JP2015205784A - Cover glass with adhesive layer - Google Patents

Abstract

An object of the present invention is to provide a cover glass with an adhesive layer that absorbs a step due to a front frame and a concealing layer and is resistant to scratches. A cover glass (10) having a glass plate (12) and a concealing layer (20) on the peripheral edge of the glass plate (12); Further, in the adhesive layer-attached cover glass 10, the glass plate 12 is a glass plate 12 having a fracture toughness of 0.7 MPa m1/2 or more, and the adhesive layer 14 has a thickness of 0.1 to 2.0 mm. and a shear elastic modulus at 25°C of 5-102 to 1-107 Pa, the cover glass 10 with an adhesive layer. The glass plate 12 is made of alkali-free glass that does not substantially contain alkali metal oxides, and is substantially composed of SiO2: 50 to 70%, Al2O3: 10 to 25%, B2O3: 0 to 15%, A cover glass 10 with an adhesive layer comprising MgO: 0 to 10%, CaO: 0 to 15%, SrO: 0 to 15%, and BaO: 0 to 15%. [Selection drawing] Fig. 1

Description

  The present invention relates to a cover glass with an adhesive layer used for protecting a display device having a display panel such as a liquid crystal panel and an organic EL, and particularly relates to a cover glass with an adhesive layer having high adhesion to the display device.

Conventionally, in order to protect the display panel, a transparent protective member that covers the display surface (display area) of the display panel has been used. These protective members are often affixed to a display panel with an adhesive film interposed between the display panel and the protective member so that there are no voids visible like bubbles.
The display panel may have a metal frame or the like on the display surface side of the display panel (hereinafter, the display surface side frame is also referred to as a front frame). The protective member is affixed to the display panel through an opening of a front frame provided for visually recognizing the display pixels. In this case, the adhesive film is disposed so as to get over the concealment layer provided on the periphery of the front frame and the protective member.
However, when the adhesive film is disposed so as to get over the front frame and the concealing layer as described above, there may be a problem that the adhesive film does not sufficiently follow the protective member due to a step formed by the front frame and the concealing layer. In order to solve this problem, a proposal has been made to increase the thickness of the adhesive layer that bonds the protective member and the display panel to a predetermined elastic modulus (see, for example, Patent Document 1).

International Publication No. 2011/148990

The protection member protects the display panel from an external force applied to the protection member. The external force applied to the protective member is various, and there are a static one, a momentary dynamic one, a large area for applying the external force, and a small one.
By the way, when the thickness of the adhesive layer is increased to a predetermined elastic modulus, the protective member is easily deformed when a static external force is applied from the protective member side. This deformation is caused by absorbing an external force. However, if the adhesive layer is thick and has a high elastic modulus, the time for absorbing becomes longer. Therefore, the surface of the protective member is easily damaged.

  This invention is made in view of the above point, Comprising: It is providing the cover glass with the adhesion layer which is hard to be damaged, absorbing the level | step difference by a front frame or a concealing layer.

One aspect of the present invention is a cover glass comprising a glass plate and a concealing layer provided on the periphery of the glass plate, an adhesive layer laminated on substantially the entire surface of the cover glass on the concealing layer side, The glass plate is a glass plate having a fracture toughness of 0.7 MPa · m ^1/2 or more, and the adhesive layer has a thickness of 0.1 to 2. The cover glass with the pressure-sensitive adhesive layer is characterized by having a shear elastic modulus at 25 ° C. of 0 × 10 ² to 1 × 10 ⁷ Pa.

  ADVANTAGE OF THE INVENTION According to this invention, the cover glass with the adhesion layer which is hard to be damaged can be provided, absorbing the level | step difference by a front frame or a concealment layer.

(A) is typical sectional drawing which shows the cover glass of the 1st Embodiment of this invention, (b) is typical plan view which shows the cover glass of the 1st Embodiment of this invention. (A) is typical sectional drawing which shows an example of the usage pattern of the cover glass shown to Fig.1 (a), (b) expands and shows the principal part of the display apparatus with which a cover glass is bonded. It is typical sectional drawing. (A)-(c) is typical sectional drawing which shows the manufacturing method of the cover glass of embodiment of this invention in order of a process. It is typical sectional drawing which shows the cover glass of the 2nd Embodiment of this invention. (A) And (b) is typical sectional drawing which shows the other manufacturing method of a cover glass in order of a process, (c) is the structure of the cover material used for the other manufacturing method of the cover glass of this invention. It is a typical sectional view shown.

Below, based on preferred embodiment shown in an accompanying drawing, the cover glass with the adhesion layer of the present invention is explained in detail.
FIG. 1A is a schematic cross-sectional view showing a cover glass of the first embodiment of the present invention, and FIG. 1B is a schematic plan view showing the cover glass of the first embodiment of the present invention. is there.

  Here, “transparent” in the present specification means that the entire or part of the display image on the display panel is bonded to the cover glass with the adhesive layer and the display surface of the display panel through the adhesive layer without any gap. It means an aspect that can be visually recognized through a cover glass with an adhesive layer without receiving optical distortion. Therefore, part of the light incident on the cover glass with the adhesive layer from the display panel is absorbed by the cover glass, reflected, or due to a change in optical phase, etc., the visible light transmittance of the cover glass with the adhesive layer is increased. Even if it is low, it is “transparent” if the display image on the display panel can be visually recognized through the cover glass with the adhesive layer without optical distortion.

A cover glass 10 with an adhesive layer (hereinafter, simply referred to as cover glass 10) shown in FIGS. 1A and 1B is bonded to a display device and used to protect the display surface (display region) of the display device. It is.
The cover glass 10 includes a transparent glass plate 12, an adhesive layer 14, and a concealing layer 20. In the illustrated example, a protective film 16 disposed for the purpose of facilitating handling before the cover glass 10 is bonded to the display device is laminated on the adhesive layer 14 side.
In the cover glass 10, the adhesive layer 14 is provided on the glass plate 12. An area where the adhesive layer 14 is provided in the glass plate 12 is referred to as an arrangement area 12a. A concealing layer 20 is formed on the peripheral edge 12 b of the glass plate 12, and an adhesive layer 14 is formed on the surface 12 c of the glass plate 12. A protective film 16 is provided on the surface 14 a of the adhesive layer 14.
The adhesive layer 14 is transparent like the glass plate 12. In order to suppress multiple reflections and obtain a good image in the display device to which the cover glass 10 is bonded, the glass plate 12 and the adhesive layer 14 preferably have a small difference in refractive index.

As shown in FIG.1 (b), the shape of the glass plate 12 and the adhesion layer 14 is a rectangular shape, for example, and the direction of the adhesion layer 14 is smaller. For example, the adhesive layer 14 is arranged with the center aligned with the glass plate 12. On the surface 12c of the glass plate 12, a concealing layer 20 is formed on the peripheral edge 12b at the periphery of the arrangement region 12a.
A protective film 16 that covers the entire surface of the glass plate 12 is detachably provided on the surface 14a of the adhesive layer 14. When the cover glass 10 is bonded to the display device, the protective film 16 is peeled off. In this case, for example, a cut is made in the surface 16a of the protective film 16, and the protective film 16 is peeled off.

The glass plate 12 has a fracture toughness of 0.7 MPa · m ^1/2 or more. Fracture toughness is measured by the “pre-crack introduction fracture test method (SEPB method)” described in JIS R1607, and more specifically, a test piece (8 mm in depth) introduced by a chevron notch method (8 mm). × 8 × 80 mm) is measured by performing a four-point bending test. The fracture toughness is an average value for a plurality of test pieces.
As such a glass plate 12, a glass plate made of soda lime glass, aluminosilicate glass that can be easily chemically strengthened, non-alkali glass that does not substantially contain an alkali metal oxide (hereinafter simply referred to as non-alkali glass). Can be illustrated.

Among these, the fracture toughness is 0.7 MPa · m ^1/2 or more, and crack initiation load (hereinafter referred to as “CIL”) is 10 N or more without performing post-treatment such as chemical strengthening. It is preferable to use a glass plate made of alkali-free glass in that it can be made.
Here, "CIL" means that cracks are formed outward from all four corners of the indentation by pushing a square pyramid-shaped Vickers indenter (diamond indenter) into the glass surface in an atmosphere with a relative humidity of about 40%. The minimum indentation load. CIL can be measured by a commercially available Vickers hardness tester. CIL is an average value for 10 or more indentations.
Such alkali-free glass, substantially represented by _{mass%, SiO 2: 50~70%, Al} 2 O 3: 10~25%, B 2 O 3: 0~15%, MgO: 0~10 %, CaO: 0 to 15%, SrO: 0 to 15%, BaO: 0 to 15%.

  In the present specification, “substantially free of alkali metal oxide” means that it contains no alkali metal oxide other than unavoidable impurities in industrial raw materials. For example, the content of alkali metal oxide Is 1 mol% or less.

  The thickness of the glass plate 12 is preferably 0.4 to 25 mm from the viewpoint of mechanical strength and transparency, and preferably 0.5 to 2.0 mm from the viewpoint of balance with the thickness of the adhesive layer. For applications such as television receivers and PC displays used indoors, 1 to 6 mm is preferable from the viewpoint of reducing the weight of the display device. For public display applications installed outdoors, 3 to 20 mm is preferable. In the use of a display device, 0.4 to 1.1 mm is preferable.

The shear modulus at 25 ° C. of the adhesive layer 14 is 5 × 10 ² to 1 × 10 ⁷ Pa. If the shear modulus is 1 × 10 ⁷ Pa or less, the adhesive layer 14 can exhibit good adhesion when bonded to a display panel. Thus, since the pressure at the time of bonding with the liquid crystal panel does not remain in the adhesive layer, the liquid crystal alignment in the liquid crystal panel is not adversely affected, and the deterioration of the image quality is suppressed.
Furthermore, in order to make the space | gap at the time of bonding lose | disappear in a short time, 1 * 10 < ³ > -5 * 10 < ⁴ > Pa is more preferable. If the shear modulus is 1 × 10 ³ Pa or more, the shape of the adhesive layer 14 can be maintained. Moreover, even when the thickness of the adhesive layer 14 is relatively thick, the thickness can be kept uniform throughout the adhesive layer 14, and when the cover glass 10 and the display panel are bonded, the display panel and the adhesive layer It is difficult for voids to be generated at the interface with. Furthermore, when the shear elastic modulus is 1 × 10 ⁴ Pa or more, it is easy to suppress deformation of the adhesive layer 14 when the protective film 16 is peeled off.

The thickness of the adhesive layer 14 is 0.1 to 2.0 mm. When the thickness of the pressure-sensitive adhesive layer 14 is 0.1 to 2.0 mm, it is easy to form the pressure-sensitive adhesive layer 14 having a uniform thickness, and voids are unlikely to remain in the pressure-sensitive adhesive layer 14. And since an impact is relieve | moderated in the case of bonding with a liquid crystal panel and it is suppressed that a display surface is pressed locally, generation | occurrence | production of a display nonuniformity can be suppressed. The thickness of the pressure-sensitive adhesive layer 14 is more preferably 0.2 to 1.6 mm from the viewpoint that it is possible to preferably achieve both the ability to follow the steps generated by the front frame and the concealing layer and the suppression of the occurrence of display villages. More preferably, it is 3 to 1.2 mm.
In addition, the thickness of the said adhesion layer 14 is the distance from the surface 12c of the glass plate 12 to the surface 14a of the adhesion layer 14 to which the protective film 16 is affixed. If the thickness is in the above range, the thickness of the adhesive layer 14 does not change greatly even if foreign matter not exceeding the thickness of the adhesive layer 14 is mixed between the display panel and the cover glass 10. Little impact on transmission performance.

The shear elastic modulus at a temperature of 25 ° C. of the adhesive layer 14 is measured as follows.
Using a rheometer (Modular rheometer Physica MCR-301, manufactured by Anton paar), the gap between the measuring spindle and the translucent plate is the same as the average thickness of the adhesive layer 14, and the gap is uncured. The shear modulus of the curing process is measured while applying the heat or light necessary for curing to the uncured composition, and the measured value under a predetermined curing condition is taken as the shear modulus of the adhesive layer 14. To do.

  About the external shape and magnitude | size of the adhesion layer 14, it is set as the substantially same shape and the same magnitude | size as the opening part of the flame | frame of the display surface side of a display apparatus. When the outer shape of the frame and the shape of the opening are the same, and the center of the outer shape of the frame and the opening coincide with each other, the adhesive layer 14 has the same shape as the glass plate 12 and the center of the glass plate 12 coincides. Arranged.

Thus, by setting the elastic modulus and thickness of the pressure-sensitive adhesive layer 14 to the above-described values, the pressure-sensitive adhesive layer can follow the steps generated by the front frame and the concealing layer. When the pressure-sensitive adhesive layer 14 is used, the glass plate is easily deformed when a static external force is applied from the glass plate side. This deformation is caused by absorbing an external force. However, due to the deformation of the glass plate, the portion to which the external force is applied shifts and an environment in which the surface of the glass plate is likely to be damaged is created.
Therefore, as the glass plate 12 in the present invention, a glass plate having a fracture toughness of 0.7 MPa · m ^1/2 or more, preferably a CIL of 10 N or more is used, and thus an external force is given by the deformation of the glass plate 12 itself. The occurrence of scratches can be suppressed even if the position of is shifted.

Furthermore, even if the thickness of the pressure-sensitive adhesive layer bonded to the glass plate is made thick and has a high elastic modulus, when the original glass plate is difficult to deform, the glass plate is easily broken by external force.
On the other hand, damage to the cover glass 10 can be further suppressed by using a glass plate made of glass having a Young's modulus of 60 to 100 GPa as the preferred glass plate 12 in the present invention. Accordingly, the glass plate 12 has a fracture toughness of 0.7 MPa · m ^1/2 or more, preferably a CIL of 10 N or more, and has a thickness of 0.1 to 2.0 mm and a shear elastic modulus at 25 ° C. of 5 × 10 ^2. The cover glass 10 that is the pressure-sensitive adhesive layer 14 of ˜1 × 10 ⁷ Pa is particularly useful when a glass plate made of glass having a Young's modulus of 60 to 100 GPa that promotes deformation that easily absorbs external force is used. is there.
Furthermore, the glass plate 12 is preferably made of glass having a Young's modulus of 70 to 90 GPa. In this case, since the Young's modulus is 90 GPa or less, the glass plate 12 is more easily bent than the glass plate made of glass having a Young's modulus exceeding 90 GPa. Therefore, the fracture toughness and CIL of the glass plate 12 are preferably as large as possible. Specifically, the glass plate 12 preferably has a fracture toughness of 0.77 MPa · m ^1/2 or more and a CIL of 15 N or more.

In order to obtain such a glass plate 12, it is preferable that the B ₂ O ₃ content ratio of the alkali-free glass is 1.0 to 15% by mass. Furthermore, when CIL is 15 N or more, a glass plate having a fracture toughness of 0.82 MPa · m ^1/2 or more, particularly 0.87 MPa · m ^1/2 or more is preferable. The fracture toughness and CIL may be equal to or higher than the above values. However, as practical upper limits, the fracture toughness is 2 MPa · m ^1/2 or less, and the CIL is 50 N or less.

  In order to improve the interfacial adhesive force, the glass plate 12 may be subjected to surface treatment by a method of treating with a silane coupling agent, a method of forming a silicon oxide thin film by an oxidation flame using a frame burner, or the like.

  The shape and size of the outer shape of the glass plate 12 are appropriately determined according to the outer shape of the display device. Since the display device generally has a rectangular shape such as a rectangle, in that case, the glass plate 12 has a rectangular external shape. From the viewpoint of appearance, the size of the glass plate 12 is preferably matched with the outer shape of the display device. Depending on the outer shape of the display device, a glass plate 12 that covers the entire display surface of the display panel and has a shape that includes a curve in the outer shape can also be used.

  The glass plate 12 may be provided with an antireflection layer on the back surface 12d in order to increase the contrast of the display image. Further, depending on the purpose, a part or the whole of the glass plate 12 may be colored, or a part or the whole of the back surface 12d of the glass plate 12 may be polished to form a glass to scatter light, or one of the back surfaces 12d of the glass plate 12 may be scattered. It is also possible to refract or reflect the transmitted light by forming fine irregularities or the like on the part or the whole. Further, a colored film, a light scattering film, a light refraction film, a light reflection film, or the like may be attached to a part or the whole of the surface of the glass plate 12.

The pressure-sensitive adhesive layer 14 is a layer made of a transparent resin obtained by curing the following liquid curable resin composition, for example.
The curable resin composition constituting the adhesive layer 14 may be a photocurable resin composition or a thermosetting resin composition. As the curable resin composition, a photocurable resin composition containing a curable compound and a photopolymerization initiator (a photopolymerization initiator (C ′) described later) can be cured at a low temperature and has a high curing rate. preferable. As a curable resin composition, the photocurable resin composition for layered part formation of patent document 1 is preferable.

  Specifically, the viscosity of the curable resin composition 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, the ratio of the low molecular weight monomer (the monomer (B ′) described later) can be suppressed, and the physical properties of the curable resin composition film 13 that becomes the adhesive layer 14 described later can be reduced. Reduction 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 are unlikely to remain in the curable resin composition film 13 that becomes the adhesive layer 14 described later.

  As the curable resin composition, one or more oligomers (A ′) having a curable group and having a number average molecular weight of 1,000 to 100,000 are used as the curable compound because the viscosity is easily adjusted to the above range. And one or more monomers (B ′) having a curable group and a molecular weight of 125 to 600, the ratio of the monomer (B ′) being the oligomer (A ′) and the monomer (B ′) And the total (100% by mass) is preferably 40 to 80% by mass.

  Examples of the curable group of the oligomer (A ′) include addition-polymerizable unsaturated groups (acryloyloxy group, methacryloyloxy group, etc.), combinations of unsaturated groups and thiol groups, and the like. A group selected from an acryloyloxy group and a methacryloyloxy group is preferable from the viewpoint of obtaining a highly transparent layered portion 23.

Examples of the curable group of the monomer (B ′) include addition polymerizable unsaturated groups (acryloyloxy group, methacryloyloxy group, etc.), combinations of unsaturated groups and thiol groups, etc. A group selected from an acryloyloxy group and a methacryloyloxy group is preferable from the viewpoint of obtaining a highly transparent layered portion 23.
As the monomer (B ′), one having 1 to 3 curable groups per molecule is preferred from the viewpoint of curability of the photocurable resin composition for layered portion formation and mechanical properties of the layered portion 23.

  Examples of the photopolymerization initiator (C ′) include acetophenone series, ketal series, benzoin or benzoin ether series, phosphine oxide series, benzophenone series, thioxanthone series, and quinone series.

The protective film 16 protects the adhesive layer 14.
It is calculated | required that the protective film 16 can be peeled from the adhesion layer 14, and can be affixed on a support surface member (not shown) in the manufacturing method mentioned later. Therefore, the protective film 16 is preferably a base film having a relatively low adhesion made of polyethylene, polypropylene, fluorine-based resin, or the like on the surface in contact with the adhesive layer 14. The surface of the protective film 16 that contacts the support surface member is preferably an adhesive surface, and the adhesive surface is preferably formed of a self-adhesive layer formed on the base film.

The thickness of the protective film 16 is preferably 0.03 to 0.2 mm, more preferably 0.05 to 0.1 mm, when a relatively flexible film such as polyethylene and polypropylene is used. If the thickness of the protective film 16 is 0.03 mm or more, deformation of the protective film 16 can be suppressed when the protective film 16 is peeled from the adhesive layer 14. If the thickness of the protective film 16 is 0.2 mm or less, the protective film 16 is easily bent at the time of peeling and can be easily peeled off. Moreover, in the protective film 16, by providing a back layer (not shown) on the side in contact with the adhesive layer 14, peeling from the adhesive layer 14 can be further facilitated.
As the back layer, it is preferable to use a film having relatively low adhesion such as polyethylene, polypropylene, a polymer blend of polypropylene and polyethylene, or a fluorine resin. Further, in order to facilitate peeling, a release agent such as silicone can be applied to the back layer as long as the adhesive layer 14 is not adversely affected.

Here, the protective film 16 preferably has an oxygen permeability of 100 cc / m ² · day · atm or less, more preferably 10 cc / m ² · day · atm or less. Thereby, after this cover glass 10 is manufactured, until it is used for bonding with a to-be-bonded body, the influence by the external air to the adhesion layer 14 can be suppressed. The oxygen permeability of the protective film 16 was measured in an environment of 25 ° C. using O ₂ gas with a gas permeation measuring device K-315-N (corresponding to JIS K7126) of TRS Tsukuba Riseki Co., Ltd. It is.

The protective film 16 may be a laminated film in which a resin film and a barrier layer that suppresses gas permeation are laminated. In this case, the resin film includes polyolefin resins such as polyethylene and polypropylene, fluorine resins, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyamide resins such as nylon-6 and nylon-66. The film is used.
As for the barrier layer, for example, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), silicon nitride, silicon oxynitride, aluminum oxynitride, magnesium oxide, zinc oxide, indium oxide, tin oxide, layered silicate It is composed of clay crystals. In particular, it is preferably composed of silicon oxide (SiO ₂ ) and aluminum oxide (Al ₂ O ₃ ).

  The adhesive layer 14 is made of a resin obtained by curing a photocurable composition, and is formed by irradiating ultraviolet light or short wavelength visible light through the protective film 16 to cure the photocurable resin composition. When doing so, the protective film 16 needs to have sufficient transparency with respect to the wavelength of light to be irradiated in a state in contact with the adhesive layer 14. In this case, it is preferable that the transmittance | permeability of the ultraviolet-ray (wavelength 365nm) of the protective film 16 is 50% or more.

  The concealment layer 20 conceals wiring members connected to the display panel other than the display surface (display area) of the display panel, which will be described later, from being visible from the back surface 12d side of the glass plate 12. The masking layer 20 is formed in a frame shape. The concealing layer 20 can be formed on either the front surface 12c or the back surface 12d of the glass plate 12 by using organic printing, ceramic printing, or the like. In terms of reducing the parallax between the hiding layer 20 and the display area, it is preferable to form it on the surface 12 c of the glass plate 12. When the glass plate 12 is a glass plate, it is preferable to form the concealment layer 20 by using ceramic printing containing a black pigment because the light shielding property is high.

  In the cover glass 10, a region (arrangement region 12 a) surrounded by the concealing layer 20 is a light transmitting part.

Next, the usage pattern of the cover glass 10 will be specifically described with an example of bonding to the LCD module 100 as a display device.
Fig.2 (a) is typical sectional drawing which shows an example of the usage pattern of the cover glass shown to Fig.1 (a), (b) expands the principal part of the display apparatus with which a cover glass is bonded. It is a typical sectional view shown.
As shown in FIG. 2A, in the LCD module 100, a liquid crystal panel 104 is placed on a backlight unit 102, and the backlight unit 102 and the liquid crystal panel 104 are accommodated in a metal frame 106. ing. The frame 106 has an opening 108, and the liquid crystal panel 104 is disposed on the opening 108 side. A region corresponding to the opening 108 of the liquid crystal panel 104 is defined as a display surface 104a.
Note that the configurations of the backlight unit 102 and the liquid crystal panel 104 are not particularly limited, and known ones can be used.

As shown in FIG. 2B, there is a step in the opening 108 of the frame 106 from the display surface 104a of the liquid crystal panel 104 to the end surface 106a of the frame 106, and the length of this step is T. The step distance T is about 0.8 to 2.3 mm.
2A and 2B, the cover glass 10 bonds the adhesive layer 14 to the display surface 104a of the liquid crystal panel 104 so as to fill the opening 108 of the frame 106. Thus, the glass plate 12 covers the display surface 104 a of the LCD module 100 to the end surface 106 a of the frame 106. This glass plate 12 functions as a protective member for the display surface 104 a of the LCD module 100.

  In addition, the cover glass 10 peels off the protective film 16, and is bonded to a display apparatus. This display device includes both a finished product and a semi-finished product of a liquid crystal display device (hereinafter referred to as an LCD) generally referred to as an LCD module. Can be pasted. The display device is not limited to the LCD module 100 described above. The display device may include, for example, an organic EL panel, a PDP, or an electronic ink type panel. Moreover, you may bond and use for coordinate input devices, such as a touchscreen.

Next, the manufacturing method of the cover glass 10 shown to Fig.1 (a), (b) is demonstrated.
Drawing 3 (a)-(c) is a typical sectional view showing a manufacturing method of a cover glass of an embodiment of the present invention in order of a process.
First, as shown in FIG. 3A, the concealment layer 20 is formed on the peripheral edge portion 12 b of the glass plate 12. The masking layer 20 is formed in a frame shape as shown in FIG.
Then, as shown in FIG. 3 (a), the entire surface 12c of the glass plate 12 is covered with the concealing layer 20, and a curable resin composition is applied using a method such as a die coater or a roll coater, and cured. The conductive resin composition film 13 is formed. This curable resin composition film 13 is cut into the adhesive layer 14 as described later.

  Next, as shown in FIG. 3B, a film material 15 is attached to the surface 13 a of the curable resin composition film 13. The film material 15 is cut to become a protective film 16 as described later. After the film material 15 is attached to the surface 13a of the curable resin composition film 13, the curable resin composition film 13 is cured by a thermosetting process or a photo-curing process, whereby a curable resin composition is obtained. A laminate 18 in which the material film 13 is protected by the film material 15 is obtained.

  When the film material 15 of the support surface member is overlaid on the curable resin composition film 13, it may be in a reduced pressure atmosphere. In this case, the pressure in the decompression chamber is, for example, 1 kPa or less, preferably 10 to 300 Pa, and more preferably 15 to 100 Pa. If the pressure in the decompression chamber is too low, each component (such as a curable compound, a photopolymerization initiator, a polymerization inhibitor, a chain transfer agent, and a light stabilizer) contained in the curable resin composition film 13 is vaporized. In addition, there is a risk of adversely affecting the pressure, and it takes time to bring the inside of the decompression chamber to a predetermined pressure.

Then, the supporting surface member is lowered and the film material 15 is adhered to the curable resin composition film 13 and bonded.
After being bonded to the curable resin composition film 13 via the film material 15, the reduced pressure atmosphere in the reduced pressure chamber is released and placed in a pressure atmosphere of 50 kPa or more for a predetermined time. At this time, since the laminated body and the support surface member are pressed in the direction in which they are in close contact with each other due to the increased pressure, the uncured curable resin composition film 13 flows in the voids when there are voids in the sealed space in the laminated body. Then, the entire sealed space is uniformly filled with the curable resin composition film 13.

  After a predetermined time has elapsed at high pressure, the uncured curable resin composition film 13 is cured, and the support surface member is peeled off from the film material 15, so that the curable resin composition is carried out under reduced pressure. A laminate 18 in which the film 13 is protected by the film material 15 is obtained.

In addition, the pressure in the decompression chamber after canceling the decompression atmosphere is usually 80 to 120 kPa. However, the pressure in the decompression chamber is most preferably atmospheric pressure because the curable resin composition film 13 can be cured without requiring special equipment.
The time from when the protective film 16 of the support surface member is superimposed on the curable resin composition film 13 to when the pressure in the decompression chamber is changed to a pressure close to atmospheric pressure is not particularly limited. For example, it may be a long time of several hours or more, but is preferably within 1 hour, more preferably within 10 minutes from the viewpoint of production efficiency.

  Moreover, the time (henceforth high pressure holding time) which puts a laminated body in the pressure atmosphere of 50 kPa or more is not specifically limited. When the process from taking out the laminated body from the decompression device to the curing device and starting the curing is performed under an atmospheric pressure atmosphere, the time required for the process becomes the high pressure holding time. Therefore, if there is no void in the sealed space of the laminate already when placed in an atmospheric pressure atmosphere, or if the void disappears during the process, the curable resin composition film 13 is immediately cured. Can do. The high pressure holding time is preferably within 6 hours from the viewpoint of production efficiency, more preferably within 1 hour, and particularly preferably within 10 minutes from the point of increasing production efficiency.

When the curable resin composition film 13 is made of a photocurable composition, it is irradiated with ultraviolet light or visible light having a short wavelength of 450 nm or less using a light source such as an ultraviolet lamp, a high-pressure mercury lamp, or a UV-LED. And let it harden.
Thereby, the laminated body 18 by which the film material 15 was affixed on the curable resin composition film | membrane 13 is formed.

Next, as shown in FIG.3 (c), in the laminated body 18, the position used as the side surface 14b of the adhesion layer 14 is set to the cutting line 18a. Using the laser beam B, the laminate 18 is cut along the cutting line 18a. Thereby, the cover glass 10 by which the protective film 16 was provided in the surface 14a of the adhesion layer 14 shown to Fig.1 (a), (b) is obtained. For the laser beam B, for example, a CO ₂ laser is used. In addition to this, a known laser can be appropriately used depending on the composition and thickness of the adhesive layer 14.

The cover glass 10 of the present embodiment is preferably formed so that the angle α of the corner C on the side of the adhesive layer 14 on which the protective film 16 is provided is 95 ° or less and the corner C is not rounded. . In this case, as shown in FIG. 2B, the LCD module 100 can be attached to the side surface 106b of the frame 106 and the display surface 104a of the liquid crystal panel 104 with high adhesion without any gap. Moreover, since the corner | angular part C is not round, peeling from a display apparatus is also suppressed. High durability can be obtained.
By cutting with the laser beam B, no pressure is applied from the protective film 16 side, and the top of the corner C can be sharpened.

Of course, the cover glass 10 can suitably protect the display surface even when the LCD module 100 has a large step between the frame and the display surface.
Moreover, the cover glass 10 may have a transparent electrode constituting a touch panel. In this case, a touch panel function can be provided to the display device by bonding the cover glass to the display device.

Next, the cover glass of the 2nd Embodiment of this invention is demonstrated.
FIG. 4 is a schematic cross-sectional view showing a cover glass according to a second embodiment of the present invention.
In addition, in cover glass 10a with the adhesion layer (henceforth cover glass 10a) of 2nd Embodiment shown in FIG. 4, it is the same as cover glass 10 of 1st Embodiment shown to FIG. 1 (a), (b). The same reference numerals are given to the components, and detailed description thereof is omitted.

The cover glass 10a of this embodiment shown in FIG. 4 is provided with a reflective layer 22 on the concealing layer 20 as compared to the cover glass 10 of the first embodiment shown in FIGS. 1 (a) and 1 (b). Since it is the same structure as the cover glass 10 shown to Fig.1 (a), (b) except the point which exists, the detailed description is abbreviate | omitted.
In 1st Embodiment, the laminated body 18 is cut | disconnected by the cutting line 18a using the laser beam B with the manufacturing method of the cover glass 10 shown to Fig.1 (a). At this time, by providing the reflective layer 22 as in the present embodiment, the laser beam B is reflected, and damage to the concealment layer 20 can be suppressed even when the output of the laser beam B changes. The laminate 18 can be cut with energy efficiency. Thereby, the cover glass 10a can be manufactured with energy efficiency.

In the cover glass 10a of this embodiment, the reflective layer 22 reflects the laser beam B as described above. The reflective layer 22 contains, for example, aluminum or copper. The reflective layer 22 may be a film or formed by ink printing. In the case of printing, it can be formed by printing such as screen printing using aluminum paste, copper paste, silver paste or the like. In the case of a film, it can be comprised from the multilayer which provided the reflecting film on films, such as PET. As the reflection film, for example, a metal film formed by vacuum deposition, sputtering, or the like, a metal foil, a film formed by ink printing, or the like can be used. In the case of a film, it arrange | positions the film | membrane side containing a metal toward the concealment layer 20. FIG.
The thickness of the reflective layer 22 is preferably such a thickness that the concealing layer 20 is not damaged by the laser beam B when irradiated with the laser beam B. The thickness of the reflective layer 22 is appropriately determined according to the output of the laser beam B and the thickness of the adhesive layer 14.
When the reflective layer 22 is in the arrangement region 12a, it becomes a reflector, and thus the reflective layer 22 is arranged so as not to protrude from the concealing layer 20. That is, the reflective layer 22 is disposed so as to be located outside the arrangement region 12a. The reflective layer 22 is not necessarily provided on the entire upper surface of the masking layer 20, and can be appropriately adjusted according to the position where the laser beam B is applied or the accuracy of the laser beam B.

The adhesion of the interface between the hiding layer 20 and the reflective layer 22 and J _1, the adhesion strength at the interface between the reflective layer 22 and the adhesive layer 14 and J _2, the adhesion of the interface between the hiding layer 20 and the adhesive layer 14 when the J _3, relates _adhesion, it is preferable to set the _{J 1> J 2> J 3} . Thereby, the edge part of the adhesion layer 14 adhere | attached with a display apparatus can be made still more difficult to peel rather than the case where the reflection layer 22 is not used.

In addition, the cover glass 10a of this embodiment forms the reflective layer 22 on the concealment layer 20 by the sputtering method using a printing method and a mask pattern compared with the cover glass 10 of 1st Embodiment. Except for the differences, the cover glass 10 can be manufactured by the same manufacturing method as the cover glass 10 of the first embodiment, and detailed description thereof will be omitted.
Even when a film having a reflective function is used as the reflective layer 22, a resin base material, for example, a PET base material having a reflective film formed thereon is attached onto the concealing layer 20 as described above. In the case of using a printed layer having a reflective function, ink containing aluminum or copper is printed by screen printing or the like to form the reflective layer 22.
In addition to being able to manufacture the cover glass 10a efficiently, the cover glass 10a of the present embodiment can obtain the effects of the cover glass 10 of the first embodiment described above.

Next, another example of the cover glass will be described.
5 (a) and 5 (b) are schematic cross-sectional views showing another method for manufacturing a cover glass in the order of steps, and FIG. 5 (c) shows a configuration of a cover material used for another method for manufacturing a cover glass. It is typical sectional drawing.
In addition, in cover glass 10b with an adhesion layer (henceforth cover glass 10b) shown in FIG.5 (b), it is the same structure as the cover glass 10 of 1st Embodiment shown to Fig.1 (a), (b). Are denoted by the same reference numerals, and detailed description thereof is omitted.
Moreover, in the manufacturing method of the cover glass 10b shown to Fig.5 (a) and (b), in the same structure as the manufacturing method of the coverglass 10 of 1st Embodiment shown to Fig.3 (a)-(c), The same reference numerals are assigned and detailed description thereof is omitted.

The cover glass 10b shown in FIG. 5 (b) is provided with a cover material 32 on the concealing layer 20 as compared with the cover glass 10 of the first embodiment shown in FIGS. 1 (a) and 1 (b). Since the configuration is the same as that of the cover glass 10 shown in FIGS. 1A and 1B except that the weir-shaped portion 34 is formed, detailed description thereof is omitted.
Moreover, in the manufacturing method of the cover glass 10b, compared with the cover glass 10 of 1st Embodiment, the cover material 32 is formed on the concealment layer 20, and in that state, for example, using a dispenser, the cover material A weir-like portion 34 is formed in a substantially rectangular frame shape on 32.

  For example, as shown in FIG. 5C, the cover material 32 is formed by laminating a first release film 40, a cover material adhesive layer 42, a blade receiving substrate 44, and a second release film 46. . The first release film 40 is peeled off, the cover material adhesive layer 42 is exposed, laminated on the concealing layer 20, and attached. And the 2nd peeling film 46 is peeled and the blade receiving base material 44 is exposed.

The blade receiving substrate 44 is a film made of a resin or the like, and is made of a film made of a polyester resin such as polyethylene terephthalate (PET). The cover material 32 can be formed in a band shape having a certain width, for example.
The thickness of the cover material 32 is, for example, 35 to 200 μm. By setting the thickness to 35 μm or more, it is possible to secure the function of protecting the glass plate 12 and the concealing layer 20 from a cutting blade 38 described later, and to form the adhesive layer 14 thick. Moreover, the whole thickness of the cover glass 10 can be suppressed by making thickness into 200 micrometers or less.

The weir-shaped portion 34 is formed of a resin composition for forming a weir-shaped portion (hereinafter simply referred to as a resin composition). The weir-shaped portion 34 may be in an uncured state or in a partially cured state that is partially cured. When the resin composition is a photocurable composition, partial curing of the weir-shaped portion 34 is performed by light irradiation. For example, the photocurable resin composition is partially cured by irradiating ultraviolet light or visible light having a short wavelength from a light source (ultraviolet lamp, high pressure mercury lamp, UV-LED, etc.).
The shear elastic modulus at 25 ° C. of the weir-like portion 34 is preferably larger than the shear elastic modulus at 25 ° C. of the curable resin composition film 36. In addition, as the curable resin composition film 36, the same thing as the curable resin composition film 13 mentioned above can be used.
As shown to Fig.5 (a), the cutting line 30a is set in the position used as the side surface 14b of the adhesion layer 14. FIG. And the laminated body 30 is cut | disconnected by the cutting line 30a using the cutting blade 38. FIG. Thereby, the cover glass 10b shown in FIG.5 (b) is obtained.

  The present invention is basically configured as described above. As described above, the cover glass with an adhesive layer of the present invention has been described in detail. However, the present invention is not limited to the above embodiment, and various improvements or modifications may be made without departing from the gist of the present invention. Of course.

10, 10a, 10b Cover glass with adhesive layer (cover glass)
DESCRIPTION OF SYMBOLS 12 Glass plate 13, 36 Curable resin composition film | membrane 14 Adhesive layer 16 Protective film 18, 30 Laminated body 20 Concealment layer 22 Reflective layer 32 Cover material 34 Weir-shaped part C Corner part

Claims (8)

A cover glass comprising a glass plate and a concealing layer provided on the periphery of the glass plate;
An adhesive layer laminated on substantially the entire surface of the cover glass on the concealing layer side;
A cover glass with an adhesive layer,
The glass plate is a glass plate having a fracture toughness of 0.7 MPa · m ^1/2 or more,
The adhesive layer has a thickness of 0.1 to 2.0 mm, and a shear elastic modulus at 25 ° C. of 5 × 10 ² to 1 × 10 ⁷ Pa.
A cover glass with an adhesive layer.   The cover glass with an adhesive layer according to claim 1, wherein the glass plate has a crack initiation load of 10 N or more.   The cover glass with an adhesive layer according to claim 1 or 2, wherein the glass plate is made of glass having a Young's modulus of 60 to 100 GPa.   The cover glass with the adhesion layer in any one of Claims 1-3 which the said glass plate consists of an alkali free glass which does not contain an alkali metal oxide substantially. The alkali-free glass is substantially represented by _{mass%, SiO 2: 50~70%, Al} 2 O 3: 10~25%, B 2 O 3: 0~15%, MgO: 0~10%, CaO The cover glass with an adhesive layer according to claim 4, which is a glass composed of: 0 to 15%, SrO: 0 to 15%, and BaO: 0 to 15%. The glass plate has a fracture toughness of 0.77 MPa · m ^1/2 or more, a crack initiation load of 15 N or more, a Young's modulus of 70 to 90 GPa, and a content ratio of B ₂ O ₃ of 1.0 to 15% by mass. The cover glass with the adhesion layer according to claim 5 which consists of glass.   The cover glass with an adhesive layer according to any one of claims 1 to 6, wherein the adhesive layer has a thickness of 0.2 to 1.6 mm. The cover glass with an adhesive layer according to any one of claims 1 to 7, wherein the adhesive layer has a shear elastic modulus at 25 ° C of 1 x 10 ^{3 to} 5 x 10 ⁴ Pa.

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