US-12624259-B2 - Adhesive film, optical member comprising the same, and optical display apparatus comprising the same

Abstract

An adhesive film, an optical member including the same, and an optical display apparatus including the same are provided. An adhesive film is formed of an adhesive composition including a (meth)acrylic copolymer, a curing agent, a mono- or higher functional monomer, a light-to-heat conversion material, and an initiator, and has a peel strength increase rate of 5.0 or more, as calculated according to Equation 1 herein.

Inventors

• Jung Hyo Lee
• Won Kim
• Tae Ji KIM
• Oh Hyeon HWANG
• Irina Nam
• Il Jin KIM

Assignees

• SAMSUNG SDI CO., LTD.

Dates

Publication Date

20260512

Application Date

20220322

Priority Date

20210323

Claims (20)

1. 1 . An adhesive film formed of an adhesive composition comprising a (meth)acrylic copolymer, a curing agent, a mono- or higher functional monomer, a light-to-heat conversion material to emit heat through absorption of light at a wavelength of about 280 nm to about 430 nm, and an initiator, the adhesive film having a peel strength increase rate of 5.0 or more, as calculated by the following Equation 1: Peel strength increase rate= P 2/ P 1, where P1 is an initial peel strength (unit: gf/inch) of the adhesive film with respect to an adherend, as measured on a specimen of the adhesive film and the adherend, and P2 is a peel strength of the adhesive film (unit: gf/inch) with respect to the adherend, as measured on the specimen of the adhesive film and the adherend after irradiation of the specimen with light, wherein the mono- or higher functional monomer comprises a mono- or higher functional(meth)acrylate having a linear or branched C 1 to C 20 alkyl group or a linear or branched C 1 to C 20 alkylene group at an ester site; or an aromatic group-containing mono functional monomer represented by Formula 1: where R 1 is hydrogen or a methyl group; s is an integer of 0 to 10; R 2 is a substituted or unsubstituted C 6 to C 50 aryl group or a substituted or unsubstituted Ce to C 50 aryloxy group; and T is a substituted or unsubstituted C 1 to C 6 alkylene group or a substituted or unsubstituted C 1 to C 6 alkyleneoxy group, wherein the light-to-heat conversion material has an average particle diameter of about 10 nm to about 300 nm, wherein the light-to-heat conversion material is selected from zinc, platinum, gold, silver, copper, titanium, silicon, chromium, nickel, germanium, aluminum or oxide thereof, and wherein the light-to-heat conversion material is present in an amount of about 0.001 parts by weight to about 5 parts by weight, relative to 100 parts by weight of the (meth)acrylic copolymer.
2. 2 . The adhesive film according to claim 1 , wherein P1 is greater than 0 gf/inch and less than or equal to about 100 gf/inch.
3. 3 . The adhesive film according to claim 1 , wherein P2 is about 300 gf/inch or more.
4. 4 . The adhesive film according to claim 1 , wherein the mono- or higher functional monomer has a higher glass transition temperature in a homopolymer phase than the (meth)acrylic copolymer.
5. 5 . The adhesive film according to claim 1 , wherein a difference in glass transition temperature between the mono- or higher functional monomer in a homopolymer phase and the (meth)acrylic copolymer is about 20° C. or more.
6. 6 . The adhesive film according to claim 1 , wherein the mono- or higher functional monomer has a glass transition temperature of about −30° C. or more in a homopolymer phase.
7. 7 . The adhesive film according to claim 1 , wherein the mono- or higher functional monomer comprises the aromatic group-containing mono-functional monomer represented by Formula 1.
8. 8 . The adhesive film according to claim 7 , wherein in Formula 1, T is a substituted or unsubstituted C 1 to C 6 alkylene group.
9. 9 . The adhesive film according to claim 1 , wherein the mono- or higher functional monomer is present in an amount of about 10 parts by weight to about 200 parts by weight relative to 100 parts by weight of the (meth)acrylic copolymer.
10. 10 . The adhesive film according to claim 1 , wherein the (meth)acrylic copolymer has a glass transition temperature Tg of about −10° C. or less.
11. 11 . The adhesive film according to claim 1 , wherein the (meth)acrylic copolymer comprises a copolymer of a monomer mixture comprising an alkyl group-containing (meth)acrylic monomer and a hydroxyl group-containing (meth)acrylic monomer, the hydroxyl group-containing (meth)acrylic monomer being present in an amount of about 0.1 mol % to about 10 mol % in the monomer mixture.
12. 12 . The adhesive film according to claim 11 , wherein at least one monomer of the monomer mixture has a glass transition temperature of about −80° C. or more in a homopolymer phase.
13. 13 . The adhesive film according to claim 11 , wherein the monomer mixture further comprises a carboxylic acid group-containing monomer.
14. 14 . The adhesive film according to claim 1 , wherein the curing agent comprises a mixture of an isocyanate curing agent and a metal chelate curing agent.
15. 15 . The adhesive film according to claim 1 , wherein the initiator comprises at least one selected from among a photo-radical initiator and a photo-cationic initiator.
16. 16 . The adhesive film according to claim 1 , wherein the adhesive composition comprises 100 parts by weight of the (meth)acrylic copolymer, about 0.01 parts by weight to about 8 parts by weight of the curing agent, about 10 parts by weight to about 200 parts by weight of the mono- or higher functional monomer, about 0.001 parts by weight to about 5 parts by weight of the light-to-heat conversion material, and about 0.01 parts by weight to about 7.5 parts by weight of the initiator.
17. 17 . The adhesive film according to claim 1 , wherein the adhesive film further comprises a binder having a melting point of about 30° C. to about 60° C.
18. 18 . The adhesive film according to claim 17 , wherein the binder comprises a binder of a monomer mixture comprising a (meth)acrylate having a linear or branched C 16 to C 22 alkyl group at an ester site.
19. 19 . The adhesive film according to claim 18 , wherein the monomer mixture further comprises at least one selected from among a (meth)acrylate having a linear or branched alkyl group containing ten or fewer carbon atoms at an ester site and a silicone-modified mono-functional(meth)acrylate.
20. 20 . The adhesive film according to claim 17 , wherein the adhesive composition comprises 100 parts by weight of the (meth)acrylic copolymer, about 0.01 parts by weight to about 8 parts by weight of the curing agent, about 10 parts by weight to about 200 parts by weight of a mono- or higher functional monomer, about 0.001 parts by weight to about 5 parts by weight of the light-to-heat conversion material, about 0.01 parts by weight to about 7.5 parts by weight of the initiator, and about 0.1 parts by weight to about 20 parts by weight of the binder having a melting point of about 30° C. to about 60° C.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0037615, filed on Mar. 23, 2021 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. BACKGROUND 1. Field Aspects of embodiments of the present invention relate to an adhesive film, an optical member including the same, and an optical display apparatus including the same. 2. Description of the Related Art In recent years, optical displays using organic light emitting diodes (OLED) have been developed. In particular, an optical display based on flexible organic light emitting diodes has been spotlighted in the art. A flexible panel based on flexible organic light emitting diodes includes a plastic film, such as a polyimide film and the like, on each of upper and lower sides of the panel. The flexible panel is more flexible than a liquid crystal panel and a typical organic light emitting diode-based panel. Accordingly, a protective film for processes is temporarily adhered to the flexible panel to protect the flexible panel or to prevent or substantially prevent occurrence of scratches on the flexible panel during a process of processing, assembling, and/or inspecting the flexible panel. When it is determined through inspection of the flexible panel that there is a defect, such as abnormal appearance or foreign matter, it is desirable for the protective film to have low peel strength in order to be easily removed from the flexible panel. After inspection of the flexible panel, a protective film for reinforcement is adhered to the flexible panel in order to support the panel while protecting the panel from external environments. Therefore, the protective film for reinforcement is desired to have higher peel strength and reliability than the protective film for processes. However, in a typical panel manufacturing process, a process of assembling a temporary protective film for processes to a panel, a process of peeling off the temporary protective film of the panel, and a process of assembling a protective film for reinforcement to the panel must be sequentially performed, thereby complicating the manufacturing process. Moreover, since the protective film for processes must be discarded after the peeling process, there is a problem of deterioration in economic efficiency and environmental friendliness. The background technique of the present invention is disclosed in JP Patent Registration No. U.S. Pat. No. 5,683,369 and the like. SUMMARY According to an aspect of one or more embodiments of the present invention, an adhesive film is provided that can be easily removed from an adherend after attachment of the adhesive film thereto and can be secured to the adherend through a process (e.g., a predetermined process). According to another aspect of one or more embodiments of the present invention, an adhesive film is provided that can be adhered at low peel strength to an adherend to provide temporary protection to the adherend in an initial stage and can be easily removed therefrom without deformation and/or damage to the adherend through selective cutting of an unnecessary portion of the adhesive film. According to another aspect of one or more embodiments of the present invention, a protective adhesive film is provided that exhibits significant increase in peel strength after irradiation with light, as compared with peel strength before irradiation with light, and is secured to an adherend to improve durability of an optical member including the adherend. According to another aspect of one or more embodiments of the present invention, an adhesive film is provided that can be concurrently (e.g., simultaneously) used as a temporary protective film for processes with respect to a flexible panel substrate and as a protective film for reinforcement of patterns, which is selectively partially peeled off to form patterns. According to an aspect of one or more embodiments of the present invention, an adhesive film is provided. According to one or more embodiments, an adhesive film is formed of an adhesive composition including a (meth)acrylic copolymer, a curing agent, a mono- or higher functional monomer, a light-to-heat conversion material, and an initiator, and has a peel strength increase rate of 5.0 or more, as calculated by the following Equation 1: Peel strength increase rate=P2/P1, where P1 is an initial peel strength (unit: gf/inch) of the adhesive film with respect to an adherend, as measured on a specimen of the adhesive film and the adherend, and P2 is a peel strength of the adhesive film (unit: gf/inch) with respect to the adherend, as measured on the specimen of the adhesive film and the adherend after irradiation with light of the specimen with light. According to one or more embodiments, an adhesive film is formed of an adhesive composition including a (meth)acrylic copolymer, a curing agent, a mono- or higher funct