How to prevent hard settling in untreated silica systems?

Incorporate a rheology modifier like Hydrophilic Fumed Silica or use higher viscosity resins to build a stable thixotropic suspension network.

GMATT 100 Series - SEMITECH | Silica Matting Agent Manufacturer

Key Features

Absolute Transparency: 100% free of wax treatments, guaranteeing zero hazing even in deep-color clear coats.
Flawless Recoatability: Lack of organic surface modification ensures perfect inter-coat adhesion in multi-layer systems.
High Matting Efficiency: Finely controlled pore volume yields maximum gloss reduction at minimal addition levels.
Rapid Curing Compatibility: Ideal for high-temperature baking enamels where wax sublimation could cause surface defects.

Applications

Coil Coatings & High-temperature Baking Enamels
Leather Finishes & Thin-film Plastics
Overprint Varnishes (OPV)
Premium Wood Coatings (requiring extreme clarity)

GMATT 100 Series: Grade Selector

The GMATT 100 Series offers the widest particle size spectrum (from ultra-fine 3.0 µm up to 18.0 µm). Select the perfect match for your Dry Film Thickness (DFT) to avoid surface roughness or loss of efficiency.

GMATT 130 / 135 d50: 3.0 - 4.0 µm

Recommended DFT: < 10 µm (Ultra-thin)

Extremely fine grades for leather finishes and OPV. Provides a highly transparent, silky touch. (130: High Oil Abs / 135: High PV).

GMATT 140 d50: 4.0 - 4.5 µm

Recommended DFT: 10 - 15 µm (Very Thin)

Perfect for thin-film clear coats and plastic coatings. Delivers high clarity without compromising film smoothness.

GMATT 155 d50: 5.5 - 6.3 µm

Recommended DFT: 15 - 25 µm (Medium)

The versatile standard. Excellent for general industrial and coil coatings. Available in standard and high Pore Volume (PV) options.

GMATT 114 d50: 14.0 - 18.0 µm

Recommended DFT: > 40 µm (Extra Thick)

Extra-large particles designed for heavy-duty industrial coatings, textured finishes, and high-build primers.

💡 Formulator Tip: Since the 100 Series is untreated, it provides the best clarity but may settle faster in low-viscosity systems. We recommend using it in higher-viscosity resins or pairing it with a rheology modifier (like fumed silica) to prevent hard caking.

General Properties

Typical properties for the untreated GMATT 100 Series. Manufactured under strict conditions to ensure high SiO₂ purity and consistent matting performance.

Parameter	Typical Value	Unit
Pore Volume	1.2 - 1.8	ml/g
Oil Absorption	220 - 370	g/100g
Loss on Drying (2h @ 105°C)	≤ 5.0	%
Loss on Ignition (2h @ 1000°C)	≤ 6.0	%
pH Value (5% aqueous)	6.0 - 8.0	-
SiO₂ Content (dry basis)	≥ 99.0	%
Surface Treatment	None (Untreated)	-

* Typical values only. Not for sales specifications. Refer to COA for batch data.

Frequently Asked Questions

Formulation advice and technical solutions from our R&D engineers.

When should I choose untreated silica over wax-treated matting agents?

Untreated silica (GMATT 100 Series) is mandatory when you need absolute maximum optical transparency (zero wax hazing), or when inter-coat adhesion is critical in multi-layer applications. It is also preferred in high-temperature coil coatings where wax sublimation might cause surface defects.

How can I prevent hard settling when using untreated silica?

Because untreated silica lacks steric hindrance from wax, it may settle faster in low-viscosity systems. To counteract this, formulate with a slightly higher viscosity resin, or incorporate an anti-settling agent / thixotropic agent (such as our Hydrophilic Fumed Silica) to build a stable suspension network.

How much silica matting agent should I add to my coating formulation?

The typical addition level ranges from 3% to 8% based on the total formulation weight. Untreated silica generally exhibits slightly higher matting efficiency per gram compared to wax-treated equivalents. We recommend conducting a step-ladder test to pinpoint your optimal dosage.

How does the particle size (d50) of matting agents affect coating transparency?

Matching the average particle size (d50) to your Dry Film Thickness (DFT) is critical. The GMATT 100 series offers an extreme range. Use our ultra-fine GMATT 130/135 (3.0-4.0 µm) for very thin films like leather finishes, and the massive GMATT 114 (14-18 µm) strictly for thick-film or textured heavy-duty coatings.

Ready to Test GMATT® 100 Series?

Download the full Technical Data Sheet (TDS) and Safety Data Sheet (SDS), or request a complimentary 500g lab sample for your formulation.

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GMATT 100 Series