KR20220050321A - composition for hard-coating with anti-fouling - Google Patents

Abstract

The present invention relates to a high-hardness coating composition with excellent antifouling properties and comprises: 10 to 30% by weight of a urethane oligomer containing a fluorine component and an acid-modified vinyl group; 20 to 40% by weight of an acrylic monomer; 0.5 to 7.0% by weight of a photoinitiator and a thermal initiator; and 40 to 60% by weight of a solvent. According to the present invention, the urethane oligomer constituting the high-hardness coating composition contains a fluorine component and an acid-modified vinyl group to provide a high-hardness coating film that improves antifouling properties and bendability while having scratch resistance and preventing a decrease in adhesion to a coated substrate, so the high-hardness coating composition is easily applied to a flexible device.

Description

High hardness coating composition with excellent antifouling properties {composition for hard-coating with anti-fouling}

The present invention relates to a high hardness coating composition having excellent antifouling properties while having scratch resistance and good bending properties.

High-hardness coating is applied to products requiring protection from foreign substances or the external environment, especially contaminants such as liquid crystal display (LCD), plasma display (PDP), solar panel, light emitting display (EL), polyester film, polycarbonate film, acrylic film, etc. It is used in products for surface protection of products that are lethal by contamination, or for resistance to marking by fingerprints, markers, etc. and/or ease of removal (ie, antifouling). The method of high-hardness coating uses a method of obtaining a coating film by applying the prepared high-hardness coating agent.

A film made of such a high hardness coating is difficult to be scratched, has little deterioration even when exposed to light or water for a long period of time, must be difficult to discolor, and properties that are difficult to adhere to and easily wipe off are required. In addition, due to the recent advent of flexible devices, there should be no damage including cracks due to bending.

In general, high hardness coating agents mainly use acrylic polymers, urethane polymers, epoxy polymers, silicon polymers, or silica compounds as polymers. These polymers exist in the form of monomers or oligomers, and photoinitiators are added thereto to By forming a polymer by this, it has high hardness coating properties.

Most of these high hardness coatings increase the abrasion resistance as the crosslinking density increases, but due to the shrinkage of the coating layer, cracks may occur during bending or transportation, and deformation of the coating seam may occur, thereby reducing the adhesion to the material. Even the slightest touch results in it falling off easily. In addition, as the thickness of the substrate becomes thinner, curvature occurs, and even when thermal processing is performed, the curvature and color may change.

It is known to mix|blend the silicone compound or fluorine compound which has antifouling property in order to provide antifouling property to a high hardness coating agent.

Korean Patent Application Laid-Open No. 2013-0032658 discloses a UV-curable coating composition including polyorganosiloxane containing a multi-vinyl group, an acrylic monomer, a photoinitiator and a curing agent, and a high-hardness coating film prepared using the same.

According to the above patent, since silicone is included, weather resistance and antifouling properties are excellent, and the hardness of the coating film can be controlled by adjusting the content of vinyl groups of polyorganosiloxane, but there was a problem that the hardness had to be lowered in order to improve bendability.

When a fluorine compound is blended to improve antifouling properties, there is a problem in that the fluorine compound bleeds from the high hardness coating film, thereby deteriorating the antifouling component and reducing adhesion to the coating substrate.

In order to solve the above problems, the present invention includes a component having antifouling properties in a photocurable polymer to prevent the antifouling component from bleed, and to provide a high hardness coating composition that improves scratch resistance, bending resistance, and adhesion to a coating substrate. do it with

In order to solve the above problems, the present invention, 10 to 30% by weight of a urethane oligomer containing a fluorine component and an acid-modified vinyl group; 20-40 wt% of acrylic monomer; 0.5-7.0 wt% of photoinitiator and thermal initiator; And it provides a high hardness coating composition excellent in antifouling properties comprising 40 to 60% by weight of a solvent.

According to the present invention, the urethane oligomer constituting the high-hardness coating composition contains a fluorine component and an acid-modified vinyl group to improve antifouling and bending properties, while providing a high-hardness coating film that does not reduce scratch resistance and adhesion to the coating substrate. It is easily applied to one device.

The present invention is a urethane oligomer containing a fluorine component and an acid-modified vinyl group; acrylic monomers; photoinitiators and thermal initiators; and a high hardness coating composition including a solvent.

The urethane oligomer containing a fluorine component and an acid-modified vinyl group may be prepared by copolymerizing a fluorinated carbon compound having hydroxy functional groups at both ends and an acid-modified vinyl group-containing urethane.

The fluorine component and acid-modified vinyl group-containing urethane oligomer is preferably included in an amount of 10 to 30% by weight in the high hardness coating composition, and when it is less than 10% by weight, the bendability of the high hardness coating film, adhesion to the substrate, and antifouling properties are reduced And, if it exceeds 30% by weight, scratch resistance and hardness may be reduced.

In addition, it is preferable that the weight average molecular weight is 20,000 to 80,000. If it is less than 20,000, bendability and adhesiveness decrease, and if it exceeds 80,000, the introduction and dispersion of fluorine component becomes non-uniform, antifouling property and hardness decrease, and coating workability is high due to high viscosity can be lowered

The fluorinated carbon compound to which a hydroxy functional group is provided at both ends is represented by the following formula (1). It is an ether diol in which 6 to 16 fluorine groups are bonded to one chain, the fluorine content is 50 to 70 mol% in one molecule, and hydroxyl functional groups are provided at both ends. The fluorine group in the molecular structure blocks external pollutants and increases interfacial tension to provide water and oil repellency, thereby suppressing the adhesion of external pollutants.

[Formula 1]

HO-CH ₂ -CF ₂ -O-(CF ₂ CF ₂ O) _m -(CF ₂ O) _n -CF ₂ -CH ₂ -OH

As a commercialized product of a fluorinated carbon compound with hydroxy functional groups at both ends, Solvay's FluoroLINK(Mw: 1,400, FLK D10-H).

The acid-modified vinyl group-containing urethane oligomer includes a vinyl group in the side chain, has a weight average molecular weight of 2,000 to 20,000, and a vinyl equivalent weight of 0.6 to 1.7 mmol/g is preferably used.

The acid-modified vinyl group-containing urethane oligomer can be synthesized by heating a diisocyanate compound to a vinyl group-containing diol compound by adding a conventional catalyst having reactivity to each in an aprotic solvent. At this time, the reaction ratio is such that all NCO groups are in excess of all OH groups. By having an isocyanate group at the end of the resulting oligomer, it can be copolymerized with a fluorinated carbon compound having a hydroxyl functional group at both ends.

As a compound for providing a vinyl group to the side chain as described above, a compound containing a vinyl group can be used without limitation, (meth)acrylate, glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth) ) acrylates and the like can be used.

In the present invention, a urethane having a vinyl group in the side chain can be easily synthesized by using one having at least one vinyl group in a diisocyanate compound or a diol compound rather than introducing a vinyl group by substitution in the side chain after synthesizing urethane. .

When photocuring by the vinyl group of the side chain, a crosslinking reaction occurs between the high hardness coating compositions, so that the strength and scratch resistance of the photocured material can be further improved.

In addition, it has good compatibility with the polyfunctional acrylic monomer and suppresses excessive shrinkage of the acrylic monomer during photocuring, thereby improving adhesion to the coating substrate.

In the present invention, if the weight average molecular weight is less than 2,000, the bendability and adhesion to the substrate may decrease in the high hardness coating film, and if it exceeds 20,000, the coatability may decrease.

In the present invention, when the vinyl group equivalent is less than 0.6 mmol/g, heat resistance and adhesion are lowered in the high hardness coating film, and when it exceeds 1.7 mmol/g, cracks may occur and hardness and scratch resistance may be reduced.

The urethane oligomer containing a fluorine component and an acid-modified vinyl group used in the present invention does not yellow, has a high hardness, has excellent durability, and has instant curing performance, giving excellent scratch resistance and abrasion resistance to various plastic substrates, and the substrate and adhesiveness can be improved.

As a radical polymerization monomer, the acrylic monomer of this invention has a boiling point of 100 degreeC or more under normal pressure, and the compound which has an ethylenically unsaturated group in which at least 1 addition polymerization is possible is preferable. As said ethylenically unsaturated group, a (meth)acryloyl group is especially preferable.

Examples of the radical polymerization monomer having a (meth)acryloyl group include monofunctional acrylates and methacrylics such as polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and phenoxyethyl(meth)acrylate. rate; polyethylene glycol di (meth) acrylate, trimethylol ethane tri (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, hexanediol (meth) acrylate, trimethylolpropane tri (acryloyloxypropyl) ether, tri (acryloyloxyethyl) ) Isocyanurate, (meth)acrylated after adding ethylene oxide or propylene oxide to polyfunctional alcohol such as glycerin or trimethylol ethane, epoxy acrylate, which is a reaction product of an epoxy resin and (meth)acrylic acid Polyfunctional acrylates and methacrylates, such as these; and mixtures thereof, etc. are mentioned.

The polymerization initiator in the high hardness coating composition of the present invention is characterized in that a photocuring initiator and a thermal curing initiator are used together.

When a photocuring initiator is used alone, uncured monomers and oligomers may exist, and when curing is performed using only a thermosetting initiator alone, contamination by dust and foreign substances occurs, resulting in lower production yield. there may be

The amount of the polymerization initiator is preferably 0.5 to 7% by weight of the total high hardness coating composition by combining the photocuring initiator and the thermal curing initiator. Looking at the contents of the photocuring initiator and the thermal curing initiator for the entire high hardness coating composition, respectively, the photocuring initiator may be included in 0.025 to 6% by weight, and the thermal curing initiator may be included in 0.025 to 1% by weight. If the content of each curing initiator is out of the above range, the curing may not be sufficient and stickiness may occur or over-curing may occur, causing the film to change color to very yellow and be easily broken.

As the photocuring initiator and the thermosetting initiator, both curing initiators generally used in the photocurable composition and the thermosetting composition may be used. In an embodiment of the present invention, 1-hydroxy-cyclohexyl-phenyl-ketone, which is non-yellowing and has a fast surface hardening, was used as the photocuring initiator, and benzoyl was used as the thermosetting initiator. Although peroxide (benzoyl peroxide) was used, it is not limited thereto.

As a solvent used in the high hardness coating composition of the present invention, a solvent having excellent compatibility with the composition may be used without limitation, for example, petroleum hydrocarbon solvents such as hexane and mineral spirit; aromatic hydrocarbon solvents such as benzene, toluene, and xylene; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, γ-butyrolactone, and propylene glycol monomethyl ether acetate; and aprotic polar solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone and pyridine.

Hereinafter, the present invention will be specifically described by way of Synthesis Examples, Preparation Examples, Examples and Comparative Examples. However, the following examples are only for illustrating the present invention, and the present invention is not limited by the following examples, and can be substituted and changed to other equivalent examples without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains.

<Synthesis Example 1>

In a 500 mL 3-neck flask equipped with a condenser and stirrer, 10.86 g (0.081 mol) of 2,2-bis(hydroxymethyl)propionic acid (DMPA) and 16.82 g (0.105 mol) of glycerol monomethacrylate were mixed with propylene glycol monomethyl. It melt|dissolved in 79 mL of ether monoacetate. Here, 4,4-diphenylmethane diisocyanate (MDI) 37.54 g (0.15 mol), 2,6-di-t-butylhydroxytoluene 0.1 g, as a catalyst, trade name Neostane U-600 (Ildong Chemical Co., Ltd.) , Japan) was added, and the mixture was heated at 75°C with stirring for 5 hours. Thereafter, it was diluted with 9.61 mL of methyl alcohol and stirred for 30 minutes to obtain an oligomer solution.

The obtained acid-modified vinyl group-containing polyurethane oligomer had a solid weight average molecular weight of 8,000 and a vinyl equivalent weight of 1.5 mmol/g.

<Synthesis Example 2>

In Synthesis Example 1, 10.86 g (0.081 mol) of 2,2-bis(hydroxymethyl)propionic acid (DMPA) and 16.82 g (0.105 mol) of glycerol monomethacrylate were replaced with 2,2-bis(hydroxymethyl) A combination of 10.22 g (0.069 mol) of butanoic acid (DMBA) and 12.97 g (0.081 mol) of glycerol monomethacrylate was used instead of 37.54 g (0.15 mol) of 4,4-diphenylmethane diisocyanate (MDI) , The same method as in Synthesis Example 1 was used except that a combination of 30.03 g (0.12 mol) of 4,4-diphenyl methane diisocyanate (MDI) and 5.05 g (0.03 mol) of hexamethylene diisocyanate (HMDI) was used. was used to synthesize an acid-modified vinyl group-containing polyurethane oligomer.

The obtained acid-modified vinyl group-containing polyurethane oligomer had a solid weight average molecular weight of 15,000 and a vinyl equivalent weight of 1.3 mmol/g.

<Synthesis Example 3>

In a 500 mL 3-neck flask equipped with a condenser and stirrer, 32.00 g (0.216 mol) of 2,2-bis(hydroxymethyl)propionic acid (DMBA) and 9.00 g (0.009 mol) of polypropylene glycol (molecular weight 1,000) (PPG1000) was dissolved in 118 mL of propylene glycol monomethyl ether monoacetate. Here, 4,4-diphenylmethane diisocyanate (MDI) 37.54 g (0.15 mol), 2,6-di-t-butylhydroxytoluene 0.1 g, Neostan U-600 (Ildong Chemical Co., Ltd.) ) was added, and after stirring at 75°C for 5 hours, 9.61 g of methyl alcohol was added. Then, 17.91 g (0.126 mol) of glycidyl methacrylate (GMA) as a vinyl group-containing epoxy and 5,000 ppm of triphenylphosphine as a catalyst were added, stirred at 110° C. for 5 hours, and then cooled to room temperature. An oligomer solution was obtained.

The obtained acid-modified vinyl group-containing polyurethane oligomer had a solid weight average molecular weight of 12,000 and a vinyl equivalent weight of 1.3 mmol/g.

<Synthesis Example 4>

In Synthesis Example 3, 2,2-bis (hydroxymethyl) propionic acid (DMBA) 32.00 g (0.216 mol) and polypropylene glycol (molecular weight 1,000) (PPG1000) 9.00 g (0.009 mol) instead of 2, 2-bis Using (hydroxymethyl) propionic acid (DMPA) 28.17 g (0.21 mol) and polypropylene glycol (molecular weight 400) (PPG400) 6.00 g (0.015 mol), 4,4-diphenyl methane diisocyanate (MDI) 37.54 g The same method as in Synthesis Example 3 was followed except that instead of (0.15 mol), 30.03 g (0.12 mol) of 4,4-diphenyl methane diisocyanate (MDI) and 5.05 g (0.03 mol) of hexamethylene diisocyanate were used. was used to synthesize an acid-modified vinyl group-containing polyurethane oligomer.

The obtained acid-modified vinyl group-containing polyurethane oligomer had a solid weight average molecular weight of 15,000 and a vinyl equivalent weight of 1.1 mmol/g.

<Production Examples 1-4>

1 mol of each of the acid-modified vinyl group-containing polyurethane oligomers obtained in Synthesis Examples 1 to 4, and 0.2 mol of a fluorinated carbon compound (trade name: FLUOROLINK D10-H, Solvay, Mw: 1,400) bonded with a hydroxyl group at both ends By addition polymerization, a polyurethane oligomer containing a fluorine component and an acid-modified vinyl group having a weight average molecular weight of 25,000 and 70,000 was prepared.

<Example>

The fluorine component and acid-modified vinyl group-containing polyurethane oligomer, acrylate monomer (dipentaerythritol penta/hexaacrylate (DPHA, manufactured by NK, Japan), photoinitiator, thermal initiator and solvent of the above preparation example), butyl acetate as a solvent 2 was mixed to prepare a photocurable high hardness coating composition.

<Comparative Examples 1-2>

A photocurable high hardness coating composition was prepared with the composition shown in Table 2 below.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 urethane
oligomer Preparation Example 1 20 10 30 Preparation 2 20 Preparation 3 20 Preparation 4 20 acryl
monomer Dipentaerythritol penta/hexaacrylate 30 30 30 30 40 20 polymerization initiator Igacure 184 3 3 3 3 3 3 benzoyl peroxide 0.3 0.3 0.3 0.3 0.3 0.3 menstruum butyl acetate 46.7 46.7 46.7 46.7 46.7 46.7 Sum 100% by weight 100% by weight 100% by weight 100% by weight 100% by weight 100% by weight *Preparation Examples 1-4: Polyurethane oligomer containing acid-modified vinyl group containing a fluorine component having a weight average molecular weight of 25,000 using Synthesis Examples 1-4 as raw materials

Example 7 Example 8 Example 9 Example 10 Comparative Example 1 Comparative Example 2 urethane oligomer Preparation 7 20 Preparation 8 20 Preparation 9 20 Preparation 10 20 Miramer PU210 20 20 acryl
monomer Dipentaerythritol penta/hexaacrylate 30 30 30 30 30 30 fluorine
Surfactants FC340 One silicone compound SH190 One polymerization initiator Igacure 184 3 3 3 3 3 3 benzoyl peroxide 0.3 0.3 0.3 0.3 0.3 0.3 menstruum butyl acetate 46.7 46.7 46.7 46.7 45.7 45.7 100% by weight 100% by weight 100% by weight 100% by weight 100% by weight 100% by weight *Preparation Examples 7 to 10: Polyurethane oligomer containing acid-modified vinyl group containing a fluorine component having a weight average molecular weight of 70,000 using Synthesis Examples 1 to 4 as raw materials
**Miramer PU210: Urethane oligomer from Miwon Corporation in Korea
***FC340: 3M fluorinated surfactant
****SH190: Silicone product from Dow Corning Toray Silicone Co., Ltd.

The high hardness coating compositions of Examples and Comparative Examples were evaluated by the following evaluation method, and the results are shown in Table 3 below.

< Evaluation method >

1. Scratch resistance

Scratch resistance was tested by reciprocating 10 times under 1kg/(2cm x 2cm) using a steel wool tester (WT-LCM100, manufactured by Protech, Korea).

Steel wool #0000 was used.

A : 0 scratches

A': 1 to 10 scratches

B: 11-20 scratches

C: 21 to 30 scratches

D: 31 or more scratches

2. Adhesion

A coating film formed by coating the high hardness coating composition of the Examples and Comparative Examples on a PMMA (polymethyl methacrylate) substrate and photocuring it as a test specimen, and then drawing lines at 2mm intervals on the test specimen to make a grid, then TAPE After adhesion, the peeling phenomenon was evaluated by pulling strongly once in the vertical direction.

When the residual amount of the coating film was 95% or more, A, 90 to 95%, B, 85 to 90%, C, and less than 85%, D were evaluated.

3. Antifouling (fingerprint wipe-off)

10 testers lightly wiped fingerprint marks on the surface of the cured coating film coated with the high hardness coating composition 10 times with clean paper (ULTIMA Ⅱ, Hansong), and the wipeability was visually evaluated.

A: There are no wipe marks left. B: There are some scratches left. C: A polishing mark remained.

4. Flexibility (Bend Test)

According to the method of measurement standard JIS K5600-5-1, the minimum diameter at which a crack of 1 mm or more does not occur was measured after the coating film was sandwiched and wound on cylindrical mandrels of various diameters.

scratch resistance adhesion antifouling Flexibility (mm) Example 1 A A A 4 Example 2 A A A 4 Example 3 A A A 4 Example 4 A A A 4 Example 5 A A A 4 Example 6 A A A 4 Example 7 A A A 3 Example 8 A A A 3 Example 9 A A A 3 Example 10 A A A 3 Comparative Example 1 A' C A 6 Comparative Example 2 A' B B 6

From the results of Table 3, the high hardness coating film by the composition containing the fluorine component and the acid-modified vinyl group-containing polyurethane oligomer of the present invention was used as an antifouling component in the scratch resistance, adhesion to the coating substrate, antifouling and bending resistance tests. It is confirmed that all of them are superior to those using fluorine or a silicone-based compound.

Claims (5)

10-30 wt% of a urethane oligomer containing a fluorine component and an acid-modified vinyl group; 20-40 wt% of acrylic monomer; 0.5-7.0 wt% of photoinitiator and thermal initiator; and a high hardness coating composition having excellent antifouling properties including 40 to 60% by weight of a solvent. The method of claim 1,
The urethane oligomer containing the fluorine component and acid-modified vinyl group has a weight average molecular weight of 20,000 to 80,000 by reacting a fluorinated carbon compound having hydroxy functional groups at both ends with an acid-modified vinyl group-containing urethane oligomer A high hardness coating composition with excellent antifouling properties. 3. The method of claim 2,
The urethane oligomer containing the acid-modified vinyl group is prepared by reacting a diol compound and a diisocyanate compound, and the diol compound includes at least one of a diol compound having a vinyl group and an alcohol, and at least one of a diol compound having a carboxyl group A high hardness coating composition having excellent antifouling properties, characterized in that 3. The method of claim 2,
The urethane oligomer containing the acid-modified vinyl group has a weight average molecular weight of 2,000 to 20,000, and a vinyl group equivalent of 0.6 to 1.7 mmol/g. The method of claim 1,
The initiator is a high hardness coating composition with excellent antifouling properties, characterized in that the photoinitiator is 0.025 to 6% by weight, and the thermal initiator is 0.025 to 1% by weight.