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JP-2026514453-A - Adhesive film, optical component, and optical display device

JP2026514453AJP 2026514453 AJP2026514453 AJP 2026514453AJP-2026514453-A

Abstract

An adhesive film is provided comprising a thermoset product of an adhesive composition containing a (meth)acrylic copolymer, a curing agent, a monofunctional or mono-functional compound containing an aromatic group, a monofunctional or mono-functional compound containing a long-chain alkyl group, and an initiator, wherein the adhesive film has a peel force change rate of 1 of formula 1 of 1.0 or less before light irradiation, an optical member containing the same and an optical display device containing the same are provided. [Selection Diagram] Figure 1

Inventors

  • イ ジョンホ
  • キム ウォン
  • キム ヨンフン
  • イ ジヘ
  • キム イルジン

Assignees

  • 三星エスディアイ株式会社

Dates

Publication Date
20260511
Application Date
20240404
Priority Date
20230407

Claims (18)

  1. An adhesive film comprising a thermoset product of an adhesive composition containing a (meth)acrylic copolymer, a curing agent, a monofunctional or mono-functional compound containing an aromatic group, a monofunctional or mono-functional compound containing a long-chain alkyl group, and an initiator, The adhesive film is an adhesive film in which, before light irradiation, the rate of change of peeling force in the following formula 1 is 1.0 or less. [Formula 1] Change rate of peeling force = (P2 - P1) / P1 (In formula 1 above, P1 is the peel force (unit: gf/inch) of the adhesive film against the adherend after leaving a test piece, manufactured by adhering the adhesive film to the adherend, at 23°C and 50% relative humidity for 30 minutes. P2 is the peel force (unit: gf/inch) of the adhesive film against the adherend after leaving a test piece, manufactured by adhering the adhesive film to the adherend, at 23°C and 50% relative humidity for 30 days.
  2. The adhesive film according to claim 1, wherein the peeling force increase rate of the following formula 2 is 10 or more. [Formula 2] Increase in peeling force = P3/P1 (In formula 2 above, P1 is the peel force (unit: gf/inch) of the adhesive film against the adherend after leaving a test piece, manufactured by adhering the adhesive film to the adherend, at 25°C and 50% relative humidity for 30 minutes. P3 is the peel force (unit: gf/inch) of the adhesive film against the adherend after a test piece, manufactured by adhering the adhesive film to the adherend, is left at 25°C and 50% relative humidity for 30 minutes, then heat-treated by light irradiation.
  3. The adhesive film according to claim 2, wherein P3 in formula 2 is 500 gf/inch or more.
  4. The adhesive film according to claim 1, wherein the adhesive film has a matrix for adhesive films, which is a thermoset product of the (meth)acrylic copolymer and the curing agent, in which the aromatic group-containing monofunctional or greater compound, the long-chain alkyl group-containing monofunctional or greater compound, and the initiator are dispersed.
  5. The adhesive film according to claim 1, wherein the long-chain alkyl group-containing monofunctional compound forms a polymer having a melting point of 30 to 60°C upon light irradiation.
  6. The adhesive film according to claim 1, wherein the long-chain alkyl group-containing monofunctional compound comprises a linear or branched alkyl group-containing (meth)acrylate having 12 or more carbon atoms.
  7. The adhesive film according to claim 1, wherein the long-chain alkyl group-containing monofunctional compound comprises one or more of stearyl (meth)acrylate, behenyl (meth)acrylate, and cetyl (meth)acrylate.
  8. The adhesive film according to claim 1, wherein the long-chain alkyl group-containing monofunctional compound is present in an amount of 1 to 50 parts by weight per 100 parts by weight of the (meth)acrylic copolymer.
  9. The adhesive film according to claim 1, wherein the glass transition temperature of the homopolymer of the aromatic group-containing monofunctional compound is higher than that of the (meth)acrylic copolymer.
  10. The adhesive film according to claim 9, wherein the difference between the glass transition temperature of the homopolymer of the aromatic group-containing monofunctional compound and the glass transition temperature of the (meth)acrylic copolymer is 20°C or more.
  11. The adhesive film according to claim 1, wherein the aromatic group-containing monofunctional or more compound includes the compound of the following chemical formula 1. ...Chemical formula 1 (In the above chemical formula 1, R1 is a hydrogen or methyl group, s is an integer between 0 and 10. R2 is a substituted or unsubstituted aryl group having 6 to 50 carbon atoms or a substituted or unsubstituted aryloxy group having 6 to 50 carbon atoms. T is a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkylene oxy group having 1 to 6 carbon atoms.
  12. The adhesive film according to claim 1, wherein the aromatic group-containing compound with one or more functionalities is included in an amount of 1 to 25 parts by weight per 100 parts by weight of the (meth)acrylic copolymer.
  13. The adhesive film according to claim 1, wherein the (meth)acrylic copolymer comprises a copolymer of a monomer mixture containing an alkyl group-containing (meth)acrylic monomer, a hydroxyl group-containing (meth)acrylic monomer, and a carboxylic acid group-containing (meth)acrylic monomer.
  14. The adhesive film according to claim 1, wherein the curing agent comprises a mixture of an isocyanate-based curing agent and a metal chelating-based curing agent.
  15. The adhesive film according to claim 1, wherein the curing agent is contained in an amount of 0.01 to 8 parts by weight per 100 parts by weight of the (meth)acrylic copolymer.
  16. An optical component comprising the adhesive film described in any one of claims 1 to 15.
  17. The optical component according to claim 16, wherein the optical component includes a panel for an optical display device including a flexible substrate, the adhesive film laminated on the lower surface of the flexible substrate, and a protective layer laminated on the lower surface of the adhesive film.
  18. An optical display device comprising an adhesive film according to any one of claims 1 to 15.

Description

This invention relates to an adhesive film, an optical component, and an optical display device. In recent years, development of optical display devices based on organic light-emitting diodes (OLEDs) has progressed. In particular, optical display devices based on flexible organic light-emitting diodes are attracting attention. Flexible panels based on organic light-emitting diodes (OLEDs) with flexible properties are equipped with plastic films, such as polyimide films, on the top and bottom of the panel. Flexible panels are relatively more flexible than liquid crystal panels and panels based on conventional OLEDs. Therefore, scratches may occur on the surface of the flexible panel during processing, assembly, and/or inspection, and a protective film for the process must be temporarily adhered to the flexible panel to protect it. If defects such as appearance abnormalities or foreign matter are found during inspection of the flexible panel, the protective film for the process must have low peel strength so that it can be easily peeled off the flexible panel. After inspection, a reinforcing protective film must be permanently adhered to the panel to support it and protect it from the external environment. Therefore, it is preferable that the reinforcing protective film has higher peel strength and reliability compared to the protective film for the process. In contrast, conventional panel manufacturing processes are complex because they require the sequential execution of three steps: laminating a temporary protective film onto the panel, peeling off the temporary protective film, and laminating a reinforcing protective film onto the panel. Furthermore, the protective film must be discarded after the peeling process, resulting in reduced economic efficiency and environmental friendliness. The background art of this invention is disclosed in Japanese Patent Publication No. 5683369, among others. Figure (a) shows a test piece for measuring T-peel strength, and Figure (b) shows the measurement drive when measuring T-peel strength from the test piece. The present invention will be described in detail with reference to the attached drawings so that it can be easily implemented by a person with ordinary skill in the art to which the invention pertains. The present invention can be embodied in a variety of different forms and is not limited to the embodiments described herein. The terms used herein are for illustrative purposes only and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, "(meth)acrylic" may mean acrylic and/or methacrylic. In this specification, "polymer" may include polymers or resins. In this specification, "glass transition temperature" may refer to the glass transition temperature (Tg) measured for the monomer or compound under test using TA Instrument's DSC Discovery. Specifically, the temperature of the monomer or compound homopolymer under test can be raised to 180°C at a heating rate of 20°C/min, then gradually cooled to -100°C, and finally heated to 100°C at a heating rate of 10°C/min. After obtaining the data for the endothermic transition curve, the inflection point of the endothermic transition curve can be determined as the glass transition temperature. In this specification, "peeling force" may be a value measured at 25°C unless otherwise specified. In this specification, the "melting point (Tm)" referred to in "compounds containing one or more long-chain alkyl groups" may refer to the melting point (Tm) measured using TA Instrument's DSC Discovery. Specifically, the temperature of the monomer homopolymer to be measured can be raised to 180°C at a heating rate of 20°C/min, then gradually cooled to -100°C, and finally heated to 100°C at a heating rate of 10°C/min. Data can then be obtained from the endothermic transition curve, and the inflection point of the endothermic transition curve can be determined as the melting point. In this specification, "weight-average molecular weight" can be determined using gel permeation chromatography as a polystyrene equivalent. In this specification, when a numerical range is described, "X to Y" means X or greater and Y or less (X ≤ and ≤ Y). The adhesive film of the present invention exhibits high temporal stability of peel strength before light irradiation, possesses both photosensitivity and heat sensitivity, and shows a significantly increased peel strength after light irradiation and heat treatment. Before light irradiation, the adhesive film can adhere to the substrate with low peel strength. The adhesive film, in its pre-light irradiation state, is an adhesive film with low peel strength (also called "initial peel strength"). While the adhesive film has an appropriate peel strength range for the adherend before light irradiation, it adheres to the adherend with low peel strength, temporarily protecting the adherend and allowing for easy