UV-curable paint composition

Abstract

The present invention relates to a UV-curable paint composition having excellent scratch and contamination resistance.

Description

UV-curable paint composition

[0001] The present invention relates to an ultraviolet-curable paint composition having excellent scratch resistance and contamination resistance.

[0002]

[0003] To improve the scratch resistance of flooring surfaces such as tiles and to easily remove surface contaminants, various technologies for applying UV coatings to the surfaces have been proposed. For example, Korean Patent No. 0103647, U.S. Patent No. 3,782,961, and U.S. Patent No. 3,912,516 disclose coating compositions containing photocurable oligomers. However, these conventional coating compositions are not suitable for coating flexible molded articles. When applied to flexible sheets such as polyvinyl chloride (PVC), cracks occur due to insufficient flexibility, and when flexibility is enhanced, scratch resistance and heat resistance are reduced.

[0004] In particular, UV paints used for LVT (Luxury Vinyl Tile) among PVC flooring materials require excellent stain resistance, gloss, and scratch resistance, but conventional UV paints do not provide sufficient stain resistance, gloss, and scratch resistance.

[0005] Furthermore, conventional UV paints are manufactured using resins, monomers, and solvents derived from fossil fuels like oil and coal, which inevitably generate carbon dioxide, a contributing factor to global warming, during their manufacturing process. As a solution to global environmental problems and the social issues associated with plastic use, interest in products that can achieve carbon neutrality is growing, necessitating the development of bioplastics derived from biomass.

[0006]

[0007] The present invention provides a UV-curable paint composition with excellent scratch resistance and stain resistance. Furthermore, the present invention provides a bio-based UV-curable paint composition that is both scratch-resistant and stain-resistant, while also being environmentally friendly.

[0008]

[0009] The present invention provides an ultraviolet-curable paint composition comprising a trifunctional urethane (meth)acrylate oligomer, a monofunctional (meth)acrylate, a monofunctional hydroxyl group-containing (meth)acrylate, a difunctional (meth)acrylate, and a photoinitiator.

[0010]

[0011] The present invention provides a UV-curable paint composition with excellent scratch and stain resistance. The UV-curable paint composition according to the present invention is environmentally friendly and exhibits excellent scratch and stain resistance. The UV-curable paint composition according to the present invention can be applied to PVC flooring materials such as LVT (Luxury Vinyl Tile).

[0012]

[0013] The present invention will be described in detail below. However, it is not limited to the following description, and each component may be modified or selectively mixed as needed. Therefore, it should be understood that all modifications, equivalents, and alternatives included within the spirit and technical scope of the present invention are included.

[0014] As used herein, “viscosity” is measured by a conventional method known in the art, and can be measured, for example, using a Brookfield viscometer at room temperature (25°C). “Weight average molecular weight” is measured by a conventional method known in the art, and can be measured, for example, by a gel permeation chromatography (GPC) method. “Glass transition temperature” is measured by a conventional method known in the art, and can be measured, for example, by a thermomechanical analysis (TMA) method or a differential scanning calorimetry (DSC) method.

[0015]

[0016] <UV-curable paint composition>

[0017] The ultraviolet curable paint composition according to the present invention comprises a trifunctional urethane (meth)acrylate oligomer, a monofunctional (meth)acrylate, a monofunctional hydroxyl group-containing (meth)acrylate, a difunctional (meth)acrylate, and a photoinitiator.

[0018] Conventional UV paints are manufactured using resins, monomers, and solvents derived from fossil fuels like oil and coal. The manufacturing process inevitably produces carbon dioxide, a contributing factor to global warming. As a solution to global environmental problems and the social issues associated with plastic use, interest in carbon-neutral products is growing. There is a growing demand for bioplastics made from biomass. However, bio-based materials often exhibit inferior coating properties compared to those derived from fossil fuels.

[0019] The ultraviolet-curable coating composition of the present invention comprises a trifunctional urethane (meth)acrylate oligomer as a main component to improve the hardness, stain resistance, scratch resistance, etc. of a dry coating film, adjust the viscosity of the coating with a monofunctional (meth)acrylate and improve the adhesion of the coating film, adjust the viscosity with a monofunctional hydroxyl group-containing (meth)acrylate and improve the elasticity and adhesion of the coating film, and improve the scratch resistance and stain resistance of the coating film with a difunctional (meth)acrylate, thereby forming a coating film having excellent appearance, scratch resistance, stain resistance, etc. In addition, the ultraviolet-curable paint composition of the present invention may use a bio-based trifunctional urethane (meth)acrylate oligomer, a bio-based monofunctional (meth)acrylate, or a bio-based bifunctional (meth)acrylate as the oligomer and monomer, and in this case, an environmentally friendly bio-based ultraviolet-curable paint composition having excellent appearance, scratch resistance, contamination resistance, etc., and a bio content (based on solid content) of 22 wt% or more can be provided.

[0020]

[0021] Trifunctional urethane (meth)acrylate oligomer

[0022] The ultraviolet-curable coating composition of the present invention comprises a trifunctional urethane (meth)acrylate oligomer. The trifunctional urethane (meth)acrylate oligomer is a main component of a dry coating film and can improve hardness, stain resistance, scratch resistance, etc.

[0023] The above trifunctional urethane (meth)acrylate oligomer may have a viscosity (25°C) of 2,000 to 3,500 cps, for example, 3,000 to 3,400 cps. If the viscosity of the above trifunctional urethane (meth)acrylate oligomer is less than the above-mentioned range, the viscosity may be too low, resulting in failure to form a coating film or reduced adhesion, scratch resistance, and contamination resistance of the coating film. If the viscosity exceeds the above-mentioned range, the paint workability may deteriorate, resulting in reduced appearance, adhesion, scratch resistance, and contamination resistance of the coating film.

[0024] The above trifunctional urethane (meth)acrylate oligomer may have a weight average molecular weight (Mw) of 1,500 to 3,500 g / mol, for example, 2,200 to 3,000 g / mol. If the weight average molecular weight of the above trifunctional urethane (meth)acrylate oligomer is less than the above-mentioned range, the viscosity may be too low, so that the coating film may be formed thinly, thereby reducing scratch resistance and contamination resistance. If it is more than the above-mentioned range, workability may be reduced, and the coating film may be formed thickly, resulting in excessively strong gloss or reduced adhesion and scratch resistance.

[0025] The above trifunctional urethane (meth)acrylate oligomer may be a bio-based urethane (meth)acrylate oligomer. When a bio-based urethane (meth)acrylate oligomer is used, carbon dioxide emissions can be reduced, unlike conventional compositions manufactured using urethane (meth)acrylate oligomers manufactured from fossil fuels.

[0026] The above bio-based urethane (meth)acrylate oligomer can be prepared from a bio-based urethane (meth)acrylate oligomer composition. For example, the bio-based urethane (meth)acrylate oligomer composition can include a polyol, a bio-based isocyanate, and a (meth)acrylate monomer. The bio-based isocyanate can be an isocyanate derived from natural materials such as rapeseed, conifers, and sugarcane. In addition, the bio-based urethane (meth)acrylate oligomer composition can further include additives such as a catalyst or polymerization inhibitor commonly used in the relevant technical field.

[0027] The above polyol may include a polyester polyol, a dimer diol, or a mixture thereof. The above (meth)acrylate monomer may include at least one selected from the group consisting of 2-hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, pentaerythritol tri(meth)acrylate, and caprolactone-modified hydroxy (meth)acrylate.

[0028] The above trifunctional urethane (meth)acrylate oligomer may have a biocontent (based on solid content) of 22 wt% or more, for example, 23 wt% or more. If the biocontent of the above trifunctional urethane (meth)acrylate oligomer is below the above-mentioned range, the effect of reducing carbon dioxide emissions may be insufficient.

[0029] The content of the trifunctional urethane (meth)acrylate oligomer may be 30 to 50 wt%, for example, 30 to 40 wt%, based on the total weight of the UV-curable paint composition. If the content of the trifunctional urethane (meth)acrylate oligomer is less than the above-mentioned range, the viscosity may be low, resulting in a decrease in crosslinking density and curing properties, which may result in a decrease in scratch resistance, contamination resistance, and adhesion. If the content exceeds the above-mentioned range, the viscosity of the composition may be high, resulting in poor workability, and may result in a decrease in the appearance, adhesion, and scratch resistance of the coating film, as well as an increase in gloss.

[0030]

[0031] 1-functional (meth)acrylate

[0032] The ultraviolet-curable coating composition of the present invention comprises a monofunctional (meth)acrylate. The monofunctional (meth)acrylate serves to control the viscosity of the coating and improve adhesion.

[0033] The above monofunctional (meth)acrylate may be, for example, 2-ethylhexyl (meth)acrylate, octyldecyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, tridecyl (meth)acrylate, nonylphenolethoxylate mono(meth)acrylate, beta-carboxyethyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclooxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, or ethoxylated mono(meth)acrylate. For example, the monofunctional (meth)acrylate may be tetrahydrofurfuryl (meth)acrylate.

[0034] The above monofunctional (meth)acrylate may have a molecular weight of 100 to 500 g / mol, for example, 100 to 200 g / mol. If the molecular weight of the above monofunctional (meth)acrylate is less than the above-mentioned range, the crosslinking efficiency may decrease, resulting in a deterioration in appearance, and scratch resistance and stain resistance may decrease. If the molecular weight exceeds the above-mentioned range, the crosslinking density may increase significantly, resulting in a decrease in the elasticity of the coating film, which may result in an increase in gloss, appearance, adhesion, and deterioration in scratch resistance.

[0035] The above monofunctional (meth)acrylate may have a glass transition temperature of -20 to -5°C, for example, -17 to -13°C. If the glass transition temperature of the above monofunctional (meth)acrylate is below the above-mentioned range, scratch resistance and stain resistance may be reduced, and if it exceeds the above-mentioned range, stain resistance may be reduced.

[0036] The above monofunctional (meth)acrylate may have a viscosity (25°C) of 5 to 20 cps, for example, 5 to 15 cps. If the viscosity of the above monofunctional (meth)acrylate is less than the above-mentioned range, the viscosity may be too low, resulting in poor workability, and as a result, poor scratch resistance and stain resistance. If the viscosity exceeds the above-mentioned range, the paint viscosity may be too high, resulting in poor workability, and as a result, the coating film may be formed thickly, increasing gloss and reducing adhesion and scratch resistance.

[0037] The above monofunctional (meth)acrylate may be a bio-based (meth)acrylate. When a bio-based (meth)acrylate is used, carbon dioxide emissions can be reduced, unlike conventional compositions manufactured using (meth)acrylates manufactured from fossil fuels.

[0038] The above monofunctional (meth)acrylate may have a biocontent (based on solid content) of 60 wt% or more, for example, 63 wt% or more. If the biocontent of the above monofunctional (meth)acrylate is below the above-mentioned range, the effect of reducing carbon dioxide emissions may be insufficient.

[0039] The content of the above monofunctional (meth)acrylate may be 1 to 10 wt%, for example, 3 to 7 wt%, based on the total amount of the UV-curable paint composition. If the content of the above monofunctional (meth)acrylate is less than the above-mentioned range, the viscosity of the paint composition may increase and the dilutability may decrease, and if it exceeds the above-mentioned range, the viscosity of the composition may be very low, resulting in decreased curing properties and decreased adhesion, scratch resistance, and contamination resistance.

[0040]

[0041] 1-functional hydroxyl group-containing (meth)acrylate

[0042] The ultraviolet-curable coating composition of the present invention comprises a monofunctional hydroxyl group-containing (meth)acrylate. The monofunctional hydroxyl group-containing (meth)acrylate serves to control the viscosity of the coating and improve adhesion.

[0043] The above monofunctional hydroxyl group-containing (meth)acrylate may be, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc. For example, the above monofunctional hydroxyl group-containing (meth)acrylate may be 2-hydroxypropyl (meth)acrylate.

[0044] The above monofunctional hydroxyl group-containing (meth)acrylate may have a molecular weight of 100 to 500 g / mol, for example, 100 to 200 g / mol. If the molecular weight of the above monofunctional hydroxyl group-containing (meth)acrylate is less than the above-mentioned range, the crosslinking efficiency may decrease, which may result in deterioration of scratch resistance, stain resistance, and appearance. If the molecular weight exceeds the above-mentioned range, the crosslinking density may increase significantly, which may result in a decrease in the elasticity of the coating film, which may result in an increase in gloss, a decrease in appearance, adhesion, and a decrease in scratch resistance.

[0045] The above monofunctional hydroxyl group-containing (meth)acrylate may have a glass transition temperature of -10 to -4°C, for example, -9 to -5°C. If the glass transition temperature of the above monofunctional hydroxyl group-containing (meth)acrylate is below the above-mentioned range, scratch resistance and stain resistance may be reduced, and if it exceeds the above-mentioned range, gloss may increase and adhesion and scratch resistance may be reduced.

[0046] The above monofunctional hydroxyl group-containing (meth)acrylate may have a viscosity (at 25°C) of 1 to 15 cps, for example, 1 to 10 cps. If the viscosity of the above monofunctional hydroxyl group-containing (meth)acrylate is less than the above-mentioned range, the crosslinking efficiency may decrease, resulting in deterioration of scratch resistance, stain resistance, and appearance. If the viscosity exceeds the above-mentioned range, the crosslinking density may increase significantly, resulting in a decrease in the elasticity of the coating film, which may result in an increase in gloss, a decrease in appearance, adhesion, and a decrease in scratch resistance.

[0047] The content of the above monofunctional hydroxyl group-containing (meth)acrylate may be 1 to 15 wt%, for example, 10 to 14 wt%, based on the total amount of the UV-curable paint composition. If the content of the above monofunctional hydroxyl group-containing (meth)acrylate is less than the above-mentioned range, crosslinking efficiency may decrease, resulting in deterioration of scratch resistance, contamination resistance, and appearance. If the content exceeds the above-mentioned range, the crosslinking density may increase significantly, resulting in a decrease in the elasticity of the coating film, which may result in an increase in gloss, a decrease in appearance, adhesion, and a decrease in scratch resistance.

[0048]

[0049] bifunctional (meth)acrylate

[0050] The ultraviolet-curable coating composition of the present invention comprises a bifunctional (meth)acrylate. The bifunctional (meth)acrylate serves to improve the scratch resistance and contamination resistance of the coating film.

[0051] The above-mentioned bifunctional (meth)acrylate may be, for example, isosorbide di(meth)acrylate, hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, glycerin di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, etc. For example, the above-mentioned bifunctional (meth)acrylate may be isosorbide di(meth)acrylate. In this case, the scratch resistance and contamination resistance of the coating film can be further improved.

[0052] The above-mentioned bifunctional (meth)acrylate may have a molecular weight of 150 to 600 g / mol, for example, 200 to 300 g / mol. If the molecular weight of the above-mentioned bifunctional (meth)acrylate is less than the above-mentioned range, the crosslinking efficiency may decrease, which may result in deterioration of scratch resistance, stain resistance, and appearance. If the molecular weight exceeds the above-mentioned range, the crosslinking density may increase significantly, which may result in a decrease in the elasticity of the coating film, which may result in an increase in gloss, appearance, adhesion, and deterioration of scratch resistance.

[0053] The above bifunctional (meth)acrylate may have a glass transition temperature of 120 to 170°C, for example, 150 to 170°C. If the glass transition temperature of the above bifunctional (meth)acrylate is below the above-mentioned range, scratch resistance may be reduced, and if it exceeds the above-mentioned range, adhesion and scratch resistance may be reduced.

[0054] The above-mentioned bifunctional (meth)acrylate may have a viscosity (at 25°C) of 300 to 800 cps, for example, 400 to 600 cps. If the viscosity of the above-mentioned bifunctional (meth)acrylate is less than the above-mentioned range, the crosslinking efficiency may decrease, which may result in deterioration of scratch resistance, contamination resistance, and appearance. If the viscosity exceeds the above-mentioned range, the crosslinking density may increase significantly, which may result in a decrease in the elasticity of the coating film, which may result in an increase in gloss, a decrease in appearance, adhesion, and a decrease in scratch resistance.

[0055] The above bifunctional (meth)acrylate may be a bio-based (meth)acrylate. When a bio-based (meth)acrylate is used, carbon dioxide emissions can be reduced, unlike conventional compositions manufactured using (meth)acrylates manufactured from fossil fuels.

[0056] The above bifunctional (meth)acrylate may have a biocontent (based on solid content) of 40 wt% or more, for example, 50 wt% or more. If the biocontent of the above bifunctional (meth)acrylate is below the above-mentioned range, the effect of reducing carbon dioxide emissions may be insufficient.

[0057] The content of the above-mentioned bifunctional (meth)acrylate may be 15 to 40 wt%, for example, 20 to 30 wt%, based on the total amount of the UV-curable paint composition. If the content of the above-mentioned bifunctional (meth)acrylate is less than the above-mentioned range, the crosslinking efficiency may decrease, which may result in deterioration of scratch resistance, contamination resistance, and appearance. If the content exceeds the above-mentioned range, the crosslinking density may increase significantly, which may result in a decrease in the elasticity of the coating film, which may result in an increase in gloss, a decrease in appearance, adhesion, and a decrease in scratch resistance.

[0058]

[0059] photoinitiator

[0060] The UV-curable composition of the present invention includes a photoinitiator. The photoinitiator is a component that initiates photopolymerization upon being excited by ultraviolet rays or the like. Any photoinitiator generally known in the relevant technical field may be used without limitation.

[0061] Non-limiting examples of available photoinitiators include MICURE BP, JRCURE MBF, Irgacure 184, Irgacure 369, Irgacure 651, Irgacure 819, Irgacure 907, Benzionalkylether, Benzophenone, Benzyl dimethyl katal, Hydroxycyclohexyl phenylacetone, Chloro acetophenone, 1,1-Dichloro acetophenone, Diethoxy acetophenone, Hydroxy Acetophenone, 2-Choro thioxanthone, There are 2-ETAQ (2-EthylAnthraquinone), 1-Hydroxy-cyclohexylphenyl-ketone, 2-Hydroxy-2-methyl-1-phenyl-1-propanone, 2-Hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone, methylbenzoylformate, phenylbis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc. These can be used alone or in combination of two or more.

[0062] The content of the photoinitiator may be 0.1 to 10 wt%, for example, 2 to 5 wt%, based on the total amount of the UV-curable paint composition. If the content of the photoinitiator is less than the above-mentioned range, the film strength and adhesion may be reduced due to reduced curing or non-curing, and if it exceeds the above-mentioned range, contamination due to unreacted photoinitiator or reduced adhesion due to low polymerization degree may occur.

[0063]

[0064] additives

[0065] In addition to the aforementioned components, the UV-curable composition of the present invention may optionally further include additives commonly used in the relevant technical field. For example, additives such as adhesion promoters, pigment wetting and dispersing agents, wetting and dispersing agents, polymerization inhibitors, slip and defoaming agents, antiblocking agents, matting agents, and beads may be further included, as needed.

[0066] As the adhesion promoter, any one known in the relevant technical field can be used without special limitation. For example, trifunctional acid ester, polyester resin, etc. can be used. As the pigment wetting and dispersing agent, any one known in the relevant technical field can be used without special limitation. For example, pigment affinic groups in MPA / dibasic ester can be used. As the wetting and dispersing agent, any one known in the relevant technical field can be used without special limitation. For example, a copolymer with pigment affinic groups can be used. As the polymerization inhibitor, any one known in the relevant technical field can be used without special limitation. For example, hydroquinone can be used.

[0067] Slip and defoaming agents can be used without particular limitation as those known in the relevant technical field, such as silicone acrylate. Antiblocking agents can be used without particular limitation as those known in the relevant technical field, such as polyether siloxane. Matting agents can be used without particular limitation as those known in the relevant technical field, such as silica. Beads are for improving scratch resistance, and those known in the relevant technical field can be used without particular limitation as those known in the relevant technical field, such as spherical alumina.

[0068] The content of the above additives is not particularly limited, and may be, for example, 0.01 to 15 wt%, for example, 0.01 to 5 wt%, based on the total weight of the ultraviolet-curable composition.

[0069]

[0070] For example, the ultraviolet-curable paint composition according to the present invention comprises a trifunctional urethane (meth)acrylate oligomer, a monofunctional (meth)acrylate, a monofunctional hydroxyl-containing (meth)acrylate, a difunctional (meth)acrylate, and a photoinitiator, and at least one of the trifunctional urethane (meth)acrylate oligomer, the monofunctional (meth)acrylate, and the difunctional (meth)acrylate may be made of a biomass raw material.

[0071] As another example, the ultraviolet curable paint composition according to the present invention comprises a trifunctional urethane (meth)acrylate oligomer, a monofunctional (meth)acrylate, a monofunctional hydroxyl group-containing (meth)acrylate, a difunctional (meth)acrylate, and a photoinitiator, and the trifunctional urethane (meth)acrylate oligomer, the monofunctional (meth)acrylate, and the difunctional (meth)acrylate may use a biomass raw material.

[0072] Biomass raw materials do not increase the amount of carbon dioxide because the sum of their emissions and absorption during their life cycle on Earth is zero. The UV-curable composition of the present invention may have a biocontent (based on solids) of at least 22% by weight, for example, 22 to 30% by weight. The UV-curable composition of the present invention is environmentally friendly due to its high biocontent, and can be applied to various industrial fields that require high biocontent.

[0073]

[0074] <LVT(Luxury Vinyl Tile)>

[0075] The present invention provides a luxury vinyl tile (LVT) using the above-described ultraviolet curable composition.

[0076] The LVT (Luxury Vinyl Tile) according to the present invention includes a UV coating layer, and the UV coating layer can be manufactured by a manufacturing method including a step of forming a coating film by applying a UV-curable composition on a substrate and a curing step. The substrate can be PVC (Poly Vinyl Chloride), for example, transparent PVC. The UV-curable composition is the UV-curable composition according to the present invention described above.

[0077] The above ultraviolet-curable composition can be applied to the substrate at a thickness of 5 to 30 μm, for example, 10 to 25 μm. If the thickness of the ultraviolet-curable composition is less than the above-mentioned range, the contamination resistance, scratch resistance, gloss, and adhesion of the coating film may be reduced, and if it exceeds the above-mentioned range, curing may be insufficient, resulting in a reduction in appearance and scratch resistance or peeling of the coating film.

[0078] The above curing step can be performed by irradiating with a mercury or metal lamp. For example, the curing step can be performed by irradiating with 500 to 1,000 mJ / cm2 using a mercury lamp having a wavelength of 200 to 400 nm.

[0079] The above LVT (Luxury Vinyl Tile) may further include a base layer, a core layer, a dimensional stabilizing layer, a stop layer, a printing layer, a wear-resistant layer, etc. in addition to the UV coating layer.

[0080]

[0081] The present invention will be described in more detail through the following examples. However, the following examples are intended only to aid understanding of the present invention and are not intended to limit the scope of the present invention in any way.

[0082]

[0083] [Synthesis Example 1: Preparation of Trifunctional Urethane Acrylate Oligomer]

[0084] In a reactor equipped with a thermometer, a stirring device, and a reflux condenser, 342.651 g of bio-based aliphatic polyisocyanate (PDI-trimer, Bio Contents 70 wt%), 145.311 g of trimethylolpropane triacrylate, and 0.089 g of hydroquinone were added and stirred for 20 minutes. 64.557 g of polytetramethylene ether glycol and 130.273 g of hydroxyethyl acrylate were added and stirred for 20 minutes. 0.089 g of dibutyl tin dilaurate was added below 30°C, and the temperature was maintained at 50-55°C while checking for exotherm. The temperature was maintained and tracked until the NCO% reached 3.52% through wet NCO% measurement. When the NCO% was satisfied, 54.441 g of hydroxyethyl acrylate was added, and the reaction was maintained until the NCO% was 0.51% or less as measured by wet NCO%. When the NCO% was satisfied, 220.555 g of hydroxypropyl acrylate was added, and the reaction was maintained at 50-55 ℃ for 30 minutes. Afterwards, 44.034 g of hydroxyethyl acrylate was added, and the reaction was monitored while maintaining the temperature until the NCO% was 0.01% or less as measured by wet NCO%. When the NCO% was satisfied, the reaction was terminated, and the trifunctional urethane acrylate oligomer of Synthesis Example 1 (solid content 100 wt%, viscosity (25 ℃) 3,200 cps, Mw 2,600 g / mol, Bio Contents 23.3 wt%) was obtained.

[0085]

[0086] [Synthesis Example 2: Preparation of Trifunctional Urethane Acrylate Oligomer]

[0087] In a reactor equipped with a thermometer, a stirring device, and a reflux condenser, 300.271 g of aliphatic polyisocyanate (HDI-trimer, Bio Contents 0 wt%), 181.554 g of trimethylolpropane triacrylate, 181.554 g of polyethylene glycol diacrylate, and 0.091 g of hydroquinone were charged and maintained with stirring for 20 minutes. 89.611 g of polyester polyol and 97.255 g of hydroxyethyl acrylate were charged and maintained with stirring for 20 minutes. 0.091 g of dibutyltin dilaurate was charged below 30°C, and maintained at 50-55°C while checking for exotherm. The temperature was maintained and tracked until the NCO% reached 2.55% through NCO% wet measurement. When the NCO% was satisfied, 50.665 g of hydroxyethyl acrylate was added and maintained at 50-55 ℃ for 30 minutes. The temperature was maintained and tracked until the NCO% became 0.35% or less through NCO% wet measurement. When the NCO% was satisfied, 98.908 g of hydroxypropyl acrylate was added and maintained at 50-55 ℃ for 60 minutes. The temperature was maintained and tracked until the NCO% became 0.01% or less through NCO% wet measurement. When the NCO% was satisfied, the reaction was terminated, and the trifunctional urethane acrylate oligomer of Synthesis Example 2 (solid content 100 wt%, viscosity (25 ℃) 1,700 cps, Mw 5,400 g / mol, Bio Contents 0 wt%) was obtained.

[0088]

[0089] [Example 1-9]

[0090] According to the compositions described in Table 1 below, ultraviolet-curable compositions for each example were prepared.

[0091]

[0092] [Comparative Example 1-8]

[0093] According to the compositions described in Table 2 below, UV-curable compositions for each comparative example were prepared.

[0094]

[0095]

[0096]

[0097]

[0098] A-1: Trifunctional urethane acrylate oligomer of Synthesis Example 1 (solid content 100 wt%, viscosity (25 ℃) 3,200 cps, Mw 2,600 g / mol, Bio Contents 23.3 wt%)

[0099] A-2: Trifunctional urethane acrylate oligomer of Synthesis Example 2 (solid content 100 wt%, viscosity (25 ℃) 1,700 cps, Mw 5,400 g / mol, Bio Contents 0 wt%)

[0100] B-1: Tetrahydrofurfuryl acrylate (Bio contents 63 wt%, molecular weight 156 g / mol, glass transition temperature -15 ℃, viscosity (25 ℃) 10 cps)

[0101] B-2: 2-Hydroxypropyl acrylate (Bio contents 0 wt%, molecular weight 130 g / mol, glass transition temperature -7 ℃, viscosity (25 ℃) 4 cps)

[0102] B-3: Isosorbide Diacrylate (Bio Contents 50 wt%, molecular weight 254 g / mol, glass transition temperature 157 ℃, viscosity (25 ℃) 500 cps)

[0103] C-1: Adhesion promoter (Trifunctional acid ester, SR 9051NS, Sartomer, 100% solids)

[0104] C-2: Pigment wetting dispersant (Pigment affinic groups in MPA / dibasic ester (1:1), Dispers 670, EVONIK, solids 40%)

[0105] C-3: Wetting & Dispersing Agent (Copolymer with pigment affinic groups, Disperbyk 103, BYK, solid content 40%)

[0106] C-4: Polymerization inhibitor (Hydroquinone)

[0107] C-5: Slip and defoaming agent (Silicone acrylate, RAD 2500, EVONIK, 100% solids)

[0108] C-6: Antiblocking (polyether siloxane, Glide 410, EVONIK, 100% solids)

[0109] C-7: Adhesion promoter (Polyester resin, Variplus 3350UV, EVONIK, solids 50%)

[0110] D-1: Photoinitiator (Benzophenone)

[0111] D-2: Photoinitiator (Methyl Benzoylformate)

[0112] D-3: Photoinitiator (1-Hydroxy-Cyclohexylphenyl-ketone)

[0113] E: Matting agent (silica)

[0114] F: Bead (spherical alumina)

[0115]

[0116] [Physical property evaluation]

[0117] For the compositions of each example and comparative example, the physical properties were evaluated using the following method and are shown in Tables 3 and 4.

[0118]

[0119] Bio-content

[0120] Biocontent was measured according to ASTM-D6866-22 Method B.

[0121]

[0122] Sample manufacturing

[0123] The UV-curable compositions manufactured in each example and comparative example were applied (thickness: 10 ㎛) on a PVC transparent layer substrate (10 mm x 10 mm) and photocured (Hg Lamp, 140 W / cm, 800 mJ / cm) to manufacture 3T LVT (Luxury Vinyl Tile) specimens.

[0124]

[0125] gloss

[0126] The gloss of the specimen surface was measured at a measurement angle of 60° using a gloss meter.

[0127]

[0128] appearance

[0129] The appearance was evaluated from grade 1 (excellent) to grade 5 (poor) by observing for visible defects such as discoloration, loss of gloss, dewetting, and orange peel.

[0130]

[0131] Adhesiveness

[0132] Adhesion was evaluated by performing a cross-cut tape test according to ASTM D3359. The surface of each specimen was scratched with a blade in the shape of 100 squares (2 mm wide X 2 mm long), and the number of squares remaining after tape was applied and removed was measured to evaluate adhesion.

[0133]

[0134] Contamination resistance

[0135] The surface of each specimen was painted with a permanent marker, and the erasability was checked after 5 minutes, and the contamination resistance was evaluated from grade 1 (excellent) to grade 5 (poor).

[0136]

[0137] Hardenable (touch hardenable)

[0138] The UV-curable compositions prepared in each example and comparative example were applied (thickness: 10 ㎛) onto a PVC transparent layer substrate (10 mm x 10 mm) and repeatedly cured under curing conditions of 50 mJ / 70 Mw / ㎠. After each curing, the coating was scratched with a fingernail and the appearance was observed, and the curability was evaluated according to the following evaluation criteria.

[0139] [metewand]

[0140] Grade 1 (Excellent): No scratches after 1 to 3 hardenings

[0141] Grade 2 (Good): No scratches after 4 hardening cycles

[0142] Grade 3 (Normal): No scratches after 5 hardenings

[0143] Grade 4 (lower): No scratches after 6 hardenings

[0144] Grade 5 (Poor): No scratches after 7 or more hardening cycles

[0145]

[0146] Lee Kwang Phenomenon

[0147] The gloss deviation before and after the contamination resistance test of each specimen was checked, and the photoluminescence phenomenon was evaluated according to the evaluation criteria below.

[0148] [metewand]

[0149] Grade 1 (Excellent): No deviation

[0150] Grade 2 (Good): Deviation of less than 2%

[0151] Grade 3 (Normal): Deviation of 2% or more but less than 5%

[0152] Grade 4 (lower): Deviation of 5% or more but less than 10% occurs.

[0153] Grade 5 (Poor): Deviation of 10% or more occurs

[0154]

[0155] Scratch resistance

[0156] After testing according to EN16094, the degree of damage to the coating was confirmed, and the scratch resistance was evaluated according to the following evaluation criteria.

[0157] [metewand]

[0158] Grade 1 (Excellent): No change

[0159] Grade 2 (Good): Minor gloss changes

[0160] Grade 3 (Normal): Less than 5 scratches

[0161] Grade 4 (lower): 5 to 10 scratches

[0162] Grade 5 (Poor): 10 or more scratches

[0163]

[0164]

[0165]

[0166]

[0167] As shown in Tables 3 and 4 above, the UV-curable composition of Examples 1-9 according to the present invention exhibited excellent physical properties in all measured items. On the other hand, the UV-curable composition of Comparative Example 1-8, which did not include at least one of a trifunctional urethane acrylate oligomer (A), a monofunctional (meth)acrylate (B-1), a monofunctional hydroxyl-containing (meth)acrylate (B-2), and a difunctional (meth)acrylate (B-3), or included all four of the above but in an amount exceeding the content range of the present invention, exhibited generally inferior physical properties compared to Example 1-9.

[0168]

[0169] The present invention provides a UV-curable paint composition with excellent scratch and stain resistance. The UV-curable paint composition according to the present invention is environmentally friendly and exhibits excellent scratch and stain resistance. The UV-curable paint composition according to the present invention can be applied to PVC flooring materials such as LVT (Luxury Vinyl Tile).

Claims

1. An ultraviolet-curable composition comprising, based on the total weight of the ultraviolet-curable paint composition, 30 to 50 wt% of a trifunctional urethane (meth)acrylate oligomer, 1 to 10 wt% of a monofunctional (meth)acrylate, 1 to 15 wt% of a monofunctional hydroxyl-containing (meth)acrylate, 15 to 40 wt% of a difunctional (meth)acrylate, and 0.1 to 10 wt% of a photoinitiator.

2. An ultraviolet-curable composition in which the viscosity (25° C.) of the trifunctional urethane (meth)acrylate oligomer in paragraph 1 is 2,000 to 3,500 cps, the weight average molecular weight (Mw) is 1,500 to 3,500 g / mol, and the bio content (based on solid content) is 22 wt% or more.

3. An ultraviolet-curable composition according to claim 1, wherein the monofunctional (meth)acrylate has a molecular weight of 100 to 500 g / mol, a glass transition temperature of -20 to -5°C, a viscosity (25°C) of 5 to 20 cps, and a bio content (based on solid content) of 60 wt% or more.

4. An ultraviolet-curable composition according to claim 1, wherein the monofunctional hydroxyl group-containing (meth)acrylate has a molecular weight of 100 to 500 g / mol, a glass transition temperature of -10 to -4 ℃, and a viscosity (25 ℃) of 1 to 15 cps.

5. An ultraviolet-curable composition according to claim 1, wherein the bifunctional (meth)acrylate has a molecular weight of 150 to 600 g / mol, a glass transition temperature of 120 to 170°C, a viscosity (25°C) of 300 to 800 cps, and a bio content (based on solid content) of 40 wt% or more.

6. An ultraviolet-curable composition having a bio content (based on solid content) of 22 wt% or more in the first paragraph.

7. LVT (Luxury Vinyl Tile) using an ultraviolet curable composition according to any one of claims 1 to 6.

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