KR20110035356A - Multi-functional hard coating composition and hard coating structure - Google Patents

Abstract

PURPOSE: A multi-functional hard coating liquid is provided to ensure easy processability, good handling property, scratch resistance, antifouling property, and high surface hardness, and to prevent cracks during in-mold lamination molding. CONSTITUTION: A hard coating liquid comprises a fluorinated polyurethaneacrylate functional copolymer, a UV curable resin, a photoinitiator, and a TiO2 nasosol for increasing abrasion resistance, wherein the fluorinated polyurethaneacrylate functional copolymer is formed by copolymerizing a polyurethane (meth)acrylate oligomer and a fluorinated (meth)acrylic monomer.

Description

Multi-Functional Hard Coating Composition And Hard Coating Structure

The present invention relates to a multifunctional hard coating liquid and a hard coating.

As a method of imparting designability to a molded article at low cost, there is an insert molding method or an in-mold molding method. The insert molding method is an injection molding die after molding a film or sheet such as a polyester resin, a polycarbonate resin, an acrylic resin or the like which has been decorated, such as printing, into a three-dimensional shape in advance by vacuum molding or the like, and removing an unnecessary film or sheet portion. It transfers in and obtains the molded article integrated by injection molding the resin used as a base material. On the other hand, in-mold molding method is a film or sheet of a polyester resin, a polycarbonate resin, an acrylic resin, or the like, which is decorated with a printing or the like is installed in an injection molding mold, and subjected to vacuum molding, and then the resin to be a substrate in the same mold. By lamination, the molded article integrated is obtained.

 Although the technology for hard coating liquid and hard coating film for in-mold molding has been known to some extent, in the related art, it has only scratch resistance properties, and in particular, it is contaminated by external contaminants such as fingerprints, and thus exhibits poor appearance, resulting in poor product quality. It has a problem of degrading. In addition, there is a problem such as cracks of the outer coating layer during in-mold molding.

The present invention is to solve the above problems, it is easy to work, good handleability, scratch resistance, antifouling, high surface hardness, especially when in-mold lamination molding does not occur cracks An object of the present invention is to provide a functional hard coating liquid and a functional hard coating prepared using the same.

As a means for achieving the above object,

The present invention relates to a fluorine-based polyurethane acrylate functional copolymer formed by copolymerizing a polyurethane (meth) acrylate oligomer and a fluorine-based (meth) acryl monomer, an ultraviolet curable resin, a photoinitiator, and a TiO ₂ nanosol to increase wear resistance. It provides a hard coating solution is included.

In addition, the TiO ₂ nanosol provides a hard coating liquid, characterized in that contained within the range of 1.0 to 3.0% by weight relative to the weight of 100 of the hard coating liquid solids.

In addition, the size of the TiO ₂ nanosol provides a hard coating liquid, characterized in that in the range of 50 ~ 100nm.

In addition, the composition ratio of the polyurethane (meth) acrylate oligomer and the fluorine-based (meth) acryl monomer provides a hard coating liquid, characterized in that in the range of 60:40 ~ 50:50.

In addition, the ultraviolet curable resin provides a hard coating liquid, characterized in that the polyurethane (meth) acrylate.

In addition, the hard coating prepared by coating the hard coating solution on the substrate and then photocured, the crack resistance of the hard coating layer provides a hard coating, characterized in that less than 1Ø.

The present invention having the above-mentioned structural features is easy to work, has good handleability, shows scratch resistance, antifouling property and high surface hardness, and especially cracking does not occur even when in-mold lamination is performed. It provides a functional hard coating solution and a functional hard coating prepared using the same.

  Hereinafter, the present invention will be described in more detail with reference to the drawings and embodiments. The following descriptions are for specific examples of the present invention, but are not intended to limit the scope of the rights set forth in the claims, even though they are assertive or limitative.

The hard coating solution according to one embodiment of the present invention is a fluorine-based polyurethane acrylate functional copolymer formed by copolymerizing a polyurethane (meth) acrylate oligomer and a fluorine-based (meth) acryl monomer, an ultraviolet curable resin, a photoinitiator, and wear resistance In order to increase the TiO ₂ nanosol is characterized in that it is included.

 According to the present invention, a polyurethane acrylate oligomer having excellent hardness and a fluorine acrylate monomer having a low surface energy are prepared as a copolymer by using a radical solution polymerization method, so that one copolymer can have durability, antifouling property and adhesion at the same time. It is a feature, through which the structure of the multi-layered multi-functional hard coating film of the conventional multi-layer structure can be produced in a single-layer structure has the advantage of improving the economics and functionality of each.

In addition, various applications are possible by including TiO ₂ nanosols within an optimum range that further increases wear resistance and does not significantly impair other physical properties, and is particularly useful for preparing a hard coating film for in-mold molding.

[Fluorinated polyurethane acrylate functional copolymer]

The fluorine-based polyurethane acrylate functional copolymer according to the embodiment of the present invention is characterized in that the copolymer is formed by including a polyurethane (meth) acrylate oligomer and a fluorine-based (meth) acryl monomer. In addition, if necessary, the copolymerization may further include one or more monomers capable of radical polymerization, but is not limited thereto.

The polyurethane (meth) acrylate oligomers may be prepared or commercialized by methods known in the art. It is preferable to introduce | transduce and manufacture a (meth) acrylate group in polyurethane. That is, after polymerizing a polyol and a diisocyanate compound to obtain an isocyanate terminated polyurethane prepolymer, the isocyanate terminated polyurethane prepolymer is reacted with a vinyl monomer having both a hydroxy group and a (meth) acryl group in a molecule to endcap the (meth) acrylate. endcapping) to prepare polyurethane (meth) acrylate oligomers.

Here, the diisocyanate is not limited, but toluene 2,4-diisocyanate, diphenyl diisocyanate, xylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, tetramethyl xylene diisocyanate, 4,4-dicyclo At least one selected from hexyl methane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate, lysine diisocyanate Can be.

Examples of the polyol include, but are not limited to, polypropylene glycol, polytetramethylene glycol, polycarbonate, polycaprolactone, polyester, ethylene glycol, propylene glycol, butanediol, 1,6 hexanediol, glycerol, trimethiropropane, pentaerythritol At least one may be selected from among.

Examples of vinyl monomers having both a hydroxy group and a (meth) acryl group in a molecule include, but are not limited to, hydroxyethyl (meth) acrylate, hydroxymethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and ε-capro One or more of lactone-β-hydroxyethyl (meth) acrylate may be selected and used.

The molecular weight of the polyurethane (meth) acrylate oligomer which can be preferably used in one embodiment of the present invention is not limited but is preferably in the range of 1000 ~ 3000. If the molecular weight is less than 1000 may be a problem such as chemical resistance, durability, adhesion, etc., if the molecular weight exceeds 3000 may be a problem of fluidity in the polymerization process.

Although the fluorine-based (meth) acryl monomer is not limited, it is preferable to use a (meth) acrylic acid ester monomer in which three or more hydrogens are substituted with fluorine, and specifically, trifluoroethyl (meth) acrylate and tetrafluoropropyl. (Meth) acrylate, tetrafluoroethyl (meth) acrylate, octafluoropentyl (meth) acrylate, tetrafluoroethyl (meth) acrylate, hexafluorobutyl (meth) acrylate, etc. are mentioned. have.

Here, the composition ratio of the polyurethane (meth) acrylate oligomer and the fluorine-based (meth) acryl monomer has been studied to act as a very important factor. That is, it is preferable that the composition ratio of the said polyurethane (meth) acrylate oligomer and a fluorine-type (meth) acryl monomer is in the range of 60: 40-50: 50. If the composition ratio of the polyurethane (meth) acrylate oligomer is out of the above range, the surface energy may increase rapidly and the antifouling property may be remarkably degraded. In addition, when the fluorine group is excessive, the hardness of the coating surface is lowered and durability becomes a problem. If the composition ratio of the fluorine-based (meth) acrylic monolayer out of the above range is excessive, the surface energy may be insignificantly lowered, resulting in a slight improvement in antifouling properties, but also lowered in durability.

Preparation of the fluorine-based polyurethane acrylate functional copolymer according to an embodiment of the present invention can be prepared as follows. Nitrogen is flowed into a reactor equipped with a nitrogen reflux device for at least 20 minutes before the reaction to form a nitrogen atmosphere. First, in order to introduce a fluorine group having a surface energy of about 5 to 10 dyne / cm, a fluorine-based acrylic monomer and a polyurethane acrylate oligomer were copolymerized using a radical solution polymerization method. First, solution 1 consisting of a polyurethane acrylate oligomer, a fluorine acrylate monomer and an organic solvent is constituted. Although not limited to the organic solvent, N-Methyl-pyrrolidone, Dimethyl Formamide, toluene, xylene, Methyl ethyl ketone may be used.

And solution 2 consists of a solvent and a radical initiator. As the radical initiator, Azobisisobutyrronitrile (AIBN) may be used. The solution 1 and the solution 2 are stirred in a nitrogen atmosphere reactor at 60-65 degrees for at least 12 hours, and the holes of the reactor are tightly packed to prevent the solvent from disappearing. And the reaction is terminated polymer is washed 5-10 times with diethyl ether (diethyl ether) and then the solvent is dried under reduced pressure to obtain a fluorine-based polyurethane acrylate functional copolymer.

[Hard coating solution with excellent antifouling and abrasion resistance]

Excellent antifouling and abrasion resistance according to an embodiment of the present invention, particularly a functional hard coating solution excellent for in-mold lamination (IML) provides a coating solution comprising the above-described fluorine-based polyurethane acrylate functional copolymer and UV curable resin do. Preferably, the fluorine-based polyurethane acrylate functional copolymer is preferably included 20 to 80% by weight relative to 100% by weight of total solids. If it is less than 20% by weight, adhesion and antifouling properties may fall, and when it exceeds 80% by weight, the hardness of the pencil may be lowered, which may lower durability.

The ultraviolet curable resin is not limited, but may be used in combination of one, two or more acrylic resins, urethane acrylate resins, silicone acrylate resins and the like. Preferably polyurethane (meth) acrylate is preferred, and more preferably fluorine-based polyurethane acrylate functionalities in the blending process using the same polyurethane (meth) acrylate used to prepare the fluorine-based polyurethane acrylate functional copolymer. The dispersibility and durability of the copolymer are improved.

The hard coating solution may further include a solvent and a photoinitiator as a diluent, and a functional additive may be further added as necessary. Although not limited to a photoinitiator, IRGACURE 184, DAROCURE TPO and the like can be used. The solvent is preferably diluted by 1 to 10 times the total weight of the fluorine-based polyurethane acrylate functional copolymer and the ultraviolet resin.

The hard coating solution is characterized in that the TiO ₂ nano sol is further included in order to increase the wear resistance, SiO ₂ nano sol may be further added as necessary. Preferably, the TiO ₂ nanosol is not limited, but the TiO ₂ nanosol may have a size of 50 nm to 1 μm or less, and more preferably, 50-100 nm nanosol may have excellent wear resistance upon addition. It is preferable because it does not affect the haze and transmittance.

In addition, the TiO ₂ nanosol is preferably included in the range of 1.0 to 5.0% by weight, in particular within the range of 1.0 to 3.0% by weight based on 100 parts by weight of the hard coating liquid solids. Critical significance for this is supported by the experimental example described later.

1 is a functional coating liquid manufacturing process flow chart according to an embodiment of the present invention can be prepared with reference to this functional coating liquid.

One embodiment of the present invention also provides a hard coating prepared by coating the substrate using the above-described hard coating solution and then photocuring. Before coating the hard coating solution, the substrate may be surface treated with a primer or the like, or may be coated after further forming a functional layer. The type of the hard coating is not limited, and any material that includes scratch and antifouling properties is included. For example, the substrate may be used in a functional hard coating film, a functional protective film for a touch panel, or a functional hard coating film for in-mold lamination.

Figure 3 is an example of a hard coating according to an embodiment of the present invention, a schematic cross-sectional view showing a functional hard coating film for in-mold molding.

In the case of the hard coating prepared by coating the above-mentioned hard coating solution on the substrate and then photocuring, the crack resistance of the hard coating layer is very excellent as 1 or less, and thus may be particularly useful as a functional hard coating film for in-mold lamination.

Experimental Example 1 Preparation of Fluorine-Based Polyurethaneacrylate Functional Copolymer

Reaction solution 1 was prepared in a 1 L four-neck round flask reactor. First, the ratio of the polyurethane acrylate oligomer and hexafluorobutyl acrylate (HFBA) to the solvent was sufficiently stirred as in <Table 1> using an electric stirrer.

Next, the reaction solution 2 was prepared. 2,2-azobisisobutyronitrile as a radical initiator in NMP was sufficiently stirred at 1.0-10.0% by weight based on monomers using an electric stirrer. When the reactor temperature was maintained at 60-80 ℃ two reaction solutions were added using a micro pump and reacted for 12 to 24 hours. After the reaction, the mixture was washed five times or more with diethyl ether, and the solvent was dried under reduced pressure. 2 is an F19-NMR spectrum of a fluorine-based polyurethane acrylate functional copolymer according to an embodiment of the present invention.

TABLE 1 Composition ratio of Experimental Example 1

FPUA A1 FPUA A2 FPUA A3 FPUA A4 FPUA A5 FPUA A6 FPUA A7 PUA 100% 80% 70% 60% 50% 40% 30% Fluorine Acrylate 0 % 20% 30% 40% 50% 60% 70% solvent NMP NMP NMP NMP NMP NMP NMP Radical initiator AIBN AIBN AIBN AIBN AIBN AIBN AIBN

(PUA: polyurethane acrylate oligomer)

Experimental Example 2 Preparation of Functional Coating Liquid Containing Fluorinated Polyurethane Acrylate Functional Copolymer

  Among the fluorine-based polyurethane acrylate functional copolymers prepared in Experimental Example 1, FPUA A5 having low surface energy and good physical properties (FPUA A7 has the smallest surface energy, but when used, the pencil hardness drops to 2H or less). ) And the polyurethane acrylate UV curing resin was blended while changing the ratio as shown in Table 2 below to prepare a coating solution.

  10.0 to 40.0% by weight of the total concentration is added so that 60.0-90.0% by weight of the total concentration of methyl ethyl ketone is occupied by the fluorine-based polyurethane acrylate and the urethane-based and acrylic UV-curable resins forming the coating film during UV curing. In order to prepare a UV-curable coating solution, 1.0-10.0 wt% of the coating material blended with IRGACURE 184, which is a photoinitiator, was added to the standard, and sufficiently stirred using an electric stirrer to prepare a functional coating solution for an optical film.

TABLE 2 Composition ratios of Experimental Example 2

GERI-R1 GERI-R2 GERI-R3 GERI-R4 GERI-R5 GERI-R6 Functional
Copolymer FPUA A5
0 % FPUA A5
20% FPUA A5
40% FPUA A5
60% FPUA A5
80% FPUA A5
100% UV-rays
Hardening resin PUA 100% PUA 80% PUA 60% PUA 40% PUA 20% PUA 0% solvent MEK MEK MEK MEK MEK MEK Photoinitiator IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184

Experimental Example 3 Preparation of Functional Hard Coating Film Using Coating Solution Containing Fluorinated Polyurethane Acrylate Functional Copolymer

First, the coating material prepared in Experimental Example 2 was applied using a bar coater, and then dried in a drying apparatus at 85 ° C. for 60 seconds, and then irradiated with ultraviolet rays to prepare a functional hard coating film. Thereafter, pencil hardness, adhesion, surface contact angle, transmittance, haze, crack resistance, reflection appearance characteristics, etc. were measured by a known method and shown in Table 3.

Table 3 Properties of Functional Films Prepared in Experimental Example 3

GERI-R1 GERI-R2 GERI-R3 GERI-R4 GERI-R5 GERI-R6 Optical
characteristic Transmittance (%) 91.52 91.50 91.45 91.30 91.20 90.8 HAZE (%) 0.75 1.00 1.05 1.10 1.50 2.28 physical
characteristic
And appearance Adhesion B A A A A A Pencil hardness 3H 3H 2H 2H H H steel wool Rank 3 Rank 3 Rank 3 Rank 2 Rank 2 Rank 1 Crack resistance 2Ø or less 2Ø or less 1Ø or less 1Ø or less 1Ø or less 1Ø or less Reflection
(rainbow) ○ ○ ○ △ △ X surface
Contact angle 60 95 100 103 105 110

<Experimental Example 4> Preparation of a functional coating solution that can simultaneously implement wear resistance and antifouling

Next, in order to increase wear resistance of the functional coating solution containing the fluorine-based polyurethane acrylate functional copolymer prepared in Experimental Example 2, TiO ₂ nanosol was added to the coating solution to prepare a functional coating solution having excellent wear resistance and antifouling properties. While increasing the content of TiO ₂ nanosol in GERI-R3 of Experimental Example 3 was prepared a functional coating solution that can realize abrasion resistance and antifouling at the same time conditions.

TABLE 4 Composition ratios of Experimental Example 4

GERI-T1 GERI-T2 GERI-T3 GERI-T4 GERI-T5 GERI-T6 Functional copolymer FPUA A5
40% FPUA A5
40% FPUA A5
40% FPUA A5
40% FPUA A5
40% FPUA A5
40% bookbinder PUA 60% PUA 60% PUA 60% PUA 60% PUA 60% PUA 60% solvent MEK MEK MEK MEK MEK MEK Photoinitiator IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 Ti O ₂
Nano Sol 0 % 1.0% 2.0% 3.0% 4.0% 5.0%

<Experiment 5> Preparation of a functional hard coating film using a coating solution that can realize abrasion resistance and antifouling at the same time

First, the coating material prepared in Experimental Example 4 was applied using a bar coater, and then dried in a drying apparatus at 85 ° C. for 60 seconds, and then irradiated with ultraviolet rays to prepare a functional hard coating film. Thereafter, pencil hardness, adhesion, surface contact angle, transmittance, haze, crack resistance, reflection appearance characteristics, etc. were measured by a known method, and are shown in Table 5. 4 is a result of the name pen TEST of one embodiment GERI-T3 and the conventional optical film of the present invention, Figure 5 is a result of the wear test of one embodiment of the present invention GERI-T3 and the existing product.

Table 5 Properties of Functional Films Prepared in Experimental Example 5

GERI-T1 GERI-T2 GERI-T3 GERI-T4 GERI-T5 GERI-T6 Optical
characteristic Transmittance (%) 91.45 91.2 91 89.5 89.0 88.0 HAZE (%) 1.05 1.1 1.2 1.7 2.45 2.84 physical
characteristic
And appearance Adhesion A A A A B C Pencil hardness 2H 2H 3H 3H 3H 3H steel wool Rank 3 Rank 3 Rank 4 Rank4 Rank 3 Rank 2 Crack resistance 1Ø or less 1Ø or less 1Ø or less 1Ø or less 2Ø or less 2Ø or less Reflection ○ ○ ○ △ X X surface
Contact angle 95 95 95 95 95 95

[Experimental example condition]

The experimental method embodied in the above experimental example was evaluated by preparing a hard coating composition and applying a bar coater on 100 μm PET film, drying at 85 ° C. for 60 seconds, and curing UV light to prepare a coating film having a thickness of 5 μm.

1. Adhesion Test

100 100 mm2 crosscuts were put on the hard coat layer of the hard coat film at room temperature, and the rubber roller was reciprocated three times under a load of 19.6 N using 3M's tape and pressed, and then peeled in a 90 ° direction. Four stages of evaluation (A: 100, B: 80-99, C: 50-79, D: 0-49) were performed according to the remaining number of hard coat layers. In the case of A and B, adhesiveness was evaluated as good.

2. steel wool

The load on the surface of the coating layer was changed to steel wool # 0000, and each load was reciprocated ten times under a constant load (speed 10 cm / s), and the maximum load with damage resistance (not damaged) was measured. Rank 2 or above is practically no problem and is judged as pass. Passing was judged by four stages. (Rank 1: 1kg / ㎠, Rank 2: 2kg / ㎠, Rank 3: 3kg / ㎠, Rank 4: 4kg / ㎠)

3. Pencil Hardness

It measured according to JIS K-5400 using HEIDON (made by Shintogagaku Co., Ltd.). 2H or more was made into the pass.

4. Transmittance and Haze

Permeability and haze of all samples were measured using a Haze meter (NDH-300A).

5. Rainbow Level

 The back side of the hard coat was treated with a matt black ink at room temperature and viewed from a 15 degree angle. "○" indicates no rainbow, "△" indicates that the rainbow is weak and "X" indicates that the rainbow is severe.

6. Coating surface contact angle

It was measured using a KRUSS, DSA attached to an illuminator using a contact liquid of water at room temperature. The measurements were made at five different points and the averages recorded.

7. Crack resistance

It evaluated by the cylindrical mandrel method. The smaller the value of Ø, the less cracking of the hard coat layer and the better crack resistance.

  According to the results of the physical property values of Experimental Example 3 using the coating solution prepared through Experimental Example 2, a distinct change in physical properties was investigated depending on the ratio of the fluorine-based polyurethane acrylate copolymer and the polyurethane polyurethane acrylate UV curable resin. In addition, as the ratio of the fluorine-based polyurethane acrylate copolymer increased, the contact angle of the surface was increased to increase the antifouling properties. However, the results of the pencil hardness and steel wool were not good. From this, it was found that problems such as durability and pencil hardness due to the properties of fluorine may occur when using a material containing fluorine, thereby inventing an optimum value.

In addition, the coating liquid was prepared under the same conditions as Experimental Example 4 in order to investigate the increase in durability and abrasion resistance according to the addition of TiO ₂ nanosol by selecting a condition that satisfies the results of the pencil hardness and steel wool among the excellent contact angle. . In addition, according to Table 5, which is a result of the physical property value of Experimental Example 5, the addition of TiO ₂ nanosol has the advantage of increasing the wear resistance of the coating surface, but since the TiO ₂ nanosol is more than 3%, the rainbow remains weakly on the coating surface. This is getting worse. Haze increases and transmittance decreases, and when TiO ₂ nanosol exceeds 5%, it is found to be inferior, and the optimal content threshold of TiO ₂ nanosol, which is 1-5%, more preferably 1-3%, is derived. .

1 is a functional coating liquid manufacturing process flow chart according to an embodiment of the present invention,

2 is a F19-NMR spectrum of the fluorine-based polyurethane acrylate functional copolymer according to an embodiment of the present invention

3 is a structure of the functional hard coating film for IML according to one embodiment of the present invention,

Figure 4 is a name pen test results of the functional film and the conventional optical film according to an embodiment of the present invention

5 is a wear test result diagram according to an embodiment of the present invention.

Claims (6)

A fluorine-based polyurethane acrylate functional copolymer formed by copolymerizing a polyurethane (meth) acrylate oligomer and a fluorine-based (meth) acryl monomer, an ultraviolet curable resin, a photoinitiator, and TiO ₂ nanosols are included to increase wear resistance. Hard coating liquid. The hard coating liquid according to claim 1, wherein the TiO ₂ nanosol is included in the range of 1.0 to 3.0% by weight based on 100 weight of the hard coating liquid solids. The hard coating solution of claim 1, wherein the TiO ₂ nanosol has a size in a range of 50 nm to 100 nm. The hard coating liquid according to claim 1, wherein the composition ratio of the polyurethane (meth) acrylate oligomer and the fluorine-based (meth) acryl monomer is in the range of 60:40 to 50:50. The hard coating liquid according to claim 1, wherein the ultraviolet curable resin is polyurethane (meth) acrylate. Hard coating prepared by coating the hard coating liquid of any one of claims 1 to 5 on the substrate and then photocuring, wherein the hard coating layer has a crack resistance of less than 1Ø.

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