Dispersion carbon black pigments

Iron. This is a specialty drier that is considered active at temperatures of about 130°C. For this reason iron 2-ethyIhexanoate [19583-54-1] is used in bake coatings that require maximum hardness. The principal drawback of using iron driers is that iron contributes a characteristic brownish red color to the coating and should only be used in dark pigmented systems. It has been reported that iron aids the dispersion of carbon black pigment and reduces the tendency for orange peel film defects (6). 

In terms of weatherabilityf polystyrene does not exhibit ultraviolet stability and is not considered we ather-re sis tan t as a clear material. Continuous, long-term exposure results in discoloration and reduction of strength. Improvement in weatherability can be obtained by the addition of ultraviolet absorbers, or by incorporating pigments. The best pigmenting results are obtained with finely dispersed carbon black. 

Generally, there are two basic types of inks. The first type contains finely dispersed carbon black or colored pigments in both solvent and water based systems. Pronounced improvements have been achieved in stabilizing aqueous pigment formulations for ink-jet applications by adding specific polymeric dispersing agents [18], The second type of ink is based on water or solvent soluble dyes. 

The use of carbon black pigmentation/stabUization in thermoplastics for external exposure is widely applicable but has to be undertaken with care since it increases radiant heat absorption and hence the possibility of distortion. The type, particle size and degree of dispersion of the carbon are important for optimum efficacy. Additions in the order of 1-3% are generally sufficient for this purpose but in rubbers, where the carbon black also has a reinforcing function, considerably more is used. Other pigments have varying effects, an example being iron oxide which protects polyolefins yet catalyses the decomposition of PVC. 

Nanofillers have actually been around for decades (the oldest for over a century) carbon blacks, pigments, precipitated silicic acid (Ultrasil, Degussa-Hiils), pyrogenic silicic acids (Aerosile, Degussa-Hiils), phyllosilicates, nucleation agents, reactive silicone nanoparticles for epoxy resins, ceramic materials and inorganic-organic hybrid particles from sol-gel transformations, for example synthetic, dispersible aluminate (boehmite) powder. 

Uses Wbtting agent, dispersant, and deflocculant tor carbon black pigments in solv.-thinn coatings... 

Carbon blacks are finely divided forms of amorphous carbons that are produced either by incomplete combustion of natural gas or by incomplete combustion of liquid hydrocarbons. As a pigment, carbon blacks are known for blackness, strength, rheology, and dispersability. Carbon blacks are among the smallest in size and highest in surface area of all pigments. They are available both in loose and pelleted forms. 

As mentioned previously, the most important pigment additive employed for light stability purposes is carbon black. The addition of 2% by weight of a well-dispersed carbon black of fine particle size should extend the outdoor life of most low- and HDPE to as much as 20 years in temperate climates, while even the addition of 0.2% should give 10 years ... 

Carbon black pigments may require dispersion at a high pH (e.g. 9) to ensure good wetting, no flocculation and a satisfactory gloss level. 

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