Synthetic azo dyes are widely used in industries. Gerhardt Domagk discovered that the antimicrobial effect of red azo dye Prontosil was caused by the reductively cleaved (azo reduction) product sulfanilamide. The significance of azo reduction is thus revealed. Azo reduction can be accomplished by human intestinal microflora, skin microflora, environmental microorganisms, to a lesser extent by human liver azoreductase, and by nonbiological means. Some azo dyes can be carcinogenic without being cleaved into aromatic amines. However, the carcinogenicity of many azo dyes is due to their cleaved product such as benzidine. Benzidine induces various human and animal tumors. Another azo dye component, p-phenylenediamine, is a contact allergen. Many azo dyes and their reductively cleaved products as well as chemically related aromatic amines are reported to affect human health, causing allergies and other human maladies.

Azo dyes and human health: A review.

Azo dyes are extensively used in textile, printing, leather, paper making, drug and food industries. Following oral exposure, azo dyes are metabolized to aromatic amines by intestinal microflora or liver azoreductases. Aromatic amines are further metabolized to genotoxic compounds by mammalian microsomal enzymes. Many of these aromatic amines are mutagenic in the Ames Salmonella/microsomal assay system. The chemical structure of many mutagenic azo dyes was reviewed, and we found that the biologically active dyes are mainly limited to those compounds containing p-phenylenediamine and benzidine moieties. It was found that for the phenylenediamine moiety, methylation or substitution of a nitro group for an amino group does not decrease mutagenicity. However, sulfonation, carboxylation, deamination, or substitution of an ethyl alcohol or an acetyl group for the hydrogen in the amino groups leads to a decrease in the mutagenic activity. For the benzidine moiety, methylation, methoxylation, halogenation or substitution of an acetyl group for hydrogen in the amino group does not affect mutagenicity, but complexation with copper ions diminishes mutagenicity. The mutagenicity of benzidine or its derivatives is also decreased when in the form of a hydrochloride salt with only one exception. Mutagenicity of azo dyes can, therefore, be predicted by these structure-activity relationships.

Mutagenicity of azo dyes: structure-activity relationships.

Processes for preparing a carbon product having an organic group attached to a carbon material. The carbon material is selected from graphite powder, a graphite fiber, a carbon fiber, a carbon cloth, a vitreous carbon product, and an activated carbon product. In one process at least one diazonium salt reacts with a carbon material in the absence of an externally applied electric current sufficient to reduce the diazonium salt. In another process at least one diazonium salt reacts with a carbon material in a protic reaction medium.

Process for preparing carbon materials with diazonium salts and resultant carbon products

Azo dyes are consumed and otherwise utilized in varying quantities in many parts of the world. Such widely used chemicals are of great concern with regard to their potential toxicity and carcinogenic properties. Their metabolism has been studied extensively and is significant for detoxication and metabolic activation. Both oxidative and reductive pathways are involved in these processes. The majority of azo dyes undergo reduction catalyzed by enzymes of the intestinal microorganisms and/or hepatic enzymes including microsomal and soluble enzymes. The selectivity of substrate and enzyme may to a large extent be determined by the oxygen sensitivity of reduction since a normal liver is mainly aerobic in all areas, whereas the microorganisms of the lower bowel exist in an anaerobic environment. However, it should be pointed out that the pO2 of centrilobular cells within the liver is only a fraction that of air, where pO2 = 150 torr. Therefore, an azo dye reduction experiment performed aerobically may not be an accurate predictor of reductive metabolism in all areas of the liver. Many of the azo dyes in common use today have highly charged substituents such as sulfonate. These resist enzymic attack and for the most part are poorly absorbed from the intestinal tract, providing poor access to the liver, the major site of the mixed-function oxidase system. Lipophilic dyes, such as DAB, which are often carcinogenic, readily access oxidative enzymes and are activated by both mixed-function oxidase and conjugating systems. Reduction of the carcinogenic dyes usually leads to loss of carcinogenic activity. By contrast, most of the highly charged water-soluble dyes become mutagenic only after reduction. Even then, most of the fully reduced amines required oxidative metabolic activation. An outstanding example is the potent human bladder carcinogen benzidine, which derives from the reduction of several azo dyes. Many problems regarding mutagenic and carcinogenic activation remain to be solved. At the present time, it is apparent that both oxidative and reductive pathways yield toxic products. Toxicologic assessment of azo dyes must consider all pathways and particularly the oxygen sensitivity of azoreduction. This is critical in the treatment of waste from chemical plants where there is a great need for soil bacteria which catalyze reduction aerobically. Consideration of secondary pathways are also of great concern. For example, azoreduction of carcinogenic dyes such as DAB removes carcinogenic activity although oxidative metabolism of the primary amines yield mutagenic products. Such apparent dilemmas must be dealt with when considering metabolism/toxicity relationships for azo dyes.

Metabolism of azo dyes: implication for detoxication and activation.

Cleaning and soil dispersing compositions comprising ethoxylated/propoxylated polyalkyleneamine polymers are provided. Thus, detergent compositions which comprise ethoxylated/propoxylated polyalkyleneamine polymers, such as poly(ethyleneimine) with a degree of ethoxylation of 1.0, provide soil dispersing performance in the wash liquor and whitening and/or cleaning benefits to fabrics, hard-surfaces, or dishware.

Compositions Comprising Ethoxylated/Propoxylated Polyalkyleneamine Polymers as Soil Dispersing Agents

An improved ink jet composition comprised of a major amount of water, a hydroxypropylated polyethyleneimine with a weight average molecular weight of from about 1,000 to about 10,000, and a dye component; and wherein the ink has a viscosity of from about 1 to about 5 centipoise.

Waterfast ink jet compositions and process

Disclosed is an ink jet ink composition comprising a liquid vehicle such as water or ethanol, a dye, and a linear N-hydroxyl substituted polyethyleneimine polymer. In a preferred embodiment, the linear N-hydroxyl substituted polyethyleneimine polymer is selected from the group consisting of linear poly(N-hydroxyethylethyleneimine), linear poly(N-hydroxypropylethyleneimine), and linear poly(N-hydroxymethylethyleneimine). Also disclosed is a process for generating images with the disclosed inks in ink jet printing processes, including continuous stream ink jet printing processes. Further, a process for preparing the linear N-hydroxyl substituted polyethyleneimine polymers included in the inks of the present invention is also disclosed.

Ink jet ink compositions

Analogs of Direct Black 19 and Direct Black 38 were synthesized and tested in the Salmonella/microsome assay. Those dyes which gave positive responses in strains TA98 and TA1538 would be expected to be metabolized to p-phenylenediamine by the liver microsomal enzymes (S9). Pure p-phenylenediamine is non-mutagenic in this assay but becomes mutagenic after it is oxidized. Thus the positive response of our synthetic azo compounds are most likely due to the formation of oxidized p-phenylenediamine. Modification of the moieties that can be metabolized to p-phenylenediamine by sulfonation, carboxylation or copper complexation eliminated the mutagenic responses.

Structure-activity relationship studies on the mutagenicity of some azo dyes in the Salmonella/microsome assay.

A color electrophotographic imaging process is disclosed employing uniquely distinct developer materials. Specific cyan, yellow, and magenta developers which uniquely cooperate to form true color images in an electrophotographic process are described. The electrophotographic processes employing these developers are also disclosed.

Color electrophotographic imaging process utilizing specific carrier-toner combinations

Disclosed are dye compositions of the formula ##STR1## wherein Cp and Cp' are each coupler compounds of the formula ##STR2## wherein the --COOH group and the --OH group can be in any position on either ring, provided that in the naphthalene ring system there is present least one hydrogen activated through resonance by the --OH group for an electrophilic aromatic substitution coupling reaction, n represents the number of substituents on the rings and is a number of from 0 to 8, and R represents the substituent groups on the ring, wherein each R is independently selected from the group consisting of hydroxyl groups, alkyl groups, substituted alkyl groups, aryl groups, substituted aryl groups, aryl-alkyl groups, substituted aryl-alkyl groups, halogen atoms, and nitro groups. Also disclosed are aqueous ink compositions containing the dyes, processes for making the dyes, processes for making the inks containing the dyes, and printing processes employing the inks.

Waterfast dye compositions

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