HQ-9208: Star Performer for Clear Topcoats
HQ-9208 is a modified silicone-acrylic emulsion independently developed by Haoqian Technology. It combines the outstanding weather resistance of organosilicon and excellent adhesion of polyacrylate, and is specially suitable for exterior wall clear topcoats, stone coating finishing, texture coating topcoating and other applications.
Core Advantages
Excellent Resistance to Water Whitening: HQ-9208 modified silicone-acrylic emulsion endows coatings with outstanding weather resistance, maintaining stable performance and beautiful appearance under all harsh environments. No whitening in rainy seasons and no softening after long-term water immersion.
Superior Anti-UV Aging Performance: No obvious chalking or discoloration after 1000 hours of QUV aging test
Excellent Stain Resistance: Contact angle＞105°, dust hardly adheres to the coating surface.
Good Low-Temperature Film-Forming Property: With TEXANOL coalescent agent, complete intact film can be formed normally at 5°C. Strong Adhesion: Synergistic effect of formula components improves coating adhesion to substrates and effectively prevents coating peeling.
Efficient Construction Workability: The addition of multifunctional additives and defoamers optimizes coating construction performance for smoother and more efficient application.
Long Shelf Life: The added high-temperature resistant biocide effectively inhibits microbial growth and extends the shelf life of coatings.
Zero-Trouble Formula System Supported by Matched HQ Series Products
HQ-9208 acts as the core film-forming resin, while precise matching with HQ series additives is equally vital:
Fully stir 600g～700g HQ-9208 modified silicone-acrylic emulsion with 230g～340g water; then add 48g TEXANOL coalescent agent to optimize low-temperature film formation; slowly add 7g ethylene glycol (EG) for anti-freezing and drying speed adjustment.
HQ-1100 Wetting Agent: Low-foam type applicable to high-gloss systems, improves substrate wettability and reduces surface tension; Dosage: 1g;
HQ-8410 Molecular Defoamer: Rapid foam breaking, long-lasting foam suppression without impairing gloss; Dosage: 1g;
HQ-3295 Multifunctional Additive: Adjusts system pH value, enhances pigment dispersion stability and improves storage stability; Dosage: 1g;
HQ-2025 High-Temperature Resistant Biocide: Prevents microbial contamination during storage, withstands high temperature and fits formulas for high-humidity environments; Dosage: 2g;
HQ-6737 Polyurethane Thickener: Polyurethane rheology modifier offering excellent leveling property and brushing feel, anti-settling and anti-sagging effects; Dosage: 6g;
Note: Target system viscosity: 65 KU (Krebs Units), suitable for roller coating, air spraying and various construction methods.
Construction Tips
Recommended to be used together with TEXANOL; supplement an extra 2~3% butyl ether in winter to enhance film-forming performance
HQ-6737 is recommended to be pre-mixed with ethylene glycol at a ratio of 1:1 before feeding, to avoid local thickening caused by direct addition
The system pH value is suggested to be controlled between 8.0~9.0, which can be precisely adjusted by HQ-3295
Measured Performance Data (Based on This Formula):
Resistance to water whitening: No abnormality after 96 hours test
Artificial weathering resistance: No chalking or discoloration after 1000 hours aging test
Stain resistance (Grey Scale Method): ≤5%
Low-temperature film-forming performance: Crack-free intact film formed normally at 5°C
Application Cases & Actual Field Performance
01 Exterior Wall Topcoating of Coastal High-Rise Residence, Nansha, Guangzhou
Climate Features: Annual average relative humidity＞80%, summer surface temperature up to 65°C, chloride ion salt fog concentration 1.2 mg/m³
Customer Pain Point: The original styrene-acrylic topcoat presented obvious rain streaks and chalking after only 2 years, leading to numerous complaints from property owners.
Solution (Constructed in April 2023)
Main Resin: 700g HQ-9208 modified silicone-acrylic emulsion
Matching HQ Series Additives: One-time feeding of HQ-1100/8410/3295/6737 in accordance with the reference formula
Construction Process: One coat wet-on-wet roller coating within 24 hours after stone coating base finish, dry film thickness: 28 μm
Measured Data (Re-inspected in October 2025)
Resistance to water whitening: No abnormality after 96 hours test
Chalking Grade: Grade 0 (GB/T 1766)
Color Difference ΔE: 0.8 (Qualified standard ≤1.5)
Contact angle: 107°, maintaining strong hydrophobicity
58% reduction in maintenance costs; the developer placed a bulk order for another 12 residential buildings of the same type at one time
02 Metal Roof Topcoating of Logistics Warehouse, Yangshan Port, Shanghai
Climate Features: Sea wind carrying salt fog, intense ultraviolet radiation, roof panel temperature up to 70°C in summer and severe condensation in winter
Customer Pain Point: The original polyurethane topcoat suffered yellowing and brittle cracking within 1 year, bringing high risk of roof water leakage
Solution (Constructed in March 2024)
Main Resin: 600g HQ-9208 modified silicone-acrylic emulsion
Matching HQ Series Additives: Same as above, plus an extra 1% HQ-2025 biocide (mold prone to grow during spring-summer transition)
Construction Process: Two coats airless high-pressure spraying, total dry film thickness: 45 μm; add 5% aluminum silver paste in the second coat for heat insulation effect
Measured Data (Re-inspected in September 2025)
Salt spray test for 1000 hours, unilateral creepage from scratch line ＜1 mm (GB/T 1771)
Yellowing Index ΔYI: 1.2 (Qualified standard ≤2.0)
Elongation retention rate: 92% (No crack after bending at -20°C low temperature)
6.3°C lower roof surface temperature than ordinary surrounding color steel plates, 11% reduction in air conditioning energy consumption
03 Exterior Wall Renovation of Teaching Building, Kashgar, Xinjiang
Climate Features: Annual sunshine duration 2800 hours, UV-B radiation intensity 180 μW/cm², diurnal temperature difference up to 25°C
Customer Pain Point: The original pure acrylic topcoat faded and lost gloss within 1 year, requiring annual repainting and bringing heavy financial burden
Solution (Constructed in July 2022)
Main Resin: 600g HQ-9208 modified silicone-acrylic emulsion
Matching HQ Series Additives: Based on the reference formula, reduce HQ-6737 thickener dosage by 0.5% to adapt leveling performance under high temperature and low humidity
Construction Process: Avoid construction when temperature exceeds 40°C at daytime; apply coatings during 17:00–22:00, single coat dry film thickness: 30 μm
Measured Data (Re-inspected in August 2024)
Q-UVB accelerated aging test for 1000 hours, color difference ΔE=1.1, gloss loss rate 8% (Qualified standard ≤20%)
Chalking Grade: Grade 0
Obvious visual difference compared with pure acrylic topcoat constructed on the adjacent building in the same year (ΔE=3.8). The local Education Bureau decided to uniformly adopt HQ-9208 system for the subsequent 8 schools to improve the aesthetic appearance of campus buildings. In terms of construction performance, the coating features easy application and fast drying, greatly boosting construction efficiency.
HQ-9208 + HQ Series: Golden Combination for High-Performance Clear Topcoats
Against the backdrop of increasingly stringent environmental regulations and continuously upgraded performance requirements from end users, HQ-9208 modified silicone-acrylic emulsion stands as an ideal choice for clear topcoat formulas thanks to its outstanding comprehensive properties. When matched with Haoqian Technology’s full range of HQ series additives, it delivers multiple advantages including simplified formula, stable performance and friendly construction, assisting coating manufacturers to quickly respond to market demands and develop high-quality differentiated coating products.
