• Journal of Adhesion and Interface
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• v.9 no.2
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• pp.32-37
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• 2008

A series of UV-curable powder coatings with different contents of photoinitiator (0.5 wt%, 1 wt%, 2 wt%) were formulated and measured gel content, tensile strength of cured film. Heat-sensitive substrates such as MDF, plywood and PVC were coated UV-curable powder and cured coatings were measured physical properties by pendulum hardness tester, glossmeter, pull-off adhesion tester. With increasing photoinitiator content, adhesion force between coating and substrate decreased because of crosslinking density increasing. The results of pendulum hardness was not significantly changed but gloss was changed according to different substrates. Adhesion of UV-curable coatings was enough to apply for heat-sensitive substrates. From these results, we concluded that contents of photoinitiator was a effective factor in UV-curable powder coatings. UV-curable coatings was a portential candidate for heat-sensitive substrates.

• Journal of the Korean Graphic Arts Communication Society
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• v.16 no.3
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• pp.61-80
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• 1998

To investigate in influence of photosensitizer used with benzophenone(BP) in the curing rate and physical properties of UV curable hard coating on plastic, we prepared UV curable clear and pigmented coatings with DEA, DMA, NPM and TEA as photosensitizer, respectively. The curing rate calculated from the decrease of the absorbance of acrylic double bond measured by FT-IR spectroscopy increased s follows; DEA>DMA>NPM>TEA. this order could be explained by the reactivity of diethylamino group of DEA and the ease of formation of activated complex between BP and photosensitizer during the curing process. In UV curable pigmented coatings, the order of curing rate increased as follows; DEA>DMA>TEA>NPM. It was found that the curing rate of the pigmented coating can be increased by light scattering of TiO$_2$. The hardness of coating film cured by photosensitization of DEA and DMA is higher than other photosensitizers due to the crosslinking reaction of DEA and DMA radical bound to polymer backbone.

• Journal of the Korean Wood Science and Technology
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• v.32 no.6
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• pp.23-35
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• 2004

The goal of study was to investigate the influence of the acrylated urethane oligomer on mechanical properties, the chemical resistance and thermal resistance of the UV curable urethane acrylate coatings for fancy veneer overlayed plywood flooring. The pencil hardness and abrasion resistance of the coated fancy veneer overlayed plywood floorings increased with increasing the acrylate functionality of the acrylated urethane oligomer. In the case of the UV cured film containing hexa-functional acrylated aliphatic urethane oligomer, high discoloration of the coated fancy veneer overlayed plywood flooring was observed near the cracks at the beginning of the chemical treatment. In this study, it was found that the degradation of the UV cured film caused by an alkaline reagent was higher than that of the UV cured film caused by an acidic treatment.

• Journal of the Korean Graphic Arts Communication Society
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• v.15 no.2
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• pp.107-115
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• 1997

The ultraviolet(UV)-curable materials are widely used in inks and coatings. In this paper is designed to develop materials having flexibility and functionality with UV-curable acrylate monomer and alkyd resin. At first, phase diagram is prepared for miscibility of UV -curable acrylate monomer with alkyd resin. Also the gel fraction and dynamic viscosity are measured to curing speed of mixing system. In results, it has been demonstrated that miscibility and curing speed are greatly influenced by alkyd resin content.

• Journal of the Korean Applied Science and Technology
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• v.28 no.2
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• pp.240-246
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• 2011

UV-Curable hybrid coatings were synthesized to improve the surface properties of plastic film. Organic-inorganic coating solutions were prepared by the sol-gel method using urethane-acrylate oligomer, acrylate monomer, photo initiator and tetraethoxysilane (TEOS). Methacryloyloxypropyltrimethoxysilane(MPTMS) was used as a silane coupling agent to improve chemical interaction between inorganic phases and UV curable acrylate. In this study, the surface hardness and adhesive properties were improved with the use of inorganic component. The experimental results showed that UV-Curable hybrid films containing aliphatic urethane oligomer, hexanedioldiacrylate, trimethylolpropanetriacrylate, hydroxy dimethyl acetophenone exhibited good surface properties. Also, the optimum curing conditions were investigated.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.121-129
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• 2008

Environmental friendly UV-curable coatings, having excellent hardness, gloss, mar and chemical resistance, are commonly used for the wooden flooring coatings. Especially epoxy acrylate oligomers are chosen for the wooden flooring coatings, due to their thermal stability and fast curing. In this study, we investigated the effect of the acrylate functionality on the thermal stability and surface hardness. The thermal degradations of monomers, oligomer, photoinitiator and formulated coatings with different acrylate functionality were measured using a thermogravimetric analysis (TGA). And the surface hardness was also measured with a pendulum hardness tester to compare relationship between the thermal stability and the physical property. The cured coatings became thermally stable by crosslinking during UV-curing. Both the thermal stability and surface hardness of cured coatings were improved with increasing acrylate functionality.

• Clean Technology
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• v.23 no.2
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• pp.148-157
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• 2017

To prepare UV-curable polyurethane-acrylate oligomer, NCO-terminated urethane prepolymers with trimethylolpropane, [TMP; 0 (0), 0.1 (0.021) and 0.2 (0.043) mole (mole fraction)] as crosslinkable tri-functional chain extender were end-capped with pentaerythritol triacrylate [PETA; 2.0 (0.400), 1.7 (0.354) and 1.4 (0.304) mole (mole fraction)] with one hydroxyl group/three vinyl functionalities. The stable as-formulated UV-curable polyurethane-acrylates [stable mixtures of PETA-capped oligomer/reactive acrylic monomer diluents without/with heptadecafluorodecyl methacrylate (PFA; 0, 6 and 9 wt%)] were formed up to 0.2 (0.043) mole (mole fraction) of TMP content in the prepolymer, while homogeneous-mixing failed at 0.3 (0.068) mole (mole fraction), in which the crosslink density in NCO-terminated urethane prepolymer was too high to enable the formation of stable mixture. This study examined the effect of TMP/PETA molar ratio and heptadecafluorodecyl methacrylate (PFA) content (wt%) on the properties of UV-cured polyurethane-acrylates as marine antifouling coating materials. The properties of UV-cured polyurethane-acrylate were found to be significantly dependent on the crosslinkable TMP/PETA ratio and PFA content. With the increasing of the TMP and PFA contents, the contact angles increased, and consequently the surface tension decreased. The adhesion of algae/barnacles to PFA contained film samples were found to be sufficiently weak to allow their easy removal. These results suggest that the UV-cured samples containing PFA have strong potential as coating materials for antifouling applications.

• Macromolecular Research
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• v.16 no.2
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• pp.128-133
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• 2008

Several dual-curable acrylic pressure-sensitive adhesives (PSA) were synthesized by the radical polymerization of acrylic monomers containing benzophenone, hydroxyl, and alkyl groups. The optimum extent of UV-induced cure was determined by varying the content of the benzophenone groups (the photoinitiator) from 0.5 to 1.5 wt%. The weight average molecular weight of the polymers obtained ranged from 300,000 to 700,000 amu. The coated pressure-sensitive adhesives were cured either by short UV exposure to induce the grafting of acrylic polymers, or by heating for 6 hat $60^{\circ}C$ to promote the reactions between the polyisocyanates and hydroxyl groups. The dual-curing behavior was determined by monitoring both processes quantitatively by infrared spectroscopy. The developed dual-curable acrylic pressure-sensitive adhesives were found to compensate for the limitations in UV-induced curing of thick coatings.

• Applied Chemistry for Engineering
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• v.16 no.3
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• pp.449-455
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• 2005

Electron beam (EB) and ultraviolet (UV) curable monomers (AF-1 with mono functionality and AF-2 with tetra functionality) containing hydroxy and acrylate group for anti-fogging coating were synthesized and applied to EB and UV-curable coating systems. The synthesized reactive AF-1 and AF-2 monomers were first formulated into UV-curable system and the optimization of film properties for anti-fogging coating was investigated. The 5:17.5 ratio for AF-1 and AF-2 was found to be the best optimized formulation for anti-fogging coating without destroying the other essential properties such as hardness, solvent resistance, and adhesion. The optimized formulation was applied to the EB-curable system, and EB and UV-curable systems were compared. The results demonstrated that both EB and UV-cured films coated on PC sheet showed excellent anti-fogging properties; however, the EB-cured film exhibited better hardness, adhesion, and water repellent properties than the UV-cured film.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.226-226
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• 2020