Adhesive tape for bonding polycarbonate alloy and preparation method thereof

Abstract

The invention aims to provide the adhesive tape for bonding the polycarbonate alloy, the adhesive layer, the sealing enhancement layer, the adhesive layer and the release material layer are sequentially laminated, and the prepared adhesive tape can effectively dredge degradation products released by polycarbonate in a hot and humid environment by adjusting the formula of the adhesive and the composition of the acrylic polymer solution, so that the service life of the adhesive tape is prolonged, and the service life of the adhesive tape is prolonged. The adhesive tape provided by the invention has the advantages that the adhesive tape upheaval phenomenon caused by interface gas accumulation is eliminated, necessary bonding and sealing performance is maintained, stripping force attenuation and waterproof failure risks caused by too strong air tightness of a traditional adhesive tape are avoided, reliable bonding under long-term high-temperature and high-humidity working conditions is ensured, and the adhesive tape is adaptive to typical application scenes such as mobile phones and tablet personal computers.

Description

Technical Field

[0001] This invention relates to the field of adhesives, and in particular to an adhesive tape for bonding polycarbonate alloys and a method for preparing the same. Background Technology

[0002] Polycarbonate, as a general-purpose engineering plastic with excellent comprehensive properties, maintains high mechanical strength, dimensional stability, and outstanding impact resistance over a wide temperature range. Glass fiber reinforcement is an important technical route for polycarbonate modification. By blending surface-dewaxed and coupling agent-treated glass fibers with polycarbonate, the heat distortion temperature, rigidity, and dimensional accuracy of the material can be significantly improved, forming high-performance polycarbonate alloy plastics. This further expands its application depth in the 3C electronics field, and it is widely used in the molding of structural components for mobile phones, tablets, and other devices.

[0003] In the manufacturing process of such products, adhesive tape is often used to fix PC+GF sheets to ensure processing accuracy. However, when these materials are subjected to high temperature and high humidity environments (such as 65℃ / 95%RH test conditions), the end groups of the polycarbonate molecular chains undergo thermal degradation, continuously releasing low-molecular-weight volatile substances. Even glass fiber reinforcement fails to eliminate the inherent thermal degradation problem of polycarbonate molecular chain end groups. When traditional high-airtightness adhesive tape is used, these degradation products cannot escape through the adhesive layer and accumulate at the interface, eventually forming localized high pressure and causing the tape to bulge, resulting in visible deformation. This phenomenon not only directly damages the integrity of the bonding interface, leading to a decrease in tape peel strength, but may also interfere with subsequent precision assembly processes.

[0004] To mitigate this problem, the industry currently employs an oversized design strategy—that is, over-designing excess tape to overcome its impact. However, this method only extends the retention time to a limited extent and cannot eliminate the physical nature of volatile substance accumulation, while also unnecessarily increasing material costs. Therefore, there is an urgent need to develop a new type of sealing tape that can specifically address the interfacial failure problem caused by the thermal degradation of polycarbonate alloys' volatiles while maintaining the necessary fixing function. Summary of the Invention

[0005] To address the aforementioned technical problems, a first aspect of the present invention provides an adhesive tape for bonding polycarbonate alloys, comprising, in sequence, an adhesive layer, a sealing reinforcement layer, another adhesive layer, and a release material layer, characterized in that the adhesive layer comprises an acrylate polymer solution, a tackifying resin, a crosslinking agent, an antioxidant, and a surfactant, wherein...

[0006] The acrylate polymer solution comprises the following components in parts by weight:

[0007] 30-50 parts of long-chain alkyl ester monomers of acrylic acid

[0008] 6-8 parts of dioctyl oxalate

[0009] 10-14 parts acrylic acid

[0010] 6-10 parts butyl acrylate

[0011] 1-5 parts of cyclohexyl methacrylate

[0012] 21-25 parts of isooctyl acrylate

[0013] 1-2 parts of hydroxyethyl acrylate

[0014] 0.3-0.35 parts of BPO initiator

[0015] 30-40 parts of ethyl acetate;

[0016] The mass ratio of the solid component in the acrylate polymer solution to the tackifying resin, crosslinking agent, antioxidant, and surfactant is 40:(0-7.8):(0.58-0.8):(0.1-0.15):(0.08-0.2).

[0017] Furthermore, the tackifying resin is Arakawa GB115 rosin ester and / or Kronen terpene phenol resin 1160.

[0018] Furthermore, the crosslinking agent is an isocyanate crosslinking agent.

[0019] Furthermore, the isocyanate crosslinking agent is L-150.

[0020] Furthermore, the antioxidant is a hindered phenolic antioxidant.

[0021] Furthermore, the hindered phenolic antioxidant is 2,6-di-tert-butyl-4-methylphenol.

[0022] Furthermore, the surfactant is PC-1344.

[0023] Furthermore, the release material layer is a solvent-free release paper or release film.

[0024] Furthermore, the sealing reinforcement layer is a closed-cell foamed PE foam substrate.

[0025] Furthermore, the thickness of the sealing reinforcement layer is 70–250 μm.

[0026] Furthermore, the thickness of the adhesive layer is 20–75 μm.

[0027] A second aspect of the present invention provides a method for preparing an adhesive tape for bonding polycarbonate alloys, characterized by comprising the following preparation steps:

[0028] S1. The long-chain alkyl acrylate monomer, dioctyl oxalate, ethyl acetate solvent, and part of the BPO initiator are reacted in a reaction vessel in the first step reaction. Then, acrylic acid, butyl acrylate, cyclohexyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, dioctyl oxalate and the remaining initiator are added to carry out the second step reaction to obtain an acrylate polymer solution.

[0029] S2. Mix the acrylate polymer solution obtained in S1, the tackifying resin, the crosslinking agent, the antioxidant, and the surfactant evenly to obtain the adhesive layer solution.

[0030] S3. The adhesive solution obtained in S2 is applied to the release material layer and dried to form a composite layer of adhesive layer and release material layer. The adhesive layer in the composite layer is bonded to the first surface of the sealing reinforcement layer. Then, the adhesive layer is coated or transferred again on the second surface of the sealing reinforcement layer. After curing, double-sided tape is obtained.

[0031] Furthermore, the first step reaction is carried out under nitrogen protection at a temperature of 50–90°C for 40–80 minutes.

[0032] Furthermore, the reaction temperature of the second step is 81–93°C, and the reaction time is 4–6 hours.

[0033] Furthermore, the curing process is carried out at a temperature of 45–65°C for 1–3 days.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The tape prepared by this invention can effectively channel the degradation products released by polycarbonate in hot and humid environments, fundamentally eliminating the tape bulging phenomenon caused by interfacial gas accumulation. This design maintains the necessary adhesive sealing performance while avoiding the risk of peel strength reduction and waterproof failure caused by excessive air tightness of traditional tapes, ensuring reliable adhesion under long-term high temperature and high humidity conditions.

[0036] 2. The tape prepared by this invention has good compatibility with polycarbonate and is suitable for typical application scenarios such as mobile phones and tablets. Its flexible interface can absorb mechanical stress during the equipment assembly process and withstand the high temperature impact of surface mounting. It maintains stable adhesion in the entire process of precision electronic assembly, providing key technical support for high-yield production. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of an adhesive tape prepared according to the present invention for bonding polycarbonate alloys. Detailed Implementation

[0038] Example 1

[0039] S1. A measured amount of long-chain alkyl acrylate monomers, dioctyl oxalate, ethyl acetate solvent, and part of BPO initiator are placed in a reaction vessel for the first step reaction. Then, acrylic acid, butyl acrylate, cyclohexyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, dioctyl oxalate, and the remaining initiator are added for the second step reaction to obtain an acrylate polymer solution.

[0040] S2. Mix the acrylate polymer solution obtained in S1, the tackifying resin, the crosslinking agent, the antioxidant, and the surfactant evenly to obtain the adhesive layer solution.

[0041] S3. The adhesive solution obtained in S2 is applied to the release material layer and dried to form a composite layer of adhesive layer and release material layer. The adhesive layer in the composite layer is bonded to the first surface of the sealing reinforcement layer. Then, the adhesive layer is coated or transferred again on the second surface of the sealing reinforcement layer. After curing, double-sided tape is obtained.

[0042] Examples 2-5

[0043] The specific operation is the same as in Example 1, but the dosage of each component is different.

[0044] The amounts of each component in the acrylic polymer solution and the amount of each component in the adhesive layer in the above five examples are shown in Table 1.

[0045] Table 1. Component content of Examples 1-5

[0046]

[0047] Performance testing

[0048] The double-sided adhesive tapes obtained in Examples 1-5 were then bonded to the boards and subjected to high temperature and high humidity evaluation. The test methods are as follows:

[0049] Board material: Polycarbonate board (containing 20% ​​glass fiber)

[0050] Sample dimensions: 25mm*200mm

[0051] Sample preparation conditions: 2 kg, 300 mm / min, rolling back and forth twice.

[0052] Test method: After bonding the boards, let them stand at room temperature for 24 hours, and then immerse them in 65℃ and 95% humidity for 120 hours.

[0053] Table 2 - Test results of tape performance in Examples 1-5

[0054]

[0055] The test results of the above embodiments show that the tape prepared in this application can effectively guide the degradation products released by polycarbonate in hot and humid environments and eliminate the tape bulging phenomenon caused by the accumulation of interfacial gases.

[0056] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure made using the contents of the present invention specification and drawings, or directly or indirectly applied to other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A tape for bonding polycarbonate alloys, comprising, in sequence, an adhesive layer, a sealing reinforcement layer, an adhesive layer, and a release material layer, characterized in that, The adhesive layer comprises an acrylate polymer solution, a tackifying resin, a crosslinking agent, an antioxidant, and a surfactant, wherein, The acrylate polymer solution comprises the following components in parts by weight: 30-50 parts of long-chain alkyl ester monomers of acrylic acid 6-8 parts of dioctyl oxalate 10-14 parts acrylic acid 6-10 parts butyl acrylate 1-5 parts of cyclohexyl methacrylate 21-25 parts of isooctyl acrylate 1-2 parts of hydroxyethyl acrylate 0.3-0.35 parts of BPO initiator 30-40 parts of ethyl acetate; The mass ratio of the solid component in the acrylate polymer solution to the tackifying resin, crosslinking agent, antioxidant, and surfactant is 40:(0-7.8):(0.58-0.8):(0.1-0.15):(0.08-0.2).

2. The tape for bonding polycarbonate alloys according to claim 1, characterized in that, The crosslinking agent is an isocyanate crosslinking agent, and the antioxidant is a hindered phenolic antioxidant.

3. The tape for bonding polycarbonate alloys according to claim 2, characterized in that, The tackifying resin is Arakawa GB115 rosin ester and / or Kerté terpene phenol resin 1160, the isocyanate crosslinking agent is L-150, the hindered phenolic antioxidant is 2,6-di-tert-butyl-4-methylphenol, and the surfactant is PC-1344.

4. The tape for bonding polycarbonate alloys according to claim 1, characterized in that, The release material layer is a solvent-free release paper or release film, and the sealing reinforcement layer is a closed-cell foamed PE foam substrate.

5. The tape for bonding polycarbonate alloys according to claim 1, characterized in that, The thickness of the sealing reinforcement layer is 70–250 μm, and the thickness of the adhesive layer is 20–75 μm.

6. A method for preparing an adhesive tape for bonding polycarbonate alloys as described in any one of claims 1-5, characterized in that, The preparation steps include the following: S1. The long-chain alkyl acrylate monomer, dioctyl oxalate, ethyl acetate solvent, and part of the BPO initiator are reacted in a reaction vessel in the first step reaction. Then, acrylic acid, butyl acrylate, cyclohexyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, dioctyl oxalate and the remaining initiator are added to carry out the second step reaction to obtain an acrylate polymer solution. S2. Mix the acrylate polymer solution obtained in S1, the tackifying resin, the crosslinking agent, the antioxidant, and the surfactant evenly to obtain the adhesive layer solution. S3. The adhesive solution obtained in S2 is applied to the release material layer and dried to form a composite layer of adhesive layer and release material layer. The adhesive layer in the composite layer is bonded to the first surface of the sealing reinforcement layer. Then, the adhesive layer is coated or transferred again on the second surface of the sealing reinforcement layer. After curing, double-sided tape is obtained.

7. The method for preparing an adhesive tape for bonding polycarbonate alloys according to claim 5, characterized in that, The first step reaction is carried out under nitrogen protection at a temperature of 50–90°C for 40–80 minutes.

8. The method for preparing an adhesive tape for bonding polycarbonate alloys according to claim 5, characterized in that, The reaction temperature for the second step is 81–93°C, and the reaction time is 4–6 hours.

9. A method for preparing an adhesive tape for bonding polycarbonate alloys according to claim 5, characterized in that, The curing process is carried out at a temperature of 45–65°C for 1–3 days.

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