KT-BR800 Bronze Gold Bronze Pigment — Copper Zinc Alloy, 800 Mesh

KT-BR800 is a mechanically processed copper-zinc alloy flake pigment, surface-treated to improve oxidation resistance and long-term stability. The 800 mesh particle size positions it in the mid-fine range — fine enough for smooth film formation in inks and spray coatings, but with sufficient particle surface area to produce a visible, reflective metallic effect.

Unlike pearlescent or mica-based alternatives, this is a true metallic pigment powder — opaque, highly reflective, and capable of producing a dense, gold-toned finish without requiring high loading levels. The copper-zinc alloy base gives it the characteristic warm bronze-gold hue, distinguishable from aluminum-based gold substitutes by its richer, more saturated color tone.

Product Series Overview

KT-BR800 is part of a broader bronze and gold-tone metallic pigment line. The full series covers multiple hue variants and mesh grades, giving formulators flexibility across applications that require different visual effects or surface finishes.

Particle size range across the full line runs from 200 to 1500 mesh. Coarser grades (200–400 mesh) are typically used in applications where visible sparkle is acceptable; finer grades (800–1500 mesh) suit smooth film systems and fine-detail printing.

Key Characteristics

• Strong golden metallic luster — warm bronze-gold tone with high reflectivity
• Good oxidation resistance — surface treatment slows color shift and tarnishing over time
• Good coverage — high hiding power at standard loading levels
• Wear resistance — maintains integrity under mechanical stress in film applications
• Acid and alkali resistance — compatible with a range of binder chemistries
• Weather resistance — suitable for both indoor and moderate outdoor exposure applications

Worth noting: oxidation resistance is relative. Copper-zinc alloys are inherently more reactive than aluminum. The surface treatment on KT-BR800 improves stability, but exposure to highly acidic environments or prolonged humidity will still accelerate oxidation over time. System design — including binder selection and topcoat — plays a significant role in long-term appearance retention.

Applications

KT-BR800 is used across a range of decorative and industrial contexts where a warm, gold metallic finish is required:

• Decorative paints and coatings — interior architectural finishes, furniture coatings, decorative metallic paints
• Printing inks — offset, gravure, and screen printing where a gold metallic effect is specified
• Powder coatings — dry blending into powder coat systems for architectural and industrial hardware
• Plastics — masterbatch or direct compounding for injection-molded or extruded parts requiring a metallic appearance
• Craft and art materials — metallic paints, specialty finishes

Practical Considerations for Formulators

In practice, copper-zinc alloy pigments require more care during formulation than aluminum-based metallics. The reactivity of the alloy means compatibility testing with binder systems is essential — particularly in waterborne formulations, where hydrogen gas generation is a known risk without appropriate passivation or binder selection.

For solvent-based systems, KT-BR800 disperses well in standard resins with gentle mixing. High-shear dispersion is generally not recommended — it can deform the flake geometry and reduce luster. A low-shear, post-add approach is preferred.

In powder coating applications, dry blending (bonding) rather than melt-mixing is the correct method. The metallic pigment powder should not go through the extruder, as heat and shear will damage the flake structure and cause significant luster loss.

Loading levels typically range from 5% to 20% depending on the target opacity and luster intensity. Coverage improves at higher loadings, but excessive levels can reduce film flexibility and adhesion — especially in thin-film ink systems.

FAQ

Q: Is KT-BR800 suitable for waterborne coating systems?
Copper-zinc alloys can react with water to generate hydrogen gas, which creates safety and formulation stability concerns. KT-BR800 is primarily suited to solvent-based and UV-curable systems. If waterborne application is required, contact contact@kolortek.com to discuss passivated or stabilized variants appropriate for aqueous environments.

Q: How does 800 mesh compare to coarser grades in terms of appearance?
800 mesh produces a finer, smoother metallic finish with less visible sparkle than 200–400 mesh grades. It is better suited to applications where surface smoothness and print definition matter more than coarse metallic glint — such as gravure inks or fine decorative coatings.

Q: What is the difference between KT-BR800 and the KT-AC antique bronze grades?
KT-BR800 delivers a clean, bright bronze-gold tone. The KT-AC antique bronze grades (e.g., KT-AC811, KT-AC800BX) have a more muted, aged appearance with cooler or darker undertones — intended for applications where a weathered or vintage metallic aesthetic is specified.

Q: Can KT-BR800 be used in plastic compounding?
It can be introduced via masterbatch at low shear conditions. Direct extrusion compounding is not recommended due to heat and mechanical shear degrading flake geometry. A surface coating masterbatch approach or dry blending prior to molding is preferred to preserve luster performance.

For technical data sheets, MSDS, COA, or sample requests, contact contact@kolortek.com. Custom particle size grades and OEM packaging are available on request.