Electric heating removable composite adhesive tape and bonding structure

Abstract

The utility model discloses an electric heating removable composite adhesive tape and a bonding structure. Specifically, the composite adhesive tape provided by the utility model comprises an electric heating layer and a thermally removable adhesive layer bonded with the electric heating layer. When the heat removable adhesive layer of the composite adhesive tape disclosed by the utility model is attached to the substrate, the adhesive on the surface of the substrate can be quickly and efficiently removed without residues only by electrifying the local electric heating layer, so that the recycling of the substrate material is facilitated.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic product assembly field more particularly to a kind of electric heating removable composite adhesive tape and bonding structure. BACKGROUND

[0002] With the increasingly fast speed of modern electronic product replacement, from the angle of sustainable development, efficient recycling of electronic product parts is an important issue. In the recycling and reuse process, the product usually needs to be disassembled, and the residual adhesive tape used in assembling and adhering the product components needs to be removed. However, the high-adhesion residual adhesive tape during disassembly of the components is easy to adhere to the surface of the components and affect the reuse of the components. For example, it is difficult to easily and cleanly remove the large amount of residual adhesive tape on the surface of the screen after the display screen is separated from the main unit, which affects the recycling of high-cost electronic product screens and other substrates.

[0003] Heating removable adhesive is commonly used to solve the problem of difficult removal of residual adhesive, but usually the entire adhered adhesive tape and component product needs to be placed in a high-temperature environment for heating treatment, which makes the substrate and other components that are not resistant to high temperature easily damaged.

[0004] Therefore, in order to avoid damage to the substrate that needs to be recycled, and at the same time solve the problem of difficult clean removal of residual adhesive tape from the surface of the substrate during disassembly of the components, it is urgent to develop an adhesive tape that has excellent adhesive properties when adhesion is needed, but can be easily and completely peeled off from the substrate when separation is needed. SUMMARY

[0005] The utility model aims at providing an electric heating removable composite adhesive tape and bonding structure.

[0006] The utility model provides an electric heating removable composite adhesive tape, along the thickness direction of the adhesive tape, the adhesive tape comprises in turn:

[0007] (a) a first adhesive layer; the first adhesive layer is a heat removable adhesive layer;

[0008] (b) an electric heating layer; the thickness of the electric heating layer is 5-15 μm;

[0009] (c) a second adhesive layer; the second adhesive layer is a heat-stable adhesive layer;

[0010] (d) a foam layer; and

[0011] (e) a third adhesive layer.

[0012] In another preferred example, the electric heating layer is selected from the group consisting of iron-nickel alloy film or metal-plated PET film.

[0013] In another preferred embodiment, at least one major surface of the PET film is plated with metal.

[0014] In another preferred embodiment, at least one major surface of the PET film is plated with aluminum, titanium, gold, or a combination thereof.

[0015] In another preferred embodiment, the metal surface of the metal-plated PET film is attached to the first adhesive layer.

[0016] In another preferred embodiment, the thickness of the electric heating layer is 8-10 μm.

[0017] In another preferred embodiment, the electric heating layer is provided with two exposed conductive terminals.

[0018] In another preferred embodiment, the conductive terminals are disposed in the xy direction of the electric heating layer.

[0019] In another preferred embodiment, the thickness of the first adhesive layer is 10-150 μm, preferably 30-100 μm.

[0020] In another preferred embodiment, the thickness of the second adhesive layer is 5-50 μm, preferably 10-30 μm.

[0021] In another preferred embodiment, the thickness of the foam layer is 60-500 μm, preferably 100-400 μm.

[0022] In another preferred embodiment, the electric resistance of the electric heating layer is 0.1-5 Ω / □, preferably 0.1-2 Ω / □, more preferably 0.1-0.5 Ω / □.

[0023] In another preferred embodiment, the voltage applied to the electric heating layer is 1-36 V; preferably 2-25 V, more preferably 3-12 V; more preferably 5-12 V.

[0024] In another preferred embodiment, the peel force of the first adhesive layer is reduced by more than 70%, more preferably more than 80%, most preferably more than 90% after the temperature is raised to more than 70 °C compared to before the voltage application treatment.

[0025] In another preferred embodiment, the peel force of the first adhesive layer is ≥ 5 N / cm, preferably ≥ 6 N / cm, more preferably ≥ 6.5 N / cm when the temperature is not more than 30 °C.

[0026] In another preferred embodiment, the peel force of the first adhesive layer is reduced to ≤ 3 N / cm, more preferably ≤ 2 N / cm, most preferably ≤ 1 N / cm after the temperature is raised to more than 70 °C.

[0027] In another preferred embodiment, the time for which the electrically heatable layer is energized is between 5 s and 30 min, preferably between 10 s and 10 min, more preferably between 30 s and 5 min.

[0028] In another preferred embodiment, the material of the foam layer is selected from the group consisting of homo- and copolymers of polyolefins, polyurethane (PU), acrylic resin, polyvinyl acetate, silicone, or combinations thereof.

[0029] In another preferred embodiment, the material of the foam carrier layer is selected from the group consisting of ethylene-vinyl acetate copolymer, polyvinyl acetate, polyethylene, EPDM (ethylene propylene diene rubber), thermoplastic elastomers based on styrene block copolymers, polyurethanes based on aromatic and aliphatic diisocyanates and diol esters or diol ethers, PVC, polychloroprene, silicone, acrylic or methacrylic acid, mixtures of acrylic and methacrylic acid polymers, natural rubber, or combinations thereof.

[0030] In another preferred embodiment, the foam layer is selected from the group consisting of polyethylene foam or polyurethane foam.

[0031] In another preferred embodiment, the heat-removable adhesive is selected from the group consisting of pressure-sensitive adhesives, hot-melt adhesives, synthetic rubber-based adhesives.

[0032] In another preferred embodiment, the heat-stable adhesive is selected from the group consisting of acrylic adhesives, synthetic rubber-based adhesives.

[0033] In another preferred embodiment, the surface of the electrically heatable layer is an untreated surface.

[0034] In another preferred embodiment, the third adhesive layer has a thickness of between 10 and 150 pm, preferably between 30 and 100 pm.

[0035] In another preferred embodiment, the third adhesive layer is a heat-stable adhesive layer.

[0036] In another preferred embodiment, the composite tape further comprises the following components:

[0037] i) a first release layer bonded to the outer surface of the first adhesive layer;

[0038] ii) a second release layer bonded to the outer surface of the third adhesive layer.

[0039] The utility model also provides a kind of electric heating removable composite tape, along the thickness direction of the tape, the tape sequentially includes:

[0040] (i) first adhesive layer; the first adhesive layer is heat-removable adhesive layer;

[0041] (ii) a metal-plated foam layer; at least one major surface of the foam layer is provided with a metal plating; and

[0042] (iii) a second adhesive layer;

[0043] wherein the first adhesive layer is attached to the outer surface of the metal plating of the foam layer.

[0044] In another preferred embodiment, the first adhesive layer has a thickness of 10-150 μm, preferably 30-100 μm.

[0045] In another preferred embodiment, the metal-plated foam layer has a metal plating thickness of 0.1-1.5 μm, preferably 0.5-1.0 μm.

[0046] In another preferred embodiment, the metal is selected from the group consisting of iron, nickel, aluminum, titanium and gold.

[0047] In another preferred embodiment, the foam in the metal-plated foam layer is composed of a material selected from the group consisting of polyethylene foam or polyurethane foam.

[0048] In another preferred embodiment, the foam in the metal-plated foam layer has a thickness of 60-500 μm, preferably 100-400 μm.

[0049] In another preferred embodiment, the second adhesive layer has a thickness of 10-150 μm, preferably 30-100 μm.

[0050] In another preferred embodiment, the second adhesive layer is a heat-stable adhesive layer.

[0051] In another preferred embodiment, the metal-plated foam layer is further provided with two conductive terminals.

[0052] In another preferred embodiment, the peel force of the first adhesive layer is rapidly reduced by the resistance heating of the metal after a voltage is applied to the two conductive terminals of the metal-plated foam layer.

[0053] In another preferred embodiment, the metal plating has a resistance of 0.1-5 Ω / D, preferably 0.1-2 Ω / D, more preferably 0.1-0.5 Ω / D.

[0054] In another preferred embodiment, the voltage applied to the metal-plated foam layer is 1-36 V; preferably 2-25 V, more preferably 3-12 V; more preferably 5-12 V.

[0055] In another preferred embodiment, the composite tape further comprises the following components:

[0056] i) a first release layer attached to the outer surface of the first adhesive layer;

[0057] ii) a second release layer bonded to an outer surface of the second adhesive layer.

[0058] The utility model also provides a removable adhesive structure of electric heating, the structure includes:

[0059] (1) first base plate;

[0060] (2) second base plate;And

[0061] (3) composite tape;The composite tape is located between first base plate and second base plate and bonds first base plate and second base plate together, wherein the composite tape is the composite tape as the utility model discloses.

[0062] In another preferred example, the first base plate and the second base plate are each independently selected from the group consisting of a glass substrate, a plastic substrate, and a metal substrate.

[0063] In another preferred example, the first base plate is selected from a display screen of an electronic product.

[0064] In another preferred example, the electronic product is selected from the group consisting of a mobile phone, a television, a monitor, a display, and a vehicle display.

[0065] It should be understood that, within the scope of the utility model, each of the above technical features of the utility model and each of the technical features specifically described in the following (such as the examples) can be combined with each other, thereby constituting a new or preferred technical scheme. Due to the limited space, they will not be listed one by one here. BRIEF DESCRIPTION OF DRAWINGS

[0066] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0067] Figure 1 It is the structure schematic diagram of the adhesive tape and the assembly containing it in one example of the utility model;Wherein, each mark is as follows: A-substrate layer;1-first adhesive layer;2-electric heating layer;The two ends of the electric heating layer have overhanging parts;3-second adhesive layer;4-closed cell foam layer;5-third adhesive layer;B-substrate layer.

[0068] Figure 2 It is the structure schematic diagram of the adhesive tape and the assembly containing it in another example of the utility model;Wherein, each mark is as follows: A-substrate layer;1-first adhesive layer;2-metal-plated closed cell foam layer, and the metal surface is in contact with the first adhesive layer;3-second adhesive layer;B-substrate layer. DETAILED DESCRIPTION

[0069] The inventors have made extensive and in-depth research, and developed an electric heating removable adhesive tape and an assembly comprising the same by optimizing the structure and material selection of the adhesive tape. Specifically, an electric heating layer and a heat removable adhesive are introduced into the adhesive tape layer. When the heat removable adhesive layer is bonded with the substrate layer, the electric heating layer generates heat by applying voltage, so that the peel strength of the heat removable adhesive is rapidly reduced, and it is unexpectedly found that the heat removable adhesive layer and the substrate layer can be efficiently and completely separated. On this basis, the utility model is completed.

[0070] Electric heating removable composite adhesive tape

[0071] The electric heating removable composite adhesive tape comprises a metal layer structure that can be heated by electrification and a heat removable adhesive layer adjacent to the structure. The metal is electrified to heat the heat removable adhesive layer, so that the peel strength of the heat removable adhesive layer is rapidly reduced, thereby separating the heat removable adhesive layer from the adhered substrate layer.

[0072] In one embodiment, the composite adhesive tape of the utility model comprises, in order along the thickness direction of the adhesive tape:

[0073] (a) a first adhesive layer; the first adhesive layer is a heat removable adhesive layer;

[0074] (b) an electric heating layer; the thickness of the electric heating layer is 5-15 μm;

[0075] (c) a second adhesive layer; the second adhesive layer is a heat stable adhesive layer;

[0076] (d) a foam layer; and

[0077] (e) a third adhesive layer.

[0078] In another embodiment, the composite adhesive tape of the utility model comprises, in order along the thickness direction of the adhesive tape:

[0079] (i) a first adhesive layer; the first adhesive layer is a heat removable adhesive layer;

[0080] (ii) a metal-plated foam layer; the foam layer is provided with a metal plating layer on at least one major surface; and

[0081] (iii) a second adhesive layer;

[0082] The first adhesive layer is attached to the outer surface of the metal plating layer of the foam layer.

[0083] Electric heating layer

[0084] The electric heating layer is at least one thin layer with a metal main surface, and the metal and the adhesive layer attached to the metal surface can be rapidly heated by passing current through the metal part. The electric heating layer can be entirely made of metal, or at least one main surface has a gold-plated material, including but not limited to a metal-plated PET film. In another embodiment, a foam layer with a metal plating layer on at least one main surface can also be directly used as an intermediate layer between the two adhesive layers.

[0085] The metal layer can completely or partially cover the adhesive layer. As long as the metal can be quickly heated by passing current, the shape of the metal layer is not limited, and in the top view of the adhesive tape, it can be planar, strip-shaped, mesh-shaped, etc. In order to facilitate the passage of electricity, two exposed conductive ends can be provided on the electric heating layer, so that an electric current passing through the main plane is generated in the xy direction of the electric heating layer (i.e., the plane direction of the layer where it is located).

[0086] Metal-plated PET film

[0087] The metal-plated PET film of the present application is a metalized film formed by evaporating a thin layer of metal atoms onto a PET film in a vacuum state. The thickness of the metal plating layer is 0.1-1.5 μm, the resistance is 0.1-0.5 Ω / □, and the total thickness of the metalized film is 12-75 μm.

[0088] Thermally removable adhesive

[0089] The thermally removable adhesive of the present application is not particularly limited and generally has a low melting point or softening point. At room temperature, it maintains a high adhesion (e.g., greater than 6 N / cm), and when heated to a high temperature (e.g., more than 70°C), it melts or softens, and the adhesion decreases to 2 N / cm or less, so that it can be easily peeled off from the substrate surface without leaving any adhesive residue on the substrate surface.

[0090] The thermally removable adhesive includes but is not limited to pressure-sensitive adhesives, hot-melt adhesives.

[0091] The pressure-sensitive adhesive can include acrylic pressure-sensitive adhesives (acrylic adhesives), urethane pressure-sensitive adhesives (urethane adhesives), synthetic rubber pressure-sensitive adhesives, natural rubber pressure-sensitive adhesives, silicone pressure-sensitive adhesives, etc.

[0092] The hot-melt adhesive can include ethylene-vinyl acetate copolymer (EVA) hot-melt adhesives, polyolefin hot-melt adhesives, polyamide hot-melt adhesives, polyurethane hot-melt adhesives, acrylic hot-melt adhesives, polyester hot-melt adhesives, styrene thermoplastic elastomers, etc.

[0093] Thermally stable adhesive

[0094] The thermally stable adhesive of the utility model is an adhesive which can still maintain good adhesion at high temperature, has a high melting point or softening point, preferably a melting point or softening point higher than 100 DEG C, more preferably higher than 120 DEG C.

[0095] The main advantages of the utility model include:

[0096] (1) has high efficient stripping effect, residual adhesive tape and substrate can be completely stripped, and the substrate after stripping can be directly recycled.

[0097] (2) stripping is fast, and the adhesion of the heat removable adhesive tape can be reduced to very low stripping force only by energizing for 1 minute.

[0098] (3) high safety, and the stripping of the adhesive tape and the substrate layer can be realized only by 5V low voltage.

[0099] (4) compared with the traditional whole assembly heating stripping mode, the assembly of the utility model avoids the heating influence on the substrate layer and other assemblies by local electric heating.

[0100] (5) the utility model uses an ultrathin electric heating metal layer, and the thickness can be as low as 8-10 mu m.

[0101] (6) reduce energy cost.

[0102] The utility model will be further described in combination with specific embodiments. It should be understood that these embodiments are only used to illustrate the utility model and are not used to limit the scope of the utility model. In addition, the drawings are schematic drawings, so the utility model device and equipment are not limited by the size or proportion of the schematic drawing.

[0103] It should be noted that in the claims and the specification of the patent, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitation, the element defined by the sentence "including one" does not exclude the existence of other identical elements in the process, method, article or equipment including the element.

[0104] General raw material

[0105] Hot removable acrylic adhesive: copolymer of 90% n-butyl acrylate (nBA) and 10% methyl acrylate (MA);

[0106] s / b acrylic adhesive: copolymer of 90% n-butyl acrylate (nBA), 6% acrylic acid (AA), 4% methyl acrylate (MA).

[0107] Iron-nickel alloy: 55% Fe, 45% Ni w / w

[0108] Peel force test

[0109] The adhesive tape sample was cut into a sample strip with a length of about 150 mm and a width of 20 mm, a 36 μm PET reinforcing film was attached to the non-measuring surface, and then the measuring surface to be adhered was adhered to a steel test plate cleaned with acetone. The attached sample was rolled under a 4 kg steel roller of the sample pressing machine at a speed of 10 m / min for 5 rounds, and left to stand at room temperature for 20 min. The peeling force value at room temperature was measured by a tensile testing machine. Subsequently, a voltage of 5 V was applied to the two conductive ends of the electric heating layer or the metal-plated foam layer of the adhesive tape for 1 min, and the peeling force value (unit: N / cm) of the adhesive tape was measured again.

[0110] Example 1

[0111] The hot removable acrylic adhesive was dissolved in ethyl acetate as a solvent, and coated on the release-treated surface of a release liner (a 75 μm-thick polyethylene terephthalate film subjected to release treatment on one side) in a dried thickness of 50 μm, and dried at 90°C for 3 min, thereby producing a first adhesive layer. Subsequently, the s / b acrylic adhesive was coated on the release-treated surface of a release liner (a 75 μm-thick polyethylene terephthalate film subjected to release treatment on one side) in a dried thickness of 20 μm and 50 μm, respectively, by the same treatment, and dried at 90°C for 3 min, thereby producing a second adhesive layer and a third adhesive layer.

[0112] As the electric heating layer, an iron-nickel alloy film (Anhui Maidefox New Material Co., Ltd.) with a thickness of 8 μm was used, and a nichrome film was extended by 25 mm at both ends in the xy direction for power supply. The first adhesive layer, the electric heating layer, the second adhesive layer, a polyethylene foam layer (Xiangyuan New Material Co., Ltd.), and the third adhesive layer were sequentially laminated and attached by a hand roller according to the structure shown in the figure. Figure 1 An electric heating removable composite adhesive tape was obtained.

[0113] Example 2

[0114] A hot removable acrylic adhesive was dissolved in ethyl acetate as a solvent, and applied to a release-treated surface of a release liner (a 75-μm-thick polyethylene terephthalate film that had been subjected to release treatment on one side) at a dried thickness of 50 μm, dried at 90°C for 3 minutes, thereby producing a first adhesive layer. Next, an s / b acrylic adhesive was applied to a release-treated surface of a release liner (a 75-μm-thick polyethylene terephthalate film that had been subjected to release treatment on one side) at a dried thickness of 50 μm in the same manner, dried at 90°C for 3 minutes, thereby producing a second adhesive layer.

[0115] As the metal-plated foam layer, a 1-μm-thick copper-plated metal film (Shenzhen Advanced Institute Technology Co., Ltd.) was used, with 25 mm of each end of the copper-plated metal film extending for connection to a power source. The metal film was laminated to a 200-μm-thick polyethylene foam (Xiangyuan New Material Co., Ltd.) using a hand roller to obtain a copper-plated polyethylene foam layer. The first adhesive layer, the copper-plated foam layer, and the second adhesive layer were laminated in that order using a hand roller to obtain an electrically heatable removable composite tape.

[0116] Comparative Example 1

[0117] A hot removable acrylic adhesive was dissolved in ethyl acetate as a solvent, and applied to a release-treated surface of a release liner (a 75-μm-thick polyethylene terephthalate film that had been subjected to release treatment on one side) at a dried thickness of 50 μm, dried at 90°C for 3 minutes, thereby producing a first adhesive layer. Next, an s / b acrylic adhesive was applied to a release-treated surface of a release liner (a 75-μm-thick polyethylene terephthalate film that had been subjected to release treatment on one side) at a dried thickness of 50 μm in the same manner, dried at 90°C for 3 minutes, thereby producing a second adhesive layer.

[0118] The first adhesive layer, a polyethylene foam layer (Xiangyuan New Material Co., Ltd.), and the second adhesive layer were laminated in that order using a hand roller to obtain a removable composite tape.

[0119] Table 1

[0120]

[0121]

[0122] From table 1 can know: in the comparative example 1, the adhesive tape and the bonded substrate screen as a whole are placed in the oven at 75 DEG C and heated for more than 10 minutes, so that the first adhesive layer reaches the peelable temperature, and the screen is always in a high temperature state. On the contrary, only the metal film in the adhesive tape of the utility model needs to be powered for 1 minute, the temperature of the heat removable adhesive rapidly increases from room temperature to 75 DEG C, the peel strength reduction rate is more than 90%, and the substrate screen bonded with the first adhesive layer can be completely peeled off from the whole adhesive tape.

[0123] All the documents mentioned in the utility model are cited as references in the present application, as if each document is cited as a separate reference. In addition, it should be understood that various modifications or changes can be made to the utility model by those skilled in the art after reading the above teaching of the utility model, and these equivalent forms also fall within the scope defined by the claims attached to the present application.

Claims

1. An electrically heatable removable composite tape, characterized in that, In the thickness direction of the adhesive tape, the adhesive tape comprises in order: (a) a first adhesive layer; the first adhesive layer is a heat-removable adhesive layer; (b) an electric heating layer; the thickness of the electric heating layer is 5-15 μm; (c) a second adhesive layer; the second adhesive layer is a heat-stable adhesive layer; (d) a foam layer; and (e) a third adhesive layer.

2. The composite tape of claim 1, wherein The electric heating layer is selected from the group consisting of iron-nickel alloy film or metal-plated PET film.

3. The composite tape of claim 2, wherein At least one major surface of the PET film is plated with metal.

4. The composite tape of claim 2, wherein The metal surface of the metal-plated PET film is attached to the first adhesive layer.

5. The composite adhesive tape according to claim 1, wherein: the thickness of the first adhesive layer is 10-150 μm; the thickness of the second adhesive layer is 5-50 μm; the thickness of the foam layer is 60-500 μm; the thickness of the third adhesive layer is 10-150 μm.

6. An electrically heatable removable composite tape, characterized in that In the thickness direction of the adhesive tape, the adhesive tape comprises in order: (i) a first adhesive layer; the first adhesive layer is a heat-removable adhesive layer; (ii) a metal-plated foam layer; the foam layer is provided with a metal plating layer on at least one major surface; and (iii) a second adhesive layer; wherein the first adhesive layer is attached to the outer surface of the metal plating layer of the foam layer.

7. The composite tape of claim 6, wherein In the metal-plated foam layer, the thickness of the metal plating layer is 0.1-1.5 μm; and the thickness of the foam is 60-500 μm.

8. The composite adhesive tape according to claim 6, wherein: the thickness of the first adhesive layer is 10-150 μm; the thickness of the second adhesive layer is 10-150 μm.

9. The composite tape of claim 6, wherein The metal is selected from the group consisting of iron, nickel, aluminum, titanium and gold.

10. An electrically heatable removable adhesive structure, characterized in that The structure comprises: (1) a first substrate; (2) a second substrate; and (3) a composite adhesive tape; the composite adhesive tape is located between the first substrate and the second substrate and bonds the first substrate and the second substrate together, wherein the composite adhesive tape is the composite adhesive tape according to any one of claims 1-9.

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