Sheetlike Composite, Especially for Production of Dimensionally Stable Food or Drink Product Containers, Comprising a Polymer Layer P Having an L Value

Abstract

The invention relates to a sheetlike composite comprising, as mutually superposed layers in a direction from an outer face of the sheetlike composite to an inner face of the sheetlike composite, a) a carrier layer, and b) a barrier layer; wherein the sheetlike composite additionally includes a polymer layer P comprising a first polymer; wherein the polymer layer P has an L value in the L*a*b* colour space within a range from 30 to 56. The invention further relates to methods of producing a sheetlike composite, a container precursor and a closed container and to the aforementioned method products; to a container precursor and a closed container each including at least one sheetlike region of the sheetlike composite; to uses of the sheetlike composite for production of a food or drink product container and in a microwave oven; and to uses of compositions for production of a sheetlike composite for a food or drink product container.

Claims

1. A sheetlike composite comprising, as mutually superposed layers, in a direction from an outer face of the sheetlike composite to an inner face of the sheetlike composite, a) a carrier layer, and b) a barrier layer; wherein the sheetlike composite additionally includes a polymer layer P including a first polymer; wherein the polymer layer P has an L value in the L*a*b* colour space within a range from 30 to 56.

2. The sheetlike composite according to claim 1, wherein the polymer layer P additionally includes a. a first type of inorganic particles, and b. a further type of inorganic particles.

3. The sheetlike composite according to claim 2, wherein the inorganic particles of the first type include a titanium oxide.

4. The sheetlike composite according to claim 3, wherein the polymer layer P includes the titanium oxide in a proportion within a range from 5% to 30% by weight, based on the weight of the polymer layer P.

5. The sheetlike composite according to claim 2, wherein the inorganic particles of the further type include elemental carbon.

6. The sheetlike composite according to claim 2, wherein the inorganic particles of the further type are carbon black particles.

7. The sheetlike composite according to claim 1, wherein the carrier layer has a transmittance of at least 0.4% for light within a wavelength range from 475 to 480 nm.

8. The sheetlike composite according to claim 1, wherein the carrier layer has at least one hole, wherein the at least one hole has been covered at least by the polymer layer P as hole-covering layer.

9. The sheetlike composite according to claim 1, wherein the polymer layer P is disposed between the carrier layer and the barrier layer.

10. The sheetlike composite according to claim 1, wherein the barrier layer includes, as mutually superposed sublayers, a. a barrier substrate layer, and b. a barrier material layer; wherein the barrier material layer has an average thickness within a range from 1 nm to 1 m.

11. A method comprising, as method steps: a) providing i) a sheetlike composite precursor including a carrier layer, and ii) a polymer composition; and b) covering the carrier layer with the polymer composition, thereby obtaining a polymer layer P overlaying the carrier layer; wherein the polymer composition includes a. a first polymer, b. a first type of inorganic particles in a proportion within a range from 5% to 30% by weight, and c. a further type of inorganic particles in a proportion within a range from 0.5% to 2.5% by weight, wherein the percentages by weight are each based on the weight of the polymer composition.

12. The method according to claim 11, wherein the polymer layer P has an L value in the L*a*b* colour space within a range from 30 to 56.

13. A sheetlike composite obtainable by the method according to claim 11.

14. A container precursor including at least one sheetlike region of the sheetlike composite according to claim 1.

15. A closed container including at least a sheetlike region of the sheetlike composite according to claim 1.

16. A method comprising, as method steps: a. providing at least one sheetlike region of the sheetlike composite according to claim 1, said at least one sheetlike region including a first longitudinal edge and a further longitudinal edge; b. folding the at least one sheetlike region; and c. contacting and joining the first longitudinal edge to the further longitudinal edge, thereby obtaining a longitudinal seam.

17. A container precursor obtainable by the method according to claim 16.

18. A method comprising, as method steps: A. providing the container precursor according to claim 14; B. forming a base region of the container precursor by folding the sheetlike composite; C. closing the base region; D. filling the container precursor with a food or drink product; and E. closing the container precursor in a top region, thereby obtaining a closed container.

19. A closed container obtainable by the method according to claim 18.

20. A use of the sheetlike composite according to claim 1 for production of a food or drink product container.

21. A use of a composition comprising i) a multitude of titanium oxide particles in a proportion within a range from 30% to 70% by weight, and ii) a multitude of carbon black particles in a proportion within a range from 0.5% to 20% by weight, based in each case on the weight of the composition, for production of a sheetlike composite for a food or drink product container.

22. A use of a composition comprising i) a multitude of titanium oxide particles in a proportion within a range from 40% to 80% by weight, and ii) a polyethylene in a proportion of at least 15% by weight, based in each case on the weight of the composition, for production of a sheetlike composite for a food or drink product container.

23. A use of a composition comprising i) a multitude of carbon black particles in a proportion within a range from 10% to 60% by weight, and ii) a polyethylene in a proportion of at least 30% by weight, based in each case on the weight of the composition, for production of a sheetlike composite for a food or drink product container.

24. A use of at least one sheetlike region of the sheetlike composite according to claim 1 in a microwave oven.

Description

[0337] The figures respectively show, unless stated otherwise in the description or the respective figure, in schematic form and not to scale:

[0338] FIG. 1 a schematic diagram of a section of a sheetlike composite of the invention in cross section;

[0339] FIG. 2 a flow diagram of a method according to the invention for producing a sheetlike composite;

[0340] FIG. 3 a schematic diagram of a container precursor according to the invention;

[0341] FIG. 4 a schematic diagram of a closed container according to the invention;

[0342] FIG. 5 a flow diagram of a method according to the invention for producing a container precursor; and

[0343] FIG. 6 a flow diagram of a method according to the invention for producing a closed container.

[0344] FIG. 1 shows a schematic diagram of a section of a sheetlike composite 100 according to the invention in cross section. The sheetlike composite 100 consists of the following layers in a layer sequence in a direction from an outer face 101 of the sheetlike composite 100 to an inner face 102 of the sheetlike composite 100: a colour application 103 which is a decoration of the sheetlike composite 100, an outer polymer layer 104, a carrier layer 105, a polymer interlayer 106, a first adhesion promoter layer 107, a barrier layer 108, a further adhesion promoter layer 112 and an inner polymer layer 113. The outer polymer layer 104 consists of LDPE 19N430 from Ineos GmbH, Cologne. The carrier layer 105 is a cardboard layer identified as Stora Enso Natura T Duplex with double coating slip (Scott bond 200 J/m.sup.2, residual moisture content 7.5%). The first adhesion promoter layer 107 and the further adhesion promoter layer 112 each consist of a maleic anhydride-grafted ethylene-acrylate copolymer identified as Dow XZ89893 from The Dow Chemical Company AG. The barrier layer 108 is a barrier film identified as GL-AE.square-solid. C-FD from Toppan Printing Co. Ltd. This barrier film consists of a barrier substrate layer 109 composed of biaxially oriented PET (BOPET), an adjoining barrier material layer 110 of AlOx and an adjoining protective layer 111. In this case, in the sheetlike composite 100, the BOPET layer of the barrier film faces the outer face 101 of the sheetlike composite 100.

[0345] The barrier layer 108 has a thickness of 12 m. The inner polymer layer 113 consists, in a direction from the barrier layer 108 to the inner face 102, of the following three sublayers: a first inner layer 114 composed of 75% by weight of HDPE and 25% by weight of LDPE, based in each case on the total weight of the first inner layer 114, a second inner layer 115 composed of 100% by weight of LDPE, based on the total weight of the second inner layer 115, and a third inner layer 116 composed of a polymer blend, where the polymer blend consists to an extent of 30% by weight of an mPE and to an extent of 70% by weight of an LDPE, based in each case on the total weight of the third inner layer 116. The polymer interlayer 106 consists of 15% by weight of TiO.sub.2 particles, 1.2% by weight of carbon black particles and 83.8% by weight of LDPE 19N430 from Ineos GmbH, Cologne, Germany, based in each case on the weight of the polymer interlayer 106. The basis weight of the polymer interlayer 106 is 18 g/m.sup.2. The polymer interlayer 106, by the test method described herein, has an L value in the L*a*b* colour space of 44.

[0346] FIG. 2 shows a flow diagram of a method 200 according to the invention for production of a sheetlike composite 100. The method 200 includes a method step a) 201 in which a sheetlike composite precursor consisting of a carrier layer 105 is provided. The carrier layer 105 is a cardboard layer identified as Stora Enso Natura T Duplex with double coating slip (Scott bond 200 J/m.sup.2, residual moisture content 7.5%). Further, in method step a) 201, a polymer composition is provided. This consists of 15% by weight of TiO.sub.2 particles, 1.2% by weight of carbon black particles and 83.8% by weight of LDPE 19N430 from Ineos GmbH, Cologne, Germany, based in each case on the weight of the polymer composition. In a method step b) 202, the carrier layer 105 is coated with the polymer composition by a layer extrusion method. This affords an outer polymer layer 104 overlaying the carrier layer 105 from the polymer composition. This outer polymer layer 104 has an L value in the L*a*b* colour space of 44. Downstream of method step b) 202, a barrier layer 108 is provided. The barrier layer 108 is a barrier film identified as GL-AE.square-solid. C-FD from Toppan Printing Co. Ltd. This barrier film consists of a barrier substrate layer 109 composed of biaxially oriented PET (BOPET), an adjoining barrier material layer 110 of AlOx and an adjoining protective layer 111. The barrier layer 108 is subjected on both sides to a surface treatment 203 in the form of a plasma treatment. This increases a surface tension of the barrier layer 108 both on the side of the barrier substrate layer 109 and on the side of the protective layer 111 to 55.Math.10.sup.3 N/m. In an immediately subsequent method step c) 204, the barrier layer 108 is overlaid onto the carrier layer 105 with the barrier substrate layer 109 facing the carrier layer 105. This involves applying the barrier layer 108 on the opposite side of the carrier layer 105 from the outer polymer layer 104 by lamination. This involves introducing a polymer interlayer 106 of LDPE and a first adhesion promoter layer 107 as lamination layers between the carrier layer 105 and the barrier layer 106 proceeding from the carrier layer 105 in the direction of the barrier layer 108. In a method step d) 205, the barrier layer 108 is overlaid on a side remote from the carrier layer 105 with a further adhesion promoter layer 111 and an inner polymer layer 113. This involves applying the further adhesion promoter layer 111 and a first inner layer 114 and a second inner layer 115, which together form the inner polymer layer 113, by coextrusion. The first inner layer 114 consists of LDPE 19N430 from Ineos GmbH, Cologne, Germany, and the second inner layer 115 of a blend of 65% by weight of LDPE 19N430 from Ineos GmbH, Cologne, Germany and 35% by weight of Eltex 1315 AZ from Ineos GmbH, Cologne, Germany. Downstream of method step d) 205, the sheetlike composite 100 obtained above is printed with a decoration (reference numeral 206) on the side of the outer polymer layer 104. In a method step e) 207, grooves 306 are introduced into the sheetlike composite 100, such that, by folding along these grooves 306 and joining of particular regions of the folded sheetlike composite 100, containers can be formed from the sheetlike composite 100. For this purpose, a grooving tool acts mechanically on the sheetlike composite 100 and produces linear depressions in the carrier layer 105, called grooves 306. Downstream of method step e) 207, the grooved sheetlike composite 100 is cut to size to form a multitude of blanks, each for production of a single closed container 400 (reference numeral 208). These blanks can be processed further by the method 500 of the invention to form container precursors 300 in shell form.

[0347] FIG. 3 shows a schematic diagram of a container precursor 300 according to the invention. The container precursor 300 includes a blank of the sheetlike composite 100 obtained by the method 200 with 4 longitudinal folds 301, each of which forms a longitudinal edge 301. In the container precursor 300, the outer face 101 of the sheetlike composite 100 faces outward. The container precursor 300 is in the form of a shell and comprises a longitudinal seam 302 in which a first longitudinal edge and a further longitudinal edge of the sheetlike composite 100 are sealed to one another. In addition, the container precursor 300 comprises a hole 305 in the carrier layer 105. The hole 305 is covered by the outer polymer layer 104 (not shown), the polymer interlayer 106 (not shown), the first adhesion promoter layer 107 (not shown), the barrier layer 108, the further adhesion promoter layer 1112 (not shown) and the inner polymer layer 113 (not shown) as hole-covering layers. By folding along grooves 306 and joining of fold regions in a top region 303 and a base region 304 of the container precursor 300, a closed container 400 is obtainable. Such a closed container 400 is shown in FIG. 4.

[0348] FIG. 4 shows a schematic representation of a closed container 400 according to the invention. The closed container 400 has been produced from the container precursor 300 according to FIG. 3. The closed container 400 comprises a food or drink product 401 and has 12 edges. In addition, the closed container 400 is connected to a lid comprising an opening aid 402 which covers the hole 305 on the outer face 101 of the sheetlike composite 100. Here, the lid 402 comprises a cutting tool as opening aid in its interior.

[0349] FIG. 5 shows a flow diagram of a method 500 according to the invention for producing a container precursor 300. In a method step a. 501, a blank of the sheetlike composite 100 obtained as described above by the method 200 is provided. This comprises a first longitudinal edge and a further longitudinal edge. In a method step b. 502, the blank is folded. In a method step c. 503, the first longitudinal edge and the further longitudinal edge are pressed against one another and joined to one another by heat-sealing. Thus, a longitudinal seam 302 is obtained. According to the above description, the container precursor 300 according to FIG. 3 is produced.

[0350] FIG. 6 shows a flow diagram of a method 600 according to the invention for producing a closed container 400. In a method step A. 601, the container precursor 300 according to FIG. 3 is provided. In a method step B. 602, a base region 304 of the container precursor 300 is formed by folding the sheetlike composite 100. In a method step C. 603, the base region 304 is closed by sealing with hot air at a temperature of 300 C. In a method step D. 604, the container precursor 300 is filled with a food or drink product 401 and, in a method step E. 605, the container precursor 300 is closed by sealing in a top region 303, thereby obtaining the closed container 400 of FIG. 4. In a method step F. 606, the closed container 400 is joined to an opening aid 402.

LIST OF REFERENCE SIGNS

[0351] 100 Sheetlike composite according to the invention

[0352] 101 Outer face

[0353] 102 Inner face

[0354] 103 Colour application

[0355] 104 Outer polymer layer

[0356] 105 Carrier layer

[0357] 106 Polymer interlayer

[0358] 107 First adhesion promoter layer

[0359] 108 Barrier layer

[0360] 109 Barrier substrate layer

[0361] 110 Barrier material layer

[0362] 111 Protective layer

[0363] 112 Further adhesion promoter layer

[0364] 113 Inner polymer layer

[0365] 114 First inner layer

[0366] 115 Second inner layer

[0367] 116 Third inner layer

[0368] 200 method according to the invention for production of a sheetlike composite

[0369] 201 Method step a)

[0370] 202 Method step b)

[0371] 203 Surface treatment

[0372] 204 Method step c)

[0373] 205 Method step d)

[0374] 206 Printing

[0375] 207 Method step e)

[0376] 208 Cutting-to-size

[0377] 300 Container precursor according to the invention

[0378] 301 Longitudinal fold/longitudinal edge

[0379] 302 Longitudinal seam

[0380] 303 Top region

[0381] 304 Base region

[0382] 305 Hole

[0383] 306 Groove

[0384] 400 Closed container according to the invention

[0385] 401 Food or drink product

[0386] 402 Lid with opening aid

[0387] 500 Method according to the invention for producing a container precursor

[0388] 501 Method step a.

[0389] 502 Method step b.

[0390] 503 Method step c.

[0391] 600 Method according to the invention for producing a closed container

[0392] 601 Method step A.

[0393] 602 Method step B.

[0394] 603 Method step C.

[0395] 604 Method step D.

[0396] 605 Method step E.

[0397] 606 Method step F.