SELF-ADHESIVE FILM FOR FIXING AN ELASTOMER PATCH AND METHOD FOR REPAIRING A MOTOR VEHICLE TIRE OR FOR CONNECTING TWO LAYERS OF AN ELASTOMER LINING

Abstract

The invention relates especially to a self-adhesive film 1 for fixing an elastomer patch 10 during a vulcanization of an elastomer component. The elastomer component can in particular be a motor vehicle tire 40 or a cavity lining 120. The film 1 can comprise a supporting layer 2 and an adhesive layer 3. The adhesive layer 2 can have a predetermined manufacturing adhesiveness at room temperature and ambient pressure and a predetermined peel strength at a vulcanization pressure and a vulcanization temperature.

Claims

1-11. (canceled)

12. A self-adhesive film for fixing an elastomer patch during a vulcanization of an elastomer component, in particular of a motor vehicle tire or a cavity lining, the self-adhesive film comprising: a supporting layer which has a predetermined temperature resistance and which is connected to an adhesive layer; and the adhesive layer which has an adhesive; wherein the adhesive layer has a predetermined manufacturing adhesiveness at room temperature and ambient pressure, and the adhesive layer has a predetermined peel strength and a predetermined sealing property under vulcanization conditions.

13. The self-adhesive film of claim 12 wherein the adhesive contains rubber, solids, in particular resins, and tackifiers, the adhesive optionally having a butyl portion.

14. The self-adhesive film of claim 12 wherein the thickness of the adhesive layer is between 5 and 500 μm and/or a specific mass of adhesive, which includes the adhesive layer on the basis of an area of the supporting layer, is between 10 and 200 g/m.sup.2.

15. The self-adhesive film of claim 12 wherein the supporting layer has a polymer or elastomer, in particular a polyamide, polyethylene or a rubber film, or the supporting layer includes paper or a fabric which is soaked with a polymer.

16. The self-adhesive film of claim 12 wherein the self-adhesive film is provided with an adhesive over the entire surface or only in some regions.

17. The self-adhesive film of claim 12 wherein the size of the area of the supporting layer and that of the adhesive layer are equal, the area being adapted to such a size that the self-adhesive film protrudes in each case from the lateral edges of the elastomer patch with a predetermined length.

18. The self-adhesive film of claim 12 wherein the adhesive layer and/or the adhesive is permanently connected to the tire surface, remains on the tire surface after the vulcanization and the removal of the film and additionally seals said surface.

19. The self-adhesive film of claim 12 wherein a protective layer is arranged on the adhesive layer and opposite the supporting layer, which can be removed from the adhesive layer before the film is used.

20. A method for repairing a motor vehicle tire or for connecting two layers of elastomer lining, the method comprising: applying an elastomer patch to a repaired damaged site of a tire/elastomer lining or arranging two layers of an elastomer lining in relation to one another in such a way that the two layers adjoin one another at a seam; coating the elastomer patch and/or the seam by adhesion using a self-adhesive film comprising: a supporting layer which has a predetermined temperature resistance and which is connected to an adhesive layer, and the adhesive layer which has an adhesive, wherein the adhesive layer has a predetermined manufacturing adhesiveness at room temperature and ambient pressure, and the adhesive layer has a predetermined peel strength and a predetermined sealing property under vulcanization conditions; wherein the elastomer patch and/or the seam are coated with adhesive in such a way that the film protrudes in each case from the lateral edges of the elastomer patch and/or from the seam; and producing and applying the pressure and temperature conditions required for a vulcanization for a predetermined period of time.

21. The method of claim 20 wherein the film is removed after the vulcanization.

22. The method of claim 20 wherein a protective layer is removed from the adhesive layer of the film prior to the coating of the film by adhesion.

Description

[0040] The invention is described by way of example below with reference to the enclosed schematic drawings, wherein:

[0041] FIG. 1 shows a sectional view of a self-adhesive film which is mounted on a tire surface,

[0042] FIG. 2 shows a sectional view of a self-adhesive film which is mounted on a cavity lining, and

[0043] FIG. 3 shows a top view of the self-adhesive film.

[0044] Various examples of the present invention are described in detail below with reference to the drawings. Equal and/or similar elements in the drawings are here designated by equal reference signs. However, the present invention is not limited to the described design features but comprises further modifications of features of the described examples and combinations of features of various examples within the scope of protection of the independent claims.

[0045] FIG. 1 shows a sectional view through a tire 40 having a repaired damaged site 60, to which a tire repair patch 10 is adhered. The illustrated section of the tire 40 has a layer of lateral wall rubber 110, the carcass 100 with fibrous inserts 150 and an inner liner 90. This figure also shows the (self-adhesive) film 1 according to the invention, which was adhered above the tire repair patch 10.

[0046] The illustrated damaged site 60 is filled with raw rubber 50. Preferably and as shown, the tire patch and/or the tire repair patch 10 has a sticky connecting layer 30, which holds the tire repair patch 10 in connection to the illustrated inner liner 90 of the tire 40. A further layer of the tire repair patch 10 is a rubber layer 20 having supporting elements 70, such as steel or carbon fiber filaments.

[0047] During the vulcanization, internal stresses are released in the tire repair patch/the repair site together with an initial viscosity drop of the initially still unvulcanized connecting layer, which may lead to the peeling of the tire repair patch 10 from the surface 90. Therefore, envelopes were formerly wrapped around the tire 40 and the tire repair patch 10, and a vacuum was applied, which hold the tire repair patch 10 at the predetermined position on the tire surface 90. According to the invention, this is no longer necessary in a technically advantageous manner since the film 1 shown in FIG. 1 adopts the technical function of the envelope on the inner side of the tire.

[0048] The illustrated film 1 has an adhesive layer 3, which establishes a connection between the inner liner 90 and the film 1. The adhesive layer 3 is arranged on a preferably polymer-based supporting layer 2. The self-adhesive film 1 according to the invention is very flexible and, as shown, adapts itself in optimum fashion to the outer contour of the tire repair patch 10 and the contour of the inner liner 90.

[0049] The film 1 protrudes in each case from lateral edges 10a of the tire repair patch 10 (see FIG. 3) in such a way that the tire repair patch 10 is fixedly held in place during the vulcanization inter alia on account of the adhesive connection between the film 1 and the inner liner 90 and/or the uppermost layer of the tire repair patch 10. Furthermore, the film 1 shall not allow a gas exchange between a cavity in which the tire repair patch 10 is arranged and an outer side of the film 1. Correspondingly, the illustrated supporting layer 2 is preferably gas-tight and the adhesive layer 3 also adopts, in addition to the adhesive function, a sealing function against the external atmosphere. This sealing property of the self-adhesive film can produce a pressure difference of e.g. 0.05 bar or more in the region coated by adhesion with respect to the external atmosphere, which has an increased pressure of e.g. 5 bar during the vulcanization. This possible pressure difference produces an (additional) holding force which acts in the direction of the surface of the elastomer component and, together with the elastomer patch, presses the self-adhesive film securely and reliably against the component, in particular during the vulcanization.

[0050] The vulcanization conditions usually range from 1 bar to 10 bar pressure and are at a temperature of about 90° C. to 180° C. These conditions are preferably maintained during a period of about 60 min to 10 h. During this period and with the above mentioned temperature and pressure conditions, the self-adhesive film 1 has a peel strength of at least 0.5 N/mm between the inner liner 90 and/or the uppermost layer of the tire repair patch 10 and the adhesive layer 3, as a result of which the tire repair patch 10 cannot be detached.

[0051] The adhesive layer 3 preferably has a portion of 20% to 70% of masticated natural rubber. Furthermore 2% to 10% of liquid polyisoprene rubber can be contained and up to 10% of resins in order to achieve the above mentioned peel strength. Further constituents can also be solids, such as soot, silica or chalk. When the adhesive layer 3 has a butyl portion, the inner side of the tire which is covered by the film is also sealed during the vulcanization at the same time.

[0052] The method for applying the self-adhesive film 1 and/or for repairing the tire 40 or the elastomer lining comprises substantially the steps of repairing the damaged site 60 and of filling the damaged site 60 with raw rubber 50. Furthermore, the tire repair patch 10 is applied to the filled damaged site 50, 60 and the tire repair patch 10 is coated by adhesion using the film 1 according to the invention. Then, the vulcanization is carried out as usual and previously known.

[0053] FIG. 2 shows the film 1 according to the invention, which is not adhered to a tire repair patch 10 of a motor vehicle tire 40 but over a seam 130 of two layers of elastomer lining 120. Large tank trucks or tank wagons have an elastomer lining 120 to protect the outer shell in order to be able to transport e.g. corrosive chemicals. The layers of elastomer lining 120 can either overlap one another or be arranged edge to edge. FIG. 2 shows by way of example an edge-to-edge arrangement. For the purposes of a repair of the lining, it is also possible to adhere an elastomer patch 10′ which is not shown in FIG. 2 to the elastomer lining 120, said patch having a similar structure as the repair patch 10 of FIG. 1. In order that the two layers of elastomer lining 120 do not leave the predetermined position during the vulcanization or in order that the elastomer patch 10′ is not detached during the vulcanization, the film 1 according to the invention is adhered to the seam 130 or the elastomer patch 10′.

[0054] As regards the connection of two layers of elastomer lining 120, the layers can also be connected to one another without using an elastomer patch 10′, as described. Should the layers be arranged in such a way that they overlap one another, the seam 130 can directly be coated by adhesion using the film 1, i.e. without repair patch 10′. The two layers of elastomer lining 120 bake together during the vulcanization. Furthermore, the layers of the elastomer lining 120 can also be arranged edge to edge. In this arrangement, too, the seam 130 can directly be coated by adhesion by means of the film 1 without using a repair patch 10′. In this case, the edge end faces of the two layers of elastomer lining 120 are joined during the vulcanization. In addition, the seam 130 can also be filled with raw rubber 50′ so as to produce in an even more reliable way a closure of the seam 130 which is as complete and continuous as possible.

[0055] FIG. 3 shows a top view of the arrangement in FIG. 1, which comprises the tire 40, the tire repair patch 10 and the film 1. FIG. 3 shows in particular that the film 1 protrudes on all lateral portions of the tire repair patch 10 from said portions, as a result of which an adhesive connection can be produced between the film 1 and the inner liner 90. Since the film shown schematically in FIG. 3 is transparent, the illustration should be comprehended in such a way that the film 1 extends continuously inside the area shown in white and here above the repair patch 10 shown in black. FIG. 3 shows by way of example a rectangular base of the repair patch 10 and the film 1. Other possible shapes comprise round, elliptic or square shapes of the base. The shape of the base of the repair patch 10 can also differ from the shape of the base of the film 1. Furthermore, FIG. 3 shows that the protruding portions of the film 1 have different widths in the longitudinal and transverse directions. The protruding portions can also have equal width.

[0056] Finally, it should be noted that the invention describes a method and a self-adhesive film 1, which considerably simplifies the repair of a tire 40 or an elastomer lining and/or the connection of two elastomer layers of an elastomer lining 120.