Primer composition for promoting adhesion of a urethane adhesive to a polymeric substrate

1. A method for priming a surface for a urethane adhesive, comprising the steps of: providing a primer composition comprising:

i) an acrylic resin wherein said resin is present in an amount of about 2 to about 10 parts by weight of said primer composition;

ii) an isocyanate in an amount of about 3 to about 30 parts by weight of said primer composition;

iii) a catalyst in an amount up to about 2 parts by weight of said primer composition; and

iv) a solvent; and contacting said primer composition with a plastic substrate.

2. A method as in claim 1 , further comprising: contacting a urethane adhesive with said primer composition.

3. A method as in claim 2 , further comprising: adhering said urethane adhesive to a second substrate.

4. A method as in claim 3 , wherein said second substrate is an automotive vehicle body member.

5. A method as in claim 1 , wherein at least a portion of said resin is a methacrylate.

6. A method as in claim 1 , wherein the isocyanate comprises a polyisocyanate.

7. A method as in claim 6 , wherein at least a portion of the polyisocyanate is a thiophosphate with an isocyanate group.

8. A method as in claim 1 , wherein said primer composition includes an agent for allowing detection of the primer composition on the substrate, said detection agent present in about 0.001 to about 1 parts by weight of said primer composition.

9. A method as in claim 8 , wherein said agent is an optical brightener.

10. A method as in claim 9 , wherein said agent is a fluorescent agent.

11. A method as in claim 1 , wherein the primer composition further comprises a polyester resin.

12. A method for bonding a plastic substrate at least partially encapsulating a transparent sheet, comprising the steps of: providing a transparent sheet assembly including a transparent sheet at least partially encapsulated with a plastic seal; contacting said plastic seal with a primer composition comprising:

i) an acrylic resin wherein said resin is present in an amount 2 parts to about 10 parts by weight of said primer composition;

ii) an isocyanate in an amount up to about 3 to about 30 parts by weight of said primer composition;

iii) a catalyst in an amount of about 0.05 to about 2 by weight of said primer composition; and

iv) a solvent; and contacting said primer composition with a polyurethane adhesive; contacting said polyurethane adhesive with an automotive vehicle member for bonding said transparent sheet assembly to said automotive vehicle member.

13. A method as in claim 12 , wherein at least a portion of said resin is a methacrylate.

14. A method as in claim 12 , wherein the isocyanate comprises a polyisocyanate.

15. A method as in claim 14 , wherein at least a portion of the polylsocyanate is a thiophosphate with an isocyanate group.

16. A method as in claim 12 , wherein said primer composition includes an agent for allowing detection of the primer composition on the substrate, said detection agent present in about 0.001 to about 1 parts by weight of said primer composition.

17. A method as in claim 16 , wherein said agent is an optical brightener.

18. A method as in claim 12 , wherein said automotive vehicle body member is a body panel.

19. A method as in claim 12 , wherein said transparent sheet is a windshield of an automotive vehicle.

20. A method as in claim 12 , wherein at least a portion of said solvent is methyl ethyl ketone.

21. A method as in claim 12 , wherein the primer composition further comprises a polyester resin.