Two-Pack Urethane Adhesive With Nanofibers for Bleed-Out Control

The patent introduces a specific inorganic filler acting as an intermediary substance between the liquid components (water and active hydrogen compound) and the polymer matrix. This filler prevents direct contact and separation of liquid components, thereby suppressing bleed-out while maintaining curing properties. The filler creates a stable interface that holds the liquid components in place during storage.

The patent changes the physical and chemical parameters of the second-pack liquid by controlling the particle size, surface area, and surface treatment of the inorganic filler. By optimizing these parameters, the filler's ability to suppress liquid component bleed-out is enhanced while maintaining compatibility with the curing system. Specific surface area and particle size distributions are controlled to achieve maximum effectiveness.

The inorganic filler serves as a stabilizing intermediary that maintains the thixotropic structure of the second-pack liquid during elevated temperature storage. The filler particles create a network structure that prevents collapse of the liquid's rheological properties, ensuring that thixotropic characteristics are preserved even after prolonged exposure to high temperatures.

The patent applies beforehand cushioning by pre-treating the inorganic filler surface and selecting specific filler types that are resistant to thermal degradation. This preparation ensures that when the adhesive is stored at elevated temperatures, the filler already has the necessary properties to cushion against thixotropic deterioration, preventing rather than merely responding to the degradation process.

The inorganic filler acts as a mediating structure that simultaneously improves storage stability and ensures curing performance. By distributing liquid components uniformly throughout the filler network, the filler prevents bleed-out during storage while ensuring proper mixing and distribution of reactive components when the adhesive is applied and cured, thus maintaining curing performance.

The patent creates a composite system in the second-pack liquid by combining inorganic filler particles with water and active hydrogen compounds. This composite structure provides both storage stability (by preventing phase separation and bleed-out) and curing performance (by ensuring proper distribution and reactivity of components). The synergistic interaction between filler and liquid components achieves both objectives simultaneously.