Disperse Violet 27, C.I. 60724, is an anthraquinone disperse dye produced as a dark violet powder standardized at 200% or 300% relative to a reference grade, with a 50% aqueous dispersion form available for continuous dyeing and automated metering. The active substance is 1,4-diamino-2,3-diphenoxyanthraquinone, CAS 19286-75-2, molecular formula C26H20N2O4, molecular weight 424.45 g/mol. The two phenoxy substituents at the 2- and 3-positions differentiate the product from low-molecular-weight anthraquinone violets such as C.I. Disperse Violet 1, molecular weight 238.24 g/mol; the increased molecular volume lowers vapor pressure and diffusivity in polyester, which is specified where dry-heat sublimation fastness and thermal migration resistance are required. Aqueous solubility is below 0.1 mg/L at 25°C; the product therefore requires anionic dispersants and shear-controlled dispersion. Typical certificates of analysis report strength tolerances of 95–105% and batch-to-batch CIELAB ΔE ≤ 0.5 under D65/10° illuminant.

The anthraquinone chromophore absorbs in the visible region with λ_max near 580 nm in acetone; the molar extinction coefficient is product-specific and is controlled during synthesis to maintain interlot shade consistency. The two phenoxy substituents increase molecular volume without introducing azo reduction liability, which is why the product is classified as non-azo. Disperse Violet 27 is synthesized by condensation of 1,4-diamino-2,3-dichloroanthraquinone with phenol under alkaline conditions; residual phenol and chlorinated intermediates are controlled to meet textile dye effluent limits. The commercial product is commonly diluted with lignosulfonate and synthetic naphthalene sulfonate condensates, which must be free from alkylphenol ethoxylates under ZDHC MRSL 3.1. Water hardness above 150 ppm CaCO₃ destabilizes the dispersion, so a sequestering agent based on acrylic acid/maleic acid copolymer is used at 0.5–1.0 g/L.

Which Physical Form and Strength Grade Are Appropriate for High-Temperature Polyester Exhaust Dyeing?

For jet and package dyeing, the 200% powder is used in medium depths at 0.5–2.0% owf, while the 300% grade is metered at 2.0–4.0% owf for deep shades. The 50% liquid dispersion is preferred where dusting, manual weighing, and dyehouse automation are critical, because it can be pumped through ring-laydown stations and avoids airborne powder contamination. In high-temperature overflow machines with liquor ratios of 1:8 to 1:15, the dye is dispersed at 40–50°C with 0.5–1.0 g/L anionic dispersant and 0.5–1.0 g/L sequestering agent. The pH is adjusted to 4.5–5.5 using an acetic acid/sodium acetate buffer; a pH above 6.5 destabilizes the dispersion and can produce filtration spots on package machinery. Particle-size control is specified by laser diffraction per ISO 13320:2020, with D90 ≤ 5 µm and D50 ≤ 2 µm required for package dyeing; coarser grades are not appropriate for high-density yarn packages because filtration deposits increase pressure differentials above 1.0 bar.

In package dyeing, the product is pumped at pressure differentials of 0.5–1.0 bar through yarn packages with density 350–400 g/L. Flow reversal is used to avoid channeling. Filtration spots caused by inadequate dispersion appear as dark specking on cheese surfaces; offline filter tests with 5 µm absolute filters are used to pre-screen batches. The product should not be prepared in water above 50°C before dispersing, because thermal shock causes agglomeration. Storage below 40°C and relative humidity below 65% prevents lignosulfonate caking and moisture-induced dispersant hydrolysis.

Exhaust application is performed by ramping at 1.0–1.5°C/min from 70°C to 130°C, holding for 30–45 min depending on depth and fabric construction. At 130°C, saturated steam pressure in the machine is approximately 2.5–3.0 bar, and carrier-free dyeing is possible because the high-energy anthraquinone molecule achieves adequate polyester segmental mobility at that temperature. Reduction clearing is applied after dyeing with 1–2 g/L sodium hydrosulfite, 1–2 g/L sodium hydroxide, and 0.5 g/L nonionic surfactant at 80°C for 20 min, followed by warm rinsing and neutralization with acetic acid; wet fastness is assessed by ISO 105-C06:2010, and dry-heat fastness by ISO 105-P01:1993. On texturized polyester, the dye is sensitive to barré because high-energy anthraquinone molecules migrate less readily than low-energy azo components; leveling requires a leveling agent with mild carrier function and a controlled exhaust rate. Published data for the adsorption rate constant on standard polyester fiber is limited; however, dyehouse trials indicate that poor pre-scouring causes unlevel uptake when residual knitting oils exceed 0.5% owf.

Atmospheric carrier dyeing at 98–100°C is possible only with carrier concentrations of 2–4 g/L; color yield is lower than at 130°C, and carrier residues must be removed by post-thermofixation to avoid lightfastness loss under ISO 105-B02:2014. This operational boundary is critical for dyehouses with unpressurized vessels.

When the pad thermofixation line runs at 205–210°C, the processing window narrows

Continuous pad-thermosol application requires a pad pickup of 60–70%, infrared predrying at 80–100°C, and hot-air drying at 110–120°C before thermofixation at 205–210°C for 60–90 s. Fixation below 195°C produces low diffusion efficiency and poor wash fastness after ISO 105-C06:2010, while fixation above 215°C accelerates thermal migration during later heat-setting of polyester/cotton blends. Fabric pre-drying must be uniform because migration during drying produces edge-to-center shade variation in stenter frames; a residual moisture difference of more than 10% across the fabric width can generate visible tailing. Pad liquors include 10–20 g/L antimigrant and 1–2 g/L wetting agent; the antimigrant raises liquor viscosity and reduces particle movement during predrying. Excessive antimigrant above 25 g/L can impair diffusion and cause surface bronzing. The pad liquor pH is held between 4.5 and 5.5; acid-liable thickeners are avoided. For polyester/cotton unions, the thermofixed disperse dye is reduction cleared at 70–80°C before reactive pad-dry-steam processing; the reactive dyeing step is run after the anthraquinone dye has been cleared to avoid alkali-induced surface reduction. Continuous dyeing with Disperse Violet 27 is specified for workwear and sportswear where dry-heat fastness under ISO 105-P01:1993 and perspiration fastness under ISO 105-E04:2013 are tested at 150°C and 180°C pressing conditions.

After infrared predrying, residual moisture is targeted at 15–20% before hot-air drying; below 10% residual moisture during early drying increases migration risk. Online moisture sensors are used to control stenter speed. The use of acid donors such as dibasic ester or ammonium sulfate is not preferred because pH shifts above 6.0 reduce exhaustion and can cause shade dulling. Volatile acetic acid is preferred; the pad liquor pH is monitored after 10 min and before ramp start.

Relative to lower-molecular-weight anthraquinone violet dyes, Disperse Violet 27 shows reduced vapor pressure because the diphenoxy substitution increases molecular weight from approximately 238 g/mol for C.I. Disperse Violet 1 to 424 g/mol. This shifts sublimation fastness upward but decreases diffusion coefficient in polyester; dyeing time must therefore be extended in exhaust processes, and the color is less suitable for rapid dyeing cycles below 30 min at 130°C. Compared with Solvent Violet 13 (C.I. 60725, 1-hydroxy-4-(p-tolylamino)anthraquinone), Disperse Violet 27 is formulated for aqueous polyester coloration rather than solvent-based ink or polymer mass coloration. Solvent Violet 13 has low water dispersibility and is not intended as a primary exhaust dye; Disperse Violet 27 contains dispersants that maintain colloidal stability in aqueous baths. Against monoazo violet disperse dyes of lower molecular weight, the anthraquinone chromophore provides higher lightfastness, commonly reported as grade 6–7 on polyester at 1/1 standard depth under ISO 105-B02:2014, but lower tinctorial strength requires higher dosage for equivalent visual depth.

The difference in application class between Disperse Violet 27 and Solvent Violet 13 is also reflected in standard test selection: disperse dyes are evaluated by ISO 105-E04:2013 and ISO 105-C06:2010, whereas solvent dye masterbatches are evaluated by melt flow rate ISO 1133-1:2022 and tensile test ASTM D638-14 in the final polymer article.

For direct printing on polyester, Disperse Violet 27 is formulated into a stock paste and fixed with high-pressure steam at 130°C for 30–40 min or superheated steam at 175°C for 7–10 min. It is not recommended for vapor-phase transfer printing at 200°C because the high molecular weight and low vapor pressure limit sublimation transfer efficiency; low-energy disperse dyes are preferred for that process. After high-pressure steam fixation, washing at 70–80°C with sodium hydrosulfite removes thickener and unfixed dye.

If the dye is substituted for Solvent Violet 13 in PET masterbatch coloration, which process limits appear?

In PET masterbatch and melt-spinning, Disperse Violet 27 is applied at 0.01–0.2% by weight in high-shear twin-screw compounding with L/D ratio 32:1 to 44:1 at melt temperatures of 260–280°C. The anthraquinone structure survives short residence times, but extended residence above 300°C can cause shade shift and decomposition. PET resin must be pre-dried to below 50 ppm moisture before compounding to limit hydrolytic chain scission. Melt filtration after compounding is specified with 20–40 µm screen packs; undispersed dye agglomerates above 10 µm can clog spinnerets in deniers below 1.0. Compared with Solvent Violet 13, Disperse Violet 27 has more polar amino functions and may show lower extraction resistance in nonpolar polymers; published data for food-contact migration from polyolefins are limited. The product is therefore not automatically a drop-in replacement for solvent dyes in polyolefin film or injection-molded articles requiring FDA 21 CFR food-contact status.

For automotive polyester fabrics, ultraviolet absorber finishes are applied after dyeing to meet ISO 105-B02:2014 grade 6–7 or higher; Disperse Violet 27 is combined with UV absorbers at 1–2% owf in the finishing bath. The anthraquinone chromophore is less susceptible to photofading than monoazo violet homologues, but prolonged xenon exposure still produces shade change; published comparative data under automotive interior standards are limited.

On polyester/elastane powernet and swimwear fabrics, Disperse Violet 27 can stain the segmented polyurethane component during dyeing. Reduction clearing removes surface dye but does not fully eliminate absorbed dye from elastane; aftertreatment with 0.5–2.0 g/L cationic fixative at 50–60°C for 20 min is required to limit wet-fastness failures under ISO 105-C06:2010. For deep shades above 3.0% owf, the producer should evaluate migration into elastane and pre-test lightfastness, because published data on the elastane uptake of this specific anthraquinone dye are limited.

Evaluating sublimation fastness after alkaline reduction clearing

Disperse Violet 27 is selected for garments that undergo finishing at 170–180°C. Sublimation fastness is assessed by ISO 105-P01:1993 at 180°C for 30 s; staining of adjacent polyester multifiber is typically controlled below grade 4 at 1/1 standard depth, but the result depends on fabric construction and heat-setting history. Alkaline reduction clearing is effective in removing unfixed surface dye because the anthraquinone structure is reduced to a leuco form under sodium hydrosulfite; however, excessive alkalinity above 3 g/L NaOH at 85°C can over-clear and shift the apparent shade. For high-wet-fastness specifications, a second clearing stage or cationic aftertreatment is used. The product is not recommended for polyester articles dyed in combination with alkali-labile azo components if the reduction clearing step is aggressive, because differential reduction can produce shade variation.

Thermal migration fastness is evaluated by heat-treating dyed polyester at 180°C for 30 s and measuring color transfer to adjacent polyurethane or plasticized PVC according to a supplier method; standard method harmonization for thermal migration is incomplete, and published data for Disperse Violet 27 under specific afterheat-set conditions are limited. The high molecular weight reduces but does not eliminate diffusion of dye to the fiber surface. Pre-drying of dyed packages at relative humidity above 60% should be performed before storage, because residual moisture can hydrolyze dispersants and produce tar-like residues.

Regulatory compliance is product-grade dependent and must be verified with the supplier; the following matrix summarizes typical control points.

The powder should be stored below 40°C at relative humidity below 65%. Contact with strong reducing agents, particularly thiourea dioxide in acidic solution, leads to premature leuco formation; contact with strong oxidizing agents can degrade the anthraquinone chromophore. The product is incompatible with concentrated sodium hydroxide in the absence of dispersant, and it should not be premixed with cationic fixatives because coagulation can occur. These boundary conditions are separate from normal dyehouse handling; they do not alter the core use of the product as a high-energy violet component for polyester exhaust, continuous thermofixation, and PET melt coloration.