Thermoplastic composition

Abstract

The present invention relates to a method for the manufacture of a thermoplastic composition comprising the steps of providing a stream of polypropylene (A) and combining said stream of polypropylene with at least one non-aromatic polyester (B) having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the polyester not including the carbonyl carbons and E is the number of ester groups in the polyester, wherein the polypropylene comprises recycled, preferably mechanically recycled, polypropylene.

Description

[0001] 24POLY0134-WO-ORD 1

[0002] THERMOPLASTIC COMPOSITION

[0003] The present invention generally relates to a thermoplastic composition comprising polypropylene and non-aromatic polyester having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the non-aromatic polyester not including the carbonyl carbons and E is the number of ester groups in the polyester. More in particular the present invention relates to the use of recycled polypropylene constituting part or all of the polypropylene in such a composition. The present invention further relates to a compound comprising such a composition.

[0004] WO2016 / 188817 discloses a composition comprising polypropylene, polyethylene and a compatibiliser, wherein said compatibiliser is a non-aromatic polyester having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the polyester not including the carbonyl carbons and E is the number of ester groups in the polyester. In that disclosure the non-aromatic polyester is used as a compatibiliser leading to a polyethylene and polypropylene blend wherein there is a more gradual transition between the polypropylene and polyethylene phases in the blend and the domain sizes of the dispersed phase are smaller compared to a composition not comprising a compatibiliser.

[0005] WO2016 / 198243 discloses a composition comprising a heterophasic polypropylene containing i) a matrix phase of a propylene homopolymer and / or a propylene copolymer with up to 3 wt.% of ethylene and / or at least one C4- C8a-olefin, the wt.% based on the weight of the copolymer and ii) a disperse phase of an ethylene - C3- C8a-olefin copolymer, wherein the ethylene content is at least 40 wt.% based on the weight of the ethylene - C3- C8a-olefin copolymer, one or more of a compatibiliser, wherein the compatibiliser is i) a non-aromatic polyester having an average M / E ratio of at least 10 and / or ii) a block copolymer comprising a polypropylene block and a polyester block, said polyester being a non-aromatic polyester and having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the polyester, not including the carbonyl carbons and E is the number of ester groups in the polyester.

[0006] The scientific paper “iPP / HDPE blends compatibilized by a polyester: An unconventional concept to valuable products, Kruszynski et al., Sci. Adv. 10, eado 1944 (2024)” 24POLY0134-WO-ORD 2 discloses blends of isotactic polypropylene and polypentadecalactone and blends of isotactic polypropylene, high density polyethylene and polypentadecalactone. The amount of polypentadecalactone is relatively high in those blends. This article was focused around the compatibilisation of isotactic polypropylene and (high density) polyethylene. In the blends of isotactic polypropylene and polypentadecalactone the amount of polypentadecalactone is relatively high (> 5 wt.%).

[0007] Polypropylene is a well-known polymer that is used in a variety of applications. The term polypropylene generally refers to a propylene homopolymer, which may be at least partially atactic, at least partially isotactic and / or at least syndiotactic, a random copolymer of propylene and one or more of ethylene and an a-olefin, or an impact copolymer which comprises a matrix phase comprising a propylene homopolymer or a random copolymer of propylene and one or more of ethylene and an a-olefin and a disperse phase comprising a copolymer of propylene and one or more of ethylene and an a-olefin. Unless indicated otherwise, the present invention is directed at all these types of polypropylene and the term “polypropylene” is accordingly considered as a generic term for the same.

[0008] As polypropylene is one of the most used polymers for a variety of applications there is a significant availability of recycled polypropylene, in particular mechanically recycled polypropylene. For the avoidance of doubt, such recycled polypropylene may comprise any of the specific types mentioned above. From a sustainability point of view there is a desire and need to re-use at least part of the available recycled polypropylene.

[0009] Compared to polyethylene, polypropylene typically has a much lower strain at break. This means, in simple terms, that a polypropylene article, at a temperature below the melting temperature, can only be stretched in one or more directions to a limited extent before the material breaks. With regards to recycled polypropylene, the strain at break and even the stress at strain may have deteriorated as a result of aging of the polymer and / or the recycling process. As a result, recycled polypropylene may not always be suitable to be used in more demanding applications, in particular applications that rely on the stress at strain or strain at break properties of the material. 24POLY0134-WO-ORD 3

[0010] The use of recycled polypropylene is accordingly somewhat limited for such high demanding applications and the amount of recycled polypropylene that is used for that purpose may accordingly below.

[0011] In view of the foregoing it is an object of the present invention to provide for a method to improve the strain at break properties of recycled polypropylene. Another object of the present invention is to improve the stress at strain properties of recycled polypropylene.

[0012] More in particular, the present invention is directed at a method for the manufacture of recycled polypropylene with an improved toughness, defined as the surface beneath the stress-strain curve of a lap shear strength (LSS) test measured in accordance with ISO 527-3. A further object of the invention is to provide a polypropylene based composition having an increased yield stress.

[0013] To that extent the present inventors surprisingly found that this object can be met, at least in part by adding to polypropylene a relatively small amount of non-aromatic polyester having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the polyester not including the carbonyl carbons and E is the number of ester groups in the polyester.

[0014] Accordingly, the present invention is directed at a method for the manufacture of a thermoplastic composition comprising the steps of i) providing a stream of polypropylene (A) ii) combining said stream of polypropylene with at least one non-aromatic polyester (B) having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the polyester not including the carbonyl carbons and E is the number of ester groups in the polyester, wherein the polypropylene (A) comprises recycled, preferably mechanically recycled, polypropylene.

[0015] For the avoidance of doubt the polypropylene (A) may be a mixture of virgin polypropylene and recycled polypropylene or may be only recycled polypropylene. Put differently, the polypropylene (A) preferably comprises virgin polypropylene. The amount of recycled polypropylene depends inter alia on the intended application and may be governed by requirements other than the toughness as explained above. 24POLY0134-WO-ORD 4

[0016] Preferably, the amount of non-aromatic polyester (B) is from 0.01 - 5 wt.%, preferably from 0.05 - 5 wt.%, more preferably from 0.1 - 4 wt.%, more preferably from 0.1 - 2.5 wt.%, most preferably from 0.1 - 1 wt.%, based on the weight of the polypropylene (A).

[0017] The virgin polypropylene and / or the recycled polypropylene in the polypropylene (A) in accordance with the method of the invention may be any known type of polypropylene. Thus, the polypropylene (A) may comprise or consist of monophasic polypropylene or heterophasic polypropylene.

[0018] The term monophasic polypropylene means a propylene homopolymer including atactic polypropylene, isotactic polypropylene and syndiotactic polypropylene. Preferably at least part of the polypropylene homopolymer is isotactic. A monophasic polypropylene may also be a random copolymer of propylene and one or more of ethylene and an a- olefin. Thus, a monophasic polypropylene may be a propylene - ethylene random copolymer with from 1 - 7 wt.%, preferably 1 - 5 wt.%, more preferably 1 - 3 wt.% of ethylene based on the weight of the random copolymer. Alternatively, the monophasic polypropylene may be a propylene - C4- C8a-olefin random copolymer with from 1 - 20 wt.%, preferably 1 - 10, more preferably 1-5 wt.% of C4- C8a-olefin based on the weight of the random copolymer.

[0019] The monophasic polypropylene may also be a propylene - C4- C8a-olefin random copolymer with both ethylene and one or more of C4- C8a-olefin, wherein the combined amount of comonomer is from 1 - 20 wt.%, preferably 1 - 10, more preferably 1-5 wt.% based on the weight of the random copolymer. For such copolymers the ethylene content is preferably at most 5 wt.% based on the weight of the random copolymer,

[0020] The polypropylene (A) may also comprises or consist of heterophasic polypropylene comprising a matrix phase and a disperse phase, the matrix phase consisting of a propylene homopolymer and / or a propylene copolymer with up to 3 wt.% of ethylene and / or at least one C4- C8a-olefin, the wt.% being based on the matrix phase, and the disperse phase consisting of an ethylene - C3- C8a-olefin copolymer. 24POLY0134-WO-ORD 5

[0021] If the polypropylene is a heterophasic copolymer it is preferred that the matrix phase consists of a propylene homopolymer or a propylene - ethylene copolymer with up to 3 wt.% of ethylene and further that the disperse phase consists of an ethylene propylene copolymer with from 20 - 80 wt.% of propylene and 80 - 20 wt.% of ethylene, the wt.% based on the disperse phase. For the avoidance of doubt the term consisting in the context of the heterophasic copolymers means that no other polymers apart from the polymers making up the matrix and disperse phase are present. The matrix and / or disperse phase may contain minor amounts of other components such as in particular anti-oxidants, light stabilisers, UV stabilisers and the like. Such components are present in an amount of at most 3 wt.%, at most 2 wt.% more preferably at most 1 wt.% based on the weight of the heterophasic copolymer.

[0022] Both monophasic and heterophasic polypropylene types are well known to the skilled person.

[0023] Isotactic polypropylene is preferred.

[0024] The polypropylene is preferably a propylene homopolymer or a propylene ethylene or a propylene C4- C8a-olefin random copolymer. The random copolymer is preferably a propylene - ethylene random copolymer.

[0025] Preferably the melt flow rate of the polypropylene is from 0.1 - 100 g / 10 min as measured in accordance with ISO 1133 (2.16 kg, 230 °C). More preferably the melt flow rate is from 5.0 to 60 g / 10 min.

[0026] The foregoing description of the polypropylene that may be comprised in polypropylene (A) apply to both the virgin polypropylene (if any) and the recycled polypropylene.

[0027] The recycled polypropylene may be any type of polypropylene as explained above. Preferably the recycled polypropylene is a monophasic polypropylene.

[0028] The recycled polypropylene may be post-consumer recycled polypropylene and accordingly, and typically contrary to virgin polypropylene, it may contain further 24POLY0134-WO-ORD 6 components and / or contaminants. The further components may include colorants, mould release agents, anti-oxidants, UV stabilisers, flame retardants and the like. Depending on the intended application the recycled polypropylene may also comprise fillers such as for example talc and glass fibers. Impact modifiers may also be present in the recycled polypropylene (other than the disperse phase of heterophasic polypropylene), but it is preferred that the recycled polypropylene does not comprise such impact modifiers.

[0029] As a contaminant the recycled polypropylene may contain some polyethylene, for example because the recycled polypropylene was obtained by separation and / or purification of mixed polyolefin waste streams. In the context of the present invention it is preferred that the amount of polyethylene in the recycled polypropylene is low, meaning at most 5 wt.%, preferably at most 3 wt.%, more preferably at most 1 wt.% based on the weight of the recycled polypropylene. Typically it is preferred that the recycled polypropylene contains at least 95 wt.%, preferably at least 98 wt.%, more preferable at least 99 wt.% of polypropylene, based on the weight of the polymer components in the recycled polypropylene.

[0030] The polyester in the composition according to the present invention is a non-aromatic polyester having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the polyester not including the carbonyl carbons and E is the number of ester groups in the polyester. With average M / E ratio is meant a numerical average.

[0031] The polyester is non-aromatic meaning the polyester does not contain aromatic groups. In the context of the present invention the term “polyester” may be used interchangeably with the term “non-aromatic polyester”.

[0032] The backbone of the polyester is preferably saturated meaning it preferably does not contain any double bonds. It is preferred the backbone of the polyester is (saturated) aliphatic.

[0033] The polyester backbone may, in an embodiment, contain short aliphatic branches such as methyl, ethyl, propyl, butyl, pentyl or hexyl branches. The amount of such branches 24POLY0134-WO-ORD 7 is preferably kept at a low amount since it may negatively affect the (co)crystallisation behaviour of the polyester block. In another embodiment the backbone contains one or more heteroatoms such as oxygen, nitrogen or sulfur.

[0034] The polyester may be a polyester homopolymer or a polyester copolymer.

[0035] If the polyester is a polyester copolymer, then the number of backbone carbon atoms between two neighbouring ester groups in the backbone is preferably randomly distributed over the polyester. Furthermore, the number of backbone carbon atoms (M) between ester functionalities in polyester copolymers is preferably at least 8, more preferably at least 10, or at least 12.

[0036] Typical examples of polyester homopolymers include the homopolymers obtainable by the ring opening polymerisation of dodecalactone, tridecanolactone, tetradecalactone, pentadecalactone, hexadecalactone, heptadecalactone, octadecalactone, nonadecalactone, ambrettolide, globalide. In other words typical examples of polyester homopolymers include polydodecalactone, polytridecanolactone, polytetradecalactone, polypentadecalactone, polyhexadecalactone, polyheptadecalactone, polyoctadecalactone, polynonadecalactone, polyambrettolide, polyglobalide.

[0037] Typical examples of polyester copolymers include copolymers of at least two lactones from a group including dodecalactone, tridecanolactone, tetradecalactone, pentadecalactone, hexadecalactone, heptadecalactone, octadecalactone, nonadecalactone, ambrettolide, globalide, valerolactone, caprolactone, massoia lactone, b-decalactone, s-decalactone, 13-hexyloxacyclotridec10-en-2-one, 13- hexyloxacyclotridecan-2-one.

[0038] Other typical examples of polyester copolymers include AABB type copolyesters, i.e. polyester copolymer, prepared of a combination of C2- C3o diols and C2- C32diacids provided the polyester copolymer has an average M / E of at least 10. Further it is preferred that the M / E ratio for the copolymers is at least 8. The term Cxrefers to the total amount of carbon atoms x in the diol or diacid, respectively. 24POLY0134-WO-ORD 8

[0039] Diols include, but are not limited to, ethylene glycol, propane-1 , 3-diol, butane-1 ,4-diol, pentane-1 ,5-diol, hexane-1 ,6-diol, heptane-1 ,7-diol, octane-1 , 8-diol, nonane-1 ,9-diol, decane-1 , 10-diol, undecane-1 ,11-diol, dodecane-1 ,12-diol, tridecane-1 ,13-diol, tetradecane-1 , 14-diol, pentadecane- 1 , 15-diol, hexadecane-1 , 16-diol, heptadecane- 1 ,17-diol, octadecane-1 ,18-diol, nonadecane-1 , 19-diol, icosane-1 ,20-diol, henicosane- 1 ,21-diol, docosane-1 ,22-diol, tricosane-1 ,23-diol, tetracosane-1 ,24-diol, pentacosane- 1 ,25-diol, hexacosane-1 , 26-diol, heptacosane-1 ,27-diol, octacosane-1 ,28-diol, nonacosane-1 , 29-diol, triacontane-1 ,30-diol as well as their unsaturated and branched analogues.

[0040] Diacids include, but are not limited to oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, heptanedioic acid, octanedioic acid, nonanedioic acid, decanedioic acid, undecandedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, icosanedioic acid, henicosanedioic acid, docosanedioic acid, tricosanedioic acid, tetracosanedioic acid, pentacosanedioic acid, hexacosanedioic acid, heptacosanedioic acid, octacosanedioic acid, nonacosanedioic acid, triacontanedioic acid and their unsaturated and branched analogues. The diols and diacids might also contain a heteroatom in the main chain like an oxygen, nitrogen or sulfur.

[0041] Cyclic carbonic acid esters can also be used as monomer or as comonomer in combination with lactones, dilactones, hydroxyl acids, hydroxy acid esters or diols plus dicarboxylic acids or a combination of these monomers to form polycarbonates or poly(ester-co-carbonate)s with an average M / E of 10 or larger. Examples of cyclic carbonic acid esters are trimethylene carbonate and decamethylene carbonate.

[0042] Instead of a combination of one or more diol and diacid, cyclic dilactones can also be added to produce AABB copolyesters with the desired M / E, which is 10 or higher. Typical examples of cyclic dilactones are: ethylene adipate, ethylene brassylate, butylene adipate.

[0043] Another type of polyester copolymers includes AB / AABB copolyesters prepared of a combination of lactones and dilactones and / or the combination of C2- C3o diols and C2- 24POLY0134-WO-ORD

[0044] C32 diacids, which result in polyesters having an average M / E of at least 10. The lactones, dilactones, diols and diacids can be selected from the lists given above.

[0045] Preferably he polyester is a polyester homopolymer or a polyester copolymer and preferably the polyester is one or more selected from the group consisting of polytetradecalactone, polypentadecalactone, polyhexadecalactone, poly(caprolactone- co-pentadecalactone) , poly(s-decalactone-co-pentadecalactone) , polyethylene brassylate-co-pentadecalactone), poly[ethylene-1 ,19-nonadecanedioate], poly[ethylene-1 ,23-tricosanedioate], poly[propylene-1 ,19-nonadecanedioate], poly[propylene-1 ,23-tricosanedioate], poly[1 ,4-butadiyl-1 ,19-nonadecanedioate], poly[1 ,4-butadiyl- 1 ,23-tricosanedioate], poly[1 ,6-hexadiyl-1 ,19-nonadecanedioate], poly[1 ,6-hexadiyl-1 ,23-tricosanedioate], poly[1 ,19-nonadecadiyl-1 ,19- nonadecanedioate], poly[1 ,19-nonadecadiyl-1 ,23-tricosanedioate], poly[1 ,23-tricosadiyl-

[0046] 1 .19-nonadecanedioate], poly[1 ,23-tricosadiyl- 1 ,23-tricosanedioate], poly[1 ,20- icosadiyl- 1 ,20-icosa-nedioate], poly[1 ,6-hexadiyl-1 ,20-icosenedionate], poly[propylene-

[0047] 1.20-icosanedionate],

[0048] More in general the polyester or copolyester is of general structure wherein

[0049] Rxis an organic group, preferably an aliphatic group having an average chain length of at least 10 carbon atoms and m is the number of repeating units, which generally is at least 25, such as at least 50, such as at least 100. Practical maximum number of repeating units can be 2,000 or 1 ,000.

[0050] Organic group Rxis a branched or straight hydrocarbon group optionally containing one or more heteroatoms provided that the atom neighbouring the -O- is a carbon atom, i.e. not a heteroatom. Rxmay contain one or more unsaturations, like -C=C-. Preferably Rxis a branched or straight hydrocarbon group, more preferably Rxis a branched or straight aliphatic group. Rxis preferably a saturated aliphatic group. In that respect the term chain length as used herein refers to the shortest number of atoms between two ester 24POLY0134-WO-ORD 10 functionalities (O=)C-O-. Hence the “chain length” does not include any optional branches or side groups. For example, if Rxis (C4H8) the chain length is four. Similarly, if Rxis CH2-C(CH3)2-CH2-CH2the chain length is also four. In the general formula above Rxmay be the same or different throughout the polyester provided the average chain length is at least 10 carbon atoms. The following general (co)polyester structures can be considered, which structures are to be considered as more detailed embodiments of the general structure provided above:

[0051] The chain lengths of R1, R2, R3and R4are selected such that for the polyester the average M / E ratio is at least 10. The description for Rxabove also applies for R1-R4.

[0052] It is preferred that the M / E ratio is at most 32. Hence the M / E ratio is preferably from 10 - 32, such as 12 -32 and more preferably from 12 - 24.

[0053] The molecular weight of the polyester may vary and is generally selected such that a material is obtained that can be blended with the polypropylene relatively easily.

[0054] The number average molecular weight of the polyester is preferably from 5,000 to 250,000 g / mol, more preferably from 10,000 to 100,000 g / mol, said number average molecular weight being determined as the polyethylene-equivalent molecular weight by high temperature size exclusion chromatography performed at 160 °C in trichlorobenzene using polyethylene as standard. 24POLY0134-WO-ORD 11

[0055] The polyester may be manufactured by various methods known in the art. For example, the polyesters may be prepared by (1) enzymatic ring-opening polymerization, (2) catalytic ring-opening polymerization using organic catalysts, (3) anionic ring-opening polymerization and catalytic ring-opening polymerization using metal-based catalysts, (4) ADMET (acyclic diene metathesis) or ROMP (ring-opening metathesis) of ester containing dienes or unsaturated cyclic esters, respectively or (5) polycondensation.

[0056] Enzymatic ring-opening polymerization of cyclic esters, in particular macrolactones (lactones with a ring size larger than 10 atoms) has proven to be a very efficient process. For example Novozyme 435, containing supported Candida Antarctica lipase B can polymerize pentadecalactone within 2 h at 70 °C with over 90% conversion to high molecular weight ( / Wn86,000 g / mol) polypentadecalactone (Bisht, K. S.; Henderson, L. A.; Gross, R. A.; Kaplan, D. L; Swift, G. Macromolecules 1997, 30, 2705-2711 ; Kumar, A.; Kalra, B.; Dekhterman, A.; Gross, R. A. Macromolecules 2000, 33, 6303-6309). Supported Humicola insolenscutinase gave comparable results for pentadecalactone polymerization (Hunson, M.; Abul, A.; Xie, W.; Gross, R. Biomacromolecules 2008, 9, 518-522).

[0057] Organic catalysts such as 1 ,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) selectively ringopen lactones and macrolactones such as pentadecalactone to the corresponding homo and copolymers. Although the conversions are high, in all reported cases the obtained molecular weights of the products remain relatively low (Bouyahyi, M.; Pepels, M. P. F.; Heise, A.; Duchateau, R. Macromolecules 2012, 45, 3356-3366).

[0058] The most well-known route to produce high molecular weight polymacrolactones and lactone-macrolactone copolymers is by anionic or catalytic ring-opening polymerization using metal-based catalysts. A wide variety of catalysts have been applied. Aluminum salen (WO 2012 / 065711 , van der Meulen, I.; Gubbels, E.; Huijser, S.; Sablong, R.; Koning, C. E.; Heise, A.; Duchateau, R. Macromolecules 2011 , 44, 4301-4305) and zinc phenoxyimine (WO 2014 / 188344; Bouyahyi, M.; Duchateau, R. Macromolecules 2014, 47, 517-524; Jasinska-Walc, L; Hansen, M. R.; Dudenko, D.; Rozanski, A.; Bouyahyi, M.; Wagner, M.; Graf, R.; Duchateau, R. Polym. Chem. 2014, 5, 3306-3320) catalysts are among the most active catalysts known for the ring-opening polymerization of macrolactones producing high molecular weight homo- and copolymers. Besides discrete catalysts consisting of a complex ancillary ligand system, simple metal alkoxides 24POLY0134-WO-ORD 12 can also be applied. For example, KOtBu and Mg(BHT)2THF2proved to be potent catalysts / initiators for the ring-opening polymerization of lactones and macrolactones (Jedlinski, Z.; Juzwa, M.; Adamus, G.; Kowalczuk, M.; Montaudo, M. Macromol. Chem. Phys. 1996, 197, 2923-2929; Wilson, J. A.; Hopkins, S. A.; Wright, P. M.; Dove, A. P. Polym. Chem. 2014, 5, 2691-2694; Wilson, J. A.; Hopkins, S. A.; Wright, P. M.; Dove, A. P. macromolecules 2015, 48, 950-958).

[0059] ADMET and ROMP are interesting methodologies to produce polyesters with high M / E values. The difference between ADMET and ROMP is that the first is a step growth process whereas the latter is a chain growth process. Though, but methods have resulted in polyesters with a significantly high molecular weight. The disadvantage of olefin metathesis is that to obtain the final saturated product, a hydrogenation step is necessary. The process is also rather costly (Fokou, P. A.; Meier, M. A. R. Macromol. Rapid. Commun. 2010, 31, 368-373; Vilela, C.; Silvestre, A. J. D.; Meier, M. A. R. Macromol. Chem. Phys. 2012, 213, 2220-2227; Pepels, M. P. F.; Hansen, M. R.; Goossens, H.; Duchateau, R. Macromolecules 2013, 46, 7668-7677).

[0060] Polycondensation of w-hydroxy fatty acids or w-hydroxy fatty acid esters has been reported using either enzymes or metal-based catalysts. For example, Candida Antarctica lipase B (Novozyme 435) polymerizes w-hydroxy fatty acids, such as 12- hydroxydodecanoic acid, albeit that degrees of polymerization remain rather low (Mahapatro, A.; Kumar, A.; Gross, R. A. Biomacromolecules 2004, 5, 62-68). The same enzyme was also used to copolymerize fatty acid-based diacids with diols to moderately high molecular weight polyesters (Yang, X.; Lu, W.; Zhang, X.; Xie, W.; Cai, M.; Gross, R. A. Biomacromolecules 2010, 11, 259-268). The titanium-catalysed polycondensation of w-hydroxy fatty acid esters proved to be highly efficient resulting in high molecular weight polyesters (Liu, C.; Liu, F.; Cai, J.; Xie, W.; Long, T. E.; Turner, S. R.; Lyons, A.; Gross, R. A. Biomacromolecules 2011 , 12, 3291-3298).

[0061] Methods for making polyesters suitable for application in the present invention are further disclosed for example in WO 2012 / 065711 , WO 2014 / 203209, WO 2014 / 147546, WO 2016 / 188817, the contents of which are incorporated herein by reference. 24POLY0134-WO-ORD 13

[0062] The amount of non-aromatic polyester is preferably from 0.01 - 5 wt.%, preferably 0.05 - 5 wt.%, more preferably 0.1 - 2.5 wt.%, based on the weight of the composition. The amount of polyester may be at most 1.5 wt.%, such as at most 1 wt.%. Accordingly the amount of polyester may be from 0.01 - 1.5 wt.% or 0.01 - 1 wt.%. If the amount of polyester is too low then no noticeable effect on the strain at break is observed. At a certain amount of polyester, the improvement in terms of strain at break will reach a plateau and adding further polyester will not result in a significant improvement anymore. Depending on the type of polypropylene the plateau may be reached within these preferred ranges. Typically, and in particular to balance the cost versus the benefit it is preferred to keep the amount of polyester low.

[0063] The thermoplastic composition that is manufactured in accordance with the method of the invention preferably comprises an amount of component (C) from 0 - 5 wt.%, preferably from 0 - 3 wt.%. The optional component (C) typically comprises commonly used additives for polymer compositions such as anti-oxidants, inorganic fillers, UV stabilisers, mould release agents, colorants and the like.

[0064] Typically, the component (C) does not comprise a polyolefin. Preferably the thermoplastic composition comprises at most 3 wt.%, based on the weight of the composition, of polyethylene. Preferably the amount of polyethylene is at most 2 wt.%, more preferably at most 1 wt.%. Most preferably the thermoplastic composition does not comprise polyethylene.

[0065] The amount of recycled polypropylene in the composition that is manufactured in accordance with the invention may be from 10 - 100 wt.%, such as 20 - 80 wt.% of 40 - 60 wt.% based on the weight of the polypropylene (A). The used amount will depend on the requirements for the intended application.

[0066] The composition as obtained in accordance with the invention preferably has a strain at break, determined in accordance with ISO 527-3 which is at least 10% higher compared to an otherwise identical thermoplastic composition not comprising the non-aromatic polyester (B). More preferably the strain at break is least 50% higher, even more preferably at least 100% higher. 24POLY0134-WO-ORD 14

[0067] The present invention further relates to an article comprising or consisting of the thermoplastic composition disclosed herein. Preferably the thermoplastic composition of the invention is used for the manufacture of articles wherein strain at break is an important property. Such applications include bitumen containing roofing materials like shingles. In another application the thermoplastic composition constitutes or is comprised in a pipe or a film.

[0068] The present invention further relates to the use of a non-aromatic polyester having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the polyester not including the carbonyl carbons and E is the number of ester groups in the polyester as an additive in a thermoplastic composition comprising polypropylene, for improving the strain at break as determined in accordance with ISO 527-3.

[0069] In accordance with the invention the polypropylene (A) may comprises at least one virgin polypropylene and at least one recycled polypropylene. In other words, the polypropylene (A) max be a mixture of several polypropylenes which may be of the same or different type and may be virgin polypropylene or recycled polypropylene.

[0070] Method

[0071] Methods for the manufacture of thermoplastic composition of the invention are known per se and include typical melt mixing processes carried out either in batch or continuous form.

[0072] If the polypropylene (A) consists of a mixture of both virgin polypropylene and recycled polypropylene then the stream of polypropylene (A) may comprise all the polypropylene prior to be being combined with the polyester and optional further components (C). Alternatively, a part of the polypropylene (A) is combined with the polyester to form an intermediate composition and only thereafter another polypropylene is added to such an intermediate composition so as to form the final thermoplastic composition. For example, recycled polypropylene may be added to a feeding section of an extruder in the form of flakes or powder and molten in the first sections of the extruder, while the polyester and / or a further stream of polypropylene is fed to the extruder more downstream of one another, for example using side-extruders. Alternatively, streams of the components 24POLY0134-WO-ORD 15 making up the polypropylene (A) and the non-aromatic polyester (B) are combined in a common feeding section of a melt mixing device such as an extruder.

[0073] In a further preferred aspect the components (A) and (B) are mixed in solid form prior to being fed to a melt mixing device such as an extruder. Components (C), if any, may be added at any stage to the other components.

[0074] While the present invention is primarily directed at a method to manufacture a thermoplastic composition, the present invention further includes the use of such composition for the manufacture of compounds.

[0075] Accordingly, the present invention further relates to a thermoplastic compound comprising the composition manufactured in accordance with the method set out herein and at least one inorganic filler and / or at least one impact modifier, provided that the compound preferably does not comprise polyethylene.

[0076] Test methods and Examples

[0077] All compositions were prepared using the same procedure, only differing in the amounts of polypropylene and polypentadecalactone (PPDL). The appropriate amounts of components were measured, mixed with antioxidant Irganox 1010, and fed into a corotating twin-screw extruder heated to 190°C and a screw rotation rate set at 130 rpm resulting in a residence time of about 1 .5 min.

[0078] Film samples were prepared via compression-moulding using a LabEcon 600 high- temperature press (Fontijne Presses, the Netherlands). The following compressionmoulding cycle was applied: heating to 190 °C, stabilizing for 5 min with no force applied, 5 min with 100 kN normal force and followed by cooling to 40 °C with 10 °C / min and 100 kN normal force.

[0079] Weight average molecular weight ( / Ww) and Number average molecular weight (Mn): is determined in accordance with ASTM D6474-12. SEC measurements were performed at 150 °C on a Polymer Char GPC-IR® built around an Agilent GC oven model 7890, equipped with an autosampler and the Integrated Detector IR4. 1 ,2-Dichlorobenzene (o- DCB) was used as an eluent at a flow rate of 1 mL / min. The data were processed using 24POLY0134-WO-ORD 16

[0080] Calculations Software GPC One®. The molecular weights ( / Wn, Mw) were calculated with respect to polystyrene standards. Polydispersity index (PDI) is calculated by dividing the weight average molecular weight ( / Ww) by the number average molecular weight ( / Wn) and wherein each of / Wwand Mnare measured in accordance with ASTM D6474-12.

[0081] The peak melting (Tm) and crystallization (Tc) temperature was determined using Differential Scanning Calorimetry (DSC) in accordance with ASTM D3418-15. Using a nitrogen purge gas at a flow rate of 50 ± 5 mL / min, two heating and cooling cycles between -40 °C to 230 °C and a heating and cooling rate of 10 °C / min were used. The peak melting temperature was determined using the second heating cycle.

[0082] The mechanical properties of the test samples were determined using a Zwick type Z020 tensile tester equipped with a 1.0 kN load cell according to ISO 527-3 standard (specimen type B5). A grip-to-grip separation of 15 mm was used. The samples were pre-stressed to 3 N, then loaded with a constant crosshead speed 15 mm / min.

[0083] The polypropylene of the examples was PP-PCR (rPP) (Moprylene B440 Jazz from Morssinkhof Rymoplast), a post-consumer recycled polypropylene resin having a melting point of 162.3 °C.

[0084] The polyester was polypentadecalactone with a number average molecular weight, Mn of 99.0 kg / mol (determined via gel-permeation chromatography in accordance with ASTM D6474-12 using polystyrene standards) and a polydispersity (weight-average molecular weight divided by the number average molecular weight, / Ww / / Wn) of 2.3. The polyester of the examples revealed the melting point of 95.5 °C.

[0085] The following thermoplastic compositions were manufactured. 24POLY0134-WO-ORD 17

[0086] E X A M P L E S

[0087] *Not determined due to the presence of coloured dyes / pigments in rPP.

[0088] The present inventors surprisingly found that addition of PPDL to the polypropylene results in a significant increase of the strain at break, without however jeopardising the intrinsic strength of the polypropylene. Present inventors conclude that even a small amount of polyester added to the polypropylene will result in a significant increase in the strain at break indicative for a significant toughening of the polypropylene. The present inventors consider that the same or at least similar effects will be obtained when the nonaromatic polyester (B) will be added to a stream comprising or consisting of recycled polypropylene.

Claims

24POLY0134-WO-ORD 18C L A I M S1 . Method for the manufacture of a thermoplastic composition comprising the steps of i) providing a stream of polypropylene (A) ii) combining said stream of polypropylene (A) with at least one non-aromatic polyester (B) having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the polyester not including the carbonyl carbons and E is the number of ester groups in the polyester, wherein the polypropylene (A) comprises recycled, preferably mechanically recycled, polypropylene.

2. The method of claim 1 wherein the amount of non-aromatic polyester (B) is from 0.01- 5 wt.%, preferably from 0.05 - 5 wt.%, more preferably from 0.1 - 4 wt.%, more preferably from 0.1 - 2.5 wt.%, most preferably from 0.1 - 1 wt.%, based on the weight of the polypropylene (A).

3. The method of claim 1 or 2 wherein the stream of polypropylene (A) comprises virgin polypropylene.

4. The method of any one or more of claims 1 - 3 wherein the recycled polypropylene comprises at most 5 wt.%, preferably at most 3 wt.%, more preferably at most 1 wt.% of components other that polypropylene polymers.

5. The method of any one or more of claims 1 - 4 wherein the recycled polypropylene contains at most 5 wt.%, preferably at most 3 wt.%, more preferably at most 1 wt.%, based on the weight of the recycled polypropylene, of polyethylene.

6. The method of any one or more of claims 1 - 4 wherein the amount of recycled polypropylene is from 5 - 100 wt.%, preferably from 5 - 75 wt.%, preferably from 10- 50 wt.%, based on the weight of the polypropylene (A).

7. The method of any one or more or claims 1 - 6 wherein the composition has a strain at break, determined in accordance with ISO 527-3, which is at least 10% higher, preferably at least 50% higher, more preferably at least 100% higher compared to an24POLY0134-WO-ORD 19 otherwise identical thermoplastic composition not comprising the non-aromatic polyester (B).

8. The method of any one or more of claims 1 - 7 wherein the M / E ratio of the non- aromatic polyester (B) is from 12 - 32.

9. The method of any one or more of claims 1 - 8 wherein the non-aromatic polyester(B) is a polyester homopolymer or a polyester copolymer and preferably the polyester is one or more selected from the group consisting of polytetradecalactone, polypentadecalactone, polyhexadecalactone, poly(caprolactone- copentadecalactone), poly(s-decalactone-co-pentadecalactone ), poly( ethylene brassylate-co-pentadecalactone ), poly[ ethylene-1 , 19-nonadecanedioate], poly[ ethylene-1 ,23-tricosanedioate], poly[propylene-1 , 19-nonadecanedioate], poly[propylene-1 ,23-tricosanedioate], poly [ 1 ,4-butad iy I- 1 , 19-nonadecanedioate], poly[1 ,4-butadiyl-1 ,23-tricosanedioate], poly[1 ,6-hexadiyl-1 , 19-nonadecanedioate], poly[1 ,6-hexadiyl-1 ,23-tricosanedioate], poly[1 , 19-nonadecadiyl-1 , 19- nonadecanedioate], poly[1 , 19-nonadecadiyl-1 ,23-tricosanedioate], poly[1 ,23- tricosadiyl-1 , 19-nonadecanedioate], poly[1 ,23-tricosadiyl-1 ,23-tricosanedioate], poly[1 ,20-icosadiyl-1 ,20-icosa-nedioate], poly[1 ,6-hexadiyl-1 ,20-icosenedionate], poly[propylene-1 ,20-icosanedionate],10. The method of any one or more of claims 1 - 9 wherein the recycled polypropylene is a polypropylene homopolymer, a random polypropylene copolymer or a heterophasic impact polypropylene copolymer.

11. The method of any one or more of claims 1 - 10 wherein the thermoplastic composition comprises said polypropylene (A), 0.01 - 5 wt.% of said polyester (B) and from 0 - 5 wt.% of optional further components (C), based on the weight of the thermoplastic composition, wherein the sum of the components (A) - (C) is 100 wt.% based on the weight of the thermoplastic composition.

12. Thermoplastic compound comprising the composition obtainable by the method of any one or more of claims 1 - 11 , and at least one further component selected from the group consisting of inorganic fillers, impact modifiers, flame retardants.24POLY0134-WO-ORD 2013. Use of a non-aromatic polyester having an average M / E ratio of at least 10, wherein M is the number of backbone carbon atoms in the polyester not including the carbonyl carbons and E is the number of ester groups in the polyester as an additive in a thermoplastic composition comprising recycled, preferable mechanically recycled, polypropylene, for improving the strain at break as determined in accordance with ISO 527-3 when compared to an otherwise identical thermoplastic composition not comprising said polyester.

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