KR100616221B1 - Hard coating solution composition, and hard coat film and anti-reflection film employing the same - Google Patents

Abstract

The present invention relates to a hard coating liquid composition, a hard coat film and an antireflection film employing the same, the hard coating liquid composition of the present invention to remove the inorganic nanoparticles and introduce a resin having a weight average molecular weight of 10,000 to 30,000 as an ionizing radiation curable resin As a result, it is possible to provide a hard coat film and an antireflection film having low physical cost, high transparency, suppressing curl, and excellent physical strength such as scratch resistance.

Hard coating solution, hard coat film, antireflection film, transparency, curling, scratch resistance, film strength

Description

Hard coating solution composition and hard coating film and anti-reflection film employing the same {Hard coating solution composition, and hard coat film and anti-reflection film employing the same}

1 is a schematic cross-sectional view of an antireflection film according to an embodiment of the present invention.

The present invention relates to a hard coating liquid composition, a hard coat film and an antireflection film employing the same, and more particularly, by introducing a resin having a weight average molecular weight of 10,000 to 30,000 as an ionizing radiation curable resin, having a low cost and high transparency. It relates to a hard coat film and an antireflection film including a hard coating liquid composition and a hard coating layer composed thereof, which can suppress (curl) and have excellent physical strength such as scratch resistance.

Transparent substrates, such as glass and a film, are used for various displays, such as a television, a computer, a liquid crystal display, and a plasma display. However, the glass substrate is weak in impact resistance and easily broken, and there is a problem in weight reduction. Recently, a transparent film that is light in weight and not easily broken to improve the disadvantages of glass has been introduced. However, the transparency of the transparent film is low in scratch resistance and scratch resistance, and thus the display quality is deteriorated because transparency is damaged by external shocks. In order to solve this disadvantage, a method of forming a hard coating film on a transparent film is used.

Most displays are used under an environment in which external light is incident, and image formation on the screen display device by external light is inevitable. Due to the image condensation caused by external light, problems such as deterioration of visibility are caused in the screen display device. In order to solve the problems of the screen display device, various anti-reflection films for reducing the reflectance of external light have been proposed and widely used to date. In the production of such an antireflection film (film), the hard coating layer is essential to suppress the damage and deformation of the transparent support.

The most widely used method of providing anti-reflective property of screen display device is using offset interference by diffraction of light. Such methods are used in image display devices such as cathode ray tubes (CRTs), liquid crystal displays (LCDs) and plasma display panels (PDPs) in all-flat computer monitors or televisions. In order to provide anti-reflection using the offset interference effect of the light diffraction, a multi-layered film is required.

Two important factors in the design of antireflective films in the production of multilayer antireflective films are the refractive indices of each layer and the other is the layer thickness of each layer. These two factors can be adjusted to produce the antireflection film (film) with the lowest reflection at the desired wavelength.

Korean Patent Laid-Open Publication No. 1999-0072670 discloses a hard coat film including a buffer layer made of an ionizing radiation curable resin of an acrylate-based functional group, and a method of manufacturing the same. Korean Laid-Open Patent Publication No. 2005-0045873 discloses an optical film in which a hard coating layer made of a curable resin layer and an ionizing radiation curable resin using a bifunctional urethane acrylate oligomer having a weight average molecular weight of 5,000 or more is sequentially laminated. On the other hand, U.S. Patent No. 6,160,067 discloses a hard coating solution including a silica sol having a surface modified in order to suppress curling in a curable resin cured by active energy rays and to improve physical strength such as scratch resistance.

However, these conventional methods complicate the structure and manufacturing of the hard coating layer, and at the same time increase the manufacturing cost of the hard coating solution and increase the production cost due to the decrease in yield and productivity.

The present invention is to solve the above-mentioned problems of the prior art, an object of the present invention is to provide a hard coating liquid composition having excellent physical strength such as scratch resistance and low transparency as well as high transparency and low curability. To provide.

Another object of the present invention is to provide a hard coat film by employing the hard coating solution composition at a low manufacturing cost and excellent transparency and scratch resistance.

One aspect of the present invention for achieving the above object is a hard coating liquid composition comprising an ionizing radiation curable resin, a polyfunctional monomer, a curing initiator and a solvent, wherein the ionizing radiation curable resin has a weight average molecular weight of 10,000 to 30,000 A hard coating liquid composition characterized by mixing an oligomer and an oligomer having a weight average molecular weight of 500 or more and less than 10,000.

Another aspect of the present invention is characterized by a hard coat film formed by laminating a hard coat layer made of the composition on a base film.

Another aspect of the invention features an antireflection film comprising the hard coat film.

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

The hard coating liquid composition of the present invention is characterized by comprising an oligomer having a weight average molecular weight of 10,000 to 30,000, an oligomer having a weight average molecular weight of 500 to less than 10,000 and a multifunctional monomer. The said weight average molecular weight is the converted value measured by GPC method.

Generally, ionizing radiation curable resins used in conventional hard coating liquids are composed of oligomers having a weight average molecular weight of 500 to 10,000, in particular, mostly oligomers of 500 to 5,000 and polyfunctional monomers. This is because when the weight average molecular weight is too high, the cured resin layer formed becomes soft, and the hard coating function is lowered or the effect of suppressing surface defects cannot be sufficiently exhibited.

However, in this molecular weight range, the performance of the hard coating can be satisfied, but the problem of curling phenomenon occurs because the scratch resistance and curing shrinkage increases. In addition, the inorganic nanoparticles introduced to solve such a problem cause turbidity by the inorganic particles, and increase the manufacturing cost of the product.

Accordingly, the present invention is intended to improve the curling phenomenon and to improve physical strength such as scratch resistance by excluding inorganic nanoparticles and mixing oligomers having a large weight average molecular weight with oligomers of conventional molecular weight. That is, by using an oligomer having a weight average molecular weight of 10,000 to 30,000, an oligomer having a weight average molecular weight of 500 to less than 10,000 and a polyfunctional monomer, curling is suppressed without inorganic nanoparticles, and physical strength such as scratch resistance is excellent and transparency It is possible to produce an excellent hard coat film with high turbidity.

The weight ratio of the oligomer having a weight average molecular weight of 10,000 to 30,000 and the oligomer having a weight average molecular weight of 500 to less than 10,000 is preferably 1: 5 to 2: 1. When the content of the high molecular weight oligomer is less than the above range, the curling of the hard coat film is severe, and when it exceeds the above range, the cured resin layer is softened, so that the hard coating function may be lowered and the scratch resistance and the film strength may be weakened.

As the ionizing radiation curable resin used in the hard coating liquid composition of the present invention, a resin made of a compound having two or more functional groups can be used. As the resin that can be used, one having an unsaturated double bond such as (meth) acrylate or one having a reactive substituent such as an epoxy group or a silanol group can be used. In particular, having an unsaturated double bond is preferable because it can be cured by irradiation of an activation energy ray.

Examples of the ionizing radiation curable resins include ethylene glycol diacrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, trimethylol propane tri (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, polyol poly (meth) acrylate, di (meth) acrylate of bisphenol A-diglycidyl ether, polyhydric alcohols and polyhydric carboxylic acids and their anhydrides and acrylic acids obtainable by esterifying Polyester (meth) acrylate, polysiloxane polyacrylate, urethane (meth) acrylate, pentaerythritol tetramethacrylate, glycerin trimethacrylate, and the like, but are not necessarily limited thereto. The ionizing radiation curable resins may be used alone or in combination.

1,6 hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate can be used as the polyfunctional monomer used for the hard coating liquid composition of the present invention.

As a curing initiator used in the hard coating liquid composition of the present invention, a benzene and a benzene ether compound, a benzyl ketal compound, an α-hydroxyalkylphenone compound, an α, α-dialkoxyacetophenone derivative compound, an α-hydroxyalkylphenone compound, α-aminoalkylphenone derivative compound, α-hydroxyalkylphenone high molecular compound, acrylphosipine oxide compound, halogen compound, phenylglyxolate compound, banjophenone derivative compound, thioxanthone derivative compound, 1,2-diketone Examples include compounds, water-soluble aromatic ketone compounds, copolymer high molecular compounds, amine initiators, tinanocene compounds, cationic photoinitiators, thermal and photopolymerization initiators such as acid anhydrides and peroxides. In the present invention, the content of the curing initiator is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the ionizing radiation curable resin. If the content is less than 0.1 parts by weight, it may not be sufficiently cured, and the hardness may not be sufficient. If the content is more than 20 parts by weight, the curing initiator, particularly the photopolymerization initiator itself, may react with radicals to inhibit polymerization. When the photopolymerization initiator is used as a curing initiator for the above reason, the content is preferably 0.5 to 10 parts by weight.

Any solvent constituting the hard coating solution of the present invention may be used as long as it is commonly used. Specifically, alcohols such as methanol, ethanol, propanol and isopropanol, ketones such as methyl isobutyl ketone and methyl ethyl ketone, methyl acetate, acetic acid Ester, such as ethyl, Aromatic compounds, such as toluene, xylene, and benzene, Ether, such as diethyl ether, etc. are mentioned. Herein, the total content of the solvent is preferably 20 to 150 parts by weight, more preferably 50 to 120 parts by weight based on 100 parts by weight of the ionizing radiation curable resin. If the content of the solvent is less than 20 parts by weight, it is difficult to uniformly apply the hard coating liquid due to the high viscosity, and if it exceeds 150 parts by weight, poor coating occurs due to the volatilization of the solvent after application and drying.

The hard coating liquid composition of the present invention is applicable to optical films including all conventional hard coat films and antireflective films.

Hereinafter, the hard coat film and the antireflection film according to the present invention will be described.

The hard coat film of the present invention is an optical hard coat film having a hardness sufficient to protect the film from scratches due to friction.

In the hard coat film of the present invention, a hard coat layer made of the composition is laminated on a base film. In the present invention, the hard coating layer means a higher hardness than the base film. The film strength of the base film is usually 4B to HB in pencil hardness, and the hard coating layer is preferably 2H or more in pencil hardness.

The base film used for the hard coat film of the present invention is not particularly limited to a plastic film which is a transparent base material, and the light transmittance of the base film is preferably 80% or more, more preferably 85% or more. Moreover, turbidity of a base film becomes like this. Preferably it is 3.0% or less, More preferably, it is 1.0% or less. In addition, the refractive index of the base film in the range of 1.4 to 1.7 is suitable as the base material of the antireflection film for screen display device. Although the thickness of a base film is not restrict | limited, Preferably it is 30-150 micrometers, More preferably, 70-120 micrometers is preferable.

Specific examples of the base film include cellulose esters (eg cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and nitro cellulose), polyimides, polycarbonates, polyesters (eg polyethylene terephthalate, polyethylene) Naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyethylene 1,2-diphenoxyethane-4,4'-dicarboxylate, and polybutylene terephthalate), polystyrene (e.g. syndio Syndiotactic polystyrene), polyolefins (such as polypropylene, polyethylene, and polymethylpentene), polysulfones, polyether sulfones, polyarylates, polyether-imides, polymethyl methacrylates, and polyether ketones, Polyvinyl alcohol, polyvinyl chloride, and the like. The base film may be used alone or in combination. On the other hand, when the base film is used in an antireflection film and applied to a liquid crystal display (LCD), an organic light emitting display (OLED), or the like, cellulose triacetate (TAC) is preferable and a cathode ray tube of a completely flat computer monitor or a television Polyethylene terephthalate (PET) is preferable when applied to a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display panel (PDP), or the like.

In addition, the anti-reflection film according to the invention is characterized in that it comprises the hard coat film. 1 is a cross-sectional schematic view of an antireflection film according to an embodiment of the present invention, the hard coating layer (2), high refractive index layer (3) and low refractive index on a transparent base film (1), such as glass, plastic film, sheet The layers 4 are laminated in order.

The anti-reflection film according to the present invention is an image display such as a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display panel (PDP) and a touch panel of a completely flat computer monitor or television. It can be used in the device.

When the antireflection film is used in a display panel or the like, an adhesive layer may be introduced on the back side of the base film. The material used for an adhesion layer is not specifically limited. Examples of usable examples include an acrylic pressure sensitive adhesive, an ultraviolet curable pressure sensitive adhesive, a heat curable pressure sensitive adhesive, and the like.

The adhesive layer introduced on the back side of the antireflection film may contain a sunscreen to block ultraviolet rays, and may also contain pigments and carbon black to improve color contrast.

In addition, in order to protect the adhesive layer, it is preferable to laminate a release film and a sheet (release film).

The coating layer stack may include a roll coater, a reverse roll coater, a reverse gravure coater, a micro gravure coater, a bar coater and a die coater. This can be done by either method.

The present invention will be further illustrated by the following examples, which are merely illustrative of the present invention and are not intended to limit or limit the scope of the present invention.

Example  1 ~ 2

Methanol (10% by weight), methyl ethyl ketone (74% by weight), methyl isobutyl ketone (10% by weight) and toluene (4% by weight) were mixed, followed by acrylates having a weight average molecular weight of 15,000 in a fully mixed solvent. A system oligomer (JH-02: Aekyung Chemical) and an acrylate oligomer (JH-05: Aekyung Chemical) having a weight average molecular weight of 2,000 and dipentaerythritol hexaacrylate (DPHA: Satomer) were prepared according to the contents of Table 1 below. Added to complete dissolution. Photo-initiator (Igacure 184, Igacure 907: Ciba-geigy) and leveling agent (BYK 354: BYK) was added according to the content of Table 1 to prepare a hard coating solution. The unit in Table 1 is parts by weight.

Subsequently, each of the hard coating solutions prepared above was poured onto the surface of PET film (A4300, Toyobo) as a base film, and the hard coating layer thickness after curing by using a bar coater (6 to 14 # bars) was 5 μm. The coating was applied as uniformly as possible and then dried in an 80 ° C. drying oven for 1 minute. After drying, a hard coat film was prepared by UV curing using a mercury lamp under a condition of roughness of 80 W / cm ² and a light quantity of 400 mJ / cm ² , and the results of the measurement of the physical properties thereof are shown in Table 1 below.

Comparative Example  1-4

A hard coating solution was prepared according to the composition as shown in Table 1 below, and the same procedure as in Example 4 was repeated except that a silica sol (Purisol-MEK, solid content: 25%: Gamatek) having a particle diameter of 20 nm was further added in Comparative Example 4. After the hard coat film was manufactured under the conditions, the physical properties thereof were measured, and the results are shown in Table 1 together.

TABLE 1

division Example Comparative Example One 2 One 2 3 4 Mixed solvent 44 44 44 44 44 14 Mw15,000 10 20 - 30 100 - Mw2,000 30 20 40 10 - 100 Dipentaerythritol hexaacrylate 10 10 10 10 10 10 Photoinitiator 5 5 5 5 5 5 Leveling agent One One One One One One Silica sol - - - - - 30 Transmittance (%) 92 92 92 92 92 91 Scratch resistance ◎ ○ ○ △ × ◎ Pencil hardness (H) 3 2 2 2 One 3 Curling (mm) 12 10 30 8 7 15

* Property measurement method

(1) Permeability: Measured using a transmittance meter (Nippon Denshoku Kogyo Co.).

(2) Scratches: After rubbing in 15 round trips with a load of 200g using steel wool, it was determined whether or not scratches.

(3) Pencil hardness: 1kg / cm ² using a Mitsubishi evaluation pencil using a pencil hardness tester (Shinto Scientific, Heidon) After drawing 10 mm 5 times by load, the presence of a wound was checked.

(4) Curing: A film sample having a size of 100 mm * 100 mm was prepared, and all four heights at the bottom were summed and expressed in mm.

As can be seen from the results of Table 1, the hard coating solution of the present invention has no curling phenomenon as compared with the silica sol, and has a high transmittance by introducing a weight average molecular weight of 10,000 to 30,000 resin at an appropriate ratio, and excellent scratch resistance. And film strength. Therefore, the hard coating liquid composition of the present invention can provide excellent physical properties in manufacturing optical films such as hard coat film and antireflection film.

Instead of excluding inorganic nanoparticles, the hard coating liquid composition of the present invention introduces a resin having a weight average molecular weight of 10,000 to 30,000 into an ionizing radiation curable resin, which is low in production cost, high in transparency, and suppresses curling. It has the advantage of excellent physical strength, such as normality.

Claims (12)

In the hard coating liquid composition comprising an ionizing radiation curable resin, a polyfunctional monomer, a curing initiator and a solvent, The ionizing radiation curable resin is a hard coating liquid composition, characterized in that the mixture of the oligomer having a weight average molecular weight of 10,000 to 30,000 and the oligomer having a weight average molecular weight of 500 or less than 10,000. According to claim 1, wherein the hard coating liquid composition, 100 parts by weight of ionizing radiation curable resin; 20 to 100 parts by weight of the multifunctional monomer; 0.1 to 20 parts by weight of a curing initiator; And 20 to 150 parts by weight of solvent; Hard coating liquid composition comprising a. The hard coating solution composition of claim 1, wherein a mixed weight ratio of the oligomer having a weight average molecular weight of 10,000 to 30,000 and the oligomer having a weight average molecular weight of 500 to less than 10,000 is 1: 5 to 2: 1. The method of claim 1, wherein the ionizing radiation curable resin is ethylene glycol diacrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylol propane tri (meth) acrylate , Dipentaerythritol hexa (meth) acrylate, polyol poly (meth) acrylate, di (meth) acrylate of bisphenol A-diglycidyl ether, polyhydric alcohol, polyhydric carboxylic acid and its anhydride, polyester ( Hard coating liquid composition, characterized in that it is selected from the group consisting of metha) acrylate, polysiloxane polyacrylate, urethane (meth) acrylate, pentaerythritol tetramethacrylate and glycerin trimethacrylate. The method of claim 1, wherein the multifunctional monomer is selected from the group consisting of 1,6 hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate and trimethylolpropane triacrylate Hard coating solution composition. According to claim 1, wherein the curing initiator is a benzene and benzene ether compound, benzyl ketal compound, α-hydroxyalkylphenone compound, α, α- dialkoxyacetophenone derivative compound, α-hydroxy alkylphenone compound, α-amino Alkylphenone derivative compound, α-hydroxyalkylphenone high molecular compound, acryl phosphine pin oxide compound, halogen compound, phenylglyxolate compound, benzophenone derivative compound, thioxanthone derivative compound, 1,2-diketone compound, water-soluble aromatic A hard coating liquid composition, characterized in that selected from the group consisting of ketone compounds, copolymer polymer compounds, amine initiators, tinanocene compounds, cationic photoinitiator, acid anhydride and peroxide. The method of claim 1, wherein the solvent is at least one selected from the group consisting of methanol, ethanol, propanol, isopropanol, methyl isobutyl ketone, methyl ethyl ketone, methyl acetate, ethyl acetate, toluene, xylene and benzene, diethyl ether. Hard coating liquid composition, characterized in that. A hard coat film comprising a hard coat layer of the composition of any one of claims 1 to 7 laminated on a base film. The hard coat film of claim 8, wherein the hard coat film has a film strength of 2H or more. The method of claim 8, wherein the base film is a cellulose ester, polyimide, polycarbonate, polyester, polystyrene, polyolefin, polysulfone, polyether sulfone, polyarylate, polyetherimide, polymethyl methacrylate and polyether Hard coat film, characterized in that at least one selected from the group consisting of ketones, polyvinyl alcohol and polyvinyl chloride. An antireflection film comprising the hard coat film of claim 8. An image display device comprising the antireflection film of claim 11.

Images