a type of polyisocyanate hardener used primarily in the formulation of polyurethane coatings, adhesives, and sealants. It is a product from Covestro, a leading producer of high-performance polymers and materials
Desmodur L75 is a type of aromatic polyisocyanate used primarily in the formulation of polyurethane coatings, adhesives, and sealants. It is a product of Covestro, a company known for its high-performance polymers and materials. Desmodur L75 is known for its reactivity and performance characteristics, especially in coatings applications.
Key Characteristics
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Chemical Composition:
- Type: Aromatic polyisocyanate based on toluene diisocyanate (TDI).
- Isocyanate Content: Typically around 13.0-14.0% by weight.
- Viscosity: Approximately 3,000-6,000 mPa·s at 23°C.
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Properties:
- Reactivity: Highly reactive, making it suitable for fast-curing applications.
- Mechanical Properties: Provides coatings with good hardness and flexibility.
- Durability: Offers good protection and performance in a variety of environments.
Applications
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Coatings:
- Industrial Coatings: Suitable for use in industrial environments where quick drying and robust performance are required.
- Wood Coatings: Provides a durable finish for wood surfaces, enhancing resistance to abrasion and chemicals.
- Protective Coatings: Used in coatings that need to withstand harsh conditions, such as floor coatings and heavy-duty maintenance coatings.
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Adhesives and Sealants:
- Construction Adhesives: Used in bonding applications requiring strong adhesion and quick curing.
- Sealants: Provides effective sealing solutions with good mechanical properties and resistance.
Advantages
- Fast Curing: High reactivity allows for quick drying and curing, which is beneficial in time-sensitive applications.
- Durability: Offers good mechanical strength and resistance to environmental factors.
- Versatility: Can be used in a wide range of formulations and applications.
Disadvantages
- Aromatic Nature: Being based on TDI, it may have higher sensitivity to UV light, leading to potential yellowing or degradation when exposed to sunlight over time.
- Handling Requirements: Requires careful handling and safety precautions due to the reactive nature of isocyanates.
Handling and Safety
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Personal Protective Equipment (PPE):
- Use appropriate PPE, including gloves, goggles, and protective clothing, to prevent skin and eye contact.
- Ensure the use of respirators or adequate ventilation to avoid inhalation of vapors.
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Storage:
- Store in tightly closed containers in a cool, dry place away from moisture and sources of ignition.
- Protect from temperatures below 10°C and above 30°C to maintain product stability.
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Safety Measures:
- Follow all safety data sheet (SDS) recommendations for safe handling and disposal.
- Use in well-ventilated areas to prevent the buildup of vapors.
