Preparation
4-Hydroxynaphthalene-1-sulfonic acid diazo, and 7-Hydroxynaphthalene-1,3-disulfonic acid coupling, and then into aluminum salt deposit color.
Properties and Applications
red. Red fine powder, odourless. Hardly soluble in water, oil and most solvent, but can be scattered, mixed with water, oil and other liquid and solid powder. Resistance to light sex, salt tolerance, good sex, heat resistance than C.I. Food Red 7 a bit better. When using the use effect of the acid and alkali through influence. This product is particularly suitable for oil products, powder solid and colloid water-soluble colorants difficult to chromatic items shading. The product is made of a certain amount of strong HCL, added with a certain volume of two potassium hydrogen sulfate solution diluted, the maximum absorption wavelength for 508 + 2 nm.
