LOCALLY DEACTIVATED RELEASE COATING

Abstract

The invention relates to a film comprising an optionally multilayer carrier layer; wherein one surface side of the carrier layer has been modified over part of its area either by surface activation or by printing with a print medium, such that the surface side has modified regions and unmodified regions; wherein the modified regions and the unmodified regions are coated over part or all of the area by a release material; and wherein the strength of adhesion of the release material to the carrier layer in the modified regions is different compared to the adhesion of the release material to the carrier layer in the unmodified regions.

Claims

1. A film (1) comprising an optionally multi-ply carrier layer (2) having a first surface side (3) and an opposite second surface side (4); wherein the second surface side (4) has had some of its area modified either by surface activation or by printing with a printing composition (6), so that the second surface side (4) comprises modified regions (7) and also unmodified regions (8); wherein the modified regions (7) and also the unmodified regions (8) have been coated over some or all of their area with a release material (9); and wherein the adhesion of the release material (9) against the carrier layer (2) in the modified regions (7) is different in degree in comparison to the adhesion of the release material (9) against the carrier layer (2) in the unmodified regions (8).

2. The film (1) as claimed in claim 1, wherein the relative difference between the adhesion of the release material (9) against the carrier layer (2) in the modified regions (7) and the adhesion of the release material (9) against the carrier layer (2) in the unmodified regions (8) is at least ±1 N/cm, preferably at least ±2 N/cm, or at least ±3 N/cm, or at least ±4 N/cm, or at least ±5 N/cm, or at least ±6 N/cm, and most preferably at least ±7 N/cm according to EN ISO 11339.

3. The film (1) as claimed in claim 1 or 2, wherein the modified regions (7) and also the unmodified regions (8) have each had all of their area coated with the release material (9).

4. The film (1) as claimed in any of the preceding claims, wherein the total area of all the modified regions (7) is less than the total area of all the unmodified regions (8).

5. The film (1) as claimed in claim 4, wherein the total area of all the modified regions is at most 45%, preferably at most 40%, or at most 35%, or at most 30%, or at most 25%, or at most 20%, or at most 15%, or at most 10%, or at most 5% of the total area of the second surface side of the carrier layer.

6. The film (1) as claimed in any of claims 1 to 3, wherein the total area of all the modified regions (7) is greater than the total area of all the unmodified regions (8).

7. The film as claimed in claim 6, wherein the total area of all the modified regions is at least 55%, preferably at least 60%, or at least 65%, or at least 70%, or at least 75%, or at least 80%, or at least 85%, or at least 90%, or at least 95% of the total area of the second surface side of the carrier layer.

8. The film (1) as claimed in any of the preceding claims, wherein the modified regions (7) form a uniform, repeating pattern.

9. The film (1) as claimed in any of the preceding claims, wherein the modified regions (7) are in each case surrounded over their full area by unmodified regions (8).

10. The film (1) as claimed in any of the preceding claims, wherein the carrier layer (2) or at least one ply of the optionally multi-ply carrier layer is based on a material selected from the group consisting of polyolefin (e.g., polyethylene, polypropylene), polyamide, polyester, elastomer, paper, sheetlike textile structures (e.g., woven fabric, knitted fabric, Tyrak).

11. The film (1) as claimed in claim 10, wherein the carrier layer consists at least to an extent of 95 wt % of C2-C8 olefin polymers, their mixtures or copolymers.

12. The film (1) as claimed in claim 11, wherein the olefin polymers are preferably selected from the group consisting of polyethylene (PE); preferably polyethylene with a low density of between 0.86 and 0.93 g/cm3 (LDPE); linear polyethylene with a low density of between 0.86 and 0.94 g/cm3 (LLDPE), which as well as ethylene may comprise as comonomer one or more α-olefins having 3-8 carbon atoms; polyethylene with a medium density of between 0.926 and 0.94 g/cm3 (MDPE); polyethylene with a high density of between 0.94 and 0.97 g/cm3 (HDPE); or ethylene copolymers with an α-olefin having 4 or more carbon atoms, preferably 6 and/or 8 carbon atoms, (mPE); polypropylenes (PP), preferably isotactic propylene homopolymers having a melting point of 140-170° C., preferably 150-165° C.; propylene-ethylene copolymers having preferably up to 20 wt % of ethylene; propylene copolymers of at least one copolymer of propylene and up to 20 wt %, preferably 10 wt %, based on the copolymer, of ethylene as a blend component.

13. The film (1) as claimed in any of the preceding claims, wherein the carrier layer is not oriented.

14. The film (1) as claimed in any of the preceding claims, wherein the carrier layer (2) has a mean layer thickness in the range from 10 μm to 200 μm, preferably 50 μm to 200 more preferably 60 μm to 150 μm, very preferably 70 μm to 90 μm.

15. The film (1) as claimed in any of the preceding claims, wherein the release material (9) is based on a material selected from the group consisting of thermally curing polysiloxanes, photochemically curing polysiloxanes (e.g., photochemically radically or photochemically cationically) and a mixture thereof (i.e., thermally curing polysiloxanes and/or photochemically curing polysiloxanes, preferably acrylic-modified polysiloxanes and/or epoxysiloxanes).

16. The film (1) as claimed in any of the preceding claims, wherein the release material (9) has a mean basis weight in the range from 0.1 g/m.sup.2 to 2 g/m.sup.2, more preferably 0.3 g/m.sup.2 to 1 g/m.sup.2.

17. The film (1) as claimed in any of the preceding claims, which has a total layer thickness in the range from 10 μm to 200 μm, preferably 50 μm to 200 μm, more preferably 60 μm to 150 μm, very preferably 70 μm to 90 μm.

18. The film (1) as claimed in any of the preceding claims, wherein the adhesion of the release material (9) against the carrier layer (2) in the modified regions (7) is stronger than the adhesion of the release material (9) against the carrier layer (2) in the unmodified regions (8).

19. The film (1) as claimed in claim 18, wherein the modified regions (8) have been modified by surface activation, so that the modified regions (7) are surface-activated regions (7a) and the unmodified regions (8) are non-surface-activated regions (8a); and wherein the surface-activated regions (7a) and also the non-surface-activated regions (8a) have had some or all of their area coated with the release material (9).

20. The film (1) as claimed in claim 19, wherein the surface activation is selected from the group consisting of plasma treatment, corona treatment, flame treatment, and combinations thereof.

21. The film (1) as claimed in any of claims 1 to 17, wherein the adhesion of the release material (9) against the carrier layer (2) in the modified regions (7) is weaker than the adhesion of the release material (9) against the carrier layer (2) in the unmodified regions (8).

22. The film (1) as claimed in claim 21, wherein the modified regions (8) have been modified by printing with a printing composition (6), so that the modified regions (7) are printed regions (7b) and the unmodified regions (8) are unprinted regions (8b); and wherein the printed regions (7b) and also the unprinted regions (8b) have had some or all of their area coated with the release material (9).

23. The film (1) as claimed in claim 22, wherein the adhesion of the release material (9) on the printing composition (6) in the printed regions (7b) and the adhesion of the release material (9) on the second surface side (4) in the unprinted regions (8b) are in each case stronger than the adhesion of the printing composition (6) on the second surface side (4) in the printed regions (7b).

24. The film (1) as claimed in any of claims 21 to 23, wherein the printing composition (6) is based on a material selected from the group consisting of one-component varnishes, two-component varnishes, waterborne varnishes, solvent borne varnishes, thermally crosslinking varnishes, photochemically crosslinking varnishes, radically crosslinking varnishes, cationically crosslinking varnishes, varnishes based on acrylates, varnishes based on polyvinyl chloride (PVC), varnishes based on polyvinyl dichloride (PVDC), varnishes based on polyurethane, varnishes based on polyamide, and/or varnishes based on nitrocellulose.

25. The film (1) as claimed in any of claims 21 to 24, wherein the printing composition (6) in the printed regions (7b) has a mean surface weight in the range from 0.5 g/m.sup.2 to 10 g/m.sup.2.

26. The film (1) as claimed in any of the preceding claims, wherein the first surface side (3) has had some or all of its area coated with a pressure-sensitive adhesive (5).

27. The film (1) as claimed in claim 26, wherein the first surface side (3) has had all of its area coated with the pressure-sensitive adhesive (5).

28. The film (1) as claimed in claim 26 or 27, wherein the pressure-sensitive adhesive (5) is based on a material selected from the group consisting of acrylate-based pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, polyisobutylene-based pressure-sensitive adhesives, and hotmelts (e.g., SBS block copolymers).

29. The film (1) as claimed in any of claims 26 to 28, wherein the pressure-sensitive adhesive (5) has a mean basis weight in the range from 50 g/m.sup.2 to 500 g/m.sup.2, more preferably 50 g/m.sup.2 to 400 g/m.sup.2, more preferably still 50 g/m.sup.2 to 300 g/m.sup.2, very preferably 150 g/m.sup.2 to 300 g/m.sup.2.

30. The film (1) as claimed in any of claims 26 to 29, wherein, in a state in which the pressure-sensitive adhesive (5) adheres to the release material (9), the adhesion of the release material (9) on the second surface side (4) in the unmodified regions (8) is weaker than the adhesion of the pressure-sensitive adhesive (5) on the release material (9).

31. The film (1) as claimed in claim 30, wherein, in a state in which the pressure-sensitive adhesive (5) adheres to the release material (9), the adhesion of the release material (9) on the second surface side (4) in the modified regions (7) is stronger than the adhesion of the pressure-sensitive adhesive (5) on the release material (9).

32. The film (1) as claimed in any of claims 26 to 29, wherein, in a state in which the pressure-sensitive adhesive (5) adheres to the release material (9), the adhesion of the release material (9) on the second surface side (4) in the unmodified regions (8) is stronger than the adhesion of the pressure-sensitive adhesive (5) on the release material (9).

33. The film (1) as claimed in claim 32, wherein the modified regions (8) have been modified by printing with a printing composition (6), wherein, in a state in which the pressure-sensitive adhesive (5) adheres to the release material (9), the adhesion of the pressure-sensitive adhesive (5) on the release material (9) is stronger than the adhesion of the printing composition (6) on the second surface side (4) in the printed regions (7b).

34. An adhesive tape comprising a film (1) as claimed in any of the preceding claims.

35. The adhesive tape as claimed in claim 34, wherein the film (1) is present as a roll wound against itself, so that the pressure-sensitive adhesive (5) adheres to the release material (9).

36. The adhesive tape as claimed in claim 35, wherein the modified regions (8) have been modified by surface activation, wherein the adhesive tape has been formulated such that during unwinding in non-surface-activated regions (8a) the release material (9) remains adhering to the pressure-sensitive adhesive (5) and is detached from the second surface side (4); in surface-activated regions (7a) the pressure-sensitive adhesive (5) is detached from the release material (9); so that within the coating of the second surface side (4) with the release material (9) in the non-surface-activated regions (8a) vacancies (10) are formed which do not have any release material (9), but at which, instead, the second surface side (4) is exposed; and also on the coating of the first surface side (3) with the pressure-sensitive adhesive (5), regions (11) corresponding thereto are formed, which are covered with the detached release material (9) adhering thereto.

37. The adhesive tape as claimed in claim 35, wherein the modified regions (8) have been modified by printing with a printing composition (6), wherein the adhesive tape has been formulated such that during unwinding, the pressure-sensitive adhesive (5) is detached from the release material (9) in unprinted regions (8b); in printed regions (7b) the release material (9) remains adhering together with the printing composition (6) to the pressure-sensitive adhesive (5), and the printing composition (6) is detached from the second surface side (4); so that within the coating of the second surface side (4) with the release material (9), in the printed regions (7b), vacancies (10) are formed which do not have any release material (9), but at which instead the second surface side (4) is exposed; and also, on the coating of the first surface side (3) with the pressure-sensitive adhesive (5), regions (11) corresponding thereto are formed, which are covered with the detached release material (9) adhering thereto and additionally with the printing composition (6).

38. The use of a film (1) as claimed in any of claims 1 to 33 or of an adhesive tape as claimed in any of claims 34 to 37 for sticking to surfaces and/or for sealing openings.

39. The use as claimed in claim 38, wherein the film (1) or the adhesive tape comprises a first section and a second section, which are bonded overlappingly in a manner such that at least a part-area of the pressure-sensitive adhesive (5) of the first section, in the region of at least some of the vacancies (10) of the second section, adheres to the second surface side (4) exposed there.

40. The use of a film (1) as claimed in any of claims 1 to 33 as a release film.

41. The use as claimed in claim 40, wherein an article (13) furnished with a self-adhesive material (12) is contacted with the film (1) in a manner such that the self-adhesive material (12) adheres over all of the area or some of the area to the release material (9) of the film (1), and wherein the film (1) and the article (13) are later separated from one another again, whereby the self-adhesive material (12) is at least partly detached again from the release material (9).

42. The use as claimed in claim 41, wherein the modified regions (8) have been modified by surface activation, wherein on detachment, in non-surface-activated regions (8a), the release material (9) remains adhering to the self-adhesive material (12) and is detached from the second surface side (4); in surface-activated regions (7a), the self-adhesive material (12) is detached from the release material (9); so that within the coating of the second surface side (4) with the release material (9), in the non-surface-activated regions (8a), vacancies (10) are formed which have no release material (9) but at which, instead, the second surface side (4) is exposed; and also, on the self-adhesive material (12) of the separated article (13), regions (11) corresponding thereto are formed, which are covered with the detached release material (9) adhering thereto.

43. The use as claimed in claim 41, wherein the modified regions (8) have been modified by printing with a printing composition (6), wherein on detachment, in unprinted regions (8b), the self-adhesive material (12) is detached from the release material (9); in printed regions (7b), the release material (9) remains adhering together with the printing composition (6) to the self-adhesive material (12), and the printing composition (6) is detached from the second surface side (4); so that within the coating of the second surface side (4) with the release material (9), in the printed regions (7b) vacancies (10) are formed which have no release material (9) but at which, instead, the second surface side (4) is exposed; and also, on the self-adhesive material (12) of the separated article (13), regions (11) corresponding thereto are formed, which are covered with the detached release material (9) adhering thereto and additionally with the printing composition (6).

44. The use as claimed in any of claims 41 to 43, wherein the self-adhesive material is selected from reactive adhesives, pressure-sensitive adhesives, hotmelt adhesives, and dispersion-based adhesives.

45. The use as claimed in any of claims 41 to 44, wherein the article (13) is selected from adhesive tapes and bitumen sheets.

46. A system comprising an article (13) furnished with a self-adhesive material (12), and a film (1) as claimed in any of claims 1 to 33, wherein the film (1) covers the self-adhesive material (12) and wherein the release material (9) of the film (1) faces the self-adhesive material (12) of the article (13) and adheres thereto.

47. The system as claimed in claim 46, wherein the self-adhesive material is selected from reactive adhesives, pressure-sensitive adhesives, hotmelt adhesives, and dispersion-based adhesives.

48. The system as claimed in claim 46 or 47, wherein the article (13) is selected from adhesive tapes and bitumen sheets.

49. A method for producing a film (1) as claimed in any of claims 1 to 33, comprising the following successive steps: (i) providing an optionally multi-ply carrier layer (2) having a first surface side (3) and an opposite second surface side (4); (ii) modifying some of the area of the second surface side (4) either by surface activation or by printing with a printing composition (6), so that modified regions (7) and also unmodified regions (8) are produced on the second surface side (4); and (iii) coating some or all of the area of the modified regions (7) and also of the unmodified regions (8) with a release material (9).

50. The method as claimed in claim 49, wherein in step (ii) there is a part-area surface activation of the second surface side (4), so that, on the second surface side (4), surface-activated regions (7a) and also non-surface-activated regions (8a) are produced; and wherein, in step (iii), there is a part-area or full-area coating of the surface-activated regions (7a) and also of the non-surface-activated regions (8a) with a release material (9).

51. The method as claimed in claim 49, wherein step (ii) comprises the following successive sub steps: (ii-1) part-area printing of the second surface side (4) with a printing composition (6), so that, on the second surface side (4), printed regions (7b) and also unprinted regions (8b) are produced; and (ii-2) part-area or full-area surface activation of the second surface side (4), so that, on the second surface side (4), surface-activated printed regions (7c) and also surface-activated unprinted regions (8c) are produced; and wherein, in step (iii), there is a part-area or full-area coating of the surface-activated printed regions (7c) and also of the surface-activated unprinted regions (8c) with a release material (9).

52. The method as claimed in claim 49, wherein step (ii) comprises the following successive substeps: (ii-a) part-area or full-area surface activation of the second surface side (4), so that, on the second surface side (4), surface-activated regions (7a) and also non-surface-activated regions (8a) are produced; and (ii-b) part-area printing of the second surface side (4) with a printing composition (6), so that, on the second surface side (4), printed surface-activated regions (7d) and also unprinted surface-activated regions (8d) are produced; and wherein, in step (iii), there is a part-area or full-area coating of the printed surface-activated regions (7d) and also of the unprinted surface-activated regions (8d) with a release material (9).

Description

[0107] The invention is illustrated in more detail by the figures.

[0108] FIG. 1A shows, schematically, one preferred method for producing the film of the invention (approach (i)) in a plan view of the second surface side (4). A sheet of the carrier layer (2) is guided in the arrow direction in succession through an apparatus for surface activation (14) and an apparatus for coating with release material (15). The surface side (4) of the carrier layer (2) is first of all surface-activated over part of its area by means of the apparatus for surface activation (14), to generate surface-activated regions (7a) and non-surface-activated regions (8a). Subsequently, using the apparatus for coating with release material (15), the surface-activated regions (7a) and the non-surface-activated regions (8a) are coated with release material. In the non-surface-activated regions (8a), the adhesion of the release material to the carrier layer (2) is weaker than in the surface-activated regions (7a).

[0109] FIG. 1B shows, schematically, the local detachment of the release material (9) from the carrier layer (2) in the non-surface-activated regions (8a), after, for example, a pressure-sensitive adhesive has been applied over the full area to the release material (9) and detached again. Here, on the one hand, in the non-surface-activated regions (8a), the adhesion of the pressure-sensitive adhesive to the release material (9) is stronger than the adhesion of the release material (9) to the carrier layer (2), and so the release material (9) is detached together with the pressure-sensitive adhesive (FIG. 1B, right). Here, on the other hand, in the surface-activated regions (7a), the adhesion of the pressure-sensitive adhesive to the release material (9) is weaker than the adhesion of the release material (9) to the carrier layer (2), and so the pressure-sensitive adhesive is detached from the release material (9) and it remains on the carrier layer (2) (FIG. 1B, left).

[0110] FIG. 2A shows, schematically, another preferred method for producing the film of the invention (approach (ii)) in a plan view of the second surface side (4). A sheet of the carrier layer (2) is guided in the arrow direction in succession through an apparatus for printing with a printing composition (16), an apparatus for surface activation (14), and an apparatus for coating with release material (15). The surface side (4) of the carrier layer (2) is first of all printed over part of its area with a printing composition (6), using the apparatus for printing with a printing composition (16), to produce printed regions (7b) and unprinted regions (8b). Thereafter the surface side (4) of the carrier layer (2) is surface-activated over its full area using the apparatus for surface activation (14), to produce surface-activated printed regions (7c) and surface-activated unprinted regions (8c). Subsequently, using the apparatus for coating with release material (15), the surface-activated printed regions (7c) and the non-surface-activated unprinted regions (8c) are coated over their full area with release material (9). In the surface-activated printed regions (8c), the adhesion of the printing composition (6) (together with the release material (9) located over it) to the carrier layer (2) is weaker than the adhesion of the release material (9) to the carrier layer (2) in the surface-activated unprinted regions (7c).

[0111] FIG. 2B shows, schematically, the local detachment of the release material (9) together with the printing composition (6) from the carrier layer (2) in the surface-activated printed regions (7c), after, for example, a pressure-sensitive adhesive has been applied over the full area to the release material (9) and detached again. Here, on the one hand, in the surface-activated printed regions (7c), the adhesion of the pressure-sensitive adhesive to the release material (9) and the adhesion of the release material (9) to the printing composition (6) are in each case stronger than the adhesion of the printing composition (6) to the carrier layer (2), and so the printing composition (6) is detached together with the release material (9) and the pressure-sensitive adhesive (FIG. 2B, right). Here, on the other hand, in the surface-activated unprinted regions (8c), the adhesion of the pressure-sensitive adhesive to the release material (9) is weaker than the adhesion of the release material (9) to the carrier layer (2), and so the pressure-sensitive adhesive is detached from the release material (9) and it remains on the carrier layer (2) (FIG. 2B, left).

[0112] FIG. 3 shows, schematically, one preferred embodiment of the film of the invention (approach (ii)) in a cross section through an adhesive tape. The film (1) has a carrier layer (2), which has been coated on its first surface side (3) with a pressure-sensitive adhesive (5). The second surface side (4) of the carrier layer (5) has been printed in printed regions (7b) with a printing composition (6), while the unprinted regions (8b) have no printing composition. Both the printed regions (7b) and the unprinted regions (8b) have been coated with a release material (9).

[0113] FIG. 4A shows, schematically, the embodiment of the film of the invention as per FIG. 3 (approach (ii)) in a cross section, where two strips of the film (1) and (1′) have been bonded against themselves, so that the pressure-sensitive adhesive (5) of the film (1) adheres on the release material (9) of the strip (1′).

[0114] FIG. 4B shows, schematically, the embodiment of the film of the invention as per FIG. 4B, after film (1) has been peeled off from film (1′). The modified regions (8) have been modified by printing with a printing composition (6), the formulation of the adhesive tape being such that on unwinding, in the unprinted regions (8b), the pressure-sensitive adhesive (5) is detached from the release material (9); in the printed regions (7b), the release material (9) together with the printing composition (6) remains adhering to the pressure-sensitive adhesive (5), and the printing composition (6) is detached from the second surface side (4) of the carrier layer (2); as a result, within the coating of the second surface side (4) with the release material (9), in the printed regions (7b), vacancies (10) are formed which have no release material (9), but instead at which the second surface side (4) is exposed; and also, on the coating of the first surface side (3) with the pressure-sensitive adhesive (5), regions (11) corresponding thereto are formed, which are covered with the detached release material (9) adhering thereto, and additionally with the printing composition (6).

[0115] FIG. 5 shows, schematically, the adhesive tape as per FIGS. 4A/B in a perspective view, with the vacancies (10), which have no release material (9) but at which the second surface side (4) is exposed, and also with the corresponding regions (11) on the pressure-sensitive adhesive (5), which are covered with the detached release material (9) adhering thereto and additionally with the printing composition (6).

[0116] FIG. 6 shows, schematically, a system which comprises an article (13), furnished with a self-adhesive material (12), and also a film (1) of the invention, where the film (1) covers the self-adhesive material (12) and where the release material (9) of the film (1) is facing the self-adhesive material (12) of the article (13) and adheres thereto.

LIST OF REFERENCE SYMBOLS

[0117] 1 Film

[0118] 2 Carrier layer

[0119] 3 First surface side

[0120] 4 Second surface side

[0121] 5 Pressure-sensitive adhesive

[0122] 6 Printing composition

[0123] 7 Modified regions

[0124] 7a Surface-activated regions

[0125] 7b Printed regions

[0126] 7c Surface-activated printed regions

[0127] 7d Printed surface-activated regions

[0128] 8 Unmodified regions

[0129] 8a Non-surface-activated regions

[0130] 8b Unprinted regions

[0131] 8c Surface-activated unprinted regions

[0132] 8d Unprinted surface-activated regions

[0133] 9 Release material

[0134] 10 Vacancies

[0135] 11 Corresponding regions

[0136] 12 Self-adhesive material

[0137] 13 Article

[0138] 14 Apparatus for surface activation

[0139] 15 Apparatus for coating with release material

[0140] 16 Apparatus for printing with a printing composition