| HS Code | 678100 |
| Chemical Class | Cationic dyes with positively charged chromophore |
| Solubility | Soluble in water and polar organic solvents such as alcohol |
| Electrical Charge | Positive (cationic) in aqueous solution |
| Color Property | Produce intensely brilliant and bright shades |
| Tinctorial Strength | High dye uptake gives deep coloration at low concentrations |
| Substrate Affinity | Bonds directly with anionic sites on acrylic, wool, silk, nylon, and paper |
| Lightfastness | Poor to moderate resistance to fading on exposure to light |
| Washfastness | Generally poor washfastness on textiles without mordanting |
| Ph Sensitivity | Color and stability are affected by pH changes in the dye bath |
| Application Condition | Applied under acidic to neutral conditions with heat to promote exhaustion |
As an accredited Basic Dyes factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Basic Dyes packaged in 25 kg sealed fiber drums with inner polyethylene liner, ensuring safe handling and storage. |
| Container Loading (20′ FCL) | 20′ FCL: Basic Dyes packed in drums/bags, palletized, secured, and containerized for safe, efficient transport. |
| Shipping | Basic Dyes are shipped in sealed, corrosion-resistant containers to prevent moisture absorption and contamination. They must be kept away from strong oxidizers and heat sources. Packaging is labeled and compliant with dangerous goods regulations, with safety data sheets provided. Transport via road, sea, or air requires proper segregation, spill containment, and protective handling procedures. |
| Storage | Store basic dyes in a cool, dry, well-ventilated area away from direct sunlight, ignition sources, and incompatible materials such as strong oxidizers and acids. Keep containers tightly sealed to prevent moisture absorption and dust generation. Label clearly, maintain segregation from foodstuffs, and follow local regulations for safe handling and disposal. |
| Shelf Life | Store in a cool, dry, tightly sealed container. Shelf life is typically 2–3 years from manufacture date. |
Competitive Basic Dyes prices that fit your budget—flexible terms and customized quotes for every order.
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Basic dyes are water-soluble cationic chromophores that exhibit substantivity for anionic groups present in polyacrylonitrile, modacrylic, acid-modified polyester, lignified paper furnish, and certain leather retanning systems. The chromophore is present as a positively charged ion, typically paired with chloride, sulphate, acetate, or zinc chloride double salt counterions. This class should not be confused with solvent-based basic dye complexes or with cationic optical brighteners. Commercial products are usually supplied as free-flowing powders, granules, or concentrated liquids standardised against a reference lot for colour strength, shade, and impurity profile.
Commercially significant types include C.I. Basic Yellow 40, C.I. Basic Blue 41, C.I. Basic Red 46, C.I. Basic Violet 10, and C.I. Basic Green 4. C.I. Basic Yellow 40 is widely used for acrylic and modacrylic shades with relatively good build-up. C.I. Basic Blue 41 finds use in acrylic, paper, and certain ink formulations where a bright blue with moderate lightfastness is acceptable. C.I. Basic Violet 10 is a xanthene dye with high tinctorial strength and fluorescence, but limited lightfastness on most substrates. C.I. Basic Green 4 is a triarylmethane dye with high colour intensity and narrow processing pH tolerance. Colour Index generic names define the chromophore type, while manufacturer-specific commercial grades differ in purity, diluents, anti-dusting treatment, and physical form. The same Colour Index type from different suppliers may therefore show different solubility, dusting behaviour, and batch-to-batch colour strength.
Commercial powder and liquid grades are standardised by dye content, moisture, water-insoluble matter, and pH rather than by trade designation alone. Table 1 lists commonly requested release parameters and methods. Dye content is determined spectrophotometrically against a certified reference lot at the absorption maximum of the specific chromophore; therefore, numerical strength values are not transferable across different Colour Index types without recalibration. Solubility at 80°C commonly ranges from 40 g/L to 100 g/L depending on the Colour Index type and counterion. Granular grades reduce dusting but dissolve more slowly than powders. Liquid grades eliminate dust but may contain 10–30% water or glycol diluents and may require heated storage above 5°C to prevent phase separation.
| Parameter | Typical release value | Test method |
|---|---|---|
| Colour strength versus reference | 95–105% | Spectrophotometric assay versus reference lot |
| Volatile matter, powder | ≤ 5.0% | ISO 787-2 |
| Water-insoluble matter | ≤ 0.5% | ISO 787-3 |
| pH of 1% aqueous solution | 3.0–6.0 | ISO 787-9 |
| Restricted aromatic amines | ≤ 30 mg/kg per listed amine | EN ISO 14362-1:2017 |
| Soluble heavy metals | Limits per consumer article category | EN 71-3:2019+A1:2021 |
Acrylic and modacrylic fibres contain pendant sulphonate or carboxylate groups introduced during polymerisation; these are the primary dye sites for cationic basic dyes. In batch dyeing, the dyebath is set with acetic acid/sodium acetate buffer at pH 3.5–5.5, and a cationic retarder is added at 0.5–3.0% owf depending on shade depth. The retarder, typically a quaternary ammonium compound, competes with dye cations and slows the strike in the critical temperature range between 70°C and 85°C. Heating from 85°C to 98°C is controlled at 1–2°C/min; above 98°C acrylic fibre softens and package distortion or crack formation may occur. The bath is then cooled slowly before unloading, because rapid cooling can freeze fibre deformation and produce crease marks.
Package dyeing machines with reversible pump flow, beam dyeing machines for warp-like tow, and hank machines for high-bulk yarns are used depending on the physical form of the fibre. High-shear dispersion is not recommended directly for powder dyes; pasting with acetic acid at 40–50°C followed by dilution through a 100–200 µm filter screen avoids filter blockages. Lightfastness is assessed according to ISO 105-B02:2014, wet fastness according to ISO 105-C10:2006, and rubbing fastness according to ISO 105-X12:2016. Build-up curves are non-linear above 2.0% owf because dye sites in acrylic fibres become saturated; further dye addition increases unfixed dye in the bath and may precipitate onto equipment surfaces. The saturation factor of the fibre and the combination index of the dye mixture determine whether a ternary shade can be reproduced. Spectrophotometric shade matching under D65 and 10° observer conditions is performed according to ISO 105-J01; metamerism risk is higher when combining xanthene and azo basic dyes due to differing absorption band shapes.
Continuous acrylic tow dyeing uses pad-steam equipment with saturated steam at 100–105°C for 20–60 seconds and a buffer/retarder system in the pad trough. The short fixation window demands that the dye be fully dissolved and the pad liquor filtered through 50–100 µm filters. Published data for high-speed continuous configurations is limited; therefore, pilot trials are required to establish fixation for specific Colour Index combinations.
In paper and tissue dyeing, the cationic charge provides direct substantivity to bleached chemical pulp without anionic fixing agents; however, elevated headbox pH or excess anionic trash can reduce retention and create mottling. Continuous tissue machines require injection into the thick stock or fan pump approach at controlled addition rates to avoid peroxide bleaching residues neutralising the cationic charge. For leather, basic dyes are limited to bright cationic shades in retanning and surface finishing where anionic dyestuff precipitation is avoided by separate application; wet fastness on chrome-tanned leather is generally lower than on acrylic, and lightfastness may fall below 4 on the blue wool scale depending on depth.
Basic dyes do not exhaust on unmodified polyester, polypropylene, or untreated cotton because the substrate cannot fix the cation by ionic bond. They are also not direct replacements for disperse dyes on polyester or for reactive dyes on cellulose. Acid-modified polyester and sulphonated polyolefin are exceptions; in these substrates the dye sites are anionic co-monomers and the same pH, retarder, and temperature principles apply. Table 2 summarises the practical differences among basic, acid, and direct dye classes.
| Property | Basic dyes | Acid dyes | Direct dyes |
|---|---|---|---|
| Ionic character | Cationic | Anionic | Anionic |
| Primary fibre chemistry | Acrylic, modacrylic, acid-modified polyester, paper | Wool, silk, polyamide | Cellulose, paper |
| Typical bath pH | 3.5–5.5 | 3.0–6.0 depending on acid dye class | 6.0–9.0 with electrolyte |
| Leveling behaviour | Retarder-dependent; rapid strike above 85°C | Good migration at boil with levelling agents | Moderate; salt-controlled exhaustion |
| Wet fastness on primary substrate | High on acrylic after controlled cooling; lower on paper and leather | High after aftertreatment on protein fibres | Moderate; cationic fixative often required |
| Lightfastness | Depth-dependent; 3–7 blue wool on acrylic | Generally 3–6 on wool; metal-complex types higher | 2–5 on cellulose without UV stabiliser |
Regulatory acceptability depends on the impurity profile of the specific Colour Index type rather than on the cationicity of the class as a whole. Azo-based basic dyes are screened for restricted aromatic amines under EN ISO 14362-1:2017; heavy metal migration is assessed for consumer articles under EN 71-3:2019+A1:2021. Some basic dyes contain zinc chloride double salts; therefore, zinc release limits under toy safety regulations should be checked for children’s articles. Powder grades with high dusting potential require local exhaust ventilation and respiratory protection, and liquid grades may contain glycols or acetic acid that affect material compatibility in dosing lines. Certain xanthene basic dyes are not suitable for food-contact or cosmetic use; formulators should verify regional restrictions before selecting these grades. For applications where lightfastness below 5 on blue wool is unacceptable, basic dyes should be reformulated or replaced with selected acid or disperse dyes that meet the same shade target.
