Patent Grant
10385199
This application is the U.S. National Phase of PCT International Application PCT/EP2016/064453, filed Jun. 22, 2016, claiming benefit of priority to European Patent Application No. 15173696.4, filed Jun. 24, 2015, the contents of which are incorporated herein by reference in its entirety.
In general, the present disclosure relates to the field of chemistry. More specifically, the present disclosure relates to polymer chemistry. In particular, the present disclosure relates to polyolefin compositions, their preparation, and their use as impact modifiers in polyolefin blends.
Impact modifier compositions made from or containing an amorphous olefin copolymer, may be added in polyolefin compositions to enhance the impact resistance. Applications include automotive applications.
There is a need for blends of impact modifier compositions and polyolefin materials, exhibiting a good balance of properties such as high values of impact resistance and elongation at break, without impairing the thermal shrinkage, and showing good optical properties.
In a general embodiment, the present disclosure provides a polyolefin composition made from or containing:
In a general embodiment, the present disclosure provides a process for the preparation of the polyolefin compositions, including at least three sequential polymerization steps, wherein components (A), (B) and (C) are prepared in separate subsequent steps, operating in each step, except the first step, in the presence of the polymer formed and the catalyst used in the preceding step.
In a general embodiment, the present disclosure provides polyolefin blends made from or containing the polyolefin composition described above and at least about 50% by weight, referred to the total weight of the polyolefin composition, of one or more additional polyolefins.
In a general embodiment, the present disclosure provides formed articles, alternatively injection molded articles, made from or containing the polymer blends.
As used herein, the term “copolymer” includes polymers containing more than one kind of comonomers, such as terpolymers.
In some embodiments the propylene-based polymer (A) may be present in amount of about 10 to about 30% by weight, alternatively in amount of about 15 to about 25% by weight, referred to the total weight of (A)+(B)+(C).
In some embodiments the propylene-based polymer (A) may contain about 95% by weight or more of propylene units, alternatively about 97% by weight or more of propylene units, referred to the weight of (A). The propylene polymer (A) may be a homopolymer or a copolymer containing units deriving from one or more comonomers selected from ethylene and C4 to C10 alpha-olefins. In some embodiments, the alpha-olefin comonomers are selected from the group consisting of butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1 and decene-1. The propylene-based polymer (A) may also be a mixture of a homopolymer and a copolymer.
In some embodiments, the propylene-based polymer (A) may contain about 8% by weight or less of a fraction soluble in xylene at 25° C. (XSA), alternatively 5% by weight or less of a fraction soluble in xylene at 25° C. (XSA), referred to the weight of (A).
In some embodiments the propylene-based polymer (A) may have a melt flow rate (230° C./2.16 kg) between about 50 to about 200 g/10 min., alternatively between about 80 to about 170 g/10 min.
In some embodiments the copolymer of ethylene (B) may be present in amount of about 25 to about 45% by weight, alternatively of about 30 to about 40% by weight, referred to the total weight of (A)+(B)+(C).
In some embodiments, the copolymer of ethylene (B) may contain from about 0.1% to about 15% by weight of C3-C8 alpha-olefin units, referred to the weight of (B). In some embodiments, the alpha-olefin comonomers are selected from the group consisting of propylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1 and octene-1.
In some embodiments the copolymer of ethylene (B) may contain about 60% by weight or less of a fraction soluble in xylene at 25° C. (XSB), alternatively about 40% by weight or less of a fraction soluble in xylene at 25° C. (XSB), referred to the weight of (B).
In some embodiments the copolymer of ethylene (B) may have a melt flow rate (230° C./2.16 kg) between about 0.1 to about 50 g/10 min., alternatively between about 0.5 to about 40 g/10 min., between about 1 to about 30 g/10 min.
In some embodiments the copolymer of ethylene (B) may have a density (determined according to ISO 1183 at 23° C.) of from about 0.915 to about 0.940 g/cm3.
In some embodiments the copolymer of ethylene and propylene (C) may be present in amount of about 35 to about 55% by weight, alternatively about 40 to about 55% by weight, referred to the total weight of (A)+(B)+(C).
In some embodiments the copolymer of ethylene and propylene (C) may contain from about 35% to about 70% by weight of ethylene units, alternatively from about 45% to about 65% by weight of ethylene units, referred to the weight of (B).
In some embodiments, the copolymer of ethylene and propylene (C) may contain from about 60% to about 95% by weight of a fraction soluble in xylene at 25° C. (XSC), alternatively from about 65% to about 90% by weight of a fraction soluble in xylene at 25° C. (XSC), referred to the weight of (C).
In some embodiments, the copolymer of ethylene and propylene (C) may also contain from about 10% to about 30% by weight, alternatively from about 15% to about 25% by weight of an alpha-olefin having 4 to 8 carbon atoms. In some embodiments, the C4-C8 alpha-olefins are selected from the group consisting of 1-butene, 1-hexene and 1-octene.
In some embodiments the polyolefin composition may have a melt flow rate (230° C./2.16 kg) between about 0.1 to about 6.0 g/10 min., alternatively between about 0.5 to about 5.5 g/10 min., between about 1.0 to about 5.0 g/10 min.
In some embodiments the polyolefin composition may contain from about 20% to about 65% by weight, of a fraction soluble in xylene at 25° C. (XSTOT), alternatively from about 30% to about 55% by weight, of a fraction soluble in xylene at 25° C.
In some embodiments the polyolefin composition may have an intrinsic viscosity [η] (measured in tetrahydronaphthalene at 135° C.) of the XS fraction of about 1.0 dl/g or more, alternatively between about 2.0 to about 4.0 dl/g.
In some embodiments the polyolefin composition may have a total content of C4-C8 alpha-olefin units (determined by IR analysis) of about 1% by weight or higher, alternatively about 2% by weight or higher, alternatively about 3% by weight or higher.
In some embodiments the polyolefin composition may have one or more of the following additional features:
In a general embodiment, various polymerization processes and catalysts can be used to prepare the polyolefin compositions disclosed herein. In some embodiments, the polyolefin compositions can be prepared by a sequential polymerization, including at least three sequential steps, wherein components (A), (B) and (C) are prepared in separate subsequent steps, operating in each step, except the first step, in the presence of the polymer formed and the catalyst used in the preceding step. The catalyst is added in the first step. The catalyst remains active for the subsequent steps.
The polymerization, which can be continuous or batch, is carried out in liquid phase, in the presence or not of inert diluent, or in gas phase, or by mixed liquid-gas techniques. In some embodiments, the polymerization is carried out in gas phase.
In some embodiments, the reaction temperature is from about 50 to about 100° C. In some embodiments, the reaction pressure can be atmospheric or higher.
In some embodiments, the regulation of the molecular weight is carried out by using regulators. In some embodiments, the regulator is hydrogen.
In some embodiments, the polymerizations are carried out in the presence of a Ziegler-Natta catalyst. In some embodiments, the Ziegler-Natta catalyst is made from or contains a product of the reaction of an organometallic compound of group 1, 2 or 13 of the Periodic Table of elements with a transition metal compound of groups 4 to 10 of the Periodic Table of Elements (new notation). In some embodiments, the transition metal compound can be selected among compounds of Ti, V, Zr, Cr and Hf. In some embodiments, the transition metal compound is supported on MgCl2.
In some embodiments, catalysts are made from or contain the product of the reaction of the organometallic compound of group 1, 2 or 13 of the Periodic Table of elements, with a solid catalyst component made from or containing a Ti compound and an electron donor compound supported on MgCl2.
In some embodiments, the organometallic compounds are aluminum alkyl compounds.
In some embodiments, the ethylene polymer composition is obtainable by using a Ziegler-Natta polymerization catalyst, alternatively a Ziegler-Natta catalyst supported on MgCl2, alternatively a Ziegler-Natta catalyst made from or containing the product of reaction of:
In some embodiments, the solid catalyst component (1) contains as electron-donor a compound selected among the group consisting of ethers, ketones, lactones, compounds containing N, P and/or S atoms, and mono- and dicarboxylic acid esters.
In some embodiments, the catalysts can be selected from those catalysts disclosed in U.S. Pat. No. 4,399,054 and European Patent No. 45977, both incorporated herein by reference.
In some embodiments, the electron-donor compounds are selected from the group consisting of phthalic acid esters and succinic acid esters. In some embodiments, the electron-donor compound is diisobutyl phthalate.
In some embodiments, the succinic acid esters are represented by the formula (I):
wherein the radicals R1 and R2, equal to or different from each other, are a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms; the radicals R3 to R6 equal to or different from each other, are hydrogen or a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms, and the radicals R3 to R6 which are joined to the same carbon atom can be linked together to form a cycle.
In some embodiments, R1 and R2 are selected from the group consisting of C1-C8 alkyl, cycloalkyl, aryl, arylalkyl and alkylaryl groups. In some embodiments, R1 and R2 are selected from primary alkyls, alternatively branched primary alkyls. In some embodiments, R1 and R2 groups are selected from the group consisting of methyl, ethyl, n-propyl, n-butyl, isobutyl, neopentyl, and 2-ethylhexyl. In some embodiments, R1 and R2 groups are selected from the group consisting of ethyl, isobutyl, and neopentyl.
In some embodiments, R3 to R5 are hydrogen and R6 is selected from the group consisting of a branched alkyl, cycloalkyl, aryl, arylalkyl and alkylaryl radical having from 3 to 10 carbon atoms. In some embodiments, at least two radicals from R3 to R6 are different from hydrogen and are selected from C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms. In some embodiments, the two radicals different from hydrogen are linked to the same carbon atom. In some embodiments, at least two radicals different from hydrogen are linked to different carbon atoms, that is R3 and R5 or R4 and R6.
In some embodiments, the electron-donors are the 1,3-diethers. In some embodiments, the 1,3-diethers are as disclosed in European Patent Application Nos. EP-A-361 493 and 728769, both incorporated herein by reference.
In some embodiments, cocatalysts (2) use trialkyl aluminum compounds, alternatively selected from the group consisting of Al-triethyl, Al-triisobutyl and Al-tri-n-butyl.
The electron-donor compounds (3) that can be used as external electron-donors (added to the Al-alkyl compound) can be selected from the group consisting of aromatic acid esters (such as alkylic benzoates), heterocyclic compounds (such as 2,2,6,6-tetramethylpiperidine and 2,6-diisopropylpiperidine), and silicon compounds containing at least one Si—OR bond (where R is a hydrocarbon radical).
In some embodiments, the silicon compounds are those of formula R1aR2bSi(OR3)c, where a and b are integer numbers from 0 to 2, c is an integer from 1 to 3 and the sum (a+b+c) is 4; R1, R2 and R3 are alkyl, cycloalkyl or aryl radicals with 1-18 carbon atoms optionally containing heteroatoms.
In some embodiments, the silicon compounds are selected from the group consisting of (tert-butyl)2Si(OCH3)2, (cyclohexyl)(methyl)Si(OCH3)2, (phenyl)2Si(OCH3)2 and (cyclopentyl)2Si(OCH3)2.
In some embodiments, 1,3-diethers are used as external donors. In some embodiments, the internal donor is a 1,3-diether and the external donor is omitted.
The catalysts may be precontacted with small quantities of olefin (prepolymerization), maintaining the catalyst in suspension in a hydrocarbon solvent, and polymerizing at temperatures from room to 60° C., thus producing a quantity of polymer from about 0.5 to about 3 times the weight of the catalyst.
The operation can also take place in liquid monomer, producing a quantity of polymer up to about 1000 times the weight of the catalyst.
The polyolefin compositions can also contain additives, such as antioxidants, light stabilizers, heat stabilizers, colorants and fillers.
In a general embodiment, the polyolefin compositions can be prepared as a physical blend of the separately-prepared components rather than as a reactor blend.
In some embodiments, the polyolefin composition can be compounded with additional polyolefins. In some embodiments, the propylene polymers are selected from the group consisting of propylene homopolymers, random copolymers, thermoplastic elastomeric polyolefin compositions and plastomers. In some embodiments, the polyolefin composition contains the ethylene polymer composition. In some embodiments, the polyolefin composition is made from or contains at least about 50% by weight, alternatively from about 50% to about 90% by weight, of one or more additional polyolefins, and about 50% or less, alternatively from about 10% to about 50% by weight, of the ethylene polymer composition, percent amounts being referred to the total weight of the ethylene polymer composition and of the additional poly olefin or polyolefins.
In some embodiments, the additional polyolefins are selected from the group consisting of the following polymers:
In some embodiments, the ethylene copolymers 5) are products marketed by Dow Chemical under the trademark Engage™ and Affinity™ or by ExxonMobil Chemical under the trademark Exact™.
In some embodiments, the propylene copolymers 6) are products marketed by Dow Chemical under the trademark Versify™, by ExxonMobil Chemical under the trademark Vistamaxx™ and by Mitsui Chemicals under the trademark Notio™.
The polyolefin blends may be manufactured by mixing the ethylene polymer composition and the additional polyolefin(s) together, extruding the mixture, and pelletizing the resulting composition.
The polyolefin blends may also contain additives such as mineral fillers, fibers, colorants and stabilizers. Some mineral fillers include talc, CaCO3, silica, such as wollastonite (CaSiO3), clays, diatomaceaous earth, titanium oxide and zeolites. In some embodiments, the mineral filler is in particle form having an average diameter ranging from about 0.1 to about 5 micrometers. In some embodiments, the fibers include glass fibers, carbon fibers, metallic or ceramic fibers.
In a general embodiment, the present disclosure provides articles. In some embodiments, the articles are injection molded articles, such as finished parts for the automotive industry, made of or containing the polyolefin blends. In some embodiments, the polyolefin blends can be injection molded into large objects which exhibit low values of thermal shrinkage in combination with enhanced mechanical properties, like impact strength and elongation at break.
These examples are illustrative and not intended to limit the scope of this disclosure in any manner whatsoever.
The following analytical methods are used to characterize the polymer compositions.
Melting Temperature (ISO 11357-3)
Determined by differential scanning calorimetry (DSC). A sample weighting 6±1 mg is heated to 200±1° C. at a rate of 20° C./min and kept at 200±1° C. for 2 minutes in nitrogen stream and thereafter cooled at a rate of 20° C./min to 40±2° C., thereby kept at this temperature for 2 min. Then, the sample is again melted at a temperature rise rate of 20° C./min up to 200° C.±1. The melting scan is recorded, a thermogram is obtained, and temperatures corresponding to peaks are read. The temperature corresponding to the two most intense melting peaks recorded during the second fusion is taken as the melting temperature. The fusion enthalpy ΔHfus is measured on both most intense melting peaks. If only one peak is detected, both melting temperature and ΔHfus are measured on that peak. To determine fusion enthalpy ΔHfus, the base-line is constructed by connecting the two closest points at which the melting endotherm peak deviate from the baseline. The heat of fusion (ΔHfus) is then calculated by integrating the area between DSC heat flow recorded signal and constructed baseline.
Xylene Soluble Fraction
2.5 g of polymer and 250 cm3 of o-xylene are introduced in a glass flask equipped with a refrigerator and a magnetic stirrer. The temperature is raised in 30 minutes from room temperature up to the boiling point of the solvent (135° C.). The obtained clear solution is then kept under reflux and stirring for further 30 minutes. The closed flask is then kept in a thermostatic water bath at 25° C. for 30 minutes as well. The formed solid is filtered on quick filtering paper. 100 cm3 of the filtered liquid is poured in a previously weighed aluminum container which is heated on a heating plate under nitrogen flow, to remove the solvent by evaporation. The container is then kept in an oven at 80° C. under vacuum to dryness and then weighed after constant weight is obtained, thereby calculating the percent by weight of polymer soluble and insoluble in xylene at 25° C.
Melt Flow Rate
Measured according to ISO 1133 at 230° C. with a load of 2.16 kg, unless otherwise specified.
Intrinsic Viscosity [η]
The sample is dissolved in tetrahydronaphthalene at 135° C. and then poured into a capillary viscometer. The viscometer tube (Ubbelohde type) is surrounded by a cylindrical glass jacket, thereby permitting 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 meniscus passes the lower lamp and the efflux time is registered. The efflux time is converted into a value of intrinsic viscosity through Huggins' equation based upon the flow time of the pure solvent at the same experimental conditions (same viscometer and same temperature). See Huggins, M. L., J. Am. Chem. Soc., 1942, 64, 2716, incorporated herein by reference. A single polymer solution is used to determine [η].
Comonomer (C2 and C4) Content
The content of comonomers was determined by infrared spectroscopy by collecting the IR spectrum of the sample vs. an air background with a Fourier Transform Infrared spectrometer (FTIR). The instrument data acquisition parameters were:
Sample Preparation—Using a hydraulic press, a thick sheet was obtained by compression molding about 1 gram of sample between two aluminum foils. A small portion was cut from this sheet to mold a film. The film thickness was set in order to have a maximum absorbance of the CH2 absorption band recorded at ˜720 cm−1 of 1.3 au. (% Transmittance>5%). Molding conditions were 180±10° C. (356° F.) and pressure was around 10 kg/cm2 (142.2 PSI) for about one minute. The pressure was then released. The sample was removed from the press and cooled to room temperature. The spectrum of pressed film sample was recorded in absorbance vs. wavenumbers (cm−1). The following measurements were used to calculate ethylene (C2) and 1-butene (C4) contents:
The ratio AC2/At was calibrated by analyzing ethylene-propylene standard copolymers of reference compositions, determined by NMR spectroscopy. In order to calculate the ethylene (C2) and 1-butene (C4) content, calibration curves were obtained by using reference samples with ethylene and 1-butene detected by 13C-NMR.
Calibration for ethylene—A calibration curve was obtained by plotting AC2/At versus ethylene molar percent (% C2m), and the coefficient aC2, bC2 and CC2 then calculated from a “linear regression”.
Calibration for 1-butene—A calibration curve was obtained by plotting FCRC4/At versus butane molar percent (% C4m) and the coefficients aC4, bC4 and CC4 then calculated from a “linear regression”.
The spectra of the samples were recorded and then (At), (AC2) and (FCRC4) of the sample were calculated.
The ethylene content (% molar fraction C2m) of the sample was calculated as follows:
The 1-butene content (% molar fraction C4m) of the sample was calculated as follows:
aC4, bC4, CC4 ace, bC2, cC2 were the coefficients of the two calibrations.
Changes from mol % to wt % were calculated by using molecular weights.
Preparative fractionations were carried out on base polymers by using a specific dissolution and crystallization protocol. A progressive dissolution was performed to collect polymer fractions. Polymer fractionation was performed using PREP mc2 (Polymer Characterization, S. A.). Ortho xylene stabilized with Irganox 1010 is used for the following steps.
PREP mc2 vessel was charged by feeding 0.4 g of polymer and 100 ml of o-xylene at room temperature. Initial dissolution step was carried out by increasing the temperature from room temperature up to 130° C. (heating ramp 20° C./min). The vessel temperature remained at 130° C. for 60 minutes under discontinuous stirring (220 rpm). A subsequent stabilization was carried out for 5 minutes at 125° C. under discontinuous stirring (150 rpm). A crystallization step was carried out by lowering the temperature from 125° C. to 77° C. with a cooling rate of 0.10° C./minute in 480 minutes. At 77° C. an equilibration step occurred (200 minutes without stirring). After this, the progressive sample fractionation started with collecting solutions at 3 different dissolution temperatures (77, 100 and 130° C.). For each temperature, 3 dissolutions were performed and 3 fractions were collected named fraction 1 (dissolution temperature 77° C.), fraction 2 (dissolution temperature 100° C.) and fraction 3 (dissolution temperature 130° C.). For the first temperature (77° C.) after 30 minutes under discontinuous stirring (150 rpm), the first polymer solution was collected by emptying the vessel. Next, 100 ml of fresh solvent was then added, the temperature was equilibrated at 77° C. (20° C./minute) and after 30 minutes under discontinuous stirring (150 rpm) the second polymer solution was collected. The same step was repeated for a third solution. The temperature was then raised to 100° C. (20° C./minute) and after an equilibration step of 30 minutes under discontinuous stirring (150 rpm) a first polymer solution was collected. A second and a third solution were collected as previously described (fraction at 77° C.). The temperature was then raised to 130° and three solutions were collected as described in the 100° C. step. Fractions collected at the same temperature were gathered in the same vessel, concentrated by solvent evaporation and then recovered by precipitation using acetone addition (the acetone volume was 2 times the final polymer solution volume). The polymer was filtered and weighed after drying in vacuum oven at 75° C. and under nitrogen flux. The drying, cooling and weighing steps were repeated until 2 consecutive weighings agree within 0.0002 g.
The relative amount of polymer collected for each temperature was estimated in weight % (using as 100% the total recovered polymer). In this protocol the polymer oligomers were not recovered, which were believed to be present in an amount of about 1 wt %. The experiment was considered successful if the difference between the initial polymer weight and the total weight was less than 2%. Repeated experiments provided a confidence interval lower that 5%.
13C NMR
13C NMR spectra of base polymers and their fractions were acquired on a Bruker AV600 spectrometer equipped with cryo probe, operating 150.91 MHz MHz in the Fourier transform mode at 120° C. The peak of the Sδδ carbon (nomenclature according C. J. Carman, R. A. Harrington and C. E. Wilkes, Macromolecules, 10, 3, 536 (1977), incorporated herein by reference) was used as an internal reference at 29.7 ppm. About 30 mg of sample were dissolved in 0.5 ml of 1,1,2,2 tetrachloro ethane d2 at 120° C. 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. The assignments of the spectra were made according to M. Kakugo, Y. Naito, K. Mizunuma and T. Miyatake, Macromolecules, 16, 4, 1160 (2082) and E. T. Hsieh, J. C. Randall, Macromolecules, 15, 353-360 (1982), both incorporated herein by reference.
Triad distribution was obtained using the following relations:
PPP=100I10/Σ
PPE=100I6/ΣEPE=100I5/Σ
BBB=100I3/Σ
BBE=100I2/Σ
EBE=100I11/Σ
XEX=100I12/Σ
XEE=100(I1+I4)/Σ
EEE=100(0.5I9+0.25(I7+I8))/Σ
wherein
Σ=I1+I2+I3+I4+I5+I6+0.25I7+0.25I8+0.5I9+I10+I11+I12 and wherein X can be propylene (P) or 1-butene (B), and I1 to I12 are the areas of the corresponding carbon atoms as reported below (selected triads and assignments being reported):
The molar contents of ethylene (E), propylene (P) and 1-butene (B) were obtained from triads using the following relations:
E(m%)=EEE+XEE+XEX
P(m%)=PPP+PPE+EPE
B(m%)=BBB+BBE+EBE
Tg Determination Via DMTA (Dynamic Mechanical Thermal Analysis)
Molded specimen of 20 mm×5 mm×1 mm were fixed to the DMTA machine for tensile stress. The frequency of the sinusoidal oscillation was fixed at 1 Hz. The DMTA translated the elastic response of the specimen starting from −100° C. (glassy state) to 130° C. (softening point). The elastic response versus temperature was plotted. The elastic modulus in DMTA for a viscoelastic material was defined as the ratio between stress and strain also defined as complex modulus E*=E′+iE“. The DMTA can split the two components E′ and E” by their resonance. E′ (elastic component), E″ (loss modulus) and E″/E′=tan δ (damping factor) were plotted against temperature. The glass transition temperature Tg was believed to be the temperature at the maximum of the curve tan=(δ) E″/E′ vs temperature.
Shore D (Sh.D) Hardness
Measured on a compression molded plaques (thickness of 4 mm) following the ISO 868.
Hexane Extractable Fraction
Determined according to FDA 177.1520, by suspending in an excess of hexane a 100 μm thick film specimen of the composition being analyzed, in an autoclave at 50° C. for 2 hours. The hexane was then removed by evaporation and the dried residue was weighed.
Flexural Modulus*
ISO 178, measured 24 hours after molding.
Tensile Strength at Yield*
ISO 527, measured 24 hours after molding.
Tensile Strength at Break*
ISO 527, measured 24 hours after molding.
Elongation at Break and at Yield*
ISO 527, measured 24 hours after molding.
Notched IZOD Impact Test*
ISO 180/1A, measured at 23° C., −20° C. and −30° C., 24 hours after molding.
Vicat Temperature*
Determined according to DIN EN ISO 306, after 24 hours (10 N load).
Heat Distortion Temperature (HDT)*
Determined according to ISO 75, after 24 hours.
Test specimens were prepared by injection molding according to ISO 1873-2: 1989.
Gloss at 60°
A ISO D1 plaque of 1 mm was molded in an injection molding machine “NB 60” (where 60 stands for 60 tons of clamping force) in accordance with the following parameters.
A plaque of 100×200×2.5 mm was molded in an injection molding machine “SANDRETTO serie 7 190” (where 190 stands for 190 tons of clamping force).
The injection conditions were:
wherein 200 was the length (in mm) of the plaque along the flow direction, measured immediately after molding; 100 is the length (in mm) of the plaque crosswise the flow direction, measured immediately after molding; the read_value is the plaque length in the relevant direction.
Catalyst Precursor
The solid catalyst component used in polymerization was a Ziegler-Natta catalyst component supported on magnesium chloride, containing titanium and diisobutylphthalate as internal donor, prepared as follows. An initial amount of microspheroidal MgCl2.2.8C2H5OH was prepared according to the method described in Example 2 of U.S. Pat. No. 4,399,054 (incorporated herein by reference) but operating at 3,000 rpm instead of 10,000. The adduct was then subjected to thermal dealcoholation at increasing temperatures from 30 to 130° C. operating in nitrogen current until the molar alcohol content per mol of Mg was 1.16. Into a 1000 mL four-necked round flask, purged with nitrogen, 500 mL of TiCl4 were introduced at 0° C. While stirring, 30 grams of the microspheroidal MgCl2.1.16C2H5OH adduct were added. The temperature was raised to 120° C. and kept at this value for 60 minutes. During the temperature increase, an amount of diisobutylphthalate was added such as to have a Mg/diisobutylphthalate molar ratio of 18. Next, the stirring was stopped, the liquid siphoned off and the treatment with TiCl4 was repeated at 100° C. for 1 hour in the presence of an amount of diisobutylphthalate such as to have a Mg/diisobutylphthalate molar ratio of 27. Next, the stirring was stopped, the liquid siphoned off and the treatment with TiCl4 was repeated at 100° C. for 30 min. After sedimentation and siphoning at 85° C. the solid was washed six times with anhydrous hexane (6×100 ml) at 60° C.
Catalyst System and Prepolymerization
Before introduction into the polymerization reactors, the solid catalyst component was contacted at 30° C. for 9 minutes with aluminum triethyl (TEAL) and dicyclopentyldimethoxysilane (DCPMS), in a TEAL/DCPMS weight ratio equal to about 15 and in such quantity that the TEAL/solid catalyst component weight ratio equaled 4. The catalyst system was then subjected to prepolymerization by maintaining the catalyst system in suspension in liquid propylene at 50° C. for about 75 minutes before introducing the catalyst system into a first polymerization reactor.
Polymerization
The polymerization was carried out continuously in a series of three gas-phase reactors equipped with devices to transfer the product from the first reactor to a second reactor. Into the first gas phase polymerization reactor a propylene-based polymer (A) was produced by feeding in a continuous and constant flow the prepolymerized catalyst system, hydrogen (used as molecular weight regulator) and propylene in the gas state. The propylene-based polymer (A) coming from the first reactor was discharged in a continuous flow and, after having been purged of unreacted monomers, was introduced, in a continuous flow, into the second gas phase reactor, together with quantitatively constant flows of hydrogen and ethylene, in the gas state. In the second reactor a copolymer of ethylene (B) was produced. The product coming from the second reactor was discharged in a continuous flow and, after having been purged of unreacted monomers, was introduced, in a continuous flow, into a third gas phase reactor, together with quantitatively constant flows of hydrogen, ethylene and propylene in the gas state. In the third reactor an ethylene-propylene polymer (C) was produced. Polymerization conditions, molar ratio of the reactants and composition of the copolymers obtained are shown in Table 1. The polymer particles exiting the third reactor were subjected to a steam treatment to remove the reactive monomers and volatile substances, and then dried. Thereafter the polymer particles were mixed with a stabilizing additive composition in a twin screw extruder Berstorff ZE 25 (length/diameter ratio of screws: 34) and extruded under nitrogen atmosphere in the following conditions:
Rotation speed: 250 rpm;
Extruder output: 15 kg/hour;
Melt temperature: 245° C.
The stabilizing additive composition was made of the following components:
The stabilized polyolefin composition were blended by extrusion with the components reported below:
The talc filled stabilized blend was extruded under nitrogen atmosphere in a twin screw extruder Leistritz 27 mm (length/diameter ratio of screws: 40) in the following conditions:
| Number | Date | Country | Kind |
|---|---|---|---|
| 15173696 | Jun 2015 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/064453 | 6/22/2016 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2016/207236 | 12/29/2016 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6743864 | Glogovsky et al. | Jun 2004 | B2 |
| 20080090062 | Breck et al. | Apr 2008 | A1 |
| 20090306299 | Kipke et al. | Dec 2009 | A1 |
| 20180179371 | Cavalieri et al. | Jun 2018 | A1 |
| Number | Date | Country |
|---|---|---|
| 2304154 | Aug 2007 | RU |
| WO-2003076511 | Sep 2003 | WO |
| WO-2011076553 | Jun 2011 | WO |
| WO-2012000885 | Jan 2012 | WO |
| Entry |
|---|
| International Search Report and Written Opinion dated Aug. 19, 2016 (Aug. 19, 2016) for Corresponding PCT/EP2016/064453. |
| Number | Date | Country | |
|---|---|---|---|
| 20180186987 A1 | Jul 2018 | US |
