Articulated polyethylene assembly

Abstract

The present invention relates to a hinged assembly comprising a polyethylene composition comprising-a high density polyethylene (HDPE) having a density in the range of 950 to 960 kg / m3, measured according to ISO 1183, a melt flow index in the range of 5 to 40 g / 10 min, measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190 DEG C, a weight average molecular weight Mw, measured by size exclusion chromatography, in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0 to 10.0; and-a linear low density polyethylene (LLDPE) having a density in the range of 920 to 940 kg / m3, measured according to ISO 1183, a melt flow index in the range of 1 to 20 g / 10 min, measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190 DEG C, a weight average molecular weight Mw, measured by size exclusion chromatography, in the range of 40,000 to 120,000 g / mol, and a molecular weight distribution Mw / Mn in the range of 3 to 7; wherein the polyethylene composition has an overall density, measured according to ISO 1183, in the range of 935 to 950 kg / m3 and an overall melt flow index, measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190 DEG C, of 5 to 30 g / 10 min; wherein the amount of HDPE is in the range of from 30 to 70% by weight of the total amount of HDPE and LLDPE, and wherein the amount of LLDPE is in the range of from 30 to 70% by weight of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100% by weight of the polyethylene composition.

Description

Technical Field

[0001] The present invention relates to a hinge assembly comprising a polyethylene composition. Background Art

[0002] The most commonly used material for hinged components is polypropylene. Polypropylene has excellent hinge fatigue performance, good environmental stress cracking (ESCR) resistance, low cost and ease of processing. However, bottles or tubes with hinged lids for cosmetics / personal care applications are usually made of polyethylene. This means that the bottle and tube, as well as the unseparated polypropylene lid, will enter the mechanical recycling stream as contaminants after use and degrade the mechanical properties of the polyethylene recyclate. Therefore, there is a need to develop hinged components based on polyethylene to achieve single-material packaging solutions, thereby achieving better sustainability.

[0003] US9783664B1 relates to a hinged assembly made from a polyethylene composition comprising a first ethylene copolymer and a second ethylene copolymer.

[0004] US2016289435A1 relates to polyethylene compositions that can be used to make shaped articles such as closures for bottles.

[0005] However, hinge assemblies still need to have superior hinge fatigue performance and good mechanical properties. In particular, hinge fatigue performance, environmental stress crack resistance (ESCR), and the workability of the materials used for the hinge assemblies are important. Similarly, impact and low-temperature toughness are also important. Therefore, there is a need to develop new materials for hinge assemblies that meet these requirements. Summary of the Invention

[0006] It has now surprisingly been found that the use of a polyethylene composition comprising high density polyethylene (HDPE) and linear low density polyethylene (LLDPE) for producing hinge components results in an excellent combination of ESCR and hinge fatigue performance. At the same time, the hinge components are easily recyclable.

[0007] The hinge assembly according to the present invention comprises a polyethylene composition comprising:

[0008] - High density polyethylene (HDPE) having a density of 950 to 960 g / cm2, measured according to ISO 1183

[0009] kg / m 3 a density in the range of 5 to 40 g / 10 min, a melt flow index in the range of 5 to 40 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0 to 10.0, and

[0010] - linear low density polyethylene (LLDPE) having a carbonyl group density of 920

[0011] Up to 940kg / m 3 Density in the range of 1 to 20 g / 10 min, melt flow index in the range of 40,000 to 50,000 g / 10 min, measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190°C

[0012] a weight average molecular weight Mw measured by size exclusion chromatography in the range of 1 to 120,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0013] wherein the polyethylene composition has a hardness of 935 to 950 kg / m 3 an overall density in the range of 5 to 30 g / 10 min and an overall melt flow index of 5 to 30 g / 10 min measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190° C.,

[0014] wherein the amount of HDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and

[0015] wherein the amount of LLDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0016] Preferably, the hinge assembly according to the present invention comprises a polyethylene composition comprising

[0017] - High density polyethylene (HDPE) having a density of 950 to 960 g / cm2, measured according to ISO 1183

[0018] kg / m 3 a density in the range of 5 to 40 g / 10 min, a melt flow index in the range of 5 to 40 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0 to 10.0, and

[0019] - linear low density polyethylene (LLDPE) having a carbonyl group density of 920

[0020] Up to 940kg / m 3Density in the range of 1 to 20 g / 10 min, melt flow index in the range of 40,000 to 50,000 g / 10 min, measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190°C

[0021] a weight average molecular weight Mw measured by size exclusion chromatography in the range of 1 to 120,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0022] wherein the polyethylene composition has a hardness of 935 to 950 kg / m 3 an overall density in the range of 5 to 30 g / 10 min and an overall melt flow index of 5 to 30 g / 10 min measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190° C.,

[0023] wherein the amount of HDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and

[0024] wherein the amount of LLDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0025] The hinge assembly according to the present invention shows an excellent combination of ESCR and hinge fatigue performance. At the same time, the hinge assembly is easy to recycle.

[0026] Preferably, the hinge assembly comprises HDPE in an amount in the range of 40-60 wt%, preferably in the range of 45-55 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0027] Preferably, the hinge assembly comprises HDPE in an amount in the range of 40-60 wt%, preferably in the range of 45-55 wt%, based on the total amount of HDPE and LLDPE, and wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0028] Preferably, the hinge assembly comprises LLDPE in an amount in the range of 40-60 wt%, preferably in the range of 45-55 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0029] Preferably, the hinge assembly comprises LLDPE in an amount in the range of 40-60 wt%, preferably in the range of 45-55 wt%, based on the total amount of HDPE and LLDPE, and wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0030] More preferably, the hinge component comprises HDPE in an amount in the range of 48-52 wt% of the total amount of HDPE and LLDPE.

[0031] More preferably, the hinge component comprises LLDPE in an amount in the range of 48-52 wt% of the total amount of HDPE and LLDPE.

[0032] Most preferably, the hinge assembly comprises HDPE in an amount in the range of 48-52 wt% of the total amount of HDPE and LLDPE;

[0033] and LLDPE in an amount ranging from 48-52 wt% of the total amount of HDPE and LLDPE.Most preferably, the hinge assembly comprises an amount of HDPE equal to or greater than the amount of LLDPE by weight based on the total amount of HDPE and LLDPE.

[0034] High-density polyethylene (HDPE)

[0035] The production of HDPE is summarized in "Handbook of Polyethylene" by Andrew Peacock (2000; Dekker; ISBN 0824795466), pages 43 to 66. Suitable catalysts for producing polyethylene include Ziegler-Natta catalysts, chromium-based catalysts and single-site metallocene catalysts.

[0036] Unimodal polyethylene can be obtained, for example, by polymerizing ethylene and optionally at least one olefin comonomer in a slurry mode in the presence of a silica-supported chromium-containing catalyst and / or an alkyl boron compound. Suitable comonomers include, for example, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene and / or 1-octene.

[0037] Unimodal polyethylene may for example be obtained by polymerising ethylene and optionally at least one olefin comonomer in a gas phase polymerisation or in a slurry polymerisation process.

[0038] The production method of bimodal high density polyethylene (HDPE) is summarized in " PE 100Pipe systems " (ed. by Bromstrup; Second edition, ISBN 3-8027-2728-2) pp. 16-20. The production of bimodal high density polyethylene (HDPE) via a low pressure slurry process is described in " Bimodal polyethylene-Interplay of catalyst and process " (Macromol.Symp.2001,163,135-143) by Alt et al. The characteristics of polyethylene are determined in particular by the catalyst system and by the concentration of catalyst, comonomer and hydrogen. The production of bimodal high density polyethylene (HDPE) via a low pressure slurry process can also be carried out via a three-stage process. The concept of a two-stage cascade process is illustrated in " Bimodal polyethylene-Interplay of catalyst and process " (Macromol.Symp.2001,163) by Alt et al. at 137-138 pages.

[0039] The HDPE according to the present invention may be unimodal HDPE or multimodal HDPE, such as bimodal HDPE and trimodal HDPE. Preferably, the HDPE is unimodal HDPE.

[0040] Unimodal HDPE needs to be understood as HDPE which has been produced in one reactor under the same reaction conditions and one type of catalyst species.

[0041] Bimodal HDPE needs to be understood as HDPE produced under different polymerisation conditions in two reactors in series. Bimodal HDPE may for example be a reactor blend of HDPE produced in one reactor and LLDPE produced in another reactor, wherein the reactors are used in series.

[0042] Bimodal HDPE may also be HDPE produced in one reactor in the presence of a catalyst system comprising two or more different catalyst species, e.g. a catalyst system using two different active metal species, wherein those catalyst species result in a reactor blend of polyethylenes having different properties, e.g. different density and / or MFI.

[0043] Multimodal HDPE needs to be understood as HDPE produced in two or more reactors in series under different polymerisation conditions.The multimodal HDPE may for example be a reactor blend of HDPE produced in one or more reactors and LLDPE produced in one or more reactors.

[0044] The molecular weight distribution of HDPE measured by SEC may show one or more distinct maxima, or may show a significantly broadened molecular weight distribution compared to the curves of separate fractions of material having different compositions.

[0045] Bimodal or multimodal HDPE may show one, two or several maxima / peaks in the size exclusion chromatogram. It should be understood that according to the present invention, the number of maxima / peaks or shoulders is irrelevant to the term unimodal, bimodal or multimodal HDPE. Bimodal HDPE may, for example, show only one maximum / peak in the size exclusion chromatogram.

[0046] The hinged component may comprise HDPE having a hardness of 952 to 956 kg / m² as measured according to ISO 1183, method A. 3 Density within the range.

[0047] The hinge component may comprise HDPE having an MFI in the range of 8 to 40 g / 10 min, preferably 20 to 35 g / 10 min, more preferably 28 to 35 g / 10 min as measured according to ISO 1131-1:2011 at 190°C and under a load of 2.16 kg.

[0048] The hinge component may comprise HDPE having an Mw in the range of 55,000 to 80,000 g / mol, preferably in the range of 55,000 to 70,000 g / mol, more preferably in the range of 55,000 to 65,000 g / mol.

[0049] The hinge component may comprise HDPE having a Mw / Mn in the range of 4 to 8, preferably in the range of 4-7, more preferably in the range of 5-6.

[0050] The hinged component may comprise HDPE having a hardness of 952 to 956 kg / m² as measured according to ISO 1183, method A. 3 range, and an MFI as measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg in the range of 8 to 40 g / 10 min, preferably 20 to 35 g / 10 min, more preferably 28 to 35 g / 10 min.

[0051] The hinged component may comprise HDPE having a hardness of 952 to 956 kg / m² as measured according to ISO 1183, method A. 3a density in the range of 100 to 200 g / 10 min, and an MFI in the range of 8 to 40 g / 10 min, preferably 20 to 35 g / 10 min, more preferably 28 to 35 g / 10 min, as measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg, and

[0052] Mw in the range of 55,000 to 80,000 g / mol, preferably in the range of 55,000 to 70,000 g / mol, more preferably in the range of 55,000 to 65,000 g / mol.

[0053] The hinged component may comprise HDPE having a hardness of 952 to 956 kg / m² as measured according to ISO 1183, method A. 3 a density in the range of 100 to 200 g / 10 min, and an MFI in the range of 8 to 40 g / 10 min, preferably 20 to 35 g / 10 min, as measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg, and

[0054] Mw in the range of 55,000 to 80,000 g / mol.

[0055] The hinged component may preferably comprise HDPE having a hardness of 952 to 956 kg / m² as measured according to ISO 1183, method A. 3 a density in the range of 100 to 200 g / 10 min, and an MFI in the range of 8 to 40 g / 10 min, preferably 20 to 35 g / 10 min, as measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg, and

[0056] Mw in the range of 55,000 to 65,000 g / mol.

[0057] The hinged component may comprise HDPE having a hardness of 952 to 956 kg / m² as measured according to ISO 1183, method A. 3 density within the range, and

[0058] an MFI in the range of 8 to 40 g / 10 min, preferably 20 to 35 g / 10 min, more preferably 28 to 35 g / 10 min, as measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg, and

[0059] an Mw in the range of 55,000 to 80,000 g / mol, preferably in the range of 55,000 to 70,000 g / mol, more preferably in the range of 55,000 to 65,000 g / mol, and

[0060] Mw / Mn in the range of 4 to 8, preferably in the range of 4-7, more preferably in the range of 5-6.

[0061] Linear low-density polyethylene (LLDPE)

[0062] Linear low density polyethylene (LLDPE) can be obtained, for example, by polymerizing ethylene with at least one α-olefin, which can be selected from 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene and / or 1-octene, preferably 1-butene.

[0063] Linear low density polyethylene (LLDPE) can be produced, for example, using at least one or exactly one metallocene catalyst or at least one or exactly one Ziegler-Natta catalyst.

[0064] Preferably, the linear low density polyethylene (LLDPE) used according to the present invention may be produced, for example, using at least one Ziegler-Natta catalyst comprising Mg and one or at least one of Ti, Hf or Zr.

[0065] LLDPE can preferably be produced using a gas phase process or a slurry process.The production processes for polyethylene are summarized in "Handbook of Polyethylene" by Andrew Peacock (2000; Dekker; ISBN 0824795466), pages 43-66.

[0066] The hinge component may comprise LLDPE having a hardness of 925 to 935 kg / m² as measured according to ISO 1183, method A. 3 range, preferably between 930 and 935 kg / m 3 Density within the range.

[0067] The hinge component may comprise LLDPE having an MFI in the range of 2.0 to 15 g / 10 min, preferably 2 to 10 g / 10 min, more preferably 2 to 8 g / 10 min as measured according to ISO 1131-1:2011 at 190°C and under a load of 2.16 kg.

[0068] The hinge component may comprise LLDPE having an Mw in the range of 50,000 to 100,000 g / mol, preferably 70,000 to 90,000 g / mol, more preferably 80,000 to 90,000 g / mol.

[0069] The hinge component may comprise LLDPE having an Mw / Mn in the range of 4 to 5.

[0070] The hinge component may comprise LLDPE having a hardness of 925 to 935 kg / m² as measured according to ISO 1183, method A. 3 range, preferably between 930 and 935 kg / m 3 range, and an MFI as measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg in the range of 2.0 to 15 g / 10 min, preferably 2 to 10 g / 10 min, more preferably 2 to 8 g / 10 min.

[0071] The hinge component may comprise LLDPE having a hardness of 930 to 935 kg / m² as measured according to ISO 1183, method A. 3 The compositions of the present invention may have a density in the range of 0.05 % to 0.1 % and a MFI in the range of 2 to 8 g / 10 min as measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg.

[0072] The hinge component may comprise LLDPE having a hardness of 925 to 935 kg / m² as measured according to ISO 1183, method A. 3 range, preferably between 930 and 935 kg / m 3 density within the range, and

[0073] an MFI in the range of 2.0 to 15 g / 10 min, preferably 2 to 10 g / 10 min, more preferably 2 to 8 g / 10 min, as measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg, and

[0074] Mw in the range of 50,000 to 100,000 g / mol, preferably 70,000 to 90,000 g / mol, more preferably 80,000 to 90,000 g / mol.

[0075] The hinge component may comprise LLDPE, preferably having a density of 930 to 935 kg / m² as measured according to ISO 1183, method A. 3 density within the range, and

[0076] An MFI in the range of 2 to 8 g / 10 min, and an Mw in the range of 80,000 to 90,000 g / mol as measured according to ISO 1131-1:2011 at 190°C and under a load of 2.16 kg.

[0077] The hinge component may comprise LLDPE having a hardness of 925 to 935 kg / m² as measured according to ISO 1183, method A. 3range, preferably between 930 and 935 kg / m 3 density within the range, and

[0078] an MFI in the range of 2.0 to 15 g / 10 min, preferably 2 to 10 g / 10 min, more preferably 2 to 8 g / 10 min, as measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg, and

[0079] an Mw in the range of 50,000 to 100,000 g / mol, preferably 70,000 to 90,000 g / mol, more preferably 80,000 to 90,000 g / mol, and

[0080] Mw / Mn in the range of 4 to 5.

[0081] Polyethylene composition

[0082] The polyethylene compositions of the present disclosure can be made using any conventional blending method, such as, but not limited to, physical blending and in-situ blending by polymerization in a multiple reactor system, also known as reactor blending.

[0083] The polyethylene composition can be produced, for example, in at least two consecutive polymerization stages, for example by a bimodal or trimodal process. Gas phase, slurry phase, or solution phase reactor systems can be used. In this case, the polyethylene composition comprises bimodal or multimodal HDPE. Thus, bimodal or multimodal HDPE is a reactor blend of HDPE and LLDPE.

[0084] The polyethylene composition may be a reactor blend of HDPE and LLDPE made under different polymerisation conditions in two or more reactors in series.Thus, the polyethylene composition may be or may comprise bimodal HDPE.

[0085] The polyethylene composition may be or may comprise a blend of bimodal HDPE and LLDPE or unimodal HDPE and LLDPE.

[0086] Polyethylene compositions comprising HDPE and LLDPE can be applied as a dry blend. All components can be added directly to an injection molding machine using a weight metering system. All components can be added together as a dry blend. Mixing of the materials can be accomplished using industrial mixing equipment such as Nauta mixers and Henschel mixers.

[0087] The polyethylene composition comprising HDPE and LLDPE according to the present invention may be obtained by physical blending, by melt mixing or by solution blending.

[0088] All components of the polyethylene composition can be added together as a compound by melt blending. Compounding is typically carried out in a mixer (also known as a compounder), a single screw extruder or a twin screw extruder, where the polymers and additives are melt blended. Compounding techniques are well known in the art.

[0089] Polyethylene composition according to the present invention and HDPE and LDPE can contain additives, for example nucleator and clarifying agent, stabilizing agent, release agent, filler, plasticizer, antioxidant, lubricant, antistatic agent, scratch-resistant agent, high-performance filler, pigment and / or coloring agent, impact modifier, foaming agent, acid scavenger, recycling additive, coupling agent, biocide, anti-fog additive, slip additive, antiblocking additive and polymer processing aid.These additives are well known in the art.Technician will select the type and amount of additive so that they can not adversely affect the target properties of composition.

[0090] The hinge assembly may comprise a polyethylene composition having a hardness in the range of 940 to 950 kg / m 3 , preferably 943 to 948 kg / m 3 Density within the range.

[0091] The hinge component may comprise a polyethylene composition having an MFI in the range of 5 to 20 g / 10 min, preferably in the range of 8 to 15 g / 10 min, most preferably in the range of 8 to 12 g / 10 min, measured according to ISO 1133 at 190°C and under a load of 2.16 kg.

[0092] The hinge assembly may comprise a polyethylene composition having a hardness in the range of 940 to 950 kg / m 3 , preferably 943 to 948 kg / m 3 range, and an MFI measured according to ISO 1133 at 190° C. and under a load of 2.16 kg in the range of 5 to 20 g / 10 min, preferably in the range of 8 to 15 g / 10 min, most preferably in the range of 8 to 12 g / 10 min.

[0093] The hinge assembly may comprise a polyethylene composition having a hardness of 940 to 950 kg / m 3 The invention further comprises a density in the range of 5 to 20 g / 10 min, preferably in the range of 8 to 15 g / 10 min, most preferably in the range of 8 to 12 g / 10 min, measured according to ISO 1133 at 190° C. and under a load of 2.16 kg.

[0094] The hinge assembly may comprise a polyethylene composition having a hardness in the range of 940 to 950 kg / m 3 The density is in the range of 100 wt % and the MFI is in the range of 8 to 15 g / 10 min measured according to ISO 1133 at 190° C. and under a load of 2.16 kg.

[0095] The hinge component may comprise a polyethylene composition having an Mw in the range of 50,000 to 120,000 g / mol, preferably in the range of 50,000 to 90,000 g / mol, more preferably in the range of 60,000 to 80,000 g / mol.

[0096] The hinge component may comprise a polyethylene composition having an Mw / Mn in the range of 4 to 20, preferably in the range of 4 to 15, more preferably in the range of 4 to 10, and most preferably in the range of 4 to 7.

[0097] The hinge component may comprise a polyethylene composition having an Mw in the range of 50,000 to 120,000 g / mol, preferably in the range of 50,000 to 90,000 g / mol, more preferably in the range of 60,000 to 80,000 g / mol and an Mw / Mn in the range of 4 to 20, preferably in the range of 4 to 15, more preferably in the range of 4 to 10, and most preferably in the range of 4 to 7.

[0098] The hinge component may comprise a polyethylene composition having an Mw in the range of 50,000 to 120,000 g / mol and an Mw / Mn in the range of 4 to 7.

[0099] The hinge assembly may comprise a polyethylene composition having a hardness in the range of 940 to 950 kg / m 3 The present invention relates to a novel polymer having a density in the range of 0.05 to 0.10 g / 10 min, and an MFI in the range of 5 to 20 g / 10 min, preferably in the range of 8 to 15 g / 10 min, most preferably in the range of 8 to 12 g / 10 min, measured according to ISO 1133 at 190° C. and under a load of 2.16 kg, and an Mw in the range of 50,000 to 120,000 g / mol, and an Mw / Mn in the range of 4 to 7.

[0100] The hinge assembly may comprise a polyethylene composition having a hardness in the range of 940 to 950 kg / m 3The present invention relates to a polyol having a density in the range of 0.05 to 0.10 % by weight, and a MFI in the range of 5 to 20 g / 10 min measured according to ISO 1133 at 190° C. and under a load of 2.16 kg, and a Mw in the range of 50,000 to 120,000 g / mol, and a Mw / Mn in the range of 4 to 7.

[0101] The hinge component may comprise a polyethylene composition having a flexural modulus measured according to ISO 178 in the range of 900 to 1000 MPa, preferably in the range of 930 to 950 MPa.

[0102] The hinge component may comprise a polyethylene composition having an ESCRF50 value in the range of 5 to 20 hours, preferably in the range of 8 to 15 hours, measured according to ASTM D1693B, Condition B, 10% Igepal CO-630, 50°C.

[0103] The hinge component may comprise a polyethylene composition having a strain hardening modulus measured according to ISO 18488 in the range of 5 to 15 MPa, preferably in the range of 8 to 10 MPa.

[0104] The hinge component may comprise a polyethylene composition having an ESCR F50 value in the range of 5 to 20 hours, in the range of 8 to 15 hours, measured according to ASTM D1693B, Condition B, 10% Igepal CO-630, 50°C, and

[0105] Strain hardening modulus measured according to ISO 18488 in the range of 5 to 15 MPa, preferably in the range of 8 to 10 MPa.

[0106] The hinge component may comprise a polyethylene composition having an ESCR F50 value in the range of 5 to 20 hours, in the range of 8 to 15 hours, measured according to ASTM D1693B, Condition B, 10% Igepal CO-630, 50°C, and

[0107] A strain hardening modulus measured according to ISO 18488 in the range of 5 to 15 MPa, preferably in the range of 8 to 10 MPa and a flexural modulus measured according to ISO 178 in the range of 900 to 1000 MPa, preferably in the range of 930 to 950 MPa.

[0108] The hinge component may comprise a polyethylene composition having an ESCR F50 value in the range of 5 to 20 hours measured according to ASTM D1693B, Condition B, 10% Igepal CO-630, 50°C, and

[0109] The strain hardening modulus measured according to ISO 18488 is in the range of 5 to 15 MPa and the flexural modulus measured according to ISO 178 is in the range of 900 to 1000 MPa.

[0110] The hinge component may comprise a polyethylene composition having an ESCR F50 value in the range of 5 to 20 hours measured according to ASTM D1693B, Condition B, 10% Igepal CO-630, 50°C, and

[0111] The strain hardening modulus measured according to ISO 18488 is in the range of 5 to 15 MPa and the flexural modulus measured according to ISO 178 is in the range of 900 to 1000 MPa.

[0112] The hinge component may comprise a polyethylene composition having an ESCR F50 value in the range of 5 to 20 hours measured according to ASTM D1693B, condition B, 10% Igepal CO-630, 50°C, and a strain hardening modulus in the range of 5 to 15 MPa measured according to ISO 18488, and a flexural modulus in the range of 900 to 1000 MPa measured according to ISO 178, and a strength in the range of 940 to 950 kg / m2 measured according to ISO 1183. 3 , preferably 943 to 948 kg / m 3 range, and an MFI measured according to ISO 1133 at 190° C. and under a load of 2.16 kg in the range of 5 to 20 g / 10 min, preferably in the range of 8 to 15 g / 10 min, most preferably in the range of 8 to 12 g / 10 min.

[0113] The hinge component may comprise a polyethylene composition having an ESCR F50 value in the range of 5 to 20 hours measured according to ASTM D1693B, condition B, 10% Igepal CO-630, 50°C, and a strain hardening modulus in the range of 5 to 15 MPa measured according to ISO 18488, and a flexural modulus in the range of 900 to 1000 MPa measured according to ISO 178, and a strength in the range of 940 to 950 kg / m2 measured according to ISO 1183. 3 The invention further comprises a density in the range of 5 to 20 g / 10 min, and an MFI in the range of 5 to 20 g / 10 min, measured according to ISO 1133 at 190° C. and under a load of 2.16 kg.

[0114] The amount of HDPE and LLDPE in the polyethylene composition may be 90%, preferably 95%, more preferably 96%, most preferably 98%.

[0115] Preferably, HDPE and LLDPE are the only polymers in the polyethylene composition.

[0116] The amount of HDPE and LLDPE in the polyethylene composition may be 90%, preferably 95%, more preferably 96%, and most preferably 98%, and based on the total amount of HDPE and LLDPE, the amount of HDPE may be in the range of 40-60%, and the amount of LLDPE may be in the range of 40-60%, wherein the total amount of HDPE and LLDPE is 100% relative to the total weight of the polyethylene composition.

[0117] The amount of HDPE and LLDPE in the polyethylene composition may be 90%, preferably 95%, more preferably 96%, most preferably 98%, and based on the total amount of HDPE and LLDPE, the amount of HDPE may be in the range of 45-55% and the amount of LLDPE may be in the range of 45-55%, preferably wherein the total amount of HDPE and LLDPE is 100% relative to the total weight of the polyethylene composition.

[0118] Preferably, the polyethylene composition may contain one or more additives in an amount less than 2.0 wt %, preferably less than 1.0 wt %, relative to the total weight of the polyethylene composition. Non-limiting examples of additives include processing stabilizers, processing aids, and antioxidants. The additives may be calcium stearate, zinc stearate, Tinuvin 783 UV stabilizer, Irganox 1010 (sterically hindered primary phenol antioxidant stabilizer), or Irgafos 168 (hydrolysis-stable phosphite processing stabilizer). For purposes of the present invention, the amount of LLDPE and HDPE resins blended to prepare the polyethylene composition may include one or more such additives present in the resins.

[0119] hinge assembly

[0120] The polyethylene compositions described herein are used to form a hinge assembly.The hinge assembly may be part of a cap or closure, or it may be the cap or closure itself.

[0121] A hinged assembly is an assembly comprising at least two bodies connected to each other by a flexible hinge. The flexible hinge can be a continuous, partial, or segmented section that is typically thinner than the two or more bodies so as to serve as a fulcrum or pivot point around which the two or more bodies can bend. For example, the two or more bodies can bend from a formed position to a flexed position around the flexible hinge.

[0122] The hinge assembly can be a living hinge. A living hinge or integral hinge is a thin, flexible hinge (flexible bearing) made of the same material as the two rigid parts it connects. It is typically thinned or cut to allow the rigid parts to bend along the hinge line.

[0123] The hinge assembly can be made according to any known method, including, for example, injection molding and compression molding techniques well known to those skilled in the art. Thus, a hinge assembly comprising the polyethylene composition defined herein can be prepared using a method comprising at least one compression molding step and / or at least one injection molding step.

[0124] The hinge assembly can be manufactured using an injection molding process that produces a thin, flexible hinge (flexible bearing) as a single piece made of the same material as the two rigid pieces at one time, and if designed and constructed correctly, it can remain functional for the life of the component.

[0125] The hinge assembly may be formed by thermoforming.

[0126] The hinge assembly may be a lid or part of a lid, such as a screw cap or snap-top cap. The hinge assembly is preferably a hinged lid or closure for a bottle, container, can, pouch, or the like.

[0127] Caps and closures can be formed by continuous compression molding or by injection molding. Such closures include, for example, hinged caps, hinged screw caps, hinged snap caps, and hinged closures for bottles, containers, and the like.

[0128] Preferably, the closure or lid including the hinge assembly is made from the same material as the remainder of the closure or lid.

[0129] Most preferably, the hinged component is a hinged closure or lid.

[0130] The hinge assembly may be a flip-top hinge closure, such as used on plastic bottles or similar containers.

[0131] The hinged assembly may be a one-piece snap-on cap having a bottom member and a top member connected to each other by a hinge.

[0132] When the closure is a hinged closure, it may include a hinged assembly and typically consists of at least two bodies connected by a thinner section that acts as a hinge, allowing the at least two bodies to bend from an initially formed position. The thinner section may be continuous or web-like, wide or narrow.

[0133] The hinge assembly can be a hinged closure (for bottles, containers, etc.) and can be composed of two bodies joined to each other by at least one thin, flexible portion (e.g., the two bodies can be joined by a single bridge portion, or more than one bridge portion, or by a webbed portion, etc.). The first body can contain the dispensing hole and can be snapped or screwed onto the container to cover the container opening (e.g., the bottle opening), while the second body can act as a snap on a lid that can mate with the first body.

[0134] The hinge assembly may be, for example, a movable hinged cover or a part of a movable hinged cover, such as a movable hinged screw cover or a movable hinged snap cover.

[0135] The hinged lids and closures may be made according to any known method, including, for example, injection molding and compression molding techniques well known to those skilled in the art. Thus, the closures (or lids) comprising the polyethylene composition are prepared using a process comprising at least one continuous compression molding step and / or at least one injection molding step.

[0136] The hinged closures and lids of the present disclosure can be used to seal bottles, containers, and the like, for example, bottles that can contain potable water and other food products (including, but not limited to, non-pressurized liquids). The hinged closures and lids can also be used to seal bottles and containers that contain non-food products, such as shampoo and cleaning solutions.

[0137] The terms cap and closure are used interchangeably in this disclosure and both mean any suitably shaped shaped article for sealing, sealing, closing or covering a suitably shaped opening, a suitably shaped hole, an open neck structure, etc., for use in combination with a container, bottle, jar, etc.

[0138] The packaging article may include a hinge assembly.The packaging article may be a bottle, a pouch, a jar, a container or a tube, such as a cosmetic tube, a hose or a squeeze tube.

[0139] The hinge assembly may comprise a polyethylene composition, wherein the polyethylene composition comprises:

[0140] High density polyethylene (HDPE) having a mass fraction of 952 to 956 kg / m² as measured according to ISO 1183 3 density of 1,000 g / 10 min, a melt flow index of 8 to 40 g / 10 min measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 55,000 to 80,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4-8,

[0141] and linear low density polyethylene (LLDPE) having a mass of 925 to 935 kg / m 3a density of 500 g / mol, a melt flow index measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190° C. of 2.0 to 15 g / 10 min, a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 100,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0142] and wherein the polyethylene composition has a mass fraction measured according to ISO 1183 of 935 to 950 kg / m 3 and an overall melt flow index of 5 to 30 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C.,

[0143] and wherein the amount of HDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE,

[0144] and wherein the amount of LLDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0145] The hinge assembly may comprise a polyethylene composition, wherein the polyethylene composition comprises:

[0146] High density polyethylene (HDPE) having a mass fraction of 952 to 956 kg / m² as measured according to ISO 1183 3 density of 20 to 35 g / 10 min, a melt flow index measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190° C. of 20 to 35 g / 10 min, a weight average molecular weight Mw measured by size exclusion chromatography in the range of 55,000 to 65,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4-8,

[0147] and linear low density polyethylene (LLDPE) having a mass of 925 to 935 kg / m 3 a density of 500 g / min, a melt flow index measured according to ISO 1133 at a load of 2.16 kg and a temperature of 190° C. of 2.0 to 10 g / 10 min, a weight average molecular weight Mw measured by size exclusion chromatography in the range of 70,000 to 90,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0148] and wherein the polyethylene composition has a mass fraction measured according to ISO 1183 of 935 to 950 kg / m 3 and an overall melt flow index of 5 to 30 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C.,

[0149] and wherein the amount of HDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE,

[0150] and wherein the amount of LLDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0151] The hinge assembly may comprise a polyethylene composition, wherein the polyethylene composition comprises:

[0152] - High density polyethylene (HDPE) having a density of 950 to 960 kg / m 3 a density of 50,000 to 110,000 g / mol, a melt flow index of 5 to 40 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0-10.0, and

[0153] - linear low density polyethylene (LLDPE) having a density of 920 to 940 kg / m 3 a density of 1000 g / min, a melt flow index measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C. of 1 to 20 g / 10 min, a weight average molecular weight Mw measured by size exclusion chromatography in the range of 40,000 to 120,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0154] wherein the polyethylene composition has a hardness of 935 to 950 kg / m 3 and an overall melt flow index of 5 to 30 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C.,

[0155] wherein the amount of HDPE is in the range of 40-60 wt% of the total amount of HDPE and LLDPE,

[0156] and wherein the amount of LLDPE is in the range of 40-60 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0157] The hinge assembly may comprise a polyethylene composition, wherein the polyethylene composition comprises:

[0158] - High density polyethylene (HDPE) having a density of 950 to 960 kg / m 3 a density of 50,000 to 110,000 g / mol, a melt flow index of 5 to 40 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0-10.0, and

[0159] - linear low density polyethylene (LLDPE) having a density of 920 to 940 kg / m 3 a density of 1000 g / min, a melt flow index measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C. of 1 to 20 g / 10 min, a weight average molecular weight Mw measured by size exclusion chromatography in the range of 40,000 to 120,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0160] wherein the polyethylene composition has a hardness of 935 to 950 kg / m 3 and an overall melt flow index of 5 to 30 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C.,

[0161] wherein the amount of HDPE is in the range of 45-55 wt% of the total amount of HDPE and LLDPE,

[0162] and wherein the amount of LLDPE is in the range of 45-55 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0163] The hinge assembly may comprise a polyethylene composition, wherein the polyethylene composition comprises:

[0164] - High density polyethylene (HDPE) having a density of 950 to 960 kg / m 3 a density of 50,000 to 110,000 g / mol, a melt flow index of 5 to 40 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0-10.0, and

[0165] - linear low density polyethylene (LLDPE) having a density of 920 to 940 kg / m 3a density of 1000 g / min, a melt flow index measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C. of 1 to 20 g / 10 min, a weight average molecular weight Mw measured by size exclusion chromatography in the range of 40,000 to 120,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0166] wherein the polyethylene composition has a hardness of 940 to 950 kg / m 3 and an overall melt flow index of 5 to 20 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C.,

[0167] wherein the amount of HDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE,

[0168] and wherein the amount of LLDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0169] The hinge assembly may comprise a polyethylene composition, wherein the polyethylene composition comprises:

[0170] - High density polyethylene (HDPE) having a density of 950 to 960 kg / m 3 a density of 50,000 to 110,000 g / mol, a melt flow index of 5 to 40 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0-10.0, and

[0171] - linear low density polyethylene (LLDPE) having a density of 920 to 940 kg / m 3 a density of 1000 g / min, a melt flow index measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C. of 1 to 20 g / 10 min, a weight average molecular weight Mw measured by size exclusion chromatography in the range of 40,000 to 120,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0172] wherein the polyethylene composition has a hardness of 935 to 950 kg / m 3 and an overall melt flow index of 5 to 30 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., and

[0173] an Mw in the range of 50,000 to 120,000 g / mol, and

[0174] Mw / Mn in the range of 4 to 20, preferably in the range of 4 to 15, more preferably in the range of 4 to 10, most preferably in the range of 4 to 7,

[0175] wherein the amount of HDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE,

[0176] and wherein the amount of LLDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0177] The hinge assembly may comprise a polyethylene composition, wherein the polyethylene composition comprises:

[0178] - High density polyethylene (HDPE) having a density of 950 to 960 kg / m 3 a density of 50,000 to 110,000 g / mol, a melt flow index of 5 to 40 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0-10.0, and

[0179] - linear low density polyethylene (LLDPE) having a density of 920 to 940 kg / m 3 a density of 1000 g / min, a melt flow index measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C. of 1 to 20 g / 10 min, a weight average molecular weight Mw measured by size exclusion chromatography in the range of 40,000 to 120,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0180] wherein the polyethylene composition has a hardness of 935 to 950 kg / m 3 and an overall melt flow index of 5 to 30 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., and

[0181] an Mw in the range of 50,000 to 120,000 g / mol, preferably in the range of 50,000 to 90,000 g / mol, more preferably in the range of 60,000 to 80,000 g / mol, and

[0182] Mw / Mn in the range of 4 to 15, more preferably in the range of 4 to 10,

[0183] wherein the amount of HDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE,

[0184] and wherein the amount of LLDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0185] The hinge assembly may comprise a polyethylene composition, wherein the polyethylene composition comprises:

[0186] - High density polyethylene (HDPE) having a density of 950 to 960 kg / m 3 a density of 50,000 to 110,000 g / mol, a melt flow index of 5 to 40 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0-10.0, and

[0187] - linear low density polyethylene (LLDPE) having a density of 920 to 940 kg / m 3 a density of 1000 g / min, a melt flow index measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C. of 1 to 20 g / 10 min, a weight average molecular weight Mw measured by size exclusion chromatography in the range of 40,000 to 120,000 g / mol and a molecular weight distribution Mw / Mn in the range of 3 to 7;

[0188] wherein the polyethylene composition has a hardness of 935 to 950 kg / m 3 and an overall melt flow index of 5 to 30 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C.,

[0189] - an ESCR F50 value in the range of 5 to 20 hours, preferably in the range of 8 to 15 hours, measured according to ASTM D1693B, condition B, 10% Igepal CO-630, 50°C, and

[0190] - a strain hardening modulus in the range of 5 to 15 MPa, preferably in the range of 8 to 10 MPa, measured according to ISO 18488, and

[0191] wherein the amount of HDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE,

[0192] and wherein the amount of LLDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

[0193] The invention will now be illustrated by the following non-limiting examples. Example

[0194] Use the following test method

[0195] -Melt flow index, MFI

[0196] For HDPE, LLDPE and the inventive examples, the MFI was measured according to ISO 1133 at 190°C and a load of 2.16 kg.

[0197] For PP, MFI is measured according to ISO 1133 at 230°C and a load of 2.16 kg.

[0198] -density

[0199] The density was measured according to ISO 1183. The test specimens were prepared according to ISO 17855-2, with a compression molding temperature of 180° C. and a compression molding cooling rate of 15° C. / min.

[0200] -ESCR F50

[0201] F50 was measured according to ASTM D1693B, Condition B, 10% Igepal CO-630, 50°C.

[0202] - Specimens: Compression-molded specimens were prepared according to ISO 17855-2, with a specimen thickness of 1.84-1.97 mm and a notch depth of 0.3-0.4 mm.

[0203] - F50 determination: Ten specimens are used, and the 50% failure point (F50) is determined by the graphical method in Appendix A1 of D1693.

[0204] -Strain hardening test

[0205] The strain hardening modulus was measured according to ISO 18488.

[0206] -Tensile test, tensile modulus

[0207] For the HDPE samples and Inventive Example 1, the following conditions applied

[0208] - Test specimens were prepared by compression molding according to ISO 1872-2;

[0209] - Test specimens according to ISO 527-2 Type 1BA, thickness 2 mm

[0210] -Test speed: 50mm / min

[0211] For PP (QR673K) samples, the following conditions were applied

[0212] -Test specimens made by injection molding

[0213] - Test specimens according to ISO 527-2 Type 1A, 4 mm thickness

[0214] -Test speed: 50mm / min

[0215] -Flexural modulus

[0216] The test specimens were made by compression molding according to ISO 17855-2;

[0217] Sample size: 80 x 10 x 4 mm

[0218] Flexural test according to ISO178

[0219] Test speed: 2mm / min

[0220] -Size Exclusion Chromatography, SEC

[0221] The molecular structure parameters were calculated by SEC general type based on IR5.

[0222] Methods: IAV Molecular Characterization, Code: SEC-HT-2 (General Computing)

[0223] Chromatography: Polymer Laboratories PL-GPC220 (System ID: C7).

[0224] Detection: Polymer Laboratories PL BV-400 viscometer; refractive index detector.

[0225] Column set: three Polymer Laboratories 13 μm PLgel Olexis, 300 x 7.5 mm.

[0226] PE molar mass calibration: performed using linear PE standards.

[0227] PP molar mass calibration: Linear PE standards were used to calibrate the system. The PP molar mass calibration was obtained by converting PE to PP using the Mark-Houwink constants for PE and PP.

[0228] Examples and Results

[0229] HDPE 1-4 are commercially available HDPE resins intended for use as screw caps. PP is a commercially available polypropylene random copolymer resin intended for use in hinged caps. The HDPE and LLDPE polymer resins include one or more additives, such as processing aids, UV stabilizers, and antioxidants, and are factored into the weight of the blended polymer resins used in the experiments. The total amount of additives present in the polyethylene composition is approximately 0.7-0.8 wt%.

[0230] Inventive Example 1 is a blend of 50 wt% HDPE (SABIC's HDPE resin CC3054) and 50 wt% LLDPE (SABIC's HDPE resin R50035EE). Inventive Example 1 was prepared by compounding in an extruder. This was accomplished using a KraussMaffei Berstorff GmbH ZE25Ax48D twin-screw extruder with a screw diameter of 25 mm and an L / D ratio of 48:1. Compounding was performed at 230°C using a screw speed of 350 rpm. Table 1 provides an overview of the materials used and their MFI and density.

[0231] Table 1

[0232]

[0233] Table 2 gives an overview of the SEC data.

[0234] Table 2

[0235]

[0236] Table 3 gives an overview of the mechanical properties

[0237] Table 3

[0238]

[0239] -Processability measured by spiral die

[0240] Table 4. Material machinability evaluation using spiral die

[0241]

[0242] Table 4 shows the processability of the materials used for injection molding. First, injection molding was performed using a spiral mold. All materials were injected at a melt temperature of 220°C and an injection speed of 56.6 mm / s until an injection pressure of 1200 bar was reached. Flow lengths were measured at various thicknesses and are listed in Table 4. A longer flow length indicates better processability during injection molding. The processability of 50% CC3054 (HDPE) + 50% R50035EE (LLDPE) was comparable to or slightly better than that of M1053.

[0243] Measuring processability during injection molding of hinged lids

[0244] A Husky H120-RS35 / 28 injection molding machine with a four-cavity hinged lid mold was used. The machine has a clamping force of 120 tons and is equipped with a standard three-zone screw with a diameter of 28 mm and an L / D of 25.1. The hinged lid tool features a typical butterfly hinge design and is suitable for both PP and HDPE materials. An in-mold closing unit is also integrated into the tool, enabling the lid to be closed in the tool before being ejected.

[0245] Table 5. Injection molding parameters of hinge components

[0246]

[0247] Table 6. Material processability evaluation during lid injection molding

[0248]

[0249] The maximum injection pressure measured during lid injection molding also indicates the processability of the material. The processability of 50% CC3054 (HDPE) + 50% R50035EE (LLDPE) is comparable or slightly better than that of M1053, which is consistent with the results from the spiral die results.

[0250] Fatigue performance of hinged components

[0251] The fatigue performance of hinged lids was evaluated by bending the hinge using a bend tester. The base and flip-top lids were clamped separately by fixtures. The base was bent along the hinge, while the flip-top lid was fixed and did not move. The base of the lid was bent from 180° (open) to a 30° angle, nearly closed. Each lid was bent until hinge failure was observed or 5,000 bends were achieved. The results are listed in Table 7.

[0252] Table 7. Hinge fatigue bending test results

[0253]

[0254] Inventive Example 1 showed good hinge fatigue performance (>5000 bending cycles).

[0255] ESCR with hinged cover

[0256] The ESCR performance of the hinged cover was evaluated in the following manner:

[0257] ESCR with hinged cover

[0258] The ESCR performance of the hinged cover was evaluated in the following manner:

[0259] 1) Emerging the closed hinged lid in a 10% aqueous solution of Igepal; and conditioning the closed hinged lid in the 10% aqueous solution of Igepal in an oven at 40°C for 3 days.

[0260] 2) The performance of the hinged lids after conditioning was evaluated by removing the hinged lids from the Igepal solution and manually opening and closing the lids until failure or a maximum of 120 cycles. Five samples of each material were tested.

[0261] Table 5 shows the ESCR test results, reporting the average number of bending cycles until hinge failure or up to 120 cycles.

[0262] Table 8. Hinge ESCR test results

[0263]

[0264] Inventive Example 1 showed good hinge performance (>120 open / close cycles) after ESCR conditioning.

[0265] The test results show that the hinge assembly made in Example 1 of the present invention provides balanced properties of injection molding processability and hinge performance (hinge fatigue bending and ESCR).

Claims

1. A hinge assembly comprising a polyethylene composition comprising: - High density polyethylene (HDPE) having a density of 950 to 960 kg / m 3 a density in the range of 5 to 40 g / 10 min, a melt flow index in the range of 5 to 40 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw measured by size exclusion chromatography in the range of 50,000 to 110,000 g / mol, a molecular weight distribution Mw / Mn in the range of 4.0 to 10.0; and - linear low density polyethylene (LLDPE) having a mass fraction of 920 to 940 kg / m², measured according to ISO 1183. 3 a density in the range of 100 to 200 g / 10 min, a melt flow index in the range of 1 to 20 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C., a weight average molecular weight Mw in the range of 40,000 to 120,000 g / mol as measured by size exclusion chromatography, and a molecular weight distribution Mw / Mn in the range of 3 to 7; in, The polyethylene composition has a density of 935 to 950 kg / m 3 an overall density in the range of 5 to 30 g / 10 min and an overall melt flow index in the range of 5 to 30 g / 10 min measured according to ISO 1133 under a load of 2.16 kg and a temperature of 190° C.; wherein the amount of HDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE, and The amount of LLDPE is in the range of 30-70 wt% of the total amount of HDPE and LLDPE; preferably the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

2. The hinge assembly according to any one of the preceding claims, wherein the LLDPE has - 925 to 935 kg / m² measured according to ISO 1183, method A 3 range, preferably between 930 and 935 kg / m 3 Density within the range, and / or - an MFI in the range of 2.0 to 15 g / 10 min, preferably 2 to 10 g / 10 min, more preferably 2 to 8 g / 10 min, measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg, and / or - an Mw in the range of 50,000 to 100,000 g / mol, preferably 70,000 to 90,000 g / mol, more preferably 80,000 to 90,000 g / mol; and / or - Mw / Mn in the range of 4 to 5.

3. The hinge assembly according to any one of the preceding claims, wherein the HDPE has - 952 to 956 kg / m² measured according to ISO 1183, method A 3 Density within the range, and / or - an MFI in the range of 8 to 40 g / 10 min, preferably 20 to 35 g / 10 min, more preferably 28 to 35 g / 10 min, measured according to ISO 1131-1:2011 at 190° C. and under a load of 2.16 kg, and / or - an Mw in the range of 55,000 to 80,000 g / mol, preferably in the range of 55,000 to 70,000 g / mol, more preferably in the range of 55,000 to 65,000 g / mol, and / or - Mw / Mn in the range of 4 to 8, preferably in the range of 4-7, more preferably in the range of 5-6.

4. Hinge assembly according to any one of the preceding claims, wherein the amount of HDPE is in the range of 40-60 wt%, preferably in the range of 45-55 wt%, of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt% of the polyethylene composition.

5. Hinge assembly according to any one of the preceding claims, wherein the amount of LLDPE is in the range of 40-60 wt%, preferably in the range of 45-55 wt% of the total amount of HDPE and LLDPE, and preferably wherein the total amount of HDPE and LLDPE is 100 wt%.

6. The hinge assembly according to any one of the preceding claims, wherein the polyethylene composition has - 940 to 950 kg / m2 measured according to ISO 1183 3 , preferably 943 to 948 kg / m 3 density within the range; and / or - an MFI in the range of 5 to 20 g / 10 min, preferably in the range of 8 to 15 g / 10 min, most preferably in the range of 8 to 12 g / 10 min, measured according to ISO 1131 at 190°C and under a load of 2.16 kg.

7. The hinge assembly according to any one of the preceding claims, wherein the polyethylene composition has an Mw in the range of 50,000 to 120,000 g / mol, preferably in the range of 50,000 to 90,000 g / mol, more preferably in the range of 60,000 to 80,000 g / mol, and / or Mw / Mn in the range of 4 to 20, preferably in the range of 4 to 15, more preferably in the range of 4 to 10, most preferably in the range of 4 to 7.

8. Hinge assembly according to any one of the preceding claims, wherein the polyethylene composition has a flexural modulus measured according to ISO 178 in the range of 900 to 1000 MPa, preferably in the range of 930 to 950 MPa.

9. The hinge assembly according to any one of the preceding claims, wherein the polyethylene composition has - an ESCR F50 value in the range of 5 to 20 hours, preferably in the range of 8 to 15 hours, measured according to ASTM D1693B, condition B, 10% Igepal CO-630, 50°C, and / or - a strain hardening modulus in the range of 5 to 15 MPa, preferably in the range of 8 to 10 MPa, measured according to ISO 18488.

10. Hinge assembly according to any one of the preceding claims, wherein the HDPE is bimodal, multimodal or unimodal HDPE.

11. Hinge assembly according to any one of claims 1 to 9, wherein the polyethylene composition is a bimodal or multimodal HDPE comprising HDPE and LLDPE.

12. A hinge assembly according to any one of the preceding claims, wherein the hinge assembly is a living hinge.

13. A hinge assembly according to any preceding claim, wherein the hinge assembly is a cap or part of a cap, such as a screw cap or a snap cap.

14. A packaging article comprising a hinge assembly according to any one of the preceding claims.

15. The packaging article of claim 14, wherein the packaging article is a bottle, a pouch, a jar, a container or a tube, such as a cosmetic tube, a hose or a squeeze tube.

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