Section
| HS Code | 324526 |
| Productname | Permanent Orange RWT |
| Producttype | Organic pigment |
| Colorindexname | Pigment Orange 34 |
| Colorindexnumber | 21115 |
| Casregistrynumber | 3468-63-1 |
| Chemicalclass | Disazo (diarylide) pigment |
| Appearance | Orange powder |
| Colorhue | Reddish orange |
| Specificgravity | Approximately 1.4-1.6 g/cm3 |
| Oilabsorption | Approximately 35-45 g/100 g |
| Lightfastness | Good; approximately 7 full shade and 5 tint |
| Heatstability | Approximately 180-200 °C |
| Acidresistance | Good; approximately rating 5 |
| Alkaliresistance | Good; approximately rating 5 |
| Solventresistance | Good; approximately rating 4-5 |
| Waterresistance | Good |
| Solubility | Insoluble in water and common organic solvents |
| Primaryapplications | Printing inks, coatings, plastics, and rubber |
As an accredited Permanent Orange RWT factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Permanent Orange RWT is supplied in a 25 kg sealed fiber drum with moisture-resistant liner and clear hazard labeling. |
| Container Loading (20′ FCL) | Permanent Orange RWT is packed in labeled drums, palletized, shrink-wrapped, and secured inside a 20′ FCL for safe export transport. |
| Shipping | Permanent Orange RWT is typically shipped as a non-hazardous chemical, not regulated for transport and without a UN number. Use sealed, labeled containers in a cool, dry, well-ventilated area, away from oxidizers, ignition sources, moisture, and direct sunlight. Follow the SDS and local regulations. |
| Storage | Store Permanent Orange RWT in a cool, dry, well-ventilated area away from direct sunlight, heat, ignition sources, and incompatible materials such as strong oxidizers, acids, and alkalis. Keep containers tightly closed, properly labeled, upright, and in secondary containment. Prevent dust generation or aerosol formation, avoid spills, and keep away from food, feed, and drinking water. Use appropriate personal protective equipment. |
| Shelf Life | Permanent Orange RWT has a shelf life of about 5 years when stored dry, tightly sealed, and protected from light, heat, and moisture. |
During high-speed dry blending of rigid PVC window profile compounds, Permanent Orange RWT is introduced after the resin has reached 80 °C and after the stabilizer-lubricant package has been absorbed, but before the final hot-mix stage at 110–120 °C. The mixer is usually a high-intensity turbo blender operating at 1,200–1,800 rpm; the dispersed pigment is then fed into a parallel twin-screw extruder with a screw diameter between 55 mm and 93 mm, a barrel profile from 150 °C to 185 °C, and a die temperature not exceeding 205 °C. At a loading of 0.5–2.0 phr, the pigment is typically combined with titanium dioxide for pastel or mid-tone shades, and the ratio is adjusted between 1:3 and 1:5 to meet the required opacity for RAL 2003 or similar orange shades. The final rigid PVC profile or pipe is produced at a screw speed of 15–25 rpm and a melt pressure of 150–250 bar; quality control includes a two-roll mill heat stability check at 180 °C for 5 min according to EN 12877-1, and a pressure filter test according to EN 13900-5 using a 14 μm filter mesh and a 100 cm³ melt pump at 190 °C. Because organic orange pigments can interact with residual hydrogen chloride generated during PVC degradation, the pH of the aqueous extract under ISO 787-9 should be measured before plant trials; values outside the supplier-notified range of 5.0–8.0 are a warning sign that the stabilizer system may need correction. Pre-drying at 60 °C for 4 h is required if storage humidity has exceeded 60%, because residual moisture can disrupt dry blend flow and reduce bulk density. For EU supply, a valid REACH registration under Regulation (EC) No 1907/2006 is required, and heavy metal limits are controlled under RoHS Directive 2011/65/EU Annex II and, for toy-scope profiles, EN 71-3. Published data for this specific configuration is limited at melt temperatures above 210 °C for residence times exceeding 10 min, so field trials must include batch-to-batch heat stability verification rather than relying on generic supplier data.
| Test property | Method | Equipment / conditions |
|---|---|---|
| Color strength and shade | ISO 787-24 | Spectrophotometer, D65 illuminant, 10° observer, CIELAB ΔE ≤ 1.0 |
| Oil absorption | ISO 787-5 | Refined linseed oil, glass plate, muller |
| pH of aqueous extract | ISO 787-9 | pH meter, 10% aqueous suspension |
| Residue on sieve | ISO 787-7 | 45 μm sieve, wet screening |
| Heat stability in PVC | EN 12877-1 | Two-roll mill at 180 °C, 5 min |
| Migration resistance | ISO 105-A03 | PVC foil contact at 50 °C, 24 h |
| Lightfastness | ISO 105-B02 | Xenon arc lamp, Blue Wool scale |
| Weathering | ISO 4892-2 | Xenon arc, black panel 65 °C, 102 min dry / 18 min water spray |
In flexible PVC cable jackets, the pigment is usually pre-masterbatched in a dioctyl phthalate or dioctyl terephthalate plasticizer slurry before addition to the high-speed mixer at 70–90 °C. The dispersion is then processed on a single-screw extruder with a compression ratio of 3.0:1 to 3.5:1, a screen pack of 60/80/100 mesh, and a melt temperature of 170–190 °C; the extruded jacket is cooled in a water trough at 20–30 °C and printed or embossed continuously. At loadings of 0.5–1.5 phr, Permanent Orange RWT provides a weather-resistant orange jacket in low-voltage and medium-voltage cables; darker shades may require 2.0 phr plus carbon black or rutile TiO2 adjustments. The main technical risk is plasticizer exudation, which is evaluated by contact bleeding tests under ISO 105-A03 at 50 °C for 24 h against a white PVC witness sheet. Thermal stability is checked with Congo Red at 200 °C for 60 min under ISO 182-1; a shift in stabilizer demand of more than 10 min compared with an unpigmented control indicates an interaction that must be resolved before full-scale extrusion. The terminal cable sheath is further tested for tensile strength and elongation under the applicable part of IEC 60811, and the pigment must not reduce elongation below the specified class limits.
For PP and HDPE masterbatch production, Permanent Orange RWT is generally compounded at 20–30 wt% pigment loading in a wax or polyolefin carrier on a co-rotating twin-screw extruder with an L/D ratio of at least 40:1 and a screw speed of 500–700 rpm. The barrel temperature from the feed zone to the die is ramped from 120 °C to 190–200 °C for PE carriers, while PP carriers may require 200–220 °C at the die. The pigment is fed gravimetrically through a side feeder after the polymer melt has been established; the screw configuration includes two or three kneading blocks with 30° or 45° offset angles and a vacuum vent at −0.8 bar to remove volatiles. The dispersion quality is measured by the pressure filter value under EN 13900-5: a filter mesh of 14 μm and a melt temperature of 190 °C should show no pressure rise above 0.5 bar/min for a 1 kg test. The let-down ratio to natural resin is typically 20:1 to 50:1; at 50:1, spiral flow mouldings under ISO 294 may reveal specks if the masterbatch has poorer dispersion, and the total colour strength under ISO 787-24 must be checked against an in-house standard. In injection moulding of PP components, the final melt is usually maintained at 200–240 °C with a hot runner temperature of 220–240 °C; permanent orange pigments of this class may show slight thermochromatic shift during cooling, and the CIELAB ΔE between 23 °C and 60 °C should not exceed 1.0. The terminal product is an automotive interior or appliance component, where lightfastness under ISO 105-B02 at 0.5 wt% is verified with Blue Wool 5–7, and weathering under ISO 4892-2 is run to 500–1,000 h. Published data for this specific configuration is limited at melt temperatures above 240 °C for cycles longer than 15 min, so high-temperature trials should include colour shift measurement after every 100 shots.
In solvent-borne alkyd or acrylic baking enamels, Permanent Orange RWT is first milled in a high-speed disperser at 2,000–3,000 rpm with a pigment volume concentration of 8–12% and a resin-to-pigment ratio of 0.2:1 to 0.4:1. The premix is then milled in a vertical bead mill with 0.8–1.2 mm zirconium oxide beads; the chamber loading is 70–80%, and the grinding temperature is maintained below 50 °C by jacket cooling. The grind fineness is checked with a Hegman gauge under ISO 1524 and should reach 5 μm or less for high-gloss finishes. The base enamel is let down to a spray viscosity of 22–25 s in a DIN 4 mm flow cup at 25 °C (DIN 53211), applied by air spray at 3–4 bar, and baked at 140–160 °C for 20–30 min. The cured film is then measured for gloss at 60° under ISO 2813 and for colour change after overbake at 160 °C for 30 min under ISO 11664-4; the target CIELAB ΔE should not exceed 1.0. In high-solids formulations, the pigment must be predispersed in a resin-cured intermediate to avoid flocculation, and the rub-out ΔE measured by ISO 18314-1 should remain below 0.8 after 24 h storage. The terminal uses are metal furniture, machinery enamel, and external trim, where the coated surface must withstand chemical spot tests under ASTM D1308 with 10% sulfuric acid and 10% sodium hydroxide for 24 h without blistering.
For flexographic and gravure printing ink production, Permanent Orange RWT is dispersed in a nitrocellulose-based solvent blend of ethanol, ethyl acetate, and n-propyl acetate with a resin-to-solvent ratio of 1:4 to 1:6 by weight. The dispersion step uses a horizontal bead mill with 0.6–0.8 mm zirconium silicate beads, a screen of 0.2 mm, and a mill-base pigment solids content of 30–40 wt%; the pass temperature is kept below 45 °C to avoid solvent loss. Grind fineness is measured under ISO 1524, with a target below 5 μm for gravure inks and below 8 μm for surface-print flexographic inks. Viscosity is adjusted to 18–25 s in a DIN 4 mm cup at 25 °C; adhesion is tested by cross-cut tape pull under ASTM D3359 method B. The terminal article is a laminated flexible package or surface-printed label, and the lightfastness under ISO 105-B02 is selected for the intended retail exposure period.
Powder coating production of Permanent Orange RWT begins with dry blending of saturated carboxyl-functional polyester resins, TGIC or β-hydroxyalkylamide curatives, flow agents, and degassing agents in a high-speed mixer at 1,200–1,500 rpm for 2–4 min. The premix is then melt-kneaded in a co-rotating twin-screw extruder with a barrel temperature of 100–120 °C, a screw speed of 300–500 rpm, and a residence time not exceeding 30 s to limit pre-reaction. The extrudate is chilled on a steel cooling roll at 5–10 °C, crushed, and milled in an air classifier mill to a final powder with a median particle size of 30–40 μm measured by laser diffraction under ISO 13320. The powder is electrostatically sprayed at 60–100 kV and cured at 180–200 °C for 10–15 min; the cured film is tested for color retention under ISO 4892-2 for 800–1,200 h xenon arc exposure and for chemical resistance using ASTM D1308 spot tests with 10% sulfuric acid and 10% sodium hydroxide. The terminal uses are metal furniture, architectural profiles, and automotive underbody components where the orange shade must not shift after overbake; overbake stability at 200 °C for 30 min is checked by measuring CIELAB ΔE under ISO 11664-4 against the standard cure condition. Because powder coatings have no solvent to disperse pigment during application, poorly dispersed aggregates may appear as pinholes or seed specks in the cured film; this is monitored by counting defects per 100 cm² at 50× magnification.
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Permanent Orange RWT is a red-shade diarylide organic pigment classified as C.I. Pigment Orange 34, C.I. 21115, CAS 15793-73-4. The product is distributed in both fine-powder and low-dusting granulate forms, with the RWT suffix denoting a surface-treated grade that is intended to improve wetting and reduce dust generation during weigh-out. Public technical data for the exact RWT surface treatment are limited; however, the unmodified C.I. Pigment Orange 34 base is well documented in industrial pigment literature. Colouristically, the grade occupies the mid-orange segment between yellow-shade diarylide oranges and blue-shade naphthol reds. In masstone it exhibits a semitransparent orange mass tone with high tinting strength; in white reductions it produces a clean, red-shade orange with moderate saturation. Typical commercial specifications for the pigment class report a density of 1.4 g/cm³ to 1.6 g/cm³ and an oil absorption value of 35 g/100 g to 50 g/100 g according to ISO 787-5:1980.
The product is normally packed in 25 kg multi-wall paper bags or 500 kg flexible intermediate bulk containers. Because the powder has a moderate dusting tendency in its untreated state, vacuum capture and local exhaust ventilation are recommended during manual addition to mixing vessels. Incoming lots should be quarantined until standard pigment quality-control tests are completed; at minimum, sieve residue, pH, moisture content, and tinting strength should be compared against the supplier’s certificate of analysis using ISO 787-7, ISO 787-9, ISO 787-2, and ISO 787-16 respectively.
The following representative specification profile is compiled from commercial technical data sheets for C.I. Pigment Orange 34. It is not a certificate of analysis for a specific production batch. Values may vary with the manufacturer’s finishing process and surface treatment.
| Parameter | Representative specification or range | Test method |
|---|---|---|
| Color Index classification | C.I. Pigment Orange 34, C.I. 21115 | — |
| CAS registry number | 15793-73-4 | — |
| Volatile matter at 105 °C | ≤ 2.0 % | ISO 787-2 |
| Oil absorption | 35 g/100 g to 50 g/100 g | ISO 787-5 |
| pH of aqueous extract | 5.5 to 8.5 | ISO 787-9 |
| Residue on 45 µm sieve | ≤ 0.5 % | ISO 787-7 |
| Specific gravity | 1.4 to 1.6 | ISO 787-10 |
| Lightfastness full shade | 5 to 6 on blue wool scale | ISO 105-B02 |
| Heat resistance in high-density polyethylene | 180 °C to 200 °C at 5 min dwell | Internal injection-moulding protocol |
| Migration in flexible PVC under load | Moderate; may stain contact PVC at high plasticizer levels | Heated compression jig at 60 °C, 7 d, 0.1 N/mm² |
The third-to-fourth position difference on the blue wool scale between full-shade and white reduction is a known limitation of diarylide orange pigments. A full-shade rating of 5 to 6 is acceptable for printed packaging that is not exposed to prolonged direct sunlight, but reductions with 5:1 titanium dioxide are usually unsuitable for exterior use. Any intended use in exterior coatings must be qualified by accelerated weathering according to ISO 11341 at the exact pigment-to-binder ratio.
In high-speed rotogravure and flexographic printing, the performance of Permanent Orange RWT is set mainly by particle-size distribution and surface wetting behaviour rather than by bulk chemical purity. On horizontal bead mills charged with 0.8 mm to 1.2 mm yttrium-stabilized zirconia beads, the pigment disperses to a Hegman gauge reading below 10 µm under standard solvent-based nitrocellulose-polyurethane letdowns. A millbase pigment load of 30 % to 40 % by weight is maintained to limit mill viscosity; after letdown, final ink viscosity is held below 25 s on a DIN 4 cup at 25 °C according to DIN 53211. Variations in oil absorption between 35 g/100 g and 50 g/100 g produce measurable differences in millbase flow and should be compensated by adjusting solvation resin content rather than by adding aromatic process oil, which can increase tack and slow solvent release.
Rheological profiling on a cone-and-plate viscometer according to ISO 3219 shows that a nitrocellulose-polyurethane millbase at 35 % pigment concentration exhibits low-shear viscosity between 80 mPa·s and 120 mPa·s at 25 °C. The flow profile is pseudoplastic; high-shear viscosity drops to 20 mPa·s to 30 mPa·s above 1000 s⁻¹, indicating effective transfer on rotogravure cylinders. When the same millbase is let down to 15 % pigment concentration, solvent retention and colour strength remain stable over 8 h of continuous print trials.
In sheet-fed lithographic inks, the pigment is evaluated for tack stability and emulsification behaviour on a Prüfbau printability tester. A tack window of 8 to 12 units at 1200 m/min is commonly targeted. Diarylide orange pigments of this class show moderate fountain-solution interaction; excessive wetting-agent dose can produce ink-in-water emulsification and roller stripping. The RWT grade is supplied with a surface treatment intended to reduce this tendency, but published data for the specific treatment is limited.
In water-based flexographic inks, the pigment is dispersed in a styrene-acrylic resin solution with a wetting agent package. Millbase pH is maintained between 8.0 and 9.0 to prevent flocculation; below 7.5, the dispersion may show a rapid increase in thixotropic body. Final ink viscosity is adjusted to 40 s to 60 s on a Zahn #2 cup at 25 °C. The product has been used in film-printing inks for low-density polyethylene bags and paper sacks, where it gives a clean mid-orange without the metamerism observed with some mixed yellow-naphthol formulations.
For industrial coatings, the pigment is typically dispersed in a short-oil alkyd or nitrocellulose lacquer at a pigment-to-binder ratio of 0.8:1 to 1.2:1. High-shear dispersion through a recirculating pin mill reduces the grind gauge reading to ≤ 10 µm more efficiently than low-speed dissolvers. The coating remains fluid at 25 °C, with a Stormer viscosity below 90 KU at 50 % solids. However, long-term exterior durability is not equivalent to high-performance orange grades.
The pigment is compatible with nitrocellulose, polyurethane, vinyl chloride-vinyl acetate copolymers, and acrylic resins. It is not recommended in high-acid-number maleic-modified rosin systems because acid-catalysed aggregate formation can occur during long storage. In solvent-based systems, a dispersant with an amine value below 20 mg KOH/g prevents flocculation while minimizing the risk of amine-promoted decomposition.
Compounding of Permanent Orange RWT into high-density polyethylene or polypropylene is carried out on a co-rotating twin-screw extruder with L/D 36:1 to 44:1. A split-feed configuration is used: pigment is metered into the polymer melt after the plastication zone to minimize thermal history. For masstone concentrates, pigment loading is 20 % to 40 % by weight; for finished-part dosing, the concentrate is let down to 0.5 % to 2.0 % by weight. The melt temperature must remain in the 180 °C to 200 °C range. Above 200 °C, measurable shade drift occurs within 5 min of residence time, and above 220 °C the pigment begins to produce decomposition-related plate-out on the die lip. Published data for this specific configuration is limited, but the thermal sensitivity is consistent with the diarylide chromophore class.
Injection moulding of the compounded material is performed with a melt cushion of 3 mm to 5 mm and back pressure of 120 bar to 180 bar. Mould temperatures of 30 °C to 60 °C are suitable for polypropylene caps and closures. Processing in nylon or polycarbonate is not recommended without prior thermal stability testing, because the melt temperatures of these polymers exceed the pigment’s stable window. When the powder has been stored at relative humidity above 60 %, a pre-drying step at 80 °C for 2 h is necessary before compounding into hygroscopic polymers such as ABS or PC/ABS blends. Residual moisture above 2.0 % produces steam volatilization at the die head and increases filter-pack pressure.
In blown-film extrusion of low-density polyethylene at die temperatures of 180 °C to 195 °C, the pigment shows acceptable bubble stability at a concentric loading of 1.0 % by weight. The gate size and screen pack should be 80 mesh or coarser to avoid screen-pressure buildup. Finer mesh packs can retain large pigment agglomerates and generate hotspots that accelerate thermal degradation.
The primary difference between C.I. Pigment Orange 34 and high-performance organic oranges lies in its fastness envelope. In full-shade printing inks, the pigment provides adequate lightfastness for indoor packaging and publication gravure; in exterior architectural coatings or automotive basecoat/clearcoat systems, the material is not a suitable replacement because its reduced weather fastness leads to visible fading after relatively short exposure. Benzimidazolone oranges such as C.I. Pigment Orange 36 exhibit improved heat stability and lightfastness in pale reductions, making them preferable for powder coatings and engineering plastics, but their raw-material cost is higher. Isoindolinone oranges such as C.I. Pigment Orange 61 provide excellent exterior durability and migration resistance, but they are typically reserved for two-component polyurethane and coil-coating applications requiring high-performance specifications.
| Property | C.I. Pigment Orange 34, diarylide | C.I. Pigment Orange 36, benzimidazolone | C.I. Pigment Orange 61, isoindolinone |
|---|---|---|---|
| Lightfastness full shade | 5 to 6 | 7 to 8 | 7 to 8 |
| Heat resistance in high-density polyethylene | 180 °C to 200 °C | 240 °C to 260 °C | 280 °C to 300 °C |
| Migration resistance in plasticized PVC | Moderate; may bleed at high plasticizer load | Very low | Very low |
| Relative raw-material cost | Low | Moderate to high | High |
| Typical application | Publication gravure, indoor packaging, polyethylene concentrates | Powder coatings, engineering plastics, automotive interior | Automotive exterior, coil coatings, architectural |
When selecting between grades, the evaluation should include lightfastness per ISO 105-B02, heat stability in the target polymer, bleeding in the intended solvent, and migration resistance under load at 60 °C for 7 d in a heated compression jig at 0.1 N/mm². The diarylide class generally shows moderate to poor resistance to aromatic solvents and plasticizers; in flexible PVC, the pigment may bleed under high plasticizer load unless a low-migration formulation is used. For applications requiring non-bleeding properties, a benzimidazolone or DPP class is preferred after raw-material cost assessment.
For polypropylene fibre spin-dyeing, C.I. Pigment Orange 34 is used only at low denier under limited residence time, because its thermal stability is marginal at fibre-spinning temperatures. The higher-melting benzimidazolone grades are preferred for fine-denier polypropylene and polyester fibre unless a cost constraint dominates.
Storage stability of Permanent Orange RWT is governed by moisture uptake and pH drift. The material should not be exposed to strong alkaline aqueous systems containing ammonia or primary amines because the resulting pH shift can destabilize dispersion and cause agglomeration in water-based ink formulations. In solvent systems, avoid combination with high-acid acrylic oligomers that may flocculate the pigment during letdown; a solubility-parameter-compatible dispersant should be used. The pigment should be stored in sealed containers at temperatures below 35 °C and protected from direct sunlight. Under these conditions, the dry powder is stable for at least 24 months from the production date, but moisture ingress can reduce flowability and raise oil absorption.
For food-contact packaging, regulatory clearances must be verified for the specific polymer, dosage, and use conditions; the pigment class is not automatically cleared under 21 CFR Part 178 or Commission Regulation (EU) 10/2011. Migration testing under the relevant compliance regime is required before commercial use. In non-food technical applications, the product may be handled using conventional particulate-hygiene controls; users should consult the current safety data sheet for occupational exposure limits and dust-control requirements.
