Polyurethane adhesives are high-performance adhesives prepared by the reaction of polyisocyanates and polyols with polyurethane resins as the main body. They feature strong adhesion, high toughness and wide substrate compatibility, and are widely used in the automotive, construction, electronics, packaging and other fields. In recent years, they have been accelerating their iteration towards environmental protection and high performance.
Core Classification and characteristics
1. Single-component (moisture-curing) : Easy to apply, no need for mixing, cures by moisture in the air, suitable for building sealing and furniture assembly; Reactive hot melt adhesives (PUR) combine the fast initial adhesion of hot melt with the final strength of structural adhesives, and have low VOC. They are often used in high-end packaging and automotive interiors.
2. Two-component (reaction curing) : The main agent and curing agent are mixed in proportion. It features fast curing, high strength, and controllable performance, making it suitable for high-end scenarios such as automotive structural components and industrial structure bonding.
3. Common advantages: Wide bonding range (metal, glass, plastic, wood, fabric, etc.), good toughness, low-temperature resistance, impact resistance and vibration resistance; The formula is adjustable and can balance rigidity and flexibility.
4. Shortcomings and Improvements: High temperature and high humidity are prone to hydrolysis, and free cyanate esters need to be controlled. In recent years, the main promotion has been the modification of water-based, solvent-free and bio-based polyols to enhance environmental protection and weather resistance.
Mainstream applications and trends
1. Automobiles: Driven by the demands for lightweighting and NVH, it is used for bonding body structures, interiors, windshields and battery packs, replacing mechanical connections and enhancing safety and energy efficiency.
2. Construction: Window and door sealing, floor laying, and insulation material bonding, taking into account both sealing and structural strength to extend service life.
3. Electronics/Packaging: PUR and water-based systems are used for module packaging, pouch batteries and high-end composite films, meeting environmental protection and reliability requirements.
4. Market and Technology: The global scale is steadily growing. Environmental protection, functionalization (low-temperature resistance, high-temperature resistance, and chemical resistance), and intelligent construction are the core directions. At the same time, applications in extreme environments such as aerospace and polar regions are being expanded.
Key points of safety and construction
When operating, ensure good ventilation to prevent poisoning and avoid direct skin contact. The safety is significantly enhanced after curing.
Single-component components need to control environmental humidity and opening time. The two components are strictly mixed and deaerated in proportion to ensure uniform curing.
