For this research, prepared water soluble milk casein resin and waterborne polyurethane-acrylic resin. Use these resin, this article has been analyzed about change of mechanical properties by increasing amount of casein resin in polyurethane-acrylic resin on coated leather. According to measure data for solvent resistance, WPA(waterborne polyurethane-acrylic resin) resin and WPA-C1, C2, C3(samples of polyurethane-acrylic resin with milk casein resin) had good property. As known in the results, increase of casein constant did not influence to big change of hybrid resin properties. As test of tensile strength, WPA had lowest tensile characteristic(1.598 kgf/㎟) and WPA-C3 had highest tensile characteristic(1.718 kgf/㎟). Also best properties of abrasion was WPA-C3(06.021 ㎎.loss). In elongation case, WPA had best properties(754 %) in this experiment.

본 연구에서는 수용성 아크릴을 합성한 다음 수성 카제인 수지를 합성하여 기합성 완성된 아크릴 수지에 카제인 수지의 적하량을 점차 증가시켜 변화하는 물성을 피혁(Lamb leather)에 표면 코팅하여 물성을 측정 분석하였다. 내용제성 측정 결과 높은 내용제성 물성을 지닌 아크릴 수지와 카제인 수지의 함량이 물성 변화에 끼치지 않았으며 모두 높은 물성치를 나타내었다. 인장 강도 측정치에서는 아크릴 단독 코팅의 측정치가 1.399kgf/mm2로 가장 낮은 수치를 나타내었으며, 카제인 수지의 합량이 제일 높은 WAC-3가 가장 높은 인장력 1.426kgf/mm2을 나타내었다. 또한 내마모도 측정에서는 WAC-3가 제일 높은 69.774 mg.loss로 우수한 물성변화를 나타내었고, 연실률의 경우 아크릴 단독 코팅인 WAR이 820 %로 가장 높은 수치를 나타내었다.

In this study we experimented that how chain extension influences to waterborne urethane-acrylic hybrid resin for leather garment coatings. We knew that polyurethane-acrylic hybrid resins had 5 grades of solvent resistance. Tensile strength measured in the polyurethane-acrylic resin(EDA 5.37 g, 1.928 kgf/mm2) had the most strong strength. Also polyurethane-acylic hybrid resin(EDA 5.37 g. 30.2 mg. loss) had better result than other hybrid resins. EDA contents higher, we obtained low elongation and low flexibility. In this result, chain extension of waterborne polyurethane-acrylic hybrid resin showed the effect in leather coating with ratio of EDA.

In this study, we experimented that how influence chain extension to waterborne urethane-epoxy hybrid resin for leather garment coatings. First of all, We had analyzed datas by FT-IR, SEM and machanical properties. By instruments analysis measurement we confirmed that synthesis of epoxy and hybrid resin. In this experiment we knew that polyurethane-epoxy hybrid resin have 5 grades of solvent resistance. Tensile strength measured in the polyurethane-epoxy resin(EDA 5.37g, 2.386 kgf/mm2) had the most strong strength.. Also polyurethane-epoxy hybrid resin had better result(EDA 5.37g. 37.4 mg. loss) than other hybrid resins. As hight proportion of EDA in hybid resin, we obtained low elongation and low flexibility. In this result, chain extension of waterborne polyurethane-epoxy hybrid resin showed that how effect in leather coating by ratio of EDA.

The relative viscosity was measured at different filler loadings for a cycloaliphatic epoxy resin and hexahydro-4-methylphthalic anhydride hardener system filled with micro/nano hybrid silica. Various empirical models were fitted to the experimental data and a fitting parameter such as critical filler fractions (φmax) was estimated. Among the models, the Zhang-Evans model gave the best fit to the viscosity data. For all the silica loadings used, ln (relative viscosity) varied linearly with filler loadings. Using the Zhang-Evans model and the linearity characteristics of the viscosity change, simple methods to predict the relative viscosity below φmax are presented in this work. The predicted viscosity values from the two methods at hybrid silica fractions of φ = 0.086 and 0.1506 were confirmed for a micro:nano = 1:1 hybrid filler. As a result, the difference between measured and predicted values was less than 11%, indicating that the proposed predicting methods are in good agreement with the experiment.

In this study, we experimented that how to synthesis waterborne urethane-epoxy hybrid resin for leather garment coatings. First of all, We had analyzed datas by FT-IR, SEM and TGA for the machanical properties. By instruments analysis measurement we confirmed that synthesis of urethane and epoxy. In this experiment we knew that polyurethane and urethane-epoxy hybrid resin have 4~5 grades of solvent resistance. Tensile strength measured in the urethane-epoxy resin(epoxy 12%, 2.033kgf/mm2) had the most strong strength than polyurethane(1.833 kgf/mm2) emulsion samples. Also urethane-epoxy hybrid resin had better result than polyurethane in acid resistance and abrasion test. As hight proportion of epoxy in hybid resin, we obtained low elongation and low flexibility. In this result, the mechanical properties of waterborne polyurethane-epoxy hybrid resin showed that how effect in leather coating by ratio of epoxy emulsion.

In this study, we experimented that how to synthesis waterborne urethane-acrylic hybrid resin for leather coatings. First of all, We had analyzed data by FT-IR, SEM and TGA for the machanical properties. By TGA analysis polymers showed heat distortion temperature. and by FT-IR measurement we confirmed that synthesis of urethane and acrylic. In the experiment, solvent resistance, polyurethane and acrylic grades 4-5 showed both a high. Tensile strength measured in the waterborne polyurethane 〉 Acrylic emulsion showed strength in the order. Films were obtained by coating the water born resin on leveled surfaces and allowing them to dry at room temperature for 72hrs. After demolding, the films were kept in a desiccator to avoid moisture contant at 25℃ for 45hrs before the measurements. In this result, the mechanical propersies of waterborne polyurethane-acrylic hybrid resin showed that how effect to resin in leather coating between polyurethane content and acrylic content. Therefore, acrylic emulsion had most high solvent resistance glade and waterborne polyurethane had good result in abrasion test and tensile strength.

본 논문에서는 정속마찰 시험기를 사용하여 공기중에서 핏치/CVI계와 페놀/CVI계 낱소/탄소 복합재료의 마찰특성을 평가하고 상호 비교하였다. 운용조건(마찰거리, 마찰속도, 마찰압력)에 관계없이 페놀/CVI계의 평균 마찰계수가 핏치/CVI계 보다 높은 값을 나타내었다. 마찰거리가 4Km이하 일때는 평균 마찰계수가 불안정한 경향을 나타내고 그 이후에서는 안정한 평균 마찰계수 값을 갖는다. 또한 마찰속도와 마찰압력이 증가할수록 평균 마찰계수는 감소하는 경향을 나타내며, 페놀/CVI계의 평균 마찰계수가 핏치/CVI계 보다 높고 마찰면 온도 상승률과 최대 마찰면 온도도 높다. 마찰계수는 마찰면 온도의 영향을 받으며, 마찰속도와 3kg/cm2이하에서 마찰압력이 커질수록 최대 마찰계수를 갖는 마찰면 온도는 높아진다.