Lake pigment

Lack-papier, n. lacquered paper, varnished paper, -pigment, n. lake pigment, -roh-stoff, m. raw material for lacquer or varnish. 

Colorants must be introduced into the coating syrups during production of pan-coated candies. Water-soluble colorants may be used but lake pigments as dispersions are preferred. Pan-coated candies require higher concentrations of colorants than jellies or creams they require 30 to 60 coatings of colored syrup. ... 

Source Warner Jenkinson Pamphlet on Lake Pigments, September 1990. 

Kirby J. (1988), The preparation of early lake pigments A survey in Dyes on Historical and Archaeological Textiles, 6th Mtg. (1987), National Museum of Scotland, Edinburgh. 

Kirby J. (1977), A spectrophotometric method for the identification of lake pigment dyestuffs, Natl. Gallery Bull. 1, 35-45. 

Yellow Lake Pigments, Identification and Study of Deterioration of Flavonoid Colorants. Arie Wallert and N. Wyplosz, Molecular Aspects of Ageing in Painted Works of Art, Progress Report 1995-1997, FOM Institute for Atomic and Molecular Physics, Amsterdam, NL, http //www.amolf.nl/research/biomacromolecular mass spectrometry/ molart/progress report98.pdf... 

R. White and J. Kirby, Preliminary research into lac lake pigments using HPLC/electrospray mass spectrometry, Dyes in History and Archaeology, 16/17, 167 178 (2001). 

Naphthalenesulfonic acid lake pigments are based on naphthalenesulfonic acid as a coupling component introduction of an additional S03H function as part of the diazo component is possible. 

Although it is uncommon for organic pigments to be affected by acid or alkali, color changes are occasionally observed with laked pigments or pigments containing free acid or amino functions. These may form salts if they are exposed to acids or bases. 

Azomethine metal complex pigments replace the metal with tin stabilizers, resulting in a change in shade. In the case of manganese-laked pigments trouble can also be expected in the presence of epoxy compounds. Pigment preparations based on epoxidized soya bean oil are normally used instead of diisodecyl phthalate pastes in the automotive sector e.g. for coloring PVC roofs etc. 

Kobayashi, N. and Ando, H. (1988a). Red monoazo lake pigment Dainippon Inc. 

Colorants and opacifiers are typically used at low concentrations in the wet gel formulation. A wide range of colorants such as FD C and D C water-soluble dyes, certified lakes, pigments, and vegetable colors have been incorporated into Softgel shells alone or in combination to produce the desired color, tint, or hue for product identification. A general rule in color selection is that the color of the capsule shell should be similar to or darker than the fill material to reduce the contrast with the seams. 

Aluminum oxide is used mainly in tablet formulations. It is used for decoloring powders and is particularly widely used in antibiotic formulations. It is also used in suppositories, pessaries, and urethral inserts. Hydrated aluminum oxide (see Section 18) is used in mordant dyeing to make lake pigments, in cosmetics, and therapeutically as an antacid. 

USE Dyeing red manuf of a red lake pigment. With alkalies = purplish-red with acids = yellow. 

Bersch, Manufacture of Mineral and Lake Pigments, translated by Wright ... 

Lake pigments consist of a dye associated with an inorganic support such as alumina hydrate. They are used in packaging to obtain special visual effects. 

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