Section
| HS Code | 912774 |
| Productname | Fast Scarlet 2BP |
| Colorindexname | Pigment Red 2 |
| Colorindexnumber | 12310 |
| Casnumber | 6410-32-8 |
| Einecsnumber | 227-930-1 |
| Chemicalclass | Monoazo naphthol pigment |
| Molecularformula | C23H15Cl2N3O2 |
| Molecularweight | 436.29 |
| Appearance | Red powder |
| Colorshade | Bluish red / scarlet |
| Specificgravity | 1.40-1.60 |
| Oilabsorption | 35-50 g/100g |
| Moisturecontent | <=1.0% |
| Watersolublematter | <=1.0% |
| Phvalue | 6.0-8.0 |
| Lightfastness | 4-5 |
| Heatresistance | 160-180 °C |
| Solubilityinwater | Insoluble |
| Application | Solvent-based inks, paints, plastics |
As an accredited Fast Scarlet 2BP factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Fast Scarlet 2BP is packed in 25 kg net moisture-resistant paper sacks with inner liners, clearly labeled and securely sealed for transport. |
| Container Loading (20′ FCL) | Chemical Fast Scarlet 2BP is securely loaded into a 20′ FCL container with proper labeling, stowage, and moisture protection for safe transport. |
| Shipping | Fast Scarlet 2BP is typically shipped in well-sealed, labeled containers as a non-hazardous solid. Protect it from moisture, heat, and direct sunlight. Follow the SDS and applicable DOT/IMDG/IATA regulations; no special dangerous-goods classification is normally required unless product-specific data indicate otherwise. |
| Storage | Store Fast Scarlet 2BP in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep containers tightly closed when not in use to prevent dust and moisture ingress. Segregate from strong oxidizers, acids, and bases, and avoid contact with food, feed, and drinking water. Use appropriate containment and label containers clearly. |
| Shelf Life | Shelf life is typically two years when stored in a cool, dry, well-ventilated area away from direct sunlight and moisture. |
The masterbatch is produced with Fast Scarlet 2BP at 40 wt% in a polypropylene carrier on a co-rotating twin-screw extruder with an L/D of 40:1 and a side feeder for pigment introduction after the carrier melting zone. Feed stability becomes a controlling variable when the dry pigment has a bulk density below 0.35 g/cm³, because bridging in the loss-in-weight feeder hopper causes pellet colour variation at the downstream moulding machine. A PP homopolymer carrier with a melt mass-flow rate of 25 g/10 min measured to ISO 1133-1:2022 at 230°C and 2.16 kg is pre-blended with 4–6 wt% maleated wax to control surface wetting, while the melt temperature is held at 220–240°C and screw speed at 400–600 rpm. The letdown ratio at the injection moulder is 1.0–1.5 wt% for caps, closures and appliance trim, producing a target red shade without increasing melt viscosity beyond the permitted process limit. Barrel residence time above 260°C is treated as a critical threshold because published supplier bulletins for this lake pigment indicate shade dulling and yellowing under prolonged hot-runner cycles; validation on the actual tool is required before production release. Extraction of low-molecular-weight binder and additive residues from the finished article is assessed by VDA 277 where automotive interior parts are involved; published data for this specific grade under that procedure are limited. No claim for indirect food contact is made unless the masterbatch producer supplies migration data under EU 10/2011 for the final article with the exact carrier and letdown resin.
| Control point | Typical window | Measurement standard or equipment |
|---|---|---|
| Pigment loading in masterbatch | 40 wt% | Gravimetric batch record |
| Carrier melt mass-flow rate | 25 g/10 min | ISO 1133-1:2022, 230°C/2.16 kg |
| Melt temperature at die | 220–240°C | IR pyrometer or melt thermocouple |
| Screw speed | 400–600 rpm | Twin-screw extruder control system |
| Letdown ratio in injection moulding | 1.0–1.5 wt% | Gravimetric dosing unit |
| Critical threshold | 260°C residence | Hot-runner validation trial |
Once the plasticizer pre-mix has reached 80–90°C, Fast Scarlet 2BP is added at 0.3–0.8 phr during high-speed mixing and before the compound is fluxed on a two-roll mill at 150–165°C and calendered into film of 0.10–0.25 mm. Because the pigment is a calcium lake, the melt temperature is kept below 185°C to avoid pressure-induced shade drift in the calendering nip; long heat history at 200°C is a documented failure mode showing progressive reddish-orange migration toward brown in flexible PVC. The grade is typically combined with calcium-zinc stabilizers rather than lead-based systems, since sulphur-containing lead stabilizers may form dull lead sulphide surface films that mask visible red colour intensity. End products include advertising tarpaulin coated fabrics, furniture edge-banding foils, and synthetic leather topcoats where abrasion resistance is checked by ISO 4649 and where colour change after humid heat exposure is measured by ISO 4611 at 70°C and 90% RH for 168 h. Regulatory screening for phthalate plasticizers is aligned with REACH Annex XVII entry 51 when the article is supplied to the EU market, and the pigment itself is controlled for heavy-metal impurities by the raw-material supplier certificate of analysis using inductively coupled plasma optical emission spectrometry; published standard limits for this exact pigment matrix are limited, so supplier-specific impurity ceilings apply.
Water-based flexo ink formulated with Fast Scarlet 2BP commonly uses a styrene-acrylic emulsion or solution resin neutralized with dimethylethanolamine to maintain pH 8.0–9.0. At pH above 9.5, the calcium lake surface undergoes partial ion exchange with the aminic base, producing a visible blue-shift in red hue and a loss of tinctorial strength; the change is measurable as a drop in colour strength below 95% on a drawdown against a control batch. Pigment loading in the finished ink is held at 10–15 wt%, and the mill base is processed on a high-shear rotor-stator mixer or a small media mill at 35–40°C to avoid temperature-induced desorption of the resin dispersant. End uses are paperboard folding cartons, corrugated preprint and multi-wall sacks printed by central-impression flexographic presses. Print density is checked to ISO 12647-6, and rub resistance of the dry print is evaluated by producer-specific Sutherland rub test or ASTM D5264; wet rub and alkali resistance at 10 g/m² deposit require the addition of crosslinking aziridine or zinc oxide type insolubilisers, but these must not be added before the pigment dispersion is fully stabilised, because premature resin crosslinking entraps coarse pigment agglomerates and creates visible specking. REACH screening for formaldehyde donors in the wet ink is performed according to EN 71-9 only when the finished print is used in toys; otherwise, lower-cost industrial packaging grades follow ISO 14001 environmental management documentation without additional toy-grade migration requirements.
Where powder coating batch correction replaces liquid tinting pastes, Fast Scarlet 2BP is introduced in a binder premix at 0.5–1.5 wt% before melt extrusion through a twin-screw extruder at 100–110°C jacket temperature and a screw speed of 300–500 rpm. The extrudate is cooled on a chill roll, flaked, and ground in an air-classifying mill to a top size below 100 μm; particle size distribution is controlled by laser diffraction and checked against ISO 8130-1 for powder coating granulometry. Curing is performed in a convection oven at 180–200°C for 10–15 min, depending on the polyester or hybrid resin system. Pigment heat sensitivity above 220°C is a defined restriction for this application; extended cure at 230°C produces a loss of chroma and a shift toward a burnt red-brown in overbaked panels. Finished powder coating films are evaluated for colour difference after overbake and for crosscut adhesion to zinc-phosphated steel by ISO 2409. Heavy-metal content is restricted through RoHS Directive 2011/65/EU Annex II limits for electrical and electronic equipment parts when such goods are coated, with lead, cadmium, mercury and hexavalent chromium each below 1000 mg/kg in homogeneous material and cadmium below 100 mg/kg. Common end products are appliance side panels, warehouse racking, tool cabinets and non-automotive general industrial surfaces; exterior-grade gloss retention is not claimed unless the formulator qualifies the system under ISO 2810 or ISO 16474-2.In rubber compounding, Fast Scarlet 2BP is incorporated in the early masterbatch stage at 1.0–2.0 phr, either as a direct dry powder or as a pre-dispersed paste, before acceleration and sulfur are added on a two-roll mill at 40–60°C. The mixing temperature is kept below 120°C because the monoazo calcium lake decomposes slowly in hot sulfur-cured nitrile and EPDM mixes, with visible shade fading and the possible formation of brown decomposition products in the vulcanizate. An internal mixer is used for large batches at a fill factor of 0.70–0.75, with a dump temperature of 100–110°C to prevent premature scorch and to preserve pigment hue. Vulcanization is carried out at 150–170°C for 5–15 min in compression moulds, depending on the cure system and part thickness. End products include extruded sealing strips, soleing compounds, matting, and industrial hoses where oil resistance or weathering is provided by the polymer matrix rather than by the pigment. Physical properties after curing are monitored by ISO 37 for tensile strength and elongation, and ISO 7619-1 for hardness; colour fastness of the vulcanizate after contact with aqueous detergent is tested by ISO 105-C10. Accelerated heat ageing at 70°C for 168 h is used to check shade retention; published data for this specific pigment in EPDM and nitrile are limited, so ageing limits are set from batch-specific laboratory data rather than universal pigment-class values. Regulatory documentation for rubber articles sold in the EU is aligned with REACH Annex XVII and EN 71-3 only when toy contact is possible.
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Fast Scarlet 2BP is the commercial designation for a calcium monoazo lake corresponding to C.I. Pigment Red 48:2, constitution number C.I. 15865:2, CAS 7023-61-2. The chromophore is formed by diazotization of 2-chloro-4-aminotoluene-5-sulfonic acid and coupling with 3-hydroxy-2-naphthoic acid, followed by precipitation as the calcium salt. The finished pigment presents a blue-shade scarlet mass tone with high tinting strength in polyolefin, plasticized PVC, rubber, and solvent-based ink systems. The product is typically supplied as a low-dusting powder or granular presscake; average primary particle size after finishing falls in the 0.05–0.10 µm range, but dry agglomerates require applied shear above 10,000 s⁻¹ during millbase letdown when dispersed in low-viscosity liquid ink vehicles. Non-resinated and resinated grades are available, with the resinated grade modifying apparent viscosity and gloss development in publication gravure inks through calcium rosinate adsorption at the pigment surface.
Typical certificate-of-analysis values include pH 6.0–8.0 measured by ISO 787-9, oil absorption 35–45 g/100 g by ISO 787-5, specific gravity 1.45–1.55 by ISO 787-10, and residue on a 45 µm sieve ≤0.50% by ISO 787-7. Surface treatment changes these values; rosin-coated lots can show oil absorption at the low end of the range and higher apparent bulk density. Water-soluble salts are controlled below 1.0% because residual calcium chloride from precipitation interferes with electrical conductivity in coil coatings and plasticized PVC insulation.
| Parameter | Method | Typical range |
|---|---|---|
| pH of aqueous extract | ISO 787-9 | 6.0–8.0 |
| Oil absorption | ISO 787-5 | 35–45 g/100 g |
| Specific gravity | ISO 787-10 | 1.45–1.55 |
| Sieve residue on 45 µm screen | ISO 787-7 | ≤0.50% |
| Water-soluble salts | ISO 787-3 | ≤1.0% |
Thermal exposure in polyolefin masterbatch requires a controlled residence-time profile. On a corotating twin-screw extruder with L/D 40:1 and screw diameter 40 mm, letdown into LLDPE at melt temperature 200°C and screw speed 400 rpm typically yields acceptable colour strength retention. Increasing melt temperature to 230°C produces measurable yellowing and chroma loss, consistent with metal-lake decomposition or crystal ripening. The effect is accelerated in high-shear hot-runner injection molding when gate shear exceeds 50,000 s⁻¹; thin-wall parts then show surface defects and brownish flow lines. Short residence time below 220°C is therefore recommended. Pre-drying at 80°C for 2 h is required when the pigment is stored at relative humidity above 60%, because moisture volatilization can create microvoids and screw slip during extrusion. This thermal boundary conflicts with polypropylene fiber spin-dyeing, where spinning temperatures of 240–280°C exceed the stable range of unmodified PR48:2; a heat-stable encapsulated grade is necessary if the pigment is selected for such applications.
Mass-tone drawdowns in plasticized PVC prepared according to ISO 787-1 show that Fast Scarlet 2BP is bluer than the barium analogue C.I. Pigment Red 48:1 and yellower than the strontium analogue C.I. Pigment Red 48:3. Equal weight substitutions therefore shift hue angle and require reformulation of tint bases. Specific gravity differences are commercially significant: the lower density of PR48:2 provides higher pigment volume per kilogram than the barium lake. In polyethylene masterbatch, a 30% calcium lake concentrate exhibits lower bulk density but higher melt torque than a barium lake concentrate of the same nominal loading because of differences in aggregate packing and melt wetting. The following comparative ranges are reported from supplier certificates and typical injection-molded plaque evaluations at 0.2% pigment loading in HDPE.
| Property | Fast Scarlet 2BP (PR48:2) | Barium analogue (PR48:1) | Strontium analogue (PR48:3) |
|---|---|---|---|
| Cation | calcium | barium | strontium |
| Specific gravity | 1.45–1.55 | 1.70–1.85 | 1.55–1.65 |
| Mass tone in plasticized PVC | blue-shade scarlet | yellow-shade red | bright blue-red |
| Heat stability in HDPE | ≤220°C | ≤200–220°C | ≤220–240°C |
| Acid resistance | moderate; avoid pH <4 | lower; barium release risk under acidic conditions | moderate; avoid pH <4 |
In flexible PVC calendering, Fast Scarlet 2BP is dispersed at loadings of 0.5–2.0 phr using a two-roll mill at 150–165°C. The pigment does not act as a PVC degradation catalyst when heavy-metal levels are controlled; nevertheless, in lead-free calcium-zinc stabilized formulations, dwell times above 8 min at 180°C can produce a slight yellow shift. The product resists migration in plasticized PVC under contact with white pigmented PVC at 80°C for 24 h, provided the plasticizer level does not exceed 45 phr dioctyl phthalate. In sulfur-cured rubber, the calcium lake is stable at cure temperatures of 160–170°C, but strongly alkaline amine-based accelerators such as diphenylguanidine should be avoided at high loadings because free amine can displace the calcium bridge and increase extraction of the dye acid under vulcanization conditions.
In publication gravure and flexographic inks, Fast Scarlet 2BP is milled in nitrocellulose-polyurethane vehicles. Dispersion on a horizontal bead mill with 0.8–1.0 mm zirconia beads at chamber temperatures of 35–45°C achieves Hegman grind 6–7 after 45–60 min residence as measured by ASTM D1210. The calcium lake structure is less solvent-resistant than high-molecular-weight organic reds; ketone-rich solvent blends containing more than 20% methyl ethyl ketone can extract dye acid and lower final gloss. In acrylic aqueous inks, unmodified PR48:2 may aggregate rapidly; surface-treated grades or anionic polymeric dispersants at 15–25% of pigment weight are required to maintain a stable pigment dispersion and prevent viscosity drift over storage periods longer than 30 days.
Lot-specific compliance for heavy metals should be verified against EN 71-3 migration limits for toy coatings and REACH Annex XVII restriction entries where applicable. The pigment is not formulated with lead, cadmium, mercury, or hexavalent chromium; however, residual barium from cross-contamination with PR48:1 production must be monitored by ICP-OES when food-contact or toy-grade documentation is required. For indirect food-contact use, 21 CFR 178.3297 may apply to colorants in polymers, but migration data for Fast Scarlet 2BP under 10/2011/EC simulants should be obtained from the supplier before use; published data for this specific configuration is limited. REACH registration status and any downstream restriction obligations must be confirmed against the lot-specific safety data sheet.
When Fast Scarlet 2BP is introduced as a single-pigment concentrate in polypropylene at 30% loading, premix viscosity increases nonlinearly with specific surface area and moisture content. A Brabender torque rheometer at 190°C and 60 rpm shows equilibrium torque approximately 18–22 N·m for a 30% masterbatch in LDPE, but the value rises to 30 N·m if residual moisture is not removed. In injection molding, screw back pressure should be maintained at 0.5–1.0 MPa to avoid unmelt agglomerates; a shut-off nozzle temperature above 230°C can cause degradation in the hot runner and lead to brown streaking in drip-free closures. Producing thin-wall cups with 1.2 mm wall thickness may require a mold temperature of 40–60°C and injection speed of 100–150 mm/s. The pigment does not significantly shift melt flow rate at 0.2% loading, but at 2% loading the MFR measured by ISO 1133-1:2022 is typically reduced by 5–10% relative to unpigmented resin.
Store Fast Scarlet 2BP in closed polyethylene-lined paper bags at 5–35°C and relative humidity below 60%. Bags exposed to high humidity should be resealed after each withdrawal because the calcium lake can absorb up to 2% moisture without visible change, which then causes screw slip during extrusion. A floor-scale audit of lot-to-lot shade variation using CIELAB ΔE*ab values below 0.8 on a 10 µm drawdown bar is recommended for sensitive cosmetic packaging lines. The product is incompatible with strong oxidizing agents and concentrated mineral acids; avoid dry blending with acidic silane coupling agents that can protonate the sulfonate group and increase water sensitivity in filled polyolefin compounds.
