Slide 1

Conductive Carbon Blacks The Influence of Conductive Carbon Blacks on Rubber Properties - New Developments & Applications - Distributor of Ensaco Products Slide 2 Conductive Carbon Blacks Structure Surface Area Surface Quality Main carbon black properties Main rubber properties Rheological Mechanical Electrical properties Slide 3 Conductive Carbon Blacks High Structure CB aggregate High void volume High DBP absorption DBP > 170 ml/100g Slide 4 Conductive Carbon Blacks High Structure Longer incorporation times Easier ultimate dispersion Better surface finish Higher extrusion speed Higher Mooney viscosity Lower cure time Higher hardness Higher modulus Lower tensile and tear strengths More compounding flexibility Higher conductivity at lower loading other parameters being similar Slide 5 Conductive Carbon Blacks High Structure Blacks bring Higher Conductivity at Lower Loading ? e - Polymer INSULATOR + _ v ~ 10 12 - 10 14 Ohm cm +CB Conductive Network ++CB e-e- CONDUCTOR e-e- Polymer _ + + _ ! e - v ~ 10 8 - 10 0 Ohm cm All CB but... Slide 6 Conductive Carbon Blacks High Structure Blacks bring Higher Conductivity at Lower Loading c [ *cm] CB % 10 5 10 15 102030 Percolation Curve SV Structure-Volume SV equivalency * SV * ( CDBP +24) * G. Kraus, J. Polymer Sci., 13, 8, 601 (1970) Slide 7 Conductive Carbon Blacks As high structure blacks take up more space/volume, one can achieve the same filling level and consequently the same conductivity at a lower concentration Slide 8 Conductive Carbon Blacks Structure Surface Area Surface Quality Main carbon black properties Main rubber properties Rheological Mechanical Electrical properties Slide 9 Conductive Carbon Blacks High Structure & High Surface Area Furnace Process porosity High Structure & Low Surface Area MMM Process - ENSACO no porosity Slide 10 Conductive Carbon Blacks Good dispersibility and excellent ultimate dispersion better mechanical performance and smoother surface finish tend to minimize curing time reduced inhibition of cure agents temper the viscosity increase imparted by the high structure High Structure & Low Surface Area Slide 11 Conductive Carbon Blacks Slide 12 Slide 13 Structure Surface Area Surface Quality Main carbon black properties Main rubber properties Rheological Mechanical Electrical properties Slide 14 Conductive Carbon Blacks Surface Quality A high oxygen content inhibits cure agent and increase cure time A high graphitization favors electrical conductivity thermal conductivity ENSACO - MMM Process TOF-SIMS surface analysis: VERY LOW O CONTENT RX Crystallographic analysis: HIGH GRAPHITIZATION Slide 15 Conductive Carbon Blacks Some Rubber Applications BELTS: conveyor belts, transmission belts... HOSES: fuel hoses, discharge hoses PROTECTIVE COATINGS, LININGS... FLOORING POWER CABLES: easy strippable, insulator and conductor shielding... FOOTWEAR: shoe sole... AUTOMOTIVE INDUSTRY: fuel injection systems... HEALTH: surgical tubing... SAFETY: safety systems for windows & doors ROLLERS: printing rolls... SEALS: o-rings, pipe gaskets... CEMENTS & PUTTY HEATING ELEMENTS PTC SWITCHES ANTICORROSION SYSTEMS Engine mount ANTI-VIBRATION SYSTEMS... Slide 16 Conductive Carbon Blacks Incorporation in an unlimitted number of elastomers and elastomer blends Slide 17 Practical Applications Conductive NEOPRENE conveyor belt cover compounds NBR conductive hose compounds FKM conductive compounds NR engine mount / anti-vibration system Slide 18 Conductive Carbon Blacks HS & High SA HS & Low SA Slide 19 Practical Applications Conductive CR Conveyor Belt Cover Compound 30 phr Slide 20 Practical Applications NBR Conductive Hose Compounds 25 phr Slide 21 Practical Applications FKM (Fluoroelastomer) Conductive Compounds Experimental data provided by DuPont Dow Elastomers, Japan Slide 22 FKM Conductive Compounds Lower Mooney Viscosity rejected Slide 23 FKM Conductive Compounds Shorter Vulcanization Time Cured properties: 177C / 10 min Slide 24 FKM Conductive Compounds Same Volume Resistivity Slide 25 FKM Conductive Compounds Lower Compression Set Slide 26 FKM Conductive Compounds Higher Moduli Slide 27 FKM Conductive Compounds Higher Tensile Strength Slide 28 FKM Conductive Compounds Lower Elongation at Break Slide 29 FKM Conductive Compounds Same Hardness Slide 30 FKM Conductive Compounds High Structure & Low Surface Area Carbon Blacks enable to compound and make Viton A conductive (20 phr) Special thanks to DuPont Dow Elastomers, Japan Slide 31 Practical Applications excellent resistance to fatigue / dynamical properties: lower storage modulus much lower tangent delta NR engine mount / anti-vibration system Ensaco 150 G required hardness and modulus at low loading higher rebound / lower hysteresis Medium-high structure black with a VERY LOW surface area DBP = 165 ml/100gBET = 44 m/g Slide 32 Carbon Black Conduction Mechanisms N. Probst, E. Grivei, Third International Conference on Carbon Black, Mulhouse (F), Proceedings 171-176 (10/2000). Conductive CB s build a network at low concentration the ultimate conductivity depends on the DBP at a given pressure the contact resistance low [O - ] content ==> pure CB s ==> [CB + polymer] Slide 33 Carbon Black Conduction Mechanisms N. Probst, E. Grivei, Third International Conference on Carbon Black, Mulhouse (F), Proceedings 171-176 (10/2000). Slide 34 Carbon Black Conduction Mechanisms 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0100200300400500 Resistivity ( cm) Pressure (kg/cm 2 ) No Significant Difference CB as such, in air Slide 35 Carbon Black Conduction Mechanisms 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 00.20.40.60.811.21.4 Density (g/cm 3 ) Clear Differentiation of Conductive Carbon Blacks CB as such, in air Resistivity ( cm) Slide 36 Carbon Black Conduction Mechanisms 0.1 1 10 100 0.1110 Resistivity in Polymer ( cm) Resistivity in Air ( cm) polyolefins crystalline elastomers SBR, NR... direct contact between the CB particles tunneling / polymer film between the CB particles CB in polymer versus CB as such, at the same VOLUME fraction c Slide 37 Conductive Carbon Blacks Another vision of conductive CB networking New generation of compounds More compounding flexibility Higher conductivity at lower CB loading Another combination of properties Rheological Cure Compounding Mechanical Dynamical Electrical