Cabot Corporation

About: Cabot Corporation is a company organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Carbon black & Carbon. The organization has 1279 authors who have published 1399 publications receiving 36736 citations.

Modified pigment containing inkjet ink compositions having a reduced conductivity increase

Abstract: The present invention relates to a modified pigment comprising a pigment having attached at least one salt of a geminal bisphosphonic acid group or partial esters thereof, as well as to dispersions and inkjet ink compositions comprising such modified pigments. Preferably the salt comprises a quaternary ammonium counterion.

Chemical processing using a dual feeder system, a sample port assembly, and a fluid flow control system

Abstract: Components of a chemical processing system are disclosed. In particular, a chemical processing system is disclosed which includes a chemical mixing or reacting zone, an inlet to the zone, an outlet to the zone, and a vacuum or fluid flow source located downstream of the outlet. The chemical processing system further includes means to control the amount of vacuum or fluid flow through the zone. Also disclosed is a continuous feeder system having a first loss-in-weight and a second loss-in-weight feeder and means for measuring a lower limit of feed in each feeder. There is also a means to activate the second feeder when the lower limit is obtained in the first feeder and means to deactivate the first feeder when the lower limit is detected in the first feeder. A sample port assembly is also disclosed for obtaining a sample of material flowing through a processing system. The sample port assembly includes a port in the assembly and a sample cup holder adapted to be moved in the port to obtain a sample of material without substantially affecting the fluid pressure or flow within the system. The components of the chemical processing system can be used in processes to make carbon black having attached organic groups.

Inappropriate exposure data and misleading calculations invalidate the estimates of health risk for airborne titanium dioxide and carbon black nanoparticle exposures in the workplace.

Abstract: Dear Editor: Ling et al. (2011) have attempted to assess the potential health risk from exposure to airborne TiO2 nanoparticles (TiO2 NPs) and carbon black nanoparticles (CB NPs) in the workplace. Unfortunately, the data used by the authors are totally inappropriate for this purpose. First, the TiO2 data were generated by an artificial laboratory experiment producing TiO2 particles of 30–60 nm diameter (Chen et al. 2007) — these particle sizes are very atypical for the workplaces with TiO2 exposure (Berges et al. 2007; Wake et al. 2002). Second, the numbers that Ling and co-workers extracted from Kuhlbusch et al. (2004) did not describe CB NPs. Kuhlbusch et al. (2004) and Kuhlbusch and Fissan (2006) clearly reported that the observed NPs in the CB workplaces were not carbon black particles but due to other sources such as forklift and gas heater emissions (see also Wake et al. 2002). Furthermore, the exposure model used by Ling et al. (2011) assumes that workers are exposed to these particle concentrations for 8 h a day, 240 days a year and for 30 years. Since the particle concentrations observed in the study by Kuhlbusch et al. (2004) do not even relate to CB NPs, these exposure assumptions vastly overestimate any actual exposures to CB production workers. In consequence, the conclusions drawn by Ling et al. (2011) are unsupported. The severe problems with the inappropriate exposure data are compounded by the dose–response modelling conducted by Ling et al. (2011). For CB NPs, the inflammationrelated effects are based on a short-term inhalation study in rats. There are some data (ILSI Risk Science Institute Workshop 2000; Hesterberg et al. 2005, 2006) indicating that a dose–response assessment based on rat data may overestimate effects in humans because rats appear to be more sensitive to the respiratory effects of poorly soluble particles, such as carbon black, compared to other species. For TiO2 NPs, the inflammation-related effects are based on an acute intra-tracheal instillation study in mice. For both CB NPs and TiO2 NPs, the cytotoxicity-related effects are based on in vitro cellular assays where the cells are dosed for 1–3 days. There are so many uncertainties involved in extrapolating data from acute studies with non-physiological routes of administration to determine long-term adverse effects in humans that the results can be very inaccurate (US-EPA 2002). To account for such uncertainties, Ling et al. (2011) include uncertainty factors ranging from 100 to 10,000 for each endpoint. Therefore, humans are considered to be 100–10,000 times more sensitive than the animal species or cellular assays used in this evaluation. While the use of these uncertainty factors is health-protective, it is important to Responsible editor: Vera Slaveykova