Iriodin 500 Bronze Equivalent KT-500 Metallic Mica Pigment

The KT-500 series belongs to Kolortek's Metal Luster line of iron oxide–coated mica pigments. The color mechanism is straightforward: ferric oxide (Fe₂O₃) is deposited onto natural mica flakes, and the thickness of that coating determines the final hue — from bronze through red-brown, wine red, mauve, and coffee. KT-500 specifically targets the bronze end of this range.

These are not interference pigments. They behave as metallic pigments — opaque, warm-toned, with a reflective character that reads as a genuine metallic finish rather than a pearlescent shimmer. That distinction matters when you're specifying for decorative paints, floor coatings, or cosmetic formulas where coverage and tone consistency are the primary drivers.

In practice, KT-500 is the natural-mica variant. For applications demanding higher purity, improved whiteness of the substrate, or regulatory environments where fluorine-containing compounds are acceptable, the KT-7500 synthetic mica (Fluorphlogopite) series covers the same bronze palette.

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KT-500 Series — Model Overview

The full series spans several particle size ranges and tone variations. Below is the complete natural mica range:

Worth noting: the "Satin" variants (5–25 μm) produce a finer, more uniform finish — typically preferred in printing and cosmetic applications. The "Flash" variants (10–100 μm) give a coarser, higher-sparkle output that reads well in decorative paints and craft applications where visual drama matters more than smoothness.

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Synthetic Mica Bronze Series (KT-7500)

For applications requiring higher purity substrate or extended particle size ranges, the Fluorphlogopite-based KT-7500 series covers the same bronze palette:

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Applications

KT-500 is used across a wide range of substrates and systems. The most common end-uses:

• Decorative paints and coatings — architectural and industrial finishes requiring warm metallic tones with strong hide
• Epoxy floor coatings — KT-530 (Flash Bronze) and larger-particle variants are particularly effective here
• Cosmetics — eyeshadow, bronzer, and body formulas; iron oxide–based pigments are well-established in regulated cosmetic applications
• Nail products — gel and lacquer systems
• Soaps and bath products — dispersion in melt-and-pour or cold-process bases
• Screen and gravure printing — finer grades (KT-520, 5–25 μm) are preferred for ink compatibility
• Craft and art applications — resin casting, hand-poured candles, decorative concrete
• Countertop and artificial marble — acrylic or polyester stone applications

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Key Characteristics

A few properties that matter when specifying this type of pigment:

• Warm metallic luster: The Fe₂O₃ coating produces a distinctly warm, brown-gold visual tone — different from the cooler silver or true-gold interference pigments. The effect reads as metallic, not pearlescent.
• Strong concealing power: Unlike TiO₂-based interference pearls, iron oxide–coated mica provides meaningful hide at typical use levels. This is useful in applications where you need both metallic effect and opacity.
• Chemical and physical stability: The pigment is stable across the pH and temperature ranges encountered in most coating and cosmetic manufacturing processes.
• Color tuning via coating thickness: The same mica substrate can produce bronze, red-brown, wine red, mauve, or coffee depending on the Fe₂O₃ layer thickness — giving formulators a coherent palette from a single chemistry.
• Batch-to-batch consistency: Controlled coating deposition keeps color and particle distribution consistent across production runs.

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Practical Formulation Notes

Dispersion of KT-500 is generally straightforward. These pigments wet out readily in most solvent-borne and waterborne systems. That said, avoid high-shear dispersion equipment — extended high-speed milling will fracture the mica flakes and reduce the reflective surface area, dulling the metallic effect. Low-shear mixing or controlled planetary dispersion is preferable.

In cosmetic formulas, compatibility with standard cosmetic-grade binders, waxes, and oils is not typically a concern. For pressed powder formats, binder selection affects adhesion and payoff of the metallic effect more than the pigment itself.

For epoxy floor systems, pre-dispersing in a small quantity of solvent or resin before adding to the bulk mix helps achieve even distribution without dry agglomeration. Use levels vary by application, but 1–5% by weight is a common starting range for coatings; cosmetic applications often run higher.

If you're switching from Merck Iriodin 500 and running existing qualified formulas, request a sample lot from KT-500 first and run a side-by-side drawdown — particularly for critical color-match applications. The functional chemistry is equivalent, but minor substrate and coating differences can shift the final visual slightly depending on your system.

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KT-500 vs. Iriodin 500 — A Direct Note

Merck's Iriodin 500 Bronze is one of the most referenced bronze iron oxide mica pigments in industrial and cosmetic specifications. KT-500 is produced on the same functional principle: natural mica substrate, ferric oxide coating, 10–60 μm particle range. It is used as a direct alternative by formulators who need a verified drop-in at competitive pricing or improved supply chain flexibility.

For teams running Merck-qualified formulations and evaluating alternatives, MSDS, TDS, and COA documentation is available on request — which matters for regulatory submissions and internal qualification processes.

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Frequently Asked Questions

Q: Is KT-500 a true drop-in for Iriodin 500 Bronze in qualified cosmetic formulas?
Functionally, yes — same chemistry, comparable particle range. That said, for regulated cosmetic applications with locked formulas, you'll want to run a qualification batch and compare TDS specs side by side. Documentation (COA, MSDS) is available to support that process.

Q: What's the difference between KT-500 (natural mica) and KT-7511 (synthetic mica)?
The base substrate differs. Natural mica contains trace mineral impurities and has a slightly yellowish substrate color. Synthetic mica (Fluorphlogopite) is purer, whiter, and typically used when cleaner color saturation or higher-purity compliance is required — particularly in premium cosmetics or applications where substrate whiteness matters to the final visual.

Q: Which grade is recommended for screen printing inks?
KT-520 (Satin Bronze, 5–25 μm) is the practical choice for most printing applications. The finer particle distribution passes through screens more cleanly and offers better compatibility with the rheology of ink systems. Coarser grades like KT-530 are better suited for brush-applied or roller-applied coatings.

Q: Are these pigments suitable for skin-contact cosmetic applications?
Iron oxide–coated mica pigments are among the most established colorants in cosmetics. For specific regulatory compliance documentation applicable to your market, request the relevant COA and MSDS from our technical team.

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For samples, technical datasheets, or pricing on KT-500 and related grades, contact contact@kolortek.com. Specify your target application and particle size preference and we'll identify the closest match from the series.