KR20090063182A - Fluorinated polyurethane acrylate copolymer and hard coating composition comprising the same - Google Patents

Abstract

A fluorinated polyurethane acrylate copolymer is provided to ensure excellent antifouling property and scratch resistance by using an polyurethaneacrylate oligomer with good hardness and a fluorinated acrylate monomer with low surface energy. A fluorinated polyurethane acrylate functional copolymer is a (meth)acrylate oligomer and a fluorinated (meth)acrylic monomer. The (meth)acrylate oligomer and a fluorinated (meth)acrylic monomer are included in a ratio of 60:40 ~ 50:50. The average molecular weight of polyurethane (meth)acrylate oligomer is 1000~3000. The hard coating liquid comprises the fluorinated polyurethane acrylate functional copolymer, binder and photoinitiator.

Description

Fluorinated Polyurethane Acrylate Copolymer And Hard Coating Composition Comprising The Same

The present invention relates to a fluorine-based polyurethane acrylate functional copolymer, and a hard coating solution and a hard coating comprising the same.

In the case of a film used in a conventional touch screen, if the contaminants are adhered or scratched at the outermost part of the panel, the quality of the panel is degraded. Accordingly, the touch screen film prevents adhesion of contaminants to contamination such as fingerprints, and requires a coating material having strong durability against external scratches by nails or a touch pen. However, the technology of the coating material that can simultaneously realize the hard coating function and anti-fingerprint properties that can prevent the adhesion of external contamination is still inadequate.

In addition, in the Republic of Korea Patent Publication No. 10-2006-0009194 to realize the function of the multi-layered optical film using the respective coating material, not a single layer. This causes a problem in the adhesion between the layers and there is a problem to increase the manufacturing cost. In addition, in the case of an anti-fingerprint coating optical film having a multi-layer structure, the coating film is easily peeled off, and there is a problem in that coating is not performed due to poor adhesion between the coating layers.

The present invention is to compensate for the above problems, the process is simple and economical, and the synthesis of a functional copolymer capable of simultaneously implementing functionally excellent anti-fingerprint and scratch resistance, and a functional coating solution and a functional film comprising the same It aims to provide.

In the present invention, in order to implement the anti-fingerprint properties and scratch resistance properties, the polyurethane acrylate oligomer having excellent hardness and the fluorinated acrylate monomer having low surface energy are used for the anti-fingerprint property and the scratch resistance property by using the radical solution polymerization method. The present invention provides a functional copolymer having excellent scratch resistance, and provides a hard coating solution including a manufactured fluorine-based polyurethane acrylate functional copolymer and a binder.

In addition, to provide an antifouling coating solution and an antifouling coating including the functional copolymer and a photoinitiator.

As a means for achieving the above object,

The present invention provides a fluorine-based polyurethane acrylate functional copolymer formed by copolymerizing a polyurethane (meth) acrylate oligomer and a fluorine-based (meth) acryl monomer.

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

Furthermore, the weight average molecular weight of the said polyurethane (meth) acrylate oligomer is 1000-3000, The fluorine-type polyurethane acrylate functional copolymer is provided.

The present invention also provides a hard coating solution comprising a fluorine-based polyurethane acrylate functional copolymer, a binder, and a photoinitiator.

In addition, the fluorine-based polyurethane acrylate functional copolymer provides a hard coating solution characterized in that the fluorine-based polyurethane acrylate functional copolymer and a binder composed of 10.0 ~ 75.0% by weight of the total weight of the binder.

In addition, the binder provides a hard coating liquid, characterized in that the polyurethane (meth) acrylate oligomer.

In addition, the binder is a polyurethane (meth) acrylate oligomer, and provides a hard coating liquid, characterized in that the same as the polyurethane (meth) acrylate oligomer which is a component of the fluorine-based polyurethane acrylate functional copolymer.

The present invention also provides a hard coating prepared by coating the hard coating solution on the substrate and then photocuring.

The present invention also provides an antifouling coating solution comprising the fluorine-based polyurethane acrylate functional copolymer and a photoinitiator.

The present invention also provides an antifouling coating prepared by coating the antifouling coating solution on a substrate and then photocuring the same.

The present invention having the structural features as described above, the functional copolymer prepared by using a radical solution polymerization method of a polyurethane acrylate oligomer having excellent hardness and a fluorine-based acrylate monomer having a low surface energy in order to implement a hard coating function is It is excellent in antifouling properties such as anti-fingerprint properties and scratch resistance, and the hard coating solution prepared using this functional copolymer provides a hard coating layer having a pencil hardness (based on 1 kgf) of 3H or more and excellent adhesion to the substrate and antifouling properties. .

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 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, it may be copolymerized by further including one or more monomers capable of radical polymerization, if necessary, is not limited.

The present invention is to prepare a polyurethane acrylate oligomer having excellent hardness and a fluorine acrylate monomer having a low surface energy as a copolymer by using a radical solution polymerization method, thereby having a scratch resistance, antifouling property and adhesion to one copolymer at the same time Through this, it is possible to manufacture the structure of the conventional multi-functional optical film of the multi-layer structure in a single layer structure, which can have the advantage of improving the economics and the respective functionality.

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 weight average 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. .

Here, the weight 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, the weight ratio of the polyurethane (meth) acrylate oligomer and the fluorine-based (meth) acryl monomer is 70:30 to 40:60, more preferably 60:40 to 50:50. When 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 antifouling property, but may result in a decrease 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 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 dried in a vacuum oven for more than 12 hours to obtain a fluorine-based polyurethane acrylate functional copolymer.

The hard coating solution according to an embodiment of the present invention provides a coating solution including the above-described fluorine-based polyurethane acrylate functional copolymer and a binder. Preferably, the fluorine-based polyurethane acrylate functional copolymer is preferably contained 10 to 75% by weight based on the total weight of the fluorine-based polyurethane acrylate functional copolymer and a binder. If it is less than 10% by weight, adhesion and antifouling properties may fall, and when it exceeds 75% by weight, the pencil hardness may be lowered and scratch resistance may be reduced.

The binder may be used without limitation as long as it is a binder that can be used in a hard coating solution, preferably polyurethane (meth) acrylate, and more preferably the same polyurethane used to prepare a fluorine-based polyurethane acrylate functional copolymer Using (meth) acrylate improves the dispersibility and durability of the fluorine-based polyurethane acrylate functional copolymer in the blending step.

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 using 1 to 10 times the total weight of the fluorine-based polyurethane acrylate functional copolymer and the binder.

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. The type of the hard coat is not limited, and any material that includes scratch and antifouling properties is included. For example, the substrate may be a functional film, an optical film, or a touch panel.

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 5 times or more with diethyl ether and dried in a vacuum oven for 60 hours or more. The chemical formula of the obtained fluorine-type polyurethane acrylate functional copolymer is as follows.

<Formula 1>

(PU here is a polyurethane group in the range of molecular weight 1000-3000, and the ratio of m and s depends on the composition ratio of Table 1)

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% Fluorinated 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 Hydrophobic Surface Modification Coating Solution

The fluorine-based polyurethane acrylate functional copolymer prepared in Experimental Example 1 is added at a concentration of 30% by weight of the total weight and toluene is added at a concentration of 70% by weight. In order to prepare a UV-curable coating solution, IRGACURE 184, a photoinitiator, was added in an amount of 1-4 % by weight based on the fluorine-based polyurethane acrylate functional copolymer and sufficiently stirred using an electric stirrer to prepare a coating material for hydrophobic surface modification.

<Table 2> Composition of coating material for hydrophobic surface modification

GERI 1 GERI 2 GERI 3 GERI 4 GERI 5 GERI 6 GERI 7 Monomer FPUA A1 30% FPUA A2 30% FPUA A3 30% FPUA A4 30% FPUA A5 30% FPUA A6 30% FPUA A7 30% Solvent Toluene 70% Toluene 70% Toluene 70% Toluene 70% Toluene 70% Toluene 70% Toluene 70% Photoinitiator IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184

Experimental Example 3 Preparation of an Antifouling Film Coated with a Hydrophobic Surface Modification Coating Material

Next, an antifouling film was prepared using the coating material prepared in Experimental Example 2. First, the coating material prepared in Experimental Example 2 was applied using a bar coater, and then sufficiently dried at 80 ° C. for 1 minute in a drying apparatus to produce ultraviolet film by irradiating ultraviolet rays, and the surface energy was measured and shown in Table 3.

Table 3 Measurement of the surface energy of the film prepared above

GERI 1 GERI 2 GERI 3 GERI 4 GERI 5 GERI 6 GERI 7 Surface energy 49.0 mJ / cm ² 31.5 mJ / cm ² 29.0 mJ / cm ² 25.5 mJ / cm ² 23.6 mJ / cm ² 22.9 mJ / cm ² 22.4 mJ / cm ²

Experimental Example 4 Preparation of Functional Coating Liquid Containing Fluorine-Based Polyurethaneacrylate 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 a polyurethane acrylate binder was blended while changing the ratio as shown in Table 4 below to prepare a coating solution.

10.0-40.0% by weight of the total concentration is taken up by the blended coating material and toluene is added to 60.0-90.0% by weight of the total concentration. 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 4 Composition ratios of Experimental Example 4

GERI-R1 GERI-R2 GERI-R3 GERI-R4 GERI-R5 GERI-R6 Functional copolymer FPUA A5 12.5% FPUA A5 25.0% FPUA A5 37.5% FPUA A5 50.0% FPUA A5 62..5% FPUA A5 75.0% bookbinder PUA 87.5% PUA 75.0% PUA 62.5% PUA 50.0% PUA 37.5% PUA 25.0% solvent toluene toluene toluene toluene toluene toluene Photoinitiator IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184 IRGACURE 184

Experimental Example 5 Functional Optical Film Using Coating Solution Containing Fluorinated Polyurethane Acrylate Functional Copolymer

Next, as shown in Figure 1 and 2, using the coating material prepared in Experimental Example 4 to prepare a functional film. First, the coating material prepared in Experimental Example 4 was applied using a bar coater, and then dried in a drying apparatus at 80 ° C. for 1 minute, and then irradiated with ultraviolet rays to produce a functional film. Thereafter, pencil hardness, adhesion, surface energy, and transmittance were measured, and are shown in Table 5, and the XPS spectrum of the functional film and the XPS C1s high resolution spectrum of the functional film surface were respectively shown in FIG. 3 ((a) GERI R. -1 (b) GERI R-2 (c) GERI R-3 (d) GERI R-4 (e) GERI R-5 (f) GERI R-6), FIG. 4 ((a) GERI R-1 ( b) GERI R-2 (c) GERI R-3 (d) GERI R-4 (e) GERI R-5 (f) GERI R-6).

In addition, as a result of the antifouling evaluation of the GERI-R6 samples of Table 4 using a name pen as shown in Figure 5, it was confirmed that significantly improved compared to the conventional optical film.

Table 5 Properties of Functional Films Prepared in Experimental Example 5

samples hardness TEST (pencil hardness) Adhesion Test (3 times cross-cut) Surface energy Transmittance GERI-R1  3H X 44.0 mJ / cm ² 91.0% GERI-R2  3H X 40.3 mJ / cm ² 91.0% GERI-R3  3H ▲ 35.0 mJ / cm ² 90.5% GERI-R4  3H ○ 31.0 mJ / cm ² 89.0% GERI-R5  3H ◎ 28.5 mJ / cm ² 91.0% GERI-R6  3H ◎ 26.0 mJ / cm ² 90.0%

(◎ Very good ○ Good ▲ Normal X Bad)

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

Figure 2 is a schematic cross-sectional view of the hard coating according to an embodiment of the present invention,

3 is an XPS spectrum of a functional film surface according to one embodiment of the present invention,

4 is an XPS C1s spectrum of a functional film surface according to one embodiment of the present invention,

Figure 5 is a name pen test results of the functional film and the conventional optical film according to an embodiment of the present invention.

Claims (11)

A fluorine-based polyurethane acrylate functional copolymer formed by copolymerizing a polyurethane (meth) acrylate oligomer and a fluorine-based (meth) acryl monomer. The fluorine-based polyurethane acrylate functional copolymer according to claim 1, wherein the 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 fluorine-based polyurethane acrylate functional copolymer according to claim 1, wherein a weight average molecular weight of the polyurethane (meth) acrylate oligomer is in a range of 1000 to 3000. Hard coating liquid comprising a fluorine-based polyurethane acrylate functional copolymer, a binder, and a photoinitiator of any one of claims 1 to 3. The hard coating solution of claim 4, wherein the fluorine-based polyurethane acrylate functional copolymer is included in an amount of 10.0 to 75.0% by weight based on the total weight of the fluorine-based polyurethane acrylate functional copolymer and a binder. The hard coating solution of claim 4, wherein the fluorine-based polyurethane acrylate functional copolymer is included in an amount of 50.0 to 75.0% by weight based on the total weight of the fluorine-based polyurethane acrylate functional copolymer and a binder. The hard coating liquid according to claim 4, wherein the binder is a polyurethane (meth) acrylate oligomer. The hard coating liquid according to claim 4, wherein the binder is a polyurethane (meth) acrylate oligomer, which is the same as the polyurethane (meth) acrylate oligomer which is a component of the fluorine-based polyurethane acrylate functional copolymer. Hard coating manufactured by coating the hard coating solution of claim 4 on the substrate and then photocuring. An antifouling coating solution comprising the fluorine-based polyurethane acrylate functional copolymer of any one of claims 1 to 3, and a photoinitiator. An antifouling coating prepared by coating the antifouling coating solution of claim 10 on a substrate and then photocuring it.

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