Red and yellow solvent dyes are often azo dyes, green and blue ones tend to be anthraquinone dyes. is also called oil dye, oil-based dye or solvent based dyes. One type of non-polar organic solvents that is commonly used with oil dyes is petrol. Accordingly, oil solvent dyes are often used in the automotive industry to color petrol fuel and other hydrocarbon-based fuel oils. Oil can be colored by oil soluble dyes. In addition, many solvent dyes are used as components by the biological stain manufacturing community to produce stains that will identify various cell structure components in medical diagnostics and scientific research.
Oil soluble solvent dyes have better temperature stability in engineering plastics, very high brightness and do result in completely transparent plastics without any haze and light scattering. Processing is easy and process parameters like viscosity remain unaffected. Process conditions for engineering plastics like polystyrene, ABS, PC, PMMA, PA and others are quite severe. During extrusion and injection moulding of PC the dyes have to withstand temperatures up to over 350°C for some minutes. Only selected oil solvent dyes do show the needed chemical resistance. Chemical stability also leads to long lasting final products which have to withstand sunlight and weather. As an example, red car taillights will last as long as the car itself without losing the bright red colour. To achieve this, the right transparent polymers and right dyes have to be taken.
Commodity polymers like Polyethylene, polypropylene, plasticized PVC or rubber are soft at low temperatures. we do not recommend any solvent dyes for coloration of these polymers but pigments have to be used.
Besides plastics industry, a major application for solvent dyes is printing or solvent based writing ink. Furthermore, oil soluble dyes are widely used in rubbers, oil inks, spinning, waxes, smoke, paints, color paste, transfer printing, marking pens, ball point pens, candles, oil, fats, solvents, bitumen, lubricants, marking inks, inkjet printing inks, dye sublimation printing, glass coloration, signalling smoke, firework and in the pyrotechnics industries, gold imitation, other transparent metallic effects of metallized polyester films, other hydrocarbon-based nonpolar materials.
Nigrosine Blacks include oil soluble nigrosine (C. I. solvent black 7), spirit soluble nigrosine or alcohol soluble nigrosine (C. I. solvent black 5), MS conc nigrosine (C. I. acid black 2) and aniline black (C.I. pigment black 1). All Nigrosine do show absorption in the infrared light making them suitable for optical character recognition. They are suitable for inkjet inks, ball point pen inks, solvent marker pen inks, water sign pen inks, industrial inks, ribbon inks, carbon paper, shoe polish, plastics, phenolic resin, polyamide resin, urea resin, lacquers, varnishes, wood stains, leather, cotton, flax, metallic products, coatings, alcohol based oil soluble self-drying alkyd coatings, nitryl paints, water based coatings, thermosetting coatings, stationery commodities, alcohol based printing ink, plastics application such as acrylic resin, unsaturated polyester resin, fibrin resin, Bakelite, polyester alkyd, polyvinyl chloride, polycarbonate, polystyrene, polypropylene, non-water soluble coloring of leather and fur, coatings, printing ink, positive charge control agent in electrostatic printing powder, coloring for stationery.
