Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/34—Layered products comprising a layer of synthetic resin comprising polyamides

Definitions

• the present invention relates to multilayer films with which the aim is not to minimize the permeability to water vapor, gases and aromas, but which have a defined gas permeability and thus enable the contents packed therein to be in a permanent, quality-maintaining balance with the external environment to deliver.
• Heat-sealable packaging films are used for the production of food packaging, which are used for the preservation, distribution and hygienic self-service packaging of foodstuffs, with different foodstuffs making different demands on the gas permeability of the packaging films to be used.
• a water vapor-tight packaging film is necessary to maintain the crispness.
• a gas-tight packaging so that the protective gas is retained as a fungistatic and so that no CO 2 loss leads to a product-deforming pseudo-vacuum.
• composite films consisting of an optionally printed biaxially oriented polyamide layer (PAB) are suitable as a carrier film with a thickness of 12 or 15 ⁇ m and 35 to 60 ⁇ m thick, olefinic sealing layers that have an oxygen permeability between 30 and 50 cm 3 / m 2 ⁇ Day x bar.
• PAB biaxially oriented polyamide layer
• PET biaxially oriented polyester films
• biaxially oriented polyamide films are relatively expensive and, particularly when used as a carrier film, have disadvantages due to the existing hygroscopy, there is a need for replacement packaging material in particular in the cheese packaging industry which does not have these disadvantages.
• packaging material in particular packaging films with a defined gas permeability, which are suitable for gassing packaging goods, such as still ripening foods, in particular natural cheese, and which have no biaxially oriented polyamide films as carrier films, the entire packaging film having one should have defined, content-dependent oxygen permeability, the preferably in the range of ⁇ 100 cm 3 / m 2 x day x bar, particularly preferably in the range from 30 to 50 cm 3 / m 2 x day x bar.
• this object is achieved by providing a multilayer film which at least
• a sealing layer as the surface layer b) a layer with a layer thickness of ⁇ 10 ⁇ m and based on a partially crystalline polyamide mixture of m-xylylenediamine adipate and an aliphatic polyamide containing dispersed, solid, anisotropic, nanoscale, nucleating fillers, which in a number-weight average of all dispersed fillers an extent of no more than one of their dimensions
• 10 nm and in at least one further dimension have an extent of at least 100 nm and c) comprises a carrier layer made of plastic, with the exception of a biaxially oriented carrier layer made of polyamide.
• the total thickness of the multilayer film according to the invention is preferably 30 to 90 ⁇ m, particularly preferably 40 to 70 ⁇ m, layer b) of the polyamide mixture containing the nanoscale particles preferably being 2 to 7 ⁇ m, particularly preferably 3 to 5 ⁇ m.
• the multilayer films according to the invention have a defined oxygen permeability ⁇ 100 cm 3 / m 2 x day x bar, preferably in the range from 20 to 60, particularly preferably from 30 to 50 cm 3 / m 2 x day x bar.
• a defined oxygen permeability ⁇ 100 cm 3 / m 2 x day x bar, preferably in the range from 20 to 60, particularly preferably from 30 to 50 cm 3 / m 2 x day x bar.
• the carrier layer As layer c), the carrier layer, the usual plastics used for the production of carrier films, preferably polyesters, such as polyethylene terephthalate, or polyolefins, such as polypropylene, can be used.
• the carrier film is preferably biaxially oriented.
• the carrier layer is preferably transparent.
• the layer thickness is preferably 10 to 25 ⁇ m, particularly preferably 12 to 20 ⁇ m.
• the carrier film can have on its surface facing away from the further film composite a sealing layer, preferably a heat sealing layer, which can correspond to the sealing layer a).
• the sealing layer a) is preferably a heat seal layer, which forms a surface layer of the multilayer film according to the invention.
• Layer a) preferably consists of polyolefins, particularly preferably of polyethylene, polypropylene, an ethylene-propylene copolymer, of a mixture of polyolefins, of an olefinic terpolymer, of mixtures of the polymers mentioned, very particularly preferably of linear low-density polyethylene (LLDPE), optionally mixed with Polybutene, or from polyvinyl acetate.
• LLDPE linear low-density polyethylene
• Layer b) of the multilayer film according to the invention which has a layer thickness of ⁇ 10 ⁇ m, preferably a layer thickness of 2 to 7 ⁇ m, has at least one adjacent layer on each of its surfaces, i. H. it has no uncovered surface.
• Layer b) is based on a partially crystalline polyamide mixture of m-xylylenediamine adipate and an aliphatic polyamide, and has dispersed, nanoscale, solid, anisotropic particles which act as nucleating fillers.
• Solid, anisotropic particles are preferably dispersed as nucleating fillers, which have a number-weight average of all dispersed particles in at least one dimension, preferably freely selectable for each dispersed particle, of an extent of not more than 10 nm. These particles particularly preferably have an extent in at least one further dimension in the range from at least 100 nm to at most 1,000 nm. Platelet-shaped particles are particularly preferably used, the thickness of which is ⁇ 10 nm, such as. B. Layered Silicates.
• phyllosilicates such as magnesium silicate or aluminum silicate, montmorillonite, saponite, beidellite, nontronite, hectorite, stevensite, vermiculite, halloysite or their synthetic analogs.
• the at least partially crystalline polyamide mixture preferably consists of 60 to 98% by weight, preferably 65 to 85% by weight, based on the total mixture of Polyamides, made from a partially aromatic polyamide composed of m-xylylenediamine and adipic acid and 2 to 40% by weight, preferably 15 to 35% by weight, based on the total mixture of the polyamides, of an aliphatic polyamide, such as PA 6, PA 11, PA 12, PA 66, PA 610, PA 6/66, particularly preferably polyamide 6.
• an aliphatic polyamide such as PA 6, PA 11, PA 12, PA 66, PA 610, PA 6/66, particularly preferably polyamide 6.
• Layer b) contains in each case ⁇ 10% by weight, preferably 1 to 5% by weight, based on the aliphatic polyamide component, of nanoscale, nucleating, solid particles are particularly preferably added during the production of the respective aliphatic polyamide.
• Layer b) preferably has a layer a) on each of its surfaces for procedural reasons, which is connected to layer b) via an adhesion promoter layer in order to increase the bond strength.
• the adhesion promoter layer is preferably coextruded and is preferably based on a polyethylene with grafted maleic anhydride.
• a solvent-free polyurethane adhesive is preferably used as the adhesion promoter, which is preferably applied with a layer thickness of less than 5 ⁇ m.
• the carrier film can be colored, printed or unprinted, it being possible for the printing to be carried out using a gravure or flexographic printing machine.
• the pressure is preferably not arranged on the outer surface.
• the multilayer film according to the invention can be produced by known techniques, such as adhesive lamination, sandwich coating or extrusion coating, the carrier film preferably being combined with the remaining film composite produced by a separate process step.
• the multilayer films according to the invention have a defined gas permeability, ie barrier function, in a certain range of gas permeability, can be printed excellently due to the minimized hygroscopy of the barrier layer and show the necessary repeat and register maintenance when printed and in particular when combined with a biaxially oriented carrier film made of polypropylene, a reduced water vapor permeability and thus less weight loss Having packaged good in it, the multilayer films according to the invention are particularly suitable as packaging material, very particularly preferably as packaging material for gassing foods, such as. B. cheese.
• Another object of the present invention is therefore the use of the multilayer films according to the invention as packaging material, preferably for gassing foods, in particular as packaging material for natural cheese.
• the present invention also relates to packaging made from a multilayer film according to the invention for gassing foods, preferably natural cheese, very particularly preferably cheese ripening packaging.
• this packaging can be produced both on horizontal and on vertical, automatically running packaging machines.
• the amount of light in% is indicated as cloudiness, which the film after scattering with a central beam as scattered light, based on the total amount of light passing through Amount of light, leaves again.
• the measurement is carried out according to ASTM test standard D 1003-61, Procedure A.
• the force in N is determined as the seal strength, which is required for the splitting separation of a seal seam produced under defined conditions (pressure, temperature, time).
• Sie ⁇ elbedin ⁇ un ⁇ en pressure 5 N / cm2, time 0.5 sec, temperature 105 to 170 ° C, five
• Measuring devices sealing device from Brugger
• Test strip cutter with cutting width 15 mm tensile testing machine with
• the melt temperature was 270 ° C
• the expansion ratio of the coextruded blown film was 1: 1.6.
• the blown film thus obtained which was separated into two webs and wound up with electrical pretreatment on one side, was applied to a carrier film made of polyethylene terephthalate (PET) with a thickness of 12 ⁇ m or onto a film using a commercially available laminating system using a solvent-free polyurethane adhesive (Primacor 1410 from DOW)
• PET polyethylene terephthalate
• POX solvent-free polyurethane adhesive
• BOPP biaxially oriented polypropylene
• LLDPE linear low density polyethylene
• PET polyethylene terephthalate
• BOPP biaxially oriented polypropylene
• Coex-Bopp biaxially oriented coextrudate with a 5 ⁇ m thick polyethylene
• a commercially available packaging film made of biaxially oriented polyamide (PAB) and a sealing layer made of linear low-density polyethylene, as is usually used for cheese packaging, has the values for oxygen permeability, haze and seal strength given in Table 2, according to the methods given above were found.

Landscapes

• Laminated Bodies (AREA)
• Wrappers (AREA)
• Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7667191

Family Applications (1)

Country Status (8)

Families Citing this family (5)

Family Cites Families (3)

• 2000
  • 2000-12-14 DE DE2000162417 patent/DE10062417A1/de not_active Withdrawn
• 2001
  • 2001-12-12 WO PCT/EP2001/014589 patent/WO2002047904A2/de not_active Application Discontinuation
  • 2001-12-12 PL PL36218001A patent/PL362180A1/xx unknown
  • 2001-12-12 RU RU2003120515/04A patent/RU2003120515A/ru not_active Application Discontinuation
  • 2001-12-12 EP EP01990550A patent/EP1358070A2/de not_active Withdrawn
  • 2001-12-12 AU AU2002229652A patent/AU2002229652A1/en not_active Abandoned
  • 2001-12-12 CA CA002431692A patent/CA2431692A1/en not_active Abandoned
• 2003
  • 2003-06-12 NO NO20032660A patent/NO20032660L/no not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events