natural rubber or synthetic rubber. Desmodur RN
materials. The use of Desmodur RN polyisocyanate
minimal discoloration on exposure to light.
After adding Desmodur RN polyisocyanate to a
polyurethane or rubber-based adhesive, the ready-to-
use two-component mixture must be used within its
pot life. Pot life is not only governed by the polymer
content of the adhesive but also by its other compo-
nents (resins, antioxidants, plasticizers, solvents, etc.).
At the end of the pot life, which can vary from
several hours to one working day, the adhesive
becomes increasingly difficult to process and its
viscosity increases rapidly. Finally, irreversible gelling
occurs. The following guide values are suggested for
determining the amount of crosslinker to be used.
Amounts given are parts by weight (pbw).
To crosslink 100 pbw adhesive: Desmocoll®
(hydroxyl
polyurethane) based adhesives (containing 20%
polyurethane) should be crosslinked with 4 - 7 pbw
Desmodur RN polyisocyanate. Baypren®
(polychloroprene rubber) based adhesives (containing
approximately 20% rubber content) should be
crosslinked with 4 - 7 pbw Desmodur RN
polyisocyanate.