KR20120097866A - Hard coating film with improved flexibility - Google Patents

Abstract

PURPOSE: A hard coating film is provided to have excellent surface hardness, excellent scratch resistance, good flexibility, and not generating crack at working or bending, thereby being suitable for protecting appearance of furniture. CONSTITUTION: A hard coating film comprises a soft plastic film as a substrate layer, and a hard coating layer on at least one side of the substrate layer. The hard coating layer is a cured material of a UV-curable hardcoating composition. The UV-curable hardcoating composition comprises a bifunctional or more acrylate-based monomer, and at least one kind of a polyfunctional urethane acrylate-based oligomer and a polyfunctional acrylate-based monomer not containing ethylene glycol.

Description

Hard coating film with improved flexibility {HARD COATING FILM WITH IMPROVED FLEXIBILITY}

The present invention relates to a hard coating film with improved flexibility that can be used as a protective film of furniture.

Lamination of hard-coating films for furniture, etc., can be performed on 1D (overlay) molding, which simply laminates on plywood that is not largely curved, 2D (wrapping) molding, which is laminated on the surface where the bending is not so severe, and on the bent parts. It is divided into 3D (membrane) molding to be laminated.

Although the moldability (flexibility) suitable for a use is important as a physical property which such a hard coat film should have, it is also important to have surface hardness which does not generate a scratch on the surface.

In case of using a general hard film such as polyethylene terephthalate (PET) film as the base film in the hard coating film, even if the thickness of the substrate itself is thin, a polyfunctional acrylate monomer or a urethane acrylate oligomer is used for the hard coating layer. Although it can be given, there is a problem that cracks occur when the stacking on the surface of the flexible due to lack of flexibility and severe.

Therefore, although it may be considered to use a relatively soft film as the base layer, in this case there is a problem that the surface hardness is lower than coating a hard coating layer of the same thickness on the PET substrate. In addition, if the thickness is further increased to increase the surface hardness, cracking occurs in the coating layer during molding.

Accordingly, it is an object of the present invention to provide a hard coat film having flexibility while maintaining proper surface hardness so that cracking does not occur during molding.

According to the above object, the present invention is a hard coating film comprising a soft plastic film as a base layer and a hard coating layer provided on at least one side of the base layer, wherein the hard coating layer (a) bifunctional or more acrylic having ethylene glycol An ultraviolet curable hard coating composition comprising at least one of a rate monomer and (b) a polyfunctional urethane acrylate oligomer and a polyfunctional acrylate monomer having no ethylene glycol is cured, and the functional group of the component (a) When the number is n, the number of ethylene glycol contained in the component (a) is n to 2n, the number average molecular weight of the component (a) is 100n to 200n, and the component (a) in the ultraviolet curable hard coating composition It provides a hard coat film, the content of which is 50% by weight to 85% by weight based on the solid content.

The hard coat film of the present invention is suitable as a protective film for the exterior of furniture or home appliances because the surface hardness is not only excellent in scratch resistance, but also excellent in flexural properties, so that no crack occurs during work or bending.

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

Soft plastic film

The soft plastic film used as the base film of the hard coat film of the present invention is, for example, polyethylene terephthalate glycol (PETG), polyvinyl chloride (PVC), polyvinyl butyral (PVB) and ethylene vinyl acetate (EVA). It is preferable that the material selected from the group consisting of.

It is preferable that the thickness of the said plastic film is 200 micrometers-450 micrometers.

Bifunctional or higher acrylate monomer having ethylene glycol

The bifunctional or higher functional acrylate monomer having ethylene glycol is characterized in that when the number of functional groups thereof is n, the number of ethylene glycol contained is n to 2n, and the number average molecular weight is 100n to 200n. For example, in the case of a bifunctional acrylate monomer, it may include 2 to 4 ethylene glycol, the number average molecular weight may be 200 to 400. In addition, in the case of a trifunctional acrylate monomer, it may include 3 to 6 ethylene glycol, the number average molecular weight may be 300 to 600.

Preferred examples of such bifunctional or higher acrylate monomers include, but are not limited to, the compounds of Table 1 or mixtures thereof.

Functional group designation EO Count / Function Mn / functional group 2-functional Diethylene glycol diacrylate One 107 Triethylene Glycol Diacrylate 1.5 129 Tetraethylene Glycol Diacrylate 2 151 Diethylene Glycol Dimethacrylate One 121 Triethylene Glycol Dimethacrylate 1.5 143 Tetraethylene Glycol Dimethacrylate 2 165 Trifunctional Trimethylolpropane (EO) ₃ triacrylate One 143 Trimethylolpropane (EO) ₆ triacrylate 2 187 4 sensuality Pentaerythritol (EO) ₄ tetraacrylate One 132

The content of the bifunctional or higher acrylate monomer having ethylene glycol is preferably 50% by weight to 85% by weight, more preferably 60% by weight to 80% by weight, based on the solid content of the ultraviolet curable hard coating composition. Do.

Multifunctional acrylate monomer which does not have ethylene glycol, and polyfunctional urethane acrylate oligomer

Polyfunctional acrylate monomers do not have ethylene glycol A bifunctional or more than polyfunctional acrylate monomer is named generically, Preferably it is trifunctional or more.

Examples of the polyfunctional acrylate monomers include 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, butanediol diacrylate, butanediol dimethacrylate, tricyclodecane diacrylate, and cyclohexane Diacrylate, tris (2-hydroxyethyl) isocyanurate diacrylate, hydroxylpivalaldehyde modified trimethylolpropane diacrylate, 1,4-butanediol diacrylate, metallic diacrylate, modified metallic di Acrylate, acrylate ester, cyclohexane dimethanol dimethacrylate, 1,4-butanediol dimethacrylate, metallic dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tri Acrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, trifunctional Ester, trifunctional acrylate ester, trifunctional methacrylate ester, dimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, pentaacrylate ester, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and the like can be used. have.

The polyfunctional urethane acrylate oligomer is a generic term for bifunctional or more than one polyfunctional urethane acrylate oligomer, and includes, for example, all aliphatic or aromatic urethane acrylate oligomers, preferably at least trifunctional and more preferably at least tetrafunctional. Do.

As an example of a polyfunctional urethane acrylate oligomer, the bifunctional urethane acrylate oligomer of the number average molecular weights 1400-25000, the trifunctional urethane acrylate oligomer of the number average molecular weights 1700-16000, the tetrafunctional urethane acrylate oligomer of the number average molecular weight 1000, 6-functional urethane acrylate oligomer of number average molecular weight 818-2600, 9-functional urethane acrylate oligomer of number average molecular weight 3500-5500, 10-functional urethane acrylate oligomer of number average molecular weight 3200-3900, 15 of 2300-20,000 number average molecular weight A functional urethane acrylate oligomer etc. can be used.

The content of such polyfunctional acrylate monomers and / or polyfunctional urethane acrylate oligomers is preferably 9% by weight to 50% by weight, and 15% by weight to 40% by weight, based on the solid content of the hard coating composition. More preferred.

The ultraviolet curable resin composition used in the manufacture of the hard coat layer in the present invention may further include the following components.

Photoinitiator

The photoinitiator component used in the present invention is not particularly limited as long as it is a free radical photoinitiator that is generally used. , Igacure 127, Igacure 819, Tarocure 2022, Igacure 2100, Tarocure TPO, or the like, or a mixture thereof.

The content of the photoinitiator is preferably 0.5% by weight to 10% by weight, more preferably 1% by weight to 8% by weight, based on the solids content of the ultraviolet curable hard coating composition, respectively.

menstruum

Solvents are used to adjust the solids content of the entire hard coating composition, specifically alcohol solvents (methanol, ethanol, isopropyl alcohol, butyl alcohol, etc.), alkoxy alcohol solvents (2-methoxyethanol, 2-ethoxyethanol , 1-methoxy-2-propanol and the like), ketone solvents (methyl ethyl ketone, methyl isobutyl ketone, methyl propyl ketone and the like), ether acetate solvents (propylene glycol monomethyl ether acetate and the like) and the like can be used.

Such a solvent may be added in an amount of 100 to 900 parts by weight based on 100 parts by weight of the solid content of the ultraviolet curable hard coating composition.

The hard coat film of the present invention can be prepared as follows.

First, (a) having ethylene glycol At least one of a bifunctional or higher functional acrylate monomer, and (b) a polyfunctional acrylate monomer having no ethylene glycol and a polyfunctional urethane acrylate oligomer is mixed, and (c) other components such as a photoinitiator are added thereto. In order to adjust the solid content of the entire hard coating solution, (d) a solvent may be added, followed by mixing and stirring to prepare a hard coating composition.

Thereafter, after applying the hard coating composition on the base film in the form of a roll, the solvent may be dried for about 30 seconds to 5 minutes by passing through a drying chamber of 60 ~ 100 ℃. In this case, the coating method of the hard coating composition may be a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a microgravure coating method and a comma coating method.

Thereafter, the obtained dried material may be cured by irradiating ultraviolet rays radiated from ultraviolet lamps such as a high pressure mercury lamp and a xenon lamp with a light amount of 250 to 2500 mJ / cm 2, thereby completing a hard coat film having a hard coating layer on the substrate.

The thickness of the cured hard coat layer is preferably 1 μm to 20 μm, more preferably 3 μm to 12 μm.

The hard coat film according to the present invention, as a protective film for the appearance of furniture or home appliances, has a suitable surface hardness, excellent scratch resistance, and further comprises a bifunctional or higher functional acrylate monomer having ethylene glycol. It increases flexibility and suppresses cracking during bending.

Preferably, the hard coating film of the present invention may exhibit a pencil hardness of HB or more, and a scratch does not occur when the steel wool (# 0000) is mounted on a friction tester and reciprocated 10 times with a load of 300 g, and JIS According to the bending resistance measurement method (cylindrical mandrel method) according to K5600-5-1, when the film sample was wound on the iron bar having a diameter of about 5 mm so that the hard coating layer was positioned outside, the crack was placed on the hard coating layer. It may indicate characteristics that do not occur.

Therefore, the hard coat film of the present invention can be used for the protective film of the appearance of furniture or home appliances.

Hereinafter, the present invention will be described in more detail with reference to the following examples. The following examples are illustrative only and the scope of the present invention is not limited thereto.

Examples 1-4

(a) a bifunctional or higher acrylate monomer having ethylene glycol (see Table 2 below), (b) a polyfunctional urethane acrylate oligomer (MU9500, Miwon Specialty Chemical Co., Ltd.), and (c) a photoinitiator (I-184, BASF). G) was added and mixed according to the composition shown in Table 4 (based on the solid content of the entire composition).

division designation product name manufacturer Example 1 Triethylene Glycol Diacrylate SR272 Satomer Example 2 Tetraethylene Glycol Diacrylate SR268 Satomer Example 3 Trimethylolpropane (EO) ₆ triacrylate SR499 Satomer Example 4 Pentaerythritol (EO) ₄ tetraacrylate SR494 Satomer

100 parts by weight of methyl ethyl ketone as a solvent was added based on 100 parts by weight of solids of the obtained mixture, followed by stirring to prepare respective UV-curable hard coating compositions.

Each UV curable hard coating composition prepared above is die coated on a polyethylene terephthalate glycol (PETG) substrate in the form of a roll having a thickness of 300 μm. The coating was applied by the method. After drying the solvent for about 1 minute by passing through a drying chamber at 70 ° C., ultraviolet rays radiated from ultraviolet lamps such as a high-pressure mercury lamp and a xenon lamp are irradiated and cured at a light amount of 1000 mJ / cm 2, and the coating film is 10 μm thick on the substrate. The hard coat film coated with was completed.

Comparative Examples 1 and 2

Example 1, except that trimethylolpropane (EO) ₆ triacrylate (SR499, Sartomer Co., Ltd.) used in Example 3 was used as component (a), and the composition of each component was mixed as shown in Table 5 below. It carried out with the same component and procedure as -4, and obtained the hard coat film which coated the coating film to the thickness of 10 micrometers on the base material.

Comparative Examples 3 to 5

Except having used the compound of Table 3 as component (a), it carried out by the same component and procedure as the said Examples 1-4, and obtained the hard coat film which coated the coating film to the thickness of 10 micrometers on the base material.

division designation product name manufacturer Comparative Example 3 Hexaethylene glycol diacrylate M284 Mewon Specialty Chemical Company Comparative Example 4 Neopentylglycol diacrylate SR247 Satomer Comparative Example 5 Trimethylolpropane (PO) ₃ Triacrylate SR492 Satomer

Comparative Examples 6 and 7

Except having used the component (a) and having performed the composition of each component, the base material layer component, and the thickness of the final film as Table 5 below. It carried out similarly to the said Examples 1-4, and obtained the hard coat film coated on the base material.

Test Example

Each film prepared in Examples and Comparative Examples was evaluated as follows, and is shown in Table 1 below.

 (1) pencil hardness

In accordance with ASTM D3363, using a pencil hardness tester was drawn five times under a load of 500g and a condition of 10mm and confirmed the presence of a wound on the surface of the coating surface.

(2) scratch resistance

The number of scratches was evaluated by mounting a steel swab (# 0000) on a rubbing tester (KPD-301, Gibae ENT) and reciprocating 10 times with a load of 300g.

 (3) Crack resistance

Based on the flex resistance measurement method (cylindrical mandrel method) according to JIS-K5600-5-1, the film sample was wound around the bar with a diameter of about 5 mm so that the hard coating layer was positioned outside, and then it was repeated several times. The presence or absence was observed visually. (Circle) that there was no crack, (triangle | delta) what existed a little, and badly generate | occur | produced and broke it evaluated by X.

division Item Example 1 Example 2 Example 3 Example 4 Ingredient (a) Organoleptic 2 2 3 4 EO water / functional group 1.5 2 2 One Mn / functional group 129 151 187 132 Hard coating
Furtherance
(weight%) (a) 74 74 74 74 (b) 18 18 18 18 (c) 8 8 8 8 Hard Coating Layer Thickness (㎛) 10 10 10 10 Base layer component PETG PETG PETG PETG film
Properties Pencil hardness ≥HB ≥HB ≥HB ≥HB Scratches (count) 0 0 0 0 Crack resistance ○ ○ ○ ○

division Item Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 ingredient
(a) Organoleptic 3 3 2 2 3 3 3 EO water / functional group 2 2 3 0.5 One 2 2 Mn / functional group 187 187 204 108 157 187 187 Hard coating
Furtherance
(weight%) (a) 28 90 74 74 74 0 0 (b) 64 2 18 18 18 92 92 (c) 8 8 8 8 8 8 8 Hard Coating Layer Thickness (㎛) 10 10 10 10 10 2 2 Base layer component PETG PETG PETG PETG PETG PET PETG film
Properties Pencil hardness ≥HB <HB HB ≥HB <HB 2H <HB Scratch Count 0 10 5 0 8 0 0 Crack resistance X ○ ○ △ ○ X △

As shown in Table 4, it can be seen that the films of Examples 1 to 4 according to the present invention are excellent in scratch resistance and crack resistance, and particularly in Examples 1 and 4, even though the thickness of the hard coating layer is about 10 μm. None of the cracks occurred. In addition, since the pencil hardness of HB or more, there was no problem to use as a hard coating film such as furniture. Therefore, it can be seen that the film of the present invention has flexibility while maintaining the surface hardness and is suitable as a hard coating film for furniture and the like.

On the other hand, as shown in Table 5, the film of Comparative Example 1 is excellent in pencil hardness and scratch resistance, but it is broken during the crack resistance test, so it can be seen that the flexibility is very low, and also in Comparative Example 4, pencil hardness and scratch resistance are excellent. However, some cracks occur, which shows a little less flexibility. In addition, in the case of Comparative Examples 2, 3 and 5 it is excellent crack resistance, but it can be confirmed that the pencil hardness and scratch resistance is weak, Comparative Examples 6 and 7 in the same composition but the pencil hardness when the thickness or the substrate is changed I could see the difference. It can be seen that it is unsuitable as a hard coating film laminated on furniture and the like which has both good hardness and scratch resistance and requires flexibility.

Claims (8)

As a hard coating film containing a soft plastic film as a base material layer, and the hard-coating layer provided in at least one surface of the said base material layer,
The hard coating layer
(a) a bifunctional or higher acrylate monomer having ethylene glycol, and
(b) at least one of a polyfunctional urethane acrylate oligomer and a polyfunctional acrylate monomer having no ethylene glycol;
UV curable hard coating composition comprising a cured,
When the number of functional groups of the component (a) is n, the number of ethylene glycol contained in the component (a) is n to 2n, the number average molecular weight of the component (a) is 100n to 200n, and the ultraviolet curable type A hard coat film, wherein the content of component (a) in the hard coat composition is 50% to 85% by weight based on solids.
The method of claim 1,
The soft plastic film is polyethylene terephthalate glycol (PETG), Hard coating film, characterized in that the film of the material selected from the group consisting of polyvinyl chloride (PVC), polyvinyl butyral (PVB) and ethylene vinyl acetate (EVA).
The method of claim 1,
Hard coating film, characterized in that the content of component (b) in the ultraviolet curable hard coating composition is 9% by weight to 50% by weight based on the solid content.
The method of claim 1,
The said component (a), Diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane (EO ) ₃ triacrylate, trimethylolpropane (EO) ₆ triacrylate, pentaerythritol (EO) ₄ tetraacrylate, and a mixture thereof.
The method of claim 1,
The UV curable hard coating composition, characterized in that it comprises a photoinitiator component in a solid content of 0.5% by weight to 10% by weight, hard coating film.
The method of claim 1,
Hard coating film, characterized in that the thickness of the hard coating layer is 1㎛ to 20㎛.
The method of claim 1,
Hard substrate film, characterized in that the thickness of the base layer is 200㎛ to 450㎛.
The method of claim 1,
The hard coating film is a hard coating film, characterized in that used as a protective film for the appearance of furniture or home appliances.