EP4685277A1 - Fiber comprising a propylene based polymers composition - Google Patents

Abstract

A fiber comprising:
A) from 40 wt% to 65 wt%; %, of a recycled polypropylene composition
B) ) from 35 wt% to 60 wt% of a propylene homopolymer

Wherein the Melt Flow Rate of the recycled polypropylene composition, determined according to the method ISO 1133 (230° C, 2.16 kg), ranges from 5.2 g/10 min to 23.2 g/10 min g/10 min;
the sum of the amounts of (A), (B) being referred to the total weight of (A) and (B) is 100.

Description

FIELD OF THE INVENTION
• The present disclosure relates to fiber comprising a propylene based polymer composition comprising a propylene homopolymer and from 15 wt% to 45 wt% of a recycled polypropylene composition.
BACKGROUND OF THE INVENTION
• In recent years, there has been increased interest in using recycled materials or fibers in disposable products, such as wipers. Generally, the thought is that using recycled materials are better for the environment and that the use of natural resources for disposable products leads to a waste of natural resources. In addition, increasing expenses associated with obtaining raw materials and constantly increasing consumption of various products provide a strong economic incentive for developing methods for recycling surplus or unused material, which would otherwise go to waste by being burned or placed in a landfill. However, the use of recycled materials and fibers has drawbacks. It is generally recognized in the art that recycled materials and fibers often result in products that have physical properties which are generally less acceptable than products made from virgin materials or fibers. As a result, the amount of recycled materials or fibers used in products is often limited due to the lost in physical properties of products prepared from recycled fibers.
• Thus there is a need in the art for fibers which are at least partially prepared from recycled materials which have properties at least comparable to those products made with virgin materials.
SUMMARY OF THE INVENTION
• Thus an object of the present disclosure is a fiber comprising:
• A) from 15 wt% to 45 wt%; preferably from 20 wt% to 40 wt%, more preferably from 25 wt% to 35 wt%, of a recycled polypropylene composition having:
  1. i) ethylene derived units content, measured by ¹³C-NMR, ranging from 1.0 wt% to 4.2 wt%, preferably ranging from 1.4 wt% to 4.0 wt%, more preferably ranging from 1.6 wt% to 3.8 wt%
  2. ii) 1-butene derived units content, measured by ¹³C-NMR, ranging from 1.5 wt% to 5.2 wt% , preferably ranging from 1.8 wt% to 5.0 wt%, more preferably ranging from 2.1 wt% to 4.8 wt%;
  3. iii) ethylene derived units content of the fraction soluble in xylene at 25°C, measured by ¹³C-NMR, ranging from 6.0 wt% to 15.0 wt%, preferably ranging from 6.4 wt% to 14.3 wt%, more preferably ranging from 7.0 wt% to 13.4 wt%;
  4. iv) 1-butene derived units content, of the fraction soluble in xylene at 25°C, measured by ¹³C-NMR, ranging from 2.8 wt% to 8.2 wt% , preferably ranging from 3.0 wt% to 7.8 wt%, more preferably ranging from 3.2 wt% to 7.2 wt%;
  5. v) Melt Flow Rate, determined according to the method ISO 1133 (230° C, 2.16 kg), ranging from 5.0 g/10 min to 20.0 g/10 min; preferably from 7.0 g/10 min to 18.0 g/10 min, more preferably from 9.0 g/10 min to 16.5 g/10 min;
  6. vi) Xylene Soluble fraction at 25°C ranging from 4.8 wt% to 10.7 wt%, preferably ranging from 5.3 wt% to 9.8 wt%, more preferably ranging from 6.2 wt% to 9.2 wt%.
  7. vii) melting point measured by DSC according to ISO 11357-3, ranging from 135 °C to 149°C; preferably from 138°C to 148°C; more preferably from 140°C to 145°C;
• (B) from 55 wt% to 85 wt%; preferably from 60 wt% to 80 wt%, more preferably from 65 wt% to 75 wt%, of a propylene homopolymer having a Melt Flow Rate, determined according to the method ISO 1133 (230° C, 2.16 kg), ranging from 5.0 g/10 min to 21.0 g/10 min; preferably from 6.0 g/10 min to 19.0 g/10 min; more preferably from 8.0 g/10 min to 15.0 g/10 min; and a Xylene Soluble fraction at 25°C,determined according to ISO 16152: 2005, ranging from 1.5 wt% to 5.6 wt%; preferably from 2.2 wt% to 4.8 wt%; more preferably from 2.6 wt% to 4.3 wt%;
• wherein the Melt Flow Rate of the polypropylene composition, determined according to the method ISO 1133 (230° C, 2.16 kg), ranges from 5.2 g/10 min to 23.2 g/10 min; preferably from 8.2 g/10 min to 21.2 g/10 min, more preferably from 10.0 g/10 min to 17.3 g/10 min;
• the sum of the amounts of (A) and (B) being referred to the total weight of (A) and (B) is 100 wt%.
DETAILED DESCRIPTION OF THE INVENTION
• The recycled polypropylene composition A) can be a Post-Industrial Resin (PIR) or a Post-Consumer Resin (PCR).
• Post-industrial waste (PIW) is a material diverted from the waste stream originating from a manufacturing process.
• Post-industrial resin (PIR) refers to a plastic material originating from the mechanical recycling of a post-industrial waste (PIW).
• Post-Consumer Resin (PCR) defined as recyclate derived from an end product that has completed its life cycle as a consumer item and would otherwise be disposed of as waste.
• Preferably the recycled polypropylene composition component A) does not contains limonene.
• Preferably the recycled polypropylene composition component A) contains a organic compound with a chemical structure based on isoquinoline, that serves as a dye, e.g. red.
• Preferably the recycled polypropylene composition component A) has at least one of the following features:
1. i) Tensile modulus ranging between 700 MPa and 1200 MPa, preferably between 750 MPa and 1150 MPa; more preferably between 820 MPa and 1050 MPa;
2. ii) Charpy notched impact strength at 23°C ranging from 3.0 kJ/m² to 9.0 kJ/m², more preferably ranging from 3.8 kJ/m² to 8.5 kJ/m^2: more preferably ranging from 4.8 kJ/m² to 8.0 kJ/m²;
3. iii) Charpy notched impact strength at 0°C ranges from 1.3 kJ/m² to 3.3 kJ/m², preferably between from 1.5 kJ/m² to 3.0 kJ/m², more preferably between from 1.6 kJ/m² to 2.5 kJ/m²;
4. iv) Elongation at break ranging from 400 % to 800 %; preferably from 500 % to 750 %, more preferably from 550 % to 700 %.
• Preferably the propylene homopolymer component B) has Charpy impact strength at 23°C ranging from ranging from 2.0 to 12.0 kJ/m2, more preferably ranging from 3.0 to 10.0 kJ/m2: more preferably ranging from 3.5 to 9.2 kJ/m2.
• Preferably the propylene homopolymer component B) preferably has a Tensile modulus ranging between 980 and 1980 MPa, preferably between 1080 and 1780 MPa; more preferably between 1180 and 1680 MPa.
• The recycled polyolefin composition according to the present disclosure preferably has a Tensile modulus ranging between 900 and 1800 MPa, preferably between 1050 and 1700 MPa; more preferably between 1150 and 1600 MPa.
• The recycled polyolefin composition preferably has a Charpy impact strength at 23°C ranging from 3.0 to 9.0 kJ/m², more preferably ranging from 3.8 to 7.0 kJ/m^2: more preferably ranging from 4.3 to 6.2 kJ/m².
• The term "copolymer" as used herein refers to polymers with two different recurring units in the chain. By "ambient temperature" and "room temperature" is meant a temperature of 25 °C.
• By the term "crystalline polypropylene" is meant in the present application a propylene polymer having an amount of isotactic pentads (mmmm), measured by 13C-MNR on the fraction insoluble in xylene at 25° C, higher than 70 molar %; by "elastomeric" polymer is meant a polymer having solubility in xylene at ambient temperature higher than 50 wt%.
• Component B) can be obtained by polymerizing propylene with processes commonly known in the art. Component B for example can be commercially available.
• Components B) can be prepared by polymerizing propylene in the presence of a catalyst comprising the product of the reaction between:
1. i) a solid catalyst component comprising Ti, Mg, Cl, and at least an internal electron donor compound;
2. ii) an alkylaluminum compound and,
3. iii) an external electron-donor compound; preferably the external donor compound has the general formula:
   
           (R⁷)_a(R⁸)_bSi(OR⁹)_c,
   
   
where a and b are integers from 0 to 2, c is an integer from 1 to 4 and the sum (a+b+c) is 4; R7, R8, and R9, are alkyl, cycloalkyl or aryl radicals with 1-18 carbon atoms optionally containing heteroatoms.
• The internal donor is preferably selected from the esters of mono or dicarboxylic organic acids such as benzoates, malonates, phthalates and certain succinates. Examples of internal donors are described in US 4522930A , EP 045977A2 and international patent applications WO 00/63261 and WO 01/57099 . Particularly suited are the phthalic acid esters and succinate acids esters. Alkylphthalates are preferred, such as diisobutyl, dioctyl and diphenyl phthalate and benzylbutyl phthalate.
• The particles of solid component (i) may have substantially spherical morphology and average diameter ranging between 5 and 150 µm, preferably from 20 to 100 µm and more preferably from 30 to 90 µm. As particles having substantially spherical morphology, those are meant wherein the ratio between the greater axis and the smaller axis is equal to or lower than 1.5 and preferably lower than 1.3.
• The amount of Mg may preferably range from 8 to 30% more preferably from 10 to 25wt. %.
• The amount of Ti may range from 0.5 to 7% and more preferably from 0.7 to 5wt. %.
• According to one method, the solid catalyst component (i) can be prepared by reacting a titanium compound of formula Ti(OR)q-yXy, where q is the valence of titanium and y is a number between 1 and q, preferably TiCl4, with a magnesium chloride deriving from an adduct of formula MgCl2•pROH, where p is a number between 0.1 and 6, preferably from 2 to 3.5, and R is a hydrocarbon radical having 1-18 carbon atoms. The adduct can be suitably prepared in spherical form by mixing alcohol and magnesium chloride, operating under stirring conditions at the melting temperature of the adduct (100-130°C). Then, the adduct is mixed with an inert hydrocarbon immiscible with the adduct thereby creating an emulsion which is quickly quenched causing the solidification of the adduct in form of spherical particles. Examples of spherical adducts prepared according to this procedure are described in USP 4,399,054 and USP 4,469,648 . The so obtained adduct can be directly reacted with Ti compound or it can be previously subjected to thermal controlled dealcoholation (80-130°C) so as to obtain an adduct in which the number of moles of alcohol is of lower than 3, preferably between 0.1 and 2.5. The reaction with the Ti compound can be carried out by suspending the adduct (dealcoholated or as such) in cold TiC14; the mixture is heated up to 80-130°C and kept at this temperature for 0.5-2 hours. The treatment with TiCl4 can be carried out one or more times. The electron donor compound can be added in the desired ratios during the treatment with TiCl4.
• The alkyl-Al compound (ii) is preferably chosen among the trialkyl aluminum compounds such as for example triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum. It is also possible to use alkylaluminum halides, alkylaluminum hydrides or alkylaluminum sesquichlorides, such as AlEt2Cl and Al2Et3Cl3, possibly in mixture with the above cited trialkylaluminums. The Al/Ti ratio is higher than 1 and may preferably range between 50 and 2000.
• Particularly preferred are the silicon compounds (iii) in which a is 1, b is 1, c is 2, at least one of R7 and R8 is selected from branched alkyl, cycloalkyl or aryl groups with 3-10 carbon atoms optionally containing heteroatoms and R9 is a C1-C10 alkyl group, in particular methyl.
• Examples of such preferred silicon compounds are methylcyclohexyldimethoxysilane (C donor), diphenyldimethoxysilane, methyl-t-butyldimethoxysilane, dicyclopentyldimethoxysilane (D donor), diisopropyldimethoxysilane, (2-ethylpiperidinyl)t-butyldimethoxysilane, (2-ethylpiperidinyl)thexyldimethoxysilane, (3,3,3-trifluoro-n-propyl)(2-ethylpiperidinyl)dimethoxysilane, methyl(3,3,3-trifluoro-n-propyl)dimethoxysilane. Moreover, are also preferred the silicon compounds in which a is 0, c is 3, R8 is a branched alkyl or cycloalkyl group, optionally containing heteroatoms, and R9 is methyl. Examples of such preferred silicon compounds are cyclohexyltrimethoxysilane, t-butyltrimethoxysilane and thexyltrimethoxysilane.
• The external electron donor compound (iii) is used in such an amount to give a molar ratio between the organoaluminum compound and said external electron donor compound (iii) of from 0.1 to 200, preferably from 1 to 100 and more preferably from 3 to 50.
• The fibers according to the present invention can be stable fibers or spunbond fibers.
• The fibers of the present invention can also contain additives commonly employed in the art, such as antioxidants, light stabilizers, heat stabilizers, nucleating agents, colorants and fillers.
• The fibers of the disclosure typically exhibit a value of tenacity at least equal to or higher than 15.0 cN/tex, preferably higher than 16.0. cN/tex, more preferably higher than 17.0 cN/tex with a titre of 3.8 dTex. Tenacity being lower than 30 cN/tex
• Typically, the fibers according to the present disclosure have a titre ranging from 1 to 8 dtex, preferably from 1.5 to 4.0 dtex.
• The fibers of the disclosure when have a titre of 3.8 dTex exhibit a value of elongation at break higher than 280 %; preferably higher than 330% the higher value being 800%.
• The fibers of the present disclosure can be efficiently spun at speeds that are typically higher than 3000 m/min, preferably higher than 3300 m/min, more preferably higher than 3500 m/min.
• The fibers of the present disclosure can be spun at temperatures generally varying from 200° to 300° C. Preferably, the spinning temperature is lower than 250°C, even more preferably, the spinning temperature is comprised between 230° and 250°C.
• The fibers of the present disclosure for a titre of 3.8d/tex preferably have an elongation at break higher than 280 %; preferably higher than 320 %, preferably lower than 800%.
• The fibers of the present invention can be used for the manufacture of fabric and non-woven fabrics, in particular carpet showing excellent properties.
• Such non-woven fabrics may be produced with various methods, preferably through the well-known spunbonding technique. The spunbonding process is a non-woven manufacturing technique, whereby polymers are directly converted into endless filaments and stochastically deposited to form a non-woven material.
• The following examples are given in order to illustrate, but not limit the present disclosure.
EXAMPLE Characterization methods
• Melting temperature and crystallization temperature: Determined by differential scanning calorimetry (DSC). weighting 6 ±1 mg, is heated to 220 ±1° C at a rate of 20 °C/min and kept at 220 ±1° C for 2 minutes in nitrogen stream and it is thereafter cooled at a rate of 20° C/min to 40 ±2° C, thereby kept at this temperature for 2 min to crystallize the sample. Then, the sample is again fused at a temperature rise rate of 20° C/min up to 220° C ±1. The melting scan is recorded, a thermogram is obtained, and, from this, melting temperatures and crystallization temperatures are read.
• Melt Flow Rate: Determined according to the method ISO 1133-1 (230° C, 2.16 kg).
• Xylene-soluble fraction (XS) at 25°C Xylene Solubles at 25°C have been determined according to ISO 16152: 2005; with solution volume of 250 ml, precipitation at 25°C for 20 minutes, 10 of which with the solution in agitation (magnetic stirrer), and drying at 70°C.
• Intrinsic Viscosity (I.V.) The sample is dissolved by tetrahydronaphthalene at 135 °C and then it is poured into the capillary viscometer.
• The viscometer tube (Ubbelohde type) is surrounded by a cylindrical glass jacket; this setup allows temperature control with a circulating thermostated liquid.
• The downward passage of the meniscus is timed by a photoelectric device. The passage of the meniscus in front of the upper lamp starts the counter which has a quartz crystal oscillator. The meniscus stops the counter as it passes the lower lamp and the efflux time is registered: this is converted into a value of intrinsic viscosity through surrounded by a cylindrical glass jacket; this setup allows for temperature control with a circulating thermostatic liquid. The downward passage of the meniscus is timed by a photoelectric device. The passage of the meniscus in front of the upper lamp starts the counter which has a quartz crystal oscillator. The meniscus stops the counter as it passes the lower lamp and the efflux time is registered: this is converted into a value of intrinsic viscosity through Huggins' equation (Huggins, M.L., J. Am. Chem. Soc., 1942, 64, 2716) provided that the flow time of the pure solvent is known at the same experimental conditions (same viscometer and same temperature). One single polymer solution is used to determine [η].
Comonomer determination via ¹³C-NMR
• Determination of the composition of PP repro via ¹H and ¹³C NMR
• PP repro is a mixture of polymers having an aliphatic hydrocarbon backbone (ethylene - E), propylene - P), and 1-butene (B, < 1.0 wt%), 1-hexene (H, < 1.0 wt%) and 1-octene (O, < 1.0 wt%) copolymers and possibly an aromatic hydrocarbon backbone (polystyrene and polyethylene terephthalate). Due to analytical complications in determining the composition of aromatic containing polymers via 13C NMR spectroscopy, the method was developed by using the combination of the results obtained via 1H and 13C NMR spectra. In particular 13C NMR was used to determine the relative amount of ethylene, propylene 1-butene, 1-hexene and 1-octene copolymers, while 1H NMR provided a quantification of the composition of aliphatic and aromatic components and the relative amounts of polystyrene and polyethylene terephthalate when present.
• 13C NMR and 1H spectra were acquired on a Bruker AV600 spectrometer equipped with cryo probe, operating at 150.91 MHz and 600.13 MHz respectively in the Fourier transform mode at 120 °C.
• About 30 mg of sample were dissolved at 120°C in 0.5 ml of 1,1,2,2 tetrachloroethane-d2 added with 0.1 mg/ml of Irganox 1010 (AO 1010) as antioxidant
• For 13C NMR spectra the peak of the Sδδ carbon (nomenclature according C.J. Carman, R.A. Harrington and C.E. Wilkes, Macromolecules, 10, 3, 536 (1977)) was used as internal reference at 29.9 ppm. Each spectrum was acquired with a 90 ° pulse, 15 seconds of delay between pulses and CPD to remove 1H-13C coupling. 512 transients were stored in 65 K data points using a spectral window of 9000 Hz.
• For 1H NMR spectra the peak of the residual C2DHCl4 at 5.95 ppm was used as internal reference. Each spectrum was acquired with a 90° pulse, 5 seconds of delay between pulses and 128 transients stored in 64K data points using a spectral window of 9600 Hz.
• Evaluation of 13C NMR spectrum of Ethylene, Propylene, 1-Butene, 1-Hexene and 1-Octene copolymers
• In the 13C NMR spectrum only the signals from Ethylene, Propylene, 1-Butene, 1-Hexene and 1-Octene copolymers were considered (assignments of peak relevant for quantification are reported in Table 1). Triad distribution (considering only EBE, EHE and EOE due to the low amount of these comonomers) was obtained from the integration of relevant peaks in 13C NMR spectrum (possible overlaps of the peaks of the antioxidant AO1010 were taken into account), using the following relations: $$\mathrm{PPP}=100{\mathrm{I}}_{11}/\mathrm{\Sigma }$$ $$\mathrm{for}{\mathrm{I}}_3/{\mathrm{I}}_4<1:\mathrm{PPE}=100{\mathrm{I}}_3/\mathrm{\Sigma }$$ $$\mathrm{for}{\mathrm{I}}_3/{\mathrm{I}}_4>1:\mathrm{PPE}=100\left({\mathrm{I}}_8-6{\mathrm{I}}_4\right)/\mathrm{\Sigma }$$ $$\mathrm{EPE}=100{\mathrm{I}}_7/\mathrm{\Sigma }$$ $$\mathrm{EBE}=100{\mathrm{I}}_1/\mathrm{\Sigma }$$ $$\mathrm{EHE}=100{\mathrm{I}}_6/\mathrm{\Sigma }$$ $$\mathrm{EOE}=100\left({\mathrm{I}}_2-{\mathrm{I}}_6\right)/\mathrm{\Sigma }$$ $$\mathrm{XEX}=100{\mathrm{I}}_{13}/\mathrm{\Sigma }$$ $$\mathrm{XEE}=100\left({\mathrm{I}}_{12}-{\mathrm{I}}_2\right)/\mathrm{\Sigma }$$ $$\mathrm{EEE}=100\left(0.5\left({\mathrm{I}}_{10}-{\mathrm{I}}_2\right)+0.25\left({\mathrm{I}}_9+{\mathrm{I}}_8\right)\right)/\mathrm{\Sigma }$$
  Where: $$\mathrm{\Sigma }={\mathrm{I}}_{11}+\left({\mathrm{I}}_3\mathrm{or}\left({\mathrm{I}}_8-6{\mathrm{I}}_4\right)\right)+{\mathrm{I}}_7+{\mathrm{I}}_1+{\mathrm{I}}_6+{\mathrm{I}}_2-{\mathrm{I}}_6+{\mathrm{I}}_{13}+{\mathrm{I}}_{12}-{\mathrm{I}}_2+0.5\left({\mathrm{I}}_{10}-{\mathrm{I}}_2\right)+0.25\left({\mathrm{I}}_9+{\mathrm{I}}_8\right)$$
  and I_n are the areas of the corresponding carbon following the numbering scheme reported in Table 1 and X can be propylene, 1-butene , 1-hexene or 1-octene
• The molar content of Ethylene, Propylene, 1-Butene and 1-Octene is obtained from triads using the following relations: $$\mathrm{P}\left(\mathrm{m}\%\right)=\mathrm{PPP}+\mathrm{PPE}+\mathrm{EPE}$$ $$\mathrm{B}\left(\mathrm{m}\%\right)=\mathrm{EBE}$$ $$\mathrm{H}\left(\mathrm{m}\%\right)=\mathrm{EHE}$$ $$\mathrm{O}\left(\mathrm{m}\%\right)=\mathrm{EOE}$$ $$\mathrm{E}\left(\mathrm{m}\%\right)=\mathrm{EEE}+\mathrm{XEE}+\mathrm{XEX}$$
• Molar content was transformed in weight using monomers molecular weight.
Evaluation of 1H NMR spectrum
• The molar content of Polyethylene terephthalate (PET), Polystyrene (PS) and ethylene/propylene/1-butene/1-hexene/1-octene copolymers were obtained from 1H spectra.
• The aromatic hydrogen peaks of PET and PS (assignments according to Table 2) were used, while the amount of ethylene/propylene/1-Butene/1-Hexene/1-Octene copolymers was determined by the integral of all the aliphatic hydrogens, from which the contribution of the 3 aliphatic hydrogens of the polystyrene was subtracted.
• Molar amounts of PET, PS and E/P/B/H/O copolymers were evaluated from the following relations: $$\mathrm{PET}=10000.25{\mathrm{I}}_{\mathrm{a}}/\mathrm{\Sigma }$$ $$\mathrm{PS}=1000.5{\mathrm{I}}_{\mathrm{c}}/\mathrm{\Sigma }$$ $$\mathrm{Total}\mathrm{aliphatic}\mathrm{E}/\mathrm{P}/\mathrm{B}/\mathrm{H}/\mathrm{O}\mathrm{copolymers}=1000.5\left({\mathrm{I}}_{\mathrm{e}}-3\mathrm{PS}-9{\mathrm{I}}_{\mathrm{d}}\right)/\mathrm{\Sigma }$$
  Where $$\mathrm{\Sigma }=0.25\mathrm{Ia}+0.5\mathrm{Ic}+0.5\left(\mathrm{Ie}-3\mathrm{PS}-9\mathrm{Id}\right)$$
• Molar content was transformed in weight percentage using monomers molecular weight considering the MW of CH2 to estimate the weight contribution from ethylene/propylene/1-butene/1-hexene/1-octene copolymers.
• The weight content of P, E, B, Hand O obtained from 13C spectrum was rescaled to obtain the weight percentage in the whole sample by multiplying each value (wt%) from triads with the rescaling factor "RF":
  RF = [100-PET(wt%)-PS(wt%)]/100 where PET(wt%) and PS(wt%) are the compositions obtained from 1H spectrum.
• Table a: Assignments of the 13C NMR spectrum of Ethylene/Propylene/1-Octene/1-Butene copolymers Table a

  Number	Chemical Shift (ppm)	Carbon	Sequence
  1	39.6	Tδδ	EBE
  2	38.8	Tδδ	EOE + EHE
  3	38.2 - 37.6	Sαγ	PE
  4	36.2	CH2	AO1010
  6	34.0	4B4	EHE
  7	33.3 - 33.2	Tδδ	EPE
  8	30.8 - 30.7	Tβδ	PPE
  8	30.3	Sγδ	XEEE
  9	30.2	Sγδ	PEEE
  10	29.9	8δδ + 4B6	EEE + O
  11	28.8 - 28.2	Tββ	PPP
  12	27.4 - 26.7	Sβδ + 5B6	XE + O
  13	24.7 - 24.1	Sββ	XEX

Samples for the mechanical tests
• Samples have been obtained according to ISO 1873-2:2007.
• Charpy impact test is determined according to ISO 179-1eA, and ISO 1873-2
• Elongation at yield: measured according to ISO 527.
• Elongation at break: measured according To ISO 527
• Stress at break: measured according to ISO 527.
• Tensile Modulus according to ISO 527-2.
Titre of filaments
• From a 10 cm long roving, 50 fibers are randomly chosen and weighed. The total weight of the 50 fibers, expressed in mg, is multiplied by 2, thereby obtaining the titre in dtex.
Tenacity and Elongation at break of filaments
• From a 500 m roving a 100 mm-long segment is cut and single fibers randomly chosen. Each single fiber is fixed to the clamps of a Dynamometer and tensioned to break with a traction speed of 20 mm/min for elongations lower than 100% and 50 mm/min for elongations greater than 100%, the initial distance between the clamps being of 20 mm. The ultimate strength (load at break) and the elongation at break are determined in machine (MD) direction.
• The tenacity is calculated by way of the following equation:
  $$\mathrm{Tenacity}=\mathrm{Ultimate}\mathrm{strength}\left(\mathrm{cN}\right)\times 10/\mathrm{Titre}\left(\mathrm{dtex}\right).$$
Maximum spinning speed
• The maximum spinning speed gives indication of the spinnability of the propylene polymer composition of the invention. The value corresponds to the highest spinning rate that can be maintained for 30 minutes with no filament break
Component A)
• Component A) is a PCR derived from protective packaging waste and contains 2,9-bis(3,5-dimethylphenyl)anthra[2,1,9-def:6,5,10-d'e'f]diisoquinoline-1,3,8,10(2H,9H)-tetrone having the features reported in Table 1. Table 1

  		A1
  MFR 2.16 kg/230°C	g/10'	11.20
  Density	kg/dm3	0.900
  XS	%	7.50
  Tm	°C	142.9
  Tc	°C	108.2
  Hc	J/g	-77.2
  Hm	J/g	69.4
  C2 (NMR)	wt%	1.90
  C4 (NMR)	wt%	4.70
  C2-(XS fraction) (NMR)	wt%	7.57
  C4-(XS fraction) (NMR)	wt%	6.57
  Tensile Modulus	N/mm2	915
  Charpy Impact @ 23°C	kJ/m2	7.2
  Charpy Impact @ 0°C	kJ/m2	2.3
  Elongation at break	%	640

Component B) Preparation of homopolymer
• The catalyst used has been prepared according to the procedure reported in example 1 of WO 2020244912
Polymerization
• The polymerization run was carried out in continuous mode in a liquid phase loop reactor. Hydrogen was used as a molecular weight regulator. Polymerization conditions are indicated in table 2. Table 2

  		Ex 1
  PRECONTACT		0.3
  Alkyl/Cat	g/g	12.4
  POLYMERIZATION
  Temperature	°C	74
  Residence time	min	66
  H2 feed (calc)	mol ppm	895
  H2O/PP	ppm wt	7
  H2O tot/teal	kg/kg	0.032
  POLYMER ANALYSIS
  MFR	g/10min	11.3
  XS	%wt	3.8
  PI		4.4

• Comparative component B1) is a propylene ethylene copolymer sold by Lyondellbasell with the tradename of Moplen HP552N having an MFR (230°C/2.16kg of 13 g/10 min, soluble in xylene at 25°C of 3.2 wt%.
Preparation of the fibers
• 30 wt% of component A and 70 wt% of component B) have been blended together and pellettized. The features of the pelletized composition are reported on table 3. Pellets are extruded in a Leonard 25 spinning pilot line with screw LID ratio of 5. The line is marketed by Costruzioni Meccaniche Leonard-Sumirago (VA). The operative spinning conditions are here reported.
• Operative conditions:
• Hole diameter: mm 0.4
• Hole number in the die: 41
• Die temperature (°C): 280
Table 3

	Units	Ex 1	Comp ex 2
MFR	g/10min	13.2	13
Tm	°C	160.2	161.6
Tc	°C	119	109.8
MET	N/mm2	1320	1511
Charpy at 23°C	KJ/m2	5.1	3.5
Stress at yield	N/mm2	31.8	33.8
Elongation at yield	%	10.7	11.1
Stress at break	N/mm2	18.7	20.8
Elongation at break	%	470	704

• The properties of the filaments are reported on Table 4. Table 4

  	Units	Ex 1	Comp ex 2
  Titre Fiber	dTex	3.8	3.8
  Tenacity	cN/Tex	18.6	17.6
  Elongation at break	%	390	455
  Maximum speed	m/min	2000	2000
  Titre Fiber	dTex	5.7	5.5
  Tenacity	cN/Tex	18.4	17.5
  Elongation at break	%	415	485
  Maximum speed	m/min	2000	2000

• Comparative example 2 is the fiber obtained by using 100 wt% of Moplen HP552N. By using the blend of recycled polymer and the homopolymer of the present disclosure it is possible to have a fiber with higher tenacity even if a recycled polymer is used.

Claims (15)

1. A fiber comprising:

   A) from 15 wt% to 45 wt%; of a recycled polypropylene composition having:

   i) ethylene derived units content, measured by ¹³C-NMR, ranging from 1.0 wt% to 4.2 wt%

   ii) 1-butene derived units content, measured by ¹³C-NMR, ranging from 1.5 wt% to 5.2 wt% ,

   iii) ethylene derived units content of the fraction soluble in xylene at 25°C, measured by ¹³C-NMR, ranging from 6.0 wt% to 15.0 wt%,

   iv) 1-butene derived units content, of the fraction soluble in xylene at 25°C, measured by ¹³C-NMR, ranging from 2.8 wt% to 8.2 wt% ,

   v) Melt Flow Rate, determined according to the method ISO 1133 (230° C, 2.16 kg), ranging from 5.0 g/10 min to 20.0 g/10 min;

   vi) Xylene Soluble fraction at 25°C ranging from 4.8 wt% to 10.7 wt%,

   vii) melting point measured by DSC according to ISO 11357-3, ranging from 135 °C to 149 °C;

   B) from 55 wt% to 85 wt%; of a propylene homopolymer having a Melt Flow Rate, determined according to the method ISO 1133 (230° C, 2.16 kg), ranging from 5.0 g/10 min to 21.0 g/10 min; and a xylene Soluble fraction at 25°C,determined according to ISO 16152: 2005, ranging from 1.5 wt% to 5.6 wt%;

   Wherein the Melt Flow Rate of the polypropylene composition, determined according to the method ISO 1133 (230° C, 2.16 kg), ranges from 5.2 g/10 min to 23.2 g/10 min;
   the sum of the amounts of (A) and (B) being referred to the total weight of (A) and (B) is 100 wt%.
2. The fiber according to claim 1 wherein:

   component (A) ranges from 20 wt% to 40 wt%,

   component (B) ranges from 60 wt% to 80 wt%.
3. The fiber according to anyone of claims 1-2 wherein component A) has ethylene derived units content, measured by ¹³C-NMR, ranging from 1.4 wt% to 4.0 wt%.
4. The fiber according to anyone of claims 1-3 wherein component A) has 1-butene derived units content, measured by ¹³C-NMR, ranging from 1.8 wt% to 5.0 wt%.
5. The fiber according to anyone of claims 1-4 wherein component (B) has Melt Flow Rate, determined according to the method ISO 1133 (230° C, 2.16 kg), ranging from 6.0 g/10 min to 19.0 g/10 min.
6. The fiber according to anyone of claims 1-5 wherein component (B) has and a Xylene Soluble fraction at 25°C,determined according to ISO 16152: 2005, ranging from 2.2 wt% to 4.8 wt%.
7. The fiber according to anyone of claims 1-6 having tenacity at least equal to or higher than 15.0 cN/tex, with a titre of 3.8.
8. The fiber according to anyone of claims 1-7 having exhibit a value of elongation at break higher than 280 % with a titre of 3.8.
9. The fiber according to anyone of claims 1-8 wherein:

   component (A) ranges from 25 wt% to 35 wt%,

   component (B) ranges from 65 wt% to 75 wt%.
10. The fiber according to anyone of claims 1-9 wherein in component A) the Xylene Soluble fraction at 25°C ranges from 6.2 wt% to 9.2 wt%.
11. The fiber according to anyone of claims 1-10 wherein in component A) wherein in component A) melting point measured by DSC according to ISO 11357-3, ranges from 138°C to 148°C.
12. The fiber according to anyone of claim 1-11 wherein component (A) has the ethylene derived units content of the fraction soluble in xylene at 25°C, measured by ¹³C-NMR, ranging from 1.6 wt% to 3.8 wt%.
13. The fiber according to anyone of claim 1-12 wherein component (A) has the 1-butene derived units content of the fraction soluble in xylene at 25°C, measured by ¹³C-NMR, ranging from 2.1 wt% to 4.8 wt%.
14. The fiber according to anyone of claim 1-13 wherein component A) contains: 2,9-bis(3,5-dimethylphenyl)anthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetrone.
15. A carpet made from the fibers according to claims 1-14.