PB15:3 vs PB15:4

How standard beta phthalocyanine blue compares to the non-flocculating beta variant for waterborne paints, automotive coatings, and process inks.

PB15:3 and PB15:4 are the same chemistry (copper phthalocyanine, beta crystal form) but with different stabilization. PB15:4 is non-flocculating — it stays dispersed under shear and through long shelf life. The price premium is real; whether it's justified depends on your application.

Property PB15:3 PB15:4
ChemistryCopper phthalocyanine, beta crystalCopper phthalocyanine, beta crystal (non-flocculating treated)
CI CodeCI Pigment Blue 15:3CI Pigment Blue 15:4
CAS Number147-14-8147-14-8 (same)
ShadeGreenish blue (process cyan)Greenish blue, virtually identical to PB15:3
Lightfastness8/8 Blue Wool8/8 Blue Wool
Heat stability300°C+300°C+
Flocculation tendencyCan flocculate in waterborne and high-shear systemsResistant to flocculation
Stability under shearModerateExcellent
Storage stability in waterborne paintVariable; may need rework over timeStable for full paint shelf life
Cost tierStandardPremium (10-25% higher)
Primary useProcess cyan inks, solvent-borne paints, plasticsAutomotive basecoat, premium waterborne paints

When to choose PB15:3

Choose PB15:3 for the vast majority of applications — process cyan inks, solvent-borne architectural and industrial paints, plastic masterbatch (PVC, HDPE, PP), powder coatings, textile printing, construction. Industry-standard, cost-effective, well-understood. The default blue.

When to choose PB15:4

Choose PB15:4 specifically for: premium waterborne paints (where flocculation is a real risk), automotive basecoat (especially waterborne basecoat under high-shear pumping), high-shelf-life waterborne coatings, premium powder coatings where shade stability through cure matters most. The price premium is justified only when flocculation would actually be a problem.

FAQ

PB15:3 vs PB15:4 Common Questions

Is PB15:4 always better than PB15:3?

No. PB15:4 costs 10-25% more and provides flocculation resistance. If your application doesn't have a flocculation problem (most solvent-borne systems, dry powder coatings, plastics), PB15:3 gives identical color performance at lower cost. Pay the premium only when flocculation is actually causing shade drift in your system.

Can I switch from PB15:3 to PB15:4 mid-project for color match?

Yes. PB15:3 and PB15:4 have virtually identical shade and lightfastness — the difference is dispersion stability, not color. You can substitute without recalibrating your formulation, just expect to pay more for PB15:4.

Why does PB15:3 flocculate in waterborne paints?

Standard beta-form phthalocyanine has surface chemistry optimized for solvent-borne systems. In waterborne emulsions, the surface charges interact with the binder differently, allowing particles to slowly aggregate (flocculate) over shelf life. PB15:4 has surface treatment that prevents this. Some PB15:3 grades are also surface-treated for waterborne use — ask your supplier.

Need Help Choosing?

Share your binder system, processing temperature, and required performance — we'll recommend the right grade and ship a free 50-100g sample for qualification.


Get a Recommendation
Contact PersonBhargav Kanani
Phone / WhatsApp+91 76008 95971
KDC AssistantAsk me about pigments
Hello! I'm the Kanani Pigment & Paste AI assistant. Ask me about our pigments, applications, pricing or exports!