The invention relates to a method for welding a polyolefin plastic and a plastic based on at least one polymer containing carbonyl groups, using a primer which contains, in relation to the proportion of polymer in said primer, at least 20 wt. % of a polymer that comprises maleic anhydride or maleic anhydride derivative units. The invention also relates to correspondingly welded products.

A method for forming a bond between substrates of a device includes providing first and second substrates, providing a first functionalized polyelectrolyte polymer (A) and providing a second functionalized polyelectrolyte polymer (B). Forming a functionalized surface on an exposed surface of the first substrate having the first functionalized polyelectrolyte polymer (A) attached thereto, forming a functionalized surface on an exposed surface of the second substrate having the second functionalized polyelectrolyte polymer (B) attached thereto, contacting at least a part of the functionalized surface of the first substrate onto at least a part of the functionalized surface of the second substrate thereby forming a contact area between the first functionalized polyelectrolyte polymer (A) and the second functionalized polyelectrolyte polymer (B), and forming a covalent bond between a first coupling moiety (A1) and a second coupling moiety (B1) in the contact area between the first and second substrates for binding the substrates.

The present invention relates to a primer composition that achieves excellent adhesion to poorly adhesive materials. Specifically, the present invention relates to a primer composition that includes (A) benzophenone, (B) a compound that has at least 2 benzene rings and a molecular weight of at least 190, and (C) a solvent.