JP6499406B2 - Method for producing optical member and curable resin composition used therefor - Google Patents

Description

  The present invention relates to a method for producing an optical member by bonding an optical substrate having a light-shielding portion and another optical substrate, and a curable resin composition therefor.

  In recent years, display devices that allow screen input by attaching a touch panel to a display screen of a display device such as a liquid crystal display, a plasma display, or an organic EL display are widely used. In this touch panel, a glass plate or a resin film on which a transparent electrode is formed is bonded with a slight gap facing each other. If necessary, a transparent protection made of glass or resin is provided on the touch surface. It has a structure in which plates are bonded together.

  There is a technique using a double-sided pressure-sensitive adhesive sheet for bonding a glass plate or film on which a transparent electrode is formed in a touch panel and a transparent protective plate made of glass or resin, or for bonding a touch panel and a display body unit. However, when a double-sided pressure-sensitive adhesive sheet is used, there is a problem that air bubbles easily enter. As a technique replacing the double-sided pressure-sensitive adhesive sheet, a technique of bonding with a flexible curable resin composition has been proposed.

  Therefore, as a method of pasting together with a flexible ultraviolet curable resin, using two types of adhesives as described in Patent Document 1, forming a flow stop (weir) with one adhesive, After that, a technique has been proposed in which an optical member is bonded to the display element by filling the frame formed by the flow-preventing portion with the other fluid adhesive and curing both to form a cured product layer. ing.

However, when an image display device is produced by the above method, after the cured product layer is formed, when the cured UV curable resin weir is pressed with a finger or the like, local force is applied to the pressed portion. As a result, the gap of the liquid crystal cell is changed to cause ripples, which causes a problem in visibility when pressed.
On the other hand, as described in Patent Document 2, a method of using a single adhesive without using two types of adhesives has been proposed. However, the occurrence of the ripples has been confirmed even in a single adhesive. Therefore, in the above situation, it has been desired to develop an image display device that does not generate ripples when touching any location on the screen of the image display device.

Patent No. 545015 International Publication No. 2013/111810

  The present invention relates to a method for producing an optical member capable of obtaining an optical member having excellent visibility without causing ripples even when any part of the image display device is pressed, and a curable resin composition used therefor. The purpose is to provide.

  The present inventors have completed the present invention as a result of intensive studies in order to solve the above problems. That is, the present invention relates to the following (1) to (14).

(1) A method of manufacturing an image display device in which a protective plate is bonded to a liquid crystal display unit,
The liquid crystal display unit includes a liquid crystal display cell, a polarizing plate disposed on the liquid crystal display cell, and a sealing body that coats the liquid crystal display cell surrounding the polarizing plate,
A second curable resin composition having fluidity when uncured is applied to at least one of the liquid crystal display unit or the protective plate, and the application region of the first curable resin composition is applied by the second curable resin composition. A second curable resin composition application step that defines:
The first curable resin composition having fluidity when uncured is applied to a region facing the application region when the application region or one substrate on which the application region is formed is bonded to the other substrate. An application step of applying the first curable resin composition;
A laminating step of laminating the liquid crystal display unit and the protective plate via the first curable resin composition;
A first curable resin composition curing step for curing the first curable resin composition and bonding the liquid crystal display unit and the protective plate together,
An image display, wherein a cured product layer obtained by curing the second curable resin composition is laminated in a projection region of the sealing body and is not laminated in a projection region of the polarizing plate. Device manufacturing method.
(2) The method for manufacturing the image display device according to (1),
Applying the second curable resin composition on the surface of the sealing body of the liquid crystal display unit to form a cured or uncured coating film;
Applying the first curable resin composition on the surface of the protective plate to form a cured or uncured coating film,
The method for manufacturing an image display device according to (1), wherein the liquid crystal display unit on which the coating film is formed and the protective plate on which the coating film is formed are bonded together.
(3) The method for manufacturing the image display device according to (1) or (2),
The average thickness of the coating film of said 1st curable resin composition is below the average thickness of the coating film of said 2nd curable resin composition, The image display as described in (1) or (2) characterized by the above-mentioned. Device manufacturing method.
(4) The method for producing an image display device according to any one of (1) to (3), wherein the second cured product layer is obtained by curing the second curable resin composition. An intermediate point of the film width does not exist in the projection area of the liquid crystal display cell but exists on the projection area of another optical member that surrounds the liquid crystal display cell. The manufacturing method of the image display apparatus as described in any one of said (1)-(3).
(5) (meth) acrylate for the first curable resin composition or the second curable resin composition of the method for producing an optical member according to any one of (1) to (4) ( A curable resin composition containing A) and a photopolymerization initiator (B).
(6) One kind selected from the group consisting of (meth) acrylate (A), urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, (meth) acrylate having a polybutadiene skeleton, and (meth) acrylate monomer The curable resin composition according to (5), which is the above (meth) acrylate.
(7) The molar extinction coefficient of the photopolymerization initiator (B) measured in acetonitrile or methanol is 300 ml / (g · cm) or more at 302 nm or 313 nm, and is 100 ml / (g · cm) or less at 365 nm. The curable resin composition according to (5) or (6).
(8) The protective plate is a transparent glass substrate having a light shielding portion, a transparent resin substrate having a light shielding portion, a glass substrate having a light shielding portion and a transparent electrode formed thereon, and a glass having a transparent electrode formed on the transparent substrate having the light shielding portion. Curable resin composition as described in any one of (5)-(7) which consists of 1 or more types chosen from the group of the board | substrate or the board | substrate with which the film was pasted together.
(9) With respect to the storage rigidity at 25 ° C. of the resin layer at a curing rate of 80% when the first curable resin composition is irradiated with ultraviolet rays, the resin layer at a curing rate of 98% when irradiated with ultraviolet rays is used. The resin composition is characterized in that the storage rigidity is 3 to 20 times, and the storage rigidity (25 ° C.) at a curing rate of 80% is 1 × 10 ² Pa to 1 × 10 ⁵ Pa (5 The curable resin composition according to any one of (8) to (8).
(10) One selected from the group consisting of (meth) acrylate (A), urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, (meth) acrylate having a polybutadiene skeleton, and (meth) acrylate monomer The curable resin composition according to any one of (5) to (9), which is the above (meth) acrylate.
(11) The curable resin composition according to any one of (5) to (10), wherein the protective plate is a touch panel.
(12) A touch panel obtained by the method for manufacturing an image display device according to any one of (1) to (11).
(13) An image display device in which a protective plate is bonded to a liquid crystal display unit,
The liquid crystal display unit includes a liquid crystal display cell, a polarizing plate disposed on the liquid crystal display cell, and a sealing body that coats the liquid crystal display cell surrounding the polarizing plate,
A first cured product layer obtained by curing the first curable resin composition formed on the polarizing plate;
A second cured product layer obtained by curing a second curable resin composition that defines a peripheral wall portion of the first cured product layer;
The image display apparatus, wherein the second cured product layer is laminated in a projection region of the sealing body and is not laminated in a projection region of the polarizing plate.
(14) The first curable resin composition and the second curable resin composition are a urethane (meth) acrylate compound, a (meth) acrylate compound having a polyisoprene skeleton, or a (meth) acrylate compound having a polybutadiene skeleton. The image display device according to (13), which is a curable resin composition containing at least one (meth) acrylate compound selected from the group consisting of: and a photopolymerization initiator.

It is process drawing which shows 1st Embodiment of the manufacturing method of this invention. 1 is a schematic diagram of a configuration of a liquid crystal display unit 1. FIG. 2 is a schematic diagram of a configuration of a protection plate 2. FIG. 6 is a schematic diagram relating to the thickness of the coating film of the liquid crystal display unit 1 and the coating film of the protective plate 2. It is process drawing which shows 2nd Embodiment of the manufacturing method of this invention. It is process drawing which shows 3rd Embodiment of the manufacturing method of this invention. It is the schematic which shows the one aspect | mode of the optical member obtained by this invention. 6 is a schematic view showing an optical member obtained by the method of Comparative Example 1. FIG.

The present invention relates to a method of manufacturing an image display device in which a protective plate is bonded to a liquid crystal display unit, the liquid crystal display unit including a liquid crystal display cell, a polarizing plate disposed on the liquid crystal display cell, and the liquid crystal display cell surrounding the polarizing plate. In regard to a method for manufacturing an image display device including an encapsulating sealing body and an image display device, the image display device is manufactured by the following [Step A] to [Step D]. And the 2nd hardened material layer obtained by hardening the 2nd curable resin composition mentioned below is laminated on the projection field of the encapsulant, and is not laminated on the projection field of the polarizing plate. It is a feature. Here, the area facing the application area when bonded on the other substrate to be bonded to the one substrate on which the application area is formed in Step B is the second area when two or more substrates are bonded. In the first cured product layer filling chamber in which the cured product layer and the first cured product layer defined by each base material exist, the filling chamber on another substrate to be bonded to one substrate on which the application region is formed is provided. Indicates the area to be defined.
[Step A] A second curable resin composition having fluidity when uncured is applied to at least one of the liquid crystal display unit or the protective plate, and the first curable resin composition is formed by the second curable resin composition. 2nd curable resin composition application | coating process which demarcates the application | coating area | region of a thing.
[Step B] The first curability having fluidity when uncured in an area facing the application area when the application area or the other substrate on which the application area is formed is bonded to the other substrate. The application | coating process of the 1st curable resin composition which apply | coats a resin composition.
[Step C] A laminating step of laminating the liquid crystal display unit and the protective plate via the first curable resin composition.
[Step D] A first curable resin composition curing step in which the first curable resin composition is cured and the liquid crystal display unit and the protective plate are bonded together.
Hereinafter, the manufacturing method of the present invention and the form of an image display device manufactured by this method will be described with reference to the drawings. The first to third embodiments are specific examples and are not limited to these specific examples.

(First embodiment)
FIG. 1 is a process diagram showing a first embodiment of a manufacturing process of an optical member of the present invention.
This method is a method of obtaining an optical member (image display device) by bonding the liquid crystal display unit 1 and the protective plate 2 together.

The liquid crystal display unit 1 is a liquid crystal display unit in which a liquid crystal material is sealed between a pair of substrates on which electrodes are formed, and a polarizing plate, a driving circuit, a signal input cable, and a backlight unit are provided.
FIG. 2 is a cross-sectional view showing a main part of an example of the liquid crystal display unit 1. In this liquid crystal display unit 1, as shown in FIG. 2, a polarizing plate 22 is disposed on the liquid crystal display cell 21, and a sealing body 23 is disposed on the liquid crystal display cell 21 so as to surround the polarizing plate 22. ing. Here, the structure in which the polarizing plate 22 is directly laminated on the liquid crystal display cell 21 is shown, but it is not necessary to directly laminate the polarizing plate 22 as long as the polarizing plate is disposed on the liquid crystal display cell. An optical member such as another functional film may be interposed between the cell and the polarizing plate.
In this state, a gap 24 having a maximum width of several mm is formed between the polarizing plate 22 and the sealing body 23, and a sealing film 25 is provided so that the surface of the liquid crystal display cell 21 is not exposed on the bottom surface of the gap 24. Shows an example in which is arranged. That is, as shown in the example of FIG. 2, before applying the second curable resin composition 11 on the polarizing plate 22, the liquid crystal display which is the bottom surface of the gap 24 between the polarizing plate 22 and the sealing body 23. On the surface of the cell 21, a sealing film 25 having adhesiveness can be disposed to block a part of the gap 24. Since one end of the sealing film 25 in the width direction is adjacent to the polarizing plate 24 and the other end is in close contact with the sealing body 23, the bottom of the gap 24 is sealed. Here, although the example in which the sealing film 25 is arranged is shown in FIG. 2, the sealing film 25 may not be arranged on the bottom surface of the gap 24 and the surface of the liquid crystal display cell 21 may be exposed.
As such a sealing film 25, an adhesive film having polyethylene terephthalate or the like as a film base and having an adhesive layer such as acrylate or an adhesive layer is preferable.
As the polarizing plate 22, known ones used in image display devices can be used. For example, a film-like absorption polarizer, a wire grid polarizer, or the like can be used.

  In addition, the sealing film 25 does not necessarily need to be solid at the time of arrangement | positioning, and the adhesive layer or adhesive agent should just be high viscosity so that it may not penetrate | invade into the gap | interval between each structural member of a liquid crystal display unit. More specifically, a curable resin composition having a viscosity of about 65 Pa · s can be used. Further, an adhesive having a thixo ratio of about 3 may be used from the viewpoint of maintaining the shape so as not to enter the gap.

A backlight side polarizing plate 27 can be laminated on the surface of the liquid crystal display cell 21 opposite to the surface on which the polarizing plate 22 is formed. Here, the structure is not limited to the structure in which the backlight side polarizing plate 27 is directly laminated on the liquid crystal display cell 21, and the liquid crystal display cell 21 and the backlight side polarizing plate need only be disposed on the liquid crystal display cell 21. 27 and another optical member such as a functional film may be interposed.
Further, in the backlight side polarizing plate 27, the backlight 28 can be formed on the surface opposite to the surface on which the liquid crystal display cell 21 is disposed. As the light source constituting the backlight, for example, a cold cathode tube, an LED (Light Emitting Diode), or the like can be used. As a specific example, an edge light system in which the light source 30 is disposed at one end of the light guide plate 31 and linear light from the light source 30 is converted into planar light by the light guide plate 31 can be exemplified. The backlight method is not limited to the edge light method. For example, a direct type system in which the light source 30 is disposed directly below the diffusion plate may be employed.

In order to protect the liquid crystal display unit 1, the liquid crystal display unit 1 is usually covered with a casing 26. The casing 26 is generally made of a metal material. Specifically, an alloy such as stainless steel, iron, aluminum, or silver can be used.
A liquid crystal display cell, a backlight, a light guide plate, and an optical film can be accommodated in the housing 26.

In the liquid crystal display unit 1, a sealing body 23 is disposed so as to cover the liquid crystal display cell 21. In FIG. 2, the sealing body 23 is disposed so as to surround the polarizing film with a gap 24 interposed in the peripheral wall portion of the polarizing film 22. In FIG. 2, the sealing body 23 is coated on the liquid crystal display cell 21 with the sealing film 25 interposed therebetween, but the liquid crystal display cell 21 may be coated directly.
The sealing body 23 is an example in which the outer wall of the image display device is coated, and in FIG. 2, the casing 26 disposed adjacent to the peripheral wall portion of the liquid crystal display cell 21 is directly coated. In particular, it is not necessary to limit the arrangement. Although not shown, as described above, the backlight side polarizing plate 27 is laminated on the surface opposite to the surface on which the polarizing plate 22 of the liquid crystal display cell 21 is formed. The backlight 28 is laminated | stacked, the housing | casing 26 has covered the backlight 28 adjacently, and the said housing | casing 26 can be arrange | positioned in the aspect which covers the surrounding wall part of these members. And the housing | casing 26 can be set as the structure which the sealing body 23 has coat | covered further.
As the sealing body 23, an organic polymer material is generally used. Specifically, a pressure-sensitive adhesive film having a pressure-sensitive adhesive layer such as an acrylic polymer or an adhesive layer on a film substrate such as PET. Can be used.

A protective plate 2 shown in FIG. 3 protects the liquid crystal display unit 1. The protective plate 2 is a member having a transparent substrate 3 and a light shielding portion 4 formed on one surface of the transparent substrate 3.
Examples of the transparent substrate 3 used for the protective plate 2 include a glass plate or a transparent resin plate. Of course, the transparent substrate 3 has high transparency with respect to light emitted from the display panel and reflected light, light resistance, and low birefringence. A glass plate is preferable because it has high plane accuracy, surface scratch resistance, and high mechanical strength.

Examples of the material for the glass plate include glass materials such as sodaime glass, and a high transmission glass that is lower than iron and less bluish is more preferable. In order to improve safety, tempered glass may be used as a surface material. In particular, when a thin glass plate is used, it is preferable to use a chemically strengthened glass plate.
Examples of the material for the transparent resin plate include highly transparent resin materials such as a polymethyl methacrylate (PMMA) plate, a polycarbonate (PC) plate, and an alicyclic polyolefin polymer (COP) plate.

  The protective plate 2 may be subjected to a surface treatment in order to improve the interfacial adhesive force with the cured resin layer. Examples of the surface treatment method include a method of treating the surface of the protective plate 2 with a silane coupling agent, a method of forming a silicon oxide thin film by an oxidation flame using a frame burner, and the like.

  The protective plate 2 is obtained by curing a second cured product layer 14 or a second cured resin composition 14 obtained by curing a first curable resin composition to be described later in order to increase the contrast of the display image. An antireflection layer may be provided on the surface opposite to the side on which the first cured product layer 13 is formed. The antireflection layer can be provided by a method of directly forming an inorganic thin film on the surface of the protective plate 2 or a method of bonding a transparent resin film provided with an antireflection layer to the protective plate 2.

  Further, depending on the purpose, a part or the whole of the protective plate 2 is colored, or a part or the whole of the surface of the protective plate 2 is polished to form a glass to scatter light, or a part of the surface of the protective plate 2 is scattered. Alternatively, the transmitted light may be refracted or reflected by forming fine irregularities on the entire surface. Further, a colored film, a light scattering film, a photorefractive film, a light reflecting film or the like may be attached to a part or the whole of the surface of the protective plate 2.

The shape of the protection plate 2 is usually rectangular.
The size of the protective plate 2 is suitably 0.5 m × 0.4 m in the case of a television receiver because the manufacturing method of the present invention is particularly suitable for manufacturing a relatively large area image display device. 0.7 m × 0.4 m or more is particularly preferable. The upper limit of the size of the protection plate 2 is often determined by the size of the display panel. Also, an image display device that is too large is likely to be difficult to handle during installation or the like. The upper limit of the size of the protective plate 2 is usually about 2.5 m × 1.5 m due to these restrictions.

  The thickness of the protective plate 2 is usually 0.5 to 25 mm in the case of a glass plate from the viewpoint of mechanical strength, transparency and the like. In applications such as television receivers and PC displays used indoors, 1 to 6 mm is preferable from the viewpoint of weight reduction of the display device, and 3 to 20 mm is preferable in public display applications installed outdoors. When chemically strengthened glass is used, the thickness of the glass is preferably about 0.5 to 1.5 mm in terms of strength. In the case of a transparent resin plate, 2 to 10 mm is preferable.

The light-shielding portion 4 hides the wiring member connected to the display panel so that the area other than the image display area of the liquid crystal display cell to be described later cannot be seen from the protective plate 2 side. The light shielding unit 4 can be formed on the surface on the side where the second cured product layer 14 to the first cured product layer 13 described later are formed, and reduces the parallax between the light shielding unit 4 and the image display area. When the protective plate 2 is a glass plate, it is preferable to use ceramic printing containing a black pigment in the light-shielding printing portion because of high light shielding properties. The light shielding part 4 may be provided on the surface to be bonded to the protective plate 2, and a film provided with an antireflection layer on the back surface thereof, that is, the outermost surface of the display device may be bonded to the protective plate. For example, the light-shielding portion 4 is formed by attaching a tape, applying paint, printing, or the like.
In the present invention, the present invention can also be applied to a device that does not have the light shielding portion 4.

[Step A]
As shown to Fig.1 (a), the 2nd curable resin composition 12 containing the (meth) acrylate (A) mentioned later and a photoinitiator (B) is used for the said sealing body 23 of the liquid crystal display unit 1. As shown in FIG. Apply to the surface. Here, although the example applied to the surface of the sealing body 23 is shown as a specific example, the second curable resin composition 12 may be applied to the projection region of the sealing body 23, and the second curable resin composition may be applied. Another optical member may be interposed between the sealing member 12 and the sealing body 23. Examples of the coating method include a dispensing method and a screen printing method. Here, since the 2nd curable resin composition 12 becomes a dam part of the 1st curable resin composition mentioned later at the time of bonding, the 1st cured product obtained by hardening | curing the 1st curable resin composition 11 Apply layer 13 to the shape you want to define. Specifically, it can be a square or rectangular frame shape, but the shape is not particularly limited. Thus, the layer which prescribes | regulates the filling chamber with which the 1st hardened | cured material layer 13 is filled when it bonds together is formed.
Here, the first curable resin composition and the second curable resin composition applied to the surfaces of the liquid crystal display unit 1 and the protective plate 2 may be the same or different curable resin compositions may be used. I do not care.
Moreover, in order to maintain the space | interval of the liquid crystal display unit 1 and the protective plate 2, you may mix | blend the spacer particle | grains of a predetermined particle diameter with the 2nd curable resin composition 12. FIG.

Here, in this invention, the 2nd curable resin composition 12 is laminated | stacked on the projection area | region of the said sealing body, and is not laminated | stacked on the projection area | region of the said polarizing plate. Thus, the 2nd hardened | cured material obtained by hardening | curing the 2nd curable resin composition 12 by apply | coating the 2nd curable resin composition 12 to the projection area | region of a sealing body avoiding the projection area | region of a polarizing plate. A layer is formed on the encapsulant 23. By laminating the second hardened material layer at the location, even when pressure is applied to the second hardened material layer 13 by pressing with a finger or the like, ripples can be prevented from being generated in the image display unit. On the other hand, when the 2nd hardened | cured material layer 12 is laminated | stacked on a polarizing plate, when a pressure is applied to the peripheral wall part of a 2nd hardened | cured material layer thru | or an image display area, a ripple will arise by interference.
Further, the intermediate point of the coating film width of the second cured product layer is arranged so as not to exist in the projection area of the liquid crystal display cell, and surrounds the liquid crystal display cell 21 instead of on the projection area of the gap 24. By disposing on the projection area of another optical member, the pressure applied on the liquid crystal display cell by pressing is reduced, so that disturbance of the image display of the liquid crystal display cell is reduced even when pressure is applied, It is possible to prevent more ripples from occurring.

Since the area outside the image display area of the liquid crystal display unit 1 is relatively narrow, the width of the coating film by the second curable resin composition 12 forming the coating film is preferably narrow. The width is preferably 0.5 to 3 mm, more preferably 0.5 to 1.6 mm, and still more preferably 0.5 to 1.0 mm. Further, the thickness of the coating film of the first curable resin composition 11 to be formed is substantially equal to the average thickness of the coating film of the second curable resin composition 12 to be formed or the first coating film to be formed. The 1-curable resin composition 11 is preferably 0.005 to 1 mm thicker, more preferably 0.01 to 0.08 mm thicker than the thickness of the second curable resin composition 12 to be formed, and 0.01 to More preferably, it is 0.05 mm thick.
The storage rigidity at 25 ° C. at the time of curing in the second curable resin composition 12 is preferably larger than the storage rigidity at 25 ° C. of the cured layer of the first curable resin composition 11. If the storage rigidity of the second cured product layer 14 is larger than the storage rigidity of the first cured product layer 13 obtained by curing the first curable resin composition, the liquid crystal display unit 1 and the protective plate 2 are When bonding, even if voids remain at the interface between the protective plate 2 and the first cured product layer 13 at the peripheral edge of the first cured product layer 13, the voids are not easily opened to the outside and are independent. It is easy to become. Therefore, after the liquid crystal display unit 1 and the protective plate 2 are bonded together in a reduced pressure atmosphere, when the pressure is returned to the atmospheric pressure atmosphere, the pressure in the gap (remains reduced pressure) and the cured resin layer 15 are applied. The volume of the void is reduced by the pressure difference from the pressure (atmospheric pressure), and the void is likely to disappear.

  The second curable resin composition 12 and the first curable resin so that the shrinkage rate at the time of curing of the second curable resin composition 12 is larger than the shrinkage rate at the time of curing of the first curable resin composition 11. It is preferable to design the composition 11. In the first cured product layer 13 formed by curing the first curable resin composition 11, it is considered that the shrinkage stress corresponding to the shrinkage rate at the time of curing remains in the thickness direction of the first cured product layer 13. In addition, the thickness of the first cured product layer 13 slightly decreases due to the shrinkage stress in the thickness direction remaining in the layered portion at the time of curing. By using the first curable resin composition 11 having a smaller shrinkage rate at the time of curing than the second curable resin composition 12, it is possible to relieve the stress in the display region and suppress the occurrence of display unevenness.

One of means for increasing the shrinkage rate at the time of curing of the second curable resin composition 12 to be larger than the shrinkage rate at the time of curing of the first curable resin composition 11 is the curable group of the second curable resin composition 12. The number is to be larger than the number of curable groups of the first curable resin composition 11. For this purpose, in the second curable resin composition 12, (i) the content of a curable compound (monomer) having a small molecular weight is increased, or (ii) the content of a polyfunctional component having a plurality of reactive groups in the molecule. Or more.
That is, the viscosity of the second curable resin composition 12 may be higher than the viscosity of the first curable resin composition 11. Specifically, the uncured viscosity of the second curable resin composition 12 is preferably 2 times or more, more preferably 5 times or more of the uncured viscosity of the first curable resin composition 11. More than double is more preferable. Moreover, in order to form the 2nd curable resin composition 12 on a transparent surface material by application | coating, the viscosity at the time of uncured at 25 degreeC of the 2nd curable resin composition 12 shall be 3000 Pa.s or less. Is preferred.
Here, the suitable viscosity of the 2nd curable resin composition 12 is 40-70 Pa.s specifically ,. If it is less than 40 Pa · s, the second curable resin composition 12 cannot maintain its shape and spreads, and it becomes difficult to control the thickness, and the second curable resin resin composition 12 becomes the second curable resin composition. There is a risk of the object 12 being destroyed. On the other hand, when the viscosity exceeds 70 Pa · s, it may be difficult to discharge from the applicator.

  Further, the second cured product layer 14 has a liquid first curable resin composition from the interface between the second cured product layer 14 and the liquid crystal display unit 1 and the interface between the second cured product layer 14 and the protective plate 2. It is necessary to have an interface adhesion strength that does not leak out and a hardness that can maintain the shape. Therefore, it is preferable to use the second curable resin composition 12 having a high viscosity for the second cured product layer 14.

  The second curable resin composition 12 may be a photocurable resin composition or a thermosetting resin composition. As the 2nd curable resin composition 12, the photocurable resin composition containing a curable compound and a photoinitiator is preferable from the point which can be hardened | cured at low temperature and a cure rate is quick.

It is possible to apply the second curable resin composition 12 formed as described above as a coating film as it is to form the weir part, and it can be applied to the next step B. It is also possible to form the weir portion by preliminarily curing to obtain a cured coating film.
In the case of curing, the second curable resin composition 12 after coating is irradiated with ultraviolet rays 5, and a cured portion (on the liquid crystal display unit side as viewed from the curable resin composition) on the lower side of the coating layer (see FIG. Is not displayed) and the second cured product layer 14 having an uncured portion (not shown in the drawing) existing on the upper side (opposite side of the liquid crystal display unit side) of the coating layer (atmosphere side in the atmosphere). obtain. Irradiation dose is preferably 5~2000mJ / cm ^2, particularly preferably, 10~1000mJ / cm ^2, particularly preferably 10 to 500 mJ / cm ^2. If the amount of irradiation is too small, there is a possibility that the degree of curing of the resin of the optical member that is finally bonded will be insufficient. There is a possibility that the bonding of the will become defective.
In the present invention, “uncured” refers to a fluid state in a 25 ° C. environment. In addition, when the resin composition layer is touched with a finger after ultraviolet irradiation and a liquid component adheres to the finger, it is determined to have an uncured portion.
For curing by ultraviolet irradiation from ultraviolet to near ultraviolet, any light source may be used as long as it is a lamp that irradiates ultraviolet to near ultraviolet rays. For example, a low-pressure, high-pressure or ultrahigh-pressure mercury lamp, metal halide lamp, (pulse) xenon lamp, LED lamp or electrodeless lamp can be used.

[Step B]
Next, as shown in FIG.1 (b), the protective plate 2 which has the light-shielding part 4 for the 1st curable resin composition 11 containing the (meth) acrylate (A) and photoinitiator (B) which are mentioned later. It is applied to the surface of the surface on which the light shielding portion 4 is formed. Examples of the coating method include a slit coater, a roll coater, a spin coater, and a screen printing method.
The obtained coating film is preferably formed so as to be within the frame formed by the second cured product layer formed in step A. This is because if there is a part outside the frame, the first curable resin composition 11 may be pressed when the liquid crystal display unit 1 and the protective plate 2 are bonded together, which may cause a problem. Here, the coating film of the first curable resin composition 11 does not necessarily have to be formed strictly along the second cured product layer 14, and is contained within the frame formed by the second cured product layer 14. It suffices if it is formed so as to fill the viewing area of the image display device. Moreover, the 1st curable resin composition 11 should just be apply | coated to the said area | region, and another optical member may intervene between the 1st curable resin composition 11 and the board | substrate to apply | coat.
The 1st curable resin composition 11 is apply | coated to the area | region which opposes the said application | coating area | region when bonding in the other board | substrate bonded together with the said board | substrate with which the said application area | region or the said application | coating area | region was formed. Thus, the first curable resin composition 11 is formed on the one substrate on which the second curable resin composition 12 is applied, which becomes the region that defines the filling chamber when bonded, or on the other substrate to be bonded. Will be applied.

In the first curable resin composition 11, a storage modulus at 25 ° C. of the first cured layer obtained by curing a first curable resin composition 11 is ^{preferably 10 2 ~10 7 Pa, 10 2} ~ 10 ⁵ Pa is more preferable. Furthermore, 10 ² to 10 ⁴ Pa is particularly preferable in order to eliminate the void at the time of bonding in a shorter time. If the storage rigidity is 10 ³ Pa or more, the shape of the first cured product layer 13 is easily maintained. Moreover, even when the thickness of the first curable resin composition 11 to be formed is relatively thick, the thickness can be kept uniform throughout the first cured product layer 13, and the protective plate 2 and the liquid crystal display unit 1 can be maintained. When pasting, voids are unlikely to occur at the interface between the liquid crystal display unit 1 and the first cured product layer 13. If the storage rigidity is 10 ⁷ Pa or less, good adhesion can be exhibited. Further, since the molecular mobility of the resin material to be formed is relatively high, the liquid crystal display unit 1 and the protective plate 2 are bonded together in a reduced pressure atmosphere, and then returned to the atmospheric pressure atmosphere. The void volume tends to decrease due to the differential pressure between the pressure of the material (with reduced pressure) and the pressure applied to the hardened material layer of the fill material (atmospheric pressure). Easily dissolved and absorbed.

The thickness of the first curable resin composition 11 is preferably 50 to 500 μm, more preferably 50 to 350 μm, and particularly preferably 100 to 350 μm. If the thickness of the 1st curable resin composition 11 is 50 micrometers or more, the 1st hardened | cured material layer 13 can buffer effectively the impact by the external force from the protective plate 2, and the liquid crystal display unit 1 can be protected. . Further, in the method for manufacturing an image display device of the present invention, even if a foreign matter not exceeding the thickness of the first cured product layer 13 is mixed between the liquid crystal display unit 1 and the protective plate 2, the first cured product layer 13. There is little influence on the light transmission performance without greatly changing the thickness. If the thickness of the 1st hardened | cured material layer 13 is 500 micrometers or less, a space | gap will hardly remain in the 1st hardened | cured material layer 13, and the thickness of the whole image display apparatus will not become unnecessarily thick.
As a method of adjusting the thickness of the first cured product layer 13, the thickness of the second cured product layer 14 is adjusted, and the liquid second curable resin composition 11 supplied to the surface of the protective plate 2 is adjusted. A method of adjusting the supply amount is mentioned.

The viscosity of the first curable resin composition 11 is preferably 0.05 to 50 Pa · s, and more preferably 1 to 20 Pa · s. If the viscosity is 0.05 Pa · s or more, a decrease in physical properties of the first cured product layer 13 is suppressed. Moreover, since the component having a low boiling point is reduced, volatilization in a reduced-pressure atmosphere described later is suppressed, which is preferable. If the viscosity is 50 Pa · s or less, voids hardly remain in the first cured product layer 13.
The viscosity of the first curable resin composition 11 is measured using an E-type viscometer at 25 ° C.

  The first curable resin composition 11 may be a photocurable resin composition or a thermosetting resin composition. As the first curable resin composition, a photocurable resin composition containing a curable compound and a photopolymerization initiator is preferable because it can be cured at a low temperature and has a high curing rate.

Here, the first curable resin composition 11 may be used for pasting without being cured, but is preferably temporarily cured as described in FIG.
Specifically, the coating film of the first curable resin composition 11 after application is irradiated with ultraviolet rays 5, and a cured portion (on the transparent substrate side as viewed from the curable resin composition) on the lower side of the application layer (on the transparent substrate side) A cured product layer having an uncured portion (not shown in the figure) existing on the upper side (opposite side of the transparent substrate side) of the coating layer (on the atmosphere side when performed in the atmosphere) is obtained. Irradiation dose is preferably 5~2000mJ / cm ^2, particularly preferably, 10~1000mJ / cm ^2, particularly preferably 10 to 500 mJ / cm ^2. If the amount of irradiation is too small, the degree of cure of the resin of the optical member that is finally bonded may be insufficient. If the amount of irradiation is too large, the amount of uncured components decreases, and the liquid crystal display unit 1 and the light-shielding portion There is a possibility that the bonding of the transparent substrate 2 will be defective.
In the present invention, “uncured” refers to a fluid state in a 25 ° C. environment. In addition, when the resin composition layer is touched with a finger after ultraviolet irradiation and a liquid component adheres to the finger, it is determined to have an uncured portion.
For curing by ultraviolet irradiation from ultraviolet to near ultraviolet, any light source may be used as long as it is a lamp that irradiates ultraviolet to near ultraviolet rays. For example, a low-pressure, high-pressure or ultrahigh-pressure mercury lamp, metal halide lamp, (pulse) xenon lamp, LED lamp or electrodeless lamp can be used.
More preferably, in step 1 of the present invention, when the maximum illuminance in the range of 320 nm to 450 nm is 100, the ratio of the maximum illuminance at 200 to 320 nm (illuminance ratio) ) Is 30 or less, and particularly preferably, the illuminance at 200 to 320 nm is 10 or less. When the maximum illuminance in the range of 320 nm to 450 nm is 100, if the ratio of maximum illuminance (illuminance ratio) in 200 to 320 nm is higher than 30, the adhesive strength of the optical member finally obtained will be inferior. This is because, when the illuminance at a low wavelength is high, the curing of the curable resin composition proceeds excessively at the time of curing in the step 1, and the contribution to the adhesiveness at the time of curing in the irradiation of ultraviolet rays in the step 3 is reduced. It is thought that it will end. The illuminance is usually 30 to 1000 mW / cm ² at each wavelength (for example, 365 nm).
Here, the method of irradiating ultraviolet rays so as to achieve the above illuminance ratio is, for example, a method of applying a lamp satisfying the illuminance ratio as a lamp that irradiates ultraviolet to near-ultraviolet rays, or the lamp itself has the illuminance. Even if the above condition is not satisfied, such illuminance can be obtained by using a base material (for example, a short wave ultraviolet cut filter, a glass plate, a film, etc.) that cuts short wavelength ultraviolet rays at the time of irradiation in step 1. Irradiation at a ratio is possible. Although it does not specifically limit as a base material which adjusts the illumination intensity ratio of an ultraviolet-ray, For example, the glass plate, soda-lime glass, PET film etc. which were given the short wave ultraviolet-ray cut process are mentioned.
In this case, it is preferable to irradiate the ultraviolet rays from the upper surface (on the side opposite to the transparent substrate as viewed from the curable resin composition layer) (normal air surface) on the coating side in normal air. Further, ultraviolet irradiation may be performed while spraying a curing-inhibiting gas on the upper surface of the coating layer after evacuation. When the resin composition is cured in the atmosphere, the side opposite to the liquid crystal display unit side or the side opposite to the transparent substrate side is the atmosphere side.

The state of the uncured portion and the film thickness of the uncured portion can be adjusted by spraying oxygen or ozone onto the surface of the ultraviolet curable resin layer (coating layer) during the ultraviolet irradiation.
That is, by spraying oxygen or ozone on the surface of the coating layer, oxygen inhibition of curing of the curable resin composition occurs on the surface, so that the uncured portion of the surface can be ensured, The film thickness can be increased.

Here, in this specification, the curing rate represents the curing rate as seen from the curing component of the curable resin composition, and represents a value calculated by excluding components that are not cured such as a softening agent. The curing rate in the present invention can be calculated from the following formula (1) from the liquid specific gravity before curing at 25 ° C. and the film specific gravity at 25 ° C. obtained by curing (Formula 1).
Curing shrinkage = (film specific gravity−liquid specific gravity) / film specific gravity × 100 (1)

The first curable resin composition 11 of the present invention has a storage rigidity at 25 ° C. of the resin layer when irradiated with ultraviolet rays in the above [Step B], when the ultraviolet rays are irradiated in [Step D]. It is preferable that the resin composition has a storage rigidity of 3 to 20 times (preferably 3 to 10 times).
As a method for measuring the storage rigidity, for example, it can be measured by the following method. Specifically, two 40 μm-thick PET films coated with a fluorine-based mold release agent are prepared, and a film obtained by curing the obtained curable resin composition on one of the release agent-coated surfaces. It was applied so that the thickness was 600 μm. Thereafter, the two PET films were bonded together so that the respective release agent application surfaces face each other. The resin composition was cured by irradiating ultraviolet rays with an integrated light amount of 2000 mJ / cm ^{2 through} a PET film with a high-pressure mercury lamp (80 W / cm, ozone-less). Thereafter, the two PET films are peeled off to produce a cured product for measuring the rigidity. And about a rigidity, a rigidity can be measured in the temperature range of 20-40 degreeC using ARES (TA Instruments).
The curing rate during the main curing in [Step D] is 95% or more.

The first curable resin composition 11 of the present invention preferably has a storage rigidity of 1 × 10 ² Pa to 1 × 10 ⁴ Pa at 25 ° C. during the temporary curing.
When the storage rigidity is greater than 1 × 10 ⁴ Pa, the first curable resin composition 11 contracts due to curing, and a contracting force is generated. Therefore, the first curable resin composition 11 is applied to the substrate. When the optical member is obtained, display unevenness occurs due to the fact that it does not follow, peels off, the base material is distorted, and the stress is not sufficiently relaxed. In addition, in bonding in vacuum, the storage rigidity at the time of pre-curing is in the above range, so that the space created at the time of bonding without causing problems when moved to atmospheric pressure is made of resin. It becomes possible to fill. On the other hand, when it is 1 × 10 ² Pa or less, since the rigidity is too low, the shape as a cured product cannot be sufficiently maintained, and thus a cured product suitable for temporary curing cannot be obtained. Here, the storage rigidity is preferably 300 to 3000 Pa, and more preferably 500 to 2000 Pa.
As the curing rate of the resin at the time of temporary curing, the curing rate at the time of temporary curing is 60 to 90%, and in the cured product of the curing rate, the storage rigidity is the above value and the preferred value, so that the distortion of the substrate and Display unevenness can be prevented.

Here, the curing rate during the main curing in [Step D] to be described later is usually 95% or more.
In the present invention, as described above, the storage rigidity of the resin layer when irradiated with ultraviolet rays in [Step D] to be described later is 1.5 to the storage rigidity at 25 ° C. of the resin layer during temporary curing. The resin composition is preferably 10 times. In terms of the curing rate, the storage rigidity of the resin layer when irradiated with ultraviolet rays at a curing rate of 98% is 1.5 with respect to the storage rigidity of the resin layer when irradiated with ultraviolet rays at a curing rate of 80%. The resin composition is preferably 10 to 10 times.
In this way, a resin whose rigidity changes rapidly in accordance with the curing rate, and by suppressing the rigidity when the curing rate is low to a certain range, it is easy for the base material in a state where the curing rate is low. Since it adhere | attaches along the curvature of a base material, it becomes possible to make it adhere | attach easily. And it will follow the change of the curvature of a substrate, and it can also prevent generating a stress in a substrate. On the other hand, in a state where the curing rate is high, the adhesion between the bonded optical base materials becomes rigid, so that the adhesive strength can be significantly increased. Furthermore, in the obtained cured member, it becomes a cured product excellent in moisture and heat resistance while maintaining appropriate flexibility.
Here, it is more preferable that the storage rigidity of the resin layer when irradiated with ultraviolet rays in [Step D] to be described later is 2 to 7 times the storage rigidity at 25 ° C. of the resin layer during temporary curing. 2.5 to 5 times is particularly preferable. In terms of the curing rate, the storage rigidity of the resin layer when irradiated with ultraviolet rays at a curing rate of 98% is 2 to 7 with respect to the storage rigidity at 25 ° C. of the resin layer when irradiated with ultraviolet rays at a curing rate of 80%. It is preferable that it is 2 times, and it is especially preferable that it is 2.5 to 5 times.

The curable resin composition of the present invention preferably has a storage rigidity of 1 × 10 ³ Pa to 1 × 10 ⁶ Pa at 25 ° C. during the main curing. Here, when the storage rigidity is higher than 1 × 10 ⁶ Pa, the shrinkage of the curable resin composition becomes too large due to curing, and thus the base material may be distorted or the stress is not sufficiently relaxed. The possibility of display unevenness when the member is obtained is reduced. On the other hand, if it is 1 × 10 ³ Pa or less, the rigidity is too low and the adhesive strength is low. Here, the storage modulus is preferably 1.0 × 10 ^{3 to} 1.0 × 10 ⁵ Pa, and more preferably 1.0 × 10 ^{3 to} 3.0 × 10 ⁴ Pa.

[Step C]
Next, the surface of the liquid crystal display unit 1 on which the second curable resin composition 12 is formed and the surface of the protective plate 2 on which the first curable resin composition 11 is formed face each other in FIG. ), The liquid crystal display unit 1 and the transparent substrate 2 having a light shielding portion are bonded together. Bonding can be performed either in air or in vacuum.
Here, in order to make it easy to prevent bubbles from being generated at the time of bonding, it is preferable to bond in a vacuum.
Here, when the first curable resin composition 11 is bonded together after obtaining a cured product of an ultraviolet curable resin having a cured portion and an uncured portion, an improvement in adhesion can be expected.
At the time of pasting, the 1st curable resin composition 11 is spread by press etc., and the 1st curable resin composition 11 is filled in space. When it is performed under vacuum, the first cured product layer 13 with few or no voids is formed when exposed to a high pressure atmosphere thereafter. Here, when the thickness A of the coating film of the first curable resin composition 11 is smaller than the thickness B of the coating film of the second curable resin composition 12, the second curable resin composition 12 is more The coating film is crushed and the liquid crystal display unit 1 and the protective plate 2 can be firmly bonded.
When bonding is performed in a reduced pressure atmosphere, the pressure is 1 kPa, preferably 10 to 300 Pa, and more preferably 15 to 100 Pa. You may cancel | release immediately after bonding a pressure reduction atmosphere state. On the other hand, by maintaining the reduced pressure atmosphere for a predetermined time (for example, within 10 minutes), the first curable resin composition 11 flows in the space, and the interval between the liquid crystal display unit 1 and the protective plate 2 is made uniform. It becomes easier to do.

[Step D]
Next, as shown in FIG.1 (d), the optical member obtained by bonding the protective plate 2 and the liquid crystal display unit 1 is irradiated with the ultraviolet-ray 5 from the protective plate 2 side, and curable resin composition (application | coating) Layer).
The dose of ultraviolet rays about 100~4000mJ / cm ² is preferably in accumulated light amount, particularly preferably from about 200~3000mJ / cm ^2, more is highly preferred 1500~3000mJ / cm ^2. The light source used for curing by irradiation with ultraviolet to near ultraviolet light may be any light source as long as it is a lamp that emits ultraviolet to near ultraviolet light. For example, a low-pressure, high-pressure or ultrahigh-pressure mercury lamp, metal halide lamp, (pulse) xenon lamp, LED lamp, or electrodeless lamp may be used.
In this way, the optical member shown in FIG. 7 can be obtained.

Thus, the 1st curable resin composition 11 and the 2nd ultraviolet curable resin composition 12 harden | cure, and the resin cured material layer 15 is formed.
The cured resin layer 15 includes a first cured product layer 13 that extends along the surface of the protective plate 2 and a second cured product layer that is disposed on the periphery of the first cured product layer and surrounds the first cured product layer 13. When the resin cured product layer 15 includes the second cured product layer, the peripheral edge of the first cured product layer 13 can be prevented from spreading outward, that is, thinning at the peripheral portion can be suppressed. The entire thickness can be kept uniform. By making the thickness of the entire second resin cured product layer uniform, it is preferable to easily prevent the voids from remaining at the interface in bonding with other face materials.

  In the cured resin layer 15, as shown in FIG. 4, the thickness A of the coating film of the first curable resin composition 11 is the same as the thickness B of the coating film of the second curable resin composition 12, It is preferable to make it thinner than the thickness B of the coating film of the second curable resin composition 12. Advantages of the setting will be described. When the liquid crystal display unit 1 and the protective plate 2 are bonded together, they are usually pressed and bonded. In that case, since the thickness of the coating film of the second curable resin composition 12 is smaller when the thickness A is the same as or thicker than the thickness B, the first curable resin The composition 12 is crushed and pasted. Therefore, since the second curable resin composition 12 generates stress on the liquid crystal display unit 1 or the protective plate 2 due to the difference between the thickness A and the thickness B, the first curable resin composition is more strongly bonded. This is because it can be bonded.

When the thickness A of the coating film of the first curable resin composition 11 is made thinner than the thickness B of the coating film of the second curable resin composition 12 in the cured resin layer 15, the first curable property. The thickness A of the coating film of the resin composition is more preferably 0.005 mm or more and more preferably 0.01 mm or more than the thickness B of the coating film of the second curable resin composition 12. More preferably.
The thickness A of the coating film of the first curable resin composition 11 suppresses the generation of voids due to a step between the coating film of the second curable resin composition 12 and the coating film of the first curable resin composition 11. Therefore, the thickness is preferably 0.05 mm or less and more preferably 0.03 mm or less than the thickness B of the coating film of the second curable resin composition 12.
The region where the coating film of the second curable resin composition 12 in the resin cured product layer 15 (the layer obtained by combining the first cured product layer and the second cured product layer) is close to the coating film of the first curable resin composition 11 When the thickness A of the coating film of the first curable resin composition 11 is smaller than the thickness B of the coating film of the second curable resin composition 12 in at least a part of the second curable resin composition 12. In the region adjacent to the coating film of the first curable resin composition 11, the thickness B of the thinnest part of the coating film of the second curable resin composition 12 is formed of the first curable resin composition 11. It is preferable that it is 1/2 or more of the thickness A of the weir-like part, more preferably 90/100 or more. If the thickness B of the thinnest part of the coating film of the second curable resin composition is equal to or greater than ½ of the thickness A of the coating film of the first curable resin composition 11, the gap should be open to the outside. It is sufficient to become an independent void and disappear at atmospheric pressure.
The difference between the thickness A of the coating film 11 of the first curable resin composition and the thickness B of the coating film of the second curable resin composition 12 was measured using a laser displacement meter (manufactured by Keyence Corporation, LK-H052K). The total thickness of the transparent substrate and the coating film of the first curable resin composition 11 or the coating film of the second curable resin composition 12 formed thereon is measured and obtained from the difference. The thickness A of the coating film of the first curable resin composition 11 is the thickness of the peripheral edge of the coating film of the first curable resin composition 11 adjacent to the coating film of the second cured resin composition 12. Say it. Usually, a flat face material is used as the transparent substrate, but there are a portion where the coating film of the first curable resin composition 11 is formed and a portion where the coating film of the second curable resin composition 12 is formed. When using a face material having a stepped surface shape, the thickness A of the coating film of the first curable resin composition 11 and the thickness B of the coating film of the second curable resin composition 12 are used. Regardless, the surface step shape is the same as the difference between the thickness A of the coating film of the first curable resin composition 11 and the thickness B of the coating film of the second curable resin composition 12 described above. It only has to be. The thickness A of the coating film of the first curable resin composition 11 and the thickness B of the coating film of the second curable resin composition 12 are the first cured by the coating film of the second curable resin composition 12. It is preferable that the thickness is uniform over the entire transparent surface material except for at least a part of the region adjacent to the coating film of the conductive resin composition 11.
Also, depending on the surface shape of the coating film of the first curable resin composition 11 or the coating film of the second curable resin composition 12, it may be difficult to measure the thickness with the laser displacement meter. The thickness A of the coating film of the first curable resin composition 11 and the thickness of the coating film of the second curable resin composition 12 using a 3D shape measuring machine (high-precision shape measuring system KS-1100) or the like. B may be measured.

  At the time of bonding, as shown in FIG. 1C, when the liquid crystal display unit 1 and the protective plate 2 are bonded via the resin composition layer 15 under a reduced pressure atmosphere, the liquid crystal display unit 1 or the protection Even when an independent void remains at the interface between the plate 2 and the curable resin composition, when the void is returned to the atmospheric pressure atmosphere, the pressure in the void (remains reduced pressure) and the curable resin composition The volume of the voids decreases due to the pressure difference from the pressure (atmospheric pressure) applied, and the fine voids disappear by being absorbed by the curable resin composition.

  In the first embodiment, the case where the first curable resin composition is applied to the protective plate 2 and the second curable resin composition is applied to the liquid crystal display unit 1 to form a coating film is described. It is also possible to apply the structure in which the first curable resin composition is applied to the liquid crystal display unit 1 and the second curable resin composition is applied to the protective plate 2 to form a coating film. .

(Second Embodiment)
In addition to the first embodiment, the optical member of the present invention may be manufactured by the second modified embodiment described below.

[Step A]
First, as shown to Fig.5 (a), the light-shielding part 4 on the protection board 2 is formed in the 2nd curable resin composition 12 containing (meth) acrylate (A) and a photoinitiator (B). Apply to the surface.
[Step B]
Then, as shown in FIG.5 (b), after apply | coating the 1st curable resin composition 11 to the surface in which the light-shielding part 4 on the protective plate 2 was formed, the ultraviolet rays 5 are irradiated to the obtained coating film A cured product having a cured portion present on the lower side of the coating layer (on the transparent substrate side as viewed from the curable resin composition) and an uncured portion present on the upper side of the coating layer (the side opposite to the transparent substrate side). Get a layer.
At this time, when the maximum illuminance in the range of 320 nm to 450 nm is 100, the ratio of the maximum illuminance at 200 to 320 nm is 30 or less, particularly preferably 200 to 320 nm. The illuminance at 10 is 10 or less. When the maximum illuminance in the range of 320 nm to 450 nm is 100, if the ratio of the maximum illuminance at 200 to 320 nm is higher than 30, the adhesive strength of the finally obtained optical member will be inferior.

[Step C]
Next, as shown in FIG. 5C, the liquid crystal is formed such that the uncured portions of the obtained first and second curable resin compositions 11 and 2 and the display surface of the liquid crystal display unit 1 face each other. The display unit 1 and the protective plate 2 are bonded together. Bonding can be performed either in air or in vacuum.

[Step D]
Next, as shown in FIG. 5 (d), the optical member obtained by laminating the protective plate 2 and the liquid crystal display unit 1 is irradiated with ultraviolet rays 5 from the protective plate 2 side, and the curable resin composition is not yet applied. The cured product layer having a cured portion is cured.

  In this way, the optical member shown in FIG. 7 can be obtained.

  In the second embodiment, the case where both the first curable resin composition and the second curable resin composition are applied to the protective plate 2 to form a coating film is described. The first curable resin composition and the second curable resin composition may be applied to the liquid crystal display unit 1 to form a coating film and applied without any problem.

(Third embodiment)
In addition to the first and second embodiments, the optical member of the present invention may be manufactured by the following modified third embodiment.
[Step A]
First, as shown to Fig.6 (a), the 2nd curable resin composition 12 containing (meth) acrylate (A) and a photoinitiator (B) is used for the display surface and the protective plate 2 of the liquid crystal display unit 1. It is applied to the surface of the surface on which the light shielding portion 4 is formed.
[Step B]
Thereafter, as shown in FIG. 6B, the first curable resin composition 11 containing (meth) acrylate (A) and the photopolymerization initiator (B) is applied to the display surface of the liquid crystal display unit 1 and the protective plate 2. It is applied to the surface of the surface where the light shielding part 4 is formed.
The obtained coating film is irradiated with ultraviolet rays 5, and the cured part existing on the lower side of the coating film (on the transparent substrate side as viewed from the curable resin composition) and the upper side of the coating layer (on the side opposite to the transparent substrate side) A cured product layer having an uncured portion present in is obtained.
At this time, when the maximum illuminance in the range of 320 nm to 450 nm is 100, the ratio of the maximum illuminance at 200 to 320 nm is 30 or less, particularly preferably 200 to 320 nm. The illuminance at 10 is 10 or less. When the maximum illuminance in the range of 320 nm to 450 nm is 100, if the ratio of the maximum illuminance at 200 to 320 nm is higher than 30, the adhesive strength of the finally obtained optical member will be inferior.

[Step C]
Next, as shown in FIG. 6C, the liquid crystal display unit 1 and the protective plate 2 are bonded so that the uncured portions face each other. Bonding can be performed either in air or in vacuum.
Here, in order to make it easy to prevent bubbles from being generated at the time of bonding, it is preferable to bond in a vacuum.
As described above, when a cured product of an ultraviolet curable resin having a cured portion and an uncured portion is obtained on each of the liquid crystal display unit and the transparent substrate, the adhesion can be improved.

[Step D]
Next, as shown in FIG.6 (d), the optical member obtained by bonding the transparent substrate 2 and the liquid crystal display unit 1 is irradiated with the ultraviolet-ray 5 from the protective plate 2 side, and curable resin composition (application | coating) Layer).
The dose of ultraviolet rays about 100~4000mJ / cm ² is preferably in accumulated light amount, particularly preferably from about 200~3000mJ / cm ^2, more is highly preferred 1500~3000mJ / cm ^2. The light source used for curing by irradiation with ultraviolet to near ultraviolet light may be any light source as long as it is a lamp that emits ultraviolet to near ultraviolet light. For example, a low-pressure, high-pressure or ultrahigh-pressure mercury lamp, metal halide lamp, (pulse) xenon lamp, LED lamp or electrodeless lamp can be used.
In this way, the optical member shown in FIG. 7 can be obtained.

In each of the above embodiments, some of the embodiments of the method for producing an optical member of the present invention are described with one specific optical substrate. In each embodiment, the liquid crystal display unit and the transparent substrate having the light-shielding portion have been described, but in the manufacturing method of the present invention, various members described later can be used as an optical substrate instead of the liquid crystal display unit. Also about a transparent substrate, the various members mentioned later as an optical base material can be used.
In addition, as an optical base material such as a liquid crystal display unit and a transparent substrate, other various optical base material layers (for example, a film bonded with a cured product layer of a curable resin composition, or the like) Other optical base material layers laminated) may be used.
Furthermore, the coating method of the curable resin composition described in the section of the first embodiment, the film thickness of the resin cured product, the irradiation amount and the light source at the time of ultraviolet irradiation, and oxygen or oxygen on the surface of the ultraviolet curable resin layer Any method for adjusting the film thickness of the uncured portion by spraying ozone is not applied only to the above-described embodiment, and can be applied to any manufacturing method included in the present invention.

Specific modes of the optical members that can be manufactured in the first to third embodiments including the liquid crystal display unit will be described below.
(I) At least one selected from the group consisting of an optical substrate having a light-shielding portion, a transparent glass substrate having a light-shielding portion, a transparent resin substrate having a light-shielding portion, and a glass substrate on which the light-shielding portion and the transparent electrode are formed. The optical base material is an optical base material, and the optical base material bonded thereto is at least one display field unit selected from the group consisting of a liquid crystal display unit, a plasma display unit, and an organic EL unit. The aspect which is a display body unit which has an optical base material which has.
(Ii) One optical base material is a protective base material having a light-shielding part, and another optical base material bonded to it is a touch panel or a display unit having a touch panel, and at least two optical base materials are bonded. A mode in which the optical member is a touch panel having a protective base material having a light-shielding portion or a display unit having the same.
In this case, in Step B, the curable resin composition is applied to either the surface of the protective base material having the light shielding portion provided with the light shielding portion, the touch surface of the touch panel, or both of them. It is preferable to do this.
(Iii) One optical substrate is an optical substrate having a light-shielding portion, the other optical substrate bonded to it is a display unit, and an optical member having at least two optical substrates bonded thereto The aspect which is a display body unit which has an optical base material which has a light-shielding part.
In this case, in Step 1, the curable resin composition is applied to either the surface of the optical substrate having the light shielding portion on the side where the light shielding portion is provided, the display surface of the display unit, or both of them. It is preferable to apply an object.
Specific examples of the optical substrate having a light shielding part include a display screen protective plate having a light shielding part, or a touch panel provided with a protective substrate having a light shielding part.
For example, when the optical substrate having the light-shielding portion is a protective plate for a display screen having the light-shielding portion, the surface of the optical substrate having the light-shielding portion is provided on the side on which the light-shielding portion is provided. It is the surface on the side where the part is provided. In addition, when the optical substrate having the light shielding portion is a touch panel having a protective substrate having the light shielding portion, the surface having the light shielding portion of the protective substrate having the light shielding portion is bonded to the touch surface of the touch panel. The surface of the optical substrate having the light shielding portion on the side where the light shielding portion is provided means the substrate surface of the touch panel opposite to the touch surface of the touch panel.
The light-shielding part of the optical base material having the light-shielding part may be provided on any of the optical base materials, but is usually formed in a frame shape around the optical base material in the form of a transparent plate or sheet, and the width is About 0.5-10 mm is preferable, More preferably, it is about 1-8 mm, More preferably, it is about 2-8 mm.

The curable resin composition that can be used as the first curable resin composition 11 to the second curable resin composition 12 of the present invention will be described.
The curable resin composition of the present invention preferably contains (meth) acrylate (A) and a photopolymerization initiator (B). Moreover, the other component which can be added to the curable resin composition used for optics as an arbitrary component can be contained.
The phrase “can be added to the curable resin composition used for optics” means that an additive that lowers the transparency of the cured product to the extent that it cannot be used for optics is not included.
In the curable resin composition used in the present invention, when a cured sheet having a thickness after curing of 200 μm is prepared, a preferable average transmittance of the sheet with light having a wavelength of 400 to 800 nm is at least It is preferably 90% or more.
A suitable composition ratio of the curable resin composition is such that the (meth) acrylate (A) is 25 to 90% by weight and the photopolymerization initiator (B) is 0.2% with respect to the total amount of the curable resin composition. -5% by weight, other components are the balance.
In the curable resin composition of the present invention, any commonly used photopolymerization initiator can be used as the photopolymerization initiator (B).

The (meth) acrylate (A) in the curable resin composition of the present invention is not particularly limited, but urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, (meth) acrylate having a polybutadiene skeleton, ( It is preferable to use any selected from the group consisting of (meth) acrylate monomers. More preferably, it is an embodiment containing both (i) at least one of urethane (meth) acrylate or (meth) acrylate having a polyisoprene skeleton and (ii) (meth) acrylate monomer.
In the present specification, “(meth) acrylate” means either one or both of methacrylate and acrylate. The same applies to “(meth) acrylic acid” and the like.

  The urethane (meth) acrylate is obtained by reacting a polyhydric alcohol, a polyisocyanate, and a hydroxyl group-containing (meth) acrylate.

Examples of the polyhydric alcohol include those having 1 to 10 carbon atoms such as neopentyl glycol, 3-methyl-1,5-pentanediol, ethylene glycol, propylene glycol, 1,4-butanediol, and 1,6-hexanediol. Triols such as alkylene glycol, trimethylolpropane, pentaerythritol, alcohols having a cyclic skeleton such as tricyclodecane dimethylol, bis- [hydroxymethyl] -cyclohexane, etc .; and these polyhydric alcohols and polybasic acids (for example, succinic acid , Phthalic acid, hexahydrophthalic anhydride, terephthalic acid, adipic acid, azelaic acid, tetrahydrophthalic anhydride, etc.) polyester polyol obtained by reaction with polyhydric alcohol and ε-caprolactone Alcohol, polycarbonate polyol (for example, polycarbonate diol obtained by reaction of 1,6-hexanediol and diphenyl carbonate), polyether polyol (for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-modified bisphenol A, etc.) And polyolefin polyols such as hydrogenated polybutadiene diol. From the viewpoint of compatibility with the other component (A), the polyhydric alcohol is preferably polypropylene glycol or hydrogenated polybutadiene diol. From the viewpoint of adhesion to the substrate, polypropylene glycol having a weight average molecular weight of 2000 or more and water. An added polybutadiene diol is particularly preferred. The upper limit of the weight average molecular weight at this time is not particularly limited, but is preferably 10,000 or less, and more preferably 5000 or less. The hydrogenated polybutadiene polyol (A) can be used as long as it is a hydrogenated reduction product of a general polybutadiene polyol, but particularly for optical applications, those having few residual double bonds are preferred, and the iodine value is 20 The following are particularly preferred: As for the molecular weight, those having a molecular weight distribution generally available can be used, but those having a molecular weight of 500 to 3000 are particularly preferred when a balance between flexibility and curability is taken.

  Examples of the organic polyisocyanate include isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylene diisocyanate, diphenylmethane-4,4'-diisocyanate, dicyclopentanyl isocyanate, and the like.

  Further, the hydroxyl group-containing (meth) acrylate is a compound having at least one hydroxyl group and one (meth) acrylate in one molecule. Specifically, 2-hydroxyethyl (meth) acrylate, propylene glycol Mono (meth) acrylate, butanediol mono (meth) acrylate, pentanediol mono (meth) acrylate, hexanediol mono (meth) acrylate, diethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, triethylene glycol mono (Meth) acrylate, tripropylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene Mono (meth) acrylates of dihydric alcohols such as ethylene glycol mono (meth) acrylate, neopentyl glycol mono (meth) acrylate, ethoxylated neopentyl glycol mono (meth) acrylate, and hydroxypivalate neopentyl glycol mono (meth) acrylate ;

Trimethylolpropane mono (meth) acrylate, ethoxylated trimethylolpropane mono (meth) acrylate, propoxylated trimethylolpropane mono (meth) acrylate, tris (2-hydroxyethyl) isocyanurate mono (meth) acrylate, glycerin mono (meta) ) Acrylate, trimethylolpropane di (meth) acrylate, ethoxylated trimethylolpropane di (meth) acrylate, propoxylated trimethylolpropane di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, glycerin Mono- and di (meth) acrylates of trivalent alcohols such as di (meth) acrylate, and some of the hydroxyl groups of these alcohols are alkyl groups or ε-caprolactone. Modified mono- and di (meth) acrylate;

Pentaerythritol mono (meth) acrylate, dipentaerythritol mono (meth) acrylate, ditrimethylolpropane mono (meth) acrylate, pentaerythritol di (meth) acrylate, dipentaerythritol di (meth) acrylate, ditrimethylolpropane di (meth) Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa Polyfunctionals (meth) of tetrahydric or higher alcohols such as (meth) acrylate and ditrimethylolpropane hexa (meth) acrylate ) And those having a hydroxyl group in acrylates, polyfunctional (meth) acrylate having a hydroxyl group partially modified with an alkyl group and ε- caprolactone hydroxyl groups of these alcohols, and the like.

Of the above (meth) acrylate compound (C) having at least one hydroxyl group, 2-hydroxyethyl (meth) acrylate is particularly preferable from the viewpoint of excellent curability and flexibility. From the viewpoint of easy workability, a polymerizable compound (F) described later in the present invention may be added during the reaction.

  Reaction for obtaining the said urethane (meth) acrylate is performed as follows, for example. That is, organic polyisocyanate is mixed with polyhydric alcohol per equivalent of hydroxyl group so that the isocyanate group is preferably 1.1 to 2.0 equivalent, more preferably 1.1 to 1.5 equivalent, and the reaction temperature Is preferably reacted at 70 to 90 ° C. to synthesize a urethane oligomer (first reaction). Next, the hydroxy (meth) acrylate compound is mixed so that the hydroxyl group is preferably 1 to 1.5 equivalents per equivalent of isocyanate group of the urethane oligomer, and reacted at 70 to 90 ° C. to obtain the target urethane (meta ) Acrylate can be obtained (second reaction).

  In the present invention, the first reaction can be carried out without a solvent, but in a solvent having a high viscosity of the product and having no alcoholic hydroxyl group for improving workability or in a polymerizable compound (F) described later. It is preferable to do so. Specific examples of the solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, aromatic hydrocarbons such as benzene, toluene, xylene, and tetramethylbenzene, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and dipropylene glycol. Glycol ethers such as dimethyl ether, dipropylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, ethyl acetate, butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate , Propylene glycol monoethyl ether acetate, Propylene glycol monomethyl ether acetate, esters such as dialkyl glutarate, dialkyl succinate and dialkyl adipate, cyclic esters such as γ-butyrolactone, petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha Can be carried out alone or in a mixed organic solvent.

  The reaction temperature is usually 30 to 150 ° C, preferably 50 to 100 ° C. The end point of the reaction is confirmed by a decrease in the amount of isocyanate. A catalyst may be added for the purpose of shortening the reaction time. As this catalyst, either a basic catalyst or an acidic catalyst is used. Examples of the basic catalyst include amines such as pyridine, pyrrole, triethylamine, diethylamine, dibutylamine and ammonia, and phosphines such as tributylphosphine and triphenylphosphine. Examples of acidic catalysts include copper naphthenate, cobalt naphthenate, zinc naphthenate, tributoxyaluminum, titanium tetraisopropoxide, zirconium tetrabutoxide, aluminum chloride, tin octylate, octyltin trilaurate, dibutyltin dilaurate, Mention may be made of Lewis acid catalysts such as octyltin diacetate. The addition amount of these catalysts is 0.1-1 weight part normally with respect to 100 weight part of total weights of a diol compound (A + D) and a polyisocyanate compound (B).

  The polyurethane compound (E) of the present invention is obtained by reacting (second reaction) a (meth) acrylate compound (C) having at least one hydroxyl group with respect to the remaining isocyanate group after the first reaction. be able to.

  The second reaction of the present invention is charged in an equivalent relationship such that the isocyanate group of the intermediate obtained after the first reaction is eliminated. Specifically, preferably, the OH group of the (meth) acrylate compound (C) having at least one hydroxyl group is 1.0 to 3.3 with respect to 1.0 mol of the NCO group of the intermediate obtained after the first reaction. 0 mol, more preferably 1.0 to 2.0 mol.

  The second reaction of the present invention can also be carried out in the absence of a solvent, but in the above-mentioned solvent and / or polymerizable compound (F) described later in the present invention in order to improve workability because the product has a high viscosity. Preferably it is done. Moreover, reaction temperature is 30-150 degreeC normally, Preferably it is the range of 50-100 degreeC. The end point of the reaction is confirmed by a decrease in the amount of isocyanate. The aforementioned catalyst may be added for the purpose of shortening the reaction time.

  Usually, a polymerization inhibitor such as 4-methoxyphenol is already added to the acrylate compound used as a raw material, but a polymerization inhibitor may be added again during the reaction. Examples of such polymerization inhibitors include hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-cresol, 3-hydroxythiophenol, Examples include p-benzoquinone, 2,5-dihydroxy-p-benzoquinone, and phenothiazine. The amount used is 0.01 to 1% by weight based on the reaction raw material mixture.

  As a weight average molecular weight of the said urethane (meth) acrylate, about 7000-25000 are preferable and 10000-20000 are more preferable. When the weight average molecular weight is less than 7000, shrinkage tends to increase, and when the weight average molecular weight is greater than 25000, curability tends to be poor.

  In the curable resin composition of this invention, urethane (meth) acrylate can be used 1 type or in mixture of 2 or more types by arbitrary ratios. As for the weight ratio in the photocurable transparent adhesive composition of this invention of urethane (meth) acrylate, 20 to 80 weight% is preferable normally, More preferably, it is 30 to 70 weight%.

The (meth) acrylate having the polyisoprene skeleton has a (meth) acryloyl group at the terminal or side chain of the polyisoprene molecule. A (meth) acrylate having a polyisoprene skeleton can be obtained as “UC-203” (manufactured by Kuraray Co., Ltd.). The (meth) acrylate having a polyisoprene skeleton preferably has a polystyrene-equivalent number average molecular weight of 1,000 to 50,000, more preferably about 25,000 to 45,000.
The weight ratio of the (meth) acrylate having a polyisoprene skeleton in the photocurable transparent adhesive composition of the present invention is usually preferably 20 to 80% by weight, more preferably 30 to 70% by weight.

  The (meth) acrylate having the polybutadiene skeleton has a (meth) acryloyl group at the terminal or side chain of the polybutadiene molecule. The (meth) acrylates having a polybutadiene skeleton are "TEAI-1000 (Nippon Soda Co., Ltd.)", "TE-2000 (Nippon Soda Co., Ltd.)", "EMA-3000 (Nippon Soda Co., Ltd.)" Manufactured by Kogyo Co., Ltd.). The (meth) acrylate having a polybutadiene skeleton preferably has a polystyrene-equivalent number average molecular weight of 1,000 to 30,000, more preferably about 1,000 to 10,000.

As the (meth) acrylate monomer, a (meth) acrylate having one (meth) acryloyl group in the molecule can be preferably used.
Here, the (meth) acrylate monomer indicates (meth) acrylate excluding the urethane (meth) acrylate, the following epoxy (meth) acrylate, and the (meth) acrylate having the polyisoprene skeleton.

Specific examples of the (meth) acrylate having one (meth) acryloyl group in the molecule include isooctyl (meth) acrylate, isoamyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, stearyl ( Alkyl (meth) acrylates having 5 to 20 carbon atoms such as (meth) acrylate, isostearyl (meth) acrylate, cetyl (meth) acrylate, isomyristyl (meth) acrylate, tridecyl (meth) acrylate, benzyl (meth) acrylate, tetrahydro Furfuryl (meth) acrylate, acryloylmorpholine, phenylglycidyl (meth) acrylate, tricyclodecane (meth) acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl ) Acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 1-adamantyl acrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, 1-adamantyl methacrylate, polypropylene oxide modified nonyl Carbon having a hydroxyl group such as (meth) acrylate having a cyclic skeleton such as phenyl (meth) acrylate and dicyclopentadieneoxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate Number 1-5 alkyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polypropylene oxide modification Polyalkylene glycol (meth) acrylate such as nonylphenyl (meth) acrylate, ethylene oxide modified phenoxylated phosphoric acid (meth) acrylate, ethylene oxide modified butoxylated phosphoric acid (meth) acrylate, ethylene oxide modified octyloxylated phosphoric acid (meth) acrylate, etc. Can be mentioned. Among them, C10-20 alkyl (meth) acrylate, 2-ethylhexyl carbitol acrylate, acryloylmorpholine, 4-hydroxybutyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isostearyl (meth) acrylate, dicyclo Pentenyloxyethyl (meth) acrylate and polypropylene oxide-modified nonylphenyl (meth) acrylate are preferred. In particular, from the viewpoint of resin flexibility, alkyl (meth) acrylate having 10 to 20 carbon atoms, dicyclopentenyloxyethyl (meth) Preferred are acrylate, polypropylene oxide-modified nonylphenyl (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate.
On the other hand, from the viewpoint of improving the adhesion to glass, a C1-C5 alkyl (meth) acrylate having a hydroxyl group and acryloylmorpholine are preferable, and acryloylmorpholine is particularly preferable.

The composition of the present invention can contain (meth) acrylates other than (meth) acrylate having one (meth) acryloyl group as long as the characteristics of the present invention are not impaired. For example, tricyclodecane dimethylol di (meth) acrylate, dioxane glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, alkylene oxide modified bisphenol A type di (meth) acrylate , Trimethylol C2-C10 alkanes such as caprolactone-modified hydroxypivalic acid neopentyl glycol di (meth) acrylate and ethylene oxide-modified phosphoric acid di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethyloloctanetri (meth) acrylate Tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri ( Trimethylol C2-C10 alkane polyalkoxy tri (meth) acrylate such as acrylate, trimethylolpropane polyethoxypolypropoxy tri (meth) acrylate, tris [(meth) acryloyloxyethyl] isocyanurate, pentaerythritol tri ( (Meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate and other alkylene oxide modified trimethylolpropane tri (meth) acrylate pentaerythritol polyethoxytetra (meth) acrylate, Pentaerythritol polypropoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrime Trimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.
In this invention, when using together, in order to suppress cure shrinkage, it is preferable to use mono- or bifunctional (meth) acrylate.

In the curable resin composition of this invention, these (meth) acrylate monomer components can be used 1 type or in mixture of 2 or more types by arbitrary ratios. As for the weight ratio in the photocurable transparent adhesive composition of this invention of a (meth) acrylate monomer, 5-70 weight% is preferable normally, More preferably, it is 10-50 weight%. If it is less than 5% by weight, the curability tends to be poor, and if it is more than 70% by weight, the shrinkage tends to increase.
In an embodiment containing both (i) urethane (meth) acrylate or (meth) acrylate having a polyisoprene skeleton and (ii) (meth) acrylate monomer in the curable resin composition, The total content of both i) and (ii) is usually preferably 25 to 90% by weight, more preferably 40 to 90% by weight, still more preferably 40 to 80% by weight, based on the total amount of the resin composition. It is.

  Epoxy (meth) acrylate can be used for the curable resin composition of this invention in the range which does not impair the characteristic of this invention. Epoxy (meth) acrylate has a function of improving curability and improving the hardness and curing speed of a cured product. Any epoxy (meth) acrylate can be used as long as it is obtained by reacting a glycidyl ether type epoxy compound with (meth) acrylic acid, and preferably used epoxy (meth) acrylate. Examples of the glycidyl ether type epoxy compound to be obtained include diglycidyl ether of bisphenol A or its alkylene oxide adduct, diglycidyl ether of bisphenol F or its alkylene oxide adduct, diglycidyl of hydrogenated bisphenol A or its alkylene oxide adduct. Diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether of ether, hydrogenated bisphenol F or its alkylene oxide adduct Neopentyl glycol diglycidyl ether, butanediol diglycidyl ether hexanediol diglycidyl ether to, cyclohexanedimethanol diglycidyl ether, and polypropylene glycol diglycidyl ether.

  Epoxy (meth) acrylate is obtained by reacting these glycidyl ether type epoxy compounds with (meth) acrylic acid under the following conditions.

  (Meth) acrylic acid is reacted at a ratio of 0.9 to 1.5 mol, more preferably 0.95 to 1.1 mol, per 1 equivalent of the epoxy group of the glycidyl ether type epoxy compound. The reaction temperature is preferably 80 to 120 ° C., and the reaction time is about 10 to 35 hours. In order to accelerate the reaction, it is preferable to use a catalyst such as triphenylphosphine, TAP, triethanolamine, or tetraethylammonium chloride. Further, in order to prevent polymerization during the reaction, for example, paramethoxyphenol, methylhydroquinone or the like can be used as a polymerization inhibitor.

An epoxy (meth) acrylate that can be suitably used in the present invention is a bisphenol A type epoxy (meth) acrylate obtained from a bisphenol A type epoxy compound. The weight average molecular weight of the epoxy (meth) acrylate is preferably 500 to 10,000.
The weight ratio of the epoxy (meth) acrylate in the curable resin composition of the present invention is usually 1 to 80% by weight, preferably 5 to 30% by weight.

The content ratio of (meth) acrylate (A) in the curable resin composition of the present invention is preferably 25 to 90% by weight, more preferably 40 to 90% by weight, based on the total amount of the curable resin composition. More preferably, it is 40 to 80% by weight.
In the curable resin composition of the present invention, the (meth) acrylate (A) is selected from the group consisting of the urethane (meth) acrylate, the (meth) acrylate having the polyisoprene skeleton, and the (meth) acrylate monomer. It is preferable to contain at least one. The content ratio of the urethane (meth) acrylate is preferably 20 to 80% by weight, more preferably 30 to 70% by weight, and the content ratio of the (meth) acrylate having the polyisoprene skeleton is preferably 20 to 80%. The content ratio of the (meth) acrylate monomer is preferably 5 to 70% by weight, more preferably 10 to 50% by weight.
In the curable resin composition of the present invention, as the (meth) acrylate (A), the urethane (meth) acrylate or the (meth) acrylate having a polyisoprene skeleton is contained, and the content ratio is 20 to 80% by weight, preferably Is more preferably 30 to 70% by weight and contains a (meth) acrylate monomer, and its content is 5 to 70% by weight, preferably 10 to 50% by weight.

  The photopolymerization initiator (B) contained in the composition of the present invention is not particularly limited. For example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphos Fin oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 1-hydroxycyclohexyl phenyl ketone ( Irgacure (trade name) 184; manufactured by BASF), 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer (Esacure (trade name) ONE; manufactured by Lamberti), 1- [4- (2-Hydroxyethoxy) -phenyl] -2- Droxy-2-methyl-1-propan-1-one (Irgacure 2959; manufactured by BASF), 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl } -2-Methyl-propan-1-one (Irgacure 127; manufactured by BASF), 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651; manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl -Propan-1-one (Darocur (trade name) 1173; manufactured by BASF), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907; manufactured by BASF), Oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester And oxy-phenyl-acetic acid 2- [2-hydroxy-ethoxy] -ethyl ester mixture (Irgacure 754; manufactured by BASF), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl)- Examples include butan-1-one, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, and isopropylthioxanthone.

In the present invention, the photopolymerization initiator (B) has a molar extinction coefficient at 302 nm or 313 nm measured in acetonitrile or methanol of 300 ml / (g · cm) or more and a molar extinction coefficient at 365 nm of 100 ml. It is preferable to use a photopolymerization initiator that is not more than / (g · cm). By using such a photopolymerization initiator, it is possible to contribute to an improvement in adhesive strength. When the molar extinction coefficient at 302 nm or 313 nm is 300 ml / (g · cm) or more, curing at the time of curing in Step 3 becomes more sufficient. On the other hand, when the molar extinction coefficient at 365 nm is 100 ml / (g · cm) or less, excessive curing at the time of curing in Step 1 can be appropriately suppressed, and adhesion can be further improved.
Examples of such a photopolymerization initiator (B) include 1-hydroxycyclohexyl phenyl ketone (Irgacure 184; manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Darocur 1173). Manufactured by BASF), 1- [4- (2-hydroxyethoxy) -phenyl-]-2-hydroxy-2-methyl-1-propan-1-one (Irgacure 2959; manufactured by BASF), phenylglyoxylic acid And methyl ester (Darocur MBF; manufactured by BASF).

  In the curable resin composition of this invention, these photoinitiators (B) can be used 1 type or in mixture of 2 or more types by arbitrary ratios. As for the weight ratio in the photocurable resin composition of this invention of a photoinitiator (B), 0.2 to 5 weight% is preferable normally, More preferably, it is 0.3 to 3 weight%. When it is more than 5% by weight, when obtaining a cured product layer having a cured part and an uncured part on the side opposite to the optical substrate side, the uncured part cannot be formed or the transparency of the resin cured product layer is low. There is a risk of getting worse.

  In addition to the (meth) acrylate (A) and the photopolymerization initiator (B), the curable resin composition of the present invention includes, as other components, a photopolymerization initiation assistant described below, a general formula (1) described later. The compound which has the structure shown by this, the softening component mentioned later, the additive mentioned later, etc. can be included. The content ratio of the other components with respect to the total amount of the curable resin composition of the present invention is a balance obtained by subtracting the total amount of the (meth) acrylate (A) and the photopolymerization initiator (B) from the total amount. Specifically, the total amount of the other components is preferably 0 to 74% by weight, more preferably about 5 to 70% by weight, based on the total amount of the curable resin composition of the present invention.

  Furthermore, amines that can serve as photopolymerization initiation assistants can be used in combination with the photopolymerization initiator. Examples of amines that can be used include benzoic acid 2-dimethylaminoethyl ester, dimethylaminoacetophenone, p-dimethylaminobenzoic acid ethyl ester, and p-dimethylaminobenzoic acid isoamyl ester. When using a photopolymerization initiation aid such as the amines, the content in the adhesive resin composition of the present invention is usually preferably 0.005 to 5% by weight, more preferably 0.01 to 3% by weight. is there.

  The curable resin composition of the present invention can contain a compound having a structure represented by the general formula (1) as necessary.

(In the formula, n represents an integer of 0 to 40, and m represents an integer of 10 to 50. R ¹ and R ² may be the same or different. R ¹ and R ² have 1 to 18 carbon atoms. And an alkyl group having 1 to 18 carbon atoms, an alkynyl group having 1 to 18 carbon atoms, or an aryl group having 5 to 18 carbon atoms.)
The compound having the structure represented by the general formula (1) can be obtained, for example, as Unisafe (trade name) PKA-5017 (polyethylene glycol-polypropylene glycol allyl butyl ether) manufactured by NOF Corporation.
The weight ratio in the curable resin composition when using the compound having the structure represented by the general formula (1) is usually preferably 10 to 80% by weight, more preferably 10 to 70% by weight.

In the curable resin composition of the present invention, a softening component can be used as necessary. Specific examples of the softening component that can be used include the polymer or oligomer excluding the (meth) acrylate and the compound having the structure represented by the general formula (1), phthalates, phosphates, glycol esters, Examples thereof include acid esters, aliphatic dibasic acid esters, fatty acid esters, epoxy plasticizers, castor oils, and terpene hydrogenated resins. Examples of the oligomer and polymer include an oligomer or a polymer having a polyisoprene skeleton, a polybutadiene skeleton, a polybutene skeleton or a xylene skeleton, and an esterified product thereof. In some cases, a polymer or an oligomer having a polybutadiene skeleton and an ester thereof. It is preferred to use a compound. Specific examples of the polymer or oligomer having a polybutadiene skeleton and esterified products thereof include butadiene homopolymer, epoxy-modified polybutadiene, butadiene-styrene random copolymer, maleic acid-modified polybutadiene, and terminal hydroxyl group-modified liquid polybutadiene or liquid hydrogenated polybutadiene. It is done. Further, in the softening component, the above-mentioned softening components can be mixed and used.
The weight ratio of the softening component in the curable resin composition is usually preferably 10 to 80% by weight, more preferably 10 to 70% by weight.

  In the curable resin composition of the present invention, an antioxidant, an organic solvent, a silane coupling agent, a polymerization inhibitor, a leveling agent, an antistatic agent, a surface lubricant, a fluorescent whitening agent, and a light stabilizer are optionally added. You may add additives, such as a hindered amine compound (for example) and a filler.

  Specific examples of the antioxidant include, for example, BHT, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine , Pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl- 4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3-t -Butyl-5-methyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N N-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t- Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, octylated diphenylamine, 2,4-bis [(octylthio) methyl-O-cresol, Isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], dibutylhydroxytoluene and the like.

  Specific examples of the organic solvent include alcohols such as methanol, ethanol and isopropyl alcohol, dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran, dioxane, toluene, xylene and the like.

  Specific examples of the silane coupling agent include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxy) (Cyclohexyl) ethyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, γ-mercapropropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane, 3 -Aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyltrimethoxysilane 3 Silane coupling agents such as chloropropylmethyldimethoxysilane and 3-chloropropyltrimethoxysilane; isopropyl (N-ethylaminoethylamino) titanate, isopropyl triisostearoyl titanate, titanium di (dioctyl pyrophosphate) oxyacetate, tetra Titanium coupling agents such as isopropyldi (dioctylphosphite) titanate and neoalkoxytri (pN- (β-aminoethyl) aminophenyl) titanate; Zr-acetylacetonate, Zr-methacrylate, Zr-propionate, neo Alkoxy zirconate, neoalkoxy trisneodecanoyl zirconate, neoalkoxy tris (dodecanoyl) benzenesulfonyl zirconate, neoalkoxy tris ( Chi range aminoethyl) zirconate, neoalkoxy tris (m-aminophenyl) zirconate, ammonium zirconium carbonate, Al- acetylacetonate, Al- methacrylate, zirconium or the like Al- propionate, or aluminum coupling agent, and the like.

  Specific examples of the polymerization inhibitor include paramethoxyphenol and methylhydroquinone.

  Specific examples of the light stabilizer include, for example, 1,2,2,6,6-pentamethyl-4-piperidyl alcohol, 2,2,6,6-tetramethyl-4-piperidyl alcohol, 1,2,2, 6,6-pentamethyl-4-piperidyl (meth) acrylate (manufactured by ADEKA Corporation, LA-82), tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3 4-butanetetracarboxylate, tetrakis (2,2,6,6-totramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, 1,2,3,4-butanetetracarboxylic acid 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] Mixed esterified product with ndecane, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate decanoate, bis (1-undecanoxy-2,2,6,6-tetramethylpiperidine-4- Yl) carbonate, 2,2,6,6, -tetramethyl-4-piperidyl methacrylate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) sebacate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetra Tilpiperidine, 1,2,2,6,6-pentamethyl-4-piperidinyl-methacrylate, bis (1,2,2,6,6-pentamethyl-4-piperidinyl) [[3,5-bis (1, 1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, decanedioic acid bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) ester, 1,1-dimethyl Reaction product of ethyl hydroperoxide and octane, N, N ′, N ″, N ″ ′-tetrakis- (4,6-bis- (butyl- (N-methyl-2,2,6,6-tetramethylpiperidine) -4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine, dibutylamine 1,3,5-triazine N, N′-bis (2,2,6) , 6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate, poly [[6- (1, 1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2 , 2,6,6-tetramethyl-4-piperidyl) imino]], dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, 2,2,4 , 4-Tetramethyl-20- (β-lauryloxycarbonyl) ethyl-7-oxa-3,20-diazadispiro [5 · 1 · 11 · 2] heneicosane-21-one, β-alanine, N,-(2 , 2,6,6 -Tetramethyl-4-piperidinyl) -dodecyl ester / tetradecyl ester, N-acetyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidinyl) pyrrolidine-2,5-dione, 2,2,4,4-tetramethyl-7-oxa-3,20-diazadispiro [5,1,11,2] heneicosan-21-one, 2,2,4,4-tetramethyl-21-oxa 3,20-diazadicyclo- [5,1,11,2] -heneicosane-20-propanoic acid dodecyl ester / tetradecyl ester, propanedioic acid, [(4-methoxyphenyl) -methylene] -bis (1,2 , 2,6,6-pentamethyl-4-piperidinyl) ester, higher fatty acid ester of 2,2,6,6-tetramethyl-4-piperidinol, , 3-benzenedicarboxamide, hindered amines such as N, N′-bis (2,2,6,6-tetramethyl-4-piperidinyl), benzophenone compounds such as octabenzone, 2- (2H-benzo Triazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- [2-hydroxy-3- (3 , 4,5,6-tetrahydrophthalimido-methyl) -5-methylphenyl] benzotriazole, 2- (3-tert-butyl-2-hydroxy-5-methylphenyl) -5-chlorobenzotriazole, 2- (2 -Hydroxy-3,5-di-tert-pentylphenyl) benzotriazole, methyl 3- (3- (2H-benzotriazole) Reaction product of 2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate and polyethylene glycol, benzotriazole such as 2- (2H-benzotriazol-2-yl) -6-dodecyl-4-methylphenol Compounds, benzoate compounds such as 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, 2- (4,6-diphenyl-1,3,5-triazine- Triazine compounds such as 2-yl) -5-[(hexyl) oxy] phenol and the like are mentioned, and hindered amine compounds are particularly preferable.

  Specific examples of the filler include, for example, crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, titania, talc and the like. Examples thereof include powder or beads obtained by spheroidizing these.

  When present in the composition of various additives, the weight ratio of the various additives in the photocurable transparent adhesive composition is preferably 0.01 to 3% by weight, more preferably 0.01 to 1% by weight. More preferably, it is 0.02 to 0.5% by weight.

  The curable resin composition of the present invention can be obtained by mixing and dissolving the above-described components at room temperature to 80 ° C., and if necessary, impurities may be removed by an operation such as filtration. In the adhesive resin composition of the present invention, considering the applicability, it is preferable to appropriately adjust the compounding ratio of the components so that the viscosity at 25 ° C. is in the range of 300 to 15000 mPa · s.

The cure shrinkage of the cured product of the curable resin composition of the present invention is preferably 3.0% or less, and particularly preferably 2.0% or less. Thereby, when the curable resin composition is cured, the internal stress accumulated in the cured resin can be reduced, and the interface between the base material and the layer made of the cured curable resin composition is distorted. What can be done can be effectively prevented.
In addition, when the substrate such as glass is thin, when the curing shrinkage rate is large, since the warpage during curing becomes large, the display performance is greatly adversely affected. Is preferred.

It is preferable that the transmittance | permeability in 400 nm-800 nm of the hardened | cured material of the curable resin composition of this invention is 90% or more. When the transmittance is less than 90%, it is difficult for light to pass therethrough, and the visibility may be lowered when used in a display device.
Moreover, since the improvement of visibility can be expected further when the transmittance at 400 to 450 nm of the cured product is high, the transmittance at 400 to 450 nm is preferably 90% or more.

As the first curable resin composition 11 or the second curable resin composition 12 of the present invention, (I) urethane (meth) acrylate or (meth) acrylate having a polyisoprene skeleton and (II) (meth) acrylate It is preferable to contain a monomer and a photopolymerization initiator.
And both the 1st curable resin composition 11 and the 2nd curable resin composition 12 use the resin composition containing the said (I) component and (II) component, and obtain an image display apparatus. Is preferred.
Moreover, it is preferable to further contain the said softening component as a softening agent, and it is preferable that especially the 1st curable resin composition 11 and the 2nd curable resin composition 12 contain the softening component. Among the softening components, it is preferable to use a terpene resin (particularly, a solid terpene resin).

Some preferred embodiments of the curable resin composition containing the (meth) acrylate (A) and the photopolymerization initiator (B) used in the production method of the present invention are described below. “Wt%” in the content of each component indicates a content ratio with respect to the total amount of the curable resin composition of the present invention.
(A1)
In the above (4), the (meth) acrylate (A) is at least one (meth) acrylate selected from the group consisting of urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, and a (meth) acrylate monomer. The curable resin composition described.
(A2)
As the (meth) acrylate (A),
(I) at least one of urethane (meth) acrylate or (meth) acrylate having a polyisoprene skeleton, and
(Ii) (meth) acrylate monomers,
The curable resin composition according to (4) or (A1) above, comprising both of the above.
(A3)
As the (meth) acrylate (A),
(I) urethane (meth) acrylate obtained by reaction of poly C2-C4 alkylene glycol, diisocyanate and hydroxy C2-C4 alkyl (meth) acrylate, and
(Ii) (meth) acrylate monomers,
The curable resin composition according to (4) or (A1) above, comprising both of the above.

(A4)
Curable resin composition as described in any one of said (A1)-(A3) whose weight average molecular weights of urethane (meth) acrylate are 7000-25000.
(A5)
In the curable resin composition containing the (meth) acrylate (A) and the photopolymerization initiator (B), as the photopolymerization initiator (B), a curable resin composition containing an acylphosphine oxide compound, or Curable resin composition as described in any one of said (A1)-(A4) containing an acyl phosphine oxide compound as a photoinitiator (B).
(A6)
Acylphosphine oxide compounds are 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide. And the curable resin composition according to (A5) above, which is at least one compound selected from the group consisting of bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide.

(A7)
Curable resin composition containing (meth) acrylate (A) and photopolymerization initiator (B), in addition to (A) component and (B) component, further contains other components. Or the curable resin composition according to any one of (A1) to (A6).
(A8)
Curable resin composition as described in said (A7) whose (meth) acrylate (A) is 25 to 90 weight%, a photoinitiator (B) is 0.2 to 5 weight%, and other components are the remainder.
(A9)
As (meth) acrylate (A), 20 to 80% by weight of at least one of (i) urethane (meth) acrylate or polyisoprene (meth) acrylate and (ii) 5 to 70% by weight of (meth) acrylate monomer, Curable resin composition as described in said (A8) whose sum total of both is 40 to 90 weight%.

(A10)
Curable resin composition as described in any one of said (A7)-(A9) containing 10 to 80weight% of compounds represented by General formula (1) as another component.
(A11)
A curable resin composition containing (meth) acrylate (A) and a photopolymerization initiator (B) whose cure shrinkage of the cured product of the curable resin composition is 3% or less, or the above (A1) to ( The curable resin composition as described in any one of A10).
(A12)
About the sheet | seat of the hardened | cured material of a 200-micrometer-thick curable resin composition, the average transmittance | permeability in a wavelength range of 400-450 nm is at least 90%, and the average transmittance | permeability in a wavelength range of 400-800 nm is at least. 90% of the curable resin composition containing (meth) acrylate (A) and the photopolymerization initiator (B), or the curable resin according to any one of (A1) to (A11) above. Composition.

The curable resin composition of the present invention can be suitably used as an adhesive for producing an optical member by laminating a plurality of optical substrates by the [Step A] to [Step D].
Examples of the optical substrate used in the method for producing an optical member of the present invention include a protective plate, a transparent plate, a sheet, a touch panel, and a display unit.
In the present invention, the “optical substrate” means both an optical substrate having no light shielding part on the surface and an optical substrate having a light shielding part on the surface. In the method for producing an optical member of the present invention, it is preferable that at least one of a plurality of optical substrates used is an optical substrate having a light shielding portion.
The position of the light shielding part in the optical substrate having the light shielding part is not particularly limited. As a preferred embodiment, a band-shaped light-shielding portion having a width of 0.05 to 20 mm, preferably about 0.05 to 10 mm, more preferably about 0.1 to 6 mm is formed on the periphery of the optical substrate. Is the case. The light-shielding portion on the optical substrate can be formed by attaching a tape, applying a coating or printing.

Various materials can be used as the material of the optical substrate used in the present invention. Specifically, resins such as PET, PC, PMMA, a composite of PC and PMMA, glass, COC, COP, plastic (such as acrylic resin), and the like can be given. As an optical substrate used in the present invention, for example, a transparent plate or sheet, a sheet or transparent plate obtained by laminating a plurality of films or sheets such as polarizing plates, a non-laminated sheet or transparent plate, and a transparent made from inorganic glass Plates (inorganic glass plates and processed products thereof, such as lenses, prisms, ITO glass) and the like can be used.
The optical substrate used in the present invention is a laminate composed of a plurality of functional plates or sheets (hereinafter referred to as “functional laminate”) such as a touch panel (touch panel input sensor) or the following display unit in addition to the polarizing plate described above. Also called "body").

Examples of the sheet that can be used as the optical substrate used in the present invention include an icon sheet, a decorative sheet, and a protective sheet. Examples of the plate (transparent plate) that can be used in the method for producing an optical member of the present invention include a decorative plate and a protective plate. As materials for these sheets or plates, those listed as materials for transparent plates can be applied.
Examples of the material of the touch panel surface that can be used as the optical substrate used in the present invention include glass, PET, PC, PMMA, a composite of PC and PMMA, COC, and COP.
The thickness of a plate-like or sheet-like optical substrate such as a transparent plate or a sheet is not particularly limited, and is usually about 5 μm to 5 cm, preferably about 10 μm to 10 mm, more preferably about 50 μm to 3 mm. Is the thickness.

As a preferable optical member obtained by the production method of the present invention, a plate-shaped or sheet-shaped transparent optical substrate having a light-shielding portion and the functional laminate are a cured product of the curable resin composition of the present invention. A bonded optical member can be exemplified.
Further, in the manufacturing method of the present invention, a display unit with an optical functional material (by using a display unit such as a liquid crystal display device as one of optical substrates and an optical functional material as another optical substrate ( Hereinafter, it is also referred to as a display panel). Examples of the display unit include display devices such as LCD, EL display, EL illumination, electronic paper, and plasma display in which a polarizing plate is attached to glass. Further, examples of the optical functional material include transparent plastic plates such as acrylic plates, PC plates, PET plates, and PEN plates, tempered glass, and touch panel input sensors.

When the optical base material is used as an adhesive, the visibility of the display image is further improved when the refractive index of the cured product is 1.45 to 1.55 in order to improve the visibility. .
Within the range of the refractive index, the difference in refractive index from the base material used as the optical base material can be reduced, and the light loss can be reduced by suppressing the irregular reflection of light.

Preferred embodiments of the optical member obtained by the production method of the present invention include the following (i) to (vii).
(I) The optical member which bonded together the optical base material which has a light-shielding part, and the said functional laminated body using the hardened | cured material of the curable resin composition of this invention.
(Ii) An optical base selected from the group consisting of a transparent glass substrate having a light shielding part, a transparent resin substrate having a light shielding part, and a glass substrate on which a light shielding material and a transparent electrode are formed, as the optical base material having the light shielding part. The optical member according to (i), which is a material and the functional laminate is a display unit or a touch panel.
(Iii) The optical member according to (ii), wherein the display unit is any one of a liquid crystal display unit, a plasma display unit, and an organic EL display unit.
(Iv) A touch panel (or touch panel input sensor) in which a plate-shaped or sheet-shaped optical substrate having a light-shielding portion is bonded to the surface on the touch surface side of the touch panel using a cured product of the curable resin composition of the present invention. .
(V) A display panel in which a plate-like or sheet-like optical substrate having a light-shielding portion is bonded to the display screen of the display unit using the cured product of the curable resin composition of the present invention.
(Vi) The display panel according to (v) above, wherein the plate-shaped or sheet-shaped optical substrate having a light-shielding portion is a protective substrate or a touch panel for protecting the display screen of the display unit.
(Vii) The curable resin composition according to any one of (i) to (vi) above, wherein the curable resin composition is the curable resin composition according to any one of (A1) to (A12). Optical member, touch panel or display panel.

Using the curable resin composition of the present invention, the optical member of the present invention is obtained by laminating a plurality of optical substrates selected from the above optical substrates by the method described in Steps A to D above. It is done. In the step B, the curable resin composition may be applied to only one of the surfaces facing each other through the cured product layer in the two optical substrates to be bonded, or may be applied to both surfaces. .
For example, in the case of the optical member according to the above (ii) in which the functional laminate is a touch panel or a display unit, in Step 1, any one surface of the protective base material having a light shielding part, preferably the light shielding part is provided. The resin composition may be applied to only one of the provided surface and the touch surface of the touch panel or the display surface of the display unit, or may be applied to both of them.
In the case of the optical member of (vi) described above in which a protective base material or a touch panel for protecting the display screen of the display body unit is bonded to the display body unit, in Step 1, a light shielding portion of the protective base material is provided. The resin composition may be applied to only one of the substrate surface opposite to the surface or the touch surface of the touch panel and the display surface of the display unit, or to both of them.

  An optical member including a display unit obtained by the manufacturing method of the present invention and an optical base material having a light shielding portion can be incorporated into an electronic device such as a television, a small game machine, a mobile phone, and a personal computer.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Preparation of curable resin composition (adjustment of first curable resin composition A)
16 parts by weight of urethane acrylate (hydrogenated polybutadiene diol (molecular weight 3000), isophorone diisocyanate, 3-hydroxyhexacrylate acrylate (molar ratio 1: 1.2: 2)), GI-2000 (both end hydroxyl groups) 18 parts by weight of hydrogenated polybutadiene, manufactured by Nippon Soda Co., Ltd., 13 parts of Nisseki Polybutene LV-100 (liquid polybutene, manufactured by JX Nippon Steel Nisseki Energy Co., Ltd.), Clearon (trade name) M105 (aromatic) Modified hydrogenated terpene resin (manufactured by Yasuhara Chemical Co., Ltd.) 16 parts, LA (lauryl acrylate, Osaka Organic Chemical Industries, Ltd.) 11 parts by weight, S-1800A (isostearyl acrylate, Shin-Nakamura Chemical Co., Ltd.) 25 parts, speed cure (trade name) TPO (2,4,6-trimethylbenzoyldiphenylphos) In'okisaido, Lambson Ltd.) 0.5 parts by weight Irgacure (trade name) 184D (BASF) was prepared by heating and mixing 0.5 part. The viscosity at 25 ° C. was 4000 mPa · s.

(Adjustment of the first curable resin composition B)
9 parts by weight of urethane acrylate (hydrogenated polybutadiene diol (molecular weight 3000), isophorone diisocyanate, 3-hydroxyhexacrylate acrylate (molar ratio 1: 1.2: 2)), GI-2000 (both end hydroxyl groups) 55 parts by weight of hydrogenated polybutadiene (manufactured by Nippon Soda Co., Ltd.), 13 parts of Nisseki Polybutene LV-100 (liquid polybutene, JX Nippon Steel Nisseki Energy Co., Ltd.), LA (lauryl acrylate, Osaka Organic Chemical Industry) 15 parts by weight, manufactured by Co., Ltd., 3 parts by weight S-1800A (isostearyl acrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.), Speed Cure (trade name) TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) , Manufactured by LAMBSON) 0.25 parts by weight, Irgacure (trade name) 184D (BASF) ) Was prepared by heating and mixing 0.5 part. The viscosity at 25 ° C. was 3500 mPa · s.

(Adjustment of the first curable resin composition C)
Urethane acrylate (hydrogenated polybutadiene diol (molecular weight 3000), isophorone diisocyanate, reaction product of 3 components (molar ratio 1: 1.5: 2) of 2-hydroxyethyl acrylate) 80 parts by weight, IBXA (isobornyl acrylate, 30 parts manufactured by Osaka Organic Chemical Industry Co., Ltd., Speed Cure (trade name) TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide, manufactured by LAMBSON) 1 part by weight, Irgacure (trade name) 184D (BASF) 3 parts by heating) was prepared by heating and mixing, and the viscosity at 25 ° C. was 14000 mPa · s.

(Adjustment of the second curable resin composition a)
LIR-390 (isoprene block polymer, manufactured by Kuraray Co., Ltd.) 20 parts, UC-203 (reactive isoprene polymer, manufactured by Kuraray Co., Ltd.) 50 parts, FA-512A (dicyclopentenyl axiethyl acrylate, Hitachi Chemical) 23 parts by Co., Ltd., A-NOD-N (nonanediol diacrylate, 3 parts by Shin-Nakamura Chemical Co., Ltd.), Speed Cure (trade name) TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide And 0.5 parts by weight of LAMBSON) and 1 part of Irgacure (trade name) 184D (manufactured by BASF) were prepared by heating and mixing, and the viscosity at 25 ° C. was 65000 mPa · s.

The following evaluation was performed using the obtained curable resin composition of the present invention.
Example 1
As shown in FIG. 1 (a), the second curable composition a is applied to the projection region of the sealing body 23 of the liquid crystal display unit 1 to a thickness of 300 μm so that the application location does not cover the projection region of the polarizing plate. Arranged.
On the other hand, the first curable composition A was applied to the protective plate with a thickness of 250 μm. Thereafter, the liquid crystal display unit 1 and the protective plate 2 were bonded together so that the uncured portion opposed. Finally, the cured resin layer is cured by irradiating ultraviolet rays 5 with an integrated light quantity of 2000 mJ / cm ² from the protective plate side using an electrodeless ultraviolet lamp (D bulb, manufactured by Heraeus Noblelight Fusion Ubuy). Then, the optical member FIG. 7 was created.

Example 2
The resin cured product layer was cured in the same manner except that the first curable composition applied to the protective plate was changed to B, and optical member FIG. 7 was created.

Comparative Example 1
The cured resin layer was cured in the same manner except that the second curable composition was applied to the projection area of the polarizing plate, and the optical member FIG. 8 was created.

  Moreover, the following evaluation was performed using obtained curable resin composition A, B, C of this invention.

(Curability) Two slide glasses having a thickness of 1 mm were prepared, and applied to one of them so that the film thickness of the curable resin composition obtained was 200 μm. The other slide glass was bonded to the coated surface. The resin composition was irradiated with ultraviolet rays having a cumulative light amount of 2000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozone-less). When the cured state of the cured product was confirmed, it was completely cured.

(Curing shrinkage)
Two slide glasses having a thickness of 1 mm coated with a fluorine-based release agent were prepared, and the obtained curable resin composition was applied to one of the release agent application surfaces so that the film thickness was 200 μm. Thereafter, the two slide glasses were bonded so that the respective release agent application surfaces face each other. The resin composition was cured by irradiating the resin composition with ultraviolet rays having an accumulated light amount of 2000 mJ / cm ^{2 through} a glass with a high-pressure mercury lamp (80 W / cm, ozone-less). Thereafter, the two slide glasses were peeled off to produce a cured product for measuring the film specific gravity. Based on JIS K7112 B method, specific gravity (DS) of hardened | cured material was measured. Moreover, the liquid specific gravity (DL) of the resin composition was measured at 25 degreeC. From the measurement results of DS and DL, the cure shrinkage rate was calculated from the following formula and found to be less than 2.5%.
Curing shrinkage (%) = (DS−DL) ÷ DS × 100

(Heat and moisture resistant adhesion)
Prepare a slide glass with a thickness of 0.8 mm and an acrylic plate with a thickness of 0.8 mm, and apply the curable resin composition obtained on one side so that the film thickness becomes 200 μm, Pasted together. Through the glass, the resin composition was irradiated with ultraviolet rays having an integrated light quantity of 2000 mJ / cm ² with a high-pressure mercury lamp (80 W / cm, ozone-less), and the resin composition was cured to prepare a sample for evaluating adhesiveness. This was left to stand at 85 ° C. and 85% RH for 250 hours. In the sample for evaluation, peeling of the slide glass or the acrylic plate from the cured resin was visually confirmed, but there was no peeling.

(Flexibility)
The obtained curable resin composition was fully cured, and the durometer E hardness was measured using a durometer hardness meter (type E) by a method based on JIS K7215 to evaluate flexibility. More specifically, the curable resin composition was poured into a cylindrical mold so that the film thickness became 1 cm, and the resin composition was sufficiently cured by irradiation with ultraviolet rays. The hardness of the obtained cured product was measured with a durometer hardness meter (type E). As a result, the measured value was less than 10, and the flexibility was excellent.

(transparency)
Two PET films having a thickness of 40 μm coated with a fluorine-based release agent are prepared, and the film thickness after curing of the obtained curable resin composition on one of the release agent-coated surfaces is 600 μm. It was applied as follows. Thereafter, the two PET films were bonded together so that the respective release agent application surfaces face each other. The resin composition was cured by irradiating ultraviolet rays with an integrated light quantity of 2000 mJ / cm 2 with a high-pressure mercury lamp (80 W / cm, ozone-less) through a PET film. Thereafter, the two PET films were peeled off to prepare a cured product for measuring the rigidity. Thereafter, the two PET films are peeled off to produce a cured product for measuring the rigidity. And about a rigidity, a rigidity can be measured in the temperature range of 20-40 degreeC using ARES (TA Instruments).

第１硬化性組成物Ｃの剛性率は硬度が高すぎるため測定範囲外。 The test results are summarized in the following table.

The rigidity of the first curable composition C is out of the measurement range because the hardness is too high.

  Although the invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

  The method for producing an optical member of the present invention can provide an optical member such as a display unit that has excellent visibility and is less likely to cause ripples due to pressing. The optical member obtained by the present invention can be suitably incorporated in a display device such as a liquid crystal display, a plasma display, or an organic EL display.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display unit, 2 Protection board, 3 Transparent substrate, 4 Light-shielding part, 5 Ultraviolet rays, 11 1st curable resin composition, 12 2nd curable resin composition, 13 1st hardened | cured material layer, 14 2nd hardened | cured material Layer, 15 resin cured material layer, 21 liquid crystal display cell, 22 polarizing plate, 23 sealing body, 24 gap, 25 sealing film, 26 housing

Claims (10)

A method of manufacturing an image display device in which a protective plate is bonded to a liquid crystal display unit,
The liquid crystal display unit includes a liquid crystal display cell, a polarizing plate disposed on the liquid crystal display cell, and a polarizing plate disposed outside the polarizing plate from the central axis of the image display device toward the outer peripheral surface, with a gap from the polarizing plate. A sealing body that coats the peripheral edge of the surface of the liquid crystal display cell,
A second curable resin composition having fluidity when uncured is applied to at least one substrate of the liquid crystal display unit or the protective plate, and the first curable resin composition is coated with the second curable resin composition. A second curable resin composition application step for defining an application region;
The first curable resin composition having fluidity when uncured is applied to a region facing the application region when the application region or one substrate on which the application region is formed is bonded to the other substrate. An application step of applying the first curable resin composition;
A laminating step of laminating the liquid crystal display unit and the protective plate via the first curable resin composition;
A first curable resin composition curing step for curing the first curable resin composition and bonding the liquid crystal display unit and the protective plate together,
Cured layer obtained by curing the second curable resin composition is laminated on the sealing body, and on said polarizing plate and on the liquid crystal display cell is characterized by not laminated Manufacturing method of image display apparatus. A manufacturing method of an image display device according to claim 1,
Applying the second curable resin composition on the surface of the sealing body of the liquid crystal display unit to form a cured or uncured coating film;
Applying the first curable resin composition on the surface of the protective plate to form a cured or uncured coating film,
The method for manufacturing an image display device according to claim 1, wherein the liquid crystal display unit on which the coating film is formed and the protective plate on which the coating film is formed are bonded together. A method for manufacturing an image display device according to claim 1 or 2,
The average thickness of the coating film of the first curable resin composition before bonding the liquid crystal display unit and the protective plate is the second curable resin composition before bonding the liquid crystal display unit and the protective plate. 3. The method for manufacturing an image display device according to claim 1, wherein the thickness is equal to or less than an average thickness of the coating film. The said 1st curable resin composition or the said 2nd curable resin composition of the manufacturing method of the optical member as described in any one of Claims 1-3 is (meth) acrylate (A) and photopolymerization start. The manufacturing method of an image display apparatus which is a curable resin composition containing an agent (B). The (meth) acrylate (A) is urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, (meth) acrylate having a polybutadiene skeleton, or one or more (meth) acrylate monomers selected from the group consisting of (meth) acrylate monomers. The method for producing an image display device, which is a curable resin composition according to claim 4, which is a meth) acrylate. The protective plate is a transparent glass substrate having a light shielding part, a transparent resin substrate having a light shielding part, a glass substrate having a light shielding part and a transparent electrode, and a glass substrate or film having a transparent electrode formed on the transparent substrate having a light shielding part. according to any one of claims 4 or 5 comprising one or more selected from bonded together the group of the substrate, a method of manufacturing an image display device. The (meth) acrylate (A) is urethane (meth) acrylate, (meth) acrylate having a polyisoprene skeleton, (meth) acrylate having a polybutadiene skeleton, or one or more (meth) acrylate monomers selected from the group consisting of (meth) acrylate monomers. meth) acrylate is a curable resin composition according to any one of claims 4-6, a method of manufacturing an image display device. The method for manufacturing an image display device according to any one of claims 4 to 7 , wherein the protective plate is a touch panel. An image display device in which a protective plate is bonded to a liquid crystal display unit,
The liquid crystal display unit includes a liquid crystal display cell, a polarizing plate disposed on the liquid crystal display cell, and a polarizing plate disposed outside the polarizing plate from the central axis of the image display device toward the outer peripheral surface, with a gap from the polarizing plate. A sealing body that coats the peripheral edge of the surface of the liquid crystal display cell,
A first cured product layer obtained by curing the first curable resin composition formed on the polarizing plate;
A second cured product layer obtained by curing a second curable resin composition that defines a peripheral wall portion of the first cured product layer, and the second cured product layer is laminated on the encapsulant. It is, and the image display apparatus characterized by not being laminated on the polarizing plate and on the liquid crystal display cell. The first curable resin composition and the second curable resin composition are composed of a urethane (meth) acrylate compound, a (meth) acrylate compound having a polyisoprene skeleton, or a (meth) acrylate compound having a polybutadiene skeleton. The image display device according to claim 9 , wherein the image display device is a curable resin composition containing at least one (meth) acrylate compound selected and a photopolymerization initiator.

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