• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.130-135
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• 2010

Paint is used as top coat in Automobile Refinishing that is divided into 1K paint of base type and 2K paint of urethane type. after using 1K paint, it can be reusable. However 2K paint is not available that is mixed a certain amount of base with hardner, so 2K paint has to be used all at a time or discarded the rest. This study covered that colored Urethane paint and colorless urethane paint in top coating process of AR. Top coat urethane paint is divided into colored urethane paint and transparent urethane paint like clear coat. Colored urethane paint is used for paint that contains resin, pigment, solvent and additives. It is color such as black and white. While transparent urethane paint is used for paint that contains resin, solvent and additives. Urethane paint has a paint system that cur after several hours of mixing base and hardner. By a paint technician of a field and empirical data, we can also recognize that according to worker's paint style and experience, although he or she paint same car model and area, paint use of one's is different. There aren't guidelines workers refer to about paint use by car models and work scope because ARP works various car models that are in different color, size and area. After using urethane paint, the rest of paint has come, and there are highs and lows in paint use each time he or she works. Therefore, this study suggest a basic guideline to use paint efficiently and regularly by understanding area, the type of work, and paint use that are appropriate for each car model and regardless of workers and work scopes in AR.

• Journal of Adhesion and Interface
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• v.24 no.2
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• pp.69-75
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• 2023

Recently, the application of paint protection films (PPFs) for automobiles having a self-recovery coating layer has been grown up. In this study, we report the evaluation results on the basic physical properties of a poly(vinyl chloride)- based PPF containing poly(urea-urethane) hybrid self-recovery coating layer. Depending on the main chemical composition and the thickness of poly(urea-urethane)-based coating layer for PPF, the self-recovery performance by an optical microscope and the stain resistance through color difference value are measured. To improve the surface properties and show its easy-cleaning effect against the polluted things, silicone-modified polyacrylate is introduced to the self-recovery coating composition. The contact angle of water on the coated surface is confirmed to show its hydrophobic surface. Finally, accelerated weathering test of paint protection film with poly(urea-urethane) hybrid coating layer is performed to check the possibility of discoloration and deformation due to long-term exposure on harsh condition.

• Journal of electromagnetic engineering and science
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• v.5 no.4
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• pp.172-175
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• 2005

Sometimes, it is more convenient to use paint-type and spray-type EM wave absorbers than bulk-type or sheet-type. Thus, in this paper, we prepared paint-type and spry-type EM wave absorbers. The proportion of ferrites to paints, particle size of magnetic material, and kinds of paint should be considered to prepare a superior paint-type EM wave absorber. There is no big gap between spray-type and paint-type in EM wave absorption of EM wave absorbers prepared with same composition.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.547-553
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• 2008

To achieve the ideal performances of paint film, resins and hardeners have to be chosen and designed in a proper way depending on the exposure circumstance of substrate and the requested physical properties. Six different kinds of clear paints were made in this experiment using alkyd polyol, polyester polyol, polyester modified acrylic polyol and another 3 acrylic polyol resins whose $T_g$ and OH value were partially modified. Then the tests for chemical, physical, and mechanical properties were measured after forming the paint films using aliphatic and aromatic polyisocyanate. The viscosity and elasticity of paint film were then measured in terms of gel point and $tan{\delta}$ using Rheometer and DMA. Through this viscoelastic characteristic test of polyurethane resin, we were able to choose the adequate resins and hardeners which are the most important in the top and primer painting system of urethane paint and, as a result of observing the physical, mechanical, and chemical properties of paint film by urethane, we have finally reached the conclusion that we could apply the proper polyol to top and primer paint for developing the polyurethane paint system.

• Journal of Applied Reliability
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• v.1 no.2
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• pp.79-93
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• 2001

Recently, new aspects of paints such as a beautiful appearance, use of environmentally friendly paints, etc., in addition to the superior performance of paints have been requested for industrial paints including the paints for heavy construction equipment and others. Particularly, the quality of appearance of coating affects the sales of heavy construction equipment. And the necessity for the paints to have a superior weather-proof property without changing the luster or color even after long-time exposure to the open air is emphasized. The change in the surface color and luster of the paint due to the natural environment progresses very slowly, and it takes a long time to verify material properties when developing new paints. In order to improve such methods, weathering tests are performed in many laboratories as a test for accelerating aging of coating, and the lifetime of the products is estimated through evaluation of the weathering (environment-proof) quality of paints. However, not a great deal of research activity has been conducted up to the present time since the interrelationship between the actual results of testing and field data is different for each paint and it takes a long time to study relevant materials. Therefore, introduced in the present study is the estimation of the change in the quality of appearance of coating in the field through the accelerated aging test among the cases of improvement of the quality of appearance of the urethane paint for heavy construction equipment.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.679-687
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• 2014

In this study, a new paint which is able to resist the cavitation erosion is tried to be developed by using urethane added with nano particles such as multi-wall and single-wall carbon nano tube and spherical and fiber type graphite. The new paint synthesized was characterized with physical properties and resistivity to cavitation erosion($t_{50}$). Among nano particles, fiber type graphite($t_{50}$ 292min) showed high hardness and wear resistance compared with spherical type($t_{50}$ 182min). For carbon nano tube, single-wall type($t_{50}$ 286min) was higher than multi-wall type in wear resistance. Fiber-type graphite was the best nano-particle for paint with resistivity to cavitation erosion. In the application test of paint, the manually painted sample showed surface with smooth but the surface of sample prepared with spray was not smooth. During spray, dust was fixed on the surface.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.628-634
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• 2014

In this study, a new paint which is able to resist the cavitation erosion is tried to be developed by using urethane added with polyol such as poly propylene glycol(PPG), poly carbonate diol(PCD), polycaprolactone polyol (PCL-1), and poly caprolactone-tetramethylene gylcolether polyol(PCL-2). The new paint synthesized by adding polyol was characterized with physical properties and resistivity to cavitation erosion. Among polyol, the prepolymer added with PCD showed high hardness and wear resistance. However, due to too high in viscosity, the prepolymer added with PCL-1 was selected as a paint. The paint added with PCL-1 showed high resistivity to cavitation erosion and its surface was monitored by using Scanning Electron Microscope.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.160-161
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• 2021

To prepare polyurethane coatings for top coatings of automobiles, acrylic resins containing 75% of solids were synthesized by a radical polymerization. The viscosity of the acrylic resins was increased with increasing OH values. Crosslinked acrylic-urethane clear coatings were obtained by curing reaction between the synthesized acrylic resins and hexamethylene diisocyanate(HDI) trimer(Desmodur N-3600). The physical properties from the following studies were carried out : viscosity(Zahn cup #2), adhesion, pensil hardness, and 60° specular gloss. Various properties of the acrylic-urethane clear coatings as top coatings of mobile coat were evaluated on the coating specimens. Adhesion property to a substrate, 60° specular gloss, and pencil hardness of prepared paint showed quite good properties.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.4 s.107
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• pp.330-334
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• 2006

In this research, we fabricated paint-type EM wave absorbers by using Mn-Zn, Ni-Zn, Ba, Sr Ferrite, and Sendust. To prepare the absorbers, enamel, epoxy and urethane paints were used as binders. We tested EM wave absorption of them. The band-width of EM wave absorbers coated with $Al(OH)_3$ was larger than non-coated EM wave absorbers. The fabricated EM wave absorbers show a reflection coefficient of 20 dB approximately at X-band for a 2 mm double-layer sample.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.65-72
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• 2007

The VOC (volatile organic compound) analyzer is devised to measure the four main aromatic hydrocarbon gases: toluene, ethylbenzene, xylene and styfene. It is not affected by ambient temperature and humidity. In addition, standby and measuring time of VOC Analyzer is a short as below 30 min and 8 min, respectively. Since the semiconductor gas sensor is supersensitive to gas components, it is not necessary to use a conventional gas concentrator or other complicated equipment. In this study, VOC emission behavior from 4 types paints (lacquer, urethane vanish, water-base paint, enamel paint) for wood-based panel was investigated using VOC Analyzer. After a specimen was spreaded on aluminum foil ($6.32{\times}6.32cm$) in $3{\ell}$ polyester bag, after 24 hours we could measure maximum VOC emission level that is a stabilized VOC value. Xylene of VOCs was high emitted from lacquer, urethane vanish and water-based paint, and TVOC (Toluene + Ethylbenzene + Xylene + Styrene) of lacquer was the highest emission concentration than another.