Patent Application
20190353951
The present invention relates to a laminate, and a display device.
In the background art, a cover member is used in a display device in order to protect a display panel such as a liquid crystal panel (see Patent Document 1).
Patent Document 1: WO 2011/148990
An in-vehicle display device such as a car navigation system is mounted on a vehicle such as a car.
In some of such in-vehicle display devices, a cover member for a display panel is used, and a laminate such as a laminated glass is used as the cover member.
The laminate used as the cover member for the in-vehicle display device demands shock resistance excellent enough to prevent the laminate from being broken by a head of a passenger when a collision accident occurs in the vehicle, or to prevent broken pieces of the laminate from scattering if the laminate is broken.
Therefore, an object of the present invention is to provide a laminate excellent in shock resistance, and a display device using the laminate.
As a result of intensive studies, the present inventors found that the aforementioned object can be attained by the following configurations.
Namely, the present invention provides the following [1] to [18].
[1] A laminate including a first glass, an intermediate film and a second glass in this order, the laminate satisfying the following Expressions (1) to (4):
B
1
=b
1
+b
2
+b
3<2.90, (1)
b
1=(0.0665t2+0.4378)t1+(−0.2367t2+0.5152), (2)
b
2=−0.16 Ln(x)+0.5152, and (3)
b
3=(0.0785x2−0.1135x+0.0182)t3+(−0.134 Ln(x)+0.5617), (4)
in which t1 is a thickness of the first glass in millimeter unit, t2 is a thickness of the second glass in millimeter unit, t3 is a thickness of the intermediate film in millimeter unit, and x is a storage shear elastic modulus of the intermediate film at a temperature of 25° C. and a frequency of 10 kHz in GPa unit.
[2] The laminate according to [1], further satisfying the following Expressions (5) to (7):
B
2
=b
4
+b
5≤3.82, (5)
b
4=(−0.0612t1+0.1357)t2−0.0596t12+0.0769t1+1.1698, and (6)
b
5=−0.1079t3+0.1282 Ln(x)+1.5774+(0.0047t3+0.1231)Ln(x)−0.0963t3+1.5660. (7)
[3] The laminate according to [2], further satisfying the following Expression (8) as to the B2:
B2<3.77. (8)
[4] The laminate according to any one of [1] to [3], in which at least one of the first glass and the second glass is a chemically-strengthened glass.
[5] The laminate according to any one of [1] to [3], in which both the first glass and the second glass are chemically-strengthened glasses.
[6] The laminate according to [4] or [5], in which the chemically-strengthened glass has a compressive stress layer, the compressive stress layer has a thickness of 10 μm or more, and the compressive stress layer has a surface compressive stress of 500 MPa or more.
[7] The laminate according to any one of [1] to [6], in which the thickness t1 of the first glass is 0.5 mm or more and 3 mm or less. [8] The laminate according to any one of [1] to [7], in which the thickness t2 of the second glass is 0.5 mm or more and 3 mm or less.
[9] The laminate according to any one of [1] to [8], in which the storage shear elastic modulus x of the intermediate film is 0.040 GPa or more and 0.800 GPa or less.
[10] The laminate according to any one of [1] to [9], in which the thickness t3 of the intermediate film is 0.1 mm or more and 5 mm or less.
[11] The laminate according to any one of [1] to [10], having an adhesive strength between the first glass and the intermediate film of 0.1 N/25 mm or more.
[12] The laminate according to any one of [1] to [11], having an adhesive strength between the second glass and the intermediate film of 0.1 N/25 mm or more.
[13] The laminate according to any one of [1] to [12], in which a resin constituting the intermediate film includes at least one selected from the group consisting of polyvinyl butyral, ethylene vinyl acetate, and cycloolefin.
[14] The laminate according to any one of [1] to [13], having a luminous transmittance of 20% or more and 85% or less.
[15] The laminate according to any one of [1] to [14],
in which the first glass includes a first main face that is one of main faces thereof, and a second main face that is the other main face,
the second main face is bonded to the intermediate film, and
the laminate includes a functional layer provided on the first main face.
[16] The laminate according to [15], in which the functional layer includes at least one layer selected from the group consisting of an antireflection layer, an antiglare layer and an antifouling layer.
[17] A display device including:
a display panel; and
the laminate according to any one of [1] to [16],
in which the laminate is a cover member that covers the display panel.
[18] The display device according to [17], in which the display device is an in-vehicle display device.
According to the present invention, a laminate excellent in shock resistance, and a display device using the laminate can be provided.
An embodiment of the present invention will be described below. However, the present invention is not limited to the following embodiment. Various modifications and replacements can be made on the following embodiment without departing from the scope of the present invention.
A laminate according to the embodiment of the present invention will be also referred to as a “laminate of the invention” conveniently. Similarly, a display device according to the embodiment of the present invention will be also referred to as a “display device of the invention” conveniently.
The display device 100 includes a housing 106 that houses some members. A backlight unit 102 is disposed on a housing bottom plate 107 that is a bottom plate of the housing 106. A display panel 104 that is a liquid crystal panel is disposed on the backlight unit 102.
The configurations of the display panel 104 and the backlight unit 102 are not particularly limited, but known configurations may be used. For example, the display device 100 may be a display device including an organic EL (Electro Luminescence) panel or an electronic ink type panel, and may include a touch panel or the like. The material or the like of the housing 106 including the housing bottom plate 107 is also not particularly limited.
As shown in
A layer including a transparent resin obtained by curing a liquid curable resin composition can be used as the adhesive layer 14. The adhesive layer 14 may be an OCA (Optical Clear Adhesive) film or an OCA tape. The thickness of the adhesive layer 14 is, for example, 5 μm to 400 μm, and preferably 50 μm to 200 μm.
The first glass 11 is a glass plate that includes a first main face 11a that is one of main faces of the first glass plate 11, and a second main face 11b that is the other main face. The second main face 11b of the first glass 11 is bonded to the intermediate film 13.
The second glass 12 is a glass plate that includes a first main face 12a that is one of main faces of the second glass plate 12, and a second main face 12b that is the other main face. The first main face 12a of the second glass 12 is bonded to the intermediate film 13.
The laminate 1 used as a cover member for the display device 100 (see
A cover member for an in-vehicle display device demands shock resistance excellent enough to prevent the cover member from being broken by a head of a passenger when a collision accident occurs in the vehicle, or to prevent broken pieces of the cover member from scattering if the cover member is broken.
The laminate of the invention satisfies the following Expressions (1) to (4) when t1 designates the thickness of the first glass in millimeter unit, t2 designates the thickness of the second glass in millimeter unit, t3 designates the thickness of the intermediate film in millimeter unit, and x designates the storage shear elastic modulus of the intermediate film at a temperature of 25° C. and a frequency of 10 kHz in GPa unit. As a result, the laminate of the invention has excellent shock resistance. In particular, breaking in the first glass is suppressed and broken pieces of the second glass can be prevented from scattering even if the second glass is broken.
In the following description, the storage shear elastic modulus x of the intermediate film at a temperature of 25° C. and a frequency of 10 kHz will be referred to as “elastic modulus x of the intermediate film” or “elastic modulus x” simply.
B
1
=b
1
+b
2
+b
3<2.90, (1)
b
1=(0.0665t2+0.4378)t1+(−0.2367t2+0.5152), (2)
b
2=−0.16 Ln(x)+0.5152, and (3)
b
3=(0.0785x2−0.1135x+0.0182)t3+(−0.134 Ln(x)+0.5617), (4)
The technical meanings of Expressions (1) to (4) will be explained.
First, in order to prevent the first glass from breaking, it is required that stress (back surface stress) generated in the back surface of the first glass in case where impact is applied thereto is low.
The present inventors simulated head impactor tests (HITs) in which the thickness t1 of the first glass and the thickness t2 of the second glass were fixed to 1.1 mm respectively, and the elastic modulus x of the intermediate film was varied.
PAM-CRASH (made by ESI Japan Ltd.) which was a commercially available analysis program was used in the simulation. The HITs were simulated using the same conditions as in “Evaluation of Shock Resistance by Head Impactor Test” in Examples which will be described later (the same thing can be applied to the following description).
As a result, it was found that an index b2 of back surface stress of the first glass in case where impact is applied decreases as the elastic modulus x of the intermediate film increases. Specifically, Expression (3) “b2=−0.16 Ln(x)+0.5152” was found. “Ln(x)” is a natural logarithm of x using e as a base.
Next, the present inventors simulated HITs in which the thickness t1 of the first glass and the thickness t2 of the second glass were fixed to 1.1 mm respectively, the elastic modulus x of the intermediate film was fixed to 0.044 GPa, 0.088 GPa, 0.0176 GPa, 0.352 GPa and 0.704 GPa, and the thickness t3 of the intermediate film was varied to 0.4 mm, 1.2 mm, 2.0 mm, 3.2 mm, 3.6 mm and 4.0 mm. As a result, it was found that an index b3 of back surface stress of the first glass in case where impact is applied varies in accordance with the elastic modulus x of the intermediate film and the thickness t3 of the intermediate film. Specifically, Expression (4) “b3=(0.0785x2−0.1135x+0.0182)t3+(−0.134 Ln(x)+0.5617)” was found.
Next, the present inventors simulated HITs in which the elastic modulus x of the intermediate film was fixed to 0.176 GPa, the thickness t2 of the second glass was set at 0.7 mm, 1.1 mm and 2.0 mm, and the thickness t1 of the first glass was varied. As a result, it was found that an index b1 of back surface stress of the first glass in case where impact is applied decreases linearly as the thickness t1 of the first glass was reduced. Specifically, Expression (2) “b1=(0.0665t2+0.4378)t1+(−0.2367t2+0.5152)” was found.
Further, the present inventors simulated further HITs. As a result, it was found that breaking in the first glass can be suppressed when a total value B1 of the aforementioned indexes b1, b2 and b3 of back surface stress of the first glass is smaller than 2.90, that is, Expression (1) “B1=b1+b2+b3<2.90” is satisfied.
Further, it is preferable that the laminate of the invention satisfies the following Expressions (5) to (7). As a result, the laminate of the invention is more excellent in shock resistance. Specifically, not only the first glass but also second glass can be suppressed from breaking.
B
2
=b
4
+b
5≤3.82, (5)
b
4=(−0.0612t1+0.1357)t2−0.0596t12+0.0769t1+1.1698, and (6)
b
5=−0.1079t3+0.1282 Ln(x)+1.5774+(0.0047t3+0.1231)Ln(x)−0.0963t3+1.5660. (7)
Technical meanings of Expressions (5) to (7) will be explained. First, in order to prevent the second glass from breaking, it is demanded that stress (back surface stress) generated in the back surface of the second glass in case where impact is applied thereto is low.
The present inventors simulated HITs in which the thickness t1 of the first glass and the thickness t2 of the second glass were fixed to 1.1 mm respectively, the elastic modulus x of the intermediate film was set at 0.044 GPa, 0.088 GPa, 0.176 GPa, 0.352 GPa and 0.704 GPa, and the thickness t3 of the intermediate film was varied. As a result, it was found that an index c4 of back surface stress of the second glass in case where impact is applied decreases linearly as the thickness t3 of the intermediate film increases. Specifically, an expression “c4=−0.1079t3+0.1282 Ln(x)+1.5774” was found.
In addition, the present inventors simulated HITs in which the thickness t1 of the first glass and the thickness t2 of the second glass were fixed to 1.1 mm respectively, the thickness t3 of the intermediate film was set at 0.4 mm, 2 mm, 3.2 mm, 3.6 mm and 4 mm, and the elastic modulus x of the intermediate film was varied. As a result, it was found that an index d4 of back surface stress of the second glass in case where impact is applied decreases as the elastic modulus x of the intermediate film decreases. Specifically, an expression “d4=(0.0047t3+0.1231)Ln(x)−0.0963t3+1.5660” was found.
That is, as for an index b5 (=c4+d4) of back surface stress of the second glass in case where impact is applied, Expression (7) “b5=−0.1079t3+0.1282 Ln(x)+1.5774+(0.0047t3+0.1231)Ln(x)−0.0963t3+1.5660” was found.
Next, the present inventors simulated HITs in which the thickness t3 of the intermediate film was fixed to 0.4 mm, the elastic modulus x of the intermediate film was fixed to 0.176 GPa, the thickness t1 of the first glass was set at 0.7 mm, 1.1 mm and 2.0 mm, and the thickness t2 of the second glass was varied. As a result, it was found that an index b4 of back surface stress of the second glass in case where impact is applied decreases as the thickness t2 of the second glass decreases. Specifically, Expression (6) “b4=(−0.0612t1+0.1357)t2−0.0596t12+0.0769t1+1.1698” was found.
The present inventors simulated further HITs. As a result, it was found that breaking in the second glass can be suppressed when a total value B2 of the aforementioned indexes b4 and b5 of back surface stress of the second glass is not more than 3.82, that is, Expression (5) “B2=b4+b5≤3.82” is satisfied.
In order to further suppress breaking in the second glass, it is more preferable that the B2 is less than 3.77. That is, it is more preferable that Expression (8) “B2<3.77” is satisfied.
Next, the first glass and the second glass will be explained in detail.
It is preferable that at least one of the first glass and the second glass is a chemically-strengthened glass, and it is more preferable that both the first glass and the second glass are chemically-strengthened glasses.
Incidentally, when at least one of the first glass and the second glass is a chemically-strengthened glass, it is preferable that the first glass is a chemically-strengthened glass.
A compressive stress layer is formed in the surface of the chemically-strengthened glass. The thickness of the compressive stress layer (DOL) is, for example, 10 μm or more, preferably 15 μm or more, more preferably 25 μm or more, and further more preferably 30 μm or more.
Surface compressive stress (CS) in the compressive stress layer of the chemically-strengthened glass is, for example, 500 MPa or more, preferably 650 MPa or more, and more preferably 750 MPa or more. The upper limit of the surface compressive stress is not particularly limited, but it is, for example, 1,200 MPa or less.
According to a typical example of a method for performing chemically strengthening treatment on a glass to obtain a chemically-strengthened glass, the glass is immersed in KNO3 molten salt to be subjected to ion exchange treatment, and then cooled down to the vicinity of a room temperature. Treatment conditions such as the temperature of the KNO3 molten salt, the immersing time, etc. may be set to adjust the surface compressive stress and the thickness of the compressive stress layer to desired values.
Examples of kinds of glasses for the first glass and the second glass include soda-lime glass, and aluminosilicate glass (SiO2—Al2O3—Na2O based glass). Among them, aluminosilicate glass is preferred from the viewpoint of strength.
As the glass material, for example, a glass material including, in terms of mol % based on the oxides, from 50% to 80% of SiO2, from 1% to 20% of Al2O3, from 6% to 20% of Na2O, from 0% to 11% of K2O, from 0% to 15% of MgO, from 0% to 6% of CaO, and from 0% to 5% of ZrO2, may be mentioned.
A glass based on aluminosilicate glass and for use in chemically strengthening (for example, “Dragontrail (registered trademark)” made by AGC Inc.) can be also used suitably.
The thickness t1 of the first glass is preferably 0.5 mm or more and 3 mm or less, and more preferably 0.7 mm or more and 2 mm or less.
The thickness t2 of the second glass is preferably 0.5 mm or more and 3 mm or less, and more preferably 0.7 mm or more and 2 mm or less.
When the thickness t1 of the first glass or the thickness t2 of the second glass is set within the aforementioned range, the laminate of the invention can keep strength required as a cover member while, for example, the weight of the display device of the invention as a final product can be reduced easily. In addition, excellent appearance can be obtained easily.
It is preferable that the first glass and the second glass have the same size and the same shape (as size and shape in planar view of the laminate of the invention).
The shape of the display device is generally a rectangle such as an oblong. In such a case, the first glass and the second glass are also rectangular.
When the first glass and the second glass are rectangular, each of the glasses is, for example, from 100 mm to 900 mm long in its longer side direction and from 40 mm to 500 mm long in its shorter side direction.
Edge portions of the first glass and the second glass may be subjected to chamfering. Each of the first glass and the second glass may have a bent portion in its part, or may have a curved shape as a whole.
Resin constituting the intermediate film is not particularly limited. Resins known in the background art can be used. For example, at least one kind selected from the group consisting of polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), and cycloolefin (COP) can be used suitably.
The thickness t3 of the intermediate film is preferably 0.1 mm or more and 5 mm or less, and more preferably 0.1 mm or more and 1.5 mm or less. When the thickness t3 of the intermediate film is made not less than the aforementioned lower limit value, the laminate of the invention can be produced with good yield. When the thickness t3 of the intermediate film is made not more than the aforementioned upper limit value, the appearance of the laminate of the invention can be kept excellent, and when a touch sensor or the like is combined, the sensing sensitivity of the touch sensor can be secured.
The storage shear elastic modulus x (elastic modulus x) of the intermediate film at a temperature of 25° C. and a frequency of 10 kHz is, for example, 0.040 GPa or more and 0.800 GPa or less, and more preferably 0.050 GPa or more and 0.176 GPa or less from the viewpoint of availability of resin constituting the intermediate film.
The elastic modulus x of the intermediate film is obtained by measuring frequency dispersion data at various temperatures by Ares G2 Rheometer made by TA Instruments and creating a master curve by Analysis Software Trios attached thereto.
An adhesive strength between the first glass and the intermediate film is preferably 0.1 N/25 mm or more, more preferably 1 N/25 mm or more, and further more preferably 10 N/25 mm or more. When the adhesive strength between the first glass and the intermediate film is made not less than the aforementioned lower limit value, the first glass and the intermediate film can be prevented from being separated from each other easily even if the laminate of the invention receives an impact. Thus, the first glass can be further prevented from breaking, and broken pieces thereof can be prevented from scattering even if the first glass is broken.
An adhesive strength between the second glass and the intermediate film is preferably 0.1 N/25 mm or more, more preferably 1 N/25 mm or more, and further more preferably 10 N/25 mm or more. When the adhesive strength between the second glass and the intermediate film is made not less than the aforementioned lower limit value, the second glass and the intermediate film can be prevented from being separated from each other easily even if the laminate of the invention receives an impact.
The upper limit value of the adhesive strength between the first glass and the intermediate film and the upper limit value of the adhesive strength between the second glass and the intermediate film are not particularly limited, but they are preferably 100 N/25 mm or less, and more preferably 95 N/25 mm or less. When the adhesive strength between each glass and the intermediate film is not more than the aforementioned upper limit value, the glass can be further prevented from breaking easily even if the laminate of the invention receives an impact, and broken pieces thereof can be further prevented from scattering even if the glass is broken since the intermediate film itself can be prevented from tearing easily.
The aforementioned adhesive strength can be obtained by a tensile test where a peel angle is 90°.
Luminous transmittance of the laminate of the invention is preferably 20% or more and 85% or less, and more preferably 50% or more and 80% or less. When the luminous transmittance is within the aforementioned range, the laminate can have appropriate light-absorbing performance. Therefore, in the display device of the invention using the laminate of the invention as a cover member, it is possible to suppress reflection at the interface between the laminate of the invention and the adhesive layer. Thus, photopic contrast can be improved.
Transmittance of incident light from the visible side (first glass side) is measured over the wavelength range of from 300 nm to 1,300 nm with a spectrophotometer (UV3150PC made by Shimadzu Corporation) according to JIS Z 8722:2009, so as to obtain luminous transmittance in a visible light wavelength range (380 nm to 780 nm).
The laminate of the invention preferably includes a functional layer on the first main face of the first glass.
The functional layer may be formed by treatment performed on a surface layer of the first glass, or may be formed by lamination of another layer on the surface of the first glass.
Examples of such functional layers include an antireflection layer, an antiglare layer, an antifouling layer, and a light shielding layer. It is preferable that the functional layer includes at least one layer selected from the group consisting of an antireflection layer, an antiglare layer, and an antifouling layer.
The antireflection layer provides an effect of reduction in reflectivity, and has an effect of reduction in glare caused by reflection of light. When the antireflection layer is provided, the transmittance of light from a display panel can be improved so that an image displayed on the display panel can be made clear.
The material of the antireflection layer is not particularly limited, but various materials can be used as long as they are materials capable of suppressing reflection of light. For example, the antireflection layer may have a configuration in which a high refractive index layer and a low refractive index layer are stacked. Here, the high refractive index layer is a layer whose refractive index is 1.9 or higher at a wavelength of 550 nm, and the low refractive index layer is a layer whose refractive index is 1.6 or lower at the wavelength of 550 nm.
The antireflection layer may be formed to include a single high refractive index layer and a single low refractive index layer. However, the antireflection layer may be configured to include two or more high refractive index layers and two or more low refractive index layers. When the antireflection layer includes two or more high refractive index layers and two or more low refractive index layers, it is preferable that the antireflection layer has a form in which the high refractive index layers and the low refractive index layers are stacked alternately.
The materials of each high refractive index layer and each low refractive index layer are not particularly limited, but may be selected in consideration of a required degree of antireflection, required productivity, and so on.
Regarding the material constituting the high refractive index layer, a material containing at least one selected from the group consisting of niobium, titanium, zirconium, tantalum and silicon can be used preferably. Specific examples of such materials include niobium oxide (Nb2O5), titanium oxide (TiO2), zirconium oxide (ZrO2), tantalum oxide (Ta2O5) and silicon nitride.
Regarding the material constituting the low refractive index layer, a material containing silicon can be used preferably. Specific examples of such materials include silicon oxide (SiO2), a material containing a mixed oxide of Si and Sn, a material containing a mixed oxide of Si and Zr, and a material containing a mixed oxide of Si and Al.
A method for forming the antireflection layer is not particularly limited, but various methods can be used. Particularly, it is preferable to form the antireflection layer by a method such as pulse sputtering, AC sputtering, or digital sputtering.
The thickness of the antireflection layer is, for example, about 100 nm to 300 nm.
The antiglare layer has a surface concave-convex shape that diffuses and reflects external light to thereby make a reflected image unclear and provide an antiglare effect and the like. Due to provision of the antiglare layer, it is possible to reduce glare of the external light when an image displayed on the display panel is viewed. Thus, the displayed image can be visually recognized clearly.
A method for forming the antiglare layer is not particularly limited. For example, a method in which the surface layer of the glass is etched, a method in which coating liquid containing fine particles and a matrix is applied onto the surface of the glass, etc. can be used.
The antifouling layer is a layer which suppresses adhesion of organic substances or inorganic substances, or a layer which provides an effect that even when organic substances or inorganic substances are adhered thereon, the adhered substances can be removed easily by cleaning such as wiping. Due to provision of the antifouling layer, even when the surface (first main face) of the first glass is touched by fingers, no fingerprint remains on the surface of the first glass, so that the surface of the first glass can be kept clean. Thus, when an image displayed on the display panel is viewed, the displayed image can be visually recognized clearly.
A method for manufacturing the laminate of the invention is not particularly limited. A method similar to a method for manufacturing a laminated glass as known in the background art can be used.
For example, the intermediate film is disposed between the first glass and the second glass, and then pressed on predetermined pressing conditions to obtain a laminated glass.
The pressing conditions are not particularly limited. For example, the pressing pressure is preferably 0.5 to 3.0 MPa, and more preferably 1.0 to 2.0 MPa. The pressing temperature is preferably 70 to 200° C., and more preferably 90 to 160° C. The pressing time is preferably 5 to 60 minutes, and more preferably 10 to 40 minutes.
The present invention will be described below more specifically with examples. However, the present invention is not limited to the following examples.
Laminates in Examples were manufactured to have different values as the thickness t1 (unit: mm) of the first glass, the thickness t2 (unit: mm) of the second glass, the storage shear elastic modulus x (unit: GPa) of the intermediate film at a temperature of 25° C. and a frequency of 10 kHz, and the thickness t3 (unit: mm) of the intermediate film, as shown in Table 1.
Specifically, the intermediate film made of EVA was disposed between the first glass and the second glass, and the thus-obtained stack was pressed for 20 minutes on conditions of a pressure of 1.3 MPa and a temperature of 130° C. In this manner, each laminate that was a laminated glass was manufactured.
A chemically-strengthened glass in which chemically strengthening treatment had been performed on an aluminosilicate glass (“Dragontrail (registered trademark)” made by AGC Inc.) for use in chemically strengthening was used as each of the first glass and the second glass. In the chemically-strengthened glass, the thickness (DOL) of a compressive stress layer was set at 35 μm and the surface compressive stress (CS) in the compressive stress layer was set at 750 MPa.
Using the laminate in each Example, a head impactor test was performed in the following manner to evaluate the shock resistance of the laminate.
A test body of an in-vehicle display device was manufactured using the laminate in each Example. The manufactured test body will be explained with reference to
In
As illustrated in
Sizes expressed by L1 to L7 in
L1: 65 mm
L3: 10 MM
L4: 300 mm
L5: 260 mm
L6: 300 mm
L7: 260 mm
Respective portions of the test body 200 will be described in detail below. Incidentally, the parameters used in the aforementioned simulation will be also described below.
First glass 11 and second glass 12 . . . Young's modulus: 74 GPa, Poisson's ratio: 0.23, density: 2.48 g/cm3
Intermediate film 13 . . . Poisson's ratio: 0.45, density: 1 g/cm3
Housing 106 (including housing bottom plate 107) . . . material: SS400, Young's modulus: 206 GPa, Poisson's ratio: 0.3, density: 7.85 g/cm3
Ring 121 . . . material: POM material (polyacetal), Young's modulus: 2.71 GPa, Poisson's ratio: 0.3, density: 1 g/cm3
POM material . . . polyacetal made by KARATANI Corporation, Young's modulus: 2.71 GPa, Poisson's ratio: 0.3, density: 1 g/cm3
Tape 124 . . . P-cut tape No. 4140 made by Teraoka Seisakusho Co., Ltd., Young's modulus: 1 GPa, Poisson's ratio: 0.35, density: 1 g/cm3
A head impactor test was performed on each of the manufactured test bodies. Specifically, a bottom face of the test body 200 was fixed on the horizontal plane, and a spherical rigid model (material: iron, diameter: 165 mm, mass: 12.9 kg) was made to fall down toward the central position of the laminate in the fixed test body, and collided with the fixed test body, so that energy at the collision reached 16 J.
After the head impactor test, the existence of breaking in the first glass and the second glass of the laminate was visually confirmed. When no breaking was confirmed in a glass, the glass was evaluated as “A” in the following Table 1. When breaking was confirmed in a glass, the glass was evaluated as “B” in Table 1. When a glass is evaluated as “A”, the glass is excellent in shock resistance.
As shown in the aforementioned Table 1, when Expression (1) “Bi=b1+b2+b3<2.90” was satisfied, breaking of the first glass could be suppressed.
In addition, when Expression (5) “B2=b4+b5≤3.82” was satisfied, breaking of the second glass could be suppressed.
The present application is based on Japanese patent application No. 2018-095184 filed on May 17, 2018, and the contents of which are incorporated herein by reference.
1 laminate
11 first glass
11
a first main face
11
b second main face
12 second glass
12
a first main face
12
b second main face
13 intermediate film
14 adhesive layer
100 display device
102 backlight unit
104 display panel
106 housing
107 housing bottom plate
121 ring
123 POM material
124 tape
200 test body
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-095184 | May 2018 | JP | national |
