecule which do not add ethylene oxide to the molecular end as in the synthesis of UA-5 (number average Molecular weight 2000) and bifunctional polypropylene glycol having two hydroxyl groups in one molecule not adding ethylene oxide at the molecular end with a larger molecular weight than that used in the synthesis of UA-5 And a number-average molecular weight of 5500 as calculated) was used to obtain a photo-curing resin composition S for resin layer formation. The viscosity of the photo-curable resin composition S for forming a resin layer at 25 캜 was 0.9 Pa · s.

The photo-curable resin composition S for forming a resin layer by a rheometer had a storage shear modulus of 2.0 × 10 ⁴ Pa and a loss tangent (tan δ) of 0.15 after the photo-curing.

A display device T was obtained in the same manner as in Example 1 except that the composition C was used as the photo-curable resin composition for forming the seal portion and the composition S was used as the photo-curable resin composition for forming a resin layer.

The display device T was returned to the case of the liquid crystal display from which the liquid crystal display device was taken out and the liquid crystal monitor was provided so that the display device A bonded to the glass plate B was perpendicular after the wiring was reconnected. As a result of turning on the power after stopping for 5 days, the display image was homogeneous and good over the entire surface of the display screen, and the display contrast was high from the beginning. The image is not disturbed even when the image display surface is strongly pressed with the finger, and the glass plate B effectively protects the display device A.

Subsequently, the display device T was installed in the same manner, and the junction position of the display device was confirmed one month later. However, the position was not shifted, and was maintained on the glass plate well.

Examples 1 to 4, 8 and 9, which contain the curable compound (II) and the non-curable oligomer (D) of the present invention and the content of the component (D) in the curable resin composition is 10 to 90 mass% The stress due to the shrinkage upon curing of the liquid crystal display screen can be reduced, and a homogeneous and good display image can be obtained over the entire surface of the liquid crystal display screen.

Examples 5 and 6 which contained the curable compound (II) of the present invention but did not contain the non-curable oligomer (D) produced display irregularities on the periphery of the liquid crystal display screen, . Particularly, in Example 7 in which the chain transfer agent was contained in an amount of more than 1.0 part by mass based on 100 parts by mass of the curable compound (II), the display device could not be satisfactorily maintained on the glass plate.

Industrial availability

The curable resin composition of the present invention is useful for the production of a laminate for use in display devices.

Further, the entire contents of the specification, claims, drawings and summary of Japanese Patent Application No. 2010-137531 filed on June 16, 2010 are incorporated herein by reference and are accepted as disclosure of the present invention.

1: Display device
10: transparent face material
12: seal portion of uncured
13: area
14: Photocurable resin composition for forming a resin layer
40: resin layer
42: seal part
50: Display device
55: Shade printing part (light shielding part)
56:

Claims (5)

A curable resin composition for use in lamination of a pair of face plates having a storage shear modulus in a dynamic viscoelasticity measurement after curing of 5 10 ² to 2.5 10 ⁴ Pa and a loss tangent of 0.01 to 0.83, Of a curable compound and a non-curable oligomer, wherein the resin layer comprises a cured product of a photo-curable curable resin composition. The method according to claim 1,
Wherein the curable compound contains at least one oligomer having a curable group and at least one monomer having a curable group. 3. The method of claim 2,
Wherein the content of the oligomer having a curable group is 20 to 90% by mass in the total (100% by mass) of the curable compound. One of the pair of face plates is a transparent face plate, the other is a display device,
A curable resin composition having a storage shear modulus in a dynamic viscoelasticity measurement after curing of 5 10 ² to 2.5 10 ⁴ Pa and a loss tangent in a range of 0.01 to 0.83 is used as a curing resin composition comprising a curing curable composition and a curing curable oligomer Wherein said pair of face members are laminated by a resin layer made of a cured product of a curable resin composition of a chemical composition. 5. The method of claim 4,
Wherein the display device is a liquid crystal display device.

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