KR20140125779A - Film for optical applications, and display device - Google Patents

Abstract

An optical film in which a resin layer containing a cured product of a curable resin composition is formed on at least one side of a substrate, wherein the curable resin composition has two or more groups represented by the general formula (1) A polymerizable compound (A) containing no alkylene oxide unit, a polymerizable compound (B) having three or more groups represented by the following general formula (2), and a polymerization initiator (C) (A) / (B)] of the component (A) and the component (B) is 15/85 to 85/15, the adhesiveness to the printing material and the adhesion to the pressure- It has excellent scratch-preventive performance because of its high surface hardness, and has excellent durability in which these properties are maintained even if left in an environment of high temperature and high humidity for a long time.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical film and a display device,

The present invention relates to an optical film and a display device using the optical film.

In many cases, an HC film having a hard coat layer (hereinafter also referred to as " HC ") is pasted through a pressure-sensitive adhesive for the purpose of preventing scratches on the surface of a mobile device such as a cellular phone. In addition, on the HC layer surface of the HC film, edible printing may be performed for the purpose of enhancing the design of the surface of the mobile device.

Since the HC layer is composed of a resin layer crosslinked at high density by polymerization of a large number of unsaturated bonds, the adhesion of the printing material such as ink to the HC layer tends to be low.

A material for forming the HC layer may be blended with a leveling agent such as silicone or fluorine for the purpose of smoothing the surface of the formed HC layer or improving the coating property. Generally, when a leveling agent such as a silicon-based or fluorine-based compound is blended, the surface of the formed HC layer becomes low in polarity, so that the affinity with the printing material is lowered and the adhesion with the printing material is lowered.

In order to solve the above problem, various proposals have been made.

For example, Patent Document 1 discloses a HC film having an HC layer having excellent scratch resistance and printability, which comprises a photopolymerization initiator, a (meth) acrylate monomer and a (meth) acryl monomer having an alkylamide group And / or a HC layer containing a phosphate (meth) acrylate in a specific mass ratio.

Patent Document 2 discloses an HC film which can be directly printed on an HC layer by a heat transfer printing method using a thermal transfer printer. In order to provide an HC film capable of printing directly on the HC layer, Discloses an HC film in which an HC layer having a tensile strength of not less than a specific value is formed.

Japanese Laid-Open Patent Publication No. 2009-161609 Japanese Laid-Open Patent Publication No. 2011-110902

However, even if a special monomer such as a (meth) acrylate monomer having an alkylamide group is used as a material for forming the HC layer as in Patent Document 1, the effect of improving the adhesion of the formed HC layer to the printing material It is insufficient.

Also, in Patent Document 2, there is no disclosure of concrete means for making the surface tension of the HC layer surface to a specific value or more.

In addition, when the HC film is used in a liquid crystal display, a liquid crystal display usually has a multilayer structure between the substrate and the liquid crystal in order to improve various optical elements. Therefore, the HC film used in the liquid crystal display is often pasted to another layer (a layer made of an optical film) via a layer made of an adhesive.

However, an HC layer of a general HC film is required to have an HC layer having an HC layer capable of improving adhesion with a pressure-sensitive adhesive, because the HC layer of the general HC film is poor in adhesiveness to a pressure-sensitive adhesive for the same reason as adhesion to a printing material is low.

An object of the present invention is to provide an optical recording medium having excellent durability in which these properties are maintained even if they are left in a high temperature and high humidity environment for a long period of time and have good scratch resistance due to high surface hardness, And a display device using the optical film.

As a result of intensive studies, the present inventors have found that, as a curable resin composition for forming a resin layer of an optical film serving as an HC layer, a resin composition containing a specific proportion of two kinds of polymerizable compounds having a specific structure And finding the solution to the above-mentioned problems, thereby leading to the present invention.

That is, the present invention provides the following [1] to [8].

[1] An optical film on which a resin layer containing a cured product of a curable resin composition is formed on at least one side of a substrate,

Wherein the curable resin composition comprises a polymerizable compound (A) having two or more groups represented by the following formula (1) in one molecule and not containing an alkylene oxide unit in the remaining structure excluding the group, (A) / (B)] of the component (A) and the component (B) is 15/50, the polymerizable compound (B) having a group represented by the following general formula (2) 85 to 85/15.

[Chemical Formula 1]

[In the above formula (1), each R independently represents a hydrogen atom or a methyl group, and * represents a bonding moiety.]

(2)

[In the formula (2), each R ¹ independently represents a hydrogen atom or a methyl group, and each A independently represents an alkylene group having 1 to 5 carbon atoms. n is independently an integer of 1 or more. * Represents a bonding part.]

[2] The optical film according to the above [1], wherein the sum of n in the general formula (2) in the molecule of the polymerizable compound (B) is 4 to 20.

[3] The optical film according to the above [1] or [2], wherein in the general formula (2), each A is independently an ethylene group or a propylene group.

[4] The optical film according to any one of [1] to [3], wherein the curable resin composition further contains a leveling agent (D).

[5] The optical film according to any one of [1] to [4], wherein the resin layer has a surface tension of 30 mN / m or more.

[6] The optical film according to any one of [1] to [5], wherein a resin layer containing a cured product of the curable resin composition is formed on both surfaces of the substrate.

[7] The optical film according to any one of [1] to [6], wherein the pressure-sensitive adhesive layer comprises a pressure-sensitive adhesive layer on at least one side of the substrate opposite to the side on which the resin layer is formed and on the same side.

[8] A display device using the optical film according to any one of [1] to [7].

The optical film of the present invention is excellent in adhesiveness to a printing material and adhesion to a pressure-sensitive adhesive, and also has good scratch-preventive performance because of its high surface hardness. Even if it is left in an environment of high temperature and high humidity for a long time, And has excellent durability.

1 is a cross-sectional view of an optical film on which a resin layer is formed on one side of a substrate, which is the first embodiment of the optical film of the present invention.
Fig. 2 is a sectional view of an optical film in which a resin layer is formed on both surfaces of a substrate, which is a second embodiment of the optical film of the present invention.
3 is a cross-sectional view of an optical film having a pressure-sensitive adhesive layer as a third embodiment of the optical film of the present invention.
4 is a cross-sectional view of an optical film having a pressure-sensitive adhesive layer as a fourth embodiment of the optical film of the present invention.

[Optical Film]

In the optical film of the present invention, a resin layer containing a cured product of the curable resin composition is formed on at least one side of the substrate. The optical film of the present invention is not limited to the optical film 1 having the resin layer 12 formed on one side of the base material 11 as shown in Fig. 11 includes an optical film 2 on which resin layers 12a, 12b containing a cured product of the curable resin composition are formed.

The optical film of the present invention may be an optical film having a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive on the side opposite to the side where the resin layer of the base is formed and on at least one side of the same side.

That is, the position of the pressure-sensitive adhesive layer may be formed on the surface of the resin layer opposite to the surface on which the resin layer is formed, or may be formed on both sides of the resin layer and on the surface of the resin layer .

Fig. 3 shows an example of the constitution of an optical film of the present invention having a pressure-sensitive adhesive layer. The optical film 1a shown in Fig. 3 (a) is an optical film having a pressure-sensitive adhesive layer 13 on a surface of the substrate 11 opposite to the surface on which the resin layer 12 is formed. The optical film 1b in Fig. 3 (b) is an optical film having a pressure-sensitive adhesive layer 13 on a surface of the substrate 11 on the same side as the surface on which the resin layer 12 is formed, 12 on the surface of the pressure-sensitive adhesive layer 13. The optical film 1c in Fig. 3 (c) has the pressure-sensitive adhesive layers 13a and 13b on both sides of the base 11 on the same side as the side on which the resin layer 12 is formed and on the opposite side The optical film has a pressure-sensitive adhesive layer 13a on the surface of the resin layer 12 and a pressure-sensitive adhesive layer 13b on the surface of the substrate 11 opposite to the surface on which the resin layer 12 is formed.

When the pressure-sensitive adhesive layer is exposed, a release material may be further laminated on the pressure-sensitive adhesive layer.

The optical film on which the resin layer is formed on both surfaces of the substrate may also have a pressure-sensitive adhesive layer on the surface of each resin layer. The constitution of the optical film on which such a pressure-sensitive adhesive layer is formed includes, for example, the constitution of the optical films 2a and 2b shown in Fig. The optical film 2a has resin layers 12a and 12b formed on both surfaces of the substrate 11 and further has a pressure-sensitive adhesive layer 13 only on the surface of the resin layer 12b. On the other hand, the optical film 2b has pressure-sensitive adhesive layers 13a and 13b on both surfaces of the resin layers 12a and 12b formed on both surfaces of the substrate 11. [

Hereinafter, components of the optical film of the present invention will be described.

[materials]

The substrate used in the present invention is not particularly limited as long as it can be used as an optical film.

Examples of the material constituting such a base material include polyethylene terephthalate (PET), polyethylene naphthalate, polyimide, polyetherimide, polyaramid, polyetherketone, polyetheretherketone, polyphenylene sulfide, poly (4-methylpentene-1), polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyurethane, ethylene-vinyl acetate copolymer, ) Acrylic acid copolymer, polystyrene, polycarbonate, fluororesin, low-density polyethylene, linear low-density polyethylene, triacetylcellulose and the like.

Of these, polyethylene terephthalate is preferable from the viewpoints of optical properties such as workability and transparency, versatility and cost.

The surface of the substrate may be subjected to an easy adhesion treatment such as primer treatment or corona treatment.

The thickness of the substrate is appropriately selected depending on the application, but is preferably 5 to 300 占 퐉, more preferably 10 to 200 占 퐉, and still more preferably 20 to 100 占 퐉.

[Resin Layer]

The resin layer constituting the optical film of the present invention is a layer containing a cured product of a curable resin composition containing the components (A) to (C) (hereinafter, simply referred to as " resin composition "

The resin layer may contain a resin component other than the cured product of the curable resin composition.

The content of the cured product of the curable resin composition in the resin layer is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and still more preferably 90 to 100% by mass with respect to the total mass of the resin layer %, Still more preferably 100% by mass.

The curable resin composition used in the present invention is a polymerizable compound having two or more groups represented by the above-mentioned general formula (1) in one molecule and containing no alkylene oxide units in the remaining structure except for the group, A polymerizable compound (B) having three or more groups represented by the above-mentioned general formula (2) in the molecule, and a polymerization initiator (C).

The resin composition may further contain a leveling agent (D) or other additives.

The resin composition used in the present invention contains the polymerizable compound (B) together with the polymerizable compound (A), thereby increasing the surface hardness of the resin layer formed from the resin composition to improve the durability, The adhesion with the material and the adhesion with the pressure-sensitive adhesive can be made good.

(Component (A): a polymerizable compound (A) having two or more groups represented by the general formula (1) in one molecule and not containing an alkylene oxide unit in the remaining structure excluding the group)

The resin composition used in the present invention contains two or more groups represented by the following general formula (1) in one molecule and further contains a polymerizable compound (A) which does not contain an alkylene oxide unit in the remaining structure excluding the group . By containing the polymerizable compound (A), the surface hardness of the resin layer formed from the resin composition can be increased. Further, the durability of the resin layer may be improved.

(3)

[In the above formula (1), each R independently represents a hydrogen atom or a methyl group, and * represents a bonding moiety.]

The number of groups represented by the general formula (1) in one molecule of the polymerizable compound (A) is 2 or more, preferably 2 to 16, more preferably 2 to 12, 3 to 10, and even more preferably 3 to 8.

When the number of the groups is less than 2, a sufficient crosslinking structure is not formed and the surface hardness of the resin layer formed from the resin composition tends to be lowered.

On the other hand, when the number of the groups is 16 or less, it is preferable because the crosslinking density becomes excessively high and the printing properties and adhesion of the resin layer formed from the resin composition can be suppressed from deteriorating. In addition, the occurrence of curl due to curing shrinkage can be suppressed.

The polymerizable compound (A) is a compound which does not contain an alkylene oxide unit in the remaining structure except for the group represented by the general formula (1). A compound containing an alkylene oxide unit has a long chain length of an alkylene oxide structure, so that the distance between crosslinking points becomes long, and the structure of the entire resin layer formed from the resin composition tends to be impaired. As a result, Resulting in a decrease in surface hardness. Thus, in the present invention, as the component (A), it is considered that by using a polymerizable compound containing no alkylene oxide unit, the surface hardness of the resin layer formed from the resin composition is increased.

Examples of such a polymerizable compound (A) include, for example, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin tri (meth) acrylate, ethylene glycol di (meth) acrylate, 1,3-butanediol di (Meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (Meth) acrylate, oligoether (meth) acrylate, oligoester (meth) acrylate having an alkylene oxide unit and a group represented by the following formula (Meth) acrylates, and oligoepoxy (meth) acrylates.

These (A) components may be used alone or in combination of two or more.

Among these, pentaerythritol tri (meth) acrylate and dipentaerythritol hexa (meth) acrylate and glycerin tri (meth) acrylate are preferable.

(Component (B): a polymerizable compound (B) having three or more groups represented by the general formula (2) in one molecule)

The resin composition used in the present invention contains a polymerizable compound (B) having three or more groups represented by the following formula (2) in one molecule.

 By containing the polymerizable compound (B) having three or more groups in which the (meth) acryloyl group represented by the general formula (2) is directly bonded to the alkylene oxide chain together with the component (A) It is considered that the crosslinking density of the resin layer to be formed can be appropriately lowered so that the resin layer is provided with a polarity while maintaining a certain degree of surface hardness so as to improve the adhesiveness to the printing material and the adhesiveness to the pressure-

[Chemical Formula 4]

In the general formula (2), each R ¹ independently represents a hydrogen atom or a methyl group. In addition, * represents a bonding portion.

A independently represents an alkylene group having 1 to 5 carbon atoms, but an ethylene group or a propylene group is preferable, and an ethylene group is more preferable. By the alkylene group as A, the crosslinking density of the resin layer formed from the resin composition can be suitably lowered, so that the adhesion to the printing material and the adhesion to the pressure-sensitive adhesive can be improved.

The content of the ethylene oxide unit relative to the total alkylene oxide units contained in one molecule of the polymerizable compound (B) is preferably from 60 to 80% by weight, 100 mol%, more preferably 75 mol% to 100 mol%, still more preferably 85 mol% to 100 mol%, still more preferably 95 mol% to 100 mol%.

n represents the number of alkylene oxide units and is independently an integer of 1 or more.

The total value of n in the formula (2) (the total number of alkylene oxide units in one molecule of the polymerizable compound (B)) in one molecule of the polymerizable compound (B) is 3 or more, Preferably from 4 to 20, more preferably from 6 to 16, and even more preferably from 8 to 16, from the viewpoints of improving the adhesiveness of the obtained optical film to the printing material and the adhesion to the pressure-sensitive adhesive, 14.

When the total value is 4 or more, the cross-linking density of the resin layer formed from the resin composition is appropriately lowered, and the adhesiveness to the printing material and the adhesion to the pressure-sensitive adhesive can be improved.

On the other hand, if the total value is 20 or less, the crosslinking density is not excessively lowered, so that a certain degree of surface hardness can be maintained.

The number of groups represented by the general formula (2) in one molecule of the polymerizable compound (B) is 3 or more, preferably 3 to 16, more preferably 3 to 12, Preferably 3 to 10, more preferably 3 to 8, particularly preferably 5 to 8.

When the number of the groups is less than 3, the crosslinking density of the resin layer formed from the resin composition is lowered and the surface hardness is lowered, which is not preferable. Moreover, the durability of the resin layer deteriorates.

On the other hand, if it is 16 or less, it is preferable because the crosslinking density can be suppressed from lowering due to excessively high printing characteristics and adhesion.

Examples of such a polymerizable compound (B) include alkylene oxide-modified glycerin tri (meth) acrylate, alkylene oxide-modified dipentaerythritol tetra (meth) acrylate, alkylene oxide-modified dipentaerythritol hexa (Meth) acrylate, and the like.

These (B) components may be used alone or in combination of two or more.

(A) / (B)) of the component (A) and the component (B) in the resin composition used in the present invention is 15/85 to 85/15, but preferably 20/80 to 80/20 , More preferably 28/72 to 72/28, still more preferably 35/65 to 65/35, still more preferably 41/59 to 59/41, still more preferably 46/54 to 54/46 .

When the mass ratio is less than 15/85, the amount of the component (B) is excessively large, which is not preferable because the surface hardness of the resin layer formed from the resin composition is lowered. In addition, the durability of the resin layer tends to be lowered.

On the other hand, if the mass ratio exceeds 85/15, the amount of the component (A) is excessively large, so that the adhesion of the resin layer formed from the resin composition to the printing material and the adhesion to the pressure-sensitive adhesive is inferior.

The total content of the component (A) and the component (B) with respect to the total components contained in the resin composition used in the present invention is preferably 70 to 99.9% by mass, more preferably 80 to 99% by mass, Is 90 to 98% by mass.

(Component (C): polymerization initiator)

The polymerization initiator (C) used in the present invention is not particularly limited as long as it accelerates the polymerization reaction of the polymerizable compound of the component (A) and the component (B), and any of a photopolymerization initiator and a thermal polymerization initiator may be used. .

Examples of the photopolymerization initiator include acetophenone, benzophenone, benzoin, thioxanthone and imidazole-based photopolymerization initiators.

Examples of the acetophenone-based photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methylpropan- -2 - [(4-methylphenyl) methyl] -1- [4- (4-morpholino) 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one, 2- Hydroxy-2-methyl-1-phenylpropan-1-one and 2-hydroxy-1- {4- [4- (2- Methyl propane-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one and the like.

Examples of the benzophenone-based photopolymerization initiator include benzophenone, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenylsulfide, 3,3 ', 4,4'- Oxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, and 4,4'-bis-dimethylaminobenzophenone.

Examples of the benzoin-based photopolymerization initiator include benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin, benzoin compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether and benzoin phenyl ether Phosphorus ether compounds and the like.

Examples of the thioxanthene photopolymerization initiator include, for example, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 1-chloro- , 2,4-dichlorothioxanthone, and the like.

Examples of the imidazole-based photopolymerization initiator include 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylbisimidazolyl, 2,2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetra- (p-methoxyphenyl) bisimidazolyl, 2,2'-bis -Tetraphenyl-1,2'-biimidazole, and the like.

These photopolymerization initiators may be used alone or in combination of two or more.

Examples of the thermal polymerization initiator include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (2-ethoxyethyl ) Peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxybenzalate, t-hexyl peroxy pivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide , Organic peroxides such as lauroyl peroxide and diacetyl peroxide, organic peroxides such as 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis Azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile) , Dimethyl 2,2'-azobis (2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile ), 2,2'-azobis And [2- (2-imidazolin-2-yl) propane].

These thermal polymerization initiators may be used alone or in combination of two or more.

Among these polymerization initiators, a photopolymerization initiator is preferable from the viewpoint of reactivity, and an acetophenone-based photopolymerization initiator is more preferable.

The blending amount of the polymerization initiator (C) is preferably from 0.1 to 30 parts by mass, more preferably from 1 to 20 parts by mass, and still more preferably from 3 to 20 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B) 15 parts by mass, still more preferably 3.5 parts by mass to 8 parts by mass.

(Component (D): leveling agent)

The resin composition used in the present invention preferably further contains a leveling agent (D) in order to improve the smoothness and coatability of the resulting HC layer.

Examples of the leveling agent (D) include acrylic leveling agents, silicone leveling agents, fluorine leveling agents, acrylic leveling agents, vinyl leveling agents and siloxane modified acrylic leveling agents.

As the silicone leveling agent, a copolymer of polyoxyalkylene and polydimethylsiloxane can be used. Examples of commercially available silicone leveling agents include KP321, KP323, KP324, KP326, KP340 and KP341 (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) such as FZ-2118, FZ-77 and FZ-2161 (trade name, BYK-300, BYK-302, BYK-306, BYK (trade name, manufactured by Momentive Performance Materials, Japan Joint-stock Company), etc., TSF4440, TSF4441, TSF4445, TSF4450, TSF4446, TSF4452, TSF4453, TSF4460 -307, BYK-320, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-341, BYK-344, BYK-345, BYK-346, , Polyether-modified silicone oil (polyoxyalkylene-modified silicone oil) such as BYK-378, BYK-UV3500, BYK-3510 and BYK-3570 (manufactured by Big Chem Japan Co., Ltd.).

As the fluorine leveling agent, a copolymer of polyoxyalkylene and fluorocarbon can be used. Examples of commercially available fluorine leveling agents include MEGAFAC series manufactured by DIC Corporation, FC series manufactured by Sumitomo 3M Co., Ltd., and the like.

BYK-381, BYK-381, and BYK-392 (trade names, manufactured by Big Chem Japan Co., Ltd.) were used as commercial products of acrylic leveling agents, such as BYK-350, BYK-352, BYK-354, BYK-355, BYK358N, BYK- And the like.

As a commercially available product of the siloxane-modified acrylic leveling agent, BYK-3550 (trade name, manufactured by Big Chem Japan Co., Ltd.) and the like can be mentioned.

These leveling agents may be used alone or in combination of two or more.

Of these, an acrylic leveling agent or a siloxane-modified acrylic leveling agent is preferred from the viewpoint of improving the smoothness and the coatability of the resin layer formed from the resin composition, and a siloxane-modified acrylic leveling agent is more preferable.

The blending amount of the leveling agent (D) is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, further preferably 0.06 to 5 parts by mass based on 100 parts by mass of the total amount of the components (A) and (B) 3 parts by mass.

(Other additives)

The resin composition used in the present invention may contain other additives other than the above insofar as the effect of the present invention is not impaired.

Examples of such an additive include a defoaming agent, a thickener, a surfactant, an organic lubricant, an organic fine particle, an inorganic fine particle, an antioxidant, an ultraviolet absorber, a foaming agent, a dye, a pigment and an antistatic agent.

When the other additives are incorporated, the total amount of the additive is preferably 0.01 to 10% by mass, more preferably 0.1 to 7% by mass, further preferably 0.3 to 3% by mass, relative to the total components contained in the resin composition, to be.

(Method of forming resin layer)

The resin composition used in the present invention may be further diluted with an organic solvent to prepare a coating liquid for forming a resin layer in order to facilitate application to the substrate and to improve workability.

Examples of the organic solvent include organic solvents such as methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, isopropanol, propylene glycol monomethyl ether, .

The solid content concentration of the coating liquid for forming the resin layer is preferably 10 to 60 mass%, more preferably 10 to 45 mass%, and still more preferably 15 to 30 mass%. When the amount is 10% by mass or more, the amount of the solvent used is sufficient, and when it is 60% by mass or less, a suitable viscosity is obtained and the coating operation becomes easy.

As a method for applying the coating liquid for forming a resin layer to a substrate, known methods can be used. For example, a gravure coating method, a bar coating method, a spray coating method, a spin coating method, a roll coating method, A knife coating method, an air knife coating method, and a curtain coating method.

It is preferable to dry the formed coating film at a temperature of about 80 캜 to 150 캜 for about 30 seconds to 5 minutes from the viewpoint of preventing the solvent and the low boiling point component from remaining after the coating liquid is applied by applying the coating liquid Do.

The resin layer can be formed by curing the coating film.

In the case of using a photopolymerization initiator as the component (C), the photopolymerization initiator can be cured by irradiation of an active energy ray, and when a thermal polymerization initiator is used as the component (C), the reaction can be proceeded by heating. Or may be used in combination.

Examples of the active energy ray include ultraviolet rays, electron rays, alpha rays and beta rays, and ultraviolet rays are preferable. For example, when the curing reaction is promoted by ultraviolet irradiation, the accumulated amount of ultraviolet light is preferably 100 mJ / cm 2 to 2000 mJ / cm 2, more preferably 150 mJ / cm 2 to 1000 mJ / cm 2.

The thickness of the resin layer obtained in this way is preferably 1 to 20 占 퐉, more preferably 1 to 15 占 퐉, more preferably 1 to 20 占 퐉, from the viewpoints of hard coat performance and cost and from the viewpoint of suppressing the generation of curling by reducing shrinkage Preferably 1 to 10 mu m.

(Physical Properties of Resin Layer)

The surface tension of the resin layer is preferably 30 mN / m or more, more preferably 33 mN / m or more, still more preferably 35 mN / m or more, from the viewpoint of suppressing the bunching of the printing material such as ink.

The value of the surface tension of the resin layer is a value measured based on the wet tensile test method of " JIS K6768: 1999 ", specifically, a value measured based on the description of the examples.

The hardness of the pencil showing the surface hardness of the resin layer is preferably F or higher, more preferably H or higher, and still more preferably 2H or higher.

The pencil hardness of the resin layer is measured in accordance with JIS K5600-5-4, specifically measured based on the description of the examples.

[Pressure sensitive adhesive layer]

In the optical film of the present invention, a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive may be formed.

The pressure-sensitive adhesive to be used is not particularly limited, and can be appropriately selected and used according to the purpose among generally accepted ones.

Examples of such a pressure sensitive adhesive include acrylic pressure sensitive adhesives, polyurethane pressure sensitive adhesives, polyester pressure sensitive adhesives, rubber pressure sensitive adhesives, and silicone pressure sensitive adhesives. The pressure-sensitive adhesive may be any of an emulsion type, a solvent type, and a solventless type, and either a crosslinking type or a non-crosslinking type may be used.

The thickness of the pressure-sensitive adhesive is appropriately selected depending on the application, but is preferably 3 to 100 占 퐉, more preferably 5 to 80 占 퐉.

[Display device]

The optical film of the present invention having the above-described constitution has excellent durability because it has excellent adhesion to a printing material and adhesion to a pressure-sensitive adhesive, as well as high surface hardness, and thus has good scratch resistance. As an application of the optical film having such characteristics, a display device such as a liquid crystal display using the optical film as the protective member of the image display portion, and the like can be given.

Since the display device of the present invention uses the optical film of the present invention as a protective member of an image display portion, the image display portion has good scratch prevention performance and excellent durability.

Example

The following Examples of the present invention will be more specifically described, but the present invention is not limited to these Examples at all.

[Examples 1 to 12, Comparative Examples 1 to 13]

The components (A) to (D) were mixed with each other in the amounts shown in Tables 1 and 2 (all parts by mass (solid content ratio)) to prepare a curable resin composition, which was then diluted with propylene glycol monomethyl ether to give a solid content concentration of 30% To obtain a coating liquid for forming a resin layer.

Then, on one surface of a polyethylene terephthalate (PET) film (trade name: "Lumirra U48", Toray Co., Ltd., thickness: 100 μm) having an easy-to- Using a Meyer bar to give a film thickness after drying of 3 mu m, to form a coating film. Thereafter, the coated film was dried at 80 DEG C for 1 minute, irradiated with ultraviolet rays of 300 mJ / cm < 2 > (cumulative light amount) using a high-pressure mercury lamp and cured to obtain an optical film having a resin layer having a film thickness of 3 mu m .

The compounds used as respective components in Tables 1 and 2 are as follows.

[Component (A)

A-TMN-3L: Pentaerythritol triacrylate (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd., represented by the above formula (1) (R: hydrogen atom) represented by the following formula (A- 3 acrylates).

[Chemical Formula 5]

A-DPH: Dipentaerythritol hexaacrylate (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd .; the group represented by the above general formula (1) (R: hydrogen atom)) represented by the following formula (A- Acrylate).

[Chemical Formula 6]

[Component (B)] [

And A-DPH-12E: the following formula (B-1) to represent an ethylene oxide-modified dipentaerythritol hexaacrylate (produced by Shin-Nakamura Chemical Co., Ltd., product name, a group (R ¹ represented by the above-mentioned formula (2) : The total number of n in the formula (2) in one molecule is 12).

(7)

And A-GLY-9E: the formula ethylene oxide modified glycerol triacrylate (Shin-Nakamura Chemical Co., Ltd., product name, a group (R ¹ represented by the above-mentioned formula (2) shown in (B-2): hydrogen atom , And A: an ethylene group) (the total value of n in the formula (2) in one molecule is 9)).

[Chemical Formula 8]

[Other polymerizable compound]

DMAA: Dimethylacrylamide.

And A-200: the following formula (b-1) a represents a polyethylene glycol diacrylate (Shin Nakamura Chemical Co., Ltd., product name, a group (R ¹ represented by the above-mentioned formula (2): the hydrogen atom, A: ethylene (The total value of n in the general formula (2) in one molecule is 4)).

[Chemical Formula 9]

A-BPE-6: An ethylene oxide-modified bisphenol A diacrylate (trade name, a group represented by the above general formula (2) (R ¹ : hydrogen (The total value of n in the formula (2) in the molecule is 6) in one molecule).

[Chemical formula 10]

[Component (C)] [

Irgacure 184: 1-hydroxycyclohexyl phenyl ketone (trade name, manufactured by BASF, acetophenone type photopolymerization initiator).

[Component (D)] [

BYK-3550: siloxane-modified acrylic leveling agent (trade name, manufactured by Big Chem Co., Ltd., Japan).

The produced optical film was subjected to the following tests to evaluate the characteristics of the optical film. The evaluation results are shown in Tables 1 and 2.

<Surface tension>

The surface tension (mN / m) of the resin layer was measured in accordance with the wet tensile test method of &quot; JIS K6768: 1999 &quot;.

&Lt; Adhesion to printing material &gt;

An ultraviolet curable ink (trade name: UVPAL911 SUMI, manufactured by Teikoku Ink Co., Ltd.) was applied to the surface of the resin layer of the optical film and the ink was cured by ultraviolet irradiation to form a print layer having a thickness of 1 m An optical film was obtained.

Then, a cross-cut of 1 mm in width was performed on the surface of the printed layer in the form of a cross-cut, and an adhesive tape (trade name "Cellotape (registered trademark)") was applied on the surface of the cross- And a peeling test of an adhesive tape was carried out in accordance with the cross-cut tape method (cross-cut method) of "JIS K5600-5-6", and the adhesion of the resin layer to the printing material was evaluated according to the following criteria.

AA: The edge of the cut line formed by crosscutting the surface of the print layer is completely smooth, and there is no peeling on the scale of any lattice.

A: There is a small peeling at the intersection of the cut line formed by crosscutting the surface of the print layer. The proportion of the parts that are clearly influenced by the crosscuts is less than 5% of the total.

B: Peeling occurs along the edge of the cut line formed by crosscutting the surface of the print layer and / or at the intersection of the cut line. The percentage of the parts that are clearly influenced by the crosscuts is more than 5% and less than 15% of the total.

C: Partial or total large peeling occurs along the edge of the cut line formed by crosscutting the surface of the print layer, and / or some scales formed partially or entirely peeled off. The proportion of the parts that are clearly influenced by the crosscuts is more than 15% and less than 35% of the total.

D: Partly or entirely large peeling along the edge of the cut line formed by crosscutting the surface of the print layer, and / or some scales formed partially or entirely peeled off. The percentage of the parts that are clearly influenced by the crosscuts is more than 35% and less than 65% of the total.

E: The percentage of the parts that are clearly influenced by the crosscuts is over 65% of the total.

<Ink lump>

The lump of the ink when the ultraviolet curable ink (product name "UVPAL911 SUMI", manufactured by Teikoku Ink Co., Ltd.) was applied to the surface of the resin layer was visually observed and evaluated according to the following criteria.

A: I can not see the bunch.

B: We see bunch only at the end (other parts do not show bunch bunch

C: I see a cluster in the whole plane.

&Lt; Adhesion property to a pressure-sensitive adhesive (Measurement of adhesive force) &gt;

Corning Glass Eagle XG ", manufactured by NSG Precision Co., Ltd., trade name:" TL-85S-12 "manufactured by Rin Tec Corporation) was used as the optical film obtained in Examples and Comparative Examples, 70 mm x 150 mm x 0.3 mm) to prepare an adherend on which a resin layer was exposed.

Then, a pressure-sensitive adhesive sheet for evaluation of adhesion ("PET25 (A) P1069111LL" manufactured by Rin Tec Co., Ltd.) was cut into a size of 25 mm x 250 mm and the release material of the pressure sensitive adhesive sheet was peeled off. .

Thereafter, the sample was allowed to stand in an environment of 23 ° C and 50% RH (relative humidity) for 24 hours. Using a tensile tester (product name: "Tensilon" (N / 25 mm) was measured under the conditions of a pressure of 5 MPa / mm and a peel angle of 180 deg.

<Pencil hardness>

The pencil hardness of the surface of the resin layer was measured using a pencil scratch hardness tester (manufactured by Yasuda Precision Machinery Co., Ltd., product name &quot; No.553-M &quot;) according to JIS K5600-5-4. The scratching speed was 1 mm / sec.

&Lt; Application suitability &

Whether or not pinholes due to aggregation occurred when the coating liquid for forming a resin layer was coated on the surface of the PET film in the process of producing the optical film described above was visually checked and evaluated according to the following criteria Respectively.

A: No pinholes were seen.

B: Some pinholes were seen.

C: The occurrence of pinholes was noticeable.

<Durability Test>

In this test, an optical film on which a print layer is formed and which was produced by the same method as the above-described &quot; adhesion property with a printing material &quot; was used. The optical film was allowed to stand for 240 hours under the environment of 60 ° C and 90% RH (relative humidity) to promote the film. Thereafter, in order to form a mass scale of 100 × 10 10 in total on the surface of the printing layer, A cross-cut of 10 x 10 &lt; 10 &gt; masses with a width of 1 mm was carried out, and an adhesive tape (manufactured by Nichia Reflective, trade name &quot; Cellotape (registered trademark) &quot;) was affixed to the surface of the cross- Then, the adhesive tape was peeled off according to the cross-cut tape method of JIS K5600-5-6 (cross-cut method) to carry out a peeling test to evaluate the durability of the resin layer. In Tables 1 and 2, among the total number of mass scales 100, the number of mass scales remaining without peeling off the print layer after the peeling test is described.

From Table 1, it can be seen that the optical films of the present invention of Examples 1 to 12 have high surface tension of the resin layer of the film, excellent adhesion to a printing material and adhesive property to a pressure-sensitive adhesive, It can be seen that the scratch prevention performance is excellent and the durability is also good.

On the other hand, in Table 2, the optical films of Comparative Examples 1 to 13 were inferior in terms of adhesion to a printing material, adhesion to a pressure-sensitive adhesive, surface strength of a resin layer of the film, and durability.

Industrial availability

INDUSTRIAL APPLICABILITY The optical film of the present invention is excellent in adhesion to a printing material and adhesion to a pressure-sensitive adhesive, and also has good scratch-preventive performance because of its high surface hardness, and has excellent durability. Because of these properties, the optical film of the present invention is preferable as a member of a display device such as a liquid crystal display.

1, 1a, 1b, 1c, 2, 2a, 2b:
11: substrate
12, 12a, 12b:
13, 13a, 13b: pressure-sensitive adhesive layer

Claims (15)

As an optical film on which a resin layer containing a cured product of a curable resin composition is formed on at least one side of a substrate,
Wherein the curable resin composition comprises a polymerizable compound (A) having two or more groups represented by the following formula (1) in one molecule and not containing an alkylene oxide unit in the remaining structure excluding the group, (A) / (B)] of the component (A) and the component (B) is 15/50, the polymerizable compound (B) having a group represented by the following general formula (2) 85 to 85/15.
[Chemical Formula 1]

[In the above formula (1), each R independently represents a hydrogen atom or a methyl group, and * represents a bonding moiety.]
(2)

[In the formula (2), each R ¹ independently represents a hydrogen atom or a methyl group, and each A independently represents an alkylene group having 1 to 5 carbon atoms. n is independently an integer of 1 or more. * Represents a bonding part.] The method according to claim 1,
Wherein the total value of n in the general formula (2) in a molecule of the polymerizable compound (B) is 4 to 20; 3. The method according to claim 1 or 2,
Wherein A in the general formula (2) is independently an ethylene group or a propylene group. 3. The method according to claim 1 or 2,
Wherein the curable resin composition further contains a leveling agent (D). 3. The method according to claim 1 or 2,
Wherein the resin layer has a surface tension of 30 mN / m or more. The method of claim 3,
Wherein the resin layer has a surface tension of 30 mN / m or more. 3. The method according to claim 1 or 2,
Wherein a resin layer containing a cured product of the curable resin composition is formed on both surfaces of the substrate. The method of claim 3,
Wherein a resin layer containing a cured product of the curable resin composition is formed on both surfaces of the substrate. 6. The method of claim 5,
Wherein a resin layer containing a cured product of the curable resin composition is formed on both surfaces of the substrate. The method according to claim 6,
Wherein a resin layer containing a cured product of the curable resin composition is formed on both surfaces of the substrate. 3. The method according to claim 1 or 2,
And a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive on at least one side of the substrate opposite to the side where the resin layer is formed and on the same side. The method of claim 3,
And a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive on at least one side of the substrate opposite to the side where the resin layer is formed and on the same side. 6. The method of claim 5,
And a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive on at least one side of the substrate opposite to the side where the resin layer is formed and on the same side. 9. The method according to claim 6 or 8,
And a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive on at least one side of the substrate opposite to the side where the resin layer is formed and on the same side. A display device using the optical film according to any one of claims 1 to 14.

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