Core pigments

Special substrate pigments include the aftertreated pigments and the core pigments. To produce aftertreated pigments the inorganic pigment particles are covered... 

Basic lead silicochromate (4(PbCr04 PbO) -t 3(Si02 4 PbO)) reached certain industrial importance. It was developed to replace red lead. The pigment is a so-called core pigment, in which the active pigment substance (PbCr04) is precipitated onto an inert core (Si02). Because this anticorrosive contains both lead and hexavalent chromium, it has lost its previous economic importance as well [5.53, 5.56]. 

As a further example, phosphate silicates that are often termed as mixed phase or core pigments, may also be mentioned. By fixing the active components onto the surface of wollastonite (calcium siUcate-core) and adjusting the pH value near neutral, these pigments show a relatively universal applicability [5.86]. 

These pigments, also termed core pigments, such as phosphate silicates (see Section 5.2.5.3),consistofa complex composite of alkaline earth silicates, like calcium silicate. Available commercial grades differ primarily in their B2O3-content and oil absorption value (Table 5.9) [5.53]. 

A., 14 particle size, 5 pm. Syn normal lead chromate coated, silica cored pigment. Kirk-Othmer encyclopedia of chemical technology pigments-powders. John Wiley and Sons, New York, 1996. Gooch JW (1993) Lead based paint handbook. Plenum Press, New York. 

Deoussa Core. Pigment Black Preparations for Plastics ... 

Rubber is a popular closure component, and additives such as vulcanizers, pigments (qv), or antioxidants may leach into the product. In cases where mbber closures are penetrated by needles in dosing, bits of the closure (coring) could enter the product. Thus, such closure components must be sufficiendy tested before use. 

AH the difficulties ia achieving dark colors for PVC siding apply also to door and wiadow frames and sashes. Coextmsion of a PVC core capped with a vinyl or acryUc film from an adjacent extmder can be used. In addition, PVC-acryUc alloys can be used for dark colors. The modifiers, stabilizers, and pigments iacorporated ia siding are used ia these products as well. To date, hiiilding codes restrict their use ia aew coastmctioa, so that their iastaHatioa is primarily as replacemeats. 

The structurally similar L and M subunits are related by a pseudo-twofold symmetry axis through the core, between the helices of the four-helix bundle motif. The photosynthetic pigments are bound to these subunits, most of them to the transmembrane helices, and they are also related by the same twofold symmetry axis (Figure 12.15). The pigments are arranged so that they form two possible pathways for electron transfer across the membrane, one on each side of the symmetry axis. 

Manufacturing dyes and pigments Core hardening of metals Nylon production Cyanogen chloride (CK) 1.25... 

Ponnazhagan and Kwon (1992) reported a putative tissue-specific ds-element (TE-1) located at-236 bp of the mouse tyrosinase promoter. They partially purified a TE-1 binding protein (approximately 49 kDa in size), but tissue specificity remains to be confirmed by a more detailed analysis. For the human tyrosinase promoter, Shibata et al. (1992) identified a 200-bp pigment cell-specific enhancer, located between -2.0 and -1.8 kb. A minimum core sequence of 39 bp was shown to be sufficient to confer the specific activity, although other regions (not identified so far) within the 200-bp fragment are required for more efficient expression in melanoma cells (Shibata et al., 1992). 

Novel pyranoanthocyanins have also been isolated and identified in blackcurrant (Ribes nigrum) seed using HPLC, 2D NMR and ES-MS. Blackcurrant seeds were extracted with acetone-water (70 30, v/v) and the components of the extract were separated in a polyamide column followed by HPLC-DAD. The new pigments were finally separated in an MCI-HP20 column. The chemical structures of anthocyanins 1-2 and the novel pyranoanthocyanins 3-6 with the pyrano[4,3,2-de]-l-bcn/opyrylium core structure are shown in Fig. 2.110. It was stated that the analytical method developed separated well the novel pyranoanthocyanins [245],... 

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