• Elastomers and Composites
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• v.36 no.1
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• pp.37-43
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• 2001

Influence of the filler composition ratio on cure characteristics and bound rubber content of the compounds and on physical properties of the vulcanizates were studied using both silica and carbon black-filled styrene-butadiene rubber (SBR) compounds with the total filler content of 80.0 phr. The bound rubber content increased slightly with increase of the silica content ratio. The viscosity also increased with increasing the silica content ratio, especially increased steeply after the silica content of 60.0 phr. The cure times obtained with a rheometer, t2, t40, and t90, are increased by increasing the silica content ratio and the cure rate decreased. The delta torque increased with the increased silica content ratio. Variation or the modulus with the silica content ratio showed a decreased trend though the delta torque increased. The tan ${\delta}$ at $60^{\circ}C$ decreased with increased of the silica content ratio.

• Journal of the Semiconductor & Display Technology
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• v.9 no.2
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• pp.33-39
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• 2010

The moisture absorption properties such as diffusion coefficient and moisture content ratio of liquid type epoxy resin systems with the filler were investigated. Bisphenol A type and Bisphenol F type epoxy resin, Kayahard MCD as hardener and 2-methylimidazole as catalyst were used in these epoxy resin systems. The nano-sized spherical type fused silica as filler were used in order to study the moisture absorption properties of these liquid type epoxy encapsulant according to the change of filler size. The temperature of glass transition (Tg) of these epoxy resin systems was measured using Dynamic Scanning Calorimeter (DSC), and the moisture absorption properties of these epoxy resin systems according to the change of time were observed at $85^{\circ}C$ and 85% relative humidity condition using a thermo-hygrostat. The diffusion coefficients in these systems were calculated in terms of modified Crank equation based on Ficks' law. An increase of Tg and diffusion coefficient with filler size in these systems can be observed, which are attributed to the increase of free volume with Tg. The change of maximum moisture absorption ratio according to the filler size and filler content cannot be observed; however, the diffusion coefficients of these systems decreased with filler content. The diffusion via free volume is dominant in the epoxy resin systems with low nano-sized filler content; however, the diffusion with the interaction of absorption according the increase of the filler surface area is dominant in the liquid type epoxy encapsulant with high nano-sized filler content.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.331-336
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• 1999

Permeable polymer concrete in this study is one of the environment conscious concrete that can be applied at road, side walks and river embankment, etc. The purpose of this study is to evaluate the effects of mix proportions such as resing content, filler-binder ratio and aggregate ratio on the freezing and thawing resistance of permeable polymer concrete. The permeable polymer concrete are prepared with the resin ratio of 5%, 6% and 7%, filler-binder ratio of 0, 0.5 and 1.0, and 2.5~5mm sized aggregate ratio to standard sand of 10:10, 10:20, 20:10 and 20:20. It is tested for freezing and thawing test according to ASTM C 666092, and then, weight change, length change, relative dynamic modulus, durability factor, and compressive and flexural strengths after test are measured. From the test results, the resistance to freezing and thawing of permeable polymer concrete increased with increase the resing content, filler-binder ratio and fine aggregate ratio.

• Journal of the Korean Society for Heat Treatment
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• v.22 no.4
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• pp.210-216
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• 2009

Stainless steel EGR cooler of diesel engine is widely used to prevent the corrosion due to the content of sulfur in diesel fuel. The strength of brazed joint between stainless steel materials is very important. It is essential to observe the spreading ratio of the filler metals under the condition of deoxidation or vacuum during heating process. In this experiment, spreading ratio was tested to find the optimum brazing condition for stainless steel using brazing filler metals of FP-613, BNi-2 and BNi-5 on sus304 and sus410. Anti-corrosion tests were also performed on the above filler metals with solution of 5% $H_2SO_4$, 65% $HNO_3$ and 5% $NH_4OH$. Consequently FP-613 has good ability for anti-corrosion with 30% of chromium content compared with other filler metals. The optimum brazing conditions are occurred at $960^{\circ}C$ for 90 min. and at $1090^{\circ}C$ for 50 min. at the same degree of vacuum, $2{\sim}3{\times}10^{-3}$ Torr.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.594-602
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• 2010

Since the requirement of the high density integration and thin package technique of semiconductor have been increasing, the main package type of semiconductor will be a chip scale package (CSP). The changes of diffusion coefficient and moisture content ratio of epoxy resin systems according to the change of liquid type epoxy resin and fillers for CSP applications were investigated. The epoxy resins used in this study are RE-304S, RE310S, and HP-4032D, and Kayahard MCD as hardener and 2-methylimidazole as catalyst were used in these epoxy resin systems. The micro-sized and nano-sized spherical type fused silica as filler were used in order to study the moisture absorption properties of these epoxy molding compound (EMC) according to the change of filler size. The temperature of glass transition (Tg) of these EMC was measured using Dynamic Scanning Calorimeter (DSC), and the moisture absorption properties of these EMC according to the change of time were observed at $85^{\circ}C$ and 85% relative humidity condition using a thermo-hygrostat. The diffusion coefficients in these EMC were calculated in terms of modified Crank equation based on Ficks' law. An increase of diffusion coefficient and maximum moisture absorption ratio with Tg in these systems without filler can be observed, which are attributed to the increase of free volume with Tg. In the EMC with filler, the changes of Tg and maximum moisture absorption ratio with the filler content can be hardly observed, however, the diffusion coefficients of these systems with filler content show the outstanding changes according to the filler size. The diffusion via free volume is dominant in the EMC with micro-sized filler; however, the diffusion with the interaction of absorption according the increase of the filler surface area is dominant in the EMC with nano-sized filler.

• Journal of the Semiconductor & Display Technology
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• v.12 no.1
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• pp.23-28
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• 2013

Epoxy resins are widely used in microelectronics packaging such as printed circuit board and encapsulating for semiconductor manufacturing. Water can diffuse into and through the epoxy matrix systems and moisture absorption at boarding interfaces of matrix resin systems can lead to a hydrolysis at the interfaces resulting in delamination of encapsulating materials. In the study, the changes of diffusion coefficient and moisture content ratio of epoxy resin systems with nano-sized fillers according to the change of liquid type epoxy resins were investigated. RE-304S, RE-310S, RE-810NM and HP-4032D as a epoxy resin, Kayahard AA as a hardener, and 1B2MI as a catalyst were used in these epoxy resin systems. After curing, moisture content ratios were measured with time under the 85 and 85% relative humidity condition using a thermo-hydrostat. The maximum moisture absorption ratio and diffusion coefficient of EMC decrease with the filler content. It can be seen that these decreases are due to the increase of filler surface area and the decrease of moisture through channel with the content of nano-sized filler.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.73-76
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• 2005

This study aims to suggest a simple and convenient design for a mix proportion method for high performance concrete by determining the optimum fine aggregate ratio and minimum binder content based on the maximum density theory. The mix design method introduced in this study adopted the optimum fine aggregate ratio with a minimum void and binder content higher than the minimum binder content level. The research results reveal that the method helps to reduce trial and error in the mixing process and is a convenient way of producing high performance concrete with self filler ability. In an experiment based on the mix proportion method, when aggregate with the fine aggregation ratio of 41$\%$ was used, the minimum binder content of high performance concrete was 470kg/$m^{3}$ and maximum aggregate capacity was $0.657m^{3}/m^{3}$. In addition, in mixing high performance concrete, the optimal slump flow to meet filler ability was 65$\pm$5cm, V load flow speed ranged from 0.5 to 1.5.

• Polymer(Korea)
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• v.34 no.4
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• pp.352-356
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• 2010

The effects of the filler shapes and contents on the coefficient of thermal expansion (CTE) for polypropylene (PP) composites which included three dimensional ellipsoids ($a_1>a_2>a_3$), as determined by two aspect ratios (${\rho}_\alpha=a_1/a_3$ and ${\rho}_\beta=a_1/a_2$) were analyzed by the theoretical approach proposed by Lee and Paul and compared with the experimental results. The shapes of fillers in the composites were various, such as spherical, fiber, disc, and ellipsoid, using barium sulfate, glass fiber, and mica. The longitudinal CTE of barium sulfate whose shape was sphere ($\rho_\alpha=\rho_\beta=1$) decreased. For the glass fiber, primary aspect ratio decreased with the filler content, and longitudinal CTE decreased as filler contents increased. Normal CTE initially increased in the lower filler content. For the mica, longitudinal and transverse CTE decreased but normal CTE increased in the lower filler content like predicted values.

• Journal of the Korea Institute of Building Construction
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• v.4 no.3
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• pp.93-100
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• 2004

In recent years, it has widely been studied on the light-weight composites for the purpose of the large space and thermal insulation of building structures. The purpose of this study is to evaluate the properties of light-weight composites made by binders as cement, resin and polymer cement slurry. The concrete composites are prepared with various conditions such as polymer-cement ratio, void-filling ratio, type of resin, filler content and light-weight aggregate content, tested for thermal conductivity. From the test results, the thermal conductivity of concrete composites with the binder of cement tends to decrease with increasing polymer-cement ratio, and to increase with increasing void-filling ratio. The thermal conductivity of concrete composites with the binder of resin are markedly affected by the light-weight aggregate content, type of resin and filler content. The composites made by polymer-modified concrete and polymer cement slurry have a good thermal insulation property. From the this study, we can recommend the proper mix proportions for thermal insulation Panel or concrete. Expecially. the thermal conductivity of concrete composites made by polyurethane resin is almost the same as that of the conventional expanded polystyrene resin.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.95-104
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• 2004

A styrene solution of waste expanded polystyrene with a crosslinking agent and an initiator was used as a binder for waste wood-plastic composite panels. The waste wood-plastic composite panels are prepared with various binder contents and filler-binder ratios by using a hot press molding method. The apparent density of the composite panels is increased with increasing binder content and filler-binder ratio, while their water absorption and expansion in thickness are decreased with increasing binder content and filler-binder ratio. The maximum flexural strength and wet flexural strength of the composite panels are obtained at a binder content of 35% and a filler-binder ratio of 0.8. Decreases in the flexural strengths of the composite panels due to water immersion at 20 and $100^{\circ}C$ are hardly recognized at binder contents of 30% or more.