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EP-4735254-A1 - PROCESS TO PRODUCE FOOD-CONTACT MULTILAYERED HOLLOW ARTICLES FROM RECYCLED POLYETHYLENE RESIN AND ARTICLES THEREOF

EP4735254A1EP 4735254 A1EP4735254 A1EP 4735254A1EP-4735254-A1

Abstract

The disclosure provides a process to produce a multilayered hollow article comprising two or three layers wherein the article comprises at least 30 wt.% of recycled polyethylene resin wherein the process comprises a preliminary step of preparing one or more recycled- containing polyethylene compositions to be used as the first, second and optional third layer.

Inventors

  • RIBOUR, DAVID
  • Brisse, Julien

Assignees

  • TotalEnergies OneTech

Dates

Publication Date
20260506
Application Date
20240718

Claims (20)

  1. 1 . A process to produce an article being a multilayered hollow article comprising; a) providing a first, a second; and an optional third polyethylene compositions, wherein each of the first polyethylene composition, the second polyethylene composition, and the third polyethylene composition, when present, has a melt index ranging from 0.4 to 2.0 g/10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; b) forming a multilayered hollow article comprising a first layer made from a first polyethylene composition being the inner layer; a second layer made from a second polyethylene composition; optionally a third layer made from a third polyethylene composition being an outer layer; wherein the process is characterized in that the article comprises at least 30 wt.% of recycled polyethylene resin based on the total weight of the article; wherein the recycled polyethylene resin is selected to have a melt index MI2 ranging from 0.2 to 2.2 g/10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; in that, the process comprises a preliminary step of preparing one or more recycled- containing polyethylene compositions to be used as the first polyethylene composition, the second polyethylene composition, and/or the third polyethylene composition, when present; and in that said step of preparation of the or at least one recycled-containing polyethylene composition comprises: - a thermal treatment of the recycled polyethylene resin to increase its melt index and obtain a thermally treated recycled polyethylene resin; and/or - blending the recycled polyethylene resin or the thermally treated recycled polyethylene resin with one or more boosters.
  2. 2. The process according to claim 1 is characterized in that the second layer has a thickness equal to or greater than the thickness of the first layer; with preference, the thickness of the second layer from 1 .1 to 4.0 times the thickness of the first layer.
  3. 3. The process according to claim 1 or 2 is characterized in that the step of preparation of the or at least one recycled-containing polyethylene composition comprises a thermal treatment of the recycled polyethylene resin to increase its melt index wherein the thermal treatment comprises extruding the recycled polyethylene resin in an extruder at a temperature of at least 300°C in one or more hot zones of the extruder to obtain a thermally treated recycled polyethylene resin.
  4. 4. The process of claim 3 is characterized in that the extrusion is performed with a residence time ranging from 10 to 180 seconds; and/or the temperature of the thermal treatment ranges from 320 to 460°C.
  5. 5. The process according to any one of claims 1 to 4 is characterized in that the step of preparation of the or at least one recycled-containing polyethylene composition comprises blending the recycled polyethylene resin or the thermally treated recycled polyethylene resin with one or more boosters selected from: a first booster being a polyethylene having a melt index greater than the melt index of the recycled polyethylene resin or the thermally treated recycled polyethylene resin; and/or a second booster being a polyethylene having a melt index lower than the melt index of the recycled polyethylene resin or the thermally treated recycled polyethylene resin.
  6. 6. The process according to claim 5 is characterized in that the first booster is a polyethylene resin having a melt index of at least 2.0 g/10 min as determined according to ISO 1133- 2011 at 190 °C under a load of 2.16 kg; with preference, a melt index ranging from 2.0 to 10.0 g/10 min.
  7. 7. The process according to claim 5 or 6 is characterized in that the first booster has: a density of at least 0.958 g/cm 3 as determined according to ISO 1183-1 :2012 at 23°C; and/or a bimodal molecular weight distribution; and/or is Ziegler Natta catalyzed.
  8. 8. The process according to any one of claims 5 to 7 is characterized in that the second booster is a polyethylene resin having a melt index of at most 0.8 g/10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; with preference, a melt index of at most 0.4 g/10 min.
  9. 9. The process according to any one of claims 5 to 8 is characterized in that the second booster has a density of at most 0.960 g/cm 3 as determined according to ISO 1183-1 :2012 at 23°C; and/or is metallocene catalyzed or Ziegler Natta catalyzed or chromium catalyzed.
  10. 10. The process according to any one of claims 1 to 9 is characterized in that the content of the one or more boosters in a recycled-containing polyethylene composition is ranging from 5 to 50 wt.% based on the total weight of recycled-containing polyethylene composition.
  11. 11. The process according to any one of claims 1 to 10 is characterized in that the recycled polyethylene resin is selected to have a melt index MI2 ranging from 0.4 to 1.8 g/10 min
  12. 12. The process according to any one of claims 1 to 11 is characterized in that the multilayered hollow article is selected from a bottle, a container, a can, a jerrycan, and a toy.
  13. 13. The process according to any one of claims 1 to 12 is characterized in that the article has a thickness of at least 150 pm; preferably ranging from 150 to 700 pm.
  14. 14. The process according to any one of claims 1 to 13 is characterized in that at least the second polyethylene composition is a recycled-containing polyethylene composition.
  15. 15. The process according to claim 14 is characterized in that the article comprises two layers, in that the second polyethylene composition is a recycled-containing polyethylene composition selected to comprise from 0.5 to 10.0 wt.% of a white pigment or colored pigment based on the total weight of the recycled-containing polyethylene composition and in that the first polyethylene composition is a virgin polyethylene composition comprising from 1.0 to 10.0 wt.% of carbon black based on the total weight of the first polyethylene composition.
  16. 16. The process according to claim 15 is characterized in that the recycled-containing polyethylene composition further comprises from 1.0 to 30.0 wt.% of reinforcement material based on the total weight of the recycled-containing polyethylene composition.
  17. 17. The process according to claim 14 is characterized in that the article comprises three layers and in that the second polyethylene composition is a recycled-containing polyethylene composition is selected to comprise carbon black at a content ranging from 0.1 to 10.0 wt.% based on the total weight of the recycled-containing polyethylene composition.
  18. 18. The process according to claim 17 is characterized in that the first polyethylene composition is a virgin polyethylene composition and/or the first and the third polyethylene composition are the same.
  19. 19. The process according to claim 14 is characterized in that the article comprises three layers, in that the second polyethylene composition is a recycled-containing polyethylene composition is selected to comprise carbon black at a content ranging from 0.1 to 10.0 wt.% based on the total weight of the recycled-containing polyethylene composition and in that the third polyethylene composition is a recycled-containing polyethylene composition.
  20. 20. The process according to claim 19 is characterized in that the third polyethylene composition is a recycled-containing polyethylene composition is selected to comprise from 0.5 to 10.0 wt.% of a white pigment based on the total weight of the recycled- containing polyethylene composition.

Description

PROCESS TO PRODUCE FOOD-CONTACT MULTILAYERED HOLLOW ARTICLES FROM RECYCLED POLYETHYLENE RESIN AND ARTICLES THEREOF TECHNICAL FIELD The disclosure relates to multilayered hollow articles comprising a recycled polyethylene resin, and to processes to produce such articles. TECHNICAL BACKGROUND The circular economy concept aims to recycle more polymers from recycled polyethylene resins such as post-consumer resins (PCR) and post-industrial resins (PIR). The postconsumer resins of polyethylene type are mainly coming from domestic or household waste. The volume of recycled polyethylene is increasing and brand-owners and converters are fostering to use of more and more recycled polyethylene resins in their marketed articles to answer final customers’ demands to lower carbon footprint impact and energy consumption. Polyethylene (PE) recycling is challenging because of several problems encountered, such as contamination and polymer degradation during the recycling process. As a consequence, recycled polyethylene shows inferior mechanical properties such as rigidity and processability by comparison to virgin products. The food industry is demanding opportunities to use recycled polyethylene resins but at the same time is facing rigorous specifications both in terms of performance of the articles (such as top load properties and drop impact resistance) and food-contact requirements WO2022216239 (A1) discloses a laminated tube comprising of post-industrial and/or postconsumer recycled resin and the amount of the blends to provide acceptable tube performances and recyclability. The use of recycled resin is to reduce the carbon footprint of packaging tube and closed-loop recycling. A layer of multilayer flexible sheet to produce recyclable packaging by the selection of virgin plastics is used. The tube is interesting but fails to provide the desired balance of mechanical properties. US2023192973 (A1) discloses a shrink film comprising a monolayer or multi-layer film having at least one layer comprising a formulated resin; wherein the formulated resin comprises: a post-consumer recycled resin sourced from recycled high density polyethylene (HDPE) resin; wherein the post-consumer recycled resin has a density of from 0.94 g/cc to 0.97 g/cc, and a melt index, 12, of from 0.2 g/10 min to 1 g/10 min, and (i) a low density polyethylene (LDPE) wherein the LDPE has a density of from 0.915 g/cc to 0.925 g/cc and a melt index, 12, of from 0.1 g/10 min to 1 g/10 min, or (ii) a linear low density polyethylene (LLDPE) wherein the LLDPE has a density of from 0.915 g/cc to 0.945 g/cc and a melt index, 12, from 0.1 g/10 min to 1 g/10 min, or (iii) a combination of (i) and (ii). US2022396689 (A1) describes compounded virgin and post-consumer recyclate HDPE compositions with improved processability and mechanical properties, including processes of making, products and application in food packaging are described herein. WO2022227014 discloses a lamination film structure including a combination of: (a) at least one first layer of an oriented polyethylene film and (b) at least one second layer of a blown or cast polyethylene film, wherein the first oriented polyethylene film layer is laminated with the second blown or cast polyethylene film layer; and wherein the blown or cast polyethylene film of component (b) is a blown polyethylene film or a cast polyethylene film comprising a formulated resin including a combination or mixture of: (bi) a predetermined amount of a postconsumer recycled resin sourced from a recycled high density polyethylene resin; and (bii) a predetermined amount of a polyethylene resin; a process for making the above lamination film structure; and a film or article made from a recyclate of the above lamination film structure. The present disclosure aims to provide polyethylene compositions and articles comprising at least 30 wt.% of recycled polyethylene resin that show the same or improved mechanical properties as the ones made from virgin material only, and at the same time comply with the food contact requirements. The present disclosure also aims to provide a process to produce such compositions and/or articles. SUMMARY It has now been found that it was possible to reconcile the use of recycled material with demanding applications such as food-contact applications such as hollow articles for dairy packaging; toys, or bottles for milk, beverage, or oil. According to a first aspect, the disclosure provides a process to produce an article being a multilayered hollow article comprising; a) Providing a first, a second and an optional third polyethylene compositions, wherein each of the first polyethylene composition, the second polyethylene composition, and the third polyethylene composition, when present, has a melt index ranging from 0.4 to 2.0 g/10 min as determined according to ISO 1133-2011 at 190 °C under a load of 2.16 kg; b) Forming a multilayered hollow article comprising a first layer made from a first polye