Self-adhesive protective film with olefin rubber adhesive
Self-adhesive protective film for the exterior of painted vehicles, especially cars, characterized in that the backing of the protective film is a film coated on one side with an adhesive composition whose bond strength on steel is between 0.2 and 2.8 N/cm, the adhesive composition comprising a copolymer of at least two different α-olefins having 2 to 12 carbon atoms and at least one diene as further comonomer, no α-olefin having a proportion of 75 mol % or more in the adhesive composition as a whole, and the copolymer having a Mooney viscosity ML (1+4) 125° C. of less than 50.
1. A method for protecting the paint finish of a vehicle or for protecting a painted vehicle component against soiling and damage during assembly, transportation or storage, said method comprising applying to said vehicle or vehicle component a self-adhesive protective film, said self-adhesive protective film comprising:
a) a backing film; and
b) an adhesive composition coated on said backing film, wherein the adhesive composition comprises a copolymer of at least two different α-olefins having 2 to 12 carbon atoms and at least one further comonomer, said further comonomer being a diene, said adhesive composition not containing 75 mol-% or more of any single α-olefin, and the copolymer having a Mooney viscosity ML (1+4) 125° C. of less than 50.
2. The method according to claim 1 , which comprises applying the self-adhesive protective film to a curved surface on an exterior portion of said vehicle.
3. The method according to claim 2 , which comprises applying the self-adhesive protective film to a painted surface of said vehicle before said vehicle is assembled.
4. The method according to claim 1 , wherein the diene is present in the adhesive composition in a proportion of between 0.5 and 10% by weight based on the total weight of the adhesive composition.
5. The method according to claim 1 , wherein the self-adhesive protective film exhibits a UV permeability in the range from 290 to 360 nm of less than 1%.
6. The method according to claim 1 , wherein the copolymer has a Mooney viscosity ML (1+4) 125° C. of less than 30.
7. The method according to claim 1 , wherein the adhesive composition is cross-linked.
8. The method according to claim 1 , wherein the copolymer comprises polar comonomers, and the proportion of said polar comonomers in the copolymer is less than 20 mol %.
9. The method according to claim 1 , wherein the self-adhesive protective film comprises at least one light stabilizer.
10. The method according to claim 9 , wherein said at least one light stabilizer is selected from the HALS class of light stabilizers.
11. The method according to claim 1 , wherein the copolymer comprises no more than 65 mol-% of any single α-olefin.
12. The method according to claim 1 , wherein the self-adhesive protective film exhibits a bond strength on steel between 0.3 and 1.5 N/cm.
13. The method according to claim 1 , wherein the proportion of each α-olefin in the copolymer is between 5 and 60 mol-%.
14. The method according to claim 1 , wherein the self-adhesive protective film exhibits a UV permeability in the range from 290 to 400 nm of below 0.1% and the backing thereof comprises one or more light stabilizers in an amount of at least 0.15% by weight.
15. The method according to claim 1 , wherein the self-adhesive protective film comprises an adhesion promoter between the backing film and the adhesive composition.
16. The method according to claim 15 , wherein the adhesion promoter comprises at least one polymer which consists to the extent of at least 50 mol-% of one or more α-olefins.
17. The method according to claim 1 , wherein the self-adhesive protective film exhibits a force at 10% extension which does not exceed 25 N/15 mm width either in the lengthwise or transverse direction.
18. The method according to claim 1 , wherein the self-adhesive protective film comprises a backing film which comprises at least one propylene copolymer.
19. The method according to claim 1 , wherein the self-adhesive protective film is formed by simultaneous coextrusion of the adhesive composition and the backing film.