KR102031802B1 - Hard coating film and display window using the same - Google Patents

Abstract

The present invention relates to a hard coat film and a display window having the same, and relates to a hard coat film characterized in that the following Equations 1 and 2 are satisfied.
[Equation 1]
(Surface friction coefficient / surface water contact angle) * 1000 <2.5
[Equation 2]
Martens hardness> 200 N / mm ²

Description

HARD COATING FILM AND DISPLAY WINDOW USING THE SAME}

The present invention relates to a hard coat film and a display window having the same.

Recently, with the development of mobile devices such as smartphones and tablet PCs, thinning and slimming of the display base material are required. Glass or tempered glass is generally used as a material having excellent mechanical properties in the display window or the front plate of the mobile device. However, the glass causes the mobile device to be heavier due to its weight and there is a problem of breakage due to external impact.

Therefore, plastic resin is being researched as a substitute material for glass. Plastic resin compositions are suitable for the trend toward a lighter mobile device because they are lightweight and less prone to breakage. In particular, a composition has been proposed for coating a hard coat layer on a supporting substrate to achieve a composition having a low surface friction coefficient and ensuring durability against scratch resistance.

Korean Patent Laid-Open No. 10-2012-0044286 relates to a photosensitive resin composition, an antireflection film and an antireflection hard coat film using the same, wherein the polyfunctional (meth) acryl has at least three (meth) acryloyl groups in a molecule thereof. Contain rate (A), colloidal silica (B) having a nanoporous structure with an average particle diameter of 1 to 200 nanometers, polysiloxane (C) having a (meth) acryloyl group, and a photoradical polymerization initiator (D) The photosensitive resin composition which is mentioned is disclosed.

In addition, Korean Patent No. 10-1069569 discloses a curable compound having at least one group of (A) component: an acrylate group and a methacrylate group on at least one surface of the transparent plastic film base material 11, (B) Component: Inorganic oxide particle surface The particle | grains modified by the organic compound containing a polymerizable unsaturated group, and (C) Component: For hard-coat layer formation containing the reactive silicone containing the compound represented by following General formula (1) The composition for hard-coat layer formation, the hard-coat film, the optical element, and the image display apparatus which form the hard-coat layer 12 using a composition are disclosed.

However, the prior arts have a problem that by adding a silicon material, the coefficient of friction can be increased during repeated scratch resistance test.

Republic of Korea Patent Publication No. 10-2012-0044286 (2012.05.07. Napon Kayaku Kabushiki Kaisha) Republic of Korea Patent No. 10-1069569 (September 27, 2011. Nitto Denko Co., Ltd.)

The present invention has been made to solve the above problems, and an object thereof is to provide a hard coating film having a high water contact angle and a low surface friction coefficient and a display window having the same.

In addition, the present invention is characterized by a display window provided with a hard coating film as described above.

In the hard coat film according to the present invention for achieving the above object, The following Equations 1 and 2 are satisfied.

[Equation 1]

(Surface friction coefficient / surface water contact angle) * 1000 <2.5

[Equation 2]

Martens hardness> 200 N / mm ²

In addition, the present invention features a display window using a hard coating film.

As described above, the hard coating film according to the present invention has a high water contact angle and a low surface friction coefficient, and has an effect of ensuring durability against scratches.

< Hard coating  Film>

In the hard coating film according to the present invention, in the hard coating film, The following Equations 1 and 2 are satisfied.

[Equation 1]

(Surface friction coefficient / surface water contact angle) * 1000 <2.5

[Equation 2]

Martens hardness> 200 N / mm ²

The surface friction coefficient is expressed as follows as a proportional coefficient between the load applied when the loaded object is dragged in the horizontal direction and the vertical load of the object after placing an object of a certain load on the film surface.

Surface friction factor = force generated when dragged horizontally / vertical load on the object

In the present invention, the friction coefficient between the film surface and the steel wool (# 0000) is expressed as the surface friction coefficient in order to represent the scratch resistance of the surface.

The hard coating film has a friction coefficient measured after one reciprocating friction and a friction coefficient measured after 10 reciprocating frictions using steel wool having a contact area of 3 * 2.5cm with a load of 3.75 kgf of 0.1 or less.

In addition, the surface water contact angle refers to the angle formed by dropping the water droplets on the surface of the coating film, the higher the surface water contact angle is more difficult to adhere to the foreign matter on the surface of the coating is more excellent scratch characteristics.

Hard coating film according to the present invention has a high water contact angle, effectively prevent the adhesion of foreign matter to the outside to prevent chemical modification of the film surface by the foreign matter attached, as well as effectively prevent physical scratches by the foreign matter attached can do.

In addition, the Martens hardness is a value measured by the indentation test of the micro load using a nano indenter, the higher the Martens hardness, the harder the coating layer does not cause scratches due to external stimulation.

The hard coating film according to the present invention was used to secure a low surface friction coefficient and a high water contact angle by using a fluorine-based additive having a low surface energy, and to adjust the hardness of the coating layer by using a monomer and silica particles having a high degree of crosslinking.

Transparency Substrate layer

The transparent base layer can be used as long as it is a transparent polymer film. In the present invention, the "transparent" means that the visible light transmittance is 70% or more or 80% or more.

The transparent base layer is specifically, for example, triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, polyamide, Polyetherimide, polyacryl, polyimide, polyether sulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether It may be a film formed of a polymer such as ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate and the like. These polymers can be used individually or in mixture of 2 or more types.

Hard coating layer

The hard coating layer may be formed by applying a hard coating composition on one surface of the transparent substrate layer and then photocuring by irradiating ultraviolet light.

The hard coating composition may further include one or more selected from the group consisting of inorganic oxide fine particles, photocurable resins, solvents, photoinitiators and fluorine-based additives, which will be described later in more detail.

At this time, the method of applying the hard coating composition is not particularly limited as long as it can be applied in the technical field to which the present technology belongs, for example, bar coating method, knife coating method, roll coating method, blade coating method, die coating method, Micro gravure coating method, comma coating method, slot die coating method, lip coating method, solution casting method and the like can be used.

Inorganic oxide fine particles

The inorganic oxide fine particles are oxide fine particles of 100 nm or less, and may reinforce hardness in the hard coat layer.

The inorganic oxide fine particles may be at least one selected from the group consisting of fine particles of silicon oxide (silica), titanium oxide, aluminum oxide, zinc oxide, tin oxide, zirconium oxide.

Photocurable  Suzy

The photocurable resin may include a photocurable (meth) acrylate oligomer and a monomer.

As said photocurable (meth) acrylate oligomer, epoxy (meth) acrylate, urethane (meth) acrylate, etc. are normally used, and urethane (meth) acrylate is more preferable. Urethane (meth) acrylate can manufacture the polyfunctional (meth) acrylate which has a hydroxyl group in a molecule, and the compound which has an isocyanate group in presence of a catalyst. Specific examples of the (meth) acrylate having a hydroxy group in the molecule include 2-hydroxyethyl (meth) acrylate, 2-hydroxyisopropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and capro It may be selected from one or more selected from the group consisting of lactone ring-opened hydroxyacrylate, pentaerythritol tri / tetra (meth) acrylate mixture, and dipentaerythritol penta / hexa (meth) acrylate mixture.

Specific examples of the compound having an isocyanate group include 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8-diisocyanatooctane, 1,12-diisocyanatododecane, 1, 5-diisocyanato-2-methylpentane, trimethyl-1,6-diisocyanatohexane, 1,3-bis (isocyanatomethyl) cyclohexane, trans-1,4-cyclohexene diisocyanate, 4,4 '-Methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylene-1,4-diisocyanate, tetramethylxylene-1, 3-diisocyanate, 1-chloromethyl-2,4-diisocyanate, 4,4'-methylenebis (2,6-dimethylphenylisocyanate), 4,4'-oxybis (phenylisocyanate), hexamethylene diisocyanate Trifunctional Isocyanates Derived from, and Trimethane Propanol Adduct Toluenediiso O it may be one or more selected from the group consisting of carbonate.

The monomer is usually used, having a unsaturated group such as a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, and the like in a photocurable functional group, and a (meth) acryloyl group is more preferred among them.

Specific examples of the monomer having a (meth) acryloyl group include neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, propylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, Dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylol ethane tri (meth) acrylate, 1 , 2,4-cyclohexane tetra (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate , Dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate Yit, tripentaerythritol tri (meth) acrylate, tripentaerythritol hexatri (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, hydroxyethyl (meth) acrylate , Hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, isooctyl (meth) acrylate, iso-decyl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth ) Acrylate, phenoxyethyl (meth) acrylate, isobornol (meth) acrylate may be selected from one or more kinds.

solvent

The solvent may be used without limitation so long as it is known as a solvent of the hard coating composition in the art that can dissolve or disperse the above-mentioned composition.

The solvents are alcohols (methanol, ethanol, isopropanol, butanol, methylcellulose, ethyl solusorb, etc.), ketones (methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, cyclo Hexanone, etc.), acetate type (ethyl acetate, propyl acetate, normal butyl acetate, tertiary butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene Glycol monopropyl ether acetate, methoxybutyl acetate, methoxypentyl acetate, etc.), hexane type (hexane, heptane, octane, etc.), benzene type (benzene, toluene, xylene, etc.), ether type (diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol Monomethyl ether, etc.) etc. can be used preferably. Solvents illustrated above can be used individually or in combination of 2 types or more, respectively.

The solvent is preferably contained 10 to 95% by weight relative to the total weight of the hard coating composition. If the content of the solvent is less than 10% by weight, the viscosity is high, not only workability is deteriorated, but also the swelling of the transparent base layer can not proceed sufficiently, if it exceeds 95% by weight it takes a long time in the drying process Poor economic problems may arise.

Photoinitiator

The photoinitiator can be used without limitation so long as it is used in the art. For example, one or more selected from the group consisting of hydroxyketones, aminoketones, hydrogen decyclic photoinitiators, and combinations thereof can be used.

Specifically, the photoinitiator is 2-methyl-1- [4- (methylthio) phenyl] 2-morpholinepropanone-1, diphenylketone, benzyldimethyl ketal, 2-hydroxy-2-methyl-1- Phenyl-1-one, 4-hydroxycyclophenyl ketone, 2,2-dimethoxy-2-phenyl-acetophenone, anthraquinone, fluorene, triphenylamine, carbazole, 3-methylacetophenone, 4-ke Noloacetophenone, 4,4-dimethoxyacetophenone, 4,4-diaminobenzophenone, 1-hydroxycyclohexylphenylketone, benzophenone, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide and One or more types selected from the group consisting of these combinations can be used.

Such photoinitiator is preferably included in 0.1 to 10% by weight, more preferably in 1 to 5% by weight within 100% by weight of the total hard coating composition. When the content of the photoinitiator is less than the above range, the curing rate of the hard coating composition may be slowed down and uncured to cause mechanical properties to drop. When the photoinitiator exceeds the above range, cracks may occur in the coating due to overcuring.

Fluorine additive

The fluorine-based additive has a photocurable reactor capable of participating in a curing reaction during UV curing, and is a surface-oriented additive having a chain containing fluorine.

As the fluorine-based additive, for example, Shin-Etsu KY-1200 series, Daikin Corporation Optool DAC-HP, DIIC Corporation Megaface series, and fluorolink FS series can be used.

<Display window >

The present invention provides a display window having a hard coating film. In this case, the display window may be flexible, and specifically, displays such as LCD, OLED, LED, FED, various mobile communication terminals, smart phones, or the like. It can be used as a functional layer or a replacement for cover glass, such as touch panels and whole paper of tablet PCs.

The present invention provides an image display device having the display window, and the image display device may be a touch sensor.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are intended to illustrate the present invention more specifically, but the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention. In addition, "%" and "part" which show content below are a basis of weight unless there is particular notice.

Production Example  1 to 6: Hard coating  Preparation of the composition

Production Example  One

30 parts by weight polyfunctional acrylate (Miwon Specialty Chemical, MIRAMER SP1106), propylene glycol monomethyl ether dispersion 50 parts by weight nano silica sol (12nm, 40% solids), 17 parts by weight ethyl acetate, 2.7 parts by photoinitiator (Shiba Corporation, I-184), 0.3 parts by weight of a fluorine-based additive (Shin-Etsu Co., Ltd., KY1203) was combined using a stirrer and filtered using a PP filter to prepare a hard coating composition.

Production Example  2

30 parts by weight polyfunctional acrylate (Miwon Specialty Chemical, MIRAMER SP1106), propylene glycol monomethyl ether dispersion 50 parts by weight nano silica sol (12nm, 40% solids), 17 parts by weight ethyl acetate, 2.7 parts by photoinitiator (Shiba Corporation, I-184), 0.3 parts by weight of a fluorine-based additive (Dikin, Optool DAC-HP) was combined using a stirrer and filtered using a PP filter to prepare a hard coating composition.

Production Example  3

20 parts by weight polyfunctional acrylate (Miwon Specialty Chemical, MIRAMER SP1106), propylene glycol monomethyl ether dispersion 60 parts by weight nano silica sol (12nm, 40% solids), 17 parts by weight ethyl acetate, 2.7 parts by photoinitiator (Shiba Corporation, I-184), 0.3 parts by weight of a fluorine-based additive (Dikin, Optool DAC-HP) was combined using a stirrer and filtered using a PP filter to prepare a hard coating composition.

Production Example  4

20 parts by weight of polyfunctional acrylate (Cheil Industries, Ltd., MF-101), propylene glycol monomethyl ether dispersion 60 parts by weight nano silica sol (12nm, 40% solids), 17 parts by weight ethyl acetate, 2.7 parts by weight photoinitiator (Shiba Corporation , I-184), 0.3 parts by weight of a fluorine-based additive (Dikin, Optool DAC-HP) was blended using a stirrer and filtered using a PP filter to prepare a hard coating composition.

Production Example  5

30 parts by weight polyfunctional acrylate (Miwon Specialty Chemical, MIRAMER SP1106), propylene glycol monomethyl ether dispersion 50 parts by weight nano silica sol (12nm, 40% solids), 17 parts by weight ethyl acetate, 2.7 parts by photoinitiator (Shiba Corporation, I-184), 0.3 parts by weight of silicone-based additives (BYK, BYK UV3570) was blended using a stirrer and filtered using a PP filter to prepare a hard coating composition.

Production Example  6

70 parts by weight of polyfunctional acrylate (Miwon Specialty Chemical, MIRAMER SP1106), propylene glycol monomethyl ether dispersion 10 parts by weight nano silica sol (12nm, 40% solids), 17 parts by weight ethyl acetate, 2.7 parts by photoinitiator (Shiba Corporation, I-184), 0.3 parts by weight of silicone-based additives (BYK, BYK UV3570) was blended using a stirrer and filtered using a PP filter to prepare a hard coating composition.

Example  1 to 5 and Comparative example  1 and Comparative example  2: Hard coating  Manufacture of film

Example  One

The hard coating solution of Preparation Example 1 was cured on one side of a polyimide film having a thickness of 50 μm, and then coated to have a thickness of 10 μm. Then, the solvent was dried and the UV accumulated light amount was 500 mJ / cm ² to prepare a hard coat film. .

Example  2

A hard coat film was prepared in the same manner as in Example 1, except that the transparent base layer was used as triacetyl cellulose (TAC, 40 μm) in Example 1.

Example  3

A hard coating film was prepared in the same manner as in Example 1 except that the hard coating solution in Example 1 was used as Preparation Example 2.

Example  4

A hard coating film was prepared in the same manner as in Example 1 except that the hard coating solution was used in Preparation Example 3 in Example 1.

Example  5

A hard coating film was prepared in the same manner as in Example 1 except that the hard coating solution in Example 1 was used as Preparation Example 4.

Comparative example  One

A hard coating film was prepared in the same manner as in Example 1 except that the hard coating solution in Example 1 was used in Preparation Example 5.

Comparative Example 2

A hard coating film was prepared in the same manner as in Example 1 except that the hard coating solution in Example 1 was used as Preparation Example 6.

Experimental Example

Physical properties of the hard coat film prepared in Examples 1 to 5 and Comparative Examples 1 to 2 were measured by the following method, and the results are shown in Table 1. Measurement and evaluation methods used in the present invention are as follows.

1) Martens hardness

After fixing the base film to the glass so that the hard coating surface to the top, using a nano indenter (Fischer, HM500) was measured for the Martens hardness of the hard coating surface with a force of 10mN load, the results are shown in Table 1 It was.

2) pencil hardness

After setting the pencil in a 45 degree direction under a load of 1 kg, the coating film was fixed on the glass, and then evaluated with a pencil having a pencil hardness of five times, and then marked with pencil hardness as a hardness not to be scratched more than four times. It is listed in Table 1 below.

3) scratch resistance

After fixing the base film to the glass so that the hard coating surface is upward, it was visually confirmed whether scratches occurred on the surface of the film after 10 reciprocating frictions with a load of 250 g / cm ² using steel wool (# 0000). Are listed in Table 1 below.

<Evaluation Criteria>

A ': 10 scratches or less

B: More than 10 scratch occurrences or less

C: More than 20 scratches

4) coefficient of friction

After the base film was fixed to the glass so that the hard coating faced upwards, the loads were evaluated by performing 10 reciprocating friction tests using steel wool having a contact area of 3 * 2.5 cm with a load of 3.75 kgf. The results are shown in Table 1 below.

<Evaluation Criteria>

Initial friction coefficient: value of horizontal load / vertical load in one round trip

Friction coefficient after 10 round trips: Value of horizontal and vertical loads during 10 round trips

5) Surface water contact angle

After fixing the base film to the glass so that the hard coating surface to the top, using a contact angle meter to drop the water drops on the surface of the coating layer was measured the angle between the coating layer and the water droplets. The measured values were measured five times, taking the values of the left and right of the water droplets, and the average value of the total 10 measured values is shown in Table 1.

Martens hardness
(N / mm ² ) Scratch resistance Surface friction coefficient
(A) surface
Water contact angle
(B) A / B * 1000 Friction coefficient after 10 round trips pencil
Hardness Example 1 240 A ' 0.25 110 2.27 0.25 3H Example 2 240 A ' 0.24 109 2.20 0.26 3H Example 3 238 A ' 0.26 108 2.41 0.29 3H Example 4 312 A ' 0.22 110 2.00 0.23 3H Example 5 502 A ' 0.21 111 1.89 0.22 5H Comparative Example 1 245 A ' 0.28 102 2.75 0.42 3H Comparative Example 2 233 B 0.31 99 3.13 0.42 2H

Referring to Table 1, Examples 1 to 5 according to the present invention has a value of (surface friction coefficient / surface water contact angle) * 1000 of less than 2.5, a Martens hardness of more than 200N / mm ² , and a change in friction coefficient. It can be seen that the 0.1 or less, the scratch generation is also 10 or less, it can be seen that the pencil hardness can be implemented more than 3H.

In particular, in the case of Example 5 using a six-functional acrylate, by using an acrylate resin harder than Examples 1 to 4 using a dendritic monomer, the Martens hardness is about 500 N / mm ² , pencil It can be seen that the hardness also implements 5H.

On the other hand, in Comparative Examples 1 and 2 (surface friction coefficient / surface water contact angle) * It can be seen that the value of more than 2.5, the amount of change of the friction coefficient also exceeds 0.1.

Claims (5)

A base film, and a hard coat layer laminated on one or both sides of the base film, wherein the hard coat layer is included as the outermost layer,
The hard coating layer contains a cured product of the hard coating composition,
The hard coating composition includes a photocurable resin and a fluorine-based additive and does not include a silicone-based additive,
The photocurable resin includes a dendritic acrylate, an acrylate having six photocurable functional groups or both,
The hard coating layer satisfies Equations 1 and 2 below, and after a single reciprocating friction using a steel wool having a contact area of 3 * 2.5 cm with a load of 3.75 kgf, after 10 reciprocating frictions Hard coating film, characterized in that the amount of change of the friction coefficient measured is 0.1 or less:
[Equation 1]
(Surface friction coefficient / surface water contact angle) * 1000 <2.5
[Equation 2]
Martens hardness> 200 N / mm ²
(The surface friction coefficient is a load applied by fixing the substrate film to the glass so that the hard coating surface is upward, and performing 10 reciprocating friction tests using steel wool having a contact area of 3 * 2.5 cm with a load of 3.75 kgf. ,
The surface water contact angle is an angle formed by the coating layer and the water drop after dropping water droplets on the surface of the coating layer using a contact angle meter after fixing the base film to the glass so that the hard coating surface to the top,
The Martens hardness is the Martens hardness of the hard coating surface when the base film is fixed to the glass so that the hard coating surface is upward, and a force of 10 mN is applied using a nano indenter (Fischer, HM500). The method of claim 1,
The hard coating composition further comprises at least one selected from the group consisting of inorganic oxide fine particles, a solvent, and a photoinitiator. delete A display window comprising a touch sensor with a hard coating film according to claim 1. An image display apparatus comprising a display window comprising a touch sensor according to claim 4.