Title of Invention

A PROCESS FOR PRODUCING CARBON BLACK

Abstract

The invention relates to a process for producing carbon blacks having a CTAB of greater than, or equal to, 140m 2/g; a CDBP of greater than or equal to 135 percentage;a triangle D50 of less than or equal to 50nm; a Dmode less than or equal to 72nm; and an Occluded Volume Index greater than or equal to 1.30. Combustion gases are produced at a temperature to pyrolyze a carbon black yielding feed stock which is injected into the combustion gases at two points. 50-80 percentage by wt of the total amount of feed stock is injected at the second point. Carbon blacks prepared by this process imparts superior treadwear resistance and abrasion resistance to rubber compounds.

Full Text

The present invention relates to a process for producing carbon black that are particularly well suited for use in rubber compounds intended for use in tires. The carbon blacks advantageously impart high abrasion resistance and treadwear resistance to rubber compounds at generally utilized loading levels. The carbon blacks also advantageously impart a combination of high abrasion resistance and treadwear resistance, and reduced hyteresis, to rubber compounds when utilized at loading levels below those normally utilized. The rubber compounds containing the carbon blacks of the present invention may also include silica in order to improve the traction performace of the rubber compounds. Carbon blacks are generally produced in a furnace-type reactor by pyrolyzing a hydrocarbon feed stock with hot combustion gases to produce combustion products containing particulate carbon black. Carbon blacks are generally characterized on the basis of analytical properties including, but not limited to, surface area, surface chemistry, aggregate size, and particle size. The properties of carbon blacks are analytically determined by tests known to the art, including, for example CTAB, CPBP and tinting strength value (TINT)1 Carbon blacks may also be characterized by their A D50, Dmode and Occluded Volume Index properties. Carbon blacks may be utilized as pigments, fillers, reinforcing agents and for a variety of other applications. For example, carbon blacks are widely utilized as fillers and reinforcing pigments in the compounding and preparation of rubber and plastic compounds. More particularly, carbon blacks are effective in the preparation of rubber vuloanizates intended for usage in prepping tires. It is generally understood that the properties of a carbon black affect the properties of mbber or plastic compounds containing the carbon black. Thus, the properties of a carbon black vial affect the properties of tire tread compounds containing the carbon black. It is generally desirable in the production of tires to utilize carbon black containing tire tread compounds which have satisfactory abrasion resistance. The greater the abrasion resistance of a mbber compound, the greater the treadwear resistance of a tire produced with the mbber compound and thus the greater the number of nailes the tire will last before wearing out. It is 1so generally desirable in the production of tires to utilize tire tread compounds, incorporating carbon blacks, which have satisfactory hysteresis. The hysteresis of a mbber compound refers to the energy dissipated under deformation. Tires produced with tread compounds having lower hysteresis values will have reduced rolling resistance which results in reduced fuel consumption by the vehicle utilizing the tire. Accordingly, an object of the present invention is new carbon blacks that impan superior abrasion resistance and treadwear resistance to natural rubbers, synthetic mbbers and blends of natural and synthetic mbbers. Another object of the present invention is to provide new mbber compounds having improved abrasion resistance and treadwear resistance prepared utilizing the carbon blacks of die present invention at conventional loading levels. A further object of the present invention is to provide new mbber compounds having a combination of improved abrasion resistance and treadwear resistance, and reduced hysteresis, when prepared utilizing the carbon blacks of the present invention at loading levels below normally utilized. The mbber compounds containing the carbon blacks of the present invention may also include silica in order to improve the traction performance of the mbber compounds. The silica should be incorporated into the mbber compounds in amounts ranging from about 5 to about 30 parts by weight for each 100 pans by weight of the mbber component The silica to be utilized in the preparation of the rubber compounds maybe any silica known to those skilled in the an. For example, the silicas prepared by precipitation or pyrolysis techniques are suitable for use. When incorporating a silica it is also preferable to utilize any of the well-known coupling agents. Other objects of the present invention will become apparent from the following description and the claims. SUMMARY OF TEiE INVENTION We have discovered new carbon blacks having a CTAB (cetyl-trimeihyl ammonium bromide absorption value) of greater than, or equal to, 140 m2/g (square meters per gram), preferably 140-250 rnVg; a CDBP (crushed dibutyl phthalate absorption) of greater than or equal to 115 cc/lOOg (cubic centimeters dibutyl phthalate per 100 grams carbon black), preferably 120-150cc/100g; a Tint value of greater than or equal to 135%, preferably 145-180%; a AD50 of less than or equal to 50 nm (nanometers), preferably less than or equal to 47 nm, more preferably 20-45 nm; a Dmode less Uian or equal to 72 nm, preferably 40-67 nm; and an Occluded Volume Index greater than or equal to 1.30, preferably 1.40-2.0. Preferably the carbon blacks of the present invention are further characterized by having a N2SA (nitrogen surface area) greater than or equal to 150 m1/g, and less than 180 m2/g; and a DBF (dibutyl phthalate absorption) of greater than or equal to 140 cc/lOOg, preferably 140-180 cc/lOOg. The carbon blacks of the present invention may be produced in a furnace carbon black reactor having a first (combustion) zone, a transition zone, and a reaction zone. A carbon black yielding feedstock is injected in any manner known to the ait into a hot combustion gas stream. The resultant mixtiire of hot combustion gases and feedstock passes into die reaction zone. Pyrolysis of the carbon black yielding feedstock is stopped by quenching the mixture when the carbon blacks of the present invention have been formed. Preferably pyrolysis is stopped by injecting a quenching fluid. A process for preparing the novel carbon black of the present invention will be described in greater detail hereinafter. We have also discovered new rubber compounds containing the carbon blacks. The rubbers for which the novel carbon black of this invention are effective include natural and synthetic rubbers or blends or mixtures thereof. The term 'loading" or "loading level" refers to the amount of carbon black utilized in the compounding of the rubber compound incorporating the carbon black. Generally, to produce rubber compounds having superior abrasion resistance and treadwear resistance, amounts of the carbon black of the present invention ranging from about 10 to about 250 parts by weight can be used for each 100 parts by weight of rubber, preferably, amounts varying from about 10 to about 100 parts by weight of carbon black per 100 parts by weight of rubber. To achieve rubber compounds having a combination of superior abrasion resistance and treadwear resistance, and low hysteresis, amounts ranging from about 10 to about 45 parts of carbon black per 100 parts of mbber may be utilized. The mbber compounds containing the carbon blacks of the present invention may also include silica in order to improve the traction performance of the mbber compounds. The silica should be incorporated into the rubber compounds in amounts ranging from about 5 to about 30 parts by weight for each 100 parts by weight of the mbber component The silica to be utilized in the preparation of the mbber compounds may be any silica known to those skilled in the art For example, the silicas prepared by precipitation or pyrolysis techniques are suitable for use. When incorporating a silica it is also preferable to utilize any of the well-known coupling agents. The treadwear resistance/hysteresis ratio of mbber compounds intended for use in tire tread coo1unds is important to those of ordinary skill in the art Higher treadwear resistance/hysteresis ratios are generally advantageous. As an example, tire tread compounds produced from mbber compounds incorporating VULCAN® lOH carbon black, manufactured and sold by Cabot Corporation, Boston, Massachusetts, have treadwear resistance/hysteresis ratios of approximately 1.0 when both properties are expressed relative to a standard tread compound. The carbon blacks of the present invention impart improved abrasion resistance and treadwear resistance at loading levels normally utilized for tire compounds. Moreover, we ■ have found that the loading levels of the carbon blacks of the present invention in rubber compounds may be reduced below levels generally utilized in tire compounds, resulting in tire compounds having reduced hysteresis values, while maintaining the superior abrasion resistance and treadwear resistance of the rubber compound. Among die mbbers suitable for use witii the present invention are any natural mbbers, syndietic rubbers, and blends of nattiral and syndietic rubbers. Typical of the rubbers are styrene-butadiene mbbers (SBR) generally known in die an including, but not limited to, oil extended and clean emulsion SBR's, high styrene SBR's, solution SBR's, starred solution SBR's and functionalized solution SBR's. An advantage of die carbon blacks of the present invention is that the carbon blacks impart improved abrasion resistance and treadwear resistance to nanual rubbers, synthetic rubbers and blends of natural and synthetic mbbers incorporating the carbon blacks. Anodier advantage of die carbon blacks of die present invention is that die carbon blacks impart a combination of improved abrasion resistance and treadwear resistance, and lower hysteresis, to natural rubbers, synthetic mbbers and blends of natural and synthetic rubbers when die carbon blacks are incorporated at loading levels below diose normally utilized to prepare tread compounds. An advantage of die rubber compounds of the present invention is that die mbber compounds are particulariy well suited for use in producing passenger car, tmck and bus tires having a higher level of treadwear resistance resulting in the tires having longer lives when compared with tires produced with rubber compounds incorporating conventional carbon blacks. These characteristics of tires are particularly advantageous in all season tires, touring tires and high performance tires for passenger vehicles and in light and medium truck/bus tires. Another advantage of die rubber compounds of die present invention is diat die mbber compounds incorporating the carbon blacks of die present invention at low loading levels are particularly well suited for use in producing tires having a higher level of treadwear resistance and reduced rolling resistance when compared to tires produced widi mbber compounds incorporating conventional carbon blacks at similar reduced loading levels. Rubber compounds incorporating the carbon blacks of the present invention at low loading levels are particularly well suited for use in passenger, light and medium truck, and off the road tires where minimizing hysteresis while maintaining treadwear resistance is beneficial. For example, in light truck and passenger oar tires, fuel economy is important and advantageously increased by tire compounds having reduced hysteresis. In medium radial truck tires, in addition to increasing fuel economy, minimizing hysteresis maximizes carcass durability which maximizes retreadability. In off the road tires, performance is often measured in ton-miles-per-hour which is increased by minimizing hysteresis. Other addvantages of the present invention will become apparent from the following more detailed description of the invention. Accordingly the present invention provides a process for producing carbon black comprising: producing combustion gases at a temperature sufficient to pyrolyze a carbon black yielding feedstock by reacting a fuel and an oxidant; passing the combustion gases through a reactor; injecting a carbon black yielding feedstock into the combustion gases so as to decompose and convert the feedstock into carbon black, quenching the mixture of combustion gases and carbon black to produce carbon 9 black having a CTAB of greater than, or equal to, 140m /g; a CDBP of greater than or equal to 115 cc/100g; a Tint value of greater than or equal to 135%; a AD50 of less than or equal to 50 nm; a Dmode less than or equal to 72 nm; and an Occluded Volume Index greater than or equal to 1.30, wherein the carbon black yielding feedstock is injected into the combustion gases at two points, 50-80% by weight, of the total amount of carbon black yielding feedstock being introduced at the first point and 20-50%, by weight, of the total amount of carbon black yielding feedstock is introduced at the second point. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS: Figure 1 is a cross-sectional view of a portion of one type of furnace carbon black reactor which may be utilized to produce the carbon blacks of the present invention. Figure 2 is a sample histogram of ±e weight fraction of the aggregates of a carbon black sample versus the Stokes Diameter in a given sample. DETAILED DESCRIPTION OF THE INVENTION The carbon blacks of the present invention are charaaerized by the following combination of analytical properties: CTAB > 140 m2/g, preferably 140 mVg CDBP> 115 cc/lOOg, preferably 120 cc/lOOg Tmt > 135, preferably 145% AD50 Dmode Occluded Volume Index > 1.30; preferably 1.40 Preferably, the carbon blacks of the present invention are further characterized by having: 130 ra2/g 140 cc/lOOg, preferably 140 cc/lOOg Referring to Figure 1, the carbon blacks of the present invention may be produced in a furnace carbon black reactor 2, having: a combustion zone 10, which has a zone of converging diameter 11; feedstock injection zones 12 and 14; and reaction zone 18. The diameter of the combustion zone, 10, up to the point where the zone of converging diameter, 11, begins is shown as D-1; the diameter of the converging zone, 11, at the narrowest point, is shown as D-2; the diameter of zone 12, as D-3, the diaipeter of zone 14, as D -4, and the diameter of the reaction zone, 18, as D-5. To produce the carbon blacks of the present invention hot combustion gases are generated in zone 10 by contacting liquid or gaseous fuel with a suitable oxidant stream such as [ air, oxygen, mixmres of air and oxygen ot the like. Among the fuels suitable for use in contacting the oxidant stream in combustion zone 10 to generate the hot combustion gases are included any of the readily combustible gas, vapor or liquid streams such as natural gas, hydrogen, carbon monoxide, methane, acetylene, alcohols, or kerosene. It is generally preferred, however, to utilize fuels having a high content of carbon-containing components and in particular, hydrocarbons. The ratio of air/fiiel utilized to produce the carbon blacks of the present invention may preferably be between 8:1 and 20:1. As understood by those of ordinary skill in the art, to facilitate the generation of hot combustion gases, the oxidant stream may be preheated. The hot combustion gas stream flows downstream from zones 10 and 11 into zones 12, 14 and then 18. Carbon blackryielding feedstock, 30 is introduced at point 32, located in zone 12, and at point 34, located in zone 14. Suitable for use.herein as carbon black-yielding hydrocarbon feedstocks, which are readily volarilizable under the conditions of the reaction, are unsaturated hydrocarbons such as acetylene; olefins such as ethylene, propylene, butylene; aromatics such as benzene, toluene and xylene; certain saturated hydrocarbons; and volatilized hydrocarbons such as kerosenes, naphthalenes, terpcnes, ediylene tars, aromatic cycle stocks and the like. To produce the carbon blacks of the present invention feedstock may be injected in an amount of from about 50% to about 80%, by weight, at point 32, and the remainder of the total amount of from about 20% to about 50%, by weight, injected at point 34. Preferably, from about 55% to about 70% of the total anxsunt of feedstock, by weight, is introduced at point 32, and thd remainder of the total amount of feedstock, from about 45% to about 30%, by weight, is introduced at point 34. In the examples described herein, carbon black-yielding feedstock, 30, was injected substantially transversely from the periphery of the stream of hot combustion gases in the form of a plurality of small, coherent jets which penetrated into the interior regions of the hot combustion gas stream to insure a high rate of mixing and shearing of the hot combustion gases and the carbon black-yielding feedstock so as to rapidly and completely decompose and convert the feedstock to the novel carbon blacks of the present invention. The distance between point 32 and point 34 is shown in die figure as L-l. The mixnire of carbon black-yielding feedstock and hot combustion gases flows downstream from zones 12 and 14, into reaction zone 18. Quench 40, located at point 42, injecting quenching fluid 50, is utilized to cool the mixture of carbon black-yielding feedstock and hot combustion gases, to stop pyrolysis of the carbon black-yielding feedstock when the novel carbon blacks of the present invention are fonned. Point 42 may be determined in any manner known to the art for selecting the position of a quench to stop pyrolysis. One method for determining the position of the quench which stops pyrolysis is by determining the point at which an acceptable toluene extract level for the carbon blacks of the present invention is achieved. Toluene extract level may be measured by using ASTM Test D1618-83 "Carbon Black Extractables - Toluene Discoloration". L-2 is the distance from the beginning of zone 18, to point 42, and will vary according to the position of the quench. After the mixture of hot combustion gases and carbon black-yielding feedstock is quenched, the cooled gases containing the carbon blacks of the present invention pass downstream into any conventional cooling and separating means whereby the carbon blacks of the present invention are recovered. The separation of the carbon black from the gas stream is readily accomplished by conventional means such as a precipitator, cyclone separator and bag filter. This separation may be followed by pelletizing using, for example, a wet peUetizer. The following testing procedures are used in the determination and evaluation of the analytical properties of the carbon blacks of the present invention, and the physical properties of die rubber compounds incorporating the carbon blacks of the present invention. Carbon Black Analvrical Properties The CTAB of the carbon blacks was determined according to ASTM Test Procedure D3765-85. The iodine absorption number (I2N0.) of the carbon blacks was determined according to ASTM Test Procedure D1510. The nitrogen surface area (N2SA) of the carbon blacks was determined according to ASTM Test Procedure D3037-Method A. The dibutyl phthalate absorption value (DBP) of the carbon was determined according to ASTM Test Procedure D3493-86. Tinting strength (Tint) of the carbon blacks was determined according to ASTM Test Procedure D3265-85a. The CDBP of the carbon black was determined according to the procedure set forth in ASTM D 3493-86. The Occluded Volume Index of a carbon black is a measure of the internal void volume of the carbon black aggregates. The significance of die Occluded Volume Index of a carbon black is known to those of ordinary skill and was published by Medalia (A. I. Medalia, J Colloid Interface Sci. 32,115 (1970)) and more recentiy discussed by Herd et al. (C.R. Herd, G.C. McDonald and W.M. Hess, Rubber Chem. and Tech. 65, 107 (1992)). The Occluded Volume Index of a carbon black is determined using certain parameter? of carbon black aggregate morphology obtained dirough the use of electron microscopy and image analysis. The procedure for electron microscopy follows ASTM Standard D-3849-87 "Standard Test Method for Carbon Black - Primary Aggregate Dimensions from Electron such as the one manufactured by Joyce Loebl Co. Ltd. of Tyne and Wear, United Kingdom. The following procedure is a modification of the procedure described in the instruction manual of the Joyce Loebl disk centrifuge file reference DCF 4.008 published on February 1, 1985, the teachings of which are hereby incorporated by reference, and was used in determining the data. The procedure is as follows. 10 mg (milligrams) of a carbon black sample are weighed in a weighing vessel, then added to 50 cc of a solution of 10% absolute ethanol and 90% distilled water which is made 0.05% NONIDET P-40 surfactant (NONIDET P-40 is a registered trademark for a surfactant manufactured and sold by Shell Qiemical Co.). The resulting suspension is dispersed by means of ultrasonic energy for 15 minutes using Sonifier Model No. W 385, manufactured and sold by Heat Systems Ultrasonics Inc., Faimingdale, New York. The following information is entered into the computer which then records additional data from the disk centrifuge: 1. The specific gravity of carbon black, taken as 1.86 g/cc; 2. The volume of the solution of the carbon black dispersed in a solution of water and ethanol, which in this instance is 0.5 cc; 3. The volume of spin fluid, which in this instance is 10 cc of water, 4. The viscosity of the spin fluid, which in this instance is taken as 0.933 centipoise at 23 degrees C; 5. The density of the spin fluid, which in this instance is 0.9975 g/cc at 23 degrees C; 6. The disk speed, which in this instance is 8000 rpm; 7. The data sampling interval, which in this instance is 1 second. The disk centrifuge is operated at 8000 rpm while the stroboscope is operating. 10 cc of distilled water are injected into the spinning disk as the spin fluid. The turbidity level is set to 0; and 1 cc of the solution of 10% absolute ethanol and 90% distilled water is injected as a buffer liquid- The cut and boost buttons of the disk centrifuge are then operated to produce a smooth concentration gradient between the spin fluid and the buffer liquid and the gradient is monitored visually. When the gradient becomes smooth such that there is no distinguishable boundary between the two fluids, 0.5 cc of the dispersed carbon black in aqueous ethanol solution is injected into the spinning disk and data collection is staned immediately. If streaming occurs the run is aboned. The disk is spun for 20 minutes following the injection of the dispersed carbon black in aqueous ethanol solution. Following the 20 minutes of spinning, the disk is stopped, the temperature of the spin fluid is measured, and the average of the temperature of the spin fluid measured at die beginning of the run and the temperature of the spin fluid measured at the end of the run is entered into the computer which records the data from the disk centrifuge. The data is analyzed according to the standaid Stokes equation and is presented using the following definitions: Carbon black aggregate - a discrete, rigid colloidal entity diat is the smallest dispersible unit; it is composed of extensively coalesced particles; Stokes diameter - the diameter of a sphere which sediments in a viscous medium in a centrifugal or gravitational field according to the Stokes equation. A non-spherical object, such as a carbon black aggregate, may also be represented in terms of the Stokes diameter if it is considered as behaving as a smooth, rigid sphere of the same density, and rate of sedimentation as the object The customary units are expressed in nanometer diameters. Mode (Dmode for reporting purposes) - The Stokes diameter at the point of the peak (Point A of Figure 2 herein) of the distribution curve for Stokes diameter. Median Stokes diameter • (Dst for reporting purposes) the point on the distribution curve of Stokes diameter where 50% by weight of the sample is either larger or smaller. It therefore represents the median value of the determination. Rubber Compound Testing Pnx:edures The abrasion resistance data of the rubber compounds were determined using an abrader which is based on a Lanjboum type machine. Abrasion resistance rates (cubic centimeter/centimeter travel) were measured at 7%, 139b and 21% slip. The slip is based on the relative velocity between the sample wheel and grindstone. In the following examples, the abrasion resistance index is the ratio of the abrasion resistance rate of a control compound containing VULCAN® lOH carbon black, a trademariced product of Cabot Corporation, Boston, Massachusetts divided by the abrasion resistance rate of a compound produced using a specified carbon black of the present invention, at the same slip. The modulus, tensile and elongation of the rubber compounds were measured by the procedure set forth in ASTM D412. The Shore A Hardness of the rubber compounds was determined according to the procedure set forth in ASTM D-2240-86. Rebound data were determined on all rubber samples utilizing a ZWICK Rebound Resilience Tester, Model 5109, manufactured by Zwick of America, Inc., Post Office Box 997, East Windsor, Connecticut 06088. Instructions for determining the rebound values accompany the instrument The dynamic mechanical properties of the rubber compounds were determined in a manner well known to those of ordinary skill in the art, using an Instrom Model 1332 Servohydraulic System. The standard test conditions were as follows: 10% double strain amplitude; 10 Hz frequency; 15% mean level and 70* C testing temperature. The specimen tested for each of the rubber compounds consisted of a cylinder 25.4 mm, in height, and 17.8mm, in diameter. The dynamic mechanical properties were measured in a compression mode and included conqilex modulus (E*), elastic nxxlulus (E*), and loss modulus (E"), with the tangent of the phase angle delta equal to loss modulus divided by elastic modulus (tangent dclta = tana = E"/E'). Treadwear resistance of the tire compounds referred to in die following examples was determined in a manner well known in the an and described in Cabot Corporation's Technical Service Report No. TG-67-1 on "The Use of Multi-Section Treads in Toe Testing" by Fred E. Jones (1967) with the exception that radial tires were substituted for bias-ply tires. A standard multi-section tread technique, i.e., five tires/seven tread sections per tire was utilized. Arrangement of the tread sections on the tires, as well as mixing and lab testing of the compounds was according to a randomized block design so as to provide a statistically sound analysis of the data. The tread wear resistance evaluations are made relative to a standard reference carbon black which is arbitrarily assigned a wear rating value of 100 percent In the following examples, an ASTM N220 type carbon black, manufactured and sold by Cabot Coiporation, Boston, Massachusetts and further characterized by having a Tint of 111%, an I2N0. of 121 rag/g, a DBP of 115 cc/lOOg, and a density of 22 lbs./cu.ft., was utilized as the reference carbon black. The road test was run at a nominal rate of 60 ± 10 miles/mil (based on the control compound) for 10,000 miles. The effectiveness and advantages of the present invention will be further illustrated by the following examples. EXAMPLES 1-3 Three examples of the novel carbon blacks of the present invention were prepared in a reactor generally described herein, and as depicted in Hgure 1, utiliziiig the reactor conditions and geometry set forth in Table 2. The fuel utilized in the combustion reaction in each of the examples was natural gas. The feedstock utilized in each of the examples had the properties indicated in Table 1 below: carbon black was used both as the control and the reference carbon black: Table 6 Rubber Compound Carbon Black 7% Slip (%) 13% Slip (%) 21% Slip (%) Rebound at70'C (%) A Ex. 1 106 105 113 61.7 B Ex.3 III 112 109 59.7 C VULCAN® lOH carbon black 100 100 100 64.9 The performance advantages of utilizing the carbon blacks of the present invention in truck tire rubber compounds is clearly demonstrated by the results in Table 6 showing that the carbon blacks of the present invention impart significandy higher abrasion resistance than the control carbon black. The lower rebound values of naniral rubber con1unds A and B, incorporating the carbon blacks of the present invention, indicate that the con1unds have increased hysteresis in comparison with natural rubber compound C, incorporating the VULCAN® lOH carbon black, which would be expected in view of the increased abrasion resistance properties of compounds A and B. EXAMPLES This Example illustrates the improved treadwear resistance of natural rubber tire compounds containing the carbon blacks of the present invention in comparison with the same rubber compound containing the control caiton black. Tire compound D was made with the caiton black of Exaniqjle I. Tire compound E was made with the carbon black of Exanqile 2. Tire coQ1und F was made with the control VULCAN® lOH carbon black. Tire compounds D, E and F were prepared according to the natural rubber road test compound formulation shown below in Table 7. with the carbon blacks of the present invention are comparable to those of a compound produced with the control VULCAN® lOH carbon black. The results set forth above indicate that incorporating the carbon blacks of the present invention at loading levels lower than conventionally utilized in the compounding of rubber tire compounds, will result in tires having reduced roiling resistance and/or heat build up, resulting from the reduced hysteresis, and improved treadwear resistance. It should be clearly understood that the forms of the present invention herein described are illustrative only and are not intended to limit the scope of the invention. IMs application has been divided out of Indian Patent implication N0.42/MAS/99 which deals vdth «A rubber composition containing carbon black". WE CLAIM: 1. A process for producing carbon black comprising producing combustion gases at a temperature sufficient to pyroly2e a carbon black yielding feedstock by reacting a fuel and an oxidant; passing the combustion gases through a reactor; injecting a carbon black yielding feedstock into the combustion gases so as to decompose and convert the feedstock into carbon black, quenching the mixture of combustion gases and carbon black to produce carbon black having a CTAB of greater than, or equal to, 140m^/g; a CDBP of greater than or equal to 115 cc/100g a Tint value of greater than or equal to 135% a D50 of less than or equal to 50 nm; a Dmode less than or equal to 72nm; and an Occluded Volume Index greater than or equal to 1.30, wherein the carbon black yielding feedstock is injected into the combuston gases at two points, 50-80%, by weight, of the total amount of carbon black yielding feedstock being introduced at the first point and 20-50%, by weight, of the total amount of carbon black yielding feedstock is introduced at the second point. 2. The process as claimed in claim 1, wherein the mixture of combustion gases and carbon black is quenched to produce a carbon black having a CTAB is 140-250m^/g; a CDBP is 120- 150oc/100g; a Tint value is 145-180%; a^ D50 is less than or equal to 47nm; a Dmode is 40-67 nm; and the Occluded Volume Index is 1.40-2.0. 3. The process as claimed in claim 2, wherein the mixture of combustion gases and carbon black is quenched to produce a carbon black having a CTAB is 140-250m^/g; a CDBP is 120-150oc/100g; a Tint value is 145-180%; a AD50 of 20-45nm; a Dmode is 40-67 nm; and the Occluded Volume Index is 1.40-2.0. 4. The process as claimed in claim 1, wherein the mixture of combustion gases and carbon black is quenched to produce a carbon black having a N2SA greater than or equal to 150m /g; and less than 180m^/g; a DBP of greater than or equal to 140oc/100g; a CTAB of greater than or equal to 140m^/g; a CDBP of greater than or equal to 115co/100g; a Tint value of greater than or equal to 135%; a ^ D50 of less than or equal to 50nm; a Dmode less than or equal to 72nm; and an Occluded Volume Index greater than or equal to 1.30. 5. The process as claimed in claim 1, wherein the mixture of combustion gases and carbon black is quenched to produce a carbon black having a DBP of 140-180cc/100g; a N2SA greater than or equal to 150m^/g, and less than 180m^/g; a CTAB of greater than or equal to 140mVg» a CDBP of greater than or equal to 115cc/100g; a Tint value of greater than or equal to 135%; a ^ D50 of less than or equal to 50nm; a Dmode less than or equal to 72nm; and an Occluded Volume Index greater than or equal to 1.30.

Documents:

1178-mas-1999 abstract-duplicate.pdf

1178-mas-1999 abstract.pdf

1178-mas-1999 claims-duplicate.pdf

1178-mas-1999 claims.pdf

1178-mas-1999 correspondence-others.pdf

1178-mas-1999 correspondence-po.pdf

1178-mas-1999 description (complete)-duplicate.pdf

1178-mas-1999 description (complete).pdf

1178-mas-1999 drawings-duplicate.pdf

1178-mas-1999 drawings.pdf

1178-mas-1999 form-1.pdf

1178-mas-1999 form-19.pdf

1178-mas-1999 form-26.pdf

1178-mas-1999 form-3.pdf