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CN-122011959-A - Special residue-free easy-to-tear film adhesive tape for OCA (optical clear adhesive) and preparation method thereof

CN122011959ACN 122011959 ACN122011959 ACN 122011959ACN-122011959-A

Abstract

The invention discloses a special residue-free easy-to-tear film adhesive tape for OCA and a preparation method thereof, and relates to the field of optical transparent adhesive protective films. The adhesive tape comprises a low-static polymer film carrier and a functional pressure-sensitive adhesive layer, wherein the functional pressure-sensitive adhesive layer comprises ultraviolet-curable pressure-sensitive adhesive resin, surface energy adjusting and structure constructing particles, an interfacial migration stripping auxiliary agent, an antistatic agent, a photoinitiator and a leveling agent. The surface energy adjustment and structure construction particles are formed by compounding low-surface energy polymer microspheres and rigid nanoparticles according to a mass ratio of 1:5-5:1. According to the invention, through the synergistic effect of physical structure viscosity reduction and chemical weak boundary layer, the excellent performances of 90-degree stripping force of 0.01-0.5N/25 mm, residual adhesive rate of less than 0.001mg/cm < 2 >, carrier surface resistance of less than or equal to 1011 omega are realized, the OCA bonding protection device can be manually torn cleanly, has no OCA warpage, and is suitable for OCA bonding protection of a touch screen production line.

Inventors

  • YE SHAOWEI
  • Zhou Zongzeng

Assignees

  • 佛山市科盈创新材料有限公司

Dates

Publication Date
20260512
Application Date
20260228

Claims (10)

  1. 1. The special residue-free easy-to-tear film adhesive tape for OCA is characterized by comprising a low-static polymer film carrier and a functional pressure-sensitive adhesive layer; The functional pressure-sensitive adhesive layer comprises, by 100% of the total weight, 35-65% of ultraviolet-curable pressure-sensitive adhesive resin, 5-20% of surface energy adjustment and structure construction particles, 3-12% of interfacial migration stripping auxiliary agent, 0.5-4% of antistatic agent, 0.5-3% of photoinitiator and 0.1-1.5% of leveling agent; The surface energy adjustment and structure construction particles are formed by compounding low surface energy polymer microspheres and rigid nanoparticles according to a mass ratio of 1:5-5:1; the surface resistivity of the low-static polymer film carrier is less than or equal to 1011 omega, and the thickness is 25-100 mu m; the thickness of the functional pressure-sensitive adhesive layer is 5-30 mu m.
  2. 2. The special residue-free easy-to-tear film adhesive tape for OCA according to claim 1, wherein the ultraviolet-curable pressure-sensitive adhesive resin is at least one of urethane acrylate, epoxy acrylate or polyester acrylate, and the glass transition temperature is-40-0 ℃.
  3. 3. The special residue-free easy-to-tear film adhesive tape for OCA according to claim 1, wherein the low-surface-energy polymer microsphere is a polydimethylsiloxane microsphere, a polytetrafluoroethylene microsphere or a perfluoroalkoxy polymer microsphere, and the average particle size is 0.1-10 μm.
  4. 4. The special residue-free easy-to-tear film adhesive tape for OCA according to claim 1, wherein the rigid nanoparticle is fumed silica or surface-modified alumina nanoparticle, and the average particle size is 10-100 nm.
  5. 5. The special residue-free easy-to-tear film adhesive tape for OCA according to claim 1, wherein the interfacial migration-capable peeling auxiliary agent is an organosilicon modified acrylate resin containing polyether or polyester chain segments, or a fluorocarbon surfactant with an HLB value of 8-18.
  6. 6. The adhesive tape of claim 1, wherein the antistatic agent is a polymeric antistatic agent or an ionic liquid type antistatic agent.
  7. 7. The residue-free easy-to-tear film tape special for OCA according to claim 1, wherein the photoinitiator is at least one of 1-hydroxycyclohexyl phenyl ketone, 2,4, 6-trimethylbenzoyl-diphenyl phosphine oxide, or bis (2, 4, 6-trimethylbenzoyl) phenyl phosphine oxide.
  8. 8. The special residue-free easy-to-tear film adhesive tape for OCA according to claim 1, wherein the low-static polymer film carrier is a PET film, a PP film or a PE film, and a conductive filler or an antistatic coating is added.
  9. 9. The special residue-free easy-to-tear film adhesive tape for OCA, as claimed in claim 1, is characterized in that the interfacial migration stripping auxiliary agent migrates to the interface between the adhesive layer and the OCA after the adhesive layer is solidified to form a weak boundary layer, and the rigid nano particles construct microscopic rigid protrusions on the surface of the adhesive layer to reduce the actual contact area between the adhesive layer and the OCA.
  10. 10. The preparation method of the special residue-free easy-to-tear film adhesive tape for OCA is characterized by comprising the following steps of: S1, weighing raw materials of all components according to a formula proportion, adding ultraviolet-curable pressure-sensitive adhesive resin, surface energy adjustment and structure construction particles, an interfacial migration stripping auxiliary agent, an antistatic agent, a photoinitiator and a leveling agent into a high-speed dispersing machine, and dispersing for 20-60 minutes at a rotating speed of 1000-3000 rpm at a temperature of 30-60 ℃ to obtain functional pressure-sensitive adhesive slurry; The rotating speed of the high-speed dispersing machine is 2000rpm, the dispersing time is 30 minutes, and the dispersing temperature is 40 ℃; S2, uniformly coating the functionalized pressure-sensitive adhesive slurry obtained in the step S1 on the surface of the low-static polymer film carrier in a precise coating mode, wherein the coating speed is 3-15 m/min, and the coating thickness is 5-30 mu m; S3, carrying out ultraviolet light curing on the film coated with the functional pressure-sensitive adhesive obtained in the step S2 through a UV curing device, wherein the UV light intensity is 50-200 mW/cm <2 >, and the curing time is 5-30 seconds; The light intensity of the UV curing is 100mW/cm < 2 >, and the curing time is 15 seconds; and S4, cooling the adhesive tape solidified in the step S3 to room temperature by a cooling roller, and rolling in a clean environment to obtain the special residue-free easy-to-tear film adhesive tape for OCA.

Description

Special residue-free easy-to-tear film adhesive tape for OCA (optical clear adhesive) and preparation method thereof Technical Field The invention relates to the field of optical transparent adhesive protective films, in particular to a special residue-free easy-to-tear film adhesive tape for OCA and a preparation method thereof. Background In the manufacturing process of Touch panels or liquid crystal display modules (LCM), optically Clear Adhesive (OCA) is used as an optical adhesive with high transmittance and high cleanliness to firmly adhere various layers of structures (such as cover glass, touch sensor, polarizer, liquid crystal Panel, etc.) of the Touch Panel together. The surface of the OCA needs to be effectively protected from scratches, contamination or dust adhesion during transportation, storage and line circulation before it is finally attached. The conventional OCA protective film generally adopts a PET film as a base material, and is matched with acrylic ester or rubber pressure-sensitive adhesive. However, these conventional protective films have problems in that the peeling force is too large, usually more than a few N/25mm, the manual peeling is difficult, the warping or tensile deformation of the OCA is easily caused in the peeling process, the problem of residual adhesive is prominent, adhesive layers are often left on the surface of the OCA after peeling, the subsequent attaching performance and the optical performance are affected, the electrostatic adsorption is serious, static electricity generated in the peeling process easily adsorbs dust, electrostatic discharge (ESD) can damage sensitive electronic elements (such as TFTs and IC driving chips) in a touch screen, the surface of the OCA is polluted, and certain components in the adhesive layers can migrate to the surface of the OCA, so that chemical pollution is caused. In the prior art, some schemes realize the easy tearing function through thermal adhesion or UV (ultraviolet) viscosity reduction technology. For example, patent CN109749672a discloses a UV-curable thermal visbreaking adhesive that is achieved by thermally expanding microspheres that expand when heated. However, such techniques require additional heating or illumination equipment, add to process complexity and energy consumption, and are inconvenient to manually adjust or rework at room temperature. Other approaches achieve low peel forces by simply reducing the cohesive strength or surface energy of the pressure sensitive adhesive, but this generally results in reduced initial and hold-down forces of the tape, making it susceptible to peeling during the process and not providing reliable protection. Therefore, developing a special protection film that can realize manual clean tearing at normal temperature, has no residue, low static electricity and no damage to the OCA surface is a technical problem to be solved in the art. Disclosure of Invention In summary, the present invention aims to overcome the above-mentioned drawbacks of the prior OCA protective film technology, and provides a residue-free easy-to-tear film adhesive tape dedicated for OCA and a preparation method thereof. The invention aims to solve the technical problems of realizing manual clean tearing at normal temperature without additional heating or illumination equipment, realizing extremely low peeling force (0.01-0.5N/25 mm), ensuring easy and stable tearing process, realizing extremely low residual adhesive rate (less than 0.001mg/cm < 2 >) and ensuring clean OCA surface, realizing low static electricity (carrier surface resistance is less than or equal to 1011 omega), preventing static electricity damage and ensuring that OCA warp or tensile deformation is not caused in the tearing process. In order to solve the technical problems, the invention provides a special residue-free easy-to-tear film adhesive tape for OCA, which comprises a low-static polymer film carrier and a functional pressure-sensitive adhesive layer; The functional pressure-sensitive adhesive layer comprises, by 100% of the total weight, 35-65% of ultraviolet-curable pressure-sensitive adhesive resin, 5-20% of surface energy adjustment and structure construction particles, 3-12% of interfacial migration stripping auxiliary agent, 0.5-4% of antistatic agent, 0.5-3% of photoinitiator and 0.1-1.5% of leveling agent; The surface energy adjustment and structure construction particles are formed by compounding low surface energy polymer microspheres and rigid nanoparticles according to a mass ratio of 1:5-5:1; the surface resistivity of the low-static polymer film carrier is less than or equal to 1011 omega, and the thickness is 25-100 mu m; the thickness of the functional pressure-sensitive adhesive layer is 5-30 mu m. Preferably, the ultraviolet-curable pressure-sensitive adhesive resin is at least one of urethane acrylate, epoxy acrylate or polyester acrylate, and the glass transition temperature is-40-0 ℃. Preferably, the low su