• Applied Chemistry for Engineering
• /
• v.10 no.6
• /
• pp.949-953
• /
• 1999

Because epoxy molding compound(EMC) for semi-conductor encapsulants contains high concentrations of fillers, its flow behaviors are affected much by the concentrations and properties of those fillers. This paper reports the effects of a filler concentration, shape, size, and size distributions on the viscosity behavior of EMC(epoxy/silica). In addition, the prediction of viscosity behavior was performed using the Mooney equation. The maximum packing volume in the Mooney equation was calculated by Ouchiyama's packing model and Taguchi's optimization method, while the shpae factor was determined by fitting the experimental data. The results showed that the Mooney equation predicted the viscosity behavior of EMC very well.

• Journal of the Korean Society of Industry Convergence
• /
• v.2 no.1
• /
• pp.97-103
• /
• 1999

The power curve during rubber mixing presents useful information for the understanding of rubber mixing process, because the power curve is determined the mixing state of rubber at the point. The time to the second peak on the power curve is known as carbon black incorporation time, BIT. This study gets the quantity relationship of BIT and viscosity of natural rubber, so by determining the mixing time of the compound on the ground of viscosity of the raw rubber. The mixing with natural rubber and carbon black is examined for various grade natural rubbers, encompassing a wide range of Mooney viscosity. Alter smoothing the mixing power curve using a polynomial, the carbon black incorporation time, BIT, was determined time to second power peak on the curve, The BIT's versus specific values on Mooney viscometer test curve show a linear relation, Especially, the peak of initial maximum torque on Mooney viscometer curve, PMT, is most relevant property relating to the BIT. PMT is useful index for determined optimum mixing time, To apply this results at the mixing, we effectively control the natural rubber mixing but can also know the grading of natural rubber upon processability.

• Elastomers and Composites
• /
• v.7 no.1
• /
• pp.21-37
• /
• 1972

We have studied the blending effects of Diene NF 35R and Turfdene 1000R at various blending ratios 100/0, 70/30, 50/50, 30/70, 0/100, and of carbon black NAF and ISAF at various compounding ratios of 55 PHR, 65PHR, 75PHR for tyre tread rubber. As the results, it was found that; 1. For tyre tread rubber, as the blending ratio, Diene NF 35R/Turfdene 1000R, indicated 30/70, the physical properties we examined were most excellent. 2. Excellent result was obtained in case of carbon black compounding ratio of 63PHR. The compounding of ISAF made better result than that of HAF for tensile strength, tearing strength, and abrasion quantity. 3. Heat buildup obtained from compounding carbon black HAF indicated low temperature than that from compounding carbon black ISAF. As the compounding amount of carbon black increased, the heat buildup improved, and as the blending amount of Diene NF 35R decreased, the heat buildup dropped. 4. Carbon black was more efficient to Turfdene 1000R than to Diene NF 35R. 5. In this pysical properties, mooney viscosity, and mooney scorch time, as the compounding amount of carbon black increased, the values of mooney viscosity increased, but that of mooney scorch time dropped.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.29 no.2
• /
• pp.7-15
• /
• 1997

High shear viscosity at several solids levels was measured for a number of pigment slurries and coating colors containing either anionic or amphoteric latex and analyzed according to Mooney and Eiler equations. Maximum packing fraction and intrinsic viscosity were obtained and compared. Eiler equation provides more credible information than Mooney equation on particle packing and intrinsic viscosity. The packing fraction obtained from Eiler equation was slightly greater than that obtained from static FCC measurement indicating the influence of pigment movement under the dynamic condition. Amphoteric latex caused 4-5% increase of maximum packing fraction of a coating color when its pH is lowered from 7 to 6, while anionic latex did not show any significant change in packing characteristics.

• The Korean Journal of Rheology
• /
• v.11 no.2
• /
• pp.128-134
• /
• 1999

Rheological characterization was examined for two different types of magenetic particle (rod-like $\gamma$-$Fe_{2}O_{3}$, $CrO_2$ )suspension in this study. The measured suspension viscosity (viscosity vs. concentration or shear rate) is used to obtain the dependence of viscous energy dissipation on the microstructural states of magnetic particle dispersions as well as the microstructural shape effects which are related to magnetic particle orientation. The empirical formulas from mean field theory and the Mooney equation are used to relate suspension viscosity to particle concentration. Intrinsic viscosities of these two different types of rod-like magnetic particle suspensions are found to exceed the prediction of hydrodynamic theory for dilute suspensions and support the existence of flocs containing significant amounts of immobilized suspending medium due to native attraction forces among particles in the microstructures.

• Journal of the Korean Magnetics Society
• /
• v.5 no.5
• /
• pp.667-671
• /
• 1995

The viscometric technique is used to study the effects of microstructure on the viscosity (viscosity vs. concentration or shear rate) of magnetic particle suspensions. In this characterization, measurement of suspension viscosity is used to obtain the dependence of viscous energy dissipation on microstructural state of dispersions. Microstructural shape effects which are related to particle orientation are then indirectly obtained. Empirical formulas from mean field theory and the Mooney equation, which are applicable at high concentration of magnetic particles, are used to relate viscosity to particle concentration. The validity and physical meaning of these equations are discussed.

• Elastomers and Composites
• /
• v.8 no.1
• /
• pp.33-51
• /
• 1973

We have studied the blending effects of Diene NF 35 R and Alfin 1530 at various blending ratios, 100/0, 70/30, 50/50, 30/70, 0/100, and of carbon black HAF-HS and ISAF-HS at various compounding ratios of 45 PHR, 55 PHR, 65 PHR, for tyre tread rubber. As the results, it was found that; 1. For tyre tread rubber, as the blending ratio, AR 1530/Diene NF 35R, indicated 70/30, the physical properties we examined were most excellent. 2. Excellent result was obtained in the case of carbon black compounding ratio of 55 PHR. The compounding of ISAF-HS made better result than that of HAF-HS for tensile strength, but the compounding of HAF-HS made better result than that of ISAF-HS for tearing strength and best result for abrasion quantity. 3. Heat buildup obtained from compounding carbon black HAF-HS indicated low temperature than that from compounding carbon black HAP-HS. As the compounding amount of carbon black increased, and as the blending amount of AR 1530 decreased, the heat buildup increased. 4. Carbon black was more efficient to AR 1630 than io Diene NF 35 R. 5. In the physical properties, mooney viscosity and mooney scorch time, as the compounding amount of carbon black increased, the values of mooney viscosity increased, but that of mooney scorch time had a max. point at the compoundiug amount of carbon black, 55 PHR.

• Elastomers and Composites
• /
• v.34 no.2
• /
• pp.121-127
• /
• 1999

Characteristics of high molecular weight styrene-butadiene rubber(HM-SBR)/low molecular weight styrene-butadiene rubber(LM-SBR) mixtures were studied to investigate how to modify the processability and the mechanical properties of styrene-butadiene rubber (SBR). Mooney viscosity of the HM-SBR/LM-SBR mixtures and torque increase due to the vulcanization decreased by increasing the LM-SBR content of the mixtures. Shore A hardness and rebound properties were decreased by increasing the LM-SBR content of the mixtures. It was found that the value of tan ${\delta}$ of the mixtures in rubbery state was increased, while glass transition temperatures of the vulcanized blends were constant by increasing the LM-SBR content of the mixtures. It was postulated that the decrease of Mooney viscosity by increasing the LM-SBR content of the blends was due to plasticizing effects of the LM-SBR and the increased polydispersity of the mixtures. Change of mechanical properties of the vulcanized HM-SBR/LM-SBR mixtures was attributed to the decreased crosslink densities of the mixtures by increasing the LM-SBR content of the mixtures.

• Elastomers and Composites
• /
• v.25 no.4
• /
• pp.280-290
• /
• 1990

The effect of surface treatment of kaolinite with silane coupling agent on the reinforcement of SBR was investigated. The possibility of the practical use of kaolinite as an organic filler was also scrutinized and it was found that the reinforcement of SBR was improved by modifying surface of the cheap inactive inorganic filler with organic silane coupling agents. 3-Chloropropyltrimethoxysilane(C-series), 3-mercaptopropyltrimethoxysilane(M-series) and 3-aminopropyltriethoxysilane(A-series) were used as coupling agents. To test the material properties of vulcanized and unvulcanized SBR, Mooney viscosity, modulus, elongation and fractured surface measurements by SEM were carried out by changing the amount of silane coupling agents. Torqe of the unvulcanized SBR following the measurement of the degree of vulcanization was to be increased as the amount of silane was increasing, and Mooney viscosity of M-series and A-series was also increased.

• Polymer(Korea)
• /
• v.25 no.2
• /
• pp.233-239
• /
• 2001

The ethylene propylene diene terpolymer (EPDM) blends with acrylonitrile butadiene rubber (NBR) were prepared by mechanical mixing method. Mooney viscosity, cure behaviors, compression set and dynamic mechanical properties were subsequently examined. Dynamic characteristics of the entire blends determined from a Rheovibron generally showed two glass transitions (T'$_{g}$s), -43$^{\circ}C$ and -4$^{\circ}C$ for NBR and EPDM, respectively. The tan $\delta$ peak monotonically shifted toward the higher temperature with increasing NBR content. It was also found that the optimum cure time was significantly decreased with loading of NBR.