Method of primerless bonding

Abstract

The present invention relates to methods for attaching a plastic component to another component where the plastic component is bonded to the other component with an adhesive in the absence of a primer on the plastic component and the adhesive is substantially solvent free. In one embodiment, a coated transparent or translucent polycarbonate substrate is connected to a frame with a polyurethane adhesive containing silicon in the absence of a primer on the substrate; or with a substantially solvent free adhesive. The inventions also related to bonded articles made according to the disclosed methods.

1 . A method for attaching a first coated plastic component to a second component comprising: 
 bonding the first coated plastic component to a second component with an adhesive in the absence of a primer on the first component, wherein the bonding forms a bond between the first component and the second component.    
     
     
         2 . The method of  claim 1 , wherein the adhesive is substantially solvent free.  
     
     
         3 . The method  claim 2 , wherein the adhesive is a silyl terminated polyether.  
     
     
         4 . The method of  claim 3 , wherein the adhesive comprises a polyurethane adhesive.  
     
     
         5 . The method of  claim 4 , wherein the adhesive comprises silicon.  
     
     
         6 . The method of  claim 5 , wherein the adhesive is selected from polyurethane admixed with a siloxane, silyl terminated polyurethane, siloxane grafted to a polyurethane backbone, or combinations thereof.  
     
     
         7 . The method of  claim 6 , wherein the first substrate comprises a coated polycarbonate.  
     
     
         8 . The method of  claim 7 , wherein the adhesive is moisture cured.  
     
     
         9 . The method of  claim 8 , wherein the second substrate further comprises a surface treatment.  
     
     
         10 . The method of  claim 9 , wherein the surface treatment comprises a primer.  
     
     
         11 . The method of  claim 10 , wherein the polycarbonate substrate is at least partially transparent or translucent.  
     
     
         12 . The method of  claim 11 , wherein the bond comprises a lap shear strength of about at least 400 psi.  
     
     
         13 . A method for attaching a polycarbonate substrate to a frame comprising: 
 connecting a coated polycarbonate substrate that is at least partially transparent or translucent to a frame with a polyurethane adhesive in the absence of a primer on the substrate, wherein the adhesive is substantially solvent free; and curing the adhesive, wherein the adhesive is moisture cured, and the cured adhesive forms a bond between the polycarbonate substrate and the frame.    
     
     
         14 . The method of  claim 14 , wherein the polyurethane adhesive comprises silicon.  
     
     
         15 . The method of  claim 15 , wherein the cured bond comprises a lap shear strength of about at least 400 psi.  
     
     
         16 . The method of  claim 15 , wherein the cured bond comprises a lap shear strength of about at least 400 psi after 15 days or more of under going weathering conditions.  
     
     
         17 . The method of  claim 16 , wherein the frame comprises a vehicle window frame.  
     
     
         18 . An adhesively bonded article comprising: 
 a. a hardcoated polycarbonate substrate that is at least partially transparent or translucent;    b. a frame; and    c. a moisture cured, substantially solvent free polyurethane adhesive,    wherein the substrate is bonded to the frame using the adhesive in the absence of a primer on the substrate.    
     
     
         19 . The article of  claim 18 , wherein the adhesive comprises silicon.  
     
     
         20 . The article of  claim 19 , wherein the cured bond comprises a lap shear strength of 400 psi.  
     
     
         21 . The article of  claim 20 , wherein the polycarbonate further comprises a vehicle window and the frame further comprises a vehicle window frame.  
     
     
         22 . The article of  claim 21 , wherein the adhesive comprises siloxane grafted to a polyurethane backbone, polyurethane backbone terminating with a silyl group, a mix of polyurethane and siloxane, or combinations thereof.