JP2019031610A - Silicone-based pressure sensitive adhesive sheet, or silicone-based adhesive layer - Google Patents

Abstract

To provide a silicone-based pressure sensitive adhesive sheet or a silicone-based adhesive layer having sufficient bending resistance under a low temperature environment, namely, having sufficient bending resistance, especially in a range from a low temperature to a high temperature, more specifically, from -20°C to 20°C.SOLUTION: A silicone-based pressure sensitive adhesive sheet or a silicone-based adhesive layer has at least one kind of requirements of (A)-(E) including requirements of the following (A)-(C): (A) a storage elastic modulus at -20°C is 1.0×10Pa or lower; (B) a storage elastic modulus at 20°C is 1.0×10Pa or lower; and (C) a yield point strain in stress-strain measurement at 20°C exceeds 150%.SELECTED DRAWING: None

Description

  The present invention relates to a silicone-based adhesive sheet and / or a silicone-based adhesive layer. In particular, the present invention relates to a silicone-based pressure-sensitive adhesive sheet and / or a silicone-based pressure-sensitive adhesive layer used for a display panel of a product such as a smartphone, a tablet-type terminal, or a laptop computer, and more particularly a foldable display panel.

  Research and development of foldable displays is progressing. For example, Patent Document 1 discloses a flexible electronic device that uses a flexible display layer, a flexible touch-sensitive layer, a flexible display cover layer, and the like, and discloses an electronic device that is resistant to damage due to an impact accident such as dropping. ing.

On the other hand, conventionally, a display uses a pressure-sensitive adhesive layer for adhering a polarizing plate or a retardation plate used in a liquid crystal display to a base material or another optical member, and an adhesive film for adhering a liquid crystal panel and a polarizing plate. Yes.
For example, Patent Document 2 discloses a pressure-sensitive adhesive layer that adheres a polarizing plate or a retardation plate used in a liquid crystal display to a base material or another optical member.
Patent Document 3 discloses an adhesive composition and an adhesive sheet for laminating an optical component such as a display and a surface protective sheet via an adhesive.

JP-T-2015-501461. JP-A-9-243824. Unexamined-Japanese-Patent No. 2015-131945.

  However, when a conventional adhesive film is used for a foldable display, there is a problem that the bending resistance is not sufficient, in particular, the bending resistance in a low temperature environment is not sufficient. Yes. Specifically, there is a problem that adhesion to a liquid crystal panel and / or a polarizing plate, which is an object to be adhered, becomes poor, and when bent, peeling or cracking is observed at the bent portion.

Accordingly, an object of the present invention is to solve the above-described problems of the prior art.
Specifically, the object of the present invention is to provide a silicone pressure-sensitive adhesive sheet having sufficient bending resistance in a low temperature environment, particularly sufficient bending resistance at low to high temperatures, specifically -20 ° C to 20 ° C. Alternatively, a silicone adhesive layer is provided.
Moreover, the objective of this invention is providing the product provided with this silicone type adhesive sheet and / or silicone type adhesive layer, specifically a display, and more specifically a flexible display.

The inventors have found the following invention.
<1> A) Storage elastic modulus at −20 ° C. is 1.0 × 10 ⁷ Pa or less, preferably 5.0 × 10 ^{6 to} 1.0 × 10 ⁴ Pa, more preferably 1.0 × 10 ^{6 to} 5 A silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer having a viscosity of 0.0 × 10 ⁴ Pa.
<2> In the above item <1>, B) a storage elastic modulus at 20 ° C. of 1.0 × 10 ⁶ Pa or less, preferably 1.0 × 10 ^{6 to} 1.0 × 10 ³ Pa, more preferably 5.0. It is good that it is * 10 < ⁵ > -1.0 * 10 < ⁴ > Pa.
<3> In the above <1> or <2>, C) the yield point strain in the stress-strain measurement at 20 ° C. exceeds 150%, preferably 180% or more, more preferably 230% or more. .

  <4> In any one of the above items <1> to <3>, D) a test conforming to IEC62715-6-1 Ed1.0, which is a test piece having the silicone-based adhesive sheet or the silicone-based adhesive layer. The test specimen consisting of three layers of PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm and having a length of 100 mm and a width of 50 mm is defined at both ends defining the length from the initial state where the length is 100 mm. In the test for changing to a bent state in which the test piece is bent by its own weight so that the distance is 5 mm, the test repeats at a temperature of −20 ° C. exceeds 100,000 times, preferably 200,000 times or more, more preferably 60 It should be 10,000 times or more.

  <5> In any one of the above items <1> to <4>, E) In the same test as the above D), the repetition of the test at a temperature of 20 ° C. exceeds 200,000 times, preferably 400,000 times or more, more preferably Is more than 600,000 times, more preferably 800,000 times or more, and most preferably 1,000,000 times or more.

<6> B) Storage elastic modulus at 20 ° C. is 1.0 × 10 ⁶ Pa or less, preferably 1.0 × 10 ^{6 to} 1.0 × 10 ³ Pa, more preferably 5.0 × 10 ⁵ to 1. A silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer that is 0 × 10 ⁴ Pa.
<7> In the above item <6>, C) The yield point strain in the stress-strain measurement at 20 ° C. exceeds 150%, preferably 180% or more, more preferably 230% or more.

  <8> In the above <6> or <7>, D) In the same test as in D) above, the repetition of the test at a temperature of −20 ° C. exceeds 100,000 times, preferably 200,000 times or more, more preferably 60 It should be 10,000 times or more.

  <9> In any one of the above items <6> to <8>, E) In the same test as in the above D), the repetition of the test at a temperature of 20 ° C. exceeds 200,000 times, preferably 400,000 times or more, more preferably Is more than 600,000 times, more preferably 800,000 times or more, and most preferably 1,000,000 times or more.

<10> C) A silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer whose yield point strain in stress-strain measurement at 20 ° C. exceeds 150%.
<11> In the above <10>, D) In the same test as in D), the repetition of the test at a temperature of −20 ° C. exceeds 100,000 times, preferably 200,000 times or more, more preferably 600,000 times or more. There should be.

  <12> In any one of the above <10> or <11>, E) In the same test as in D), the repetition of the test at a temperature of 20 ° C. exceeds 200,000 times, preferably 400,000 times or more, more preferably Is more than 600,000 times, more preferably 800,000 times or more, and most preferably 1,000,000 times or more.

  <13> D) A silicone-based pressure-sensitive adhesive sheet or silicone-based pressure-sensitive adhesive layer having a bending resistance in which the repetition of the test at a temperature of −20 ° C. exceeds 100,000 times in the same test as in the above D).

  <14> In <13> above, E) In the same test as in D) above, whether the repetition of the test at a temperature of 20 ° C. exceeds 200,000 times, preferably 400,000 times or more, more preferably 600,000 times More preferably, it should be 800,000 times or more, most preferably 1 million times or more.

  <15> E) In the same test as D) above, the repetition of the test at a temperature of 20 ° C. exceeds 200,000 times, preferably 400,000 times or more, more preferably 600,000 times, or more preferably 800,000 times. A silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer having a bending resistance of at least once, most preferably at least 1,000,000 times.

<16> A product comprising the silicone pressure-sensitive adhesive sheet and / or the silicone-based pressure-sensitive adhesive layer according to any one of the above items <1> to <15>.
<17> A display comprising the silicone-based pressure-sensitive adhesive sheet and / or the silicone-based pressure-sensitive adhesive layer according to any one of the above items <1> to <15>.
<18> A flexible display comprising the silicone pressure-sensitive adhesive sheet and / or the silicone-based pressure-sensitive adhesive layer according to any one of the above items <1> to <15>.

According to the present invention, the above-mentioned problems of the prior art can be solved.
Specifically, according to the present invention, a silicone-based pressure-sensitive adhesive sheet or silicone having sufficient bending resistance under a low temperature environment, particularly sufficient bending resistance at low to high temperatures, specifically −20 ° C. to 20 ° C. A system adhesive layer can be provided.
Further, according to the present invention, a product including the silicone-based pressure-sensitive adhesive sheet and / or the silicone-based pressure-sensitive adhesive layer, specifically a display, more specifically a flexible display can be provided.

It is a schematic diagram of the bending tolerance test in the requirements D) and E) of the present application. It is a graph which shows the stress-strain curve (20 degreeC) of Example 1, Example 3, and the comparative example 3, and the yield point distortion in this curve. It is the graph which made the yield point distortion of Example 1, Example 3, and Comparative Example 3 a horizontal axis, and made the bending test result (20 degreeC) the vertical axis | shaft.

Hereinafter, the invention described in the present application will be described in detail.
The present application provides a silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer having at least one of the above requirements A) to E).
Moreover, this application provides the product provided with this silicone type adhesive sheet and / or a silicone type adhesive layer, specifically a display, and more specifically a flexible display.
Hereinafter, the silicone type adhesive sheet or silicone type adhesive layer provided by the present application will be described.

The present application provides a silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer having at least one of the following requirements A) to E).
A) Storage elastic modulus at −20 ° C. is 1.0 × 10 ⁷ Pa or less, preferably 5.0 × 10 ^{6 to} 1.0 × 10 ⁴ Pa, more preferably 1.0 × 10 ^{6 to} 5.0 ×. 10 ⁴ Pa;
B) Storage elastic modulus at 20 ° C. is 1.0 × 10 ⁶ Pa or less, preferably 1.0 × 10 ^{6 to} 1.0 × 10 ³ Pa, more preferably 5.0 × 10 ^{5 to} 1.0 × 10. ⁴ Pa;
C) The yield point strain in the stress-strain measurement at 20 ° C. exceeds 150%. Preferably the yield point strain is 180% or more, more preferably 230% or more;
D) In the bending resistance test in accordance with IEC62715-6-1 Ed1.0 (details of the bending resistance test will be described later), the test is repeated 100,000 times, preferably 200,000 times at a temperature of −20 ° C. Preferably has a bending resistance of more than 600,000 times;
E) In the same bending resistance test as in the above D), the test conforms to IEC62715-6-1 Ed1.0, and the repetition of the test at a temperature of 20 ° C exceeds 200,000 times, preferably 400,000 times or more More preferably, it has a bending resistance exceeding 600,000 times, more preferably 800,000 times or more, and most preferably 1,000,000 times or more.
Here, the bending resistance test based on IEC62715-6-1 Ed1.0 is performed as follows. The test piece used in the test is a test piece having a silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer. Is 50 mm. The thickness of the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer depends on the thickness of the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer to be tested. The obtained test piece is changed from an initial state with a length of 100 mm to a bent state in which the test piece is bent by its own weight so that both ends defining the length are 5 mm apart. The initial state and the bent state are repeated, and the number of times that the break has occurred is measured.

The silicone-based pressure-sensitive adhesive sheet or silicone-based pressure-sensitive adhesive layer of the present invention has at least one of the above requirements A) to E).
Among the requirements A) to E), it is preferable to provide at least two types. For example, a combination of A) and B), a combination of A) and C), a combination of A) and D), a combination of A) and E), a combination of B) and C), and B) A combination of D), a combination of B) and E), a combination of C) and D), a combination of C) and E), and a combination of D) and E) Is good.

  Moreover, it is good to provide at least 3 types among the requirements of said A) -E). For example, a combination of A) and B) and C), a combination of A) and B) and D), a combination of A) and B) and E), a combination of A) and C) and D), A), C) and E), A), D) and E), B), C) and D), B), C) and E), B) And a combination of D) and E), or a combination of C), D) and E).

Furthermore, it is good to provide 4 types among the requirements of said A) -E). For example, a combination of A), B), C) and D), a combination of A), B), C) and E), a combination of A), B), D) and E), A) and Any combination of C), D) and E), and B), C), D) and E) may be provided.
Moreover, it is good to provide all the requirements of said A) -E).

In the present application, the “adhesion” of the silicone-based adhesive sheet or the silicone-based adhesive layer means that the adhesiveness measured at 23 ° C. by an adhesive test of JIS Z-0237 is 5 N / (25 mm) or more. The tackiness value is preferably 8 to 30 N / (25 mm), more preferably 8 to 25 N / (25 mm).
In addition, as above-mentioned, adhesiveness can be measured at 23 degreeC by the adhesiveness test of JISZ-0237, and is not limited to the apparatus used for a measurement.

  Further, in the present application, the “sheet” or “layer” of the silicone-based pressure-sensitive adhesive sheet or silicone-based pressure-sensitive adhesive layer is intended to be in the form of a “sheet” regardless of whether or not it is self-supporting. To do. In addition, when it is formed on a substrate or the like, it is generally referred to as a “layer”. In this application, “sheet” or “layer” is defined in parallel with the intention of including this “layer”. is there.

  Further, in the present application, the “silicone-based” of the silicone-based pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer uses silicone as an essential component and may contain other components.

Hereinafter, the requirements A) to E) will be described in detail.
<Requirement A)> and <Requirement B)>
Both the requirements of A) and B) specify the storage modulus.
The requirement of A) prescribes | regulates the storage elastic modulus in -20 degreeC, the value is 1.0 * 10 < ⁷ > Pa or less, Preferably it is 5.0 * 10 < ⁶ > -1.0 * 10 < ⁴ > Pa, More preferably, it is 1 It is defined that it is 0 × 10 ^{6 to} 5.0 × 10 ⁴ Pa.
The requirements B), defines the storage modulus at 20 ° C., the value is 1.0 × ¹⁰ 6 Pa or less, preferably ^{1.0 × 10 6 ~1.0 × 10 3} Pa, more preferably 5. It is defined that it is 0 × 10 ^{5 to} 1.0 × 10 ⁴ Pa.
The storage elastic modulus can be measured by a conventionally known technique, and is not particularly limited to the technique used and the apparatus used. For example, the storage elastic modulus can be measured by a shearing method, for example, a method based on JIS K 7244, and can be measured by a commercially available rheometer.

<Requirement C)>
The requirement of C) defines the yield point strain in the stress-strain measurement at 20 ° C., the value of which exceeds 150%, preferably 180% or more, more preferably 230% or more. Stipulate that
Here, the stress-strain measurement can be performed by a shearing method, for example, a method based on JIS K 6850, and can be measured by a commercially available apparatus.

<Requirement D)> and <Requirement E)>
Both the requirements of D) and E) define the bending resistance, in particular the bending test according to IEC 62715-6-1 Ed1.0.
The bending resistance test defined by the requirements of D) and E) of the present application will be described in detail.
The bending resistance test defined by the requirements of D) and E) of the present application is a test based on IEC62715-6-1 Ed1.0.
The test piece used in the test is a test piece having a silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer. Is 50 mm. The thickness of the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer depends on the thickness of the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer to be tested.
The obtained test piece is repeatedly changed from the initial state in which the length is 100 mm to a bent state in which the test piece is bent by its own weight so that both ends defining the length have an interval of 5 mm. The test is repeated, and when a break such as a crack or a crack occurs in the test piece, the number of repetitions up to the previous time is measured as the number of times of resistance.

FIG. 1 is a schematic diagram of a bending resistance test in the above requirements D) and E). Hereinafter, the bending resistance test in the requirements D) and E) will be described with reference to FIG.
One end of the test piece in the length direction is fixed by the fixed end 1, and the multi-end in the length direction is fixed by the free end 2. When the free end 2 is set to the position in the state A, the state is close to the initial state (length 100 mm). State D is a bent state in which both ends defining the length of the test piece are spaced 5 mm apart. While moving the free end 2 in the X direction so that the initial state → the state A → the state B → the state C → the state D, the test piece is bent by its own weight. Thereafter, the free end 2 is moved in the Y direction from the state D, so that the state C → the state B → the state A → the initial state.
Initial state-> state A-> state B-> state C-> state D-> state C-> state B-> state A-> initial state is repeated once, and if the test piece breaks, such as cracks or cracks, the previous The number of repetitions up to is measured as the number of times of tolerance.

The environmental temperature of the test was −20 ° C. in requirement D) and 20 ° C. in requirement E).
In requirement D), the number of repetitions should be 100,000 times, preferably 200,000 times, more preferably 600,000 times at a temperature of −20 ° C., and whether or not bending resistance is determined is determined by whether or not to achieve this. To do.
In the requirement E), the temperature is 20 ° C. and the number of repetitions exceeds 200,000 times, preferably 400,000 times or more, more preferably more than 600,000 times, further preferably 800,000 times or more, most preferably 1,000,000 times. It is good that it is the above, and the presence or absence of bending tolerance is determined by whether it is achieved.

  As mentioned above, by providing at least one, preferably at least 2, more preferably at least 3, more preferably at least 4 and most preferably 5 of the above requirements A) to E) The object of the invention is to achieve a silicone pressure-sensitive adhesive sheet or silicone pressure-sensitive adhesive layer having sufficient bending resistance under a low temperature environment, particularly sufficient bending resistance from low temperature to high temperature, specifically -20 ° C to 20 ° C. can do.

As long as the silicone pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer of the present application satisfies the requirements A) to E) as described above, the thickness thereof is not limited. In addition, although the thickness of the silicone type adhesive sheet or silicone type adhesive layer of this application is dependent on the silicone type material to be used, it is 200-10 micrometers, Preferably it is 100-10 micrometers, More preferably, it is good that it is 50-10 micrometers.
The silicone pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer of the present application may have desired optical characteristics.
Examples of the optical characteristics include, but are not limited to, transmittance, haze, refractive index, and color difference.
For example, a sample obtained by sandwiching a silicone adhesive sheet or silicone adhesive layer of the present application having a desired thickness with a slide glass having a thickness of 0.3 mm is measured according to JIS-K-7130. By measuring the transmittance and color difference, the optical properties of haze: 1.0% or less, transmittance (wavelength: visible light region): 92% or more, color difference (b * value): 0.5 or less A suitable optical silicone-based pressure-sensitive adhesive sheet or silicone-based pressure-sensitive adhesive layer is preferable.

  As for the manufacturing method of the above-mentioned silicone type adhesive sheet or silicone type adhesive layer, although the one mode is described in the below-mentioned example, if the silicone type adhesive sheet or silicone type adhesive layer which meets the above-mentioned requirements can be manufactured, It is not limited to the manufacturing method described in the below-mentioned Example.

The present invention further provides a product comprising the above-mentioned silicone-based adhesive sheet or silicone-based adhesive layer.
The product is not particularly limited as long as it has desired tackiness and is required to have bending resistance.
Examples of the product include, but are not limited to, products such as smartphones, tablet terminals, and notebook computers, particularly displays of those products, more particularly flexible displays and foldable displays.

  Hereinafter, although the present invention is explained in full detail using the following examples, the present invention is not limited to the following examples.

Example 1
<Preparation of adhesive sheet X-1>
An adhesive sheet X-1 was prepared by the following procedure.
75 parts of addition-curable silicone adhesive (KR3700, Shin-Etsu Chemical Co., Ltd.), 25 parts of addition-curable silicone adhesive (X-40-3365, Shin-Etsu Chemical Co., Ltd.), and platinum catalyst (CAT, Shin-Etsu Chemical Co., Ltd.) -PL-50T) 0.47 part and 12.5 parts of toluene were added, and the coating agent A mixed uniformly was prepared.
The obtained coating agent A was applied to a base material (PET75-FSC6, manufactured by Nipper Corp., thickness: 75 μm) and dried with hot air at 150 ° C. for 4 minutes, and then the base material (PET75-FSC6, manufactured by Nipper Corp., thickness) The pressure-sensitive adhesive sheet X-1 was obtained between the substrates.
It was 50 micrometers when the thickness of obtained adhesive sheet X-1 was measured.

<Measurement of storage modulus and yield point strain of adhesive sheet X-1>
The storage elastic modulus and yield point strain of the pressure-sensitive adhesive sheet X-1 obtained above were measured.
Specifically, the pressure-sensitive adhesive sheet X-1 was peeled from the base material to prepare a test piece having a diameter of 8 mm and a thickness of 500 to 1000 μm.
The storage elastic modulus of the obtained test piece was measured by using a viscoelasticity measuring device (TA Instruments DHR-2) at a strain of 1%, a frequency of 1 Hz, and a shear for each temperature (20 ° C, -20 ° C). The elastic modulus was measured.
In addition, the stress-strain curve (20 ° C.) of the test piece was similarly measured using a viscoelasticity measuring device (DHR-2 manufactured by TA Instruments), and the strain value at which the shear stress yielded was determined. The yield point was measured by reading and yield point distortion was obtained.
The obtained results are shown in Table 1.

<Bending test>
The bending test specified in requirement D) and requirement E) was performed.
Specifically, a test piece having a length of 297 mm, a width of 210 mm, and a thickness of 50 μm was prepared for the adhesive sheet X-1.
Moreover, two PET base materials having a length of 297 mm, a width of 210 mm, and a thickness of 100 μm were prepared.
The test piece of the pressure-sensitive adhesive sheet X-1 was sandwiched between PET base materials having a thickness of 100 μm so that the PET base material was up and down.
What was cut so that it might become 100 mm in length x 50 mm in width was used as the test piece of a bending test.
A bending test was performed at −20 ° C. (requirement D) and 20 ° C. (requirement E), and the time (number of bendings) at which breakage occurred was observed. As for the bending test at −20 ° C. (requirement D), a result of enduring 100,000 times or more, that is, a result of 100,000 times or more was obtained.
The results of the bending test are shown in Table 1 together with the storage elastic modulus and yield point strain.

(Example 2)
Using the same coating agent A as in Example 1, the pressure-sensitive adhesive sheet X-2 (thickness 20 μm) was obtained in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive sheet was 20 μm.
About the obtained adhesive sheet X-2, the storage elastic modulus and the yield point distortion were measured similarly to Example 1, and the bending test was done.
The results are shown in Table 1.

(Comparative Example 1)
Using the same coating agent A as in Example 1, the pressure-sensitive adhesive sheet CX-1 (thickness: 100 μm) was obtained in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive sheet was 100 μm.
About the obtained adhesive sheet CX-1, the storage elastic modulus and yield point distortion were measured similarly to Example 1, and the bending test was done.
The results are shown in Table 1.

(Example 3)
Instead of the addition-curable silicone pressure-sensitive adhesive and platinum catalyst used in coating agent A of Example 1, 100 parts of addition-curable silicone pressure-sensitive adhesive (SD4580PSA manufactured by Toray Dow Corning) and platinum catalyst (Toray Dow Corning) A coating agent B was prepared using 0.54 part of SRX 212 P CATALYST).
Moreover, the adhesive sheet X-3 (thickness 50 micrometers) was obtained by the method similar to Example 1 except having used the coating agent B instead of the coating agent A in Example 1. FIG.
About the obtained adhesive sheet X-3, the storage elastic modulus and yield point distortion were measured similarly to Example 1, and the bending test was done.
The results are shown in Table 1.

(Comparative Example 2)
Using the same coating agent B as in Example 3, the pressure-sensitive adhesive sheet CX-2 (thickness: 100 μm) was obtained in the same manner as in Example 3 except that the thickness of the pressure-sensitive adhesive sheet was 100 μm.
About obtained adhesive sheet CX-2, the storage elastic modulus and the yield point distortion were measured similarly to Example 1, and the bending test was done.
The results are shown in Table 1.

(Comparative Example 3)
In coating agent A of Example 1, 100 parts of addition-curable silicone adhesive (KR3700 manufactured by Shin-Etsu Chemical Co., Ltd.) instead of addition-curable silicone-based adhesive, platinum catalyst and toluene, platinum catalyst (Shin-Etsu Chemical Co., Ltd.) Coating agent C was prepared using 0.20 part of CAT-PL-50T manufactured by KK and 46.1 parts of toluene.
Moreover, adhesive sheet CX-3 (thickness 50 μm) was obtained in the same manner as in Example 1 except that coating agent C was used instead of coating agent A in Example 1 and the thickness was 50 μm. .
About the obtained adhesive sheet CX-3, the storage elastic modulus and yield point distortion were measured similarly to Example 1, and the bending test was done.
The results are shown in Table 1.

(Comparative Example 4)
A storage elastic modulus and yield point strain were measured in the same manner as in Example 1 using an acrylic adhesive sheet instead of a silicone adhesive sheet, and a bending test was performed.
Specifically, an acrylic pressure-sensitive adhesive sheet CX-4 (thickness 50 μm) was obtained as follows. That is, 100 parts of an acrylic two-component curable pressure-sensitive adhesive (SK2981 manufactured by Soken Chemical Co., Ltd.), 0.06 part of a curing agent (Y-75 manufactured by Soken Chemical Co., Ltd.) and a uniformly mixed coating agent were prepared.
The obtained coating agent was applied to a substrate (US-20, manufactured by Toyama Film Co., Ltd., thickness: 50 μm) and dried with hot air at 100 ° C. for 4 minutes, and then the substrate (E7002, manufactured by Toyobo Co., Ltd., thickness: 50 [mu] m) and the adhesive surface were bonded together to obtain an adhesive sheet CX-4 between the substrates.
About obtained adhesive sheet CX-4, the storage elastic modulus and the yield point distortion were measured similarly to Example 1, and the bending test was done.
The results are shown in Table 1.

(Comparative Example 5)
A storage elastic modulus and yield point strain were measured in the same manner as in Example 1 using an acrylic adhesive sheet instead of a silicone adhesive sheet, and a bending test was performed.
Specifically, an acrylic pressure-sensitive adhesive sheet CX-5 (thickness 50 μm) was obtained as follows. That is, 100 parts of an acrylic two-component curable pressure-sensitive adhesive (SK1831 manufactured by Soken Chemical Co., Ltd.) and 0.15 part of a curing agent (E-AX manufactured by Soken Chemical Co., Ltd.) were uniformly mixed.
The obtained coating agent was applied to a substrate (US-20, manufactured by Toyama Film Co., Ltd., thickness: 50 μm) and dried with hot air at 100 ° C. for 4 minutes, and then the substrate (E7002, manufactured by Toyobo Co., Ltd., thickness: 50 [mu] m) and the adhesive surface were bonded together to obtain an adhesive sheet CX-5 between the substrates.
About obtained adhesive sheet CX-5, the storage elastic modulus and the yield point distortion were measured similarly to Example 1, and the bending test was done.
The results are shown in Table 1.

FIG. 2 is a graph showing stress-strain curves (20 ° C.) and yield point strains in Examples 1, 3 and Comparative Example 3 in which the thickness of the PSA sheet or PSA layer is the same. .
FIG. 3 is a graph in which the yield point strains of Example 1, Example 3, and Comparative Example 3 obtained in FIG. 2 are plotted on the horizontal axis and the bending test result (20 ° C.) is plotted on the vertical axis. is there.

2 and 3, particularly FIG. 3, it can be seen that the yield point strain and the bending resistance are correlated, and that the higher the yield point strain, the higher the bending resistance. In particular, when the yield point strain exceeds 150%, it can be seen that high bending resistance is exhibited.
From Table 1, it can be seen that the pressure-sensitive adhesive sheets or pressure-sensitive adhesive layers of Examples 1 to 3 have high bending resistance in the bending test. In particular, it can be seen that the pressure-sensitive adhesive sheets or pressure-sensitive adhesive layers of Examples 1 and 2 have high bending resistance in the bending test.

Claims (18)

A) A silicone pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer having a storage elastic modulus at −20 ° C. of 1.0 × 10 ⁷ Pa or less. B) The silicone type adhesive sheet or silicone type adhesive layer of Claim 1 whose storage elastic modulus in 20 degreeC is 1.0 * 10 < ⁶ > Pa or less.   C) The silicone-based pressure-sensitive adhesive sheet or silicone-based pressure-sensitive adhesive layer according to claim 1 or 2, wherein a yield point strain in stress-strain measurement at 20 ° C exceeds 150%.   D) It is a test based on IEC62715-6-1 Ed1.0, and is a test piece having the silicone-based pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer, and the configuration thereof is PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm. A bent state in which a test piece consisting of three layers and having a length of 100 mm and a width of 50 mm is bent by its own weight so that both ends defining the length are 5 mm apart from the initial state where the length is 100 mm. The silicone pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer according to any one of claims 1 to 3, which has a bending resistance that exceeds 100,000 times in a test at a temperature of -20 ° C in the test to be changed to -20 ° C.   E) IEC62715-6-1 Test conforming to Ed1.0, which is a test piece having the silicone-based pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer, the configuration of which is PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm. A bent state in which a test piece consisting of three layers and having a length of 100 mm and a width of 50 mm is bent by its own weight so that both ends defining the length are 5 mm apart from the initial state where the length is 100 mm. The silicone pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer according to any one of claims 1 to 4, which has a bending resistance in which the test at a temperature of 20 ° C is repeated more than 200,000 times in a test to be changed to a temperature. B) A silicone-based pressure-sensitive adhesive sheet or silicone-based pressure-sensitive adhesive layer having a storage elastic modulus at 20 ° C. of 1.0 × 10 ⁶ Pa or less.   C) The silicone-based pressure-sensitive adhesive sheet or silicone-based pressure-sensitive adhesive layer according to claim 6, wherein the yield point strain in stress-strain measurement at 20 ° C. exceeds 150%.   D) It is a test based on IEC62715-6-1 Ed1.0, and is a test piece having the silicone-based pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer, and the configuration thereof is PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm. A bent state in which a test piece consisting of three layers and having a length of 100 mm and a width of 50 mm is bent by its own weight so that both ends defining the length are 5 mm apart from the initial state where the length is 100 mm. The silicone pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer according to claim 6 or 7, which has bending resistance in which the test repeated at a temperature of -20 ° C exceeds 100,000 times in the test to be changed to 980C.   E) IEC62715-6-1 Test conforming to Ed1.0, which is a test piece having the silicone-based pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer, the configuration of which is PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm. A bent state in which a test piece consisting of three layers and having a length of 100 mm and a width of 50 mm is bent by its own weight so that both ends defining the length are 5 mm apart from the initial state where the length is 100 mm. The silicone pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer according to any one of claims 6 to 8, which has bending resistance in which the test at a temperature of 20 ° C is repeated more than 200,000 times in the test to be changed to 200 ° C.   C) A silicone-based pressure-sensitive adhesive sheet or silicone-based pressure-sensitive adhesive layer having a yield point strain of more than 150% in a stress-strain measurement at 20 ° C.   D) It is a test based on IEC62715-6-1 Ed1.0, and is a test piece having the silicone-based pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer, and the configuration thereof is PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm. A bent state in which a test piece consisting of three layers and having a length of 100 mm and a width of 50 mm is bent by its own weight so that both ends defining the length are 5 mm apart from the initial state where the length is 100 mm. The silicone pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer according to claim 10, which has bending resistance in which the test repeated at a temperature of −20 ° C. exceeds 100,000 times in the test to be changed to ≧ 10.   E) IEC62715-6-1 Test conforming to Ed1.0, which is a test piece having the silicone-based pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer, the configuration of which is PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm. A bent state in which a test piece consisting of three layers and having a length of 100 mm and a width of 50 mm is bent by its own weight so that both ends defining the length are 5 mm apart from the initial state where the length is 100 mm. The silicone pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer according to claim 10 or 11, which has bending resistance in which a test at a temperature of 20 ° C is repeated more than 200,000 times in a test to be changed to 200 ° C.   D) Test conforming to IEC62715-6-1 Ed1.0, which is a test piece having a silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer, the structure of which is 3 of PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm. A test piece made of a layer, having a length of 100 mm and a width of 50 mm, is bent from the initial state in which the length is 100 mm to be bent by its own weight so that both ends defining the length are 5 mm apart. A silicone pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer having a bending resistance that exceeds 100,000 times at a temperature of −20 ° C. in the test to be changed.   E) IEC62715-6-1 Test conforming to Ed1.0, which is a test piece having the silicone-based pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer, the configuration of which is PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm. A bent state in which a test piece consisting of three layers and having a length of 100 mm and a width of 50 mm is bent by its own weight so that both ends defining the length are 5 mm apart from the initial state where the length is 100 mm. The silicone pressure-sensitive adhesive sheet or the silicone-based pressure-sensitive adhesive layer according to claim 13, which has bending resistance in which the test at a temperature of 20 ° C. is repeated more than 200,000 times.   E) Test conforming to IEC62715-6-1 Ed1.0, which is a test piece having a silicone-based pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer, the structure of which is 3 of PET 100 μm / the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive layer / PET 100 μm. A test piece made of a layer, having a length of 100 mm and a width of 50 mm, is bent from the initial state in which the length is 100 mm to be bent by its own weight so that both ends defining the length are 5 mm apart. A silicone pressure-sensitive adhesive sheet or a silicone-based pressure-sensitive adhesive layer having a bending resistance in which the repetition of the test at a temperature of 20 ° C. exceeds 200,000 times.   A product comprising the silicone-based pressure-sensitive adhesive sheet and / or the silicone-based pressure-sensitive adhesive layer according to any one of claims 1 to 15.   A display provided with the silicone type adhesive sheet and / or silicone type adhesive layer of any one of Claims 1-15.   A flexible display provided with the silicone type adhesive sheet and / or silicone type adhesive layer of any one of Claims 1-15.

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