UV-curable paint composition

Abstract

The present invention provides a UV-curable paint composition comprising a bio-based urethane (meth)acrylate resin, a bio-based (meth)acrylate monomer, and a photoinitiator, the UV-curable paint composition being environmentally friendly and capable of minimizing carbon dioxide emissions.

Description

UV-curable paint composition

[0001] The present invention relates to an environmentally friendly ultraviolet curable paint composition.

[0002]

[0003] UV-curable coating compositions are widely used as coatings to protect the surfaces of various materials, such as buildings, ships, bridges, and automobiles. Coatings formed from these UV-curable coating compositions require various physical properties, such as excellent appearance characteristics, scratch resistance, adhesion, impact resistance, and moisture resistance. Active research is being conducted to improve the physical properties of UV-curable coating compositions. For example, Korean Patent No. 10-1035822 discloses a photocurable coating for a hard coating material for plastics, comprising urethane acrylate, an acrylate compound, and a photoinitiator, but excluding an acrylate compound having an aromatic ring structure.

[0004] However, conventional UV-curable paint compositions are manufactured using resins, monomers, and solvents derived from fossil fuels like petroleum and coal. The manufacturing process inevitably produces carbon dioxide, a contributor to global warming. Therefore, there is a need to develop environmentally friendly UV-curable paint compositions that can minimize carbon dioxide emissions.

[0005]

[0006] The present invention provides an environmentally friendly ultraviolet-curable paint composition capable of minimizing carbon dioxide emissions.

[0007]

[0008] The present invention provides an ultraviolet curable paint composition comprising a bio-based urethane (meth)acrylate resin, a bio-based (meth)acrylate monomer, and a photoinitiator.

[0009]

[0010] The present invention provides an environmentally friendly UV-curable paint composition capable of minimizing carbon dioxide emissions. The UV-curable paint composition according to the present invention is environmentally friendly and provides excellent paintability, appearance, scratch resistance, abrasion resistance, and resistance to daily scratches. The UV-curable paint composition of the present invention has a high bio-content and is therefore applicable to various industrial fields requiring a high bio-content. For example, the UV-curable paint composition of the present invention can be used as a paint for automotive interiors subject to strict environmental standards.

[0011]

[0012] Figure 1 illustrates a scratcher used for evaluating scratch resistance.

[0013] Figure 2 shows the evaluation criteria for chemical resistance.

[0014] Figure 3 illustrates a reciprocating wear tester used for evaluating wear resistance.

[0015]

[0016] 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.

[0017] The “weight average molecular weight” used herein is measured by a conventional method known in the art, and can be measured, for example, by the GPC (gel permeation chromatography) method. The “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). Functional values ​​such as “acid value” or “hydroxyl value” are measured by a conventional method known in the art, and can be measured, for example, by the titration method.

[0018] The UV-curable paint composition according to the present invention provides a UV-curable paint composition comprising a bio-based urethane (meth)acrylate resin, a bio-based (meth)acrylate monomer, and a photoinitiator. The paint composition according to the present invention may further comprise additives such as a solvent, an adhesion promoter, an ultraviolet absorber, a dispersant, a catalyst, a surface conditioner, a polymerization inhibitor, and a matting agent, which are commonly used in the field of UV-curable paints, as needed.

[0019] The UV-curable coating composition of the present invention uses a bio-based urethane (meth)acrylate resin and a bio-based (meth)acrylate monomer, which are biomass raw materials. Since the sum of carbon dioxide emissions and absorption during the life cycle of biomass raw materials on Earth is zero, it does not increase the amount of carbon dioxide.

[0020] The biocontent (based on solid content) of the UV-curable coating composition of the present invention is 15 wt% or more, for example, 15 to 40 wt%, or another example, 15 to 30 wt%. The UV-curable coating composition of the present invention is environmentally friendly due to its high biocontent, and can be applied to various industrial fields requiring a high biocontent. The biocontent is measured by a radiocarbon analysis technique according to ASTM-D6866-12 (% BiobasedCarbon Content). Biomass materials contain radiocarbon (C14), an isotope of carbon, whereas petrochemical-derived materials do not contain C14. Therefore, the biocontent can be calculated by calculating the content of C14 in the total carbon content.

[0021]

[0022] Bio-based urethane (meth)acrylate resin

[0023] The ultraviolet-curable coating composition of the present invention comprises a urethane (meth)acrylate resin. The urethane (meth)acrylate resin is a main component of the dry coating film and serves to provide basic properties such as adhesion, scratch resistance, and iodine resistance.

[0024] The above urethane (meth)acrylate resin is a bio-based urethane (meth)acrylate resin. The ultraviolet-curable paint composition of the present invention can reduce carbon dioxide emissions by using a bio-based urethane (meth)acrylate resin, unlike conventional paint compositions manufactured using urethane (meth)acrylate resins manufactured from fossil fuels.

[0025] The above bio-based urethane (meth)acrylate resin is prepared from a bio-based urethane (meth)acrylate resin composition. The bio-based urethane (meth)acrylate resin composition includes a bio-based polyol and a bio-based polyisocyanate.

[0026] The above bio-based polyol may be a polyol derived from vegetable oils such as rapeseed oil, castor oil, corn oil, etc. The above bio-based polyol may include at least one selected from the group consisting of polyester polyol, polyether polyol, polycarbonate polyol, and fatty acid-modified polyol.

[0027] The hydroxyl value of the above bio-based polyol may be 30 to 100 mgKOH / g, for example, 40 to 70 mgKOH / g. If the hydroxyl value is less than the above-mentioned range, the urethane acrylate content decreases, which may result in a decrease in crosslinking degree and thus a decrease in physical properties such as adhesion and chemical resistance. If the hydroxyl value exceeds the above-mentioned range, the crosslinking degree may increase, which may result in a decrease in flexibility, and the molecular weight may be low, which may result in a decrease in mechanical properties.

[0028] The number average molecular weight of the bio-based polyol may be 800 to 3,000 g / mol, for example, 950 to 2,800 g / mol, or as another example, 1,500 to 2,500 g / mol. If the number average molecular weight of the bio-based polyol is less than the above-mentioned range, the bio-content may be lower than the standard, and if it is more than the above-mentioned range, the bio-content may increase, but the acrylate modification rate may be lowered, which may lower the adhesion and chemical resistance.

[0029] The above bio-based polyisocyanate may be an isocyanate derived from natural materials such as rapeseed, conifers, and sugarcane. The above bio-based isocyanate may include at least one selected from the group consisting of pentamethylene diisocyanate, pentane diisocyanate, isocyanurate derived from pentane diisocyanate, biuret, and allophanate.

[0030] The NCO content of the above bio-based polyisocyanate may be 10 to 40%, for example, 20 to 30%, and the bio-content may be 50 wt% or more, for example, 50 to 80 wt%. If the NCO content is less than the above-mentioned range, unreacted acrylate monomer may remain in the coating film, which may reduce workability, and if it exceeds the above-mentioned range, unreacted polyisocyanate may react with surrounding moisture, which may reduce storage properties. If the bio-content is less than the above-mentioned range, the bio-content of the finally manufactured bio-based urethane (meth)acrylate resin may be reduced.

[0031] For example, the bio-based urethane (meth)acrylate resin composition may contain 15 to 55 wt%, for example, 25 to 45 wt%, of the bio-based polyol and 1 to 20 wt%, for example, 1 to 10 wt%, of the bio-based polyisocyanate, based on the total weight of the resin composition. If the content of the bio-based polyisocyanate is less than the above-mentioned range, a high content of low-molecular-weight bio-based polyol may be present, which may excessively lower the viscosity and thereby deteriorate workability, and an excessive amount of unreacted substances may be present in the coating film, which may deteriorate the adhesion. If the content of the bio-based polyisocyanate exceeds the above-mentioned range, an excessive amount of unreacted polyisocyanate may be present, which may cause a decrease in storage properties, such as by reacting with surrounding moisture, etc.

[0032] The above bio-based urethane (meth)acrylate resin composition may further include additives such as non-bio-based acrylic monomers, reactive diluents, catalysts, and polymerization inhibitors commonly used in the field of ultraviolet-curable paints.

[0033] The above-mentioned bio-based acrylic monomer may include at least one selected from the group consisting of trimethylolpropane triacrylate, hexanediol diacrylate, 2-hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, caprolactone-modified (meth)acrylate, pentaerythritol triacrylate (PETA), and dipentaerythritol pentaacrylate.

[0034] The above bio-based urethane (meth)acrylate resin may be an 8- to 10-functional, for example, a 9-functional urethane (meth)acrylate resin. When an 8- to 10-functional urethane (meth)acrylate resin is used, the hardness and curing density of the coating film can be increased, thereby further improving iodine resistance and scratch resistance, and excellent physical properties of the paint, such as yellowing prevention, can be secured.

[0035] The bio-content of the above-mentioned bio-based urethane (meth)acrylate resin may be 30 wt% or more, for example, 30 to 50 wt%, or as another example, 35 to 45 wt%, and the viscosity (25° C.) may be 5,000 to 300,000 cP, for example, 10,000 to 200,000 cP. If the bio-content is less than the above-mentioned range, it may be difficult to apply it to automobile interior parts due to the low bio-content. If the viscosity is less than the above-mentioned range, a coating film may not be formed or the adhesion of the coating film may be reduced, and if it exceeds the above-mentioned range, the paint workability may be poor, which may deteriorate the appearance of the coating film.

[0036] The ultraviolet-curable paint composition of the present invention may contain 5 to 35 wt%, for example 10 to 25 wt%, of the bio-based urethane (meth)acrylate resin based on the total weight of the paint composition. If the content of the bio-based urethane (meth)acrylate resin is less than the above-mentioned range, the viscosity may be low, resulting in a decrease in crosslinking density and thus reduced heat resistance and adhesion. If the content exceeds the above-mentioned range, the viscosity of the composition may be high, resulting in poor workability and thus a deterioration in the appearance of the paint film.

[0037]

[0038] bio-based (meth)acrylate monomer

[0039] The ultraviolet-curable coating composition of the present invention comprises a (meth)acrylate monomer. The (meth)acrylate monomer is an auxiliary component of a dry coating film, which improves the flowability, leveling properties, and workability of the coating composition, while also improving the iodine resistance, scratch resistance, and adhesion of the coating film.

[0040] The above (meth)acrylate monomer is a bio-based (meth)acrylate monomer. The ultraviolet-curable coating composition of the present invention can reduce carbon dioxide emissions by using a bio-based (meth)acrylate monomer, unlike conventional coating compositions manufactured using (meth)acrylate monomers manufactured from fossil fuels.

[0041] The above bio-based (meth)acrylate monomer may be a (meth)acrylate monomer derived from nature. The above bio-based (meth)acrylate monomer may include at least one selected from the group consisting of isobornyl methacrylate, isobornyl acrylate (IBOA) prepared from camphene derivatives, glycerin tri(meth)acrylate derived from vegetable oils, 2-octyl (meth)acrylate, stearyl (meth)acrylate derived from castor oil, and tetrahydrofurfuryl acrylate (THFA) derived from woody biomass.

[0042] The above bio-based (meth)acrylate monomer may be a mono- or bi-functional, for example, a mono-functional (meth)acrylate monomer.

[0043] The bio-content of the above bio-based (meth)acrylate monomer may be 30 wt% or more, for example, 30 to 90 wt%, or as another example, 40 to 80 wt%. If the bio-content is less than the above-mentioned range, the bio-content may be low and thus difficult to apply to automobile interior parts.

[0044] The ultraviolet-curable paint composition of the present invention may contain 5 to 25 wt%, for example 5 to 15 wt%, of the bio-based (meth)acrylate monomer based on the total weight of the paint composition. If the content of the bio-based (meth)acrylate monomer is less than the above-mentioned range, the viscosity of the composition may increase, resulting in poor workability and deterioration of the appearance of the coating film. If the content exceeds the above-mentioned range, the viscosity may decrease, resulting in a decrease in crosslinking density, which may result in deterioration of heat resistance and adhesion.

[0045]

[0046] acrylic resin

[0047] The UV-curable paint composition of the present invention may further include an acrylic resin. In this case, the physical properties, such as paintability, appearance characteristics, scratch resistance, abrasion resistance, and life scratch resistance, can be further improved.

[0048] The above acrylic resin can be used with an acid value of 1 to 45 mgKOH / g.

[0049] The ultraviolet-curable paint composition of the present invention may include 5 to 25 wt%, for example, 10 to 15 wt%, of the first acrylic resin and 5 to 25 wt%, for example, 10 to 15 wt%, of the second acrylic resin, based on the total weight of the paint composition.

[0050]

[0051] photoinitiator

[0052] The UV-curable coating composition of the present invention includes a photoinitiator. The photoinitiator is a component that initiates photopolymerization when excited by ultraviolet rays or the like. Any photoinitiator generally known in the relevant technical field may be used without limitation.

[0053] 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, 2-ETAQ (2-EthylAnthraquinone), 1-Hydroxy-cyclohexylphenyl-ketone, 2-Hydroxy-2-methyl-1-phenyl-1-propanone, 2-Hydroxy-2-methylpropiophenone, 2-Hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone, methylbenzoylformate, phenylbis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine There are oxide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc. These can be used alone or in combination of two or more.

[0054] The UV-curable coating composition of the present invention may contain 0.1 to 10 wt%, for example 1 to 5 wt%, of the photoinitiator based on the total weight of the coating composition. If the content of the photoinitiator is less than the above-mentioned range, the coating 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.

[0055]

[0056] additives

[0057] In addition to the aforementioned components, the UV-curable coating composition of the present invention may optionally further include additives commonly used in the relevant technical field, depending on the intended use and environment of the coating composition. For example, additives such as solvents, UV absorbers, surface conditioners, adhesion promoters, dispersants, polymerization inhibitors, and matting agents may be further included, as needed.

[0058] The solvent improves the solubility and reduces the viscosity of the paint composition, thereby enabling spray painting. As the solvent, any organic solvent known in the art can be used without particular limitation, and examples thereof include butyl acetate, isobutyl alcohol, and ethyl acetate. The solvent may be included in an amount satisfying 100 wt% of the total paint composition, and for example, may be included in an amount of 10 to 70 wt%, for example, 30 to 60 wt%, based on the total weight of the paint composition.

[0059] The UV absorber absorbs UV rays to protect the coating film, and any known material in the relevant technical field can be used without particular limitation. For example, 2-hydroxyphenyl-S-triazine, HALS (hindered amine light stabilizer), etc. can be used. The surface conditioner reduces the surface tension of the paint to improve the leveling property, and any known material in the relevant technical field can be used without particular limitation. For example, a siloxane-based surface conditioner such as polyether-modified polydimethyl siloxane can be used.

[0060] The content of each of the above additives is not particularly limited, and may be, for example, 0.01 to 20 wt% based on the total weight of the paint composition.

[0061]

[0062] 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.

[0063]

[0064] [Manufacturing Example 1: Manufacturing of Bio-Based Urethane (Meth)Acrylate Resin 1]

[0065] In a reactor equipped with a thermometer, a stirring device, a reflux condenser, an air injection device, and a nitrogen injection device, 37.444 g of bio-based polyester polyol (100% solid content, 14,000 mPas viscosity, 100 wt% Bio Content, 56 mgKOH / g hydroxyl value, 2,004 g / mol number average molecular weight), 19.995 g of trimethylolpropane triacrylate, 19.995 g of hexanediol diacrylate, and 5.763 g of bio-based pentamethylene diisocyanate (54.5% NCO, 100% Solid, 9 mPas Viscosity, 71 wt% Bio content) were charged under nitrogen injection, and the temperature was raised to 40°C while stirring. At 40℃, 0.012 g of dibutyl tin dilaurate was added, and while checking for exotherm, the temperature was raised to 70℃ and maintained for 2 hours. The temperature was maintained and tracked until the NCO% reached 1.89% through NCO% wet measurement. When the NCO% reached 1.89%, 16.775 g of pentaerythritol triacrylate and 0.017 g of dibutylhydroxytoluene were added, and the temperature was raised to 90℃ and the reaction was maintained until the NCO% became 0.05% or less. When the NCO% became 0.05% or less, the reaction was terminated, and the bio-based urethane (meth)acrylate resin 1 of Manufacturing Example 1 was manufactured (solid content 100%, viscosity (25℃) 16,000 cPS, Bio Content 42 wt%).

[0066]

[0067] [Manufacturing Example 2: Manufacturing of Bio-Based Urethane (Meth)Acrylate Resin 2]

[0068] In a reactor equipped with a thermometer, a stirring device, a reflux condenser, an air injection device, and a nitrogen injection device, 37.444 g of bio-based polyether polyol (100% solid content, 1,800 mPas viscosity, 55 mgKOH / g hydroxyl value, 100 wt% Bio Content, number average molecular weight 2,040 g / mol), 19.995 g of trimethylolpropane triacrylate, 19.995 g of hexanediol diacrylate, and 5.763 g of bio-based pentamethylene diisocyanate (54.5% NCO, 100% Solid, Viscosity 9 mPas, 71 wt% Bio Content) were charged under nitrogen injection, and the temperature was raised to 40°C while stirring. At 40℃, 0.012 g of dibutyl tin dilaurate was added, and while checking for exotherm, the temperature was raised to 70℃ and maintained for 2 hours. The temperature was maintained and tracked until the NCO% reached 1.89% through NCO% wet measurement. When the NCO% reached 1.89%, 16.775 g of pentaerythritol triacrylate and 0.017 g of dibutylhydroxytoluene were added, and the temperature was raised to 90℃ and the reaction was maintained until the NCO% became 0.05% or less. When the NCO% became 0.05% or less, the reaction was terminated, and a bio-based urethane (meth)acrylate resin 2 of Manufacturing Example 2 was manufactured (solid content 100%, viscosity (25℃) 14,000 cPS, Bio Content 42 wt%).

[0069]

[0070] [Manufacturing Example 3: Manufacturing of a non-bio-based urethane (meth)acrylate resin]

[0071] In a reactor equipped with a thermometer, a stirring device, a reflux condenser, an air injection device, and a nitrogen injection device, 50 g of polyester polyol (hydroxyl value 56 mgKOH / g, Bio Content 0 wt%, number average molecular weight 2,004 g / mol), 22.5 g of trimethylolpropane triacrylate, 22.5 g of hexanediol diacrylate, and 11.1 g of isophorone diisocyanate were charged under nitrogen injection, and the temperature was raised to 40°C while stirring. At 40°C, 0.01 g of dibutyl tin dilaurate was added, and while confirming exotherm, the temperature was raised to 70°C and maintained for 2 hours. The temperature was maintained and tracked until the NCO% reached 1.9% through NCO% wet measurement. When the NCO% reached 1.9%, 6.1 g of hydroxyethyl acrylate and 0.015 g of dibutylhydroxytoluene were added, and the temperature was raised to 90°C to maintain the reaction until the NCO% became 0.05% or less. When the NCO% became 0.05% or less, the reaction was terminated, and the urethane (meth)acrylate resin of Manufacturing Example 3 was manufactured (solid content 100%, viscosity (25°C) 7,000 cPS, Bio Content 0 wt%). The urethane (meth)acrylate resin of Manufacturing Example 3 is a non-bio-based urethane (meth)acrylate resin that does not contain biomaterials.

[0072]

[0073] [Experimental Example 1-13]

[0074] According to the compositions described in Tables 1 and 2 below, ultraviolet-curable paint compositions for each experimental example were prepared.

[0075]

[0076]

[0077]

[0078]

[0079] Urethane acrylate 1: Bio-based urethane (meth)acrylate resin 1 of Manufacturing Example 1 (9 functional, NV 100%, viscosity (25°C) 16,000 cPS, Bio Content 42 wt%)

[0080] Urethane acrylate 2: Bio-based urethane (meth)acrylate resin 2 of Manufacturing Example 2 (9 functional, NV 100%, viscosity (25°C) 14,000 cPS, Bio Content 42 wt%)

[0081] Urethane acrylate 3: Non-bio-based urethane (meth)acrylate resin of Manufacturing Example 3 (NV 100%, viscosity (25 ℃) 7,000 cPS, Bio Content 0 wt%)

[0082] Bio-based monomer 1: Isobornyl acrylate (IBOA, Bio Content 75 wt%)

[0083] Bio-based monomer 2: Glycerine(PO)3 Triacrylate (GPTA, Bio Content 14 wt%)

[0084] Bio-based monomer 3: Stearyl acrylate (Octadecyl acrylate, Bio Content 80 wt%)

[0085] Acrylate Monomer: Bio-Based 1,6-Hexanediol diacrylate

[0086] Photoinitiator 1: DAROCURE 1173

[0087] Photoinitiator 2: IRGACURE 819

[0088] Solvent 1: Butyl acetate

[0089] Solvent 2: Isobutyl alcohol

[0090] UV absorber 1: TINUVIN 400

[0091] UV absorber 2: TINUVIN-123

[0092] Surface conditioner: BYK 306

[0093] Acrylic resin: Synthalat A-TS 1558 (manufacturer: Synthopol Chemie)

[0094]

[0095] [Physical property evaluation - bio-content]

[0096] According to ASTM D6866, the bio-content of the UV-curable paint composition manufactured according to each experimental example was measured, and the results are shown in Table 3 below. A bio-content of 15 wt% or more was judged to be acceptable.

[0097]

[0098]

[0099]

[0100] [Property Evaluation - Paint Properties]

[0101] For the UV-curable paint compositions of each experimental example, specimens were prepared using the following method and paint properties were evaluated, and the results are shown in Tables 4 and 5 below. However, paint properties were not measured for the paint compositions of Experimental Examples 10 and 13, which showed low bio contents.

[0102]

[0103] Sample manufacturing

[0104] The paint composition of each experimental example was applied (thickness: 20-30 ㎛) on the plastic of an automobile interior part and photocured (light quantity: 1,000 mJ / cm2, light intensity: 140 mW / cm2) to prepare a specimen.

[0105]

[0106] appearance

[0107] Each specimen was visually observed for defects such as swelling, peeling, surface cracks, pinholes, bubbles, and foreign matter, and the appearance was evaluated according to the following criteria.

[0108] [metewand]

[0109] Excellent (◎): No defects (surface cracks, bubbles, etc.)

[0110] Defective (X): Occurrence of defects (surface cracks, bubbles, etc.)

[0111]

[0112] Scratch resistance

[0113] Using a sapphire scratcher (load 4.9 N (0.5 kgf), friction speed 100 mm / sec, stroke 100 mm) of the shape shown in Figure 1 below, the surface of the specimen was scratched once, and then the surface condition was observed to evaluate the scratch resistance.

[0114] [metewand]

[0115] Grade 5: No surface damage is recognized.

[0116] Grade 4: Slightly noticeable surface damage

[0117] Grade 3: Some surface damage is noticeable, but not severe.

[0118] Grade 2: Surface damage is recognized.

[0119] Grade 1: Surface damage is significantly visible.

[0120] Passing Criteria: Level 4 or higher

[0121]

[0122] Adhesiveness

[0123] The cross-cut tape test was performed according to ASTM D3359 to evaluate the adhesiveness. 100 scratches were made on the surface, each measuring 1 mm X 1 mm in width and height, using a cross cutter, and the number of scratches that remained adhered to the coating out of 100 were counted when the tape was attached with Nichiban tape. The adhesiveness was evaluated according to the following criteria. In cases where the intermediate properties of each classification were observed, the intermediate value (e.g., M-1.5, M-2.5) was used for evaluation.

[0124] [metewand]

[0125] M-1.0: Meets IS0 2409 CLASS 0 and delamination of less than 50% of the total area of ​​1 cell

[0126] M-2.0: Meets IS0 2409 CLASS 1 and total delamination area is less than 5%

[0127] M-3.0: Meets IS0 2409 CLASS 2, and total peeling area is 5% or more and less than 15%

[0128] M-4.0: Meets IS0 2409 CLASS 3, with a total peeling area of ​​15% or more and less than 35%.

[0129] M-5.0: Meets IS0 2409 CLASS 4, and total peeling area is 35% or more and less than 65%.

[0130] M-6.0: Fully peeled

[0131] Passing Criteria: M-2.5 or less

[0132]

[0133] Impact resistance

[0134] Using the drop tester of ISO 6272-2, an impact was applied to the coating surface of each specimen (room temperature, weight of 4.9 N (0.5 kgf), drop height of 20 cm, core diameter of 12.7 mm (0.5 inch)), and the condition of the coating was checked, and the impact resistance was evaluated based on the following criteria.

[0135] [metewand]

[0136] Pass (◎): No minor cracks or peeling

[0137] Fail (X): Peeling occurred

[0138]

[0139] moisture resistance

[0140] Each specimen was left for 168 hours under conditions of 50±2 ℃ and 95±2%, taken out and left for 1 hour, and then moisture resistance was evaluated using the same method as the adhesiveness described above.

[0141] [metewand]

[0142] Passing Criteria: M-2.5 or less

[0143]

[0144] Chemical resistance

[0145] After immersing each specimen in 5% NaOH and 5% HCl for 24 hours, the appearance of the coating was observed and the chemical resistance was evaluated according to the criteria shown in Figure 2 below.

[0146] [metewand]

[0147] Passing Criteria: Gray Scale Level 3 or higher

[0148]

[0149] My sunscreen

[0150] Two sheets of cotton cloth (equivalent to Toyosynthetic CH2070-3) of the same size were placed on an acrylic plate (50 mm X 50 mm, width X height), and 0.25 g of sunscreen (Nivea SPF47) was applied to the entire surface. The sunscreen application area was placed on the coating of each specimen and the acrylic plate was pressed to adhere it. After that, it was left in a constant temperature bath at 80±2℃ for 1 hour, taken out, the cotton cloth and acrylic plate were removed, and left at room temperature for 10 minutes. After that, it was washed with a neutral detergent, dried, and the sunscreen resistance was evaluated in the same manner as the adhesion described above.

[0151] [metewand]

[0152] Passing Criteria: M-2.5 or less

[0153]

[0154] Heat cycle resistance

[0155] Each specimen was sequentially left at 80±2℃ for 3 hours, room temperature for 1 hour, 40±2℃ for 3 hours, room temperature for 1 hour, 50±2℃ 95±2%RH for 7 hours, and room temperature for 1 hour, and 3 cycles were performed, and after taking it out and leaving it at room temperature for 1 hour, the heat cycle resistance was evaluated using the same method as the adhesiveness described above.

[0156] [metewand]

[0157] Passing Criteria: M-2.5 or less

[0158]

[0159] Heat resistance

[0160] Each specimen was left for 300 hours under conditions of 90±2 ℃, taken out, left at room temperature for 1 hour, and then heat resistance was evaluated using the same method as for adhesion described above.

[0161] [metewand]

[0162] Passing Criteria: M-2.5 or less

[0163]

[0164] Lightfastness

[0165] Using Xenon arc (BORO SILICATE (inner filter) / SODA LIME (outer filter)), 84 MJ / m² (700 KJ / m) 2 ), the specimens were irradiated under conditions of a black panel temperature of 89±3℃ and an internal humidity of 50±5% RH with an illuminance of 65.5±2.5 W / m² (300-400 nm). After irradiation, the specimens were washed with a neutral detergent to remove surface moisture, and left at room temperature for 1 hour. Then, the light resistance was evaluated using the same method as the adhesion described above.

[0166] [metewand]

[0167] Passing Criteria: M-2.5 or less

[0168]

[0169] wear resistance

[0170] Using a reciprocating wear tester (load 4.9 N (0.5 kgf), speed 30 reciprocations / min, width 20 X 20 mm, stroke 100 mm) made of KS K1450 material with a shape shown in Figure 3 below, a reciprocating test was performed 1,000 times, and then the wear resistance was evaluated according to the evaluation criteria below.

[0171] [metewand]

[0172] Pass criteria: No damage to the pattern / color after 1,000 tests (however, changes in gloss due to wear and surface damage due to wearer are allowed)

[0173]

[0174] My life is scratchy

[0175] Using the reciprocating abrasion tester used in the aforementioned abrasion resistance test, 300 reciprocating tests were performed under the following test conditions, and each test piece was wiped with an ultra-fine non-woven fabric (1 denier or less) to prevent scratches. Then, each test piece was placed on a table and the appearance of the effective surface (16 X 60 mm) was visually observed from a distance of 50 cm under natural light or an artificial light source of 6,500 K, and the scratch resistance to daily life was evaluated according to the evaluation criteria below.

[0176] [metewand]

[0177] Pass criteria: No surface scratches

[0178]

[0179]

[0180]

[0181]

[0182] As shown in Tables 4 and 5 above, the paint compositions of Experimental Examples 1-9 according to the present invention exhibited excellent physical properties across all measured items. On the other hand, the paint composition of Experimental Example 10, which included a non-bio-based urethane (meth)acrylate resin (urethane acrylate 3) that did not contain a biomaterial, had a biocontent that fell below the passing standard, and the paint composition of Experimental Example 11, which did not include a urethane (meth)acrylate resin, had an excessively low viscosity, so that a coating film was not formed well, and the adhesion, moisture resistance, sunscreen resistance, heat cycle resistance, heat resistance, and light resistance were poor. In addition, the paint composition of Experimental Example 12, which did not include a bio-based monomer but contained an excessive amount of bio-based urethane (meth)acrylate resin, had a high viscosity, which resulted in surface cracking and bubbles occurring during the curing process, resulting in a deteriorated appearance, and exhibited poor scratch resistance, impact resistance, chemical resistance, abrasion resistance, and life scratch resistance. In addition, the paint composition of Experimental Example 13, which did not include a bio-based monomer but contained an excessive amount of non-bio-based monomer, had a bio-content below the passing standard. No property evaluation was performed on the paint compositions of Experimental Examples 10 and 13, which had bio-contents below the passing standard.

[0183]

[0184] The present invention provides an environmentally friendly ultraviolet-curable paint composition capable of minimizing carbon dioxide emissions.

Claims

1. Contains a bio-based urethane (meth)acrylate resin, a bio-based (meth)acrylate monomer and a photoinitiator, The above bio-based urethane (meth)acrylate resin is manufactured from a bio-based urethane (meth)acrylate resin composition, The above bio-based urethane (meth)acrylate resin composition is an ultraviolet-curable paint composition comprising a bio-based polyol and a bio-based polyisocyanate.

2. In paragraph 1, the bio-based polyol is derived from vegetable oil, The above bio-based polyol comprises at least one selected from the group consisting of polyester polyol, polyether polyol, polycarbonate polyol and fatty acid modified polyol, The hydroxyl value of the above bio-based polyol is 30 to 100 mgKOH / g, and the number average molecular weight is 800 to 3,000 g / mol. The above bio-based polyisocyanate is derived from at least one selected from the group consisting of rapeseed, coniferous and sugarcane, The above bio-based polyisocyanate comprises at least one selected from the group consisting of pentamethylene diisocyanate, pentane diisocyanate, isocyanurate derived from pentane diisocyanate, biuret and allophanate, An ultraviolet-curable paint composition having an NCO content of 10 to 40% of the above bio-based polyisocyanate and a bio content of 50 wt% or more.

3. In the first paragraph, the bio-based urethane (meth)acrylate resin composition is an ultraviolet-curable paint composition comprising 15 to 55 wt% of the bio-based polyol and 1 to 20 wt% of the bio-based isocyanate based on the total weight of the resin composition.

4. In the first paragraph, the bio-based urethane (meth)acrylate resin is an 8 to 10 functional urethane (meth)acrylate resin, An ultraviolet-curable paint composition having a bio-content of the above bio-based urethane (meth)acrylate resin of 30 wt% or more and a viscosity (25°C) of 5,000 to 300,000 cp.

5. In the first paragraph, the bio-based (meth)acrylate monomer is derived from nature, The above bio-based (meth)acrylate monomer comprises at least one selected from the group consisting of isobornyl methacrylate, isobornyl acrylate (IBOA) manufactured from camphene derivatives, glycerin tri(meth)acrylate derived from vegetable oils, 2-octyl (meth)acrylate derived from castor oil, stearyl (meth)acrylate, and tetrahydrofurfuryl acrylate (THFA) derived from woody biomass. The above bio-based (meth)acrylate monomer is a 1-2 functional (meth)acrylate monomer, An ultraviolet-curable paint composition having a bio content of the above bio-based (meth)acrylate monomer of 30 wt% or more.

6. An ultraviolet-curable paint composition having a bio content (based on solid content) of 15 wt% or more in the first paragraph.

7. An ultraviolet-curable paint composition comprising, in paragraph 1, 5 to 35 wt% of the bio-based urethane (meth)acrylate resin, 5 to 25 wt% of the bio-based (meth)acrylate monomer, and 0.1 to 10 wt% of the photoinitiator, based on the total weight of the paint composition.

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