Composite adhesive layer, preparation method thereof and electronic display device

Abstract

The invention relates to the technical field of pressure-sensitive adhesives, in particular to a composite adhesive layer, a preparation method thereof and an electronic display device. The composite adhesive layer provided by the invention comprises a first pressure-sensitive adhesive layer, a middle layer and a second pressure-sensitive adhesive layer which are stacked in sequence, the middle layer comprises a polyethylene glycol terephthalate layer and an antistatic layer arranged on the surface of one side of the polyethylene glycol terephthalate layer, and the impedance value of the antistatic layer is 4 * 10 < 6 > omega to 2 * 10 < 9 > omega. The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are independently obtained by curing a pressure-sensitive adhesive composition; the pressure-sensitive adhesive composition is prepared from the following components in parts by weight: 500 parts of prepolymer, 15 to 25 parts of fatty acrylate, 60 to 70 parts of hydroxyalkyl acrylate, 5 to 10 parts of polyfunctional group acrylate, 0.5 to 1 part of polymer regulator, 1 to 3 parts of silane coupling agent, 0.05 to 0.5 part of photoinitiator and 0.3 to 0.8 part of antioxidant. The composite adhesive layer has excellent antistatic performance and touch control performance, and can be effectively applied to the field of electronic display devices.

Description

Technical Field

[0001] The present application relates to the technical field of pressure-sensitive adhesives, and in particular to a composite adhesive layer and a preparation method thereof, and an electronic display device. Background Art

[0002] Pressure-sensitive adhesive is an adhesive that is extremely sensitive to pressure, can quickly adhere to the surface of the adherend under slight pressure, and will not leave residue when removed.

[0003] With the rapid development of the display and electronics industry and electronic science and technology, pressure-sensitive adhesives are increasingly used in mobile phones, displays and electronic devices. However, at present, pressure-sensitive adhesives used in electronic devices have the following problems: (1) Pressure-sensitive adhesives carry a certain amount of static electricity to varying degrees, which causes dust or other particles to be adsorbed on the surface of the material, and a high degree of static electricity may even affect the service life of related electronic devices; (2) Pressure-sensitive adhesives used in mobile phones, displays and other electronic devices may cause changes in the electric field distribution of the touch screen, thereby interfering with the transmission of touch signals; or the accumulation of static electricity in the pressure-sensitive adhesive may also cause the sensitivity of the touch screen to decrease. Summary of the invention

[0004] Based on this, the present application provides a composite adhesive layer and a preparation method thereof, and an electronic display device. The composite adhesive layer provided in the present application has both excellent antistatic performance and touch performance, and can be effectively applied to the field of electronic display devices.

[0005] In a first aspect of the present application, there is provided a composite adhesive layer, comprising a first pressure-sensitive adhesive layer, an intermediate layer, and a second pressure-sensitive adhesive layer stacked in sequence;

[0006] The intermediate layer includes a polyethylene terephthalate layer and an antistatic layer disposed on one surface of the polyethylene terephthalate layer, and the impedance value of the antistatic layer is 4×10 6 Ω~2×10 9 Ω;

[0007] The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are each independently obtained by curing the pressure-sensitive adhesive composition;

[0008] The pressure-sensitive adhesive composition comprises the following components: 500 parts of prepolymer, 15 parts to 25 parts of fatty acrylate, 60 parts to 70 parts of hydroxyalkyl acrylate, 5 parts to 10 parts of multifunctional acrylate, 0.5 parts to 1 part of polymer regulator, 1 part to 3 parts of silane coupling agent, 0.05 parts to 0.5 parts of photoinitiator, and 0.3 parts to 0.8 parts of antioxidant;

[0009] The prepolymer is prepared from the following raw materials: 700 to 800 parts of alkyl acrylate, 130 to 180 parts of hydroxy acrylate, and 0.4 to 1.2 parts of photocuring agent.

[0010] In one embodiment, when the impedance value of the antistatic layer is 4×10 6 Ω~2×10 7 Ω, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are each independently obtained by curing the pressure-sensitive composition.

[0011] In one embodiment, when 2×10 7 Ω<The impedance value of the antistatic layer≤2×10 9 Ω, the pressure-sensitive adhesive composition for obtaining the first pressure-sensitive adhesive layer after curing further comprises 0.5 to 5 parts of an antistatic agent; the second pressure-sensitive adhesive layer is obtained by curing the pressure-sensitive adhesive composition;

[0012] Wherein, in the intermediate layer, compared with the polyethylene terephthalate layer, the antistatic layer is closer to the first pressure-sensitive adhesive layer.

[0013] In one embodiment, the pressure-sensitive adhesive composition has one or more of the following characteristics:

[0014] (1) The acrylic acid fatty ester includes one or more of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and cyclohexyl methacrylate;

[0015] (2) The hydroxyalkyl acrylate includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate;

[0016] (3) The multifunctional acrylate includes one or more of HS-268 special acrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate and trimethylolpropane triacrylate;

[0017] (4) The polymer regulator includes one or more of dodecanethiol, dithioesters and aliphatic thiols;

[0018] (5) The silane coupling agent includes one or more of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, γ-glycidyloxypropyl trimethoxysilane and γ-(2,3-epoxypropoxy)propyl trimethoxysilane;

[0019] (6) The photoinitiator includes one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-2-methyl-1-phenylpropanone;

[0020] (7) The antioxidant includes one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, dilauryl thiodipropionate and phosphite antioxidants.

[0021] In one embodiment, the antistatic agent includes one or more of anionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents, nonionic antistatic agents and polymer antistatic agents.

[0022] In one embodiment, the prepolymer has one or more of the following characteristics:

[0023] (1) The alkyl acrylate includes one or more of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and cyclohexyl methacrylate;

[0024] (2) The hydroxy acrylate includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate;

[0025] (3) The photocuring agent includes one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-2-methyl-1-phenylpropanone;

[0026] (4) The step of preparing the prepolymer includes: mixing the alkyl acrylate, the hydroxy acrylate, the photocuring agent and a solvent, and performing prepolymerization under ultraviolet light irradiation to prepare the prepolymer.

[0027] In one embodiment, the composite film layer further includes a first substrate layer and a second substrate layer, wherein the first substrate layer is disposed on a surface of the first pressure-sensitive adhesive layer away from the intermediate layer, and the second substrate layer is disposed on a surface of the second pressure-sensitive adhesive layer away from the intermediate layer.

[0028] In one embodiment, the composite adhesive layer has one or more of the following characteristics:

[0029] (1) The first substrate layer is polyethylene terephthalate treated with silicone resin;

[0030] (2) The second substrate layer is polyethylene terephthalate treated with silicone resin;

[0031] (3) The thickness of the first substrate layer is 80 μm to 120 μm;

[0032] (4) The thickness of the second substrate layer is 80 μm to 120 μm;

[0033] (5) The thickness of the intermediate layer is 40 μm to 60 μm;

[0034] (6) The thickness of the first pressure-sensitive adhesive layer is 90 μm to 110 μm;

[0035] (7) The thickness of the second pressure-sensitive adhesive layer is 90 μm to 110 μm.

[0036] The second aspect of the present application provides a method for preparing the composite adhesive layer according to any one of the embodiments of the first aspect of the present application, comprising the following steps:

[0037] The pressure-sensitive adhesive composition is respectively coated between the intermediate layer and the first substrate layer and between the intermediate layer and the second substrate layer. After curing, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are respectively formed. After release treatment, the first substrate layer and the second substrate layer are removed to prepare the composite adhesive layer.

[0038] In one embodiment, the composite adhesive layer has one or more of the following characteristics:

[0039] (1) The curing is carried out under ultraviolet light irradiation conditions at a wavelength of 300nm to 400nm;

[0040] (2) The total energy exposure of the curing is 1800mJ / cm 2 ~2200mJ / cm 2 .

[0041] A third aspect of the present application provides an electronic display device, comprising the composite adhesive layer described in any one of the embodiments of the first aspect of the present application.

[0042] The composite adhesive layer provided in this application has at least the following beneficial effects:

[0043] In the composite adhesive layer provided in the present application, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are respectively arranged on the two surfaces of the middle layer, which can provide good adhesion and adhesion to ensure the close combination of the composite adhesive layer with the touch panel and other components.

[0044] In addition, the middle layer includes a polyethylene terephthalate layer and an antistatic layer disposed on one side of the polyethylene terephthalate layer. The polyethylene terephthalate has excellent mechanical properties and dimensional stability, and can provide certain support and strength for the composite adhesive layer to prevent it from being excessively deformed or damaged during use. At the same time, the antistatic layer with a specific impedance value on the surface of one side of the middle layer cooperates with the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer obtained by curing the pressure-sensitive adhesive composition of a specific component, which not only ensures the antistatic performance, but also does not affect the touch performance of the pressure-sensitive adhesive layer. The three work synergistically, so that the composite adhesive layer has both good antistatic performance and touch performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of the structure of the composite adhesive layer provided in this application.

[0046] In the figure, 10 is a first pressure-sensitive adhesive layer, 20 is an intermediate layer, 30 is a second pressure-sensitive adhesive layer, 201 is an antistatic layer, and 202 is a polyethylene terephthalate layer. DETAILED DESCRIPTION

[0047] The following is a further complete and clear description of the composite adhesive layer and its preparation method and the electronic display device of the present application in combination with specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0049] As used herein, "one or more" refers to any one, any two, or any two or more of the listed items.

[0050] In this application, "first aspect", "second aspect", "third aspect", "fourth aspect", "fifth aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", "fifth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0051] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0052] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0053] The percentage contents involved in this application, unless otherwise specified, refer to mass percentage for solid-liquid mixing and solid-solid mixing, and refer to volume percentage for liquid-liquid mixing.

[0054] The percentage concentrations mentioned in this application, unless otherwise specified, refer to the final concentration, which refers to the percentage of the added component in the system after the addition of the component.

[0055] The temperature parameters in this application, unless otherwise specified, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the accuracy range of instrument control.

[0056] Pressure-sensitive adhesive is a double-sided laminating tape with high transmittance and no substrate. It is extremely sensitive to pressure and can stick to the surface of an object by simply pressing lightly with your fingers. It is simple and convenient to use and generally has the advantages of being easy to stick to, easy to peel off, and not easy to fall off. It is widely used in diapers, labels, medical sealing tapes, book binding, metal processing, etc., and is one of the most widely used types of adhesives.

[0057] There are many types of pressure-sensitive adhesives, such as acrylic, silicone and polyurethane. Among them, acrylic pressure-sensitive adhesives have good pressure sensitivity, adhesion and weather resistance, and are widely used in various fields. There are many types of pressure-sensitive adhesives, such as solvent-based and non-solvent-based. Solvent-based pressure-sensitive adhesives appeared the earliest, but due to the presence of solvents, an additional desolvation step is required, so there is a problem of high energy consumption. UV-curable pressure-sensitive adhesives do not have solvents, so no additional energy is required for solvent evaporation, and the reaction speed during the polymerization process is faster, the energy consumption is less, it is green and environmentally friendly, and it will not pollute the air. Therefore, UV-curable pressure-sensitive adhesives have been widely developed.

[0058] With the rapid development of the display and electronic industries, and electronic science and technology, adhesives are increasingly used in mobile phones, displays, and electronic devices. However, at present, adhesives used in electronic devices carry a certain amount of static electricity to varying degrees, which causes dust or other particles to be adsorbed on the surface of the material; especially with the increasing use of touch display functions in the electronics industry, a high degree of static electricity may even affect the service life of related electronic devices. At the same time, the adhesive force of the adhesive will also affect the fit between the adherend and the adhesive. If the adhesion is not strong, it will cause contaminants to enter or stratification to occur, affecting the function and service life of the display device.

[0059] See also Figure 1 In a first aspect of the present application, a composite adhesive layer is provided, comprising a first pressure-sensitive adhesive layer 10, an intermediate layer 20, and a second pressure-sensitive adhesive layer 30 stacked in sequence.

[0060] The intermediate layer 20 includes a polyethylene terephthalate layer 202 and an antistatic layer 201 disposed on one side of the polyethylene terephthalate layer 202. The impedance value of the antistatic layer 201 is 4×10 6 Ω~2×10 9 Ω.

[0061] The first pressure-sensitive adhesive layer 10 and the second pressure-sensitive adhesive layer 30 are each independently obtained by curing the pressure-sensitive adhesive composition.

[0062] The pressure-sensitive adhesive composition comprises the following components: 500 parts of prepolymer, 15 parts to 25 parts of fatty acrylate, 60 parts to 70 parts of hydroxyalkyl acrylate, 5 parts to 10 parts of multifunctional acrylate, 0.5 parts to 1 part of polymer regulator, 1 part to 3 parts of silane coupling agent, 0.05 parts to 0.5 parts of photoinitiator, and 0.3 parts to 0.8 parts of antioxidant.

[0063] In the pressure-sensitive adhesive composition provided in the present application, the prepolymer, as an important component of the pressure-sensitive adhesive composition, has a certain molecular weight and molecular structure, and can provide a basic performance basis for the pressure-sensitive adhesive layer. The pressure-sensitive adhesive can have appropriate viscosity and rheology when not cured, which is convenient for construction and coating, and can form a stable network structure after curing to ensure the bonding performance of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer.

[0064] In the present application, the weight parts of fatty acrylate can be selected from any value between 15 and 25 parts. For example, the weight parts of fatty acrylate include but are not limited to 15, 18, 20, 22, 24 or 25 parts. The weight parts of hydroxyalkyl acrylate can be selected from any value between 60 and 70 parts. For example, the weight parts of hydroxyalkyl acrylate include but are not limited to 60, 62, 64, 66, 68 or 70 parts. The weight parts of multifunctional acrylate can be selected from any value between 5 and 10 parts. For example, the weight parts of multifunctional acrylate include but are not limited to 5, 6, 7, 8, 9 or 10 parts. The weight parts of polymer regulator can be selected from any value between 0.5 and 1 parts. For example, polymer regulator includes but is not limited to 0.5, 0.6, 0.7, 0.8, 0.9 or 1 part. The weight portion of the silane coupling agent can be selected from any value between 1 and 3 parts. For example, the weight portion of the silane coupling agent includes, but is not limited to, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts or 3 parts. The weight portion of the photoinitiator can be selected from any value between 0.05 and 0.5 parts. For example, the weight portion of the photoinitiator includes, but is not limited to, 0.05, 0.08, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5 parts. The weight portion of the antioxidant can be selected from any value between 0.3 and 0.8 parts. For example, the weight portion of the antioxidant includes, but is not limited to, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8 parts.

[0065] Fatty acrylates can give the pressure-sensitive adhesive layer good flexibility and initial adhesion, allowing the adhesive layer to quickly adhere to the surface of the adherend and provide good initial adhesion. At the same time, the hydroxyl group in the hydroxyalkyl acrylate can participate in the cross-linking reaction and work together with the fatty acrylate to significantly improve the cohesive strength of the pressure-sensitive adhesive layer, making the adhesive layer less likely to be damaged during long-term use and maintaining stable bonding performance.

[0066] Multifunctional acrylates can introduce special functional groups or structures to improve the flexibility, transparency and other properties of the pressure-sensitive adhesive layer, so that when it is attached to the touch panel, it can better adapt to touch operations without affecting the transmission and response of touch signals. The addition of silane coupling agents further enhances the interfacial bonding between the pressure-sensitive adhesive layer and the touch panel substrate, reduces the loss or distortion of touch signals caused by interface problems, and thus ensures excellent touch performance. The content of the photoinitiator is between 0.05 and 0.5 parts. Under light conditions, it can quickly initiate the polymerization reaction in the pressure-sensitive adhesive composition, so that the prepolymer and other monomers are quickly cured to form a pressure-sensitive adhesive layer with a suitable degree of crosslinking. This precisely controllable curing process can ensure the performance stability of the pressure-sensitive adhesive layer, so that it can maintain consistent performance in different application environments, which is conducive to improving the reliability and stability of touch devices. Antioxidants can effectively prevent the performance degradation of the pressure-sensitive adhesive layer due to oxidation during use. Under long-term exposure to environmental factors such as air, light, and temperature changes, antioxidants can capture free radicals, inhibit the occurrence of oxidation reactions, extend the service life of the pressure-sensitive adhesive layer, and ensure that it maintains good bonding and touch properties throughout its entire use cycle.

[0067] The components of the pressure-sensitive adhesive composition cooperate with each other to give full play to their respective advantages, and jointly achieve good adhesion, excellent touch performance, a precisely controllable curing process and excellent anti-oxidation performance.

[0068] The prepolymer is prepared from the following raw materials: 700 to 800 parts of alkyl acrylate, 130 to 180 parts of hydroxy acrylate, and 0.4 to 1.2 parts of photocuring agent.

[0069] In the preparation of the prepolymer, the alkyl acrylate provides the prepolymer with a basic polymer backbone structure, which gives the prepolymer good flexibility and viscosity. The hydroxyl group in the molecular structure of the hydroxy acrylate can undergo a cross-linking reaction with other monomers or prepolymers containing active functional groups during the photocuring process to form a three-dimensional network structure. This cross-linked structure can significantly improve the cohesive strength and heat resistance of the prepolymer, making the final pressure-sensitive adhesive layer less likely to deform and lose viscosity under high temperature conditions. In addition, the photocuring agent can absorb light energy and produce active species such as free radicals or cations, triggering the polymerization reaction of monomers such as alkyl acrylate and hydroxy acrylate, so that the prepolymer is rapidly cured to form a three-dimensional network structure with a certain degree of cross-linking. It is understandable that the weight percentage of the alkyl acrylate includes but is not limited to 700 parts, 710 parts, 720 parts, 730 parts, 740 parts, 750 parts, 760 parts, 770 parts, 780 parts, 790 parts or 800 parts. The weight percentage of hydroxy acrylate includes, but is not limited to, 130 parts, 135 parts, 140 parts, 145 parts, 150 parts, 155 parts, 160 parts, 165 parts, 170 parts, 175 parts or 180 parts. The weight percentage of photocuring agent includes, but is not limited to, 0.4 parts, 0.6 parts, 0.8 parts, 1 parts or 1.2 parts.

[0070] In one example, the impedance value of the antistatic layer 201 is 4×10 6 Ω~2×10 9 Ω. Furthermore, the impedance value of the antistatic layer includes but is not limited to 4×10 6 Ω、6×10 6 Ω、8×10 6 Ω、1×10 7 Ω、2×10 7 Ω、5×10 7 Ω、7×10 7 Ω、9×10 7 Ω、1×10 8 Ω、2×10 8 Ω、5×10 8 Ω、7×10 8 Ω、9×10 8 Ω、1×10 9 Ω or 2×10 9 Ω.

[0071] In one example, when the impedance value of the antistatic layer 201 is 4×10 6 Ω~2×10 7 Ω, the first pressure-sensitive adhesive layer 10 and the second pressure-sensitive adhesive layer are obtained by curing the pressure-sensitive adhesive composition.

[0072] When the impedance value of the antistatic layer 201 is 4×10 6Ω~2×10 7 Ω, the pressure-sensitive adhesive composition of the first pressure-sensitive adhesive layer 10 obtained after curing includes the following components: 500 parts of prepolymer, 15 parts to 25 parts of fatty acrylate, 60 parts to 70 parts of hydroxyalkyl acrylate, 5 parts to 10 parts of multifunctional acrylate, 0.5 parts to 1 part of polymer regulator, 1 part to 3 parts of silane coupling agent, 0.05 parts to 0.5 parts of photoinitiator, and 0.3 parts to 0.8 parts of antioxidant. Among them, the prepolymer is prepared by the following components: 700 parts to 800 parts of alkyl acrylate, 130 parts to 180 parts of hydroxy acrylate, and 0.4 parts to 1.2 parts of photocuring agent. It can be understood that when the impedance value of the antistatic layer 201 is 4×10 6 Ω~2×10 7 Ω, the pressure-sensitive adhesive composition of the first pressure-sensitive adhesive layer 10 obtained after curing does not include an antistatic agent.

[0073] When the impedance value of the antistatic layer 201 is 4×10 6 Ω~2×10 7 Ω, the pressure-sensitive adhesive composition of the second pressure-sensitive adhesive layer 20 obtained after curing includes the following components: 500 parts of prepolymer, 15 parts to 25 parts of fatty acrylate, 60 parts to 70 parts of hydroxyalkyl acrylate, 5 parts to 10 parts of multifunctional acrylate, 0.5 parts to 1 part of polymer regulator, 1 part to 3 parts of silane coupling agent, 0.05 parts to 0.5 parts of photoinitiator, and 0.3 parts to 0.8 parts of antioxidant. Among them, the prepolymer is prepared by the following components: 700 parts to 800 parts of alkyl acrylate, 130 parts to 180 parts of hydroxy acrylate, and 0.4 parts to 1.2 parts of photocuring agent. It can be understood that when the impedance value of the antistatic layer 201 is 4×10 6 Ω~2×10 7 When Ω, the pressure-sensitive adhesive composition obtained after curing to obtain the second pressure-sensitive adhesive layer 30 does not include an antistatic agent.

[0074] In another example, when 2×10 7 Ω<The impedance value of the antistatic layer≤2×10 9 Ω, the pressure-sensitive adhesive composition obtained after curing to obtain the first pressure-sensitive adhesive layer 10 further includes 0.5 parts to 5 parts of an antistatic agent; the second pressure-sensitive adhesive layer 30 is obtained by curing the pressure-sensitive adhesive composition.

[0075] When 2×10 7 Ω<The impedance value of the antistatic layer≤2×10 9Ω, after curing, the pressure-sensitive adhesive composition of the first pressure-sensitive adhesive layer 10 includes the following components: 500 parts of prepolymer, 15 parts to 25 parts of fatty acrylate, 60 parts to 70 parts of hydroxyalkyl acrylate, 5 parts to 10 parts of multifunctional acrylate, 0.5 parts to 1 part of polymer regulator, 1 part to 3 parts of silane coupling agent, 0.05 parts to 0.5 parts of photoinitiator, 0.3 parts to 0.8 parts of antioxidant, and 0.5 parts to 5 parts of antistatic agent. Among them, the prepolymer is prepared by the following components: 700 parts to 800 parts of alkyl acrylate, 130 parts to 180 parts of hydroxy acrylate, and 0.4 parts to 1.2 parts of photocuring agent. It can be understood that when 2×10 7 Ω<The impedance value of the antistatic layer≤2×10 9 Ω, the pressure-sensitive adhesive composition obtained after curing to obtain the first pressure-sensitive adhesive layer 10 further includes 0.5 parts to 5 parts of an antistatic agent.

[0076] When 2×10 7 Ω<The impedance value of the antistatic layer≤2×10 9 The pressure-sensitive adhesive composition of the second pressure-sensitive adhesive layer 30 obtained after curing at Ω includes the following components: 500 parts of prepolymer, 15 parts to 25 parts of fatty acrylate, 60 parts to 70 parts of hydroxyalkyl acrylate, 5 parts to 10 parts of multifunctional acrylate, 0.5 parts to 1 part of polymer regulator, 1 part to 3 parts of silane coupling agent, 0.05 parts to 0.5 parts of photoinitiator, and 0.3 parts to 0.8 parts of antioxidant. The prepolymer is prepared by the following raw materials: 700 parts to 800 parts of alkyl acrylate, 130 parts to 180 parts of hydroxy acrylate, and 0.4 parts to 1.2 parts of photocuring agent. It can be understood that when 2×10 7 Ω<The impedance value of the antistatic layer≤2×10 9 When Ω, the pressure-sensitive adhesive composition obtained after curing to obtain the second pressure-sensitive adhesive layer 30 does not include an antistatic agent.

[0077] When 2×10 7 Ω<The impedance value of the antistatic layer≤2×10 9 Ω, in the intermediate layer 20, compared with the polyethylene terephthalate layer 202, the antistatic layer 201 is closer to the first pressure-sensitive adhesive layer 10.

[0078] In one example, the fatty acrylate includes one or more of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and cyclohexyl methacrylate.

[0079] In one example, the hydroxyalkyl acrylate includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

[0080] In one example, the multifunctional acrylate includes one or more of HS-268 special acrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate and trimethylolpropane triacrylate.

[0081] In one example, the polymer modifier includes one or more of dodecanethiol, dithioesters, and aliphatic thiols.

[0082] In one example, the silane coupling agent includes one or more of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, γ-glycidyloxypropyl trimethoxysilane and γ-(2,3-epoxypropoxy)propyl trimethoxysilane.

[0083] In one example, the photoinitiator includes one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-2-methyl-1-phenylpropanone.

[0084] In one example, the antioxidant includes one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], dilauryl thiodipropionate, and phosphite antioxidants.

[0085] In one example, the antistatic agent includes one or more of anionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents, nonionic antistatic agents and polymer antistatic agents.

[0086] Among them, the types of anionic antistatic agents include but are not limited to alkyl sulfonates, alkyl sulfates, alkyl phosphates and alkylphenol polyoxyethylene ether sulfates. The types of amphoteric antistatic agents include but are not limited to betaine, alkyl imidazolinium salts and alkyl amino acids. The types of nonionic antistatic agents include but are not limited to fatty acid polyol esters, alkanolamines, alkanolamides, and ethylene oxide adducts of fatty acids, fatty alcohols and alkylphenols. Polymeric antistatic agents refer to polymers containing conductive units of polyethylene oxide chains and polyquaternary ammonium salt structures in the molecules. In one example, the polymeric antistatic agent includes one or more of polyethylene oxide, polyether ester amide, (meth) acrylate copolymers containing quaternary ammonium salts, and silicone containing hydrophilic groups.

[0087] In one example, the alkyl acrylate includes one or more of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and cyclohexyl methacrylate.

[0088] In one example, the hydroxy acrylate includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

[0089] In one example, the photocuring agent includes one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-2-methyl-1-phenylpropanone.

[0090] In one example, the step of preparing the prepolymer includes: mixing the alkyl acrylate, the hydroxy acrylate, the photocuring agent and a solvent, and performing prepolymerization under ultraviolet light irradiation to prepare the prepolymer.

[0091] In one example, in the step of preparing the prepolymer, the process parameters of the prepolymerization include: the power of the ultraviolet lamp irradiation is 15W to 20 W. Further, the power of the ultraviolet lamp irradiation includes but is not limited to 15 W, 16 W, 17 W, 18 W, 19 W or 20 W.

[0092] In one example, in the step of preparing the prepolymer, the process parameters of the prepolymerization include: the time of ultraviolet light irradiation is 1 min to 5 min. Further, the time of ultraviolet light irradiation includes but is not limited to 1 min, 2 min, 3 min, 4 min or 5 min.

[0093] In one example, in the step of preparing the prepolymer, the prepolymerization is carried out under a nitrogen atmosphere.

[0094] In one example, the thickness of the intermediate layer is 40 μm to 60 μm. Further, the thickness of the intermediate layer includes but is not limited to 40 μm, 45 μm, 50 μm, 55 μm, 58 μm or 60 μm.

[0095] In one example, the thickness of the first pressure-sensitive adhesive layer is 90 μm to 110 μm. For example, the thickness of the first pressure-sensitive adhesive layer includes but is not limited to 90 μm, 95 μm, 98 μm, 100 μm, 103 μm, 105 μm, 108 μm or 110 μm.

[0096] In one example, the thickness of the second pressure-sensitive adhesive layer is 90 μm to 110 μm. For example, the thickness of the second pressure-sensitive adhesive layer includes but is not limited to 90 μm, 95 μm, 98 μm, 100 μm, 103 μm, 105 μm, 108 μm or 110 μm.

[0097] In one example, the composite film layer also includes a first substrate layer and a second substrate layer, the first substrate layer is arranged on the side surface of the first pressure-sensitive adhesive layer away from the middle layer, and the second substrate layer is arranged on the side surface of the second pressure-sensitive adhesive layer away from the middle layer.

[0098] It can be understood that the first substrate layer and the second substrate layer are adhered layers. In this case, the first substrate layer and the second substrate layer can be components of an electronic display screen.

[0099] In one example, the first substrate layer is silicone-treated polyethylene terephthalate.

[0100] In one example, the second substrate layer is silicone-treated polyethylene terephthalate. The first substrate layer and the second substrate layer are selected from silicone-treated polyethylene terephthalate, which has good release properties with the pressure-sensitive adhesive layer, can effectively peel off the pressure-sensitive adhesive layer, and use it to bond the adherend.

[0101] In one example, the thickness of the first substrate layer is 80 μm to 120 μm. Further, the thickness of the first substrate layer includes but is not limited to 80 μm, 90 μm, 100 μm, 110 μm or 120 μm.

[0102] In one example, the thickness of the second substrate layer is 80 μm to 120 μm. Further, the thickness of the second substrate layer includes but is not limited to 80 μm, 90 μm, 100 μm, 110 μm or 120 μm.

[0103] The second aspect of the present application provides a method for preparing the composite adhesive layer according to any one of the embodiments of the first aspect of the present application, comprising the following steps:

[0104] The pressure-sensitive adhesive composition is respectively coated between the intermediate layer and the first substrate layer and between the intermediate layer and the second substrate layer. After curing, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are respectively formed. After release treatment, the first substrate layer and the second substrate layer are removed to prepare the composite adhesive layer.

[0105] In one example, the curing is performed under ultraviolet light irradiation conditions at a wavelength of 300nm~400nm.

[0106] In one example, the total energy exposure of the curing is 1800 mJ / cm 2 ~2200mJ / cm 2 .

[0107] It can be understood that during the preparation process, the first substrate layer and the second substrate layer are used as release films, which are peeled off to form a composite adhesive layer with the outermost pressure-sensitive adhesive layer, and are used to bond adherends.

[0108] A third aspect of the present application provides an electronic display device, comprising the composite adhesive layer described in any one of the embodiments of the first aspect of the present application.

[0109] The composite adhesive layer provided in the present application has good bonding force, so it can effectively bond adherends. At the same time, it has good antistatic and touch performance, and can be effectively applied to electronic display devices.

[0110] In order to make it easier to understand and implement the present application, the following easier-to-implement, more specific and detailed embodiments and comparative examples are provided as references.

[0111] Unless otherwise specified, the raw materials used in the following experiments can be purchased from the market.

[0112] Preparation Example 1

[0113] Preparation Example 1 of the present application provides a pressure-sensitive adhesive composition and a preparation method thereof, comprising the following steps:

[0114] Preparation of prepolymer: The following reagents were added to a 2000mL three-necked flask equipped with a stirring paddle, a nitrogen inlet and a thermometer: 750g of n-butyl acrylate (alkyl acrylate), 160g of hydroxybutyl acrylate (hydroxy acrylate), 90g of N-vinyl-2-pyrrolidone (solvent), and 0.8g of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (photocuring agent). After passing high-purity (99.99%) nitrogen through the above device for 1 hour, an 18W ultraviolet lamp was turned on for 2 minutes to obtain a prepolymer with a viscosity of about 400cps.

[0115] Preparation of pressure-sensitive adhesive composition:

[0116] 500 g of prepolymer, 20 g of n-butyl methacrylate (fatty acrylate), 65 g of hydroxybutyl acrylate (hydroxyalkyl acrylate), 7.5 g of HS-268 special acrylate (from Shanghai Hesheng Chemical Technology Co., Ltd., multifunctional acrylate), 0.7 g of n-dodecanethiol (polymer regulator), 1.5 g of silane coupling agent (γ-(2,3-epoxypropoxy)propyltrimethoxysilane), 0.25 g of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (photoinitiator), 0.5 g of antioxidant 1010 and 0.6 g of antistatic agent L-607 (quaternary ammonium salt antistatic agent) were added, the mixture was fully stirred and mixed, and then degassed to obtain a pressure-sensitive adhesive composition.

[0117] Preparation Example 2

[0118] Preparation Example 2 of the present application provides a pressure-sensitive adhesive composition and a preparation method thereof, comprising the following steps:

[0119] Preparation of prepolymer: The following reagents were added to a 2000mL three-necked flask equipped with a stirring paddle, a nitrogen inlet and a thermometer: 750g of n-butyl acrylate (alkyl acrylate), 160g of hydroxybutyl acrylate (hydroxy acrylate), 90g of N-vinyl-2-pyrrolidone (solvent), and 0.8g of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (photocuring agent). After passing high-purity (99.99%) nitrogen through the above device for 1 hour, an 18W ultraviolet lamp was turned on for 2 minutes to obtain a prepolymer with a viscosity of about 400cps.

[0120] Preparation of pressure-sensitive adhesive composition:

[0121] 500 g of prepolymer, 20 g of n-butyl methacrylate (fatty acrylate), 65 g of hydroxybutyl acrylate (hydroxyalkyl acrylate), 7.5 g of HS-268 special acrylate (from Shanghai Hesheng Chemical Technology Co., Ltd., multifunctional acrylate), 0.7 g of n-dodecanethiol (polymer regulator), 1.5 g of silane coupling agent (γ-(2,3-epoxypropoxy)propyltrimethoxysilane), 0.25 g of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (photoinitiator), 0.5 g of antioxidant 1010 and 3 g of antistatic agent L-607 (quaternary ammonium salt antistatic agent) were added, the mixture was fully stirred and mixed, and then degassed to obtain a pressure-sensitive adhesive composition.

[0122] Preparation Example 3

[0123] Preparation Example 3 of the present application provides a pressure-sensitive adhesive composition and a preparation method thereof, comprising the following steps:

[0124] Preparation of prepolymer: The following reagents were added to a 2000mL three-necked flask equipped with a stirring paddle, a nitrogen inlet and a thermometer: 750g of n-butyl acrylate (alkyl acrylate), 160g of hydroxybutyl acrylate (hydroxy acrylate), 90g of N-vinyl-2-pyrrolidone (solvent), and 0.8g of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (photocuring agent). After passing high-purity (99.99%) nitrogen through the above device for 1 hour, an 18W ultraviolet lamp was turned on for 2 minutes to obtain a prepolymer with a viscosity of about 400cps.

[0125] Preparation of pressure-sensitive adhesive composition:

[0126] 500 g of prepolymer, 20 g of n-butyl methacrylate (fatty acrylate), 65 g of hydroxybutyl acrylate (hydroxyalkyl acrylate), 7.5 g of HS-268 special acrylate (from Shanghai Hesheng Chemical Technology Co., Ltd., multifunctional acrylate), 0.7 g of n-dodecanethiol (polymer regulator), 1.5 g of silane coupling agent (γ-(2,3-epoxypropoxy)propyltrimethoxysilane), 0.25 g of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (photoinitiator), 0.5 g of antioxidant 1010 were added, the mixture was fully stirred and mixed, and then degassed to obtain a pressure-sensitive adhesive composition.

[0127] Preparation Example 4

[0128] Preparation Example 4 of the present application provides a pressure-sensitive adhesive composition and a preparation method thereof, comprising the following steps:

[0129] Preparation of prepolymer: The following reagents were added to a 2000mL three-necked flask equipped with a stirring paddle, a nitrogen inlet and a thermometer: 750g of n-butyl acrylate (alkyl acrylate), 160g of hydroxybutyl acrylate (hydroxy acrylate), 90g of N-vinyl-2-pyrrolidone (solvent), and 0.8g of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (photocuring agent). After passing high-purity (99.99%) nitrogen through the above device for 1 hour, an 18W ultraviolet lamp was turned on for 2 minutes to obtain a prepolymer with a viscosity of about 400cps.

[0130] Preparation of pressure-sensitive adhesive composition:

[0131] 500 g of prepolymer, 20 g of n-butyl methacrylate (fatty acrylate), 65 g of hydroxybutyl acrylate (hydroxyalkyl acrylate), 7.5 g of HS-268 special acrylate (from Shanghai Hesheng Chemical Technology Co., Ltd., multifunctional acrylate), 0.7 g of n-dodecanethiol (polymer regulator), 1.5 g of silane coupling agent (γ-(2,3-epoxypropoxy)propyltrimethoxysilane), 0.25 g of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (photoinitiator), 0.5 g of antioxidant 1010 and 6 g of antistatic agent L-607 (quaternary ammonium salt antistatic agent) were added, the mixture was fully stirred and mixed, and then degassed to obtain a pressure-sensitive adhesive composition.

[0132] Preparation Example 5

[0133] Preparation Example 5 of the present application provides a pressure-sensitive adhesive composition and a preparation method thereof, comprising the following steps:

[0134] Preparation of prepolymer: The following reagents were added to a 2000mL three-necked flask equipped with a stirring paddle, a nitrogen inlet and a thermometer: 700g of n-butyl acrylate (alkyl acrylate), 180g of hydroxybutyl acrylate (hydroxy acrylate), 120g of N-vinyl-2-pyrrolidone (solvent), and 0.8g of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (photocuring agent). After passing high-purity (99.99%) nitrogen through the above device for 1 hour, an 18W ultraviolet lamp was turned on for 2 minutes to obtain a prepolymer with a viscosity of about 400cps.

[0135] Preparation of pressure-sensitive adhesive composition:

[0136] 500 g of prepolymer, 20 g of n-butyl methacrylate (fatty acrylate), 65 g of hydroxybutyl acrylate (hydroxyalkyl acrylate), 7.5 g of HS-268 special acrylate (from Shanghai Hesheng Chemical Technology Co., Ltd., multifunctional acrylate), 0.8 g of n-dodecanethiol (polymer regulator), 1.5 g of silane coupling agent (γ-(2,3-epoxypropoxy)propyltrimethoxysilane), 0.25 g of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (photoinitiator), 0.5 g of antioxidant 1010 were added, the mixture was fully stirred and mixed, and then degassed to obtain a pressure-sensitive adhesive composition.

[0137] Example 1

[0138] Prepare a roll of antistatic coating (impedance 2×10 9 The pressure-sensitive adhesive composition of Preparation Example 1 was coated between the antistatic coating side surface of the middle layer and the silicone-treated polyethylene terephthalate (100 μm thick, first substrate layer), and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy irradiation of 2000 mJ / cm 2 , and obtain a semi-finished product with a first pressure-sensitive adhesive layer thickness of 100 μm.

[0139] The pressure-sensitive adhesive composition of Preparation Example 3 was coated between the intermediate layer (the coated surface was the polyethylene terephthalate side surface of the intermediate layer) and the silicone-treated polyethylene terephthalate (100 μm thick, the second substrate layer) of the semi-finished product, and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , and a composite adhesive layer with a second pressure-sensitive adhesive layer thickness of 100 μm is obtained. The structure of the composite adhesive layer is PET / first pressure-sensitive adhesive layer / intermediate layer / second pressure-sensitive adhesive layer / PET, and the antistatic coating in the intermediate layer is in contact with the first pressure-sensitive adhesive layer.

[0140] Example 2

[0141] Prepare a roll of antistatic coating (impedance 2×10 9 The pressure-sensitive adhesive composition of Preparation Example 2 was coated between the antistatic coating side surface of the middle layer and the silicone-treated polyethylene terephthalate (100 μm thick, first substrate layer), and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy irradiation of 2000 mJ / cm 2 , and obtain a semi-finished product with a first pressure-sensitive adhesive layer thickness of 100 μm.

[0142] The pressure-sensitive adhesive composition of Preparation Example 3 was coated between the intermediate layer (the coated surface was the polyethylene terephthalate side surface of the intermediate layer) and the silicone-treated polyethylene terephthalate (100 μm thick, the second substrate layer) of the semi-finished product, and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , and a composite adhesive layer with a second pressure-sensitive adhesive layer thickness of 100 μm is obtained. The structure of the composite adhesive layer is PET / first pressure-sensitive adhesive layer / intermediate layer / second pressure-sensitive adhesive layer / PET, and the antistatic coating in the intermediate layer is in contact with the first pressure-sensitive adhesive layer.

[0143] Example 3

[0144] Prepare a roll with an antistatic coating (impedance 4×10 6 The pressure-sensitive adhesive composition of Preparation Example 3 was coated between the antistatic coating side surface of the middle layer and the silicone-treated polyethylene terephthalate (100 μm thick, first substrate layer), and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , and obtain a semi-finished product with a first pressure-sensitive adhesive layer thickness of 100 μm.

[0145] The pressure-sensitive adhesive composition of Preparation Example 3 was coated between the intermediate layer (the coated surface was the polyethylene terephthalate side surface of the intermediate layer) and the silicone-treated polyethylene terephthalate (100 μm thick, the second substrate layer) of the semi-finished product, and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , and a composite adhesive layer with a second pressure-sensitive adhesive layer thickness of 100 μm is obtained. The structure of the composite adhesive layer is PET / first pressure-sensitive adhesive layer / intermediate layer / second pressure-sensitive adhesive layer / PET, and the antistatic coating in the intermediate layer is in contact with the first pressure-sensitive adhesive layer.

[0146] Comparative Example 1

[0147] Prepare a roll with an antistatic coating (impedance 4×10 6 The pressure-sensitive adhesive composition of Preparation Example 4 was coated between the antistatic coating side surface of the middle layer and the silicone-treated polyethylene terephthalate (100 μm thick, first substrate layer), and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy irradiation of 2000 mJ / cm 2 , and obtain a semi-finished product with a first pressure-sensitive adhesive layer thickness of 100 μm.

[0148] The pressure-sensitive adhesive composition of Preparation Example 3 was coated between the intermediate layer (the coated surface was the polyethylene terephthalate side surface of the intermediate layer) and the silicone-treated polyethylene terephthalate (100 μm thick, the second substrate layer) of the semi-finished product, and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , and a composite adhesive layer with a second pressure-sensitive adhesive layer thickness of 100 μm is obtained. The structure of the composite adhesive layer is PET / first pressure-sensitive adhesive layer / intermediate layer / second pressure-sensitive adhesive layer / PET, and the antistatic coating in the intermediate layer is in contact with the first pressure-sensitive adhesive layer.

[0149] Comparative Example 2

[0150] The pressure-sensitive adhesive composition of Preparation Example 3 was coated between a silicone-treated polyethylene terephthalate (thickness 100 μm, first substrate layer) and a silicone-treated polyethylene terephthalate (thickness 100 μm, second substrate layer), and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , a composite adhesive layer with a pressure-sensitive adhesive layer thickness of 250 μm is obtained. The structure of the composite adhesive layer is PET / pressure-sensitive adhesive layer / PET.

[0151] Comparative Example 3

[0152] The pressure-sensitive adhesive composition of Preparation Example 5 was coated between a silicone-treated polyethylene terephthalate (100 μm thick, first substrate layer) and a silicone-treated polyethylene terephthalate (100 μm thick, second substrate layer), and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , a composite adhesive layer with a pressure-sensitive adhesive layer thickness of 250 μm is obtained. The structure of the composite adhesive layer is PET / pressure-sensitive adhesive layer / PET.

[0153] Comparative Example 4

[0154] Prepare a roll of antistatic coating (impedance 6×10 9 The pressure-sensitive adhesive composition of Preparation Example 3 was coated between the antistatic coating side surface of the middle layer and the silicone-treated polyethylene terephthalate (100 μm thick, first substrate layer), and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , and obtain a semi-finished product with a first pressure-sensitive adhesive layer thickness of 100 μm.

[0155] The pressure-sensitive adhesive composition of Preparation Example 3 was coated between the intermediate layer (the coated surface was the polyethylene terephthalate side surface of the intermediate layer) and the silicone-treated polyethylene terephthalate (100 μm thick, the second substrate layer) of the semi-finished product, and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , and a composite adhesive layer with a second pressure-sensitive adhesive layer thickness of 100 μm is obtained. The structure of the composite adhesive layer is PET / first pressure-sensitive adhesive layer / intermediate layer / second pressure-sensitive adhesive layer / PET, and the antistatic coating in the intermediate layer is in contact with the first pressure-sensitive adhesive layer.

[0156] Comparative Example 5

[0157] Prepare a roll of antistatic coating (impedance 1×10 5 The pressure-sensitive adhesive composition of Preparation Example 3 was coated between the antistatic coating side surface of the middle layer and the silicone-treated polyethylene terephthalate (100 μm thick, first substrate layer), and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , and obtain a semi-finished product with a first pressure-sensitive adhesive layer thickness of 100 μm.

[0158] The pressure-sensitive adhesive composition of Preparation Example 3 was coated between the intermediate layer (the coated surface was the polyethylene terephthalate side surface of the intermediate layer) and the silicone-treated polyethylene terephthalate (100 μm thick, the second substrate layer) of the semi-finished product, and then exposed to ultraviolet radiation with a spectral output of 400 nm and a total energy exposure of 2000 mJ / cm 2 , and a composite adhesive layer with a second pressure-sensitive adhesive layer thickness of 100 μm is obtained. The structure of the composite adhesive layer is PET / first pressure-sensitive adhesive layer / intermediate layer / second pressure-sensitive adhesive layer / PET, and the antistatic coating in the intermediate layer is in contact with the first pressure-sensitive adhesive layer.

[0159] The hardness test method is: using a hardness tester DTAA II from Germany. The hardness test method includes: coating the pressure-sensitive adhesive on two layers of release film for UV curing, cutting and stacking the adhesive layer into an adhesive layer thickness of 2000μm, then tearing off the two layers of release film, laminating the pressure-sensitive adhesive layer to the glass plate, and performing a hardness test. When the composite adhesive layer includes a single pressure-sensitive adhesive layer, the hardness is the hardness of the single pressure-sensitive adhesive layer. When the composite adhesive layer includes a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer, the hardness is expressed as the average value of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer.

[0160] The adhesion test method is as follows: tear off the side of the composite adhesive layer with less release force, cover it with a non-release PET film, cut it into a sample with a length of 15 cm and a width of 2.5 cm, stick it on a glass plate and let it stand for 20 minutes before testing its adhesion.

[0161] The test method of the antistatic value is as follows: the first pressure-sensitive adhesive layer and the first substrate layer in the composite adhesive layer are torn apart, and the impedance of the adhesive layer is tested using an electrostatic tester, with the distance between electrodes being 8 cm.

[0162] The test method for antistatic effect and touch effect is as follows: tear off the first pressure-sensitive adhesive layer and the first substrate layer, tear off the second pressure-sensitive adhesive layer and the second substrate layer, and then laminate them between the glass cover and the module, wherein the first pressure-sensitive adhesive layer is in contact with the glass cover, and use a fixture to light up the laminated sample to test the product touch effect; then adjust the screen to a gray screen, use an electric shock gun with a voltage of +8KV to touch the surface of the cover, and record the screen status. The corresponding test results are shown in Table 1.

[0163] Table 1

[0164]

[0165] In Example 1, the impedance value of the antistatic coating of the middle layer is 2×10 9 Ω, the first pressure-sensitive adhesive layer includes 0.3 g of antistatic agent, and the second pressure-sensitive adhesive layer does not include antistatic agent. In Example 2, the impedance value of the antistatic coating is 2×10 9 Ω, the first pressure-sensitive adhesive layer includes 3g of antistatic agent, and the second pressure-sensitive adhesive layer does not include antistatic agent. In Example 3, the impedance value of the antistatic coating is 4×10 6 Ω, the first pressure-sensitive adhesive layer does not include an antistatic agent, and the second pressure-sensitive adhesive layer does not include an antistatic agent. The above three embodiments can ensure that the composite adhesive layer has good adhesion and has both excellent touch performance and antistatic performance.

[0166] In Comparative Example 1, the impedance value of the antistatic coating is 4×10 6Ω, the first pressure-sensitive adhesive layer includes 6g of antistatic agent, and the second pressure-sensitive adhesive layer does not include antistatic agent. In this case, the antistatic effect is excellent, but the touch performance cannot be taken into account. In Comparative Examples 2 and 3, no intermediate layer is included, and the antistatic property of the prepared composite adhesive layer is poor. In Comparative Example 4, the impedance value of the antistatic coating is 6×10 9 Ω, the first pressure-sensitive adhesive layer does not include an antistatic agent, and the second pressure-sensitive adhesive layer does not include an antistatic agent; in Comparative Example 5, the impedance value of the antistatic coating is 1×10 5 Ω, the first pressure-sensitive adhesive layer does not include an antistatic agent, and the second pressure-sensitive adhesive layer does not include an antistatic agent; in these two comparative examples, the impedance value of the antistatic coating is low or high, so that it cannot have both antistatic and touch performance.

[0167] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0168] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims, and the description may be used to interpret the content of the claims.

Claims

1. A composite adhesive layer, characterized in that: It comprises a first pressure-sensitive adhesive layer, an intermediate layer, and a second pressure-sensitive adhesive layer stacked in sequence; The intermediate layer includes a polyethylene terephthalate layer and an antistatic layer disposed on one surface of the polyethylene terephthalate layer, and the impedance value of the antistatic layer is 4×10 6 Ω~2×10 9 Ω; The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are each independently obtained by curing the pressure-sensitive adhesive composition; The pressure-sensitive adhesive composition comprises the following components: 500 parts of prepolymer, 15 parts to 25 parts of fatty acrylate, 60 parts to 70 parts of hydroxyalkyl acrylate, 5 parts to 10 parts of multifunctional acrylate, 0.5 parts to 1 part of polymer regulator, 1 part to 3 parts of silane coupling agent, 0.05 parts to 0.5 parts of photoinitiator, and 0.3 parts to 0.8 parts of antioxidant; The prepolymer is prepared from the following raw materials: 700 to 800 parts of alkyl acrylate, 130 to 180 parts of hydroxy acrylate, and 0.4 to 1.2 parts of photocuring agent.

2. The composite adhesive layer according to claim 1, characterized in that: When the impedance value of the antistatic layer is 4×10 6 Ω~2×10 7 Ω, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are each independently obtained by curing the pressure-sensitive composition.

3. The composite adhesive layer according to claim 1, characterized in that: When 2×10 7 Ω<The impedance value of the antistatic layer≤2×10 9 Ω, the pressure-sensitive adhesive composition for obtaining the first pressure-sensitive adhesive layer after curing further comprises 0.5 to 5 parts of an antistatic agent; the second pressure-sensitive adhesive layer is obtained by curing the pressure-sensitive adhesive composition; Wherein, in the intermediate layer, compared with the polyethylene terephthalate layer, the antistatic layer is closer to the first pressure-sensitive adhesive layer.

4. The composite adhesive layer according to any one of claims 1 to 3, characterized in that: The pressure-sensitive adhesive composition has one or more of the following characteristics: (1) The acrylic acid fatty ester includes one or more of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and cyclohexyl methacrylate; (2) The hydroxyalkyl acrylate includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate; (3) The multifunctional acrylate includes one or more of HS-268 special acrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate and trimethylolpropane triacrylate; (4) The polymer regulator includes one or more of dodecanethiol, dithioesters and aliphatic thiols; (5) The silane coupling agent includes one or more of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, γ-glycidyloxypropyl trimethoxysilane and γ-(2,3-epoxypropoxy)propyl trimethoxysilane; (6) The photoinitiator includes one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-2-methyl-1-phenylpropanone; (7) The antioxidant includes one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, dilauryl thiodipropionate and phosphite antioxidants.

5. The composite adhesive layer according to claim 3, characterized in that: The antistatic agent includes one or more of anionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents, nonionic antistatic agents and polymer antistatic agents.

6. The composite adhesive layer according to any one of claims 1 to 3, characterized in that: The prepolymer has one or more of the following characteristics: (1) The alkyl acrylate includes one or more of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and cyclohexyl methacrylate; (2) The hydroxy acrylate includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate; (3) The photocuring agent includes one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-2-methyl-1-phenylpropanone; (4) The step of preparing the prepolymer includes: mixing the alkyl acrylate, the hydroxy acrylate, the photocuring agent and a solvent, and performing prepolymerization under ultraviolet light irradiation to prepare the prepolymer.

7. The composite adhesive layer according to any one of claims 1 to 3 or 5, characterized in that: The composite film layer also includes a first substrate layer and a second substrate layer. The first substrate layer is arranged on a surface of the first pressure-sensitive adhesive layer away from the middle layer, and the second substrate layer is arranged on a surface of the second pressure-sensitive adhesive layer away from the middle layer.

8. The composite adhesive layer according to claim 7, characterized in that: The composite adhesive layer has one or more of the following characteristics: (1) The first substrate layer is polyethylene terephthalate treated with silicone resin; (2) The second substrate layer is polyethylene terephthalate treated with silicone resin; (3) The thickness of the first substrate layer is 80 μm to 120 μm; (4) The thickness of the second substrate layer is 80 μm to 120 μm; (5) The thickness of the intermediate layer is 40 μm to 60 μm; (6) The thickness of the first pressure-sensitive adhesive layer is 90 μm to 110 μm; (7) The thickness of the second pressure-sensitive adhesive layer is 90 μm to 110 μm.

9. A method for preparing the composite adhesive layer according to any one of claims 1 to 8, characterized in that: The following steps are involved: The pressure-sensitive adhesive composition is respectively coated between the intermediate layer and the first substrate layer and between the intermediate layer and the second substrate layer. After curing, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are respectively formed. After release treatment, the first substrate layer and the second substrate layer are removed to prepare the composite adhesive layer.

10. An electronic display device, characterized in that: Comprising the composite adhesive layer as described in any one of claims 1 to 8.

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