How does waterproofing acrylic coating achieve high solar reflectivity?
Release Time : 2025-12-10
With the growing acceptance of "dual carbon" goals and green building concepts, building energy-saving materials are undergoing a profound transformation from single-function to multi-functional and highly efficient materials. Waterproofing acrylic coating is a representative product of this trend—it is not only an environmentally friendly water-based coating, but also integrates high solar reflectivity, excellent waterproofing, good elasticity, and weather resistance, making it widely used in exposed areas such as roofs, exterior walls, and balconies.
1. High Reflectivity Stems from Intelligent Optical Design
Approximately 50% of solar radiation energy is concentrated in the near-infrared band, while visible light accounts for about 43%. The key to waterproofing acrylic coating's effective reduction of surface temperature lies in the introduction of highly reflective functional fillers into its formula, such as hollow ceramic microspheres, titanium dioxide, zinc oxide, and infrared reflective pigments. These micron- or nano-sized particles have high refractive index and low thermal conductivity, reflecting most sunlight back into the atmosphere rather than being absorbed by the substrate. For example, high-quality rutile TiO₂ not only provides whiteness and hiding power but also efficiently scatters ultraviolet and visible light; while hollow ceramic microspheres form a "micro-vacuum insulation layer," further blocking heat conduction. Through scientific formulation, the solar reflectance index of the coating surface can reach over 100, and the summer roof temperature can be 15–25°C lower than ordinary coatings.
2. Waterproofing Performance Depends on a Dense Continuous Membrane Structure
Despite emphasizing "high reflectivity," the coating is by no means a porous or loose structure. On the contrary, its waterproofing ability stems from the high cross-linking density and low permeability of the high-quality acrylic emulsion after film formation. Once the coating dries and cures, the acrylic polymer chains intertwine to form a seamless, continuous, and dense elastic membrane, effectively blocking liquid water penetration. Simultaneously, the hydrophobic agent added to the formula reduces the surface energy of the coating, allowing rainwater to roll off quickly, reducing retention time and preventing blistering or peeling caused by prolonged immersion. This dual mechanism of "external hydrophobicity and internal density" ensures a long-term reliable waterproof barrier even in heavy rain or high humidity environments.
3. Elasticity and Durability Ensure Long-Term Service Safety
Building structures inevitably develop micro-cracks under temperature differences, loads, or settlement. If the coating is too rigid, it is prone to cracking and failure. Waterproofing acrylic coatings, by controlling the glass transition temperature of the acrylic emulsion and introducing flexible segments, achieve an elongation at break of over 300%. This means the coating can deform synchronously with the expansion and contraction of the substrate, automatically "bridging" cracks up to 0.5mm in diameter and preventing moisture intrusion along the cracks. Furthermore, the aliphatic acrylic structure itself is stable against ultraviolet light; combined with UV absorbers and antioxidants, it can significantly delay yellowing, chalking, and embrittlement, achieving outdoor durability of over 10 years.
4. Environmental Protection and Energy Saving Synergistically Support Green Buildings
As a water-based system, this coating has extremely low VOC content, produces no irritating odor during application, and meets national green building material standards. More importantly, its high reflectivity and heat insulation performance can significantly reduce the building's air conditioning load. According to actual measurement data, rooftops using this coating in hot regions can see a 3–6°C reduction in indoor top-floor temperature and a 15%–30% reduction in air conditioning energy consumption, demonstrating significant energy-saving benefits throughout their entire lifecycle.
The success of waterproofing acrylic coating is essentially a clever synergy of multiple physical fields—light, heat, water, and force—through materials science. Using an environmentally friendly water-based system, it achieves a triple unity of reflective cooling, waterproof sealing, and elastic crack resistance, not only improving building comfort but also contributing a practical technical path to mitigating the urban heat island effect and promoting building energy conservation. In the future, with the integration of new technologies such as smart pigments and phase change materials, this type of coating is expected to move towards a higher level of "adaptive" energy saving.
1. High Reflectivity Stems from Intelligent Optical Design
Approximately 50% of solar radiation energy is concentrated in the near-infrared band, while visible light accounts for about 43%. The key to waterproofing acrylic coating's effective reduction of surface temperature lies in the introduction of highly reflective functional fillers into its formula, such as hollow ceramic microspheres, titanium dioxide, zinc oxide, and infrared reflective pigments. These micron- or nano-sized particles have high refractive index and low thermal conductivity, reflecting most sunlight back into the atmosphere rather than being absorbed by the substrate. For example, high-quality rutile TiO₂ not only provides whiteness and hiding power but also efficiently scatters ultraviolet and visible light; while hollow ceramic microspheres form a "micro-vacuum insulation layer," further blocking heat conduction. Through scientific formulation, the solar reflectance index of the coating surface can reach over 100, and the summer roof temperature can be 15–25°C lower than ordinary coatings.
2. Waterproofing Performance Depends on a Dense Continuous Membrane Structure
Despite emphasizing "high reflectivity," the coating is by no means a porous or loose structure. On the contrary, its waterproofing ability stems from the high cross-linking density and low permeability of the high-quality acrylic emulsion after film formation. Once the coating dries and cures, the acrylic polymer chains intertwine to form a seamless, continuous, and dense elastic membrane, effectively blocking liquid water penetration. Simultaneously, the hydrophobic agent added to the formula reduces the surface energy of the coating, allowing rainwater to roll off quickly, reducing retention time and preventing blistering or peeling caused by prolonged immersion. This dual mechanism of "external hydrophobicity and internal density" ensures a long-term reliable waterproof barrier even in heavy rain or high humidity environments.
3. Elasticity and Durability Ensure Long-Term Service Safety
Building structures inevitably develop micro-cracks under temperature differences, loads, or settlement. If the coating is too rigid, it is prone to cracking and failure. Waterproofing acrylic coatings, by controlling the glass transition temperature of the acrylic emulsion and introducing flexible segments, achieve an elongation at break of over 300%. This means the coating can deform synchronously with the expansion and contraction of the substrate, automatically "bridging" cracks up to 0.5mm in diameter and preventing moisture intrusion along the cracks. Furthermore, the aliphatic acrylic structure itself is stable against ultraviolet light; combined with UV absorbers and antioxidants, it can significantly delay yellowing, chalking, and embrittlement, achieving outdoor durability of over 10 years.
4. Environmental Protection and Energy Saving Synergistically Support Green Buildings
As a water-based system, this coating has extremely low VOC content, produces no irritating odor during application, and meets national green building material standards. More importantly, its high reflectivity and heat insulation performance can significantly reduce the building's air conditioning load. According to actual measurement data, rooftops using this coating in hot regions can see a 3–6°C reduction in indoor top-floor temperature and a 15%–30% reduction in air conditioning energy consumption, demonstrating significant energy-saving benefits throughout their entire lifecycle.
The success of waterproofing acrylic coating is essentially a clever synergy of multiple physical fields—light, heat, water, and force—through materials science. Using an environmentally friendly water-based system, it achieves a triple unity of reflective cooling, waterproof sealing, and elastic crack resistance, not only improving building comfort but also contributing a practical technical path to mitigating the urban heat island effect and promoting building energy conservation. In the future, with the integration of new technologies such as smart pigments and phase change materials, this type of coating is expected to move towards a higher level of "adaptive" energy saving.