Structural PU adhesive for composite bonding
A new polyurethane (PU) adhesive composition having unique properties in automotive related applications such as composite bonding.
1. A one-component adhesive composition comprising 3 to 50 wt %, based on the total weight of the adhesive composition, of o,o′-diallyl-bisphenol A, 5 to 50 wt %, based on the total weight of the adhesive composition, of a dimeric isocyanate selected from dimeric toluene diisocyanate and dimeric methylene diphenyl diisocyanate encapsulated by deactivating the surface of the dimeric isocyanate with an aliphatic polyamine, an aliphatic polyol having a functionality greater than 2 and a catalyst; wherein the composition has an elastic modulus of above 50 MPa.
2. The composition of claim 1 wherein the catalyst comprises Sn—, Zr, Ti, Bi-metallo-organic compound or mixture thereof.
3. The composition of claim 1 , wherein the catalyst comprises Bi-neodecanoate.
4. The composition of claim 1 wherein the catalyst is a Sn—, Zr—, Ti— or Bi-metallo-organic compound in combination with chelating ligands.