Multilayer Biodegradable Tube Laminate with Paper Layer and Protective Coating Arranged Thereon, Tube Body, and Tube

Abstract

A multilayer tube laminate for producing a tube container, having: at least one paper layer, a polymer layer with a sealable exposed polymer surface on one side of the at least one paper layer, and a polymer coating from an olefin-based material applied directly on the at least one paper layer on another side of the at least one paper layer facing away from the sealable polymer layer;
the polymer layer being formed to more than 90% by weight from a biodegradable polymer.

Claims

1-15. (canceled)

16. A multilayer tube laminate for producing a tube container, comprising: at least one paper layer, a polymer layer with a sealable exposed polymer surface on one side of the at least one paper layer, and a polymer coating from an olefin-based material applied directly on the at least one paper layer on another side of the at least one paper layer facing away from the sealable polymer layer, wherein the polymer layer is formed to more than 90% by weight from a biodegradable polymer.

17. The multilayer tube laminate according to claim 16, wherein the polymer layer consists of a biodegradable polymer.

18. The multilayer tube laminate according to claim 16, wherein the biodegradable polymer comprises or is at least one polymer out of polylactic acid, polybutylene succinate, a polyhydroxyalkanoate, in particular polyhydroxy butyrate and/or polyhydroxy butyrate hexanoate, polyvinyl alcohol, polybutylene adipate terephthalate, polycaprolactone, polyglycolide, a lignin-based thermoplastic, and an epoxy acrylate based on at least one oil.

19. The multilayer tube laminate according to claim 16, wherein the protective polymer coating carries applied printing formed from a layer of overprint varnish and a layer region of printing inks arranged between the overprint varnish layer and the protective polymer coating, where the overprint varnish lies free with its surface which faces away from the at least one paper layer.

20. The multilayer tube laminate according to claim 16, wherein the protective polymer coating comprises at least one acid-modified olefin.

21. The multilayer tube laminate according to claim 16, wherein the protective polymer coating consists of at least one acid-modified olefin.

22. The multilayer tube laminate according to claim 16, wherein the polymer coating is a protective polymer coating with a weight per area in the range from 0.5 g/m.sup.2 to 4.9 g/m.sup.2.

23. The multilayer tube laminate according to claim 16, wherein the polymer coating is a protective polymer coating with a weight per area in the range from 1 g/m.sup.2 to 2.5 g/m.sup.2.

24. The multilayer tube laminate according to claim 16, wherein the tube laminate exhibits at least one barrier layer for reducing an oxygen permeability and/or a water vapor permeability of the tube laminate, where the at least one barrier layer comprises a vinyl alcohol polymer and/or a metallization and/or a metal oxide or is formed from such a material.

25. The multilayer tube laminate according to claim 24, wherein the at least one barrier layer comprises a vinyl alcohol polymer or is formed from a vinyl alcohol polymer, where the vinyl alcohol polymer comprises or is polyvinyl alcohol and/or butenediol vinyl alcohol copolymer.

26. The multilayer tube laminate according to claim 24, wherein the tube laminate has an oxygen permeability of no more than 2.0 cm.sup.3/(m.sup.2.Math.d.Math.bar), measured in accordance with DIN 53380-3 at 23? C. and 50% relative humidity, and a water vapor permeability of no more than 2.0 g/(m.sup.2.Math.d), measured in accordance with ISO 15106-2 at 23? C. and 85% relative humidity.

27. The multilayer tube laminate according to claim 16, wherein the tube laminate exhibits a weight per area in the range from 150 g/m.sup.2 to 400 g/m.sup.2.

28. The multilayer tube laminate according to claim 16, wherein the tube laminate exhibits a thickness in the range from 200 ?m to 400 ?m.

29. The multilayer tube laminate according to claim 25, wherein the tube laminate exhibits more than one paper layer, where one of the paper layers carries the barrier layer.

30. A tube body formed from a tube laminate according to claim 16, where the tube body comprises a tube laminate blank which is rolled about a tube body longitudinal axis, where end regions of the tube laminate blank which face towards one another in the circumferential direction about tube body longitudinal axis are bonded with one another through sealing, forming a sealed seam running in the direction along the tube body longitudinal axis, where the sealed seam either i) is a overlap sealed seam, in which the sealable polymer layer overlaps the protective polymer coating in an overlap region, where the overlap region extends in the circumferential direction and in the direction along the tube body longitudinal axis and where the sealable polymer layer and the protective polymer coating are firmly bonded with one another in the overlap region, or ii) is a butt sealed seam, in which the end regions which face towards one another in forming a butt joint which proceeds in the direction along the tube body longitudinal axis and radially away from the tube body longitudinal axis approach one another, where the butt joint on at least one radial side with respect to the tube body longitudinal axis is covered by a sealing strip which extends along the butt joint, spans the butt joint in the circumferential direction, and on each of the two circumferential sides of the butt joint with is firmly bonded with an exposed surface section of the tube laminate in the end regions.

31. A tube with a tube body according to claim 30 and further with a tube shoulder bonded with the tube body which exhibits at least one exposed surface consisting of a polyolefin encircling the tube body longitudinal axis, where an exposed surface of the tube body is firmly bonded through sealing with the encircling exposed surface of the tube shoulder.

32. The tube according to claim 31, wherein the tube shoulder is made predominantly from a biodegradable polymer.

33. The tube according to claim 31, wherein the tube shoulder is made completely from a biodegradable polymer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail and illustrated in the accompanying drawings which forms a part hereof and wherein:

[0071] FIG. 1A schematic cross-sectional view of a first embodiment of a tube laminate according to the invention,

[0072] FIG. 2A schematic cross-sectional view of a second embodiment of a tube laminate according to the invention,

[0073] FIG. 3A schematic cross-sectional view of a first embodiment of a tube body when considering a sectional plane orthogonal to a tube body longitudinal axis,

[0074] FIG. 4A schematic cross-sectional view of a second embodiment of a tube body when considering a sectional plane orthogonal to a tube body longitudinal axis, and

[0075] FIG. 5A rough schematic elevation view of a tube formed from a tube laminate of FIG. 1 or 2.

[0076] The depictions in the drawings are not to scale.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0077] Referring now to the drawings wherein the showings are for the purpose of illustrating preferred and alternative embodiments of the invention only and not for the purpose of limiting the same, in FIG. 1, a first embodiment of a tube laminate according to the invention is denoted generally by 10. The tube laminate 10 exhibits an inner side or inner surface 10a facing towards a packaging space V of a tube container formed from the tube laminate 10 and exhibits on the tube container formed from the tube laminate 10 an outer side or outer surface 10b exposed towards the external environment U (see also FIGS. 3 and 4).

[0078] The tube laminate 10 of the first embodiment exhibits a single paper layer 12 with a preferred weight per area of 100 to 200 g/m.sup.2. On its one side 12a there is applied on the paper layer 12 by means of wet printing, layer 14 of a water-based wet laminating adhesive, for instance casein-based, for instance with a roller. The weight per area of the adhesive layer 14 is preferably between 2 and 10 g/m.sup.2.

[0079] On the side 14a of the adhesive layer 14 which faces away from the paper layer 12 there is arranged a multilayer combined barrier and sealing film 15, which is bonded with the paper layer 12 by the adhesive layer 14.

[0080] The combined barrier and sealing 15 is formed through coextrusion of all the layers contained in it and exhibits a sealable layer 16 made from biodegradable PBS, a first intermediate layer 18 made from a biodegradable polymer, preferably from PBSA, a second intermediate layer 21 made from a biodegradable polymer, preferably from PBSA, and an outer layer 23 made from a biodegradable polymer, preferably from PBSA. Between the biodegradable sealable layer 16 and the biodegradable outer layer 23, in particular between the first and the second intermediate layer 18 and 21, there is arranged a barrier layer 20 made from butenediol vinyl alcohol copolymer (BVOH).

[0081] Solely for the sake of completeness let it be mentioned that the barrier layer 20 is bonded through an interposed adhesive coating 17 or 19 as the case may be likewise made from BVOH both with the surface 18b of the biodegradable first intermediate layer 18 facing towards it and with the surface 21a of the biodegradable second intermediate layer 21 facing towards it and.

[0082] The barrier layer 20 made from BVOH reduces the oxygen permeability of the barrier film 15 and the biodegradable polymer coatings 16, 18, 21, and 23the biodegradable polymer coatings 18, 21, and 23 to a greater extent than 16reduce the water vapor permeability of the barrier film 15.

[0083] The combined barrier and sealing film 15 exhibits a thickness in the range from 30 to 160 ?m, preferably from 40 to 150 ?m.

[0084] The biodegradable sealable layer 16 exhibits a sealable surface 16a, forming the surface 10a of the tube laminate 10 which is exposed towards the packaging space V.

[0085] On its other side 12b there is applied onto the paper layer 12 a protective polymer coating 24 which preferably is made from ethylene-methacrylic acid copolymer, namely with a preferred thickness of 1 to 2.5 g/m.sup.2, especially preferably of approximately 2 g/m.sup.2. The protective polymer coating 14 protects the paper layer 12 against influences from the external environment U and at the same time allows, due to its low thickness, radiation-based detection of the paper layer 12, which makes possible automated feeding of the tube laminate 10 to a paper-assigned recycling stream.

[0086] The protective polymer coating 24 is applied by printing, for example through a pressure roller. Consequently, the application is a wet process.

[0087] In FIG. 2 there is depicted in cross-section an alternative second embodiment of a tube laminate 110 according to the invention. Identical and functionally identical components and component sections as in FIG. 1 are labelled in FIG. 2 by the same reference symbols, but increased numerically by 100. The second embodiment depicted in FIG. 2 is described below only in so far as it differs from the first embodiment, to whose description express reference is otherwise made also for elucidating the second embodiment.

[0088] The tube laminate 110 of the second embodiment exhibits not only one paper layer 112, but instead exhibits additionally a second paper layer 126. The second paper layer 126 exhibits on its side 126b which faces towards the external environment U the barrier layer 120 as a layer made from polyvinyl alcohol (PVOH) or from butenediol vinyl alcohol copolymer (BVOH).

[0089] The paper layer 112 and the second paper layer 126 with the barrier layer 120 arranged on the latter are bonded through extrusion lamination by means of an extrusion laminating layer 128 made from PBSA and/or PBS. The extrusion laminating layer 128 for bonding the two paper layers 112 and 126 exhibits a weight per area of between 10 g/m.sup.2 and 50 g/m.sup.2, in particular of 10 g/m.sup.2 and 30 g/m.sup.2. Application weights of between 30 g/m.sup.2 and 50 g/m.sup.2 serve inter alia to improve the water impermeability of the tube laminate 110.

[0090] The paper layer 112 exhibits a weight per area of between 40 g/m.sup.2 and 150 g/m.sup.2. The second paper layer 126 likewise exhibits a weight per area of between 40 g/m.sup.2 and 150 g/m.sup.2, which however does not mean that the first and the second paper layer 112 and 126 always have to exhibit the same weight per area.

[0091] In the present second embodiment example, the biodegradable polymer layer 116 is not arranged as a blown film or a cast film as in the first embodiment example, but instead is extruded. The biodegradable polymer layer 116 exhibits a thickness of between 10 ?m and 70 ?m, in particular of 12.4 ?m to 62 ?m. The biodegradable polymer layer 116 can, as in the first embodiment example, be made from PBS or from a blend of PBS and PBSA.

[0092] The exposed surface 116a of the biodegradable sealable polymer layer 116 forms the inner surface 110a of the tube laminate 110 of the second embodiment.

[0093] On the surface 124b of the protective polymer coating 124 facing away from the paper layer 112 there is applied by printing an applied printing 130. This applied printing 130 exhibits a layer region with applied printing ink 132 and an acryl-based overprint varnish 134 which covers the applied printing ink 132 towards the external environment U. The applied printing ink 132 is therefore situated between the overprint varnish 134 and the protective polymer coating 124. An exposed surface 134b of the overprint varnish facing towards the external environment U forms the outer surface 110b of the tube laminate 110 of the second embodiment.

[0094] The applied printing 130, which of course can also be arranged at an appropriate place of the first embodiment, exhibits a thickness of less than 3 ?m.

[0095] Despite the applied printing 130 on the protective polymer coating 124, the spacing between the outer surface 110b of the tube laminate and the surface 112b facing towards the external environment U of the paper layer 112 nearest to the external environment is so small, maximum 5 to 7 ?m, that detection of the tube laminate 110 as paper-containing through near-infrared technology is possible without problems.

[0096] In FIG. 3 there is shown in rough schematic form a cross-section of a first embodiment of a tube body 40 formed from the tube laminate 10 of the first embodiment example of FIG. 1. The tube body 40 extends in the depiction as an idealized cylindrical tube body 40 along a tube body longitudinal axis TKLA which proceeds orthogonally to the drawing plane of FIG. 3.

[0097] A tube body blank 42 of the tube laminate 10 is rolled in the circumferential direction about the tube body longitudinal axis TKLA, where after the rolling end regions 42a and 42b of the tube body blank 42 which face towards one another in the circumferential direction overlap in an overlap region 44. In the overlap region 44, the sealable inner surface 10a of the tube laminate 10 overlies the outside 10b formed by the protective polymer coating 24. Due to the choice of materials, for example PBS or PBSA for the inner surface 10a of the tube laminate 10 and ethylene-methacrylic acid copolymer for the protective polymer coating 24, the inner surface 10a and the outer surface 10b are thermally sealable with one another, such that in the overlap region 44 an overlap sealed seam 46 can be formed through which the inner surface 10a and the outer surface 10b of the tube laminate 10 can be firmly bonded with one another.

[0098] The overlap sealed seam 46 extends over the entire overlap region 44, that is, essentially over the entire axial length of the tube body 40 with respect to the tube body longitudinal axis TKLA and in the circumferential direction along the actually existing overlap of the two end regions 42a and 42b of the tube body blank 42.

[0099] In FIG. 4 there is shown roughly schematically a cross-section of a second embodiment of a tube body 50, which again is formed from the tube laminate 10 of the first embodiment examples of FIG. 1. The tube body 50 of the second embodiment also extends in the depiction as an idealized cylindrical tube body 50 along a tube body longitudinal axis TKLA, which proceeds orthogonally to the drawing plane of FIG. 4. The tube body 50 of FIG. 4 is preferable to the tube body 40 of FIG. 3 due to the expected higher bonding safety.

[0100] A tube body blank 52 of the tube laminate 10 is again rolled in the circumferential direction about the tube body longitudinal axis TKLA, where after the rolling end regions 52a and 52b of the tube body blank 52 which face towards one another in the circumferential direction face each other butt-to-butt, forming a butt joint 58 extending along the tube body longitudinal axis TKLA, preferably even in parallel to it. Consequently, no overlap of the end regions 52a and 52b takes place.

[0101] The butt joint 58 is covered at each of its two radial sides with a sealing strip 60 and 62 respectively in such a way that each sealing strip extends along the butt joint 58 over essentially its entire axial length with respect to the tube body longitudinal axis TKLA and spanning the butt joint 58 in the circumferential direction on the exposed surfaces of the end regions 52a and 52b. Consequently, the sealing strips 60 and 62 overlap the end regions 52a and 52b in an overlap region 54.

[0102] The radially inner sealing strip 60, whose longitudinal direction likewise proceeds orthogonally to the drawing plane of FIG. 4, contacts the inner surface 10a of the tube laminate 10 in the two circumferential end regions 52a and 52b. The radially outer sealing strip 62, whose longitudinal direction likewise proceeds orthogonally to the drawing plane of FIG. 4, contacts the outer surface 10b of the tube laminate 10 in the two circumferential end regions 52a and 52b.

[0103] The sealing strips 60 and 62 are preferably constructed identically. They exhibit on their side which contacts the tube body 50 a sealable layer from a biodegradable polymer, preferably from PBS. The sealable PBS layer can be stabilized through a substrate layer.

[0104] The substrate layer is preferably likewise made from a biodegradable polymer, for instance from PBSA, to name just one example.

[0105] The sealing strips 60 and 62 are each firmly bonded through thermal sealing with the surface contacted by them of the tube laminate 10 or of the tube body 50 as the case may be. The sealing strip 60 forms with the inner surface 10a of the tube laminate 10 at the end regions 52a and 52b a part-butt sealed seam 56a spanning the butt joint 58, whereas the sealing strip 62 forms with the outer surface 10b of the tube laminate 10 at the end regions 52a and 52b a part-butt sealed seam 56b spanning the butt joint 58. The part-butt sealed seams 56a and 56b form together a butt sealed seam.

[0106] If the outside 10b of the tube laminate 10 is formed through applied printing, the latter is omitted in the overlap region 44 on the radially inner overlapping end section 42b and/or in the overlap section 54 respectively, so that sealable polymer surfaces can touch each other directly there.

[0107] The tube bodies 40 and 50 of FIGS. 3 and/or 4 respectively can be formed, instead of with the tube laminate 10 of the first embodiment example, with the tube laminate 110 of the second embodiment example.

[0108] FIG. 5 shows a schematic front view of a tube container 70 exhibiting a tube body 40 made from the multilayer tube laminate 10 and a tube shoulder 72, where the tube shoulder 72 in the depicted example is configured integrally with a pivotable cap 74 on which the tube container 70 can stand. Alternatively, the tube body 40 can also be produced from the second embodiment of the multilayer tube laminate 110. Equally, instead of the tube body 40 with an overlap sealed seam, a tube body 50 with a butt sealed seam could be used in the tube container 70. The latter is even preferable.

[0109] For producing the tube body 40, as already described in connection with FIGS. 3 and 4, a cutting or blank 42 as the case may be of the multilayer tube laminate 10 is rolled around a mandrel such that the end regions 42a and 42b of the rolled blank 42 which are on the end side in the circumferential direction overlap. In the overlap region 44 thus created, the inner surface 10a overlaps the outer surface 10b axially along the tube body longitudinal axis TKLA and in the circumferential direction around the tube body longitudinal axis TKLA. The two end regions 42a and 42b are bonded in the overlap region 44 through hot sealing, in order to form the described overlap sealed seam 46.

[0110] At the longitudinal end 41 facing away from the tube shoulder 72, the tube body 40 is sealed by a fin sealed seam 76. Unlike the overlap sealed seam 46, where the inner surface 10a is sealed with the outer surface 10b of the tube laminate 10, in the fin sealed seam 76 opposite regions of the inner surface 10a are sealed with one another.

[0111] At the longitudinal end near the tube shoulder 72, the tube body 40 encloses part of the tube shoulder 72 and overlaps this part in the axial direction with respect to the tube body longitudinal axis TKLA and in the circumferential direction completely. The overlapping parts of the tube body 40 and of the tube shoulder 72 are likewise bonded through hot sealing. To this end, the tube shoulder 72 is preferably made from injection-molded biodegradable polymer such that the materials of the tube shoulder 72 and of the sealable layer 16 of the multilayer tube laminate 10, which forms the inner surface 10a of the tube laminate 10, are compatible with one another. In a preferred embodiment, the tube shoulder 72 can be injection molded from the same synthetic as the sealable layer 16 bonded with it through sealing, i.e. in the present example for instance PBS.

[0112] The tube shoulder 72 can alternatively, in order to achieve good recyclability, be made to more than 50% by weight, preferably to more than 75% by weight, as a preformed component from molded fiber. The tube shoulder 72, predominantly made from molded fiber, can exhibit an outer polymer skin for sealing bonding with the tube body 40, for instance from the same material as the sealable layer 16 or 116 or from a material compatible with it. The tube shoulder 72, predominantly made from molded fiber, can exhibit an inner polymer skin in order to shield the molded fiber against the product packaged in the tube container.

[0113] Molded fiber is mentioned here only by way of example for fiber-containing material, whose fibers at least in part, preferably predominantly in terms of mass, especially preferably completely, are of plant origin. The fiber-containing material is preferably made from a fiber-containing suspension through dehydration. Possible fiber material includes in particular cellulose, i.e. for example chemically broken-down plant fibers, mechanical pulp, i.e. for example lignin-containing woody material broken down through defibration, and waste paper.

[0114] The cap 74 is pivotable about a pivot axis PA, e.g. through a film hinge which connects the cap 74 integrally with the tube shoulder 72. A depression 78 facilitates the gripping and lifting of the cap 74 off the tube shoulder 72, in order to open the tube container 70.

[0115] Instead of a cap 74 bonded integrally with the tube shoulder 72, the cap can be formed separately from the tube shoulder and for example be screwable onto it and unscrewable from it. This embodiment is preferable for prefabricated tube shoulders made from fiber-containing material, in particular molded fiber.

[0116] While considerable emphasis has been placed on the preferred embodiments of the invention illustrated and described herein, it will be appreciated that other embodiments, and equivalences thereof, can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. Furthermore, the embodiments described above can be combined to form yet other embodiments of the invention of this application. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.