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
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • 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
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B15/08—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • 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
  • B32B33/00—Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
• • 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
  • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
  • B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
  • B32B37/24—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer not being coherent before laminating, e.g. made up from granular material sprinkled onto a substrate
  • B32B2037/246—Vapour deposition
• • 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
  • B32B38/00—Ancillary operations in connection with laminating processes
  • B32B38/0012—Mechanical treatment, e.g. roughening, deforming, stretching
  • B32B2038/0028—Stretching, elongating
• • 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
  • B32B38/00—Ancillary operations in connection with laminating processes
  • B32B2038/0052—Other operations not otherwise provided for
  • B32B2038/0092—Metallizing
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/514—Oriented
  • B32B2307/518—Oriented bi-axially
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
• • 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
  • B32B2310/00—Treatment by energy or chemical effects
  • B32B2310/14—Corona, ionisation, electrical discharge, plasma treatment
• • 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
  • B32B2323/00—Polyalkenes
  • B32B2323/10—Polypropylene
• • 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
  • B32B2553/00—Packaging equipment or accessories not otherwise provided for
• • 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
  • B32B38/00—Ancillary operations in connection with laminating processes
  • B32B38/0008—Electrical discharge treatment, e.g. corona, plasma treatment; wave energy or particle radiation

Definitions

• This invention relates to a metallized polypropylene film containing a polyolefin layer and a metal deposited layer, and a method of making the same.
• Biaxially oriented polypropylene metallized films are used for many packaging applications, particularly in food packaging, because they have important sealing and protective qualities.
• the films minimize the amount of light, moisture, and oxygen that can normally enter an ordinary, unprotected package.
• the films are often used in food packaging in combination with gas-flushing applications to protect the contents from moisture and oxidation. Also, the films often provide a heat sealable inner layer for bag forming and sealing.
• Metallized films used in vertical-form-fill-seal (VFFS) packaging provides an excellent barrier in either unlaminated or laminated forms.
• the laminated packaging containing the metallized film can be stretched in the packaging machine from 5 to 15% beyond the dimensions of the original film packaging. This stretching may cause fracture or cracks to form in the metal layer of the film.
• the packaging loses its protective properties. For instance, oxygen can readily pass through a damaged packaging film and cause unwanted oxidation of the contents.
• High barrier metallized OPP films are typically metallized to an optical density range of 2.0 - 2.4. This has been shown to be adequate to provide good flat sheet (non- elongated) barrier properties. However, such an optical density level has not been shown to provide good barrier durability during the bag forming process.
• U.S. Patent No. 5,698,317 discloses the use of a four layer packaging film having a polyolefin resin layer sandwiched between a polyolefin mixed resin layer comprising a petroleum or terpene resin and a heat sealable layer or non-sealable winding layer. A metal layer is then deposited on the surface of the polyolefin mixed resin layer. The metal layer is deposited following the discharge treatment of the polyolefin mixed resin layer.
• U.S. Patent No. 4,297,187 discloses the use of a discharge treatment method on a plastic surface in a controlled atmosphere comprised of N 2 and CO 2 .
• This invention provides a method to improve the flat sheet barrier and barrier durability of conventional metallized films resulting in a metallized high barrier packaging film with good formed bag barrier properties.
• the invention helps solve the problem of leaky bags associated with conventional metallized film packaging and the bag-forming process by providing a metal layer with an optical density of at least about 2.6.
• the metal layer is deposited on a polymer laminate film having at least two layers, a high crystalline polypropylene resin layer of isotactic content of greater than about 93% and a heat sealable or a non-heat sealable, winding layer.
• the invention improves upon the moisture and gas barrier properties of laminate films.
• the laminate film of the invention includes at least a 1, 2 or 3-layer coextruded film and a metal layer, preferably a vapor deposited aluminum layer, with at least an optical density of about 2.6, preferably with an optical density of about 2.6 to 4, and even more preferably between 2.8 and 3.2.
• the high optical density aluminum layer is vapor deposited upon a discharge treated surface, preferably a discharge-treatment produced in a CO 2 and N 2 environment. Such discharge-treatment in a CO 2 N 2 atmosphere results in a treated surface containing at least 0.3% nitrogen-containing functional groups, and preferably at least 0.5% nitrogen-containing functional groups.
• the laminate film comprises a high crystalline, high isotactic polymer resin, preferably a homopolymer polypropylene resin of isotactic content greater than about 93%, and more preferably greater than about 95% isotactic, which has been discharge treated in the preferred method.
• the metal vapor is deposited upon a discharge treated surface (via the preferred method) containing a polyolefin mixed resin. This polyolefin mixed resin layer is disposed on one side of a high crystalline, high isotactic homopolymer propylene core layer of isotactic content of greater than about 93%.
• a heat sealable surface or a winding surface containing antiblock and/or optionally slip additives for good machinability and low coefficient of friction (COF) is disposed on the opposite side of the high crystalline, high isotactic propylene core layer of greater than about 93% isotacticity. Additionally, if the third layer is used as a winding surface, its surface may also be modified with a discharge treatment to make it suitable for laminating or converter applied adhesives and inks.
• the laminate film comprises: a high crystalline, high isotactic polypropylene resin layer, preferably greater than about 93% isotacticity, more preferably greater than about 95%, and even more preferably between about 95 and 98% isotactic content; a heat sealable layer or a non-heat sealable, winding layer; and a metal layer.
• the polypropylene resin layer will have a thickness of about 6 to 40 ⁇ m thick.
• the polypropylene resin layer is discharge treated, and the metal layer deposited on the treated resin layer.
• the discharge treatment is preferably conducted in an atmosphere of air, CO 2 , N 2 or a mixture thereof, more preferably in a mixture of CO 2 and N 2 .
• This preferred method of discharge treatment results in a treated surface that comprises nitrogen-bearing functional groups, preferably 0.3% or more nitrogen in atomic %, and more preferably 0.5% or more nitrogen in atomic %.
• the polypropylene core resin layer is a high crystalline polypropylene of a specific isotactic content and can be uniaxially or biaxially oriented.
• High crystalline polypropylenes are generally described as having an isotactic content of about 93% or greater.
• Conventional polypropylenes (non-high crystalline) are generally described as having an isotactic content of about 90-93%.
• those high crystalline polypropylenes in the range of about 93% or greater isotactic content have significantly better tensile properties and resistance to the stresses and deformations imposed by the packaging machines' forming collars than non-high crystalline polypropylenes of isotactic content of less than about 93%.
• the high crystalline polypropylene isotactic content is in the range of between about 95% and about 98% for the best combination of forming collar deformation resistance and BOPP processing.
• the desirable attributes of the high crystalline polypropylene of 93% or greater isotactic content is, of course, the isotactic content itself as measured by C NMR spectra obtained in 1,2,4-trichlorobenzene solutions at 130°C.
• the % percent isotactic can be obtained by the intensity of the isotactic methyl group at 21.7 ppm versus the total (isotactic and atactic) methyl groups from 22 to 19.4 ppm.
• Suitable examples of high crystalline polypropylenes for oil resistant film production are Fina 3270, Exxon 1043N, Huntsman 6310, and Amoco 9117.
• These resins also have melt flow rates of about 0.5 to 5 g/10 min, a melting point of about 163 - 167°C, a crystallization temperature of about 108 -126°C, a heat of fusion of about 86 - 110 J/g, a heat of crystallization of about 105 - Ill J/g, and a density of about 0.90 - 0.91.
• the core resin layer can also include an optional amount of hydrocarbon resin additive. Inclusion of this additive aids in the biaxial orientation of the film, although it is not necessary. As a processing aid, inclusion of the hydrocarbon resin allows a wider "processing window" in terms of processing temperatures for MD and particularly TD orientation.
• a suitable hydrocarbon resin is of the polydicyclopentadiene type available in masterbatch form from ExxonMobil as PA609A or PA610A, which are 50% masterbatches of polypropylene carrier resin and 50% hydrocarbon resin. Suitable amounts of the hydrocarbon masterbatch are concentrations of up to 10% masterbatch or up to 5% of the active hydrocarbon resin component.
• the core resin layer is typically 5 ⁇ m to 50 ⁇ m in thickness after biaxial orientation, preferably between 10 ⁇ m and 25 ⁇ m, and more preferably between 12.5 ⁇ m and 17.5 ⁇ m in thickness.
• the core resin layer can be surface treated with either a corona-discharge method, flame treatment, atmospheric plasma, or corona discharge in a controlled atmosphere of nitrogen, carbon dioxide, or a mixture thereof.
• the latter treatment method in a mixture of CO 2 and N 2 is preferred.
• This method of discharge treatment results in a treated surface that comprises nitrogen-bearing functional groups, preferably 0.3% or more nitrogen in atomic %, and more preferably 0.5% or more nitrogen in atomic %.
• This treated core layer can then be metallized, printed, coated, or extrusion or adhesive laminated.
• a preferred embodiment is to metallize the treated surface of the core resin layer.
• the metal layer is preferably a vapor deposited metal and more preferably vapor deposited aluminum.
• the metal layer shall have a thickness between 5 and 100 nm, preferably between 50 and 80 nm, more preferably between 60 and 70 nm; and an optical density between 2.6 and 5.0, preferably between 2.6 and 4.0, more preferably between 2.8 and 3.2.
• a relatively thin outside layer of aluminum oxide is formed on the outermost surface of the metal layer; second, below this oxide layer is a region of less than 95% Al purity; third, is a layer of 95-98% Al purity; fourth is a layer of 98-100% Al purity; fifth, is a layer of 95-98% Al purity; and sixth is a layer of less than 95% Al purity extending to the Al / polymer substrate interface.
• the low optical density metal layer deposition results in a different set of strata within the metal layer.
• the low optical density metal layer does not contain the highly pure strata of Al, which the high optical density metal layer does.
• these bands of highly pure aluminum (95% or greater Al purity) are substantially thicker in the high optical density metal layer compared to the low optical density metal layer. Without being bound to any theory, applicants believe that these relatively thick bands of highly pure aluminum provide superior oxygen and moisture barrier properties.
• the adhesion of the metal layer to the polymer substrate is substantially higher in the case of the high optical density metal layer compared to the low optical density metal layer.
• This improvement in metal adhesion in combination with high optical density metal layer appears to be correlated to the amount of nitrogen functional groups at the metal layer/polymer substrate interface formed by the preferred method of discharge treatment in a ⁇ 2 and CO 2 atmosphere.
• this improvement in metal layer adhesion found in combination with the high optical density metal layer provides the improved oxygen and moisture barrier durability improvement after elongation and after bag-making.
• the heat sealable layer may contain an anti-blocking agent and/or optionally slip additives for good machinability and a low coefficient of friction in about 0.05 - 0.5% by weight of the heat-sealable layer.
• the heat sealable layer will preferably comprise a ternary ethylene-propylene-butene copolymer. If the invention comprises a non-heat sealable, winding layer, this layer will comprise a crystalline polypropylene or a matte layer of a block copolymer blend of polypropylene and one or more other polymers whose surface is roughened during the film formation step so as to produce a matte finish on the winding layer.
• the surface of the winding layer is discharge-treated to provide a functional surface for lamination or coating with adhesives and or inks.
• the high crystalline polypropylene resin is coextruded with the heat sealable layer which will have a thickness between 0.2 and 5 ⁇ m, preferably between 0.6 and 3 ⁇ m, and more preferably between 0.8 and 1.5 ⁇ m.
• the coextrusion process includes a two-layered compositing die. The two layer laminate sheet is cast onto a cooling drum whose surface temperature is controlled between 20 °C and 60 °C to solidify the non-oriented laminate sheet.
• the non-oriented laminate sheet is stretched in the longitudinal direction at about 135 to 165 °C at a stretching ratio of about 4 to about 5 times the original length and the resulting stretched sheet is cooled to about 15 °C to 50 °C to obtain a uniaxially oriented laminate sheet.
• the uniaxially oriented laminate sheet is introduced into a tenter and preliminarily heated between 130 °C and 180 °C, and stretched in the transverse direction at a stretching ratio of about 7 to about 12 times the original length and then heat set to give a biaxially oriented sheet.
• the biaxially oriented film has a total thickness between 6 and 40 ⁇ m, preferably between 10 and 20 ⁇ m, and most preferably between 12 and 18 ⁇ m.
• the surface of the polyolefin resin layer of the biaxially oriented laminate film is subjected to a discharge treatment, preferably a corona-discharge treatment.
• the discharge treatment is preferably conducted in an atmosphere of air, CO 2 , N 2 or a mixture thereof, and more preferably in a mixture of CO 2 and N 2 .
• the treated laminate sheet is then wounded in a roll.
• the roll is placed in a metallizing chamber and the metal was vapor-deposited on the discharge treated polyolefin resin layer surface.
• the metal film may include titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminum, gold, or palladium, the preferred being aluminum.
• the metallized film is then tested for oxygen and moisture permeability, optical density, metal adhesion, and film durability.
• the invention comprises: a polyolefin resin layer; a high crystalline propylene polymer core layer of isotactic content of greater than about 93%; a heat sealable layer or non-sealable winding layer formed on the surface of a high crystalline propylene polymer core layer opposite the polyolefin resin layer; and a metal layer disposed on the polyolefin resin layer.
• the polymer core layer is sandwiched between the resin layer and the heat sealable layer.
• the polyolefin resin layer will contain a polymer additive present in about 1 to 30 percent by weight, preferably 1 to 20 percent by weight, more preferably 1 to 10 percent by weight of the polyolefin mixed resin layer.
• the polymer additive could be selected from a group of synthetic' polymer waxes, preferably a polyethylene, crystalline wax.
• the polymer additive could be selected from the group of petroleum resins and or terpene resins as described in U.S. Patent No. 5,698,317.
• Another alternative preferred use could be as a metal adhesion layer.
• This metal adhesion layer may be composed of any of the following or blends thereof: polypropylene, low isotactic polypropylene, ethylene propylene random copolymer, butene propylene copolymer, and other polyolefins and additives that are suitable for metallizing.
• the metal adhesion layer comprises a blend of about 50-100% by weight of polypropylene and about 10-100% by weight of an ethylene-propylene copolymer, wherein the copolymer has about 2-10% by weight of ethylene. More preferably, the metal adhesion layer comprises a blend of about 80% by weight of polypropylene and about 20% by weight of an ethylene-propylene copolymer, wherein the copolymer has about 4% by weight of ethylene. In addition, it is desirable to add antiblock additives to this layer in concentrations of 0.01-0.1% by weight of this third layer such as silicas, aluminosilicates, or metal-aluminosilicates.
• the heat sealable layer or non-sealable winding layer may also contain antiblock components such as silicas, aluminosilicates, or polymeric antiblocks such as crosslinked silicone polymer in the amount of 0.10 - 0.50% by weight of the heat sealable or non-sealable winding layer.
• antiblock components such as silicas, aluminosilicates, or polymeric antiblocks such as crosslinked silicone polymer in the amount of 0.10 - 0.50% by weight of the heat sealable or non-sealable winding layer.
• the surface of the polyolefin resin layer is corona discharge treated, preferably in an atmosphere of N 2 and CO 2 , to give excellent printability and promote adhesion between the polyolefin resin layer and the metal layer.
• a metal layer is deposited on the discharge treated polyolefin resin layer.
• the metal layer is preferably a vapor deposited metal and more preferably vapor deposited aluminum.
• the metal layer shall have a thickness of about 5 to 100 nm, and an optical density between 2.6 and 5.
• a laminate film of the invention comprises the following material components, and is made according to the following procedure.
• a propylene polymer resin and a polyethylene wax having a molecular weight of about 3000, a viscosity of about 110 cp at 149°C, and a melting point of about 129 °C are blended together.
• a crystalline, propylene polymer resin is blended with a crystalline, linear, polyethylene wax.
• a crystalline, propylene polymer resin is blended with the ethylene-propylene copolymers of the types disclosed above.
• an antiblock additive preferably sodium calcium aluminosilicate powder having a mean particle diameter of about 3 ⁇ m is added to the polymer blend.
• the mixture is then extruded to form a polyolefin mixed resin film with a thickness of 0.75 ⁇ m.
• the polyolefin mixed resin film is coextruded with a polymer core layer, preferably a polypropylene core layer, having a thickness between 5 and 36 ⁇ mm preferably between 10 and 20 ⁇ m, and more preferably between 10 and 15 ⁇ m, and a heat sealable layer opposite the mixed resin layer having a thickness between 0.2 and 5 ⁇ m, preferably between 0.6 and 3 ⁇ m, and more preferably between 0.8 and 1.5 ⁇ m.
• the coextrusion process includes a three-layered compositing die.
• the polymer core layer is sandwiched between the polyolefin mixed resin layer and the heat sealable layer.
• the three layer laminate sheet is cast onto a cooling drum whose surface temperature is controlled between 20 °C and 60 °C to solidify the non-oriented laminate sheet.
• the non-oriented laminate sheet is stretched in the longitudinal direction at about 135 to 165 °C at a stretching ratio of about 4 to about 5 times the original length and the resulting stretched sheet is cooled to about 15 °C to 50 °C to obtain a uniaxially oriented laminate sheet.
• the uniaxially oriented laminate sheet is introduced into a tenter and preliminarily heated between 130 °C and 180 °C, and stretched in the transverse direction at a stretching ratio of about 7 to about 12 times the original length and then heat set to give a biaxially oriented sheet.
• the biaxially oriented film has a total thickness between 6 and 40 ⁇ m, preferably between 10 and 20 ⁇ m, and most preferably between 12 and 18 ⁇ m.
• the surface of the polyolefin mixed resin layer of the biaxially oriented laminate film is subjected to a discharge treatment, preferably a corona discharge treatment.
• the discharge treatment is preferably conducted in an atmosphere of air, CO 2 , N 2 or a mixture thereof, and more preferably in an atmosphere of N 2 and CO .
• the treated laminate sheet is then wounded in a roll.
• the roll is placed in a metallizing chamber and aluminum was vapor-deposited on the discharge-treated polyolefin mixed resin layer surface.
• the metal film may comprise any first row transition metal, aluminum, gold, or palladium, the preferred being aluminum.
• the metallized film is then tested for oxygen and moisture permeability, optical density, metal adhesion, and film durability.
• This mixture was coextruded with a heat sealable ternary ethylene-propylene-butene copolymer containing 4000 ppm of a crosslinked silicone polymer of mean particle diameter of 2 ⁇ m by weight of the heat sealable layer, and biaxially oriented to produce a 2-layer film where the propylene homopolymer resin layer was 16 ⁇ m thick and the accompanying coextruded ternary ethylene-propylene-butene copolymer layer was 1.5 ⁇ m thick.
• the total oriented film thickness was 17.5 ⁇ m or 70G or 0.7 mil thick.
• the film was then discharge-treated in a controlled atmosphere of N 2 and CO 2 , on the propylene homopolymer side (the metallizing surface) and wound in roll form.
• the roll was then metallized by vapor-deposition of aluminum onto the discharge- treated surface to get an optical density of 2.8 - 3.2.
• the metallized laminate film was then tested for oxygen and moisture permeability, optical density,
• Example 2 A process similar to Example 1 was repeated except that the high crystalline propylene homopolymer had an isotactic content of about 97.3%.
• Example 3 A process similar to Example 2 was repeated except that the multi-laminate film included a coextruded third layer comprised of a conventional propylene homopolymer resin with 0.027% of a 3 ⁇ m sodium calcium aluminosilicate antiblock which is formed on the high crystalline propylene homopolymer core resin layer opposite the heat sealable layer.
• the surface of this coextruded third layer was then discharge-treated in a controlled atmosphere of N 2 and CO 2 and wound into roll form for subsequent vapor deposition metallizing.
• the roll was then placed in a metallizing chamber and aluminum was vapor-deposited on the discharge-treated polyolefin mixed resin layer surface to an optical density target of 2.8 - 3.2.
• the metallized laminate film was then tested for oxygen and moisture permeability, optical density, metal adhesion, and film durability.
• Example 2 A process similar to Example 1 was repeated except that an optical density target of 2.0 - 2.6 was used for the vapor-deposited aluminum layer.
• Example 2 A process similar to Example 2 was repeated except that an optical density target of 2.0 - 2.6 was used for the vapor-deposited aluminum layer.
• Example 3 A process similar to Example 3 was repeated except that an optical density target of 2.0 - 2.6 was used for the vapor-deposited aluminum layer.
• Comparative Example 4 A process similar to Example 1 was repeated except that the crystalline polypropylene resin had an isotacticity of about 92.5%. This comparative example properly compares the barrier property results with those of Example 1 because the optical densities of Example 1 and this comparative example are within experimental error, which is plus/minus 10%.
• the preferred value was an average value equal to or less than 15.5 cc/m /day with a maximum of 46.5 cc/m /day.
• Moisture transmission rate of the film was measured by using a Mocon Permatran 3/31 unit measured substantially in accordance with ASTM F1249.
• the preferred value was an average value equal to or less than 0.155 g/m 2 /day with a maximum of 0.49g/m /day.
• Optical density was measured using a Tobias Associates model TBX transmission densitometer. Optical density is defined as the amount of light reflected from the test specimen under specific conditions. Optical density is reported in terms of a logarithmic conversion. For example, a density of 0.00 indicates that 100% of the light falling on the sample is being reflected. A density of 1.00 indicates that 10% of the light is being reflected; 2.00 is equivalent to 1%, etc.
• O 2 TR ⁇ oxygen transmission rate which is a measurement of the permeation rate of oxygen through a substrate
• MVTR moisture vapor transmission rate
• a Physical Electronics model 5700LSci X-ray photoelectron/ESCA spectrophotometer was used to high-resolution depth profiles of O, C, and Al using a 3kN Ar + beam.
• Analytical conditions used a monochromatic aluminum x-ray source with a source power of 350 watts, a take-off angle of 65°, analysis region of 0.8 mm diameter, a charge correction of C-(C,H) in C Is spectra at 284.6 eV, charge neutralization with electron flood gun, ion sputtering of 3kV Ar + , and SiO 2 sputter rate of 48A/min for Si0 2 .

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• 2003
  • 2003-02-21 WO PCT/US2003/005153 patent/WO2003072353A1/en not_active Ceased
  • 2003-02-21 EP EP03725995A patent/EP1485249A1/de not_active Withdrawn
  • 2003-02-21 AU AU2003228218A patent/AU2003228218A1/en not_active Abandoned

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