Extrusion-grade styrenic polymer compositions

Abstract

Extrusion-Grade Styrenic Polymer Compositions The present invention relates to a composition comprising: - a styrenic polymer, and - at least one flow-modifying additive selected from polyolefins functionalized with at least one heterocycle comprising at least one oxygen atom. These compositions are particularly suitable for extrusion forming. Figure for the abstract: None

Description

Title of the invention: Extrusion-grade styrenic polymer compositions

[0001] The present invention relates to a styrenic polymer composition comprising one or more specific additives. The present invention also relates to a method for preparing such a composition. The present invention further relates to the use of such a composition for manufacturing a part. The present invention also relates to a part comprising such a composition.

[0002] Plastic products are generally formed from virgin plastic materials (also called native materials). For example, styrenic polymers, such as acrylonitrile-butadiene-styrene (known by the acronym ABS) or polystyrene (known by the acronym PS) are plastic materials used in many everyday applications: consumer goods, packaging, household appliances, parts for example of motor vehicles, building construction materials.

[0003] Although these materials possess interesting properties in themselves, there is always a need to improve and / or modulate their performance according to the intended application. For example, styrenic polymers are often processed by extrusion. However, this process requires that the styrenic polymer have characteristics suitable for this type of processing, i.e., that it exhibits good extrudability.

[0004] There is therefore a need for styrenic polymers exhibiting improved extrudability.

[0005] Furthermore, impact resistance is a major property of styrenic polymers, which must be adapted to the intended application.

[0006] There is therefore a need for styrenic polymers exhibiting both improved extrudability and good impact resistance performance.

[0007] In addition, societal expectations regarding environmental preservation and resource reduction are increasingly strong, and it is therefore necessary to develop new materials obtained from recycled materials, in particular from recycled styrenic polymers.

[0008] The disadvantage of using recycled materials is that their performance is generally degraded compared to the performance of the corresponding virgin material. Furthermore, the future use of the recycled polymer is not necessarily identical to its past use, which implies that its properties must be modified / adapted to this new use.

[0009] There is a need for recycled styrenic polymers exhibiting good performance, particularly extrudability, and possibly coupled with good mechanical properties, similar to or superior to the performance of native styrenic polymers.

[0010] An objective of the present invention is therefore to provide a styrenic polymer composition, in particular recycled styrenic polymer, exhibiting good extrudability.

[0011] In particular, an objective of the present invention is to provide a styrenic polymer composition, in particular of recycled styrenic polymer, having a hot melt index value of less than or equal to 15 g / 10min, preferably less than or equal to 10 g / 10min.

[0012] More particularly, an objective of the present invention is to provide an acrylonitrile-butadiene-styrene polymer composition, in particular of recycled acrylonitrile-butadiene-styrene polymer, having a hot melt index value of less than or equal to 15 g / 10min, preferably less than or equal to 10 g / 10min and / or to provide a polystyrene composition, in particular of recycled polystyrene, having a hot melt index value of less than or equal to 6 g / 10min, preferably less than or equal to 5 g / 10min, advantageously less than or equal to 4 g / 10min.

[0013] Another objective of the present invention is to provide a styrenic polymer composition, in particular recycled styrenic polymer, exhibiting both good extrudability and high impact resistance.

[0014] Another particular objective of the invention is therefore to provide a styrenic polymer composition, in particular recycled styrenic polymer, having a hot melt index value of less than or equal to 15 g / 10min, preferably less than or equal to 10 g / 10min, and an IZOD impact resistance value greater than or equal to 9 kJ / m2, preferably greater than or equal to 10 kJ / m2.

[0015] More particularly, an objective of the present invention is to provide an acrylonitrile-butadiene-styrene polymer composition, in particular of recycled acrylonitrile-butadiene-styrene polymer, having a melt flow index value less than or equal to 15 g / 10min, preferably less than or equal to 10 g / 10min and an IZOD impact resistance value greater than or equal to 9 kJ / m2, preferably greater than or equal to 10 kJ / m2, and / or to provide a polystyrene composition, in particular of recycled polystyrene, having a melt flow index value less than or equal to 6 g / 10min, preferably less than or equal to 5 g / 10min, advantageously less than or equal to 4 g / 10min and an IZOD impact resistance value greater than or equal to 6 kJ / m2, preferably greater than or equal to 8 kJ / m2.

[0016] The present invention therefore relates to a composition comprising:

[0017] - a styrenic polymer, and

[0018] - at least one fluidity-modifying additive selected from polyolefins functionalized by at least one heterocycle comprising at least one oxygen atom.

[0019] Preferably, in the composition according to the invention, the mass content of fluidity modifying additive varies from 2% to 25%, preferably from 3% to 20%, more preferably from 4% to 15%, even more preferably from 5% to 10% by mass relative to the total mass of the composition.

[0020] According to one embodiment, the composition according to the invention further comprises an impact modifying additive.

[0021] Preferably, in the composition according to the invention, the mass content of impact modifier additive varies from 0.1% to 15%, preferably from 0.5% to 12%, more preferably from 1% to 10%, advantageously from 2% to 8% by mass relative to the total mass of the composition.

[0022] Preferably, in the composition according to the invention, the ratio between the total mass content of fluidity modifying additive and the total mass content of impact modifying additive varies from 0.1 to 10, preferably from 0.2 to 5, advantageously from 0.3 to 3.

[0023] Preferably, in the composition according to the invention, the styrenic polymer content varies from 75% to 98%, preferably from 80% to 97%, more preferably from 85% to 96%, even more preferably from 90% to 95%, by mass relative to the total mass of the composition.

[0024] Preferably, the composition according to the invention is characterized by a melt flow index (or Melt Flow Index (MFI) according to Anglo-Saxon terminology) having a value less than or equal to 15 g / 10min, preferably less than or equal to 12 g / 10min, preferably less than or equal to 10 g / 10min, preferably between 1 g / 10min and 15 g / 10min.

[0025] The value of the hot melt index of the composition according to the invention is determined according to ISO 1133 (version of 2022).

[0026] Preferably, the composition according to the invention is characterized by an IZOD impact resistance of a value greater than or equal to 5 kJ / m2, preferably greater than or equal to 6 kJ / m2, more preferably between 5 and 20 kJ / m2, even more preferably between 6 and 15 kJ / m2.

[0027] The IZOD impact resistance value of the composition according to the invention corresponds to the IZOD impact resistance notched at 23 °C determined according to ISO 180 of 2019. Styrenic polymer

[0028] The composition according to the invention comprises at least one styrenic polymer.

[0029] According to the invention, a styrenic polymer is a polymer resulting from the polymerization of monomers comprising at least styrene or a styrene derivative, preferably comprising at least styrene.

[0030] A styrenic polymer can therefore be a homopolymer of styrene or of a styrene derivative, or a copolymer of styrene and / or of a styrene derivative and of at least one monomer other than styrene and / or other than a styrene derivative, preferably chosen from monomers comprising at least one unsaturation, advantageously chosen from butadiene, acrylonitrile and C1-C6 alkyl (meth)acrylates, preferably methyl (meth)acrylates.

[0031] Throughout the description, (m)ethyl means methyl or ethyl group and (meth)acrylate means acrylate or methacrylate.

[0032] For the purposes of this invention, copolymer means a polymer resulting from the copolymerization of at least two or more types of chemically different monomers, called comonomers.

[0033] A styrene derivative is a monomer preferably selected from the group consisting of α-methylstyrene, β-methylstyrene, α-methylstyrene, β-methylstyrene, β-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, β-tert-butylstyrene, and α-methyl-β-methylstyrene, hydroxystyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene and vinylnaphthalene.

[0034] The styrenic polymer according to the invention is preferably chosen from styrene homopolymers, styrene derivative homopolymers, acrylonitrile-butadiene-styrene polymers and acrylonitrile-butadiene-styrene polymer derivatives.

[0035] According to the invention, an acrylonitrile-butadiene-styrene polymer derivative is a copolymer in which an aromatic vinyl monomer and a vinyl cyanide monomer are grafted to a rubbery polymer.

[0036] The rubber copolymer is preferably selected from the group consisting of diene-based rubbers such as polybutadiene, polystyrene-butadiene, and polyacrylonitrile-butadiene; saturated rubbers obtained by hydrogenation of diene-based rubbers; acrylic rubbers such as C1-C8 alkyl acrylate, polybutyl acrylate, and ethylhexyl acrylate; isoprene rubbers; chloroprene rubbers; ethylene-propylene rubbers (EPM); and ethylene-propylene-diene monomer rubbers (EPDM). Preferably, the rubber polymer is selected from among the diene-based rubbers, and more preferably polybutadiene.

[0037] The rubbery polymer content preferably ranges from 5 to 30% by weight relative to the total weight of the acrylonitrile-butadiene-styrene polymer derivative

[0038] The aromatic vinyl monomer is preferably chosen from the group consisting of styrene, α-methylstyrene, γ-methylstyrene, β-methylstyrene, ethylstyrene, hydroxystyrene, vinylxylene, monochlorostyrene, dichlorostyrene, dibromostyrene and vinylnaphthalene, and is preferably styrene.

[0039] The aromatic vinyl compound content preferably ranges from 35 to 80% by weight relative to the total weight of the acrylonitrile-butadiene-styrene polymer derivative.

[0040] The vinyl cyanide monomer is preferably chosen from saturated nitriles such as acrylonitrile and unsaturated nitriles such as methacrylonitrile and rethacrylonitrile, and is preferably acrylonitrile.

[0041] The vinyl cyanide compound content preferably ranges from 15 to 35% by weight relative to the total weight of the acrylonitrile-butadiene-styrene polymer derivative.

[0042] Advantageously, the styrenic polymer is selected from among styrene homopolymers and acrylonitrile-butadiene-styrene polymers. The styrenic polymer according to the invention is therefore preferably an acrylonitrile-butadiene-styrene polymer or polystyrene. In one embodiment, the styrenic polymer according to the invention is an acrylonitrile-butadiene-styrene polymer.According to this embodiment, the composition according to the invention is characterized by a hot flow index having a value less than or equal to 15 g / 10min, preferably less than or equal to 12 g / 10min, preferably less than or equal to 10 g / 10min, preferably between 1 g / 10min and 15 g / 10min, and optionally an IZOD impact resistance of a value greater than or equal to 7.5 kJ / m2, preferably greater than or equal to 8 kJ / m2, more preferably greater than or equal to 9.8 kJ / m2, more preferably between 8.5 and 20 kJ / m2, even more preferably between 9 and 15 kJ / m2, advantageously between 9.8 and 12.5 kJ / m2.

[0043] According to another embodiment, the styrenic polymer according to the invention is a polystyrene. According to this embodiment, the composition according to the invention is characterized by a hot melt index having a value less than or equal to 6 g / 10 min, preferably less than or equal to 5 g / 10 min, preferably less than or equal to 4 g / 10 min, preferably between 1 g / 10 min and 6 g / 10 min, and optionally an IZOD impact resistance of a value greater than or equal to 5 kJ / m2, preferably greater than or equal to 5.5 kJ / m2, more preferably greater than or equal to 6 kJ / m2, more preferably between 5.5 and 12 kJ / m2, even more preferably between 6 and 10 kJ / m2, advantageously between 6 and 9 kJ / m2.

[0044] According to the invention, an acrylonitrile-butadiene-styrene polymer is a polymer obtained by grafting, preferably by emulsion grafting, acrylonitrile and styrene onto polybutadiene, by dispersing an acrylonitrile-butadiene copolymer in an acrylonitrile-styrene copolymer matrix, or by bulk polymerization of acrylonitrile and styrene in the presence of polybutadiene. Preferably, the acrylonitrile-butadiene-styrene polymer is a resin in which a styrene-acrylonitrile copolymer is grafted to a polybutadiene.

[0045] It generally comprises 15% to 35% by weight of acrylonitrile, 5% to 30% by weight of butadiene and 35% to 80% by weight of styrene, relative to the total weight of the acrylonitrile-butadiene-styrene polymer.

[0046] The nature of the polystyrene is not especially limited, and can be atactic, isotactic, syndiotactic polystyrene or any of their mixtures.

[0047] According to a particular embodiment, the styrenic polymer is recycled.

[0048] According to ISO 472 of 2013, recycled plastic is plastic obtained by transformation in a production process of plastic waste for the purposes of its original function or for other purposes, with the exception of energy recovery.

[0049] More precisely, for the purposes of this invention, a recycled polymer is understood to mean a post-consumer polymer, that is, one that has already served its intended purpose, for example, in the manufacture of a consumer product, and which would otherwise be discarded as waste. In contrast, a virgin (or native) polymer is a polymer obtained through a polymerization process that prepares it from one or more monomers. There are also post-industrial polymers, which refer to plastic waste generated by manufacturers of the consumer products mentioned above. Finally, post-production polymers are waste generated by producers of plastic materials. The thermomechanical properties of post-production polymers are much closer to those of virgin polymers than to those of post-consumer or post-industrial polymers.Indeed, a post-consumer polymer has been subjected to shocks and / or temperature variations and / or UV radiation, and its thermomechanical properties are diminished compared to those of a virgin polymer or a post-production polymer. A post-industrial polymer also exhibits modified properties compared to a virgin polymer insofar as it has undergone transformation steps.

[0050] A recycled styrenic polymer according to the invention is a post-consumer styrenic polymer or a post-industrial styrenic polymer, preferably post-consumer.

[0051] Advantageously, the recycled styrenic polymer is selected from recycled polystyrene, recycled acrylonitrile-butadiene-styrene polymers, and any mixture thereof. In one embodiment, the styrenic polymer according to the invention is a recycled acrylonitrile-butadiene-styrene polymer. In another embodiment, the styrenic polymer according to the invention is recycled polystyrene.

[0052] The recycled acrylonitrile-butadiene-styrene polymer can be a mixture consisting of recycled acrylonitrile-butadiene-styrene, less than 8% by weight of recycled polystyrene, preferably less than 3% by weight, for example from 0.1% to 8% by weight, and less than 5% by weight of recycled polypropylene, preferably less than 2% by weight, for example from 0.1% to 5% by weight, relative to the total weight of the recycled polymer.

[0053] Typically, a recycled (or post-consumer) acrylonitrile-butadiene-styrene polymer may have a hot melt value greater than or equal to 15 g / lOmins, preferably greater than or equal to 20 g / lOmins, preferably from 20 to 35 g / lOmins, preferably from 20 to 30 g / lOmins.

[0054] Recycled polystyrene can be a mixture consisting of recycled polystyrene, less than 8% by weight of recycled acrylonitrile-butadiene-styrene polymer, preferably less than 5% by weight, for example from 0.1% to 8% by weight, and less than 5% by weight of recycled polypropylene, preferably less than 2% by weight, for example from 0.1% to 5% by weight, relative to the total weight of the recycled polymer.

[0055] Typically, recycled (or post-consumer) polystyrene can have a hot melt value greater than or equal to 5 g / lOmins, preferably greater than or equal to 6 g / lOmins, preferably from 5 to 10 g / lOmins, preferably from 6 to 8 g / lOmins.

[0056] Polyolefins functionalized by at least one heterocycle comprising at least one oxygen atom

[0057] The composition according to the invention comprises at least one fluidity-modifying additive selected from polyolefins functionalized by at least one heterocycle comprising at least one oxygen atom.

[0058] By polyolefin functionalized by at least one heterocycle, we mean a polymer comprising at least one heterocycle in the main chain and / or on a side chain, and being obtained from the polymerization of at least one unsaturated monomer, that is to say a monomer comprising at least one covalent double bond between two carbon atoms.

[0059] Preferably, the functionalized polyolefin comprises at least one cyclic ether or cyclic ester type functional group, advantageously at least one epoxide type functional group.

[0060] Preferably, the functionalized polyolefin is a copolymer obtained by copolymerization of an olefinic (or unsaturated) monomer comprising at least one heterocycle including at least one oxygen atom, and one or more other monomers, different from the olefinic monomer comprising at least one heterocycle including at least one oxygen atom.

[0061] This copolymer can be linear, branched, statistical, grafted, block, or have a core-crown or comb structure.

[0062] The olefinic monomer comprising at least one heterocycle including at least one oxygen atom is, according to a particular embodiment, a (meth)acrylic monomer with a cyclic ether functional group, preferably with an epoxy functional group. The term "(meth)acrylic" includes acrylic and methacrylic monomers, as well as their C1-C4 alkyl salts or esters, preferably C1-C2. For example, (meth)acrylic monomers with a cyclic ether functional group include those containing 1,2-epoxy groups, such as glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, and glycidyl ethacrylate.

[0063] Preferably, the fluidity modifying additive is chosen from polymers obtained by copolymerization of a (meth)acrylic monomer with a cyclic ether function with at least one other monomer different from the (meth)acrylic monomer with a cyclic ether function.

[0064] Advantageously, the fluidity-modifying additive is chosen from polymers obtained by copolymerization of glycidyl (meth)acrylate with at least one other monomer different from glycidyl (meth)acrylate.

[0065] The other monomer(s) are preferably chosen from vinyl monomers.

[0066] By vinyl monomer is meant an organic molecule comprising at least one carbon-carbon double bond. Preferably, the vinyl monomer has the following formula: CH2=CRR', with R and R' being independently selected from the group consisting of a hydrogen atom, an aromatic group, preferably a phenyl group, a hydrocarbon group comprising from 1 to 10 carbon atoms, preferably from 2 to 10 carbon atoms, saturated or unsaturated, and optionally comprising an ester group, a nitrile group, a carboxyl group, an amine group, or an amide group. Preferably, the other monomer(s) is / are selected from the group consisting of a C2-C8 alkene, a C4-C8 diene, a styrenic monomer, and an acrylic monomer.Preferably, the other monomer(s) is / are chosen from the group consisting of ethylene, 1-octene, styrene, butadiene, acrylonitrile and C1-C4 alkyl (meth)acrylates (preferably methyl or ethyl (meth)acrylate).

[0067] In a preferred embodiment, the fluidity-modifying additive is selected from polymers obtained by copolymerization of glycidyl (meth)acrylate with at least one other monomer as defined above. Preferably, the mass content of glycidyl (meth)acrylate varies from 4 to 20% by weight, preferably from 8 to 15% by weight, relative to the total weight of the polymer obtained by copolymerization of glycidyl (meth)acrylate with said at least one other monomer. Preferably, said at least one other monomer comprises ethylene or styrene, and possibly a C1-C4 alkyl (meth)acrylate, preferably a methyl (meth)acrylate.

[0068] Preferably, the fluidity modifying additive is chosen from among the terpolymers obtained by polymerization of a (meth)acrylic monomer with epoxy function, preferably glycidyl (meth)acrylate, advantageously glycidyl, ethylene or styrene methacrylate, and possibly of a (meth)acrylic monomer without cyclic ether function, preferably a C1-C4 alkyl (meth)acrylate, advantageously a methyl (meth)acrylate.

[0069] In a particularly preferred embodiment, the fluidity-modifying additive is chosen from among terpolymers, preferably statistical, obtained by polymerization of a (meth)acrylic monomer with an epoxy function, preferably glycidyl (meth)acrylate, a C2-C8 alkene, preferably ethylene, and a (meth)acrylic monomer without a cyclic ether function, preferably a C1-C4 alkyl (meth)acrylate, preferably a methyl (meth)acrylate, advantageously methyl acrylate.

[0070] Advantageously, the fluidity modifying additive is chosen from among the terpolymers, preferably statistical, obtained by polymerization of glycidyl methacrylate, ethylene and methyl acrylate.

[0071] In another preferred embodiment, the fluidity-modifying additive is chosen from terpolymers, preferably statistical, obtained by polymerization of a (meth)acrylic monomer with an epoxy function, preferably glycidyl (meth)acrylate, advantageously glycidyl methacrylate, styrene, and a (meth)acrylic monomer without a cyclic ether function, preferably a C1-C4 alkyl (meth)acrylate, preferably a methyl (meth)acrylate, advantageously methyl methacrylate.

[0072] In another preferred embodiment, the fluidity-modifying additive is selected from copolymers comprising a main chain made of an ethylene and 1-octene copolymer, and side chains made of a styrene terpolymer, glycidyl (meth)acrylate, advantageously glycidyl methacrylate and (m)ethacrylate of (m)ethyl, advantageously methyl methacrylate.

[0073] In another preferred embodiment, the fluidity modifying additive is chosen from core-crown copolymers with a butadiene-styrene dibloc copolymer core and an epoxy crown.

[0074] In another preferred embodiment, the fluidity-modifying additive is chosen from copolymers obtained by polymerization of styrene, acrylonitrile and glycidyl (meth)acrylate.

[0075] By way of example, polyolefins functionalized with at least one heterocycle comprising at least one oxygen atom may be chosen from:

[0076] - glycidyl methacrylate, ethylene and methyl acrylate terpolymer commercially available under the reference Lotader AX8900® from SK-FP,

[0077] - the copolymer of styrene, methyl methacrylate and methacrylate glycidyl available under the reference AddiCo 9300® from Rheomod, or under the reference Xibond 950® from Polyscope,

[0078] - the ethylene and glycidyl methacrylate copolymer available under the reference IGETABOND® 7M and IGETABOND® E from the company Sumitomo;

[0079] - the branched copolymer of ethylene, 1-octene, styrene, methacrylate glycidyl and methyl methacrylate available under the reference AddiCo 5156® from the company Rheomod,

[0080] - the styrene-butadiene core-crown copolymer exhibiting surface epoxy groups available under reference SBG-001® from Fine Blend Polyester, or

[0081] - the copolymer of styrene, acrylonitrile and glycidyl methacrylate available under the reference SAG-002® from the company Fine-blend Polymer.

[0082] According to certain embodiments, the composition according to the invention comprises at least two fluidity-modifying additives as defined above.

[0083] Preferably, the impact modifying additive is chosen from:

[0084] - terpolymers, preferably statistical, obtained by polymerization of a epoxy (meth)acrylic monomer, preferably glycidyl (meth)acrylate, of a C2-C8 alkene, preferably ethylene, and of a cyclic ether-free (meth)acrylic monomer, preferably a C1-C4 alkyl (meth)acrylate, preferably a methyl (meth)acrylate, advantageously methyl acrylate,

[0085] - terpolymers, preferably statistical, obtained by polymerization of a epoxy (meth)acrylic monomer, preferably glycidyl (meth)acrylate, advantageously glycidyl methacrylate, and styrene, and a cyclic ether-free (meth)acrylic monomer, preferably a C1-C4 alkyl (meth)acrylate, preferably a methyl (meth)acrylate, advantageously methyl methacrylate, and

[0086] - any one of their mixtures.

[0087] According to one embodiment, the fluidity-modifying additive comprises at least a first fluidity-modifying additive and a second fluidity-modifying additive. The first and second fluidity-modifying additives are different from each other and preferably each independently is a fluidity-modifying additive according to any variant defined above.

[0088] Preferably, the first fluidity-modifying additive is chosen from among the terpolymers, preferably statistical, obtained by polymerization of a monomer (meth)acrylic with epoxy function, preferably glycidyl (meth)acrylate, of a C2-C8 alkene, preferably ethylene, and of a (meth)acrylic monomer without cyclic ether function, preferably a C1-C4 alkyl (meth)acrylate, preferably a methyl (meth)acrylate, advantageously methyl acrylate.

[0089] Preferably, the second fluidity-modifying additive is chosen from among the terpolymers, preferably statistical, obtained by polymerization of a (meth)acrylic monomer with an epoxy function, preferably glycidyl (meth)acrylate, advantageously glycidyl methacrylate, and styrene, and a (meth)acrylic monomer without a cyclic ether function, preferably a C1-C4 alkyl (meth)acrylate, preferably a methyl (meth)acrylate, advantageously methyl methacrylate.

[0090] Preferably, the ratio between the total mass content of impact modifier additives and the total mass content of first and second fluidity modifier additives varies from 0.1 to 10, preferably from 0.3 to 8, from 0.5 to 5, preferably from 1 to 3.

[0091] Preferably, the ratio between the mass content of the second fluidity modifying additive and the mass content of the first fluidity modifying additive varies from 0.1 to 5, preferably varies from 0.2 to 5, preferably from 0.5 to 3, preferably from 0.8 to 1.2.

[0092] Preferably, the mass content of the first fluidity modifying additive varies from 0.5% to 10%, preferably from 1% to 5%, preferably from 1.5% to 3% by mass relative to the total mass of the composition.

[0093] Preferably, the mass content of the second fluidity modifying additive varies from 0.5% to 10%, preferably from 1% to 5%, preferably from 1.5% to 3% by mass relative to the total mass of the composition. Impact modifier additive

[0094] According to one embodiment, the composition according to the invention further comprises at least one impact modifying additive.

[0095] An impact modifier additive is a chemical compound which, when mixed with a polymer, makes the polymer more impact-resistant. In particular, an impact modifier additive is a polymeric material that improves the impact properties of a polymer, for example, the IZOD notch impact resistance at 23°C, as determined according to ISO 180 (2019 version). This term is also known as "impact modifiers," "impact additives," or "impact modifiers." This term is well known to those skilled in the art.

[0096] Preferably, according to the invention, an impact modifying additive is an additive that allows a polymer comprising 5% by weight of this additive, relative to the total weight of polymer-additive mixture, to exhibit a rate of increase in its impact resistance greater than or equal to 1.2, preferably greater than or equal to 1.5, more preferably greater than or equal to 2.0. Thus, preferably, the impact modifier additive makes it possible to increase by at least 10% the IZOD impact resistance of a composition consisting of the recycled polymer and 5% by weight of said impact modifier additive.

[0097] Examples of suitable impact-modifying additives include, for example, grafted polymers, core-shell polymers, and sequenced copolymers. These polymers can be obtained from at least one monomer selected from the group consisting of an alkene, an alkadiene, an arene, and an acrylate.

[0098] Preferably, the impact modifying additive is a copolymer obtained from at least one vinyl monomer, preferably as defined above.

[0099] Preferably, the impact modifying additive is a copolymer of ethylene and / or styrene, that is to say that at least one of the comonomers of the copolymer is chosen from styrene and ethylene.

[0100] Preferably, the impact modifying additive comprises a copolymer resulting from the copolymerization of at least two monomers selected from the group consisting of a C2-C8 alkene, a C4-C8 diene, a styrenic monomer and an acrylic monomer.

[0101] Preferably, the impact modifying additive comprises a copolymer resulting from the copolymerization of at least two monomers selected from the group consisting of ethylene, butene, styrene, butadiene, acrylonitrile, (m)ethyl (meth)acrylate and butyl (meth)acrylate.

[0102] In some embodiments, the impact modifier additive is functionalized or grafted. The functionalized or grafted ethylene copolymer may comprise polar compounds, including, for example, an anhydride or epoxy function, preferably cyclic, preferably maleic anhydride or glycidyl (meth)acrylate.

[0103] Preferably, the impact modifying additive is chosen from:

[0104] - copolymers of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and (meth)butyl acrylate,

[0105] - modified acrylonitrile-butadiene-styrene copolymers having a level of butadiene greater than or equal to 60% by weight relative to the total weight of the modified acrylonitrile-butadiene-styrene polymer,

[0106] - styrene-ethylene / butene-styrene copolymers grafted with anhydride maleic,

[0107] - ethylene-butyl acrylate copolymers, optionally grafted by maleic anhydride,

[0108] - copolymers obtained by polymerization of maleic anhydride, of an alkene in C2-C8, preferably ethylene, and alkyl (meth)acrylate in C1-C4, advantageously ethyl acrylate,

[0109] - styrene-butadiene copolymers, preferably styrene- Block butadiene, preferably multiblock or diblock styrene-butadiene copolymers,

[0110] - styrene-ethylene / butene-styrene copolymers, preferably copolymers styrene-ethylene / butene-styrene block, and

[0111] - any one of their mixtures.

[0112] As an example of a styrene-ethylene / butene-styrene copolymer functionalized with maleic anhydride, we can cite the product referenced SEBS-g-MA® from the company Kraton Polymer.

[0113] As an example of styrene-ethylene / butene-styrene copolymers grafted with maleic anhydride, we can cite the product referenced C1010® from the company Kraton Polymer.

[0114] As an example of styrene-ethylene / butene-styrene copolymers grafted with glycidyl methacrylate, we can cite the product referenced 02520 C® from the company Graft polymer.

[0115] As an example of ethylene-butyl acrylate copolymers, we can cite the product Lucofin® 1400PN from the company Lucobit.

[0116] As an example of maleic anhydride grafted ethylene-butyl acrylate copolymers, we can cite the product Lucofin® 1492 MGH from the company Lucobit.

[0117] As an example of a styrene-butadiene copolymer, we can cite the product referenced SBS-C3000® from the company Kraton Polymer or the product referenced DENKA NSBC® from the company DENKA.

[0118] As an example of a styrene-ethylene / butene-styrene copolymer, the product referenced SBS-C2000® from Kraton Polymer can be cited.

[0119] As an example of a copolymer of ethylene, ethyl acrylate and maleic anhydride, the product referenced Lotader 4700T® from SK-FP may be cited.

[0120] Copolymers of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and (meth)butyl acrylate

[0121] Preferably, the copolymer of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and butyl (meth)acrylate is a copolymer of ethylene and a polar monomer selected from (m)ethyl acrylate and (m)ethyl methacrylate.

[0122] Preferably, the copolymer of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and (meth)acrylate butyl is a random copolymer. Such a copolymer can be prepared at high pressure from a mixture of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and (meth)butyl acrylate in the presence of a radical polymerization initiator.

[0123] The copolymer of ethylene and a polar monomer selected from (m)ethyl acrylate and (m)ethyl methacrylate preferably comprises 5 to 30% by mass, preferably 10% to 30% by mass, preferably still 15% to 31% by mass of polar monomer relative to the total mass of the copolymer, and 70 to 95% by mass of ethylene, preferably 70% to 90% by mass, preferably still 69 to 85% by mass relative to the total mass of the copolymer.

[0124] Preferably, the copolymer of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and butyl (meth)acrylate is a copolymer of ethylene and methyl acrylate.

[0125] By way of example of a copolymer of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and butyl (meth)acrylate, one may cite the commercial ethylene / methylacrylate copolymers available under the reference Lotryl ©29MA03T, from SK Functional Polymer, the Elvaloy® copolymers (AC1125, AC12024 S, AC1330) from Dow, or the EMAC® SP2260, EMAC® SP2403, EMAC® SP2268 products from Westlake.

[0126] Modified acrylonitrile butadiene styrene polymer having a butadiene content greater than or equal to 60% by weight

[0127] Preferably, the modified acrylonitrile butadiene styrene polymer having a butadiene content greater than or equal to 60% by weight comprises a modified acrylonitrile butadiene styrene polymer having a butadiene content ranging from 60% to 80%, preferably ranging from 60% to 65% by mass relative to the total mass of the modified acrylonitrile butadiene styrene polymer.

[0128] This polymer therefore differs in particular from the acrylonitrile-butadiene-styrene polymer described in the "styrenic polymer" section above in that it comprises a higher butadiene content (greater than or equal to 60% by weight).

[0129] As an example of a modified acrylonitrile butadiene styrene polymer having a butadiene content greater than or equal to 60% by mass, we can cite the product referenced KUMHO® HR 181 from the company Korea Kurnho Petrochemical.

[0130] Preferably, the impact modifier additive is chosen from:

[0131] - copolymers of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and (meth)butyl acrylate,

[0132] - modified acrylonitrile-butadiene-styrene copolymers having a content of butadiene greater than or equal to 60% by weight relative to the total weight of the modified acrylonitrile-butadiene-styrene polymer, and

[0133] - any one of their mixtures,

[0134] in any combination of variants defined above for each of these copolymers.

[0135] According to one embodiment, the impact modifier additive comprises at least a first impact modifier additive and a second impact modifier additive. The first impact modifier additive and the second impact modifier additive are different from each other and preferably each independently is an impact modifier additive according to any variant defined above.

[0136] The combination of two impact modifying additives advantageously presents a synergistic effect on the IZOD impact resistance of the composition.

[0137] Preferably, the first impact modifying additive is selected from ethylene and / or butene copolymers and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and butyl (meth)acrylate as described above.

[0138] Preferably, the second impact modifying additive is chosen from among modified acrylonitrile-butadiene-styrene copolymers having a butadiene content greater than or equal to 60% by weight relative to the total weight of the modified acrylonitrile-butadiene-styrene polymer.

[0139] Preferably, the ratio between the total mass content of first and second impact modifier additives and the total mass content of fluidity modifier additive varies from 0.1 to 10, preferably from 0.3 to 8, from 0.5 to 5, preferably from 1 to 3.

[0140] Preferably, the ratio between the mass content of the second impact modifier additive and the mass content of the first impact modifier additive varies from 0.1 to 10, preferably varies from 0.25 to 8, preferably from 0.5 to 5, preferably from 1 to 2.

[0141] Preferably, the mass content of the first impact modifying additive varies from 0.5% to 15%, preferably from 1% to 10%, preferably from 2% to 7%, advantageously from 3% to 5% by mass relative to the total mass of the composition.

[0142] Preferably, the mass content of the second impact modifier additive varies from 1% to 15%, preferably from 3% to 12%, advantageously from 5% to 10% by mass relative to the total mass of the composition.

[0143] In this embodiment, the fluidity-modifying additive is preferably chosen from:

[0144] - terpolymers, preferably statistical, obtained by polymerization of a (meth)acrylic monomer with epoxy function, preferably (meth)acrylate of glycidyl, a C2-C8 alkene, preferably ethylene, and a (meth)acrylic monomer without a cyclic ether function, preferably a C1-C4 alkyl (meth)acrylate, preferably a methyl (meth)acrylate, advantageously methyl acrylate, and

[0145] - terpolymers, preferably statistical, obtained by polymerization of a epoxy (meth)acrylic monomer, preferably glycidyl (meth)acrylate, advantageously glycidyl methacrylate, and styrene, and a cyclic ether-free (meth)acrylic monomer, preferably a C1-C4 alkyl (meth)acrylate, preferably a methyl (meth)acrylate, advantageously methyl methacrylate.

[0146] According to another embodiment, the impact modifier additive comprises at least a first impact modifier additive and a second impact modifier additive, and the fluidity modifier additive comprises at least a first fluidity modifier additive and a second fluidity modifier additive. The first and second impact modifier additives and the first and second fluidity modifier additives are preferably as defined above.The contents and ratio of first and second impact modifier additives and first and second fluidity modifier additives are as defined above with respect to the embodiment in which the impact modifier additive comprises at least one first impact modifier additive and one second impact modifier additive, and the embodiment in which the fluidity modifier additive comprises at least one first fluidity modifier additive and one second fluidity modifier additive.

[0147] This combination of additives advantageously makes it possible to obtain a styrenic polymer composition exhibiting both a hot melt index much less than or equal to 10 g / lOmin, and a very high impact resistance.

[0148] The present invention also relates to a method for preparing a composition according to the invention, comprising:

[0149] - a step of mixing a styrenic polymer with at least one additive fluidity modifier chosen from polyolefins functionalized by at least one heterocycle comprising at least one oxygen atom.

[0150] All definitions and preferred embodiments described in the above description apply.

[0151] The mixing step is preferably carried out at a temperature between 200 and 290°C, preferably between 220°C and 270°C. The mixing step is preferably carried out using an extruder equipped with a co-rotating twin screw. The screw rotation speed is preferably between 150 and 300 revolutions per minute, preferably between 190 and 250 revolutions per minute. Such conditions allow advantageously to optimize the hot flow index, and possibly the IZOD shock resistance of the composition.

[0152] During the injection molding of molded parts, the temperature of the screw-barrel assembly of the injection molding machine must be between 220°C and 250°C at the time of injection. The recommended mold temperature during injection is between 40 and 70°C.

[0153] The present invention also relates to the use of a composition according to the invention for the manufacture of a part, for example an extruded sheet or a plate intended for thermoforming.

[0154] The present invention also relates to a method of manufacturing a part, preferably an extruded sheet having a thickness less than or equal to 500 microns or a plate for thermoforming having a thickness less than 1 mm, comprising the extrusion of a composition according to the invention.

[0155] The present invention also relates to a part, for example a plate preferably having a thickness of less than 1 mm intended for thermoforming, or an extruded sheet preferably having a thickness less than or equal to 500 microns, comprising a composition according to the invention.

[0156] The present invention also relates to a method for improving at least one processability property, preferably extrudability, and optionally at least one mechanical property, preferably impact resistance, of a styrenic polymer, preferably recycled, comprising adding to the styrenic polymer a fluidity-modifying additive selected from polyolefins functionalized by at least one heterocycle comprising at least one oxygen atom

[0157] All definitions and preferred embodiments described in the above description apply.

[0158] Preferably, the process for improving at least one processability property, and optionally at least one mechanical property of a styrenic polymer is a process for improving the melt flow index, and optionally the impact resistance IZOD of the polystyrenic polymer, preferably up to values ​​such as defined in this description.

[0159] The present invention further relates to the use of a fluidity modifying additive selected from polyolefins functionalized by at least one heterocycle comprising at least one oxygen atom to improve the extrudability, preferably to increase the fluidity, preferably to increase the hot melt index, of a styrenic polymer, preferably of a recycled styrenic polymer.

[0160] All definitions and preferred embodiments described in the above description apply.

[0161] The present invention also relates to the use of a combination of:

[0162] - a fluidity-modifying additive selected from polyolefins functionalized by at least one heterocycle comprising at least one oxygen atom, and

[0163] - an impact modifying additive,

[0164] to improve at least one processability property, preferably extrudability, and possibly at least one mechanical property, preferably impact resistance, of a styrenic polymer, preferably recycled.

[0165] All definitions and preferred embodiments described in the above description apply.

[0166] Preferably, the use of the combination of additives to improve at least one processability property and possibly at least one mechanical property of a styrenic polymer improves the hot melt index, and possibly the impact resistance IZOD of the polystyrene polymer, preferably up to values ​​such as defined in this description.

[0167] The invention will now be described by means of the following non-limiting examples.

[0168] EXAMPLES

[0169] In all the following examples, the compositions were prepared as follows:

[0170] The recycled ABS or PS ground material is first mechanically mixed with the impact modifier additive, if present. During compounding, the fluidity modifier additive(s) are added using metering hoppers.

[0171] In all the following examples, the various thermomechanical properties of the compositions were determined according to the following standards:

[0172] IZOD: ISO 180 (2019 version);

[0173] MFI:1133 (version 2022).

[0174] Example 1: Influence of the nature and quantity of fluidity-modifying additive

[0175] In the compositions of Table 1 below, the following materials and additives have were used:

[0176] Styrenic polymer: Recycled ABS

[0177] Fluidity modifier additive 1: Lotader AX8900®

[0178] Fluidity modifier additive 2: AddiCo 9300®

[0179] [Tables] Ref Fluidity modifier additive 1 (% mass) Fluidity modifier additive 2 (% mass) MFI (g / 10 mins) Notched IZOD 23°C (kJ / m2) Cl-0* - - 28 8 Cl-1 1 - 21.1 - Cl-2 5 - 15.6 8.8 Cl-3 8 - 12.3 9.4 Cl-4 10 - 18.1 9 Cl-5 - 3 12.8 6.4+0.2 Cl-6 - 5 11.3 5.6+0.2

[0180] * : comparative example

[0181] In the compositions of Table 2 below, the following materials and additives were used:

[0182] Styrenic polymer: Recycled ABS

[0183] Fluidity modifier additive 1: Lotader AX8900®

[0184] Fluidity modifier additive 2: AddiCo 9300®

[0185] Fluidity modifier additive 3: Xibond950®

[0186] Fluidity modifier additive 4: Igetabond E®

[0187] Fluidity modifier additive 5: Igetabond 7M®

[0188] Fluidity modifier additive 6: ABS GMA 00530®

[0189] [Tables2] Ref Nature of the fluidity modifier additive (5% by mass) MFI (g / 10 mins) IZOD notched 2 3°C (kJ / m2) Cl-0* - 28 8 Cl-7 1 15.6 8.8 Cl-8 2 11.3 5.5 Cl-9 3 11.8 5.8 Cl-10 4 17.1 7.3 Cl-11 5 18.7 9.5 Cl-12 6 25 8

[0190] * : comparative example

[0191] These results show that adding a fluidity modifier as defined in this application makes it possible to significantly decrease the hot fluidity index of an ABS.

[0192] Example 2: Adding an impact modifier additive

[0193] In the compositions of Table 3 below, the following materials and additives were used:

[0194] Styrenic polymer: Recycled ABS

[0195] Fluidity modifier additive 1: Lotader AX8900®

[0196] Impact modifier additive 1: Lotryl 29MA03T®

[0197] [Tables3] Ref Fluidity modifier additive 1 (% mass) Impact modifier additive 1 (% mass) MFI (g / 10 mins) IZOD cut at 23°C (kJ / m2) Cl-0* - - 28 8 C2-1 5 - 15.6 8.8 C2-2 8 - 12.3 9.4 C2-3 8 5 21.4 18.7 C2-4 5 5 20.3 16.7 C2-5* - 5 25.9 13.8

[0198] * : comparative examples

[0199] In the compositions of Table 4 below, the following materials and additives were used:

[0200] Styrenic polymer: Recycled PS

[0201] Fluidity modifier additive 1: Lotader AX8900®

[0202] Impact modifier additive 1: Lotryl 29MA03T®

[0203] [Tables4] Ref Fluidity modifier additive 1 (% mass) Impact modifier additive 1 (% mass) MFI (g / 10 mins) IZOD notched at 23°C (kJ / m2) C2-0* - - 5.7 4.5 C2-6 3 - 4.5 5.7 C2-7 5 - 4.0 6.1 C2-8 7 - 4.3 7 C2-9 7 2.5 4.3 11.4 C2-10* - 2.5 5.7 7

[0204] * : comparative examples

[0205] The results in Tables 3 and 4 show a synergy between the fluidity modifier and the impact modifier, particularly with regard to impact resistance. Indeed, it is shown that adding the fluidity modifier in combination with an impact modifier leads to a significant increase in impact resistance. This is a completely unexpected result because the fluidity modifier alone has no significant influence on the impact resistance of the composition.

[0206] In the compositions of Table 5 below, the following materials and additives were used:

[0207] Styrenic polymer: Recycled ABS

[0208] Fluidity modifier additive 3: Xibond950®

[0209] Impact modifier additive 1: Lotryl 29MA03T®

[0210] [Tables5] Ref Fluidity modifier additive 3 (% mass) Impact modifier additive 1 (% mass) MFI (g / 10 mins) IZOD notched at 23°C (kJ / m2) Cl-O* - - 28 8 C2-11 8 - 6.8 5.1 C2-12 8 3 5.9 6.9 C2-13 8 5 5.7 7.8

[0211] * : comparative example

[0212] Example 3: Compositions according to the invention comprising a fluidity-modifying additive and two impact-modifying additives

[0213] In the compositions of Table 6 below, the following materials and additives were used:

[0214] Styrenic polymer: Recycled ABS

[0215] Fluidity modifier additive 3: Xibond950®

[0216] Impact modifier additive 1: Lotryl 29MA03T®

[0217] Impact modifier additive 2: HR181®

[0218] [Tableauxô] Ref Fluidity modifier additive 3 (% mass) Impact modifier additive 1 (% mass) Impact modifier additive 2 (% mass) MFI (g / 10 min s) IZOD notched at 23°C (kJ / m2) Cl-0* - - - 28 8 C3-1 8 10 - 8.8 9.8 C3-2 8 6.7 3.3 4.0 10.5 C3-3 8 5 5 3.0 10.6 C3-4 8 3.3 6.7 3.1 10.3 C3-5 8 - 10 2.0 8.8 C3-6 6 3.3 6.7 4.8 11.6 C3-7 4 10 - 13.9 12.2 C3-8 4 3.3 6.7 6.8 12.7 C3-9 4 - 10 8.4 10.4 C3-10 3 4 8 7.6 16.3 C3-11 4 4 8 5.9 14.2

[0219] * : comparative example

[0220] A synergistic effect is observed between the two impact modifying additives. Indeed, for an equivalent total quantity of impact modifying additive, compositions C3-2, C3-3, and C3-4 exhibit better mechanical strength than compositions C3-1 and C3-5, which contain only one impact modifying additive. Composition C3-8 also exhibits better mechanical strength than compositions C3-7 and C3-9, which contain only one impact modifying additive.

[0221] In the compositions of Table 7 below, the following materials and additives were used:

[0222] Styrenic polymer: Recycled ABS

[0223] Fluidity modifier additive 1: LotaderAX8900®

[0224] Impact modifier additive 1: Lotryl 29MA03T®

[0225] Impact modifier additive 2: HR181®

[0226] [Tables?] Ref Fluidity modifier additive 1 (% mass) Impact modifier additive 1 (% mass) Impact modifier additive 2 (% mass) MFI (g / 10 min s) IZOD notched 2 3°C (kJ / m2) Cl-O* - - - 28 8 C3-12 8 - - 12.3 9.4 C3-13 8 - 6 10.7 10.2 C3-14 8 2 4 13.2 15.1

[0227] * : comparative example

[0228] Example 4: Synergy between fluidity-modifying additives and impact-modifying additives

[0229] In the compositions of Table 7 below, the following materials and additives were used:

[0230] Styrenic polymer: Recycled ABS

[0231] Fluidity modifier additive 1: LotaderAX8900®

[0232] Fluidity modifier additive 3: Xibond950®

[0233] Impact modifier additive 1: Lotryl 29MA03T®

[0234] Impact modifier additive 2: HR181® Ref Fluidity modifier additive 1 (% mass) Fluidity modifier additive 3 (% mass) Implant modifier additive 1 (% mass) Implant modifier additive 2 (% mass) MFI (g / 10 min s) IZODe notched 2 3°C (kJ / m2) C4- 1 4 - 4 8 5.9 14.2 C4- 2 2 2 4 8 8.1 18.4

[0235] These results demonstrate that the combination of one or two fluidity modifier additives with two impact modifier additives makes it possible to obtain ABS compositions exhibiting both a hot melt index well below 10 g / 10 mins and extremely high impact resistance.

Claims

Demands

1. Composition comprising: - a styrenic polymer, - at least one fluidity modifier additive selected from polyolefins functionalized with at least one heterocycle comprising at least one oxygen atom, - a first impact modifier additive selected from copolymers of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and butyl (meth)acrylate, and - a second impact modifier additive selected from modified acrylonitrile-butadiene-styrene copolymers having a butadiene content greater than or equal to 60% by weight relative to the total weight of the modified acrylonitrile-butadiene-styrene polymer.

2. Composition according to claim 1, wherein the fluidity modifying additive is selected from polymers obtained by copolymerization of a (meth)acrylic monomer with a cyclic ether function with at least one other monomer, different from the (meth)acrylic monomer with a cyclic ether function, preferably the other monomer(s) are selected from vinyl monomers.

3. Composition according to claim 1 or 2, wherein the fluidity modifying additive is selected from polymers obtained by copolymerization of glycidyl (meth)acrylate with at least one other monomer selected from the group consisting of ethylene, 1-octene, styrene, butadiene, acrylonitrile and C1-C4 alkyl (meth)acrylates.

4. Composition according to any one of the preceding claims, wherein the mass content of fluidity modifying additive varies from 2% to 25%, preferably from 3% to 20%, more preferably from 4% to 15%, even more preferably from 5% to 10% by mass relative to the total mass of the composition.

5. Composition according to any one of the preceding claims, wherein the mass content of first impact modifier additive varies from 0.5% to 15%, preferably from 1% to 10%, more preferably from 2% to 7%, advantageously from 3% to 5% by mass relative to the total mass of the composition.

6. Composition according to any one of the preceding claims, wherein the mass content of the second impact modifier additive varies from 1% to 15%, preferably from 3% to 12%, advantageously from 5% to 10% by mass relative to the total mass of the composition.

7. Composition according to any one of the preceding claims, wherein the ratio between the mass content of the second impact modifier additive and the mass content of the first impact modifier additive varies from 0.1 to 10, preferably from 0.25 to 8, preferably from 0.5 to 5, preferably from 1 to 2.

8. Composition according to any one of the preceding claims, wherein the styrenic polymer is an acrylonitrile-butadiene-styrene polymer or a polystyrene.

9. Composition according to any one of the preceding claims, wherein the styrenic polymer is recycled.

10. A process for preparing a composition according to any one of claims 1 to 9, comprising: - a step of mixing a styrenic polymer with at least one fluidity modifier additive selected from polyolefins functionalized with at least one heterocycle comprising at least one oxygen atom, a first impact modifier additive selected from copolymers of ethylene and / or butene and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and butyl (meth)acrylate, and a second impact modifier additive selected from modified acrylonitrile-butadiene-styrene copolymers having a butadiene content greater than or equal to 60% by weight relative to the total weight of the modified acrylonitrile-butadiene-styrene polymer.

11. Use of a composition according to any one of claims 1 to 9, for the manufacture of a part, for example an extruded sheet or a plate for thermoforming.

12. Part, for example a plate for thermoforming or an extruded sheet, comprising a composition according to any one of claims 1 to 9.

13. A method for improving at least one processability property, preferably extrudability, and optionally at least one mechanical property, preferably impact resistance, of a styrenic polymer, preferably recycled, comprising adding to styrenic polymer of a fluidity modifier additive selected from polyolefins functionalized by at least one heterocycle comprising at least one oxygen atom, of a first impact modifier additive selected from ethylene and / or butene copolymers and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and butyl (meth)acrylate, and of a second impact modifier additive selected from modified acrylonitrile-butadiene-styrene copolymers having a butadiene content greater than or equal to 60% by weight relative to the total weight of the modified acrylonitrile-butadiene-styrene polymer.

14. Use of a fluidity-modifying additive selected from polyolefins functionalized with at least one heterocycle comprising at least one oxygen atom to improve extrudability, preferably to increase fluidity, preferably to increase the hot melt index, of a styrenic polymer, preferably of a recycled styrenic polymer.

15. Use of a combination of: - a fluidity-modifying additive selected from polyolefins functionalized with at least one heterocycle comprising at least one oxygen atom, - a first impact modifying additive selected from ethylene and / or butene copolymers and a polar monomer selected from (m)ethyl acrylate, (m)ethyl methacrylate and butyl (meth)acrylate, and - a second impact modifying additive selected from modified acrylonitrile-butadiene-styrene copolymers having a butadiene content greater than or equal to 60% by weight relative to the total weight of the modified acrylonitrile-butadiene-styrene polymer, to improve at least one processability property, preferably extrudability, and possibly at least one mechanical property, preferably impact resistance, of a styrenic polymer, preferably recycled.