KR20180036317A

KR20180036317A - Composition for window film and flexible window film prepared using the same

Info

Publication number: KR20180036317A
Application number: KR1020160126749A
Authority: KR
Inventors: 한동일; 김민혜; 우창수; 임지선; 장승우
Original assignee: 삼성에스디아이 주식회사; 삼성전자주식회사
Priority date: 2016-09-30
Filing date: 2016-09-30
Publication date: 2018-04-09
Also published as: WO2018062664A1; KR101967026B1

Abstract

Provided are a composition for a window film comprising a silicone resin of the chemical formula 1 and an initiator, and to a flexible window film prepared therefrom, wherein the chemical formula 1 is represented by (R^1SiO_3/2)_x(R^2SiO_3/2)_y(R^3SiO_3/2)_z(R^4R^5SiO_2/2)_w(R^6R^7R^8SiO_1/2)_u(SiO_4/2)_v. Another object of the present invention is to provide the composition for the window film which can realize the flexible window film having high hardness.

Description

FIELD OF THE INVENTION The present invention relates to a composition for a window film,

The present invention relates to a composition for a window film and a flexible window film formed therefrom.

Flexible display devices have been developed that can be folded and unfolded while replacing a glass substrate or a hardened substrate with a film in a display device. The flexible display device is thin, light, strong against impact, and can be folded and unfolded.

Since the window film is located at the outermost side of the display device, flexibility and hardness should be good when used in a flexible display device. The window film is composed of a base layer and a coating layer. When used in a flexible display device, the window film should be folded to the base layer side or the window coating layer. In particular, if the window film is well folded toward the base layer, the display will be highly useful since not only a single viewer but also a plurality of viewers can view the display at the same time. Further, since the window film is manufactured by coating the coating layer composition on the base layer, curling may occur. Therefore, the window film should have a low curl.

The background art of the present invention is disclosed in Japanese Laid-Open Patent Application No. 2007-176542.

A problem to be solved by the present invention is to provide a composition for a window film which is excellent in hardness and which can realize a flexible window film having excellent flexibility when folded toward a substrate layer.

Another object of the present invention is to provide a composition for a window film which can realize a flexible window film having a low curling degree.

A further object of the present invention is to provide a flexible window film comprising a coating layer formed from the composition for a window film of the present invention.

The composition for a window film of the present invention may comprise a silicone resin of the following formula (1), a crosslinking agent and an initiator:

&Lt; Formula 1 >

(R ¹ SiO _3/2 ) _x (R ² SiO _3/2 ) _y (R ³ R ⁴ SiO _2/2 ) _z (R ⁵ R ⁶ R ⁷ SiO _1/2 ) _w (SiO _4/2 ) _v

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , x, y, z, w and v are as defined in the detailed description of the present invention.

The flexible window film of the present invention comprises a substrate layer and a coating layer formed on the base layer, and the flexible window film may have a pencil hardness of 3H or more and a tensile direction curvature radius of 5.0 mm or less.

The present invention provides a composition for a window film which is excellent in hardness and capable of realizing a flexible window film having excellent flexibility when folded toward a substrate layer.

The present invention provides a composition for a window film capable of realizing a flexible window film with low curling.

The present invention provides a flexible window film comprising a coating layer formed from the composition for a window film of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram of a composite of silica and one embodiment of the silicone resin of Formula 1 according to one embodiment of the present invention. FIG.
2 is a cross-sectional view of a flexible window film according to an embodiment of the present invention.
3 is a cross-sectional view of a flexible window film according to another embodiment of the present invention.
4 is a cross-sectional view of a flexible display device according to an embodiment of the present invention.
5 is a cross-sectional view of a flexible display device according to another embodiment of the present invention.
6 is a cross-sectional view of a flexible display device according to another embodiment of the present invention.
7 is a conceptual diagram of the curl measurement in this specification.

The present invention is not limited to the above embodiments and various changes and modifications may be made by those skilled in the art without departing from the scope of the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

The terms "upper" and "lower" in this specification are defined with reference to the drawings, wherein "upper" may be changed to "lower", "lower" What is referred to as "on" may include not only superposition, but also intervening other structures in the middle. On the other hand, what is referred to as "directly on" or "directly above"

As used herein, "(meth) acrylic" means acrylic and / or methacrylic.

As used herein, unless specifically stated otherwise, at least one hydrogen atom of the functional group may be replaced by a hydroxyl group, an unsubstituted C1 to C10 alkyl group, a C1 to C10 alkoxy group, a C3 to C10 cycloalkyl group, C20 aryl group, a C7 to C20 arylalkyl group, a C6 to C20 aryl group substituted with a C1 to C10 alkyl group, or a C1 to C10 alkyl group substituted with a C1 to C10 alkoxy group.

As used herein, "halogen" means fluorine, chlorine, bromine or iodine.

In the present specification, "Me" means a methyl group, "Ph" means a phenyl group, "Et" means an ethyl group, "Ety" means an ethylene group, "Pry" means a propylene group, "Buty" means a butylene group, "X ₁ " (* -OC (= O) -CH (CH 2), * is a connection portion), "X _2" is a methacrylate group (* -OC (= O) -CCH 3 (CH 2), * the connection region )to be.

The "weight average molecular weight" of a resin herein is measured by gel filtration chromatography.

The composition for a window film of the present invention may comprise a silicone resin containing a urethane functional group and a radical reactive functional group, a crosslinking agent and an initiator. The radical reactive functional group may be a (meth) acrylate group or the like.

Hereinafter, a composition for a window film according to an embodiment of the present invention will be described.

The composition for a window film according to an embodiment of the present invention may include a silicone resin having the following formula (1), a crosslinking agent, and an initiator.

The composition for a window film according to the present embodiment includes a silicone resin having a urethane functional group and a (meth) acrylate group. Therefore, the composition for a window film can produce a flexible window film having excellent flexibility and excellent hardness. In particular, the composition for a window film can realize a flexible window film having excellent flexibility when a window film composed of a substrate layer and a window coating layer formed of the composition for a window film is folded toward the substrate layer. Window films that are folded toward the substrate layer are more useful than window films that can be folded into a window coating layer because many viewers can simultaneously view the displays together. In addition, the composition for a window film according to this embodiment can realize a window film with a low curl. A composition for a window film comprising a silicone resin having only a (meth) acrylate group without a urethane group may have low flexibility and curl due to a high curvature radius of the window film when folded toward the substrate layer.

In addition, the composition for a window film according to the present embodiment can include a silicone resin having the following formula (1), so that a window film can be produced without additional heat treatment and / or aging after UV curing. A composition for a window film, which typically contains a silicone resin having an epoxy group such as an alicyclic epoxy group, requires UV curing and aging treatment in forming a window coating layer.

The silicone resin of Formula 1 may be incorporated into the composition for a window film alone. However, the silicone resin of Formula 1 may be incorporated into the composition for a window film by bonding to inorganic particles or organic particles to form a silicone resin-particle composite. This will be described in detail below.

The silicone resin may be represented by the following Formula 1:

&Lt; Formula 1 >

(In the formula 1,

R ¹ is a monovalent organic group having at least one (meth) acrylate group and at least one urethane group,

R ² is a non-urethane-based monovalent organic group having at least one (meth) acrylate group, an unsubstituted or substituted C 1 to C 20 alkyl group, an unsubstituted or substituted C 5 to C 20 cycloalkyl group, A C6 to C30 aryl group,

R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent hydrogen, a monovalent organic group having at least one (meth) acrylate group, an unsubstituted or substituted C 1 to C 20 alkyl group, A substituted or unsubstituted C2 to C20 alkenyl group, an unsubstituted or substituted C5 to C20 cycloalkyl group, or an unsubstituted or substituted C6 to C30 aryl group,

0 < v < 1, x + y + z + w + v = 1).

Specifically, R ¹ is a monovalent organic group having at least one (meth) acrylate group at the terminal thereof and at least one urethane group (urethane bond) in the organic group. In one embodiment, R < ¹ > can be represented by the formula (2)

(2)

* -Ra-NH- (C = O) -O-Rb-X

(In the formula (2)

* Indicates the connection site,

Ra and Rb each independently represent a substituted or unsubstituted C1 to C10 alkylene group,

X is a (meth) acrylate group).

Preferably, Ra and Rb each independently represent a substituted or unsubstituted C1 to C5 alkylene group, for example, a methylene group, an ethylene group, a propylene group, a butylene group or a pentylene group.

For example, R ¹ may be a monovalent organic group having one (meth) acrylate group at the end and one urethane group in the organic group.

Specifically, R ² may be a monovalent organic group having no urethane group (urethane bond) and having at least one (meth) acrylate group at the terminal. R ¹ and R ² are different from each other. For example, R < ² > may be represented by the following formula (3)

(3)

* -Rc-X

(3)

* Indicates the connection site,

Rc is a substituted or unsubstituted C1 to C10 alkylene group,

X is a (meth) acrylate group).

Preferably, Rc may be a substituted or unsubstituted C1 to C5 alkylene group, for example, a methylene group, an ethylene group, a propylene group, a butylene group or a pentylene group.

Alternatively, R ² may be an unsubstituted or substituted C 1 to C 20 alkyl group, an unsubstituted or substituted C 5 to C 20 cycloalkyl group, or an unsubstituted or substituted C 6 to C 30 aryl group. Preferably, it may be a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C5 to C10 cycloalkyl group, or a substituted or unsubstituted C6 to C10 aryl group.

R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent hydrogen, a monovalent organic group having at least one (meth) acrylate group, a substituted or unsubstituted C 1 to C 10 alkyl group, A substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C5 to C10 cycloalkyl group, or a substituted or unsubstituted C6 to C10 aryl group. At this time, the monovalent organic group having at least one (meth) acrylate group may be represented by the above formula (2) or (3). Preferably, R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent a substituted or unsubstituted C 1 to C 5 alkyl group such as methyl, ethyl, propyl, butyl or pentyl groups .

In Formula ^{_{1, (R 1 SiO 3/}} 2), ^{_{(R 2 SiO 3/2)}} , ^{_{(R 3 R 4 SiO 2/}} 2), ^{(R 5 R 6 R 7 SiO} 1/2), (SiO _4/2) may also contain two or more different units, respectively. That is, for ^{_{example, (R 1a SiO 3/2) x1}} (R 1b SiO 3/2) contains only (R ¹ SiO _3/2) as shown in Formula 1-1 to the resin of the formula 1 _x2 ( R ^1a and R ^1b are the same as R ¹ defined in Formula 1 and R ^1a and R ^1b are different from each other and 0 <x 1 <1, 0 <x 2 <1, x 1 + x 2 = 1) .

In one embodiment, the silicone resin of Formula 1 may be a silicone resin of T units represented by Formula 1-1:

&Lt; Formula 1-1 >

^{_{(R 1 SiO 3/2)}} x

(Wherein R ¹ is as defined in the above formula (1), and x is 1)

For example, the silicone resin of Formula 1-1 may include silicone resins of the following Formulas 1-1-1 to 1-1-3:

&Lt; Formula 1-1-1-1 &

((X-Ety-O- (C = O) NH-Pry) SiO3 / ₂ )

(1-1-2)

((X-Buty-O- (C = O) NH-Pry) SiO3 / ₂ )

&Lt; Formula 1-1-3 &

((X-Pry-O- (C = O) NH-Pry) SiO3 / ₂ )

In another embodiment, the silicone resin of Formula 1 may be a silicone resin of T units and T units represented by Formula 1-2:

(1-2)

(R ¹ SiO _3/2 ) _x (R ² SiO _3/2 ) _y

(Wherein R ¹ and R ² are the same as defined in Formula 1 and 0 <x <1, 0 <y <1, x + y = 1).

Specifically, in the above formula 1-2, 0.20? X? 0.99, 0.01? Y? 0.80, x + y = 1, preferably 0.40? X? 0.95, 0.05? Y? Most preferably, 0.80? X? 0.95, 0.05? Y? 0.20, and x + y = 1. Within this range, when the window film is folded toward the substrate layer, it is excellent in flexibility, excellent in hardness and low in curling.

For example, the silicone resin of Formula 1-2 may include silicone resins of the following Formulas 1-2-1 to 1-2-9.

((X-Ety-O- ( C = O) -NH-Pry) SiO 3/2) x ((X-Pry) SiO 3/2) y

((X-Buty-O- ( C = O) NH-Pry) SiO 3/2) x ((X-Pry) SiO 3/2) y

((X-Pry-O- ( C = O) NH-Pry) SiO 3/2) x ((X-Pry) SiO 3/2) y

(1-2-4)

((X-Ety-O- ( C = O) -NH-Pry) SiO 3/2) x (MeSiO 3/2) y

((X-Buty-O- ( C = O) NH-Pry) SiO 3/2) x (MeSiO 3/2) y

((X-Pry-O- ( C = O) NH-Pry) SiO 3/2) x (MeSiO 3/2) y

&Lt; Formula 1-2-7 &

((X-Ety-O- ( C = O) -NH-Pry) SiO 3/2) x (PhSiO 3/2) y

&Lt; Formula 1-2-8 &

((X-Buty-O- ( C = O) NH-Pry) SiO 3/2) x (PhSiO 3/2) y

((X-Pry-O- ( C = O) NH-Pry) SiO 3/2) x (PhSiO 3/2) y

(0 <x <1, 0 <y <1, x + y = 1).

In another embodiment, the silicone resin of Formula 1 may be a silicone resin having T units and D units represented by the following Formula 1-3:

(R ¹ SiO _3/2 ) _x (R ³ R ⁴ SiO _2/2 ) _z

1, 0 < z < 1, x + z = 1), wherein R ¹ , R ³ and R ⁴ are as defined in the above formula (1).

Specifically, in the above Formula 1-3, 0.40? X? 0.99, 0.01? Y? 0.60, x + y = 1, preferably 0.60? X? 0.95, 0.05? Y? . Within this range, when the window film is folded toward the substrate layer, it is excellent in flexibility, excellent in hardness and low in curling.

In still another embodiment, the silicone resin of Formula 1 may be a silicone resin of T units and M units represented by the following Formula 1-4:

(R ¹ SiO _3/2 ) _x (R ⁵ R ⁶ R ⁷ SiO _1/2 ) _w

1, 0 < w < 1, x + w = 1), wherein R ¹ , R ⁵ , R ⁶ and R ⁷ are as defined in the above formula (1). Specifically, in Formula 1-4, 0.40? X? 0.995, 0.005? W? 0.60, x + w = 1, preferably 0.60? X? 0.995, 0.005? W? . Within this range, when the window film is folded toward the substrate layer, it is excellent in flexibility, excellent in hardness and low in curling.

In another embodiment, the silicone resin of Formula 1 may be a silicone resin of T units and Q units represented by the following Formula 1-5:

&Lt; Formula 1-5 >

(R ¹ SiO _3/2 ) _x (SiO _4/2 ) _v

(Wherein R ¹ is as defined in Formula 1 and 0 <x <1, 0 <v <1, x + v = 1). Specifically, in the above Formula 1-5, 0.20? X? 0.99, 0.01? V? 0.80, x + v = 1, preferably 0.40? X? 0.95, 0.05? V? . Within this range, when the window film is folded toward the substrate layer, it is excellent in flexibility, excellent in hardness and low in curling.

The silicone resin of the above formula (1) can be end-capped to enhance storage stability. For example, the silicone resin of Formula 1 may be end-capped with hexamethyldisiloxane or the like, but is not limited thereto.

The silicone resin of Formula 1 has a weight average molecular weight of 1,000 g / mol to 5,000 g / mol, specifically 1,000 g / mol to 4,000 g / mol, more specifically 1,000 g / mol to 3,000 g / mol, It can be 1,000 g / mol to 2,500 g / mol. Within the above range, the appearance of the window film can be improved and transparency can be enhanced. The silicone resin of Formula 1 may have a polydispersity index (PDI) of 1.0 to 3.0, specifically 1.5 to 2.5. Within the above range, coating properties of the composition are good and coating properties may be stable.

The silicone resin of Formula 1 is contained in an amount of 20 to 90 parts by weight, specifically 30 to 90 parts by weight, 40 to 80 parts by weight, and 50 parts by weight, based on 100 parts by weight of the total of the silicone resin and the cross- To 80 parts by weight. Within this range, the hardness and flexibility of the window film is good and the curling can be low.

The crosslinking agent may be cured together with the silicone resin of Formula 1 to improve the hardness and flexibility of the window film. The crosslinking agent may include one or more, preferably two or more, for example, two or more, and up to ten (meth) acrylate-based (meth) acrylate-based monomers.

(Meth) acrylate monomer may be at least one selected from the group consisting of 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (Meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate, di Acrylate, trimethylolpropane di (meth) acrylate, (meth) acryloxyethyl isocyanurate, allyl cyclohexyl di (meth) acrylate, tricyclodecane dimethanol (Meth) acrylate, neopentyl glycol modified trimethylpropane di (meth) acrylate, adamantane di (meth) acrylate, tricyclodecane dimethanol Bifunctional (meth) acrylates such as 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene and the like; (Meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide Trifunctional (meth) acrylates such as modified trimethylolpropane tri (meth) acrylate, trifunctional urethane (meth) acrylate or tris (meth) acryloxyethylisocyanurate; Tetrafunctional (meth) acrylates such as diglycerin tetra (meth) acrylate or pentaerythritol tetra (meth) acrylate; Pentafunctional (meth) acrylates such as dipentaerythritol penta (meth) acrylate; (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (ex. Isocyanate monomer and trimethylol propane tri Hexafunctional (meth) acrylate such as a reaction product, etc., but are not limited thereto. These may be used alone or in combination of two or more.

The (meth) acrylate-based monomer further includes a urethane group, so that the hardness and flexibility of the window film can be improved together with the silicone resin of the formula (1), and the curl can be further lowered. The (meth) acrylate-based monomer having a urethane group can be used by using a conventional product known to those skilled in the art or by synthesizing it. For example, the (meth) acrylate monomer having a urethane group may include, but is not limited to, CHTU-9607 (Camton Co., Ltd.), AN-9696 (Camton Co., Ltd.) and the like.

The crosslinking agent may further comprise, in addition to the (meth) acrylate-based monomer, a monomer having an epoxy group or oxetane group. The monomer having an epoxy group or oxetane group may further include at least one of a chain aliphatic hydrocarbon group, a cyclic aliphatic hydrocarbon group, and a hydrogenated aromatic hydrocarbon group to further increase the flexibility of the coating layer. The monomer having an epoxy group or oxetane group may include at least one of a chained aliphatic epoxy monomer, a cyclic aliphatic epoxy monomer, a hydrogenated aromatic hydrocarbon epoxy monomer, and an oxetane monomer, and these monomers may be included singly or in combination.

The chain type aliphatic epoxy monomer may be 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylol propane triglycidyl ether, polyethylene glycol diglycidyl ether, Cidyl ether, glycerin triglycidyl ether, polypropylene glycol diglycidyl ether; Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin; Diglycidyl esters of aliphatic long chain dibasic acids; Monoglycidyl ethers of aliphatic higher alcohols; Glycidyl ethers of higher fatty acids; Epoxidized soybean oil; Butyl stearate; Octyl stearate; Epoxidized linseed oil; Epoxylated polybutadiene, and the like.

The cyclic aliphatic epoxy monomer is a compound having at least one epoxy group in the alicyclic group, and may specifically include an alicyclic epoxy carboxylate, an alicyclic epoxy (meth) acrylate, and the like. More specifically, (3,4-epoxycyclohexyl) methyl-3 ', 4'-epoxycyclohexanecarboxylate, diglycidyl 1,2-cyclohexanedicarboxylate, 2- (3,4- Epoxycyclohexyl) -5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxy-6-methylcyclohexyl) adipate, 3,4- Cyclohexylmethyl-3 ', 4'-epoxy-6'-methylcyclohexanecarboxylate, ε-caprolactone modified 3,4-epoxycyclohexylmethyl-3', 4'-epoxycyclohexanecarboxylate, trimethyl Caprolactone-modified 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone-modified 3,4-epoxycyclohexylmethyl- Epoxycyclohexanecarboxylate, 1,4-cyclohexanedimethanol bis (3,4-epoxycyclohexanecarboxylate), di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis (3, 4-epoxycyclohexane (3,4-epoxycyclohexylmethyl) adipate, 4-vinylcyclohexene-oxide, vinylcyclohexene monoxide (vinylcyclohexylmethoxide) And the like.

The hydrogenated aromatic hydrocarbon epoxy monomer means a compound obtained by selectively hydrogenating an aromatic epoxy monomer under a pressure in the presence of a catalyst. Aromatic epoxy monomers include, for example, bisphenol-type epoxy resins such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, diglycidyl ether of bisphenol S and the like; Novolak type epoxy resins such as phenol novolak epoxy resin, cresol novolak epoxy resin, and hydroxybenzaldehyde phenol novolak epoxy resin; Glycidyl ethers of tetrahydroxyphenylmethane, glycidyl ethers of tetrahydroxybenzophenone, and epoxy polyvinylphenols, and the like.

The oxetane monomer may be selected from the group consisting of 3-methyloxetane, 2-methyloxetane, 2-ethylhexyloxetane, 3-oxethanol, 2-methylene oxetane, Methyl-3-oxetanemethanamine, N- (1,2-dimethylbutyl) -3-methyl-3- (3-ethyloxetan-3-yl) methoxy] butan-1-ol, 3-ethyloxetane- May include at least one of 3-hydroxymethyloxetane, xylene bisoxetane and 3- [ethyl-3 [[(3-ethyloxetan-3-yl)] methoxy] methyl] oxetane, But is not limited thereto.

The crosslinking agent in the total amount of 100 parts by weight of the silicone resin of the formula (1) and the crosslinking agent is 10 parts by weight to 80 parts by weight, specifically 10 parts by weight to 70 parts by weight, 20 parts by weight to 60 parts by weight and 20 parts by weight to 50 parts by weight . Within this range, the hardness and flexibility of the window film is good and the curling can be low.

The initiator is used to cure the silicone resin and the crosslinking agent of the formula (1), and may contain a photo radical initiator alone or in combination of two or more. As the photo-radical initiator, those conventionally known to those skilled in the art can be used. For example, as the photo radical initiator, a hydroxy ketone base, a phosphine oxide base, a benzoin base, an aminoketone base photo radical initiator and the like can be used. Specific examples include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenyl-phosphine oxide, benzoin, benzoin methyl ether, benzoin ethyl ether , Benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, 2,2-dimethoxy-2-phenylacetophenone, 2,2'-diethoxyacetophenone, 2,2'-dibutoxy Acetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyl trichloroacetophenone, pt-butyldichloroacetophenone, 4-chloroacetophenone, 2,2'- Acetophenone compounds such as dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy- 1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 1-hydroxycyclohexyl phenyl ketone, Thio) phenyl] -2-morpholino-propan-l- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-nonocydiethylaminobenzophenone, dichlorobenzophenone, 2 2-ethyl anthraquinone, 2-t-butyl anthraquinone, 2-amino anthraquinone, thioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4- Diethyl thioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethyl amino benzoic acid ester, oligo [2-hydroxy-2-methyl-1- [4- ) Phenyl] propanone] and the like. Preferably, a hydroxyketone-based initiator such as 1-hydroxycyclohexyl phenyl ketone or the like can be used.

The initiator may further comprise conventional photon ionic initiators known to those skilled in the art. For example, the Gwangyang ion initiator may comprise an onium salt compound.

The initiator may be included in an amount of 0.1 to 10 parts by weight, specifically 0.5 to 5 parts by weight, and 1 to 3 parts by weight based on 100 parts by weight of the total amount of the silicone resin and the crosslinking agent of Formula 1. In this range, the silicone resin can be sufficiently cured and the remaining amount of the initiator remains, thereby preventing the optical characteristics (transmittance, hue, and light reliability) of the window film from being lowered.

The composition for a window film according to this embodiment may further include nanoparticles.

The nanoparticles may be independently incorporated into the composition for a window film without bonding with the silicone resin of Formula 1. Nanoparticles can further increase the hardness of the window film. The nanoparticles may include, but are not limited to, one or more of silica, aluminum oxide, zirconium oxide, and titanium oxide.

The nanoparticles may include non-surface treated nanoparticles. Or the nanoparticles may be surface treated with some or all of the surface with a silicone compound for mixing with the silicone resin. Alternatively, the nanoparticles may comprise nanoparticles surface-treated with (meth) acrylate groups, through which the hardness of the window film can be increased by crosslinking with the silicone resin of formula (I).

Nanoparticles are not limited in shape and size. Specifically, the nanoparticles may include spherical, plate-like, amorphous, etc. particles. The nanoparticles may have an average particle diameter (D50) of 1 nm to 200 nm, specifically 5 nm to 50 nm, 10 nm to 20 nm, and 10 nm to 15 nm. The hardness of the window film can be increased without affecting the surface roughness and transparency of the window film in the above range.

The nanoparticles may be included in an amount of 0.1 part by weight to 60 parts by weight, specifically 10 parts by weight to 50 parts by weight, based on 100 parts by weight of the total amount of the silicone resin and the crosslinking agent of Formula 1. The hardness of the window film can be increased without affecting the surface roughness and transparency of the window film in the above range.

The composition for a window film according to this embodiment may further include an additive. The additive may provide additional functionality to the window film. The additive may include an additive typically added to the window film. Specifically, the additive may include at least one of a UV absorber, a reaction inhibitor, an adhesion improver, a thixotropic agent, a conductivity imparting agent, a colorant adjusting agent, a stabilizer, an antistatic agent, an antioxidant, Do not. The reaction inhibitor may include ethynylcyclohexane. The adhesion improver may include a silane compound having an epoxy or alkoxysilyl group. The thixotropic agent may include pyrous silica and the like. The conductivity-imparting agent may include a metal powder such as silver, copper aluminum and the like. The colorant-adjusting agent may include a pigment, a dye, and the like. The UV absorber can increase the light reliability of the window film. The UV absorbers can be conventional absorbents known to those skilled in the art. Specifically, the UV absorber may include, but is not limited to, one or more UV absorbers based on triazine, benzimidazole, benzophenone, and benzotriazole. The leveling agent may include, but is not limited to, a silicone leveling agent such as a silicon-based leveling agent containing a (meth) acrylate group (e.g., BYK-3500).

The additive may be added in an amount of 0.01 to 5 parts by weight, specifically 0.1 to 2.5 parts by weight based on 100 parts by weight of the total amount of the silicone resin and the cross-linking agent of the formula (1). In this range, the hardness and flexibility of the window film can be improved and the additive effect can be realized.

The composition for a window film according to this embodiment may further include a solvent to facilitate coating, coating or processability. The solvent may include, but is not limited to, one or more of methyl ethyl ketone, methyl isobutyl ketone, and propylene glycol monomethyl ether acetate.

Hereinafter, a composition for a window film according to another embodiment of the present invention will be described.

The composition for a window film according to the present embodiment is an embodiment of the present invention except that the composition further comprises nanoparticles and at least a part of the silicone resin of Formula 1 is bonded to the nanoparticles. Is substantially the same as the composition for a window film according to the invention.

At least a portion of the silicone resin of Formula 1 is bonded to the nanoparticles. Therefore, the window film can further increase the hardness of the contrast window film when the silicone resin of Formula 1 and the nanoparticles are contained in the same amount. Preferably, the composition for the window film may comprise a mixture of the silicone resin of Formula 1 and the silicone resin of Formula 1 bonded to the nanoparticles. In this case, the hardness and flexibility of the window film can be increased at the same time.

The complex (B) of the silicone resin and the nanoparticles of the formula (1) in the mixture of the silicone resin (A) of the formula (1) and the silicone resin (B) %, Specifically from 20% to 50% by weight. Within this range, the hardness and flexibility of the window film can be improved and the curl can be improved.

The nanoparticles in the mixture of the silicone resin (A) of the formula (1) and the silicone resin (B) bound to the nanoparticles of the formula (1) contain 0.1% to 60% by weight, preferably 5% to 50% , And 30% by weight to 50% by weight. Within this range, the hardness and flexibility of the window film can be improved and the curl can be improved.

The nanoparticles may comprise the nanoparticles described above.

1 is a conceptual diagram of a composite of the silicone resin and the silica nanoparticle of Formula 1 according to another embodiment of the present invention. Referring to FIG. 1, the OH group on the surface of the silica and the silicon of the silicone resin of Formula 1 may be bonded to each other, and the silica may be surface-treated with the silicone resin of Formula 1. Therefore, the nanoparticles and the silicone resin of the formula (1) are mixed well, and the optical transparency of the window film can be improved, and the production of the window film can be facilitated.

The composition for a window film according to this embodiment may include a silicone resin having no (meth) acrylate group. For example, the composition for a window film according to this embodiment may further comprise a silicone resin having an epoxy group. The silicone resin having an epoxy group may be represented by the following formula (4)

&Lt; Formula 4 >

(R ⁸ SiO _3/2 ) x (R ⁹ SiO _3/2 ) y (R ¹⁰ R ¹¹ SiO _2/2 ) z (R ¹² R ¹³ R ¹⁴ SiO _1/2 ) w (SiO _4/2 ) u

(In the formula 4,

R ⁸ represents an epoxy group or an epoxy group-containing functional group,

R ⁹ is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, or a substituted or unsubstituted C6 to C10 aryl group,

R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, or a substituted or unsubstituted C6 to C10 An epoxy group, or an epoxy group-containing functional group,

1, 0? Y <1, 0? Y <1, 0? Z <1, 0? W <1, 0? U <1, x + y + z + w + u = 1).

The epoxy group may be a C4 to C10 epoxidized cycloalkyl group such as a 3,4-epoxycyclohexyl group or a glycidoxy group as the alicyclic epoxy group. The epoxy group-containing functional group may be a C1 to C10 alkyl group having an epoxy group, for example, a 2- (3,4-epoxycyclohexyl) ethyl group, or a 3-glycidoxypropyl group.

Hereinafter, a flexible window film according to an embodiment of the present invention will be described with reference to FIG. 2 is a cross-sectional view of a flexible window film of an embodiment of the present invention.

2, a flexible window film 100 according to an exemplary embodiment of the present invention includes a substrate layer 110 and a coating layer 120, and the coating layer 120 may be a window film according to embodiments of the present invention. And the like.

The substrate layer 110 supports the flexible window film 100 and the coating layer 120 to increase the mechanical strength of the flexible window film 100. The base layer 110 may be adhered to a display portion, a touch screen panel, or a polarizing plate by an adhesive layer or the like. The substrate layer 110 may be formed of an optically transparent and flexible resin. For example, the resin includes a polyester resin including a polyethylene terephthalate, a polyethylene naphthalate, a polybutylene terephthalate, a polybutylene naphthalate, etc., a polycarbonate resin, a polyimide resin, a polystyrene resin, polymethylmethacrylate (Meth) acrylate resin. &Lt; / RTI > The resin may be contained in the base layer 110 alone or in combination. The base layer 110 may have a thickness of 10 占 퐉 to 200 占 퐉, specifically, 20 占 퐉 to 150 占 퐉, more specifically, 50 占 퐉 to 100 占 퐉. Can be used in the flexible window film in the above range.

The coating layer 120 is formed on the base layer 110 to protect the base layer 110, the display portion, the touch screen panel or the polarizing plate, improve the appearance, have high flexibility and high hardness and can be used in a flexible display device can do. The thickness of the coating layer 120 may be 5 占 퐉 to 100 占 퐉, specifically 10 占 퐉 to 80 占 퐉. Can be used in the flexible window film in the above range.

Although not shown in FIG. 2, a functional surface layer such as an antireflection layer, an antiglare layer, a hard coat layer, a textured layer, a stain resistant layer, a low reflection layer, and a diffusion layer is further formed on the other surface of the coating layer 120, . 2, the coating layer 120 may be further formed on the other surface of the substrate layer 110. [

The flexible window film 100 may have a light transmittance of 88% or more and specifically 88% to 100% in a visible light region specifically at a wavelength of 400 nm to 800 nm. It can be used as a flexible window film in the above range. The flexible window film 100 may have a pencil hardness of 3H or more and a tensile direction curvature radius of 5.0 mm or less. In the above range, the film can be used as a flexible window film with good hardness and flexibility. The "tensile radius of curvature" is a radius of curvature measured when the window film is folded toward the base layer after the base layer of the window film is contacted with the jig for measuring the radius of curvature. Specifically, the flexible window film 100 may have a pencil hardness of 3H to 9H and a radius of curvature in the tensile direction of 0.1 mm to 5.0 mm. The flexible window film 100 may have a thickness of 5 占 퐉 to 300 占 퐉. It can be used as a flexible window film in the above range.

Hereinafter, a flexible window film according to another embodiment of the present invention will be described with reference to FIG. 3 is a cross-sectional view of a flexible window film according to another embodiment of the present invention.

3, the flexible window film 200 according to another embodiment of the present invention includes a flexible window film 200 according to an exemplary embodiment of the present invention, except that the adhesive layer 130 is further formed on the other surface of the substrate layer 110. As shown in FIG. Is substantially the same as the flexible window film (100). The adhesive layer 130 is further formed on the other surface of the base layer 110, so that adhesion between the flexible window film and the touch screen panel, the polarizing plate, or the display portion can be facilitated. Is substantially the same as the flexible window film according to an embodiment of the present invention, except that an adhesive layer is further formed. Hereinafter, only the adhesive layer 130 will be described.

The adhesive layer 130 adheres to a polarizing plate, a touch screen panel, or a display unit that can be disposed under the flexible window film 200, and may be formed of a composition for a pressure-sensitive adhesive layer. Specifically, the adhesive layer 130 may be formed of a composition for a pressure-sensitive adhesive layer including a pressure-sensitive adhesive resin such as a (meth) acrylic resin, a urethane resin, a silicone resin, and an epoxy resin, a curing agent, a photoinitiator and a silane coupling agent.

The (meth) acrylic resin is a (meth) acrylic copolymer having an alkyl group, a hydroxyl group, an aromatic group, a carboxylic acid group, an alicyclic group, a heteroalicyclic group, or the like and may include a conventional (meth) acrylic copolymer. Specifically, a (meth) acrylic monomer having an unsubstituted C1 to C10 alkyl group, a (meth) acrylic monomer having a C1 to C10 alkyl group having at least one hydroxyl group, a (meth) acrylic monomer having an C6 to C20 aromatic group (Meth) acrylic monomer having a carboxylic acid group, a (meth) acrylic monomer having a C3 to C20 alicyclic group, a C3 to C10 heteroalicyclic group having at least one of nitrogen (N), oxygen (O) (Meth) acryl-based monomer having at least one group selected from the group consisting of (meth) acryl-based monomers.

The curing agent may be a bifunctional (meth) acrylate such as hexanediol diacrylate as a polyfunctional (meth) acrylate; Trifunctional (meth) acrylates of trimethylolpropane tri (meth) acrylate; Tetrafunctional (meth) acrylates such as pentaerythritol tetra (meth) acrylate; Pentafunctional (meth) acrylates such as dipentaerythritol penta (meth) acrylate; (Meth) acrylate such as dipentaerythritol hexa (meth) acrylate, but are not limited thereto.

The photoinitiator may include the above-described photoinitiator as a conventional photoinitiator.

The silane coupling agent may include a silane coupling agent having an acryl group such as 3-acryloxypropyltrimethoxysilane and the like.

The composition for the adhesive layer may comprise 100 parts by weight of a (meth) acrylic resin, 0.1 to 30 parts by weight of a curing agent, 0.1 to 10 parts by weight of a photoinitiator, and 0.1 to 20 parts by weight of a silane coupling agent. Within this range, the flexible window film can be adhered well onto the display portion, the touch screen panel or the polarizing plate.

The thickness of the adhesive layer 130 may be 10 占 퐉 to 100 占 퐉. In the above range, the optical element such as the flexible window film and the polarizing plate can be sufficiently adhered.

Hereinafter, a flexible display device according to an embodiment of the present invention will be described with reference to FIG. 4 is a cross-sectional view of a flexible display device according to an embodiment of the present invention.

4, the flexible display device 300 according to an exemplary embodiment of the present invention includes a display portion 350a, an adhesive layer 360, a polarizing plate 370, a touch screen panel 380, a flexible window film 390 , And the flexible window film 390 may comprise a flexible window film according to embodiments of the present invention.

The display unit 350a is for driving the flexible display device 300 and may include an optical element including an OLED, an LED, or an LCD device formed on a substrate and a substrate. The display portion 350a may include a conventional structure known to those skilled in the art, and may include a lower substrate, a thin film transistor, an organic light emitting diode, a planarization layer, a protection layer, and an insulation layer.

The lower substrate supports the display portion, and a thin film transistor and an organic light emitting diode may be formed on the lower substrate. A flexible printed circuit board for driving the touch screen panel may be formed on the lower substrate. The flexible printed circuit board may further include a timing controller for driving the organic light emitting diode array, a power supply unit, and the like.

The lower substrate may include a substrate formed of a flexible resin. Specifically, the lower substrate may include a flexible substrate such as a silicon substrate, a polyimide substrate, a polycarbonate substrate, and a polyacrylate substrate, but is not limited thereto.

A plurality of pixel regions are defined by a plurality of driving wirings (not shown) and sensor wirings (not shown) crossing the display region of the lower substrate, and an organic light emitting diode connected to the thin film transistors and the thin film transistors is included in each pixel region An organic light emitting diode array may be formed. In a non-display area of the lower substrate, a gate driver for applying an electrical signal to the driving wiring may be formed in the form of a gate in panel. The gate-in panel circuit portion may be formed on one side or both sides of the display region.

The thin film transistor can be formed on the lower substrate by controlling the electric current flowing in the semiconductor by applying an electric field perpendicular thereto. The thin film transistor may include a gate electrode, a gate insulating film, a semiconductor layer, a source electrode, and a drain electrode. The thin film transistor includes an oxide thin film transistor using an oxide such as indium gallium zinc oxide (IGZO), ZnO, or TiO.sub.2 as a semiconductor layer, an organic thin film transistor using an organic material as a semiconductor layer, an amorphous silicon thin film transistor using amorphous silicon as a semiconductor layer, Or a polycrystalline silicon thin film transistor using polycrystalline silicon as a semiconductor layer.

The planarization layer may be formed by flattening the top surface of the thin film transistor and the circuit part by covering the thin film transistor and the circuit part, thereby forming the organic light emitting diode. The planarization layer may be formed of a spin-on-glass (SOG) film, a polyimide-based polymer, a polyacrylic polymer, or the like, but is not limited thereto.

The organic light emitting diode emits light by self-emission, and may include a first electrode, an organic light emitting layer, and a second electrode sequentially stacked. The adjacent organic light emitting diodes can be separated by an insulating film. The organic light emitting diode may include a bottom emission structure in which light generated in the organic emission layer is emitted through the bottom substrate, or a top emission structure in which light generated in the organic emission layer is emitted upward.

The protective film may cover the organic light emitting diode to protect the organic light emitting diode. The protective film may be formed of an inorganic material such as SiOx, SiNx, SiC, SiON, SiONC and aC (amorphous carbon) and an organic material such as (meth) acrylate, And the like. Specifically, the protective film may include an encapsulation layer in which a layer formed of an inorganic material and a layer formed of an organic material are sequentially stacked one or more times.

Referring again to FIG. 4, the adhesive layer 360 is formed of a pressure-sensitive adhesive composition comprising a (meth) acrylate resin, a curing agent, an initiator and a silane coupling agent to adhere the display portion 350a and the polarizing plate 370 .

The polarizing plate 370 can implement polarizing of the inner light or prevent reflection of the external light to realize the display or to increase the contrast ratio of the display. The polarizing plate may be composed of a polarizer alone. Or the polarizing plate may include a polarizing film and a protective film formed on one or both sides of the polarizing film. Or the polarizing plate may include a polarizer and a protective coating layer formed on one or both sides of the polarizer. The polarizer, the protective film, and the protective coating layer may be conventional ones known to those skilled in the art.

The touch screen panel 380 senses a change in capacitance generated when a conductor such as a human body or a stylus touches, and generates an electrical signal. The display unit 350a can be driven by this signal. The touch screen panel 380 is formed by patterning a flexible conductive conductive material. The touch screen panel 380 may include a first sensor electrode and a second sensor electrode formed between the first sensor electrode and the first sensor electrode. have. The conductor for the touch screen panel 380 may include, but is not limited to, metal nanowires, conductive polymers, carbon nanotubes, and the like.

The flexible window film 390 may be formed at the outermost portion of the flexible display device 300 to protect the display device.

Although not shown in FIG. 4, an adhesive layer is further formed between the polarizer 370 and the touch screen panel 380 and / or between the touch screen panel 380 and the flexible window film 390 to form a polarizing plate, a touch screen panel, It is possible to strengthen the bonding between the window films. The pressure-sensitive adhesive layer may be formed of a pressure-sensitive adhesive composition comprising a (meth) acrylate resin, a curing agent, an initiator, and a silane coupling agent. Further, although not shown in FIG. 3, a polarizing plate is further provided under the display unit 350a, so that polarized light can be realized.

Hereinafter, a flexible display device according to another embodiment of the present invention will be described with reference to FIG. 5 is a cross-sectional view of a flexible display device according to another embodiment of the present invention.

5, the flexible display device 400 according to another embodiment of the present invention includes a display portion 350a, a touch screen panel 380, a polarizer 370, and a flexible window film 390, The window film 390 may comprise a flexible window film according to embodiments of the present invention. Except that the touch screen panel 380 is not directly formed on the flexible window film 390 but the touch screen panel 380 is formed below the polarizer 370. In this case, Device. At this time, the touch screen panel 380 may be formed together with the display portion 350a. In this case, since the touch screen panel 380 is formed on the display unit 350a together with the display unit 350a, the thickness of the touch screen panel 380 can be thinner and brighter than that of the flexible display device according to an embodiment of the present invention. In this case, the touch screen panel 380 can be formed by deposition or the like, but is not limited thereto. Although not shown in FIG. 5, a gap between the display portion 350a and the touch screen panel 380 and / or between the touch screen panel 380 and the polarizer 370 and / or between the polarizer 370 and the flexible window film 390 An adhesive layer is further formed, thereby increasing the mechanical strength of the display device. The pressure-sensitive adhesive layer may be formed of a pressure-sensitive adhesive composition comprising a (meth) acrylate resin, a curing agent, an initiator, and a silane coupling agent. Although not shown in FIG. 5, a polarizing plate is further provided under the display unit 350a to thereby guide polarized light to improve the display image.

Hereinafter, a flexible display device according to another embodiment of the present invention will be described with reference to FIG. 6 is a cross-sectional view of a flexible display device according to another embodiment of the present invention. 6, the flexible display device 500 according to another exemplary embodiment of the present invention includes a display portion 350b, an adhesive layer 360, and a flexible window film 390. The flexible window film 390 includes a flexible window film 390, May comprise a flexible window film according to embodiments of the present invention. Is substantially the same as the flexible display device according to an embodiment of the present invention, except that only the display portion 350b is capable of driving the device and the polarizing plate and the touch screen panel are excluded.

The display portion 350b may include an LCD, an OLED, or an optical element including an LED element formed on the substrate, and the display portion 350b may have a touch screen panel formed therein.

Hereinafter, a method for producing a silicone resin of Formula 1 according to an embodiment of the present invention will be described.

A silicone resin of formula (1) (R ¹ SiO _3/2) silicone monomer alone, or (R ¹ SiO _3/2) a silicon monomer to provide a silicon monomer, ^{_{and, (R 2 SiO 3/2}} ) to provide that service , the (R ³ R ⁴ SiO _2/2) a silicon monomer providing a silicon monomer to provide ^{(R 5 R 6 R 7 SiO} 1/2), one or more of the silicone monomers to provide a (SiO _4/2) By hydrolysis and condensation reaction of the mixture containing it.

Silicone monomers to provide a (R ¹ SiO _3/2) may be used for products that are sold commercially and synthesized by a conventional method, or known to those skilled in the art. For example, by condensation reaction of a silicone monomer having an isocyanate group (NCO) and an alkoxysilane group with a (meth) acrylic monomer having a hydroxyl group and a (meth) acrylate group. The silicone monomer having an isocyanate group and an alkoxysilane group may include 3-isocyanatopropyltriethoxysilane and the like. Examples of the (meth) acrylic monomer having a hydroxyl group and a (meth) acrylate group include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and 4-hydroxybutyl . During the condensation reaction, the reaction rate can be increased by using a catalyst. For example, tin catalysts such as dibutyldilaurate, amine catalysts and the like.

(R ^₂ SiO ^_3/2) to provide a silicon monomer is a (meth) acrylate monomer having a silicon to one oxy-trimethoxysilane, 3- (meth) acrylic as 3- (meth) acryloxy-propyltriethoxysilane Ethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, and the like. (R ³ R ⁴ SiO _2/2 ) may include dimethyl dimethoxysilane and the like. (R ⁵ R ⁶ R ⁷ SiO _1/2 ) may include hexamethyldisiloxane, tetramethyldisiloxane, divinyltetramethyldisiloxane, chlorotrimethylsilane, dimethylvinylchlorosilane, and the like. (SiO _4/2) silicone monomer for the can to tetramethoxysilane, tetra-ethoxysilane and the like, tetra propoxy silane.

The hydrolysis and condensation reaction of the monomer mixture can be carried out according to a conventional method for producing a silicone resin. Hydrolysis may comprise reacting the monomer mixture with water and a mixture of one or more of the desired acids and bases. Specifically, the acid may be HCl, HNO ₃ , acetic acid, para-toluenesulfonic acid, and the base may be NaOH, KOH, or the like. The hydrolysis is carried out at 20 ° C to 100 ° C for 10 minutes to 10 hours, and the condensation reaction can be carried out at 20 ° C to 100 ° C for 10 minutes to 12 hours under the same conditions as the hydrolysis. The production yield of the silicone resin in the above range may be high.

Hereinafter, a method of manufacturing a window film according to an embodiment of the present invention will be described.

The flexible window film 100 can be manufactured by a method of manufacturing a flexible window film including coating and curing a composition for a window film according to embodiments of the present invention on a substrate layer 110. [

The method for coating the composition for a window film on the base layer 110 may be, but not limited to, bar coating, spin coating, dip coating, roll coating, flow coating, die coating and the like. A composition for a window film can be coated on the base layer 110 to a thickness of 5 to 100 mu m. It is possible to secure a desired coating layer within the above range, and to have an excellent hardness and flexibility. Curing is the curing of the composition for the window film to form a coating layer, which may include photo-curing. Photocuring may involve irradiation with light amount of 10mJ / cm ² to 1,000mJ / cm ² at a wavelength of 400nm or less. Within this range, the composition for a window film can be sufficiently cured. As described above, the composition for a window film of the present invention can produce a window film having sufficient hardness by photocuring only after photocuring and without additional heat treatment or aging, thereby improving the processability. The method may further include drying the composition for the window film before coating the composition for the window film on the substrate layer 110 and then curing the composition. By drying and curing, it is possible to prevent the surface roughness of the coating layer from becoming high due to long-time photocuring. The drying may be performed at 40 캜 to 200 캜 for 1 minute to 30 hours, but is not limited thereto.

Hereinafter, the present invention will be described in more detail by way of examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Manufacturing example 1: Silicon monomer

One mole of 3-isocyanatopropyltriethoxysilane (KBE-9007, Shinetu) and 1.05 mole of 2-hydroxyethyl acrylate (Aldrich) were placed in a 1 L 3-neck flask and toluene was added in the same amount as the monomer total. 2500 ppm of tin catalyst dibutyltin dilaurate relative to the monomer was added and stirred at room temperature for 8 hours. Toluene was added, and the mixture was washed with water and then concentrated to obtain a compound of the following chemical formula with a purity of 95% (by gas chromatography).

Manufacturing example 2: Silicon monomer

In the same manner as in Production Example 1, except that 1.05 mole of 4-hydroxybutyl acrylate (Aldrich) was used instead of 1.05 mole of 2-hydroxyethyl acrylate (Aldrich), the compound of the following formula was reacted with 95% &Lt; / RTI > by chromatography).

Example One

One mole of the silicone monomer prepared in Preparation Example 1 was placed in a 1 L 3-neck flask. Subsequently, 0.1 mol% of paratoluenesulfonic acid catalyst and 1.3 equivalents of water relative to the alkoxy group of the silicone monomer were slowly added to the mixture at room temperature, and the mixture was stirred at 50 캜 for 6 hours. After the solvent was replaced with methyl ethyl ketone, And then filtered through a filter to prepare a silicone resin (weight average molecular weight: 1800 mol / g) of the formula (1) in T units with ((X ₁ -Ety-O- (C═O) NH-Pry) SiO _3/2 .

(Manufactured by BASF) as a initiator, and BYK-3500 (BYK) as a leveling agent were added to the silicone resin of the above formula (1) as the crosslinking agent, urethane acrylate CHTU-9607 Unit: parts by weight), and methyl ethyl ketone was added as a solvent to prepare a composition for a window film having a solid content of 45% by weight.

The prepared composition for a window film was coated on a polyimide film (Samsung Advanced Institute of Technology, thickness: 80 탆), dried at 80 캜 for 2 minutes, irradiated with UV at 1000 mJ / cm ² to form a coating layer having a thickness of 10 탆 A window film was prepared.

Example 2

95 mol% of the silicone monomer prepared in Preparation Example 1 and 5 mol% of 3-acryloxypropyltrimethoxysilane (KBM 5103, Shinetsu) were placed in a 1 L 3-neck flask. Subsequently, 0.1 mol% of para-toluenesulfonic acid catalyst and 1.3 equivalents of water equivalent to the alkoxy groups of the entire silicon monomers were slowly added to the mixture at room temperature and stirred at 50 ° C for 6 hours. Subsequently, after solvent substitution with methyl ethyl ketone, the filter implemented in Teflon _{filter, ((X 1 -Ety-O-} (C = O) NH-Pry) SiO 3/2) 0.95 ((X 1 -Pry) SiO 3/2) 0.05 with T units and the T units (Weight average molecular weight: 1800 mol / g) represented by the following formula (1) was prepared.

Example 3

((X ₁ -Ety-O (C═O) NH 2) in Example 2, except that 80 mole% of the silicone monomer prepared in Preparation Example 1 and 20 mole% of 3-acryloxypropyltrimethoxysilane were used, (Weight average molecular weight: 1800 mol / g) having a unit of T and a unit of T in terms of (Tg-Pry) SiO _3/2 _0.80 ((X ₁ -Pry) SiO _3/2 ) _0.20 . A window film was prepared in the same manner as in Example 2 except that the silicone resin of Formula 1 was used.

Example 4

One mole of the silicone monomer prepared in Preparation Example 1 was placed in a 1 L 3-neck flask. Subsequently, 0.1 mol% of para-toluenesulfonic acid catalyst and 1.3 equivalents of water equivalent to the alkoxy group of the silicone monomer were slowly added to the mixture at room temperature and stirred at 50 ° C for 6 hours. Then, volatile components were removed by using a vacuum pump, 378.22 g of toluene, disiloxane 0.1mole% (Aldrich社) the input after stirring at 50 ℃ for 3 hours, after solvent replacement with methyl ethyl ketone to a filter carried by the pore size 0.1㎛ Teflon filter, end-capping trimethylsilyl group ((X ₁ -Ety (Weight-average molecular weight: 2500 mol / g) of the following formula 1-1-4 of -O (C = O) NH-Pry) SiO _3/2 .

&Lt; Formula 1-1-4 &

A window film was prepared in the same manner as in Example 1 except that the silicone resin of Formula 1 was used.

Example 5

One mole of the silicone monomer prepared in Preparation Example 2 was placed in a 1 L 3-neck flask. Subsequently, 0.1 mol% of paratoluenesulfonic acid catalyst and 1.3 equivalents of water relative to the alkoxy group of the silicone monomer were slowly added to the mixture at room temperature, and the mixture was stirred at 50 캜 for 6 hours. After the solvent was replaced with methyl ethyl ketone, (Weight average molecular weight: 1900 mol / g) of T in the unit of ((X ₁ -Buty-O (C═O) NH-Pry) SiO _3/2 .

Example 6

(1 mol of the silicone monomer prepared in Production Example 1, MA-ST (Nissan SiO ₂ (30% by weight), average particle diameter (D50): 10 nm to 15 nm)) were charged into a 1 L 3-neck flask. Then, 5 g of a 0.1N HCl catalyst and 1 equivalent of water relative to the alkoxy group of the silicone monomer were slowly added to the mixture at room temperature, followed by stirring at 50 ° C for 6 hours. Removed after hwibalbunreul filter with a pore size 1㎛ Teflon filter, followed by solvent replacement with methyl ethyl ketone, it is adsorbed on the silica surface _{((X 1 -Ety-O- (} C = O) NH-Pry) SiO 3/2) complex _{and, ((X 1 -Ety-O-} (C = O) NH-Pry) SiO 3/2) formula silicone resin (weight-average molecular weight: 1400mol / g) of 1 of the mixture was prepared. The silica in the mixture is contained in an amount of 30% by weight.

The mixture containing the silicone resin of the above formula (1), urethane acrylate AN-9696 (Camton Company) as a crosslinking agent, Irgacure-184 (BASF) as a photo-radical initiator as a initiator, and BYK-3500 2 (unit: parts by weight), and methyl ethyl ketone was added as a solvent to prepare a composition for a window film having a solid content of 45% by weight.

Example 7

(1 mol of the silicone monomer prepared in Preparation Example 1, MA-ST (Nissan SiO ₂ (30% by weight), average particle diameter (D50): 10 nm to 15 nm)) was charged into a 1 L 3-neck flask. Then, 5 g of a 0.1N HCl catalyst and 1 equivalent of water relative to the alkoxy group of the silicone monomer were slowly added to the mixture at room temperature, followed by stirring at 50 ° C for 6 hours. Removed after hwibalbunreul filter with a pore size 1㎛ Teflon filter, followed by solvent replacement with methyl ethyl ketone, it is adsorbed on the silica surface _{((X 1 -Ety-O- (} C = O) NH-Pry) SiO 3/2) complex _{and, ((X 1 -Ety-O-} (C = O) NH-Pry) SiO 3/2) formula (1) silicone resin (weight-average molecular weight: 1400mol / g) of the mixture was prepared. The silica in the mixture is contained in an amount of 40% by weight.

A window film was prepared in the same manner as in Example 6 using the mixture containing the silicone resin of the formula (1).

Example 8

(1 mol of the silicone monomer prepared in Preparation Example 1, MA-ST (Nissan SiO ₂ (30% by weight), average particle diameter (D50): 10 nm to 15 nm)) was placed in a 1 L 3-neck flask at a ratio of 841.60 g. Then, 5 g of a 0.1N HCl catalyst and 1 equivalent of water relative to the alkoxy group of the silicone monomer were slowly added to the mixture at room temperature, followed by stirring at 50 ° C for 6 hours. Removed after hwibalbunreul filter with a pore size 1㎛ Teflon filter, followed by solvent replacement with methyl ethyl ketone, it is adsorbed on the silica surface _{((X 1 -Ety-O- (} C = O) NH-Pry) SiO 3/2) complex _{and, ((X 1 -Ety-O-} (C = O) NH-Pry) SiO 3/2) formula (1) silicone resin (weight-average molecular weight: 1400mol / g) of the mixture was prepared. The silica in the mixture is contained in an amount of 50% by weight.

Comparative Example One

A light radical initiator Irgacure-184 (BASF) as a initiator, and BYK-3500 (BYK) as a leveling agent were mixed in the same manner as in Example 1 except that the urethane acrylate CHTU-9607 (Camaton Company), urethane acrylate AN-9696 (Unit: parts by weight), and methyl ethyl ketone was added as a solvent to prepare a composition for a window film having a solid content of 45% by weight. The prepared composition for a window film was coated on a polyimide film (Samsung Advanced Institute of Technology, thickness: 80 탆), dried at 80 캜 for 2 minutes, irradiated with UV at 1000 mJ / cm ² to form a coating layer having a thickness of 10 탆 A window film was prepared.

Comparative Example 2

3-acryloxypropyltrimethoxysilane (KBM 5103, Shin-Etsu) was placed in a 1 L 3-neck flask. Subsequently, 0.1 mol% of para-toluenesulfonic acid catalyst and 1.3 equivalents of water equivalent to the alkoxy groups of the entire silicon monomers were slowly added to the mixture at room temperature and stirred at 50 ° C for 6 hours. Subsequently, after solvent substitution with methyl ethyl ketone, the filter implemented in Teflon _{filter, ((X 1 -Pry) SiO} 3/2) with the silicone resin (weight-average molecular weight: 1800mol / g) was prepared.

(Manufactured by BASF) as a crosslinking agent, urethane acrylate CHTU-9607 (manufactured by CAMTON Co., Ltd.) as a crosslinking agent, BYC-3500 (BYK) as a leveling agent as a initiator, Irgacure- By weight), and methyl ethyl ketone was added as a solvent to prepare a composition for a window film having a solid content of 45% by weight. A window film was prepared in the same manner as in Example 1 except that the composition for a window film was used.

The following properties of the window films prepared in Examples and Comparative Examples were measured and shown in Tables 1 and 2 below.

(1) Pencil hardness: Measured by the JIS K5400 method using a pencil hardness meter (Heidon) for the coating layer of the window film. In the pencil hardness measurement, a pencil was used from Mitsubishi's 6B to 9H pencil. The load of the pencil on the coating layer was 1 kg, the angle of drawing the pencil was 45 °, and the drawing speed of the pencil was 60 mm / min. 5 times, and when a scratch occurs more than once, it is measured by using a pencil of the pencil hardness level, and when it is 5 times of the evaluation, it is the maximum pencil hardness value when there is no scratch.

(2) Curling: Referring to FIG. 7, the window film 1 prepared in Examples and Comparative Example in which the thickness of the base layer was 80 μm and the thickness of the coating layer was 10 μm was cut into a width x length (10 cm x 10 cm) And the maximum height H from the bottom surface 2 to the edge portion of the flexible window film 1 when the window coating layer is placed on the bottom surface 2 at the top and left at 25 ° C and 40% And the average value was calculated. In the curled display, "+" means that the window film is dried toward the coating layer, and "-" means that the window film is dried toward the substrate layer. The lower the absolute value of the curl value, the lower the curl value.

(3) Curvature radius: A window film (width x length x thickness, 3 cm x 15 cm x 90 m) was wound around a curvature testing JIG (CFT-200R, COVOTECH) Whether or not a crack occurred was visually evaluated. At this time, the substrate layer was brought into contact with the JIG. The radius of curvature was measured by gradually decreasing the diameter of the JIG starting from the maximum radius of the JIG, and the minimum radius of the JIG without cracking was determined by the radius of curvature in the tensile direction.

Example 1 Example 2 Example 3 Example 4 Example 5 The silicone resin of formula (1) 80 80 80 80 80 Cross-linking agent CHTU-9607 20 20 20 20 20 AN-9696 - - - - - Initiator Irgacure-184 2 2 2 2 2 Leveling agent BYK-3500 0.1 0.1 0.1 0.1 0.1 Pencil hardness 3H 3H 3H 3H 3H Curling (mm) 0 +1 +2 0 0 Radius of curvature (mm) 1.5 1.8 2 1.5 1.2

Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 The silicone resin of formula (1) 50 50 50 - - A silicone resin and a silica complex of formula (1); (% By weight) of the silica in the mixture of the silicone resin of the formula (1) 30 40 50 - - Silicone resin - - - - 80 Cross-linking agent CHTU-9607 - - - 50 20 AN-9696 50 50 50 50 - Initiator Irgacure-184 2 2 2 2 2 Leveling agent BYK-3500 0.1 0.1 0.1 0.1 0.1 Pencil hardness 3H 3H 3H 2H 3H Curling (mm) 0 +1 +1 +5 +10 Radius of curvature (mm) One 1.5 1.8 5 8

As shown in Tables 1 and 2, the flexible window film of the present invention has excellent hardness and flexibility when the window film is folded toward the substrate layer because the radius of curvature is low. Further, the flexible window film of the present invention has a low curling degree.

On the other hand, Comparative Example 1 and Comparative Example 2, which do not include the silicone resin of Formula 1 of the present invention, have a problem of curvature radius and curling.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

A composition for a window film comprising a silicone resin of the following formula (1), a crosslinking agent and an initiator:
(R ¹ SiO _3/2 ) _x (R ² SiO _3/2 ) _y (R ³ R ⁴ SiO _2/2 ) _z (R ⁵ R ⁶ R ⁷ SiO _1/2 ) _w (SiO _4/2 ) _v
(In the formula 1,
R ¹ is a monovalent organic group having at least one (meth) acrylate group and at least one urethane group,
R ² is a non-urethane-based monovalent organic group having at least one (meth) acrylate group, an unsubstituted or substituted C 1 to C 20 alkyl group, an unsubstituted or substituted C 5 to C 20 cycloalkyl group, A C6 to C30 aryl group,
R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent hydrogen, a monovalent organic group having at least one (meth) acrylate group, an unsubstituted or substituted C 1 to C 20 alkyl group, A substituted or unsubstituted C2 to C20 alkenyl group, an unsubstituted or substituted C5 to C20 cycloalkyl group, or an unsubstituted or substituted C6 to C30 aryl group,
0 < v < 1, x + y + z + w + v = 1).

The composition for a window film according to claim 1, wherein the silicone resin of Formula 1 is a silicone resin having a T unit represented by Formula 1-1:
&Lt; Formula 1-1 >
^{_{(R 1 SiO 3/2)}} x
(Wherein R ¹ is as defined in Formula 1, and x is 1).

The composition for a window film according to claim 1, wherein the silicone resin of Formula 1 is a silicone resin having T units and T units represented by Formula 1-2:
(1-2)
(R ¹ SiO _3/2 ) _x (R ² SiO _3/2 ) _y
(Wherein R ¹ and R ² are the same as defined in Formula 1 and 0 <x <1, 0 <y <1, x + y = 1).

The composition for a window film according to claim 3, wherein in the formula 1-2, 0.20? X? 0.99, 0.01? Y? 0.80, and x + y =

The composition for a window film according to claim 1, wherein the cross-linking agent comprises a (meth) acrylate-based monomer having a urethane group.

[2] The method of claim 1, wherein the silicone resin of Formula 1 is contained in an amount of 20 to 90 parts by weight, and the crosslinking agent is contained in an amount of 10 to 80 parts by weight based on 100 parts by weight of the total of the silicone resin and the cross- / RTI >

The composition for a window film according to claim 1, wherein the composition for a window film further comprises nanoparticles.

The composition for a window film according to claim 7, wherein the nanoparticles are surface-treated with a (meth) acrylate group.

The composition for a window film according to claim 7, wherein at least a part of the silicone resin of Formula 1 is bonded to the nanoparticles to form a composite.

The composition for a window film according to claim 9, wherein the composition for a window film comprises a mixture of the silicone resin of the formula (1) and the composite.

The composition for a window film according to claim 10, wherein the nanoparticles in the mixture comprise 0.1 wt% to 60 wt%.

8. The composition of claim 7, wherein the nanoparticles comprise silica.

The composition for a window film according to claim 1, wherein the silicone resin of formula (1) is end-capped.

The composition for a window film according to claim 1, wherein the silicone resin of Formula 1 further comprises a silicone resin having an epoxy group.

The composition for a window film according to claim 1, wherein the composition for a window film comprises at least one additive selected from UV absorbers, reaction inhibitors, adhesion improvers, thixotropic agents, conductivity imparting agents, colorant adjusting agents, stabilizers, antistatic agents, antioxidants, &Lt; / RTI >

And a coating layer formed on the substrate layer, wherein the flexible window film has a pencil hardness of 3H or more and a tensile direction radius of curvature of 5.0 mm or less.

The flexible window film of claim 16, wherein the coating layer is formed from the composition for a window film of any one of claims 1 to 15.