WO2017013258A1 - Article comprenant plusieurs couches d'acide polylactique avec du d-lactide - Google Patents

Article comprenant plusieurs couches d'acide polylactique avec du d-lactide Download PDF

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Publication number
WO2017013258A1
WO2017013258A1 PCT/EP2016/067580 EP2016067580W WO2017013258A1 WO 2017013258 A1 WO2017013258 A1 WO 2017013258A1 EP 2016067580 W EP2016067580 W EP 2016067580W WO 2017013258 A1 WO2017013258 A1 WO 2017013258A1
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Prior art keywords
ratio
lactide units
polylactic acid
article according
lactide
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PCT/EP2016/067580
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English (en)
Inventor
Guerino MADEDDU
Laurent BENOIT-MARECHAL
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Compagnie Gervais Danone
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Publication of WO2017013258A1 publication Critical patent/WO2017013258A1/fr

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    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B1/00—Layered products having a non-planar shape
    • 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
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/065—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of foam
    • 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
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin 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
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • 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
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
    • 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
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
    • 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
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • 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
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
    • 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
    • B32B2250/00—Layers arrangement
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    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2264/00—Composition or properties of particles which form a particulate layer or are present as additives
    • B32B2264/02—Synthetic macromolecular particles
    • B32B2264/0207—Particles made of materials belonging to B32B25/00
    • 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
    • B32B2264/00—Composition or properties of particles which form a particulate layer or are present as additives
    • B32B2264/02—Synthetic macromolecular particles
    • B32B2264/0214—Particles made of materials belonging to B32B27/00
    • 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
    • B32B2264/00—Composition or properties of particles which form a particulate layer or are present as additives
    • B32B2264/10—Inorganic particles
    • 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
    • B32B2266/00—Composition of foam
    • B32B2266/02—Organic
    • B32B2266/0214—Materials belonging to B32B27/00
    • B32B2266/0264—Polyester
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
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    • B32B2270/00—Resin or rubber layer containing a blend of at least two different polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
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    • B32B2307/00—Properties of the layers or laminate
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
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    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
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    • 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
    • B32B2307/732—Dimensional properties
    • B32B2307/734—Dimensional stability
    • 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
    • B32B2307/738—Thermoformability
    • 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
    • B32B2439/00—Containers; Receptacles
    • B32B2439/40—Closed containers
    • 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
    • B32B2439/00—Containers; Receptacles
    • B32B2439/40—Closed containers
    • B32B2439/62—Boxes, cartons, cases

Definitions

  • the invention concerns an article in a material comprising polylactic acid.
  • the material has L-Lactide units and D-Lactide units.
  • Polylactic Acid is a thermoplastic polymer made from renewable resources. It has a significant biodegradability. PLA plastic sheets are used to make thermoformed containers, such as cups, for example yogurt cups.
  • Thermoforming is performed by applying a plug to force a heated material into a mold cavity. During thermoforming the material is stretched and the initial thickness of the material is reduced. Higher form factors (deepness dimension / section dimension) of thermoformed articles are obtained with higher stretch ratios. Mechanical properties of the stretched zone decrease as the thickness decreases. Stretching inhomogeneity can also be a source of mechanical properties degradations by generating local defaults.
  • Thermoforming PLA materials comprising L-Lactide units and D-Lactide units has been described.
  • PLA resins of higher D- isomer contents (4-8%) are more suitable for thermoforming (page 822).
  • the same article discloses on figure 8 the effect on crystallinity, at concentrations of D-Lactide units of from 1 .8% to 7.2%, when drawing a biaxially stretched PLA at 80°C to draw ratios up-to 4 in an experimental setting that does not correspond to thermoforming.
  • thermoformed articles and thermoforming process with higher stretching and/or with higher form factors, and/or with well-formed shapes, for example without retraction after mold removal.
  • Document EP1577346B1 discloses blends of PLA polymers having various D- Lactide units amounts, properties of the blends, and thermoforming.
  • Paragraphs [0103] and [0104] disclose thermoforming a bi-oriented sheet of 300 ⁇ in a mold having a diameter of 100 mm and being 30 mm deep. This corresponds to a cylinder with a total stretch ratio of 2.2.
  • articles that can be thermoformed and for thermoforming processes with higher stretching and/or with higher form factors There is also a need for articles having a thermoformed part that can be made, with higher productivity processes and/or with higher processability windows.
  • articles, such as sheets that can allow this. The is also a need for articles and/or processes thereto with better formed shapes, for example without retraction after mold removal.
  • the invention addresses at least one of the problems or needs above with an article comprising a multilayer plastic material comprising at least:
  • the article of the invention can be a plastic sheet or a container comprising a thermoformed part typically obtained from the plastic sheet.
  • the invention also concerns a process of making a plastic sheet article, comprising a step of co-extruding the layers.
  • the invention also concerns process of making an article comprising a thermoformed part, comprising the steps of:
  • thermoforming at least a part of the plastic sheet b) thermoforming at least a part of the plastic sheet.
  • the articles and/or the processes of the invention allow or present good mechanical properties such as compression resistance and/or good thickness profiles, and/or good homogeneity and/or control of thickness profiles and/or lack of retraction in the mold and/or good other properties such as banderoles adhesion. It has been surprisingly found that it was possible to achieve an improved control and/or homogeneity while avoiding retraction in the thermoforming mold. Definitions
  • non-foamed polylactic acid (PLA) material refers to polylactic acid substantially depleted of gas inclusions, either directly in the PLA or in microspheres embedded in the PLA.
  • Non-foamed PLA has typically a density of higher than 1 .2.
  • Non-foamed PLA is also referred to as "compact PLA”.
  • a foamed polylactic acid (PLA) material refers to polylactic acid comprising gas inclusions, preferably directly in the PLA, typically as opposed to gas inclusions in microspheres embedded in the PLA.
  • Foamed PLA has typically a density of up to 1 .2, preferably of at less than 1 .2, preferably of up to 1 .1 .
  • additives refer to products that can be added to polylactic acid or other thermoplastic materials.
  • total stretch ratio refers to the ratio between the surface of the article opening, corresponding to the thermoforming area of a sheet, and the surface of the developed thermoformed part, corresponding to the surface of the plastic in contact with a mold.
  • the "local stretch ratio” or “local draw ratio” refers to the stretch ratio at a local zone of the thermoformed part.
  • the local stretch ratio can be estimated by dividing the local thickness in the thermoformed part by the initial thickness before thermoforming. Non thermoformed parts, such as flanges, typically have this initial thickness.
  • a "stereocomplex” refers to a complex organized structure of a L-Lactide homopolymer and a D-Lactide homopolymer having a crystalline structure that the melting temperature is of more than 210°C.
  • PLA materials that are different from a stereocomplex typically have a melting temperature of 150°C-180°C.
  • the article has a multilayer structure, for example a bi-layer structure or a three- layer structure.
  • the article comprises a multilayer plastic material comprising at least: A) one layer A of a material A comprising polylactic acid having D-Lactide units and L- Lactide units, as a copolymer and/or blend, with a ratio A between D-Lactide units and L- Lactide units, B) one layer B of a material B comprising polylactic acid having D-Lactide units and L- Lactide units, as a copolymer and/or blend, with a ratio B between D-Lactide units and L- Lactide units,
  • the article can comprise further layers, for example at least one layer C, for example between layer A and layer B.
  • Layer C can be of a material C comprising polylactic acid, comprising polylactic acid having D-Lactide units and L-Lactide units, as a copolymer and/or blend, with a ratio C between D-Lactide units and L-Lactide units.
  • ratio B ⁇ ratio C ⁇ ratio A.
  • ratio A - ratio B > 0.3, preferably [ratio A - ratio B] > 1 .0, preferably [ratio A - ratio B] > 2.0.
  • the amounts of the layers by distance along the article thickness can correspond to the following profile:
  • the total of all layers being 100% of the thickness.
  • the amount of layer A can be of from 15% to 85%, for example from 15% to 50%.
  • the amount of layer B can be of from 15% to 85%, for example from 15% to 50%.
  • the amounts by distance along the article thickness are as follows:
  • - layer C from 10% to 80%
  • the total of all layers being 100% of the thickness.
  • the materials of the layers can be a foamed polylactic acid material or a non-foamed polylactic acid material. In a particular embodiment all the materials are non-foamed polylactic acid materials. In a particular embodiment at least one layer is in a foamed polylactic acid material.
  • layer C can be of a foamed polylactic acid material, while layers A and B are of a non-foamed polylactic acid material.
  • the article is a plastic sheet. It has typically a thickness e. It has typically two other dimensions such as a length I and a broadness b. Typically both other dimensions I and b are at least 10 times, preferably 100 times the thickness e.
  • the plastic sheet can typically have a thickness 0.5 mm to 2.0 mm, preferably from 0.6 mm to 1 .0 mm. Examples of thicknesses are 0.5 mm, or 0.7 mm, or 0.8 mm, or 0.9 mm, or 1 .0 mm.
  • the broadness can be typically of from 20 cm to 200 cm. The length can be of at least 200 cm.
  • the plastic sheets can be presented as rolls.
  • the article comprises a thermoformed part.
  • Such an article can be a container.
  • the container can be a thermoformed article, preferably obtained from the plastic sheet. It can be for example a thermoformed cup, preferably in a multipack form or in an individual cup form.
  • the container typically comprises at least a part corresponding to the multilayer structure. It can comprise a stretched part and a non-stretched part.
  • the non-stretched part can typically correspond to the plastic sheet, with the plastic sheet thickness.
  • the non-stretched part can be for example a flange at the periphery of a stretched part.
  • the article can be a thermoformed cup, having a body corresponding to a stretched, typically thermoformed, part of a sheet, and flanges at the periphery of the body, corresponding to a non-stretched part of a sheet. Further details about containers are given below.
  • layer A is the internal layer of the thermoformed part.
  • layer B is the external layer of the thermoformed part, optionally at least partially covered by a banderole. Despite a ratio B toward less amorphous behavior, it has been surprising found that layer B allows a better adhesion of banderoles.
  • Material A comprises polylactic acid having D-Lactide units and L-Lactide units, as a copolymer and/or blend, with a ratio A between D-Lactide units and L-Lactide units of from 4.0/96.0 to 20.0/80.0, preferably from 5.0/95.0 to 10.0/90.0.
  • a ratio A between D-Lactide units and L-Lactide units of from 4.0/96.0 to 20.0/80.0, preferably from 5.0/95.0 to 10.0/90.0.
  • the ratios by weight and the ratios by number are considered herein as identical.
  • ratio A can be of from 4.0/96.0 to 5.0/95.0, or from 5.0/95.0 to 6.0/94.0, or from 6.0/96.0 to 7.0/93.0, or from 7.0/93.0 to 8.0/92.0, or from 8.0/92.0 to 9.0/91 .0, or from 9.0/91 .0 to 10.0/90.0, or from 10.0/90.0 to 1 1 .0/89.0, or 1 1 .0/89.0 to 12.0/88.0, or from 12.0/88.0 to 13.0/87.0, or from 13.0/87.0 to 14.0/86.0, or from 14.0/86.0 to 15.0/85.0, or from 15.0/85.0 to 16.0/84.0, or from 16.0/84.0 to 17.0/83.0, or from 17.0/83.0 to 18.0/82.0, or from 18.0/82.0 to 19.0/81 .0, or from 19.0/81 .0 to 20.0/80.
  • the polylactic acid is preferably different from a stereocomplex.
  • Polylactic Acid (PLA) polymers are known by the one skilled in the art. These are typically obtained by polymerization of lactic acid monomers, in an L-Lactide form and/or in a D-Lactide form. The lactic acid monomers are typically obtained by a microbiological process, involving micro-organisms such as bacteria. Polylactic Acid (PLA) polymers with various ratios between D-Lactide units and L-Lactide units are commercially available. Examples of PLA polymers that can be used, typically in blends, to obtain layer A include for example Ingeo® 2003D and Ingeo® 4060D, both marketed by NatureWorks.
  • the polylactic acid of Material A is a copolymer having D- Lactide units and L-Lactide units in the ratios mentioned above.
  • Such copolymers are typically obtained by copolymerizing D-Lactide monomers and L-Lactide monomers in the ratios mentioned above.
  • the copolymers do not comprise more than 10% by weight, preferably 7.5%, preferably 5%, preferably 2.5%, preferably 1 %, preferably 0.5%, preferably 0.1 %, of units different from L-Lactide and D-Lactide units.
  • the polylactic acid of Material A is a blend of at least a first polylactic acid polymer and at least a second polylactic acid polymer.
  • the first polylactic acid polymer comprises L-Lactide and optionally D-Lactide units.
  • the second polylactic acid comprises D-Lactide units and L-Lactide units.
  • the blend is such that the ratios between D-Lactide units comprised in all the polylactic acid polymers of the blend and the L-Lactide units comprised in all the polylactic acid polymers of the blend are in the ranges mentioned above.
  • the at least first polylactic acid polymer and the at least second polylactic acid polymer are mixed in amounts appropriate to obtain the ratios mentioned above.
  • the blend can be obtained by mixing and melting the polymers, typically upon extruding a sheet.
  • the ratios by weight between the first and second polymers can be from example of from 1 /99 to 99/1 , preferably from 10/90 to 90/10, preferably from 20/80 to 90/10, preferably from 34/66 to 80/20.
  • one implements for Material A a blend of a first polylactic acid polymer having less than 4.2% units of D-Lactide and more than 95.8% units of L-Lactide, and a second polylactic acid polymer having from 4.3% to 80.0%, preferably 4.3% to 50.0%, preferably 4.3% to 20.0%, preferably 8.0% to 15.0%, units of D-Lactide and from 20.0% to 96.0%, preferably 50.0% to 96.0%, preferably 80.0% to 96.0%, preferably 85.0% to 92.0%, units of L-Lactide.
  • the second polylactic acid polymer is present in an amount of less than 50% of the first polylactic acid polymer.
  • material A can comprise a non polylactic acid masterbatch polymer, preferably polyethylene, or Ethylene-Vinyl Acetate.
  • the material can comprise further additives.
  • Material B comprises polylactic acid having D-Lactide units and L-Lactide units, as a copolymer and/or blend, with a ratio B between D-Lactide units and L-Lactide units of from 0.1/99.1 to lower than 4.0/96.0, preferably from 1 .0/99.0 to 3.7./96.3.
  • the ratios by weight and the ratios by number are considered herein as identical.
  • ratio B can be of from 0.1/99.9 to 0.5/99.5, or from 0.5/99.5 to 1 .0/99.0, or from 1 .0/99.0 to 1 .5/98.5, or from 1 .5/98.5 to 2.0.0/98.0, or from 2.0/98.0 to 2.5/97.5, or from 2.5/97.5 to 3.0/97.0, or from 3.0/97.0 to 3.5.0/96.5, or 3.5/96.5.0 to 3.7/96.3.
  • the polylactic acid is preferably different from a stereocomplex.
  • Polylactic Acid (PLA) polymers are known by the one skilled in the art. These are typically obtained by polymerization of lactic acid monomers, in an L-Lactide form and/or in a D-Lactide form. The lactic acid monomers are typically obtained by a microbiological process, involving micro-organisms such as bacteria. Polylactic Acid (PLA) polymers with various ratios between D-Lactide units and L-Lactide units are commercially available. Examples of PLA polymers that can be used, typically in blends, to obtain layer B include for example Ingeo® 2003D and Ingeo® 4032D, both marketed by NatureWorks.
  • the polylactic acid of Material B is a copolymer having D- Lactide units and L-Lactide units in the ratios mentioned above.
  • Such copolymers are typically obtained by copolymerizing D-Lactide monomers and L-Lactide monomers in the ratios mentioned above.
  • the copolymers do not comprise more than 10% by weight, preferably 7.5%, preferably 5%, preferably 2.5%, preferably 1 %, preferably 0.5%, preferably 0.1 %, of units different from L-Lactide and D-Lactide units.
  • the polylactic acid of Material B is a blend of at least a first polylactic acid polymer and at least a second polylactic acid polymer.
  • the first polylactic acid polymer comprises L-Lactide and optionally D-Lactide units.
  • the second polylactic acid comprises D-Lactide units and L-Lactide units.
  • the blend is such that the ratios between D-Lactide units comprised in all the polylactic acid polymers of the blend and the L-Lactide units comprised in all the polylactic acid polymers of the blend are in the ranges mentioned above.
  • the at least first polylactic acid polymer and the at least second polylactic acid polymer are mixed in amounts appropriate to obtain the ratios mentioned above.
  • the blend can be obtained by mixing and melting the polymers, typically upon extruding a sheet.
  • the ratios by weight between the first and second polymers can be from example of from 1 /99 to 99/1 , preferably from 10/90 to 90/10, preferably from 20/80 to 90/10, preferably from 34/66 to 80/20.
  • one implements for Material B a blend of a first polylactic acid polymer having from 3.7 to 4.1 % units of D-Lactide and more than 95.9% to 96.3% units of L-Lactide, and a second polylactic acid polymer having less than 3.7% units of D- Lactide and more than 96.3% units of L-Lactide.
  • material B can comprise a non polylactic acid masterbatch polymer, preferably polyethylene, or Ethylene-Vinyl Acetate.
  • the material can comprise further additives.
  • the materials of the layers can comprise further additives, for example an impact and/or snapability modifier.
  • Other additives that can be used include for example:
  • Pigments can be for example Ti0 2 pigments, for example described in document WO 201 1 1 19639.
  • Mineral fillers can be for example calcium carbonates of natural or synthetic origin, magnesium carbonate, zinc carbonate, mixed salts of magnesium and calcium such as dolomites, limestone, magnesia, barium sulfate, calcium sulfates, magnesium and aluminum hydroxides, silica, wollastonite, clays and other silica-alumina compounds such as kaolins, silico-magnesia compounds such as talc, mica, solid or hollow glass beads, metallic oxides such as zinc oxide, iron oxides, titanium oxide and, more particularly, those selected from natural or precipitated calcium carbonates such as chalk, calcite.
  • the further additives can be added in the form of masterbatches, wherein the additive is dispersed in a polymer matrix, for example PLA or a polymer of ethylenically unsaturated monomers, such as an ethylene vinyl acetate copolymer.
  • a polymer matrix for example PLA or a polymer of ethylenically unsaturated monomers, such as an ethylene vinyl acetate copolymer.
  • additives if present, in the material can be typically present in an amount of 0.1 % to 15% by weight, for example in an amount of 1 % to 10% by weight.
  • Impact and/or snapability modifiers compounds are known by the one skilled in the art, and available on the market as such. They typically modify the mechanical properties of thermoplastics by increasing the tensile stress of said thermoplastics. Various mechanisms can be involved, such as cavitation upon impact or diffused energy released upon impact. Compounds that have such properties are typically appropriate.
  • impact modifiers include alkyl sulfonates, aromatic-aliphatic polyesters, poly(butylene adipate-co-terephthalate), for example those described in document EP 2065435, ethylene copolymers, for example described in document WO 201 1 1 19639, Acetyl TriButyl citrate, Triethyl citrate, Polybutylene Succinate, Polyvinyl Alcohol (PVA), ethylene vinyl acetate, hydrogenated soil oil.
  • alkyl sulfonates aromatic-aliphatic polyesters
  • poly(butylene adipate-co-terephthalate) for example those described in document EP 2065435
  • ethylene copolymers for example described in document WO 201 1 1 19639
  • Acetyl TriButyl citrate Triethyl citrate
  • Polybutylene Succinate Polyvinyl Alcohol (PVA)
  • PVA Polyvinyl Alcohol
  • the impact and/or snapability modifier is a core/shell polymeric compound or an alkyl sulfonate compound.
  • the material comprises from 0.01 % to 20% by weight of impact and/or snapability modifier, preferably from 0.1 % to 10%, preferably from 0.2 to 5%.
  • material A comprises from 0.01 % to 20% by weight of impact and/or snapability modifier, preferably from 0.1 % to 10%, preferably from 0.2 to 5%.
  • material B comprises from 0.01 % to 20% by weight of impact and/or snapability modifier, preferably from 0.1 % to 10%, preferably from 0.2 to 5%.
  • Material C can either comprise or not comprise impact and/or snapability modifier.
  • material C comprises from 0.01 % to 20% by weight of impact and/or snapability modifier, preferably from 0.1 % to 10%, preferably from 0.2 to 5%.
  • Impact and/or snapability modifiers can be added in the form of masterbatches, wherein the impact modifier is dispersed in a polymer matrix, for example PLA or a polymer of ethylenically unsaturated monomers, such as an ethylene vinyl acetate copolymer.
  • a polymer matrix for example PLA or a polymer of ethylenically unsaturated monomers, such as an ethylene vinyl acetate copolymer.
  • the core-shell polymeric compound also referred to as core-shell copolymer
  • core-shell copolymer is typically in the form of fine particles having an elastomer core and at least one thermoplastic shell, the particle size being generally less than 1 micron and advantageously between 150 and 500 nm, and preferably from 200 nm to 450 nm.
  • the core-shell copolymers may be monodisperse or polydisperse.
  • isoprene homopolymers or butadiene homopolymers copolymers of isoprene with at most 3 mol % of a vinyl monomer and copolymers of butadiene with at most 35 mol % of a vinyl monomer, and preferably 30 mol % or less.
  • the vinyl monomer may be styrene, an alkylstyrene, acrylonitrile or an alkyl(meth)acrylate.
  • Another core family consists of the homopolymers of an alkyl (meth)acrylate and the copolymers of an alkyl(meth)acrylate with at most 35 mol % of a vinyl monomer, and preferably 30 mol % or less.
  • the alkyl(meth)acrylate is advantageously butyl acrylate.
  • Another alternative consists in an all acrylic copolymer of 2-octylacrylate with a lower alkyl acrylate such as n-butyl-, ethyl-, isobutyl- or 2-ethylhexyl- acrylate.
  • the alkyl acrylate is advantageously butyl acrylate or 2-ethylhexyl- acrylate or mixtures thereof.
  • the comonomer of 2- octylacrylate is chosen among butyl acrylate and 2-ethylhexyl acrylate.
  • the vinyl monomer may be styrene, an alkylstyrene, acrylonitrile, butadiene or isoprene.
  • the core of the copolymer may be completely or partly crosslinked. All that is required is to add at least difunctional monomers during the preparation of the core; these monomers may be chosen from poly(meth)acrylic esters of polyols, such as butylene di(meth)acrylate and trimethylolpropane trimethacrylate.
  • difunctional monomers are, for example, divinylbenzene, trivinylbenzene, vinyl acrylate and vinyl methacrylate.
  • the core can also be crosslinked by introducing into it, by grafting, or as a comonomer during the polymerization, unsaturated functional monomers such as anhydrides of unsaturated carboxylic acids, unsaturated carboxylic acids and unsaturated epoxides. Mention may be made, by way of example, of maleic anhydride, (meth)acrylic acid and glycidyl methacrylate.
  • the shells are typically styrene homopolymers, alkylstyrene homopolymers or methyl methacrylate homopolymers, or copolymers comprising at least 70 mol % of one of the above monomers and at least one comonomer chosen from the other above monomers, vinyl acetate and acrylonitrile.
  • the shell may be functionalized by introducing into it, by grafting or as a comonomer during the polymerization, unsaturated functional monomers such as anhydrides of unsaturated carboxylic acids, unsaturated carboxylic acids and unsaturated epoxides.
  • the shell could also contain functional or hydrophilic groups to aid in dispersion and compatibility with different polymer phases.
  • core-shell copolymers (A) having two shells, one made of polystyrene and the other, on the outside, made of PMMA. Examples of copolymers (A) and their method of preparation are described in the following U.S. Pat. No. 4,180,494, U.S. Pat. No.
  • the core / shell ratio can be for example in a range between 10/90 and 90/10, more preferably 40/60 and 90/10 advantageously 60/40 to 90/10 and most advantageously between 70/30 and 95/15.
  • Examples of appropriate core/shell impact and/or snapability modifiers include Biostrength ranges, for example Biostrength 150, marketed by Arkema.
  • Impact and/or snapability modifier can be comprised is one or several layer of the article, for example in layer A and/or layer B.
  • the article of the invention can comprise a thermoformed part.
  • the thermoformed part can comprise at least one zone wherein the local stretch ratio is of at least 4.2, preferably 4.3, preferably at least 4.5, preferably at least 5 (5.0), preferably at least 6 (6.0), preferably at least 7 (7.0).
  • the thermoformed part can have a total stretch ratio of at least 2.5, preferably at least 3 (3.0), preferably at least 4 (4.0), preferably at least 5 (5.0).
  • the article can comprise a part that has not undergone any stretch, said part being considered herein as a non-thermoformed part.
  • the article can be typically obtained by thermoforming a plastic sheet in the material.
  • thermoforming is a process known by the one skilled in the art. It typically comprises stretching under heating a plastic material such as a sheet, typically by applying in a mold cavity mechanical means such as plugs and/or by aspiration.
  • the mechanical means can optionally be enhanced by applying a gas under pressure.
  • the stretching results in local stretch ratios in zones forming the thermoformed part. If the stretching is uniform the local stretch ratios are equal everywhere. As the stretching is typically non uniform, the thermoformed part typically presents various zones having different local stretch ratios.
  • the thermoformed part of the article can have a thickness varying in a range of from 60 ⁇ to 750 ⁇ , preferably from 70 ⁇ to 500 ⁇ .
  • the article is a container having a hollow body and optionally at least one flange, the hollow body defining said thermoformed part, the hollow body being provided with an opening);
  • the hollow body is at least partially covered by a banderole
  • the hollow body comprises:
  • the opening is a generally circular opening and the bottom has a generally circular outer edge;
  • the side wall has a generally cylindrical upper portion having a height h2 and a lower portion having a height hi , tapering from the upper portion toward the bottom in a curved manner, the upper portion and the lower portion intersecting and interconnecting at a peripheral intersection line;
  • the bottom is a planar bottom, and wherein the peripheral intersection line is spaced at a substantially constant distance from the planar bottom, the lower portion having a height hi corresponding to a minoritary fraction of the height H of the container;
  • the height h2 of said upper portion is constant, the ratio h2/H being comprised between 3:5 and 6:7, and preferably between 2:3 and 4:5;
  • the side wall has a thickness profile such that the average thickness of the lower portion is superior to the average thickness of the upper portion;
  • the opening has an inner diameter which is inferior to the height H of the container and superior to the height hi of the lower portion.
  • the article can be thermoformed from a sheet having for example a thickness of higher than 300 ⁇ , preferably at least 500 ⁇ , preferably at least 750 ⁇ , preferably from 750 to 1500 ⁇ .
  • the flange, if present in the article, typically has such a thickness.
  • the article can be a container, for example a container used as a dairy product container, like a yogurt cup.
  • the invention also concerns the container filled with a food or non-food product, preferably a dairy product, preferably a milk-based (milk being an animal milk or a vegetal milk substitute such as soy milk or rice milk etc ..) product, preferably a fermented dairy product, for example a yogurt.
  • the container can have a yogurt cup shape, for example with a square cross section or a square with rounded corners cross section, or round cross section.
  • the container can have a tapered bottom, preferably a tapered rounded bottom.
  • the container has walls (perpendicular to the cross section), typically a tubular side wall, that can be provided with elements such as stickers or banderoles. Elements such as banderoles can contribute to re-enforcing the mechanical resistance of the container.
  • the container filled with a food or non-food product may comprise a closure element to seal the opening.
  • a flange defines a support surface for attachment of the closure element to the containing part of the container.
  • the closure element remains above and at a distance from the side wall.
  • a membrane seal or thin foil, optionally suitable for food contact, may form the closure element.
  • the closure element may have the same general cut as the flange.
  • the container can be for example a container of 50 ml (or 50 g), to 1 L (or 1 kg), for example a container of 50 ml (or 50 g) to 80 ml (or 80 g), or 80 ml (or 80 g) to 100 ml (or 10Og), or 100 ml (or 100 g) to 125 ml (or 125 g), or 125 ml (or 125 g) to 150 ml (or 150 g), or 150 ml (or 150 g) to 200 ml (or 200 g), or 200 ml (or 200 g) to 250 ml (or 250 g), or 250 ml (or 250 g) to 300 ml (or 300 g), or 300 ml (or 300 g) to 500 ml (or 500 g), or 500 ml (or 500 g) to 750 ml (or 750 g), or 750 ml (or 750 g) to 1 L (
  • the article can be prepared by any appropriate process.
  • Material A and/or material B can be prepared before forming the article or during the formation of the article.
  • Thermoplastic materials, such as PLA, can be introduced in the form of powder, pellets or granules.
  • Materials A and B can be mixture of several ingredients: a blend of PLAs and optionally further additives such as an impact and/or snapability modifier. These ingredients can be mixed upon forming the article, typically in an extruder. One can implement masterbatches of impact and/or snapability modifiers and optionally of further additives to be mixed with the thermoplastic material. In another embodiment one can use pre-mixed compounds typically in the form of powder, pellets or granules.
  • layer A and layer B, and optional further layers are co- extruded, typically from flows of material A and material B, and optional further layer material, in a molten form.
  • Co-extrusion processes are known from the one skilled in the art. These typically involve extruding separates flows through separates side by side dies. Beyond the dies the flows merge and form at least one interface. There is one interface for two-layer articles and two interfaces for three-layer articles. The materials are then cooled to form a solid article.
  • Treatment steps are for example press treatments, calendering, stretching etc...
  • the article is a sheet prepared by a process involving co-extruding and calendering.
  • the article can be obtained by thermoforming a plastic sheet.
  • a typical process of making the article comprises the steps of:
  • thermoforming at least a part of the plastic sheet preferably such that the thermoformed part comprises at least one zone wherein the local stretch ratio is of at least 4.2, preferably at least 4.5, preferably at least 5 (5.0), preferably at least 6 (6.0), preferably at least 7 (7.0) and/or such that the total stretch ratio of at least 2.5, preferably at least 3 (3.0), preferably at least 4 (4.0), preferably at least 5 (5.0).
  • the sheet has a thickness of higher than 300 ⁇ , preferably at least 500 ⁇ , preferably at least 750 ⁇ , preferably from 750 ⁇ to 1500 ⁇ .
  • the material can be prepared before forming the sheet or during the formation of the sheet.
  • Thermoplastic materials such as PLA, can be introduced in the form of powder, pellets or granules.
  • the process comprises a step of providing the polylactic acid, for example by mixing a first polylactic acid polymer and a second polylactic acid polymer and optionally further additives. These can be mixed upon forming the sheet, typically in an extruder.
  • Thermoforming is a known operation. One can thermoform the sheet so as to obtain the final product of the desired shape. It is mentioned that some stretching occurs upon thermoforming. Local stretching ratios of at least 4.2, preferably at least 4.5, preferably at least 5 (5.0), preferably at least 6 (6.0), preferably at least 7 (7.0) are considered as quite high ratios, corresponding to deep thermoforming. Total stretching ratios of at least 2.5, preferably at least 3 (3.0), preferably at least 4 (4.0) preferably at least 5 (5.0) are considered as quite high ratios, corresponding to deep thermoforming. The higher the ratio is, the deeper the thermoforming is, the more difficult the control is.
  • the total stretching ratio can be for example of from 2.5 to 8.0, preferably between 3.0 to 7.0, preferably between 4.0 to 6.5.
  • the article can present some local stretching ratios of from 2.5 to 10.0, for example of from 2.5 to 4 and/or from 4 to 6 and/or from 6 to 8 and/or from 8 to 10.
  • Thermoforming may be for example performed thanks to a Form Fill Seal thermoforming line. The thermoforming can present the following steps:
  • guide chains i.e. spike or jaws
  • the mold may comprise or not a label for example a banderole.
  • the banderol can be a partial banderole positioned only in the top of the mold, to obtain an article that is covered by the banderole on the upper portion of the body or similar upper area of the thermoformed part, and not covered by the banderole in a lower portion.
  • a Form Fill Seal thermoforming line one typically performs the following steps after the thermoforming:
  • M Masterbatch of an impact and/or snapability modifier in PLA.
  • a multilayer (layer A)-(layer C)-(layer B) PLA plastic sheet is prepared by co-extrusion according to the procedure below. All the layers are compact layers.
  • the materials (PLA1 , PLA2, PLA3, M) of the different layers are separately extruded with extruders.
  • the temperature along the screws is between 170°C and 200°C.
  • the different material flows are fed into feedblock channels through different passages separated by two thin planes (die). At the end of the separation planes, the three flows merge and form two interfaces, and the sheet is extruded through a die with a temperature of about 160°C.
  • the sheet is then calendered on 3 rolls having a temperature of about 35 °C to control the thickness.
  • the thickness of the sheet is 0.75 mm.
  • Table 1 below presents the arrangement and the compositions of the various layers.
  • the plastic sheet of example 1 is thermoformed into yogurt cups according to the procedure below.
  • the sheet is introduced into a F.F.S. thermoforming line and is then thermoformed in 4 oz cups with the following parameters:
  • the sheet is gradually heated thanks to six heating steps, each of the heating boxes having a closing time of 1 .2 s.
  • thermoforming step is performed with conventional felt forming plug, applied on layer A, such that layer A is the container internal layer and layer B is the container external layer. Mold temperature is fixed at 55°C to activate the label hot melt and to cool down the PLA material;
  • Forming air pressure 4.0 bars
  • Machine speed 30 strokes per minute.
  • Banderole a full banderole, as shown on figure 1 , made of paper or a paper/plastic based complex applied in the mold.
  • the cups present both a good homogeneity resulting from and/or allowing a good processability, while being well formed, showing no substantial retraction after mold removal, with good or regular adhesion of the banderoles.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)

Abstract

La présente invention concerne un article comprenant un matériau en plastique multicouche comprenant au moins une couche d'acide polylactique A et une couche d'acide polylactique B, avec différentes quantités d'unités de D-lactide.
PCT/EP2016/067580 2015-07-22 2016-07-22 Article comprenant plusieurs couches d'acide polylactique avec du d-lactide WO2017013258A1 (fr)

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US62/195,428 2015-07-22

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112739284A (zh) * 2018-10-16 2021-04-30 蛇牌股份公司 用于医疗技术产品的可吸收的包装
CN115515788A (zh) * 2020-03-06 2022-12-23 道达尔能源科碧恩私人有限公司 基于聚丙交酯的多层结构体及由其制成的制品

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6153276A (en) * 1996-11-22 2000-11-28 Dainippon Ink And Chemicals, Inc. Heat-sealable lactic acid-based polymer laminates
US20100104882A1 (en) * 2007-03-16 2010-04-29 Toray Industries, Inc. Aliphatic polyester sheet and molded body composed of the same
US20120128974A1 (en) * 2008-06-13 2012-05-24 Toray Plastics (America), Inc. Matte biaxially oriented polylactic acid film
WO2014186902A1 (fr) * 2013-05-23 2014-11-27 Solegear Bioplastics Inc. Polylactide polymère thermoformable

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6153276A (en) * 1996-11-22 2000-11-28 Dainippon Ink And Chemicals, Inc. Heat-sealable lactic acid-based polymer laminates
US20100104882A1 (en) * 2007-03-16 2010-04-29 Toray Industries, Inc. Aliphatic polyester sheet and molded body composed of the same
US20120128974A1 (en) * 2008-06-13 2012-05-24 Toray Plastics (America), Inc. Matte biaxially oriented polylactic acid film
WO2014186902A1 (fr) * 2013-05-23 2014-11-27 Solegear Bioplastics Inc. Polylactide polymère thermoformable

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112739284A (zh) * 2018-10-16 2021-04-30 蛇牌股份公司 用于医疗技术产品的可吸收的包装
CN112739284B (zh) * 2018-10-16 2023-08-29 蛇牌股份公司 用于医疗技术产品的可吸收的包装
CN115515788A (zh) * 2020-03-06 2022-12-23 道达尔能源科碧恩私人有限公司 基于聚丙交酯的多层结构体及由其制成的制品

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