HDI Biuret (Hexamethylene Diisocyanate Biuret) is a class of aliphatic polyisocyanates widely used as curing agents for two-component polyurethane (2K PU) coating systems. Due to their excellent weather resistance, UV stability, chemical resistance, and balanced processing characteristics, HDI Biuret polyisocyanates are extensively used in industrial, automotive, protective, and high-performance coating applications.

HDI Biuret curing agents provide outstanding adhesion, mechanical durability, corrosion protection, and long-term outdoor performance. Their relatively low viscosity and excellent compatibility with hydroxyl-functional resins make them particularly suitable for formulations requiring easy application, high film build, and reliable curing performance.

Our portfolio includes a comprehensive range of HDI Biuret polyisocyanates with different NCO contents, viscosities, solids levels, and solvent options to meet the requirements of modern polyurethane coating technologies.

^{Key Features and Benefits}

HDI Biuret polyisocyanates combine excellent application properties with outstanding coating performance.

^{Main Benefits}

• Excellent UV resistance
• Outstanding weatherability
• Superior chemical resistance
• Excellent adhesion to a wide range of substrates
• High mechanical strength
• Excellent abrasion resistance
• Good flexibility
• Lower viscosity for improved application
• Excellent compatibility with hydroxyl-functional binders
• Long-term coating durability
• Consistent product quality for industrial production

^{Typical Applications}

HDI Biuret polyisocyanates are widely used in:

• Industrial polyurethane coatings
• Protective and anti-corrosion coatings
• Automotive OEM coatings
• Automotive refinish coatings
• Commercial vehicle coatings
• Agricultural machinery coatings
• Construction equipment coatings
• Structural steel coatings
• Rail coatings
• Equipment and machinery finishes
• Plastic coatings
• Polyurethane primers
• High-performance clear coats

^{Typical Technical Properties}

Typical characteristics of HDI Biuret polyisocyanates include:

Actual values depend on the specific product grade.

^{HDI Biuret Product Range}

Our HDI Biuret portfolio includes products designed for different coating technologies and formulation requirements.

The values shown are typical and should be verified against the latest Technical Data Sheet (TDS).

^{Resin Compatibility}

HDI Biuret polyisocyanates are compatible with most hydroxyl-functional binders used in polyurethane coating formulations, including:

• Hydroxyl acrylic resins
• Polyester polyols
• Polyurethane polyols
• Acrylic polyol systems
• Polyaspartic resins
• Specialty hydroxyl-functional polymers

This broad compatibility enables formulators to develop coating systems with optimized cure speed, flexibility, corrosion protection, and long-term outdoor durability.

^{Countertypes (Equivalent Products)}

Our HDI Biuret polyisocyanates are designed as functional alternatives to products from leading global manufacturers.

Disclaimer: Countertype information is provided for reference only. Product selection should always be confirmed through laboratory evaluation based on NCO content, viscosity, solids content, solvent system, reactivity, functionality, and formulation compatibility.

^{How to Select the Right HDI Biuret}

Selecting the appropriate HDI Biuret depends on several formulation parameters, including:

• NCO content
• Viscosity
• Non-volatile content
• Solvent system
• VOC requirements
• Cure speed
• Pot life
• Required film build
• Chemical resistance
• Weather resistance
• Coating flexibility
• Compatibility with the selected resin system

Our technical specialists can assist in selecting the most suitable curing agent for new formulations, process optimization, or replacement of imported materials.

^{Frequently Asked Questions (FAQ)}

^{What is HDI Biuret?}

HDI Biuret is an aliphatic polyisocyanate produced from hexamethylene diisocyanate (HDI) through a biuret reaction. It is primarily used as a curing agent for two-component polyurethane coatings, providing excellent weatherability, chemical resistance, mechanical durability, and long-term outdoor performance.

^{What is the difference between HDI Biuret and HDI Trimer?}

Although both are based on HDI chemistry, they have different molecular structures and performance characteristics.

HDI Biuret generally offers lower viscosity, excellent wetting properties, and easier application, particularly in formulations requiring higher film thickness or improved application characteristics.

HDI Trimer typically provides higher solids content, superior gloss retention, improved UV durability, and enhanced long-term weather resistance, making it the preferred choice for premium High Solids and exterior coating systems.

^{How do I select an alternative to Desmodur® N75?}

Choosing an equivalent product requires evaluation of several technical parameters, including:

• NCO content
• Viscosity
• Solids content
• Solvent system
• Reactivity
• Compatibility with the selected resin system

Our technical team can recommend the most suitable functional alternative based on your formulation and performance requirements.

^{Can imported HDI Biuret products be replaced without reformulating?}

In many applications, yes. Modern HDI Biuret polyisocyanates are developed to match the performance of leading international products and can often be used as functional replacements. However, laboratory validation is always recommended before commercial production.

^{What industries use HDI Biuret polyisocyanates?}

HDI Biuret products are widely used in:

• Industrial coatings
• Protective coatings
• Automotive coatings
• Automotive refinish coatings
• Heavy equipment coatings
• Structural steel coatings
• Polyurethane primers
• Clear coats
• Machinery and equipment finishes

^{When should HDI Biuret be selected instead of HDI Trimer?}

HDI Biuret is often preferred when lower viscosity, improved application properties, higher film build capability, and excellent processing characteristics are required. HDI Trimer is generally selected when maximum gloss retention, UV resistance, weatherability, and High Solids performance are the primary objectives.

^{Technical Support}

In addition to supplying high-quality HDI Biuret polyisocyanates, we provide comprehensive technical support for polyurethane coating manufacturers.

Our specialists assist customers with product selection, formulation development, replacement of imported curing agents, and optimization of existing coating systems.

Technical Data Sheets (TDS), Safety Data Sheets (SDS), Certificates of Analysis (COA), product samples, and application recommendations are available upon request.