TW202231458A - Picture display unit and manufacturing method thereof - Google Patents

Abstract

To provide a picture display unit excellent in optical reliability and excellent in durability against various impacts, and also to provide a manufacturing method thereof. An organic EL display device 1 sequentially includes a window member 2, an impact absorption member 3, an organic EL panel member 4 and a protective member 5 on a back side thereof. The impact absorption member 3 has a total light transmittance of 60% or more, a ball impact absorption rate of 0.27%/[mu]m or more per unit thickness and a pen impact absorption rate of 0.10%/[mu]m or more per unit thickness.

Description

Image display device and manufacturing method thereof

The present invention relates to an image display device and a manufacturing method thereof.

Conventionally, an image display device is known to include an image display member. The image display device is required to have high optical reliability.

Furthermore, an image display device including an impact-absorbing film was examined, which can suppress surface damage to the image display member even if an impact is applied to the image display device.

For example, a shock-absorbing film including a support layer and an adhesive layer in this order in the thickness direction has been proposed (for example, refer to the following Patent Document 1). The shock-absorbing film described in the comparative example of Patent Document 1 reveals that the support layer is a thick PET film. prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2020-060689

The problem to be solved by the invention However, the shock-absorbing film described in Patent Document 1 has the disadvantage that the shock-absorbing rate per unit thickness is insufficient. In this case, although the thickness can be reduced, the impact absorption is not good, or the thickness is increased although the impact absorption is excellent.

In particular, the impact absorbing film is required to have durability against various impacts such as ball impact and pen point impact.

The present invention provides an image display device excellent in optical reliability and excellent in durability against various impacts, and a method for producing the same.

means of solving problems The present invention (1) includes an image display device, which includes a window member, an impact absorbing member, a panel member and a protective member in this order from one side in the thickness direction; the aforementioned impact absorbing member has a total light transmittance of 60% or more; the aforementioned impact absorbing member The ball impact absorption rate per unit thickness of the member is 0.27%/µm or more. The ball impact absorption rate per unit thickness of the impact absorption member is made by dropping a stainless steel ball with a weight of 10g and a diameter of 13mm from a height of 20cm to the aforesaid impact absorption Calculate the ball impact absorption rate of the shock absorbing member, and then divide the ball shock absorption rate by the thickness of the shock absorbing member; the pen shock absorption rate per unit thickness of the shock absorbing member is 0.10%/ µm or more, the pen shock absorption rate per unit thickness of the shock absorbing member was calculated by dropping a ballpoint pen with a weight of 7 g and a ball diameter of 0.7 mm at the tip of the shock absorbing member from a height of 20 cm to the shock absorbing member. The impact absorption rate of the pen is obtained by dividing the impact absorption rate of the pen by the thickness of the aforementioned impact absorbing member.

In the image display device, the shock absorbing member has a total light transmittance of 60% or more. Therefore, the optical reliability of the image display device is high.

Furthermore, in the image display device, the ball impact absorption rate per unit thickness of the shock absorbing member is 0.27%/µm or more, and the pen shock absorption rate per unit thickness of the shock absorbing member is 0.10%/µm or more. Therefore, the image display device is excellent in durability against impact to the ball and impact to the pen. Therefore, the image display device is excellent in durability against various impacts.

The present invention (2) includes the image display device according to (1), wherein in the test of bending the image display device in such a way that the window members face outwards, even if two of the window members face outwards The surface was folded 200,000 times so that the distance between the surfaces was 8 mm, and the panel member was not damaged.

In this image display device, even if the image display device was bent 200,000 times in the above-mentioned bending test, the panel member was not damaged. Therefore, the bending resistance of the image display device is excellent.

The present invention (3) includes the image display device according to (1) or (2), wherein the shock absorbing member includes a first adhesive layer, a base material, and a second adhesive layer in this order toward one side in the thickness direction.

The present invention (4) includes the image display device according to (3), wherein the first adhesive layer is in contact with the window member, and the second adhesive layer is in contact with the panel member.

In the image display device, the first adhesive layer is adhered to the window member. The second adhesive layer is adhered to the panel member. Therefore, the window member is adhered to the panel member through the impact absorbing member. Furthermore, since the shock absorbing member including the base material and the first adhesive layer and the second adhesive layer sandwiching the base material is adhered to the window member and the panel member, it is more excellent in bending resistance.

The present invention (5) includes the image display device according to (3) or (4), wherein the shear storage elastic modulus G' of the second adhesive layer at 25°C and the shear modulus of the first adhesive layer at 25°C The storage elastic modulus G' is the same or higher.

The present invention (6) includes the image display device according to any one of (3) to (5), wherein the shear storage elastic modulus G' of the first adhesive layer at 25° C. is 0.01 MPa or more and 0.05 MPa or less .

The present invention (7) includes the image display device according to any one of (3) to (6), wherein the shear storage elastic modulus G' of the second adhesive layer at 25° C. is 0.10 MPa or more and 0.15 MPa or less .

The present invention (8) includes the image display device according to any one of (3) to (7), wherein the shear storage elastic modulus G' of the second adhesive layer at 25°C minus the first adhesive layer is The value of the shear storage elastic modulus G' at 25°C is 0.06 MPa or more.

The present invention (9) includes the image display device according to any one of (3) to (8), wherein the aforementioned substrate is singular.

Moreover, in this image display apparatus, since the base material is singular, the structure is simple.

The present invention (10) includes the image display device according to any one of (3) to (8), wherein the substrates are plural, and the image display device further includes an intermediate adhesive layer, and the intermediate adhesive layer is disposed on the plurality of substrates. between the aforementioned substrates.

In this image display device, the base material is plural. In addition, the image display device further includes an intermediate adhesive layer, and the intermediate adhesive layer is disposed between the plurality of substrates. Therefore, it is easy to design various shock absorption properties suitable for the application and purpose.

The present invention (11) includes the image display device according to (10), wherein the shear storage elastic modulus G' of the intermediate adhesive layer at 25°C is the shear storage elastic modulus G' of the first adhesive layer at 25°C G' or more and the shear storage elastic modulus G' of the said 2nd adhesive layer at 25 degreeC or less.

The present invention (12) includes the image display device according to (10) or (11), wherein the shear storage elastic modulus G' of the intermediate adhesive layer at 25°C is higher than the shear modulus G' of the first adhesive layer at 25°C The shear storage elastic modulus G' is lower than the shear storage elastic modulus G' of the second adhesive layer at 25°C.

The present invention (13) includes the image display device according to any one of (10) to (12), wherein the shear storage elastic modulus G' of the intermediate adhesive layer at 25°C is greater than 0.05 MPa and less than 0.15 MPa.

The present invention (14) includes the image display device according to any one of (10) to (13), wherein the substrate comprises: a first substrate, which is in contact with the first adhesive layer; and a second substrate, which is in contact with the second adhesive layer; and the first substrate is thinner than the second substrate.

The present invention (15) includes the image display device according to any one of (10) to (13), wherein the substrate comprises: a first substrate, which is in contact with the first adhesive layer; and a second substrate, which is in contact with the second adhesive layer; and the first base material is thicker than the second base material.

The present invention (16) includes the image display device according to any one of (3) to (15), wherein the ratio of the thickness of the substrate to the thickness of the shock absorbing member is 0.20 or more and 0.35 or less.

The present invention (17) includes the image display device according to any one of (3) to (16), wherein the material of the aforementioned substrate is a cycloolefin resin and/or a polyester resin.

The present invention (18) includes the image display device according to (17), wherein the aforementioned olefin resin is a cycloolefin resin.

The present invention (19) includes the image display device according to (17), wherein the aforementioned polyester resin is polyethylene terephthalate.

The present invention (20) includes a method for manufacturing an image display device, the image display device includes a window member, a first adhesive layer, a substrate, a second adhesive layer, a panel member and a protective member in this order from one side in the thickness direction; the manufacturing method The method includes the following steps: the first step is to make a trial work; the second step is to evaluate the aforementioned trial work; the third step is to determine manufacturing conditions based on the aforementioned evaluation; and the fourth step is to manufacture a product based on the aforementioned manufacturing conditions ; The aforementioned second step includes the following steps: the fifth step is to make the first sample and the second sample from the aforementioned test work; the sixth step is to drop the ball to the aforementioned first sample and drop the ballpoint pen to the The second sample; and the seventh step, which is after the sixth step, to determine whether the first sample and the second sample are damaged; in the third step, when evaluating the test piece is in the first test. When the sample is damaged, the manufacturing conditions are changed to make the total thickness of the first adhesive layer and the second adhesive layer thicker; when the test piece is evaluated as being damaged in the second sample, changes are made to make the base material thicker. Thicker.

According to this manufacturing method, the manufacturing conditions are determined only after evaluating the trial work, so that the productivity can be improved.

Invention effect The image display device of the present invention is excellent in optical reliability and excellent in durability against various impacts.

The manufacturing method of the present invention can improve the yield.

[1st Embodiment] An organic electroluminescence display device according to a first embodiment of the image display member of the present invention will be described with reference to FIG. 1 . Hereinafter, the organic electroluminescence display device is simply referred to as an "organic EL display device". In FIG. 1 , the front side of the organic EL display device 1 is the visual side of the user and the other side in the thickness direction. The back side is the opposite side to the front side, and is an example of one side in the thickness direction.

As shown in FIG. 1 , the organic EL display device 1 extends in the plane direction. The face direction is orthogonal to the front and back direction. The organic EL display device 1 has, for example, a flat plate shape. The organic EL display device 1 has a front surface 21 and a back surface 22 . Both the front surface 21 and the back surface 22 are flat. The surface 21 is the surface that can be visually recognized by the user. The organic EL display device 1 can be bent, for example, with the intermediate portion 24 as the center. The middle portion 24 is located between the two sides 23 . The two sides 23 are opposed to each other with an interval therebetween in the plane direction.

The organic EL display device 1 includes a window member 2 , a shock absorbing member 3 , an organic EL panel member 4 , and a protective member 5 in this order toward the back side. On the other hand, in the present embodiment, the organic EL display device 1 does not include a polarizer. The polarizer is usually arranged between the window member 2 and the organic EL panel member 4 . The organic EL display device 1 of the first embodiment includes a shock absorbing member 3 instead of a polarizer. The organic EL display device 1 preferably includes only the window member 2 , the shock absorbing member 3 , the organic EL panel member 4 , and the protective member 5 .

The window member 2 forms the surface 21 of the organic EL display device 1 . The window member 2 extends in the face direction. The window member 2 includes, for example, a hard coat layer 6 (refer to an imaginary line) and a window film 7 in this order toward the back side. Alternatively, the window member 2 includes only the window film 7 .

If the material of the window film 7 is resin, the hard coat layer 6 can be inexpensively provided on the window member 2 . The hard coat layer 6 is a protective member to suppress damage due to sliding on the surface 21 of the organic EL display device 1 . The hard coat layer 6 is composed of, for example, a cured product of a curable composition or a molded body of a thermoplastic composition. The thickness of the hard coat layer 6 is, for example, 5 µm or more, preferably 7 µm or more, or, for example, 30 µm or less. The hard coat layer 6 is described in, for example, Japanese Patent Laid-Open No. 2020-064236. On the other hand, if the material of the window film 7 is glass, the hard coat layer 6 is not provided on the window member 2 .

When the window member 2 includes the hard coat layer 6 , the window film 7 is arranged on the back surface of the hard coat layer 6 . Specifically, the window film 7 is in contact with the entire rear surface of the hard coat layer 6 . When the window member 2 does not have the hard coat layer 6 , the window film 7 forms the surface 21 of the organic EL display device 1 . As a material of the window film 7, resin and glass are mentioned, for example. Examples of resins include polyimide resins, acrylic resins, and polycarbonate resins. The thickness of the window film 7 is, for example, 1 µm or more, or, for example, 100 µm or less. A commercially available product can be used for the window film 7 . Commercially available products include, for example, "CPI" (manufactured by KOLON Corporation) and G-LEAF (manufactured by Nippon Electric Glass Co., Ltd.). The window film 7 is described in, for example, Japanese Patent Laid-Open No. 2020-064236.

The total light transmittance of the window member 2 is, for example, 80% or more, preferably 85% or more. The upper limit of the total light transmittance of the window member 2 is not particularly limited. The upper limit of the total light transmittance of the window member 2 is, for example, 100%. The total light transmittance of the window member 2 was measured according to JIS K 7375-2008. The total light transmittance of the following other members was also measured in the same manner as above.

The shock absorbing member 3 extends in the face direction. The shock absorbing member 3 is arranged on the back surface of the window member 2 . Specifically, the shock absorbing member 3 is in contact with the entire rear surface of the window member 2 . The shock absorbing member 3 is arranged at the same position as the polarizer included in the conventional organic EL display device. The shock absorbing member 3 includes a first adhesive layer 8 , a base material 9 , and a second adhesive layer 10 in this order toward the back side. In the first embodiment, the shock absorbing member 3 preferably includes only the first adhesive layer 8 , the base material 9 and the second adhesive layer 10 .

The first adhesive layer 8 extends in the surface direction. In the first embodiment, the first adhesive layer 8 is a singular number. The first adhesive layer 8 forms the surface of the shock absorbing member 3 . The first adhesive layer 8 is disposed on the back surface of the window film 7 . Specifically, the first adhesive layer 8 is in contact with the entire rear surface of the window film 7 . Details of the material and physical properties of the first adhesive layer 8 will be described later.

The substrate 9 extends in the face direction. In the first embodiment, the base material 9 is singular. The base material 9 has a sheet shape. The base material 9 is arranged on the back surface of the first adhesive layer 8 . Specifically, the base material 9 is in contact with the entire rear surface of the first adhesive layer 8 . Details of the material and physical properties of the base material 9 will be described later.

The second adhesive layer 10 extends in the surface direction. The second adhesive layer has a single number of 10. The second adhesive layer 10 forms the back surface of the shock absorbing member 3 . The second adhesive layer 10 is disposed on the back surface of the base material 9 . Specifically, the second adhesive layer 10 is in contact with the entire rear surface of the substrate 9 . Details of the material and physical properties of the second adhesive layer 10 will be described later.

The thickness of the shock absorbing member 3 is not particularly limited. The thickness of the shock absorbing member 3 is, for example, 40 µm or more, preferably 70 µm or more, or, for example, 200 µm or less, preferably 150 µm or less, and more preferably 100 µm or less. When the thickness of the shock absorbing member 3 is below the above-mentioned upper limit, the pen shock absorption rate per unit thickness can be easily improved.

The impact absorbing member 3 has a total light transmittance of 60% or more, a ball impact absorption rate per unit thickness of 0.27%/µm or more, and a pen impact absorption rate per unit thickness of 0.10%/µm or more.

When the total light transmittance of the shock absorbing member 3 is less than 60%, the visibility is lowered. The total light transmittance of the impact absorbing member 3 is preferably 65% or more, more preferably 70% or more, more preferably 80% or more, particularly preferably 85% or more, and most preferably 90% or more. The upper limit of the total light transmittance of the shock absorbing member 3 is not particularly limited. The upper limit of the total light transmittance of the shock absorbing member 3 is, for example, 100% and 99%. Moreover, if the total light transmittance of the laminated body of the window member 2 and the shock absorbing member 3 is 60% or more, it can be said that the total light transmittance of the window member 2 is 60% or more. Other lower limit values can also be defined in the same manner as in the case where the lower limit value is 60%.

The ball shock absorption rate per unit thickness of the shock absorbing member 3 is 0.27%/µm or more.

On the other hand, if the ball impact absorption rate per unit thickness of the impact absorbing member 3 is less than 0.27%/µm, the impact resistance to balls per unit thickness is low. Therefore, an efficient impact absorbing effect on the ball 90 (see FIG. 7 ) cannot be obtained. The ball impact absorption rate per unit thickness of the impact absorbing member 3 is preferably 0.30%/µm or more, more preferably 0.32%/µm or more, and more preferably 0.34%/µm or more.

The ball shock absorption rate per unit thickness of the shock absorbing member 3 is a value obtained by dividing the ball shock absorption rate of the shock absorbing member 3 by the thickness of the shock absorbing member 3 . As shown in FIG. 2A , the ball shock absorption rate of the shock absorbing member 3 was obtained by dropping a stainless steel ball 90 having a weight of 10 g and a diameter of 13 mm on the shock absorbing member 3 from a height of 20 cm.

The spherical shock absorption rate of the shock absorbing member 3 is not particularly limited. The ball impact absorption rate of the impact absorbing member 3 is, for example, 20% or more, preferably 25% or more, more preferably 30% or more, more preferably 40% or more, and particularly preferably 50% or more. The upper limit of the spherical shock absorption rate of the shock absorbing member 3 is not particularly limited. The upper limit of the spherical shock absorption rate of the shock absorbing member 3 is, for example, 90% and 85%.

The pen shock absorption rate per unit thickness of the shock absorbing member 3 is 0.10%/µm or more.

On the other hand, if the pen impact absorption rate per unit thickness of the impact absorbing member 3 is less than 0.10%/µm, the impact resistance to the pen per unit thickness is low. Therefore, the impact absorption effect on the pen (see FIG. 8 ) with high efficiency cannot be obtained. The pen shock absorption rate per unit thickness of the shock absorbing member 3 should preferably be 0.11%/µm or more, more preferably 0.12%/µm or more, more preferably 0.13%/µm or more, more preferably 0.14%/µm or more, 0.15%/µm or more. µm or more, preferably 0.17%/µm or more, 0.19%/µm or more, 0.20%/µm or more, 0.22%/µm or more.

The pen shock absorption rate per unit thickness of the shock absorbing member 3 is a value obtained by dividing the pen shock absorption rate of the shock absorbing member 3 by the thickness of the shock absorbing member 3 . As shown in FIG. 3A , the pen shock absorption rate of the shock absorbing member 3 was obtained by dropping a pen 95 with a weight of 7 g and a ball 96 having a diameter of 0.7 mm at the tip of the shock absorbing member 3 from a height of 20 cm. .

The pen shock absorption rate of the shock absorbing member 3 is not particularly limited. The shock absorption rate of the shock absorbing member 3 is, for example, 5% or more, preferably 6% or more, more preferably 7% or more, more preferably 8% or more, particularly preferably 9% or more, more preferably 10% or more, 11% or more Above, above 15%, above 20%, above 25%, above 30% is preferred. The upper limit of the shock absorption rate of the shock absorbing member 3 is not particularly limited. The upper limit of the shock absorption rate of the shock absorbing member 3 is, for example, 85% and 80%.

The organic EL panel member 4 shown in FIG. 1 is an example of a panel member. The organic EL panel member 4 extends in the surface direction. The organic EL panel member 4 is arranged on the back surface of the shock absorbing member 3 . The organic EL panel member 4 is in contact with the entire rear surface of the shock absorbing member 3 . Specifically, the organic EL panel member 4 is in contact with the second adhesive layer 10 . The organic EL panel member 4 includes a film sealing layer 11 and a panel body 12 .

The film sealing layer 11 is called TFE (Thin Film Encapsulation). The film sealing layer 11 extends in the face direction. The thin film sealing layer 11 forms the surface of the organic EL panel member 4 . The film sealing layer 11 is arranged on the back surface of the second adhesive layer 10 . Specifically, the film sealing layer 11 is in contact with the entire rear surface of the second adhesive layer 10 . The film sealing layer 11 has high hardness but low toughness. The material of the film sealing layer 11 is not particularly limited. Specifically, the material of the thin film sealing layer 11 can be, for example, an inorganic compound and a resin. Examples of inorganic compounds include silicon nitride, silicon oxynitride, carbon nitride, and aluminum oxide.

The panel body 12 extends in the face direction. The surface of the panel body 12 is covered by the film sealing layer 11 . The panel body 12 forms the back surface of the organic EL panel member 4 . Although not shown, the panel body 12 includes a substrate, two electrodes, and an organic EL layer sandwiched by the two electrodes.

The thickness of the organic EL panel member 4 is, for example, 40 µm or less, preferably 30 µm or less, more preferably 20 µm or less, and, for example, 10 µm or more.

The protective member 5 extends in the face direction. The protection member 5 is arrange|positioned at the back surface of the organic electroluminescent panel member 4. Specifically, the protective member 5 is in contact with the entire rear surface of the organic EL panel member 4 . The protective member 5 protects the organic EL panel member 4 from the back side. The protective member 5 forms the back surface 22 of the organic EL display device 1 . The protective member 5 includes a front-side adhesive layer 13 and a protective base material 14 in this order toward the back side. In addition, the protective member 5 may include, for example, a backside adhesive layer 15 and a metal plate 16 on the backside of the protective base material 14 in this order, as shown by a phantom line. At this time, the protective member 5 includes the front side adhesive layer 13 , the protective base material 14 , the back side adhesive layer 15 and the metal plate 16 in this order toward the back side.

The front side adhesive layer 13 is disposed on the back surface of the panel body 12 . Specifically, the front-side adhesive layer 13 is in contact with the entire rear surface of the panel body 12 . In addition, the surface-side adhesive layer 13 forms the surface of the protective member 5 . The material of the surface side adhesive layer 13 is not particularly limited. The surface-side adhesive layer 13 may be formed of the same material as the first adhesive layer 8 to be described later. The thickness of the surface-side adhesive layer 13 is, for example, 1 µm or more, preferably 5 µm or more, and, for example, 50 µm or less, preferably 40 µm or less.

The protective substrate 14 is disposed on the back of the front-side adhesive layer 13 . Specifically, the protective substrate 14 is in contact with the entire rear surface of the protective substrate 14 . The material of the protective substrate 14 is not particularly limited. The protective base material 14 may be made of the same material as the base material 9 . The thickness of the protective substrate 14 is, for example, 5 µm or more, preferably 10 µm or more, and, for example, 250 µm or less, preferably 100 µm or less.

When the protective member 5 includes the backside adhesive layer 15 and the metal plate 16 , the backside adhesive layer 15 is disposed on the backside of the protective substrate 14 . Specifically, the backside adhesive layer 15 is in contact with the entire backside of the protective substrate 14 . The backside adhesive layer 15 may be formed of the same material as the first adhesive layer 8 to be described later. The thickness of the backside adhesive layer 15 is, for example, 10 µm or more, preferably 30 µm or more, and, for example, 100 µm or less, preferably 50 µm or less.

The metal plate 16 extends in the face direction. The metal plate 16 forms the back surface 22 of the organic EL display device 1 . The metal plate 16 is disposed on the backside of the backside adhesive layer 15 . Specifically, the metal plate 16 is in contact with the entire back surface of the backside adhesive layer 15 . The material of the metal plate 16 can be, for example, metal. Examples of metals include aluminum, titanium, steel, 42 alloy, stainless steel, and magnesium alloy. The metal should be stainless steel. The thickness of the metal plate 16 is, for example, 5 µm or more, preferably 10 µm or more, more preferably 70 µm or more, and, for example, 200 µm or less.

The thickness of the protective member 5 is, for example, 20 µm or more, preferably 25 µm or more, or, for example, 1,000 µm or less, preferably 500 µm or less.

As shown in FIGS. 4A and 4B , in the test of bending the organic EL display device 1 so that the window member 2 faces the outside, even if the interval between the above-mentioned surfaces 21 of the window member 2 becomes 8 mm, 200,000 times are folded. , the organic EL panel member 4 should not be damaged.

If the organic EL panel member 4 is not damaged by the above-mentioned bending times, the organic EL display device 1 can suppress the damage of the film sealing layer 11 after the bending.

In a test in which the organic EL display device 1 is bent so that the window member 2 faces outward, even if it is bent 200,000 times so that the interval between the surfaces 21 of the window member 2 is 6 mm, the panel member is not damaged. Therefore, the organic EL display device 1 can suppress breakage of the film sealing layer 11 after bending.

[Details of the shock absorbing member 3] Hereinafter, the elastic modulus, material, and thickness of the shock absorbing member 3 will be described.

[Modulus of elasticity] The shear storage elastic modulus G' of each of the second adhesive layer 10 and the first adhesive layer 8 is not particularly limited. The shear storage elastic modulus G' of the second adhesive layer 10 at 25°C is preferably the same or higher than the shear storage elastic modulus G of the first adhesive layer 8 at 25°C. The shear storage elastic modulus G' of the second adhesive layer 10 at 25°C is preferably higher than the shear storage elastic modulus G of the first adhesive layer 8 at 25°C. The shear storage elastic modulus G' of each of the first adhesive layer 8 and the second adhesive layer 10 was measured using a viscoelasticity measuring apparatus. The heating rate was 5°C/min, and the frequency was 1 Hz. The details are described in the following examples. In addition, if the shear storage elastic modulus G' of the second adhesive layer 10 is the same as the shear storage elastic modulus G' of the first adhesive layer 8, it is convenient to describe the embodiment shown by the thick line in FIG. 12 . If the shear storage elastic modulus G' of the second adhesive layer 10 is higher than the shear storage elastic modulus G' of the first adhesive layer 8, it is convenient to describe the embodiment at the upper left area than the thick line shown in FIG. 12 .

If the shear storage elastic modulus G′ of the second adhesive layer 10 and the first adhesive layer 8 satisfies the above-mentioned ideal relationship, the organic EL display device 1 has better impact resistance per unit thickness to balls, and per unit thickness The thickness is more excellent in the impact resistance of the pen. Moreover, the bending resistance of the organic EL display device 1 is more excellent.

More specifically, the value obtained by subtracting the shear storage elastic modulus G' of the first adhesive layer 8 at 25° C. from the storage elastic modulus G' of the second adhesive layer 10 at 25° C. is, for example, 0.03 MPa or more, It should be above 0.06MPa. The upper limit of the above-mentioned value is not limited. The upper limit of the above-mentioned value is, for example, 0.15 MPa. If the above-mentioned value is at least the above-mentioned lower limit, the organic EL display device 1 will be more excellent in impact resistance to balls per unit thickness. In addition, the area|region where the said value is 0.06 Mpa or more includes the area above the thin solid line shown in FIG. 12, and the area|region inclined to the left more than this solid line.

The shear storage elastic modulus G' of the first adhesive layer 8 at 25° C. is, for example, 0.15 MPa or less, preferably 0.10 MPa or less, and more preferably 0.05 MPa or less. The lower limit of the shear storage elastic modulus G' of the first adhesive layer 8 at 25°C is not limited. The lower limit of the shear storage elastic modulus G' of the first adhesive layer 8 at 25° C. is, for example, 0.01 MPa. If the shear storage elastic modulus G' of the first adhesive layer 8 is below the upper limit, the organic EL display device 1 has excellent impact resistance to balls per unit thickness and excellent impact resistance per unit thickness to pens. In addition, the organic EL display device 1 is excellent in bending resistance. If the shear storage elastic modulus G' of the first adhesive layer 8 is equal to or greater than the above-mentioned lower limit, the shape of the shock absorbing member 3 can be surely maintained.

The shear storage elastic modulus G' of the second adhesive layer 10 at 25° C. is, for example, 0.05 MPa or more, preferably 0.10 MPa or more. The upper limit of the shear storage elastic modulus G' of the second adhesive layer 10 at 25°C is not limited. The upper limit of the shear storage elastic modulus G' of the second adhesive layer 10 at 25° C. is 0.15 MPa. When the shear storage elastic modulus G' of the second adhesive layer 10 is at least the above lower limit, the organic EL display device 1 has excellent impact resistance per unit thickness and excellent impact resistance per unit thickness to a pen. In addition, the organic EL display device 1 is excellent in bending resistance. If the shear storage elastic modulus G' of the second adhesive layer 10 is below the upper limit, the shock absorbing member 3 can sufficiently absorb the external force.

The total light transmittance of each of the first adhesive layer 8 and the second adhesive layer 10 is, for example, 80% or more, preferably 85% or more. The upper limit of the total light transmittance of each of the first adhesive layer 8 and the second adhesive layer 10 is not particularly limited. The upper limit of the total light transmittance of each of the first adhesive layer 8 and the second adhesive layer 10 is, for example, 100%.

The tensile modulus E of the base material 9 at 25° C. is, for example, 0.1 GPa or more, preferably 1 GPa or more, and more preferably 2 GPa or more. When the tensile modulus E of the base material 9 is at least the above lower limit, the organic EL display device 1 is excellent in impact resistance per unit thickness of a ball and impact resistance per unit thickness of a pen. In addition, the organic EL display device 1 is excellent in bending resistance.

The tensile modulus E of the base material 9 is, for example, 15 GPa or less, preferably 5 GPa or less, and more preferably 1 GPa or less. When the tensile modulus E of the base material 9 is equal to or less than the above-mentioned upper limit, the impact resistance to a ball per unit thickness is excellent.

The tensile modulus E of the base material 9 was measured using a tensile tester. The details of the measurement of the tensile modulus of elasticity E of the substrate 9 are described in the following examples.

The total light transmittance of the base material 9 is, for example, 80% or more, preferably 85% or more. The upper limit of the total light transmittance of the base material 9 is, for example, 100%.

[Material] The 1st adhesive layer 8 and the 2nd adhesive layer 10 are comprised by the material which can satisfy|fill the said physical property. Examples of materials include: acrylic adhesives, rubber-based adhesives, vinyl alkyl ether-based adhesives, polysiloxane-based adhesives, polyester-based adhesives, polyamide-based adhesives, urethane-based adhesives adhesives, fluorine-based adhesives, epoxy-based adhesives and polyether-based adhesives. Preferably, an acrylic adhesive can be cited.

The acrylic adhesive may, for example, be a cross-linked product of an acrylic base polymer. The acrylic base polymer can be obtained by polymerizing monomer components. The monomer component contains, for example, a (meth)acrylate having an alkyl moiety having 1 to 24 carbon atoms as a main component. (Meth)acrylate means methacrylate and/or acrylate. The definition and usage of the above-mentioned (meth)acrylate are the same as below. The alkyl moiety has a straight-chain or branched-chain shape. Examples of (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, tertiary butyl (meth)acrylate, and tributyl (meth)acrylate. Grade butyl ester, isobutyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, isohexyl (meth)acrylate, (meth)acrylate Isoheptyl acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate , decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, (meth)acrylic acid Cetyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, behenyl (meth)acrylate and behenyl (meth)acrylate. From the viewpoint of preparing a relatively hard second adhesive layer 10, a (meth)acrylate having an alkyl moiety having 1 to 4 carbon atoms is preferably used. From the viewpoint of preparing a relatively soft first adhesive layer 8, a (meth)acrylate having an alkyl moiety having 6 to 24 carbon atoms is preferably used. The ratio of the (meth)acrylate in the monomer component is, for example, 80 mass % or more, preferably 90 mass % or more, or, for example, 100 mass % or less, and preferably 99.5 mass % or less.

The monomer component further includes a functional group-containing (meth)acrylate as an optional component. As the functional group-containing (meth)acrylate, for example, a hydroxyl group-containing (meth)acrylate and an amide group-containing (meth)acrylate can be mentioned. As a hydroxyl-containing (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate are mentioned, for example. Examples of the amide group-containing (meth)acrylate include (meth)acrylamide and dimethyl(meth)acrylamide. In addition, the amide group-containing (meth)acrylate may include an amide group-containing (meth)acrylate in the molecule. The (meth)acrylate containing an amide group in the molecule includes, for example, N-vinyl-2-pyrrolidone. The ratio of the functional group-containing (meth)acrylate in the monomer component is, for example, 1 mass % or more, preferably 5 mass % or more, or, for example, 25 mass % or less, or preferably 20 mass % or less.

The monomer components can be polymerized, for example, in the presence of a chain transfer agent. As a chain transfer agent, a thiol compound is mentioned, for example. As a thiol compound, alpha-thioglycerol is mentioned, for example. The mass ratio of the chain transfer agent is, for example, 1 part by mass or more, or, for example, 10 parts by mass or less with respect to 100 parts by mass of the monomer component.

The cross-linked product can be obtained by blending and reacting the cross-linking agent to the acrylic base polymer. The crosslinking agent includes, for example, an isocyanate crosslinking agent, a silane coupling agent, a peroxide, and (meth)acrylate having a plurality of (meth)acryloyl groups. The isocyanate crosslinking agent includes, for example, a modified trimethylolpropane of diisocyanate and a modified trimethylolpropane of tolyl diisocyanate. The silane coupling agent may, for example, be an epoxy group-containing silane coupling agent. The epoxy group-containing silane coupling agent may, for example, be 3-glycidoxypropyltrimethoxysilane. As a peroxide, an organic peroxide is mentioned, for example. As the organic peroxide, for example, benzyl peroxide can be mentioned. As the (meth)acrylate having a plurality of (meth)acryloyl groups, for example, hexanediol (meth)acrylate is exemplified. These can be used alone or in combination. The mass ratio of the crosslinking agent is, for example, 0.1 parts by mass or more, or, for example, 2 parts by mass or less with respect to 100 parts by mass of the acrylic base polymer.

Additives can be added to the acrylic base polymer at the same time as the crosslinking agent is blended. Examples of additives include oligomers. As an oligomer, (meth)acrylic acid oligomer is mentioned, for example. The weight average molecular weight of the (meth)acrylic oligomer is, for example, 1,000 or more, preferably 2,000, or, for example, 30,000 or less, preferably 10,000 or less. The weight average molecular weight of the (meth)acrylic oligomer is obtained by standard polystyrene conversion by GPC. The (meth)acrylic oligomer can be obtained by polymerizing monomer components. The monomer component includes the above-mentioned (meth)acrylate having an alkyl moiety having 1 to 24 carbon atoms, and an alicyclic (methyl) having an alicyclic alkyl (cycloaliphatic alkyl) moiety having 1 to 24 carbon atoms. Acrylate. The alicyclic alkyl moiety includes, for example, a monocyclic type and a polycyclic type. The monocyclic alicyclic (meth)acrylate may, for example, be cycloalkyl (meth)acrylate. Cycloalkyl (meth)acrylate may, for example, be cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate. Examples of polycyclic alicyclic (meth)acrylates include isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, and tricyclopentyl (meth)acrylate. The ratio of the (meth)acrylate in the monomer component is, for example, 10 mass % or more, preferably 20 mass % or more, or, for example, 70 mass % or less, and preferably 45 mass % or less. The ratio of the alicyclic (meth)acrylate in the monomer component is, for example, 30% by mass or more, preferably 55% by mass or more, or, for example, 90% by mass or less, or preferably 80% by mass or less.

The glass transition temperature of the oligomer is, for example, 20°C or higher, preferably 50°C or higher, more preferably 80°C or higher, and, for example, 150°C or lower. The glass transition temperature of the oligomer was calculated by the Fox equation.

The mass ratio of the oligomer is, for example, 0.01 part by mass or more, or, for example, 1 part by mass or less with respect to 100 parts by mass of the acrylic base polymer.

The material of the base material 9 is composed of a material that can satisfy the above-mentioned physical properties. The material of the base material 9 can be, for example, resin. The resins may be used alone or in combination. Examples of resins include olefin resins, polyester resins, acrylic resins, polycarbonate resins, polyether resins, polyarylate resins, melamine resins, polyamide resins, polyimide resins, cellulose resins, and polyphenylenes. vinyl. Preferable resins include olefin resins, polyester resins, acrylic resins, polycarbonate resins, polyether resins, polyarylate resins, melamine resins, cellulose resins and polystyrene resins. More suitable resins include olefin resins and polyester resins.

As an olefin resin, polyethylene, a polypropylene, and a cyclic olefin polymer (COP) are mentioned, for example. The olefin resin is preferably COP. COP is a polymer containing a cycloolefin-containing monomer component. As a cyclic olefin, norbornene is mentioned, for example.

As polyester resin, polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate are mentioned, for example. The polyester resin includes, for example, a soft polyester resin (transparent soft polyester resin). The polyester resin is preferably PET.

The material of the base material 9 is preferably COP. Compared to PET, COP can further improve the pen impact absorption rate per unit thickness.

As the base material 9, commercially available ones can be used. Commercially available products include, for example: Lumirror series (PET base material, manufactured by Toray Co., Ltd.), ZEONOR series (COP base material, made by Japan ZEON Co., Ltd.), and OKY series (transparent flexible polyester resin base material, Bell Polyester Products, Inc.).

[thickness] The thicknesses of the first adhesive layer 8 , the base material 9 and the second adhesive layer 10 are not particularly limited.

The thickness of each of the first adhesive layer 8 and the second adhesive layer 10 is, for example, 1 µm or more, preferably 5 µm or more, or, for example, 50 µm or less, preferably 40 µm or less. The second adhesive layer 10 may have the same thickness as the first adhesive layer 8 , or may have a different thickness from the first adhesive layer 8 .

The thickness of the substrate 9 is, for example, 5 µm or more, preferably 10 µm or more, or 100 µm or less, preferably 75 µm or less, more preferably 50 µm or less, more preferably less than 50 µm, particularly preferably 45 µm or less, and most preferably 30 µm or less.

The ratio of the thickness of the base material 9 to the thickness of the shock absorbing member 3 is, for example, 0.10 or more, preferably 0.20 or more, for example, 0.70 or less, preferably 0.60 or less, preferably 0.40 or less, and more preferably 0.35 or less. If the thickness ratio of the base material 9 is more than the said lower limit, it will be excellent in bending resistance. If the thickness ratio of the base material 9 is below the said upper limit, the pen shock absorption rate per unit thickness will be high.

[Manufacture of Organic EL Display Device 1] The organic EL display device 1 can be obtained by laminating the window member 2 , the shock absorbing member 3 , the organic EL panel member 4 , and the protective member 5 .

In addition, although not shown, the shock absorbing member 3 is prepared as a shock absorbing member with a release sheet. The shock-absorbing member with a release sheet includes a shock-absorbing member 3 and a release sheet laminated on the front and back surfaces of the shock-absorbing member 3, respectively. The shock absorbing member 3 is prepared by peeling the peeling sheet from the shock absorbing member 3 in the shock absorbing member with the peeling sheet.

Further, another method of manufacturing the organic EL display device 1 using the prototype 40 will be described with reference to FIGS. 5 to 6 . As shown in FIG. 5 , the method includes a first step S1 , a second step S2 , a third step S3 and a fourth step S4 in sequence.

The first step S1 is a trial work. For example, a plurality of trial works 40 are produced. Each of the plurality of test pieces 40 has, for example, the same structure, the same thickness, and the same physical properties. The plurality of test pieces 40 include, for example, a first sample 61 and a second sample 62 , and further includes a third sample 63 . Sample 40 is also a mock sample. The prototype 40 has the same configuration as the above-described organic EL display device 1 except for the following points. The organic EL panel member 4 of the prototype 40 is provided with the ITO layer 35 instead of the film sealing layer 11 . The ITO layer 35 is formed to evaluate damage due to strain that may be imparted to the thin film sealing layer 11 . The ITO layer 35 is composed of a complex oxide (ITO) of indium oxide and tin oxide. The thickness of the ITO layer 35 is, for example, 100 nm or less, preferably 70 nm or less, more preferably 50 nm or less, and, for example, 20 nm or more. By varying the thickness of the ITO layer 35, cracking to strain can be controlled. The organic EL panel member 4 including the above-described ITO layer 35 and the panel body 12 is a substitute panel member 44 . In addition, in the prototype 40, for example, the shear storage elastic modulus G' at 25° C. of the first adhesive layer 8 and the second adhesive layer 10 is the same.

In the second step S2, the trial work 40 is evaluated. As shown in FIG. 6 , the second step S2 includes a fifth step S5, a sixth step S6, and a seventh step S7.

In the fifth step S5 , the first sample 61 and the second sample 62 are selected from the sample 40 . The first sample 61 and the second sample 62 have the same structure, the same thickness, and the same physical properties. In addition, the third sample 63 may be subjected to a bending test described later.

In the sixth step S6, a ball drop test (refer to FIG. 7 ) and a pen drop test (refer to FIG. 8 ) are performed.

As shown in FIG. 7 , in the drop ball test, the ball 90 is dropped to the first sample 61 . The weight of the ball 90 in the ball drop test is, for example, 1 g or more, preferably 2 g or more, or, for example, 100 g or less, preferably 50 g or less. The diameter of the ball 90 in the drop ball test is, for example, 1 mm or more, preferably 2 mm or more, or, for example, 100 mm or less, preferably 50 mm or less. The material of the ball is not limited, for example, it is metal. The drop height of the ball 90 in the ball drop test is, for example, 2 cm or more, preferably 5 cm or more, or, for example, 200 cm or less, preferably 100 cm or less.

As shown in FIG. 8 , in the pen drop test, a pen (ballpoint pen) 95 is dropped on the second sample 62 . The pen 95 has a ball 96 at its front end.

The weight of the pen 95 in the pen drop test is, for example, 0.5 g or more, preferably 1 g or more, and, for example, 50 g or less, preferably 30 g or less. The diameter of the ball 96 in the pen drop test is, for example, 0.01 mm or more, preferably 0.1 mm or more, or, for example, 5 mm or less, preferably 1 mm or less. The drop height in the pen drop test is, for example, 2 cm or more, preferably 5 cm or more, or, for example, 200 cm or less, preferably 100 cm or less.

In the seventh step S7, it is determined whether or not the first sample 61 and the second sample 62 are damaged.

Then, in the third step, when the evaluation test piece 40 is damaged in the first sample 61, it is determined by changing the manufacturing conditions so that the total thickness of the first adhesive layer 8 and the second adhesive layer 10 is thicker. In addition, in the third step, when the second sample 62 of the evaluation test piece 40 is damaged, it is determined by changing the manufacturing conditions so that the thickness of the base material 9 is thicker.

In the fourth step S4, the organic EL display device 1 is manufactured according to the above-mentioned manufacturing conditions.

Thereby, the organic EL display device 1 can be manufactured as a product.

In addition, in the seventh step S7, when it is determined that neither the first sample 61 nor the second sample 62 is damaged, the organic EL display device 1 is manufactured without going through the above-mentioned third step S3, that is, without changing the manufacturing conditions. finished product.

[Use of Organic EL Display Device 1] As shown in FIG. 4A , when the user sees the entire surface 21 of the organic EL display device 1 , the organic EL display device 1 is in an open state. At this time, the surface 21 is a flat surface. The organic EL display device 1 includes an intermediate portion 24 , a first portion 17 and a second portion 18 . The middle portion 24 is located between the two sides 23 . The two sides 23 include a first side 23A and a second side 23B. The first portion 17 is an area including the first side 23A. The second portion 18 is an area including the second side 23B.

As shown in FIG. 4B , there is a case where the organic EL display device 1 is bent around the intermediate portion 24 . That is, the organic EL display device 1 may be used by being bent. At this time, the intermediate portion 24 is formed with a crease. The surface 21 of the first part 17 and the surface 21 of the second part 18 face outward from each other. At this time, the back surface 22 of the first portion 17 and the back surface 22 of the second portion 18 are closely opposed to each other.

[Function and effect of the first embodiment] Furthermore, in the organic EL display device 1, the shock absorbing member 3 has a total light transmittance of 60% or more. Specifically, the shock absorbing member 3 provided in the organic EL display device 1 instead of the polarizer has a high total light transmittance. Therefore, the optical reliability of the organic EL display device 1 is high. In particular, since the organic EL display device 1 of the first embodiment does not include a polarizer, the optical reliability is particularly high.

In addition, in the organic EL display device 1, the impact absorbing member 3 has a ball impact absorption rate per unit thickness of 0.27%/µm or more, and has a pen impact absorption rate per unit thickness of 0.10%/µm or more. Therefore, the organic EL display device 1 is excellent in durability against impact to a ball and impact to a pen. Therefore, the organic EL display device 1 is excellent in durability against various impacts.

In addition, in the test of bending the organic EL display device 1 so that the window member 2 faces the outside, even if it is bent 200,000 times so that the interval between the two surfaces 21 of the window member 2 becomes 8 mm, the organic EL panel member 4 is also not damaged. Therefore, the organic EL display device 1 is excellent in bending resistance.

In addition, in this organic EL display device 1 , the first adhesive layer 8 is adhered to the window member 2 . The second adhesive layer 10 is adhered to the organic EL panel member 4 . Therefore, the window member 2 is adhered to the organic EL panel member 4 through the impact absorbing member 3 . Furthermore, since the shock absorbing member 3 including the base material 9 and the first adhesive layer 8 and the second adhesive layer 10 sandwiching the base material 9 is adhered to the window member 2 and the organic EL panel member 4, the bending resistance is better.

In addition, in the organic EL display device 1, when the shear storage elastic modulus G' of the second adhesive layer 10 at 25°C is the same as the shear storage elastic modulus G' of the first adhesive layer 8 at 25°C or When it is higher, the organic EL display device 1 is excellent in the impact resistance per unit thickness of the ball and the impact resistance per unit thickness of the pen. Moreover, this organic EL display device 1 is excellent in bending resistance.

In particular, in the organic EL display device 1, when the shear storage elastic modulus G' of the second adhesive layer 10 at 25°C is higher than the shear storage elastic modulus G' of the first adhesive layer 8 at 25°C , the organic EL display device 1 is more excellent in impact resistance per unit thickness of balls, and more excellent in impact resistance per unit thickness of pens.

In addition, in the organic EL display device 1, if the shear storage elastic modulus G' of the first adhesive layer 8 at 25°C is 0.01 MPa or more, the shape of the shock absorbing member 3 can be surely maintained. If the shear storage elastic modulus G' at 25°C of the first adhesive layer 8 is 0.05 MPa or less, the organic EL display device 1 has excellent impact resistance per unit thickness of balls.

In the organic EL display device 1 , when the shear storage elastic modulus G′ of the second adhesive layer 10 at 25° C. is 0.10 MPa or more, the organic EL display device 1 has excellent bending resistance. If the shear storage elastic modulus G' of the second adhesive layer 10 at 25° C. is 0.15 MPa or less, the shock absorbing member 3 can sufficiently absorb the external force.

Furthermore, in the organic EL display device 1, the shear storage elastic modulus G' of the first adhesive layer 8 at 25° C. is subtracted from the shear storage elastic modulus G' of the second adhesive layer 10 at 25° C. If the value is 0.06 MPa or more, the organic EL display device 1 is excellent in the impact resistance per unit thickness of the ball and the impact resistance per unit thickness of the pen. In addition, the organic EL display device 1 is excellent in both bending resistance and bending resistance.

Moreover, in this organic EL display device 1, since the base material 9 is singular, the structure is simple.

In addition, in the organic EL display device 1, if the ratio of the thickness of the base material 9 to the thickness of the impact absorbing member 3 is 0.20 or more, the impact resistance per unit thickness of the pen is good. If the ratio of the thickness of the base material 9 to the thickness of the shock absorbing member 3 is 0.35 or less, the ball shock absorption rate per unit thickness is high.

In addition, in the organic EL display device 1, if the material of the base material 9 is olefin resin and/or polyester resin, the ball impact absorption rate per unit thickness and the pen impact absorption rate per unit thickness can be improved.

If the organic EL display device 1 is manufactured by the manufacturing method including the first step S1 to the third step S3 described above, the manufacturing conditions are determined only after evaluating the trial work 40, so that the yield can be improved.

[Second Embodiment] In the following second embodiment, the same reference numerals are assigned to the same members and steps as those of the above-described first embodiment, and detailed descriptions thereof will be omitted. In addition, unless otherwise specified, the second embodiment can exhibit the same functions and effects as those of the first embodiment.

As shown in FIG. 9, in 2nd Embodiment, the base material 9 is a plurality of pieces. Specifically, the base material 9 includes a first base material 25 and a second base material 26 . In addition, the shock absorbing member 3 further includes an intermediate adhesive layer 19 .

The first base material 25 is in contact with the first adhesive layer 8 . The first base material 25 is disposed on the back surface of the first adhesive layer 8 . The first base material 25 does not contact the second adhesive layer 10 .

The second base material 26 is disposed on the back side of the first base material 25 with an interval therebetween. The second substrate 26 is in contact with the second adhesive layer 10 . The second base material 26 is disposed on the surface of the second adhesive layer 10 . The second base material 26 does not contact the first adhesive layer 8 .

The intermediate adhesive layer 19 is singular in the second embodiment. The intermediate adhesive layer 19 is interposed between the first base material 25 and the second base material 26 . The intermediate adhesive layer 19 is in contact with the first substrate 25 and the second substrate 26 . Specifically, the intermediate adhesive layer 19 is in contact with the back surface of the first substrate 25 and the surface of the second substrate 26 .

The shock absorbing member 3 includes a first adhesive layer 8 , a first base material 25 , an intermediate adhesive layer 19 , a second base material 26 , and a second adhesive layer 10 in this order toward the back side. In the second embodiment, the shock absorbing member 3 preferably includes only the first adhesive layer 8 , the first base material 25 , the intermediate adhesive layer 19 , the second base material 26 , and the second adhesive layer 10 .

[Details of the intermediate adhesive layer 19] The shear storage elastic modulus G' of the intermediate adhesive layer 19 at 25°C is not particularly limited. Preferably, the shear storage elastic modulus G' of the intermediate adhesive layer 19 at 25°C is greater than the shear storage elastic modulus G' of the first adhesive layer 8 at 25°C and the second adhesive layer 10 is at 25°C. Shear storage elastic modulus G' or less.

It can be seen that if the shear storage elastic modulus G' of the intermediate adhesive layer 19 is greater than the shear storage elastic modulus G' of the first adhesive layer 8 and the shear storage elastic modulus G' of the second adhesive layer 10 at 25°C Below the value, the organic EL display device 1 is excellent in impact resistance and bending resistance per unit thickness of a ball and a pen.

Preferably, the shear storage elastic modulus G' of the intermediate adhesive layer 19 at 25°C is higher than the shear storage elastic modulus G' of the first adhesive layer 8 at 25°C, and lower than that of the second adhesive layer 10 at 25°C. Shear storage elastic modulus G' at 25°C. In this case, high impact resistance and high bending resistance per unit thickness of the ball can be more reliably achieved.

The shear storage elastic modulus G' of the intermediate adhesive layer 19 at 25°C is, for example, 0.01 MPa or more, preferably 0.05 MPa or more, preferably more than 0.05 MPa, and for example, 0.15 MPa or less, preferably 0.10 MPa or less.

If the shear storage elastic modulus G' of the intermediate adhesive layer 19 is larger than the above lower limit and smaller than the above upper limit, the impact resistance and bending resistance per unit thickness of the ball will be more excellent.

The thickness of the intermediate adhesive layer 19 is, for example, 1 µm or more, preferably 10 µm or more, and, for example, 40 µm or less, preferably 30 µm or less.

[Details of the first base material 25 and the second base material 26 ] The ratio of the total thickness of the first base material 25 and the second base material 26 to the thickness of the shock absorbing member 3 is the same as the ratio of the thickness of the base material 9 to the thickness of the above-mentioned shock absorbing member 3 .

The thickness of the first base material 25 is, for example, 1 µm or more, preferably 3 µm or more, and, for example, 50 µm or less, preferably 20 µm or less.

The thickness of the second base material 26 is, for example, 5 or more, preferably 15 µm or more, and, for example, 100 µm or less, preferably 50 µm or less.

The first base material 25 is, for example, thicker or thinner than the second base material 26 . The first base material 25 may have the same thickness as the second base material 26 . Preferably, the first base material 25 is thinner than the second base material 26 .

When the first base material 25 is thinner than the second base material 26 , the impact resistance per unit thickness of the ball is more excellent.

The ratio of the thickness of the first base material 25 to the thickness of the second base material 26 is preferably 0.9 or less, and preferably 0.7 or less. In addition, the lower limit of the ratio of the thickness of the first base material 25 to the thickness of the second base material 26 is, for example, 0.1, or, for example, 0.2.

On the other hand, when the first base material 25 is thicker than the second base material 26, the impact resistance per unit thickness of the pen is more excellent.

The ratio of the thickness of the first base material 25 to the thickness of the second base material 26 is preferably 1.1 or more, and preferably 1.4 or more. Moreover, the upper limit of the ratio of the thickness of the 1st base material 25 with respect to the thickness of the 2nd base material 26 is 10, for example, and it is 5, for example.

The tensile elastic modulus E at 25°C of each of the first base material 25 and the second base material 26 is the same as the tensile elastic modulus E at 25°C of the base material 9 of the first embodiment.

[Function and effect of the second embodiment] In this organic EL display device 1, the substrates 9 are plural. In addition, the organic EL display device 1 further includes an intermediate adhesive layer 19 , and the intermediate adhesive layer 19 is arranged between the plurality of substrates 9 . Therefore, it is easy to design various shock absorption properties suitable for the application and purpose.

In addition, in the organic EL display device 1, if the shear storage elastic modulus G' of the intermediate adhesive layer 19 is greater than the shear storage elastic modulus G' of the first adhesive layer 8 and the second adhesive layer 10 is at 25° C. Below the value of the shear storage elastic modulus G', the organic EL display device 1 is excellent in impact resistance and bending resistance per unit thickness of the ball.

In addition, in the organic EL display device 1, if the shear storage elastic modulus G' of the intermediate adhesive layer 19 at 25°C is higher than the shear storage elastic modulus G' of the first adhesive layer 8 at 25°C and lower than With the shear storage elastic modulus G′ of the second adhesive layer 10 at 25° C., the organic EL display device 1 can more reliably achieve both high impact resistance and high bending resistance per unit thickness of balls.

Specifically, in the organic EL display device 1, if the shear storage elastic modulus G' of the intermediate adhesive layer 19 at 25° C. is greater than 0.05 MPa and less than 0.15 MPa, it is possible to take into account the high performance per unit thickness of the ball. Impact resistance, high impact resistance per unit thickness of the pen and high flex resistance.

In addition, in the organic EL display device 1, if the first base material 25 is thinner than the second base material 26, it is possible to ensure both high impact resistance and high bending resistance per unit thickness of the ball.

On the other hand, in the organic EL display device 1, if the first base material 25 is thicker than the second base material 26, the high impact resistance per unit thickness of the pen is excellent.

[Variation of the second embodiment] In the following modified examples, the same reference numerals are assigned to the same members and steps as those of the second embodiment described above, and detailed descriptions thereof will be omitted. In addition, unless otherwise noted, the modification can exhibit the same functions and effects as those of the second embodiment. The second embodiment and its modifications can be appropriately combined.

In this modification, as shown in FIG. 10 , the number of intermediate adhesive layers 19 is plural. Specifically, the intermediate adhesive layer 19 includes a first intermediate adhesive layer 27 and a second intermediate adhesive layer 28 . The base material 9 further includes a third base material 29 .

The first intermediate adhesive layer 27 is in contact with the first substrate 25 . However, the first intermediate adhesive layer 27 does not contact the second substrate 26 . The first intermediate adhesive layer 27 is disposed on the back surface of the first base material 25 .

The second intermediate adhesive layer 28 is in contact with the second substrate 26 . However, the second intermediate adhesive layer 28 does not contact the first substrate 25 . The second intermediate adhesive layer 28 is disposed on the surface of the second substrate 26 .

The third base material 29 is disposed between the first intermediate adhesive layer 27 and the second intermediate adhesive layer 28 . The third substrate 29 is in contact with the back surface of the first intermediate adhesive layer 27 and the surface of the second intermediate adhesive layer 28 .

The shock absorbing member 3 includes a first adhesive layer 8 , a first base material 25 , a first intermediate adhesive layer 27 , a third base material 29 , a second intermediate adhesive layer 28 , a second base material 26 and a 2 adhesive layer 10. In this modification, the shock absorbing member 3 preferably includes only the first base material 25 , the first intermediate adhesive layer 27 , the third base material 29 , the second intermediate adhesive layer 28 , the second base material 26 , and the second adhesive layer 10 .

The ratio of the total thickness of the first base material 25 , the second base material 26 and the third base material 29 to the thickness of the shock absorbing member 3 is the same as the ratio of the thickness of the base material 9 to the thickness of the shock absorbing member 3 .

The shear storage elastic modulus G' of each of the first intermediate adhesive layer 27 and the second intermediate adhesive layer 28 at 25°C and the shear storage elastic modulus G' of the intermediate adhesive layer 19 of the second embodiment at 25°C same.

In the first embodiment, as shown in FIG. 1 , a shock absorbing member 3 composed of three layers is disclosed. In the second embodiment, as shown in FIG. 9, a shock absorbing member 3 composed of five layers is disclosed. In a modification of the second embodiment, as shown in FIG. 10 , a shock absorbing member 3 composed of seven layers is disclosed. Although not shown, the shock absorbing member 3 may be composed of [2n+1 layers]. In the modified example, n is a positive number of 4 or more. In the modified example, the shock absorbing member 3 is composed of the adhesive layer of the [n+1] layer and the base material of the [n] layer.

In the first embodiment, the shock absorbing member 3 is in contact with both the back surface of the window member 2 and the surface of the organic EL panel member 4 . However, the shock absorbing member 3 may be disposed between the window member 2 and the organic EL panel member 4 , for example, with a space between the rear surface of the shock absorbing member 3 and the surface of the organic EL panel member 4 . In addition, the shock absorbing member 3 may be in contact with any one of the back surface and the front surface, and may be spaced apart from the other. Specifically, as shown in FIG. 11 , the shock absorbing member 3 is in contact with the back surface of the window member 2 and is spaced apart from the organic EL panel member 4 . Specifically, the shock absorbing member 3 and the organic EL panel member 4 are arranged via the polarizing film 50 and the adhesive layer 51 .

The polarizing film 50 is in contact with the back surface of the second adhesive layer 10 . The polarizing film 50 includes a polarizer. As the polarizer, for example, a hydrophilic film is dyed and stretched, a hydrophilic film is dehydrated, and a polyvinyl chloride film is dehydrochlorinated. The hydrophilic film may be, for example, a PVA film. The total light transmittance of the polarizer is, for example, 30% or more, preferably 35% or more, preferably 40% or more, and, for example, 50% or less. The thickness of the polarizer is, for example, 1 µm or more, preferably 3 µm or more, and, for example, 15 µm or less, preferably 10 µm or less. Polarizers are described in Japanese Patent Laid-Open No. 2020-149065 and Japanese Patent Laid-Open No. 2019-218513. The polarizing film 50 is formed by laminating a protective film on the above-mentioned polarizer through an adhesive.

The adhesive layer 51 is interposed between the polarizing film 50 and the organic EL panel member 4 . The adhesive layer 51 is in contact with the back surface of the polarizing film 50 and the surface of the organic EL panel member 4 . The material, thickness and physical properties of the adhesive layer 51 are the same as those of the first adhesive layer 8 or the second adhesive layer 10 .

In the organic EL display device 1 of the modification example of FIG. 11 , the window member 2 , the shock absorbing member 3 , the polarizing film 50 , the adhesive layer 51 , the organic EL panel member 4 and the protective member 5 are arranged in this order toward the back side.

Comparing the organic EL display device 1 of the first embodiment shown in FIG. 1 with the organic EL display device 1 of the modification example of FIG. 11 , the organic EL display device 1 of the first embodiment does not include the polarizing film 50 and the adhesive layer 51 . Therefore, the organic EL display device 1 of the first embodiment is excellent in optical reliability because the polarizer in the polarizing film 50 has the above-mentioned low total light transmittance.

Example The present invention will be described in more detail below by showing Examples and Comparative Examples. In addition, this invention is not limited to any Example and a comparative example. In addition, the specific numerical values such as the blending ratio (ratio), physical property value, and parameter used in the following description may be replaced by the blending ratio (ratio), physical property value, and parameter corresponding to the blending ratio (ratio), physical property value, and parameter described in the above-mentioned "Forms for Carrying Out the Invention". the upper limit (the numerical value defined by "below" and "less than") or the lower limit (the numerical value defined by "above" and "greater than") of such description.

[Adhesive Sheet Preparation] Adhesive Sheet A to Adhesive Sheet D were prepared as described below.

[Adhesive Sheet A] 43 parts by mass of lauryl acrylate (LA), 44 parts by mass of 2-ethylhexyl acrylate (2EHA), 6 parts by mass of 4-hydroxybutyl acrylate (4HBA), N-vinyl-2-pyrrolidone ( NVP) 7 parts by mass and 0.015 parts by mass of "IRGACURE 184" manufactured by BASF, were irradiated with ultraviolet rays and polymerized to obtain a base polymer composition (polymerization rate: about 10%).

In addition, 60 parts by mass of dicyclopentyl methacrylate (DCPMA), 40 parts by mass of methyl methacrylate (MMA), 3.5 parts by mass of α-thioglycerol, and 100 parts by mass of toluene were mixed, and the mixture was heated at 70° C. in a nitrogen atmosphere. under stirring for 1 hour. Next, after adding 0.2 mass part of 2,2'-azobisisobutyronitrile (AIBN), and making it react at 70 degreeC for 2 hours, it heated up to 80 degreeC, and was made to react for 2 hours. Then, the reaction liquid was heated to 130 degreeC, and toluene, a chain transfer agent, and an unreacted monomer were dried and removed, and a solid acrylic oligomer was obtained. The weight average molecular weight of the acrylic oligomer was 5,100. The glass transition temperature (Tg) was 130°C.

With respect to 100 parts by mass of the solid content of the base polymer composition, 0.07 part by mass of 1,6-hexanediol diacrylate (HDDA), 1 part by mass of acrylic oligomer, and a silane coupling agent ("KBM403 manufactured by Shin-Etsu Chemical Co., Ltd.") were added. ”) 0.3 parts by mass, these were uniformly mixed to prepare an adhesive composition.

The adhesive composition was applied to the surface of the release sheet made of PET film ("DIAFOIL MRF75" made by Mitsubishi Chemical Co.), and then the release sheet made of another PET film ("DIAFOIL MRF75" made by Mitsubishi Chemical Co.) was attached. fit on the coating film. Then, ultraviolet rays were irradiated to the coating film to prepare an adhesive sheet A with a thickness of 50 µm.

[Adhesive Sheet B] 99 parts by mass of butyl acrylate (BA) and 1 part by mass of 4-hydroxybutyl acrylate (HBA) were fed into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a cooler. Thereby, a monomer mixture is prepared.

In addition, 0.1 part by mass of 2,2'-azobisisobutyronitrile was fed with ethyl acetate relative to 100 parts by mass of the monomer mixture, and nitrogen gas was introduced while stirring slowly for nitrogen substitution. The temperature was kept around 55°C and the polymerization was carried out for 7 hours. Then, ethyl acetate was added to the obtained reaction liquid, and the solution of the acrylic base polymer whose solid content concentration was adjusted to 30% and the weight average molecular weight of 1.6 million was prepared.

With respect to 100 parts by mass of the solid content of the solution of the acrylic base polymer, 0.1 part by mass of an isocyanate-based crosslinking agent (trade name: TAKENATE D110N, trimethylolpropane diisocyanate, manufactured by Mitsui Chemicals) was blended , 0.3 part by mass of benzyl peroxide (trade name: Nyper BMT, manufactured by NOF Corporation), and 0.08 part by mass of silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.), to prepare an acrylic adhesive composition.

The acrylic adhesive composition was uniformly coated on the surface of the release sheet composed of PET film by a spray coater, and dried in an air circulation constant temperature oven at 155°C for 2 minutes, thereby preparing an adhesive sheet with a thickness of 20µm B.

[Adhesive Sheet C] 99 parts by mass of butyl acrylate (BA) and 1 part by mass of 4-hydroxybutyl acrylate (HBA) were fed into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a cooler.

In addition, 0.1 part by mass of 2,2'-azobisisobutyronitrile was fed with ethyl acetate relative to 100 parts by mass of the monomer mixture, and nitrogen gas was introduced while stirring slowly for nitrogen substitution. The temperature was kept around 55°C and the polymerization was carried out for 7 hours. Then, the mixed solvent of ethyl acetate and toluene (95/5 in mass ratio) was added to the obtained reaction liquid, and the solution of the acrylic base polymer whose solid content concentration was adjusted to 30% was prepared.

With respect to 100 parts by mass of the solid content of the solution of the acrylic base polymer, 0.15 part by mass of trimethylolpropane/toluene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: CORONATE L) and 0.08 mass part of silane coupling agent (trade name: KBM403, the Shin-Etsu Chemical Co., Ltd. make), and the acrylic adhesive composition was prepared.

The surface of the release sheet composed of PET film was uniformly coated with a spray coater, and dried in an air circulation constant temperature oven at 155°C for 2 minutes to prepare an adhesive sheet C with a thickness of 15µm.

[Adhesive Sheet D] 99 parts by mass of butyl acrylate (BA) and 1 part by mass of 4-hydroxybutyl acrylate (HBA) were fed into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a cooler. Thereby, a monomer mixture is prepared.

In addition, 0.1 part by mass of 2,2'-azobisisobutyronitrile was fed with ethyl acetate relative to 100 parts by mass of the monomer mixture, and nitrogen gas was introduced while stirring slowly for nitrogen substitution. The temperature was kept around 55°C and the polymerization was carried out for 7 hours. Then, ethyl acetate was added to the obtained reaction liquid, and the solution of the acrylic base polymer whose solid content concentration was adjusted to 30% and the weight average molecular weight of 1.6 million was prepared.

With respect to 100 parts by mass of the solid content of the solution of the acrylic base polymer, 0.1 part by mass of an isocyanate-based crosslinking agent (trade name: TAKENATE D110N, trimethylolpropane diisocyanate, manufactured by Mitsui Chemicals) was blended , 0.3 part by mass of benzyl peroxide (trade name: Nyper BMT, manufactured by NOF Corporation), and 0.08 part by mass of silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.), to prepare an acrylic adhesive composition.

The acrylic adhesive composition was uniformly coated on the surface of the release sheet composed of PET film by a spray coater, and dried in an air circulation constant temperature oven at 155°C for 2 minutes, thereby preparing an adhesive sheet with a thickness of 5µm D.

[Shear storage elastic modulus G' of adhesive sheet] The shear storage elastic modulus G' at 25°C of each of the adhesive sheets A to C was measured.

Specifically, the peeling sheet is peeled off, its outer shape is processed into a disk shape, and it is sandwiched by parallel plates, and is obtained by measuring the dynamic viscoelasticity under the following conditions using the "Advanced Rheometric Expansion System (ARES)" manufactured by Rheometric Scientific Co., Ltd. The shear storage elastic modulus G' of the adhesive sheet is obtained.

[Measurement conditions] Mode: Twist Temperature: -40℃ to 150℃ Heating rate: 5°C/min Frequency: 1Hz

[Substrate preparation] Substrates A to D were prepared as described below.

[Substrate A] As the base material A, a base material composed of COP (trade name "ZEONOR", manufactured by ZEON Corporation of Japan) was prepared.

[Substrate B] As the base material B, a base material made of PET (trade name "Lumirror S10", manufactured by Toray Corporation) was prepared.

[Substrate C] As the substrate C, a substrate (trade name "OKY100", manufactured by Bell Polyester Products, Inc.) composed of a transparent flexible polyester resin was prepared.

[Substrate D] As the base material D, a base material (product name "C_50", manufactured by KOLON Corporation) made of transparent polyimide was prepared.

[Tensile elastic modulus E of substrate] The tensile elastic modulus E at 25° C. of each of the substrates A to D was measured.

Substrate A to Substrate D were processed to have a rectangular shape with a width of 10 mm and a length of 100 mm, respectively. The substrate was set on a tensile tester (product name "Autograph AG-IS" manufactured by Shimadzu Corporation), and the strain and stress when stretched at 200 mm/min were measured, and the strain and stress were measured when the strain was in the range of 0.05% to 0.25%. The slope of the curve calculates the tensile modulus of elasticity E of the substrate. The tensile modulus E of each of the substrates A to D at 25° C. is 3GPa, 3.5GPa, 0.13GPa, and 7GPa, respectively.

[Manufacture of a dummy sample corresponding to the organic EL display device 1 of the first embodiment] Example 1 The first adhesive layer 8 composed of the adhesive sheet A and the second adhesive layer 10 composed of the adhesive sheet C are respectively disposed on the front and back surfaces of the substrate 9 composed of the substrate A, respectively. Thereby, the shock absorbing member 3 including the first adhesive layer 8 , the base material 9 , and the second adhesive layer 10 in this order in the thickness direction is produced. That is, the shock absorbing member 3 composed of three layers was produced.

As shown in FIG. 1 , the window member 2 , the shock absorbing member 3 , the organic EL panel member 4 , and the protective member 5 were then laminated to produce a mock sample of the organic EL display device 1 . In addition, an ITO layer 35 is arranged on the surface of the organic EL panel member 4 instead of the thin film sealing layer 11 . The thickness of the ITO layer 35 is 40 nm.

The window member 2 includes: a hard coat layer 6 having a thickness of 10 µm and consisting of a cured product of the curable composition of Example 1 of Japanese Patent Laid-Open No. 2020-064236; and a window film 7 having a thickness of 80 µm and consisting of "CPI" (made by KOLON Corporation).

A polyimide sheet (trade name "UPILEX", manufactured by Ube Industries, Ltd.) having a thickness of 25 µm was prepared as the panel body 12 of the substitute panel member 44 .

The protective member 5 is made of the same material as the adhesive sheet A, and the front side adhesive layer 13 with a thickness of 15 µm and a polyimide sheet with a thickness of 50 µm (trade name "UPILEX", Ube Kosan Co., Ltd. The protective substrate 14 constituted by the system).

Example 2 to Example 10, Example 27 to Example 29, Comparative Example 1 to Comparative Example 5, Comparative Example 10 and Comparative Example 11 In the same manner as in Example 1, a prototype 40 (simulation sample) of the organic EL display device 1 was produced. However, the first adhesive layer 8 , the base material 9 and/or the second adhesive layer 10 were changed as described in Tables 1 to 3 and Table 11.

[Manufacture of the organic EL display device 1 corresponding to the second embodiment] Example 11 to Example 23 Processing was carried out in the same manner as in Example 1, and a prototype 40 (simulation sample) of the organic EL display device 1 was produced. However, as shown in FIG. 9, the shock absorbing member 3 composed of five layers was used. In addition, each layer was changed as described in Table 4 to Table 8. Specifically, the shock absorbing member 3 includes the first adhesive layer 8 , the first base material 25 , the intermediate adhesive layer 19 , the second base material 26 , and the second adhesive layer 10 in this order.

[Manufacture of an organic EL display device 1 corresponding to a modification of the second embodiment] Example 24 to Example 26 Processing was carried out in the same manner as in Example 1, and a prototype 40 (simulation sample) of the organic EL display device 1 was produced. However, as shown in FIG. 10, the shock absorbing member 3 composed of seven layers was used. In addition, each layer was changed as described in Table 9. Specifically, the shock absorbing member 3 includes the first adhesive layer 8 , the first base material 25 , the first intermediate adhesive layer 27 , the third base material 29 , the second intermediate adhesive layer 28 , the second base material 26 , and the second base material 27 in this order. Adhesive layer 10 .

[Manufacture of the organic EL display device 1 in which the shock absorbing member 3 consists only of the adhesive layer 30 ] Comparative Example 6 to Comparative Example 9 Processing was carried out in the same manner as in Example 1, and a prototype 40 (simulation sample) of the organic EL display device 1 was produced. However, although not shown, the shock absorbing member 3 composed of one layer is used. The shock absorbing member 3 is composed of only the adhesive layer 30 . The adhesive layer 30 was changed as described in Table 10.

[Evaluate] Evaluate the following items. These results are described in Tables 1 to 11.

[Ball impact absorption rate per unit thickness of impact absorbing member 3] The shock absorbing member 3 of each Example and each Comparative Example was prepared. Next, as shown in FIG. 2B , only the window member 2 is placed on the surface of the sensor (product name: 480C02) 92 provided on the surface of the stainless steel plate 91 by PCB Company. At this time, the window film 7 is brought into contact with the surface of the sensor 92 . A stainless steel ball with a weight of 10 g and a diameter of 13 mm was vertically dropped onto the surface of the hard coat layer 6 of the window member 2 from a height of 20 cm. The peak value SA1 of the impact load of the window member 2 alone was measured with a recorder (product name: MR8870) manufactured by HIOKI Co., Ltd. connected to the sensor 92 .

Next, as shown in FIG. 2A , instead of the window member 2 , a laminate of the window member 2 and the shock absorbing member 3 is placed on the surface of the sensor 92 . The rear surface of the shock absorbing member 3 is brought into contact with the surface of the sensor 92 . The above-mentioned ball was vertically dropped from a height of 20 cm to the surface of the hard coat layer 6 of the window member 2 . The peak value SB1 of the impact load of the laminated body of the window member 2 and the impact absorbing member 3 was measured with the above-mentioned recorder.

The spherical shock absorption rate of the shock absorbing member 3 was calculated using the following formula.

Ball impact absorption rate (%)={(SA1-SB1)/SA1}×100 Next, the ball impact absorption rate per unit thickness of the shock absorption member 3 was calculated by dividing the ball impact absorption rate by the thickness of the impact absorption member 3 .

[Pen shock absorption rate of the shock absorbing member 3, Pen shock absorption rate per unit thickness of the shock absorbing member 3] The shock absorbing member 3 of each Example and each Comparative Example was prepared. Next, as shown in FIG. 3B , only the window member 2 is placed on the surface of the sensor (product name: 480C02) 92 provided on the surface of the stainless steel plate 91 by the PCB company. At this time, the window film 7 is brought into contact with the surface of the sensor 92 . A ballpoint pen with a weight of 7g and a ball diameter of 0.7mm (oil-based ballpoint pen "BK407 Black" manufactured by Pentel Co., Ltd.) was vertically dropped onto the surface of the hard coat layer 6 of the window member 2 from a height of 20cm. The peak value SA2 of the impact load of the window member 2 alone was measured with a recorder (product name: MR8870) manufactured by HIOKI Co., Ltd. connected to the sensor 92 .

Next, as shown in FIG. 3A , instead of the window member 2 , a laminate of the window member 2 and the shock absorbing member 3 is placed on the surface of the sensor 92 . The rear surface of the shock absorbing member 3 is brought into contact with the surface of the sensor 92 . The above-mentioned pen was vertically dropped to the surface of the hard coat layer 6 of the window member 2 from a height of 20 cm. The peak value SB2 of the impact load of the laminated body of the window member 2 and the impact absorbing member 3 was measured with the above-mentioned recorder.

The pen shock absorption rate of the shock absorbing member 3 was calculated using the following formula.

Pen shock absorption rate (%)={(SA2-SB2)/SA2}×100 Next, the pen shock absorption rate was divided by the thickness of the shock absorbing member 3 to calculate the pen shock absorption rate per unit thickness of the shock absorbing member 3 .

[Bending test of organic EL display device 1] (1) Bending test with a distance of 8 mm between the surfaces 21 The external shape of the organic EL display device 1 (dummy sample) was processed to produce a third sample 63 . As shown in FIGS. 4A to 4B , a flexure test of 200,000 repeated flexures and spreads was performed. Specifically, a durability tester (model "DMLHB-FS-C", manufactured by Yuasa Corporation) was used. Regarding the window member 2, the interval between the two outer surfaces 21 was set to 8 mm. The ratio of the resistance value of the ITO layer 35 after the flexure test to the resistance value of the ITO layer 35 before the flexure test was measured using a testing machine. The change in the resistance value of the ITO layer 35 was used to evaluate whether the thin film sealing layer 11 was damaged or not.

○: The ratio of the resistance value of the ITO layer 35 after the test to the resistance value of the ITO layer 35 after the test was less than 1.1 times before the test. ×: The ratio of the resistance value of the ITO layer 35 after the test to the resistance value of the ITO layer 35 after the test is 1.1 times or more before the test.

(2) Bending test with a distance of 6 mm between the surfaces 21 With respect to the organic EL display device 1 evaluated by "◯" in the above (1), the same bending test as above was carried out so that the interval was 6 mm.

[Total light transmittance of the shock absorbing member 3] A laminate of the shock absorbing member 3 and the window member 2 was prepared. The total light transmittance of the laminate was measured using a haze meter manufactured by Suga Test Instruments Co., Ltd. The measurement was in accordance with JIS K7105.

The total light transmittance of the shock absorbing member 3 was obtained from the above results. If the total light transmittance of the above-mentioned laminated body is 60% or more, it can also be said that the total light transmittance of the shock absorbing member 3 is 60% or more.

For ease of comparison, the various examples are recorded in a plurality of tables. Example 1 is repeatedly described in Tables 1 and 2. Example 7 is repeated in Table 2 and Table 11. Example 12 is repeatedly described in Tables 4 and 6. Example 13 is repeated in Table 4 and Table 7. Example 15 is repeatedly described in Tables 5 and 6. Example 16 is repeatedly described in Tables 5 and 7.

12 shows the shear storage elastic modulus G' of the first adhesive layer 8 and the shear storage elastic modulus G' of the second adhesive layer 10 of Examples 1 to 6.

[Verification of Examples and Comparative Examples] It can be seen from Table 3, Table 10 and Table 11 that the ball impact absorption rate per unit thickness of Comparative Examples 1 to 5, Comparative Example 7, Comparative Example 10 and Comparative Example 11 is all less than 0.27%/µm. The ball impact absorption rate per unit thickness of Comparative Examples 1 to 5, Comparative Example 7, Comparative Example 10, and Comparative Example 11 was insufficient.

It can be seen from Table 10 that the pen impact absorption rate per unit thickness of Comparative Examples 6 to 9 is all less than 0.10%/µm. In Comparative Examples 6 to 9, the pen shock absorption rate per unit thickness of the pen was insufficient.

In Comparative Example 7, peeling occurred during bending. The bending resistance of Comparative Example 7 was insufficient.

In contrast, it can be seen from Table 1, Table 2, Table 4 to Table 9 and Table 11 that the ball impact absorption rate per unit thickness of Examples 1 to 29 is all 0.27%/µm or more, and the pen per unit thickness The shock absorption rate is above 0.10%/µm. Therefore, the organic EL display device 1 is excellent in durability against impact to the ball 90 and impact to the pen 95 . Therefore, Examples 1 to 29 are excellent in durability against various impacts.

[Verification of each embodiment] As can be seen from Table 1, in Examples 1 to 6, although the base material 9 is the same, the shear storage elastic modulus G' of the first adhesive layer 8 and/or the second adhesive layer 10 varies.

Specifically, the shear storage elastic modulus G' of the first adhesive layer 8 in each of Example 1, Example 2, and Example 3 was 0.03 MPa, 0.08 MPa, and 0.12 MPa.

In Examples 1 to 3, the shear storage elastic modulus G' of the second adhesive layer 10 at 25°C is higher than that of the first adhesive layer 8 at 25°C in Examples 1 and 2 Example of elastic modulus G'. It turned out that, compared with Example 3, Example 1 and Example 2 are more excellent in the impact resistance per unit thickness of a ball and a pen.

Among Examples 1 to 6, Example 1, Example 4 and Example 5 are examples in which the shear storage elastic modulus G' of the first adhesive layer 8 at 25°C is 0.05 MPa or less. It can be seen that Example 1, Example 4, and Example 5 are more excellent in impact resistance per unit thickness of the ball than in Example 2, Example 3, and Example 6.

In addition, among Examples 1 to 6, Examples 1 to 3 are examples in which the shear storage elastic modulus G' of the second adhesive layer 10 at 25° C. is 0.10 MPa or more. It can be seen that the bending resistance of Examples 1 to 3 is more excellent than that of Examples 4 to 6.

In addition, among Examples 1 to 6, in Example 1, the shear storage elasticity of the first adhesive layer 8 at 25° C. was subtracted from the shear storage elastic modulus G′ of the second adhesive layer 10 at 25° C. Examples in which the value of the modulus G' is 0.06 MPa or more. It can be seen that, compared with Examples 2 to 6, Example 1 can more reliably achieve both high impact resistance per unit thickness to the ball and high impact resistance per unit thickness to the pen.

As can be seen from Table 2, among Examples 1 and 7 to 9, Examples 1 and 8 are examples in which the ratio of the thickness of the base material 9 to the thickness of the shock absorbing member 3 is 0.20 or more and 0.35 or less. . It can be seen that Examples 1 and 8 are more excellent in impact absorption per unit thickness of the ball than in Example 7 in which the ratio is greater than 0.35. It can be seen that Examples 1 and 8 are more excellent in impact resistance per unit thickness of the pen than in Example 9 in which the ratio is less than 0.20. These tendencies are also the same in Example 12, Example 13, and Example 15 to Example 26 in which the substrates 9 are plural.

That is, as can be seen from Table 6, the ball impact absorption rate per unit thickness of Example 12, Example 15 and Example 18 in which the thickness of the substrate 9 has the above ratio is higher than that in Example 17 in which the ratio is greater than 0.35. high.

As can be seen from Table 7, compared to Example 19 with a ratio greater than 0.35, Examples 13, 16 and 20 with the thickness of the substrate 9 having the above ratio have higher ball impact absorption per unit thickness.

As can be seen from Table 8, compared to Example 23 with a ratio greater than 0.35, Example 21 and Example 22 with the thickness of the substrate 9 having the above ratio have higher ball impact absorption per unit thickness.

As can be seen from Table 9, compared to Example 26 with a ratio greater than 0.35, Example 24 and Example 25 with the thickness of the substrate 9 having the above ratio have higher ball impact absorption rate per unit thickness.

In addition, as can be seen from Table 2, Example 1 and Example 10 differ only in the material of the base material 9 . It can be seen that the ball impact absorption rate per unit thickness of Example 1 in which the material of the substrate 9 is COP is higher than that of Example 10 in which the material of the substrate 9 is PET.

As can be seen from Table 11, Example 7, Example 29 and Comparative Example 11 differ only in the material of the base material 9. It can be seen that compared with Comparative Example 11 in which the material of the substrate 9 is polyimide resin, the material of Example 7 in which the material of the substrate 9 is COP and the material of Example 29 in which the material of the substrate 9 is polyester resin has a The ball impact absorption rate is higher.

In addition, it can be seen from Table 4 that among Examples 11 to 13, the shear storage elastic modulus G' of the intermediate adhesive layer 19 in Example 11 at 25°C is higher than that of the first adhesive layer 8 at 25°C. An embodiment in which the shear storage elastic modulus G' is lower than the shear storage elastic modulus G' of the second adhesive layer 10 at 25°C. Compared with Example 12 and Example 13, Example 11 can achieve both high impact resistance and high bending resistance per unit thickness of the ball.

In addition, it can be seen from Table 5 that among Examples 14 to 16, the shear storage elastic modulus G' of the intermediate adhesive layer 19 in Example 14 at 25°C is higher than that of the first adhesive layer 8 at 25°C. An embodiment in which the shear storage elastic modulus G' is lower than the shear storage elastic modulus G' of the second adhesive layer 10 at 25°C. Compared with Example 15 and Example 16, Example 14 can achieve both high impact resistance and high bending resistance per unit thickness of the ball.

It can be seen from Table 4 that among Examples 11 to 13, Examples 11 and 13 are examples in which the shear storage elastic modulus G' of the intermediate adhesive layer 19 at 25°C is greater than 0.05 MPa and less than 0.15 MPa . Compared with Example 12, Example 11 and Example 13 can better take into account the high impact resistance per unit thickness of the ball, the high impact resistance per unit thickness of the pen, and the high bending resistance.

In addition, it can be seen from Table 5 that among Examples 14 to 16, the shear storage elastic modulus G' of the intermediate adhesive layer 19 in Examples 14 and 16 at 25°C is greater than 0.05 MPa and less than 0.15 MPa. Example. Compared with Example 15, Example 14 and Example 16 can better take into account the high impact resistance per unit thickness of the ball, the high impact resistance per unit thickness of the pen, and the high bending resistance.

In addition, as can be seen from Table 8, among Examples 21 and 22, Example 22 is an example in which the first base material 25 is thicker than the second base material 26 . Compared with Example 21, Example 22 can achieve both high impact resistance and high bending resistance per unit thickness of the ball.

As can be seen from Table 8, among Examples 21 and 22, Example 21 is an example in which the first substrate 25 is thinner than the second substrate 26 . It can be seen that compared with Example 22, Example 21 has a higher pen impact absorption rate per unit thickness.

As can be seen from Table 9, among Examples 24 and 25, Example 25 is an example in which the first substrate 25 is thinner than the second substrate 26 . Compared with Example 24, Example 25 can achieve both high impact resistance and high bending resistance per unit thickness of the ball.

As can be seen from Table 11, the tensile elastic modulus E of the base material 9 of Example 7, Example 29 and Comparative Example 11 was 3GPa, 0.13GPa, and 7GPa, respectively. The tensile elastic modulus E of the base material 9 of Comparative Example 11 was too high to 7 GPa. Therefore, compared with Comparative Example 11, Example 1 and Example 29 were more excellent in the ball impact absorption rate per unit thickness.

In addition, the materials of the base material 9 of Example 1, Example 29 and Comparative Example 11 are COP, polyester resin and polyimide resin, respectively. Ball impact per unit thickness of Example 1 in which the material of the substrate 9 is COP and Example 29 in which the material of the substrate 9 is polyester resin compared to Comparative Example 11 in which the material of the substrate 9 is polyimide resin The absorption rate is more excellent.

[Table 1]

[Table 2]

[table 3]

[Table 4]

[table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

[Table 10]

[Table 11]

In addition, although the above-mentioned invention provides the embodiment as an example of this invention, it is only an illustration, and should not be construed as a limitation. It will be apparent to those skilled in the art that modifications of the present invention are included in the scope of the patent application described later.

industrial availability The image display member is used as, for example, an organic electroluminescence display device.

1: Organic EL display device 2: Window widget 3: Shock Absorber 4: Organic EL panel components 5: Protective components 6: Hard coating 7: Window film 8: The first adhesive layer 9: Substrate 10: 2nd adhesive layer 11: Film sealing layer 12: Panel body 13: Adhesive layer on the surface side 14: Protect the substrate 15: Back Adhesive Layer 16: sheet metal 17: Part 1 18: Part 2 19: Middle adhesive layer 21: Surface 22: Back 23: Sides 23A: Side 1 23B: Side 2 24: Middle part 25: 1st substrate 26: 2nd substrate 27: The first intermediate adhesive layer 28: The second intermediate adhesive layer 29: 3rd substrate 35: ITO layer 40: Trial works 44: Substitute panel components 50: polarizing film 51: Adhesive layer 61: 1st sample 62: 2nd sample 63: 3rd sample 90: Ball 91: stainless steel plate 92: Sensor 95: Pen 96: Ball (the tip of the pen) S1: Step 1 S2: Step 2 S3: Step 3 S4: Step 4 S5: Step 5 S6: Step 6 S7: Step 7

FIG. 1 is a cross-sectional view of an organic EL display device according to a first embodiment of the image display member of the present invention. In Fig. 2, Fig. 2A and Fig. 2B illustrate the falling ball test; Fig. 2A calculates the impact of the laminated body of the window member and the impact absorbing member; Fig. 2B calculates the impact load of the window member alone. In Fig. 3, Figs. 3A and 3B illustrate the pen drop test; Fig. 3A calculates the impact load of the laminated body of the window member and the impact absorbing member; Fig. 3B calculates the impact load of the window member alone. In FIG. 4 , FIGS. 4A and 4B illustrate the bending of the organic EL display device; FIG. 4A is the organic EL display device before bending; and FIG. 4B is the organic EL display device after bending. FIG. 5 is a process diagram of a method of manufacturing an organic EL display device. FIG. 6 is a step diagram of the second step. Figure 7 shows the drop ball test on the first sample. Figure 8 shows the pen-drop test on the second sample. FIG. 9 shows an organic EL display device according to the second embodiment. FIG. 10 shows an organic EL display device according to a modification of the second embodiment. FIG. 11 shows an organic EL display device of a modification example. FIG. 12 is a graph showing the shear storage elastic modulus G′ of the first adhesive layer and the second adhesive layer of Examples 1 to 6. FIG.

1: Organic EL display device

2: Window widget

3: Shock Absorber

4: Organic EL panel components

5: Protective components

6: Hard coating

7: Window film

8: The first adhesive layer

9: Substrate

10: 2nd adhesive layer

11: Film sealing layer

12: Panel body

13: Adhesive layer on the surface side

14: Protect the substrate

15: Back Adhesive Layer

16: sheet metal

21: Surface

22: Back

23: Sides

24: Middle part

35: ITO layer

40: Trial works

44: Substitute panel components

61: 1st sample

62: 2nd sample

Claims (20)

An image display device, which is provided with a window member, an impact absorbing member, a panel member and a protection member in this order from one side in the thickness direction; The aforementioned impact absorbing member has a total light transmittance of more than 60%; The ball impact absorption rate per unit thickness of the aforementioned shock absorbing member is 0.27%/µm or more, and the ball shock absorption rate per unit thickness of the shock absorbing member is a stainless steel ball with a weight of 10g and a diameter of 13mm dropped from a height of 20cm. The aforementioned impact absorbing member is used to calculate the aforementioned ball impact absorption rate of the aforementioned impact absorbing member, and then the ball impact absorption rate is divided by the thickness of the aforementioned impact absorbing member to obtain; The pen shock absorption rate per unit thickness of the shock absorbing member is 0.10%/µm or more, and the pen shock absorption rate per unit thickness of the shock absorbing member is such that a ball pen with a weight of 7 g and a ball diameter of 0.7 mm at the front end is The pen shock absorption rate of the shock absorption member was calculated by dropping the shock absorption member from a height of 20 cm, and then the pen shock absorption rate was divided by the thickness of the shock absorption member. The image display device according to claim 1, wherein in the test of bending the image display device in such a way that the window member faces the outside, even if the distance between the two outer surfaces of the window member is 8 mm The method was bent 200,000 times, and the aforementioned panel members were not damaged. The image display device according to claim 1 or claim 2, wherein the shock absorbing member includes a first adhesive layer, a base material, and a second adhesive layer in this order toward one side in the thickness direction. The image display device of claim 3, wherein the first adhesive layer contacts the window member, and The second adhesive layer is in contact with the panel member. The image display device according to claim 3, wherein the shear storage elastic modulus G' of the second adhesive layer at 25°C is the same as or higher than the shear storage elastic modulus G' of the first adhesive layer at 25°C high. The image display device according to claim 3, wherein the shear storage elastic modulus G' of the first adhesive layer at 25°C is 0.01 MPa or more and 0.05 MPa or less. The image display device according to claim 3, wherein the shear storage elastic modulus G' of the second adhesive layer at 25°C is 0.10 MPa or more and 0.15 MPa or less. The image display device according to claim 3, wherein the value of the shear storage elastic modulus G' of the second adhesive layer at 25°C minus the shear storage elastic modulus G' of the first adhesive layer at 25°C 0.06MPa or more. The image display device of claim 3, wherein the aforementioned substrate is singular. The image display device of claim 3, wherein the substrates are plural, and The image display device further includes an intermediate adhesive layer, and the intermediate adhesive layer is disposed between a plurality of the aforementioned substrates. The image display device of claim 10, wherein the shear storage elastic modulus G' of the intermediate adhesive layer at 25°C is greater than the shear storage elastic modulus G' of the first adhesive layer at 25°C and the first 2 The shear storage elastic modulus G' of the adhesive layer at 25°C is below. The image display device of claim 10, wherein the shear storage elastic modulus G' of the intermediate adhesive layer at 25°C is higher than the shear storage elastic modulus G' of the first adhesive layer at 25°C, and lower The shear storage elastic modulus G' of the second adhesive layer at 25°C. The image display device of claim 10, wherein the shear storage elastic modulus G' of the intermediate adhesive layer at 25°C is greater than 0.05 MPa and less than 0.15 MPa. The image display device of claim 10, wherein the aforementioned substrate comprises: a first substrate in contact with the first adhesive layer; and a second substrate, which is in contact with the second adhesive layer; Moreover, the said 1st base material is thinner than the said 2nd base material. The image display device of claim 10, wherein the aforementioned substrate comprises: a first substrate in contact with the first adhesive layer; and a second substrate, which is in contact with the second adhesive layer; Moreover, the said 1st base material is thicker than the said 2nd base material. The image display device according to claim 3, wherein the ratio of the thickness of the base material to the thickness of the shock absorbing member is 0.20 or more and 0.35 or less. The image display device according to claim 3, wherein the material of the substrate is olefin resin and/or polyester resin. The image display device according to claim 17, wherein the olefin resin is a cycloolefin resin. The image display device of claim 17, wherein the polyester resin is polyethylene terephthalate. A method of manufacturing an image display device, the image display device is provided with a window member, a first adhesive layer, a base material, a second adhesive layer, a panel member and a protection member in this order from one side in the thickness direction; The manufacturing method has the following steps: The first step is a trial work; The second step is to evaluate the aforementioned trial works; The third step is to determine the manufacturing conditions based on the aforementioned evaluation; and The fourth step is to manufacture the product according to the aforementioned manufacturing conditions; The aforementioned second step has the following steps: The fifth step is to make the first sample and the second sample from the aforementioned test work; The sixth step is to drop the ball to the first sample, and drop the ballpoint pen to the second sample; and The seventh step is to judge whether the first sample and the second sample are damaged after the sixth step; In the third step, when the first sample is evaluated for damage, the manufacturing conditions are changed to make the total thickness of the first adhesive layer and the second adhesive layer thicker; when the sample is evaluated as When the second sample was damaged, the thickness of the base material was changed to be thicker.

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