OCA (Optical Clear Adhesive) tape with high re-disassembly performance and preparation method of OCA tape

Abstract

The invention relates to the technical field of OCA (Optical Clear Adhesive) tapes, and discloses an OCA tape with high re-disassembly performance and a preparation method thereof, the OCA tape structurally comprises a release film C, an upper surface adhesive A, a core material adhesive film B, a lower surface adhesive A and a release film D in sequence from top to bottom, the surface adhesive A comprises 60-85 parts by weight of an acrylate soft monomer A, 15-40 parts by weight of a hard monomer A, 4-8 parts by weight of a polyfunctional group cross-linking agent A and the like. The acrylate soft monomer A comprises butyl acrylate, acrylic acid-2-ethylhexyl ester and the like. The polyfunctional group cross-linking agent A comprises triethylene glycol dimethacrylate and the like, the initiator A is TPO and the like, the OCA adhesive tape is excellent in moisture resistance and weather resistance, adhesive tape colloid is not broken after stripping, and the detaching and returning effect is good.

Description

Technical Field

[0001] This invention relates to the field of OCA tape technology, specifically to an OCA tape with high re-opening performance and its preparation method. Background Technology

[0002] OCA tape is a permanent adhesive that can bond various substrates. It is widely used in automotive, electronics, military, and medical fields. The topcoat of OCA tape is primarily composed of different types of monomers polymerized together. The diverse monomer types determine its performance variations; therefore, different monomers and crosslinking agents can be added to give OCA tape different application properties. However, with continuous industrial development, ordinary OCA tape cannot meet the requirements for re-attachment and die-cutting, leading to re-attachment failure during application.

[0003] Furthermore, OCA adhesive suffers from problems such as ineffective separation from the bonded substrate after application, easy damage to the bonded substrate after peeling, or leaving residue and blemishes when peeled off the surface of the adhered object. Based on these issues, this invention provides an OCA with excellent re-peeling performance and its preparation method to meet market demands. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an OCA tape with high re-opening performance and its preparation method, solving the problem of poor re-opening performance of acrylic resin tapes.

[0005] The technical solution of the present invention is: an OCA tape with high re-removal performance, the structure of the tape from top to bottom is as follows: release film C, upper layer of surface adhesive A, core material film B, lower layer of surface adhesive A, and release film D.

[0006] The raw materials of adhesive A include 60-85 parts by weight of acrylate soft monomer A, 15-40 parts by weight of hard monomer A, 0.8-1.5 parts by weight of photoinitiator A, 4-8 parts by weight of multifunctional crosslinking agent A, and 0.2-0.4 parts by weight of chain transfer agent A.

[0007] The raw materials of the core film B include 70-95 parts by weight of acrylate soft monomer B, 5-30 parts by weight of hard monomer B, 0.6-1.4 parts by weight of photoinitiator B, 4-7 parts by weight of multifunctional crosslinking agent B, and 0.2-0.35 parts by weight of chain transfer agent B.

[0008] Furthermore, the multifunctional crosslinking agent A includes one or more of triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, and 1,2-bis(cyclohexylaminoethyl acrylate) ethane.

[0009] Further, the preparation method of 1,2-bis(cyclohexylaminoethyl acrylate) ethane is as follows: 100 parts by weight of 1,2-bis(cyclohexylamino)ethane (CAS Registry No. 4013-98-3) and 160-256 parts by weight of 2-bromoethyl acrylate (CAS Registry No. 4823-47-6) are added to tetrahydrofuran. An aqueous solution containing 60-70 parts by weight of potassium hydroxide is added dropwise. The mixture is heated to 60-70°C and refluxed for 12-18 hours. Ethyl acetate is added for extraction. The organic layer is separated and collected, and the crude product is separated by vacuum distillation. The crude product is separated by silica gel column chromatography and eluted with ethyl acetate and petroleum ether solution to obtain 1,2-bis(cyclohexylaminoethyl acrylate) ethane. The reaction formula is: .

[0010] Furthermore, the raw materials for adhesive A may include isoborneol acrylate, isoborneol methacrylate, cyclohexyl methacrylate, cyclohexyl acrylate, N-vinylpyrrolidone, and N,N-dimethylacrylamide.

[0011] Furthermore, the acrylate soft monomer A includes one or more of butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and isooctyl acrylate.

[0012] Furthermore, hard monomer A is one or more of methyl acrylate, methyl methacrylate, acrylic acid, and methacrylic acid.

[0013] Furthermore, photoinitiator A is one or more of TPO, Irgacure 184, Irgacure 819, Darocure 1173, and Omnirad 651.

[0014] Furthermore, chain transfer agent A is a thiol molecular weight regulator, including dodecanethiol.

[0015] Furthermore, the acrylate soft monomer B includes one or more of butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, isooctyl acrylate, and lauryl methacrylate.

[0016] Furthermore, the hard monomer B is one or more of methyl acrylate, methyl methacrylate, acrylic acid, and methacrylic acid.

[0017] Furthermore, the multifunctional crosslinking agent B includes one or more of triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate.

[0018] Furthermore, photoinitiator B is one or more of TPO, Irgacure184, Irgacure819, Darocure1173, and Omnirad651.

[0019] Furthermore, the preparation method of OCA tape with high re-tear performance includes: (1) Add acrylate soft monomer B, hard monomer B, photoinitiator B, and chain transfer agent B to the reactor. Stir for 4-8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 4000-6000cps, stop the light irradiation, add multifunctional crosslinking agent B, add photoinitiator B, stir and mix evenly, filter and degas to obtain core material adhesive; coat the core material adhesive between two layers of release film B through a two-roller machine, and cure under ultraviolet light irradiation for 2-4 minutes to obtain core material film B.

[0020] (2) Add acrylate soft monomer A, hard monomer A, photoinitiator A and chain transfer agent A to the reactor, stir for 4-8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the system viscosity reaches 4500-6200cps, stop the light irradiation to generate acrylic resin prepolymer; then add multifunctional crosslinking agent A, add photoinitiator A, stir and mix evenly, filter and degas to obtain surface adhesive A.

[0021] (3) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer and the lower layer of adhesive A respectively. Under the protection of the upper and lower release films C and D, the OCA tape with high re-removal performance is obtained after being irradiated by ultraviolet lamp for 2-3 minutes.

[0022] Furthermore, the thickness of the upper layer of adhesive A is 35-45μm, and the thickness of the lower layer of adhesive A is 55-65μm.

[0023] Furthermore, the thickness of the core material film B is 75-85μm.

[0024] Furthermore, release film B can be a PET release film; release film C can be a PET release film with a thickness of 70-80 μm; and release film D can be a PET release film with a thickness of 90-110 μm. Beneficial technical effects: Using butyl methacrylate and 2-ethylhexyl acrylate as soft monomers, methyl methacrylate as hard monomers, and diethylene glycol dimethacrylate and 1,2-bis(cyclohexylaminoethyl acrylate) ethane as reactive diluents, a topcoat is obtained through a photocuring reaction. This topcoat is then coated onto both sides of the core adhesive film, and finally protected with a release film, resulting in an OCA tape with high re-peeling performance. The addition of 1,2-bis(cyclohexylaminoethyl acrylate) ethane as a reactive diluent in the topcoat, with its hydrophobic cyclohexane structure, helps improve the moisture and weather resistance of the OCA tape. After moisture and weather resistance testing, no obvious bubbles were generated. Furthermore, 1,2-bis(cyclohexylaminoethyl acrylate) ethane contains a cyclohexane macrocyclic structure. The macrocyclic structure has a large molecular volume, which forms defects in the acrylic resin molecular chain and the adhesive matrix. When heated, it undergoes thermal shrinkage, causing wrinkles on the adhesive surface, reducing the adhesion between the tape and the substrate, thereby reducing the peel strength. The tape is easy to peel off, and the tape adhesive does not break after peeling, resulting in good disassembly and reassembly performance. Attached Figure Description

[0025] Figure 1 This is a structural diagram of OCA tape with high rework performance. Detailed Implementation

[0026] The following specific examples illustrate the implementation methods of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0027] Example 1 (1) Add 452g butyl methacrylate, 145g 2-ethylhexyl acrylate, 78g isooctyl acrylate, 155g lauryl methacrylate, 133g methyl methacrylate, 48g methacrylic acid, 2.5g photoinitiator Darocure1173, and 2.4g chain transfer agent dodecyl mercaptan to the reactor. Stir for 8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light. When the viscosity of the system reaches 5300cps, stop the light irradiation, add 4.8g diethylene glycol dimethacrylate, add 7.6g photoinitiator Darocure1173, stir and mix evenly, filter and degas to obtain core material adhesive; coat the core material adhesive between two layers of PET release film B through a two-roller machine, and cure under ultraviolet light for 2 minutes to obtain core material film B.

[0028] (2) Add 5g of 1,2-bis(cyclohexylamino)ethane and 8g of 2-bromoethyl acrylate to 100mL of tetrahydrofuran, add 30mL of aqueous solution containing 3.5g of potassium hydroxide, heat to 70℃, reflux for 12h, extract with ethyl acetate, separate and collect the organic layer, distill under reduced pressure, separate the crude product by silica gel column chromatography, and elute with ethyl acetate and petroleum ether solution to obtain 1,2-bis(cyclohexylaminoethyl acrylate)ethane.

[0029] (3) Add 472g butyl methacrylate, 172g 2-ethylhexyl acrylate, 106g isooctyl acrylate, 177g methyl methacrylate, 73g methacrylic acid, 3.6g photoinitiator Darocure1173, and 4g chain transfer agent dodecyl mercaptan to the reactor. Stir for 8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 5500cps, stop the light irradiation, add 23g diethylene glycol dimethacrylate, 17g 1,2-bis(cyclohexylaminoethyl acrylate) ethane, and add 7.8g photoinitiator Darocure1173. Stir and mix evenly, filter and degas to obtain surface adhesive A.

[0030] (4) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer of adhesive A and the lower layer of adhesive A respectively. Under the protection of the upper and lower PET release films C and D, the OCA tape with high re-removal performance is obtained after being irradiated with ultraviolet light for 3 minutes.

[0031] Example 2 (1) Add 523g butyl acrylate, 160g 2-ethylhexyl acrylate, 91g isooctyl acrylate, 176g lauryl methacrylate, 36g methyl methacrylate, 14g acrylic acid, 1.5g photoinitiator TPO, and 2g chain transfer agent dodecanethiol to the reactor. Stir for 4 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light. When the viscosity of the system reaches 6000cps, stop the light irradiation, add 7g triethylene glycol dimethacrylate, add 4.5g photoinitiator TPO, stir and mix evenly, filter and degas to obtain core material adhesive; coat the core material adhesive between two layers of PET release film B through a two-roller machine, and cure under ultraviolet light for 4 minutes to obtain core material film B.

[0032] (2) Add 5g of 1,2-bis(cyclohexylamino)ethane and 12.8g of 2-bromoethyl acrylate to 120mL of tetrahydrofuran, add 20mL of aqueous solution containing 3g of potassium hydroxide, heat to 60℃, reflux for 18h, extract with ethyl acetate, separate and collect the organic layer, distill under reduced pressure, separate the crude product by silica gel column chromatography, and elute with ethyl acetate and petroleum ether solution to obtain 1,2-bis(cyclohexylaminoethyl acrylate)ethane.

[0033] (3) Add 484g butyl acrylate, 186g 2-ethylhexyl acrylate, 130g isooctyl acrylate, 138g methyl methacrylate, 62g acrylic acid, 5g photoinitiator TPO, and 2g chain transfer agent dodecyl mercaptan to the reactor. Stir for 8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light. When the viscosity of the system reaches 6200cps, stop the light irradiation, add 37g triethylene glycol dimethacrylate, 31g 1,2-bis(cyclohexylaminoethyl acrylate) ethane, and add 6g photoinitiator TPO. Stir and mix evenly, filter and degas to obtain surface adhesive A.

[0034] (4) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer of adhesive A and the lower layer of adhesive A respectively. Under the protection of the upper and lower PET release films C and D, the OCA tape with high re-removal performance is obtained after being irradiated by ultraviolet lamp for 2 minutes.

[0035] Example 3 (1) Add 503g butyl acrylate, 122g 2-ethylhexyl acrylate, 54g isooctyl acrylate, 131g lauryl methacrylate, 215g methyl acrylate, 85g methacrylic acid, 4g photoinitiator Irgacure184, and 3.2g chain transfer agent dodecyl mercaptan to the reactor. Stir for 8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light. When the viscosity of the system reaches 4000cps, stop the light irradiation, add 6.5g diethylene glycol dimethacrylate, add 10g photoinitiator Irgacure184, stir and mix evenly, filter and degas to obtain core material adhesive; coat the core material adhesive between two layers of PET release film B through a two-roller machine, and cure under ultraviolet light for 3 minutes to obtain core material film B.

[0036] (2) Add 485g butyl acrylate, 205g 2-ethylhexyl acrylate, 160g isooctyl acrylate, 106g methyl acrylate, 44g methacrylic acid, 2g photoinitiator Irgacure184, and 2.7g chain transfer agent dodecyl mercaptan to the reaction vessel. Stir for 4 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 4500cps, stop the light irradiation, add 47g diethylene glycol dimethacrylate and 33g 1,2-bis(cyclohexylaminoethyl acrylate) ethane (prepared from Example 1), add 6g photoinitiator Irgacure184, stir and mix evenly, filter and degas to obtain surface adhesive A.

[0037] (3) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer of adhesive A and the lower layer of adhesive A respectively. Under the protection of the upper and lower PET release films C and D, the OCA tape with high re-removal performance is obtained after being irradiated with ultraviolet light for 3 minutes.

[0038] Example 4 (1) Add 416g butyl methacrylate, 136g 2-ethylhexyl acrylate, 57g isooctyl acrylate, 151g lauryl methacrylate, 161g methyl methacrylate, 79g methacrylic acid, 3.2g photoinitiator Darocure1173, and 3.5g chain transfer agent dodecyl mercaptan to the reactor. Stir for 4min under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light. When the viscosity of the system reaches 4600cps, stop the light irradiation, add 4g 1,3-butanediol dimethacrylate, add 8.1g photoinitiator Darocure1173, stir and mix evenly, filter and degas to obtain core material adhesive; coat the core material adhesive between two layers of PET release film B through a two-roller machine, and cure under ultraviolet light for 3min to obtain core material film B.

[0039] (2) Add 377g butyl methacrylate, 129g 2-ethylhexyl acrylate, 94g isooctyl acrylate, 275g methyl methacrylate, 125g methacrylic acid, 4g photoinitiator Darocure1173, and 3.3g chain transfer agent dodecyl mercaptan to the reaction vessel. Stir for 4 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 6200cps, stop the light irradiation, add 30g 1,3-butanediol dimethacrylate and 25g 1,2-bis(cyclohexylaminoethyl acrylate) ethane (prepared from Example 1), add 11g photoinitiator Darocure1173, stir and mix evenly, filter and degas to obtain surface adhesive A.

[0040] (3) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer of adhesive A and the lower layer of adhesive A respectively. Under the protection of the upper and lower PET release films C and D, the OCA tape with high re-removal performance is obtained after being irradiated with ultraviolet light for 2 minutes.

[0041] Comparative Example 1: The main difference between this comparative example and Example 1 is that diethylene glycol dimethacrylate is used instead of 1,2-bis(cyclohexylaminoethyl acrylate) ethane.

[0042] (1) Add 472g butyl methacrylate, 172g 2-ethylhexyl acrylate, 106g isooctyl acrylate, 177g methyl methacrylate, 73g methacrylic acid, 3.6g photoinitiator Darocure1173, and 4g chain transfer agent dodecyl mercaptan to the reaction vessel. Stir for 8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 5500cps, stop the light irradiation, add 40g diethylene glycol dimethacrylate, add 7.8g photoinitiator Darocure1173, stir and mix evenly, filter and degas to obtain surface adhesive A.

[0043] (2) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer of adhesive A and the lower layer of adhesive A respectively. Under the protection of the upper and lower PET release films C and D, the film is cured by UV irradiation for 3 minutes to obtain OCA tape.

[0044] Comparative Example 2, the main difference between this comparative example and Example 1 is that it uses cyclohexyl 2-acrylate (structural formula: () replaces 1,2-bis(cyclohexylaminoethyl acrylate) ethane.

[0045] (1) Add 472g butyl methacrylate, 172g 2-ethylhexyl acrylate, 106g isooctyl acrylate, 177g methyl methacrylate, 73g methacrylic acid, 3.6g photoinitiator Darocure1173, and 4g chain transfer agent dodecyl mercaptan to the reaction vessel. Stir for 8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 5500cps, stop the light irradiation, add 23g diethylene glycol dimethacrylate, 17g cyclohexyl 2-acrylate, and add 7.8g photoinitiator Darocure1173. Stir and mix evenly, filter and degas to obtain surface adhesive A.

[0046] (2) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer of adhesive A and the lower layer of adhesive A respectively. Under the protection of the upper and lower PET release films C and D, the film is cured by UV irradiation for 3 minutes to obtain OCA tape.

[0047] Comparative Example 3, the main difference between this comparative example and Example 1 is that isobornyl acrylate is used instead of 1,2-bis(cyclohexylaminoethyl acrylate) ethane.

[0048] (1) Add 472g butyl methacrylate, 172g 2-ethylhexyl acrylate, 106g isooctyl acrylate, 177g methyl methacrylate, 73g methacrylic acid, 3.6g photoinitiator Darocure1173, and 4g chain transfer agent dodecanethiol to the reaction vessel. Stir for 8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 5500cps, stop the light irradiation, add 23g diethylene glycol dimethacrylate, 17g isobornyl acrylate, and add 7.8g photoinitiator Darocure1173. Stir and mix evenly, filter and degas to obtain surface adhesive A.

[0049] (2) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer of adhesive A and the lower layer of adhesive A respectively. Under the protection of the upper and lower PET release films C and D, the film is cured by UV irradiation for 3 minutes to obtain OCA tape.

[0050] Comparative Example 4, the main difference between this comparative example and Example 1 is that N-vinylpyrrolidone is used instead of 1,2-bis(cyclohexylaminoethyl acrylate) ethane.

[0051] (1) Add 472g butyl methacrylate, 172g 2-ethylhexyl acrylate, 106g isooctyl acrylate, 177g methyl methacrylate, 73g methacrylic acid, 3.6g photoinitiator Darocure1173, and 4g chain transfer agent dodecyl mercaptan to the reaction vessel. Stir for 8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 5500cps, stop the light irradiation, add 23g diethylene glycol dimethacrylate, 17g N-vinylpyrrolidone, and add 7.8g photoinitiator Darocure1173. Stir and mix evenly, filter and degas to obtain surface adhesive A.

[0052] (2) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer of adhesive A and the lower layer of adhesive A respectively. Under the protection of the upper and lower PET release films C and D, the film is cured by UV irradiation for 3 minutes to obtain OCA tape.

[0053] Moisture and weather resistance test: Peel off the PET release film C and release film D on both sides of the OCA tape. Adhesive A on both sides of the tape is then bonded to the mobile phone LCD display module and the glass cover plate, respectively. Degassing is performed at 40℃ for 20 minutes at a degassing pressure of 0.3MPa. After standing for 24 hours, the tape is placed at 60℃ and 85% relative humidity for 360 hours to observe the bonding performance.

[0054] Peel off the PET release films C and D on both sides of the OCA tape. Adhesive A (upper and lower layers) on both sides of the tape are then bonded to the mobile phone LCD display module and the mobile phone cover, respectively. The tape is degassed at 40°C for 20 minutes under a degaussing pressure of 0.3 MPa. After standing for 24 hours, the 180° peel strength (a) is tested according to the method specified in GB / T2792-2014.

[0055] Removal and re-bonding performance test: The PET release films C and D on both sides of the OCA tape were peeled off. The upper and lower layers of adhesive A on both sides of the tape were then bonded to the mobile phone LCD display module and the mobile phone cover plate, respectively. Degassing was performed at 40℃ for 20 minutes under a degassing pressure of 0.3 MPa. After standing for 24 hours, the tape was placed at 70℃ for 2 minutes, and then the 180° peel strength (b) was tested. The deformation of the tape adhesive and the residual adhesive on the display module and cover plate were observed.

[0056] Table 1: Performance Tests of OCA Tape

[0057] In Examples 1-4, 1,2-bis(cyclohexylaminoethyl acrylate) ethane was added to the adhesive as an active diluent. After moisture and weather resistance tests, the resulting OCA tapes showed no significant bubble formation. This is mainly because the 1,2-bis(cyclohexylaminoethyl acrylate) ethane contains a hydrophobic cyclohexane structure, which improves the moisture and weather resistance of the OCA tape. Furthermore, after heat treatment at 70°C for 2 minutes, the peel strength b was at least 2.2 N / 25 mm, exhibiting excellent easy-peeling properties. After peeling, the tape adhesive did not break, and there was no residue on the display module and mobile phone cover. This is primarily because the 1,2-bis(cyclohexylaminoethyl acrylate) ethane added to the adhesive contains a cyclohexane macrocyclic structure. The large molecular volume of the macrocyclic structure creates defects in the acrylic resin molecular chain and the adhesive matrix. Upon heating, thermal shrinkage occurs, causing wrinkles on the adhesive surface and reducing the adhesion between the tape and the substrate, thus lowering the peel strength. The tape is easy to peel and has good re-peeling performance.

[0058] Comparative Example 1 did not contain 1,2-bis(cyclohexylaminoethyl acrylate) ethane. The adhesive tape surface had poor moisture and weather resistance, and a small number of bubbles were generated. After heat treatment at 70℃, the peel strength was low, and the tape was not easy to peel off. There was residual adhesive on the display module and the mobile phone cover, and the disassembly and reassembly effect was not good.

[0059] Comparative Examples 2, 3, and 4 used conventional cyclohexyl acrylate, isobornyl acrylate, and N-vinylpyrrolidone instead of 1,2-bis(cyclohexylaminoethyl acrylate) ethane. Since cyclohexyl acrylate, isobornyl acrylate, and N-vinylpyrrolidone contain only one alkenyl group, their crosslinking performance with the acrylic resin prepolymer is poor, affecting the adhesion and mechanical properties of the tape surface adhesive. This results in lower peel strength (a) of the tapes in Comparative Examples 2-4 before removal and re-removal. Furthermore, after heat treatment at 70℃, the poor mechanical properties of the surface adhesives of these three types of tapes led to easy breakage of the surface adhesive, with a small amount of residual adhesive adhering to the display module and mobile phone cover surface, resulting in poor removal and re-removal performance.

[0060] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. An OCA tape with high re-opening performance, characterized in that, The structure of the high-return-removal-performance OCA tape, from top to bottom, is as follows: release film C, upper layer of adhesive A, core material film B, lower layer of adhesive A, and release film D; The raw materials of the adhesive A include 60-85 parts by weight of acrylate soft monomer A, 15-40 parts by weight of hard monomer A, 0.8-1.5 parts by weight of photoinitiator A, 4-8 parts by weight of multifunctional crosslinking agent A, and 0.2-0.4 parts by weight of chain transfer agent A. The multifunctional crosslinking agent A includes one or more of triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, and 1,2-bis(cyclohexylaminoethyl acrylate) ethane.

2. The OCA tape with high rework performance according to claim 1, characterized in that, The acrylate soft monomer A includes one or more of butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; the hard monomer A is one or more of methyl acrylate, methyl methacrylate, acrylic acid, and methacrylic acid.

3. The OCA tape with high re-opening performance according to claim 1, characterized in that, The photoinitiator A includes one or more of TPO, Irgacure 184, Irgacure 819, Darocure 1173, and Omnirad 651.

4. The OCA tape with high re-opening performance according to claim 1, characterized in that, The chain transfer agent A is a thiol molecular weight regulator, including dodecathiol.

5. The OCA tape with high re-opening performance according to claim 1, characterized in that, The preparation method of 1,2-bis(cyclohexylaminoethyl acrylate) ethane is as follows: 100 parts by weight of 1,2-bis(cyclohexylamino) ethane and 160-256 parts by weight of 2-bromoethyl acrylate are added to tetrahydrofuran, and an aqueous solution containing 60-70 parts by weight of potassium hydroxide is added dropwise. The mixture is heated to 60-70°C and refluxed for 12-18 hours. After extraction, the crude product is separated by silica gel column chromatography to obtain 1,2-bis(cyclohexylaminoethyl acrylate) ethane.

6. The OCA tape with high rework performance according to claim 1, characterized in that, The raw materials of the core material film B include 70-95 parts by weight of acrylate soft monomer B, 5-30 parts by weight of hard monomer B, 0.6-1.4 parts by weight of photoinitiator B, 4-7 parts by weight of multifunctional crosslinking agent B, and 0.2-0.35 parts by weight of chain transfer agent B.

7. The OCA tape with high re-opening performance according to claim 6, characterized in that, The acrylate soft monomer B includes one or more of butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, isooctyl acrylate, and lauryl methacrylate; the hard monomer B is one or more of methyl acrylate, methyl methacrylate, acrylic acid, and methacrylic acid.

8. The OCA tape with high re-opening performance according to claim 6, characterized in that, The multifunctional crosslinking agent B includes one or more of triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate.

9. The OCA tape with high rework performance according to claim 6, characterized in that, The photoinitiator B is one or more of TPO, Irgacure184, Irgacure819, Darocure1173, and Omnirad651.

10. A method for preparing an OCA tape with high re-tear performance as described in any one of claims 1-8, characterized in that, The preparation method includes: (1) Add acrylate soft monomer B, hard monomer B, photoinitiator B, and chain transfer agent B to the reactor. Stir for 4-8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 4000-6000cps, stop the light irradiation, add multifunctional crosslinking agent B, add photoinitiator B, stir and mix evenly, filter and degas to obtain core material adhesive; coat the core material adhesive between two layers of release film B through a two-roller machine, and cure under ultraviolet light irradiation for 2-4 minutes to obtain core material film B; (2) Add acrylate soft monomer A, hard monomer A, photoinitiator A and chain transfer agent A to the reactor, stir for 4-8 minutes under nitrogen protection, and then carry out prepolymerization reaction under ultraviolet light irradiation. When the viscosity of the system reaches 4500-6200cps, stop the light irradiation, add multifunctional crosslinking agent A, add photoinitiator A, stir and mix evenly, filter and degas to obtain surface adhesive A; (3) Apply the adhesive A to both sides of the core material film B in sequence using a double roller machine to form the upper layer and the lower layer of adhesive A respectively. Under the protection of the upper and lower release films C and D, the OCA tape with high re-removal performance is obtained after being irradiated by ultraviolet lamp for 2-3 minutes.

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