Method of primerless bonding
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.