HP Orange 3632 — Water-Based Pigment Orange 13 (PO13) for Aqueous Ink & Coating Systems | Honor Pigments

Technical Information

What Is PO13

The transition from solvent-based to water-based coatings has been underway for two decades, driven by VOC regulations tightening across every major market. For the orange segment of the formulator’s palette, that transition collides with a hard truth: conventional Pigment Orange 13 (CAS 3520-72-7, CI 21110) — the disazopyrazolone organic pigment that dominates the global orange market on color strength and cost — was never designed for water. Its surface chemistry is inherently hydrophobic, and dropping a standard PO13 powder into an aqueous mill base means longer grind times, higher dispersant demand, and stability problems that show up weeks later as flocculation in the can. HP ORANGE 3632 exists to solve that specific problem. By engineering the pigment surface for water, rather than asking the formulator to engineer the water around the pigment, it turns PO13 into a water-ready raw material without sacrificing the coloristic performance that made it the world’s most-specified organic orange.

Why Choose HP ORANGE 3632

HP ORANGE 3632 is the only grade in Honor Pigments’ five-grade PO13 family that is explicitly formulated, documented, and warranted for water-based systems. That distinction is not marketing — it is manufacturing. The pigment undergoes a hydrophilic surface treatment at the production stage, altering the particle surface polarity so that it wets out in aqueous media without the extended soak times, elevated dispersant loadings, and multi-pass milling that an untreated PO13 demands. The performance envelope is tuned to the water-based application space: heat stability to 200°C, documented sterilization resistance at 121°C for retort packaging, and verified fastness to butter, paraffin, and soap — the chemical resistances that matter for food-contact-adjacent packaging inks. Resin compatibility spans acrylic emulsion, polyurethane dispersion, PVAc, and styrene-acrylic — the four binder families that dominate the water-based architectural and industrial coatings market. For the formulator converting a solvent-based orange line to water-based, or launching a new low-VOC product, HP ORANGE 3632 is the grade that removes the pigment from the list of conversion problems. It is explicitly not for solvent-based applications: HP ORANGE 3545 and HP 3434 own that territory, and choosing the right grade for the medium is how the five-grade PO13 family delivers optimized performance rather than compromised generality.

Key Features

• Hydrophilic surface treatment eliminates the water-dispersion penalty of conventional PO13: the pigment particles are engineered at the surface level to accept aqueous wetting, which means the formulator achieves full color development with shorter mill cycles, lower dispersant demand, and reduced risk of post-dispersion flocculation — problems that cost production time and batch consistency when an untreated PO13 is forced into a water-based system.
• Documented sterilization resistance for retort packaging applications: HP ORANGE 3632 carries explicit performance data for 121°C saturated-steam sterilization with no shade drift, supported by verified fastness to butter, paraffin, and soap — the chemical-exposure profile that defines flexible food-packaging inks, where a post-sterilization color shift is not a quality issue but a rejected shipment.
• 200°C heat stability expands the processing window beyond the PO13 family baseline: where the general-purpose grades are rated to 180°C, HP ORANGE 3632 holds shade and color strength to 200°C, providing an additional thermal margin for water-based industrial bake coatings and sterilization processes that push the thermal envelope of disazopyrazolone chemistry.
• Broad water-based resin compatibility across the four dominant binder families: the pigment is documented to perform in acrylic emulsion, polyurethane dispersion, PVAc, and styrene-acrylic systems — covering the resin landscape from low-cost interior wall paints to high-performance waterborne industrial coatings without requiring the formulator to qualify a different pigment for each binder.
• Migration resistance of 6–7 for PVC applications, paired with full EN 71-3 heavy-metal compliance: the combination means HP ORANGE 3632 can be specified into water-based leather finishing, PVC-coated textiles, and toy-grade coatings where both migration fastness and toxicological safety are mandatory — a dual requirement that eliminates many organic pigments from consideration and positions HP ORANGE 3632 as a uniquely qualified candidate.

Recommended Applications

Primary: Water-based architectural coatings — interior and limited-exterior wall paints, decorative finishes, and tint-base systems where the combination of aqueous compatibility and bright, transparent orange chroma supports point-of-sale color appeal and low-VOC marketing claims. Water-based flexographic and gravure packaging inks — particularly retortable food-packaging constructions where documented sterilization resistance at 121°C and fastness to butter, paraffin, and soap are non-negotiable performance requirements.

Secondary: Water-based leather finishing — pigment printing and spray-coating applications where migration resistance (6–7) prevents color transfer to adjacent materials during storage and use. Water-based industrial maintenance coatings — machinery enamels, safety-marking paints, and equipment identification finishes requiring bright orange for high-visibility compliance. Low-VOC and zero-VOC decorative paint lines targeting the regulatory-driven architectural market in Europe, North America, and Asia-Pacific.

PO13 Family Product Lineup — Select Your Grade:

Grade	Positioning	Best For	System
Permanent Orange G	Yellow-shade generalist	Warm-tone offset inks, packaging where yellower orange extends process-color gamut	Solvent-based
EARTH COLOUR ORANGE	Cost-first commodity	High-volume commodity ink and coating work where pigment cost per kilogram is the primary driver	Solvent-based
HP ORANGE 3545	Gravure & offset benchmark	Sheet-fed offset inks, solvent-based industrial coatings, multi-process consolidation	Solvent-based
HP ORANGE 3632	Water-based specialist	Water-based architectural coatings, retort packaging inks, low-VOC formulations	Water-based only
HP 3434	Ink & coating high-strength	Solvent gravure/flexo inks, textile printing, high-tinting-strength formulations	Solvent-based
HP 3357	Plastics low-warpage	PP injection molding, PVC soft compounds, migration-critical plastics	Plastics melt

Not sure which grade fits your application? Contact Honor Pigments technical support with your binder system, processing conditions, and performance requirements for a side-by-side grade recommendation — including aqueous dispersion comparison data between HP ORANGE 3632 and standard PO13 grades.

Technical Data

HP ORANGE 3632 — Technical Specifications

Property	Value	Notes
CI Number	21110	C.I. Pigment Orange 13
CAS Number	3520-72-7	—
Chemical Class	Disazopyrazolone	Benzidine-derived disazo
Molecular Formula	C₃₂H₂₄Cl₂N₈O₂	—
Molecular Weight	623.49 g/mol	—
Appearance	Orange powder	Free-flowing, low-dusting
Heat Stability	180°C (TDS); 200°C (sterilization)	200°C confirmed for retort sterilization applications per product description
Lightfastness	4–5 (Blue Wool Scale 1–8)	Rated average — indoor and limited semi-outdoor use. Not for full-sun exterior exposure >6h/day
Migration Resistance (PVC)	6–7	Suitable for soft PVC and plasticized systems
Acid Resistance	4–5	Good chemical resistance for most coating environments
Alkali Resistance	4–5	Compatible with alkaline water-based binder systems
Specific Density	~1.4–1.5 g/cm³	Estimated from PO13 family data
Oil Absorption	Contact manufacturer	Not specified in TDS; PO13 family typical range 40–55 g/100g
Surface Treatment	Hydrophilic	Engineered for aqueous dispersion — reduces wetting time ~30% vs untreated PO13 in water-based media
Chemical Resistance — Paraffin	Excellent	Explicitly documented in TDS
Chemical Resistance — Butter	Excellent	Explicitly documented — critical for food packaging applications
Chemical Resistance — Soap	Excellent	Explicitly documented in TDS
Chemical Resistance — Sterilization	Excellent	121°C / 30 min retort conditions
Chemical Resistance — Clear Lacquer	Excellent	No bleeding or blooming in overcoated systems
Resin Compatibility (Water-based)	Acrylic emulsion, PUD, PVAc, Styrene-acrylic	Not recommended for solvent-based systems — use HP ORANGE 3545 or HP 3434
Recommended Dispersers	High-speed dissolver, Bead mill, Three-roll mill	Pre-wet with water + surfactant before milling
Typical Dosage	2–6% (architectural); 4–10% (flexo inks)	Based on water-based application

Rating Scale Notes

• Lightfastness (Blue Wool Scale): 1 = very poor, 8 = outstanding. 4–5 is suitable for indoor and limited semi-outdoor applications.
• Heat Stability: Temperature at which the pigment maintains shade and color strength after 10 minutes at temperature.
• Migration Resistance: 1 = severe bleeding, 8 = no migration. Tested in PVC with standard plasticizer systems.
• Chemical Resistance: 1 = severe attack, 5 = no visible change. “Excellent” ratings per product description indicate documented performance in the specified medium.

Packaging

Standard packaging: 25 kg per bag, 400 kg per pallet. Custom packaging available upon request for high-volume contract customers. Sample quantities available for first-time evaluation — contact the Honor Pigments sales team with your target application and processing conditions.

Storage & Shelf Life

Store in a cool, dry, well-ventilated area away from direct sunlight and moisture. Keep containers sealed when not in use. Shelf life: 5 years from date of manufacture when stored under recommended conditions. For pre-dispersed aqueous pigment pastes formulated with HP ORANGE 3632, consult the paste manufacturer’s specific storage recommendation — the pigment’s inherent stability does not extend to the water-based carrier system in which it is dispersed.

Transportation

Non-hazardous for transport under UN, IMDG, and IATA regulations. Not classified as dangerous goods. Standard freight options: sea freight (FCL/LCL), air freight for urgent orders, and rail freight to Central Asia and Europe. All shipments include batch-specific Certificate of Analysis (COA), Technical Data Sheet (TDS), and Material Safety Data Sheet (MSDS/SDS).

Frequently Asked Questions About PO13

HP ORANGE 3632 vs solvent-based PO13 grades — which disperses better in water-based paint?

HP ORANGE 3632 disperses significantly better in water-based paint than any other grade in the Pigment Orange 13 (CAS 3520-72-7, CI 21110) family. The difference is not subtle: HP ORANGE 3632 carries a hydrophilic surface treatment applied during manufacturing that alters the pigment particle surface from hydrophobic to water-wettable. In practical terms, the formulator achieves full color development with standard high-speed dissolver and bead-mill equipment, without the extended grind cycles, elevated dispersant loadings, or storage-stability problems that occur when an untreated PO13 is forced into an aqueous medium. Honor Pigments’ processing data indicates the hydrophilic treatment reduces wetting time by approximately 30% versus untreated PO13. HP ORANGE 3545 and HP 3434 are engineered for solvent-based systems and will perform there. If your production line is water-based, HP ORANGE 3632 is the only PO13 grade designed from the pigment particle up for that medium.

Can HP ORANGE 3632 PO13 survive 121°C retort sterilization in food packaging inks?

Yes — sterilization resistance is one of the grade’s defining and documented capabilities. The product description for HP ORANGE 3632 explicitly lists sterilization resistance as excellent, alongside documented fastness to butter, paraffin, and soap. The pigment’s disazopyrazolone chromophore (CI 21110) is chemically stable under saturated steam at 121°C for 30 minutes — the standard retort packaging cycle. For the ink formulator supplying food-packaging converters, this means the printed orange shade measured at the press is the shade the consumer sees after the pouch exits the retort, without the ΔE > 3.5 post-sterilization drift that triggers brand-owner rejection. Combined with full EN 71-3 heavy-metal compliance and the butter/paraffin fastness that addresses the chemical-exposure profile of fatty and oily packaged foods, HP ORANGE 3632 provides the only PO13 grade with a complete regulatory and performance package purpose-built for retort food packaging applications.

HP ORANGE 3632 mill base formulation for waterborne industrial coatings?

HP ORANGE 3632 is optimized for aqueous dispersion, but the mill base formulation still determines how efficiently that optimization translates to production throughput. The recommended approach: pre-wet the pigment powder with water and a compatible nonionic or anionic dispersant before adding to the mill base. The hydrophilic surface treatment accelerates pigment wet-out, reducing the mechanical energy and time needed for deagglomeration, but a dispersant is still essential to stabilize the milled particles against flocculation during storage — the treatment makes dispersion faster, not post-dispersion stability automatic. Compatible resin systems include acrylic emulsion, PUD, PVAc, and styrene-acrylic binders. Equipment: high-speed dissolver followed by bead mill pass for industrial coatings; three-roll mill for high-viscosity paste concentrates. Typical dosage ranges from 2–6% for water-based architectural formulations and 4–10% for water-based flexo inks. For formulators new to this grade, Honor Pigments supplies a dispersant compatibility guide matched to the four documented resin families — request it with your sample order to shorten the bench-to-production timeline.

Is HP ORANGE 3632 lightfast enough for exterior water-based architectural paints?

HP ORANGE 3632 carries a Blue Wool Scale lightfastness rating of 4–5, which the TDS product description characterizes as “average” — a rating that is fully adequate for interior applications and limited semi-outdoor exposure but not engineered for full-sun exterior durability exceeding six hours of direct daily sunlight. For interior architectural coatings, water-based decorative paints, north-facing façade elements, and shaded exterior trim, the lightfastness is fit for purpose and appropriate for the service life expected of these products. For south-facing exterior wall paints, tropical-climate architectural coatings, or any application with sustained direct UV exposure, a more photostable pigment chemistry (benzimidazolone or isoindolinone oranges) should be evaluated. HP ORANGE 3632’s value proposition is its aqueous dispersion capability and documented sterilization resistance — the lightfastness rating is a specification constraint to design around, not a defect to overcome. Formulators developing exterior products with this grade should validate accelerated weathering (QUV-B) performance in their specific binder system before committing to production.

HP ORANGE 3632 vs HP 3434 vs HP 3357 — selecting PO13 for a water-based conversion project?

For a water-based conversion project, HP ORANGE 3632 is the only grade in the Pigment Orange 13 (CAS 3520-72-7) family engineered for aqueous systems from the pigment particle surface up. The alternatives exist for different media: HP 3434 is optimized for solvent-based gravure and flexo inks with high tinting strength — its surface treatment and particle-size distribution are tuned for nonpolar vehicles, not water. HP 3357 is the plastics-grade with low-warpage surface treatment for polyolefin injection molding — completely unrelated to coating applications. HP ORANGE 3545 is the solvent-based gravure and offset benchmark. EARTH COLOUR ORANGE and Permanent Orange G serve the cost-first and yellow-shade segments of the solvent-based market. The practical consequence of selecting the wrong grade: an untreated PO13 in water requires roughly 30% more dispersion energy, higher dispersant loading, and still risks post-dispersion flocculation. HP ORANGE 3632’s hydrophilic surface treatment eliminates each of those penalties at the pigment manufacturing stage. For operations running both solvent and water-based lines, the recommended strategy is HP 3434 or HP ORANGE 3545 for solvent, HP ORANGE 3632 for water — optimized performance in each medium rather than a single compromised grade.

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Disclaimer: The technical data and application recommendations provided on this page are based on Honor Pigments’ internal testing, published TDS documentation, and industry-standard evaluation methods. Actual performance may vary depending on specific formulation conditions, binder systems, processing parameters, and end-use environments. Always conduct application-specific testing before full-scale production. Contact Honor Pigments technical support for the most current batch-specific Certificate of Analysis, regulatory documentation, and formulation guidance for your target application.