Elastomer composite and method for producing it

An elastomer composite, the elastomer composite formed by a method comprising:

• A) combining a first fluid comprising elastomer latex with a second fluid comprising particulate filler;
• B) causing the elastomer latex to coagulate, thereby forming masterbatch crumb;
• C) bringing the masterbatch crumb to a water content of about 1 weight percent to about 20 weight percent, thereby forming a dewatered coagulum;
• D) removing water from the dewatered coagulum by subjecting the dewatered coagulum to mechanical energy, thereby causing the dewatered coagulum to heat as a result of friction, while allowing the dewatered coagulum to achieve a temperature of about 130° C. to about 190° C., wherein water content is reduced to about 0.5% to about 3% moisture and wherein substantially all of the decrease in water content is accomplished by evaporation, thereby producing a masticated masterbatch;
• and
• E) subjecting the masticated masterbatch to at least an additional 0.3 MJ/kg of mechanical energy while further reducing the water content.

A method of producing an elastomer composite, comprising:

• A) feeding a continuous flow of first fluid comprising elastomer latex to a mixing zone of a coagulum reactor;
• B) feeding a continuous flow of second fluid comprising particulate filler under pressure to the mixing zone of the coagulum reactor to form a mixture with the elastomer latex, the particulate filler being effective to coagulate the elastomer latex and the feeding of the first fluid and the second fluid within the mixing zone being sufficiently energetic to substantially completely coagulate the elastomer latex with the particulate filler in the coagulum reactor to form a masterbatch crumb;
• C) discharging a substantially continuous flow of masterbatch crumb from the coagulum reactor;
• D) bringing the masterbatch crumb to a water content of about 1 weight percent to about 20 weight percent, thereby forming a dewatered coagulum;
• E) removing water from the dewatered coagulum by subjecting the dewatered coagulum to mechanical energy, thereby causing the dewatered coagulum to heat as a result of friction, while allowing the dewatered coagulum to achieve a temperature of about 130° C. to about 190° C., wherein water content is reduced to about 0.5% to about 3% moisture and wherein substantially all of the decrease in water content is accomplished by evaporation, thereby producing a masticated masterbatch;
• and
• F) subjecting the masticated masterbatch to at least an additional 0.3 MJ/kg of mechanical energy while further reducing the water content.

An elastomer composite produced by a method comprising:

• A) feeding a continuous flow of first fluid comprising elastomer latex to a mixing zone of a coagulum reactor;
• B) feeding a continuous flow of second fluid comprising particulate filler under pressure to the mixing zone of the coagulum reactor to form a mixture with the elastomer latex, the particulate filler being effective to coagulate the elastomer latex and the feeding of the first fluid and the second fluid within the mixing zone being sufficiently energetic to substantially completely coagulate the elastomer latex with the particulate filler in the coagulum reactor;
• to form a masterbatch crumb;
• C) discharging a substantially continuous flow of masterbatch crumb from the coagulum reactor;
• D) bringing the masterbatch crumb to a water content of about 1 weight percent to about 20 weight percent, thereby forming a dewatered coagulum;
• E) removing water from the dewatered coagulum by subjecting the dewatered coagulum to mechanical energy, thereby causing the dewatered coagulum to heat as a result of friction, while allowing the dewatered coagulum to achieve a temperature of about 130° C. to about 190° C., wherein water content is reduced to about 0.5% to about 3% moisture and wherein substantially all of the decrease in water content is accomplished by evaporation, thereby producing a masticated masterbatch;
• and
• F) subjecting the masticated masterbatch to at least an additional 0.3 MJ/kg of mechanical energy while further reducing the water content.

A method of producing an elastomer composite, comprising:

• A) combining a first fluid comprising elastomer latex with a second fluid comprising particulate filler;
• B) causing the elastomer latex to coagulate, thereby forming masterbatch crumb;
• C) bringing the masterbatch crumb to a water content of about 3 weight percent to about 6 weight percent, thereby forming a dewatered coagulum;
• D) removing water from the dewatered coagulum by subjecting the dewatered coagulum to mechanical energy, thereby causing the dewatered coagulum to heat as a result of friction, while allowing the dewatered coagulum to achieve a temperature of about 140° C. to about 190° C., wherein substantially all of the decrease in water content is accomplished by evaporation, thereby producing a masticated masterbatch;
• and
• E) subjecting the masticated masterbatch to at least an additional 0.3 MJ/kg of mechanical energy while further reducing the water content.

An elastomer composite comprising carbon black dispersed in natural rubber, wherein, when the elastomer composite is processed using CTV Method A, it exhibits a resistivity satisfying the equation ln(resistivity)≧0.33δ+X, where X is 5.8 and

• δ=(6000[0.806φ−1/3β−1/3−1]β1.43)/ρS
• where:
• φ=volume fraction of carbon black in the composite,
• S=specific surface area of the carbon black in m2/g measured by the nitrogen BET method,
• ρ=carbon black density,
• β=φeff/φ, and
• φeff=φ[1+(0.0181*CDBP)]/1.59.