Carbon blacks masterbatches

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. 

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. 

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

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

E-0010. [Goldsmith Eggleton] Iso-prene/FED/carbon black masterbatch. 

Conductive carbon black masterbatch in PA 6, 165 Cabosil M5 Silica, 381 Calprene ... 

Carbon black masterbatch 3.06 Carbon black (30%) reinforcing filler... 

Canrier of carbon-black masterbatch. MA maleic anhydride. Dissolution/precipitation. ... 

In the 1970s, a number of polymer suppliers introduced a marketing policy which discontinued the supply of polyolefin compounds in favour of supplying natural materials. The discontinued compounds included black polyethylene for water pipe extrusion in which the pipe producers substituted the black compound fed to their extruders with pellet blends of natural polyethylene and carbon black masterbatch. 

Pipes made to technical standards applicable at the time [2-4] contained 2.5% carbon black suitably dispersed and distributed to provide protection for the polyethylene against the UV component of sunlight. The advantage offered to pipe producers for using a blend of natural polyethylene and carbon black masterbatch was a very... 

Figure 2.3 Photomicrographs showing real mixing situations when incorporating carbon black masterbatch to give 2.5% carbon black in polypropylene.

Real situations for the same material composition are shown in the three photomicrographs of Figures 2.3(a), (b) and (c). All three are for the same pellet blend of polypropylene and carbon black masterbatch giving a final carbon black concentration of 2.5%. This is typical for an extruder feed for a product to be used outdoors and consequently requiring protection against the UV component of sunlight. 

Eillers and flame retardants snch as alumina trihydrate are frequently nsed at concentrations of np to 50 wt%. Being of a similar concentration to a pigment or carbon black masterbatch, they are prepared like masterbatches in internal and twin screw componnding machines, but often with no dilution required in the final prodnct extrnsion. 

Experiments were then carried out to compare specific output rate and masterbatch distribution. The material was natural low-density polyethylene blended with 5% of a 40% carbon black masterbatch. 

As discussed in the previous chapters, single screw extruders are not good dispersive mixers, and therefore reliance is placed on suppliers to provide well dispersed additives in compounds and masterbatches. When it is considered necessary to test incoming materials or compare samples from different suppliers, which may, in particular, be required for carbon black masterbatch, there are a number of quality standards. These are mainly for carbon black in polyethylenes used in water pipes and cables, but can also be used for coloured pipes and cables where agglomerates can cause electrical failures. The tests can be divided between those that examine thin samples, and those which use extrusion filtering. 

A pellet blend of natural LDPE and 5 wt% of a carbon black masterbatch. 

Further trials using screw jacking following rapid barrel cooling compared sections from a conventional screw with the one fitted with the Maddock element. The feed material was LDPE with carbon black masterbatch. Figure 7.12 shows photomicrographs of microtomed channel cross sections taken every two turns and Figure 7.13 shows cross sections from the die adaptor. 

In comparison, the Maddock element ensured melting was completed, but laminar carbon black masterbatch streaks were still present although much thinner. There was also a reduction in specific output rate of about 8%. 

Figure 7.19 Photomicrographs of extrusions containing 6% of a 40% carbon black masterbatch extruded at 80 rpm Comparisons of four screw configurations.

Black material Polymer compounded with 5% of a 40% carbon black masterbatch. 

A turbine mixing head patented by ICI in 1955 [1, 2] enabled polyethylene pipe manufacturers to meet appropriate pipe standards when feeding pellet blends of natural polyethylene and carbon black masterbatch into the pipe extruder. Until then it was necessary to use the more expensive pre-compounded material. The turbine mixers were used by at least two large polyethylene pipe producers until being superseded by CTM, and at a later date, becoming unnecessary in some cases when price distortions and the polymer supply situation produced a switch back to extrusion of pre-compounded materials. 

Oil-extended polybutadiene also is produced. The production process is basically the same with the exception that a higher molecular weight polymer is produced, which upon oil extension has about the same bulk viscosity as the nonextended polymers. The oil is added to the polymer solution prior to the desolventization step. Oil carbon black masterbatches also are produced. In these processes the carbon black must be ground or debeaded in some mechanical manner and then transferred as a slurry, either in solvent or water, to the polymer solution. 

Since the original hot polymerized NBRs there have been many improvements and expansion of the types and ranges of properties available to the mbber industry. Cold polymerization is the predominant process for the emulsion polymerization of NBR with Acrylonitrile (ACN) contents now ranging from 18%-50% and Mooney viscosity going from 25 to 120. In addition, modifications now include carboxylated, precrosslinked, ACN/isoprene/butadiene, liquid, carbon black masterbatches, plasticizer extended, and nitrile/pvc blends (with and without plasticizer). Nitrile latices, powdered and crumb will not be covered in this book. Hydrogenated NBR is dealt with in a separate chapter. 

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