Water-based polyurethane automotive topcoat (two-component)

Water-based polyurethane automotive topcoat (two-component)

Product Description:

This product utilizes a water-based hydroxyl acrylic dispersion specifically designed for automotive paint to prepare Component A, with the curing agent serving as Component B. The cured film exhibits superior light and color retention when exposed to outdoor sunlight. It is primarily designed for application on engineering vehicles, road sweeping equipment, forklifts, logistics vehicles, buses, and other environmentally friendly vehicles and engineering machinery that demand high aesthetic and decorative standards along with strict outdoor durability requirements.

Product Features:

1. This product offers excellent decorative properties, with a full, glossy film appearance.

2. It features high hardness and good adhesion.

3. The coating film produced by this product exhibits excellent resistance to yellowing and chalking in outdoor environments.

4. This product has excellent workability.

Typical Film Thickness and Coverage Rate

Physical Properties

Fully dried: 7d
Solid content: Mass solid content ≥40%
Density: (1.2±0.1) g/ml
Storage period: Store in a cool, dry place. Valid for six months (can be reused after passing inspection post six months).
Packing: 20kg/drum

Surface Treatment:

Surface Treatment - Before painting, the substrate surface should be clean, dry, smooth, and firm, free from oil, rust, and other contaminants. If there are issues such as oil stains, old paint films, or weld spatter on the steel surface, mechanical methods should be used for treatment (preferably sandblasting or shot blasting for rust removal if conditions permit). The requirement is to achieve Sa2.5 or higher (Sa3.0). Manual rust removal must reach St3 level. For surfaces already coated with primer, the topcoat must be applied within the recoating interval. Avoid applying the topcoat immediately after the primer or leaving the primed surface untreated.
For topcoat application after more than 7 days, the primer should be sanded before applying the topcoat.
Dust Removal - Use an air gun to blow off loose dust or clean with a soft brush.
Old Paint Film Treatment - Remove old paint films with a scraper, fill the surface with putty, then sand it smooth, or use other methods as appropriate.
Grease treatment – First remove with solvent-based thinner or perform overall degreasing using solvent treatment equipment. After treatment, dry with circulating hot air or wipe clean with a clean non-woven cloth.

Construction conditions:

The optimal application temperature for this product is between 10°C and 40°C. Relative humidity must be below 70%, and application should be avoided during rain, snow, or fog. Contact with acids, alkalis, salts, or oily chemicals is prohibited. During application and drying in confined spaces, ensure adequate ventilation and maintain humidity below 70%. The substrate surface must be dry and clean, with the substrate temperature at least 3°C above the dew point, preferably above 10°C.

Application Method:

As this is a water-based product, the latent heat of water evaporation is very high, leading to slower drying compared to solvent-based coatings. Therefore, air spraying is recommended for application to allow faster moisture evaporation.

Application Parameters:

Mixing Ratio —— Follow the proportion indicated on the packaging. Thinner —— Purified water.
Dilution Ratio —— Typically 20–25% of the amount of Component A used.

Gelation Time —— Use within 2 hours after mixing, at a temperature of (23±2)℃. The gelation time will shorten as the ambient temperature rises and extend as it decreases.
Special Note! —— When adding Component B and water to Component A of this product, the following steps must be followed: 1. Add according to the ratio specified on the packaging; 2. Slowly add Component A to Component B under electric stirring, then increase the stirring speed and continue mixing for 3-5 minutes; 3. Water must be added only after stirring Component B for 3-5 minutes, and it must be gradually and slowly added while stirring. The recommended water addition is generally 20-25%, and the amount must be strictly controlled. After adding water, stir for another 3-5 minutes. 4. After preparation, the product needs to sit for curing for 5-10 minutes to ensure better workability and coating performance.

Curing Time —— The curing time is 5-10 minutes.
Spray Gun Pressure —— 0.4-0.6MPa. Tool Cleaning —— Purified water.

Recommended Product Combinations:

Water-based polyurethane automotive topcoats can be paired with our company's water-based epoxy anticorrosive primers, water-based epoxy micaceous iron oxide intermediate paints, water-based polyurethane intermediate paints, etc. For other matching products, please consult our product center.

Drying Conditions:

Factors such as ventilation conditions, temperature, and film thickness can affect drying time. The typical data listed in the table below is based on the following conditions: good ventilation (outdoors or natural air circulation) and typical coating intervals.

Note: 1. For all drying processes requiring baking, a flash-off period of at least 30 minutes after spraying is necessary before proceeding with baking and drying. 2. The spraying environment must have circulating air to proceed, and the baking environment must be a circulating hot air environment. Due to the high latent heat of water evaporation, without hot air, moisture is difficult to evaporate quickly, which can easily lead to film defects such as blistering, bubbling, and swelling on the paint surface.

Storage:

Storage must comply with national regulations. The storage environment should be maintained between 5-40°C, kept dry, cool, and well-ventilated, while avoiding corrosive substances such as acids, alkalis, and salts.

Loading and Unloading:

Handle with care and stir well before use.

Health and Safety:

To prevent skin and eye contact with the product, wear protective clothing, gloves, goggles, and masks before application. If paint splashes onto the skin, wash immediately with warm water and soap. If it gets into the eyes, rinse thoroughly with plenty of water and seek medical attention promptly.
The construction site should be well-ventilated, and never pour paint into sewers or drainage pipes.

Although this product is water-based, it should still be kept out of reach of children to prevent accidents.

Note:

The above information and data are based on laboratory tests and experimental experience, and may vary under specific circumstances (such as construction techniques, testing methods, or paint improvements).