Dachin PU 770
Various polyurethane coatings

Main Composition

The coating consists of acrylic resin, pigments and fillers, specialty functional additives, and a secondary component of aliphatic isocyanate curing agent.

Main Characteristics

The cured film exhibits excellent adhesion, hardness, gloss retention, weather resistance, and color stability. Complies with standards: Technical Specifications for Cold-Sprayed Zinc Corrosion Protection on Bridge Steel Structures (JT/T 1266-2019), Technical Conditions for Highway Bridge Steel Structure Corrosion Protection Coatings (JT/T 722-2023), and Technical Specifications for Port Machinery Steel Structure Surface Coatings (JT/T 733-2021).

Main Applications

Designed for high-performance protective and decorative coating of steel structures on transportation vehicles, construction machinery, and critical engineering projects.

Technical Specifications

Film Color and Appearance	Conforms to color requirements, uniform surface with no particles, pinholes, bubbles, or defects
Density, kg/L	1.45±0.04
Fineness, μm	≤35

Package Specifications

Component	Package Weight / kg	Package Volume / L
A	21.4	14.2
B	3.6	3.8
Total	25	18

Basic Parameters

Mix Ratio	Coating : Curing Agent = 6:1 (by weight)
	Coating : Curing Agent = 4:1 (by volume)
Pot Life	5℃: 5 hours; 15℃: 4.5 hours; 25℃: 4 hours
Theoretical Consumption	Approx. 20㎡/L @ 30μm dry film thickness

Recoat Interval

Temperature	Surface Dry	Hard Dry	Recommended Topcoat Recoat Interval
			Minimum	Maximum
5℃	120 minutes	16 hours	16 hours	2 days
15℃	90 minutes	10 hours	10 hours
25℃	60 minutes	6 hours	6 hours
40℃	40 minutes	4 hours	4 hours

Data based on standard film thickness applied to steel substrate.

Application

• Dachin PU 770 Polyurethane Coating is recommended for airless spray application to achieve optimal single-coat film build compared to other methods.
• Surface temperature must remain at least 3℃ above dew point with humidity <85%.
• Ensure ventilation in enclosed spaces during application.
• Mix the coating with curing agent strictly according to the ratio before use. Mix only the required quantity and use within 4 hours after preparation. Stir thoroughly before use.
• Maintain tool cleanliness and dryness before and after application.
• Avoid contact with water, acids, or alkalis during mixing and application. Ensure curing agent containers are sealed tightly after use to prevent curing and material loss.
• Allow full curing for 7 days before putting the coated surface into service.

Compatible Coatings

Dachin EP 550 Epoxy Iron Oxide Intermediate Coat, Dachin H53-90 Cold-Sprayed Zinc Sealer, Dachin ZP 210 Zinc Phosphate Anti-Corrosive Primer

Recommended Coats

Apply 1-2 coats for a dry film thickness of 60±5μm.

Surface Preparation

Clean the surface to remove oil, dust, and other contaminants. Ensure no acid/alkali residues or moisture condensation. For cured polyurethane, fluorocarbon, or epoxy coatings, lightly sand and roughen the surface before applying topcoats.

Mixing

This 2-component system (A base resin and B curing agent) requires thorough stirring with power tools separately before mixing. Strictly follow the ratio and mix again until homogeneous.

Application Methods

Application Method	Diluent	Dilution Rate	Nozzle Orifice	Pressure
Airless Spraying	Dachin Thinner X10	0-5% (by paint weight)	0.4-0.5mm	15-20 MPa
Air Spraying	Dachin Thinner X10	0-10% (by paint weight)	1.5-2.0mm	0.3-0.5 MPa
Roller/Brush	Dachin Thinner X10	0-5% (by paint weight)	-	-

Dilution rates are calculated by paint weight.