Infrared Reflecting TiO₂. Exterior wall coatings are no longer evaluated only by color, hiding power and weather resistance. In hot climates, urban buildings, solar-reflective exterior wall coatings and public infrastructure, coating formulators are increasingly asked one additional question:
Can the coating help reflect solar heat without limiting color design?
This is where infrared reflecting TiO₂ becomes valuable. Unlike conventional pigmentary TiO₂, infrared reflecting titanium dioxide is designed to improve reflection in the near-infrared region, which is closely related to solar heat build-up. For exterior wall coatings, this can help formulators develop cool façade coatings, thermal insulation architectural coatings and colored exterior coatings with better solar reflective performance.
Inter-China Chemical offers two infrared reflecting TiO₂ products for this purpose: IR-600 and IR-1000. Both are rutile TiO₂-based materials designed for heat-reflective applications, but they are not positioned for exactly the same color systems.
In short, IR-600 is more suitable for white, light-color and medium-lightness exterior wall coatings, while IR-1000 is more suitable for vibrant, dark and broad-color solar-reflective exterior wall coatings where color freedom is a key requirement.
What is infrared reflecting TiO₂?
Infrared reflecting TiO₂ is a functional titanium dioxide material designed to reflect near-infrared solar radiation. Solar radiation includes ultraviolet light, visible light and infrared light. The infrared region contributes significantly to solar heat. By increasing near-infrared reflection, coating systems can reduce heat absorption while maintaining the required visual color.
For exterior wall coatings, this is important because the wall surface is exposed to long-term sunlight. A coating that reflects more near-infrared radiation can help reduce surface heat build-up, especially in colored solar-reflective exterior wall coatings where traditional dark pigments often absorb more solar energy.
Why exterior wall coatings need different IR TiO₂ choices
A white exterior wall coating and a dark blue solar-reflective exterior wall coating do not behave the same way under sunlight. The pigment system, color shade, L* value, binder system and film structure all affect total solar reflectance and near-infrared reflectance.
This is why one infrared reflecting TiO₂ grade is rarely the best answer for every color system. The more practical question is:
Which grade is better for the target color range and coating design?
For IR-600 and IR-1000, the answer can be summarized as follows.
| Application requirement | Recommended product | Reason |
|---|---|---|
| White exterior wall coating | IR-600 or IR-1000 | Both can support high reflectance systems |
| Light-color façade coating | IR-600 | Strong match for white and light-color systems |
| Medium-lightness exterior coating | IR-600 | Suitable for moderate L* architectural coatings |
| Dark or vibrant colored solar-reflective exterior wall coating | IR-1000 | Broader color design flexibility |
| Color systems with L* 20–96 | IR-1000 | Designed for wide lightness range |
| Formulations requiring simple color adjustment | IR-1000 | Can work as infrared reflective base paint or color masterbatch |
| Coatings requiring durable outdoor performance | IR-600 or IR-1000 | Both are designed for exterior heat-reflective applications |
IR-600 for white and medium-lightness exterior wall coatings
IR-600 is an infrared reflecting TiO₂ designed for white or light-color coating and plastic systems. It is especially suitable for coatings where the formulator wants a balance between high reflectance, durability and practical processing.
According to Inter-China Chemical’s IR-600 technical data, IR-600 has a TiO₂ content of 90%, rutile crystal form, dense SiO₂ and Al₂O₃ inorganic treatment, oil absorption of 19 g/100 g and specific gravity of 4.0 g/cm³. The dense surface treatment supports durability, which is critical for exterior wall coatings exposed to sunlight, rain and weathering.
Architectural coating tests also confirmed the strong reflectance performance of IR-600. In a white coating system, IR-600 achieved L* 97.31, TSR 0.87 and NIR 0.88. For a medium-lightness architectural coating system, the result was L* 79.27, TSR 0.64 and NIR 0.80. These results make IR-600 a practical option for white, light-color and medium-lightness exterior wall coatings.
For formulators, the positioning is clear: IR-600 is not mainly about making very dark colors cooler. Its value is in stable reflectance performance for light and medium-light architectural coating systems.
IR-1000 for vibrant and dark colored exterior wall coatings
IR-1000 is positioned differently. It is designed for broader color systems, especially where color freedom is important.
According to the IR-1000 product catalog, IR-1000 can be used to produce infrared reflecting products with L* between 20 and 96. This means it can support not only white and light colors, but also grey, blue, yellow, green, brown and other colored exterior wall systems.
For architectural reflective thermal insulation coatings, the catalog shows several RAL color examples:
| Color system | IR-1000 dosage | L* | TSR 300–2500 nm | NIR 780–2500 nm |
|---|---|---|---|---|
| RAL 9016 Traffic white | 2% | 96.04 | 0.86 | 0.83 |
| RAL 7010 Tarpaulin grey | 10% | 43.00 | 0.29 | 0.48 |
| RAL 5005 Signal blue | 5% | 36.30 | 0.36 | 0.65 |
| RAL 1005 Honey yellow | 8% | 65.95 | 0.52 | 0.67 |
| RAL 6029 Mint green | 6% | 44.00 | 0.31 | 0.55 |
| RAL 8004 Copper brown | 7% | 41.52 | 0.37 | 0.59 |
These data points are useful because they reflect real formulation concerns. Exterior wall coatings are rarely just white. Developers, architects and coating brands often need yellow, blue, green, brown, grey or low-lightness colors. IR-1000 gives formulators more room to design colored cool exterior wall coatings without relying only on high-brightness white systems.
IR-600 vs IR-1000: which one should formulators choose?
The choice between IR-600 and IR-1000 should start with color design.
If the exterior wall coating is white, light beige, light grey or medium-light color, IR-600 is often the more direct choice. It provides strong near-infrared reflection and is suitable for architectural coatings where high TSR and durability are required.
If the exterior wall coating is dark grey, blue, brown, green, yellow or another vibrant architectural color, IR-1000 is usually the better starting point. Its key advantage is broader color compatibility, especially in systems where the L* value may fall below the comfortable range for conventional white-based cool coating design.
A simple formulation logic is:
Use IR-600 when the project is reflectance-first and color range is relatively light.
Use IR-1000 when the project is color-first but still requires near-infrared reflection.
That difference matters. In real coating development, a material that performs well in white may not deliver the same value in a dark or highly chromatic color. IR-1000 helps solve that gap by supporting a wider color design window.
Why NIR reflection matters more in colored solar-reflective exterior wall coatings
In white coatings, visible reflection is naturally high. The challenge becomes more complex in colored coatings because formulators must maintain visual appearance while reducing heat absorption.
Near-infrared reflection allows coatings to reflect part of the solar energy that is not visible to the human eye. This means a colored exterior wall coating can remain visually blue, grey, brown or green while still improving solar reflective performance compared with conventional pigment systems.
For building owners, this can support cooler wall surfaces and more comfortable exterior environments. For coating producers, it opens a higher-value product category: colored cool wall coatings.
Formulation considerations for IR-600 and IR-1000
When developing exterior wall coatings with infrared reflecting TiO₂, formulators should not evaluate the powder alone. The final performance depends on the complete coating system.
Key factors include binder type, pigment combination, filler selection, PVC, film thickness, substrate color, dispersion quality and target L* value. For dark colors, the use of carbon black should be carefully reviewed because carbon black strongly absorbs near-infrared radiation and can reduce the benefit of infrared reflecting pigments.
IR-1000 is particularly useful when formulators want to avoid conventional carbon black-based dark formulations and instead build dark or vibrant colors with infrared reflective pigment combinations.
For white and medium-light systems, IR-600 can be evaluated as a functional TiO₂ component for improving solar reflective performance while maintaining coating durability.
Application recommendation
For colored exterior wall coating projects, Inter-China Chemical recommends using IR-600 and IR-1000 according to the target color range:
IR-600 is recommended for white, light-color and medium-lightness exterior wall coatings.
IR-1000 is recommended for vibrant, dark and broad-color exterior wall coatings with L* values from 20 to 96.
For coating manufacturers developing cool façade coatings, the most efficient evaluation method is to test both products in the target formulation and compare TSR, NIR reflectance, color difference, hiding power, dispersion and weather resistance.
FAQ: IR-600 and IR-1000 for exterior wall coatings
What is the main difference between IR-600 and IR-1000?
IR-600 is more suitable for white, light-color and medium-lightness coating systems. IR-1000 is more suitable for vibrant, dark and broad-color systems, especially when the coating needs near-infrared reflection across a wider L* range.
Can IR-1000 be used in white exterior wall coatings?
Yes. IR-1000 can be used in white systems. In the IR-1000 architectural coating data, a RAL 9016 Traffic white formulation achieved L* 96.04, TSR 0.86 and NIR 0.83. However, if the project focuses mainly on white or light-color coatings, IR-600 may also be a strong option.
Which product is better for dark exterior wall coatings?
IR-1000 is generally the better starting point for dark or vibrant exterior wall coatings. It is designed to support infrared reflecting products with L* between 20 and 96, making it more flexible for colored solar-reflective exterior wall coatings design.
Is infrared reflecting TiO₂ the same as normal pigmentary TiO₂?
No. Normal pigmentary TiO₂ is mainly used for whiteness, opacity and hiding power. Infrared reflecting TiO₂ is designed to improve reflection in the near-infrared region, helping reduce solar heat absorption in coatings and plastics.
Can IR-600 and IR-1000 reduce building surface temperature?
They are designed to improve solar and near-infrared reflectance in coating systems. The actual surface temperature reduction depends on the complete coating formulation, color, substrate, film thickness, application environment and testing conditions.
What data should be tested before commercial use?
Coating manufacturers should test TSR, NIR reflectance, Lab* color values, weather resistance, dispersion, film appearance, hiding power, adhesion and compatibility with the target binder system.
Conclusion
IR-600 and IR-1000 are both infrared reflecting TiO₂ products for heat-reflective coating applications, but they serve different formulation strategies.
IR-600 is the practical choice for white, light-color and medium-lightness exterior wall coatings where high reflectance and durability are key.
IR-1000 is the more flexible choice for colored exterior façade coatings, especially vibrant, dark or broad-color systems where the coating must balance visual design with near-infrared reflection.
For coating manufacturers, the best product is not simply the one with the highest reflectance number in isolation. The best product is the one that matches the target color, formulation system and performance requirement.
For exterior wall coatings, that means choosing IR-600 for light-color cool façade systems, and IR-1000 for color-rich cool façade systems.