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KR-20260068011-A - Pressure-Sensitive Adhesive Composition for Display Applications and Method of Manufacturing the Same

KR20260068011AKR 20260068011 AKR20260068011 AKR 20260068011AKR-20260068011-A

Abstract

The present invention provides a pressure-sensitive adhesive composition for a display and a method for manufacturing the same, wherein the composition comprises: an acrylic pressure-sensitive adhesive base resin; a curing agent; and a nanofiller powder containing silica surface-treated with a silane coupling agent in an amount of 0.1 to 0.9 parts by weight per 100 parts by weight of the solid content of the base resin; wherein the nanofiller powder containing silica has an average particle size of 0.3 μm to 15 μm, and the adhesive layer formed by the pressure-sensitive adhesive composition has an impact transmission rate of 29 to 34 MPa, a surface roughness (Sa) of 0.5 to 1.5 μm, and a stamping rate of 0.85 or higher.

Inventors

  • 현승헌
  • 김기수

Assignees

  • (주)켐코스

Dates

Publication Date
20260513
Application Date
20251105
Priority Date
20241106

Claims (13)

  1. As a pressure-sensitive adhesive composition for displays, Acrylic pressure-sensitive adhesive base resin; Curing agent ; Nanofiller powder comprising silica surface-treated with a silane coupling agent in an amount of 0.1 to 0.9 parts by weight per 100 parts by weight of the base resin solid content; and The nanofiller powder containing the above silica has an average particle size of 0.3 μm to 15 μm, and The adhesive layer formed by the above pressure-sensitive adhesive composition has an impact transmission rate of 29 to 34 MPa, and The surface roughness (Sa) is 0.5 to 1.5 μm, and Pressure-sensitive adhesive composition for displays characterized by a die-cutting rate of 0.85 or higher.
  2. A pressure-sensitive adhesive composition for displays according to claim 1, characterized in that the curing agent is an isocyanate-based curing agent and is included in an amount of 0.03 to 0.1 parts by weight per 100 parts by weight of the base resin solid content.
  3. In paragraph 1, A pressure-sensitive adhesive composition for displays, characterized by further comprising 0.01 to 0.1 parts by weight of an epoxy-based curing agent per 100 parts by weight of the base resin solid content.
  4. A pressure-sensitive adhesive composition for displays according to claim 1, characterized in that the nanofiller powder containing silica has an average particle size of 0.3 μm to 3 μm.
  5. A pressure-sensitive adhesive composition for displays according to claim 1, characterized in that the silane coupling agent is one or more selected from the group consisting of aminosilane, vinylsilane, epoxysilane, methacrylsilane, and mercaptosilane.
  6. A pressure-sensitive adhesive composition for a display according to claim 1, wherein the acrylic pressure-sensitive adhesive base resin has a glass transition temperature (Tg) of -50℃ to -20℃.
  7. A pressure-sensitive adhesive composition for a display, characterized in that, in claim 1, the adhesive strength of the adhesive layer is 700 to 1,500 gf/in.
  8. A pressure-sensitive adhesive composition according to claim 1, wherein the surface of the silica powder is coated with polydopamine, and the amount of polydopamine coating is 5 to 15 wt% relative to the weight of the silica.
  9. A pressure-sensitive adhesive composition according to claim 1, further comprising 0.1 to 1.0 parts by weight of silane-treated titania nanoparticles per 100 parts by weight of the base resin solid content, wherein the titania nanoparticles have an average particle size of 10 nm to 150 nm.
  10. A method for manufacturing a pressure-sensitive adhesive sheet for displays, (a) A step of mixing a curing agent into an acrylic pressure-sensitive adhesive base resin; (b) a step of preparing a pressure-sensitive adhesive composition by adding 0.1 to 0.9 parts by weight of silica powder surface-treated with a silane coupling agent to the above mixture, relative to 100 parts by weight of the base resin solid content; (c) a step of forming an adhesive layer by applying the above pressure-sensitive adhesive composition onto a release film; and (d) a step of drying and curing the adhesive layer; Includes, The nanofiller powder containing the above silica has an average particle size of 0.3 μm to 15 μm, and A method for manufacturing a pressure-sensitive adhesive sheet for a display, characterized in that the pressure-sensitive adhesive sheet has an impact transmission rate of 29 to 34 MPa, a surface roughness (Sa) of 0.5 to 1.5 μm, and a die-cutting rate of 0.85 or higher.
  11. A manufacturing method according to claim 10, characterized in that the surface treatment of the silica powder is performed by a sequential two-step treatment of aminosilane and methacrylsilane.
  12. As a pressure-sensitive adhesive sheet for displays, An adhesive layer formed solely of a pressure-sensitive adhesive composition without a substrate layer; comprising The pressure-sensitive adhesive sheet for a display comprises an adhesive layer comprising: an acrylic pressure-sensitive adhesive base resin; a cured product; and silica powder with an average particle size of 0.3 μm to 15 μm, surface-treated with 0.1 to 0.9 parts by weight of a silane coupling agent per 100 parts by weight of the base resin solid content; wherein the impact transmission rate is 29 to 34 MPa, the surface roughness (Sa) is 0.5 to 1.5 μm, the stamping rate is 0.85 or higher, and no discoloration or moisture penetration occurs after a 240-hour reliability test under conditions of 85°C and 85% RH.
  13. A pressure-sensitive adhesive sheet for a display according to claim 11, characterized in that the thickness of the adhesive layer is 50 μm to 200 μm.

Description

Pressure-Sensitive Adhesive Composition for Display Applications and Method of Manufacturing the Same The present invention relates to a pressure-sensitive adhesive composition for displays and a method for manufacturing the same, and more specifically, to a pressure-sensitive adhesive composition for displays capable of simultaneously realizing excellent stamping and shock absorption characteristics by including silica powder surface-treated with a silane coupling agent, and a method for manufacturing the same. With the recent surge in demand for display devices such as smartphones and tablet PCs, interest in damping materials used between the display panel and the case is growing. Damping materials serve to protect the display panel from external shocks and dampen vibrations. Traditionally, urethane foam or acrylic foam has been used as damping materials for displays. While these foam materials offer excellent shock absorption properties, they have limitations in applications requiring excellent die-cutting properties and optical transparency. Accordingly, pressure-sensitive adhesives (PSAs) capable of replacing foam materials are being developed. PSAs have the advantages of excellent die-cutting properties and a simple process. However, existing PSAs have a low glass transition temperature (Tg) and low modulus; while they exhibit excellent shock absorption characteristics, they suffer from a problem of tearing during die-cutting due to insufficient cohesion. The following approaches have been attempted to improve stamping performance: (1) Increase in curing agent content: Increasing the curing agent improves stamping performance, but there are problems such as increased impact transmission rate and reduced adhesion. (2) Use of substrate layer: Using a substrate such as PET film improves stamping performance, but there is a significant increase in impact transmission rate and optical problems where the substrate layer is visible on the display. (3) Use of non-woven fabric substrate: Using non-woven fabric as a substrate causes localized bouncing and a problem where the white surface is visible. Therefore, there is a demand for pressure-sensitive adhesives for displays that maintain shock absorption characteristics while exhibiting excellent punchability and not compromising optical properties. Figure 1 is a graph showing the TGA analysis results for the composition of the present invention. FIG. 2 is a conceptual diagram illustrating the structure of the composition of the present invention. FIG. 3 is a drawing illustrating an overall embodiment and a comparative example of the present invention. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to sufficiently convey the concept of the present invention to those skilled in the art. In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Additionally, in the drawings, the thicknesses of the films and regions are exaggerated for the effective description of the technical content. Additionally, although terms such as first, second, third, etc., have been used to describe various components in the various embodiments of this specification, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. Accordingly, what is referred to as the first component in one embodiment may be referred to as the second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiment. Furthermore, in this specification, "and/or" is used to mean including at least one of the components listed before and after it. In the specification, singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, components, or combinations thereof described in the specification, and should not be understood as excluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. In addition, in describing the present invention below, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the invention, such detailed description will be omitted. First, the terms used in the present invention will be explained. The pressure-sensitive adhesive (PSA) used in this invention refers to an adhesive material also calle