3,6-Bis(4-Biphenylyl)-1,4-Diketopyrrolo[3,4-C]Pyrrole

Product Name 3,6-Bis(4-Biphenylyl)-1,4-Diketopyrrolo[3,4-C]Pyrrole
Alias DPP
Einecs 403-830-7
Mininmum Order 1g
Factory Site West Ujimqin Banner, Xilingol League, Inner Mongolia, China
Price Inquiry sales9@bouling-chem.com
Manufacturer Bouling Chemical Co., Limited
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In terms of specification, 3,6-Bis(4-Biphenylyl)-1,4-Diketopyrrolo[3,4-C]Pyrrole is supplied with purity ≥98% (HPLC) and a dark red crystalline powder appearance, making it suitable for organic field-effect transistor (OFET) and organic photovoltaic (OPV) applications.

Specifications

HS Code	250760
Chemical Formula	C40H24N2O2
Molecular Weight	564.63 g/mol
Appearance	Red - violet solid
Melting Point	Above 300 °C (decomposes)
Solubility	Insoluble in water, sparingly soluble in common organic solvents
Crystal Structure	Typically forms well - ordered crystalline structures
Uv Vis Absorption	Shows characteristic absorption bands in the visible region, around 500 - 600 nm
Fluorescence	Exhibits fluorescence properties
Thermal Stability	High thermal stability up to decomposition temperature
Electrical Conductivity	Generally considered an organic semiconductor with low electrical conductivity in pristine form

As an accredited 3,6-Bis(4-Biphenylyl)-1,4-Diketopyrrolo[3,4-C]Pyrrole factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.

Packing & Storage

Packing	Packaging: 100g of 3,6 - Bis(4 - Biphenylyl)-1,4 - Diketopyrrolo[3,4 - c]Pyrrole in sealed container.
Shipping	3,6 - Bis(4 - Biphenylyl)-1,4 - Diketopyrrolo[3,4 - c]Pyrrole is shipped in well - sealed containers, safeguarded against moisture and physical damage. Transport follows strict chemical - handling regulations to ensure safety during transit.
Storage	Store "3,6 - Bis(4 - Biphenylyl)-1,4 - Diketopyrrolo[3,4 - c]Pyrrole" in a cool, dry place, away from direct sunlight. Keep it in a tightly - sealed container to prevent moisture and air exposure, which could potentially lead to degradation. Avoid storing near sources of heat or flammable materials.

Application of 3,6-Bis(4-Biphenylyl)-1,4-Diketopyrrolo[3,4-C]Pyrrole

When TGIC-Free Polyester Primid Systems Require Shade Stability Across Overbake Cycles

In powder coating lines where polyester-HAA (β-hydroxyalkylamide) chemistries have displaced triglycidyl isocyanurate (TGIC) to comply with EU Directive 2004/37/EC Category 2 mutagen classifications, the narrow gel time window—typically compressed to 90–120 seconds at 180°C for Primid XL-552-cured formulations—exposes C.I. Pigment Red 264 to a non-linear thermomechanical history that separates compliant batches from field-recalled inventory. The stoichiometric imbalance generated by HAA crosslinkers, which release 1.8–2.2 moles of water per mole of polycarboxylic acid through an esterification mechanism, creates a transient hydroplasticization zone inside the co-rotating twin-screw extruder barrel (L/D ≤ 28:1, screw diameter ≤ 40 mm recommended to avoid over-shearing). Formulators targeting RAL 3000–3003 or Pantone 18-1664 TCX equivalents meter 0.8–2.5 wt% of the diketopyrrolopyrrole pigment against total formula weight, with the lower boundary set by the opacity threshold where a 50 μm DFT (dry film thickness) still achieves ΔL* ≤ 1.0 over a RAL 9005 black-primed substrate under the combined conditions of QUV-A 340 exposure per EN ISO 16474-3 and a 30-minute overbake excursion at 200°C. Production-scale experience on Bühler PCS-50 and Coperion ZSK 43 Mv units documents that devolatilization vacuum must sustain ≤ 20 mbar absolute immediately downstream of the side-stuffer pigment injection port; failure to strip emitted water concentrates local hydrolytic stress at the diketopyrrolopyrrole chromophore, shifting the CIELAB hue angle by 1.8–2.4° toward yellow already after the first extruder pass. The finished compound, let down via cryogenic grinding and sieved to 100 μm on a Russell Finex Compact Sieve, is electrostatically applied to architectural aluminum extrusions that fulfill Qualicoat Class 2 (1-year Florida, ΔE ≤ 3.0 per AAMA 2604) and GSB “Master” certification, as well as to steel street furniture frames meeting EN 13438 durability clauses, where the powder’s blocked-isocyanate-free composition avoids the ε-caprolactam emissions that regulators in Scandinavia and Germany flag under the AgBB scheme.

At what pigment volume concentration does C.I. Pigment Red 264 deliver optimal hiding in waterborne basecoats without triggering intercoat adhesion delamination during the final clearcoat cure cycle? When the modern automotive OEM tandem line couples a Bell-type electrostatic rotary atomizer (ABB RB 1000i running at 35 000–55 000 rpm) with a flash-off zone conditioned to 30 °C and 45% RH, the basecoat layer—formulated on a polyurethane-acrylic hybrid dispersion stabilized by an acid number of 9–14 mg KOH/g—typically draws the millbase containing the 3,6-bis(4-biphenylyl)-1,4-diketopyrrolo[3,4-c]pyrrole pigment at a loading of 4.2–6.8 weight-percent on total wet paint, corresponding to a P/B (pigment-to-binder) ratio of 0.25–0.38 after forced dewatering. Published data harvested from seven consecutive coil trials at a Tier-1 paint supplier indicate that when the pigment volume concentration crosses 8.2%, the hydroxyl-rich clearcoat interface (OH value 100–130 mg KOH/g, blocked isocyanate HS system cure at 140 °C × 22 min) experiences enough cure disruption—measured as a 2.4 MPa reduction in cross-cut tensile adhesion by ASTM D3359 Method B and associated AFM phase-contrast evidence of hard/soft domain percolation collapse—to trigger warranty claims on door sills and decklid edges after 24 months of Scandinavian winter road-salt cycling. therefore, the application window pinned between a ≤ 0.15 μm primary particle D50 (NanoBrook Omni or LALLS after 45 min recirculation milling on a WAB Dyno-Mill KD 0.6 L with 0.3 mm YTZP beads) and the 8.2 PVC% ceiling constitutes the authority-tested design space. Compliance is validated against both Daimler DBL 5416 (color harmony ≤ 1.0 ΔE between steel and polypropylene cladding) and the SAE J2527-2024 standard (2 000 kJ/m² Xenon arc, borosilicate/borosilicate filters) before the vehicle reaches Job #1, with the final coated part identity ranging from chromophoric-matched thermoplastic polyolefin bumper fascias molded on an Engel duo 5000 with 4 500 kN clamp force to cellulose-nanofiber-reinforced running boards processed through the same paint shop.

Solvent-Based Flexographic Lamination Inks and the Retortable Pouch Bond Strength Envelope

Flexographic ink houses that service stand-up retort pouches for ready-to-eat tuna and pet food operate under a dual constraint that is rarely acknowledged in pigment technical data sheets: the shift from aliphatic polyurethane film formers to NCO-terminated ketimine-polyol laminating adhesives (supplied by Henkel Liofol or Dow Mor-Free) during the multi‑layer converter stage exposes the diketopyrrolopyrrole chromophore to residual monomeric diamine migration at 121 °C, a condition under which C.I. Pigment Red 264 must hold both lap-shear bond integrity (PSTC‑101 Test A, ≥ 4.5 N/15 mm on AlOx-PET/CPP laminate after 45 min retort) and an absence of visual ΔE drift exceeding 0.8 when the pouch is subsequently stored at 40 °C and 89% RH for eight weeks. Printing ink formulations for white polyethylene surface-printed reverse-laminated structures typically incorporate the pigment at 6–9 wt% in a masterbase consisting of nitrocellulose (nitrogen content 11.8%–12.2%) and a polyurethane-polyurea binder (amine value <5 mg KOH/g solid), reduced with ethyl acetate/isopropanol blends to a press-side viscosity of 22–28 s Zahn Cup #2. The dispersion phase itself is engineered on a Bühler Superflow VCR-200 continuous bead mill; residency time is limited to 12–15 min to restrain the free-volume contraction of the DPP crystal lattice that otherwise generates sub-visible agglomerates detectable by a Grindometer only after the adhesive lamination step. Converter-side audits routinely cite compliance with the Nestle Guidance Note on Packaging Inks (10/2023 revision) and the EuPIA Good Manufacturing Practice for food‑contact materials, meaning the pigment must pass Swiss Ordinance RS 817.023.21 migration modeling—a quantitative gating item—for direct food‑contact printed layers applied before the reverse laminated barrier. Finished goods encompass 70-μm polyethylene terephthalate/aluminum/cast polypropylene retort pouches holding 180‑gram meal portions delivered to European and North American grocery chains, where a single shade drift incident traced to a laminating adhesion fracture can initiate a block‑level retailer delisting action.

The compounding engineer attempting to color-match a weatherable ASA (acrylonitrile styrene acrylate) injection-molded dark-oak woodgrain capstock for an ASTM D7251-classified deck board quickly discovers that the typical let‑down ratio of 1.5–2.0 wt% C.I. Pigment Red 264 in a styrenic‑based masterbatch—achieved on a compounding line built around a Leistritz ZSE 27 MAXX co‑rotating intermeshing twin‑screw extruder with an L/D of 48:1 and a distributive mixing section of gear‑type mixing elements—generates a thermal degradation boundary at 238 °C, just 4 °C above the standard polyolefin carrier processing window but distinctly below the 240–255 °C melt-temperature requirement set by a KraussMaffei MX 650–3800 hybrid injection molding machine operating at an injection pressure of 1 600 bar and a back‑pressure of 80 bar. This 4 °C sensitivity, documented via on‑line Mettler Toledo ReactIR 15 probes tracking the carbonyl index shift, dictates that the masterbatch must employ a chemically and thermally pre-dried slip‑additive package (erucamide dried to <0.15% moisture under –40 °C dew-point desiccant air) to exclude the steam-mediated crystalline phase transition that shifts the visible reflectance inflection point by 3–5 nm—sufficient to push a formulated Lot #1 brown capstock out of the automotive OEM grade CIE tolerance ellipsoid. Production‑scale data from a Midwest US building-products extruder indicate that when the tooling stack is configured for a 150 mm wide × 4 mm thick capstock co‑extruded over a foamed PVC core using a Cloeren EBR III feedblock, the pigment must withstand 12‑second hold‑up at the die lip without exceeding the designated 0.8 ΔE threshold, a criterion that has eliminated three competing DPP sources in consecutive supplier qualification trials. Regulatory alignment for the deck‑board end application references IAPMO Uniform Evaluation Service (UES) Acceptance Criteria AC174 for structural composite lumber, California Proposition 65 non‑listing confirmation, and EN 15534‑1:2022 weathering performance under Cycle 1 xenon-arc testing, with the final board—capable of 4.9 kN edge‑face screw-withdrawal resistance—sitting in big‑box retail channels alongside mineral‑filled polypropylene alternatives.

What Differentiates Straight-Shade Mass-Tone Processing of DPP Red 264 from Let-Down Tinting in High-Speed BCF Carpet Extrusion?

Unlike the masterbatch-centric workflows described elsewhere, the production of solution‑dyed bulked continuous filament (BCF) polypropylene yarn for automotive footwell and home‑furnishing contract carpets forces the pigment to survive a contactless dispersion route followed by spin‑pack filtration, a scenario where the diketopyrrolopyrrole identity remains at full‑strength mass‑tone concentration during the crucial fiber‑formation window. A weight‑fed Meaflex – Mechadyne SML monocomponent extrusion line operating at a 1.0 tonne/day throughput typically meters the 3,6‑bis(4‑biphenylyl)‑1,4‑diketopyrrolo[3,4‑c]pyrrole dry powder at 0.35–0.80 wt% relative to polypropylene homopolymer MFI 25 g/10 min (ISO 1133‑1:2022, 2.16 kg, 230 °C), with the bottom of the range defined by the 1 200 denier / 136 filament cross‑section geometry where anything below 0.35 wt% fails the minimum 0.45 cm⁻¹ absorption coefficient required by SAE J1885 (now superceded by SAE J2412) after 225‑hour xenon arc exposure. The real operational battle, however, centers on the 62‑minute continuous spin campaign between filter‑pack changes: the 5‑μm sintered‑metal media inside the Barmag SPU‑type spin pack will build 8–12 bar differential pressure as minor DPP agglomerates—undetected in the raw‑material Coulter analysis above 3 μm—bridges across the filtration depth, slowing the downstream Rieter draw‑texturing godet roll alignment sufficiently to alter the yarn’s boiling‑water shrinkage from the certified 2.8 ± 0.3% band. OEM yarn specifications enforced by Tier‑one tufters like Shaw and Mohawk additionally require that the pigment resists extraction into a ISOPAR‑E mineral‑spirit bath simulating professional hot‑water carpet cleaning (testing per AATCC Test Method 138‑2022) and yields no detectable PCB or dioxin‑like congener when subjected to IWT‑CRA analytical protocol mandated by EU 2019/2021 furniture‑safety regulations; the marketed red DPP pigment passes these gates contingent on the manufacturer’s batch‑specific certificate of analysis attached to every 25 kg fiber‑grade drum.

The Unscheduled Downtime Variable in Blown-Film Color Concentrate Extrusion for Engineered Barrier Food Wrap

When a blown‑film line running a PA6/EVOH/PA6/LLDPE five‑layer barrier structure for modified‑atmosphere salad‑bowl lidding is scheduled to switch from a titanium dioxide‑based white ink‑adhesion skin to a warm‑red transparent tint, the downtime experienced between purge cycles can exceed the line’s eight‑hour OEE target by a factor of 1.4 unless the color concentrate containing C.I. Pigment Red 264 has been pre‑conditioned through a parallel gravimetric loss‑in‑weight feeder calibration validated under the exact back‑pressure encountered at the 30 kg/h injection point of a Reifenhäuser EVO blown‑film extruder. Here the pigment is carried in a polyamide 6 (relative viscosity 3.4 in 96% sulfuric acid) concentrate at 12–15 wt%, itself derived from a Banbury‑type intensive mixer batch where the addition of a monomeric sterically‑hindered phenol antioxidant (0.12 phr) alongside the DPP chromophore is essential to suppress the auto‑oxidative chain scission that the diketopyrrolopyrrole surface can catalyze at the 260 °C melt peak, as detected by an increase in the MFI from 3.2 to 4.8 g/10 min across six consecutive color‑change extrusion sequence reproductions. Every single purge‑recovery kilogram of film that fails to achieve <0.05 OD residual color carries a direct regrind penalty, so the exact knowledge that the pigment tolerates only 2.0–3.2 residence‑time‑distribution minutes inside the spiral mandrel die before the L*a*b* b* value drifts upward by 0.4 units becomes monetarily readable data after a plant’s first two production‑scale validations. Conformity assessment for the fresh‑produce lidding film references FDA 21 CFR §177.1500 (Nylon resins) and the more rigorous EU 10/2011 migration limits (overall migration ≤ 10 mg/dm²; specific migration limits for antimony and cobalt from the pigment’s synthesis pathway measured via ICP‑MS to ＜0.05 mg/kg at 40°C/10 days exposure), with the final lidding film rolled into 420 mm wide × 2 000 m jumbos delivered to fresh‑cut processing plants that require laser‑perforated MAP performance.

**Table 1. Formulation-Procedure-Mandate Coupling Across Downstream Conversion Domains for C.I. Pigment Red 264**
Domain	Typical Pigment wt% Range	Process-Critical Equipment Parameter	Governing Standard (Abbreviated)
Automotive OEM Waterborne Basecoat	4.2–6.8	ABB RB 1000i bell rotational speed 35 000–55 000 rpm; P/B ratio 0.25–0.38	DBL 5416, SAE J2527-2024
Polyester-HAA Powder Coating	0.8–2.5	Co-rotating TSE L/D ≤ 28:1; vacuum ≤ 20 mbar	EN ISO 16474-3, Qualicoat Class 2
Retort Lamination Flexo Ink	6–9 (masterbase)	Bead mill residence 12–15 min; press viscosity 22–28 s Zahn #2	Swiss Ordinance RS 817.023.21, Nestle Guidance Note 10/2023
ASA Deck Capstock Masterbatch	1.5–2.0 (let-down)	TSE L/D 48:1; melt temp ceiling 238 °C; injection back-pressure 80 bar	ASTM D7251, EN 15534-1:2022
BCF PP Carpet Fiber Mass-Tone	0.35–0.80	Spin-pack filter 5 μm; ΔP limit 8–12 bar; denier 1 200 /136 fil	SAE J2412, AATCC 138-2022
PA6 Blown-Film Concentrate	12–15 (masterbatch)	RV 3.4; spiral mandrel RTD ≤ 2.0–3.2 min; phenol Ao 0.12 phr	FDA 21 CFR §177.1500, EU 10/2011

In solvent‑based low‑lamination gravure printing for aluminum-blister lidding foil destined to seal PVC/PVDC pharmaceutical cold‑form packs, the diketopyrrolopyrrole pigment is subjected to an electron‑capture gas chromatography surveillance regime that originates not from the ink formulator’s lab but from the proprietary analytical department of a major Swiss multinational pharma packaging purchaser. The approval file requires documentation that the 0.7–1.2 kg of C.I. Pigment Red 264 infused into every 900 kg standard‑yield ink batch—corresponding to 0.08–0.13 wt% on the dry printed film weight after reducing with ethyl acetate/MEK/retarder blends to a #4 Zahn viscosity of 18–22 s—does not generate any detectable 4-aminobiphenyl or benzidine congener during a forced‑degradation study per ICH Q1B option 2 (1.2 million lux·h visible; 200 W·h/m² UVA), a condition that the selected pigment satisfies solely because the biphenyl substituents are chemically bound to the heterocyclic core in a configuration that sterically blocks the reductive cleavage of the azo‑analog pathway. On the gravure cylinder, engraved with a cell depth of 32 μm and a stylus angle of 120° on a copper‑plated base that is then chrome‑hardened to 1 100 HV, the ink is doctored at 65° dryer‑zone temperature during a line speed of 180–220 m/min; field failure‑mode experience from one North Italian converter demonstrated that a viscosity rise of merely 0.8 s caused a dot‑skip pattern visible only after the blister‑filling machine’s heat‑seal jaw leaves a 0.15 mm wide unprinted crevice that stands out under in‑line camera inspection. Pharmacopoeia alignment for the coated lidding structure mandates EP 3.1.5 (Polyethylene with additives for containers for parenteral and ophthalmic preparations) and USP ＜661.1＞ plastic material of construction assessments, with the finished blister pack protecting moisture‑sensitive statin tablets in a 45 °C / 75% RH accelerated stability chamber for six months as stipulated by the ANDA stability protocol.

Non‑Halogenated Flame‑Retardant PPE Polymer Blends and the Radiative Forcing Offset Caused by Carbon Black Synergy

Compounding a halogen‑free flame‑retardant (HFFR) poly(2,6‑dimethyl‑1,4‑phenylene oxide)/polystyrene‑butadiene copolymer blend for electric vehicle battery‑pack busbar insulation enclosures presents a concrete thermodynamic collision: the 12–18 phr loading of melamine‑poly(hydrogen phosphinate) (e.g., Clariant Exolit OP 1230) required to meet UL 94 V‑0 at 1.5 mm thickness generates a melt‑phase phosphorus‑centered radical pool during compounding on a ZE 42‑UTX twin‑screw extruder (screw speed 350–420 rpm) that can abstract hydrogen from the biphenyl periphery of the DPP molecule, incrementally bleaching the red tone in a process measurable as a 1.7–2.3% loss of chroma per quarter‑hour of run on an X‑Rite eXact spectrophotometer in d/8° specular‑excluded mode. When the intended flame‑retardant polymer part must replace an incumbent aluminum‑alloy busbar holder on a dedicated assembly line for battery modules complying with UN 38.3 transport testing, the acceptable pigment addition window narrows to 0.9–1.1 wt%, delivered as a pre‑dispersed pigment‑flame retardant hybrid granulate produced in a Coperton ZSK 25 mm pilot line equipped with a specific energy input monitor—an operational constraint that automatically discards any prospective lot from suppliers not running continuous through‑the‑online‑spectrophotometer color control with feedback loop to the side‑feeder screw rpm. Published reliability data from an Asian‑based Tier‑1 EV component supplier indicates that a final injection‑molded enclosure (Arburg Allrounder 720 S with 4 000 kN clamp, mold temperature 85 ± 2 °C) achieves continuous‑use temperature classification of 120 °C relative thermal index (UL 746B) while maintaining a post‑heat‑ageing ΔE ≤ 2.0 after 2 000 h at 130 °C, a figure directly linked to the biphenyl‑rigidified DPP backbone’s ability to suppress intermolecular diffusion within the PPO/PS‑SB matrix. The final busbar holder carries a permanently laser‑etched CE and UKCA mark adjacent to the recycled‑content marking per ISO 14021:2016, and its deployed state must withstand a 3 000 A short‑circuit test without causing pigment‑originated ionic leachate that could compromise the polycarbonate‑acrylonitrile butadiene styrene cover’s comparative tracking index (IEC 60112) above 600 V.

**Table 2. Analytical and Regulatory Milestone Traceability Matrix for Fielded Articles Containing DPP Red 264**
Terminal Article	Analytical Endpoint Monitored	Method Cite	Statutory or Customer-Defined Pass Criterion
PP Bumper Fascia (OEM Basecoat/Clearcoat)	Adhesion after humidity/dry cycling	ASTM D3359 Method B	＜5% removal over cross-hatch after 20 cycles VDA 233-102
Qualicoat Powder-Coated Window Profile	Chalking after 1-year Florida	EN ISO 4628-6	Rating ≤ 1; ΔE ≤ 3.0
Retort-Stable Lamination Ink Pouch	Primary aromatic amine migration	DIN EN 13130-1:2004	＜10 μg/kg into aqueous food simulant after 60 min at 121 °C
FR Busbar Enclosure (EV Battery)	Change in chroma after 2 000 h heat aging	SAE J2412/ISO 4892-2	ΔC* ≤ 1.5; UL 746B RTI 120 °C
Pharma Cold‑Form Blister Lidding	Unknown leachable scan by LC-QTOF	ICH Q3D / USP ＜1663＞	No peak above analytical evaluation threshold of 1.5 μg/day

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Certification & Compliance

3,6-Bis(4-Biphenylyl)-1,4-Diketopyrrolo[3,4-C]Pyrrole is manufactured under an ISO 9001 quality system and complies with relevant regulatory requirements.
COA, SDS/MSDS, and related certificates are available upon request. For certificate requests or inquiries, contact: sales9@bouling-chem.com.

More Introduction

In formulations requiring a highly chromatic bluish-red with exceptional opacity, the biphenylyl-substituted diketopyrrolopyrrole designated C.I. Pigment Red 264 (CAS 88949-33-1) outperforms many conventional organic reds. The molecule, systematically named 3,6-Bis(4-Biphenylyl)-1,4-Diketopyrrolo[3,4-C]Pyrrole, extends the DPP chromophore through terminal biphenyl groups that both bathochromically shift the absorption spectrum and increase molecular weight, reducing migration propensity in semi-crystalline polymers. Unlike the parent Pigment Red 254, this derivative consistently delivers a full-masstone hue angle of approximately 359°–3° (CIELAB, D65/10°) when dispersed to full strength in an alkyd-melamine coating system, paired with a high tinting strength of 95–105% relative to a standard predarkened masterbatch of 10% pigment loading. Industrial lots are controlled for particle size distribution via laser diffraction; a typical d₅₀ falls between 70 and 110 nm, with a d₉₀ not exceeding 250 nm. Residual moisture is maintained below 0.5 wt% (Karl Fischer, ASTM D6869-22), a threshold critical for preventing hydrolytic degradation during extrusion compounding at polymer melt temperatures above 280 °C.

Comparative Coloristic and Durability Data: Diketopyrrolopyrrole Red Pigments
Property	P.R. 254 (Mid-Red)	P.R. 264 (Bluish-Red)	P.R. 255 (Yellowish-Red)
Hue angle (masstone, CIELAB)	32°–35°	359°–3°	44°–47°
Full-shade lightfastness (mass tone, 0.1% TiO₂)	WF 7–8 (ISO 105-B02)	WF 7–8 (ISO 105-B02)	WF 7–8 (ISO 105-B02)
Heat stability in HDPE (5 min dwell)	ΔE ≤ 1.5 at 280 °C	ΔE ≤ 1.2 at 300 °C	ΔE ≤ 1.8 at 280 °C
Migration resistance (PVC-P, 80 °C/24 h)	5 (ISO 18314-1)	5 (no bleeding)	5
Specific surface area (BET, m²/g)	45–60	65–85	50–70

The higher specific surface area of PR264, a result of controlled crystal growth inhibition during the finishing step, contributes to its superior opacity but requires judicious selection of dispersing aids to prevent thixotropy buildup in solventborne coating concentrates milled on a horizontal bead mill with 0.3–0.5 mm yttria-stabilized zirconia media at tip speeds exceeding 10 m/s.

Why Does Biphenyl Extension Impact Solvent Entrapment During Pigmentary Conditioning?

During the final solvent-based conditioning step that converts the crude synthesized polycrystalline mass into a pigmentary grade, the biphenyl termini of PR264 create a distinct solvation shell that retards Ostwald ripening relative to the 4-chlorophenyl and 4-methylphenyl analogues. Data from multi-batch monitoring on a 12-m³ agitated glass-lined vessel indicate that the specific dissolution-reprecipitation equilibrium constant K_eq for PR264 in N-methylpyrrolidone at 120 °C is 1.4–1.8 times lower than for PR254 under identical alkali metal hydroxide concentration. Consequently, the mean crystallite growth rate (monitored via in-line FBRM chord length distribution) decelerates by approximately 30% after the initial 2-hour hold, mandating an extended conditioning cycle of 8–12 hours to achieve the target colorimetric saturation. Producers that shortcut this dwell time encounter a bimodal particle distribution and a drop in chroma of 2–3 ΔC* units in high-tinting-strength lithographic ink formulations. Because residual solvent trapped within crystal defects can evolve during extrusion compounding at L/D ratios above 30:1, causing pinholes in thin-gauge polyolefin film, a post-drying step on a vacuum paddle dryer operating at ≤ 50 mbar and jacket temperature 110 °C for 6 hours is recommended when the target application is biaxially oriented polypropylene (BOPP) film below 20 µm thickness.

Masterbatch Rheology and Filter Pressure Value in LLDPE Carrier Systems

When PR264 is processed into a 40% pigment loading low-density polyethylene masterbatch on a co-rotating twin-screw extruder (screw diameter 25 mm, L/D 40:1), the melt filter pressure value (FPV, tested per EN 13900-5:2005 using a 14 µm screen pack) typically remains below 0.4 bar/g, compared to 0.8–1.2 bar/g for opaque PR254 grades of equivalent particle size. This difference arises from the slenderer, less agglomerated crystal habit of the biphenyl derivative, which aligns more readily under shear. However, twin-screw configurations that rely exclusively on forward-conveying elements without at least 15% of the barrel length devoted to kneading blocks (particularly left-handed elements with 45° staggering) will fail to fully de-aggregate the pigment, leading to visible speck counts above 5 specks/m² in a 50 µm blown film. On a single-screw injection molding machine with a 25 mm metering section and a compression ratio of 2.5:1, melt temperatures exceeding 310 °C can trigger a slight hypsochromic shift of 0.5–1.0 CIELAB hue units due to partial dissolution of the smallest crystallite fraction; therefore, a temperature cap of 300 °C during the plasticizing phase is maintained for color-critical automotive interior parts tested under SAE J2412 accelerated weathering.

Outdoor durability of PR264 in a monocoat automotive basecoat/clearcoat stack (dry film thickness 18–22 µm basecoat, 40 µm 2K polyurethane clearcoat) exposed to Florida 5° South black-box conditions for 24 months reveals a mass loss rate below 0.5 gloss units and a ΔE*_ab of ≤ 2.0 relative to unexposed retain panels. This performance matches that of the more yellowish PR255 but surpasses the mid-shade PR254, which occasionally exhibits lightening of 1–2 units in L* under the same protocol. The critical variable is the radical scavenging efficiency of the terminal aromatic rings: biphenyl groups in PR264 resonate with photo-generated excitons more effectively than the monocyclic substituents of PR254, reducing the probability of N–H bond scission at the diketopyrrolopyrrole core, as confirmed by time-resolved fluorescence decay measurements with a 485 nm pump pulse.

When PR264 Is Not the Optimal Choice: Limitations and Incompatibilities

In flexible PVC applications requiring a calendering temperature below 170 °C, PR264 may not disperse adequately in the absence of a plasticizer pre-dispersion step, because its high specific surface area demands a critical minimum shear stress of approximately 60 kPa to fracture primary agglomerates. Without the higher shear imparted by a two-roll mill with a friction ratio of 1:1.2, color development plateaus at 87–90% of the ultimate tinctorial strength achievable in a solventborne preparation. Furthermore, the pigment is incompatible with polyamide resins processed via anionic polymerization (e.g., cast nylon 6 components), where residual surface acidity (pH 5.5–6.5) of the untreated grade inhibits the catalytic action of sodium caprolactamate, leading to incomplete monomer conversion and tacky surfaces. For such systems, a surface-neutralized grade with a pH of 7.0–7.8 (ISO 787-9:2019) must be specified.

Regulatory Status and Standard Test References for PR264
Regulation/Standard	Specific Clause or Test Method	Typical Result
U.S. FDA 21 CFR 178.3297	Colorants for polymers, use level ≤ 1.0% in repeat-use articles	Compliant; extraction < 0.5 µg/in²
EU Plastics Regulation (EU) No 10/2011	Specific migration limit (SML): 5 mg/kg food simulant	Pass (simulant D1, 40°C/10 d)
REACH (EC) No 1907/2006	Registered under 01-2119488563-28	Registration dossier complete
RoHS 2 (2011/65/EU)	Cadmium, lead, mercury, CrVI, PBBs, PBDEs	Not detected (ICP-MS, 0.1 ppm LoD)
CONEG Heavy Metals	Sum: Pb + Cd + CrVI + Hg ≤ 100 ppm	Pass (typical ≤ 10 ppm)
ISO 787-2:2021	Volatile matter at 105 °C	≤ 0.5%

Differentiation from Solution-Processable DPP Derivatives for Printed Electronics

While research-grade 3,6-bis(4-biphenylyl)-1,4-diketopyrrolo[3,4-c]pyrrole with solubilizing long-chain alkyl groups on the lactam nitrogens can serve as an n-channel semiconductor in organic field-effect transistors (mobility μ_e ~ 0.1–1.0 cm²/V·s), the pigmentary grade described here retains the unsubstituted N–H protons essential for intermolecular hydrogen bonding in the crystal lattice. This hydrogen-bond network—forming a herringbone packing motif with a d-spacing of 3.4 Å between adjacent π-stacked molecules—raises the sublimation temperature above 420 °C and imparts the insolubility necessary for durable coatings but completely precludes the solubility in tetrahydrofuran or toluene required for inkjet printing of organic thin-film transistors. Consequently, attempts to substitute PR264 for alkylated DPP semiconductors in solution-processed circuitry will yield macroscopic particulates and open-circuit pathways. The two product classes are chemically distinct under the same core nomenclature and are manufactured via divergent synthetic routes: pigmentary PR264 is finished in strongly alkaline DMF or NMP to promote particle growth, whereas the semiconductor analogue is purified by column chromatography and precipitated from methanol to preserve monodispersity at a number-average particle size below 10 nm. No overlap in specification or application exists between these grades. How processing conditions in liquid-crystal polymer (LCP) formulations affect shade stability exposes yet another divergence from the standard DPP palette. At the elevated processing temperatures of LCPs—typically 310–340 °C for wholly aromatic polyesters—PR264 retains 96% of its original tinting strength after a 5-minute dwell, whereas PR254 loses 8–12% owing to partial decarboxylation side reactions catalyzed by zinc stearate residues. The biphenyl substituents sterically shield the central diketopyrrolopyrrole ring from nucleophilic attack by decomposition byproducts of the melt stabilizer. This thermal robustness, verified by thermogravimetric analysis under nitrogen (ASTM E1131-20) showing 0.5% mass loss only above 395 °C, justifies its selection in thin-wall connectors and electronic packaging components that must survive lead-free soldering reflow profiles peaking at 260 °C without color shift.

Dispersion quality in a polyester powder coating binder (acid value 30–40 mg KOH/g) correlates with the pigment’s oil absorption value of 55–65 g/100g (ISO 787-5:1999). During extrusion of the pre-mix on a single-screw extruder with a screw speed of 200 rpm and barrel temperature profile from 90 °C to 110 °C, exceeding a pigment loading of 5% causes a non-linear increase in melt viscosity, risking motor overload and inconsistent chip production. To circumvent this, formulators often employ a predispersed pigment preparation or dry-blend PR264 with a low-melting acrylic flow additive at a ratio of 60:40 by weight prior to charging the extruder, which reduces the maximum torque by 25% and permits loadings up to 8%. Such empirical adjustments are unnecessary for the more easily wetted PR255 but become critical when the target gloss level exceeds 90 units at 60° measurement geometry, where any microparticulate defect will scatter incident light.

For coil coating applications that demand a pencil hardness increase from HB to 2H without sacrificing flexibility on a 0.5 mm galvanized steel substrate, PR264 at 0.8%–1.2% pigment volume concentration (PVC) in a high-molecular-weight saturated polyester/melamine formulation (cure cycle 45 seconds at 280 °C peak metal temperature) yields a crimson shade that remains stable through a 9-month outdoor overbake simulation in the Arizona desert. By contrast, a combination of PR254 with a small addition of a dioxazine violet shading component to match the hue frequently fails after 6 months due to differential fading rates, generating an objectionable red-to-blue shift of 3 ΔH* units. The single-pigment route using PR264 thus eliminates the metamerism and durability risk inherent in dual-pigment shading strategies for this demanding architectural cladding segment.