Pigments copper acetate

The basic copper acetate is used as a mordant in dyeing and printing in the manufacture of Paris green and other pigments and as a fungicide and insecticide. 

Pigments and dyes provide paint and ink colors. Many highly toxic pigments, such as copper acetate (blue-green), arsenic trisulfide (yellow), and mercury II iodide (red), are no longer used. However, other hazardous pigment compounds, such as lead carbonate, mercury II sulfide, and cadmium sulfide, are still used today. These compounds present a danger to those artists who use their mouths to make a brush more pointed. 

Basic copper acetate Cu2(0H)2(C2H202)2 Paint pigment... 

Uses uses are similar to those of copper aceto-arsenite, cupric acetate cupric copper acetate or cupric acetate is used in the manufacture of pigments, fungicides, algaecides, and insecticides copper aceto-arsenite is used as a pigment, an insecticide, and a wood preservative... 

Copper acetates are used as pigments in oil and water colours. 

Professor Henri Braconnot (1780-1855) was a French chemist more famous for the extraction of glucose from cellulose and the discovery of a precursor form of plastic than for pigment research. However, he received a sample of pigment for analysis from a Mr Noel, the owner of a wallpaper factory in Nancy and published a paper on the preparation of copper acetate arsenite green in 1822, shortly after the German chemist Liebig (1822,1823). For more historical information see emerald green. 

Salter (1869) hsts catechu brown(s) prepared from extracts of Acacia catechu L. Various salts were used to give a range of colours from greenish brown (iron), brownish yellow (tin) and brick coloured (lead) copper acetate and potassium bichromate gave brown residues. These were apparently speculative pigments although another brown prepared from catechn bark is recorded that was recommended for painting if not too thinly applied . 

Verdigris (q.v.) and its variants will essentially be one or, more probably, several of these compounds. Scott has also pointed out that a range of copper formate compounds can be formed and that these may occur in the context of pigments. Useful reviews of copper acetate compounds used as pigments have been given by Kiihn (1993a) and Scott. 

A synthetic, anhydrous, neutral copper acetate with the formula Cu(CH3COO) (Rahn-Koltermann et al., 1991 Scott, 2002). This compound has probably limited relevance as a pigment, but may be a component of some verdigris-related compounds (q.vl). This is compound G in Scott s (2002) classification. 

Seemingly a copper-arsenic green (q.v.). Terry (1893) describes the process as involving the preparation of copper arsenite from copper sulfate and sodium arsenite ( arsenite of soda ). The precipitate is then treated widi acetic acid or, interestingly, formic acid the former would result in the usual copper acetate arsenite, the latter in copper formate arsenite. Terry comments The pigment thus produced is of good colour, but its superiority would not seem to justify the use of such an expensive article as pure formic acid, nor the minute adjustment of the proportions of die ingredients, in an operation to be conducted on a commercial scale. ... 

---