Adding white corundum (mainly composed of α-Al₂O₃) to UV coatings is a common functional filler choice. It is widely used in industries such as industry, electronics, and furniture by improving the physical properties and chemical stability of the coating. The following are the specific roles, application scenarios, and selection recommendations of white corundum in UV coatings:
—The role of white corundum in UV coatings
1. Enhancing wear resistance and extending life
The Mohs hardness of white corundum is 9.0, which is much higher than most coating substrates. It can significantly improve the wear resistance of the coating and is suitable for frequent friction scenarios (such as floor coatings and automotive coatings).
2. Improving coating hardness and scratch resistance
The hardness characteristics of white corundum make the coating surface more scratch-resistant, especially suitable for applications such as mechanical equipment and electronic product housings that require high surface hardness.
3. Improving adhesion and crack resistance
White corundum particles can enhance the bonding between the coating and the substrate, reduce coating shedding or cracking, and at the same time improve crack resistance and weather resistance to adapt to outdoor or harsh environments.
4. Optimize surface texture and function
– Gloss control: By adjusting the particle size of white corundum (such as F120# to 4000 mesh), the surface roughness of the coating can be adjusted to achieve a matte or high-gloss effect.
– Anti-slip performance: The uniform distribution of white corundum forms a micro-convex structure, which increases friction and is suitable for anti-slip coatings such as stairs and bathrooms.
5. Corrosion resistance and chemical stability
White corundum has stable chemical properties and is resistant to acid and alkali erosion. It can protect the substrate from corrosion and is suitable for corrosive environments such as ships and chemical equipment.
6. Improved thermal conductivity
The high thermal conductivity of white corundum helps the coating dissipate heat, improves high temperature resistance and cold resistance, and is suitable for high-temperature industrial equipment coatings.
—Available size for UV coating
1. Coarse particles (F80#-F120#)
Used to quickly remove surface defects or enhance anti-slip properties, commonly used in floor coatings and metal sandblasting pretreatment.
2. Medium-fine particles (F180#-F220#)
Balance wear resistance and surface finish, suitable for scenes requiring medium roughness such as furniture and electronic products.
3. Ultrafine powder (F240#-4000 mesh)
Used for high-gloss, high-precision coatings (such as denture sandblasting, optical device polishing) to achieve nano-level surface treatment.
| Typical Chemical composition | |
| AL2O3 | 99.3%min |
| SiO2 | 0.06% |
| Na2O | 0.3%max |
| Fe2O3 | 0.05%max |
| CaO | 0.04%max |
| MgO | 0.01%max |
| K2O | 0.02#max |
| Typical physical properties | |
| Hardness: | Mohs:9.0 |
| Maximum service temperature: | 1900 ℃ |
| Melting Point: | 2250 ℃ |
| Specific Gravity: | 3.95g/cm3 |
| Volume density | 3.6g/cm3 |
| Bulk density(LPD): | 1.75-1.95 g/cm3 |
| Color: | White |
| Particle shape: | Angular |
| Available size: | |
| FEPA | F230 F240 F280 F320 F360 F400 F500 F600 F800 F1000 F1200 F1500 |
| JIS | 240# 280# 320# 360# 400# 500# 600# 700# 800# 1000# 1200# 1500# 2000# 2500# 3000# 4000# 6000# 8000# 10000# |
| ITEM | D0（um） | D3(um) | D50(um) | D94(um) |
| #240 | ＜127 | ＜103 | 57.0±3.0 | ＞40 |
| #280 | ＜112 | ＜87 | 48.0±3.0 | ＞33 |
| #320 | ＜98 | ＜74 | 40.0±2.5 | ＞27 |
| #360 | ＜86 | ＜66 | 35.0±2.0 | ＞23 |
| #400 | ＜75 | ＜58 | 30.0±2.0 | ＞20 |
| #500 | ＜63 | ＜50 | 25.0±2.0 | ＞16 |
| #600 | ＜53 | ＜41 | 20.0±1.5 | ＞13 |
| #700 | ＜45 | ＜37 | 17.0±1.5 | ＞11 |
| #800 | ＜38 | ＜31 | 14.0±1.0 | ＞9.0 |
| #1000 | ＜32 | ＜27 | 11.5.±1.0 | ＞7.0 |
| #1200 | ＜27 | ＜23 | 9.5±0.8 | ＞5.5 |
| #1500 | ＜23 | ＜20 | 8.0±0.6 | ＞4.5 |
| #2000 | ＜19 | ＜17 | 6.7±0.6 | ＞4.0 |
| #2500 | ＜16 | ＜14 | 5.5±0.5 | ＞3.0 |
| #3000 | ＜13 | ＜11 | 4.0±0.5 | ＞2.0 |
| #4000 | ＜11 | ＜8.0 | 3.0±0.4 | ＞1.8 |
| #6000 | ＜8.0 | ＜5.0 | 2.0±0.4 | ＞0.8 |
| #8000 | ＜6.0 | 3.5 | 1.2±0.3 | ＞0.6 |
Application:
1. Industrial field
– Steel pipe sandblasting: White corundum F80# is used to remove the oxide layer and improve the adhesion of subsequent coatings.
– Mechanical sealing ring: High-purity white corundum powder (such as 99.8% Al₂O₃) is used for high-temperature resistant and wear-resistant coatings.
2. Electronics and medical
– Circuit substrate: Ultrafine white corundum (4000 mesh) enhances insulation and heat dissipation.
– Denture sandblasting: F180#-F240# white corundum is used for surface cleaning and texture optimization.
3. Architecture and home
– UV wood paint: Add white corundum F220# to improve wear resistance and anti-slip effect, suitable for floors and furniture.
– Anti-slip coating: By adjusting the particle size, the anti-slip requirements of stairs, swimming pools and other areas can be achieved.