Double-sided adhesive tape, preparation method thereof and electronic equipment comprising double-sided adhesive tape

Abstract

The invention provides a double-sided adhesive tape, a preparation method thereof and an electronic device comprising the same. Specifically, the double-sided adhesive tape sequentially comprises a first pressure-sensitive adhesive layer, a polyamide layer, a polyurethane foam layer, a polyester layer and a second pressure-sensitive adhesive layer. The electronic equipment (such as a display and the like) adhered by the double-sided adhesive tape according to the technical scheme of the invention has good reworking performance, and the double-sided adhesive tape also provides excellent aging resistance (such as high temperature and high humidity resistance).

Description

Technical Field

[0001] The present invention relates to the technical field of display devices, and in particular to a double-sided adhesive tape used for bonding a display panel to a narrow frame in a frameless design, a preparation method thereof, and an electronic device comprising the double-sided adhesive tape. Background Art

[0002] As consumers' requirements for aesthetics and design increase, frameless design has become a global trend for TV and monitor products. This design requires the use of soft polyurethane foam tape, which is converted into strips of about 3 mm width and appropriate length to bond the display panel to the narrow frame.

[0003] In frameless design, when repairing TV and monitor products, polyurethane foam tape with good rework performance is required. This means that the foam layer of the tape can be easily cut by the repair operator, and the residue of the tape on both sides of the display product (panel side and frame side) can be easily removed without leaving any part.

[0004] However, in the case of polyurethane foam tapes currently on the market, the adhesive layer on one side adheres to the TV panel and the other side adheres to the polyurethane foam layer. This design is difficult to clean during rework, and the foam is easily broken during cleaning. Although some tape manufacturers have added thermoplastic polyurethane (TPU) film between the adhesive layer and the foam layer to improve rework performance, the TPU film is not sufficiently resistant to high temperature and high humidity environments. Under high temperature and high humidity conditions (such as 65°C / 95%RH), TPU tends to become very soft / creep and even hydrolyze, which has a negative impact on adhesion and easily leads to failure in adhesion tests. In addition, the cost of TPU film is very high, resulting in expensive tape costs.

[0005] Therefore, there is an urgent need for a new type of reworkable polyurethane foam tape that not only provides good reworkability to help maintenance personnel easily remove tape residues on both sides of display products during maintenance, but also provides excellent resistance to high temperature and high humidity aging conditions. In addition, this tape should also be cost-effective. Summary of the invention

[0006] In summary, the existing technology has obvious deficiencies in the repair and bonding stability of frameless design TV and display products. The present invention aims to solve the challenges of existing tapes in heavy-duty performance, high temperature and high humidity resistance, and cost-effectiveness through innovative tape design, so as to meet market demand and improve product competitiveness.

[0007] Based on the technical problems explained above, one of the objects of the present invention is to provide a double-sided tape for bonding a display panel to a narrow frame in a frameless design. Electronic devices (e.g., displays, etc.) bonded by the double-sided tape according to the technical solution of the present invention have good rework performance, and the double-sided tape also provides excellent aging resistance (e.g., resistance to high temperature and high humidity).

[0008] Specifically, the present invention provides a double-sided adhesive tape, which comprises a first pressure-sensitive adhesive layer, a polyamide layer, a polyurethane foam layer, a polyester layer and a second pressure-sensitive adhesive layer in sequence.

[0009] According to another aspect of the present invention, a method for preparing the double-sided tape described above is provided, the method comprising sequentially stacking the first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the polyester layer and the second pressure-sensitive adhesive layer.

[0010] According to another aspect of the present invention, there is provided an electronic device, the electronic device comprising:

[0011] A display module, wherein the display module has a glass panel or a polarizer;

[0012] Framework; and

[0013] According to the double-sided tape described above, the double-sided tape bonds the glass panel or polarizer to the frame.

[0014] Compared with the double-sided tape used in the prior art for bonding the display panel to the narrow frame in the frameless design, the double-sided tape according to the present invention has the following advantages:

[0015] Good reworkability: The double-sided tape design of the present invention allows the maintenance operator to easily remove the tape residue on both sides of the display product during the maintenance process without leaving any part. This solves the problem that the tape is difficult to clean and easily causes fragments during the maintenance process in the prior art.

[0016] Excellent high temperature and high humidity resistance: The tape of the present invention can provide excellent high temperature and high humidity resistance and can withstand aging tests under high temperature and high humidity conditions, such as 70°C / 95%RH. This is compared with the thermoplastic polyurethane (TPU) film used in the prior art, which tends to become very soft / creep and even hydrolyze under high temperature and high humidity conditions, thereby affecting the bonding effect and possibly causing bonding failure.

[0017] Cost-effectiveness: Compared to the expensive TPU films used in the prior art, the tape of the present invention has a lower cost because it does not rely on expensive materials while providing the desired properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 shows a schematic cross-sectional view of a double-sided tape according to a specific embodiment of the present invention;

[0019] Figure 2 A schematic cross-sectional view showing a double-sided tape according to another specific embodiment of the present invention; and

[0020] Figure 3 A schematic cross-sectional view of a double-sided adhesive tape according to still another specific embodiment of the present invention is shown. DETAILED DESCRIPTION

[0021] The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments. It will be appreciated that other embodiments are contemplated and may be implemented without departing from the scope or spirit of the present invention. Therefore, the following detailed description is non-restrictive.

[0022] Unless otherwise indicated, all numbers used in the specification and claims to represent feature sizes, quantities and physicochemical properties should be understood as being modified by the term "about" in all cases. Therefore, unless otherwise indicated, the numerical parameters listed in the above specification and the attached claims are approximate values, and those skilled in the art can use the teachings disclosed herein to seek to obtain the desired properties and appropriately change these approximate values. The use of numerical ranges expressed as endpoints includes all numbers within the range and any range within the range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4 and 5, etc.

[0023] As mentioned above, the present invention aims to solve the problems of difficult reworking of the tape in the prior art, decreased adhesive performance in high temperature and high humidity environments, and high cost through innovative tape design, while meeting the market demand for high-performance tapes.

[0024] Specifically, according to one aspect of the present invention, a double-sided adhesive tape is provided, which includes, in sequence, a first pressure-sensitive adhesive layer, a polyamide layer, a polyurethane foam layer, a polyester layer and a second pressure-sensitive adhesive layer.

[0025] According to the above technical scheme of the present invention, through the combination of polyamide layer / polyurethane foam layer / polyester layer with a specific structure, good heavy work performance and high temperature and high humidity aging resistance are achieved at the same time. Not bound by theory, it is believed that the polyamide layer (such as nylon) generally has high mechanical strength and wear resistance, which can protect the polyurethane foam layer from physical damage and enhance the mechanical properties of the overall tape. The high temperature resistance of the polyamide layer can prevent the polyurethane foam layer from performance degradation under high temperature environment and maintain the adhesive strength of the tape. As a buffer material, the polyurethane foam layer can absorb and disperse pressure, while the polyester layer provides the necessary support to ensure the stability of the tape during use. The polyurethane foam layer has a certain heat insulation effect, while the polyester layer has good chemical resistance. The combination of the two enables the tape to maintain performance under high temperature and high humidity environment. Both the polyamide layer and the polyester layer have high mechanical strength, and their combination significantly improves the overall strength of the tape and improves the durability of the tape. In addition, both the polyamide layer and the polyester layer have good environmental resistance, including high temperature resistance, moisture resistance, chemical corrosion resistance, etc., which enables the tape to maintain performance even in harsh environments. Therefore, the combination of the polyamide layer, the polyurethane foam layer and the polyester layer provides a stable structure for the tape, allowing the tape to maintain its performance under various conditions of use. In addition, this structural design allows the tape to be easily removed by peeling off when it needs to be reworked without damaging the surface of the adherend. The combination of the three improves the anti-aging performance of the tape, making it less likely for the tape to degrade in high temperature and high humidity environments, and extending the service life of the tape.

[0026] Specifically, polyamide (PA), also known as nylon, is a polymer compound obtained by polycondensation of diamine and dibasic acid or by ring-opening polymerization of lactam, and contains a large amount of amide groups (-NHCO-) ​​in its molecular structure. Polyamide has good toughness and wear resistance and is widely used in the fields of manufacturing machinery, chemical industry, and electrical parts. However, compared with polyimide (PI, a polymer material with high heat resistance and electrical insulation performance, containing amide groups (-CO-NR-CO-) in its molecular structure, usually polymerized by aromatic diamine and aromatic diacid), polyamide is less used in the adhesive tape for bonding electronic equipment. However, the inventor of the present invention found that when a polyamide layer, a polyurethane foam layer and a polyester layer of a specific structure are combined for double-sided tape, a double-sided tape with excellent aging resistance (e.g., high temperature and high humidity resistance) can be obtained while having good heavy work performance. In contrast, the inventors of the present invention surprisingly found that when the polyamide layer in the technical solution according to the present invention is replaced with a polyimide film which is more common in the prior art, the rework performance and resistance to high temperature and high humidity aging are significantly deteriorated.

[0027] According to certain embodiments of the present invention, the thickness of the polyamide layer is in the range of 5-300 μm. In order to further improve the reworkability and aging resistance of the double-sided tape, the thickness of the polyamide layer is preferably in the range of 10-300 μm, more preferably 20-70 μm.

[0028] According to certain embodiments of the present invention, the polyamide layer has a tensile strength of 0.2 N / mm or more and an elongation at break of 50% or more. The inventors of the present invention have found in their research that when the tensile strength of the polyamide layer is less than 0.2 N / mm or the elongation at break is less than 50%, the rework performance deteriorates significantly, making it difficult for maintenance operators to completely remove the tape residues on both sides of the display product during the maintenance process. In order to further improve the rework performance and aging resistance of the double-sided tape, the polyamide layer has a tensile strength of preferably 0.5 N / mm or more, more preferably 0.7 N / mm or more, and an elongation at break of preferably 100% or more, more preferably 250% or more.

[0029] According to certain embodiments of the present invention, the polyamide layer is prepared by a polycondensation reaction of a diamine and a dibasic acid or by a ring-opening polymerization of a lactam.

[0030] More specifically, the polyurethane foam layer can be prepared by the reaction between at least one diisocyanate and at least one polyol, wherein the at least one diisocyanate is, for example, selected from methylene diphenyl isocyanate (MDI), toluene diisocyanate (TDI), methylene diphenyl isocyanate (MDI) oligomers, toluene diisocyanate (TDI) oligomers, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), hydrogenated MDI (HMDI) and methylene diisocyanate modified with carbodiimide, etc.; and the at least one polyol is, for example, selected from polypropylene glycol, polytetramethylene glycol and polyethylene glycol, etc.

[0031] A crosslinking agent may be optionally used to increase the crosslinking between the diisocyanate and the polyol in the polymerization reaction. Specifically, the crosslinking agent may be at least one agent selected from the following: trimethylolpropane, triethanolamine, pentaerythritol, toluenediamine, ethylenediamine, glycerol, hexamethylenediamine, m-phenylenediamine, dimethanolamine, triethanolamine, etc.

[0032] The polyurethane foam layer is characterized by one or more of the following mechanical or physical properties. In particular, the polyurethane foam layer may have a specific gravity or density of up to 1 g / cm 3 (Especially 0.08g / cm 3 Up to 0.8g / cm 3 ) of an open-cell compressible foam. In one embodiment, the density is 0.12 g / cm 3 Up to 0.75g / cm 3In one embodiment, the polyurethane foam layer may have a strength of up to 10.0 kgf / cm 2 (Especially 0.01kgf / cm 2 Up to 5.0kgf / cm 2 ) of 25% of the compressive strength. The tensile strength of polyurethane foam can be 1kgf / cm 2 Up to 300kgf / cm 2 , especially 15kgf / cm 2 Up to 200kgf / cm 2 , more specifically 15kgf / cm 2 Up to 150kgf / cm 2 , and the elongation at break of the polyurethane foam may be 100% to 600%, specifically 300% to 500% (determined according to ASTM D3574).

[0033] According to certain embodiments of the present invention, in order to improve the reworkability and aging resistance of the double-sided tape, the thickness of the polyurethane foam layer is in the range of 50-3000 μm, preferably 100-1600 μm, more preferably 250-1400 μm.

[0034] According to some embodiments of the present invention, the polyester layer is a polyethylene terephthalate (PET) layer or a polybutylene terephthalate (PBT) layer.

[0035] According to certain embodiments of the present invention, in order to improve the reworkability and aging resistance of the double-sided tape, the thickness of the polyester layer is in the range of 12-300 μm, preferably 25-150 μm, more preferably 38-75 μm.

[0036] The double-sided adhesive tape according to the present invention further comprises a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer. The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are used to bond the display panel to the narrow frame in a frameless design. Preferably, the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer comprises one or more of an acrylate pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, a polyurethane pressure-sensitive adhesive, a synthetic resin pressure-sensitive adhesive and a rubber pressure-sensitive adhesive.

[0037] According to some embodiments of the present invention, in the double-sided tape:

[0038] The double-sided tape further comprises a first adhesive layer, the first adhesive layer being located on the polyamide layer and the polyurethane foam layer and bonding them together, and / or

[0039] The double-sided tape further includes a second adhesive layer, which is located on the polyurethane foam layer and the polyester layer and bonds them together.

[0040] Preferably, the first adhesive layer and / or the second adhesive layer comprises one or more of an acrylic adhesive, a polyurethane adhesive, a polysiloxane adhesive and an epoxy resin adhesive.

[0041] In order to improve the reworkability and aging resistance of the double-sided adhesive tape, the thickness of the first adhesive layer and / or the second adhesive layer is in the range of 2-200 μm, preferably 2-100 μm, more preferably 2-50 μm.

[0042] It should be noted that the first adhesive layer and the second adhesive layer are optional structures. The double-sided tape according to the present invention may not include one or both of the first adhesive layer and the second adhesive layer. The polyamide layer / polyurethane foam layer structure stacked in contact with each other can be obtained by directly preparing the polyurethane foam layer on the polyamide layer by a foaming process. The polyester layer / polyurethane foam layer structure stacked in contact with each other can be obtained by directly preparing the polyurethane foam layer on the polyester layer by a foaming process.

[0043] Specifically, the double-sided adhesive tape according to the present invention may include:

[0044] The first pressure-sensitive adhesive layer, the polyamide layer, the first adhesive layer, the polyurethane foam layer, the second adhesive layer, the polyester layer and the second pressure-sensitive adhesive layer are sequentially contacted and stacked; or

[0045] The first pressure-sensitive adhesive layer, the polyamide layer, the first adhesive layer, the polyurethane foam layer, the polyester layer and the second pressure-sensitive adhesive layer are contacted and stacked in sequence; or

[0046] The first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the second adhesive layer, the polyester layer and the second pressure-sensitive adhesive layer are contact-stacked in sequence.

[0047] Most preferably, the double-sided tape comprises the first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the polyester layer and the second pressure-sensitive adhesive layer which are sequentially contacted and stacked. The polyamide layer / polyurethane foam layer / polyester layer structure which are contacted and stacked can be obtained by directly preparing the polyurethane foam layer between the polyamide layer and the polyester layer through a foaming process. The inventors of the present invention surprisingly found that the polyamide layer / polyurethane foam layer / polyester layer structure which are contacted and stacked can obtain the best effect in terms of the balance performance of heavy workability and aging resistance.

[0048] According to some embodiments of the present invention, the double-sided tape has a release layer on one side of the first pressure-sensitive adhesive layer and / or one side of the second pressure-sensitive adhesive layer. Preferably, the release layer is release paper or a transparent or colored plastic material thereof, but is not limited thereto.

[0049] Preferably, the double-sided adhesive tape has a release layer only on one side of the second pressure-sensitive adhesive layer, so that the double-sided adhesive tape can be provided in a roll form.

[0050] Preferably, in the double-sided adhesive tape according to the present invention, one or more of the first pressure-sensitive adhesive layer, the polyamide layer, the first adhesive layer, the polyurethane foam layer, the second adhesive layer, the polyester layer and the second pressure-sensitive adhesive layer are black, gray or other light-shielding colors, so that the display panel can be bonded to the narrow frame to provide a light-shielding effect. Preferably, the first pressure-sensitive adhesive layer, the polyamide layer, the first adhesive layer, the polyurethane foam layer, the second adhesive layer, the polyester layer and the second pressure-sensitive adhesive layer are all black. Preferably, one or more of the first pressure-sensitive adhesive layer, the polyamide layer, the first adhesive layer, the polyurethane foam layer, the second adhesive layer, the polyester layer and the second pressure-sensitive adhesive layer contain a black pigment or dye.

[0051] Figure 1 The cross-sectional schematic diagram of a double-sided adhesive tape 1 according to a specific embodiment of the present invention is shown. Specifically, the double-sided adhesive tape 1 comprises a first pressure-sensitive adhesive layer 2, a polyamide layer 3, a first adhesive layer 4, a polyurethane foam layer 5, a second adhesive layer 6, a polyester layer 7, a second pressure-sensitive adhesive layer 8 and a peeling layer 9 which are sequentially contacted and stacked.

[0052] Figure 2 A schematic cross-sectional view of a double-sided adhesive tape 1 according to another specific embodiment of the present invention is shown. Specifically, the double-sided adhesive tape 1 comprises a first pressure-sensitive adhesive layer 2, a polyamide layer 3, a first adhesive layer 4, a polyurethane foam layer 5, a polyester layer 7, a second pressure-sensitive adhesive layer 8 and a release layer 9 which are sequentially contacted and stacked.

[0053] Figure 3 A schematic cross-sectional view of a double-sided adhesive tape 1 according to another specific embodiment of the present invention is shown. Specifically, the double-sided adhesive tape 1 comprises a first pressure-sensitive adhesive layer 2, a polyamide layer 3, a polyurethane foam layer 5, a polyester layer 7, a second pressure-sensitive adhesive layer 8 and a release layer 9 which are sequentially contacted and stacked.

[0054] According to another aspect of the present invention, there is provided a method for preparing the above-mentioned double-sided adhesive tape, the method comprising laminating the first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the polyester layer and the second pressure-sensitive adhesive layer in sequence. There is no particular restriction on the specific steps of the method, and the method comprises separately preparing or purchasing one or more layers of the layers and laminating them together.

[0055] According to yet another aspect of the present invention, there is provided an electronic device, the electronic device comprising:

[0056] A display module, wherein the display module has a glass panel or a polarizer;

[0057] Framework; and

[0058] According to the double-sided tape described above, the double-sided tape bonds the glass panel or polarizer to the frame.

[0059] Preferably, the first pressure-sensitive adhesive layer of the double-sided tape is bonded to the glass panel or polarizer, and the second pressure-sensitive adhesive layer of the double-sided tape is bonded to the frame. Bonding in this manner can provide better reworkability.

[0060] The following detailed description is intended to illustrate the present disclosure by way of example only and not by way of limitation.

[0061] Specific implementation mode 1 is a double-sided adhesive tape, which comprises a first pressure-sensitive adhesive layer, a polyamide layer, a polyurethane foam layer, a polyester layer and a second pressure-sensitive adhesive layer in sequence.

[0062] Specific embodiment 2 is a double-sided tape according to specific embodiment 1, wherein the thickness of the polyamide layer is in the range of 5-300 μm.

[0063] Specific embodiment 3 is the double-sided tape according to specific embodiment 1, wherein the polyamide layer has a tensile strength of 0.2 N / mm or more and an elongation at break of 50% or more.

[0064] Specific embodiment 4 is a double-sided tape according to specific embodiment 1, wherein the polyamide layer is prepared by a polycondensation reaction of a diamine and a dibasic acid or by a ring-opening polymerization of a lactam.

[0065] Embodiment 5 is the double-sided tape according to embodiment 1, wherein the thickness of the polyurethane foam layer is in the range of 50-3000 μm.

[0066] Embodiment 6 is a double-sided tape according to embodiment 1, wherein the polyurethane foam layer is prepared by a reaction between at least one diisocyanate and at least one polyol.

[0067] Embodiment 7 is the double-sided tape according to embodiment 1, wherein the thickness of the polyester layer is in the range of 12-300 μm.

[0068] Specific embodiment 8 is the double-sided tape according to specific embodiment 1, wherein the polyester layer is a polyethylene terephthalate (PET) layer or a polybutylene terephthalate (PBT) layer.

[0069] Specific embodiment 9 is a double-sided adhesive tape according to specific embodiment 1, wherein the thickness of the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer is in the range of 25-200 μm.

[0070] Specific embodiment 10 is a double-sided tape according to specific embodiment 1, wherein the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer comprises one or more of acrylate pressure-sensitive adhesive, silicone pressure-sensitive adhesive, polyurethane pressure-sensitive adhesive, synthetic resin pressure-sensitive adhesive and rubber pressure-sensitive adhesive.

[0071] Specific embodiment 11 is a double-sided tape according to specific embodiment 1, wherein:

[0072] The double-sided tape further comprises a first adhesive layer, the first adhesive layer being located on the polyamide layer and the polyurethane foam layer and bonding them together, and / or

[0073] The double-sided tape further includes a second adhesive layer, which is located on the polyurethane foam layer and the polyester layer and bonds them together.

[0074] Specific embodiment 12 is a double-sided tape according to specific embodiment 11, wherein the first adhesive layer and / or the second adhesive layer comprises one or more of an acrylic adhesive, a polyurethane adhesive, a polysiloxane adhesive and an epoxy resin adhesive.

[0075] Specific embodiment 13 is the double-sided tape according to specific embodiment 11, wherein the thickness of the first adhesive layer and / or the second adhesive layer is in the range of 2-200 μm.

[0076] Specific embodiment 14 is a double-sided tape according to specific embodiment 11, wherein the double-sided tape comprises:

[0077] The first pressure-sensitive adhesive layer, the polyamide layer, the first adhesive layer, the polyurethane foam layer, the second adhesive layer, the polyester layer and the second pressure-sensitive adhesive layer are sequentially contacted and stacked; or

[0078] The first pressure-sensitive adhesive layer, the polyamide layer, the first adhesive layer, the polyurethane foam layer, the polyester layer and the second pressure-sensitive adhesive layer are contacted and stacked in sequence; or

[0079] The first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the second adhesive layer, the polyester layer and the second pressure-sensitive adhesive layer are contact-stacked in sequence.

[0080] Specific embodiment 15 is a double-sided tape according to specific embodiment 11, wherein the double-sided tape comprises the first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the polyester layer and the second pressure-sensitive adhesive layer which are sequentially contacted and stacked.

[0081] Specific embodiment 16 is a double-sided tape according to specific embodiment 1, wherein the double-sided tape has a release layer on one side of the first pressure-sensitive adhesive layer and / or one side of the second pressure-sensitive adhesive layer.

[0082] Specific embodiment 17 is a double-sided tape according to specific embodiment 1, wherein the double-sided tape has a release layer only on one side of the second pressure-sensitive adhesive layer.

[0083] Specific embodiment 18 is the double-sided tape according to specific embodiment 17, wherein the double-sided tape is in the form of a roll.

[0084] Specific embodiment 19 is a method for preparing a double-sided tape according to any one of specific embodiments 1-18, the method comprising stacking the first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the polyester layer and the second pressure-sensitive adhesive layer in sequence.

[0085] Specific implementation 20 is an electronic device, the electronic device comprising:

[0086] A display module, wherein the display module has a glass panel or a polarizer;

[0087] Framework; and

[0088] According to the double-sided tape described in any one of embodiments 1 to 18, the double-sided tape bonds the glass panel or the polarizer to the frame.

[0089] Specific embodiment 21 is an electronic device according to specific embodiment 20, wherein the first pressure-sensitive adhesive layer of the double-sided tape is bonded to the glass panel or polarizer, and the second pressure-sensitive adhesive layer of the double-sided tape is bonded to the frame.

[0090] The present invention is described in more detail below in conjunction with the examples. It should be noted that these descriptions and examples are intended to facilitate the understanding of the present invention, rather than to limit the present invention. The protection scope of the present invention shall be subject to the attached claims.

[0091] Example

[0092] In the present invention, unless otherwise indicated, the reagents used are commercial products and are used directly without further purification. In addition, the "%", "wt%" mentioned are "percentage by weight", and the "parts" mentioned are "parts by weight".

[0093] Test Method

[0094] In the present invention, the double-sided adhesive tapes prepared in the following Examples 1 and 2 were subjected to a rework performance test and an anti-aging performance test according to the methods described in detail below.

[0095] Heavy industry performance test

[0096] The double-sided tape is subjected to a peel test. Specifically, the peel test is used to evaluate the reworkability of the reworkable polyurethane foam tape, that is, whether the tape can be easily removed from the adhesive surface without leaving residue in actual application.

[0097] Specifically, two test boards are prepared, one is a glass plate and the other is an aluminum plate, which are used to simulate the panel and frame of the display product. The release layer of the double-sided tape is peeled off, and then the first pressure-sensitive adhesive layer of the tape is pasted on the glass plate, and the second pressure-sensitive adhesive layer of the tape is pasted on the aluminum plate to ensure that the tape is fully bonded to the test board. Then, a metal feeler gauge with a thickness of 0.10 mm is used as an auxiliary tool, inserted into the tape, and force is applied slowly and evenly to move the metal feeler gauge along the length direction of the tape, so that the foam layer of the tape breaks and is divided into two parts. The remaining part of the foam tape is peeled off from the adhesive surface of the test board. During the peeling process, observe whether the tape is easy to break and whether it can be cleanly peeled off from the surface of the test board without leaving residue.

[0098] Anti-aging performance test (high temperature and high humidity resistance)

[0099] Each double-sided tape prepared below was subjected to an aging test under high temperature and high humidity conditions to examine its aging resistance (e.g., high temperature and high humidity resistance). The aging test is mainly used to verify the adhesive performance of the tape under simulated harsh environmental conditions to ensure that the tape can still maintain good adhesive strength and stability in a high temperature and high humidity environment for a long time. The aging test includes a static shear test and a split test.

[0100] In the static shear test, a 1-inch square piece of double-sided tape is attached to a test panel, and then a 1-kg weight is applied to the tape for 7 days to check if the tape falls off or fails.

[0101] In the split test, the tape is pasted between two test panels to form an "L" shape, and then a 300-gram weight is applied to the tape for 7 days to check whether the tape can resist the peel force and maintain adhesion.

[0102] Example 1

[0103] First, the adhesive Liostar-1000-GS20 (from Shanghai Toyo Ink Manufacturing Co., Ltd.), CAT-T85 (from Shanghai Toyo Ink Manufacturing Co., Ltd.) and ethyl acetate were mixed in a weight percentage ratio of 100:7:100 to prepare a mixed adhesive for preparing an adhesive layer. Then, the mixed adhesive was coated on one surface of a 20-micron thick black polyamide film KF-20 (from Shanghai Kefei Film Co., Ltd.), and the polyamide film was corona treated before coating. Then, at a temperature of about 60°C, the adhesive layer side of the polyamide film coated with the adhesive layer was attached to the corona-treated polyurethane foam layer side of a composite film (Hubei Xiangyuan New Materials Co., Ltd.) including a polyurethane foam layer and a PET polyester layer. Next, 3M acrylic adhesive 27074 (from 3M Company), 3M crosslinker RD-1054 (from 3M Company) and black pigment JS49313 (from Shanghai Jiasheng Materials Company) were mixed in a weight ratio of 100:0.75:3.0 to obtain a pressure-sensitive adhesive for preparing a pressure-sensitive adhesive layer. The pressure-sensitive adhesive is coated on a release carrier, and then the dried pressure-sensitive adhesive layer is heat-pressed onto one side of the PET polyester layer and one side of the polyamide film, respectively, to prepare a double-sided adhesive tape 1.

[0104] In the double-sided tape prepared above, the thickness of the first pressure-sensitive adhesive layer is 50 μm; the thickness of the polyamide layer is 20 μm; the thickness of the first adhesive layer is 10 μm; the thickness of the polyurethane foam layer is 1080 μm; the thickness of the polyester layer is 50 μm; and the thickness of the second pressure-sensitive adhesive layer is 50 μm.

[0105] The mechanical properties (including tensile strength and elongation at break) of the black polyamide film KF-20 used above are as follows: tensile strength (MD) is 1.03 N / mm; tensile strength (CD) is 0.86 N / mm; elongation at break (MD) is 364%; elongation at break (CD) is 409%.

[0106] The results obtained according to the rework performance test method described in detail above show that during the peeling process, the double-sided tape 1 can be easily peeled off from the glass plate and the aluminum plate surface without the tape breaking or residue adhering to the test plate surface. The glass plate and the aluminum plate surface after peeling are clean and no additional cleaning work is required, indicating that the tape has good rework performance.

[0107] In addition, the results obtained according to the anti-aging performance test method described in detail above show that under the conditions of 70°C / 95%RH, after 7 days of static shear test and splitting test, the double-sided tape 1 sample did not show any bonding failure, which indicates that the double-sided tape 1 has excellent bonding performance and stability under high temperature and high humidity environment.

[0108] Example 2

[0109] A double-sided tape was prepared in a manner similar to Example 1, except that the composite film comprising a polyurethane foam layer and a PET polyester layer (Hubei Xiangyuan New Materials Co., Ltd.) was replaced by a polyurethane foam layer (Hubei Xiangyuan New Materials Co., Ltd.) and a PET polyester film (from Nanyang Technology Co., Ltd.).

[0110] Specifically, first, the adhesive Liostar-1000-GS20 (from Shanghai Toyo Ink Manufacturing Co., Ltd.), CAT-T85 (from Shanghai Toyo Ink Manufacturing Co., Ltd.) and ethyl acetate are mixed in a ratio of 100:7:100 by weight to prepare a mixed adhesive for preparing an adhesive layer. Then, the mixed adhesive is coated on one surface of a 20-micron-thick black polyamide film KF-20 (from Shanghai Kefei Film Co., Ltd.), and the polyamide film is corona-treated before coating. Then, at a temperature of about 60°C, one side of the adhesive layer of the polyamide film coated with the adhesive layer is attached to one surface of a corona-treated polyurethane foam layer (Hubei Xiangyuan New Materials Co., Ltd.). Subsequently, the mixed adhesive is applied on another surface of the polyurethane foam layer to form a second adhesive layer. Then, a PET polyester film (from Nanyang Technology Company) is laminated on the second adhesive layer. Next, 3M acrylic adhesive 27074 (from 3M Company), 3M crosslinker RD-1054 (from 3M Company) and black pigment JS49313 (from Shanghai Jiasheng Materials Company) were mixed at a weight ratio of 100:0.75:3.0 to obtain a pressure-sensitive adhesive for preparing a pressure-sensitive adhesive layer. The pressure-sensitive adhesive was coated on a release carrier. The dried pressure-sensitive adhesive layer was then attached to one side of the PET polyester layer and one side of the polyamide film, respectively, to prepare a double-sided tape 2.

[0111] In the double-sided tape prepared above, the thickness of the first pressure-sensitive adhesive layer is 50 μm; the thickness of the polyamide layer is 20 μm; the thickness of the first adhesive layer is 10 μm; the thickness of the polyurethane foam layer is 1070 μm; the thickness of the second adhesive layer is 10 μm; the thickness of the polyester layer is 50 μm; and the thickness of the second pressure-sensitive adhesive layer is 50 μm.

[0112] The mechanical properties (including tensile strength and elongation at break) of the black polyamide film KF-20 used above are as follows: tensile strength (MD) is 1.03 N / mm; tensile strength (CD) is 0.86 N / mm; elongation at break (MD) is 364%; elongation at break (CD) is 409%.

[0113] The results obtained according to the rework performance test method described in detail above show that during the peeling process, the double-sided tape 2 can be easily peeled off from the glass plate and the aluminum plate surface, and there is no tape breakage or residue attached to the test plate surface. The glass plate and aluminum plate surfaces after peeling are clean and no additional cleaning is required, indicating that the tape has good rework performance.

[0114] In addition, according to the results of the anti-aging performance test method described in detail above, under the conditions of 70°C / 95%RH, after 7 days of static shear test and splitting test, the double-sided tape 2 sample did not show any bonding failure, which indicates that the double-sided tape 2 has excellent bonding performance and stability under high temperature and high humidity environment.

[0115] From the results of Examples 1 and 2 above, it can be seen that the double-sided tape according to the technical solution of the present invention can be easily peeled off from the bonding surface without damaging the bonded material (for example, a glass panel or a polarizer), and will not leave residues that are difficult to clean. This shows that the tape design meets the needs of easy removal and replacement, and is suitable for use in the repair and replacement of display products. In addition, the tape according to the technical solution of the present invention can maintain its bonding performance under the aging test conditions of 70°C and 95% relative humidity, and there is no bonding failure. This shows that the tape has good high temperature and high humidity resistance, and is suitable for application scenarios that may be exposed to harsh environmental conditions.

[0116] The embodiments described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have all been recorded in the claims.

Claims

1. A double-sided adhesive tape, comprising in sequence a first pressure-sensitive adhesive layer, a polyamide layer, a polyurethane foam layer, a polyester layer and a second pressure-sensitive adhesive layer. 2 . The double-sided tape according to claim 1 , wherein the thickness of the polyamide layer is in the range of 5-300 μm. 3 . The double-sided tape according to claim 1 , wherein the polyamide layer has a tensile strength of 0.2 N / mm or more and an elongation at break of 50% or more. 4 . The double-sided tape according to claim 1 , wherein the polyamide layer is prepared by a polycondensation reaction of a diamine and a dibasic acid or by a ring-opening polymerization of a lactam. 5 . The double-sided tape according to claim 1 , wherein the thickness of the polyurethane foam layer is in the range of 50-3000 μm.

6. The double-sided tape according to claim 1, wherein the polyurethane foam layer is prepared by a reaction between at least one diisocyanate and at least one polyol.

7. The double-sided tape according to claim 1, wherein the thickness of the polyester layer is in the range of 12-300 μm. 8 . The double-sided tape according to claim 1 , wherein the polyester layer is a polyethylene terephthalate (PET) layer or a polybutylene terephthalate (PBT) layer. 9 . The double-sided adhesive tape according to claim 1 , wherein the thickness of the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer is in the range of 25-200 μm.

10. The double-sided adhesive tape according to claim 1, wherein the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer comprises one or more of an acrylate pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, a polyurethane pressure-sensitive adhesive, a synthetic resin pressure-sensitive adhesive and a rubber pressure-sensitive adhesive.

11. The double-sided tape according to claim 1, in: The double-sided tape further comprises a first adhesive layer, the first adhesive layer being located on the polyamide layer and the polyurethane foam layer and bonding them together, and / or The double-sided tape further includes a second adhesive layer, which is located on the polyurethane foam layer and the polyester layer and bonds them together. 12 . The double-sided tape according to claim 11 , wherein the first adhesive layer and / or the second adhesive layer comprises one or more of an acrylic adhesive, a polyurethane adhesive, a polysiloxane adhesive, and an epoxy resin adhesive. 13 . The double-sided tape according to claim 11 , wherein a thickness of the first adhesive layer and / or the second adhesive layer is in the range of 2-200 μm.

14. The double-sided tape according to claim 11, wherein the double-sided tape include: The first pressure-sensitive adhesive layer, the polyamide layer, the first adhesive layer, the polyurethane foam layer, the second adhesive layer, the polyester layer and the second pressure-sensitive adhesive layer are sequentially contacted and stacked; or The first pressure-sensitive adhesive layer, the polyamide layer, the first adhesive layer, the polyurethane foam layer, the polyester layer and the second pressure-sensitive adhesive layer are contacted and stacked in sequence; or The first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the second adhesive layer, the polyester layer and the second pressure-sensitive adhesive layer are contact-stacked in sequence. 15 . The double-sided tape according to claim 11 , wherein the double-sided tape comprises the first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the polyester layer, and the second pressure-sensitive adhesive layer which are sequentially contact-laminated. 16 . The double-sided adhesive tape according to claim 1 , further comprising a release layer on one side of the first pressure-sensitive adhesive layer and / or one side of the second pressure-sensitive adhesive layer. 17 . The double-sided adhesive tape according to claim 1 , comprising a release layer only on one side of the second pressure-sensitive adhesive layer. The double-sided tape according to claim 17 , which is in the form of a roll.

19. A method for preparing the double-sided adhesive tape according to any one of claims 1 to 18, the method comprising sequentially laminating the first pressure-sensitive adhesive layer, the polyamide layer, the polyurethane foam layer, the polyester layer and the second pressure-sensitive adhesive layer.

20. An electronic device, the electronic device include: A display module, wherein the display module has a glass panel or a polarizer; frame; and The double-sided tape according to any one of claims 1 to 18, wherein the double-sided tape bonds the glass panel or polarizer to the frame. 21 . The electronic device according to claim 20 , wherein the first pressure-sensitive adhesive layer of the double-sided tape is bonded to the glass panel or the polarizer, and the second pressure-sensitive adhesive layer of the double-sided tape is bonded to the frame.

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