Recycling of polyolefin waste by adding a amide clarifier

Abstract

The invention relates to a method for recycling a clarified polyolefin waste comprising the steps of collecting the clarified polyolefin waste which contains a sorbitol clarifier, and introducing an amide clarifier into the clarified polyolefin waste to form a recycled polyolefin. It also relates to the recycled polyolefin which comprises the amide clarifier and the clarified polyolefin waste which contains the sorbitol clarifier; and to a use of a amide clarifier for reducing the haze of the clarified polyolefin waste which contains the sorbitol clarifier after recycling of the clarified polyolefin waste.

Description

[0001] Recycling of polyolefin waste by adding a amide clarifier

[0002] The invention relates to a method for recycling a clarified polyolefin waste comprising the steps of collecting the clarified polyolefin waste which contains a sorbitol clarifier, and introducing an amide clarifier into the clarified polyolefin waste to form a recycled polyolefin. It also relates to the recycled polyolefin which comprises the amide clarifier and the clarified polyolefin waste which contains the sorbitol clarifier; and to a use of a amide clarifier for reducing the haze of the clarified polyolefin waste which contains the sorbitol clarifier after recycling of the clarified polyolefin waste.

[0003] Recycled polyolefins are expected to be a growing market and an important element in recycling management of natural resources. The recycled polyolefins usually are being intended to replace virgin polyolefins by an identical or at least comparable property profile.

[0004] Polyolefins such as polyethylene, polypropylene or poly(propylene-co-ethylene) have applications in multiple industries, for example in packaging for consumer products. In some of these applications, such as injection molded thermoformed polypropylene food and storage containers, cups, trays, lids, or blow molded bottles, good clarity of these articles is desired. Hence, several types of clarifiers were developed to achieve good clarity. Equally desired is the retention of such good clarity in recycled polyolefin articles.

[0005] During recycling of polyolefin which contains sorbitol clarifiers often an undesired increase in haze occurs, e.g. upon multiple pass extrusions. Thus, polyolefins which contain sorbitol clarifiers are often not usable in recycling, as this recycled polyolefin material loses its initial clarity. Object was to overcome this problem and to produce recycled polyolefin with good clarity, low haze and low color.

[0006] The object was solved by a method for recycling a clarified polyolefin waste comprising the steps of a) collecting the clarified polyolefin waste which contains a sorbitol clarifier, and b) introducing an amide clarifier into the clarified polyolefin waste to form a recycled polyolefin.

[0007] The object was solved by the recycled polyolefin which comprises the amide clarifier and the clarified polyolefin waste which contains the sorbitol clarifier.

[0008] The object was solved by a use of a amide clarifier for reducing the haze of the clarified polyolefin waste which contains the sorbitol clarifier after recycling of the clarified polyolefin waste.

[0009] The clarified polyolefin waste can be

[0010] - pre-user waste, such as production waste collected from producers or converters; - post user waste, such as household packaging collected via kerbside collection or bring systems, or end of life products returned by consumers; or

[0011] - demolition waste, such as waste from demolition of civil constructions.

[0012] Material that is collected and reused within the same manufacturing process is usually not considered a clarified polyolefin waste.

[0013] The polyolefin in the clarified polyolefin waste usually has a pre-damage, for example new chemical groups (such as carbonyl groups) are produced on the polymer chain by oxidative or photooxidative processes. Usually, the polyolefin in the clarified polyolefin waste has carbonyl groups that are not present with virgin polyolefin. The concentration of the carbonyl groups is often a measure for the pre-damage of the polyolefin. The concentration of carbonyl groups can be determined by infrared spectroscopy, such as by a measurement of the absorption of the carbonyl oscillation in the range of 1720 cm1.

[0014] The clarified polyolefin waste may comprise further plastic additives, which were introduced during the production of the virgin polyolefin, such as antioxidants, UV absorbers, light stabilizers, metal deactivators, phosphites, phosphonates, hydroxylamines and amine N-oxides, nitrones, thiosynergists, rheology modifiers, peroxide scavengers, acid scavengers, basic-co-stabilizers, nucleating agents, benzofuranones and indolinones, and flame retardants.

[0015] The collection of the clarified polyolefin waste can be made in different ways and often depend on their origin. The collection of post user waste can be made by kerbside collection of specific fractions, by bring systems where used products are deposited in containers by users, by returning of end of life products (e.g. electronic equipment or vehicles) to the supplier which then can send it to specialized companies for dismantling and ultimate recovery of the plastics content. The collection of pre-user waste can be made by collection production waste from the producers and converters, such as by dealers who may granulate or otherwise concentrate the pre-user waste. The collection of demolition waste, which usually is produced upon demolition of civil constructions, can be made by separating plastics-containing parts out which can be sent to specialized companies for further sorting.

[0016] The form of the clarified polyolefin waste can be flakes, powder, pellets, chips, film, bottles, sacks, fiber offcuts, and mixtures thereof.

[0017] The clarified polyolefin waste can be cleaned, e.g. by washing with solvents, such as water. The cleaning can be done before, after or before and after the collecting of the clarified waste. Preferably, the clarified polyolefin waste is cleaned after collecting it. The clarified polyolefin waste can be comminuted, e.g. by grounding, milling, chipping, pelleting, or micronizing. The comminuting can be done before, after or before and after the collecting of the clarified waste. Preferably, the clarified polyolefin waste is comminuted after collecting it.

[0018] The clarified polyolefin waste can be sorted, e.g. by hand or by machines. During the sorting undesired material can be removed. The sorting can be done before, after or before and after the collecting of the clarified waste. Preferably, the clarified polyolefin waste is sorted after collecting it.

[0019] The concentration of the sorbitol clarifier may vary in different batches, e.g. batches collected from different sources or collected on different days. The clarified polyolefin waste from different batches can be mixed to adjust the concentration of the sorbitol clarifier in the clarified polyolefin waste.

[0020] The clarified polyolefin waste may contain at least 0.01 wt%, preferably at least 0.05 wt%, and in particular at least 0.1 wt% of the sorbitol clarifier.

[0021] The clarified polyolefin waste may contain up to 1 .5 wt%, preferably up to 0.8 wt%, and in particular up to 0.5 wt% of the sorbitol clarifier.

[0022] The clarified polyolefin waste may contain 0.01 to 3 wt%, preferably 0.05 to 1.0 wt%, and in particular 0.1 to 0.6 wt% of the sorbitol clarifier.

[0023] The clarified polyolefin waste usually comprises at least 80, 85, 90, 95, 96, 97, 98, or 99 wt% of the polyolefin, preferably poly (propy lene-co-ethylene), when it is used in step b). The concentration of the polyolefin in the clarified polyolefin waste may be lower when it is collected in step a), and then it can be cleaned and / or sorted.

[0024] Suitable polyolefins are polymers of monoolefins and diolefins, for example of polypropylene, polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene, polyvinylcyclohexane, polyisoprene or poly-butadiene, polyhexene, polyoctene, as well as polymers of cycloolefins (for instance of cyclopentene, cyclohexene, cyclooctene or norbornene), polyethylene (which optionally can be crosslinked), for example high density polyethylene (HDPE), high density and high molecular weight polyethylene (HDPE-HMW), high density and ultrahigh molecular weight polyethylene (HDPE-UHMW), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), (VLDPE) and (ULDPE), or polypropylene, for example isotatic, syndiotatic and atatic polypropylene.

[0025] Suitable polyolefins are also copolymers of monoolefins and diolefins with each other, for example ethylene / propylene copolymers (also known as poly (propylene-co-ethylene)), linear low density polyethylene (LLDPE) and mixtures thereof with low density polyethylene (LDPE), very low density polyethylene, propylene / but-1- ene copolymers, propylene / isobutylene copolymers, ethylene / but-1-ene copolymers, ethylene / hexene copolymers, ethylene / methylpentene copolymers, ethylene / heptene copolymers, ethylene / octene copolymers, ethylene / vinylcyclohexane copolymers, ethylene / cycloolefin copolymers (e.g. ethylene / norbornene like COC), ethylene / 1 -olefins copolymers, where the 1 -olefin is generated in-situ; propylene / butadiene copolymers, isobutylene / isoprene copolymers.

[0026] Suitable polyolefins are also mixtures of polyolefins, for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP / HDPE, PP / LDPE) and mixtures of different types of polyethylene (for example LDPE / HDPE).

[0027] Preferred polyolefin is polypropylene or copolymers of polypropylene (such as poly(propylene-co-ethylene)). Preferably, the clarified polyolefin waste is clarified poly(propylene-co-ethylene) waste. where R1, R2, and R3are independently selected from H or Ci-Ce alkyl. Mixtures of sorbitol clarifiers are also possible.

[0028] Suitable R1are independently selected H, methyl, ethyl, propyl, butyl, pentyl or hexyl, which can be linear or branched and where linear is preferred. Preferred R1are independently selected from H, methyl, ethyl or n-propyl.

[0029] Suitable R2are independently selected from H, methyl, ethyl, propyl, butyl, pentyl or hexyl, which can be linear or branched and where linear is preferred. Preferred R2are H or methyl.

[0030] Suitable R3are independently selected from H, methyl, ethyl, propyl, butyl, pentyl or hexyl, which can be linear or branched and where linear is preferred. Preferred R3are H or n-propyl.

[0031] Preferably, the sorbitol clarifiers is of the formula (I) where R1is independently selected from H, methyl, ethyl or propyl, R2 is independently selected from H or methyl, and R3 is H or propyl.

[0032] In a preferred form of the formula (I) R1, R2, and R3are H. In another preferred form of the formula (I) R1is methyl, and R2and R3are H.

[0033] In another preferred form of the formula (I) R1is ethyl, and R2and R3are H.

[0034] In another preferred form of the formula (I) R1and R2are methyl, and R3is H.

[0035] In another preferred form of the formula (I) R1is n-propyl, R2is H, and R3is n-propyl.

[0036] The clarified polyolefin waste may contain only a single type of the sorbitol clarifier of the formula (I) (for example where R1is methyl, and R2and R3are H; or as another example where R1is n-propyl, R2is H, and R3is n-propyl) or a mixture of different types of sorbitol clarifiers of the formula (I).

[0037] Step b) comprises the introducing of the amide clarifier into the clarified polyolefin waste to form a recycled polyolefin.

[0038] The amide clarifier can be introduced into the clarified polyolefin waste in a concentration of below 500 ppm, preferably below 250 ppm, and in particular below 200 ppm.

[0039] The amide clarifier can be introduced into the clarified polyolefin waste in a concentration of at least 1 ppm, preferably at least 10 ppm, and in particular at least 25 ppm.

[0040] The amide clarifier can be introduced into the clarified polyolefin waste in a concentration of 0.0001 to 0.1 wt%, preferably 0.001 to 0.025 wt%, and in particular 0.003 to 0.018 wt%.

[0041] In another form the amide clarifier is introduced into the clarified polyolefin waste in a weight ratio of the amide clarifier to the sorbitol clarifier of 1 : 4 to 1 : 80, preferably 1 : 7 to 1 : 50, and in particular 1 : 10 to 1 : 40.

[0042] The amount of the sorbitol clarifier in clarified polyolefin waste can be analyzed by high pressure liquid chromatography (HPLC).

[0043] Preferably, no further sorbitol clarifier is added to the clarified polyolefin waste in the present method for recycling, such as in step a) or step b). The term "no further sorbitol clarifier” usually means that neither additional amounts of the same sorbitol clarifier is added which is already contained in the clarified polyolefin waste, nor that any sorbitol clarifier is added which is different to the sorbitol clarifiers which are already contained in the clarified polyolefin waste.

[0044] The amide clarifier can be introduced in the clarified polyolefin waste by melting the clarified polyolefin waste and by mixing the clarified polyolefin waste with the amide clarifier. The melting of the clarified polyolefin waste and the mixing the clarified polyolefin waste with the amide clarifier can be made simultaneously or consecutively in any order.

[0045] In a preferred form the amide clarifier can be introduced in the clarified polyolefin waste by melting the clarified polyolefin waste and by mixing the clarified polyolefin waste with the amide clarifier, for example by a side feeder addition to the extruder.

[0046] In another form the amide clarifier can be introduced in the clarified polyolefin waste by first mixing the clarified polyolefin waste with the amide clarifier and followed by melting the clarified polyolefin waste.

[0047] The amide clarifier can be introduced in the clarified polyolefin waste

[0048] - in pure form, preferably in pure powder form,

[0049] - as masterbatch, which comprises the amide clarifier incorporated in a carrier polymer, or

[0050] - as compounded polymer, which comprises the amide clarifier incorporated in a polymer matrix.

[0051] In one form the amide clarifier is introduced in the clarified polyolefin waste in form of a masterbatch which comprises the amide clarifier incorporated in the carrier polymer. The masterbatch can be in powder or granular form, preferably in granular form. The carrier polymer can be a polyolefin, e.g. polyethylene or polypropylene. The carrier polymer can be a virgin polymer or a recyclate. The masterbatch usually comprises 0.1 to 5 wt%, preferably 0.25 to 2 wt% of the amide clarifier. The masterbatch may comprise further plastic additives or pigments, e.g. the further plastic additives listed below. The masterbatch can be introduced in the clarified polyolefin waste by first melting the clarified polyolefin waste followed by mixing the clarified polyolefin waste with the masterbatch, for example by a side feeder addition to the extruder.

[0052] In another form the amide clarifier is introduced in the clarified polyolefin waste in form of a compounded polymer, which comprises the amide clarifier incorporated in a polymer matrix.

[0053] The polymer matrix can be a polyolefin, e.g. polyethylene or polypropylene. The polymer matrix can be a virgin polymer or a recyclate. The compounded polymer usually comprises 0.0001 to 0.1 wt%, preferably 0.001 to 0.025 wt%, and in particular 0.003 to 0.018 wt% of the amide clarifier. The compounded polymer may comprise further plastic additives or pigments, e.g. the further plastic additives listed below. The compounded polymer can be introduced in the clarified polyolefin waste by first premixing it with the clarified polyolefin waste followed by melting the premix comprising the compounded polymer and the clarified polyolefin waste, e.g. in an extruder.

[0054] The melting of the clarified polyolefin waste can be achieved at a temperature of at least 80, 90, 100, 110, or 150 °C. The melting of the clarified polyolefin waste in step b) can be achieved at a temperature in the range of 800 to 300 °C, preferably 100 to 250 °C. The amide clarifier can be introduced in the clarified polyolefin waste by mixers, kneaders or extruders, where extruders are preferred. Suitable extruders are single-screw extruders, twin- screw extruders, planetary gear extruders, or ring extruders. The introducing of the amide clarifier can take place under air or under inert gas conditions such as under nitrogen. The introducing of the amide clarifier can take place under ambient pressure or under vacuum.

[0055] A suitable amide clarifier can be a bisamide, a trisamide or a tetraamide of any of the formulae (IA), (IB), and (IC) wherein x and y are 2 or 3 or 4; z' and z” independently of one another are 1 or 2 or 3 with the proviso that the sum of z' and z” is either 2 or 3 or 4; Xo is a residue which is formed by elimination of x carboxyl groups of a saturated or unsaturated aliphatic polycarboxylic acid having 3 to 25 carbon atoms, a residue which is formed by elimination of x carboxyl groups of a saturated or unsaturated alicyclic polycarboxylic acid having 7 to 25 carbon atoms or a residue which is formed by elimination of x carboxyl groups of an aromatic polycarboxylic acid having 8 to 25 carbon atoms; any of said polycarboxylic acids optionally contains further hetero atoms in its skeleton; the radicals Xi independently of one another are

[0056] C1-C20 alkyl unsubstituted or substituted by one or more hydroxy, amino and / or nitro groups;

[0057] C2-C20 alkenyl unsubstituted or substituted by one or more hydroxy, amino and / or nitro groups;

[0058] C2-C20 alkyl interrupted by oxygen or sulfur;

[0059] C3-C12 cycloalkyl unsubstituted or substituted by one or more C1-C20 alkyl; bis[C3-Ci2 cyclo alkyl]— C1-C10 alkyl unsubstituted or substituted by one or more C1-C20 alkyl; a bicyclic or tricyclic hydrocarbon radical with 5 to 20 carbon atoms unsubstituted or substituted by one or more Ci- 020 alkyl; phenyl unsubstituted or substituted by one or more radicals selected from C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylamino, di-(Ci-C2o alkyl)amino, amino, hydroxy and nitro; pheny I-C1-C20 alkyl unsubstituted or substituted by one or more radicals selected from C1-C20 alkyl, C1-C20 alkoxy, Ci- 020 alkylamino, di-(Ci-C2o alkyl)amino, amino, hydroxy and nitro; phenylethenyl unsubstituted or substituted by one or more C1-C20 alkyl; bipheny l-(Ci-Cio alkyl) unsubstituted or substituted by one or more C1-C20 alkyl; naphthyl unsubstituted or substituted by one or more C1-C20 alkyl; naphthy I-C1-C20 alkyl unsubstituted or substituted by one or more C1-C20 alkyl; naphthoxymethyl and substituted or substituted by one or more C1-C20 alkyl; biphenylenyl, fluorenyl, anthryl; a 5 to 6 membered heterocyclic radical unsubstituted or substituted by one or more C1-C20 alkyl; a C1-C20 hydrocarbon radical containing one or more halogen or pseudo-halogen; tri(Ci-Cio alkyl)silyl; or tri(Ci-Cio alkyl)silyl(Ci-Cio alkyl);

[0060] Yo is a residue which is formed by elimination of y amino groups of a saturated or unsaturated aliphatic polyamine having 3 to 25 carbon atoms, a residue which is formed by elimination of y amino groups of a saturated or unsaturated alicyclic polyamine having 6 to 25 carbon atoms or a residue which is formed by elimination of y amino groups of an aromatic polyamine having 6 to 25 carbon atoms; any of said polyamines optionally contains further hetero atoms in its skeleton;

[0061] Zo is a residue which is formed by elimination of z' amino groups and z" carboxyl groups of an unsaturated or saturated aliphatic amino carboxylic acid having 2 to 25 carbon atoms, a residue which is formed by elimination of z' amino groups and z" carboxyl groups of a saturated or unsaturated alicyclic amino carboxylic acid having 7 to 25 carbon atoms or a residue which is formed by elimination of z' amino groups and z" carboxyl groups of an aromatic amino carboxylic acid having 7 to 25 carbon atoms; any of said amino carboxylic acids optionally contains further hetero atoms in its skeleton; the radicals Z1 and Z2 independently of one another have the same definition given for Xi.

[0062] Examples of a saturated or unsaturated aliphatic polycarboxylic acid having 3 to 25, preferably 3 to 16, in particular 4 to 12, carbon atoms and x carboxyl groups and optionally containing further hetero atoms in its skeleton are malonic acid, diphenylmalonic acid, succinic acid, phenylsuccinic acid, diphenylsuccinic acid, glutaric acid, 3,3- dimethylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1 ,12-dodecanedioic acid, 1 , 14-tetradecanedioic acid, 1 ,18-octadecanedioic acid, citric acid, methanetricarboxylic acid, tricarballylic acid, propenetricarboxylic acid, pentanetricarboxylic acid, ethanetetracarboxylic acid, propanetricarboxylic acid (particularly 1 , 2, 3-propanetricarboxylic acid), propanetetracarboxylic acid, pentanetetracarboxylic acid, butanetetracarboxylic acid (particularly 1 ,2,3,4-butanetetracarboxylic acid), dodecanetetracarboxylic acid, ethylenediaminetetraacetic acid, nitrilotriacetic acid, ethyleneglycolbis[beta- aminoethylether]N, N,N', N'-tetraacetic acid, N-hydroxyethylethylenediamine-N, N', N'-triacetic acid, 1 ,3-diaminopropane-2-ol-N, N,N',N'- tetraacetic acid, 1 ,2- diaminopropane-N, N,N', N '-tetraacetic acid, nitrilotripropionic acid, 1,6-hexanediaminetetraacetic acid, N-(2- carboxyethyl)iminodiacetic acid and the like.

[0063] Examples of a saturated or unsaturated alicyclic polycarboxylic acid having 7 to 25, preferably 8 to 16, carbon atoms and x carboxyl groups and optionally containing further hetero atoms in its skeleton are 1,2-cyclohexane dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanediacetic acid, cyclohexanetricarboxylic acid, cyclobutanetetracarboxylic acid, cyclopentanetetracarboxylic acid, cyclohexanetetracarboxylic acid, tetrahydrofurantetracarboxylic acid, 5-(succinic acid)-3-methyl-3-cylohexene-1 ,2-dicarboxylic acid, bicyclo[2,2,2]octa-7-ene-2,3,5,6- tetracarboxylic acid, 5,6,9, 10-tetracarboxytricyclo[6.2.2.0.sup.2,7 ]dodeca- 2,11 -diene which may have a lower alkyl group as a substituent (such as a methyl group at the 3-, 8- 11- or 12-position), 1,2-cyclohexanediaminetetraacetic acid, 2,3,5- tricarboxycyclopentylacetic acid, 6-methyl-4-cyclohexene-1 ,2,3-tricarboxylic acid, 3,5,6- tricarboxynorbornene-2-acetic acid, thiobis(norbornene-2,3-dicarboxylic acid), bicyclo[4.2.0]octane-3, 4,7,8- tetracarboxylic acid, 1,1 '-bicyclopropane-2, 2', 3, 3'-tetracarboxylic acid, 1 ,2-bis(2,3-dimethyl-2,3- dicarboxycyclobutyl)ethane, pyrazine-2,3, 5, 6- tetracarboxy lie acid, tricyclo[4.2.2.0.sup.2, 5 ]decane-9-ene-3, 4,7,8- tetracarboxylic acid, 3,4-dicarboxy- 1,2, 3, 4-tetrahydro-1 -naphthalenesuccinic acid which may have a lower alkyl group as a substituent (such as a methyl group at the 1-, 5-, 6- or 7-position), 2,3,4,5,6,7,12,13- octahydro- phenanthrene-3,4,5,6-tetracarboxylic acid and the like.

[0064] Examples of an aromatic polycarboxylic acid having 8 to 25, preferably 8 to 22, in particular 8 to 17, carbon atoms and x carboxyl groups and optionally containing further hetero atoms in its skeleton are p-phenylenediacetic acid, p- phenylenediethanoic acid, phthalic acid, 4-tert-butylphthalic acid, isophthalic acid, 5-tert-butylisophthalic acid, terephthalic acid, 1,8- naphthalic acid, 1 ,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7- naphthalenedicarboxylic acid, diphenic acid, 3,3'-biphenyldicarboxylic acid, 4,4'- biphenyldicarboxylic acid, 4,4'- binaphthy Idicarboxy lie acid, bis(3-carboxyphenyl)methane, bis(4-carboxyphenyl)methane, 2,2-bis(3- carboxyphenyl)propane, 2,2-bis(4-carboxyphenyl)propane, 3,3'-sulfonyldibenzoic acid, 4, 4, -sulfonyldibenzoic acid, 3,3'-oxydibenzoic acid, 4,4'-oxydibenzoic acid, 3,3'-carbonyldibenzoic acid, 4,4'-carbonyldibenzoic acid, 3,3'- thiodibenzoic acid, 4,4'-thiodibenzoic acid, 4,4'-(p-phenylenedioxy)dibenzoic acid, 4,4'-isophthaloyldibenzoic acid, 4,4'-terephthaloyldibenzoic acid, dithiosalicylic acid, benzenetricarboxylic acid such as trimesic acid, benzenetetracarboxylic acid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid, diphenylethertetracarboxylic acid, diphenylsulfonetetracarboxylic acid, diphenylmethanetetracarboxylic acid, perylenetetracarboxylic acid, naphthalenetetracarboxylic acid, 4,4'-dinaphthalic acid, benzidine-3,3'-dicarboxyl- N, N'-tetraacetic acid, diphenylpropanetetracarboxylic acid, anthracenetetracarboxylic acid, phthalocyaninetetracarboxylic acid, ethyleneglycol-trimellitic acid diester, benzenehexacarboxylic acid, glycerinetrimellitic acid triester and so on.

[0065] Examples of linear or branched alkyl having up to 20 carbon atoms and being optionally substituted by one or more hydroxy, amino and / or nitro groups are ethyl, n-propyl, 1 -methylethyl, n-butyl, 2-methylpropyl, 1 -methylpropyl, tert- butyl, pentyl, 1 -methylbutyl, 2-methylbutyl, 3-methylbutyl, 1 ,1 -dimethylpropyl, 1 -ethylpropyl, tert-butylmethyl, hexyl, 1- methylpentyl, heptyl, isoheptyl, 1-ethylhexyl, 2-ethylpentyl, 1 -propylbutyl, octyl, nonyl, isononyl, neononyl, 2,4,4- trimethylpentyl, undecyl, tridecyl, pentadecyl, heptadecyl, hydroxymethyl, 1 -hydroxyethyl and 1 -aminoethyl. Branched Ca-Cioalkyl is particularly preferred. One of the preferred meanings of the radicals Xi, Yi, Zi and Z2 is branched C3-C10 alkyl with a quaternary C atom in position 1, in particular -C(CH3)2-H or -C(CH3)2-(Ci-C7alkyl).

[0066] Examples of C2-C2oalky I interrupted by oxygen or sulfur are t-butoxymethyl, t-butoxyethyl, t-butoxypropyl, t- butoxybutyl, (H3C)3C-S-CH2-, (H3C)3C-S-C2H4-, (H3C)3C-S-C3H5- and (HsC^C-S-C^s-.

[0067] Examples of Ci-Csalkoxy are methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy and octyloxy. Methoxy is particularly preferred.

[0068] Examples of Ci-Csalky Ithio are methylthio, ethylthio, propylthio, butylthio, pentylthio, hexylthio, heptylthio and octylthio.

[0069] Examples of Ci-Csalky Isulfoxy are methylsulfoxy, ethylsulfoxy, propylsulfoxy, butylsulfoxy, pentylsulfoxy, hexylsulfoxy, heptylsulfoxy and octylsulfoxy.

[0070] Examples of Ci-C2oalkeny I unsubstituted or substituted by one or more hydroxy, amino and / or nitro groups are 9- decenyl, 8-heptadecenyl, 11-hydroxy-8-heptadecenyl and 11-amino-8-heptadecenyl.

[0071] Examples of C3-Ci2cycloalkyl unsubstituted or substituted by one or more Ci-C2oalkyl, e.g. 1 , 2, 3 or 4 Ci-C4alkyl, are cyclopropyl, 3-methylcyclopropyl, 2,2,3,3-tetramethylcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 1- methylcyclohexyl, 2-methylcyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl and cycloheptyl.

[0072] An example of bis[C3-Ci2cycloalkyl]-CiCioalkyl unsubstituted or substituted by one or more Ci-C2oalkyl, e.g. 1 , 2 or 3 Ci-C4alkyl, is dicyclohexylmethyl.

[0073] Examples of a bicyclic or tricyclic hydrocarbon radical with 5 to 20 carbon atoms unsubstituted or substituted by one or more Ci-C2oalkyl, e.g. 1 , 2 or 3 Ci-C4alkyl, are and

[0074] Examples of phenyl unsubstituted or substituted by one or more radicals selected from Ci-C2oalkyl, Ci-C2oal koxy , Ci- C2oalkylamino, di(Ci-C2oalkyl)amino, amino, hydroxy and nitro, preferably Ci-C4alkyl, Ci-C4alkoxy, Ci-C4alkylamino, di(Ci-C4alkyl)amino, hydroxy and nitro, are phenyl, 3-methylphenyl, 3-methoxyphenyl, 4-methylphenyl, 4-ethylphenyl, propylphenyl, 4-isopropylphenyl, 4-tert-butylphenyl, 4-isopropoxyphenyl, 2,3-dimethoxyphenyl, 2-nitrophenyl, 3- methyl-6-nitrophenyl, 4-dimethylaminophenyl, 2,3-dimethylphenyl, 2,6-dimethylphenyl, 2,4-dimethylphenyl, 3,4- dimethylphenyl, 3,5-dimethylphenyl, 3,5-di-tert-butylphenyl, 2,4,6-trimethylphenyl and 3,5-di-tert-butyl-4- hydroxyphenyl.

[0075] Examples of phenyl-Ci-C2oalkyl unsubstituted or substituted by one or more radicals selected from Ci-C2oalkyl, C3- Ci2cycloalkyl, phenyl, Ci-C2oalkoxy, amino, hydroxy and nitro, preferably Ci-C4alkyl, Cs-Cscycloalkyl, phenyl, C1- C4alkoxy and hydroxy, are benzyl, a-cyclohexylbenzyl, diphenylmethyl, 1 -phenylethyl, a-hydroxybenzyl, 2- phenylethyl, 2-phenylpropyl, 3-pheny I propyl, 3-methylbenzyl, 3,4-dimethoxybenzyl and 2-(3,4-dimethoxyphenyl)ethyl.

[0076] An example of phenylethenyl unsubstituted or substituted by one or more Ci-C2oalkyl, e.g. 1 , 2 or 3 C1 -C4alkyl, is 2- (4-methylphenyl)ethenyl.

[0077] An example of bi pheny l-(Ci -C wal ky I) unsubstituted or substituted by one or more Ci-C2oalky I, e.g. 1 , 2 or 3 C1- C4alkyl, is 4-biphenylmethyl.

[0078] Examples of naphthyl unsubstituted or substituted by one or more Ci-C2oalkyl, e.g. 1 , 2 or 3 Ci-C4alkyl, are 1- naphthyl and 2-naphthyl. Examples of naphthyl-Ci-C2oalkyl unsubstituted or substituted by one or more Ci-C2oalkyl, e.g. 1 , 2 or 3 Ci-C4alkyl, are 1 -naphthylmethyl and 2-naphthylmethyl.

[0079] An example of naphthoxymethyl unsubstituted or substituted by one or more Ci-C2oalkyl, e.g. 1 , 2 or 3 Ci-C4alkyl, is 1 -naphthoxymethyl.

[0080] An example of biphenylenyl, fluorenyl or anthryl is 2-biphenylenyl, 9-fluorenyl, 1 -fluorenyl or 9-anthryl, respectively.

[0081] Examples of a 5- to 6-membered heterocyclic radical unsubstituted or substituted by one or more Ci-C2oalkyl, e.g. 1 , 2 or 3 Ci-C4alkyl, are 3-pyridinyl, 4-pyridinyl, 2-hydroxypyridin-3-yl, 3-quinolinyl, 4-quinolinyl, 2-furyl, 3-furyl and 1- methyl-2-pyrryl.

[0082] Examples of a Ci-C2ohydrocarbon radical containing one or more halogen or pseudo halogen, e.g. 1 , 2, 3, 4, 5, or 6 - F, -Cl or -I, are 1-bromo-2-methylpropyl, dichloromethyl, pentafluoroethyl, 3,5-bis[trifluoromethyl]phenyl, 2, 3,5,6- tetrafluoro-p-tolyl, 2,3-dichlorophenyl, 3,4-dichlorophenyl and 2,4-bis[trifluoromethyl]phenyl.

[0083] An example of tri(Ci-Cioalkyl)silyl is (HsQsSi-.

[0084] An example of tri(Ci-Cioalkyl)silyl(Ci-Cioalkyl) is (H3C)3Si-(CH2)2-.

[0085] Examples of a saturated or unsaturated aliphatic polyamine having 3 to 25 carbon atoms and y amino groups and optionally containing further hetero atom in its skeleton are 1 ,3-diaminopropane, 1 ,4-diaminobutane and 1 ,5- diaminopentane.

[0086] Examples of a saturated or unsaturated alicyclic polyamine having 6 to 25, preferably 6 to 13, carbon atoms and y amino groups and optionally containing further hetero atom in its skeleton are 1 ,2-diaminocyclohexane, 1 ,4- diaminocyclohexane, 4,4'-diaminodicyclohexyl, 4,4'-diamino-3,3'-dimethyldicyclohexyl, 4,4'- diaminodicyclohexylmethane, 4,4'-diamino-3,3' dimethyldicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane, 1 ,4- bis(aminomethyl)cyclohexane, isophoronediamine, menthenediamine, melamine, 1 ,3,5-triaminocyclohexane, 1 ,2,4- triaminocyclohexane, 1 ,2,4,5-tetraaminocyclohexane and the like.

[0087] Examples of an aromatic polyamine having 6 to 25, preferably 6 to 17, in particular 6 to 13, carbon atoms and y amino groups and optionally containing further hetero atoms in its skeleton are o-phenylenediamine, m- phenylenediamine, p-phenylenediamine, 2,3-diaminotoluene, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,4- diaminotoluene, 4,6-dimethyl-m-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, 4,5-dimethyl-o- phenylenediamine, 2,4-diaminomesitylene, 2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 1,5- diaminonaphthalene, 1 ,8-diaminonaphthalene, 2,3-diaminonaphthalene, 2,7-diaminonaphthalene, 9,10- diaminophenanthrene, 3,3',5,5'-tetramethylbenzidine, 3,3' dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'- diaminobiphenyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4' methylenedi-o-toluidine, 4, 4'-methy lenedi-2, 6-xy I idi ne, 4, 4'-methy lened i-2,6-d iethyl an i I i ne, 4, 4'-diamino- 1 ,2- diphenylethane, 4,4'-diamino-2,2'-dimethylbibenzyl, 4,4'-diaminostilbene, 3,4'-diamino-2,2-diphenylpropane, 4,4'- diamino-2,2-diphenylpropane, 4,4' diaminodiphenylether, 3,4'-diaminodiphenylether, 4,4'-thiodianiline, 2,2'- dithiodianiline, 4,4'-dithiodianiline, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'- diaminobenzophenone, 4,4'-diaminobenzophenone, 4,4'-diaminobenzanilide, o- tolidinesulfone, 2,7-diaminofluorene, 3,7-diamino-2-methoxyfluorene, bis-p aminophenylaniline, 1,3-bis(4-aminophenylpropyl)benzene, 1 ,4-bis(4- aminophenylpropyl)benzene, 1 ,3-bis(4-aminophenoxy)benzene, 1 ,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4- aminophenoxy)biphenyl, bis[4-(4- aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]sulfone, 9,9-bis(4- aminophenyl)fluorene-1,2,4,5-tetraaminobenzene, 1,3,5-triaminobenzene, 1,2,4- triaminobenzene, Para Rosaniline, 2,4,6-triaminophenol, 3,3'-diaminobenzidine, tris(4-aminophenyl)methane, 2,4,6-triaminopyrimidine, and the like.

[0088] Examples of an unsaturated or saturated aliphatic amino carboxylic acid having 2 to 25, preferably 2 to 12, in particular 2 to 5, carbon atoms, z' amino groups and z" carboxyl groups and optionally containing further hetero atoms in its skeleton are aminoacetic acid, alpha-aminopropionic acid, beta-aminopropionic acid, alpha-aminoacrylic acid, alpha-aminobutyric acid, beta-aminobutyric acid, gamma-aminobutyric acid, alpha-amino-alpha-methylbutyric acid, gamma-amino-alpha-methylbutyric acid, alpha-aminoisobutyric acid, beta aminoisobutyric acid, alpha-amino-n- valeric acid, delta-amino-n-valeric acid, beta-aminocrotonic acid, alpha-amino-beta-methylvaleric acid, alphaaminoisovaleric acid, 2-amino-4-pentenoic acid, alpha-amino-n-caproic acid, 6-aminocaproic acid, alphaaminoisocaproic acid, 7-aminoheptanoic acid, alpha-amino-n-caprylic acid, 8-aminocaprylic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, 2- aminoadipic acid, arginine, asparagine, aspartic acid, cystine, glutamic acid, glutamine, ornithine, creatine, aminomalonic acid, and the like.

[0089] Examples of a saturated or unsaturated alicyclic amino carboxylic acid having 7 to 25, preferably 7 to 9, carbon atoms, z' amino groups and z" carboxyl groups and optionally containing further hetero atoms in its skeleton care 1- aminocyclohexanecarboxylic acid, 2- aminocyclohexanecarboxylic acid, 3-aminocyclohexanecarboxylic acid, 4- aminocyclohexanecarboxylic acid, p-aminomethylcyclohexanecarboxylic acid, 2-amino-2-norbornanecarboxylic acid, 3,5-diaminocyclohexanecarboxylic acid, 1-amino-1,3-cyclohexanedicarboxylic acid and the like.

[0090] Examples of an aromatic amino carboxylic acid having 7 to 25, preferably 7 to 15, in particular 7 to 11 , carbon atoms, z' amino groups and z" carboxyl groups and optionally containing further hetero atoms in its skeleton are alphaaminophenylacetic acid, alpha-amino-beta-phenylpropionic acid, 2-amino-2-phenylpropionic acid, 3-amino-3- phenylpropionic acid, alpha-amino cinnamic acid, 2-amino-4-phenylbutyric acid, 4-amino-3-phenylbutyric acid, anthranilic acid, m-aminobenzoic acid, p-aminobenzoic acid, 2-amino-4-methylbenzoic acid, 2-amino-6- methylbenzoic acid, 3-amino-4-methylbenzoic acid, 2-amino-3-methylbenzoic acid, 2-amino-5-methylbenzoic acid, 4- amino-2-methylbenzoic acid, 4-amino-3-methylbenzoic acid, 2-amino-3-methoxybenzoic acid, 3-amino-4- methoxybenzoic acid, 4-amino-2-methoxybenzoic acid, 4-amino-3-methoxybenzoic acid, 2-amino-4,5- dimethoxybenzoic acid, o-aminophenylacetic acid, m-aminophenylacetic acid, p-aminophenylacetic acid, 4-(4- aminophenyl)butyric acid, 4-aminomethylbenzoic acid, 4- aminomethylphenylacetic acid, o-aminocinnamic acid, m- aminocinnamic acid, p- aminocinnamic acid, p-aminohippuric acid, 2-amino-1 -naphthoic acid, 3-amino-1 -naphthoic acid, 4-amino-1 -naphthoic acid, 5-amino-1-naphthoic acid, 6-amino-1 -naphthoic acid, 7-amino-1-naphthoic acid, 8- amino-1 -naphthoic acid, 1-amino-2-naphthoic acid, 3-amino-2-naphthoic acid, 4-amino-2-naphthoic acid, 5-amino-2- naphthoic acid, 6-amino-2-naphthoic acid, 7-amino-2-naphthoic acid, 8-amino-2-naphthoic acid, 3,5-diaminobenzoic acid, 3,5-dicarboxyaniline, 4,4' diamino-3,3'-dicarboxydiphenylmethane and the like.

[0091] Examples of halogen or pseudo-halogen are -F, -Cl, -Br, -I, -CN, -CNO, -OCN, -SCN and -CNS.

[0092] In one desirable embodiment the amide clarifier is a trisamide or a tetraamide according to formula (IA). In this desirable embodiment x is an integer of 3 or 4;

[0093] Xo is a residue obtained by removing all of the carboxyl groups from 1 ,2,3-propanetricarboxylic acid or 1 , 2,3,4- butanetetracarboxylic acid; and

[0094] Xi is represented by the formula (ID) and the three or four X2S are the same or different, and each independently represent a hydrogen atom or a C1-C10, linear or branched alkyl group. Examples of a C1-C10, linear or branched alkyl group include methyl, ethyl, n- propyl, 1 -methylethyl, n-butyl, 2-methylpropyl, 1-methylpropyl, tert-butyl, pentyl, 1 -methylbutyl, 2-methylbutyl, 3-methylbutyl, 1, 1 -dimethylpropyl, 1 -ethylpropyl, tert-butylmethyl, hexyl, 1 -methylpentyl, heptyl, isoheptyl, 1- ethylhexyl, 2-ethylpentyl, 1-propylbutyl, octyl, nonyl, isononyl, neononyl and 2,4,4-trimethylpentyl.

[0095] Preferably the amide clarifier is an aromatic bisamide, an aromatic trisamide or an aromatic tetraamide.

[0096] In a preferred embodiment, the amide clarifier is a bisamide, a trisamide or a tetraamide according to any of the formulae (I A), (IB), and (I C) . In one such preferred embodiment x, y or the sum of z' and z” are 2, Xo, Yo, and Zo are the group of the formula (II), (III), (IV A) or (IV B)

[0097] (ID wherein R represents a hydrogen atom, C1-C4 alkyl which is optionally substituted or branched, C3-C12 cycloalkyl which is optionally substituted, or C6-C20 aryl which is optionally substituted.

[0098] Examples of C1-C4 alkyl include methyl, ethyl, n-propyl, 1 -methylethyl, n-butyl, 2-methylpropyl, 1 -methylpropyl and tert-butyl. Examples of C3-Ci2cycloalky I optionally substituted include cyclopropyl, 3-methylcyclopropyl, 2, 2,3,3- tetramethylcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 1 -methylcyclohexyl, 2-methylcyclohexyl, 3- methylcyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl and cycloheptyl. Examples of C6-C20 aryl which is optionally substituted include phenyl, 3-methylphenyl, 3-methoxyphenyl, 4-methylphenyl, 4-ethylphenyl, propylphenyl, 4-isopropylphenyl, 4-tert-butylphenyl, 4-isopropoxyphenyl, 2,3-dimethoxyphenyl, 2-nitrophenyl, 3- methyl-6-nitrophenyl, 4-dimethylaminophenyl, 2,3-dimethylphenyl, 2,6-dimethylphenyl, 2,4-dimethylphenyl, 3,4- dimethylphenyl, 3,5-dimethylphenyl, 3,5-di-tert-butylphenyl, 2,4,6-trimethylphenyl and 3,5-di-tert-butyl-4- hydroxyphenyl, benzyl, a-cyclohexylbenzyl, diphenylmethyl, 1 -phenylethyl, a-hydroxybenzyl, 2-phenylethyl, 2- phenylpropyl, 3-phenylpropyl, 3-methylbenzyl, 3,4-dimethoxybenzyl and 2-(3,4-dimethoxyphenyl)ethyl, 2-(4- methylphenyl)ethenyl, 4-biphenylmethyl, naphthyl, 1-naphthyl, 2-naphthyl, 1 -naphthylmethyl, 2-naphthylmethyl, 1- naphthoxymethyl, 2-biphenylenyl, 9-fluorenyl, 1-fluorenyl and 9-anthryl.

[0099] One group of particularly suitable amide clarifiers is aromatic bisamides based on formula (VI): wherein R1 and R2 are each independently selected from C1-C5 linear or branched alkyl or substituted or unsubstituted C3-C6 cycloalkyl, preferably R1 and R2 both being tertiary butyl. In this case, R1 and R2 represent each Y1 of formula (IB). One preferred compound according to formula (II) is the compound of formula (XI).

[0100] One preferred compound according to formula (VI) is the compound of formula (XII). One preferred compound according to formula (IV A) is the compound of formula (XIII).

[0101] Another preferred compound according to formula (IV A) is the compound of formula (XIV).

[0102] In a preferred embodiment, the amide clarifier is a trisamide according to any of the formulae (IA), (IB), and (10). In one such preferred embodiment x, y or the sum of z' and z” are 3, Xo, Yo, and Zo are the group of the formula (V) (V). More preferred embodiments according to formula (V) include compounds according to the structures (V A), (V B), (V C) or (V D).

[0103] (V C) (V D) wherein each Xi, each Yi, each Zi and each Z2 independently of one another have the same meanings ascribed to them as previously provided.

[0104] Preferably, the amide clarifier is a bisamide or a trisamide of formula (IB) wherein when the amide clarifier is a bisamide Yo is represented by formula (III) or formula (II) and when the amide clarifier is a trisamide Yo is represented by formula (V).

[0105] More preferably, the amide clarifier is a trisamide of formula (IB) wherein Yo is represented by formula (V). It is particularly preferred that the amide clarifier is an aromatic trisamide of formula (VII), in which R1, R2 and R3 each independently selected from C1-C5 linear or branched alkyl or substituted or unsubstituted C3-C6 cycloalkyl, preferably R1 , R2 and R3 all being tertiary butyl. In this case, R1, R2 and R3 represent each Y1 of formula (IB).

[0106] In one desirable embodiment R1 is a substituted cyclohexyl group. Suitably R1 has the structure shown in formula (VII A):

[0107] (VII A) wherein W may be selected from C1-C10 linear or branched substituted or unsubstituted alkyl and may be in any substitution position of the cyclohexyl group, preferably in the para-position. In this instance R2 and R3 would have the same definitions given for the structure of formula (VI I). Preferably, W is located in the para- position and is in the cis-position relative to the bond of the carbonyl carbon attached to the cyclohexanediyl ring. Preferably, W is located in the para-position and is in the trans-position relative to the bond of the carbonyl carbon attached to the cyclohexanediyl ring.

[0108] In a further preferred embodiment R2 has independently of R1 the same definition as ascribed to R1 as represented by formula (VII A).

[0109] In a still further preferred embodiment both R2 and R3 independently of each other and R1 have the same definition as ascribed to R1 as represented by formula (VI I A).

[0110] Thus, according to the still further preferred embodiment the amide clarifier is an aromatic trisamide having the formula (VII B):

[0111] wherein each V group is independently selected from C1-C5 linear or branched alkyl, preferably C3 or C4 branched alkyl, more preferably the V groups all being tertiary butyl. One specific suitable compound according to formula (VI I B) is 1 ,3,5-tris[cis-4-tert- butylcyclohexylcarbonylamino]benzene, illustrated by formula (XV):

[0112] Another specific suitable compound according to formula (VII B) is trans-4-tert-butylcyclohexylcarbonylamino-3,5-bis [cis-4-tert-butylcyclohexylcarbonylamino] benzene, illustrated by formula (XVI):

[0113]

[0114] A further specific suitable compound according to formula (VII B) is cis-4-tert-butylcyclohexylcarbonylamino-3,5- bis[trans-4-tert-butylcyclohexylcarbonylamino] benzene, illustrated by formula (XVII): A still further specific suitable compound according to formula (VII B) is 1, 3, 5-tris[trans-4-tert- butylcyclohexylcarbonylamino] benzene, illustrated by formula (XVIII):

[0115]

[0116] Additional specific suitable compounds according to formula (VII B) are 1 ,3,5-tris[cis-4-iso- propycyclohexylcarbonylamino]benzene, trans-4-iso-propylylcyclohexylcarbonylamino-3,5-bis [cis-4-iso- propylcyclohexylcarbonylamino] benzene, trans-4-iso-propylcyclohexylcarbonylamino-3,5-bis [cis-4-iso-propyl cyclohexylcarbonylamino] benzene and 1, 3, 5-tris[trans-4-iso-propylcyclohexyl carbonylamino] benzene.

[0117] As indicated above the preferred embodiment of compounds of formula (VII) are where R1, R2 and R3 are all tertiary butyl. Such particularly preferred amide clarifier is N,N',N"-1,3,5-benzenetriyltris(2,2-dimethylpropanamide), which may have the structure according to formula (XIX):

[0118] In addition to the amide clarifier further plastic additives can be introduced into the clarified polyolefin waste in step b). Suitable further plastic additives are antioxidants, UV absorbers, light stabilizers, metal deactivators, phosphites, phosphonates, hydroxylamines and amine N-oxides, nitrones, thiosynergists, rheology modifiers, , acid scavengers, basic-co-stabilizers, nucleating agents, benzofuranones and indolinones, and flame retardants.

[0119] The invention also relates to the recycled polyolefin which comprises the amide clarifier and the clarified polyolefin waste which contains a sorbitol clarifier. The recycled polyolefin usually can replace virgin polyolefins by an identical or at least comparable property profile. The recycled polyolefin has a pre-damage, for example new chemical groups (such as carbonyl groups) are produced on the polymer chain by oxidative or photooxidative processes. Usually, the recycled polyolefin has carbonyl groups that are not present with virgin polyolefin. The concentration of the carbonyl groups is often a measure for the pre-damage of the recycled polyolefin. The concentration of carbonyl groups can be determined by infrared spectroscopy, such as by a measurement of the absorption of the carbonyl oscillation in the range of 1720 cm-1.

[0120] The recycled polyolefin is usually obtainable by the method for recycling the clarified polyolefin waste comprising the steps of a) collecting the clarified polyolefin waste which contains a sorbitol clarifier, and b) introducing an amide clarifier into the clarified polyolefin waste to form a recycled polyolefin.

[0121] The invention also relates to a use of the amide clarifier for reducing the haze of clarified polyolefin waste which contains a sorbitol clarifier after recycling.

[0122] The reducing of the haze can be determined in comparison to a sample where instead of the amide clarifier a sorbitol clarifier (such as bis(4-propylbenzylidene)propylsorbitol, which may be added in an amount of 100 ppm to 5000 ppm, preferably 150 ppm to 4000 ppm, more preferred from 200 ppm to 2500 ppm, e.g. 300 ppm) was introduced into the clarified polyolefin waste.

[0123] The haze can be determined on plaques in accordance with ASTM standard D1003, e.g. on a haze testing instrument from BYK Gardner GmbH, Germany. In this test the haze is usually defined as that portion of visible light that is scattered at wider angles (2.5°< 0 <90°). The haze is usually a measure for the turbidity of a sample.

[0124] Sorbitol A: Millad® 3998, commercially available from Milliken, 1 , 3: 2, 4- Bi s(3, 4-d i methyl benzylidene) sorbitol.

[0125] Sorbitol B: Millad® NX8000, commercially available from Milliken, bis(4-propylbenzylidene)propylsorbitol.

[0126] Trisamide A: N,N',N"-1,3,5-benzenetriyltris[2,2-dimethylpropanamide].

[0127] Polyolefin A: Poly(propylene-co-ethylene), random copolymer, free of antiblocking agent, free of slip agent, free of calcium stearate, melting point about 150 °C (ISO 11357-3), Vicat softening temperature about 140 °C (ISO 306), flexural modulus 1100 mPa (ISO178), powder, commercially available as RD204CF from Borealis AG, Austria.

[0128] Example 1 a) Clarified polyolefin waste with sorbitol clarifiers

[0129] A clarified polyolefin waste model system was prepared as follows: A powder form of Polyolefin A was mixed with 1800 ppm Sorbitol A ("Waste 1”) or with 1800 ppm Sorbitol B ("Waste 2”) in a high speed mixer and compounded at 230°C to pellets by a twin-screw extruder. The pellets were molded at 230°C to plaques with a thickness of 2 mm by using an injection molding machine. The hazes of the plaques were analysed by a Haze testing instrument in accordance with ASTM standard D1003. The haze was defined as that portion of visible light that is scattered at wider angles (2.5°< 0 <90°) and is a measure for the turbidity of the sample. The results are listed in Table 1 or 2. b) Recycled polyolefin with Sorbitol A and Trisamide A

[0130] A recycled polyolefin waste model system with 1800 ppm Sorbitol A and added Trisamide A was prepared as follows: A powder form of Polyolefin A was mixed with 1800 ppm Sorbitol A as used in Waste 1, and additionally 50 or 150 ppm Trisamide A (samples "Recycled 1 or 2”) in a high speed mixter and compounded at 230°C to pellets by a twin- screw extruder. For comparison, the random copolymer polypropylene was mixed with 1800 ppm Sorbitol A as used in Waste 1 and 300 ppm of the Sorbitol B (sample "Recycled Comparative A”) in a high speed mixer and compounded at 230°C to pellets by a twin-screw extruder.

[0131] The pellets were molded at 230°C to plaques with a thickness of 2 mm by using an injection molding machine. The hazes of the plaques were analysed as described in Example 1a). The results are listed in Table 1.

[0132] T able 1 . Haze of 2 mm plaques

[0133] The data of this model system for recycled polyolefin demonstrated that a clarified polyolefin waste model which contains only Sorbitol A ("Waste 1”) showed an increased haze when it was tried to clarify by addition of a further sorbitol clarifier ("Recycled Comparative A”). However, the haze remained on a similar level as "Waste 1” in "Recycled 1” or even was reduced ("Recycled 2”) by addition of Trisamide A. c) Recycled polyolefin with Sorbitol B and Trisamide A A recycled polyolefin waste model system with 1800 ppm Sorbitol B and added Trisamide A was prepared as follows: A powder form of Polyolefin A was mixed with 1800 ppm Sorbitol B as used in Waste 1, and additionally 50 or 150 ppm Trisamide A (samples "Recycled 3 or 4”) in a high speed mixter and compounded at 230°C to pellets by a twin- screw extruder. For comparison, the random copolymer polypropylene was mixed with 1800 ppm Sorbitol B as used in Waste 1 and 300 ppm of the Sorbitol A (sample "Recycled Comparative B”) in a high speed mixer and compounded at 230°C to pellets by a twin-screw extruder.

[0134] The pellets were molded at 230°C to plaques with a thickness of 2 mm by using an injection molding machine. The hazes of the plaques were analysed as described in Example 1a). The results are listed in Table 2.

[0135] Table 2. Haze of 2 mm plaques

[0136] The data of this model system for recycled polyolefin demonstrated that a clarified polyolefin waste model which contained only Sorbitol B ("Waste 2”) showed an increased Haze when it was tried to clarify by addition of a further sorbitol clarifier ("Recycled Comparative B”). However, the haze remained on a similar level as "Waste 2” in "Recycled 4” or even was reduced ("Recycled 3”) by addition of the Trisamide A.

[0137] Example 2 a) Clarified polyolefin waste with sorbitol clarifiers

[0138] A clarified polyolefin waste model system was prepared as follows: A powder form of Polyolefin A was mixed with 1800 ppm Sorbitol A ("Waste 3”) or with 1800 ppm Sorbitol B ("Waste 4”) in a high speed mixer and compounded at 230°C to pellets by a twin-screw extruder. The pellets were molded at 200 °C, respectively at 230°C (cf Table 3) to plaques with a thickness of 1 mm by using an injection molding machine. The hazes of the plaques were analysed as described in Example 1a). The results are listed in Table 3 or 4. b) Recycled polyolefin with Sorbitol A and Trisamide A

[0139] A recycled polyolefin waste model system with 1800 ppm Sorbitol A and added Trisamide A was prepared as follows: A powder form of Polyolefin A was mixed with 1800 ppm Sorbitol A as used in Waste 3, and additionally 100 or 150 ppm Trisamide A (samples "Recycled 5 or 6”) in a high speed mixer and compounded at 230°C to pellets by a twin- screw extruder. For comparison, the random copolymer polypropylene was mixed with 150 ppm Trisamide A (instead of 1800 ppm Sorbitol A) (sample "Comparative C”) in a high speed mixer and compounded at 230°C to pellets by a twin-screw extruder.

[0140] The pellets were molded at 200 °C, respectively at 230°C (cf Table 3) to plaques with a thickness of 1 mm by using an injection molding machine. The hazes of the plaques were analysed as described in Example 1a). The results are listed in Table 3.

[0141] Table 3. Haze of 1 mm plaques

[0142] The data of this model system for recycled polyolefin demonstrated that the haze of a clarified polyolefin waste model which contained only Sorbitol A ("Waste 3”) was reduced by addition of the Trisamide A ("Recycled 5” and "Recycled 6”). For comparison, when Trisamide A was used in the absence of any sorbitol clarifier ("Comparative C”), the haze was even worser than the Waste 3. c) Recycled polyolefin with Sorbitol B and Trisamide A

[0143] A recycled polyolefin waste model system with 1800 ppm Sorbitol B and added Trisamide A was prepared as follows: A powder form of Polyolefin A was mixed with 1800 ppm Sorbitol B as used in Waste 4, and additionally 100 or 150 ppm Trisamide A (samples "Recycled 7 or 8”) in a high speed mixer and compounded at 230°C to pellets by a twin- screw extruder.

[0144] The pellets were molded at 230°C to plaques with a thickness of 1 mm by using an injection molding machine. The hazes of the plaques were analysed as described in Example 1a). The results are listed in Table 4.

[0145] Table 4. Haze of 1 mm plaques

[0146] The data of this model system for recycled polyolefin demonstrated that the haze of a clarified polyolefin waste model which contained only Sorbitol B ("Waste 4”) was reduced by addition of the Trisamide A ("Recycled 7” and "Recycled 8”). This was also shown when clarified polyolefin waste model contained higher concentrations of Sorbitol B.

[0147] Example 3

[0148] The following example showcases a model recyclate stream, in which only 20% of the material had been clarified for first life cycle. Consequently, such recyclate stream needs to be re-clarified by topping up the residual legacy clarifier level (20% of original) with at least 80% of new clarifier. The appropriate waste models were prepared as follows: a) waste model containing 20% polymer pre-clarified with sorbitol A (''waste 6”)

[0149] 360 ppm of Sorbitol A (20% of the regular 1800 ppm loading) was compounded with PP (Borealis RD204CF) in a twin screw extruder at 230°C. To mimic additional processing step during recycling an additional single-screw extrusion at 230°C was followed. b) waste model containing 20% polymer pre-clarified with sorbitol A, re-clarified with Phosphate A (''Recycled Comparative D”)

[0150] For comparison, a commercial clarifier ADK Stab® NA-71 from Adeka Co., Japan was used ("Phosphate A”, comprising lithium 2,2'-methylene-bis (4,6-di-tert-butylphenyl) phosphate). 360 ppm of Sorbitol A (20% of the regular 1800 ppm loading) and 1440 ppm of Phosphate A (80% of the regular 1800 ppm loading) were compounded with PP (Borealis RD204CF) in a twin screw extruder at 230°C. To mimic additional processing step during recycling an additional single-screw extrusion at 230°C was followed. c) waste model containing 20% polymer pre-clarified with sorbitol A, re-clarified with Trisamide A ("Recycled 12”)

[0151] 360 ppm of Sorbitol A (20% of the regular 1800 ppm loading) and 96 ppm of Trisamide (80% of a 120 ppm loading) were compounded with PP (Borealis RD204CF) in a twin screw extruder at 230°C. To mimic additional processing step during recycling an additional single-screw extrusion at 230°C was followed. All pellets were molded at 230°C to plaques with a thickness of 1 mm by using an injection molding machine. The hazes of the plaques were analysed as described in Example 1a). The results are listed in Table 5. Table 5. Haze of 1 mm plaques

[0152] This example shows, by utilizing Sorbitol A, Sorbitol B and Trisamide A, that re-clarifying recyclate streams already containing fractions of pre-clarified polymer, was superior if Trisamide A is used. The data of these model systems for recycled polyolefin demonstrated that better haze is achieved with Trisamide A as re-clarifier if mixed clarifier systems were produced due to legacy clarifiers being present in recyclate stream. This was shown for recyclates containing Sorbitol A as legacy stabilizers which are re-clarified (Trisamide A better than Phosphate A),

Claims

Claims1 . A method for recycling a clarified polyolefin waste comprising the steps of a) collecting the clarified polyolefin waste which contains a sorbitol clarifier, and b) introducing an amide clarifier into the clarified polyolefin waste to form a recycled polyolefin.

2. The method according to claim 1 where 0.0001 to 0.1 wt% of the amide clarifier are introduced into the clarified polyolefin waste.

3. The method according to claims 1 or 2 where the amide clarifier is introduced in the clarified polyolefin waste in a weight ratio of the amide clarifier to the sorbitol clarifier of 1 : 4 to 1 : 80.

4. The method according to any of claims 1 to 3 where the amide clarifier is introduced in the clarified polyolefin waste by melting the clarified polyolefin waste and by mixing the clarified polyolefin waste with the amide clarifier.

5. The method according to any of claims 1 to 4 where the amide clarifier is introduced in the clarified polyolefin waste- in pure form,- as masterbatch, which comprises the amide clarifier incorporated in a carrier polymer, or- as compounded polymer, which comprises the amide clarifier incorporated in a polymer matrix.

6. The method according to any of claims 1 to 5 where the clarified polyolefin waste contains 0.01 to 3 wt% of the sorbitol clarifier.

7. The method according to any of claims 1 or 6 where in step a) the clarified polyolefin waste from different batches is mixed to adjust the concentration of the sorbitol clarifier in the clarified polyolefin waste.

8. The method according to any of claims 1 to 7 where the clarified polyolefin waste is- pre-user waste, such as production waste collected from producers or converters;- post-user waste, such as household packaging collected via kerbside collection or bring systems, or end of life products returned by consumers; or- demolition waste, such as waste from demolition of civil constructions.

9. The method according to any of claims 1 to 8, where the amide clarifier is a bisamide, a trisamide or a tetraamide of any of the formulae (IA), (IB), and (IC)wherein x and y are 2 or 3 or 4; z' and z” independently of one another are 1 or 2 or 3 with the proviso that the sum of z' and z” is either 2 or 3 or 4;Xo is a residue which is formed by elimination of x carboxyl groups of a saturated or unsaturated aliphatic polycarboxylic acid having 3 to 25 carbon atoms, a residue which is formed by elimination of x carboxyl groups of a saturated or unsaturated alicyclic polycarboxylic acid having 7 to 25 carbon atoms or a residue which is formed by elimination of x carboxyl groups of an aromatic polycarboxylic acid having 8 to 25 carbon atoms; any of said polycarboxylic acids optionally contains further hetero atoms in its skeleton; the radicals Xi independently of one another areC1-C20 alkyl unsubstituted or substituted by one or more hydroxy, amino and / or nitro groups;C2-C20 alkenyl unsubstituted or substituted by one or more hydroxy, amino and / or nitro groups;C2-C20 alkyl interrupted by oxygen or sulfur;C3-C12 cycloalkyl unsubstituted or substituted by one or more C1-C20 alkyl; bis[C3-Ci2 cycloalky I]— C1-C10 alkyl unsubstituted or substituted by one or more C1-C20 alkyl; a bicyclic or tricyclic hydrocarbon radical with 5 to 20 carbon atoms unsubstituted or substituted by one or more C1-C20 alkyl; phenyl unsubstituted or substituted by one or more radicals selected from C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylamino, di-(Ci-C2o alkyl)amino, amino, hydroxy and nitro; pheny I-C1-C20 alkyl unsubstituted or substituted by one or more radicals selected from C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylamino, di-(Ci-C2o alkyl)amino, amino, hydroxy and nitro;phenylethenyl unsubstituted or substituted by one or more C1-C20 alkyl; bipheny l-(Ci-Cio alkyl) unsubstituted or substituted by one or more C1-C20 alkyl; naphthyl unsubstituted or substituted by one or more C1-C20 alkyl; naphthy I-C1-C20 alkyl unsubstituted or substituted by one or more C1-C20 alkyl; naphthoxymethyl and substituted or substituted by one or more C1-C20 alkyl; biphenylenyl, fluorenyl, anthryl; a 5 to 6 membered heterocyclic radical unsubstituted or substituted by one or more C1-C20 alkyl; a C1-C20 hydrocarbon radical containing one or more halogen or pseudo-halogen; tri(Ci-Cio alkyl)silyl; or tri(Ci-Cio alkyl)silyl(Ci-Cio alkyl);Yo is a residue which is formed by elimination of y amino groups of a saturated or unsaturated aliphatic polyamine having 3 to 25 carbon atoms, a residue which is formed by elimination of y amino groups of a saturated or unsaturated alicyclic polyamine having 6 to 25 carbon atoms or a residue which is formed by elimination of y amino groups of an aromatic polyamine having 6 to 25 carbon atoms; any of said polyamines optionally contains further hetero atoms in its skeleton;Y1 has the same definition as Xi;Zo is a residue which is formed by elimination of z' amino groups and z" carboxyl groups of an unsaturated or saturated aliphatic amino carboxylic acid having 2 to 25 carbon atoms, a residue which is formed by elimination of z' amino groups and z" carboxyl groups of a saturated or unsaturated alicyclic amino carboxylic acid having 7 to 25 carbon atoms or a residue which is formed by elimination of z' amino groups and z" carboxyl groups of an aromatic amino carboxylic acid having 7 to 25 carbon atoms; any of said amino carboxylic acids optionally contains further hetero atoms in its skeleton; the radicals Z1 and Z2 independently of one another have the same definition given for Xi.

10. The method according to any of claims 1 to 9 where the amide clarifier is an aromatic trisamide of formula (VI I)in which R1 , R2 and R3 each independently selected from C1-C5 linear or branched alkyl or substituted or unsubstituted C3-C6 cycloalkyl, preferably R1 , R2 and R3 all being tertiary butyl.11 . The method according to any of claims 1 to 10 where the sorbitol clarifier is a sorbitol clarifier of the formula (I)where R1, R2, and R3are independently selected from H or Ci-Ce alkyl.

12. The method according to any of claims 1 to 11 where the sorbitol clarifier is a sorbitol clarifier of the formula (I), where R1is independently selected from H, methyl, ethyl or propyl, R2is independently selected from H or methyl, and R3is H or propyl.

13. The method according to any of claims 1 to 12 where no further sorbitol clarifier is added in the method for recycling.

14. A recycled polyolefin as defined in any of the preceding claims which comprises the amide clarifier and the clarified polyolefin waste which contains a sorbitol clarifier.

15. The recycled polyolefin according to claim 14 which is obtainable by the method as defined in any of the claims 1 to 13.

16. A use of a amide clarifier for reducing the haze of clarified polyolefin waste which contains a sorbitol clarifier after recycling of the clarified polyolefin waste.

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