White Fused Alumina Micropowder for Coatings
White fused alumina micropowder features excellent wear resistance, scratch resistance, acid and alkali resistance, high whiteness, UV resistance and other properties. Therefore, it is the most commonly used hard filler for industrial coatings, including epoxy flooring coatings, anti-corrosion paints, polyurethane coatings, powder coatings, wear-resistant topcoats and industrial anti-slip coatings.
I. Chemical Composition of White Fused Alumina Micropowder for Coatings
1. Chemical Composition (Strict control of iron impurities to avoid yellow discoloration)
| Composition | Control Standard | Conventional Test Value | Explanation |
|---|---|---|---|
| Al₂O₃ (Aluminum Oxide) | ≥99.0% | 99.3%~99.7% | Higher purity brings higher hardness and better chemical resistance |
| Fe₂O₃ (Ferric Oxide) | ≤0.08% | ≤0.05% | Extremely low iron content prevents yellowing and graying of light-colored and white coatings |
| SiO₂ (Silicon Dioxide) | ≤0.20% | ≤0.12% | Reduces oil absorption value of coatings and improves compatibility with resin |
| Na₂O (Sodium Oxide) | ≤0.30% | ≤0.25% | Reduces moisture absorption and avoids caking of coatings during storage |
| CaO, MgO, K₂O | Single component ≤0.05% | Trace amount | Ensures chemical inertness |
| S, P | ≤0.003% | Ultra-low content | No sulfur precipitation, compatible with anti-corrosion systems |
2. Physical Properties of White Fused Alumina Micropowder for Coatings
| Physical Parameter | Index |
|---|---|
| Mohs Hardness | 9.0 (much harder than calcium carbonate, talc powder and quartz powder) |
| True Density (Specific Gravity) | 3.90~3.95 g/cm³ |
| Bulk Density | 1.75~1.95 g/cm³ |
| pH Value | 7.0~8.0, neutral to weakly alkaline |
| Melting Point | 2050~2250℃, high temperature resistant |
| Oil Absorption Value | Relatively low, enabling good fluidity of slurry and low thickening tendency |
| Appearance | Pure white powder with uniform color and no black spots |
| Corrosion Resistance | Resistant to strong acids, strong alkalis and various organic solvents |
| Weather Resistance | Anti-ultraviolet, anti-chalking, no aging or discoloration for outdoor use |
II. Common Particle Size Specifications of White Fused Alumina Micropowder for Coatings (Mesh & Micron Conversion)
General national standard mesh sizes are adopted. Customization in accordance with FEPA and JIS standards is available. It features narrow particle size range and concentrated particle size distribution to prevent paint film scratches caused by oversized particles.
Matching Table of Main Mesh Sizes
| Mesh Number | Median Particle Size D50 (μm) | Application Scenarios for Coatings |
|---|---|---|
| 240# | 70-78 | Wear-resistant flooring |
| 280# | 60-68 | Wear-resistant flooring |
| 320# | 52-58 | High-build wear-resistant flooring, anti-slip primer, heavy-duty anti-corrosion coating |
| 400# | 37-42 | General wear-resistant topcoat, epoxy self-leveling floor |
| 600# | 25-29 | General industrial topcoat, polyurethane anti-corrosion paint |
| 800# | 17.5-21 | High-gloss coating, plastic paint, hardware baking finish |
| 1000# | 15-17μm | High-end light-color paint, powder coating, matte paint |
| 1200# | 11.5-13.5μm | Ultra-fine high-gloss topcoat, coating for mobile phone and metal casings |
| 1500#~3000# | 2-10.5 | Ultra-thin clear coat, mirror finish coating, ceramic glaze coating |
Full optional particle sizes for white fused alumina micropowder for coatings:
240#, 280#, 320#, 400#, 500#, 600#, 800#, 1000#, 1200#, 1500#, 2000#, 2500#, 3000#, 4000#, 6000#
III. Core Functions in Coatings
Outstanding Wear and Scratch Resistance
It forms a rigid hard skeleton inside the paint film and raises the pencil hardness of coatings from regular H to 4H~6H. Wear resistance is greatly improved. The coating resists friction, gravel impact and sandpaper scratching, extending the service life of flooring, mechanical equipment housings and pipeline topcoats significantly.
Improved Compactness and Anti-corrosion Performance
Angular particles interlock with resin and fill tiny pores in the paint film, lowering penetration of water, salt spray and corrosive substances. It is ideal for marine anti-corrosion coating, chemical equipment paint and steel structure anti-rust coating with remarkably enhanced salt spray resistance.
Stable Color, Compatible with Light-colored Coatings
High whiteness and low iron content deliver pure white without yellowing, avoiding discoloration of white, light gray and colorful topcoats. Unlike brown fused alumina (prone to yellowing) and quartz powder (prone to graying), it is the only viable fused alumina filler for high-end colored coatings.
High Temperature Resistance and Anti-aging Weatherability
It will not soften under high temperatures, and remains free of chalking, cracking and discoloration under long-term outdoor sunlight exposure. Suitable for topcoats of high-temperature equipment, outdoor curtain wall coatings and photovoltaic protective coatings.
Adjustable Matte Effect and Anti-slip Texture
Coarse grades are applied to anti-slip flooring and anti-slip walkway paint; fine grades create matte and semi-matte effects as a substitute for matting powder with far better wear resistance than conventional matting agents.
Optimized Construction Performance
Good thixotropy prevents sagging during spray and roller coating. Water-classified powder boasts excellent dispersibility without extra dispersing additives, applicable to water-based paint, oil paint, solvent-based paint and solvent-free epoxy paint.
IV. Applicable Coating Categories
Flooring Coatings
Epoxy wear-resistant flooring, anti-static flooring, polyurethane flooring, anti-slip ramp coating
Anti-corrosion Coatings
Zinc-rich anti-corrosion paint, heavy-duty pipeline anti-corrosion coating, marine paint, container topcoat, acid and alkali resistant coating for chemical equipment
Industrial Baking Finishes
Hardware baking paint, protective coating for aluminum alloy and stainless steel, topcoat for construction machinery
Powder Coatings
Outdoor electrostatic powder coating, high-temperature resistant powder coating, wear-resistant powder coating for pipelines
Special Coatings
High-temperature resistant coating, UV curable coating, FRP topcoat, ceramic glaze coating
Architectural Coatings
Weather-resistant exterior stone paint, anti-slip wall paint, waterproof wear-resistant topcoat
V. Product Advantages Compared with Ordinary Fillers
- Versus calcium carbonate / talc powder: Higher hardness, superior wear resistance and much better outdoor weather resistance.
- Versus quartz powder: Better toughness to avoid brittle cracking of paint film; free of free silica for environmental compliance.
- Versus brown fused alumina: Higher whiteness supporting light-color coating without yellowing and fewer impurities.
- Surface modification via silane treatment is available to strengthen bonding force with epoxy resin and acrylic resin and prevent powder agglomeration and sedimentation.
VI. Recommended Dosage
Total addition proportion in regular coating formula: 5%~20%
- General topcoat: 5%~10%
- Wear-resistant flooring and heavy anti-corrosion coating: 12%~20%
- Ultra-fine high-end matte coating: 3%~8%
VII. Supply Information
White Fused Alumina Micropowder for Coatings
– Zhengzhou haixu abrasives Co., Ltd.
Contact: cassielWang
Phone / WeChat/Whatsapp: +86 18039336686
Email: cassiel@zzhaixu.cnTel: 0086-371-63211281
Address:Gaocun Town, Xingyang Henan China
Contact: cassielWang
Phone / WeChat/Whatsapp: +86 18039336686
Email: cassiel@zzhaixu.cnTel: 0086-371-63211281
Address:Gaocun Town, Xingyang Henan China
Packaging: 25kg laminated woven bags, 1-ton bulk bags. Custom neutral export packaging is supported