Aqueous film-forming mixtures and conformable films and articles made therefrom
View Patent ↗This invention relates to an aqueous film-forming mixture which does not contain a vinyl halide and which can be utilized to prepare conformable films which are useful in various applications such as adhesive tapes, labels and decorative sheets. The aqueous film-forming mixtures generally comprise, based on the weight of the solids in the aqueous mixture, (A) from about 50% to about 80% by weight of an acrylic-urethane copolymer which forms a film having an elongation at break of at least about 300%, and (B) from about 5% to about 25% by weight of an acrylic polymer or copolymer having a T g of less than about 55° C., wherein the acrylic polymer or copolymer (B) is different from the acrylic-urethane copolymer (A). The aqueous mixtures also may contain up to about 40% by weight of a pigment. These aqueous film-forming mixtures are useful in preparing conformable films and other articles such as adhesive articles which comprise an adhesive layer and a layer of the conformable film of this invention which is adhered to the adhesive layer. The conformable films of the present invention may be printed with various graphics, and the films are die-cuttable.
1. A conformable film having an elongation at break of at least about 100% prepared from an aqueous film-forming mixture free of PVC and comprising, based on the weight of the solids in the aqueous mixture, (A) from about 50% to about 80% by weight of an acrylic-urethane copolymer which forms a film having an elongation at break of at least about 300%. (B) from about 5% to about 25% by weight of an acrylic polymer or copolymer having a T g of less than about 55° C. wherein the acrylic polymer or copolymer (B) is not an acrylic-urethane copolymer and (c) from about 20% to about 40% by weight of at least one pigment.
2. The film of claim 1 wherein the conformable film is also characterized as having a stress relaxation of less than about 4 Newtons.
3. The film of claim 1 characterized as having an elongation at break of at least about 150%.
4. The film of claim 1 wherein the T g of the acrylic polymer or copolymer (B) is from about −15° to about 50° C.
5. The film of claim 1 wherein the acrylic-urethane copolymer (A) is an aliphatic urethane-acrylic copolymer.
6. The film of claim 1 wherein the pigment is titanium dioxide.
7. An adhesive article comprising an adhesive layer having a first surface and a second surface, and the film of claim 1 adhered to the first surface of the adhesive layer.
8. The adhesive article of claim 7 wherein the adhesive layer is a pressure sensitive adhesive layer.
9. The adhesive article of claim 7 wherein the acrylic-urethane copolymer (A) included in the aqueous mixture used to form the film is an aliphatic urethane-acrylic copolymer.
10. The adhesive article of claim 7 wherein the pigment is titanium dioxide.
11. A conformable film having an elongation at break of at least about 100% prepared from an aqueous film-forming mixture free of PVC and comprising, based on the weight of the solids in the aqueous mixture, (A) from about 55% to about 75% by weight of an acrylic-urethane copolymer which forms a film having an elongation at break of at least about 300%, and (B) from about 7% to about 20% by weight of an acrylic polymer or copolymer having a T g of less than about 55° C., and (C) from 20 to about 40% by weight of at least one pigment, wherein the acrylic polymer or copolymer (B) is not an acrylic-urethane copolymer.
12. The film of claim 11 wherein the conformable film is also characterized as having a stress relaxation of less than about 4 Newtons.
13. The film of claim 11 characterized as having an elongation at break of at least about 150%.
14. The film of claim 11 characterized as having an elongation at break of at least about 200%.
15. The film of claim 11 wherein the T g of the acrylic polymer or copolymer (B) is from about −15° to about 50° C.
16. The film of claim 11 wherein the acrylic-urethane copolymer (A) is an aliphatic urethane-acrylic copolymer.
17. The film of claim 11 wherein the aqueous mixture also comprises as least one rheology control agent.
18. The film of claim 11 wherein the pigment is titanium dioxide.
19. The film of claim 11 wherein the film is characterized as having a stress relaxation of less than about 2 Newtons.