KR20170097401A - Photo hardening adhesive composition, adhesive layer, laminate film and image display device formed therefrom - Google Patents

Abstract

The present invention relates to a photocurable adhesive composition, an adhesive layer formed thereby, and an image display device. More specifically, the present invention relates to a photocurable adhesive composition containing a photo-acid generator which is represented by chemical formula 1. The present invention further relates to an adhesive layer formed thereby, an adhesive film, and an image display device. According to the present invention, it is possible to increase attachability and adhesiveness with base materials.

Description

TECHNICAL FIELD [0001] The present invention relates to a photo-curing adhesive composition, an adhesive layer formed therefrom, a bonding film, and an image display device. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002]

The present invention relates to a photo-curable adhesive composition comprising a photoacid generator, an adhesive layer formed therefrom, a bonding film and an image display device.

Recently, with the development of mobile devices such as smart phones and tablet PCs, attempts have been made not only to thin and slim down substrates for displays but also to develop foldable displays.

Glass is generally used as a material having excellent mechanical properties on a display window or a front plate of such a mobile device. However, glass has a problem of breakage due to an external impact, and it is difficult to apply to a folding display.

Accordingly, attempts have been made to form a functional hard coating to protect the surface of a display window or front plate and to prevent scratches and the like, and to use a flexible material such as plastic instead of a glass substrate.

When a hard coating film is bonded to another base film using an adhesive, cracks do not occur, and an excellent adhesion, adhesion and flexibility to the film are required.

Korean Patent Laid-Open Publication No. 2015-0043596 discloses an adhesive composition containing an epoxy resin. However, the adhesive composition has a problem of insufficient adhesion, adhesion, and flexibility when bonding a flexible hard coating film to another substrate.

Korean Patent Laid-Open Publication No. 2015-0043596 (Apr. 23, 2015)

It is an object of the present invention to provide a photocurable adhesive composition capable of improving the adhesive strength and the curing rate.

It is also an object of the present invention to provide an adhesive layer capable of improving adhesion, durability, flexibility, flexibility and curing rate.

It is also an object of the present invention to provide a window of a bonding film, an image display device or a display device including the aforementioned adhesive layer.

In order to accomplish the above object, the present invention provides a photo-curable adhesive composition comprising a photoacid generator represented by the following formula (1).

[Chemical Formula 1]

In Formula 1,

X ^& lt ^{; + &} gt ^; is represented by the formula (2)

(2)

In Formula 2,

,

, 탄소수 1 내지 12의 직쇄 또는 분지쇄의 알킬기, 탄소수 3 내지 12의 사이클로 알킬기, 탄소수 1 내지 6의 알콕시기, 탄소수 1 내지 6의 알킬카르보닐기, 또는 탄소수 6 내지 14의 아릴기이고, R ₁ to R ₃ each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group,

,

, A straight or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 14 carbon atoms,

The aryl group may form a fused ring together with the bonded benzene ring,

R ₁ to R ₃ each independently may be substituted at least once in one ring, and may be different substituents when they are substituted one or more times.

The present invention also provides an adhesive layer comprising a cured product of the photo-curable adhesive composition described above.

The present invention also relates to a hard coating film in which a hard coating layer is formed on one surface of a first base film; An adhesive layer formed on the other surface of the first base film; And a second base film formed on the adhesive layer, wherein the adhesive layer provides the bonding film as the adhesive layer described above.

Further, the present invention provides an image display device including the above-mentioned junction film.

Further, the present invention provides a window of a display device including the above-mentioned junction film.

The photo-curable adhesive composition according to the present invention has an advantage of improving adhesion and adhesion between substrates because it contains a specific photoacid generator.

In addition, the adhesive layer formed from the above-described photo-curable adhesive composition according to the present invention has an advantage in that durability, flexibility, flexibility and curing speed are improved, so that it can be applied to a window of a flexible display device as well as an image display device.

Hereinafter, the present invention will be described in more detail.

When a member is referred to as being " on "another member in the present invention, this includes not only when a member is in contact with another member but also when another member exists between the two members.

Whenever a part is referred to as "including " an element in the present invention, it is to be understood that it may include other elements as well, without departing from the other elements unless specifically stated otherwise.

는 다른 치환기 또는 결합부에 결합되는 부위를 의미한다.In the present invention,

Quot; refers to a moiety bonded to another substituent or bond.

< Photocurable  Adhesive composition>

The photo-curable adhesive composition of the present invention includes a specific photoacid generator, and may further include an epoxy-based binder resin and a photo-curable cationic polymerization initiator.

The total solids content of the photocurable adhesive composition in the present invention means the total content of the remaining components excluding the solvent from the photocurable adhesive composition.

The photo-curable adhesive composition may further contain additives such as inorganic nanoparticles. At this time, when the inorganic nanoparticles are dispersed, only the inorganic nanoparticles are considered in the total solid content of the photo-curable adhesive composition.

Photoacid generator

An embodiment of the present invention relates to a photo-curable adhesive composition comprising a photoacid generator represented by the following formula (1). Specifically, the photoacid generator may include a sulfonyl salt compound represented by the following formula (1).

[Chemical Formula 1]

In Formula 1,

X ^& lt ^{; + &} gt ^; is represented by the formula (2)

(2)

In Formula 2,

,

, 탄소수 1 내지 12의 직쇄 또는 분지쇄의 알킬기, 탄소수 3 내지 12의 사이클로 알킬기, 탄소수 1 내지 6의 알콕시기, 탄소수 1 내지 6의 알킬카르보닐기, 또는 탄소수 6 내지 14의 아릴기이고, R ₁ to R ₃ each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group,

,

, A straight or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 14 carbon atoms,

The aryl group may form a fused ring together with the bonded benzene ring,

R ₁ to R ₃ each independently may be substituted at least once in one ring, and may be different substituents when they are substituted one or more times.

The alkyl group may be linear or branched and preferably has 1 to 12 carbon atoms. Specific examples include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec- N-pentyl, 3-dimethylbutyl, 2-ethylbutyl, heptyl, n-hexyl, Methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, Heptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl and the like.

The cycloalkyl group preferably has 3 to 12 carbon atoms. Specific examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4- But are not limited to, methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl and the like.

The alkoxy group may be linear, branched or cyclic, and the number of carbon atoms may be 1 to 6. Specific examples include methoxy, ethoxy, n-propoxy, isopropoxy, i-propyloxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, N-hexyloxy, n-hexyloxy, 3,3-dimethylbutyloxy, 2-ethylbutyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, benzyloxy, But is not limited thereto.

The alkylcarbonyl group represents a group of the formula -COR (wherein R is hydrogen or a C1-C5 alkyl group), preferably having 1 to 6 carbon atoms. Specific examples thereof include, but are not limited to, formyl group, isecyl group and the like.

The aryl group is not particularly limited, but preferably has 6 to 14 carbon atoms, and may be monocyclic or polycyclic.

Specific examples of the monocyclic aryl group include a phenyl group, a biphenyl group, a terphenyl group, and the like, but are not limited thereto.

When the aryl group is a polycyclic aryl group, it may be a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a crycenyl group or a fluorenyl group, but is not limited thereto.

In still another embodiment of the present invention, R ₁ to R ₃ may be a hydrogen atom.

In still another embodiment of the present invention, at least one of R ₁ to R ₃ may be a methyl group.

Although it is not desired to be bound by theory, when the photoacid generator (PAG) represented by Formula 1 is included, the photoacid generator is photo-degraded by light irradiation such as ultraviolet rays to generate strong acid, React with the acid-reactive compound to initiate a chain reaction and produce a desired chemical bond, thereby improving the curing rate.

In one embodiment of the present invention, the photoacid generator represented by Formula 1 may be represented by Formula 1-1 or 1-2 below.

[Formula 1-1]

[Formula 1-2]

In another embodiment of the present invention, the photoacid generator may be added in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the total of the photocurable adhesive composition. When the photoacid generator is contained within the above range, it is preferable in terms of the curing rate. When the photoacid generator is contained in an amount of less than 0.1 part by weight, the generation of strong acid is somewhat unsatisfactory and it may be insufficient to act as a catalyst. When the photoacid generator is contained in an amount exceeding 10 parts by weight, the curing rate may be more excellent, There is a problem that it may affect the adhesive composition.

The photoacid generator containing the compound represented by the formula (1) may be directly produced and used, or a commercially available form may be used. Commercially available examples of the photoacid generator containing the compound represented by the formula (1) include, but not limited to, WPAG-281 and WPAG-336 (Wako Pure Chemical).

In another embodiment of the present invention, the photo-curable adhesive composition may further include an epoxy-based binder resin and a photo-curable cationic polymerization initiator.

Epoxy-based binder resin

The epoxy-based binder resin according to the present invention may be a compound having two or more epoxy groups in the molecule and capable of curing reaction or a polymer thereof. At least one of the epoxy groups may be an alicyclic epoxy group, preferably having a ring of 5 to 7 carbon atoms, and more preferably an alicyclic epoxy group having a cyclohexane ring having 6 carbon atoms (epoxycyclohexyl group) . The alicyclic epoxy group may be substituted with an alkyl group having 1 to 20 carbon atoms.

The epoxy-based binder resin is not particularly limited, and a known epoxy resin compound can be used. However, it is preferable that the epoxy resin compound does not contain an aromatic ring in order to shorten the curing time and improve adhesion and adhesion.

The epoxy-based binder resin may further contain a saturated or unsaturated hydrocarbon group having 1 to 8 carbon atoms, an ester group, an ether group, a ketone group or a carbonate group in the molecule. In order to lower the viscosity and improve the adhesion to the substrate, Is preferably 8 or less. When the number of carbon atoms is 8 or less, there is an advantage that it is easy to handle in the case of coating.

The epoxy-based binder resin according to the present invention may include a compound represented by the following formula (2).

 (2)

In Formula 2,

A1 and A2 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,

B is an oxygen atom or an alkanediyl group having 1 to 20 carbon atoms.

More specifically, in the case where Al and A2 in the general formula (2) are alkyl groups, the position bonding to the alicyclic ring may be any position of 1 to 6 of the ring. The alkyl group having 1 to 6 carbon atoms may be a straight or an alicyclic group or a branched group, and when the alkyl group has 1 to 6 carbon atoms, the curing rate may be improved.

In the above formula (2), when B is an alkanediyl group having 1 to 20 carbon atoms, it is advantageous in terms of diagnosis because of low viscosity.

The epoxy-based binder resin is preferably contained in an amount of 60 to 90 parts by weight, and more preferably 65 to 85 parts by weight, based on 100 parts by weight of the photocurable adhesive composition. When the content of the epoxy-based binder resin is less than the above-mentioned range, it is difficult to exhibit improvement in adhesion and adhesion due to lowering of the curing rate, and when the content of the epoxy-based binder resin exceeds the above range, a bending property due to an increase in the curing rate is given It becomes difficult.

Photocurable cationic polymerization initiator

The photocurable cationic polymerization initiator may be a cationic photoinitiator known in the art without any particular limitation. For example, an onium salt or its derivative which releases Lewis acid by light irradiation may be used.

When the photocurable cationic polymerization initiator is used together with the epoxy-based binder resin, curing is inhibited when the adhesive composition is stored, and excellent storage stability can be imparted. Further, it is preferable because it can prevent the adhesive itself and the adhesion object film, which are caused by the thermal history which occurs when a thermosetting polymerization initiator is used, from discoloring.

The photocurable cationic polymerization initiator includes, for example, an onium salt or a derivative thereof which releases Lewis acid by light irradiation.

Such a compound is a salt form composed of a cation and an anion represented by the general formula [X] ^{x +} [Y] ^x- , and specific examples of the cation include aromatic diazonium salt, aromatic iodonium salt, aromatic halonium salt, aromatic sulfonium salt and the like Specific examples of the anion include tetrafluoroborate (BF ₄ ), hexafluorophosphate (PF ₆ ), hexafluoroantimonate (SbF ₆ ), hexafluoroarsenate (AsF ₆ ), hexa And chlorantimonate (SbCl ₆ ). These photocurable cationic polymerization initiators may be used singly or in combination of two or more.

The content of the photocurable cationic polymerization initiator is not particularly limited and may be 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total adhesive composition, based on the solid content . When the content is less than 0.01 part by weight, the curing of the adhesive composition is insufficient and it is difficult to obtain sufficient adhesion and adhesion. When the content is more than 10 parts by weight, the hygroscopicity increases due to excessive ionic substance content of the adhesive layer, have.

The photoinitiator is not limited as long as it is commonly used in the art, for example, Igacure 250 from BASF can be used.

Inorganic nanoparticles having a reactive functional group

The inorganic nanoparticles having a reactive functional group may be selectively added to improve the durability of the adhesive composition. Specifically, the surface of the inorganic nano-particles is substituted with a hydroxyl group and has a characteristic of being able to participate in the photo-curing reaction. In addition, when the inorganic nanoparticles are contained in the adhesive composition, the mechanical properties can be further improved.

The inorganic nanoparticles may have an average particle diameter of 1 to 100 nm, specifically 1 to 80 nm, more specifically 5 to 50 nm. When the average particle diameter of the inorganic nanoparticles satisfies the above range, there is an advantage that uniform light curing can be achieved by preventing aggregation from occurring in the composition.

The reactive functional group may be a hydroxyl group, and the above-mentioned "inorganic nanoparticle having a reactive functional group" means that at least a part of the surface of the inorganic nanoparticle is substituted with the hydroxyl group.

The inorganic nanoparticles may be formed of at least one of Al ₂ O ₃ , SiO ₂ , ZnO, ZrO ₂ , BaTiO ₃ , TiO ₂ , Ta ₂ O ₅ , Ti ₃ O ₅ , ITO, IZO, ATO, ZnO -Al, Nb ₂ O _3, SnO, MgO, and may however comprise one or more of the group consisting of, and not limited to this may include a metal oxide that is commonly used in the art.

Specifically, the inorganic nanoparticles may be Al ₂ O ₃ , SiO ₂ , or ZrO ₂ . The inorganic nanoparticles may be prepared directly or commercially available ones. In the case of commercially available products, the inorganic nanoparticles may be dispersed in an organic solvent at a concentration of 10 to 80% by weight. Commercially available products include, but are not limited to, IPA-ST, IPA-ST-L, IPA-ST-UP and IPA-ST-ZL (Nissan chemical).

The inorganic nanoparticles having a reactive functional group may be included in an amount of 5 to 20 parts by weight, preferably 8 to 17 parts by weight, more preferably 10 to 15 parts by weight, based on the adhesive resin mixture. When the inorganic nanoparticles are contained in the above range, they are preferable in terms of imparting mechanical properties. If the amount of the inorganic nanoparticles is less than 5 parts by weight, mechanical properties such as durability may not be sufficient, and if it exceeds 20 parts by weight, curability may be deteriorated, resulting in deterioration of mechanical properties and durability.

additive

The photo-curable adhesive composition according to the present invention may further contain additives as required. The kind of the additive is not particularly limited, and examples thereof include a solvent, a sensitizer, an adhesion promoter, a leveling agent, an ultraviolet absorber, an antioxidant, a dye, a processing aid, an ion trap agent, an antioxidant, a tackifier, , An antistatic agent, a fragrance, etc. These may be used singly or in combination of two or more.

The content of the additive is not particularly limited, and may be, for example, 0.01 to 10 parts by weight based on 100 parts by weight of the total photo-curable adhesive composition. When the additive is contained within the above range, there is an advantage that stability can be improved, discoloration can be prevented, curing speed can be improved, and good adhesion or adhesion can be ensured.

Adhesive layer

Another aspect of the present invention relates to an adhesive layer comprising a cured product of the photo-curable adhesive composition described above. The method for producing the adhesive layer is not particularly limited, and can be produced by a conventional method. For example, the photocurable adhesive composition may be coated on one surface of a substrate and then cured. At this time, the coating method is not particularly limited, and various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used.

The adhesive layer may be formed by curing the photo-curable adhesive composition, and it is preferably 0.5 to 50 mu m, more preferably 1 to 20 mu m. If the thickness of the adhesive layer is less than the above range, the adhesive force may be insignificant. If the thickness of the adhesive layer exceeds the above range, the effect may not be improved in proportion to the thickness of the adhesive layer. desirable.

Another aspect of the present invention is a hard coating film comprising a first base film and a hard coating layer formed on one surface of the first base film; An adhesive layer formed on the other surface of the first base film; And a second base film formed on the adhesive layer, wherein the adhesive layer is a bonding film which is the adhesive layer described above. That is, the adhesive layer includes a cured product of the photo-curable adhesive composition described above.

For example, a hard coating film in which a hard coating layer is formed on one surface of a first base film; An adhesive layer formed on the other surface of the first base film; And a second base film formed on the adhesive layer.

Wherein the bonding film comprises a coating step of coating the second base film with the photo-curable adhesive composition in an uncured state to form a photo-curable adhesive layer, an adhesive bonding the hard coat film to the photo- And a curing step of curing the photo-curable adhesive composition. However, the present invention is not limited thereto.

The base film is not limited as long as it is a transparent polymer film. In the present invention, the base film may be a term including the first base film and the second base film described above.

In the present invention, the term "transparent" means that the transmittance of the visible ray is 70% or more or 80% or more. Incidentally, the case where the entire area is not transparent and the aperture ratio is 60% or more may be included.

The polymer film may be manufactured by a film-forming method or an extrusion method according to a manufacturing method, but is not limited thereto. Specifically, the transparent polymer film may be a cycloolefin-based derivative having a unit of a monomer including a cycloolefin such as norbornene or a polycyclic norbornene monomer, a cellulose (diacetylcellulose, triacetylcellulose, acetylcellulose butyrate, iso Propyl cellulose, butyryl cellulose, acetyl propionyl cellulose), ethylene vinyl acetate copolymer, polyester, polystyrene, polyamide, polyetherimide, polyacryl, polyimide, polyether sulfone, polysulfone, polyethylene , Polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyethersulfone, polymethyl methacrylate, polyethylene terephthalate, polybutyl Ren Terephthal Sites may be used polyethylene naphthalate, polycarbonate, polyurethane, and can be selected from among epoxy, non-stretched, uniaxially or biaxially stretched film.

More specifically, among the transparent substrates exemplified above, monoaxially or biaxially stretched polyester films excellent in transparency and heat resistance, cycloolefin-based derivative films excellent in transparency and heat resistance and capable of coping with the enlargement of the film, transparent and optically anisotropic A triacetylcellulose film having no transparency and a low transparency and a low cost acrylic copolymer film can be suitably used. However, the present invention is not limited thereto, and a substrate including a transparent plastic generally used in the art can be appropriately selected and used .

Another aspect of the present invention relates to an image display apparatus provided with the above-described junction film.

The image display device may include a liquid crystal display device, an OLED, a flexible display, and the like. However, the present invention is not limited thereto, and any image display device known in the art can be applied.

Further, another aspect of the present invention relates to a window of a flexible display device provided with the aforementioned bonding film.

Hereinafter, the present invention will be described in detail by way of examples to illustrate the present invention. However, the embodiments according to the present disclosure can be modified in various other forms, and the scope of the present specification is not construed as being limited to the above-described embodiments. Embodiments of the present disclosure are provided to more fully describe the present disclosure to those of ordinary skill in the art. In the following, "%" and "part" representing the content are by weight unless otherwise specified.

Examples 1 to 8 and Comparative Examples 1 to 3: Photosetting adhesive composition

The compositions according to Examples 1 to 8 and Comparative Examples 1 to 3 were prepared with the ingredients shown in Table 1 below. (WPAG-281, manufactured by Wako Pure Chemical), the compound of formula 1-2 (WPAG-336, manufactured by Wako Pure Chemical), b-1 as a photoacid generator, (Celloxide-2081, Dicelsa). The cationic initiator was Irgacure 250 (manufactured by BASF), inorganic nanoparticles IPA-ST (Nissan Chemical Co.) was used.

Photoacid generator Epoxy resin Photocurable cationic polymerization initiator Inorganic nanoparticle (1-1) 1-2 ingredient Weight portion Example 1 One One b-1 75 3 12 Example 2 2 One b-1 80 3 12 Example 3 One 2 b-1 70 3 13 Example 4 One One b-2 66 2 15 Example 5 One 2 b-2 60 3 10 Example 6 2 One b-3 77 One 10 Example 7 2 0 b-3 80 3 10 Example 8 0 2 b-3 70 3 10 Comparative Example 1 - - b-1 80 3 10 Comparative Example 2 - - b-2 80 3 10 Comparative Example 3 - - b-3 80 3 10

Experimental Example

10 parts by weight of urethane acrylate (10-functional group, product of Mitsubishi Chemical Corporation, SC2153), 10 parts by weight of pentaerythritol triacrylate, 50 parts by weight of nano-silica sol (12 nm, solid content 40%, catalysed silica, V8802) 2.7 parts by weight of a photoinitiator (Shibasai, I-184), and 0.3 parts by weight of a leveling agent (BYK-MEMS, BYK-UV3570) , And filtered through a filter made of PP to obtain a composition for forming a hard coat layer.

The composition for forming a hard coat layer was coated on one side of a polyimide film (50 탆, first base film) to a thickness of 20 탆, dried, and cured to form a hard coat layer Respectively.

The photo-curable adhesive composition having the composition and content shown in Table 1 was coated on the other surface of the film to a thickness of 5 m to form an adhesive layer. Then, a polyethylene terephthalate film (50 占 퐉, Base film) was bonded and cured by ultraviolet irradiation (1500 mJ / cm ² ) to prepare a bonded film.

(1) Evaluation of initial adhesion force development time

When the bonded film produced in the above Experimental Example was allowed to stand at 23 DEG C and 55% relative humidity for 24 hours and the cutter blade was pushed in at intervals of 5 minutes between the base films, The time when it entered was measured as the initial adhesive force development time, and the measurement standard is as follows.

◎: Within 1 hour

○: Within 3 hours

△: Within 6 hours

×: exceeding 6 hours

(2) Evaluation of adhesion

After the bonded film produced in the above Experimental Example was allowed to stand at 23 캜 and 55% relative humidity for 24 hours, the adhesive property was evaluated to such an extent that the blades were inserted when the blade of the cutter was pushed between the base films.

◎: The cutter blade does not enter between the bonded films

○: The cutter blade enters a gap of 2 mm or less between the bonded films

DELTA: The cutter blade enters between 2 mm and 5 mm or less between the bonded films

X: The blade of the cutter is smoothly inserted between the bonded films

(3) Mandrell  evaluation

In order to evaluate the bending property and the cracking property of the bonding film, the bonding film prepared in the above Experimental Example was cut into a size of 1 cm x 10 cm and placed on a metal rod (mandolel) of each diameter, The smallest diameter is indicated.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 Comparative Example 3 Initial adhesive force development time ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ △ △ △ Adhesiveness ◎ ◎ ◎ ◎ ◎ ◎ ○ ○ △ △ △ Mandrell 6φ 5φ 4φ 5φ 4φ 4φ 5φ 5φ 12φ 12φ 11φ

Referring to Table 2, the adhesive film formed using the photo-curable adhesive composition according to the Example had excellent initial adhesive force development time, adhesive property, and mandrel property, whereas the adhesive film according to the comparative example exhibited an initial adhesive force development time, It can be seen that the properties and the mandrel properties are not excellent.

Claims (10)

1. A photo-curable adhesive composition comprising a photoacid generator represented by the following Formula 1:
[Chemical Formula 1]

In Formula 1,
X ^& lt ^{; + &} gt ^; is represented by the formula (2)
(2)

In Formula 2,
R ₁ to R ₃ each independently represent a hydrogen atom, a halogen atom, a cyano group, a nitro group,

,

, A straight or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 14 carbon atoms,
The aryl group may form a fused ring together with the bonded benzene ring,
R ₁ to R ₃ each independently may be substituted at least once in one ring, and may be different substituents when they are substituted one or more times. The method according to claim 1,
Wherein the photoacid generator represented by the formula (1) is represented by the following formula (1-1) or (1-2):
[Formula 1-1]

[Formula 1-2]

The method according to claim 1,
Wherein the photoacid generator is contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the total photo-curable adhesive composition. The method according to claim 1,
An epoxy-based binder resin, and a photo-curable cationic polymerization initiator. The method according to claim 1,
Further comprising an inorganic nanoparticle having a reactive functional group. 6. The method of claim 5,
Wherein the inorganic nanoparticles are contained in an amount of 5 to 60 parts by weight based on 100 parts by weight of the total photo-curable adhesive composition. An adhesive layer comprising a cured product of the photo-curable adhesive composition of any one of claims 1-6. A hard coating film having a hard coating layer formed on one side of the first base film;
An adhesive layer formed on the other surface of the first base film; And
And a second base film formed on the adhesive layer,
Wherein the adhesive layer is the adhesive layer according to claim 7. An image display device comprising the junction film according to claim 8. A window of a flexible display device provided with a bonding film according to claim 8.