Names | |
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Preferred IUPAC name 1-[(E)-(4-Nitrophenyl)diazenyl]naphthalen-2-ol | |
Other names 1-[(4-Nitrophenyl)azo]-2-naphthalenol, 1-((4-nitrophenyl)azo)-2-naphthol, 1-[(p-nitrophenyl)azo]-2-naphthalenol, 1-[(p-nitrophenyl)azo]-2-naphthol, 1-[(E)-(4-Nitrophenyl)diazenyl]-2-naphthol, paranitraniline red, Pigment Red 1, C.I. 12070, Recolite Para Red B, Carnelio Para Red BS | |
Identifiers | |
3D model (JSmol) | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.026.449 |
EC Number |
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PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C16H11N3O3 | |
Molar mass | 293.282 g·mol−1 |
Appearance | Red solid |
Melting point | 248 to 252 °C (478 to 486 °F; 521 to 525 K) |
Hazards | |
GHS labelling: | |
Warning | |
H315, H319, H335 | |
P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Para red (paranitraniline red, Pigment Red 1, C.I. 12070) is a dye. Chemically, it is similar to Sudan I. It was discovered in 1880 by von Gallois and Ullrich and was the first azo dye. It dyes cellulose fabrics a brilliant red color, but is not very fast. The dye can be washed away easily from cellulose fabrics if not dyed correctly. Acidic and basic stages both occur during the standard formation of Para Red, and acidic or basic byproducts may be present in the final product.
Para red is prepared by diazotization of para-nitroaniline at ice-cold temperatures, followed by coupling with β-naphthol: [1]
Para red is not approved for use in food in any jurisdiction. In 2005, Old El Paso dinner kits were found to be contaminated with the dye and removed from supermarket shelves. [2] [3]
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and may require a mordant to improve the fastness of the dye on the fiber.
Kombucha is a fermented, lightly effervescent, sweetened black tea drink. Sometimes the beverage is called kombucha tea to distinguish it from the culture of bacteria and yeast. Juice, spices, fruit or other flavorings are often added.
A mordant or dye fixative is a substance used to set dyes on fabrics. It does this by forming a coordination complex with the dye, which then attaches to the fabric. It may be used for dyeing fabrics or for intensifying stains in cell or tissue preparations. Although mordants are still used, especially by small batch dyers, it has been largely displaced in industry by directs.
Carmine – also called cochineal, cochineal extract, crimson lake, or carmine lake – is a pigment of a bright-red color obtained from the aluminium complex derived from carminic acid. Specific code names for the pigment include natural red 4, C.I. 75470, or E120. Carmine is also a general term for a particularly deep-red color.
In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and as a frame material for eyeglasses; it is also used as a synthetic fiber in the manufacture of cigarette filters and playing cards. In photographic film, cellulose acetate film replaced nitrate film in the 1950s, being far less flammable and cheaper to produce.
Tie-dye is a term used to describe a number of resist dyeing techniques and the resulting dyed products of these processes. The process of tie-dye typically consists of folding, twisting, pleating, or crumpling fabric or a garment, before binding with string or rubber bands, followed by the application of dye or dyes. The manipulations of the fabric before the application of dye are called resists, as they partially or completely prevent ('resist') the applied dye from coloring the fabric. More sophisticated tie-dye may involve additional steps, including an initial application of dye before the resist, multiple sequential dyeing and resist steps, and the use of other types of resists and discharge.
Sulfur dyes are the most commonly used dyes manufactured for cotton in terms of volume. They are inexpensive, generally have good wash-fastness, and are easy to apply. Sulfur dyes are predominantly black, brown, and dark blue. Red sulfur dyes are unknown, although a pink or lighter scarlet color is available.
Tannic acid is a specific form of tannin, a type of polyphenol. Its weak acidity (pKa around 6) is due to the numerous phenol groups in the structure. The chemical formula for commercial tannic acid is often given as C76H52O46, which corresponds with decagalloyl glucose, but in fact it is a mixture of polygalloyl glucoses or polygalloyl quinic acid esters with the number of galloyl moieties per molecule ranging from 2 up to 12 depending on the plant source used to extract the tannic acid. Commercial tannic acid is usually extracted from any of the following plant parts: Tara pods (Caesalpinia spinosa), gallnuts from Rhus semialata or Quercus infectoria or Sicilian sumac leaves (Rhus coriaria).
Mercerisation is a textile finishing treatment for cellulose fabric and yarn, mainly cotton and flax, which improves dye uptake and tear strength, reduces fabric shrinkage, and imparts a silk-like luster.
An acid dye is a dye that is typically applied to a textile at low pH. They are mainly used to dye wool, not cotton fabrics. Some acid dyes are used as food colorants, and some can also be used to stain organelles in the medical field.
Carboxymethyl cellulose (CMC) or cellulose gum is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. It is often used as its sodium salt, sodium carboxymethyl cellulose. It used to be marketed under the name Tylose, a registered trademark of SE Tylose.
Sodium bisulfate, also known as sodium hydrogen sulfate, is the sodium salt of the bisulfate anion, with the molecular formula NaHSO4. Sodium bisulfate is an acid salt formed by partial neutralization of sulfuric acid by an equivalent of sodium base, typically in the form of either sodium hydroxide (lye) or sodium chloride (table salt). It is a dry granular product that can be safely shipped and stored. The anhydrous form is hygroscopic. Solutions of sodium bisulfate are acidic, with a 1M solution having a pH of slightly below 1.
Allura Red AC is a red azo dye that goes by several names, including FD&C Red 40. It is used as a food dye and has the E number E129.
Old El Paso is a brand of Tex-Mex-style foods from American food producer General Mills. These include dinner kits, tacos and tortillas, taco seasoning, sauces, condiments, rice, and refried beans.
Dylon International is a British brand of textile dyes and other household chemicals. It was founded in 1946 by the Mayborn Group. The Mayborn Group sold Dylon International to European homecare company Spotless Group in 2008. Spotless Group was acquired by Henkel in 2014 which is the current owner of Dylon.
In textile manufacturing, finishing refers to the processes that convert the woven or knitted cloth into a usable material and more specifically to any process performed after dyeing the yarn or fabric to improve the look, performance, or "hand" (feel) of the finish textile or clothing. The precise meaning depends on context.
The cochineal is a scale insect in the suborder Sternorrhyncha, from which the natural dye carmine is derived. A primarily sessile parasite native to tropical and subtropical South America through North America, this insect lives on cacti in the genus Opuntia, feeding on plant moisture and nutrients. The insects are found on the pads of prickly pear cacti, collected by brushing them off the plants, and dried.
Natural dyes are dyes or colorants derived from plants, invertebrates, or minerals. The majority of natural dyes are vegetable dyes from plant sources—roots, berries, bark, leaves, and wood—and other biological sources such as fungi.
Wet Processing Engineering is one of the major streams in Textile Engineering or Textile manufacturing which refers to the engineering of textile chemical processes and associated applied science. The other three streams in textile engineering are yarn engineering, fabric engineering, and apparel engineering. The processes of this stream are involved or carried out in an aqueous stage. Hence, it is called a wet process which usually covers pre-treatment, dyeing, printing, and finishing.
The Fruit and Vegetable Preservation Research Station (FVPRS) was a former British government research institute, now a private research company, that has made important industry-wide advances in food preservation, notably canning.