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, b) a first adhesion promoter layer having a first acrylate content, c) a barrier layer, d) a further adhesion promoter layer having a further acrylate content, and e) an inner polymer layer; wherein the first acrylate content and the further acrylate content are each in a range from 7% to 40% by weight, based on the weight of the respective adhesion promoter layer. 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 a use of an adhesion promoter composition A and of an adhesion promoter composition B 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, b) a first adhesion promoter layer having a first acrylate content, c) a barrier layer, d) a further adhesion promoter layer having a further acrylate content, and e) an inner polymer layer; wherein the first acrylate content and the further acrylate content are each in a range from 7% to 40% by weight, based on the weight of the respective adhesion promoter layer.
2. The sheetlike composite according to claim 1, wherein the first acrylate content and the further acrylate content differ from one another by not more than 10% by weight.
3. The sheetlike composite according to claim 1, wherein the first adhesion promoter layer has a first Vicat softening temperature and the further adhesion promoter layer a further Vicat softening temperature, wherein the first Vicat softening temperature and the further Vicat softening temperature are each in a range from 20 to 120 C.
4. The sheetlike composite according to claim 1, wherein the first adhesion promoter layer includes an adhesion promoter polymer A, wherein the further adhesion promoter layer includes an adhesion promoter polymer B.
5. The sheetlike composite according to claim 4, wherein the adhesion promoter polymer A and the adhesion promoter polymer B are polyolefin-acrylate copolymers.
6. The sheetlike composite according to claim 5, wherein the polyolefin in the adhesion promoter polymer A or the polyolefin in the adhesion promoter polymer B or each of them is based on ethylene.
7. The sheetlike composite according to claim 4, wherein the adhesion promoter polymer A or the adhesion promoter polymer B or each of them is a polyolefin-alkyl acrylate copolymer.
8. The sheetlike composite according to claim 4, wherein the adhesion promoter polymer A or the adhesion promoter polymer B or each of them is a grafted copolymer.
9. The sheetlike composite according to claim 4, wherein the adhesion promoter polymer A or the adhesion promoter polymer B or each of them is a copolymer grafted with a diacid anhydride.
10. The sheetlike composite according to claim 1, wherein the barrier layer on a side facing the carrier layer consists of a different material from that of a side facing away from the carrier layer.
11. 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 in a range from 1 nm to 1 m.
12. A method comprising, as method steps: a) providing a sheetlike composite precursor including a carrier layer; b) overlaying the carrier layer on one side of the carrier layer in the following sequence proceeding from the carrier layer with i) an adhesion promoter composition A having a first acrylate content, and ii) a barrier layer; and c) overlaying the barrier layer on a side remote from the carrier layer in the following sequence proceeding from the barrier layer with i) an adhesion promoter composition B having a further acrylate content, and ii) an inner polymer layer; wherein the first acrylate content and the further acrylate content are each in a range from 7% to 40% by weight, based on the weight of the respective adhesion promoter composition.
13. A sheetlike composite obtainable by the method according to claim 12.
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, in each case 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 an adhesion promoter composition A having a first acrylate content and an adhesion promoter composition B having a further acrylate content B for production of a sheetlike composite for a food or drink product container, wherein the sheetlike composite includes a barrier layer, wherein, in the sheetlike composite, a) a first adhesion promoter layer obtainable from the adhesion promoter composition A overlays the barrier layer on a first side, and b) a further adhesion promoter layer obtainable from the adhesion promoter composition B overlays the barrier layer on a side opposite the first side, wherein the first acrylate content and the further acrylate content are each in a range from 7% to 40% by weight, based on the weight of the respective adhesion promoter composition.
21. A use of the sheetlike composite according to claim 1 for production of a food or drink product container.
22. A use of at least one sheetlike region of the sheetlike composite according to claim 1 in a microwave oven.
Description
[0298] The figures respectively show, in schematic form and not to scale, unless stated otherwise in the description or the respective figure:
[0299] FIG. 1 a schematic diagram of a section of a sheetlike composite of the invention in cross section;
[0300] FIG. 2 a schematic diagram of a section of a further sheetlike composite according to the invention in cross section;
[0301] FIG. 3 a flow diagram of a method according to the invention for producing a sheetlike composite;
[0302] FIG. 4 a schematic diagram of a container precursor according to the invention;
[0303] FIG. 5 a schematic diagram of a closed container according to the invention;
[0304] FIG. 6 a flow diagram of a method according to the invention for producing a container precursor;
[0305] FIG. 7 a flow diagram of a method according to the invention for producing a closed container;
[0306] FIG. 8 a photograph regarding sample preparation in the seal seam strength test method;
[0307] FIG. 9 a photograph regarding sample preparation in the seal seam strength test method;
[0308] FIG. 10 a photograph of multiple samples for the seal seam strength test method;
[0309] FIG. 11 a photograph of the test setup for the seal seam strength test method; and
[0310] FIG. 12 illustrative ATR spectra regarding the acrylate content test method.
[0311] 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 of a layer sequence in the direction from an outer face 101 of the sheetlike composite 100 to an inner face 102 of the sheetlike composite 100: a carrier layer 103, a first adhesion promoter layer 104, a barrier layer 105, a further adhesion promoter layer 106 and an inner polymer layer 107. The carrier layer 103 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 104 and the further adhesion promoter layer 106 each consist of the adhesion promoter Lotader 4613 from Arkema SA. The barrier layer 105 is a barrier film identified as GL-AEC-FD from Toppan Printing Co. Ltd. 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. The inner polymer layer 107 consists, in a direction from the barrier layer 105 to the inner face 102, of a sublayer consisting of LDPE 19N430 from Ineos GmbH, Cologne, Germany, and a sublayer of a blend consisting 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. Accordingly, the first adhesion promoter layer 104 and the further adhesion promoter layer 106 have the same acrylate content of 24% by weight, based on the weight of the respective adhesion promoter layer. The barrier layer 105 has a thickness of 12 m.
[0312] FIG. 2 shows a schematic diagram of a section of a further sheetlike composite 100 according to the invention in cross section. The sheetlike composite 100 consists of the following layers of 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 201 which is a decoration of the sheetlike composite 100, an outer polymer layer 202, a carrier layer 103, a polymer interlayer 203, a first adhesion promoter layer 104, a barrier layer 105, a further adhesion promoter layer 106 and an inner polymer layer 107. The outer polymer layer 202 and the polymer interlayer 203 each consist of LDPE 19N430 from Ineos GmbH, Cologne, Germany. The carrier layer 103 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 104 and the further adhesion promoter layer 106 each consist of a maleic anhydride-grafted ethylene-methyl acrylate copolymer identified as Lotader 4613 from Arkema. The barrier layer 105 is a barrier film identified as GL-AEC-FD from Toppan Printing Co. Ltd. This barrier film consists of a barrier substrate layer 204 composed of biaxially oriented PET (BOPET), an adjoining barrier material layer 205 of AlOx and an adjoining protective layer 206. 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. The barrier layer 105 has a thickness of 12 m. The inner polymer layer 107 consists, in a direction from the barrier layer 105 to the inner face 102, of the following three sublayers: a first inner layer 207 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 207, a second inner layer 208 composed of 100% by weight of LDPE based on the total weight of the second inner layer 208 and a third inner layer 209 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 209. Accordingly, the first adhesion promoter layer 104 and the further adhesion promoter layer 106 consist of the same adhesion promoter polymer which has an acrylate content of 24% by weight.
[0313] FIG. 3 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) 301 in which a sheetlike composite precursor is provided. For this purpose, a carrier layer 103 of cardboard is coated with an outer polymer layer 202 of LDPE. The carrier layer 103 includes a multitude of holes 405one such hole 405 for each container 500 to be produced from the carrier layer 103. In addition, a barrier layer 105 is provided in the form of a film identified as GL-AEC-FD from Toppan Printing Co. Ltd. Both sides of the film are prepared by a plasma treatment effected under reduced pressure so as to increase a surface tension on these two sides of the film to 65.Math.10.sup.3 N/m. In an immediately subsequent method step b) 302, the carrier layer 103 is coated on a side remote from the outer polymer layer 202, in the following sequence proceeding from the carrier layer 103, with an intermediate polymer composition of LDPE; with an adhesion promoter composition A consisting of a maleic anhydride-grafted ethylene-ethyl acrylate copolymer identified as Dow XZ89893 from The Dow Chemical Company AG as adhesion promoter polymer A; and with the barrier layer 105. In this case, the intermediate polymer composition and the adhesion promoter composition A are applied by coextrusion. A polymer interlayer 203 is obtained from the intermediate polymer composition, and a first adhesion promoter layer 104 from the adhesion promoter composition A. The barrier layer 105 has a thickness of 12 m and its BOPET layer faces the carrier layer 103. In a method step c) 303, the barrier layer 105 is coated on a side remote from the carrier layer 103 by coextrusion, in the following sequence proceeding from the carrier layer 105, with an adhesion promoter composition B consisting of the maleic anhydride-grafted ethylene-ethyl acrylate copolymer identified as Dow XZ89893 from The Dow Chemical Company AG as adhesion promoter polymer B; and with an inner polymer layer 107. A further adhesion promoter layer 106 is obtained from the adhesion promoter composition B. The inner polymer layer 107 consists, in this sequence, in a direction proceeding from the further adhesion promoter layer 106, of a sublayer of an LDPE and a further sublayer of a blend consisting of 65% by weight of LDPE and 35% by weight of mPE, based in each case on the weight of the blend. Accordingly, in accordance with the invention, the first adhesion promoter layer 104 and the further adhesion promoter layer 106 consist of the same adhesion promoter polymer which has an acrylate content of 10% by weight. In a method step d) 304, the outer polymer layer 202 is printed on a side remote from the carrier layer 103 with a colour application 201 in the form of a decoration. The decoration includes 6 colourants of different colours and forms an outer face 101 of the sheetlike composite 100 thus obtained from the sheetlike composite precursor. In a method step e) 305, the sheetlike composite 100 obtained from the sheetlike composite precursor above is grooved. For this purpose, a grooving tool acts mechanically on the sheetlike composite 100 and produces linear depressions in the carrier layer 103, called grooves 406. In a method step f) 306, the sheetlike composite 100 is cut to size to form a multitude of blanks, in each case for production of a single closed container 500. These blanks can be processed further by the method 600 of the invention to form container precursors 400 in shell form.
[0314] FIG. 4 shows a schematic diagram of a container precursor 400 according to the invention. The container precursor 400 includes a blank of the sheetlike composite 100 obtained by the method 300 with 4 longitudinal folds 401, each of which forms a longitudinal edge 401. In the container precursor 400, the outer face 101 of the sheetlike composite 100 faces outward. The container precursor 400 is in the form of a shell and comprises a longitudinal seam 402 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 400 comprises a hole 405 in the carrier layer 103. The hole 405 is covered by the outer polymer layer 202 (not shown), the polymer interlayer 203 (not shown), the first adhesion promoter layer 104, the barrier layer 105, the further adhesion promoter layer 106 (not shown) and the inner polymer layer 107 (not shown) as hole-covering layers. By folding along grooves 406 and joining of fold regions in a top region 403 and a base region 404 of the container precursor 400, a closed container 500 is obtainable. Such a closed container 500 is shown in FIG. 5.
[0315] FIG. 5 shows a schematic representation of a closed container 500 according to the invention. The closed container 500 has been produced from the container precursor 400 according to FIG. 4. The closed container 500 comprises a food or drink product 501 and has 12 edges. In addition, the closed container 500 is joined to a lid comprising an opening aid 502 which covers the hole 405 on the outer face 101 of the sheetlike composite 100. Here, the lid 502 comprises a cutting tool as opening aid in its interior.
[0316] FIG. 6 shows a flow diagram of a method 600 according to the invention for producing a container precursor 400. In a method step A. 601, a blank of the sheetlike composite 100 obtained as described above by the method 300 is provided. This comprises a first longitudinal edge and a further longitudinal edge. In a method step B. 602, the blank is folded. In a method step C. 603, 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 402 is obtained. According to the above described, the container precursor 400 according to FIG. 4 is produced.
[0317] FIG. 7 shows a flow diagram of a method 700 according to the invention for producing a closed container 500. In a method step A) 701, the container precursor 400 according to FIG. 4 is provided. In a method step B) 702, a base region 404 of the container precursor 400 is formed by folding the sheetlike composite 100. In a method step C) 703, the base region 404 is closed by sealing with hot air at a temperature of 300 C. In a method step D) 704, the container precursor 400 is filled with a food or drink product 501 and, in a method step E) 705, the container precursor 400 is closed by sealing in a top region 403, thereby obtaining the closed container 500 of FIG. 5. In a method step F) 706, the closed container 500 is joined to an opening aid 502.
[0318] FIG. 8 shows a photograph regarding the sample preparation according to the seal seam strength test method. What can be seen is a top region 403 separated from a closed container 500.
[0319] FIG. 9 shows a photograph regarding the sample preparation according to the seal seam strength test method. What can be seen is the cutting-to-size of samples 1001 with the safety guillotine 901.
[0320] FIG. 10 shows a photograph of multiple samples 1001 for the seal seam strength test method.
[0321] FIG. 11 shows a photograph of the test setup for the seal seam strength test method. What can be seen is a sample 1001 in the TIRA test 27025 tensile tester from TIRA GmbH, Schalkau, Germany (reference numeral 1101 in FIG. 11).
[0322] FIG. 12 shows illustrative ATR spectra 1200 regarding the acrylate content test method. The wavenumber 1201 is plotted on the abscissa axis of the diagram, and the absorption/extinction 1202 measured on the ordinate axis. What can be seen are a curve 1204 drawn in a somewhat darker colour for the adhesion promoter Dow XZ89893 from The Dow Chemical Company AG and a curve 1203 drawn in a somewhat lighter colour for the adhesion promoter Lotader 4613 from Arkema SA. In addition, the maximum A 1205 and the maximum B 1206 are identified for the curve 1203 of the Lotader.
LIST OF REFERENCE SIGNS
[0323] 100 Sheetlike composite according to the invention
[0324] 101 Outer face
[0325] 102 Inner face
[0326] 103 Carrier layer
[0327] 104 First adhesion promoter layer
[0328] 105 Barrier layer
[0329] 106 Further adhesion promoter layer
[0330] 107 Inner polymer layer
[0331] 201 Colour application
[0332] 202 Outer polymer layer
[0333] 203 Polymer interlayer
[0334] 204 Barrier substrate layer
[0335] 205 Barrier material layer
[0336] 206 Protective layer
[0337] 207 First inner layer
[0338] 208 Second inner layer
[0339] 209 Third inner layer
[0340] 300 Method according to the invention for production of a sheetlike composite
[0341] 301 Method step a)
[0342] 302 Method step b)
[0343] 303 Method step c)
[0344] 304 Method step d)
[0345] 305 Method step e)
[0346] 306 Method step f)
[0347] 400 Container precursor according to the invention
[0348] 401 Longitudinal fold/longitudinal edge
[0349] 402 Longitudinal seam
[0350] 403 Top region
[0351] 404 Base region
[0352] 405 Hole
[0353] 406 Groove
[0354] 500 Closed container according to the invention
[0355] 501 Food or drink product
[0356] 502 Lid with opening aid
[0357] 600 Method according to the invention for producing a container precursor
[0358] 601 Method step A.
[0359] 602 Method step B.
[0360] 603 Method step C.
[0361] 700 Method according to the invention for producing a closed container
[0362] 701 Method step A)
[0363] 702 Method step B)
[0364] 703 Method step C)
[0365] 704 Method step D)
[0366] 705 Method step E)
[0367] 706 Method step F)
[0368] 901 Safety guillotine
[0369] 1001 Sample for the seal seam strength test method
[0370] 1100 Test setup for the seal seam strength test method
[0371] 1101 TIRA test 27025 universal tensile tester
[0372] 1200 Illustrative ATR spectra regarding the acrylate content test method
[0373] 1201 Wavenumber
[0374] 1202 Absorption/extinction
[0375] 1203 Curve for Lotader 4613 from Arkema SA
[0376] 1204 Curve for Dow XZ89893 from The Dow Chemical Company AG
[0377] 1205 Maximum A
[0378] 1206 Maximum B
