Process to produce a polyethylene composition for caps and closures comprising recycled polymer

Abstract

The invention relates to a process to produce a composition of polyethylene for the manufacture of caps and closures, wherein the process comprises submitting a component A to a thermal treatment to obtain a component CRA and blending the component CRA with component B which is booster to produce the composition.

Description

[0001] PROCESS TO PRODUCE A POLYETHYLENE COMPOSITION FOR CAPS AND CLOSURES COMPRISING RECYCLED POLYMER

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to caps and closures made from a polyethylene composition preferably comprising recycled material, to the process for producing such a polyethylene composition, and to the process of producing such caps or closures as well as to their use.

[0004] TECHNICAL BACKGROUND

[0005] Today’s ecological challenges are pushing more and more towards the fossil fuel economy and the recycling of plastic materials. The demand from the final customers to reduce their carbon footprint impact and energy consumption is important and implies a high content of recycled material in such compositions. The compositions comprising recycled material may have at least 20 wt.% of recycled material based on the total weight of the composition for a commercial interest.

[0006] Caps and closures are widely used for various applications ranging from food and drink applications to non-food applications such as containers for agrochemicals or chemicals (e.g. motor oil), cosmetics, or pharmaceuticals. Caps and closures are in general required to be strong enough to withstand the closure needs and soft enough to provide an excellent seal on the bottle or the container.

[0007] Polyethylene has become a material of choice in the market of caps and closures because it offers a good balance of mechanical properties and it can easily be processed either by injection moulding or compression moulding. The composition to be used to produce caps and closures must show a good balance of mechanical properties comprising stiffness and environmental stress crack resistance (ESCR) but also have good slip properties (easier removal torque) and good processing properties.

[0008] A good balance of properties has been obtained on the compositions described in WO2022 / 218996. The preferred recycled polymers used were preferably regrind from postconsumer sorted caps or closures. However, such fluxes of recycled material are not important in volume and have the defect of being coloured. The fact that one of the components (here the recycled material) is coloured has an impact on the final colour of the polyethylene composition obtained. There is a need for alternative polymer compositions that do not show the same disadvantages.

[0009] An objective of the invention is to provide a process for the production of polyethylene compositions suitable for the manufacture of articles (such as caps and closures) with the same balance of properties or an improved one as compared to known resins, noticeably, considering one or more from stiffness and closure (cap) environmental stress crack resistance (cap-ESCR) or other mechanical properties and has good processing properties.

[0010] Another objective of the invention is to provide a process for the production of a recycled-based composition that contains at least 20 wt.% of recycled material based on the total weight of the composition for the manufacture of articles (such as caps and closures), wherein the composition and shows the same balance of properties or an improved one as compared to a corresponding virgin composition (i.e. without recycled material), noticeably considering stiffness and closure (cap) environmental stress crack resistance (cap-ESCR) or other mechanical properties, and has good processing properties.

[0011] A further objective is to provide a process for the production of a composition comprising recycled polyethylene resins (rPE), such as post-consumer resins, suitable for the manufacture of articles (such as caps and closures). A further objective is to provide a cost-effective process. It is also an objective of the invention to provide such a composition comprising recycled polyethylene resins (rPE), such as post-consumer resins, and the use of such composition in themanufacture of articles such as caps or closures .

[0012] SUMMARY OF THE INVENTION

[0013] Surprisingly, it has been found that the above objectives can be attained either individually or in any combination, by the use of a combination of a second polyethylene (PE), acting as a booster, in a blend comprising at least 20 wt.% based on the total weight of the blend of a first polyethylene resin (PE) (that can be a recycled-polyethylene resin (rPE)), and preferably at least 30 wt.%, or at least 40 wt.%, or at least 45 wt.%, wherein the first polyethylene resin (PE) has been submitted to a thermal treatment to increase its melt index. In the disclosed composition, the first and second polyethylene resins and the thermal treatment conditions are selected to contribute to the final balance of properties. The present invention allows for enlarging the number of possible polyethylene resins (such as the recycled-polyethylene resin (rPE)) that can be used for such applications.

[0014] According to a first aspect, the invention provides a process to produce a composition of polyethylene for the manufacture of caps and closures, the process being remarkable in that it comprises the steps of providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133- 1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and blending the components CRA and B to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

[0015] In another definition, the invention provides a process to produce a composition of polyethylene for the manufacture of caps and closures, the process being remarkable in that it comprises the steps of providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and blending the components CRA and B to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

[0016] With preference, the step of providing a thermally treated component CRA comprises: providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133- 1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg.

[0017] Whatever is the definition, it is understood that the step of submitting component A to a thermal treatment to obtain a component CRA and the step of blending the components CRA and B can be performed in different extruders or apparatus. Alternatively, the step of submitting component A to a thermal treatment to obtain a component CRA and the step of blending the components CRA and B are performed in a single extruder that is divided into two successive sections, a first section wherein the component A is submitted to a thermal treatment to obtain the thermally treated component CRA and a second section wherein the component B is added via the one or more side feeders and is blended with the thermally treated component CRA under classical conditions (such as at a temperature of at most 250°C).

[0018] In a preferred embodiment, the one or more polyethylene resins of the component (A) are one or more recycled polyethylene resins (rPE) so that the composition of polyethylene for the manufacture of caps and closures comprises recycled polyethylene (rPE).

[0019] It was found that thanks to a thermal treatment on a first polyethylene of a low melt index (MI2) of at most 1.8 g / 10 min (i.e., component A), it was possible to use polymers such as recycled polymers with a lower melt index, such as white or natural fluxes. Surprisingly good results in cap ESCR have been obtained on the resulting composition, as shown by the examples, even when said resulting composition of polyethylene comprises a high content of component A of at least 20 wt.% (such as a high content of recycled material), such as at least 30 % or at least 40 wt.%. The composition can be used in the manufacture of caps or closures as it shows a desired balance of mechanical properties comprising stiffness and closure environmental stress crack resistance (cap-ESCR) and good processing properties. Indeed, as shown by the examples, it displays a tensile modulus of at least 900 MPa as determined according to ISO 527-1 :2012, preferably at least 1000 MPa, and good elongation at break of at least 300 %, together with good ESCR properties such as a Cap-ESCR is of at least 10 hours or at least 15 hours. In addition, the composition shows improved processability with an injection pressure at 220°C of less than 135 MPa. In one or more embodiments, the step of blending the components CRA and B to form a composition of polyethylene is conducted at a temperature of at most 280°C; preferably, at a temperature ranging from 160 to 280°C; more preferably at temperature ranging from 170 to 250°C.; and even more preferably from 180 to 230°C.

[0020] In one or more embodiments, the step submitting component A to a thermal treatment comprises the following sub-steps: i) providing a twin-screw extruder with thermal regulation devices; ii) extruding the component A to obtain a thermally treated component CRA; wherein extrusion is performed with a residence time of less than 20 min; and comprises a thermal treatment of the component A at a temperature of at least 300°C in one or more hot zones of the extruder; iii) recovering a thermally treated component CRA.

[0021] In one or more embodiments, the composition of polyethylene has a density of at least 0.942 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably, at least 0.945 g / cm3; more preferably, at least 0.950 g / cm3; even more preferably, at least 0.955 g / cm3; and most preferably, at least 0.960 g / cm3.

[0022] In an embodiment, the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 8.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably, from 0.8 to less than 7.0 g / 10 min; more preferably, from 0.8 to 4.5 g / 10 min, and more preferably from 1.0 to 3.5 g / 10 min. Alternatively, the composition of polyethylene has a melt index (MI2) ranging from 6.0 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably, from 7.0 to 12.0 g / 10 min; more preferably from 7.5 to 11.0 g / 10 min.

[0023] For example, the composition of polyethylene has a melt index (MI2) ranging from 0.5 to less than 7.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg or ranging from 7.0 to 12.0 g / 10 min.

[0024] In one or more embodiments, the composition of polyethylene has a weight-average molecular weight (Mw) of at most 150,000 g / mol as determined by gel permeation chromatography; and / or the composition of polyethylene has a z-average molecular weight (Mz) of at most 340,000 g / mol as determined by gel permeation chromatography.

[0025] In one or more embodiments, the content of component B in the composition is at least 10 wt.% based on the total weight of the composition of polyethylene; and / or the content of component CRA in the composition ranges from 35 wt.% to 80 wt.% based on the total weight of the composition of polyethylene. In one or more embodiments, the component A: has a melt index (MI2) ranging from 0.1 to 1.5 g / 10 min, preferably 0.1 to 1.3 g / 10 min, as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; and / or has a density ranging from 0.945 to 0.980 g / cm3as determined according to ISO 1183- 1 :2012 at 23°C; and / or has an Mz / Mw of at least 4.0 as determined by gel permeation chromatography; and / or has an Mw / Mn of at least 4.0 as determined by gel permeation chromatography; preferably, at least 5.0; more preferably, at least 6.0; even more preferably, at least 7.0.

[0026] In one or more embodiments, the thermally treated component CRA has a melt index (MI2) ranging from 1.8 to 15.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably from 2.0 to 10.0 g / 10 min.

[0027] The component B can further be selected according to the desired properties of the final product. For example, component B has a melt index (MI2) ranging from 0.1 to 3.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; or has a melt index (MI2) ranging from more than 3.5 to 12.0 g / 10 min.

[0028] In a first embodiment, the component B has a melt index (MI2) ranging from 0.1 to 3.5 g / 10 min; preferably from 0.2 to 3.0 g / 10 min, as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; and, has a density ranging from 0.940 to 0.965 g / cm3, preferably from 0.940 to 0.955 g / cm3as determined according to ISO 1183-1 :2012 at 23°C.

[0029] In a second embodiment, the component B has a melt index (MI2) ranging from more than 3.5 to 12.0 g / 10 min; preferably from 6.0 to 12.0 g / 10 min; more preferably from 8.0 to 12.0 g / 10 min, as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; and has a density ranging from 0.940 to 0.965 g / cm3, preferably from 0.950 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C.

[0030] In one or more embodiments (that can be alternative or complementary to the above first and second embodiments related to the component B), the component B: is a Ziegler-Natta catalysed resin or a metallocene-catalysed polyethylene resin; and / or has a molecular weight distribution of Mw / Mnwhich is ranging from 2.0 to 11.0 as determined by gel permeation chromatography, with Mwbeing the weight-average molecular weight and Mnbeing the number average molecular weight and / or is a polyethylene resin being a copolymer of ethylene and one or more alpha-olefin comonomers selected from the group comprising C3-C20 alpha-olefins; with preference, the co-monomer is 1 -hexene.

[0031] In one or more embodiments, component B is a polyethylene resin comprising at least two polyethylene fractions B1 and B2, wherein fraction B1 : has an MI2 of at least 120 g / 10 min or at least 150 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, preferably at least 200 g / 10 min; and / or has a density of at least 0.960 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and / or is a polyethylene homopolymer.

[0032] In an embodiment, the composition of polyethylene further comprises from 100 to 5000 ppm of the one or more antioxidants based on the total weight of the composition; and / or the one or more antioxidants comprises at least one phenolic antioxidant and / or at least one organic phosphite or phosphonite antioxidant.

[0033] In an embodiment, the composition of polyethylene has a cap ESCR of at least 10 h as dertemined by the method of the description.

[0034] According to a second aspect, the invention provides a composition of polyethylene remarkable in that it is produced according to the first aspect.

[0035] According to a third aspect, the invention provides a composition of polyethylene comprising optionally one or more antioxidants; the composition is characterized in that it shows: a MI2 ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and a Mz / Mw of at most 3.3 as determined by gel permeation chromatography;

[0036] - with preference, a cap ESCR of at least 10 h.

[0037] In a preferred embodiment, the polyethylene composition comprises one or more recycled polyethylene resins (rPE) in a content of from 20 wt.% to 90 wt.% based on the total weight of the composition of polyethylene. With preference, the composition of polyethylene has a density ranging from 0.940 to 0.962 g / cm3as determined according to ISO 1183-1 :2012 at 23°C.

[0038] In an embodiment, the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 8.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably, from 0.8 to less than 7.0 g / 10 min; more preferably, from 0.8 to 4.5 g / 10 min, and more preferably from 1.0 to 3.5 g / 10 min. Alternatively, the composition of polyethylene has a melt index (MI2) ranging from 6.0 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably, from 7.0 to 11.0 g / 10 min.

[0039] For example, the composition of polyethylene has a melt index (MI2) ranging from 0.5 to less than 7.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg or ranging from 7.0 to 12.0 g / 10 min.

[0040] It is understood that the composition of the third aspect can be according to the second aspect; i.e. the composition of the third aspect is produced by the process according to the first aspect.

[0041] According to a fourth aspect, the invention provides a process for the manufacture of caps or closures, said process comprising the steps: producing a composition of polyethylene according to the process of the first aspect or providing a composition of polyethylene according to the second or the third aspect; and injection moulding or compression moulding of the composition of polyethylene into a cap or closure.

[0042] With preference, the composition of polyethylene comprises one or more recycled polyethylene resins (rPE); more preferably the composition of polyethylene comprises one or more recycled polyethylene resins (rPE) in a content of from 20 wt.% to 90 wt.% based on the total weight of the composition of polyethylene.

[0043] According to a fifth aspect, the invention provides the use of a composition of polyethylene according to the second or the third aspect for the manufacture of a cap or closure; with preference, the cap or the closure is made by injection moulding or compression moulding.

[0044] According to a sixth aspect, the invention provides a cap or closure made of a composition of polyethylene according to the second or the third aspect; with preference, the cap or closure is a screw cap.

[0045] According to a seventh aspect, the invention provides a cap or closure produced from the process according to the fourth aspect. According to an eighth aspect, the invention provides for a process for the manufacture of articles, said process comprising the steps of: providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; blending the components CRA and B to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography forming an article from the composition of polyethylene obtained.

[0046] For example, forming an article can be made by extrusion, injection moulding, or compression moulding.

[0047] With preference, the articles are caps and closures.

[0048] In one or more embodiments, the step of providing a thermally treated component CRA comprises providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1 .5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg.

[0049] In one or more embodiments, the article produced is made of the composition according to the third aspect.

[0050] According to an ninth aspect, the invention provides a process for the manufacture of articles, said process comprising the steps of providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, wherein the thermally treated component CRA is obtained by submitting a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, to a thermal treatment at a temperature of at least 300°C ; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; dry blending the component CRA and the component B and providing them together to an extruder, an injection molding apparatus, or a compression molding apparatus; and forming an article wherein the article is made from a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

[0051] It is understood that the article is therefore formed by extrusion, injection moulding, or compression moulding.

[0052] With preference, the articles are caps and closures.

[0053] In one or more embodiments, the step of providing a thermally treated component CRA comprises providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1 .5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg.

[0054] In one or more embodiments, the article produced is made of the composition according to the third aspect. According to a tenth aspect, the invention provides a process for the manufacture of articles by extrusion, said process comprising the steps of providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, wherein the thermally treated component CRA is obtained by submitting a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, to a thermal treatment at a temperature of at least 300°C ; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and providing an extruder having a main feeder and one or more side feeders and feeding the component CRA and the component B to the extruder wherein one selected from the component CRA and the component B is fed by the main feeder and the other one by one or more side feeders to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography; forming an article by extrusion.

[0055] In one or more embodiments, the step of providing a thermally treated component CRA comprises providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1 .5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg.

[0056] In one or more embodiments, the article produced is made of the composition according to the third aspect. With preference, the articles are caps and closures.

[0057] According to an eleventh aspect, the invention provides a process for the manufacture of articles by extrusion, said process comprising the steps of providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133- 1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and providing an extruder having a main feeder and one or more side feeders and feeding the component A and the component B to the extruder wherein the component A is fed by the main feeder and the component B is fed by one or more side feeders; forming an article by extrusion; wherein the extruder is divided into two successive sections, a first section wherein the component A is submitted to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a second section wherein the component B is added via the one or more side feeders and is blended with the thermally treated component CRA at a temperature of at most 250°C to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

[0058] In one or more embodiments, the article produced is made of the composition according to the third aspect.

[0059] With preference, the articles are caps and closures.

[0060] According to a twelfth aspect, the invention provides an article of polyethylene remarkable in that it is produced according to the eighth aspect, the ninth aspect, the tenth aspect, or the eleventh aspect.

[0061] Description of the figures Figure 1 illustrates possible screw profiles to be used in the context of the disclosure.

[0062] Figures 2 and 3 are the screw profile used in the Examples.

[0063] Figure 4 illustrates the increase in melt index of PCR-PE3 as a function of thescrew speed.

[0064] DETAILED DESCRIPTION OF THE INVENTION

[0065] When describing the invention, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise.

[0066] As used herein, the singular forms "a", "an", and "the" include both singular and plural referents unless the context dictates otherwise. By way of example, "a resin" means one resin or more than one resin.

[0067] The terms "comprising", "comprises" and "comprised of' as used herein are synonymous with "including", "includes" or "containing", and "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. It will be appreciated that the terms "comprising", "comprises" and "comprised of" as used herein comprise the terms "consisting of", "consists" and "consists of".

[0068] The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1 , 2, 3, 4, 5 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of endpoints also includes the endpoint values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[0069] All references cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings of all references herein specifically referred to are incorporated by reference.

[0070] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this invention, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments, as would be understood by those in the art.

[0071] As used herein, the terms “melt blending” involve the use of shear force, extensional force, compressive force, ultrasonic energy, electromagnetic energy, thermal energy or combinations comprising at least one of the foregoing forces or forms of energy and is conducted in a processing equipment wherein the aforementioned forces are exerted by a single screw, multiple screws, intermeshing co-rotating or counter-rotating screws, non-intermeshing corotating or counter-rotating screws, reciprocating screws, screws with pins, barrels with pins, rolls, rams, helical rotors, or combinations comprising at least one of the foregoing. Melt blending may be conducted in machines such as, single or multiple screw extruders, Buss kneader, Eirich mixers, Henschel, helicones, Ross mixer, Banbury, roll mills, moulding machines such as injection moulding machines, vacuum forming machines, blow moulding machines, or the like, or combinations comprising at least one of the foregoing machines. It is generally desirable during melt or solution blending of the composition to impart a specific energy of about 0.01 to about 10 kilowatt-hours / kilogram (kW h / kg) of the composition. In a preferred embodiment, melt blending is performed in a twin-screw extruder, such as a Brabender co-rotating twin screw extruder.

[0072] The terms “polyethylene” (PE) and “ethylene polymer” may be used synonymously. The term “polyethylene” encompasses homopolymer of ethylene as well as copolymer of ethylene which can be derived from ethylene and one or more comonomers selected from the group consisting of C3-C20 alpha-olefins, such as propylene, 1 -butene, 1 -pentene, 4-methyl-1 -pentene, 1- hexene, 1 -octene, 1 -decene, 1 -dodecene, 1 -tetradecene, 1 -hexadecene, 1 -octadecene and 1- eicosene.

[0073] The terms “polyethylene resin”, as used herein, refer to polyethylene fluff or powder that is extruded, and / or melted and / or pelletized and can be produced through compounding and homogenizing of the polyethylene resin as taught herein, for instance, with mixing and / or extruder equipment. As used herein, the term “polyethylene” may be used as a shorthand for “polyethylene resin”. The terms “fluff’ or “powder” as used herein refer to polyethylene material with the hard catalyst particle at the core of each grain and is defined as the polymer material after it exits the polymerization reactor (or the final polymerization reactor in the case of multiple reactors connected in series).

[0074] ‘The composition” may be used as a shorthand for “the composition of polyethylene”.

[0075] Under normal production conditions in a production plant, it is expected that the melt index (M 12, HLMI, MI5) will be different for the fluff than for the polyethylene resin. Under normal production conditions in a production plant, it is expected that the density will be slightly different for the fluff, than for the polyethylene resin. Unless otherwise indicated, density and melt index for the polyethylene resin refer to the density and melt index as measured on the polyethylene resin as defined above.

[0076] The terms “Post-Consumer Resin”, which may be abbreviated as “PCR”, is used to denote the components of domestic waste, household waste or end of life vehicle waste. In other words, the PCRs are made of recycled products from waste created by consumers. The terms “PostIndustrial Resin”, which may be abbreviated as “PIR”, is used to denote the waste components from pre-consumer resins during packaging processes. In other words, the PIRs are made of recycled products created from scrap by manufacturers.

[0077] The term “recycled polyethylene resin” contrasts to the term “virgin polyethylene resin”, the term “virgin” is used to denote a polyethylene resin directly obtained from a polyethylenecontaining polymerization plant. The terms “directly obtained” is meant to include that the polyethylene resin may optionally be passed through a pelletization step or an additivation step or both.

[0078] The invention provides a process to produce a composition of polyethylene for the manufacture of caps and closures, the process being remarkable in that it comprises the steps of providing a component A being one or more polyethylene resin (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133- 1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and blending the components CRA and B to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography. The invention also provides a process to produce a composition of polyethylene for the manufacture of caps and closures, the process being remarkable in that it comprises the steps of providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; wherein the thermally treated component CRA is obtained by submitting a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, to a thermal treatment at a temperature of at least 300°C ; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and blending the components CRA and B to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

[0079] With preference, the step of providing a thermally treated component CRA comprises: providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133- 1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg. In both above definitions of the process to produce a composition of polyethylene for the manufacture of caps and closures according to the invention, the step of submitting component A to a thermal treatment to obtain a component CRA and the step of blending the components CRA and B can be performed in different extruders. Alternatively, the step of submitting component A to a thermal treatment to obtain a component CRA and the step of blending the components CRA and B are performed in a single extruder that is divided into two successive sections, a first section wherein the component A is submitted to a thermal treatment to obtain the thermally treated component CRA and a second section wherein the component B is added via the one or more side feeders and is blended with the thermally treated component CRA at a lower temperature, such as a temperature of at most 250°C. Selection of component A being one or more polyethylene resins (PE)

[0080] In a preferred embodiment, the one or more polyethylene resins of the component (A) are one or more recycled polyethylene resins (rPE) so that the composition of polyethylene for the manufacture of caps and closures comprises recycled polyethylene (rPE).

[0081] Wherein the component A is one or more recycled-polyethylene resins (rPE), it is selected from Post-Consumer Resins (PCR), Post-Industrial Resins (PIR), and any mixture thereof.

[0082] A post-consumer resin (PCR) generally originates from a specific collection of domestic or household waste. Preferably, the recycled polyethylene resin (rPE) is devoid of industrial waste (PIR). In a preferred embodiment, the component A is or comprises a regrind from postconsumer sorted caps. However, any recycled polyethylene resin fulfilling the requirements of the invention may be used.

[0083] Examples of virgin resins that can be used as component A and that are commercially available are 5502 and 2008SN60 both marketed by TotalEnergies.

[0084] For the process of the invention, the component A is selected to have a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min or from 0.1 to 1.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg. In a preferred embodiment, the component A has a melt index (MI2) ranging from 0.1 to 1.4 g / 10 min or from 0.1 to 1.3 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably ranging from 0.1 to 1.2 g / 10 min, more preferably ranging from 0.1 to 1.1 g / 10 min or from 0.1 to 1.0 g / 10 min; even more preferably ranging from 0.2 to 0.9 g / 10 min or from 0.2 to 0.8 g / 10 min; and most preferably ranging from 0.2 to 0.7 g / 10 min.

[0085] With preference, component A has an MI2 of at least 0.1 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably of at least 0.2 g / 10 min; more preferably, of at least 0.3 g / 10 min.

[0086] Preferably, component A has an MI2 of at most 1.8 g / 10 min as determined according to conditions D at a temperature of 190°C and under a load of 2.16 kg; preferably, of at most 1.7 g / 10 min or of at most 1 .6 g / 10 min, more preferably of at most 1 .5 g / 10 min or of at most 1 .4 g / 10 min; even more preferably of at most 1.3 g / 10 min or of at most 1.2 g / 10 min, most preferably of al most 1.1 g / 10 min or of at most 1.0 g / 10 min, and even most preferably of at most 0.9 g / 10 min or of at most 0.8 g / 10 min or of at most 0.7 g / 10 min, or of at most 0.6 g / 10 min, or of at most 0.5 g / 10 min.

[0087] According to the invention, the component A is selected to have a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C. In a preferred embodiment, component A has a density ranging from 0.941 to 0.975 g / cm3or ranging from 0.942 to 0.970 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably ranging from 0.945 to 0.968 g / cm3; more preferably, ranging from 0.947 to 0.965 g / cm3; and most preferably, ranging from 0.949 to 0.962 g / cm3or from 0.940 to 0.955 g / cm3or from 0.951 to 0.960 g / cm3.

[0088] With preference, component A has a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably, of at least 0.941 g / cm3, or of at least 0.942 g / cm3; more preferably, of at least 0.945 g / cm3; even more preferably, of at least 0.947 g / cm3; most preferably, of at least 0.948 g / cm3; and even most preferably, of at least 0.949 g / cm3or at least 0.950 g / cm3or of at least 0.951 g / cm3.

[0089] Preferably, component A has a density of at most 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably, of at most 0.978 g / cm3, or of at most 0.975 g / cm3, or of at most 0.970 g / cm3, more preferably of at most 0.968 g / cm3; even more preferably of at most 0.965 g / cm3, most preferably of at most 0.962 g / cm3, and even most preferably of at most 0.960 g / cm3or of at most 0.958 g / cm3or of at most 0.955 g / cm3.

[0090] Preferably, component A has an Mz / Mw of at least 4.0 as determined by gel permeation chromatography; preferably, ranging from 4.0 to 50.0; preferably, from 5.0 to 25.0; preferably, from 6.0 to 15.

[0091] Preferably, component A has an Mw / Mn of at least 4.0 as determined by gel permeation chromatography; preferably, ranging from 5.0 to 25.0; preferably, from 6.0 to 20.0; preferably, from 7.0 to 15.

[0092] For example, component A has an Mw / Mn of at least 4.0 as determined by gel permeation chromatography; preferably, at least 5.0; more preferably, at least 6.0; even more preferably, at least 7.0.

[0093] In a preferred embodiment, the content of component A in the composition ranges from 25 wt.% to 90 wt.% based on the total weight of the composition of polyethylene; preferably, ranging from 30 wt.% to 85 wt.%; more preferably, ranging from 35 wt.% to 80 wt.%; even more preferably, ranging from 40 wt.% to 75 wt.%; most preferably ranging from 40 wt.% to 70 wt.%; even most preferably ranging from 45 wt.% to 65 wt.%; or ranging from 40 wt.% to 60 wt.%. With preference, the content of component A in the composition is at least 25 wt.% or at least 30 wt.% based on the total weight of the composition of polyethylene; preferably at least 35 wt.%; more preferably at least 40 wt.%; even more preferably at least 50 wt.%; and most preferably at least 55 wt.%, or at least 60 wt.%, or at least 65 wt.%, or at least 70 wt.%.

[0094] With preference, the content of component A in the composition is at most 88 wt.% based on the total weight of the composition of polyethylene; preferably at most 85 wt.% or at most 80 wt.%; more preferably at most 75 wt.%; even more preferably at most 70 wt.%; and most preferably at most 65 wt.% or at most 60 wt.%.

[0095] When the component A is or comprises one or more recycled-polyethylene resins (rPE), they may comprise up to 15 wt.% of one or more polymers different from polyethylene relative to the total weight of the recycled polyethylene resin (rPE). The one or more polymers different from polyethylene are or comprise polypropylene, polystyrene, polyacrylate, polyethylene terephthalate, polylactic acid, and any mixture thereof.

[0096] In an embodiment, the component A is a blend of recycled polyethylene and one or more polymers different from polyethylene, wherein the content of the one or more polymers different from polyethylene ranges from 0.01 to 15.0 wt.% based on the total weight of the component A; more preferably from 0.5 to 13.0 wt.% even more preferably from 0.7 to 10.0 wt.%; most preferably from 0.9 to 8.0 wt.%; and even most preferably from 1.0 to 5.0 wt.%. The content of the one or more polymers different from polyethylene can be determined by13C-NMR analysis.

[0097] The presence of one or more polymers different from polyethylene in component A is difficult to avoid and is due to the recycling process. Following its collection, the PCR needs to be processed. The processing comprises the following steps of: recovering the polyethylene post-consumer resin (PCR-PE) from the domestic or household polymer waste by separating it, grinding, and cleaning.

[0098] The above grinding and cleaning steps may be performed in any order. The separation of domestic waste into several fractions such as polyethylene post-consumer resin (PCR-PE) can be performed by any method generally used in the industry such as near-infrared analysis (NIR), wherein the respective polymers are identified by their NIR fingerprint. Further separation can be made according to colour with known separation systems.

[0099] Cleaning is preferably done in a liquid bath. The preferred liquid is water. Depending upon the density of the liquid, the cleaning step may also be used to eliminate undesired components of the domestic polymer waste. For example, polyethylene and polypropylene waste will generally float on water, while components such as metals sink. Preferably the grinding step is performed to obtain the PCR in a flake form.

[0100] The step of submitting component A to a thermal treatment to obtain a thermally treated component CRA

[0101] According to the disclosure, the process comprises a step of submitting component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg. Such a step preferably comprises the following sub-steps: i) providing a twin-screw extruder with thermal regulation devices; ii) extruding the component A to obtain a thermally treated component CRA; wherein extrusion is performed with a residence time of less than 20 min; and comprises a thermal treatment of the component A at a temperature of at least 300°C in one or more hot zones of the extruder; iii) recovering a thermally treated component CRA.

[0102] In one or more embodiments, the sub-step (ii) is performed by heating the component A using the thermal regulation devices of the extruder to have a maximum barrel temperature ranging from 300 to 460°C in at least one hot zone of the extruder.

[0103] In one or more embodiments, the sub-step (ii) is performed by self-heating the component A wherein the one or more hot zones have a total length equal to or greater than 6 D with D being the screw diameter, wherein the extrusion is performed with mechanical specific energy greater than or equal to 0.4 kWh / kg, wherein the screw profile comprises at least one hot zone with successive kneading blocks elements over a length of at least 4 D followed by a lefthanded element with D being the screw diameter, wherein the thermal regulation devices are set to initial imposed barrel temperatures ranging between 240 and 320 °C and are switched off when the barrel temperature in the zone spontaneously exceeds the imposed barrel temperature by at least 1 °C without the need of external heat application.

[0104] The process of treating the component A involves increasing the melt index of the said component A to produce a thermally treated component CRA.

[0105] The twin-screw extruder with thermal regulation devices and the sub-step (ii) of extruding the component A to obtain a thermally treated component CRA

[0106] The treatment of the component A to obtain a thermally treated component CRA is performed by extrusion wherein extrusion is performed with a residence time of less than 20 min and wherein sub-step (ii) of extruding comprises a thermal treatment of the component A at a temperature of at least 300°C in one or more hot zones of the extruder.

[0107] The extruder is a twin-screw extruder. The extruder is provided with a screw profile that shows an aggressive design, as shown in figure 1 , to impart high mechanical energy to the component A.

[0108] As known to the person skilled in the art, thermal regulation devices can be used as heating means to impart thermal energy to the component A in the extruder, in addition to the thermal energy already generated by the mixing.

[0109] Extrusion mixing varies with the type of screw and screw profile and is capable of significant generation of mechanical energy, such as shear energy and / or elongation energy. Therefore, energy is introduced into the extrusion process in terms of mechanical energy and thermal energy. Heating and / or cooling of the barrels can be achieved, for example, electrically, by steam, or by the circulation of thermally controlled liquids such as oil or water.

[0110] The extruder screw comprises a screw main body, that is composed of cylindrical elements and an axis of rotation supporting the elements. The axis of rotation extends straight from its basal end to its tip. In a state in which the extruder screw is rotatably inserted in the cylinder of the barrel, the basal end of the extruder screw is positioned on one end side of the barrel, on which the supply port is provided, and the tip of the extruder screw is positioned on the other end side of the barrel, on which the discharge port is provided.

[0111] Screw extruders have a modular system that allows different screw elements to be drawn into the central shaft to build a defined screw profile. The extruder screw may comprise one or more elements selected from conveying elements, kneading elements, right-handed (normal) screw elements, left-handed (inverse) screw elements, and any combination thereof. The elements are arranged in a defined order from the basal end to the tips of the extruder screw and this order, as well as the type and number of elements involved, defines the screw profile. Extruders and screw elements are commercially available for example at Leistritz.

[0112] In an embodiment of the disclosure, the treatment of the component A is handled by mechanical energy.

[0113] When high mechanical energy is requested, the extruder provided has a specific screw profile that is built to be “aggressive”, meaning that high mechanical energy will be imparted to the component A. High mechanical energy will increase the temperature in the extruder as known to the person skilled in the art so that the thermal treatment is performed by self-heating of the component A. In such an embodiment, the twin-screw extruder is selected to comprise one or more hot zones, preferably being filled mixing zones, wherein the total length of the one or more hot zones is equal to or greater than 6 D with D being the screw diameter.

[0114] It is understood that in case the screw profile is selected to comprise a single hot zone, then the total length of the said hot zone is equal to or greater than 6 D with D being the screw diameter. In such a case, the hot zone is also the melting zone of the twin-screw extruder.

[0115] In case, the screw profile comprises two or more hot zones, then a first hot zone comprises successive kneading blocks elements over a length of at least 4 D followed by a left-handed element with D being the screw diameter, and one or more additional hot zones placed downstream the first hot zone are filled mixing zones, each comprising kneading blocks elements over a length of at least 4 D followed by a kneading left-handed element or by a lefthanded element with D being the screw diameter. For example, the twin-screw extruder comprises two filled mixing zones wherein each of the filled mixing zones has a length equal to or greater than 4 D with D being the screw diameter. Preferably the first hot zone is or comprises the melting zone of the extruder. For example, the twin-screw extruder comprises three filled mixing zones wherein each of the filled mixing zones has a length equal to or greater than 4 D with D being the screw diameter.

[0116] Various mixing elements could be considered in the one or more hot zones but the most preferred ones do not drive any forward conveying (dispersive kneading blocks elements with disks offset by 90 degrees). Other disk offset angles could be considered (for example, 30 degrees, 45 degrees, and / or 60 degrees) but 90 degrees is preferred. The preferred minimum width of the disk is 0.3 D.

[0117] Thus, preferably, the successive kneading blocks elements of at least one hot zone comprise disks with disks offset by 90 degrees and a disk width of at least 0.3 D wherein D is the screw diameter. More preferably the successive kneading blocks elements of three hot zones comprise disks with disks offset by 90 degrees and a disk width of at least 0.3 D wherein D is the screw diameter.

[0118] For example, the twin-screw extruder comprises more than two filled mixing zones wherein the total length of filled mixing zones is equal to or greater than 8 D with D being the screw diameter. For example, the twin-screw extruder comprises more three filled mixing zones wherein the total length filled mixing zones is equal to or greater than 9 D with D being the screw diameter. For example, the strong melting zone of the twin-screw extruder is made of successive mixing elements over a length of 4 D, with D being the screw diameter, followed by a left-handed element; preferably a full-flight left-handed element.

[0119] In a preferred embodiment, the thermal regulation devices of the twin-screw extruder allow cooling the barrels and the process comprises switching off the thermal regulation devices when the barrel temperature in the zone spontaneously exceeds the imposed barrel temperature by at least 1 °C without the need for external heat application; preferably, by at least 2 °C, preferably, by at least 3 °C; more preferably by at least 5 °C; even more preferably, by at least 8 °C; and most preferably, by at least 10 °C.

[0120] Indeed, when starting extrusion, thermal regulation devices will be switched on, in particular in the melting zone to allow the component A to melt. Then, when the polymer is self-heating the thermal regulation devices are switched off to allow the increase of the temperature inside the extruder.

[0121] In a preferred embodiment, sub-step (ii) of extruding the component A comprises performing the extrusion with mechanical specific energy greater than or equal to 0.25 kWh / kg, preferably greater than or equal to 0.28 kWh / kg; more preferably greater than or equal to 0.30 kWh / kg; even more preferably greater than or equal to 0.35 kWh / kg; most preferably greater than or equal to 0.40 kWh / kg

[0122] High rotation screw speeds are preferred, but the precise value of a high rotation screw speed is “extruder diameter” dependent. For example, when considering a diameter D of 18 mm twin- screw extruder, high rotational screw speed is considered to be higher than 500 rpm, preferably higher than 800 rpm. For example, when considering a diameter D = 58 mm twin-screw extruder, high rotational screw speed is considered to be higher than 250 rpm, preferably higher than 350 rpm.

[0123] Non-limiting examples of suitable extruder screws with specific screw profiles are illustrated in figure 1 as PTE1 and PTE2.

[0124] The thermal treatment of component A in sub-step (ii) is preferably performed at a maximum barrel temperature ranging from 300 to 460 °C; preferably, ranging from 310 °C to 440 °C; more preferably ranging from 315 °C to 410 °C; even more preferably, ranging from 320 °C to 390 °C and most preferably, ranging from 325 °C to 340 °C. The maximum barrel temperature is the highest temperature amongst the imposed or measured temperatures along the extruder.

[0125] For example, sub-step (ii) of extruding the component A comprises a thermal treatment at a temperature of at least 305°C or at least 310°C in one or more hot zones of the extruder; preferably at a temperature of at least 315°C or at least 320 °C; more preferably at a temperature of at least 325 °C; even more preferably at a temperature of at least 330 °C.

[0126] For example, step (ii) of extruding the component A comprises a thermal treatment at a temperature of at most 460 °C in one or more hot zones of the extruder; preferably, at most 450 °C; more preferably, at most 430 °C; even more preferably, at most 410 °C; most preferably, at most 390 °C; even most preferably, at most 370 °C or at most 350°C or at most 345°C or at most 340°C.

[0127] For example, sub-step (ii) of extruding the component A comprises a thermal treatment at a temperature ranging from 300 to 460°C in one or more hot zones of the extruder; preferably at a temperature ranging from 310 to 440°C; more preferably at temperature ranging from 315 to 410°C; even more preferably at a temperature ranging from 320 to 390°C and most preferably at a temperature ranging from 340 to 390 °C, or at a temperature ranging from 325 to 340 °C.

[0128] The temperature of the thermal treatment is the maximum barrel temperature.

[0129] The extrusion conditions may be adapted by the person skilled in the art to impart sufficient energy to obtain a thermally treated component CRA with a melt index (MI2 T) in the targeted range.

[0130] Screw speed can be adapted in function of the targeted maximum barrel temperature and of the capacity of the extruder. Higher screw speed allows a higher increase in the polymer temperature. For example, the screw speed ranges from 100 to 1200 rpm; preferably from 110 rpm to 1200 rpm; more preferably from 150 rpm to 1100 rpm; even more preferably from 200 rpm to 1000 rpm; most preferably from 300 rpm to 900 rpm; and even most preferably from 320 to 800 rpm or from 350 to 700 rpm.

[0131] In an 18 mm screw diameter twin-screw extruder, the preferred screw speed is higher than 500 rpm; in a 58 mm screw diameter twin-screw extruder, the preferred screw speed is at least 250 rpm.

[0132] For example, sub-step (ii) of extruding the component A comprises performing the extrusion with a residence time ranging from 10 seconds to 10 minutes; preferably with a residence time ranging from 20 seconds to 5 minutes; more preferably with a residence time ranging from 10 to 180 seconds or from 10 to 120 seconds or from 20 to 100 seconds or from 30 to 80 seconds.

[0133] The thermally treated component CRA

[0134] The thermal treatment is conducted to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg. In a preferred embodiment, the component A has a melt index (MI2) ranging from 1.6 to 18.0 g / 10 min or from 1.7 to 16.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably ranging from 1.8 to 15.0 g / 10 min, more preferably ranging from 1.9 to 12.0 g / 10 min or from 2.0 to 10.0 g / 10 min; even more preferably ranging from 2.1 to 9.0 g / 10 min; and most preferably ranging from 2.2 to 8.0 g / 10 min.

[0135] With preference, thermally treated component CRA has an MI2 of greater than 1.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably of at least 1.6 g / 10 min; more preferably, of at least 1.7 g / 10 min; even more preferably of at least 1.8 g / 10 min, most preferably of at least 1.9 g / 10 min, and even most preferably of at least 2.0 g / 10 min, or of at least 2.1 g / 10 min, or of at least 2.2 g / 10 min.

[0136] Preferably, thermally treated component CRA has an MI2 of at most 20.0 g / 10 min or of at most 18.0 g / 10 min as determined according to conditions D at a temperature of 190°C and under a load of 2.16 kg; preferably, of at most 16.0 g / 10 min or of at most 15.0 g / 10 min, more preferably of at most 12.0 g / 10 min or of at most 10.0 g / 10 min; even more preferably of at most 9.5 g / 10 min, most preferably of at most 9.0 g / 10 min, and even most preferably of at most 8.5 g / 10 min or of at most 8.0 g / 10 min.

[0137] Selection of component B being a polyethylene resin

[0138] The component B is a specific polyethylene resin selected to act as a booster, enhancing the properties of the resulting composition of polyethylene. In a preferred embodiment, component B is a virgin polyethylene resin or a blend of at least two virgin polyethylene resin. In some embodiments, the component B has a melt index of more than 3.5 g / 10 min and can be a recycled polyethylene resin or a blend of one or more virgin polyethylene resins and a recycled polyethylene resin.

[0139] The component B is selected to have a melt index (MI2) ranging from 0.1 to 15.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg. In a preferred embodiment, the component B is a polyethylene resin having a melt index (MI2) ranging from 0.2 to 12.0 g / 10 min or from 0.2 to 11.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably ranging from 0.2 to 11.0 g / 10 min and more preferably ranging from 0.2 to 10.5 g / 10 min or from 0.2 to 10.0 g / 10 min or from 0.2 to 9.8 g / 10 min.

[0140] The component B can further be selected according to the desired properties of the final product. In a first embodiment, for ESCR-demanding applications, component B is selected to have a melt index (MI2) ranging from 0.1 to 3.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg. In a preferred embodiment, component B is a polyethylene resin having a melt index (MI2) ranging from 0.2 to 3.4 g / 10 min or from 0.2 to 3.2 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably ranging from 0.2 to 3.0 g / 10 min and more preferably ranging from 0.2 to 2.8 g / 10 min or from 0.2 to 2.6 g / 10 min or from 0.2 to 2.4 g / 10 min.

[0141] With preference, component B has an MI2 of at least 0.1 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably, of at least 0.2 g / 10 min.

[0142] Preferably, component B has an MI2 of at most 3.5 g / 10 min as determined according to conditions D at a temperature of 190°C and under a load of 2.16 kg; preferably of at most 3.2 g / 10 min, more preferably of at most 3.0g / 10 min; even more preferably of at most 2.8 g / 10 min; and most preferably of at most 2.6 g / 10 min or of at most 2.4 g / 10 min.

[0143] In a second embodiment, component B is selected to have a melt index (MI2) ranging from more than 3.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg. In a preferred embodiment, component B is a polyethylene resin having a melt index (MI2) ranging from 4.0 to 11.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably ranging from 5.0 to 11.0.0 g / 10 min and more preferably ranging from 6.0 to 10.5 g / 10 min or from 7.0 to 10.0 g / 10 min or from 8.0 to 9.8 g / 10 min.

[0144] With preference, component B has an MI2 of more than 3.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably, of at least 4.0 g / 10 min; more preferably, of at least 5.0 g / 10 min; and even more preferably, of at least 6.0 g / 10 min or of at least 7.0 g / 10 min, or of at least 8.0 g / 10 min.

[0145] Preferably, component B has an MI2 of at most 12.0 g / 10 min as determined according to conditions D at a temperature of 190°C and under a load of 2.16 kg; preferably of at most 11 .5 g / 10 min, more preferably of at most 11.0 g / 10 min; even more preferably of at most 10.5 g / 10 min; and most preferably of at most 10.0 g / 10 min or of at most 9.8 g / 10 min.

[0146] According to the invention, component B is selected to have a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C. In a preferred embodiment, component B is a polyethylene resin having a density ranging from 0.942 to 0.960 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably ranging from 0.945 to 0.957 1 g / cm3; more preferably, ranging from 0.947 to 0.955 g / cm3; and most preferably, ranging from 0.948 to 0.954 g / cm3or from 0.944 to 0.953 g / cm3or from 0.950 to 0.956 g / cm3.

[0147] With preference, component B has a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably of at least 0.942 g / cm3; more preferably of at least 0.945 g / cm3; even more preferably of at least 0.947 g / cm3; most preferably of at least 0.948 g / cm3; and even most preferably of at least 0.950 g / cm3.

[0148] Preferably, component B has density of at most 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably of at most 0.962 g / cm3, more preferably of at most 0.960 g / cm3; even more preferably of at most 0.959 g / cm3, most preferably of at most 0.957 g / cm3, and even most preferably of at most 0.955 g / cm3or of at most 0.954 g / cm3or of at most 0.953 g / cm3.

[0149] In the first embodiment, for ESCR-demanding applications, wherein the component B is selected to have a melt index (MI2) ranging from 0.1 to 3.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, the density is preferably ranging from 0.940 to 0.955 g / cm3as determined according to ISO 1183-1 :2012 at 23°C.

[0150] In a second embodiment, wherein component B is selected to have a melt index (MI2) ranging from more than 3.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, the density is preferably ranging from 0.950 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C.

[0151] Whatever is the embodiment, component B has preferably a z average molecular weight (Mz) ranging from 100,000 g / mol to 2,000,000 g / mol as determined by gel permeation chromatography; preferably from 120,000 to 1 ,90,000 g / mol; more preferably from 140,000 to 1 ,850,000 g / mol.

[0152] Preferably, component B has a z average molecular weight (Mz) of at least 100,000 g / mol as determined by gel permeation chromatography; preferably of at least 120,000 g / mol; more preferably of at least 140,000 g / mol; and most preferably of at least 150,000 g / mol or of at least 155,000 g / mol.

[0153] Preferably, component B has a z average molecular weight (Mz) of at most 2,000,000 g / mol as determined by gel permeation chromatography; preferably of at most 1 ,950,000 g / mol; more preferably of at most 1 ,900,000 g / mol or at most 1 ,850,000 g / mol.

[0154] With preference, component B is a polyethylene resin having weight-average molecular weight (Mw) ranging from 50,000 to 250,000 g / mol or from 50,000 to 230,000 g / mol as determined by gel permeation chromatography; preferably from 55,000 to 210,000 g / mol; from 60,000 to 200,000 g / mol, more preferably from 65,000 to 190,000 g / mol; and even more preferably from 70,000 to 180,000 g / mol.

[0155] With preference, component B is a polyethylene resin having weight-average molecular weight (Mw) of at least 50,000 g / mol as determined by gel permeation chromatography; preferably of at least 60,000 g / mol; more preferably of at least 65,000 g / mol; and even more preferably of at least 68,000 g / mol and most preferably of at least 70,000 g / mol.

[0156] With preference, component B is a polyethylene resin having weight-average molecular weight (Mw) of at most 250,000 g / mol or at most 230,000 g / mol as determined by gel permeation chromatography; preferably of at most 220,000 g / mol or at most 210,000 g / mol; more preferably of at most 200,000 g / mol; and even more preferably of at most 195,000 g / mol and most preferably of at most 190,000 g / mol, or of at most 180,000 g / mol.

[0157] In an embodiment, component B is a polyethylene resin having an Mz / Mw ranging from 1.5 to 15.0, preferably from 1.8 to 14.0 as determined by gel permeation chromatography; preferably from 2.0 to 12.0; more preferably from 2.2 to 11.0; and most preferably from 2.4 to 10.5.

[0158] In an embodiment, component B has a melting temperature as determined according to ISO 11357-3:2018 ranging from 122 °C to 135 °C; preferably ranging from 125 °C to 130°C.

[0159] In a preferred embodiment, component B is a polyethylene resin having a molecular weight distribution Mw / Mnwhich is at most 15.0 as determined by gel permeation chromatography, with Mwbeing the weight-average molecular weight and Mnbeing the number average molecular weight; preferably at most 12.0; more preferably at most 11.0; and even more preferably at most 10.5.

[0160] In a preferred embodiment, component B is a polyethylene resin having a molecular weight distribution Mw / Mnwhich is at least 2.0 as determined by gel permeation chromatography, with Mwbeing the weight-average molecular weight and Mnbeing the number average molecular weight; preferably at least 2.5; more preferably at least 3.0; even more preferably at least 3.5; most preferably at least 4.0 or at least 4.1.

[0161] In a preferred embodiment, component B is a polyethylene resin having a molecular weight distribution Mw / Mnwhich ranges from 2.0 to 15.0 as determined by gel permeation chromatography; preferably from 2.0 to 14.0; more preferably from 2.5 to 12.0, even more preferably from 3.0 to 11 .0, and most preferably from 3.5 to 10.5.

[0162] In a preferred embodiment, the content of component B in the composition is at least 10 wt.% based on the total weight of the composition of polyethylene; preferably at least 15 wt.%; more preferably at least 20 wt.%; even more preferably at least 25 wt.%; most preferably at least 30 wt.%; even most preferably at least 35 wt.%; or at least 40 wt.%; or at least 45 wt.%, or at least 50 wt.%.

[0163] In a preferred embodiment, the content of component B in the composition ranges from 15 wt.% to 80 wt.% based on the total weight of the composition of polyethylene; preferably ranging from 15 wt.% to 75 wt.%; more preferably ranging from 20 wt.% to 70 wt.%; even more preferably ranging from 20 wt.% to 65 wt.%; most preferably ranging from 30 wt.% to 60 wt.%; even most preferably ranging from 35 wt.% to 60 wt.%; even most preferably ranging from 35 wt.% to 55 wt.%; or ranging from 40 wt.% to 60 wt.%; or ranging from 45 wt.% to 70 wt.%.

[0164] The component B is preferably a polyethylene resin being a copolymer of ethylene and one or more alpha-olefin co-monomers selected from the group comprising C3-C20 alpha-olefins; preferably, C3-C12 alpha-olefins; more preferably, C4-C8 alpha-olefins; most preferably, the comonomer is selected from 1 -butene or 1 -hexene; even most preferably the co-monomer is 1- hexene. In case the polyethylene resin is a copolymer of ethylene and one or more alphaolefin co-monomers it comprises at least 0.1 wt.% of comonomer(s), preferably at least 1 wt.% as based on the total weight of the copolymer of ethylene and one or more alpha-olefin comonomers as determined by13C-NMR analysis. Preferably, it comprises up to 10 wt.% of comonomer(s) and most preferably up to 6 wt.% as determined by13C-NMR analysis.

[0165] When the polyethylene resin (i.e. component B) is a virgin resin, it can be produced using any catalyst known in the art, such as, chromium catalysts, Ziegler-Natta catalysts and metallocene catalysts.

[0166] The term "Ziegler-Natta catalyst" or “ZN catalyst” refers to catalysts having a general formula M1XV, wherein M1is a transition metal compound selected from group IV to VII, wherein X is a halogen, and wherein v is the valence of the metal. Preferably, M1is a group IV, group V, or group VI metal, more preferably titanium, chromium, or vanadium and most preferably titanium. Preferably, X is chlorine or bromine, and most preferably, chlorine. Illustrative examples of the transition metal compounds comprise but are not limited to TiCh, and TiCk Suitable ZN catalysts for use in the invention are described in US6930071 and US6864207, which are incorporated herein by reference. A preferred Ziegler-Natta catalyst system comprises a titanium compound having at least one titanium-halogen bond and an internal electron donor, both on a suitable support (for example on a magnesium halide in an active form), an organoaluminium compound (such as an aluminium trialkyl), and an optional external electron donor.

[0167] Preferably, the polyethylene resin is formed using at least one metallocene catalyst. The term "metallocene catalyst" is used herein to describe any transition metal complexes comprising metal atoms bonded to one or more ligands. The metallocene catalysts are compounds of Group IV transition metals of the Periodic Table such as titanium, zirconium, hafnium, etc., and have a coordinated structure with a metal compound and ligands composed of one or two groups of cyclopentadienyl, indenyl, fluorenyl or their derivatives. The structure and geometry of the metallocene can be varied to adapt to the specific need of the producer depending on the desired polymer. Metallocenes comprise a single metal site, which allows for more control of branching and molecular weight distribution of the polymer. Monomers are inserted between the metal and the growing chain of the polymer.

[0168] In one embodiment of the present invention, the metallocene catalyst is a compound of formula (I) or (II)

[0169] (Ar)2MQ2(I); or R”(Ar)2MQ2(II), wherein the metallocenes according to formula (I) are non-bridged metallocenes and the metallocenes according to formula (II) are bridged metallocenes; wherein said metallocene according to formula (I) or (II) has two Ar bound to M which can be the same or different from each other; wherein Ar is an aromatic ring, group or moiety and wherein each Ar is independently selected from the group consisting of cyclopentadienyl, indenyl (IND), tetrahydroindenyl (THI), and fluorenyl, wherein each of said groups may be optionally substituted with one or more substituents each independently selected from the group consisting of halogen, hydrosilyl, SiRs wherein R is a hydrocarbyl having 1 to 20 carbon atoms, and a hydrocarbyl having 1 to 20 carbon atoms, and wherein said hydrocarbyl optionally contains one or more atoms selected from the group comprising B, Si, S, O, F, Cl, and P; wherein M is a transition metal selected from the group consisting of titanium, zirconium, hafnium, and vanadium; and preferably is zirconium; wherein each Q is independently selected from the group consisting of halogen; a hydrocarboxy having 1 to 20 carbon atoms; and a hydrocarbyl having 1 to 20 carbon atoms and wherein said hydrocarbyl optionally contains one or more atoms selected from the group comprising B, Si, S, O, F, Cl, and P; and wherein R” is a divalent group or moiety bridging the two Ar groups and selected from the group consisting of Ci-C2o alkylene, germanium, silicon, siloxane, alkylphosphine, and an amine, and wherein said R” is optionally substituted with one or more substituents each independently selected from the group consisting of halogen, hydrosilyl, SiRs wherein R is a hydrocarbyl having 1 to 20 carbon atoms and a hydrocarbyl having 1 to 20 carbon atoms and wherein said hydrocarbyl optionally contains one or more atoms selected from the group comprising B, Si, S, O, F, Cl, and P.

[0170] Preferably, the metallocene comprises a bridged bis-indenyl and / or a bridged bistetrahydrogenated indenyl component. In some embodiments, the metallocene can be selected from one of the following formula (Illa) or (I lib): wherein each R in formula (Illa) or (lllb) is the same or different and is selected independently from hydrogen or XR’Vin which X is chosen from Group 14 of the Periodic Table (preferably carbon), oxygen or nitrogen and each R’ is the same or different and is chosen from hydrogen or a hydrocarbyl of from 1 to 20 carbon atoms and v+1 is the valence of X, preferably R is a hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl group; R" is a structural bridge between the two indenyl or tetrahydrogenated indenyls that comprises a C-1-C4 alkylene radical, a dialkyl germanium, silicon or siloxane, or an alkyl phosphine or amine radical; Q is a hydrocarbyl radical having from 1 to 20 carbon atoms or a halogen, preferably Q is F, Cl or Br; and M is a transition metal Group 4 of the Periodic Table or vanadium.

[0171] Each indenyl or tetrahydro indenyl component may be substituted with R in the same way or differently from one another at one or more positions of either of the fused rings. Each substituent is independently chosen.

[0172] If the cyclopentadienyl ring is substituted, its substituent groups must not be so bulky so as to affect the coordination of the olefin monomer to the metal M. Any substituents XR’Von the cyclopentadienyl ring are preferably methyl. More preferably, at least one and most preferably both cyclopentadienyl rings are unsubstituted.

[0173] In a particularly preferred embodiment, the metallocene comprises a bridged unsubstituted bis-indenyl and / or bis-tetrahydrogenated indenyl i.e. all R are hydrogens. More preferably, the metallocene comprises a bridged unsubstituted bis-tetrahydrogenated indenyl.

[0174] Illustrative examples of metallocene catalysts comprise but are not limited to bis(cyclopentadienyl) zirconium dichloride (Cp2ZrCh), bis(cyclopentadienyl) titanium dichloride (Cp2TiCh), bis(cyclopentadienyl) hafnium dichloride (Cp2HfCh); bis(tetrahydroindenyl) zirconium dichloride, bis(indenyl) zirconium dichloride, and bis(n-butyl-cyclopentadienyl) zirconium dichloride; ethylenebis(4,5,6,7-tetrahydro-1-indenyl) zirconium dichloride, ethylenebis(l-indenyl) zirconium dichloride, dimethylsilylene bis(2-methyl-4-phenyl-inden-1-yl) zirconium dichloride, diphenylmethylene (cyclopentadienyl)(fluoren-9-yl) zirconium dichloride, and dimethylmethylene [1-(4-tert-butyl-2-methyl-cyclopentadienyl)](fluoren-9-yl) zirconium dichloride. Most preferably the metallocene is ethylene-bis(tetrahydroindenyl)zirconium dichloride or ethylene-bis(tetrahydroindenyl) zirconium difluoride.

[0175] As used herein, the term “hydrocarbyl having 1 to 20 carbon atoms” refers to a moiety selected from the group comprising a linear or branched C1-C20 alkyl; C3-C20 cycloalkyl; C6-C20 aryl; C7- C20 alkylaryl and C7-C20 arylalkyl, or any combinations thereof. Exemplary hydrocarbyl groups are methyl, ethyl, propyl, butyl, amyl, isoamyl, hexyl, isobutyl, heptyl, octyl, nonyl, decyl, cetyl, 2-ethylhexyl, and phenyl.

[0176] As used herein, the term “hydrocarboxy having 1 to 20 carbon atoms” refers to a moiety with the formula hydrocarbyl-O-, wherein the hydrocarbyl has 1 to 20 carbon atoms as described herein. Preferred hydrocarboxy groups are selected from the group comprising alkyloxy, alkenyloxy, cycloalkyloxy or aralkoxy groups.

[0177] As used herein, the term “alkyl”, by itself or as part of another substituent, refers to straight or branched saturated hydrocarbon group joined by single carbon-carbon bonds having 1 or more carbon atoms, for example 1 to 12 carbon atoms, for example 1 to 6 carbon atoms, for example 1 to 4 carbon atoms. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group may contain. Thus, for example, Ci-i2alkyl means an alkyl of 1 to 12 carbon atoms. Examples of alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert- butyl, 2-methylbutyl, pentyl and its chain isomers, hexyl and its chain isomers, heptyl and its chain isomers, octyl and its chain isomers, nonyl and its chain isomers, decyl and its chain isomers, undecyl and its chain isomers, dodecyl and its chain isomers. Alkyl groups have the general formula CnH2n+i.

[0178] As used herein, the term “cycloalkyl”, by itself or as part of another substituent, refers to a saturated or partially saturated cyclic alkyl radical. Cycloalkyl groups have the general formula CnH2n-i. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group may contain. Thus, examples of Cs-ecycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl.

[0179] As used herein, the term “aryl”, by itself or as part of another substituent, refers to a radical derived from an aromatic ring, such as phenyl, naphthyl, indanyl, or 1 ,2,3,4-tetrahydro- naphthyl. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group may contain.

[0180] As used herein, the term “alkylaryl”, by itself or as part of another substituent, refers to an aryl group as defined herein, wherein a hydrogen atom is replaced by an alkyl as defined herein. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group or subgroup may contain.

[0181] As used herein, the term “arylalkyl”, by itself or as part of another substituent, refers to an alkyl group as defined herein, wherein a hydrogen atom is replaced by a aryl as defined herein. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group may contain. Examples of Ce- arylCi-ealkyl radicals include benzyl, phenethyl, dibenzylmethyl, methylphenylmethyl, 3-(2-naphthyl)-butyl, and the like.

[0182] As used herein, the term “alkylene”, by itself or as part of another substituent, refers to alkyl groups that are divalent, i.e., with two single bonds for attachment to two other groups. Alkylene groups may be linear or branched and may be substituted as indicated herein. Non-limiting examples of alkylene groups include methylene (-CH2-), ethylene (-CH2-CH2-), methylmethylene (-CH(CH3)-), 1-methyl-ethylene (-CH(CH3)-CH2-), n-propylene (-CH2-CH2- CH2-), 2-methylpropylene (-CH2-CH(CH3)-CH2-), 3-methylpropylene (-CH2-CH2-CH(CH3)-), n- butylene (-CH2-CH2-CH2-CH2-), 2-methylbutylene (-CH2-CH(CH3)-CH2-CH2-), 4- methylbutylene (-CH2-CH2-CH2-CH(CH3)-), pentylene and its chain isomers, hexylene and its chain isomers, heptylene and its chain isomers, octylene and its chain isomers, nonylene and its chain isomers, decylene and its chain isomers, undecylene and its chain isomers, dodecylene and its chain isomers. When a subscript is used herein following a carbon atom, the subscript refers to the number of carbon atoms that the named group may contain. For example, C1-C20 alkylene refers to an alkylene having between 1 and 20 carbon atoms.

[0183] Exemplary halogen atoms include chlorine, bromine, fluorine and iodine, wherein fluorine and chlorine are preferred.

[0184] The metallocene catalysts used herein are preferably provided on a solid support. The support can be an inert organic or inorganic solid, which is chemically unreactive with any of the components of the conventional metallocene catalyst. Suitable support materials for the supported catalyst include solid inorganic oxides, such as silica, alumina, magnesium oxide, titanium oxide, thorium oxide, as well as mixed oxides of silica and one or more Group 2 or 13 metal oxides, such as silica-magnesia and silica-alumina mixed oxides. Silica, alumina, and mixed oxides of silica and one or more Group 2 or 13 metal oxides are preferred support materials. Preferred examples of such mixed oxides are the silica-aluminas. Most preferred is a silica compound. In a preferred embodiment, the metallocene catalyst is provided on a solid support, preferably silica support. The silica may be in granular, agglomerated, fumed or other form.

[0185] In some embodiments, the support of the metallocene catalyst is a porous support, and preferably porous silica support.

[0186] Preferably, the supported metallocene catalyst is activated. The cocatalyst, which activates the metallocene catalyst component, can be any cocatalyst known for this purpose such as an aluminium-containing cocatalyst, a boron-containing cocatalyst or a fluorinated catalyst. The aluminium-containing cocatalyst may comprise an alumoxane, an alkyl aluminium, a Lewis acid and / or fluorinated catalytic support.

[0187] In some embodiments, alumoxane is used as an activating agent for the metallocene catalyst. The alumoxane can be used in conjunction with a catalyst in order to improve the activity of the catalyst during the polymerization reaction.

[0188] As used herein, the term “alumoxane” and “aluminoxane” are used interchangeably and refer to a substance, which is capable of activating the metallocene catalyst. In some embodiments, alumoxanes comprise oligomeric linear and / or cyclic alkyl alumoxanes. In a further embodiment, the alumoxane has formula (IV) or (V)

[0189] Ra-(AI(Ra)-O)x-AIRa2 (IV) for oligomeric, linear alumoxanes; or

[0190] (-AI(Ra)-O-)y(V) for oligomeric, cyclic alumoxanes wherein x ranges from 1 to 40, and preferably from 10 to 20; wherein y ranges from 3 to 40, and preferably from 3 to 20; and wherein each Rais independently selected from a Ci-Csalkyl, and preferably is methyl. In a preferred embodiment, the alumoxane is methylalumoxane (MAO).

[0191] In a preferred embodiment, the metallocene catalyst used is a supported metallocene- alumoxane catalyst comprising a metallocene and an alumoxane which are bound on a porous silica support. Preferably, the metallocene catalyst is a bridged bis-indenyl catalyst and / or a bridged bis-tetrahydrogenated indenyl catalyst.

[0192] One or more aluminiumalkyl represented by the formula AIRbxcan be used as additional cocatalyst, wherein each Rbis the same or different and is selected from halogens or from alkoxy or alkyl groups having from 1 to 12 carbon atoms and x ranges from 1 to 3. Non-limiting examples are tri-ethyl aluminum (TEAL), tri-iso-butyl aluminum (TIBAL), tri-methyl aluminum (TMA), and methyl-methyl-ethyl aluminum (MMEAL). Especially suitable are trialkylaluminiums, the most preferred being triisobutylaluminium (TIBAL) and triethylaluminum (TEAL).

[0193] With preference, the polyethylene resin has a multimodal molecular weight distribution and preferably a bimodal molecular weight distribution.

[0194] As used herein, the term “polyethylene with a bimodal molecular weight distribution” or “bimodal polyethylene” refers to polyethylene having a distribution curve being the sum of two unimodal molecular weight distribution curves, and refers to a polyethylene product having two distinct but possibly overlapping populations of polyethylene macromolecules each having different weight average molecular weights. By the term “polyethylene with a multimodal molecular weight distribution” or “multimodal polyethylene” it is meant polyethylene with a distribution curve is the sum of at least two, preferably more than two unimodal distribution curves, and refers to a polyethylene product having two or more distinct but possibly overlapping populations of polyethylene macromolecules each having different weight average molecular weights. The multimodal polyethylene resin can have an “apparent monomodal” molecular weight distribution, which is a molecular weight distribution curve with a single peak and no shoulder. Nevertheless, the polyethylene resin will still be multimodal if it comprises two distinct populations of polyethylene macromolecules each having a different weight average molecular weights, as defined above, for example when the two distinct populations were prepared in different reactors and / or under different conditions.

[0195] The polyethylene resin may be produced by gas, slurry, or solution phase process in one or several reactors connected in series. Preferably the polyethylene is produced in two or more serially connected reactors. Slurry polymerization is preferably used, preferably in a slurry loop reactor or a continuously stirred reactor.

[0196] Preferably, the polyethylene resin is produced in two or more serially connected reactors, comprising at least one first reactor and at least one second reactor, preferably loop reactors, more preferably slurry loop reactors. The polyethylene is produced in at least two serially connected slurry loop reactors, preferably in a double loop reactor.

[0197] The polymerization temperature can range from 20 °C to 125 °C, preferably from 55 °C to 105 °C, more preferably from 60 °C to 100 °C and most preferably from 65 °C to 98 °C. Preferably, the temperature range may be within the range from 75 °C to 100 °C and most preferably from 78 °C to 98 °C. The polymerization pressure can range from 2 MPa to 10 MPa, preferably from 3 MPa to 5 MPa, and more preferably from 3.7 MPa to 4.5 MPa.

[0198] In a preferred embodiment, component B is a polyethylene resin comprising at least two polyethylene fractions B1 and B2, wherein fraction B1 has MI2 of at least 120 g / 10 min or at least 150 g / 10 min or at least 200 g / 10 min or at least 250 g / min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and / or a density of at least 0.960 g / cm3or of at least 0.970 g / cm3as determined according to ISO 1183-1 :2012 at 23°C.

[0199] With preference, fraction B1 has an MI2 ranging from 120 to 500 g / 10 min or from 150 to 500 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably ranging from 200 to 480 g / 10 min or from 220 to 450 g / 10 min; more preferably ranging from 240 to 420 g / 10 min; even more preferably ranging from 250 to 400 g / 10 min; and most preferably ranging from 270 to 350 g / 10 min.

[0200] With preference, fraction B1 has a density ranging from 0.960 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably ranging from 0.965 to 0.978 g / cm3; more preferably ranging from 0.970 to 0.976 g / cm3, or ranging from 0.968 to 0.975 g / cm3.

[0201] In a preferred embodiment, component B comprises from 30 to 60 wt.% of fraction B1 based on the total weight of component B; preferably from 40 to 50 wt.%

[0202] With preference, fraction B1 is a polyethylene homopolymer.

[0203] In a preferred embodiment; the step of providing component B comprises the sub-steps of preparing component B, wherein component B comprises at least two polyethylene fractions B1 and B2; with the fraction B1 having an MI2 of at least 120 g / 10 min, or at least 150 g / 10 min, or at least 200 g / 10 min or of at least 250 g / 10 min as determined according to ISO 1133- 1 :2011 at a temperature of 190°C and under a load of 2.16 kg and / or a density of at least 0.960 g / cm3or at least 0.970 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, the substeps comprising: feeding ethylene monomer, a diluent, at least one catalyst, optionally hydrogen, and optionally one or more alpha-olefin comonomers into at least one first reactor, polymerizing the ethylene monomer and optionally one or more alpha-olefin comonomers, in the presence of the catalyst and optional hydrogen, in said first reactor to produce a polyethylene fraction B1 ; and feeding the polyethylene fraction B1 to a second reactor serially connected to the first reactor, and in the second reactor, polymerizing ethylene and optionally one or more alpha-olefin co-monomers, in the presence of the polyethylene fraction B1 and optionally hydrogen to produce the polyethylene resin of component B.

[0204] With preference, the one or more alpha-olefin co-monomers are selected from the group comprising C3-C20 alpha-olefins; preferably C3-C12 alpha-olefins; more preferably C4-C8 alphaolefins; most preferably, the co-monomer is selected from 1 -butene or 1 -hexene; even most preferably the co-monomer is 1 -hexene. The melt flow index (MI2) of the polyethylene produced in the second reactor is calculated using the following equation (1):

[0205] Log (MI2finai) = wBix (Log MI2BI) + wB2 x Log(MI2B2) (1) wherein M I2fjnaiis the melt flow index of the total polyethylene produced, MI2BI and MI2B2 are the respective melt flow index of the polyethylene fractions produced in the first and the second polymerization loop reactors, and WBI and WB2 are the respective weight fractions of the polyethylene produced in the first and in the second polymerization loop reactors as expressed in weight percent (wt.%) of the total polyethylene produced in the two polymerization loop reactors. These weight fractions are also commonly described as the contribution by the respective loop.

[0206] Selection of the one or more antioxidants

[0207] The composition of polyethylene may further comprise one or more antioxidants. The process according to the disclosure may comprise further a step of providing one or more antioxidants and the step of blending comprises blending the components B and CRA together with the one or more antioxidants to form a composition of polyethylene.

[0208] In preferred embodiment, the one or more antioxidants comprise at least one phenolic antioxidant and / or at least one organic phosphite or phosphonite antioxidant.

[0209] With preference, the composition of polyethylene comprises at least 100 ppm of the one or more antioxidants based on the total weight of the composition of polyethylene; preferably at least 150 ppm, more preferably at least 200 ppm; even more preferably at least 250 ppm, and most preferably at least 300 ppm.

[0210] With preference, the composition of polyethylene comprises from 100 to 5000 ppm of the one or more antioxidants based on the total weight of the composition of polyethylene; preferably from 150 to 4000 ppm; more preferably from 200 to 3000 ppm; even more preferably from 250 to 2500 ppm; and most preferably from 300 to 2000 ppm.

[0211] In preferred embodiment, the one or more antioxidants are or comprise one or more phenolic antioxidants selected from octadecyl 3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate and / or pentaerythrityl-tetrakis(3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate.

[0212] With preference, the composition of polyethylene comprises at least 100 ppm of one or more phenolic antioxidants based on the total weight of the composition of polyethylene; preferably at least 150 ppm, more preferably at least 200 ppm; even more preferably at least 250 ppm and most preferably at least 300 ppm. The composition of polyethylene comprises from 100 to 5000 ppm based on the total weight of the composition of polyethylene of one or more phenolic antioxidants selected from octadecyl 3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate and / or pentaerythrityl-tetrakis(3-(3',5'- di-t-butyl-4-hydroxyphenyl)propionate; preferably from 150 to 4000 ppm; more preferably from 200 to 3000 ppm; even more preferably from 250 to 2500 ppm; and most preferably from 300 to 2000 ppm.

[0213] In a preferred embodiment, the one or more antioxidants are or comprise at least one organic phosphite or phosphonite antioxidant selected from tris(2,4-ditert-butylphenyl) phosphite, bis(2,4-di-tert.-butyl-6-methylphenyl)-ethyl-phosphite, tris-nonylphenyl phosphite, tetrakis- (2,4-di-t-butylphenyl)-4,4'-biphenylen-di-phosphonite, 2,4,6-T ri-tert-buty I phenyl 2-butyl-2- ethyl-1 ,3-propanediol phosphite and any blend thereof.

[0214] With preference, the composition of polyethylene comprises at least 100 ppm of one or more organic phosphite or phosphonite antioxidants based on the total weight of the composition of polyethylene; preferably at least 150 ppm, more preferably at least 200 ppm; even more preferably at least 250 ppm and most preferably at least 300 ppm

[0215] The composition of polyethylene comprises from 100 to 5000 ppm based on the total weight of the composition of polyethylene of one or more organic phosphite or phosphonite antioxidants selected from tris(2,4-ditert-butylphenyl) phosphite (CAS number 31570-04-4, Irgaphos 168®), bis(2,4-di-tert.-butyl-6-methylphenyl)-ethyl-phosphite (Irgafos 38®), tris- nonylphenyl phosphite (CAS number 26523-78-4), tetrakis-(2,4-di-t-butylphenyl)-4,4'- biphenyl-di-phosphonite (CAS number 119345-01-6, Irgafos P-EPQ®), 2,4,6-tri-tert- butylphenyl 2-butyl-2-ethyl-1 ,3-propanediol phosphite (CAS number 161717-32-4, Ultranox 641®), or a blend thereof; preferably from 150 to 4000 ppm; more preferably from 200 to 3000 ppm; even more preferably from 250 to 2500 ppm; and most preferably from 300 to 2000 ppm.

[0216] In an embodiment, the one or more antioxidants comprise one or more selected from pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]; tris(2,4-ditert- butylphenyl) phosphite and / or octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0217] In an embodiment, the one or more antioxidants comprise at least two selected from pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate], tris(2,4-ditert- butylphenyl) phosphite and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0218] Pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate] is commercially available as Irganox® 1010 by BASF. Tris(2,4-ditert-butylphenyl) phosphite is commercially available as Irgafos® 168 by BASF. Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is commercially available as Irganox® 1076 by BASF. Other additives

[0219] In a preferred embodiment, the composition of polyethylene comprises additives, such as slip agents and / or ultraviolet absorbers.

[0220] Therefore, in a preferred embodiment, the process further comprises a step of adding at least one slip agent selected from erucamide (i.e. cis-13-docosenoamide, CAS number 112-84-5), behenamide (i.e. docosanamide, CAS number 3061-75-4) or any mixture thereof to the composition of polyethylene.

[0221] When the composition of polyethylene comprises at least one slip agent, said at least one slip agent is present in a content of at least 300 ppm based on the total weight of the composition of polyethylene; preferably of at least 400 ppm; more preferably of at least 500 ppm; even more preferably, of at least 600 ppm; most preferably of at least 700 ppm, and even most preferably, of at least 800 ppm, or of at least 900 ppm. In a preferred embodiment, said at least one slip agent is present in a content of at most 4,000 ppm based on the total weight of the composition of polyethylene; preferably, of at most 3,000 ppm; preferably, of at most 2,500 ppm, or of at most 2,000 ppm, or of at most 1 ,050 ppm, or of at least 1 ,000 ppm.

[0222] In another preferred embodiment, the process further comprises a step of adding at least one ultraviolet absorber selected from the hydroxyphenylbenzotriazole class to the composition of polyethylene.

[0223] In an embodiment, the composition of polyethylene comprises at least 500 ppm based on the total weight of the composition of polyethylene of at least one ultraviolet absorber, which is preferably selected from the hydroxyphenylbenzotriazole class. Preferably, the composition of polyethylene comprises at least 600 ppm of at least one ultraviolet absorber based on the total weight of the composition of polyethylene; more preferably at least 700 ppm; and / or at most 4,000 ppm, preferably at most 3,000 ppm, more preferably at most 2,000 ppm, and even more preferably at most 1 ,000 ppm.

[0224] In an embodiment, the ultraviolet absorber is selected from the hydroxyphenylbenzotriazole class consisting of 2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5-chlorobenzotriazole, 2-(2- hydroxy-5-methylphenyl)benzotriazole, 2-(3',5'-di-t-butyl-2'-hydroxyphenyl)benzotriazole, 2- (5'-t-butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2-(3'- s-butyl-2'-hydroxy-5'-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-4'- octyloxyphenyl)benzotriazole, 2-(3',5'-di-t-amyl-2'-hydroxyphenyl)benzotriazole, 2-[2'-hydroxy- 3',5'-bis(a,a-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-[(3'-t-butyl-2'-hydroxyphenyl)-5'-(2- octyloxycarbonylethyl)phenyl]-5-chlorobenzotriazole, 2-[3'-t-butyl-5'-[2-(2- ethylhexyloxy)carbonylethyl]-2'-hydroxyphenyl]-5-chlorobenzotriazole, 2-[3'-t-butyl-2'- hydroxy-5'-(2-methoxycarbonylethyl)phenyl]-5-chlorobenzotriazole, 2-[3'-t-butyl-2'-hydroxy-5'- (2-methoxycarbonylethyl)phenyl]benzotriazole, 2-[3'-t-butyl-2'-hydroxy-5-(2- octyloxycarbonylethyl)phenyl]benzotriazole, 2-[3'-t-butyl-2'-hydroxy-5'-[2-(2- ethylhexyloxy)carbonylethyl]phenyl]benzotriazole, 2-[2-hydroxy-3-(3, 4,5,6- tetrahydrophthalimidemethyl)-5-methylphenyl]benzotriazole, 2-(3,5-di-t-butyl-2- hydroxyphenyl)-5-chlorobenzotriazole; a mixture of 2-(3'-dodecyl-2'-hydroxy-5'- methylphenyl)benzotriazole and 2-[3'-t-butyl-2'-hydroxy-5'-(2- isooctyloxycarbonylethyl)phenyl]benzotriazole; 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4- (1 , 1 ,3,3-tetramethylbutyl)phenol, 2,2'-methylenebis[4-t-butyl-6-(2H-benzotriazol-2-yl)phenol]; a condensate of poly(3 to 11)(ethylene glycol) with 2-[3'-t-butyl-2'-hydroxy-5'-(2- methoxycarbonylethyl)phenyl]benzotriazole, a condensate of poly(3 to 11)(ethylene glycol) with methyl 3-[3-(2H-benzotriazol-2-yl)-5-t-butyl-4-hydroxyphenyl]propionate; 2-ethylhexyl-3- [3-t-butyl-5-(5-chloro-2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate, octyl 3-[3-t-butyl-5- (5-chloro-2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate, methyl 3-[3-t-butyl-5-(5-chloro- 2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate, 3-[3-t-butyl-5-(5-chloro-2H-benzotriazol-2- yl)-4-hydroxyphenyl]propionic acid and mixtures thereof.

[0225] Preferably, the ultraviolet absorber is 2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5- chlorobenzotriazole (CAS number. 3896-11-05), commercially available under the denomination Tinuvin® 326.

[0226] The resin composition may further contain additives, in particular additives suitable for injection and compression moulding, such as processing aids, mould-release agents, acid scavengers, flame retardants, fillers, nanocomposites, lubricants, antistatic additives, nucleating / clarifying agents, antibacterial agents, plasticizers, colorants / pigments / dyes and any mixtures thereof. Illustrative pigments or colorants include titanium dioxide, carbon black, cobalt aluminium oxides such as cobalt blue, and chromium oxides such as chromium oxide green. Pigments such as ultramarine blue, phthalocyanine blue, and iron oxide red are also suitable. Specific examples of additives include lubricants and mould-release agents such as calcium stearate, zinc stearate, and nucleating agents such as Milliken HPN20E™, and hindered amine light stabilizers (HALS) such as those taught for instance in U.S. Pat. Nos. 5,004,770; 5,204,473; 5,096,950; 5,300,544; 5,112,890; 5,124,378; 5,145,893; 5,216,156; 5,844,026; 5,980,783; 6,046,304; 6,117,995; 6,271 ,377; 6,297,299; 6,392,041 ; 6,376,584 and 6,472,456. The contents of these U.S. Patents are incorporated by reference. These additives may be included in amounts effective to impart the desired properties.

[0227] An overview of the additives that can be used in the injection- or compression-moulded articles of the present invention may be found in Plastics Additives Handbook, ed. H. Zweifel, 5th edition, 2001 , Hanser Publishers. The of blending the

[0228] The blending of the components and the optional one or more antioxidants can be carried out according to any physical blending method and combinations thereof known in the art. This can be, for instance, dry blending, wet blending or melt blending. The blending conditions depend upon the blending technique and polyethylene involved.

[0229] If dry blending is employed, the dry blending conditions may include temperatures from room temperature up to just under the melting temperature of the polymer. The components can be dry blended before a melt blending stage, which can take place for example in an extruder.

[0230] Melt processing is fast and simple and makes use of standard equipment in the thermoplastics industry. The components can be melt blended in a batch process such as in a Banbury, Haake, or Brabender Internal Mixer, or in a continuous process, such as in an extruder e.g. a single or twin-screw extruder, such as a ZKS twin screw extruder. During melt blending, the temperature at which the polymers are combined in the blender will generally be in the range between the highest melting point of the polymers employed and up to about 80 °C above such melting point, preferably between such melting point and up to 30 °C above it. The time required for the melt blending can vary broadly and depends on the method of blending employed. The time required is the time sufficient to thoroughly mix the components.

[0231] For example, the step of blending the components CRA and B to form a composition of polyethylene is conducted at a temperature of at most 280°C; preferably, at a temperature ranging from 160 to 280°C; more preferably at temperature ranging from 170 to 250°C.; and even more preferably from 180 to 230°C.

[0232] One or more antioxidants can be provided in addition to the components CRA and B, and / or can be provided with the component CRA and / or with the component B. For example, at least part of the one or more antioxidants are already present in the component CRA and / or in the component B and provided together with the component CRA and / or the component B. In a preferred embodiment, at least a part of the one or more antioxidants are provided in addition to the components CRA and B.

[0233] In an embodiment, the step of providing a component B and the step providing one or more antioxidants form are distinct steps.

[0234] In an embodiment, the step of providing from 20 wt.% to 85 wt.% based on the total weight of the composition of a component CRA and the step of providing one or more antioxidants are distinct steps. Alternatively, the step of providing a component B and the step providing one or more antioxidants form a single step and / or the step of providing from 20 wt.% to 90 wt.% based on the total weight of the composition of a component CRA and the step of providing one or more antioxidants form a single step.

[0235] The

[0236] The process according to the invention results in a composition that can be defined as follows.

[0237] The composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably ranging from 0.7 to 11.8 g / 10 min, or ranging from 0.9 to 11.5 g / 10 min, more preferably ranging from 1.0 to 11.2 g / 10 min; even more preferably ranging from 1.2 to 11.0 g / 10 min, or ranging from 1.4 to 10.8 g / 10 min; and most preferably ranging from 1.6 to 10.5 g / 10 min, or from 1.7 to 10.2 g / 10 min. from 1.8 to 10.0 g / 10 min.

[0238] In a first embodiment, for ESCR-demanding applications, the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 8.0 g / 10 min or from 0.5 to less than 7.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably ranging from 0.7 to 5.0 g / 10 min, or ranging from 0.9 to 4.0 g / 10 min, more preferably ranging from 1.0 to 3.5 g / 10 min; even more preferably ranging from 1.2 to 3.3 g / 10 min, or ranging from 1.4 to 3.0 g / 10 min; and most preferably ranging from 1.6 to 2.8 g / 10 min, or from 1.7 to 2.6 g / 10 min. from 1.8 to 2.4 g / 10 min.

[0239] With preference, the composition of polyethylene has an MI2 of at least 0.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably of at least 0.7 g / 10 min; more preferably of at least 0.9 g / 10 min; even more preferably of at least 1.0 g / 10 min; most preferably of at least 1.2 g / 10 min; and even most preferably of at least 1.4 g / 10 min, or of at least 1.5 g / 10 min, or of at least 16 g / 10 min, or of at least 1 .7 g / 10 min, or of at least 1.8 g / 10 min.

[0240] Preferably, the composition of polyethylene has an MI2 of at most 8.0 g / 10 min or less than 7.0 g / 10 min as determined according to conditions D at a temperature of 190°C and under a load of 2.16 kg; preferably of at most 5.0 g / 10 min, more preferably of at most 4.0 g / 10 min; even more preferably of at most 3.5 g / 10 min, most preferably of at most 3.3 g / 10 min, and even most preferably of at most 3.0 g / 10 min or of at most 2.9 g / 10 min or of at most 2.8 g / 10 min or of at most 2.7 g / 10 min, or of at most 2.6 g / 10 min or of at most 2.5 g / 10 min or of at most 2.4 g / 10 min.

[0241] In a second embodiment, the composition of polyethylene has a melt index (MI2) ranging from 6.0 to 12.0 g / 10 min or from 6.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably ranging from 7.0 to 11.8 g / 10 min, or ranging from 7.0 to 11.5 g / 10 min, more preferably ranging from 7.0 to 11.0 g / 10 min; even more preferably ranging from 7.0 to 10.8 g / 10 min, or ranging from 7.0 to 10.5 g / 10 min; and most preferably ranging from 7.0 to 10.2 g / 10 min, or from 7.0 to 10.0 g / 10 min. from 7.5 to 10.0 g / 10 min.

[0242] With preference, the composition of polyethylene has an MI2 of at least 6.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; preferably of at least 6.5 g / 10 min; more preferably of at least 7.0 g / 10 min; even more preferably of at least 7.5 g / 10 min; most preferably of at least 8.0 g / 10 min.

[0243] Preferably, the composition of polyethylene has an MI2 of at most 12.0 g / 10 min as determined according to conditions D at a temperature of 190°C and under a load of 2.16 kg; preferably of at most 11.8 g / 10 min, more preferably of at most 11.5 g / 10 min; even more preferably of at most 11.2 g / 10 min, most preferably of at most 11.0 g / 10 min, and even most preferably of at most 10.8 g / 10 min or of at most 10.5 g / 10 min or of at most 10.2 g / 10 min or of at most 10.0 g / 10 min, or of at most 9.8 g / 10 min.

[0244] The composition of polyethylene has a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably ranging from 0.940 to 0.964 g / cm3or from 0.942 to 0.963 g / cm3; or ranging from 0.945 to 0.962 g / cm3; more preferably ranging from 0.949 to 0.962 g / cm3; and most preferably ranging from 0.951 to 0.962 g / cm3.

[0245] With preference, the composition of polyethylene has a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably of at least 0.942 g / cm3; more preferably of at least 0.945 g / cm3; even more preferably of at least 0.947 g / cm3; most preferably of at least 0.949 g / cm3; and even most preferably of at least 0.950 g / cm3, or of at least 0.951 g / cm3.

[0246] Preferably, the composition of polyethylene has density of at most 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; preferably of at most 0.963 g / cm3, more preferably of at most 0.962 g / cm3.

[0247] When it contains recycled material, the composition of polyethylene may comprise from 0.01 to 15.0 wt.% of polypropylene based on the total weight of the composition of polyethylene; preferably from 0.1 to 13.5 wt.%; more preferably from 0.5 to 10.0 wt.% even more preferably from 0.7 to 8 wt.%, and most preferably from 1.0 to 5.0 wt.%.

[0248] In a preferred embodiment, the composition of polyethylene has a z average molecular weight (Mz) ranging from 160,000 g / mol to 340,000 g / mol as determined by gel permeation chromatography; preferably from 170,000 to 330,000 g / mol or from 180,000 to 320,000 g / mol; more preferably from 185,000 to 310,000 g / mol; even more preferably from 190,000 to 300,000 g / mol; and most preferably from 192,000 to 290,000 g / mol. In a preferred embodiment, the composition of polyethylene has a z average molecular weight (Mz) of at least 160,000 g / mol as determined by gel permeation chromatography; preferably of at least 170,000 g / mol; more preferably of at least 180,000 g / mol; and most preferably of at least 185,000 g / mol or of at least 190,000 g / mol.

[0249] Preferably, the composition of polyethylene is having a z average molecular weight (Mz) of at most 340,000 g / mol as determined by gel permeation chromatography; preferably of at most 330,000 g / mol; more preferably of at most 320,000 g / mol; and most preferably of at most 315,000 g / mol, or of at most 310,000 g / mol, or of at most 300,000 g / mol, or of at most 290,000 g / mol.

[0250] In a preferred embodiment, the composition of polyethylene has a weight-average molecular weight (Mw) of at most 150,000 g / mol as determined by gel permeation chromatography; preferably at most 120,000 g / mol; more preferably at most 110,000 g / mol; even more preferably at most 100,000 g / mol; and most preferably at most 95,000 g / mol.

[0251] For example, the composition of polyethylene has a weight-average molecular weight (Mw) of at least 45,000 g / mol as determined by gel permeation chromatography; preferably at least 50,000 g / mol; more preferably at least 55,000 g / mol; even more preferably at least 60,000 g / mol; and most preferably at least 65,000 g / mol.

[0252] With preference, the composition of polyethylene has a weight-average molecular weight (Mw) ranging from 45,000 to 150,000 g / mol as determined by gel permeation chromatography; more preferably from 50,000 to 120,000 g / mol, more preferably from 55,000 to 100,000 g / mol; and even more preferably from 60,000 to 95,000 g / mol.

[0253] In an embodiment, the composition of polyethylene has an Mz / Mw of at most 4.0 or of at most 3.8 as determined by gel permeation chromatography; preferably at most 3.7; more preferably at most 3.6; most preferably at most 3.5; and even most preferably at most 3.4 or at most 3.3.

[0254] In an embodiment, the composition of polyethylene has an Mw / Mn of at least 2.0 as determined by gel permeation chromatography; preferably ranging from 2.0 to 8.0; more preferably ranging from 3.0 to 7.0; even more preferably, ranging from 4.0 to 6.5; and most preferably ranging from 4.3 to 6.2; and even most preferably ranging from 4.4 to 6.0. or ranging from 4.5 to 5.9.

[0255] In addition, the composition of polyethylene is showing good processability performances as it can be injected at a pressure of less than 135 MPa, preferably of less than 130 MPa during the manufacture of caps or closures. In an embodiment, the composition of polyethylene has a Cap-ESCR of at least 10 hours, as determined according to the method of the description at 10% Igepal® and 40°C; preferably of at least 12 hours or of at least 14 hours, more preferably of at least 15 hours.

[0256] In an embodiment, the composition of polyethylene has Bell-ESCR of at least 10 hours, as determined according to ASTM D1693-15, conditions B at 50 °C using 100% Igepal® as a chemical agent; preferably of at least 12 hours.

[0257] In an embodiment, the composition of polyethylene has a tensile modulus of at least 900 MPa as determined according to ISO 527-1 : 2012; preferably, of at least 950 MPa; more preferably, of at least 1000 MPa.

[0258] The invention provides the use of a composition of polyethylene as described above for the manufacture of a cap or closure; with preference, by injection moulding or compression moulding.

[0259] Caps or closures and process of manufacture

[0260] The invention provides caps or closures made of a composition of polyethylene as defined above; with preference, the cap or closure is a screw cap.

[0261] The invention also provides a process for the manufacture of caps or closures, said process comprising the steps of: producing a composition of polyethylene comprising one or more recycled-polyethylene resins (rPE) according to the process above described; and injection moulding or compression moulding of the composition of polyethylene into a cap or closure.

[0262] The caps or closures of the present invention can be prepared by injection moulding or compression moulding the resin composition as already defined herein-above. Preferably, the caps or closures are prepared by injection moulding. Any injection machine known in the art may be used in the present invention, such as for example ENGEL 125T or NETSTAL Synergy 1000 injection moulding machine.

[0263] All mould types may be used. The caps or closures of the present invention are particularly suitable for closing bottles, in particular bottles for carbonated or still drinks or for non-food bottles such us for lubricant agrochemicals. Advantageously, the resin used in the invention is particularly suitable for single-piece caps or closures, including screw caps.

[0264] The injection moulding cycle may be split into three stages: filling, packing-holding, and cooling. During filling, melt polymer is forced into an empty cold cavity; once the cavity is filled; extra material is packed inside the cavity and held under high pressure in order to compensate for density increase during cooling. The cooling stage starts when the cavity gate is sealed by polymer solidification; further temperature decreases and polymer crystallization takes place during the cooling stage. Typical temperatures for the filling step are from 160 °C to 280 °C, preferably from 180 °C to 260 °C, preferably from 200 °C to 230 °C. Injection-moulding, as used herein, is performed using methods and equipment well known to the person skilled in the art. An overview of injection moulding and compression moulding is, for example, given in Injection Moulding Handbook, D.V. Rosato et al., 3rd edition, 2000, Kluwer Academic Publishers.

[0265] The moulds used in the production of the present caps or closures may be any mould usually used in the manufacture of caps or closures, such as for example multi-cavity moulds wherein a number of caps or closures is produced simultaneously.

[0266] The caps or closures of the present application are not especially limited. They may include screw-caps, caps or closures with a living hinge, glossy caps or closures, transparent caps or closures.

[0267] The caps or closures of the present application may be used in various packaging applications, such as for example detergent packaging, cosmetic packaging or paint packaging. Examples in detergent packaging are caps or closures for washing powders, dish soap, household cleaners. Examples in cosmetic packaging are shower gels, shampoos, oils, creams, liquid soaps. Examples in medical packaging are packaging for pills, solutions, disinfectants.

[0268] Hence, the present invention encompasses a packaging comprising the above-defined caps or closures.

[0269] Articles and process of manufacture of said articles

[0270] The present invention encompasses processes wherein a composition of polyethylene as defined above is produced and pelletized and then is used in a process for the manufacture of articles. In such a case, the step of blending components B and CRA to form a composition of polyethylene is a melt blending step and is distinct from the step of manufacture of articles. In all cases, the articles are preferably caps and closures.

[0271] Thus, in an embodiment, the invention provides for a process for the manufacture of articles, said process comprising the steps of: providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; blending the components CRA and B to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography forming an article from the composition of polyethylene obtained.

[0272] Forming an article can be made by extrusion, injection moulding, or compression moulding.

[0273] The thermally treated component CRA is obtained by submitting a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183- 1 :2012 at 23°C, to a thermal treatment at a temperature of at least 300°C.

[0274] In one or more embodiments, the step of providing a thermally treated component CRA comprises providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1 .5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg.

[0275] The component A, the component CRA, the component B and the composition of polyethylene are as defined above.

[0276] The thermally treated component CRA is obtained by submitting a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183- 1 :2012 at 23°C, to a thermal treatment at a temperature of at least 300°C. The present invention also encompasses processes wherein a composition of polyethylene as defined above is produced as a dry blend and then is used in a process for the manufacture of articles.

[0277] Thus in an embodiment, the invention provides a process for the manufacture of articles, said process comprising the steps of: providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; dry blending the component CRA and the component B and providing them together to an extruder, an injection molding apparatus, or a compression molding apparatus; and forming an article wherein the article is made from a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

[0278] The thermally treated component CRA is obtained by submitting a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183- 1 :2012 at 23°C, to a thermal treatment at a temperature of at least 300°C.

[0279] It is understood that the article is therefore formed by extrusion, injection moulding, or compression moulding. This embodiment is interesting in that it allows to avoid the step of melt blending and pelletizing the composition of polyethylene.

[0280] In one or more embodiments, the step of providing a thermally treated component CRA comprises providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1 .5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg.

[0281] The component A, the component CRA, the component B and the composition of polyethylene are as defined above.

[0282] The present invention also encompasses processes wherein a composition of polyethylene as defined above is blended simulteanoulsy with the manufacture of articles. This is the case, for example when the article is produced (manufactured) by extrusion. In such a case the component CRA and the component B can be provided separately to the extruder.

[0283] Thus in an embodiment, the invention provides a process for the manufacture of articles by extrusion, said process comprising the steps of providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and providing an extruder having a main feeder and one or more side feeders and feeding the compoents CRA and the component B to the extruder wherein one selected from the component CRA and the component B is fed by the main feeder and the other one by one or more side feeders to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography; forming an article by extrusion.

[0284] The thermally treated component CRA is obtained by submitting a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183- 1 :2012 at 23°C, to a thermal treatment at a temperature of at least 300°C. In one or more embodiments, the step of providing a thermally treated component CRA comprises providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1 .5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg.

[0285] The present invention also encompasses processes wherein a composition of polyethylene as defined above is blended simulteanoulsy with the manufacture of articles. This is the case, for example when the article is produced (manufactured) by extrusion. In such a case the component CA and the component B can be provided separately to the extruder and the component CRA is produced with the extruder before being blended with the component B.

[0286] Thus in an embodiment, the invention provides a process for the manufacture of articles by extrusion, said process comprising the steps of providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133- 1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and providing an extruder having a main feeder and one or more side feeders and feeding the component A and the component B to the extruder wherein the component A is fed by the main feeder and the component B is fed by one or more side feeders; forming an article by extrusion; wherein the extruder is divided into two successive sections, a first section wherein the component A is submitted to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a second section wherein the component B is added via the one or more side feeders and is blended with the thermally treated component CRA at a temperature of at most 250°C to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

[0287] The component A, the component CRA, the component B and the composition of polyethylene are as defined above.

[0288] The invention encompasses all articles produced from the composition of polyethylene as defined above. The invention encompasses all articles produced from a blend of the component CRA and the component B as defined above. With preference, the articles are caps and closures.

[0289] TEST METHODS

[0290] The density was measured according to the method of standard ISO 1183-1 :2012 (immersion method) at a temperature of 23 °C.

[0291] The melt index MI2 was measured according to the method of standard ISO 1133-1 :2011 at 190 °C and under a load of 2.16 kg.

[0292] The molecular weight distribution (MWD) is the ratio of the weight average molecular weight Mw to the number average molecular weight Mn i.e. Mw / Mn. The molecular weight (Mn(number average molecular weight), Mw(weight average molecular weight) and molecular weight distributions D (Mw / Mn) were determined by size exclusion chromatography (SEC) and in particular by gel permeation chromatography (GPC). Briefly, a GPC-IR5 from Polymer Char was used: 10 mg polyethylene sample was dissolved at 160 °C in 10 ml of trichlorobenzene for 1 hour. Injection volume: about 400 pl, automatic sample preparation and injection temperature: 160 °C. Column temperature: 145 °C. Detector temperature: 160 °C. Two Shodex AT-806MS (Showa Denko) and one Styragel HT6E (Waters) columns were used with a flow rate of 1 ml / min. Detector: Infrared detector (2800-3000 cm-1). Calibration: narrow standards of polystyrene (PS) (commercially available). Calculation of molecular weight Mi of each fraction i of eluted polyethylene is based on the Mark-Houwink relation (log (MpE) = 0.965909 x log (Mps) - 0.28264) (cut off on the low molecular weight end at MPE = 1000).

[0293] The molecular weight averages used in establishing molecular weight / property relationships are the number average (Mn), weight average (Mw) and z average (Mz) molecular weight. These averages are defined by the following expressions and are determined from the calculated Mi:

[0294] Here Nj and Wj are the number and weight, respectively, of molecules having molecular weight Mi. The third representation in each case (farthest right) defines how one obtains these averages from SEC chromatograms, hi is the height (from baseline) of the SEC curve at the ithelution fraction and Mj is the molecular weight of species eluting at this increment.

[0295] The molecular weight distribution (MWD) is then calculated as Mw / Mn.

[0296] The13C-NMR is performed using a 400 MHz or 500 MHz Bruker NMR spectrometer under conditions such that the signal intensity in the spectrum is directly proportional to the total number of contributing carbon atoms in the sample. Such conditions are well known to the skilled person and include for example sufficient relaxation time etc. In practice the intensity of a signal is obtained from its integral, i.e. the corresponding area. The data is acquired using proton decoupling, 2000 to 4000 scans per spectrum with 10 mm room temperature through or 240 scans per spectrum with a 10 mm cryoprobe, a pulse repetition delay of 11 seconds and a spectral width of 25000 Hz (+ / - 3000 Hz). The sample is prepared by dissolving a sufficient amount of polymer in 1 ,2,4-trichlorobenzene (TCB, 99%, spectroscopic grade) at 130 °C and occasional agitation to homogenize the sample, followed by the addition of hexadeuterobenzene (CeDe, spectroscopic grade) and a minor amount of hexamethyldisiloxane (HMDS, 99.5+ %), with HMDS serving as internal standard. To give an example, about 200 mg to 600 mg of polymer are dissolved in 2.0 mL of TCB, followed by the addition of 0.5 mL of CeDe and 2 to 3 drops of HMDS.

[0297] Following data acquisition, the chemical shifts are referenced to the signal of the internal standard HMDS, which is assigned a value of 2.03 ppm.

[0298] The comonomer content of a polyethylene is determined by13C-NMR analysis of pellets according to the method described by G.J. Ray et al. in Macromolecules, vol. 10, n° 4, 1977, p. 773-778.

[0299] The melting (Tm) was determined according to ISO 11357-3:2018. The environmental stress crack resistance (Bell ESCR) was determined according to ASTM D1693-15, conditions B at 50 °C using 100% Igepal® CO-630 as a chemical agent (wherein Igepal® CO-630 (CAS number 68412-54-4) is commercially available from Rhodia). In the test, 10 notched strips of molded PE were bent and contacted with a surfactant being 10% Igepal at 40°C. The failures were tracked by regular camera snapshots. Size of the strips 1 .30 cm x 3.80 cm x 1.84-1.97 mm) Notch size: 0.3-0.4 mm depth x 1.25 cm length. The ESCR value is reported as F50, the calculated 50 percent failure time from the probability graph.

[0300] The closure (cap) environmental stress crack resistance (Cap ESCR) was measured at 40 °C, 6 bar air pressure using 10 % Igepal® CO-630 as a chemical agent (wherein Igepal® CO-630 (CAS number 68412-54-4) is commercially available from Rhodia) on closures. Closures were prepared by injection moulding using a Netstal Elion 3200 apparatus. A temperature-controlled chamber was set to 40 °C. Closures were clamped to pre-formed injection-moulded bottles by tightening the closures at a tightening torque of 2.2 Nm. The bottle part of the assembly is outfitted with tubing that is then attached to an air supply of the controlled chamber. The bottles with closures are turned upside down and immersed in a 10 % Igepal® CO-630 solution. The pressure inside the assembly is then monitored until a crack develops on the closure. The time it takes for a crack to develop is recorded. The ESCR value is reported as F50.

[0301] The tensile modulus was determined according to ISO 527-1 :2012 at 23°C using specimen type 1A.

[0302] The stress at yield was determined according to ISO 527-1 :2012 at 23°C using specimen type 1A.

[0303] EXAMPLES

[0304] The invention will now be illustrated by the following, non-limiting illustrations of particular embodiments of the invention.

[0305] Example 1 -Preparation of the thermally treated component CRA

[0306] The component A and the thermally treated component CRA

[0307] PE1 = Polyethylene HDPE 5502 commercialized by TotalEnergies. The density according to ISO 1183-1 :2012 is 0.954 g / cm3; the Ml2according to ISO 1133-2011 (190°C, 2.16 kg) is 0.25 g / 10 min; the HLMI according to ISO 1133-2011 (190°C, 21.6 kg) is 22 g / 10 min. The polyethylene was produced using a chromium-based catalyst.

[0308] In terms of viscosity, such PE1 grade is representative of the properties of several PCR-PE streams of interest when transformation into injection (recycled) grades is concerned. PE2 = Polyethylene HDPE 2008SN60 - commercialized by TotalEnergies. The density according to ISO 1183-1 :2012 is 0.961 g / cm3; the MI2 according to ISO 1133-2011 (190°C, 2.16 kg) is 0.80 g / 10 min; the HLMI according to ISO 1133-2011 (190°C, 21.6 kg) is 52 g / 10 min.

[0309] PCR-PE3 is a commercially available recycled polyethylene. The density according to ISO 1183-1 :2012 is about 0.969 g / cm3; the Ml2according to ISO 1133-2011 (190°C, 2.16 kg) is 0.28 g / 10 min; the HLMI according to ISO 1133-2011 (190°C, 21.6 kg) is 22 g / 10 min.

[0310] PE4 = Polyethylene HDPE The density according to ISO 1183-1 :2012 is 0.959 g / cm3; the HLMI according to ISO 1133-2011 (190°C, 21.6 kg) is 26 g / 10 min.

[0311] Thermal treatment by mechanical processing

[0312] The extruder used in the experiment was Leistritz ZSE 18 HPe. The screw design was modified from the standard configuration to the crew screw design as shown in figure 3. (please provide a short description of the screw design).

[0313] The extrusion was performed at different screw speeds with the temperature profile as indicated in Table 1. The “set values” temperature correspond to the values imposed during the start-up of the test. When progressing to stable conditions, due to the transfer of mechanical heat into polymer heat in the barrel, the barrel temperatures exceed these targets. When, in a zone, the temperature exceeds the target by more than 10 °C, the temperature regulation is switched off in this zone and the temperature of the zone could increase and stabilize to a higher value. The temperature “read value” is the barrel temperature at which the thermal is performed. In all cases the feeding rate was 2.5 kg / h

[0314] The examples illustrates how the temperature profile is to be adapeted to obtain a CRA in within the targeted MI2 range. Indeed, in case the temperature is too low such as in CRA07 the targeted melt index is not achieved meaning that a higher temperature is to be used. In case the temperature is too high the resulting melt index will be to high for the targeted application such as in CRA13 so a lower temperature is to be used.

[0315] Table 1 : temperature profile

[0316]

[0317] Table 2 other extrusion conditions

[0318] Another series of experiments were conducted wherein the thermal treatment was performed by heating the PCR-PE3 polymer (component A). The experiments were performed at different screw speeds. Figure 4 illustrates the increase obtained in the MI2 for the thermally treated component CRA.

[0319] Example 2 - Selection of material and production of polyethylene compositions

[0320] Polyethylene compositions containing PCR have been produced, two series of experiments were conducted.

[0321] Selection of suitable components B

[0322] Examples of component B according to the disclosure are provided in Table 3.

[0323] Table 3: Component B

[0324] Booster 1 is metallocene-catalyzed and has a bimodal molecular weight distribution. It is a copolymer of ethylene and 1-hexene, commercially available from TotalEnergies, used for cap and closures and produced with a metallocene catalyst in two sequentially connected slurry loop reactors, having a density of about 0.952 g / cm3, a MI2 ranging from 2.0 g / 10 min + / - 0.2 and a MWD of about 4.5.

[0325] The polyethylene booster 1 has been produced according to the below conditions of polymerization with the catalyst being the metallocene catalyst ethylene- bis(tertrahydroindenyl)zirconium dichloride, which was added in the first reactor only. The cocatalyst used was tri-iso-butyl aluminum (TIBAL).

[0326] Table 4

[0327] After pelletization, the final density was 952.3 g / cm3and the final MI2 was 1.9 g / 10 min.

[0328] Selection of Component A being recycled material Component A being commercially available PCR-PE materials are provided in the below table 5

[0329] Table 5: component A | Elongation at break | % | 12 177

[0330] PCR-PE1 is a reference example and was used without thermal treatment.

[0331] PCR-PE2 and PCR-PE3 were subjected to thermal treatment before being blended resulting in CR-PCR-PE2 and CR-PCR-PE3 under the below conditions:

[0332] Polyethylene flakes (post-consumer resin - PCR-PE2, i.e. flakes described as “standard noncolor sorted bottles from yellow bag” commercialized by Vogt-Plastic GmbH, Rheinfelden) were used. After an appropriate treatment to reduce the maximum size of the flakes to 7 mm due to the specifiy of the screw elements, the flakes were introduced in a ZSE 50MAXX extruder (pilot line - 50 mm diameter twin screw extruder with L / D = 48) as shown in Figure 2, with three hot zones each comprising one left-handed element.

[0333] Processing conditions :

[0334] Screw speed : 500 rpm;

[0335] Througput : 250 kg / h;

[0336] Torque : 84 %;

[0337] Mechanical specific energy (MSE) : 0.373 kWh / kg;

[0338] Pressure at the melt pump was 47 bar.

[0339] Measured temperature (Tmelt) inside the extruder, close to the die was 257°C.

[0340] Wien starting the production of the grade, temperatures targets are set to 250 C in block A to J and 220 C in blocks K to M. After the start-up of the extruder, in blocks D to J the temperature regulations were switched off as soon as the temperature reach the temperature targets.

[0341] Table 7

[0342] Properties of the CR-PCR-PE2 obtained after the thermal treatment are provided in the below table 7

[0343] Table 7

[0344] Polyethylene flakes (post-consumer resin - PCR-PE3) were used to produce the CRA06 according to example 1 with an MI2 of 2.83 g / 10 min.

[0345] In the first series of experiments, a booster of the disclosure (i.e., Booster 1) was blended with PCR-PE1 resulting in samples E1 to E3. Blending was done Extrusion on Coperion ZSK18 with gentle screw profile at a screw speed of 200 rpm and a read temperature below 250°C E4 is Eltex® B4020, a monomdal resin commercially available from Ineos. Results of the tests performed are provided in Table 8.

[0346] Table 8 - reference examples

[0347] Comparative examples E1 to E3 correspond to blends produced from the same components nut with different PCR-PE1 lots. Dispersion of the E1 - E3 measured properties originates from the fluctuations of the properties inside the PCR-PE1 grade.

[0348] In the second series of experiments, PCR-PE2 and PCR-PE3 (i.e. components A) were subjected to a thermal treatment resulting in CR-PCR-PE2 and CRA06 respectively (i.e. components CRA). Then, Booster 1 was blended with respectively CR-PCR-PE2 and CRA06 resulting in compositions E5 and E6. The compositions were prepared by classical twinextrusion process. The barrel temperature used was 230° C. and the screw speed was 50 rpm. Results of the tests performed are provided in Table 9.

[0349] Table 9 - Inventive examples

[0350] From the results, it can be seen that it is possible to obtain a good balance of mechanical properties on the inventive samples as compared to the reference samples. In particular, it is possible to get the same level of Cap ESCR and processability. The elongation at break is improved for the inventive samples.

[0351] It is therefore possible to produce caps and closures with a good balance of mechanical properties in a composition comprising more than 40 wt. % of recycled material wherein the starting recycled material has a melt index ranging from 0.1 to 1.8 g / min. Comparison with the reference examples shows that a good balance of properties concerning mechanical properties such as environmental stress crack resistance (Cap-ESCR) and tensile modulus, and processability (injection pressure) can be obtained from a composition containing 50 wt.% of recycled material. Indeed, the balance of properties is even improved compared to the one of a virgin commercial product (reference example E4).

Claims

CLAIMS1 . Process to produce a composition of polyethylene for the manufacture of caps and closures, wherein the process is characterized in that it comprises the steps of providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133- 1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; submitting the component A to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and blending the components CRA and B to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

2. The process according to claim 1 , is characterized in that the step submitting component A to a thermal treatment comprises the following sub-steps: i) providing a twin-screw extruder with thermal regulation devices; ii) extruding the component A to obtain a thermally treated component CRA; wherein extrusion is performed with a residence time of less than 20 min; and comprises a thermal treatment of the component A at a temperature of at least 300°C in one or more hot zones of the extruder; iii) recovering a thermally treated component CRA.

3. The process according to any one of claims 1 to 2, characterized in that the composition of polyethylene has a melt index (MI2) ranging from 0.5 to less than 7.0 g / 10 min or from 7.0 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg.

4. The process according to any one of claims 1 to 3, characterized in that the content of component B in the composition is at least 10 wt.% based on the total weight of the composition of polyethylene; and / or the content of component CRA in the composition is ranging from 35 wt.% to 85 wt.% based on the total weight of the composition of polyethylene5. The process according to any one of claims 1 to 4, characterized in that component B: has a melt index (MI2) ranging from 0.1 to 3.5 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; or has a melt index (MI2) ranging from more than 3.5 to 12.0 g / 10 min.

6. The process according to any one of claims 1 to 5, characterized in that component A: has a melt index (MI2) ranging from 0.1 to 1.5 or max 1.3 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; and / or has a density ranging from 0.945 to 0.980 g / cm3as determined according to ISO 1183- 1 :2012 at 23°C; and / or has an Mw / Mn of at least 6.0 as determined by gel permeation chromatography.

7. The process according to any one of claims 1 to 6, characterized in that the thermally treated component CRA has a melt index (MI2) ranging from 1.8 to 15.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C; preferably from 2.0 to 10.0 g / 10 min.

8. The process according to any one of claims 1 to 7, characterized in that the composition of polyethylene: has a weight-average molecular weight (Mw) of at most 150,000 g / mol as determined by gel permeation chromatography; and / or has a z-average molecular weight (Mz) of at most 340,000 g / mol as determined by gel permeation chromatography.

9. The process according to any one of claims 1 to 8, characterized in that component B is a polyethylene resin being a copolymer of ethylene and one or more alpha-olefin co-monomers selected from the group comprising C3-C20 alpha-olefins; and / or in that component B is a polyethylene resin comprising at least two polyethylene fractions B1 and B2, wherein fraction B1 : has an MI2 of at least 120 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; and / or has a density of at least 0.960 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and / or is a polyethylene homopolymer.

10. The process according to any one of claims 1 to 9, characterized in that the step of blending the components CRA and B to form a composition of polyethylene is conducted at a temperature of at most 250°C.

11. The process according to any one of claims 1 to 10, characterized in that the step of submitting component A to a thermal treatment to obtain a component CRA and the step of blending the components CRA and B are performed in a single extruder that is divided into two successive sections, a first section wherein the component A is submitted to a thermal treatment to obtain the thermally treated component CRA and a second section wherein the component B is added via the one or more side feeders and is blended with the thermally treated component CRA at a temperature of at most 250°C.

12. A composition of polyethylene characterized in that it is produced by the process according to any one of claims 1 to 11 .

13. A composition of polyethylene comprising optionally one or more antioxidants; wherein the composition is characterized in that it shows: a MI2 ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; andMz / Mn of at most 3.3 as determined by gel permeation chromatography;- with preference, a cap ESCR of at least 10 h.

14. Process for the manufacture of caps or closures, said process comprising the steps of producing a composition of polyethylene according to the process of any one of claim 1 to 11 , or providing a composition of polyethylene according to claim 12 or 13; and injection moulding or compression moulding of the composition of polyethylene into a cap or closure;- with preference, the composition of polyethylene comprises one or more recycled- polyethylene resins (rPE).

15. Cap or closure characterized in that it is made of a composition of polyethylene according to claim of 12 or 13.

16. Process for the manufacture of articles, said process comprising the steps of providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at atemperature of 190°C and under a load of 2.16 kg, wherein the thermally treated component CRA is obtained by submitting a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, to a thermal treatment at a temperature of at least 300°C ; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; dry blending the component CRA and the component B and providing them together to a extruder, an injection molding apparatus: or a compression molding apparatus; and forming an article wherein the article is made from a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

17. Process for the manufacture of articles by extrusion, said process comprising the steps of providing a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg, wherein the thermally treated component CRA is obtained by submitting a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, to a thermal treatment at a temperature of at least 300°C; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and providing an extruder having a main feeder and one or more side feeders and feeding the component CRA and the component B to the extruder, wherein one selected from the component CRA and the component B is fed by the main feeder and the other oneby one or more side feeders to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183-1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography; forming an article by extrusion.

18. Process for the manufacture of articles by extrusion, said process comprising the steps of providing a component A being one or more polyethylene resins (PE) having a melt index (MI2) ranging from 0.1 to 1.8 g / 10 min as determined according to ISO 1133- 1 :2011 at a temperature of 190°C and under a load of 2.16 kg, and a density ranging from 0.940 to 0.980 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; providing a component B being a polyethylene resin having a melt index (MI2) ranging from 0.1 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a density ranging from 0.940 to 0.965 g / cm3as determined according to ISO 1183-1 :2012 at 23°C; and providing an extruder having a main feeder and one or more side feeders and feeding the component A and the component B to the extruder wherein the component A is fed by the main feeder and the component B is fed by one or more side feeders; forming an article by extrusion; wherein the extruder is divided into two successive sections, a first section wherein the component A is submitted to a thermal treatment at a temperature of at least 300°C to obtain a thermally treated component CRA having a melt index (MI2) ranging from greater than 1.5 to 20.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg and a second section wherein the component B is added via the one or more side feeders and is blended with the thermally treated component CRA at a temperature of at most 250°C to form a composition of polyethylene comprising from 20 wt.% to 90 wt.% based on the total weight of the composition of the component CRA; wherein the composition of polyethylene has a melt index (MI2) ranging from 0.5 to 12.0 g / 10 min as determined according to ISO 1133-1 :2011 at a temperature of 190°C and under a load of 2.16 kg; a density of at least 0.940 g / cm3as determined according to ISO 1183- 1 :2012 at 23°C, and an Mz / Mw of at most 3.3 as determined by gel permeation chromatography.

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