US007070852B1
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`(12) United States Patent
`Reiners et al.
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`(10) Patent No.:
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`(45) Date of Patent:
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`US 7,070,852 B1
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`Jul. 4, 2006
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`............. .. 156/78
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`(54) PACKAGING MATERIAL WITH A FOAMED
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`POLYOLEFIN LAYER
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`(56)
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`(75)
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`Inventors: Ulrich Reiners, Venray (NL); Michel
`Pittet, Billens (CH)
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`(73) Assignee: Covenience Food Systems B.V., Bakel
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`(NL)
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`( * ) Notice:
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`Subject to any disclaimer, the term of this
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`patent is extended or adjusted under 35
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`U.S.C. l54(b) by 765 days.
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`(21) Appl. No.:
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`09/763,679
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`(22) PCT Filed:
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`Aug. 24, 1999
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`(86) PCT No.:
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`PCT/EP99/06191
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`§ 371 (OX1),
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`(2), (4) Date: May 15, 2001
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`References Cited
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`U.S. PATENT DOCUMENTS
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`10/2000 Laurent et al.
`6,132,539 A
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`FOREIGN PATENT DOCUMENTS
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`37 22 139 A1
`1/1989
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`0 570 222
`11/1993
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`0 570 222 A1
`11/1993
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`96 25290
`8/1996
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`WO 96/25290
`8/1996
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`OTHER PUBLICATIONS
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`DE
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`EP
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`EP
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`W0
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`W0
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`Derwent Abstract for DE 3722 139 entitled “Thermoplastic
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`Foamed Film Partic. For Carrier Bags, etc. by Extruding in
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`at Least 2 Layers, one Contg, Blowing Agent and One
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`Contg. No Blowing Agent”, Patent Assignee: Stoll
`Kunststolfe.
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`Primary Examiner—Victor Cheng
`(74) Attorney, Agent, or Firm—Norris McLaughlin &
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`Marcus PA
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`(87) PCT Pub. No.: W000/13886
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`(57)
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`ABSTRACT
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`PCT Pub. Date: Mar. 16, 2000
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`(30)
`Sep. 2, 1998
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`Foreign Application Priority Data
`(DE)
`.............................. .. 198 40 046
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`(51)
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`Int. Cl.
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`(2006.01)
`B32B 3/26
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`(2006.01)
`B32B 7/12
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`(2006.01)
`B32B 9/00
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`428/304.4; 428/317.7;
`(52) U.S. Cl.
`............................. ..
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`428/318.4; 428/318.6; 428/319.7
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`(58) Field of Classification Search ........... .. 428/304.4,
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`428/317.7, 318.6, 319.7, 318.4
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`See application file for complete search history.
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`The invention relates to a multilayer film comprising the
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`following sequence of layers:
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`A) a basis layer of polyolefin foam,
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`B) a layer based on at least one of the polyolefins of the
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`foam layer A),
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`C) optionally a tie layer based on a polyolefin,
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`D) optionally an adhesive layer,
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`E) optionally a gas- and/or flavortight barrier layer,
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`F) an adhesive layer,
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`G) an optionally sealable and/or peelable surface layer,
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`whereby the total thickness of layers A) and B) ranges from
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`0.5 to 2 mm and the thickness of layer B) ranges from 1/5 to
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`1/2 of the thickness of layer A).
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`20 Claims, No Drawings
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`PAGE 1 OF 5
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`BOREALIS EXHIBIT 1010
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`BOREALIS EXHIBIT 1010
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`PAGE 1 OF 5
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`US 7,070,852 B1
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`1
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`PACKAGING MATERIAL WITH A FOAMED
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`POLYOLEFIN LAYER
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`This is a 371 of PCT/EP99/06191 filed 24 Aug. 1999
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`(international filing date).
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`The invention is in the field of packaging industry and
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`relates to packaging material comprising a polyolefin foam
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`layer having on one of its surfaces further layers.
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`5
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`2
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`F) an adhesive layer,
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`G) an optionally sealable and/or peelable surface layer,
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`whereby the total thickness of layers A) and B) ranges from
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`0.5 to 2 mm and the thickness of layer B) ranges from 1/5 to
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`1/2 of the thickness of layer A).
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`DETAILED DESCRIPTION
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`BACKGROUND OF THE INVENTION
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`Packaging materials with a foam layer of e.g. polypropy-
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`lene in the form of quasi endless rolled webs are used for
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`producing thermoformed self-supporting packaging items as
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`trays for food. Therefore these kinds of packaging
`e.g.
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`materials are formed on so called “forrn-fill-seal” packaging
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`machines (“FFS-machines”) to packaging items. According
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`to this method the web of packaging material is fed into the
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`machine in which it is formed into a web of trays which trays
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`in the same machine are filled and sealed with a preferable
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`transparent sealing film. Then usually the trays are separated
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`from each other.
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`In the known packaging materials the polypropylene foam
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`layer is carrying on at least one of its surfaces further layers.
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`Depending on the composition and the thickness of these
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`layers these layers may also serve as further means for
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`increasing the stiffness as well as protection of the foam
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`layer surface or as gas and/or aroma barrier and/or as surface
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`layer for bounding the packaging tray and a preferable
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`transparent lidding film.
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`Packaging materials with a polypropylene foam layer for
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`producing trays by thermoforrning are disclosed e.g.
`in
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`EP-A-0 570 222. These materials comprise a foam layer and
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`a multilayer film which multilayer film may include a barrier
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`layer rendering the packaging material gas- and/or aroma
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`tight. The properties of this multilayer packaging material
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`need some improvement as far as the use of this material as
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`self-supporting packaging items is concerned.
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`Therefore it is has been proposed to bond the foam sheet
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`with the multilayer film by means of a bonding layer of a
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`polyolefin based on the main monomer of the polyolefin of
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`the foam layer (WO 96/25290). This results in an excellent
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`adhesion between the laminate and the foam layer. However
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`the packaging items especially self-supporting ones pro-
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`duced from this known multilayer film composition are not
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`rigid enough for some applications.
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`Therefore there is a need to improve the stiffness of such
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`packaging items, preferably trays, without increasing the
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`thickness of the packaging material. Besides improving the
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`mechanical properties of the packaging material there is also
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`a demand to provide a packaging material suitable for
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`therrnoforming over a broader temperature range in order to
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`achieve a faster production of packaging items.
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`SUMMARY OF THE INVENTION
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`According to the present invention, this object is achieved
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`by providing a multilayer film comprising the following
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`sequence of layers:
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`A) a base layer of a polyolefin foam,
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`B) a layer based on at least one polyolefin of the foam layer
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`A),
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`C) optionally a tie layer composed of a polyolefin, which is
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`preferably based on the monomer that is the main mono-
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`mer of the polyolefin of the foam layer A),
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`D) optionally an adhesive layer,
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`E) optionally a gas- and/or flavortight barrier layer,
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`10
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`25
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`Preferably the total thickness of the layers A) and B)
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`ranges from 0.6 to 1.4 mm and the thickness of layer B) is
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`from 1/5 to 1/3 of the thickness of layer A).
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`The foam layer A) consists of at least one foamed poly-
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`olefin. For producing packaging items such as trays appli-
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`in food packaging foamed propylene- homo-
`cable
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`and/or -copolymers are used advantageously as such mate-
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`rials are self-supporting with lower thickness and lower
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`density. A mixture of polyolefins can also be used for the
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`manufacture of the foam layer. A mixture of polypropylene
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`with long chain branching (high-melt-strength polypropy-
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`lene) and a propylene ethylene copolymer (e.g. heterophasic
`propylene ethylene blockcopolymer) can preferably be used.
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`Particularly suitable is a mixture of a polypropylene with
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`long chain branching and a melt-index (MFI) in the range of
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`1.4 to 4.2 g/ 10 min and a heterophasic propylene ethylene
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`block copolymer in a mixing ratio of 1:1.
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`The polyolefin of layer A) can be foamed by addition of
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`liquid and/or gaseous blowing agents in known
`solid,
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`amounts preferable in an amount of 0.5 to 3 wt. %. The
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`relevant disclosure of EP-A-0 570 222 is herewith cited as
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`referential disclosure for the present application.
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`Foam layers of polyolefins, preferable of polypropylene,
`optionally admixed with copolymers of olefins, preferable
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`with propylene ethylene copolymers, used for the produc-
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`tion of packaging materials preferably have a density of 0.1
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`to 0.8 g/cm3, preferably 0.25 to 0.5 g/cm3, and a cell count
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`of 75 to 300 cells per m3. Density and cell count can be
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`influenced by the process conditions like, e.g., extrusion
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`temperature or other process condition during the preferred
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`method for producing foam layers, namely by extrusion and
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`expansion.
`Layer B) of compact polyolefin essentially consists of a
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`polyolefin of the foamed layer A). In case the basis layer A)
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`is made of a foamed polypropylene or a foamed mixture of
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`polypropylene and propylene ethylene copolymer the com-
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`pact polyolefin layer B)
`is preferably made either of
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`polypropylene or a propylene ethylene copolymer. Particu-
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`larly preferred a heterophasic propylene ethylene blockco-
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`polymer is used. The melt index (MFI) of the polyolefin used
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`for the manufacture of layer B) ranges preferably from 1.8
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`to 5.5 g/ 10 min. The thickness of layer B) is 1/5 to 1/2, most
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`preferably 1/5 to 1/3 of the thickness of layer A).
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`Layer C) is present when layers D) to G) are pre-produced
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`by coextrusion preferable by blown film coextrusion and to
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`be combined with the other layers. Layer C) is based on a
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`polyolefin which is preferably made from a monomer which
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`is also the main monomer of the polyolefin of the foam layer
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`A). In case layer A) consists of a foamed polypropylene and
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`optionally a propylene ethylene copolymer, layer C) can be
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`made of polypropylene optionally grafted with maleic acid
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`anhydride. Copolymers of ethylene vinylacetate can also be
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`used as materials for layers C). The thickness of layer C)
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`ranges preferably from 5 to 25, most preferably from 8 to 15
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`pm.
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`In case the inventive multilayer film should have a low
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`gas permeability,
`i.e. a low permeability of oxygen and
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`moisture and a high flavor tightness it comprises a barrier
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`PAGE 2 OF 5
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`PAGE 2 OF 5
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`US 7,070,852 B1
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`4
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`is simultaneously coextruded with the other layers, option-
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`ally without layer C), and by expanding layer A).
`The inventive multilayer films have an excellent thermo-
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`formability on so called FFS-machines (form-fill and sealing
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`machines) and thus can be formed to packaging items
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`preferable to trays by deep drawing. These trays can also be
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`filled and sealed on the same machine. It was surprising to
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`find out that the multilayer films according to the present
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`invention cannot only be excellently processed on these
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`FFS-machines but can also be formed to packaging items,
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`particularly deep drawn trays with a higher speed when
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`compared to known multilayer packaging materials.
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`The inventive multilayer
`films show an unexpected
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`improvement of the mechanical properties such as resistance
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`to breaking and stiffness of the E-modulus, although their
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`total thickness is reduced compared to known comparable
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`packaging materials. This considerable improvement
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`achieved without any increase of the thickness of the mul-
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`tilayer films which is being required as for the films known
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`from the prior art. Surprisingly the mechanical properties are
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`even improved although the total thickness of the multilayer
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`packaging material is reduced.
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`A further object of the invention is therefore the use of the
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`multilayer film according to the present invention as pack-
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`aging material, preferably on form-,
`fill- and sealing
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`machines (FFS-machines) for packaging of food, especially
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`for packaging of perishable food such as meat, ham or sliced
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`meat. Because packaging on FFS-machines is very often
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`carried out discontinuously in order to pack dilfernt goods,
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`the packaging material must show a relatively broad so
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`called thermoforming window in which the thermo-forming
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`of the film can occur. This is achieved by providing the
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`inventive packaging material, which has excellent thermo-
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`formability, especially deep drawing qualities.
`The thermo-formed, preferably deep-drawn, packaging
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`items, such as, e.g., deep drawn trays, which can be pro-
`
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`
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`duced from the multilayer materials according to the present
`
`
`
`
`
`
`
`invention can be sealed with known lidding film after they
`
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`
`
`have been filled. Suitable lidding films are multilayer films,
`
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`
`
`preferably from polyethylene terephthalate/SiO,/adhesive
`layer/low density polyethylene or from polyethylene tereph-
`
`
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`
`
`
`thalate/adhesive layer/polyethylene/adhesive layer/ethylene
`
`
`
`
`vinyl alcohol copolymer/adhesivel layer/polyethylene.
`Of the above mentioned lidding films, the first-mentioned
`
`
`
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`
`
`multilayer films are particularly suitable. Therefore the
`
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`biaxially oriented polyethylene terephthalate is coated with
`
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`
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`SiOX by plasma vacuo technique. In a following step the
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`prefabricated polyethylene film is laminated thereto with an
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`adhesive. Such a lidding film is characterized by a excellent
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`
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`transparency and a high breaking resistance. The packaging
`
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`
`
`items having such a lidding film show an excellent gas
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`barrier property.
`
`
`In the following examples the E-modulus is determined
`
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`
`
`according to DIN 43457 in the machine direction and
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`transverse to this direction. Furthermore he elongation at
`
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`
`
`break in the machine direction and transverse thereto is
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`determined according to DIN 53455.
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`EXAMPLES
`
`Example 1
`
`
`An inventive multilayer film is produced with the follow-
`
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`ing sequence of layers:
`
`
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`Layer A) Foam layer with a density of 0.3 g/cm3 and a cell
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`count of 120 cells per mm3 made ofa 50:50 wt % mixture
`
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`10
`
`15
`
`20
`
`
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`25
`
`
`30
`
`
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`35
`
`
`40
`
`
`
`45
`
`
`50
`
`
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`55
`
`
`60
`
`
`
`65
`
`
`3
`
`layer E). This barrier layer is preferably made of ethylene
`
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`vinyl alcohol copolymer having an ethylene content of 32 to
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`45 Mol %, preferably 35 to 42 Mol %.
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`The barrier layer E) is bonded on its respective surfaces
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`to the tie layer C) or to the surface protecting layer G) by
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`means of an adhesive layer D) or F), respectively. The
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`material used for this is preferably a propylene copolymer or
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`a polyethylene grafted with maleic acid anhydride, respec-
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`tively.
`The surface protecting layer G) is preferably sealable or
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`peelable. Thus, preferably low density polyethylene (LDPE)
`having a melt index (MFI) in the range of 0.5 to 8.0 g/ 10
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`min, preferably of 1
`to 5 g/10 min (2.16 kg, 190° C.
`
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`measured according to ASTM D 1238) or a ionomer poly-
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`mer like, e.g., a copolymer of an or-olefin and an ethylem-
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`cally unsatured monomer with a carboxylic group, which are
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`present in an amount of 20 to 100% by weight as metal salt,
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`preferably Zn-salt; or ethylene-vinylacetate copolymers
`
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`with a vinylacetate content of 3 to 10% by weight, prefer-
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`
`ably 4 to 6% by weight is used for the manufacture of the
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`sealable layer.
`According to a particularly preferred embodiment the
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`sealing layer is also peelable. The sealing layer then pref-
`erably comprises a mixture of LDPE and polybutylene (PB).
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`To this end the mixture comprises 15 to 30 weight %,
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`preferably 20 to 28 weight % of polybutylene. The melt
`
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`index (MFI) of the polybutylene is preferably in the range of
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`0.3 to 2.0 g/10 min (190° C. and 2.16 kg, ASTM 1238).
`
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`Preferably the thickness of the surface layer is in the range
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`of 10 to 50 um, preferably 15 to 30 pm.
`
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`When using LDPE as a sealing layer material and the
`
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`
`
`inventive multilayer film comprises a barrier layer, usually
`
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`an adhesive layer is required for connecting the barrier layer
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`and the sealing layer, unless ethylene vinyl alcohol is used
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`as material for the barrier layer. As adhesive material a
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`polyolefin, preferably a polyethylene grafted with maleic
`
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`acid anhydride may be used.
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`A LDPE and LLDPE mixture can also be used in a ratio
`
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`from 3:1 to 4:1 as adhesive material. The thickness of the
`
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`respective adhesive layer ranges from 2 to 8 pm, preferably
`
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`from 3 to 6 pm.
`
`
`The surface layer G) may contain usual and known
`
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`lubricating agents and anti-blocking agents, as, for example,
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`erucic acid amide, polyalkylsiloxane, such as for example
`
`
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`polydimethyl siloxane and/or SiO2. All or individual layers
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`can contain stabilizers and further additives of known kind.
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`Furthermore layer B) can contain 0.5 to 2% by weight of
`
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`a white pigment like, e.g., kaolin, calcium carbonate, talcum
`
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`or titanium dioxide or mixtures thereof. These inorganic
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`pigments are added to the polymer of which layer B) is
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`made, preferably in form of a master batch containing 30 to
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`50% by weight of pigments. Layer B) can also be composed
`
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`of up to 30% by weight of recycled inventive multilayer film
`
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`material.
`
`The multilayer film according to the invention is prefer-
`
`
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`
`
`
`
`ably produced by the usual blown film coextrusion or cast
`
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`film coextrusion processes as far as the production of the
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`sequence of layers C) to G) is concerned and preferably by
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`an extrusion lamination step for combining with the poly-
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`olefin foam layer A). Thereby the foam layer A) and the
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`multilayer film consisting of layers C) to G) are guided
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`together in such a way that layer B) is extruded between
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`them. Immediately after the extrusion a sufficiently high
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`pressure is applied to the so produced laminate, so that
`
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`
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`layers A) to G) are sufficiently bonded to one another.
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`
`
`However it
`is also possible to produce the inventive
`
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`multilayer films by coextrusion, whereby the foam layer A)
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`PAGE 3 OF 5
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`PAGE 3 OF 5
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`

`
`
`
`US 7,070,852 B1
`
`6
`
`
`
`The invention claimed is:
`
`
`
`1. Amultilayer film comprising the following sequence of
`
`
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`
`
`layers:
`A) a base layer of foamed propylene homopolymers,
`
`
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`
`
`copolymer or mixtures thereof,
`
`
`
`B) a layer comprising at
`least one of the propylene
`
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`
`
`homopolymers or copolymers of the foam layer A,
`
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`
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`C) optionally a tie layer based on a polyolefin
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`
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`
`
`
`D) optionally an adhesive layer
`
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`
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`E) optionally a gas barrier layer, a flavortight barrier layer,
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`
`or both,
`
`
`F) an adhesive layer,
`
`
`
`G) an optionally sealable or peelable surface layer,
`
`
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`
`
`
`whereby the total thickness of layers A and B ranges from
`
`
`
`
`
`
`0.5 to 2 mm and the thickness of layer B ranges from
`
`
`
`
`
`1/5 to 1/2 of the thickness of layer A.
`
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`
`
`2. Amultilayer film according to claim 1, wherein the total
`
`
`
`
`
`
`
`thickness of layers A and B ranges from 0.6 to 1.4 mm.
`
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`
`
`3. A multilayer film according to claim 1 wherein the
`
`
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`
`
`thickness of layer B ranges from 1/5 to 1/3 of the thickness of
`
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`
`layer A.
`
`4. A multilayer film according to claim 1, wherein layerA
`
`
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`
`
`is made of a foamed mixture of polypropylene with long
`
`
`
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`
`
`
`
`chain branching and a propylene-ethylene-blockcopolymer.
`
`
`
`
`5. A multilayer film according to claim 1, wherein layer B
`
`
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`
`
`is made of polypropylene or a propylene-ethylene-copoly-
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`
`
`mer.
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`5
`
`of a polypropylene with long chain branching (high melt
`
`
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`
`
`strength polypropylene) and a heterophasic propylene
`
`
`
`
`
`
`
`ethylene blockcopolymer,
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`Layer B) consists of 100% by weight of heterophasic
`propylene ethylene block copolymer like the one used for
`
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`foam layer layer A),
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`
`Layer C) consists of polypropylene,
`Layer D) consists of an adhesive based on polypropylene
`
`
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`
`
`
`grafted with maleic acid anhydride,
`
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`
`
`Layer E) as a gas barrier layer consisting of an ethylene
`
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`
`
`vinylalcohol copolymer,
`Layer F) as adhesive layer having the same composition as
`
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`
`
`Layer D),
`Layer G) as a sealing layer based on low density polyeth-
`
`
`
`
`
`
`
`
`ylene.
`The multilayer film is produced by co-extrusion.
`
`
`
`
`
`The thickness of the individual layers are set forth in table
`
`
`
`
`
`
`
`
`
`
`1.
`
`
`Table 1 :
`
`
`Layer
`
`Thickness in pin
`
`
`
`A)
`
`800
`
`
`B)
`
`160
`
`
`TABLE 1
`
`D)
`
`C)
`
`
`
`
`
`15
`
`
`
`5
`
`
`E)
`
`
`
`5
`
`
`F)
`
`
`
`5
`
`
`G)
`
`
`
`20
`
`
`Total
`
`
`
`1010
`
`
`The mechanical properties of said fim are set forth in table
`
`
`
`
`
`
`
`
`3.
`
`
`
`
`Comparative Example
`
`
`
`10
`
`15
`
`20
`
`25
`
`
`
`30
`
`A multilayer film having an identical layer sequence as
`
`
`
`
`
`
`
`well as identical
`layer compositions, but different thick-
`
`
`
`
`
`
`
`
`nesses of layers is produced corresponding to the multilayer-
`
`
`
`
`
`
`film according to example 1.
`
`
`
`The thickness of the individual layers of this multilayer
`
`
`
`
`
`
`
`
`film is set forth in table 2:
`
`
`
`
`Table 2:
`
`
`
`
`35
`
`
`
`40
`
`G)
`
`Total
`
`6. A multilayer film according to claim 1, wherein layer C
`
`
`
`
`
`
`
`is made of a polyolefin based on a monomer which is present
`
`
`
`
`
`
`
`in a predominant amount in the polyolefins of foam layer A.
`
`
`
`
`
`
`
`7. A multilayer film according to claim 6, wherein the
`
`
`
`
`
`
`
`
`
`polyolefin is polypropylene.
`8. A multilayer film according to claim 1, wherein layer E
`
`
`
`
`
`
`
`is present and is made of ethylene-vinylalcohol copolymer.
`
`
`
`
`
`
`9. Amultilayer film according to claim 1, wherein layer G
`
`
`
`
`
`
`
`is made of a sealable polymer and optionally contains
`
`
`
`
`
`
`
`additives.
`
`10. A multilayer film according to claim 9, wherein layer
`
`
`
`
`
`
`G is made of a low density polyethylene or an ionomer.
`
`
`
`
`
`
`11. A multilayer film according to claim 1, wherein layer
`
`
`
`
`
`
`
`G is made of a peelable polymer and optionally contains
`
`
`
`
`
`
`
`additives.
`
`12. Amultilayer film according to claim 11, wherein layer
`
`
`
`
`
`
`
`
`G is made of a mixture of low density polyethylene and a
`
`
`
`
`
`
`
`
`polybutylene.
`13. A multilayer film according to claim 1, wherein the
`
`
`
`
`
`
`
`total thickness of layers C to G ranges from 20 to 70 um.
`
`
`
`
`
`
`
`14. A multilayer film according to claim 13, wherein the
`
`
`
`
`
`
`
`
`total thickness is 30 to 50 um.
`
`
`
`
`
`15. A packaging material comprising the multilayer film
`
`
`
`
`
`
`of claim 1.
`
`
`16. A packaging item made of a film according to claim
`
`
`
`
`
`
`
`
`
`
`
`1.
`
`
`
`17. A packaging item according to claim 16, wherein said
`
`
`
`
`
`
`
`packaging item is a packaging tray.
`
`
`
`
`18. A method for packaging meat, sausage or cheese
`
`
`
`
`
`
`
`
`which comprises packaging said meat, sausage or cheese in
`
`
`
`
`
`
`
`a multilayer film according to claim 1.
`
`
`
`
`
`19. A method of packaging material on form-, fill- and
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`sealing packaging machines which comprises packaging
`said material in a film of claim 1.
`
`
`
`
`20. A food packaging container which comprises the
`
`
`
`
`
`
`multilayer film of claim 1.
`
`
`
`*
`*
`
`*
`
`*
`
`*
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`45
`
`
`
`50
`
`55
`
`60
`
`Layer
`
`Thickness in pin
`
`
`
`A)
`
`1160
`
`
`B)
`
`40
`
`
`TABLE 2
`
`D)
`
`C)
`
`
`
`
`
`15
`
`
`5
`
`
`E)
`
`
`
`5
`
`
`F)
`
`
`
`5
`
`
`
`
`20
`
`
`
`
`1250
`
`
`The mechanical properties of this multilayer film are set
`
`
`
`
`
`
`
`
`forth in table 3:
`
`
`Table 3:
`
`
`TABLE 3
`
`
`E-modulus (machine direction)
`
`
`
`E-modulus (transverse direction)
`
`
`
`Elongation at break (machine direction)
`
`
`
`
`Elongation at break (transverse direction)
`
`
`
`
`
`
`unit
`
`N/mm2
`
`N/mm2
`
`N/mm2
`
`N/mm2
`
`
`ex. 1
`
`788
`
`584
`
`10.2
`
`8.4
`
`
`comp.
`ex
`
`
`
`
`
`564
`
`426
`
`6.9
`5.6
`
`
`
`
`As can be seen from table 3, the inventive multilayer films
`
`
`
`
`
`
`
`
`
`have far superior mechanical values, even though the total
`
`
`
`
`
`
`
`
`
`thickness of the film is less than of the known packaging
`
`
`
`
`
`
`
`
`
`materials. Therefore the inventive multilayer films are by far
`
`
`
`
`
`
`
`superior for the production of self-supporting packaging,
`
`
`
`
`
`
`
`particularly deep drawn trays.
`
`
`
`
`
`PAGE 4 OF 5
`
`PAGE 4 OF 5
`
`

`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`
`
`
`
`
`
`CERTIFICATE OF CORRECTION
`
`
`
`PATENT NO.
`
`
`APPLICATION NO.
`
`
`DATED
`INVENTOR(S)
`
`
`
`: 7,070,852 B1
`
`
`: 09/763679
`
`
`
`
`
`: July 4, 2006
`: Reiners et al.
`
`
`
`
`
`
`
`
`It is certified that error appears in the above—identified patent and that said Letters Patent is
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`hereby corrected as shown below:
`
`
`
`
`
`
`
`
`
`
`
`
`
`Column 4, Line 56, “Furthermore he elongation” should read -- Furthermore the
`elongation --
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Column 5, Line 27, “properties of said fim” should read -- properties of said film --
`
`
`
`
`Signed and Sealed this
`
`
`
`
`
`
`Eighteenth Day of March, 2008
`
`
`
`M WQW
`
`
`
`
`JON W. DUDAS
`
`
`Director ofthe United States Patent and Trademark Oflice
`
`
`
`
`
`
`
`
`
`
`PAGE 5 OF 5
`
`PAGE 5 OF 5