| 摘要 |
Production of an adhesive layer containing at least one isocyanate reactive polymer and a solid surface-deactivated polyisocyanate and to increase its shear strength, comprises heat treatment at a temperature, preferably ≥ 40 degrees C above the drying temperature. The shear strength of the resulting adhesive joint is at least 10% higher than without the heat treatment. A process for the production of an adhesive layer and to increase its shear strength comprises: (A) preparation of an aqueous dispersion or solution containing at least one isocyanate reactive polymer and a solid surface-deactivated polyisocyanate; (B) application of the aqueous dispersion or solution onto a substrate; (C) production of an adhesive layer by removal of the water by drying at 20-95 degrees C (preferably 50-95 degrees C); and (D) performing heat treatment where the layer is heated continuously, stepwise or directly to a temperature, preferably at least 40 degrees C above the drying temperature. The shear strength of the resulting adhesive joint is at least 10% higher than without the heat treatment and the isocyanate reactive polymer and the solid surface-deactivated polyisocyanate are chosen such that following step (C), the adhesive layer has a loop tack of at least 2 N/inch. |
