Carbon Black Wiki

THE HISTORY OF CARBON BLACK

From anci­ent Chi­na to an important pig­ment / fil­ler of the 21st century

In the ear­ly civi­liza­ti­ons, the unde­si­red pro­duct soot was used in the anci­ent Egypt and Chi­na as a black pig­ment for wri­ting let­ters. In the late 19th cen­tu­ry car­bon black star­ted to be pro­du­ced with the chan­nel pro­cess. The indus­tri­al mass pro­duc­tion star­ted in the begin­ning of the 20th cen­tu­ry, with the deve­lo­p­ment of other car­bon black pro­duc­tion pro­ces­ses, main­ly dri­ven by expan­ding the tire industry.

Today car­bon black is a high-tech raw mate­ri­al with clear defi­ned pro­per­ties, wide­ly used in various fields of appli­ca­ti­ons, from pig­ment to elec­tric con­duc­ti­ve agent of high-tech­no­lo­gy materials.

WHAT IS CARBON BLACK?

Car­bon black is one of the dar­kest and most wide­ly spread mate­ri­als known. Che­mi­cal­ly, car­bon black is a col­lo­idal form of ele­men­tal car­bon con­sis­ting of 95 to 99% car­bon. Made in spe­ci­al­ly desi­gned reac­tors, ope­ra­ting at inter­nal tem­pe­ra­tures in the ran­ge of 2600° to 3600°F, dif­fe­rent gra­des of Car­bon black can be pro­du­ced with vary­ing aggre­ga­te size and struc­tu­re. It is not the unde­si­red by-pro­duct soot, which is known from chim­neys or exhausts. Car­bon black is an indus­tri­al pro­du­ced raw mate­ri­al with clear defi­ned pro­per­ties like pri­ma­ry par­tic­le size, sur­face and struc­tu­re. Car­bon black is a high-tech pro­duct that can be manu­fac­tu­red repro­du­ci­b­le with defi­ned parameters/properties. Car­bon black typi­cal­ly con­ta­ins more than 95% pure car­bon with mini­mal quan­ti­ties of oxy­gen, hydro­gen and nitrogen.

The cha­rac­te­ristics of car­bon black depend main­ly on the manu­fac­tu­ring process/method, and the­r­e­fo­re car­bon black is clas­si­fied by the manu­fac­tu­ring process.

Manu­fac­tu­ring methods include fur­nace, gas, lamp and ther­mal black pro­ces­ses. Abo­ve 98% of the world’s annu­al car­bon black pro­duc­tion is cover­ed by the fur­nace black process.

CARBON MARKET SHARES

The glo­bal car­bon black mar­ket is a con­so­li­da­ted mar­ket, whe­re the three lar­gest play­ers in the mar­ket – Bir­la Car­bon, Cabot Cor­po­ra­ti­on & Ori­on con­tri­bu­te to rough­ly 50% of the mar­ket share.

Bir­la Car­bons’ mar­ket share is appro­xi­m­ate­ly 2,1 mil­li­on ton­nes with regis­tra­ted trade­na­mes like Raven®, Con­duc­tex®, Cop­eb­lack®, Pureb­lack®, Sta­tex® & XT®.

Cabot Cor­po­ra­ti­on is respon­si­ble for more than 2,2 mil­li­on ton­nes with regis­tra­ted trade­na­mes like Elf­tex®, Vul­can®, Black Pearls®, Regal®, Mogul®, Sphe­ron® & Mon­arch®, whe­re­as Ori­on Engi­nee­red Car­bons has a mar­ket share of appro­xi­m­ate­ly 1,2 mil­li­on ton­nes with regis­tra­ted trade­na­mes like Prin­tex®, HiB­lack®, Spe­cial Black®, Aerosper­se®, Lamp black®, Colour Black®, Nerox®, Pan­ther®, Nipex® & Purex®.

Diagramm-Market-Volume-Shares-Carbon-Black

The world’s main pro­du­cers of con­duc­ti­ve and super­con­duc­ti­ve car­bon black are Tim­Cal Gra­phi­te & Car­bon® with Tim­cal Ensa­co® 150G, Tim­cal Ensa­co® 250G, Tim­cal Ensa­co® 350G and Lion Spe­cial­ty Che­mi­cals Co., Ltd.® with Ket­jenb­lack EC-300J® & Ketjenblack-600JD®.

CARBON BLACK FEEDSTOCK

Feedstock base for all car­bon blacks are hydro­car­bons like, aro­ma­tic oils based on coal tar or cru­de oil. Main coal tar distil­la­te for car­bon black pro­duc­tion is for exam­p­le anthr­a­ce­ne oil. Both groups have a high con­tent of aro­ma­tic hydro­car­bons in com­mon. Fur­ther feedstocks are hea­vy petro­le­um frac­tion, distil­la­ti­on resi­dues form oil refi­ne­ries, and dif­fe­rent oil mix­tures. Fur­ther can be used natu­ral gas, naph­tha, gas oil and acetylene.

The 2 main para­me­ters for car­bon black feedstock that are influen­cing the yield are BMCI (Bureau of Mines Cor­re­la­ti­on Index) and Sulp­hur con­tent. The most important is the BMCI, a num­ber cor­re­la­ted with the aro­ma­ti­ci­ty of the feedstock.
To eva­lua­te the BMCI, the spe­ci­fic gra­vi­ty and the mean boi­ling point are significant.
High con­tent of sulp­hur is unde­si­red in car­bon black feedstock, becau­se sulp­hur con­tent in the feedstock is cor­re­la­ted with the sulp­hur in car­bon black.

HOW IS CARBON BLACK PRODUCED?

The­re are seve­ral pro­ces­ses for car­bon black pro­duc­tions. In the fur­nace black pro­cess aro­ma­tic oils (based on cru­de oil) are cra­cked under high tem­pe­ra­tu­re in a reac­tor, pro­du­cing car­bon black and tail gas. After coo­ling, the car­bon black is sepa­ra­ted from the tail gas, den­si­fied and pro­ces­sed into pel­lets of vary­ing grades/sizes. This pro­cess is the most wide­ly used in the world com­pri­sing over 98% of all car­bon black pro­duc­tion, becau­se it per­mits the to influence and con­trol the main car­bon black pro­per­ties like spe­ci­fi­cal­ly engi­nee­red aggre­ga­tes of car­bon par­tic­les that vary in par­tic­le size, aggre­ga­te size, shape, poro­si­ty and sur­face chemistry.

Furnace black process:

The world­wi­de most com­mon pro­duc­tion pro­cess uses a clo­sed reac­tor to ato­mi­ze hea­vy aro­ma­tic oils under pres­su­re and tem­pe­ra­tu­re con­trol­led con­di­ti­ons. This feedstock is induc­ted into a hot gas stream and a pre­hea­ted air stream whe­re it vapo­ri­zes and then pyro­ly­zes in the vapor pha­se to form micro­sco­pic car­bon par­tic­les. In most fur­nace reac­tors, the reac­tion rate is con­trol­led by steam or water sprays. The car­bon black pro­du­ced is con­vey­ed through the reac­tor, coo­led and coll­ec­ted in bag fil­ters in a con­ti­nuous process.

Illustration_FurnaceBlackProcess

Thermal black process:

Dis­con­ti­nuous or cyclic pro­cess, with natu­ral gas metha­ne as the most com­mon­ly used feedstock, alt­hough hig­her gra­de hydro car­bon oils are also used as feedstock mate­ri­al. The natu­ral gas is injec­ted into the inert atmo­sphe­re of the fur­nace whe­re it decom­po­ses into car­bon black and hydro­gen. It has the lar­gest par­tic­le size and among the lowest degrees of par­tic­le aggre­ga­ti­on or struc­tu­re. Sin­ce it is made from natu­ral gas, it is also one of the purest forms of car­bon available on an indus­tri­al scale.

Illustration_ThermalBlackProcess

Channel black process:

The cru­de oil is vapo­ri­zed in the chan­nel black pro­cess and is fed to the bur­ners tog­e­ther with 
the car­ri­er gas. A spe­ci­fic influence on the struc­tu­re of the car­bon blacks pro­du­ced in this way is not pos­si­ble. Nowa­days the chan­nel black pro­cess is pri­ma­ri­ly used to manu­fac­tu­re car­bon black pig­ments with very fine par­tic­les, which are pri­ma­ri­ly distin­gu­is­hed by their high con­tent of oxy­ge­nic sur­face groups.

Illustration_ChannelBlackProcess

Lamp black process:

This pro­cess is the oldest way to pro­du­ce car­bon black (form­er­ly from oil lamps). The hea­ting is con­duc­ted on a cast-iron pan with the feedstock. Radi­ant heat from the hood cau­ses the feedstock to vapo­ri­ze and par­ti­al­ly com­bust. Most of it is con­ver­ted into car­bon black.

Illustration_LampBlackProcess

Acetylene black process:

Ace­tyl­e­ne Black is a high puri­ty car­bon black pro­du­ced in clo­sed reac­tors obtai­ned from the ther­mal decom­po­si­ti­on of ace­tyl­e­ne. Due to the pro­duc­tion pro­cess, ace­tyl­e­ne blacks dif­fers from other car­bon black gra­des. Ace­tyl­e­ne blacks are available in pow­der form, as they are cha­rac­te­ri­zed by a high struc­tu­re, which makes it dif­fi­cult to den­si­fy and impos­si­ble to pel­le­ti­ze them. Due to a very high ther­mal as well as elec­tri­cal con­duc­ti­vi­ty, ace­tyl­e­ne blacks are pri­ma­ri­ly used as con­duc­ti­ve blacks in elec­tric cells, anti­sta­tic rub­ber and pla­s­tic appli­ca­ti­ons and cable manufacturing.

Illustration_AcetyleneBlackProcess

Carbon Black manufacturing process:

The fol­lo­wing flow dia­gram shows the indi­vi­du­al pro­cess steps in a car­bon black production.

Wiki 1

Surface oxidation/after treatment of Carbon Black:

After tre­at­ment of Car­bon Black – so cal­led sur­face oxi­da­ti­on – is not a clas­si­cal pro­duc­tion pro­cess. The sur­face of the Car­bon Blacks pro­du­ced in the fur­nace- ther­mal-, gas- and lamp black pro­cess can be modi­fied by the use of oxi­da­tive agents, which will influence on the tin­ting, colo­ristic, PH and the wet­ting of the Car­bon Black.

Illustration_Surface Oxidation

Raw materials for Carbon Black:

  • Fuel (natu­rel gas or oil)
  • Oxi­dizer – air
  • Feedstock oil (LSFO)
  • Water
  • Struc­tu­re con­trol addi­ti­ve (pot­as­si­um salt)
  • Pel­let binder

END USES FOR CARBON BLACK

The par­tic­le size, struc­tu­re and sur­face area of car­bon black play a signi­fi­cant role in the mate­ri­al pro­per­ties of rub­ber, pla­s­tics, inks, paint, coa­tings, cos­me­tics, fibres, paper, ener­gy, foundry, metall­ur­gic, fric­tion and refrac­to­ry pro­ducts. The total mar­ket for car­bon black was pro­ba­b­ly around 13 mil­li­on metric tons in 2016. For this reason, car­bon black is made in various gra­des to meet the vary­ing mate­ri­al needs and spe­ci­fi­ca­ti­ons of manufacturers.

THE 3 MAIN PROPERTIES OF CARBON BLACK

Primary particle size and distribution

The dia­me­ter of sphe­ric par­tic­les is the fun­da­men­tal pro­per­ty, which lar­ge­ly affects black­ness and disper­si­bi­li­ty when car­bon black is mixed with resins or other vehic­les. In gene­ral, the smal­ler the par­tic­le size, the hig­her the black­ness of car­bon black. Disper­si­on howe­ver, beco­mes dif­fi­cult due to an increase in coagu­la­ti­on force.

Structure of Carbon Black– DBP absorption

Pri­ma­ry par­tic­les – aggre­ga­tes – agglo­me­ra­tes. Struc­tu­re of car­bon black shows the length of the chains of agglo­me­ra­tes. Like par­tic­le size, the size of the struc­tu­re also affects the black­ness and disper­si­bi­li­ty of car­bon black. Gene­ral­ly the increase of struc­tu­re size impro­ves disper­si­bi­li­ty but lowers black­ness. Car­bon black with a lar­ger struc­tu­re in par­ti­cu­lar shows an excel­lent con­duc­ti­ve property.

Illustration of the structure development of Carbon Black
Illus­tra­ti­on of the struc­tu­re deve­lo­p­ment of Car­bon Black

Illus­tra­ti­on of the struc­tu­re deve­lo­p­ment of Car­bon Black

Below two images taken by a Scan­ning elec­tron micro­scope (SEM) show the struc­tu­re of one Car­bon Black gra­des in two dif­fe­rent scales.
The buil­ding of aggre­ga­tes and agglo­me­ra­tes beco­me visual­ly visi­ble this way.

SEM image showing the primary particles of Carbon Black
SEM image show­ing the pri­ma­ry par­tic­les of Car­bon Black

SEM image show­ing the pri­ma­ry par­tic­les of Car­bon Black

SEM image showing the aggregates and agglomerates building the structure of Carbon Black
SEM image show­ing the aggre­ga­tes and agglo­me­ra­tes buil­ding the struc­tu­re of Car­bon Black

SEM image show­ing the aggre­ga­tes and agglo­me­ra­tes buil­ding the struc­tu­re of Car­bon Black

Surface and surface chemistry of Carbon Black

The spe­ci­fic sur­face area of a car­bon black is main­ly deri­ved from the par­tic­le geo­me­try using adsorp­ti­on methods. Iod­i­ne adsorp­ti­on, mea­su­red in mg/g, is the most com­mon tech­ni­que. Various func­tion­al groups exist on car­bon black’s sur­face. The affi­ni­ty of car­bon black with inks or paint varnishes/resins chan­ges depen­ding on the type and amount of the func­tion­al groups. Car­bon black, with a lar­ge amount of hydro­xyl group given with oxi­da­ti­on tre­at­ment, has a great­ly enhan­ced affi­ni­ty to print inks or var­nis­hes, show­ing an excel­lent dispersibility.

The Pic­tu­re below shows 3 dif­fe­rent car­bon black types with dif­fe­rent sur­face are­as influen­cing the black­ness of car­bon black.

Smal­ler sur­face, big­ger par­tic­les → lower tinting
Hig­her sur­face, smal­ler par­tic­les → hig­her tinting

3 different shades of black, depending on the surface of Carbon Black.
3 dif­fe­rent shades of black, depen­ding on the sur­face of Car­bon Black.

3 dif­fe­rent shades of black, depen­ding on the sur­face of Car­bon Black.

FUNDAMENTAL PROPERTIES OF CARBON BLACK AND THEIR INFLUENCE ON PERFORMANCE

Several fundamental Carbon Black properties that influence the final product properties include:

  • Fine­n­ess or par­tic­le size distribution
  • Struc­tu­re or aggre­ga­te size/shape distribution
  • Poro­si­ty or pore size distribution
  • Sur­face che­mis­try or sur­face acti­vi­ty distribution

Carbon Black properties, which can have an important influence on the performance of final product include:

Smal­ler par­tic­le size (Hig­her sur­face area)

  • Increa­ses blackness
  • Increa­ses tint strength
  • Increa­ses UV pro­tec­tion and absorption
  • Increa­ses elec­tri­cal conductivity
  • Increa­ses vehic­le demand and viscosity
  • Lowers disper­si­bi­li­ty
  • Increa­ses car­bon and com­pound mois­tu­re pickup*

(Car­bon black mois­tu­re pick­up is pri­ma­ri­ly influen­ced by nitro­gen sur­face area. When incor­po­ra­ted into a com­pound the par­tic­le size of the Car­bon black beco­mes the pri­ma­ry influence on mois­tu­re pickup.)

Higher structure (Increasing DBPA)

  • Redu­ces black­ness and tint strength
  • Impro­ves dispersibility
  • Increa­ses vehic­le demand and viscosity
  • Increa­ses elec­tri­cal conductivity

Higher porosity

  • Increa­ses vehic­le demand and viscosity
  • Increa­ses elec­tri­cal conductivity

Poro­si­ty effec­tively redu­ces the „weight“ of a given par­tic­le of car­bon black. The­r­e­fo­re, for equal „weight %“ loa­dings hig­her poro­si­ty car­bons increase the num­ber of par­tic­les pre­sent in the com­pound redu­cing the inter-par­tic­le distances and great­ly incre­asing conductivity.

Total vs. external surface area

Poro­si­ty is often indi­ca­ted by lar­ger dif­fe­ren­ces bet­ween NSA and STSA whe­re NSA and STSA mea­su­re total sur­face area and exter­nal sur­face area respectively.

Increased surface oxides (Higher volatile content)

  • Increa­ses rate of mois­tu­re pick­up (does not affect equi­li­bri­um mois­tu­re pickup).

Additional Carbon Black properties

May affect the per­for­mance of com­pounds inclu­ding other con­sti­tu­ents of car­bon black such as sulp­hur, ash, resi­due, etc. and its phy­si­cal form i.e., pow­der or beads.

Physical form

Car­bon black is available in pow­der and bea­ded form. Howe­ver, bulk hand­ling, eco­no­mics, freight, cle­an­li­ne­ss or a par­ti­cu­lar requi­red pro­per­ty may man­da­te the use of a bea­ded black. When using bea­ded blacks, wetting/premix times should be exten­ded as much as pos­si­ble to ensu­re that the beads have been bro­ken down. The com­poun­der can anti­ci­pa­te disper­si­on to requi­re more work when using a bea­ded black. Howe­ver, this addi­tio­nal work can be off­set by fas­ter incor­po­ra­ti­on of the bea­ded black into the vehic­le and signi­fi­cant impro­ve­ments in hand­ling and housekeeping.

Carbon Black beads – the granulated form of Carbon Black
Car­bon Black beads – the gra­nu­la­ted form of Car­bon Black

Car­bon Black beads – the gra­nu­la­ted form of Car­bon Black

Carbon Black in powder
Car­bon Black in powder

Car­bon Black in powder

PROPERTIES & APPLICATIONS FOR COMMON CARBON BLCK RUBBER GRADES

TYPE (DESIGNATION) AVERAGE PARTICLE SIZE (NM) ASTM DESCRIPTION PRODUCTION PROCESS MAJOR PROPERTIES MAJOR APPLICATION
Super abra­si­on
fur­nace black
(SAF)
15-25 N110 Fur­nace black High rein­force­ment, pro­vi­des high abra­si­on resis­tance and tensile Used in road tires treads
N115 Fur­nace black High rein­force­ment, high sur­face impro­ve abra­si­on resistance Used in road tires treads
N121 Fur­nace black High rein­force­ment, high struc­tu­re, giving maxi­mum tread wear and easy dispersion Used in road tires treads
Inter­me­dia­te super abrasion
fur­nace black
(ISAF)
24-33 N220 Fur­nace black High rein­force­ment, pro­vi­des high abra­si­on resis­tance and ten­si­le, good processing Used in pas­sen­ger off-road tires and mecha­ni­cal goods, semi con­duc­ti­ve compounds
N234 Fur­nace black High rein­force­ment, increased struc­tu­re pro­vi­des hig­her level of reinforcing Used in pas­sen­ger off-road tires and mecha­ni­cal goods, semi con­duc­ti­ve compounds
High-abra­si­on
fur­nace black
(HAF)
28-36 N330 Fur­nace black Medi­um-high rein­force­ment, pro­vi­des good abra­si­on, high elon­ga­ti­on, easy processing Used in tire tread, con­vey­or belts, rub­ber mecha­ni­cal goods, pla­s­tics com­pounds, pigments
N326 Fur­nace black Medi­um-high rein­force­ment, low struc­tu­re, tear resistant Used in tire tread, gas­kets, mecha­ni­cal rub­ber goods, pig­ment and pla­s­tics applications
N339 Fur­nace black Medi­um-high rein­force­ment, high struc­tu­re, good excur­si­on and abra­si­on resistance Used in tire tread, con­vey­or belts, indus­tri­al rub­ber goods
N347 Fur­nace black Medi­um-high rein­force­ment, high struc­tu­re, good extru­si­on properties Used in tire tread, mecha­ni­cal rub­ber goods
N375 Fur­nace black Medi­um-high rein­force­ment, pro­vi­des high ten­si­le strength Used in tire tread, con­vey­or belts, mecha­ni­cal rub­ber goods
Fast-extru­ding
fur­nace black
(FEF)
50-70 N539 Fur­nace black Medi­um-high rein­force­ment, lower struc­tu­re, smooth extrusion Used in extru­ded goods, auto­mo­ti­ve seal­ing sys­tems, pro­files, mecha­ni­cal rub­ber goods
N550 Fur­nace black Medi­um-high rein­force­ment, pro­vi­des high modulus and hard­ness, smooth extrusion Used in cable jackets, extru­ded goods, hoses, tire inners, seals, profiles
Gene­ral purpose
fur­nace black
(GPF)
50-70 N650 Fur­nace black Medi­um rein­force­ment, pro­vi­des good rein­force­ment and modulus, good flex, smooth pro­ces­sing, low heat Used in tire car­cass, inner tubes, cable jackets, mecha­ni­cal rub­ber goods
N660 Fur­nace black Medi­um rein­force­ment, low struc­tu­re pro­vi­des good rein­force­ment and easy processing Used in tire car­cass, hoses, mecha­ni­cal rub­ber goods, plastics
Semi rein­for­cing
fur­nace black
(SFR)
70-90 N762 Fur­nace black Medi­um rein­force­ment, pro­vi­des high elon­ga­ti­on and resi­li­ence, low compression Used in rub­ber hoses, rub­ber sheets, gas­kets, mats, pla­s­tics compounds
N772 Fur­nace black Medi­um rein­force­ment, pro­vi­des very dyna­mic performance Used in rub­ber hoses, rub­ber sheets, gas­kets, mats, pla­s­tics compounds
N774 Fur­nace black Medi­um rein­force­ment, slight­ly increased sur­face, high elon­ga­ti­on and resilience Used in rub­ber hoses, rub­ber sheets, gas­kets, mats, pla­s­tics compounds
Medi­um ther­mal black (MT) 250-350 N990 Ther­mal black Low rein­force­ment, low modulus, low hard­ness and ten­si­le strength, high loa­ding capacity Used in belts, hoses, mecha­ni­cal goods, o-rings, FKM

CARBON BLACK DICTIONARY

Chi­ne­se: 炭黑
Dutch: Indus­trie­r­o­et, Roet
French: Noi­re de Carbone
Ger­man: Indus­trie­ruß, Ruß
Hin­di: कार्बन ब्लैक
Ita­li­an: Nero di Car­bo­nio, Nerofumo
Japa­ne­se: カーボンブラック
Polish: Sad­za techniczna
Por­tu­gue­se: Pre­to de Car­bo­no, Negro de Carbono
Rus­si­an: Tехнический углерод, техуглерод, сажа
Spa­nish: Negro de Humo, Negro de Carbon
Tur­ki­sh: İs karası

SUMMERY OF MAIN CARBON BLACK TERMS

Aci­n­i­form: Shaped like a clus­ter of gra­pes. The sphe­ro­idal pri­ma­ry par­tic­les of car­bon black are fused into aggre­ga­tes of col­lo­idal dimen­si­on forming an aci­n­i­form morphology.

Agglo­me­ra­te: A clus­ter of phy­si­cal­ly bound and ent­an­gled aggre­ga­tes. See Test Method ASTM D 3849.

Aggre­ga­te: A dis­crete, rigid, col­lo­idal mass of exten­si­ve­ly coale­s­ced par­tic­les; it is the smal­lest disper­si­ble unit.

Ash con­tent: Con­tent in % of ash in car­bon black. See Test Method ASTM D 1506.

ASTM D: The most important tar­get values of car­bon black are descri­bed by ASTM methods (Ame­ri­can Socie­ty for Test­ing Materials).

Car­bon Black: An engi­nee­red mate­ri­al, pri­ma­ri­ly com­po­sed of ele­men­tal car­bon, obtai­ned from the par­ti­al com­bus­ti­on or ther­mal decom­po­si­ti­on of hydro­car­bons, exis­ting as aggre­ga­tes of aci­n­i­form mor­pho­lo­gy which are com­po­sed of sphe­ro­idal pri­ma­ry par­tic­les, uni­for­mi­ty of pri­ma­ry par­tic­le sizes within a given aggre­ga­te and tur­bostra­tic laye­ring within the pri­ma­ry par­tic­les. Par­tic­le size and aggre­ga­te size (num­ber of par­tic­les per aggre­ga­te) are dis­tri­bu­tio­nal pro­per­ties and vary depen­ding on the car­bon black gra­de. The par­tic­le and aggre­ga­te sizes vary great­ly within a given gra­de of car­bon black, the pri­ma­ry par­tic­le size is essen­ti­al­ly uni­form within an indi­vi­du­al aggregate.

Car­bon Black REACH Regis­tra­ti­on num­ber: 01-2119384822-32-xxxx

Car­cass gra­de Car­bon Black: A type of fur­nace car­bon black having an avera­ge par­tic­le size in the ran­ge from 31 to 200 nm. Car­cass gra­de car­bon blacks are pro­du­ced by the oil fur­nace pro­cess. The use of the­se gra­des in the rub­ber indus­try is not limi­t­ed to the car­cass por­ti­on of the tire. The­se gra­des are desi­gna­ted with an “N” first cha­rac­ter and a second cha­rac­ter of “1, 2, 3, 5, 6 or 7” in Table 1 of Clas­si­fi­ca­ti­on ASTM D 1765. See Ter­mi­no­lo­gy ASTM D 1566 for the defi­ni­ti­on of carcass.

CAS Num­ber of Car­bon Black: 1333-86-4: Uni­que nume­ri­cal ident assi­gned by Che­mi­cal Abs­tracts Service.

Com­pres­sed Oil Absorp­ti­on Num­ber (COAN): See oil absorp­ti­on num­ber of com­pres­sed sam­ple, the pre­fer­red term.

EG Num­ber of Car­bon Black: EG 215-669-9 EG num­ber is important to iden­ti­fy pro­ducts in IUCLID

Fines con­tent: That por­ti­on of pel­le­ted car­bon black that pas­ses throught a spe­ci­fied sie­ves. See Test Method ASTM D 1508.

Fur­nace Car­bon Black: A type of car­bon black pro­du­ced by the decom­po­si­ti­on reac­tion of hydro­car­bons when injec­ted into a high-velo­ci­ty stream of com­bus­ti­on gases under con­trol­led conditions.

Hard Car­bon Blacks: See tread gra­de car­bon black, rein­for­cing car­bon black, the pre­fer­red term. All car­bon blacks pro­vi­de some level of rein­force­ment when mixed in rub­ber. The amount of rein­force­ment is a func­tion of the car­bon black gra­de and amount used. See Ter­mi­no­lo­gy ASTM D 1566 for the defi­ni­ti­on of reinforcement.

Har­mo­nis­ed Sys­tem HS Code of Car­bon Black 28030000

Hea­ting loss: Mass loss in % when car­bon black is hea­ted at 125°C for 1h; the hea­ting loss is pri­ma­ri­ly attri­bu­ted to mois­tu­re con­tent. See Test Method ASTM D 1509.

Indi­vi­du­al pel­let hard­ness: The force requi­red to frac­tu­re or crush a car­bon black pel­let. See Test Methods ASTM D 3313 and D 5230.

Iod­i­ne adsorp­ti­on num­ber: The num­ber of grams of iod­i­ne adsor­bed per kilo­gram of car­bon black under spe­ci­fied con­di­ti­ons. See Test Method ASTM D 1510.

Lot: A defi­ned quan­ti­ty of car­bon black that is essen­ti­al­ly uni­form in com­po­si­ti­on and characteristics.

Lot sam­ple: A quan­ti­ty of car­bon black sel­ec­ted to repre­sent a lot for test­ing pur­po­ses and taken in accordance with Prac­ti­ce ASTM D 1799 or D 1900.

Mass strength: A mea­su­re of the ten­den­cy for car­bon black pel­lets to pack tog­e­ther and to influence flow in a bulk hand­ling sys­tem. See Test Method ASTM D 1937.

Micros­truc­tu­re: Arran­ge­ment of car­bon atoms within a car­bon black particles.

Mois­tu­re con­tent: The per­cen­ta­ge, by mass, of water absor­bed and adsor­bed by car­bon black. See defi­ni­ti­on of car­bon black hea­ting loss. Accor­ding to ASTM D 1509.

Nitro­gen sur­face area (NSA): Nitro­gen sur­face area of car­bon black, defi­ned by ASTM D 6556. Total and exter­nal sur­face area by Nitro­gen Absorbtion.

Oil absorp­ti­on num­ber (OAN): The num­ber of cubic cen­ti­me­ters of dibu­tyl phtha­la­te (DBP) or par­af­fin oil absor­bed by 100 g of car­bon black under spe­ci­fied con­di­ti­ons. The OAN value is pro­por­tio­nal to the degree of aggre­ga­ti­on of struc­tu­re level of the car­bon black. See Test Methods ASTM D 2414 and D 3493.

Oil absorp­ti­on num­ber of com­pres­sed sam­ple (COAN): The num­ber of cubic cen­ti­me­ters of dibu­tyl phtha­la­te (DBP) or par­af­fin oil absor­bed by 100 g of car­bon black after being com­pres­sed four times in a com­pres­si­on cylin­der at 165 MPa (24 000 psi) under spe­ci­fied con­di­ti­ons. The COAN value gives some mea­su­re of the sta­bi­li­ty of the struc­tu­re of the car­bon black. See Test Methods ASTM D 2414 and D 3493.

Oil fur­nace pro­cess: A pro­cess for pro­du­cing fur­nace car­bon blacks that uses oil as the source of hydro­car­bons for decom­po­si­ti­on by injec­tion into a high-velo­ci­ty stream of com­bus­ti­on gases. Oil or natu­ral gas are typi­cal­ly used as com­bus­ti­on fuel to crea­te the high-velo­ci­ty stream of com­bus­ti­on gases, alt­hough other fuels may be used.

Par­tic­le: A small sphe­ro­idal­ly shaped (paracrystal­li­ne, non-dis­crete) com­po­nent of a car­bon black aggre­ga­te; it is sepa­ra­ble from the aggre­ga­te only by fracturing.

Par­tic­le dia­me­ter: Arith­me­tic avera­ge of the dia­me­ters of par­tic­les within a car­bon black aggre­ga­te as mea­su­red by elec­tron micro­sco­py. See Test Method ASTM D 3849.

Pel­let: A rela­tively lar­ge agglo­me­ra­te mass that has been den­si­fied in sphe­ro­idal form to faci­li­ta­te hand­ling and pro­ces­sing. See Test Method ASTM D 1511.

Pel­let size dis­tri­bu­ti­on: The per­cen­ta­ge, by mass, of car­bon black retai­ned on each of a spe­ci­fied series of sie­ve screens arran­ged with pro­gres­si­ve­ly smal­ler ope­nings. See Test Method D 1511.

Pig­ment 6 PBK – 6 inter­na­tio­nal Color index of Car­bon Black

Pig­ment 7 PBK – 7 Inter­na­tio­nal Color index of Lamp Black

ph-Value: Accor­ding to ASTM D 1512.

Pour den­si­ty: Mass per unit volu­me of car­bon black, deter­mi­ned in kg/m3. See Test Method ASTM D 1513.

Reco­ver­ed Car­bon Black (rCB): Reco­ver­ed Car­bon Black (rCB) beca­me one of most popu­lar topics the last years in cor­re­la­ti­on with the car­bon black mar­ket. The main idea of rCB is to trans­form rub­ber was­te into valuable com­mer­cial pro­ducts. Due to inno­va­tions and tech­no­lo­gy impro­ve­ments pyro­ly­se pro­cess beca­me more effi­ci­ent and envi­ron­ment fri­end­ly. On the other side the end of life tires (ELT) dis­po­sal repres­ents a glo­bal envi­ron­men­tal pro­blem. Sta­tis­tics show that 1,5 bil­li­on ELT’s are gene­ra­ted every year world­wi­de. The pro­duc­tion of recy­cled car­bon black is devi­ded into seve­ral stages, as car­bon pow­der is not the only raw mate­ri­al obtai­ned from recy­cled tires. After pyro­ly­sis tre­at­ment the pro­cess basi­cal­ly pro­du­ces char, hydro car­bon oil, steel, car­bon com­po­si­te and gas (which usual­ly remains insi­de the instal­la­ti­on as ener­gy gene­ra­tor). By some play­ers rCB is intro­du­ced to sub­sti­tu­te stan­dard fur­nace car­bon blacks. This car­bon pow­der (rCB) is not the same as vir­gin Car­bon Black. Car­bon black is an almost pure ele­men­tal car­bon pro­du­ced from hea­vy petro­le­um feedstock. Puri­ty is key dif­fe­rence in com­pa­ris­ment to the reco­ver­ed car­bon black which is pro­du­ced from solid frac­tion. Tires pro­du­ced from com­pounds and various che­mi­cal com­po­si­ti­ons, con­tain seve­ral con­ta­mi­nants and impu­ri­ties (tex­ti­les, steel etc.). Tho­se dif­fe­ren­ces are visi­ble on most data­sheets with a much hig­her ash con­tent, due to the used sili­ca in tread com­pounds. It is dif­fi­cult to compa­re and clas­si­fy reco­ver­ed car­bon black in com­pa­ris­ment with a vir­gin one, as vir­gin Car­bon Black is pro­du­ced with raw mate­ri­als deri­ved from petro­le­um, while the reco­ver­ed one has a big varie­ty of feedstock and pro­cess types. In some appli­ca­ti­ons rCB is used in small loa­dings as a fil­ler or low-end colo­rant, howe­ver it can­not sub­sti­tu­te for vir­gin car­bon black as it does not offer the same level of per­for­mance. Nevert­hel­ess we are con­vin­ced that rCB will find its place in the gro­wing car­bon black mar­ket, espe­ci­al­ly becau­se the big tire manu­fac­tu­r­ers are invol­ved in the­se pro­jects. In our opi­ni­on any solu­ti­on which is envi­ron­men­tal­ly fri­end­ly and helps redu­ce the CO2 foot­print is to be supported.

Rein­for­cing Car­bon Black: See tread gra­de car­bon black, the pre­fer­red term. All car­bon blacks pro­vi­de some level of rein­force­ment when mixed in rub­ber. The amount of rein­force­ment is a func­tion of the car­bon black gra­de and amount used. See Ter­mi­no­lo­gy ASTM D 1566 for the defi­ni­ti­on of reinforcement.

Rub­ber Car­bon Black: The nomen­cla­tu­re curr­ent­ly used for the rub­ber gra­de car­bon blacks was insti­tu­ted by the D 24ASTM Com­mit­tee on car­bon black in 1968. It con­sists of a pre­fix let­ter fol­lo­wed by a three-digit num­ber. The pre­fix, eit­her N or S indi­ca­tes whe­ther the gra­de is a (N)ormal or a (S)low curing mate­ri­al. When the sys­tem was deve­lo­ped chan­nel blacks were still com­mon­ly used and were slow curing. After­wards, a fif­ty-fold increase in natu­ral gas pri­ce ended rub­ber gra­de chan­nel black pro­duc­tion. For a time fur­nace gra­des trea­ted to emu­la­te the cure cha­rac­te­ristics of chan­nel were available. The­se too have lar­ge­ly dis­ap­peared lea­ving litt­le need for or use of the „S“ pre­fix let­ter. Con­se­quent­ly, most (if not all) curr­ent­ly acti­ve rub­ber gra­des car­ry the pre­fix „N“.

Semi-rein­for­cing Car­bon Black: See car­cass gra­de car­bon black, the pre­fer­red term. All car­bon blacks pro­vi­de some level of rein­force­ment when mixed in rub­ber. The amount of rein­force­ment is a func­tion of the car­bon black gra­de and amount used. See Ter­mi­no­lo­gy ASTM D 1566 for the defi­ni­ti­on of reinforcement.

Soft Car­bon Black: See car­cass gra­de car­bon black, semi-rein­for­cing car­bon black, the pre­fer­red term. All car­bon blacks pro­vi­de some level of rein­force­ment when mixed in rub­ber. The amount of rein­force­ment is a func­tion of the car­bon black gra­de and amount used. See Ter­mi­no­lo­gy ASTM D 1566 for the defi­ni­ti­on of reinforcement.

Sta­tis­ti­cal Thic­k­ness Sur­face Area (STSA): The exter­nal sur­face area of car­bon black that is cal­cu­la­ted from nitro­gen adsorp­ti­on data using the de Boer theo­ry and a car­bon black model. See Test Methods ASTM D 5816- 6556.

Struc­tu­re: The qua­li­ty of irre­gu­la­ri­ty and devia­ti­on from sphe­ri­ci­ty of the shape of a car­bon black aggregate.

Sulp­hur con­tent: Con­tent in % of sulp­hur in car­bon black. See Test Method ASTM D 1619.

Sur­face acti­vi­ty: The inher­ent abili­ty of the car­bon black sur­face to inter­act phy­si­cal­ly or che­mi­cal­ly, or both, with rub­ber or other molecules.

Unfort­u­na­te­ly the­re is no direct method for mea­su­ring car­bon black sur­face acti­vi­ty. The term refers to the che­mi­cal reac­ti­vi­ty of the sur­face. Sur­face acti­vi­ty is influen­ced by the gra­phi­tic pla­ne ori­en­ta­ti­on as well as the num­ber and type of orga­nic side groups. On a mole­cu­lar level, car­bon black is com­po­sed of amor­phous gra­phi­te lay­er pla­nes crea­ted from the con­den­sa­ti­on of aro­ma­tic rings. The edges of such pla­nes have unsa­tis­fied car­bon bonds which can act as che­mi­cal reac­tion sites.

The reac­tion time for the pro­duc­tion of ther­mal black is long in com­pa­ri­son to the fur­nace black pro­cess. Long reac­tion times com­bi­ned with the high tem­pe­ra­tu­re requi­red for the ther­mal decom­po­si­ti­on of natu­ral gas feed stock (1300 ̊C) allows the gra­phi­te lay­er pla­nes of ther­mal black to beco­me high­ly orde­red so that only lay­er pla­ne sur­faces are at the sur­face of the par­tic­le. As a result, no unsa­tis­fied car­bon bonds at the lay­er pla­ne edges are expo­sed and the­r­e­fo­re no poten­ti­al reac­tion sites for elas­to­mer inter­ac­tion are pre­sent in ther­mal black. Con­ver­se­ly, the shorter reac­tion times used in making fur­nace black pro­du­ce lay­er pla­nes at the sur­face which are less orde­red, resul­ting in num­e­rous sites for che­mi­cal bonds with elastomers.

Recent scan­ning tun­nel­ing elec­tron micro­sco­py (STM) stu­dies, which cha­rac­te­ri­ze the sur­face of car­bon black, cle­ar­ly sup­port the fact that lar­ger par­tic­le size car­bon blacks like ther­mal black tend toward a more orga­ni­zed sur­face struc­tu­re with fewer acti­ve sites.

The for­ma­ti­on of ther­mal black occurs in the absence of fla­me or air while fur­nace black is gene­ral­ly the pro­duct of incom­ple­te com­bus­ti­on of petro­le­um refi­nery resi­dues. As a result, fur­nace blacks con­tain num­e­rous types of orga­nic func­tion­al groups such as phe­nols, hydro­xyls, lac­to­nes and qui­no­nes which also con­tri­bu­te to the level of sur­face acti­vi­ty. The same orga­nic func­tion­al groups are vir­tual­ly absent from ther­mal black.

Car­bon blacks with a high amount of sur­face acti­vi­ty often pro­vi­de high rein­force­ment. While ther­mal black does impart some degree of rein­force­ment to elas­to­mers it is most often refer­red to as an inac­ti­ve or non-rein­for­cing black.

The influence of car­bon black on rub­ber can best be descri­bed in terms of pro­ces­sing and vul­ca­niza­te pro­per­ties. In choo­sing car­bon black(s) for an elas­to­mer for­mu­la­ti­on, the gra­de of car­bon black and the degree of loa­ding must be taken into con­side­ra­ti­on. The gene­ral effects of car­bon black on any given rub­ber pro­per­ty can be sum­ma­ri­zed accor­ding to sur­face area (par­tic­le size), struc­tu­re and loa­ding level.

Sur­face area CTAB: (Form­er­ly Test Method ASTM D 3765) Has been with­drawn. The CTAB value may be esti­ma­ted from the STSA value using Eq 1. The equa­ti­on is based on a line­ar regres­si­on of the STSA and CTAB mea­su­red values of the SRB 5 stan­dards. CTAB 5 STSA * 1.0170 1 2.6434.

Tar­get value: A con­sen­sus value for sel­ec­ted pri­ma­ry pro­per­ties on which pro­du­cers cen­ter their manu­fac­tu­ring pro­cess and users cen­ter their spe­ci­fi­ca­ti­on. Tar­get values for car­bon black pro­per­ties are shown in Clas­si­fi­ca­ti­on ASTM D 1765 for most rub­ber gra­de car­bon blacks curr­ent­ly in commerce.

Ther­mal Car­bon Black: One of the purest car­bon blacks, which is often refer­red to as medi­um ther­mal car­bon black, pro­du­ced under con­trol­led con­di­ti­ons by the ther­mal decom­po­si­ti­on of hydro­car­bons in the absence of air or fla­mes. The­se gra­des are desi­gna­ted with an “N” first cha­rac­ter and a second cha­rac­ter of “8 or 9” in Table 1 of Clas­si­fi­ca­ti­on ASTM D 1765.

Tint strength: The ratio, expres­sed as tint units, of the reflec­tance of a stan­dard pas­te to a sam­ple pas­te, both pre­pared and tes­ted under spe­ci­fied con­di­ti­ons. See Test Method ASTM D 3265.

Tolue­ne dis­co­lo­ra­ti­on: The trans­mit­tance, at 425 nm, of the fil­tra­te obtai­ned from the tolue­ne extra­ct of car­bon black, com­pared with that of pure tolue­ne. See Test Method ASTM D 1618.

Tread gra­de Car­bon Black: A type of fur­nace car­bon black having an avera­ge par­tic­le size in the ran­ge from 1 to 30 nm. Tread gra­de car­bon blacks are pro­du­ced by the oil fur­nace pro­cess. The use of the­se gra­des in the rub­ber indus­try is not limi­t­ed to the tread por­ti­on of the tire. The­se gra­des are desi­gna­ted with an “N” first cha­rac­ter and a second cha­rac­ter of “0, 1, 2, or 3” in Table 1 of Clas­si­fi­ca­ti­on ASTM D 1765.

Typi­cal value: A con­sen­sus value for tho­se car­bon black pro­per­ties that are not spe­ci­fi­cal­ly tar­ge­ted for con­trol in the manu­fac­tu­ring pro­cess and that are some­what depen­dent upon the tar­ge­ted pro­per­ties. Typi­cal values for car­bon black pro­per­ties are shown in Clas­si­fi­ca­ti­on ASTM D 1765 for most rub­ber gra­de car­bon blacks curr­ent­ly in com­mer­ce. The­se are con­sen­sus values based upon the ran­ge in values sup­pli­ed by the manu­fac­tu­r­ers. Typi­cal values are useful in making com­pa­ri­sons bet­ween gra­des but they are not the set-point tar­gets for the pro­cess and may be expec­ted to dif­fer signi­fi­cant­ly bet­ween producers.

Weight mean par­tic­le size: ratio equal to the sum of indi­vi­du­al par­tic­le dia­me­ters, each rai­sed to the fourth power, divi­ded by the sum of the indi­vi­du­al par­tic­le dia­me­ters, rai­sed to the third power.