Laminate comprising a composition based on a polyamide homopolymer or copolymer and a thermoplastic elastomer

Abstract

The invention relates to a laminate comprising at least one core layer arranged between and in contact with an adjacent first layer and an adjacent second layer. The core layer comprises a polymer composition, the polymer matrix of which comprises from 40% to 60% by mass of at least one polymer A comprising repeating units A1 interconnected by an amide bond, and from 40% to 60% by mass of at least one thermoplastic elastomer B comprising at least one flexible polyether-type block and at least one rigid polyamide-type block, the rigid block comprising repeating units B1 interconnected by an amide bond, which units B1 are different from the repeating units A1. The adjacent layers respectively comprise polymers C and D having a polyamide block that comprises repeating units C1 that are identical to the repeating units A1 and a polyamide block that comprises repeating units D1 that are identical to the repeating units B1.

Description

[0001] LAMINATE COMPRISING A COMPOSITION BASED ON A POLYAMIDE HOMOPOLYMER OR COPOLYMER AND A THERMOPLASTIC ELASTOMER

[0002] The field of the present invention is that of laminates comprising an adhesion composition enabling the assembly of at least two layers, in particular layers intended for use in a non-pneumatic bandage.

[0003] A non-pneumatic tire typically comprises a base (mounting band), designed, for example, for mounting on a rigid rim; a crown reinforcement (or shear band), which connects to a tread; and a deformable structure, such as spokes, ribs, or dimples, positioned between the base and the crown. Non-pneumatic tires are described, for example, in documents WO 03 / 018332A1 and FR2898077A1.

[0004] In the manufacture of a non-pneumatic tire, for example, the various constituent elements of the tire, in particular the tread, the crown reinforcement, the spokes (or rib or cells) and the mounting strip, are assembled together.

[0005] The assembly of the constituent elements of a non-pneumatic bandage can be carried out by overinjection, by gluing, by riveting or by welding.

[0006] Although riveting allows for the mechanical assembly of the component parts, it has the disadvantage of being difficult to implement industrially, and also increases the weight of the non-pneumatic tire, which is detrimental to the fuel consumption of vehicles equipped with such tires. Furthermore, riveting has the disadvantage of concentrating mechanical stress at the rivets, which can potentially initiate cracking at these points.

[0007] The same applies to welding, which has the disadvantage of being difficult to implement industrially.

[0008] Thus, assemblies made by overinjection or by gluing remain preferred.

[0009] Furthermore, each component of a non-pneumatic tire performs a specific function. The tread, for example, which is designed to make contact with the ground as the tire rolls, must possess very specific properties, including good grip on both dry and wet surfaces, low rolling resistance, and good wear resistance. The shear strip, on the other hand, must be deformable and allow for even pressure distribution across the tire. The spokes are responsible for supporting the vehicle's load. As for the mounting strip, it must ensure a secure attachment of the wheel to the hub and allow for the transfer of driving forces to the vehicle or braking forces to the vehicle. Thus, each of these components comprises very specific materials, generally different from one another, and meeting the aforementioned requirements.

[0010] These differences in composition can lead to a decrease in the adhesion properties between the different constituent elements of the bandage.

[0011] Therefore, it remains important to have laminates with a composition that has good adhesion properties to the adjacent layers to be assembled, especially when the compositions of the adjacent layers are of a different nature.

[0012] Thus, a first object of the invention is a laminate comprising at least:

[0013] - a central layer of polymeric composition whose polymer matrix comprises: o 40% to 60% by mass of at least one polymer A, which polymer A is a homopolymer or copolymer comprising a polyamide block comprising repeat units Al linked together by an amide bond, o 40% to 60% by mass of at least one thermoplastic elastomer B comprising at least one flexible polyether block and at least one rigid polyamide block, the rigid block comprising repeat units B1 linked together by an amide bond, which B1 units are different from the repeat units Al,

[0014] - a first adjacent layer of polymeric composition whose polymer matrix comprises more than 50% by mass of at least one polymer C, which polymer C is a homopolymer or copolymer comprising a polyamide block which includes repeat units Cl linked together by an amide bond, which Cl units are identical to the repeat units Al,

[0015] - a second adjacent layer of polymeric composition whose polymer matrix comprises more than 50% by mass of at least one polymer D, which polymer D is a homopolymer or copolymer comprising a polyamide block comprising DI repeat units linked together by an amide bond, which DI units are identical to the BL repeat units, the central layer being disposed between and in contact with the first adjacent layer and the second adjacent layer. The present invention also relates to an article, in particular a non-pneumatic tire, comprising a laminate according to the invention.

[0016] I- DEFINITIONS

[0017] The expression "composition based on" means a composition comprising the mixture and / or the in situ reaction product of the different constituents used, some of these constituents being able to react and / or being intended to react with each other, at least partially, during the different phases of manufacturing the composition; the composition can thus be in a totally or partially crosslinked state or in a non-crosslinked state.

[0018] Unless otherwise stated, the rates of units resulting from the insertion of a monomer into a copolymer are expressed as a mole percentage relative to the total monomer units of the copolymer.

[0019] In this document, unless expressly stated otherwise, all percentages (%) shown are percentages (%) by mass.

[0020] The term "polymer matrix" refers to all the thermoplastic polymers and thermoplastic elastomers present in a given composition. Various additives, such as plasticizers (liquids or resins) and fillers, which may be present in a given composition, are not included and do not form part of the polymer matrix of that composition.

[0021] On the other hand, any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​from greater than a to less than b (that is, excluding the bounds a and b), while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​from a to b (that is, including the strict bounds a and b). In this context, when an interval of values ​​is designated by the expression "from a to b," it also and preferentially designates the interval represented by the expression "between a and b."

[0022] The compounds mentioned in the description can be of fossil origin or bio-based. In the latter case, they may be partially or entirely derived from biomass or obtained from renewable raw materials derived from biomass. Similarly, the compounds mentioned may also come from the recycling of previously used materials; that is, they may be partially or entirely produced through a recycling process, or obtained from raw materials themselves derived from a recycling process. This includes, in particular, polymers, plasticizers, fillers, etc.

[0023] Unless otherwise stated, all glass transition temperature “Tg” or melting temperature “Tf” values ​​described herein are measured in a known manner by DSC (Differential Scanning Calorimetry) according to ASTM D3418 (1999).

[0024] II- DESCRIPTION OF THE INVENTION

[0025] As previously stated, the present invention relates to a laminate comprising at least:

[0026] - a central layer of polymeric composition whose polymer matrix comprises: o 40% to 60% by mass of at least one polymer A, which polymer A is a homopolymer or copolymer comprising a polyamide block comprising repeat units Al linked together by an amide bond, o 40% to 60% by mass of at least one thermoplastic elastomer B comprising at least one flexible polyether block and at least one rigid polyamide block, the rigid block comprising repeat units B1 linked together by an amide bond, which B1 units are different from the repeat units Al,

[0027] - a first adjacent layer of polymeric composition whose polymer matrix comprises more than 50% by mass of at least one polymer C, which polymer C is a homopolymer or copolymer comprising a polyamide block which includes repeat units Cl linked together by an amide bond, which Cl units are identical to the repeat units Al,

[0028] - a second adjacent layer of polymeric composition whose polymer matrix comprises more than 50% by mass of at least one polymer D, which polymer D is a homopolymer or copolymer comprising a polyamide block which includes DI repeat units linked together by an amide bond, which DI units are identical to the Bl repeat units, the central layer being disposed between and in contact with the first adjacent layer and the second adjacent layer.

[0029] The mass percentages of at least one polymer A, at least one thermoplastic elastomer B, at least one polymer C and at least one polymer D are of course, as indicated, mass percentages relative to the mass of their respective elastomer matrix.

[0030] The monomer unit (or repeating unit) of a polymer is, in a manner known to those skilled in the art, the smallest constituent unit whose repetition describes the polymer. For example, the monomer unit of PA6 is -[(CH2)5-CONH]- and that of PAI 1 is -[(CH2)IO-CO-NH]-.

[0031] A person skilled in the art understands the expression "repeating units linked together by an amide bond" with the help of this general knowledge (Odian (2004), "Principles of Polymerization", 4 e edition, page 3, Table 1-1).

[0032] In this document, "at least one polymer A" refers to "at least one polymer A, which polymer A is a homopolymer or copolymer comprising a polyamide block comprising repeating Al units linked together by an amide bond".

[0033] The at least one polymer A can thus be a homopolymer consisting of a polyamide block which includes repeat units Al linked together by an amide bond or a mixture of homopolymer consisting of a polyamide block which includes repeat units Al linked together by an amide bond, for example of different molecular masses.

[0034] At least one polymer A may also be a copolymer comprising a polyamide block containing repeat units Al linked together by an amide bond; that is, a polymer comprising repeat units Al linked together by an amide bond and repeat units other than Al without any particular limitation. It is possible that the repeat units other than Al of copolymer A may be identical or different from the repeat units B1 of at least one thermoplastic elastomer B. Preferably, the repeat units other than Al of copolymer A are different from the repeat units B1 of at least one thermoplastic elastomer B.

[0035] The at least one polymer A may also be a mixture of at least one homopolymer comprising a polyamide block which includes repeat units Al linked together by an amide bond and at least one copolymer comprising a polyamide block which includes repeat units Al linked together by an amide bond.

[0036] When polymer A is a copolymer comprising a polyamide block containing Al repeating units linked by an amide bond, the Al units advantageously represent 20% to 80% by mass of the copolymer, preferably 30% to 70% by mass. When polymer A is a copolymer comprising a polyamide block containing Al repeating units linked by an amide bond, it may, for example, be a copolymer comprising at least one PA6 block and at least one block of a polymer other than PA6, for example, but not limited to, a PA66, PA10, or PA12 block.

[0037] Most advantageously, at least one polymer A is a homopolymer or a mixture of homopolymers consisting of a polyamide block comprising repeating Al units linked together by an amide bond.

[0038] Advantageously, the number-average molecular weight (Mn) of the at least polymer A is in the range of 5,000 to 200,000 g / mol, preferably 7,000 to 100,000 g / mol, preferably 10,000 to 30,000 g / mol.

[0039] The number-average molecular weight (Mn) of thermoplastic polymers is determined using a known method, by size-exclusion chromatography (SEC). For example, in the case of polyamides, the sample is first solubilized in 2-hexafluoropropanol with the addition of 0.02 M sodium trifluoroacetate at a concentration of approximately 2 g / L. The equipment used is a WATERS Alliance chromatographic system. The elution solvent is 2-hexafluoropropanol with the addition of 0.02 M sodium trifluoroacetate, the flow rate is 0.5 mL / min, and the system temperature is 35°C. A set of three Phenomenex columns in series, commercially known as "Phenogel" (10 µm x 10⁻³), is used. 5 ", "lOpm lO 4" And

[0040] "10pm 10 3 The injected volume of the polymer sample solution is 100 µL. The detector is a WATERS 2410 differential refractometer, and its associated chromatographic data processing software is the WATERS MILLENIUM system. The calculated average molar masses are relative to a calibration curve established with PMMA standards. The conditions are adaptable by a person skilled in the art.

[0041] The repeating units Al of the polyamide block of polymer A can be of any type as long as they are different from the repeating units B1 of the rigid block of thermoplastic elastomer B. Thus, the polyamide block of polymer A can be a block selected from the group comprising, preferably, PA6, PA12, PAU, PA4.6, PA6.6, PA6.9, PA6.10, PA6.12, PA10.10, PA10.12, PA6.6 / 6, PA6 / 6.6 / 6 and PA6 / 6.6 / 10. Preferably, the polyamide block of polymer A is a block selected from the group comprising PA6, PA12, PAU, PA4.6, PA6.6, PA6.9, PA6.10, PA6.12, PA10.10, PA10.12. Preferably, the polyamide block of polymer A is a block selected from the group consisting of PA6, PA12, and PAU. Advantageously, polymer A is a thermoplastic polymer. In other words, it is not a thermoplastic elastomer.

[0042] Examples of commercially available homopolymer A polymer include "Akulon F223-D" from Envalior NV or PA6 in "UDea™ Akulon® K20HG60" from DSM, which is composed of PA6 and reinforced with 60% by mass of glass fiber.

[0043] Examples of commercially available copolymer A polymers include "Ultramid® C3" from BASF, which is a copolymer of PA6 and PA66; "Grilon® TS V0" from EMS-GRIVORY, which is a PA6 / PA66 copolymer with a flame retardant; "Vestamid® L1930" from Evonik, which is a copolymer of PA6 and PA12; and "Rilsan® PA6-10" from Arkema, which is a copolymer of PA6 and PAIO.

[0044] In this document, "at least one thermoplastic elastomer B" refers to "at least one thermoplastic elastomer B comprising at least one flexible polyether-type block and at least one rigid polyamide-type block, the rigid block comprising repeat units B1 linked together by an amide bond, which B1 units are different from the repeat units Al".

[0045] In general, thermoplastic elastomers (abbreviated "TPE") have a structure intermediate between thermoplastic polymers and elastomers. They are block copolymers, made up of rigid, thermoplastic blocks linked by flexible, elastomer blocks.

[0046] In what follows, references to a polyether-type block preferably refer to an elastomeric block composed of more than 50% by mass (preferably more than 80%, preferably more than 90%, preferably 100%) of a polymer resulting from the polymerization of an ether-type monomer. References to a polyamide-type block preferably refer to a block composed of more than 50% by mass (preferably more than 80%, preferably more than 90%, preferably 100%) of a polymer resulting from the polymerization of a polyamide monomer.

[0047] Preferably, the melting temperature (Tf) of thermoplastic elastomer B is in the range of 120°C to 200°C. Advantageously, the Tf of the thermoplastic elastomer is in the range of 140°C to 195°C, preferably from 160°C to 190°C. It can be noted that the Tf of the thermoplastic elastomer corresponds to the Tf of the thermoplastic blocks of the thermoplastic elastomer.

[0048] The number-average molecular weight (Mn) of the thermoplastic elastomer B is preferably between 30,000 and 500,000 g / mol, and more preferably between 45,000 and 350,000 g / mol. Even more preferably, the Mn of the thermoplastic elastomer is in the range of 50,000 to 300,000 g / mol, and better still, from 60,000 to 150,000 g / mol.

[0049] The Mn of thermoplastic elastomers is determined in a known manner, by size exclusion chromatography (SEC), in the same way as described above for thermoplastic polymers.

[0050] Thermoplastic elastomer B can be in a linear form. For example, thermoplastic elastomer can be a diblock copolymer: a polyether block / a polyamide block. Thermoplastic elastomer can also be a triblock copolymer: a polyether block / a polyamide block / a polyether block, that is, a central elastomer block and two terminal thermoplastic blocks, one at each end of the elastomer block. Additionally, multiblock thermoplastic elastomer can be a linear sequence of polyether blocks and polyamide blocks.

[0051] The thermoplastic elastomer B useful for the purposes of the invention may also be in a star shape with at least three points. For example, the thermoplastic elastomer B may then consist of a star-shaped polyether block with at least three points and a thermoplastic polyamide block located at the end of each of the points of the polyether block. The number of points of the central elastomer may vary, for example, from 3 to 12, and preferably from 3 to 6.

[0052] Thermoplastic elastomer B can also be in branched or dendrimer form. In this case, thermoplastic elastomer B can consist of a branched or dendrimer polyether block and a polyamide block located at the ends of the branches of the dendrimer polyether block.

[0053] Preferably, the thermoplastic elastomer B is in linear and multiblock form. The elastomer blocks of the thermoplastic elastomer B, for the purposes of the invention, can be any polyether-type elastomers known to those skilled in the art.

[0054] These polyether type elastomer blocks preferably have a Tg below -20°C, preferably with a Tg in a range from -110°C to -35°C, preferably from -90°C to -40°C.

[0055] The polyether-type elastomer blocks of thermoplastic elastomer B may be composed of monomers selected from cyclic alcohols or ethers, preferably aliphatic cyclic alcohols or ethers, such as, for example, ethanol or tetrahydrofuran. Preferably, at least one flexible polyether-type block of thermoplastic elastomer B is selected from the group consisting of polytetramethylene glycols (PTMG), polyethylene glycols (PEG), polypropylene ether glycols (PPG), polyhexamethylene ether glycols, polytrimethylene ether glycols (PO3G), poly(3-alkyltetrahydrofurans), and mixtures thereof. Most preferably, the polyether elastomer block(s) of the thermoplastic elastomer are selected from the group consisting of polytetramethylene glycols (PTMG), polyethylene glycols (PEG), and mixtures thereof.

[0056] Advantageously, the polyether type elastomer blocks of the thermoplastic elastomer have, in total, a Mn ranging from 25,000 g / mol to 350,000 g / mol, preferably from 35,000 g / mol to 250,000 g / mol so as to give the thermoplastic elastomer good elastomeric properties and sufficient mechanical strength compatible with use in the article according to the invention.

[0057] The thermoplastic blocks (rigid polyamide-type blocks) of thermoplastic elastomer B can be homopolymer or copolymer blocks. In other words, the rigid polyamide-type blocks of thermoplastic elastomer B can comprise polyamide sequences (or blocks) whose repeating units may or may not all be identical.

[0058] Preferably, at least one rigid polyamide block of at least one thermoplastic elastomer B is a homopolymer or copolymer, preferably a homopolymer, comprising 30% to 80% by mass, preferably 50% to 70% by mass, of repeat units B1 linked together by an amide bond, which B1 units are different from the AL repeat units. The B1 repeat units of the rigid block of the thermoplastic elastomer B can be of any type as long as they are different from the AL repeat units of the polyamide block of polymer A. Thus, the rigid polyamide block of the thermoplastic elastomer B can be a block selected from the group comprising, preferably consisting of, PA6, PA12, PAU, PA4.6, PA6.6, PA6.9, PA6.10, PA6.12, PAIO.10, PAIO.12, PA6.6 / 6, PA6 / 6.6 / 6 and PA6 / 6.6 / 10. Preferably, the rigid polyamide block of thermoplastic elastomer B is a block selected from the group consisting of PA6, PA12, PAU, PA4.6, PA6.6, PA6.9, PA6.10, PA6.12, PAIO.10, PAIO.12. Preferably still, the rigid polyamide block of thermoplastic elastomer B is a block selected from the group consisting of PA6, PA12 and PAU.

[0059] The mass fraction of the flexible polyether type block of the thermoplastic elastomer B may be in the range of 1% to 70%, preferably 10% to 65%, preferably 20% to 60%, and the mass fraction of the rigid polyamide type block of the thermoplastic elastomer B may be in the range of 30% to 99%, preferably 35% to 90%, preferably 40% to 80%.

[0060] Specific thermoplastic elastomers in which the thermoplastic blocks are polyamides are usually denoted TPE-A or TPA (thermoplastic copolyamide) or PEBA (block amide copolyether), and they are particularly preferred for the purposes of the invention. Advantageously, thermoplastic elastomer B is chosen from the group consisting of polyether-polyamide block copolymers (PEBA), said polyamide blocks preferably being a homopolymer or copolymer, preferably a homopolymer, of PAU.

[0061] According to the invention, the thermoplastic blocks of the thermoplastic elastomer B have, in total, an average number molecular mass ("Mn") ranging from 5,000 g / mol to 150,000 g / mol, preferably from 10,000 to 100,000 g / mol, so as to give the thermoplastic elastomer good elastomeric properties and sufficient mechanical strength compatible with use in the article according to the invention.

[0062] As an example of commercially available thermoplastic elastomer B, we can cite for example the "Pebax® Rnew® 55R53 SP 01" from the company Arkema which is a TPE based on PAI 1.

[0063] In the composition of the central layer of the laminate according to the invention, the content of polymer A is preferably in the range of 41% to 59% by mass, preferably from 45% to 55% by mass, relative to the mass of the polymer matrix. Furthermore, in the composition of the central layer of the laminate according to the invention, the content of thermoplastic elastomer B is in the range of 41% to 59% by mass, preferably from 45% to 55% by mass, relative to the mass of the polymer matrix.

[0064] Advantageously, the polymer matrix does not comprise any polymer other than at least polymer A and at least one thermoplastic elastomer B, or comprises less than 20% by mass, preferably less than 10% by mass, and preferably less than 5% by mass. Even more preferably, the polymer matrix does not comprise any polymer other than at least polymer A and at least one thermoplastic elastomer B; that is, at least one polymer A and at least one thermoplastic elastomer B constitute 100% by mass of the polymer matrix.

[0065] The composition of the central layer of the laminate according to the invention may include compounds other than at least one polymer A and at least one thermoplastic elastomer B. These may be additives, known to those skilled in the art, for use with thermoplastics or thermoplastic elastomers. Examples of additives include plasticizers, fillers, processing aids, pigments, and protective agents such as UV stabilizers, ozone inhibitors, antioxidants, and anti-fatigue agents. Of course, reinforcing elements such as metal or textile cables, inorganic fibers (e.g., glass fibers), etc., which may potentially be embedded in a composition, are not additives and are therefore not part of the composition under consideration.

[0066] The rate of additives in the composition of the central layer can represent from 0% to 20% by mass, for example from 1% to 10% by mass, relative to the mass of the composition according to the invention.

[0067] Thus, the total proportion of polymer A and thermoplastic elastomer B in the composition can be from 80% to 100% by mass, for example from 90% to 99% by mass.

[0068] The laminate according to the invention comprises a first adjacent layer of polymeric composition, the polymer matrix of which comprises more than 50% by mass of at least one polymer C, which polymer C is a homopolymer or copolymer comprising a polyamide block comprising repeating units Cl linked together by an amide bond, which Cl units are identical to the repeating units AL

[0069] In this document, "at least one polymer C" refers to "at least one polymer C, which polymer C is a homopolymer or copolymer comprising a polyamide block comprising repeat units Cl linked together by an amide bond, which Cl units are identical to the repeat units Al".

[0070] The at least one polymer C can thus be a homopolymer consisting of a polyamide block which includes repeat units Cl linked together by an amide bond or a mixture of homopolymer consisting of a polyamide block which includes repeat units Cl linked together by an amide bond, for example of different molecular masses.

[0071] The at least one polymer C may also be a copolymer comprising a polyamide block containing repeat units Cl linked together by an amide bond; that is, a polymer comprising repeat units Cl linked together by an amide bond and repeat units other than Cl without any particular limitation. The repeat units other than Cl of copolymer C may be identical or different from the repeat units B1 of the at least one thermoplastic elastomer B. Preferably, the repeat units other than Cl of copolymer C are different from the repeat units B1 of the at least one thermoplastic elastomer B.

[0072] The at least one polymer C may also be a mixture of at least one homopolymer comprising a polyamide block which includes repeat units Cl linked together by an amide bond and at least one copolymer comprising a polyamide block which includes repeat units Cl linked together by an amide bond.

[0073] When polymer C is a copolymer comprising a polyamide block which includes repeating Cl units linked together by an amide bond, the Cl units advantageously represent from 5% to 95% by mass of the copolymer, for example from 9% to 70% by mass of the copolymer.

[0074] The repeating units Cl of the polyamide block of polymer C can be of any type as long as they are identical to the repeating units Al of polymer A. Thus, the polyamide block of polymer C can be a block selected from the group comprising, preferably, PA6, PA12, PAU, PA4.6, PA6.6, PA6.9, PA6.10, PA6.12, PAIO.10, PAIO.12, PA6.6 / 6, PA6 / 6.6 / 6 and PA6 / 6.6 / 10. Preferably, the polyamide block of polymer C is a block selected from the group comprising PA6, PA12, PAU, PA4.6, PA6.6, PA6.9, PA6.10, PA6.12, PAIO.10, PAIO.12. Even more preferably, the polyamide block of polymer C is a block selected from the group comprising PA6, PA12 and PA1. Advantageously, polymer C is a thermoplastic polymer. In other words, it is not a thermoplastic elastomer.

[0075] Advantageously, the Mn of at least one polymer C is in the range of 5,000 to 200,000 g / mol, preferably 7,000 to 100,000 g / mol, preferably 10,000 to 30,000 g / mol.

[0076] Advantageously, the polymer matrix of the first adjacent layer comprises more than 60% by mass, preferably more than 65% by mass, preferably more than 80% by mass of polymer C. Preferably, the polymer matrix of the composition of the first adjacent layer may not comprise any polymer other than at least one polymer C, or may comprise less than 20% by mass, preferably less than 10% by mass, preferably less than 5% by mass. Even more preferably, the polymer matrix comprises no polymer other than at least one polymer C, that is, at least one polymer C constitutes 100% by mass of the polymer matrix of the composition of the first adjacent layer of the laminate according to the invention.

[0077] The composition of the first layer may include compounds other than at least one polymer C. These may include, in particular, the aforementioned additives for the composition according to the invention.

[0078] The rate of additives in the composition of the first layer can represent from 0% to 20% by mass, for example from 1% to 10% by mass, relative to the mass of the composition according to the invention.

[0079] Thus, preferably, the total rate of polymer C in the composition of the first adjacent layer can be 80% to 100% by mass, for example 90% to 99% by mass.

[0080] The laminate according to the invention comprises a second adjacent layer of polymeric composition whose polymer matrix comprises more than 50% by mass (preferably more than 80%, preferably more than 90%, preferably 100%) of at least one polymer D, which polymer D is a homopolymer or copolymer comprising a polyamide block which includes DI repeat units linked together by an amide bond, which DI units are identical to the Bl repeat units.

[0081] In this document, "at least one polymer D" refers to "at least one polymer D, which polymer D is a homopolymer or copolymer comprising a polyamide block which includes DI repeat units linked together by an amide bond, which DI units are identical to the B1 repeat units".

[0082] The at least one polymer D can thus be a homopolymer consisting of a polyamide block which includes DI repeat units linked together by an amide bond or a homopolymer mixture consisting of a polyamide block which includes DI repeat units linked together by an amide bond, for example of different molecular masses.

[0083] The at least one polymer D may also be a copolymer comprising a polyamide block containing DI repeat units linked by an amide bond; that is, a polymer comprising DI repeat units linked by an amide bond and non-DI repeat units without any particular limitation. The non-DI repeat units of copolymer D may be identical to or different from the A1 repeat units of the at least one polymer A. Preferably, the non-DI repeat units of copolymer D are different from the B1 repeat units of the at least one polymer A.

[0084] The at least one polymer D may also be a mixture of at least one homopolymer comprising a polyamide block which includes DI repeat units linked together by an amide bond and at least one copolymer comprising a polyamide block which includes DI repeat units linked together by an amide bond.

[0085] When polymer D is a copolymer comprising a polyamide block which includes DI repeat units linked together by an amide bond, the DI units advantageously represent from 5% to 95% by mass of the copolymer, for example from 9% to 70% by mass of the copolymer.

[0086] The repeat units DI of the polyamide block of polymer D can be of any type as long as they are identical to the repeat units B1 of the rigid block of thermoplastic elastomer B. Thus, the polyamide block of polymer D can be a block selected from the group comprising, preferably, PA6, PA12, PAU, PA4.6, PA6.6, PA6.9, PA6.10, PA6.12, PAIO.10, PAIO.12, PA6.6 / 6, PA6 / 6.6 / 6, and PA6 / 6.6 / 10. Preferably, the polyamide block of polymer D is a block selected from the group comprising PA6, PA12, PAU, PA4.6, PA6.6, PA6.9, PA6.10, PA6.12, PAIO.10, and PAIO.12. Even more preferably, the polyamide block of polymer D is a block selected from the group comprising PA6, PA12, and PAU. Advantageously, polymer D is a thermoplastic polymer. In other words, it is not a thermoplastic elastomer.

[0087] Advantageously, the Mn of the at least polymer D is in the range of 5,000 to 200,000 g / mol, preferably 7,000 to 100,000 g / mol, preferably 10,000 to 30,000 g / mol.

[0088] Advantageously, the polymer matrix of the second adjacent layer comprises more than 60% by mass, preferably more than 65% by mass, preferably more than 80% by mass of polymer D. Preferably, the polymer matrix of the composition of the second adjacent layer does not comprise any polymer other than at least one polymer D, or comprises less than 20% by mass, preferably less than 10% by mass, preferably less than 5% by mass. Even more preferably, the polymer matrix comprises no polymer other than at least one polymer D, that is, at least one polymer D constitutes 100% by mass of the polymer matrix of the composition of the second adjacent layer of the laminate according to the invention.

[0089] The composition of the second adjacent layer may include compounds other than at least one polymer D. These may include the aforementioned additives for the composition according to the invention.

[0090] The rate of additives in the composition of the second adjacent layer can represent from 0% to 20% by mass, for example from 1% to 10% by mass, relative to the mass of the composition according to the invention.

[0091] Thus, preferably, the total rate of polymer D in the composition of the second adjacent layer can be from 80% to 100% by mass, for example from 90% to 99% by mass.

[0092] Examples of commercially available homopolymer C or D polymers include "Rilsan® - Polyamide 11" from Arkema.

[0093] Examples of commercially available C or D polymer copolymers include "Rilsan® Clear G850" from Arkema.

[0094] Advantageously, polymer C differs from polymer D. This is particularly useful when bonding layers of different materials through the composition of the central layer of the laminate according to the invention. Preferably, polymer A comprises at least one PA6 polyamide block, thermoplastic elastomer B comprises a rigid polyamide block, polymer C comprises at least one PAU polyamide block, and polymer D comprises at least one PAU polyamide block.

[0095] The compositions of the central and adjacent layers of the laminate according to the invention can be manufactured in a manner known to those skilled in the art, for example, by mixing the various constituents in a molten state in a suitable mixer or extruder (twin-screw extruders, single-screw extruders, mixers). The compositions can be granulated for subsequent use (simply by remelting) or directly injected into a mold or an extrusion or co-extrusion device.

[0096] The laminate according to the invention can be manufactured (in other words, the layers of the laminate can be assembled) in a manner known to a person skilled in the art, for example by overinjection using an injection press or by assembly by welding.

[0097] The laminate according to the invention can be used in various articles, particularly when the article requires improved adhesion between two compositions of different nature that constitute it.

[0098] Thus, the present invention also relates to an article comprising at least one laminate according to the invention.

[0099] This product has applications in a wide range of fields, including food packaging, electronics, automotive, and medical materials. A specific application in the field of non-pneumatic vehicle tires is described below.

[0100] Thus, the article according to the invention can be a non-pneumatic bandage.

[0101] Preferably, the article is a non-pneumatic tire comprising a tread, an annular band, a plurality of spokes extending transversely and radially within the annular band, and a mounting band for connecting the plurality of spokes to a wheel. The tire comprises cushions made of a composition of the central layer of the laminate according to the invention, said cushions being arranged between and in contact with the spokes and the radially inner portion of the annular band and / or between and in contact with the spokes and the radially inner portion of the mounting band. Preferably, the radially inner portion of the annular band and / or the radially inner portion of the mounting band is made of a composition of the first adjacent layer of the laminate according to the invention, and the spokes in contact with the cushions are made of a composition of the second adjacent layer of the laminate according to the invention.

[0102] III- EXAMPLES

[0103] Adhesion tests were performed to determine the quality of the interface between two materials in contact with each other. For this purpose, the following protocol, based on the ASTM DI 002 (2019) standard, was implemented.

[0104] Various sheets of "Material A" were prepared. Materials MAI and MA3 were prepared by injection molding using a Béwéplast Boy XS injection molding machine in an 80x20x2mm mold. The injection conditions were as follows: material temperature: 280°C, mold temperature during injection: 80°C, injection pressure: 1000 bar. Material MA2 is a strip that was cut to the desired dimensions (80x20x2mm). The Material A materials tested were as follows: MAI: "Akulon® F223-D" from Envalior NV, which is a PA6;

[0105] MA2: “UDea™ Akulon® K20HG60” from the company DSM which is composed of PA6 in which approximately 60% by mass of fiberglass is embedded at least partially;

[0106] MA3: “Rilsan® Clear G850” from the company Arkema which is a copolymer comprising a PAU block.

[0107] In these examples, materials MAI and MA2 conform to the first adjacent layer of the laminate according to the invention and material MA3 conforms to the second adjacent layer of the laminate according to the invention.

[0108] Various "Material B" blends were prepared by mixing a thermoplastic (TP), a thermoplastic elastomer (TPE), or a blend thereof, using a Krauss Maffei "32D Twin Screw Extruder." The mixing conditions were as follows: rotation speed: 300 rpm, total throughput: 3 kg / h, temperature at the extruder barrel: 220°C. The blend was immediately granulated underwater at the screw outlet using a GALA MAP (Manual Adjustable Pelletizer). The Material Bs tested were as follows:

[0109] MB1: 100% by mass of MAY;

[0110] MB2: mixture of 50% by mass of MAI and 50% by mass of "Arkema Pebax® Rnew® 55R53 SP 01" from the company Arkema which is a TPE whose rigid blocks are in PAI 1;

[0111] MB3: mixture of 30% by mass of MAI and 70% by mass of "Arkema Pebax® Rnew® 55R53 SP 01";

[0112] MB4: 100% by mass of MA3.

[0113] Materials MB1, MB3, and MB4 are control compositions that do not conform to the composition of the core layer of the laminate according to the invention. Material MB2, on the other hand, does conform to the composition of the core layer of the laminate according to the invention.

[0114] Specimens of "Material A+B" were produced by over-injecting "Material B" into a 20x20 mm area at one end of a "Material A" wafer. This wafer had been previously cleaned with ethanol before being placed in its dedicated cavity in the over-injection mold. The over-injection conditions were as follows: material temperature: 280°C, mold temperature during injection: 80°C, injection pressure: 1000 bar. The resulting specimens consisted of two wafers, one of "Material A" and the other of "Material B," both measuring 80x20x2 mm, with a 20x20 mm overlap at the wafer ends.

[0115] Once cooled, the test specimens were placed in a tensile testing machine (Instron 6800 series) by inserting the free ends of the plates into the jaws. The longitudinal force required to break the specimens was measured using the "BlueHill" software associated with Instron tensile testing equipment.

[0116] The adhesion results, expressed in Newtons (N), of different specimens of "Material A" / "Material B" are presented in Table 1 below.

[0117] The higher the adhesion value, the better the adhesion. Since Material B is intended to bond two compositions of Material A of different natures, it is understood that the best Material B will be the one that exhibits the highest minimum adhesion result with respect to two Material A compositions.

[0118] [Table 1]

[0119] The results presented in Table 1 above show that only the MB2 material conforming to the central layer of the laminate according to the invention exhibits results greater than 1000 N compared to the MAI, MA2 and MA3 materials.

[0120] As expected, the MAI material exhibits stronger adhesion to itself than to other materials (MB2, MB3, MB4). Conversely, and somewhat surprisingly, Material MB2 (consisting of a 50% by mass mixture of MAI and 50% by mass of TPE with rigid blocks of PAI 1) adheres better to Material MA3 (consisting of a copolymer containing a PAI 1 block) than Material MB4 (consisting of TPE with rigid blocks of PAI 1) adheres better to Material MA3.

[0121] Similarly, it would have been expected that MA2 material (made of PA6) would adhere better to MB1 (made of PA6) than to MB2 (made of a 50% by mass mixture of PA6 and 50% by mass TPE, with rigid blocks made of PAU). As previously stated, MA2 material is a compound comprising 60% by mass of reinforcing elements (glass fibers) embedded at least partially in a PA6 composition. This implies that some of the glass fibers are exposed at the surface of the MA2 material plate. Unexpectedly, MB2 material, according to the invention, exhibits better adhesion to MA2 material (and therefore to the glass fibers) than to MB1 material.

[0122] The various tests carried out by the Applicant showed that this surprising effect is obtained when Material B comprises between 40% and 60% by mass of at least one polymer A and between 40% and 60% by mass of at least one thermoplastic elastomer B. Beyond these levels, the surprising effect described above is not observed, as shown by the adhesion tests of material MB3 on materials MAI and MA2.

[0123] The present invention therefore provides very interesting materials for improving the adhesion of two materials of different natures. It finds applications in many fields, for example in that of non-pneumatic bandages.

Claims

Demands 1. Laminate comprising at least: - a central layer of polymeric composition whose polymer matrix comprises: o 40% to 60% by mass of at least one polymer A, which polymer A is a homopolymer or copolymer comprising a polyamide block which includes repeat units Al linked together by an amide bond, o 40% to 60% by mass of at least one thermoplastic elastomer B comprising at least one flexible block of the polyether type and at least one rigid block of the polyamide type, the rigid block comprising repeat units B1 linked together by an amide bond, which units B1 are different from the repeat units Al, - a first adjacent layer of polymeric composition whose polymer matrix comprises more than 50% by mass of at least one polymer C, which polymer C is a homopolymer or copolymer comprising a polyamide block which includes repeat units Cl linked together by an amide bond, which Cl units are identical to the repeat units Al, - a second adjacent layer of polymeric composition whose polymer matrix comprises more than 50% by mass of at least one polymer D, which polymer D is a homopolymer or copolymer comprising a polyamide block which includes DI repeat units linked together by an amide bond, which DI units are identical to the Bl repeat units, the central layer being disposed between and in contact with the first adjacent layer and the second adjacent layer.

2. Laminated according to claim 1, wherein the polymer A content is in the range of 41% to 59% by mass, preferably 45% to 55% by mass, relative to the mass of the polymer matrix of the middle layer.

3. Laminated according to any one of the preceding claims, wherein the thermoplastic elastomer B content is in the range of 41% to 59% by mass, preferably 45% to 55% by mass, relative to the mass of the polymer matrix of the middle layer.

4. Laminated according to any one of the preceding claims, wherein at least one flexible polyether-type block of thermoplastic elastomer B is selected in the group consisting of polytetramethylene glycol (PTMG), polyethylene glycols (PEG), polypropylene ether glycol (PPG), polyhexamethylene ether glycol, polytrimethylene ether glycol (PO3G), poly(3-alkyltetrahydrofurans), and mixtures thereof, preferably in the group consisting of polytetramethylene glycol (PTMG), polyethylene glycols (PEG) and mixtures thereof.

5. Laminated according to any one of the preceding claims, wherein at least one rigid block of polyamide type of at least one thermoplastic elastomer B comprises from 30% to 80% by mass, preferably from 50% to 70% by mass of repeating units Bl.

6. Laminated according to any one of the preceding claims, wherein the mass fraction of flexible poly ether-type block of at least one thermoplastic elastomer B is in the range of 1% to 70%, preferably 10% to 65%, preferably 20% to 60%, and the mass fraction of rigid polyamide-type block of at least one thermoplastic elastomer B is in the range of 30% to 99%, preferably 35% to 90%, preferably 40% to 80%.

7. Laminated according to any one of the preceding claims, wherein the polymer matrix of the middle layer does not comprise any polymer other than at least one polymer A and at least one thermoplastic elastomer B, or comprises less than 20% by mass, preferably less than 10% by mass, preferably less than 5% by mass.

8. Laminated according to any one of the preceding claims, wherein the polymer matrix of the first adjacent layer comprises more than 60% by mass, preferably more than 65% by mass, preferably more than 80% by mass of polymer C.

9. Laminated according to any one of the preceding claims, wherein the polymer matrix of the second adjacent layer comprises more than 60% by mass, preferably more than 65% by mass, preferably more than 80% by mass of polymer D.

10. Laminated according to any one of the preceding claims, wherein polymer A, polymer C and polymer D are thermoplastic polymers.

11. Article comprising a laminate according to any one of claims 1 to 10.

12. Article according to claim 11, the article being a non-pneumatic tire comprising a tread, an annular band, a plurality of spokes extending transversely and radially within the annular band, a mounting band for connecting the plurality of spokes with a wheel, characterized in that the tire comprises cushions made of a composition of the central layer as defined in any one of claims 1 to 10, said cushions being arranged between and in contact with the spokes and the radially inner part of the annular band and / or between and in contact with the spokes and the radially inner part of the mounting band.

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