2-Component polyurethane adhesive filter industry Kestopur 20 hardener 2-Component polyurethane adhesive filter industry Kestopur 400/4 2-Component polyurethane adhesive filter industry Kestopur 600/10 T 2-Component polyurethane adhesive filter industry Kestopur 600/5 2-Component polyurethane adhesive filter industry Kestopur CR 101 2-Component polyurethane adhesive filter industry