OLED display module device

Abstract

The present application relates to the technical field of display devices, and provides an OLED display module device. The OLED display module device provided by the present application comprises an OLED display module and a composite acrylic foam buffer material, which are arranged in a stacked manner. The composite acrylic foam buffer material comprises a layer of self-adhering acrylic foam and a layer of damping pressure-sensitive adhesive which are arranged in a stacked manner. The present application compounds self-adhering acrylic foam and damping pressure-sensitive adhesive, and, since two sides of the resulting composite acrylic foam buffer material are sticky, no adhesive needs to be applied thereto. Moreover, the composite acrylic foam buffer material exhibits excellent properties such as impact resistance compression resistance while having a reduced thickness, and can be directly used to provide buffer protection for an OLED display module.

Description

An OLED display module device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on October 27, 2023, with application number CN202311416553.0 and application name “A Type of OLED Display Module Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of display devices, and in particular to an OLED display module device. Background Art

[0003] Acrylic foam is a specialized foam based on acrylic resin. Due to its unique viscoelastic composition and closed-cell foaming technology, it exhibits excellent adhesion, sealing, filling, cushioning, and weather resistance. Acrylic foam tape can be made by coating both sides of the foam with acrylic pressure-sensitive adhesive. It is widely used for bonding and fixing in the electronics, automotive, energy, home appliances, and construction industries.

[0004] With the rapid development of electronic products and the information technology industry, especially the development of consumer mobile terminals such as mobile phones, tablets, and laptops, display screens, as key components, have been constantly innovating and gradually developing in multiple directions such as lightweight, narrow-frame, and flexible screens. Among them, the mainstream technology has also transitioned from liquid crystal (LCD) displays to organic light-emitting diode (OLED) displays. The unique structure of OLED displays is easily broken by external impact or squeezed between glass during use. Therefore, there is usually a layer of buffer material in the structure of OLED displays to play a protective role during the production process and use. The mainstream OLED buffer material on the market is acrylic foam (the structure is shown in Figure 1). The two sides of the acrylic foam are respectively backed with glue (acrylic pressure-sensitive adhesive) and then bonded to the OLED display module and copper foil. It has good impact absorption function and long-term reliable working performance. However, as the design of OLED displays continues to develop towards ultra-thin, curved, and foldable directions, the current buffer material has gradually failed to meet the requirements.

[0005] Summary of the Invention

[0006] The present application aims to provide an OLED display module device. This application combines self-adhesive acrylic foam with a damping pressure-sensitive adhesive. The resulting composite acrylic foam cushioning material is adhesive on both sides, eliminating the need for adhesive backing. Furthermore, it exhibits excellent impact and extrusion resistance at a relatively thin thickness, making it suitable for direct cushioning and protection of OLED display modules.

[0007] In order to achieve the above application objectives, this application provides the following technical solutions:

[0008] The present application provides an OLED display module device, comprising a stacked OLED display module and a composite acrylic foam cushioning material, wherein the composite acrylic foam cushioning material comprises a stacked self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer.

[0009] Preferably, the damping pressure-sensitive adhesive layer has a thickness of 10 to 100 μm, a 180° peeling force of ≥8 N / 25 mm, and an initial adhesion force of ≥4 N / 25 mm.

[0010] Preferably, the damping pressure-sensitive adhesive layer is prepared from raw materials including damping pressure-sensitive adhesive, and the damping pressure-sensitive adhesive includes at least one of silicone damping pressure-sensitive adhesive, acrylic damping pressure-sensitive adhesive and rubber damping pressure-sensitive adhesive, and the maximum loss factor of the damping pressure-sensitive adhesive is greater than 0.5 at a temperature of -40 to 0°C and a frequency of 1 Hz.

[0011] Preferably, the thickness of the self-adhesive acrylic foam layer is 100-300 μm, the 180° peeling force is ≥10 N / 25 mm, and the initial adhesion force is ≥6 N / 25 mm.

[0012] Preferably, the self-adhesive acrylic foam layer is formed of self-adhesive acrylic foam; based on water, the relative density of the self-adhesive acrylic foam is 0.4-1.2; the elongation at break of the self-adhesive acrylic foam is greater than 400%, and the tensile strength is greater than 0.5 MPa.

[0013] Preferably, the self-adhesive acrylic foam is formed by a foamed self-adhesive acrylic polymer; the storage modulus of the foamed self-adhesive acrylic polymer at 25°C is ≤10 6 Pa, glass transition temperature ≤10℃.

[0014] Preferably, the raw materials for preparing the self-adhesive acrylic foam include the following components in parts by mass:

[0015] 100 parts of acrylic acid prepolymer, wherein the raw materials for preparing the acrylic acid prepolymer include acrylic acid monomer and a first initiator;

[0016] 0-10 parts of fumed silica;

[0017] 0.01 to 5 parts of cross-linking agent;

[0018] 0.01-10 parts of foaming agent;

[0019] 0.01 to 2 parts of the second initiator;

[0020] 0 to 10 parts of additives.

[0021] Preferably, the viscosity of the acrylic prepolymer is 2000-10000 cps.

[0022] Preferably, the mass of the first initiator is 0.01-1% of the mass of the acrylic monomer.

[0023] Preferably, the acrylic monomer includes one or more of an acrylic acid ester monomer with an alkyl group of C1 to 12, a methacrylic acid ester monomer with an alkyl group of C1 to 12, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, styrene, vinyl acetate, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile and isooctyl acrylate.

[0024] Preferably, the crosslinking agent is diacrylate.

[0025] Preferably, the foaming agent includes one or more of a filler-type foaming agent, a surfactant-type foaming agent and a physical foaming agent.

[0026] Preferably, the auxiliary agent includes one or more of a color paste, a chain transfer agent, an anti-aging agent and a light stabilizer.

[0027] Preferably, the first initiator and the second photoinitiator independently comprise a photoinitiator or a thermal initiator.

[0028] Preferably, the method for preparing the self-adhesive acrylic foam comprises the following steps:

[0029] The self-adhesive acrylic foam is obtained by mixing acrylic prepolymer, fumed silica, a crosslinking agent, a foaming agent, a second initiator and an auxiliary agent and then curing the mixture.

[0030] Preferably, the composite acrylic foam cushioning material further comprises a plastic film layer, the thickness of the plastic film layer is 3 to 30 μm, and the arrangement position of the plastic film layer is at least one of the following:

[0031] The laminate is arranged between the self-adhesive acrylic foam layer and the damping pressure-sensitive adhesive layer;

[0032] The laminate is arranged on one side of the self-adhesive acrylic foam layer and does not contact the damping pressure-sensitive adhesive layer;

[0033] The laminate is arranged on one side of the damping pressure-sensitive adhesive layer and is not in contact with the self-adhesive acrylic foam layer.

[0034] Preferably, the structure of the composite acrylic foam cushioning material is:

[0035] A self-adhesive acrylic foam layer, a plastic film layer and a damping pressure-sensitive adhesive layer are stacked in sequence;

[0036] Alternatively, a plastic film layer, a self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer are laminated in sequence;

[0037] Alternatively, a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer, and a plastic film layer are sequentially laminated;

[0038] Alternatively, a plastic film layer, a self-adhesive acrylic foam layer, a plastic film layer and a damping pressure-sensitive adhesive layer are sequentially laminated;

[0039] Alternatively, a self-adhesive acrylic foam layer, a plastic film layer, a damping pressure-sensitive adhesive layer, and a plastic film layer are sequentially laminated;

[0040] Alternatively, a plastic film layer, a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer and a plastic film layer are sequentially laminated;

[0041] Alternatively, a plastic film layer, a self-adhesive acrylic foam layer, a plastic film layer, a damping pressure-sensitive adhesive layer and a plastic film layer are stacked in sequence.

[0042] Preferably, the plastic film used for the plastic film layer includes at least one of a polyester film, a polyolefin polymer film, a polyurethane elastomer film, a polycarbonate film, a polyimide film and a synthetic rubber film.

[0043] Preferably, the composite acrylic foam cushioning material further comprises a release film, and the release film laminate is arranged on the outside of the self-adhesive acrylic foam layer and / or the damping pressure-sensitive adhesive layer.

[0044] Preferably, the release film is provided with an embossed grid; the release film includes a silicon release film and / or a fluorine release film.

[0045] Preferably, the silicon release film is a transparent PET release film with a thickness of 15 to 75 μm and a release force of 5 to 15 gf / 25 mm or 15 to 25 gf / 25 mm; the fluorine release film has a thickness of 15 to 75 μm.

[0046] Preferably, the structure of the composite acrylic foam cushioning material is any one of the following;

[0047] A release film, a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer, and a release film are sequentially laminated;

[0048] A release film, a self-adhesive acrylic foam layer, a plastic film layer, a damping pressure-sensitive adhesive layer, and a release film are sequentially laminated;

[0049] A plastic film layer, a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer and a release film are stacked in sequence.

[0050] Preferably, the OLED display module is in contact with the damping pressure-sensitive adhesive layer.

[0051] Preferably, the OLED display module device further comprises a metal foil, and the metal foil laminate is arranged on one side of the composite acrylic foam buffer material and does not contact the OLED display module.

[0052] Preferably, the metal foil includes copper foil or aluminum foil.

[0053] This application provides an OLED display module device comprising a laminated OLED display module and a composite acrylic foam cushioning material. The composite acrylic foam cushioning material comprises a laminated self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer. This application laminates the self-adhesive acrylic foam with the damping pressure-sensitive adhesive. The resulting composite acrylic foam cushioning material is adhesive on both sides and exhibits excellent impact and extrusion resistance at a relatively thin thickness, making it suitable for direct cushioning and protection of OLED display modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIG1 is a schematic structural diagram of an OLED display module device in the prior art;

[0055] FIG2 is a schematic structural diagram of an OLED display module device in this application. DETAILED DESCRIPTION

[0056] The present application provides an OLED display module device, comprising a stacked OLED display module and a composite acrylic foam cushioning material, wherein the composite acrylic foam cushioning material comprises a stacked self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer.

[0057] Unless otherwise specified, the raw materials used in this application are all commercially available products well known to those skilled in the art.

[0058] The OLED display module device provided in the present application includes a composite acrylic foam cushioning material, which includes a stacked self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer. The composite acrylic foam cushioning material is first described in detail below.

[0059] The composite acrylic foam cushioning material provided herein includes a self-adhesive acrylic foam layer. In the present application, the thickness of the self-adhesive acrylic foam layer is preferably 100 to 300 μm, more preferably 100 to 200 μm, and even more preferably 120 to 150 μm; the 180° peel strength is preferably ≥10 N / 25 mm, more preferably ≥12 N / 25 mm, even more preferably ≥14 N / 25 mm, even more preferably ≥20 N / 25 mm, and even more preferably ≥22 N / 25 mm; and the initial tack is preferably ≥8 N / 25 mm, more preferably ≥10 N / 25 mm, even more preferably ≥14 N / 25 mm, even more preferably ≥17 N / 25 mm, and even more preferably ≥20 N / 25 mm.

[0060] In the present application, the self-adhesive acrylic foam layer is specifically formed by self-adhesive acrylic foam; based on water, the relative density of the self-adhesive acrylic foam is preferably 0.4-1.2, more preferably 0.4-0.9, further preferably 0.75-0.86, and further preferably 0.82-0.83; the elongation at break of the self-adhesive acrylic foam is preferably >400%, more preferably >500%, further preferably >600%, further preferably >650%, and further preferably 1000-1050%; the tensile strength is preferably >0.5MPa, more preferably >0.6MPa, and further preferably >0.75MPa.

[0061] In the present application, the self-adhesive acrylic foam is preferably formed by a foamed self-adhesive acrylic polymer; the storage modulus of the foamed self-adhesive acrylic polymer at 25°C is preferably ≤10 6 Pa, more preferably ≤4.5×10 5 Pa, more preferably ≤4.0×10 5 Pa, more preferably ≤3.0×10 5 Pa; the glass transition temperature is preferably ≤10°C, more preferably ≤6°C, even more preferably ≤2°C, and even more preferably ≤-1°C. The present application preferably limits the storage modulus and glass transition temperature of the foamed self-adhesive acrylic polymer to the above ranges to ensure that it meets the so-called Dahlquist criterion and is a type of viscoelastic material with pressure-sensitive self-adhesive properties.

[0062] The raw materials and preparation method of the self-adhesive acrylic foam described in this application are described in detail below.

[0063] In this application, the raw materials for preparing the self-adhesive acrylic foam include the following components in parts by mass:

[0064] 100 parts of acrylic acid prepolymer, wherein the raw materials for preparing the acrylic acid prepolymer include acrylic acid monomer and a first initiator;

[0065] 0-10 parts of fumed silica;

[0066] 0.01 to 5 parts of cross-linking agent;

[0067] 0.01-10 parts of foaming agent;

[0068] 0.01 to 2 parts of the second initiator;

[0069] 0 to 10 parts of additives.

[0070] The raw materials for preparing the self-adhesive acrylic foam described in the present application include 100 parts by mass of acrylic prepolymer. In the present application, the viscosity of the acrylic prepolymer is preferably 2000 to 10000 cps, more preferably 3000 to 5000 cps.

[0071] In the present application, the raw materials for preparing the acrylic prepolymer include acrylic monomers and a first initiator. In the present application, the mass of the first initiator is preferably 0.01-1% of the mass of the acrylic monomers, more preferably 0.02-0.05%, and even more preferably 0.03-0.04%. In the present application, the acrylic monomers preferably include one or more of: C1-12 alkyl acrylate monomers, C1-12 alkyl methacrylate monomers, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, styrene, vinyl acetate, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, and isooctyl acrylate, more preferably isooctyl acrylate (2-EHA) and acrylic acid (AA). When the acrylic monomers are isooctyl acrylate and acrylic acid, the mass ratio of isooctyl acrylate to acrylic acid is preferably (80-99):(1-20), more preferably (90-91):(9-10). This application preferably uses the aforementioned acrylic monomers, which exhibit excellent initial tack, peel strength, and temperature resistance, facilitating a balanced performance of self-adhesive acrylic foam. In this application, the first initiator preferably includes a photoinitiator, thermal initiator, or other initiator capable of generating free radicals, more preferably a photoinitiator; the photoinitiator is preferably photoinitiator 651.

[0072] In the present application, the acrylic prepolymer is preferably prepared by free radical polymerization of raw materials including an acrylic monomer and a first initiator. In the present application, the free radical polymerization reaction preferably includes solution polymerization, bulk polymerization, emulsion polymerization, or suspension polymerization, more preferably bulk polymerization. The free radical polymerization reaction is preferably carried out under heating (i.e., thermally initiated polymerization) or UV irradiation (i.e., UV-induced polymerization), more preferably under UV irradiation.

[0073] In the present application, taking the acrylic monomers as isooctyl acrylate and acrylic acid, and the first initiator as photoinitiator 651 as an example, the preparation method of the acrylic prepolymer preferably includes the following steps: mixing the acrylic monomer and the first initiator, introducing N2 to the liquid surface under stirring for deoxygenation treatment; after N2 is introduced for 30 to 40 minutes, using a UV LED lamp to irradiate for polymerization reaction, and after the polymerization reaction is initiated, continue stirring and keep N2 introduced. When the reaction temperature rises by 10°C, stop UV LED lamp irradiation, stop introducing N2, and introduce air for quenching; then continue stirring for 10 to 15 minutes to stop the reaction, and obtain an acrylic prepolymer. In the present application, the conditions for the UV LED lamp irradiation preferably include: a light wavelength of 365nm, a light power of 1W / cm 2 .

[0074] Based on the mass fraction of the acrylic prepolymer, the raw materials for preparing the self-adhesive acrylic foam described in this application include 0 to 10 parts, preferably 2 to 5 parts, and more preferably 3 to 4 parts, of fumed silica. In this application, the function of the fumed silica is to increase the cohesion and temperature resistance of the self-adhesive acrylic foam.

[0075] Based on the mass fraction of the acrylic prepolymer, the raw materials for preparing the self-adhesive acrylic foam described in the present application include 0.01 to 5 parts of a cross-linking agent, preferably 0.05 to 0.2 parts, and more preferably 0.1 to 0.15 parts. In the present application, the cross-linking agent is preferably a small molecule compound or oligomer containing two or more functionalities that can participate in free radical polymerization, more preferably a diacrylate, and more preferably 1,6-hexanediol diacrylate (HDDA). In the present application, the role of the cross-linking agent is to increase the molecular weight of the cured acrylic polymer, thereby increasing cohesion and temperature resistance.

[0076] Based on the mass fraction of the acrylic prepolymer, the raw materials used to prepare the self-adhesive acrylic foam described in this application include 0.01 to 10 parts of a foaming agent, preferably 0.2 to 5 parts, and more preferably 1 to 2.5 parts. In this application, the foaming agent preferably includes one or more of a filler-type foaming agent, a surfactant-type foaming agent, and a physical foaming agent. In this application, the filler-type foaming agent preferably includes a microsphere foaming agent, preferably glass microspheres and / or plastic microspheres, preferably expanded plastic foam microspheres. The D50 particle size of the microsphere foaming agent is preferably 20 to 100 μm, more preferably 40 to 50 μm, to better match the thickness of the self-adhesive acrylic foam layer. In this application, the surfactant-type foaming agent preferably includes a silicone surfactant or a fluorocarbon surfactant. In this application, the physical foaming agent preferably includes a low-boiling-point solvent, nitrogen, or carbon dioxide. This application preferably uses microsphere-based foaming agents, which facilitate high impact resistance and improved process stability for the self-adhesive acrylic foam. In this application, when using different foaming agents, foaming methods familiar to those skilled in the art are used. For example, when using filler-type foaming agents, mechanical stirring and dispersion methods are preferred for foaming. When combining surfactant-type foaming agents with physical foaming agents, high-shear mixing and dispersion methods are preferred for foaming.

[0077] Based on the mass fraction of the acrylic prepolymer, the raw materials for preparing the self-adhesive acrylic foam described in this application include 0.01 to 2 parts of a second initiator, preferably 0.05 to 0.5 parts, and more preferably 0.15 to 0.2 parts. In this application, the optional range of types of the second initiator is preferably consistent with the optional range of types of the first initiator, and will not be repeated here; specifically, the type of the second initiator can be the same as or different from the type of the first initiator, and this application does not specifically limit this; in the embodiment of this application, the second initiator is specifically a photoinitiator 651.

[0078] Based on the mass fraction of the acrylic prepolymer, the raw materials used to prepare the self-adhesive acrylic foam described in this application include 0-10 parts, preferably 1-3 parts, of additives. In this application, the additives preferably include one or more of a color paste, a chain transfer agent, an anti-aging agent, and a light stabilizer to meet specific appearance and weather resistance requirements. The color paste is preferably a black pigment; the chain transfer agent is preferably 2-ethylhexyl thioglycolate. The type and amount of additives used in this application are preferably selected based on the desired function.

[0079] In the present application, the preparation method of the self-adhesive acrylic foam preferably comprises the following steps:

[0080] Acrylic prepolymer, fumed silica, a cross-linking agent, a foaming agent, a second initiator and an auxiliary agent are mixed and then cured to obtain a self-adhesive acrylic foam.

[0081] The present application mixes an acrylic prepolymer, fumed silica, a crosslinking agent, a foaming agent, a second initiator, and an auxiliary agent. The present application does not particularly limit the mixing, and it suffices to fully mix the components. In the present application, taking the foaming agent as a filler-type foaming agent as an example, the mixing method preferably includes: mixing the acrylic prepolymer and fumed silica, dispersing the mixture using a high-speed tubular shear, adding the filler-type foaming agent to the resulting dispersion, dispersing the mixture using mechanical stirring, and finally adding the crosslinking agent, the second initiator, and the auxiliary agent, dispersing the mixture using mechanical stirring to obtain a mixed material.

[0082] After obtaining the mixed material, the present application preferably degassing the mixed material, and then coating and curing it on a coating machine to obtain self-adhesive acrylic foam. In the present application, the degassing is preferably vacuum degassing; the time of the vacuum degassing is preferably 50 to 70 minutes, more preferably 60 minutes. In the present application, the coating is preferably carried out using a double-roller extrusion coating head, and two layers of support film are used as support on the upper and lower surfaces; the support film can be a release film or a plastic film according to the specific structure of the composite acrylic foam buffer material, which will be described in detail later. In the present application, the curing is preferably UV curing, and the UV lamp used for the UV curing is preferably set in a segmented manner, and the curing energy is preferably: 0.5W for 1 minute, 1W for 1 minute, 2W for 1 minute, and 2W for 1 minute. After the curing is completed, the present application preferably rolls up the obtained self-adhesive acrylic foam (with support films set on the upper and lower surfaces) for standby use.

[0083] The composite acrylic foam cushioning material provided herein includes a damping pressure-sensitive adhesive layer laminated on one side of the self-adhesive acrylic foam layer. In the present application, the thickness of the damping pressure-sensitive adhesive layer is preferably 10 to 100 μm, more preferably 15 to 60 μm, and even more preferably 30 to 50 μm; the 180° peel strength is preferably ≥8 N / 25 mm, more preferably ≥10 N / 25 mm, even more preferably ≥12 N / 25 mm, and even more preferably ≥14 N / 25 mm; and the initial tack is preferably ≥4 N / 25 mm, more preferably ≥5 N / 25 mm, even more preferably ≥10 N / 25 mm, even more preferably ≥13 N / 25 mm, and even more preferably ≥16 N / 25 mm.

[0084] In the present application, the damping pressure-sensitive adhesive layer is specifically prepared from raw materials including a damping pressure-sensitive adhesive. The damping pressure-sensitive adhesive preferably includes at least one of a silicone damping pressure-sensitive adhesive, an acrylic damping pressure-sensitive adhesive, and a rubber damping pressure-sensitive adhesive, and more preferably a silicone damping pressure-sensitive adhesive, an acrylic damping pressure-sensitive adhesive, or a rubber damping pressure-sensitive adhesive. The present application can use commercially available pressure-sensitive adhesives with damping properties, or can use self-synthesized or formulated pressure-sensitive adhesives. In the present application, to ensure relatively good impact resistance, the maximum loss factor of the damping pressure-sensitive adhesive at a temperature of -40 to 0°C and a frequency of 1 Hz is preferably greater than 0.5, and more preferably greater than 0.6.

[0085] Furthermore, considering the impact resistance, filling and wetting properties of the damping pressure-sensitive adhesive, in the present application, the damping pressure-sensitive adhesive is more preferably an organosilicon damping pressure-sensitive adhesive. In this case, the damping pressure-sensitive adhesive layer is specifically an organosilicon damping pressure-sensitive adhesive layer. The raw materials for preparing the organosilicon damping pressure-sensitive adhesive layer preferably include an organosilicon damping pressure-sensitive adhesive and a curing agent. The curing agent preferably includes a platinum curing agent or a peroxide curing agent, more preferably a peroxide curing agent. In an embodiment of the present application, the organosilicon damping pressure-sensitive adhesive preferably uses a commercially available commercial brand with damping properties, such as Silgrip 6573 or Silgrip 6574 from Maitu. In the present application, the peroxide curing agent is preferably benzoyl peroxide (BPO). In the present application, the mass of the peroxide curing agent is preferably 0.01 to 2% of the mass of the organosilicon damping pressure-sensitive adhesive, more preferably 0.05 to 0.5%.

[0086] In the present application, the composite acrylic foam cushioning material preferably also includes a plastic film layer, and the setting position of the plastic film layer is preferably at least one of the following: the laminate is arranged between the self-adhesive acrylic foam layer and the damping pressure-sensitive adhesive layer; the laminate is arranged on one side of the self-adhesive acrylic foam layer and does not contact the damping pressure-sensitive adhesive layer; the laminate is arranged on one side of the damping pressure-sensitive adhesive layer and does not contact the self-adhesive acrylic foam layer. Specifically, when the composite acrylic foam cushioning material includes a plastic film layer, the structure of the composite acrylic foam cushioning material may be: a self-adhesive acrylic foam layer, a plastic film layer and a damping pressure-sensitive adhesive layer stacked in sequence; or, a plastic film layer, a self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer stacked in sequence; or, a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer and a plastic film layer stacked in sequence; or, a plastic film layer, a self-adhesive acrylic foam layer, a plastic film layer and a damping pressure-sensitive adhesive layer stacked in sequence; or, a self-adhesive acrylic foam layer, a plastic film layer, a damping pressure-sensitive adhesive layer and a plastic film layer stacked in sequence; or, a plastic film layer, a self-adhesive acrylic foam layer, a plastic film layer, a damping pressure-sensitive adhesive layer and a plastic film layer stacked in sequence; or, a plastic film layer, a self-adhesive acrylic foam layer, a plastic film layer, a damping pressure-sensitive adhesive layer and a plastic film layer stacked in sequence. In the present application, a plastic film layer is provided between the self-adhesive acrylic foam layer and the damping pressure-sensitive adhesive layer, which is beneficial to improving the overall tensile strength and dimensional stability of the composite acrylic foam cushioning material during operation and construction; a plastic film layer is provided on the outside of the self-adhesive acrylic foam layer and / or the damping pressure-sensitive adhesive layer, which can not only meet the overall tensile strength and dimensional stability requirements of the composite acrylic foam cushioning material, but also meet the requirements of some applications for one-sided non-stickiness of the composite acrylic foam cushioning material.

[0087] In the present application, the plastic film used for the plastic film layer preferably includes at least one of a polyester film, a polyolefin polymer film, a polyurethane elastomer (TPU) film, a polycarbonate (PC) film, a polyimide (PI) film, and a synthetic rubber film. From the perspectives of dimensional stability, tensile strength, and impact resistance, the plastic film is preferably a polyester film, and more preferably a polyethylene terephthalate (PET) film. In the present application, the thickness of the plastic film layer is preferably 3 to 30 μm, more preferably 5 to 20 μm, and even more preferably 5 to 12 μm. The present application preferably uses a plastic film layer of the above thickness to achieve a better balance between dimensional stability and cushioning performance.

[0088] In the present application, for greater convenience of use, the composite acrylic foam cushioning material preferably also includes a release film, and the release film is preferably laminated on the outside of the self-adhesive acrylic foam layer and / or the damping pressure-sensitive adhesive layer (that is, the release film is directly in contact with the outside of the self-adhesive acrylic foam layer and / or the damping pressure-sensitive adhesive layer). In the present application, the release film is preferably provided with an embossed grid to form an exhaust-capable microstructure on the surface of the self-adhesive acrylic foam layer and / or the damping pressure-sensitive adhesive layer, which is more conducive to the construction convenience and appearance of the composite acrylic foam cushioning material when it is pasted to the OLED display module. This application does not specifically limit the type of the release film, and common commercial products on the market can be selected. In the embodiments of the present application, a silicon release film and / or a fluorine release film is specifically used; the silicon release film is specifically a transparent PET release film, the thickness of which is preferably 15 to 75 μm, more preferably 20 to 25 μm, and the release force is preferably 5 to 15 gf / 25 mm or 15 to 25 gf / 25 mm; the thickness of the fluorine release film is preferably 15 to 75 μm, more preferably 50 to 60 μm.

[0089] In the present application, the composite acrylic foam cushioning material may be provided with only a plastic film layer, only a release film, or both a plastic film layer and a release film, depending on actual needs. When both a plastic film layer and a release film are provided, the plastic film layer and the release film do not contact each other. In the embodiments of the present application, the structure of the composite acrylic foam cushioning material may be any of the following:

[0090] A release film (preferably a silicone release film), a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer, and a release film (preferably a silicone release film if acrylic damping pressure-sensitive adhesive is used; preferably a fluorine release film if silicone damping pressure-sensitive adhesive is used) are laminated in sequence;

[0091] A release film (preferably a silicone release film), a self-adhesive acrylic foam layer, a plastic film layer (preferably a PET film layer), a damping pressure-sensitive adhesive layer, and a release film (preferably a silicone release film if an acrylic damping pressure-sensitive adhesive is used; preferably a fluorine release film if a silicone damping pressure-sensitive adhesive is used) are laminated in sequence;

[0092] The plastic film layer (preferably a PET film layer), the self-adhesive acrylic foam layer, the damping pressure-sensitive adhesive layer and the release film (if acrylic damping pressure-sensitive adhesive is selected, it is preferably a silicone release film; if silicone damping pressure-sensitive adhesive is selected, it is preferably a fluorine release film) are stacked in sequence.

[0093] In the present application, the preparation method of the composite acrylic foam cushioning material preferably includes the following steps:

[0094] coating a raw material for preparing a damping pressure-sensitive adhesive layer on one side of a support film, and forming a damping pressure-sensitive adhesive layer on the one side of the support film after curing;

[0095] The damping pressure-sensitive adhesive layer is laminated with the self-adhesive acrylic foam prepared by the above technical solution to obtain a composite acrylic foam cushioning material.

[0096] In the present application, the raw materials for preparing the damping pressure-sensitive adhesive layer are coated on one side of the support film, and after curing, a damping pressure-sensitive adhesive layer is formed on the single side of the support film. In the present application, when the damping pressure-sensitive adhesive is a silicone damping pressure-sensitive adhesive, it can be a peroxide-cured silicone pressure-sensitive adhesive and / or a platinum-cured silicone pressure-sensitive adhesive, and can be commercially available or synthesized by the method reported in the prior art, as long as its material properties meet the aforementioned indicators; when the damping pressure-sensitive adhesive is an acrylic damping pressure-sensitive adhesive, it can be a single-component acrylic resin or a two-component acrylic resin, or an acrylic resin with a tackifying resin added, and can be commercially available or synthesized by the method reported in the prior art, as long as its material properties meet the aforementioned indicators; when the damping pressure-sensitive adhesive is a rubber damping pressure-sensitive adhesive, it can be a natural rubber pressure-sensitive adhesive and / or a synthetic rubber pressure-sensitive adhesive, and can be commercially available or synthesized or formulated by the method reported in the prior art, as long as its material properties meet the aforementioned indicators. This application does not specifically limit the specific coating operation; coating methods familiar to those skilled in the art may be used. In this application, the support film may be a release film or a plastic film, depending on the specific structure of the composite acrylic foam cushioning material. In this application, the curing temperature is preferably 90-180°C, more preferably 150°C. This application does not specifically limit the curing time; sufficient curing is sufficient.

[0097] After obtaining the damping pressure-sensitive adhesive layer, the present application laminates the damping pressure-sensitive adhesive layer with the self-adhesive acrylic foam prepared according to the above technical solution to obtain a composite acrylic foam cushioning material. The present application preferably selects an appropriate lamination method based on the specific structure of the composite acrylic foam cushioning material. For example, when a plastic film layer is provided between the damping pressure-sensitive adhesive layer and the self-adhesive acrylic foam layer, the support film used to prepare the self-adhesive acrylic foam includes at least one layer of plastic film, and then the plastic film on the self-adhesive acrylic foam is laminated to a single side of the damping pressure-sensitive adhesive layer.

[0098] The applicant has studied the performance of existing acrylic foam and found that although the existing acrylic foam has a certain viscoelasticity, under the action of high-speed force, the buffering effect on the impact force is mainly achieved through the elastic compression of the pores. Under the action of impact force, the compression of the acrylic foam prolongs the duration of the impact force, thereby reducing the magnitude of the force acting on the object, and the impact energy is converted into potential energy. Since the elastic compression capacity of the pores is directly related to the size of the pores, as the thickness decreases and the diameter of the pores becomes smaller, its compression buffering capacity is also greatly weakened, resulting in acrylic foam being unsuitable for use in the buffering protection of ultra-thin OLED display screens. The applicant has studied the performance of damping pressure-sensitive adhesive and found that its buffering performance under impact is very excellent. Under the action of impact force, the damping pressure-sensitive adhesive mainly absorbs the impact energy through deformation, thereby reducing the magnitude of the force acting on the object, and the impact energy is dissipated as heat energy. However, pure damping pressure-sensitive adhesive has the following two disadvantages as a buffer material: 1) After being impacted, the deformation of the damping pressure-sensitive adhesive cannot be restored, which affects the secondary realization of the buffering performance; in addition, the deformation has a certain squeezing effect on the display module, causing display defects; 2) The damping pressure-sensitive adhesive as a buffer material has poor protection and buffering effects against external squeezing forces. The composite acrylic foam buffer material provided in the present application includes a self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer that are stacked. Both sides of the composite acrylic foam buffer material are sticky and do not require backing glue. It has high impact resistance and excellent anti-extrusion performance at a relatively thin thickness. At the same time, it has good and reliable adhesion to surfaces such as metal, glass, and PET, and is suitable for buffering protection of OLED display modules. Moreover, the present application can adjust the overall performance of the composite acrylic foam buffer material by adjusting the material properties of the self-adhesive acrylic foam layer and the damping pressure-sensitive adhesive layer respectively, which has great flexibility in product design. In addition, when the damping pressure-sensitive adhesive is silicone damping pressure-sensitive adhesive, it has good air-discharging properties. During use, the composite acrylic foam cushioning material can be directly used for bonding the polarizer surface of the OLED display module without the aid of an embossed structure, and the display effect will not be affected by the presence of bubbles.

[0099] In the present application, as shown in the results of the examples, the impact resistance of the composite acrylic foam cushioning material is preferably 50-60 cm, more preferably 55-60 cm; the extrusion resistance is preferably 15-25 N, more preferably 20-25 N; the 70°C heat resistance is preferably >72 hrs; and the 25% CFD (compression rebound) is preferably 20-30 KPa, more preferably 24-28 KPa. The provision of a plastic film in the composite acrylic foam cushioning material of the present application can significantly improve the tensile strength. Specifically, as shown in the results of the examples, when the composite acrylic foam cushioning material is not provided with a plastic film, the tensile strength is preferably 0.7-0.8 MPa; when the composite acrylic foam cushioning material is provided with a plastic film, the tensile strength can reach 10 MPa.

[0100] The OLED display module device provided in this application is described in detail below.

[0101] The OLED display module device provided in the present application includes a stacked OLED display module and a composite acrylic foam cushioning material, wherein the composite acrylic foam cushioning material includes a stacked self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer. In the present application, specifically, the OLED display module can be in contact with the damping pressure-sensitive adhesive layer of the composite acrylic foam cushioning material, or can be in contact with the self-adhesive acrylic foam layer of the composite acrylic foam cushioning material; preferably, the OLED display module is in contact with the damping pressure-sensitive adhesive layer. The present application does not specifically limit the specific type and structure of the OLED display module, and any OLED display module familiar to those skilled in the art can be used.

[0102] In the present application, the OLED display module device preferably also includes a metal foil, and the metal foil is preferably laminated on one side of the composite acrylic foam cushioning material and is not in contact with the OLED display module. At this time, the OLED display module device includes an OLED display module, a composite acrylic foam cushioning material and a metal foil that are laminated in sequence. Specifically, when the OLED display module is in contact with the damping pressure-sensitive adhesive layer, the metal foil is in contact with the self-adhesive acrylic foam layer; when the OLED display module is in contact with the self-adhesive acrylic foam layer, the metal foil is in contact with the damping pressure-sensitive adhesive layer. In the present application, the metal foil preferably includes copper foil or aluminum foil, more preferably copper foil. The present application does not specifically limit the thickness of the metal foil, and a metal foil of a thickness familiar to those skilled in the art can be used. In the present application, the metal foil plays a role in electromagnetic shielding and protection.

[0103] Figure 2 is a schematic structural diagram of the OLED display module device in this application, which specifically includes an OLED display module, a buffer material and a copper foil stacked in sequence, and the OLED display module is in contact with the damping pressure-sensitive adhesive layer, and the copper foil is in contact with the self-adhesive acrylic foam layer.

[0104] The following will be combined with the embodiments of this application to clearly and completely describe the technical solutions in this application. Obviously, the embodiments described are only some of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0105] The raw materials used in the following examples and comparative examples of this application are all commercially available products.

[0106] Example 1

[0107] In this embodiment, the composite acrylic foam cushioning material includes a silicone release film, a self-adhesive acrylic foam layer, a silicone damping pressure-sensitive adhesive layer and a fluorine release film stacked in sequence, wherein the thickness of the silicone release film is 25 μm (Zhejiang Yaoyang, heavy film release force 15-25 gf / 25mm, specifically a transparent PET release film), the thickness of the self-adhesive acrylic foam layer is 150 μm, the thickness of the silicone damping pressure-sensitive adhesive layer is 30 μm, and the thickness of the fluorine release film is 50 μm.

[0108] The material of the self-adhesive acrylic foam layer is self-adhesive acrylic foam, which is prepared from the following raw materials in parts by weight: 90 parts of isooctyl acrylate (2-EHA, BASF), 10 parts of acrylic acid (AA, BASF), 0.15 parts of a crosslinker (1,6-hexanediol diacrylate, HDDA, Changxing Materials), 4 parts of fumed silica (R972, Evonik Materials), 1 part of an auxiliary agent (black pigment, UV Black N30, Klein), 1 part of a foaming agent (expanded plastic foam microspheres, D50 particle size 40 μm, Akzo Nobel), and 0.19 parts of a photoinitiator 651 (added in two batches).

[0109] The preparation method of the self-adhesive acrylic foam comprises the following steps:

[0110] (1) 90 parts of isooctyl acrylate (2-EHA, BASF), 10 parts of acrylic acid (AA, BASF) and 0.04 parts of photoinitiator 651 were weighed and added to a transparent glass reactor. A fixed flow of nitrogen was introduced below the liquid surface under stirring for deoxygenation. After nitrogen was introduced for 30 minutes, the reactor was irradiated with a UV LED lamp with a wavelength of 365 nm and an illumination power of 1 W / cm 2After the polymerization reaction is initiated, stirring is continued and N2 is kept flowing. When the reaction temperature rises by 10°C, the UV LED lamp irradiation is stopped, the N2 flow is stopped, and the vent valve is opened to allow air to flow for quenching. Then, stirring is continued for 10 minutes to stop the reaction, and an acrylic acid prepolymer with a viscosity of 3000 cps is obtained.

[0111] (2) The acrylic prepolymer and 4 parts of fumed silica were mixed and dispersed using a high-speed tubular shearing machine, and 1 part of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel) was added to the obtained dispersion, and the mixture was slowly stirred by mechanical stirring. Finally, 1 part of black pigment, 0.15 parts of photoinitiator 651 and 0.15 parts of cross-linking agent were added and stirred to obtain a mixture. After the mixture was vacuum degassed for 1 hour, it was coated on a coating machine and UV cured. The coating was specifically carried out using a double-roller extrusion coating head and two layers of release film (Zhejiang Yaoyang, light film release force 5-15gf / 25mm, heavy film release force 15-25gf / 25mm, specifically both transparent PET release film) as support. The UV lamp used for UV curing was set in a segmented manner, and the curing energy was as follows: 0.5W for 1 min, 1W for 1 min, 2W for 1 min, and 2W for 1 min. After curing, the mixture was rolled up for use.

[0112] The preparation method of the composite cushioning foam material comprises the following steps:

[0113] 100 parts of silicone damping pressure-sensitive adhesive Silgrip 6574 (solid content 55 wt %, Momentive) and 0.2 parts of benzoyl peroxide (BPO) were uniformly mixed, then coated on a fluorine release film (original color), and dried and cured at 150° C. to form a silicone damping pressure-sensitive adhesive layer on the fluorine release film;

[0114] The light film on the surface of the self-adhesive acrylic foam is removed, and the organic silicone damping pressure-sensitive adhesive layer is laminated to the self-adhesive acrylic foam to form a self-adhesive acrylic foam layer on one side of the organic silicone damping pressure-sensitive adhesive layer to obtain a composite buffer foam material.

[0115] Example 2

[0116] A composite acrylic foam cushioning material was prepared according to the method of Example 1, except that:

[0117] The raw materials for preparing the self-adhesive acrylic foam include 91 parts of isooctyl acrylate (2-EHA, BASF) and 9 parts of acrylic acid (AA, BASF).

[0118] Example 3

[0119] A composite acrylic foam cushioning material was prepared according to the method of Example 1, except that:

[0120] The raw materials for preparing self-adhesive acrylic foam include 91 parts of isooctyl acrylate (2-EHA, BASF), 9 parts of acrylic acid (AA, BASF), and 2.5 parts of a blowing agent, specifically 2 parts of glass microspheres (D50 particle size 50 μm, Porter 5014, USA) and 0.5 parts of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel).

[0121] Example 4

[0122] A composite acrylic foam cushioning material was prepared according to the method of Example 1, except that:

[0123] The raw materials for preparing the self-adhesive acrylic foam include 91 parts of isooctyl acrylate (2-EHA, BASF) and 9 parts of acrylic acid (AA, BASF); 2.5 parts of a blowing agent, specifically 2 parts of glass microspheres (D50 particle size 50 μm, Porter 5014, USA) and 0.5 parts of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel); and 1.05 parts of an auxiliary agent, specifically 1 part of a black pigment (UV Black N30, Klein) and 0.05 parts of a chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1).

[0124] Example 5

[0125] A composite acrylic foam cushioning material was prepared according to the method of Example 1, except that:

[0126] The thickness of the self-adhesive acrylic foam layer is 120 μm;

[0127] The raw materials for preparing the self-adhesive acrylic foam include 91 parts of isooctyl acrylate (2-EHA, BASF) and 9 parts of acrylic acid (AA, BASF); 2.5 parts of a blowing agent, specifically 2 parts of glass microspheres (D50 particle size 50 μm, Porter 5014, USA) and 0.5 parts of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel); and 1.05 parts of an auxiliary agent, specifically 1 part of a black pigment (UV Black N30, Klein) and 0.05 parts of a chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1).

[0128] Example 6

[0129] A composite acrylic foam cushioning material was prepared according to the method of Example 1, except that:

[0130] The thickness of the self-adhesive acrylic foam layer is 100 μm, and the thickness of the silicone damping pressure-sensitive adhesive layer is 50 μm;

[0131] The raw materials for preparing the self-adhesive acrylic foam include 91 parts of isooctyl acrylate (2-EHA, BASF) and 9 parts of acrylic acid (AA, BASF); 2.5 parts of a blowing agent, specifically 2 parts of glass microspheres (D50 particle size 50 μm, Porter 5014, USA) and 0.5 parts of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel); and 1.05 parts of an auxiliary agent, specifically 1 part of a black pigment (UV Black N30, Klein) and 0.05 parts of a chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1).

[0132] Example 7

[0133] In this embodiment, the composite acrylic foam cushioning material includes a silicone release film 1, a self-adhesive acrylic foam layer, an acrylic damping pressure-sensitive adhesive layer and a silicone release film 2 stacked in sequence, wherein the thickness of the silicone release film 1 is 25 μm (Zhejiang Yaoyang, heavy film release force 15-25 gf / 25 mm, specifically a transparent PET release film), the thickness of the self-adhesive acrylic foam layer is 150 μm, the thickness of the acrylic damping pressure-sensitive adhesive layer is 30 μm, and the thickness of the silicone release film is 50 μm.

[0134] The self-adhesive acrylic foam layer is made of self-adhesive acrylic foam, which is prepared from the following raw materials in parts by weight: 91 parts of isooctyl acrylate (2-EHA, BASF) and 9 parts of acrylic acid (AA, BASF); 2.5 parts of a foaming agent, specifically 2 parts of glass microspheres (D50 particle size 50 μm, American Porter 5014) and 0.5 parts of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel); and 1.05 parts of an auxiliary agent, specifically 1 part of a black pigment (UV Black N30, Klein) and 0.05 parts of a chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1).

[0135] The preparation method of the self-adhesive acrylic foam comprises the following steps:

[0136] (1) 91 parts of isooctyl acrylate (2-EHA, BASF), 9 parts of acrylic acid (AA, BASF) and 0.04 parts of photoinitiator 651 were weighed and added to a transparent glass reactor. A fixed flow of nitrogen was introduced below the liquid surface under stirring for deoxygenation. After nitrogen was introduced for 30 minutes, the reactor was irradiated with a UV LED lamp with a wavelength of 365 nm and an illumination power of 1 W / cm 2After the polymerization reaction is initiated, stirring is continued and N2 is kept flowing. When the reaction temperature rises by 10°C, the UV LED lamp irradiation is stopped, the N2 flow is stopped, and the vent valve is opened to allow air to flow for quenching. Then, stirring is continued for 10 minutes to stop the reaction, and an acrylic acid prepolymer with a viscosity of 3000 cps is obtained.

[0137] (2) The acrylic prepolymer was mixed with 4 parts of fumed silica and dispersed using a high-speed tubular shear. 2 parts of glass microspheres (D50 particle size 50 μm, American Porter 5014) and 0.5 parts of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel) were added to the resulting dispersion and stirred slowly and uniformly using a mechanical stirrer. Finally, 1 part of black pigment, 0.15 parts of photoinitiator 651, 0.15 parts of crosslinking agent HDDA and 0.05 parts of chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1) were added and stirred uniformly. Then a mixed material is obtained; after the mixed material is vacuum degassed for 1 hour, it is coated on a coating machine and UV cured. The coating specifically adopts a double-roller extrusion coating head, and two layers of release film (Zhejiang Yaoyang, light film release force 5-15gf / 25mm, heavy film release force 15-25gf / 25mm, specifically both are transparent PET release films) as support; the UV lamp used for UV curing adopts a segmented setting, and the curing energy is: 0.5W for 1min, 1W for 1min, 2W for 1min, and 2W for 1min; after curing is completed, it is rolled up for use.

[0138] The preparation method of the composite cushioning foam material comprises the following steps:

[0139] An acrylic damping pressure-sensitive adhesive (Aroset 951062, Bostik, 45% solid content) was coated on a silicone release film (Yaoyang), and dried and cured at 110° C. to form an acrylic damping pressure-sensitive adhesive layer on the silicone release film;

[0140] The light film on the surface of the self-adhesive acrylic foam is removed, and the acrylic damping pressure-sensitive adhesive layer is laminated to the self-adhesive acrylic foam to form a self-adhesive acrylic foam layer on one side of the acrylic damping pressure-sensitive adhesive layer to obtain a composite buffer foam material.

[0141] Example 8

[0142] In this embodiment, the composite acrylic foam cushioning material includes a silicone release film, a self-adhesive acrylic foam layer, a PET film layer, a silicone damping pressure-sensitive adhesive layer and a fluorine release film stacked in sequence, wherein the thickness of the silicone release film is 25 μm (Zhejiang Yaoyang, release force 5-15 gf / 25 mm, specifically a transparent PET release film), the thickness of the self-adhesive acrylic foam layer is 135 μm, the thickness of the PET film layer (black PET, Zhejiang Nanyang Technology) is 12 μm, the thickness of the silicone damping pressure-sensitive adhesive layer is 30 μm, and the thickness of the fluorine release film is 50 μm.

[0143] The material of the self-adhesive acrylic foam layer is self-adhesive acrylic foam, which is prepared from the following raw materials in parts by weight: 91 parts of isooctyl acrylate (2-EHA, BASF), 9 parts of acrylic acid (AA, BASF); 0.15 parts of a crosslinking agent (1,6-hexanediol diacrylate, HDDA, Changxing Materials); 4 parts of fumed silica (R972, Evonik Materials); 1.05 parts of an auxiliary agent, specifically 1 part of a black pigment (UV Black N30, Klein) and 0.05 parts of a chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1); 2.5 parts of a foaming agent, specifically 2 parts of glass microspheres (D50 particle size 50 μm, American Porter 5014) and 0.5 parts of expanded plastic foaming microspheres (D50 particle size 40 μm, Akzo Nobel); and 0.19 parts of a photoinitiator 651 (added in two batches).

[0144] The preparation method of the self-adhesive acrylic foam comprises the following steps:

[0145] (1) 91 parts of isooctyl acrylate (2-EHA, BASF), 9 parts of acrylic acid (AA, BASF) and 0.04 parts of photoinitiator 651 were weighed and added to a transparent glass reactor. A fixed flow of nitrogen was introduced below the liquid surface under stirring for deoxygenation. After nitrogen was introduced for 30 minutes, the reactor was irradiated with a UV LED lamp with a wavelength of 365 nm and an illumination power of 1 W / cm 2 After the polymerization reaction is initiated, stirring is continued and N2 is kept flowing. When the reaction temperature rises by 10°C, the UV LED lamp irradiation is stopped, the N2 flow is stopped, and the vent valve is opened to allow air to flow for quenching. Then, stirring is continued for 10 minutes to stop the reaction, and an acrylic acid prepolymer with a viscosity of 3000 cps is obtained.

[0146] (2) The acrylic prepolymer was mixed with 4 parts of fumed silica and dispersed using a high-speed tubular shearing machine. 0.5 parts of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel) and 2 parts of glass microspheres (D50 particle size 50 μm, American Porter 5014) were added to the obtained dispersion and slowly stirred evenly using a mechanical stirrer. Finally, 1 part of black pigment, 0.15 parts of photoinitiator 651, 0.05 parts of chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1) and 0.15 parts of cross-linking agent were added and stirred evenly to obtain a mixture. After vacuum degassing the mixture for 1 hour, the mixture was coated on a coating machine and UV cured. The coating was specifically carried out using a double-roll extrusion coating head, with a release film (Zhejiang Yaoyang, release force 5-15 gf / 25 mm) used as support for the upper layer and a 12 μm film used as support for the lower layer. PET film is used as support; the UV lamp used for UV curing adopts a segmented setting, and the curing energy is: 0.5W for 1 minute, 1W for 1 minute, 2W for 1 minute, and 2W for 1 minute; after curing is completed, it is rolled up for use.

[0147] The preparation method of the composite cushioning foam material comprises the following steps:

[0148] 100 parts of silicone damping pressure-sensitive adhesive Silgrip 6574 (solid content 55 wt %, Momentive) and 0.2 parts of benzoyl peroxide (BPO) were uniformly mixed, then coated on a fluorine release film (original color), and dried and cured at 150° C. to form a silicone damping pressure-sensitive adhesive layer on the fluorine release film;

[0149] The PET surface of the self-adhesive acrylic foam is laminated to the organic silicon damping pressure-sensitive adhesive layer, and a self-adhesive acrylic foam layer is formed on one side of the organic silicon damping pressure-sensitive adhesive layer to obtain a composite buffer foam material.

[0150] Example 9

[0151] In this embodiment, the composite acrylic foam cushioning material includes a PET film layer, a self-adhesive acrylic foam layer, a silicone damping pressure-sensitive adhesive layer and a fluorine release film stacked in sequence, wherein the thickness of the silicone release film is 25 μm (Zhejiang Yaoyang, release force 5-15 gf / 25mm, specifically a transparent PET release film), the thickness of the self-adhesive acrylic foam layer is 135 μm, the thickness of the PET film layer is 12 μm, the thickness of the silicone damping pressure-sensitive adhesive layer is 30 μm, and the thickness of the fluorine release film is 50 μm.

[0152] The material of the self-adhesive acrylic foam layer is self-adhesive acrylic foam, which is prepared from the following raw materials in parts by weight: 91 parts of isooctyl acrylate (2-EHA, BASF), 9 parts of acrylic acid (AA, BASF); 0.15 parts of a crosslinking agent (1,6-hexanediol diacrylate, HDDA, Changxing Materials); 4 parts of fumed silica (R972, Evonik Materials); 1.05 parts of an auxiliary agent, specifically 1 part of a black pigment (UV Black N30, Klein) and 0.05 parts of a chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1); 2.5 parts of a foaming agent, specifically 2 parts of glass microspheres (D50 particle size 50 μm, American Porter 5014) and 0.5 parts of expanded plastic foamed microspheres (D50 particle size 40 μm, Akzo Nobel); and 0.19 parts of a photoinitiator 651 (added in two batches).

[0153] The preparation method of the self-adhesive acrylic foam comprises the following steps:

[0154] (1) 91 parts of isooctyl acrylate (2-EHA, BASF), 9 parts of acrylic acid (AA, BASF) and 0.04 parts of photoinitiator 651 were weighed and added to a transparent glass reactor. A fixed flow of nitrogen was introduced below the liquid surface under stirring for deoxygenation. After nitrogen was introduced for 30 minutes, the reactor was irradiated with a UV LED lamp with a wavelength of 365 nm and an illumination power of 1 W / cm 2 After the polymerization reaction is initiated, stirring is continued and N2 is kept flowing. When the reaction temperature rises by 10°C, the UV LED lamp irradiation is stopped, the N2 flow is stopped, and the vent valve is opened to allow air to flow for quenching. Then, stirring is continued for 10 minutes to stop the reaction, and an acrylic acid prepolymer with a viscosity of 3000 cps is obtained.

[0155] (2) The acrylic prepolymer was mixed with 4 parts of fumed silica and dispersed using a high-speed tubular shearing machine. 0.5 parts of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel) and 2 parts of glass microspheres (D50 particle size 50 μm, American Porter 5014) were added to the obtained dispersion and slowly stirred evenly using a mechanical stirrer. Finally, 1 part of black pigment, 0.15 parts of photoinitiator 651, 0.05 parts of chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1) and 0.15 parts of cross-linking agent were added and stirred evenly to obtain a mixture. After vacuum degassing the mixture for 1 hour, the mixture was coated on a coating machine and UV cured. The coating was specifically carried out using a double-roll extrusion coating head, with a release film (Zhejiang Yaoyang, release force 5-15 gf / 25 mm) used as support for the upper layer and a 12 μm film used as support for the lower layer. PET film is used as support; the UV lamp used for UV curing adopts a segmented setting, and the curing energy is: 0.5W for 1 minute, 1W for 1 minute, 2W for 1 minute, and 2W for 1 minute; after curing is completed, it is rolled up for use.

[0156] The preparation method of the composite cushioning foam material comprises the following steps:

[0157] 100 parts of silicone damping pressure-sensitive adhesive Silgrip 6574 (solid content 55 wt %, Momentive) and 0.2 parts of benzoyl peroxide (BPO) were uniformly mixed, then coated on a fluorine release film (original color), and dried and cured at 150° C. to form a silicone damping pressure-sensitive adhesive layer on the fluorine release film;

[0158] The release film is removed from the sticky surface (non-PET surface) of the self-adhesive acrylic foam, and the self-adhesive acrylic foam is laminated with the organic silicone damping pressure-sensitive adhesive layer, and the composite cushioning foam material is rolled up.

[0159] Comparative Example 1

[0160] Only silicone damping pressure-sensitive adhesive is used as the buffer material, and the preparation is specifically carried out in the following steps:

[0161] 100 parts of silicone damping pressure-sensitive adhesive Silgrip6574 (solid content 55 wt %, Maitu) and 0.2 parts of benzoyl peroxide (BPO) were uniformly mixed, and then coated on a 50 μm thick fluorine release film (original color). The mixture was dried and cured at 150°C to form a 120 μm thick silicone damping pressure-sensitive adhesive layer on the fluorine release film.

[0162] Comparative Example 2

[0163] Only self-adhesive acrylic foam with a thickness of 120 μm was used as the cushioning material; the self-adhesive acrylic foam was prepared according to the method of Example 1, except that:

[0164] The raw materials for preparing the self-adhesive acrylic foam include 91 parts of isooctyl acrylate (2-EHA, BASF) and 9 parts of acrylic acid (AA, BASF); 2.5 parts of a blowing agent, specifically 2 parts of glass microspheres (D50 particle size 50 μm, Porter 5014, USA) and 0.5 parts of expanded plastic foam microspheres (D50 particle size 40 μm, Akzo Nobel); and 1.05 parts of an auxiliary agent, specifically 1 part of a black pigment (UV Black N30, Klein) and 0.05 parts of a chain transfer agent (2-ethylhexyl thioglycolate, CAS: 7659-86-1).

[0165] Comparative Example 3

[0166] The OLED buffer material that has been maturely applied in the market is used. The brand of this material is ISR-ACF-JPC-25E. The manufacturer is Iwatani of Japan. The total thickness of the product is 180μm. The product structure is: embossed release film, 25μm acrylic damping pressure-sensitive adhesive layer, 5μm PET, and 150μm acrylic foam.

[0167] Test Example 1

[0168] The index parameters of the self-adhesive acrylic foams prepared in Examples 1 to 9 were tested, and the specific results are shown in Table 1 (the viscosity of the acrylic prepolymer in each example is 3000 cps).

[0169] Test Item 1: Density Test

[0170] A circular sample with a diameter of 10 cm is taken by a sampler, the thickness and weight of the sample are tested, and the density of the sample is obtained by calculation.

[0171] Test Item 2: Tensile Test

[0172] Measured according to ASTM D3759, 10mm wide samples were tested at 23°C, 50% RH, and a speed of 300mm / min using a universal testing machine (Kejian). The average value of N=3 was used as the measured value. Elongation at break and maximum tensile strength were also measured simultaneously.

[0173] Test items 3 and 4: Glass transition temperature and storage modulus

[0174] The glass transition temperature was determined by reading the temperature at the highest point of the loss coefficient during rheological testing, and the elastic modulus was obtained by reading the storage modulus curve at 25°C. Self-adhesive acrylic foam samples were stacked to a thickness of approximately 1 mm and processed into 8 mm circular specimens using a sample preparation device. Testing was performed using a TA HR10 rheometer with a set frequency of 1 Hz and a temperature sweep from -40°C to 150°C at a temperature ramp rate of 5°C / min.

[0175] Table 1 Index parameters of self-adhesive acrylic foam prepared in Examples 1 to 9

[0176] Test Example 2

[0177] The damping pressure-sensitive adhesives (i.e., silicone damping pressure-sensitive adhesives or acrylic damping pressure-sensitive adhesives) described in Examples 1-9 were subjected to rheological property testing. Specifically, the damping pressure-sensitive adhesives were coated and stacked to a thickness of 1 mm. The samples were then processed into 8 mm circular samples using a sample preparation device. The rheological properties were then tested using a TA HR10 rheometer. The test frequency was set at 1 Hz, and a temperature sweep was performed over a temperature range of -40 to 150°C at a temperature ramp rate of 5°C / min. The glass transition temperature was determined by reading the temperature at the highest point of the loss factor during the rheological test. The maximum damping temperature was determined by reading the maximum loss factor within the range of -40 to 0°C. The maximum damping temperature was the temperature at which the maximum loss factor was measured. The specific test results are shown in Table 2.

[0178] Table 2 Index parameters of silicone damping pressure-sensitive adhesive or acrylic damping pressure-sensitive adhesive in Examples 1 to 9

[0179] Test Example 3

[0180] In order to verify the effect of the present invention, the following tests were performed on the samples in the examples and comparative examples:

[0181] Test Item 1: 180° Peel Force

[0182] The test was conducted according to ASTM D3330. A 25mm wide sample was attached to a standard steel plate and rolled back and forth once with a 2kg roller. The sample was allowed to stand for 20 minutes at 23°C and 50% humidity. The sample was then peeled off using a universal testing machine (Kejian) at a speed of 300mm / min. The 180° peel strength was measured. The average value of N = 3 was used as the measured value.

[0183] Test Item 2: Initial Adhesion (LOOPTACK Method)

[0184] The test was conducted according to ASTM D6195. The sample was 25 mm wide and tested using a universal material testing machine (Kejian) at a temperature of 23° C. and a humidity of 50% RH. The average value of N=3 was used as the measured value.

[0185] Test Item 3: Tensile Strength

[0186] The test was conducted according to ASTM D3759. A 10 mm wide sample was tested at 23°C and 50% RH using a universal testing machine (Kejian) at a speed of 300 mm / min. The average value of N = 3 was taken as the measured value.

[0187] Test Item 4: Heat Resistance

[0188] The test was carried out according to ASTM D3654. The sample size was 25 mm × 25 mm. A 2 kg roller was used to roll the sample back and forth twice. The sample was left to stand at 23°C and 50% RH for 20 minutes. A 1 kg weight was then hung on the sample and tested under the specified conditions.

[0189] Test Item 5: Foam Compression and Rebound CFD Test

[0190] The test was conducted according to ASTM D3574C method. The sample size was 50 mm × 50 mm × 25 mm (multi-layer sample thickness superimposed). The test was conducted at a temperature of 23°C and a humidity of 50% RH. The compression speed was 50 mm / min. The rebound force at 25% compression was calculated by reading the compression-rebound force curve.

[0191] Test Item 6: Impact Resistance

[0192] After assembling the cushioning material within the OLED display, place it on the impact test platform, facing up and the display down. Then, drop an 11.2g steel ball with a diameter of 14mm onto the composite cushioning material from a fixed height. After the test, power on the display to verify normal operation. If an OK result is detected, continue testing by raising the steel ball height. If an NG result is detected, lower the steel ball height and continue testing. Record the maximum impact height the display module can withstand.

[0193] Test Item 7: Anti-extrusion performance

[0194] After assembling the cushioning material within the OLED display, place it with the cushioning material facing up and the display facing down. Set the applied pressure, then press a 3mm diameter spherical extrusion head against the composite cushioning material surface at a fixed speed (10mm / min). Once the pressure reaches the set value, maintain the pressure for 10 seconds, then return the extruder to its original position. After the test, power on the display to verify that the display is functioning properly. If an OK value is displayed, continue testing with the set pressure. If an NG value is displayed, reduce the pressure and record the maximum pressure the display module can withstand.

[0195] Tables 3 and 4 are the test results of sample performance in each embodiment and comparative example. It can be seen from Tables 3 and 4 that the use of silicone damping pressure-sensitive adhesive alone as a buffer material can obtain excellent impact resistance, but the anti-extrusion performance is relatively weak. The use of self-adhesive acrylic foam alone can obtain better anti-extrusion performance. By stacking the self-adhesive acrylic foam and the damping pressure-sensitive adhesive and using the resulting composite material as a buffer material, more balanced performance can be obtained, with excellent impact resistance and anti-extrusion performance. It can be seen from Examples 8 and 9 that the introduction of PET film into the composite material can significantly enhance the tensile strength of the material, while having little effect on the peeling force, impact resistance and anti-extrusion performance.

[0196] Table 3 Performance test results of samples in various embodiments and comparative examples

[0197] Table 4 Performance test results of samples in various embodiments and comparative examples

[0198] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An OLED display module device, characterized in that: The invention comprises an OLED display module and a composite acrylic foam cushioning material which are stacked in layers. The composite acrylic foam cushioning material comprises a self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer which are stacked in layers.

2. The OLED display module device according to claim 1, characterized in that: The thickness of the damping pressure-sensitive adhesive layer is 10-100 μm, the 180° peeling force is ≥8N / 25mm, and the initial adhesion is ≥4N / 25mm.

3. The OLED display module device according to claim 1 or 2, characterized in that: The damping pressure-sensitive adhesive layer is prepared from raw materials including damping pressure-sensitive adhesive, and the damping pressure-sensitive adhesive includes at least one of silicone damping pressure-sensitive adhesive, acrylic damping pressure-sensitive adhesive and rubber damping pressure-sensitive adhesive. The maximum loss factor of the damping pressure-sensitive adhesive at a temperature of -40 to 0°C and a frequency of 1 Hz is greater than 0.

5.

4. The OLED display module device according to claim 1, characterized in that: The thickness of the self-adhesive acrylic foam layer is 100-300 μm, the 180° peeling force is ≥10 N / 25 mm, and the initial adhesion is ≥6 N / 25 mm.

5. The OLED display module device according to claim 1 or 4, characterized in that: The self-adhesive acrylic foam layer is formed of self-adhesive acrylic foam; based on water, the relative density of the self-adhesive acrylic foam is 0.4-1.2; the elongation at break of the self-adhesive acrylic foam is greater than 400%, and the tensile strength is greater than 0.5 MPa.

6. The OLED display module device according to claim 5, characterized in that: The self-adhesive acrylic foam is formed by a foamed self-adhesive acrylic polymer; the storage modulus of the foamed self-adhesive acrylic polymer at 25° C. is ≤10 6 Pa, glass transition temperature ≤10℃.

7. The OLED display module device according to claim 6, characterized in that: The raw materials for preparing the self-adhesive acrylic foam include the following components by weight: 100 parts of acrylic acid prepolymer, wherein the raw materials for preparing the acrylic acid prepolymer include acrylic acid monomer and a first initiator; 0-10 parts of fumed silica; Cross-linking agent 0.01-5 parts; 0.01 to 10 parts of foaming agent; 0.01 to 2 parts of the second initiator; Additives 0 to 10 parts.

8. The OLED display module device according to claim 7, characterized in that: The viscosity of the acrylic prepolymer is 2000-10000 cps.

9. The OLED display module device according to claim 7, characterized in that: The mass of the first initiator is 0.01-1% of the mass of the acrylic monomer.

10. The OLED display module device according to any one of claims 7 to 9, characterized in that: The acrylic monomers include one or more of acrylic acid ester monomers with an alkyl group of C1 to 12, methacrylic acid ester monomers with an alkyl group of C1 to 12, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, styrene, vinyl acetate, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile and isooctyl acrylate.

11. The OLED display module device according to claim 7, characterized in that: The crosslinking agent is diacrylate.

12. The OLED display module device according to claim 7, characterized in that: The foaming agent includes one or more of a filler type foaming agent, a surfactant type foaming agent and a physical type foaming agent.

13. The OLED display module device according to claim 7, characterized in that: The auxiliary agent includes one or more of a color paste, a chain transfer agent, an anti-aging agent and a light stabilizer.

14. The OLED display module device according to claim 7, characterized in that: The first initiator and the second photoinitiator independently include a photoinitiator or a thermal initiator.

15. The OLED display module device according to any one of claims 6 to 9 and 11 to 14, characterized in that: The preparation method of the self-adhesive acrylic foam comprises the following steps: The acrylic prepolymer, fumed silica, a crosslinking agent, a foaming agent, a second initiator and an auxiliary agent are mixed and then cured to obtain the self-adhesive acrylic foam.

16. The OLED display module device according to claim 1, characterized in that: The composite acrylic foam cushioning material further comprises a plastic film layer, the thickness of the plastic film layer is 3 to 30 μm; the setting position of the plastic film layer is at least one of the following: The laminate is disposed between the self-adhesive acrylic foam layer and the damping pressure-sensitive adhesive layer; The laminate is arranged on one side of the self-adhesive acrylic foam layer and does not contact the damping pressure-sensitive adhesive layer; The laminate is arranged on one side of the damping pressure-sensitive adhesive layer and is not in contact with the self-adhesive acrylic foam layer.

17. The OLED display module device according to claim 16, characterized in that: The structure of the composite acrylic foam cushioning material is: A self-adhesive acrylic foam layer, a plastic film layer and a damping pressure-sensitive adhesive layer are stacked in sequence; Alternatively, a plastic film layer, a self-adhesive acrylic foam layer and a damping pressure-sensitive adhesive layer are sequentially laminated; Alternatively, a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer and a plastic film layer are sequentially laminated; Alternatively, a plastic film layer, a self-adhesive acrylic foam layer, a plastic film layer and a damping pressure-sensitive adhesive layer are sequentially laminated; Alternatively, a self-adhesive acrylic foam layer, a plastic film layer, a damping pressure-sensitive adhesive layer and a plastic film layer are sequentially laminated; Alternatively, a plastic film layer, a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer and a plastic film layer are sequentially laminated; Or a plastic film layer, a self-adhesive acrylic foam layer, a plastic film layer, a damping pressure-sensitive adhesive layer and a plastic film layer are stacked in sequence.

18. The OLED display module device according to claim 16 or 17, characterized in that: The plastic film used in the plastic film layer includes at least one of a polyester film, a polyolefin polymer film, a polyurethane elastomer film, a polycarbonate film, a polyimide film and a synthetic rubber film.

19. The OLED display module device according to claim 1, 16 or 17, characterized in that: The composite acrylic foam cushioning material further comprises a release film, and the release film is laminated and arranged on the outer side of the self-adhesive acrylic foam layer and / or the damping pressure-sensitive adhesive layer.

20. The OLED display module device according to claim 19, characterized in that: The release film is provided with an embossed grid; the release film includes a silicon release film and / or a fluorine release film.

21. The OLED display module device according to claim 20, characterized in that: The silicon release film is a transparent PET release film with a thickness of 15 to 75 μm and a release force of 5 to 15 gf / 25 mm or 15 to 25 gf / 25 mm; the fluorine release film has a thickness of 15 to 75 μm.

22. The OLED display module device according to claim 20 or 21, characterized in that: The structure of the composite acrylic foam cushioning material is any one of the following; A release film, a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer and a release film are sequentially laminated; A release film, a self-adhesive acrylic foam layer, a plastic film layer, a damping pressure-sensitive adhesive layer and a release film are sequentially laminated; A plastic film layer, a self-adhesive acrylic foam layer, a damping pressure-sensitive adhesive layer and a release film are stacked in sequence.

23. The OLED display module device according to claim 1, characterized in that: The OLED display module is in contact with the damping pressure-sensitive adhesive layer.

24. The OLED display module device according to claim 1 or 23, characterized in that: The OLED display module device further comprises a metal foil, and the metal foil laminate is arranged on one side of the composite acrylic foam cushioning material and does not contact the OLED display module.

25. The OLED display module device according to claim 24, characterized in that: The metal foil includes copper foil or aluminum foil.

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