KR20070094184A - Hard coating film with high hardness, polarizing plate and display device having the same - Google Patents

Abstract

A hard coating film with high hardness, a polarizing plate having the same and a display device are provided to secure good high hardness, wear resistance, weather resistance, and optical high transparency and to prevent curling. A hard coating film with high hardness has a hard coating layer formed by spreading hard coating solution containing a UV(Ultraviolet)-curable resin composition, on one surface of a transparent base film. The UV-curable resin composition contains reactive silica particle produced by chemically bonding multi-functional organic matter having a polymer unsaturated group, with a siloxy group formed on the surface of the silica particle. The thickness of the hard coating layer is within a range of 5~30 micrometers and the curling characteristic is below 15mm.

Description

Hard Coating Film With High Hardness, Polarizing Plate and Display Device Having The Same}

The present invention relates to a high hardness hard coating film, a polarizing plate and a display device having the same, and more particularly, as a hard coating film for protecting various displays, having excellent high hardness, abrasion resistance, and weather resistance, and is very suitable for protecting a surface of a display. It relates to a hard coating film, a polarizing plate and a display device having the same.

BACKGROUND ART Conventionally, hard coating films are used for various surface protection panels such as liquid crystal displays (LCDs), plasma displays (PDPs), CRTs, electroluminescent displays (ELs), and the like. In addition, in recent years, in addition to the surface protection function, resistance to the display of fingerprints, markers and the like and / or ease of removal (that is, antifouling) are also required.

As a material for forming such a hard coating film, UV curable acrylic hard coating materials such as polyester, acrylate, urethane acrylate and epoxy acrylate have sufficient surface protection to have as a hard coating film when the organic material alone is used. It did not show the characteristics of. Therefore, various organic-inorganic coating compositions including colloidal silica particles as inorganic materials have been used to improve the high hardness and wear resistance of hard coating films.

However, the problems of stability due to the precipitation and gel generation of colloidal silica particles whose silica surface is modified with organic materials or silane, and the degree of curing, optical transparency and adhesion still fall short of the requirements of the hard coating film for display protection.

In addition, the conventional hard coating film is thickened to improve the hardness, the hardness of the obtained hard coat film is improved, but in this case, the hard coating layer is easily cracked or peeled off, and at the same time increase in curing shrinkage and hot-weather shrinkage. By doing so, the curl of the end of the hard coat film rolled up (curl) is large, there is a problem that handling aptitude is degraded or cracks are likely to occur.

The present invention is to solve the above problems, a hard coating liquid containing a UV curable resin composition comprising a reactive silica particles chemically bonded to a siloxy group on the surface of the silica particles of a multifunctional organic material having a polymerizable unsaturated group of the transparent base film The purpose of the present invention is to provide a hard coating layer formed by coating on one surface, to provide a high hardness hard coating film having excellent high hardness, wear resistance, weather resistance and optical transparency, and no curling phenomenon, a polarizing plate and a display device having the same. do.

The present invention for achieving the above object,

It comprises a hard coating layer formed by applying a hard coating liquid containing an ultraviolet curable resin composition to one surface of the transparent base film, wherein the ultraviolet curable resin composition is a polyfunctional organic material having a polymerizable unsaturated group to the siloxy on the surface of the silica particles Comprising combined reactive silica particles, the thickness of the hard coating layer is in the range of 5 ~ 30 ㎛, provides a high hardness hard coating film, characterized in that the curling property is 15 mm or less.

In addition, the transparent substrate film is diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, polyamide, polyether Mid, polyacryl, polyimide, polyether sulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polymethyl meta At least one selected from the group consisting of acrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene or phthalate, polycarbonate, polyurethane, and epoxy, and is unstretched, monoaxial or biaxially stretched. High characterized by the film Also it provides a hard coat film.

In addition, the transparent base film is a triacetyl cellulose film or a polymethyl methacrylate film, when the thickness of the hard coating layer provides a high hardness hard coating film, characterized in that the surface hardness is 5H or more.

In addition, it provides a polarizing plate provided with the above-described high-hardness hard coating film.

In addition, the present invention provides a display device including the high hardness hard coat film.

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

The high hardness hard coating film according to the present invention comprises a hard coating layer formed by applying a hard coating liquid containing an ultraviolet curable resin composition to one surface of a transparent base film, wherein the ultraviolet curable resin composition is a multi-tube having a polymerizable unsaturated group. It characterized in that it comprises reactive silica particles chemically bonded to the functional organic material to the siloxy group on the surface of the silica particles.

The reactive silica particles included in the ultraviolet curable resin composition may be prepared by chemical bonding by mixing silica particles with a hydrolyzable silane having a polymerizable unsaturated group. The amount of hydrolyzable silane having a polymeric unsaturated group bonded to the reactive silica particles is about 0.05 to 99% by weight, preferably 5 to 85% by weight. Less than 0.05% by weight affects the transparency and wear resistance of the cured film, while more than 99% by weight only slightly improves the wear resistance.

Hydrolyzable silyl groups include, but are not limited to, carboxylate silyl groups such as acetoxy silyl groups, alkoxy silyl groups such as methoxy or ethoxy silyl groups, halogen silyl groups such as chloro silyl groups, amino and hydride silyl groups, and the like. Preferably, the alkoxy silyl group is the best to use.

The polymeric unsaturated group is not limited, but examples thereof include carboxy, hydroxy, acryloxy, methacryloxy, vinyl, propenyl, butadienyl, styryl, cinnamoyl, malate, acrylamide, and the like. Among these, unsaturated aliphatic carboxylic acid and methacrylate compound containing a hydroxyl group are preferable.

The average particle diameter of the reactive silica particles is not limited, but may be used in the range of 0.0001 ~ 20㎛, when used in the cured transparent film is preferably 0.001 ~ 0.01㎛.

In addition, silica particles are not limited, but it is recommended in nano size, the specific surface area is, but not limited to 0.001 to 2m ² / g range I good, more preferably 0.001 ~ 0.1m ² / g, the hitting and most preferably from 0.001 to 0.01 m ² / g. The silica particles may be a colloidal silica dispersed in an organic solvent such as a dry powder or a silica sol of methanol. The production of the reactive silica particles is carried out at 20 to 150 ° C, and is performed in a range of 5 minutes to 24 hours.

The ultraviolet curable resin composition may include an unsaturated organic material, for example, dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, hexanediol diacrylate, urethane acrylate oligomer, acryloloyl morpholine , 2-acryloxypropyl hexahydrozen phthalate and the like can be used.

The ultraviolet curable resin composition may include a photoinitiator, for example, diphenyl ketone benzyldimethyl ketal, 2-hydroxy-2-methyl-1-phenyl-1-one, 4-hydroxy cyclophenyl ketone, dimethoxy -2-phenylatetophenone, anthraquinone, fluorene, triphenylamine, carbazole, 3-methylacetophenone, 4-knoloacetophenone, 4,4-dimethoxyacetophenone, 4,4-diaminobenzo It is possible to use 0.1 to 10% by weight of phenone alone or in combination. If less than 0.1% by weight, the curing speed is slow and more than 10% by weight is uneconomical. Photostimulants can be used with photoinitiators, for example triethylamine, diethylamine, methyldiethanolamine, ethanolamine, 4-dimenylamino-benzoic acid, isoamyl-4-dimethylaminobenzoate, and the like. Can be used.

In addition to the above materials, antioxidants, UV absorbers, light stabilizers, thermal polymerization inhibitors, labelling agents, surfactants, lubricants and the like may be used together in the UV curable resin composition or the hard coating solution.

As the transparent base film, any film can be used as long as it is a transparent plastic film. For example, cellulose derivatives such as diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose , Butyryl cellulose, acetyl propionyl cellulose or polyester, polystyrene, polyamide, polyetherimide, polyacryl, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, poly Vinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane , To When made available that is selected for at least one of the thermoplastic polymers, such as, and may be a non-stretched (未 延伸), 1-axis or two-axis drawn film. Among them, preferably a uniaxial or biaxially stretched polyester film having excellent transparency and heat resistance, but a triacetyl cellulose film is suitably used in view of transparency and optically no anisotropy. The thickness of a transparent base film is about 8-1000 micrometers, Preferably 40-100 micrometers is used.

In particular, the transparent base film is a triacetyl cellulose film or a polymethyl methacrylate film, the thickness of the hard coating layer is characterized in that the surface hardness measurement results 5H or more.

In the present invention, the coating of the hard coating film may be applied by a suitable method such as die coater, air knife, reverse roll, spray, blade, casting, gravure and spin coating.

Coating thickness is 0.1-200 micrometers normally, Preferably it is 5-30 micrometers, More preferably, it is 10-25 micrometers. After application, the composition is dried by evaporation of volatiles for 1 second to 2 hours, preferably 10 seconds to 1 hour at a temperature of 30 ~ 150 ℃. The irradiation amount of UV light is about 0.01-10 J / cm <^2> , Preferably it is 0.1-2J / cm <^2> .

 The thickness of the hard coating layer is not limited, but is preferably in the range of 5 to 30 μm, more preferably in the range of 10 to 25 μm, and the curling property can be adjusted to 15 mm or less while the hard coating film can be obtained with high hardness. have.

The high hardness hard coat film prepared as described above has excellent high hardness, abrasion resistance, weather resistance, and optical high transparency, and has a high curing speed at the time of its manufacture, and thus has high productivity, and the film produced after curing does not generate curling phenomenon. Did.

The present invention also provides a polarizing plate having excellent physical properties formed by laminating the above-mentioned high hardness hard coat film on at least one surface.

The polarizing plate is not particularly limited, but various kinds may be used. As a polarizing plate, the film polyvinyl which uniaxially stretched by adsorb | sucking dichroic substances, such as iodine and a dichroic dye, to hydrophilic polymer films, such as a polyvinyl alcohol-type film and an ethylene-vinyl acetate copolymerization partial saponification film, for example. And polyene-based alignment films such as alcohol dehydration products and polyvinyl chloride dehydrochlorination products. Among these, the polarizing plate which consists of dichroic substances, such as a polyvinyl alcohol-type film and iodine, is preferable. Although the thickness of these polarizing plates is not specifically limited, Generally, it is about 5-80 micrometers.

The present invention also provides a display device to which the above-mentioned high hardness hard coat film is applied.

By incorporating the polarizing plate having the high hardness hard coat film of the present invention into a display device, various display devices of the present invention having excellent visibility can be manufactured. The hard coat film of the present invention can be preferably used in reflective, transmissive, semi-transmissive LCD or LCD of various driving methods such as TN type, STN type, OCB type, HAN type, VA type, and IPS type. In addition, the hard coat film of the present invention is excellent in wear resistance and antifouling property, and thus can be preferably used for various display devices such as plasma displays, field emission displays, organic EL displays, inorganic EL displays, electronic papers, and the like.

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

<Example 1>

Hard coating solution (Product name: DN-0081. Manufacturer: DSM Desotech Inc.) was applied on a transparent substrate film (80㎛, TAC) to a thickness of 10㎛ with a Meyer bar and dried at 70 ℃ for 1 minute , Hardened to 720mJ / cm ² to prepare a hard coating film.

<Example 2>

Hard coating solution (Product name: DN-0081. Manufacturer: DSM Desotech Inc.) was applied on a transparent substrate film (80㎛, TAC) with a meyer bar to have a thickness of 15㎛ and dried at 70 ℃ for 1 minute , Hardened to 720mJ / cm ² to prepare a hard coating film.

<Example 3>

Hard coating solution (DN-0081, DSM Desotech Inc.) was applied on a transparent substrate film (80㎛, TAC) to 20㎛ thickness with a meyer bar and dried at 70 ℃ for 1 minute, then cured to 720mJ / cm ² Also a hard coating film was prepared.

Comparative Example 1

30% by weight of dipentaerythritol pentaacrylate (Japanese gunpowder), 10% by weight of colloidal silica (MEK-ST, Ilsan Chemical), 1% by weight of 1-hydroxy cyclohexyl phenylketone (Shiba gauge), methyl isobutyl 0.1% by weight of 58.9% by weight of ketone fluorine-based surfactant (FC430, 3M Co. Ltd) was applied on a transparent substrate film (80 μm, TAC) to a thickness of 20 μm and dried at 70 ° C. for 1 minute. It was cured at 720mJ / cm ² to prepare a high hardness hard coating film.

Comparative Example 2

Dipentaerythritol pentaacrylate (Japanese gunpowder) 35% by weight, colloidal silica (MEK-ST, Ilsan Chemical) 5% by weight, 1-hydroxy cyclohexyl phenyl ketone (Shiba gauge) 1% by weight, methyl isobutyl ketone 58.9% by weight of the siloxane-based surfactant (BYK-325, BIC Chem) 0.1% by weight of the composition on a transparent substrate film (80㎛, TAC) to a thickness of 20㎛ and dried for 1 minute at 70 ℃, It was cured at 720mJ / cm ² to prepare a high hardness hard coating film.

Comparative Example 3

Dipentaerythritol pentaacrylate (Japanese gunpowder) 30% by weight, 10% by weight, 10% by weight of 3-methacryloxa propyltrimethoxy silane (KBM-530, Shin-Etsu Chemical), 1-hydroxy cyclohexyl phenyl ketone ( Shiba gauge) 1% by weight, methyl isobutyl ketone 59% by weight of the composition on a transparent substrate film (80㎛, TAC) to 20㎛ thickness with a meyer bar and dried at 70 ℃ for 1 minute, then 720mJ / cm ² It was cured to prepare a high hardness hard coat film.

Experimental Example

The hard coat films prepared in Examples and Comparative Examples were measured as follows, and the results are shown in Table 2 below.

(1) surface smoothness

The coated surface of the film is observed in the direction of inclination of 20 to 30 degrees by shining with electric light, and the presence or absence of wrinkles or wrinkles that is thought to be caused by the uniformity (microscopic) of the surface layer or the surface property of the hard coating layer is observed. Confirmed.

A: There is no micro aggregation in the surface layer, and it is uniform, and unevenness | corrugation and a wrinkle are not recognized by a hard coat layer.

B: Although microscopic aggregation is seen in the surface layer, it is very mild and unevenness | corrugation and a wrinkle are not recognized by a hard coat layer.

C: Although micro aggregates are seen in the surface layer, irregularities and wrinkles are not observed in the hard coat layer.

D: Microscopic aggregation is remarkable in the surface layer, and irregularities and wrinkles are also seen in the hard coat layer.

(2) transmittance and haze

Total light transmittance and total haze were measured using a spectrophotometer (HZ-1, manufactured by Suga Japan).

(3) pencil hardness

The pencil hardness is measured using a pencil hardness tester (PHT, manufactured by Seokbo Science, Korea) under a 500g load. The pencil is made with Mitsubishi products and is used five times per pencil hardness. If there were two or more gases, it was determined to be defective.

Kiss: 0 OK

Kiss: 1 OK

Ges: 2 or more NG

(4) scratch resistance

The scratch resistance was tested by using a steel wool tester (WT-LCM100, manufactured by Protec Co., Ltd.) for 10 reciprocations at 1 kg / (2 cm × 2 cm).

Steel wool uses # 0000.

A: 0 scratches

A ': 1 to 10 scratches

B: 11 to 20 scratches

C: 21 to 30 scratches

D: 31 or more scratches

(5) adhesion

After eleven straight lines each at 1 mm intervals were made on the coated surface of the film to make 100 squares, three peel tests were conducted using a tape (CT-24, Nichi Nippon Corp.). Three 100 squares were tested and averaged.

The adhesion is recorded as follows.

Adhesion = n / 100

n: number of rectangles that do not peel out of the entire rectangle

100: total number of squares

Therefore, if none were peeled off, record 100/100.

(6) curl

The sample cut into the square shape of A4 size (29.7 X 21.0 cm) was placed on a flat glass plate with the coated surface of the film facing up, and the distance from the square glass plate was measured at 25 ° C. and 50% RH, and then averaged. Was taken as a measured value.

Very good: 0 to 15 mm, good: 15 to 30 mm, poor: 30 to 50 mm, very poor: more than 50 mm.

(7) fingerprint wiping

Fingerprint marks on the coated surface of the film were ten times wiped lightly by 10 people with clean paper (ULTIMA II, Hansong), and the wiping property was visually evaluated.

A: No wipe marks remained. B: A little wipe left. C: Wipe marks remained.

(8) chemical resistance

The hard coat film of the present invention was rubbed 10 times with a cloth embedded with the following chemicals at 25 ° C., and chemical resistance was evaluated based on the following criteria from the presence or absence of abnormality in the appearance of the coating film after drying the chemicals.

○: no abnormality, △: discoloration, X: peeling

TABLE 1

One  Saline (10%) 2  Neutral detergent (10%) 3  Low Alkaline Detergent (10%) 4  LCD cleaner, weak alkali (a) 5  LCD cleaner, neutral (b) 6  ethanol 7  IPA (50%)

a: Scotch office screener OC-20

b: Scotch office screener OC-100M

(9) heat resistance

The sample was placed in an oven at 100 ° C. for 10 minutes and then taken out, and the surface was visually observed using a slide project.

○: no abnormality on the surface. Ⅹ: Cracks on the surface.

(10) weather resistance

After 300 hours using the Sunshine weatherability (Japan Suga tester), the state of the sample surface was visually observed.

A: no change in surface, B: surface is rough, C: surface is dissolved.

TABLE 2

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Base film and thickness (㎛) TAC (80) TAC (80) TAC (80) TAC (80) TAC (80) TAC (80) Hard Coat Film Thickness (㎛) 10 15 20 20 20 20 Surface smoothness A A A A B B Total light transmittance (%) 91.1 90.8 90.6 90.1 91.0 87.0 Haze (%) 0.2 0.1 0.1 0.2 0.1 0.4 Pencil hardness 4H 5H 6H H 2H H Scratch resistance A A A C B D Adhesion 100/100 100/100 100/100 95/100 95/100 85/100 Curl (mm) Very good Very good Very good Bad Very bad Very bad Fingerprint Wipe A A A A C C Chemical resistance ○ ○ ○ - ○ - Heat resistance ○ ○ ○ - ○ - Weather resistance A A A - C -

* TAC: triacetylcellulose

* In Comparative Examples 1 and 3, the pencil hardness was not sufficient and poor, so it was not meaningful to evaluate other properties, and thus, the chemical resistance, heat resistance, and weather resistance were not evaluated. Comparative Examples 2 and 3 had very poor curl characteristics and thus could not be polarized plated.

When the polarizing film was manufactured by using the hard coating films of the above examples as the protective layer of the iodine-based absorbing dichroic polarizing plate, the chip was cut when the prepared polarizing film showed an excellent appearance without cracking of the cut surface. The polarizing film which has the high practical surface protection function which maintained the characteristic of the coating film was obtained.

The high hardness hard coat film produced according to the present invention has excellent high hardness, wear resistance, weather resistance and optical high transparency. In addition, according to the present invention, the curing rate is high at the time of manufacturing a high hardness hard coating film, and the productivity is excellent, and the film produced after curing does not generate a curling phenomenon. The polarizing plate and the display device using the high hardness hard coat film of the present invention exhibited excellent physical and optical properties.

Claims (5)

It comprises a hard coating layer formed by applying a hard coating liquid containing an ultraviolet curable resin composition to one surface of a transparent substrate film, The UV curable resin composition includes reactive silica particles chemically bonded to a polyfunctional organic material having a polymerizable unsaturated group with a siloxy group on the surface of silica particles, and the thickness of the hard coating layer is in the range of 5 to 30 μm, and the curling characteristics are 15 mm. A high hardness hard coat film, characterized by the following. The method of claim 1, wherein the transparent substrate film is diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, poly Amide, polyetherimide, polyacryl, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, poly At least one selected from the group consisting of ether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane, and epoxy; (未 延伸), 1 axis or 2 High hardness, characterized in that the stretched film is also a hard coating film. The hard coating film of claim 1, wherein the transparent base film is a triacetyl cellulose film or a polymethyl methacrylate film, and when the thickness of the hard coating layer is 15 µm or more, the surface hardness is 5H or more. The polarizing plate provided with the high hardness hard coat film of any one of Claims 1-3. The display device of claim 1, wherein the hard coating film of claim 1 is provided.