Acrylic polyvinyl acetal films comprising an adhesive layer
A film is described comprising a (meth)acrylic polymer and polyvinyl acetal polymer composition. A layer of an adhesive composition is disposed proximate the film. The adhesive composition has a tensile elastic modulus of less than 1 MPa at 25° C. and 1 hertz.
1. A film comprising a (meth)acrylic polymer and polyvinyl acetal polymer composition comprising polymerized units having the following formula
wherein R 1 is hydrogen or a C1-C7 alkyl group; and
wherein a layer of an adhesive composition is disposed proximate the film and the adhesive composition has a tensile elastic modulus of less than 1 MPa at 25° C. and 1 hertz.
2. The film of claim 1 wherein the adhesive composition has a Tg of less than 25° C.
3. The film of claim 1 wherein the adhesive composition is a pressure sensitive adhesive having a tensile elastic modulus of less than 0.9 MPa at 25° C. and 1 hertz.
4. The film of claim 1 wherein the film is a backing of an adhesive coated sheet or tape.
5. The film of claim 1 wherein the film further comprises a second backing proximate the base film.
6. The film of claim 5 wherein the second backing comprises a substrate selected from polymeric films, woven or nonwoven fabrics, metal foils, foams, paper, and combinations thereof.
7. The film of claim 1 wherein the film and/or second backing is a conformable polymeric film.
8. The film of claim 1 wherein the adhesive composition is an acrylic adhesive composition.
9. The film of claim 1 wherein the layer of adhesive is structured.
10. The film of claim 1 wherein the film comprises a structured layer.
11. The film of claim 1 further comprising a release coating disposed on an outer exposed surface of the film.
12. The film of claim 1 further comprising a removable release liner covering the layer of adhesive.
13. The film of claim 1 wherein the film has a Tg of at least 30° C.
14. The film of claim 1 wherein the film has a gel content of at least 20%.
15. The film of claim 1 wherein the film has a tensile elastic modulus of at least 1 MPa at 25° C. and 1 hertz.
16. The film of claim 1 wherein the film comprises at least 10 wt.-% of polymerized units of monofunctional alkyl (meth)acrylate monomer having a Tg of less than 0° C.
17. The film of claim 16 wherein the film comprises polymerized units of monofunctional alkyl (meth)acrylate monomer having a Tg of less than −40° C.
18. The film of claim 1 wherein the film comprises at least 10 wt.-% and no greater than 65 wt.-% of polymerized units of polar monomers selected from acid-functional, hydroxyl functional monomers, nitrogen-containing monomers, and combinations thereof.
19. The film of claim 1 wherein the film further comprises polymerized units of a multifunctional crosslinker wherein the crosslinker comprises functional groups selected from (meth)acrylate, alkenyl, and hydroxyl-reactive groups.
20. The film of claim 1 wherein the (meth)acrylic polymer and polyvinyl acetal polymer composition of the film has a single phase.
21. The film of claim 2 wherein the adhesive composition has a Tg of less than 0° C.