Masterbatch carbon black

As formed, carbon black is a fluffy powder possessing low density. The densification process involves the removal of occluded air by agitation and followed by dry or wet process pelletization. In both the dry and wet pelletization process, nearly spherical pellets or beads will form that are typically composed of >99% carbon black and trace impurities such as sulfur. Thus, carbon black is sold as a low density powder or as a pelleted form in pigmenting and other end uses. The choice of a fluffy or pelleted carbon black for dispersion in a given system depends upon the dispersion and handling equipment and end use. For example, pelleted carbon blacks are used most frequently in production of black masterbatch carbon black powders are typically used to tint chromatic compounds. 

Masterbatches with Carbon Black. Two producers (Zeon Chemicals and Copolymer) offer nitrile mbber—carbon black masterbatches. These grades are prepared by mixing the carbon black with the mbber latex prior to the coagulation and drying process. 

In order to test this concept a series of compounds was prepared in a 5 L Shaw Intermix (rubber internal mixer, Mark IV, Kl) with EPDM (Keltan 720 ex-DSM elastomers an amorphous EPDM containing 4.5 wt% of dicyclopentadiene and having a Mooney viscosity ML(1 +4) 125°C of 64 MU 100 phr), N550 carbon black (50 phr), diisododecyl phthalate (10 phr), stearic acid (2 phr), and l,3-bis(tert-butylperoxy-isopropyl)benzene (Perkadox 14/40 MB ex Akzo Nobel 40% active material 6 or 10 phr). A polar co-agent (15 phr) was admixed to the masterbatch on an open mill and compounds were cured for 20 min at 180°C in a rheometer (MDR2000, Alpha Technologies). The maximum torque difference obtained in the rheometer experiments was used as a measure of... 

An enormous amount of work has been reported on the issue of carbon black dispersion improvement. One of the approaches has been to produce carbon black-polymer masterbatches by mixing... 

FI CU RE 35.12 Typical fingerprint of a masterbatch mixing process on an intermeshing internal mixer (GK 320E (Harburg Freudenberger) with PES5 rotors styrene-butadiene rubber/carbon black [SBR/CB] tread compound). 

Results of a Fingerprint Analysis of a Masterbatch and Remill Mixing Process of a Styrene-Butadiene Rubber-Carbon Black (SBR-CB) Compound on a CK320E Intermeshing Mixer with PES3 Rotors (Harburg Freudenberger)... 

FIGURE 37.4 Flow diagram to prepare the latex carbon black (CB) masterbatch. (From unpublished results of HASETRI, India. Appbed for Indian patent in 2002 [application no Del/2301/02].)... 

Oil extended SBR, and SBR carbon black masterbatches are supplied by the polymer producers and such grades give the advantage of reducing the necessity of further additions of filler and oil at the mixing stage. 

There are specific grades and masterbatches of carbon blacks especially marketed as additives for conductive plastics. It should be noted that the carbon blacks modify other properties of the polymer, especially its colour. 

ISO 4659, 2003. Rubber, Raw Styrene Butadiene (carbon black or carbon black and oil masterbatches) - Evaluation procedure. 

The use of the concentrate or masterbatch method has proven to be one of the most effective methods of incorporating carbon black into a resin. A masterbatch, as defined in the plastics industry, is a resin containing a high concentrate (20-50%) of pigment and other fillers that is subsequently reduced in a compound resin to accommodate the end-use requirement. 

In plastics, relative viscosity can be defined as the ratio of the viscosity of a concentrate to that of the neat carrier polymer at the same temperature. In this use, relative viscosity predicts relative jetness—defined in the same manner—more accurately than the carbon black loading in a concentrate. A mismatch between masterbatch and letdown viscosities causes incomplete mixing and is the reason that relative jetness can decrease with an increase in relative viscosity [5]. 

Figure 22.3. Evaluation of pigment dispersion using optical microscopy. The photograph shows four fields of view of LDPE film colored with 40% masterbatch of carbon black letdown to yield 1 % pigment in the film. Fields 14 and 15 show agglomerates of various sizes. Fish-eye defects are evident in fields 16 and 17. (Courtesy of Ferro Corporation.)...

Dispersion is also an important factor. Light reflection depends on the surface area of carbon black after dispersion. If large agglomerates are present light reflection (and UV protection and opacity) is reduced. It is a frequent practice to use fully dispersed masterbatches offered either by carbon black manufacturers or compounders to achieve good results. ... 

A-0020 Series. [Goldsmith Eggleton] SBR/carbon black masterbatches. 

Carbomix . [Copolymer Rubber] SBR/ carbon black masterbatches for ex-ttuded and molded mechanical goods, tires. 

Hubron. ubronLtd.] Carbon black in SAN, LI)PE, PP, or PS carrier black masterbatch for compounding, molding, film, sheet extrusion. 

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