Chlorinated Para Red

Under certain conditions, dry mixtures of lead chromate pigments with the azo-dyes l-(2. 4 -dimtrobenzcncazo)-2-hydroxynaphthalene (dinitroaniline orange) or l-(4 -chloro-2 -nitrobenzcncazo)-2-hydroxynaphthalene (chlorinated para-red) may lead to violent explosions dining mixing/blending operations. 

P.R.4 is also known as chlorinated Para Red. It has lost much of its commercial impact in recent years. The pigment affords a yellowish red shade, somewhere between the more yellowish P.O.5 and the more bluish P.R.3. Tinctorially, P.R.4 is the weakest of the three. In order to formulate equal depth of shade in an air drying alkyd system, three equivalents of TiOz are necessary per equivalent of P.R.4 while P.O.5 and P.R.3 require 5 and 6 parts of TiOz, respectively, per equivalent of organic pigment provided all other parameters are equal. Full shades exhibit good lightfastness (step 6), but darken somewhat upon exposure. Addition of even... 

SAFETY PROFILE Confirmed carcinogen with experimental neoplastigenic and tumorigenic data. Poison by intraperitoneal route. Mildly toxic by ingestion. Human mutation data reported. Potentially explosive reactions with azodyestuffs (e.g., dinitro-aniline orange, chlorinated para red). Violent reaction with aluminum -t- dinitronaphthal-... 

Chlorinated para-nitraniline red See chlorinated para reds. 

Chlorinated para reds n. Pigment red 4 (12085). There are two varieties of chlorinated para red (1) Ortho-chlor-papa... 

Para-chlor-ortho-nitraniline n. Pigment red 6 (12090). The parachlor variety of chlorinated para red is redder (less yellow) in shade and more transparent compared to the ortho-chlor but much superior in lightfastness. It is superior in tint lightfastness to toluidine red. Special precautions are required in drier addition to parachlor red paints since it discolors (dark and dull) with cobalt and/or iron driers. Syn parachlor red. 

Chlorinated Para Nitraniline Red See Chlorinated Para Reds. 

Ortho-chlor-para Nitraniline n Pigment Red 4 (12085). This pigment has general properties similar to those of para red, although it is slightly superior in tint lightfastness to para red. See Chlorinated Para Reds. 

UV-visible spectral measurements show that substituted indolo[ 3,2-ib] carbazoles (5) absorb significantly below 450 nm (Fig. 4.12). Their band gaps in the solid state, estimated from the on-set UV-visible absorption, were >2.55 eV, which are significantly larger than those of most p-channel organic semiconductors for OTFTs (Table 4.1). In addition, whereas chlorine substitution at the 3,9 positions of 5,ll-dialkylindolo[3,2-jb]carbazole (i.e. 5d) did not cause noticeable changes in the spectral properties, substitution at the 2,8 positions (i.e. 5c) results in red-shifts in both solution and thin film absorption - a phenomenon that clearly indicates the pronounced electronic effects of substituents at positions para to the radical cation sites (5-N and 11-N positions). 

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