Butene-1 polymer compositions having short crystallization times

Abstract

The present invention relates to a butene-1 polymer composition particularly suitable for the preparation of pipes, comprising: A) 97.5% to 99.85% by weight of a butene-1 polymer or polymer composition, relative to the total weight of A) and B); B) 0.15% to 2.5% by weight of talc in particulate form, relative to the total weight of A) and B), having a volume-based particle size distribution Dv(0.95) of 45 μm or less; and, optionally C) 0.01% to 2% by weight of an ethylene polymer; the amount of C) refers to the total weight of A)+B)+C), which totals 100%.

Description

Technical Field

[0001] The present invention relates to butene-1 polymer compositions having reduced crystallization times. Background Art

[0002] Butene-1 polymers are known in the art and have a wide range of applicability. In particular, butene-1 homopolymers and copolymers with high crystallinity are generally characterized by good properties in terms of pressure resistance, creep resistance, impact strength, and can be used to make pipes to replace metal pipes.

[0003] One of the key requirements for their application in the pipe sector is an excellent combination of flexibility and tensile strength.

[0004] Furthermore, in order to achieve high-speed extrusion, a sufficiently short crystallization time is required in the tube molding process generally performed by extrusion.

[0005] More generally, short crystallization times are beneficial in many polymer molding processes in order to achieve high processing speeds.

[0006] It is known in the art that the properties can be influenced by the addition of nucleating agents. These nucleating agents are generally foreign materials that promote the crystallization of the polymer from the melt (heterogeneous nucleation).

[0007] Many nucleating agents have been discovered that exhibit the described effects in crystalline polymers, however, in the field of polyolefin nucleation, an effective nucleating agent for one polymer may be ineffective even for closely related polymers, thus making it very difficult to identify the nucleating agent that is most suitable for a particular polymer, especially butene-1 polymers, which also crystallize in at least two different crystalline forms.

[0008] Furthermore, it should be considered that different applications require different characteristics.

[0009] For example, in pipe applications, too high a flexural stiffness (high flexural modulus) would be disadvantageous because, as previously mentioned, a certain level of flexibility is desired.

[0010] However, too low a flexural modulus value may reduce long term pressure resistance.

[0011] Even too short a crystallization time would be disadvantageous since it would make it difficult to consistently produce tubes with the desired shape and properties.

[0012] Therefore, there is an ongoing effort in the art to find nucleating agents that provide the best balance of mechanical and processing properties, depending on the type of polymer used and the desired application.

[0013] For example, according to JP2007186563, by adding ethylene bisstearamide and talc to butene-1 polymers, a good balance of properties for pipe applications is achieved.

[0014] It has now been found that by incorporating talc having a defined particle size in relatively low amounts, butene-1 polymer compositions having a particularly valuable balance of crystallization time, flexural modulus and tensile strength are obtained. Summary of the invention

[0015] Therefore, the present invention provides a butene-1 polymer composition comprising:

[0016] A) from 97.5% to 99.85% by weight, preferably from 98% to 99.8% by weight, more preferably from 98% to 99.5% by weight, relative to the total weight of A) and B), of a butene-1 polymer, or a polymer composition selected from crystalline butene-1 homopolymers and copolymers, or a combination thereof;

[0017] B) 0.15 to 2.5 wt. %, preferably 0.2 to 2 wt. %, more preferably 0.5 to 2 wt. %, relative to the total weight of A) and B), of talc in the form of particles having a volume-based (by volume) particle size distribution Dv(0.95) determined by laser diffraction of 45 μm or less, preferably 35 μm or less, more preferably 25 μm or less, in particular 20 μm or less, the lower limit being preferably 5 μm in each case; and, optionally

[0018] C) 0.01 to 2% by weight, preferably 0.01 to 1% by weight, more preferably 0.01 to 0.5% by weight, in particular 0.01 to 0.2% by weight, of an ethylene polymer;

[0019] The amount of C) refers to the total weight of A)+B)+C), which adds up to 100%. DETAILED DESCRIPTION

[0020] "Crystalline butene-1 homopolymers and copolymers" are those homopolymers and copolymers A) which, when subjected to differential scanning calorimetry (DSC) measurement, exhibit at least one crystallization temperature T c of the crystallization peak.

[0021] Thus, when subjected to DSC measurements, the butene-1 polymer compositions of the present invention comprising components A), B) and optionally C) also exhibit at least one crystallization temperature T c of the crystallization peak.

[0022] Preferably, the T of the butene-1 polymer component A) is c The value is 75°C or higher, particularly in the range of 75°C to 85°C.

[0023] The T of the butene-1 polymer composition of the present invention is c The value is preferably 80°C or higher, particularly in the range of 80°C to 90°C.

[0024] The T of the butene-1 polymer composition of the present invention is c The value is preferably greater than the T of the butene-1 polymer component A). c The value is at least 2°C higher, in particular 2°C to 5°C higher.

[0025] The crystallization temperature was determined after one melting cycle at a scanning rate of 10°C / min.

[0026] Therefore, since the crystallization temperature was measured in a cooling run (using DSC as described above) after first melting the polymer sample, this crystallization temperature can be attributed to the crystalline Form II of the butene-1 polymer.

[0027] If more than one crystallization peak is detected, the temperature of the strongest peak is regarded as the Tc value for both the butene-1 polymer component A) and the butene-1 polymer composition of the present invention.

[0028] As mentioned previously, the butene-1 polymer composition of the present invention has a short crystallization time.

[0029] Preferably, its crystallization half time at 90° C. is from 90 to 160 seconds, in particular from 100 to 150 seconds.

[0030] The determination is carried out by DSC, first melting the sample, then rapidly cooling it to the desired temperature (90°C in the present case) and measuring the heat flow caused by the crystallization exotherm. The integral of the heat transfer is recorded as a function of time until crystallization is complete, i.e., heat transfer ceases.

[0031] The crystallization half-time is the time at which the heat transfer integral reaches half of its final value.

[0032] Furthermore, the butene-1 polymer composition of the present invention preferably has at least one of the following additional features:

[0033] - a flexural modulus of 450 to 650 MPa, more preferably 500 to 600 MPa, measured according to standard ISO 178:2019, 10 days after molding;

[0034] - a tensile modulus of elasticity of 500 to 800 MPa, more preferably 560 to 750 MPa, at 23°C, measured via DMTA analysis on 1 mm thick compression moulded plaques according to ISO 6721-4:2019;

[0035] - Izod impact resistance at 23°C measured according to ISO 180:2000 on compression panels according to ISO 8986-2:2009, values ​​of 3 to 15 kJ / m 2 , especially 3 to 10 kJ / m 2 ;

[0036] - Izod impact resistance values ​​at 0°C measured according to ISO 180:2000 on compression panels in the range of 2 to 10 kJ / m according to ISO 8986-2:2009 2 , especially 2 to 8 kJ / m 2 .

[0037] The butene-1 homopolymers and copolymers A) are preferably highly isotactic linear polymers, in particular having an isotacticity of 90% to 99%, more preferably 95% to 99%, the isotacticity being measured using NMR analysis in terms of mmmm pentads / total pentads or in terms of the amount by weight of the soluble matter in xylene at 0°C.

[0038] Furthermore, the butene-1 homopolymers and copolymers A) preferably have at least one of the following features:

[0039] - X-ray crystallinity of 50% to 60%;

[0040] -Density 0.90 to 0.94 g / cm 3 .

[0041] Preferably, the butene-1 homopolymers and copolymers A) and the butene-1 polymer compositions of the present invention comprising components A), B) and optionally C) have a melting temperature (melting peak) of 90 to 125° C., more preferably 100 to 125° C., measured by the aforementioned DSC method at a scanning speed of 10° C. / min during a second heating run after the first melting and cooling.

[0042] The melting temperature is attributable to the crystalline form II of the butene-1 polymer.

[0043] Also in this case, if more than one melting peak was detected, the temperature of the strongest peak was considered the melting temperature.

[0044] Suitable butene-1 copolymers are preferably those containing up to 5 mol %, in particular 0.1 mol % to 5 mol %, more preferably 0.1 mol % to 3 mol % of an olefinic comonomer. The comonomer is generally selected from ethylene, propylene or R-CH=CH2 olefins, wherein R is a C3-C8 alkyl or cycloalkyl group (in particular ethylene, propylene or α-olefins containing 5 to 8 carbon atoms, such as pentene-1, hexene-1, 4-methylpentene-1 and octene-1).

[0045] The homopolymers and copolymers can be obtained by low-pressure Ziegler-Natta polymerization of butene-1, for example by polymerizing butene-1 (and any comonomers) with a catalyst based on TiC13 or a titanium halide compound (especially TiC14) supported on magnesium chloride and a cocatalyst (especially an alkyl compound of aluminum). Electron donor compounds can be added to the catalyst component to adjust polymer properties, such as molecular weight and isotacticity. Examples of the electron donor compounds are esters of carboxylic acids and alkylalkoxysilanes.

[0046] In particular, the butene-1 homopolymers and copolymers A) can be prepared by polymerization of monomers in the presence of a stereospecific catalyst comprising (i) a solid component comprising a Ti compound and an internal electron donor compound supported on MgCl2; (ii) an alkylaluminum compound, and optionally (iii) an external electron donor compound.

[0047] Magnesium dichloride in active form is preferably used as a carrier. It is well known from the patent literature that magnesium dichloride in active form is particularly suitable as a carrier for Ziegler-Natta catalysts. In particular, USP 4,298,718 and USP 4,495,338 first described the use of these compounds in Ziegler-Natta catalysis. It is known from these patents that magnesium dihalides in active form are used as carriers or co-carriers in catalyst components for olefin polymerization, characterized in that the intensity of the strongest diffraction lines that appear in the inactive halide spectrum is reduced and replaced by halogens whose maximum intensity is shifted to lower angles relative to stronger lines.

[0048] Preferred titanium compounds used in catalyst component (i) are TiCl4 and TiCl3; in addition, compounds of the formula Ti(OR) n-y X y Ti-halohydrin wherein n is the valence of titanium, X is a halogen, preferably chlorine, and y is a number between 1 and n.

[0049] The internal electron donor compound is preferably selected from esters, more preferably from alkyl, cycloalkyl or aryl esters of monocarboxylic acids (e.g. benzoic acid) or polycarboxylic acids (e.g. phthalic acid, succinic acid or glutaric acid), the alkyl, cycloalkyl or aryl groups having 1 to 18 carbon atoms. Examples of such electron donor compounds are diisobutyl phthalate, diethyl phthalate, dihexyl phthalate, diethyl 3,3-dimethylglutarate or diisobutyl 3,3-dimethylglutarate. Typically, the internal electron donor compound is used in a molar ratio of 0.01 to 1, preferably 0.05 to 0.5, relative to MgCl2.

[0050] The alkyl-A1 compound (ii) is preferably selected from trialkylaluminum compounds, such as triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum. It is also possible to use a mixture of a trialkylaluminum compound with an alkylaluminum halide, an alkylaluminum hydride or an alkylaluminum sesquichloride (e.g. AlEt2Cl and Al2Et3Cl3).

[0051] The external donor (iii) is preferably selected from the group consisting of a 1 R b 2 Si(OR 3 ) c A silicon compound wherein a and b are integers from 0 to 2, c is an integer from 1 to 3 and the sum of (a+b+c) is 4; R 1 , R 2 and R 3 is an alkyl, cycloalkyl or aryl group having 1 to 18 carbon atoms and optionally containing heteroatoms. Particularly preferred groups of silicon compounds are those in which a is 0, c is 3, b is 1 and R 2 is a branched alkyl or cycloalkyl group optionally containing heteroatoms, and R 3 is methyl. Examples of such preferred silicon compounds are cyclohexyltrimethoxysilane, butyltrimethoxysilane, diisopropyltrimethoxysilane and tert-hexyltrimethoxysilane. Tert-hexyltrimethoxysilane is particularly preferably used.

[0052] The electron donor compound (iii) is used in such an amount that the molar ratio between the organoaluminum compound and the electron donor compound (iii) is 0.1 to 500, preferably 1 to 300, more preferably 3 to 100.

[0053] In order to make the catalyst particularly suitable for the polymerization step, the catalyst may be prepolymerized in a prepolymerization step. The prepolymerization may be carried out in liquid (slurry or solution) or in gas phase at a temperature generally below 100° C., preferably between 20° C. and 70° C. The prepolymerization step is carried out with a small amount of monomer for a time required to obtain a polymer at 0.5-2000 g / g solid catalyst component, preferably 5-500 g / g, more preferably 10-100 g / g solid catalyst component.

[0054] Butene-1 polymers can also be prepared by polymerization in the presence of a catalyst obtained by contacting a metallocene compound with an aluminoxane, as disclosed, for example, in WO 03 / 042258.

[0055] The polymerization process can be carried out according to known techniques, such as slurry polymerization using a liquid inert hydrocarbon as diluent, or solution polymerization using, for example, liquid butene-1 as reaction medium. In addition, the polymerization process can also be carried out in the gas phase, operating in one or more fluidized or mechanically stirred bed reactors. The polymerization carried out with liquid butene-1 as reaction medium is highly preferred.

[0056] In order to control the molecular weight, molecular weight regulators, in particular hydrogen, are fed into the polymerization environment.

[0057] Examples of polymerization catalysts and processes are disclosed in WO99 / 45043 and WO2004048424.

[0058] Although there are no particular restrictions on the molecular weight of the butene-1 homopolymer and copolymer A) and the butene-1 polymer composition of the present invention, it is preferred that they (both) have an MIE of 100 to 0.01, more preferably 10 to 0.1 g / 10 min, wherein MIE is the melt flow index measured at 190° C. / 2.16 kg according to ISO 1133-2:2011. In particular, when they are used in an extrusion device for making pipes, it is preferred that the MIE ranges from 1 to 0.1 g / 10 min. High MIE values ​​can be obtained directly in the polymerization or by subsequent chemical treatment of the polymer components (chemical visbreaking).

[0059] Chemical visbreaking of the polymer is carried out in the presence of a free radical initiator, such as a peroxide. Examples of free radical initiators that can be used for this purpose are 2,5-dimethyl-2,5-di(tert-butylperoxide)-hexane and dicumyl peroxide.

[0060] Preferred intrinsic viscosity values ​​for the butene-1 homopolymers and copolymers A) are from 1.5 to 4 dl / g as measured in decalin at 135°C.

[0061] The molecular weight distribution (MWD) of the butene-1 homopolymers and copolymers A) is not particularly critical and can generally be included within wide ranges. However, for pipe applications, when the molecular weight distribution (MWD) is determined according to M w / M n (where M w is the weight average molecular weight and M n When MWD is expressed as number average molecular weight, the MWD value measured by GPC analysis is preferably equal to or higher than 4, particularly equal to or higher than 5.

[0062] In all cases, M w / M n The preferred upper limit of the value is 9.

[0063] M w / M n Values ​​greater than 5 are generally considered to correspond to a wide MWD.

[0064] Butene-1 polymers with broad MWD can be obtained in several ways. One of the methods consists in using a catalyst inherently capable of producing broad MWD polymers when (co)polymerizing butene-1. Another possible method is to mechanically blend butene-1 polymers with sufficiently different molecular weights using conventional mixing equipment.

[0065] It is also possible to operate according to a multi-step polymerization process, wherein the butene-1 polymers of different molecular weights are prepared sequentially in two or more reactors with different reaction conditions (eg, the concentration of the molecular weight regulator fed to each reactor).

[0066] Component B) according to the invention is a talc which is characterized by the aforementioned volume-based particle size distribution values.

[0067] In addition to the Dv(0.95) value, component B) of the present invention preferably has at least one of the following volume-based particle size distribution characteristics:

[0068] - Dv(0.99) is 100 μm or less, or 50 μm or less, or 30 μm or less, with the lower limit preferably being 10 μm in all cases;

[0069] - Dv(0.90) is 20 μm or less, or 15 μm or less, with the lower limit preferably being 3 μm in all cases;

[0070] - Dv(0.50) is 10 μm or less, or 8 μm or less, and the lower limit is preferably 2 μm.

[0071] - Dv(0.10) is 5 μm or less, or 4 μm or less, and the lower limit is preferably 1 μm.

[0072] Volume-based particle size refers to the diameter of an equivalent sphere having the same volume as the subject particle.

[0073] Thus, the volume-based particle size distribution value means a particular volume fraction of particles, e.g. 95% by volume for Dv(0.95), which have an equivalent diameter smaller than a given value.

[0074] This determination is carried out by laser diffraction. The analytical equipment used is preferably a Malvern Mastersizer instrument.

[0075] As is well known, talc is hydrated magnesium silicate.

[0076] It is reported to generally have the formula Mg3Si4O 10 (OH)2.

[0077] In practice, it is a mineral consisting mainly or essentially of said hydrated magnesium silicate, optionally in association with other mineral materials such as chlorite (hydrated magnesium aluminium silicate) and dolomite.

[0078] To achieve the stated particle size distribution values, the talc can be ground by known techniques, for example by air classifier mills, compressed air, steam and impact grinding.

[0079] Preferably, component B) contains no chemical additives, in particular no acid acceptors, such as stearates, in particular metal stearates, such as Zn stearate.

[0080] Preferred examples of ethylene polymers C) are preferably those having a density of 0.940 to 0.965 g / cm 3 High-density polyethylene HDPE, preferably with a density of 0.900 to 0.939 g / cm 3 Linear low density polyethylene LLDPE (both are usually obtained by low pressure polymerization), and preferably a density of 0.917 to 0.935 g / cm 3 Low-density polyethylene LDPE (usually obtained by high-pressure polymerization). Typically, the low-pressure polymerization is carried out in the presence of a Ziegler-Natta catalyst of the same type as described above, while the high-pressure polymerization is carried out in the presence of a free radical initiator (e.g., a peroxide).

[0081] The HDPE may be an ethylene homopolymer or an ethylene copolymer containing one or more olefin comonomers.

[0082] The LLDPE may be an ethylene copolymer containing one or more olefin comonomers.

[0083] The comonomers present in the HDPE and LLDPE are generally selected from olefins having the formula CH2=CHR, wherein R is a linear or branched alkyl group having from 1 to 10 carbon atoms.

[0084] Specific examples are propylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1 and decene-1.

[0085] When present, the preferred comonomer content in the HDPE is 0.1-15 wt%, especially 0.5 to 10 wt%, relative to the total weight of the HDPE polymer.

[0086] The preferred comonomer content in the LLDPE is 5-20 wt%, in particular 8 to 15 wt%, relative to the total weight of the LLDPE polymer.

[0087] The LDPE may be an ethylene homopolymer or an ethylene copolymer containing a minor amount of a comonomer such as butyl acrylate.

[0088] Among the ethylene polymers C), HDPE is particularly preferred.

[0089] Preferably, the ethylene polymer C) has a MIF of 1 to 50 g / 10 min, or 5 to 50 g / 10 min, in particular 10 to 40 g / 10 min, wherein MIF is the melt flow index measured at 190°C / 21.6 kg according to ISO 1133-2:2011.

[0090] Obviously, other additives commonly used in the art, such as stabilizers, antioxidants, anticorrosive agents, processing aids, pigments, and organic and inorganic fillers, may also be added to the polybutene-1 composition of the present invention.

[0091] The polybutene-1 composition of the present invention can be obtained by blending components A), B) and optionally C) using blending techniques and equipment well known in the art.

[0092] Thus, one can use extruders known in the art, including single screw extruders, conventional and mixing extruders (such as Buss), twin co-rotating screw extruders, mixers (continuous and intermittent). Such blending equipment can be equipped with separate feed systems for components A), B) and C), respectively. Component B) and optionally component C) can be added to the polymer mass in the blending equipment, in particular the extruder, at the same feed port or downstream of the point where A) is fed into the blending equipment, so that the distance between them allows A) to reach a molten homogeneous mass form.

[0093] Component B) may be fed in the form of a masterbatch in a polymer carrier, more preferably in a polyolefin carrier, especially a polybutene carrier of the same type as the butene-1 polymer component A).

[0094] Components A), B) and optionally C) are preferably premixed before the blending step. For the premixing step, any method and apparatus used in the art may be used, in particular low-speed mixers such as single-shaft or double-shaft paddle conveyors, ribbon mixers, plowshare mixers.

[0095] To obtain the final composition, it is also possible to use static mixing devices, such as the A static mixer in which the melt streams of components (A), (B) and (C) are fed into its inlet and pushed through using a gear pump, a twin screw or a single screw extruder.

[0096] The processing temperature during the blending step must be sufficient to keep (and maintain) component A) in a molten state, or to keep component A) in a molten state if A) is already molten when adding B) and optionally C). Such temperatures are preferably in the range of 100°C to 230°C, more preferably 100 to 220°C, and most preferably 120 to 210°C.

[0097] As mentioned above, the preferred use of the polybutene-1 composition of the present invention is for the manufacture of pipes, in particular pipes for conveying water and hot fluids, and pipe fittings. Generally, it can be advantageously used in any application where improved mechanical and processing properties are desired.

[0098] The practice and advantages of various embodiments, compositions and methods as provided herein are disclosed in the following examples. These examples are illustrative only and are not intended to limit the scope of the invention in any way.

[0099] Particle size distribution

[0100] Particle size distribution (PSD) is measured by laser diffraction according to ISO 13320:2009.

[0101] The equipment used was a 1000 MW 2000 MW 1000 MW with a sample dispersion unit from Malvern UK. 2000.

[0102] The detection system has the following features:

[0103] -Red light: forward scatter, side scatter, back scatter;

[0104] -Blue light: wide-angle forward and backscatter;

[0105] -Light source: red light He-Ne laser; blue light solid-state light source;

[0106] -Optical alignment system: Automatic fast alignment system with dark field optical reticle;

[0107] -Laser System: Class 1 Laser Product.

[0108] PSD measurement is based on the optical diffraction principle of laser monochromatic light scattered by dispersed particle samples. The signals are received by a computer connected to the instrument interface, which is used to process the received signals and convert them into physical quantities of size.

[0109] The results are presented by a PSD report consisting of 106 class diameters (virtual sieves) and the associated cumulative percentages according to volume and other derived parameters.

[0110] The measurement data is contaminated by background electrical noise as well as scattered data from dust on the optics and contaminants floating in the dispersant. For this reason, it is important to ensure that the sample dispersion unit is clean and that all trace impurities and residual materials have been removed.

[0111] Therefore, a background measurement of pure dispersant (solvent) as well as an electrical background measurement is performed. The total background value obtained is subtracted from the sample measurement to obtain the true sample data.

[0112] For background measurement, 250 cc. of anhydrous n-heptane solvent containing 2 g / l SPAN 80 Pure as antistatic agent was introduced into the sample dispersion unit. Before each measurement, the trapped air in the solvent was removed by ultrasonic treatment (60 seconds).

[0113] The solvent was then fed to the measuring chamber while the stirrer and circulation pump were operated at an output range of 2205 rpm.

[0114] Measurement

[0115] The sample, which is kept in suspension in anhydrous n-heptane by stirring, is added directly to the sample cell.

[0116] Recirculation of the sample suspension for 2 minutes was necessary to promote disaggregation of aggregates, if present.

[0117] An obscuration bar is visible on the monitor, which allows to reach the optimal volume concentration of the sample. The sample concentration must correspond to an obscuration value in the range of 10% to 30%. This range guarantees representative and stable results.

[0118] The refractive index (RI) is set to:

[0119] Particle RI: 1.596;

[0120] Dispersant RI: 1.390.

[0121] The measurement time is 4 seconds.

[0122] The signal received from the laser device is processed and the PSD is then calculated using the software provided with the Mastersizer device.

[0123] Crystallization and melting temperatures

[0124] The crystallization temperature (T) was determined using the following procedure: c ) and melting temperature values.

[0125] Differential Scanning Calorimetry (DSC) data were obtained using a Perkin Elmer DSC-7 instrument. Weighed samples (5-10 mg) were sealed into aluminum pans and heated at 200°C at a scanning rate corresponding to 10°C / min. The sample was kept at 200°C for 5 minutes to allow all crystallites to melt completely, thereby eliminating the thermal history of the sample. Next, the peak temperature was considered the crystallization temperature (T) by cooling to -20°C at a scanning rate corresponding to 10°C / min. c ), the area is regarded as the crystallization enthalpy. After standing at -20 ° C for 5 minutes, the sample is heated to 200 ° C for the second time at a scanning speed corresponding to 10 ° C / min. In this second heating run, the peak temperature is regarded as the melting temperature (TmII) of the polybutene-1 crystalline form II, and the area is regarded as the melting enthalpy (ΔHfII).

[0126] To determine the melting temperature (TmI) of polybutene-1 crystalline form I, the sample was melted, held at 200°C for 5 minutes, and then cooled to 20°C at a cooling rate of 10°C / min. The sample was then stored at room temperature for 10 days. After 10 days, the sample was subjected to DSC, cooled to -20°C, and then heated at 200°C at a scanning rate corresponding to 10°C / min. In this heating run, the first peak temperature from the lower temperature side in the thermogram was regarded as the melting temperature (Tm1).

[0127] Crystallization half-life at 90°C

[0128] Differential Scanning Calorimetry (DSC) data were obtained using a Perkin Elmer DSC-7 instrument.Weighed samples (5-10 mg) were sealed into aluminum pans and heated from room temperature to 180°C at a scan rate corresponding to 10°C / min.

[0129] The sample was held at 180°C for 5 minutes to allow all crystallites to melt completely, thereby eliminating the thermal history of the sample.

[0130] Next, it is cooled to 90° C. at a scanning rate corresponding to 60° C. / min and the heat flow caused by the crystallization exotherm at 90° C. is measured. The integral of the heat transfer is recorded as a function of time until crystallization is complete, ie, heat transfer stops.

[0131] The crystallization half-time is the time at which the heat transfer integral reaches half of its final value.

[0132] MIF and MIE

[0133] Determined at 190°C and a specified load according to ISO 1133-2:2011.

[0134] Intrinsic viscosity

[0135] Determined in tetralin at 135° C. according to standard ASTM D 2857-16.

[0136] Tensile elastic modulus (MET-DMTA)

[0137] Determined via Dynamic Mechanical Thermal Analysis (DMTA) at 23°C on 1 mm thick compression molded plaques according to ISO 6721-4:2019.

[0138] Flexural modulus

[0139] Measured 10 days after moulding according to standard ISO 178:2019.

[0140] Izod impact resistance at 23°C and 0°C

[0141] According to ISO 89862:2009, measured according to ISO 180:2000 on compression panels.

[0142] Comonomer content

[0143] Determined by IR spectroscopy or by NMR.

[0144] In particular, for butene-1 copolymers, the amount of comonomer can be determined based on the 13 C NMR spectra calculated.

[0145] An example of an analytical procedure is described below.

[0146] 13 C NMR spectra were acquired on a Bruker AV-600 spectrometer equipped with a cryogenic probe, operating at 120 °C in Fourier transform mode at 150.91 MHz.

[0147] T βδ The peak of carbon (named after CJ Carman, RA Harrington and CE Wilkes, Macromolecules, 10, 3, 536 (1977)) at 37.24 ppm was used as an internal reference. The samples were dissolved in 1,1,2,2-tetrachloroethane-d2 at 8% wt / v at 120°C. Each spectrum was acquired with a 90° pulse and a delay of 15 seconds between the pulse and CPD to remove 1 H- 13 C coupling. About 512 transients were stored in 32K data points using a spectral window of 9000 Hz.

[0148] According to Kakugo [M. Kakugo, Y. Naito, K. Mizunuma and T. Miyatake, Macyomolecules, 16, 4, 1160 (1982)] and Randall [JC Randall, Macromol. Chem Phys., C30, 211 (1989)], the following was used:

[0149] BBB=100(T ββ ) / S=I5

[0150] BBE=100T βδ / S=I4

[0151] EBE=100P δδ / S=I14

[0152] BEB=100S ββ / S=I13

[0153] BEE=100S αδ / S=I7

[0154] EEE=100(0.25S γδ +0.5S δδ ) / S=0.25I9+0.5I10

[0155] Where S = I5 + I4 + I14 + I13 + I7 + 0.25I9 + 0.5I10

[0156] Spectral assignment, triplet distribution and composition evaluation were performed.

[0157] The total amount of 1-butene and ethylene (molar percent) was calculated from the triad using the following relationship:

[0158] [E]=EEE+BEE+BEB

[0159] [B]=BBB+BBE+EBE

[0160]

[0161] Determination of isotactic pentad content

[0162] 13 C NMR spectra were acquired on di-deuterated 1,1,2,2-tetrachloroethane polymer solutions (8-12 wt %) at 120 °C. 13C NMR spectra were acquired on a Bruker AV-600 spectrometer equipped with a cryogenic probe, operating at 120 °C in Fourier transform mode at 150.91 MHz with a 15 s delay between pulse and CPD (WALTZ16) to remove 1 H- 13 C coupling. About 512 transients were stored in 32K data points using a spectral window of 60 ppm (0-60 ppm). The mmmm pentad peak (27.73 ppm) was used as a reference. The values ​​were assigned as described in the literature (Asakura T. Macromolecules 1991, 24, 2334-2340).

[0163] The percentage value of the pentad stereoregularity (mmmm%) of a butene-1 polymer is the percentage of stereoregular pentads (isotactic pentads) calculated from the relevant pentad signals (peak areas) in the branched methylene carbon NMR region, as follows:

[0164] mmmm%=100A1 / (A1+A2)

[0165] Where A1 is the area between 28.0 and 27.59 ppm;

[0166] A2 is the area between 27.59 and 26.52 ppm.

[0167] Soluble and insoluble fractions in xylene at 0℃ (XS-0℃)

[0168] 2.5 g of the polymer sample is dissolved in 250 ml of xylene under stirring at 135° C. After 30 minutes, the solution is cooled to 100° C., still under stirring, and then placed in a water and ice bath to cool to 0° C. Then, the solution is allowed to settle in the water and ice bath for 1 hour. The precipitate is filtered with filter paper. During the filtration, the flask is placed in a water and ice bath to keep the internal temperature of the flask as close to 0° C. as possible. Once the filtration is completed, the filtrate temperature is balanced at 25° C., the volumetric flask is immersed in a running water bath for about 30 minutes, and then divided into two 50 ml aliquots. The solution aliquots are evaporated in a nitrogen stream, and the residue is vacuum dried at 80° C. until a constant weight is reached. The weight difference between the two residues must be less than 3%; otherwise the test must be repeated. Therefore, one calculates the weight percentage of the polymer solubles (xylene solubles at 0° C. = XS 0° C.) based on the average weight of the residues. The insoluble fraction in o-xylene at 0°C (xylene insolubles at 0°C = X1% 0°C) is:

[0169] XI%0°C=100-XS%0°C.

[0170] Determination of X-ray crystallinity

[0171] X-ray crystallinity was measured with an X-ray diffraction powder diffractometer using Cu-Kα1 radiation with a fixed slit and collecting spectra between diffraction angles 2Θ=5° and 2Θ=35° at a step size of 0.1° every 6 seconds.

[0172] The measurements are carried out on compression moulded samples in the form of discs of about 1.5-2.5 mm thickness and 2.5-4.0 cm diameter. These samples are subjected to compression moulding in a compression moulding press at a temperature of 200°C ± 5°C for 10 minutes without any appreciable applied pressure and then to an applied pressure of about 10 kg / cm 2 The pressure lasts for about several seconds and is obtained by repeating this last operation 3 times.

[0173] All components required for crystallinity are derived using the diffraction pattern by defining a suitable linear baseline for the entire spectrum and calculating the total area (Ta) between the spectrum curve and the baseline (expressed in counts / second·2Θ). A suitable amorphous curve is then defined along the entire spectrum, which separates the amorphous regions from the crystalline regions according to the two-phase model. Thus, the amorphous area (Aa) (expressed in counts / second·2Θ) can be calculated as the area between the amorphous curve and the baseline; and the crystalline area (Ca) (expressed in counts / second·2Θ) is calculated as Ca=Ta-Aa.

[0174] Then calculate the crystallinity of the sample according to the formula: %Cr = 100 × Ca / Ta

[0175] Determination of Mw / Mn by GPC

[0176] The average Mn and Mw and the Mw / Mn derived therefrom were determined using a Waters GPCV 2000 device equipped with four PLgel Olexis mixed gel column sets (Polymer Laboratories) and an IR4 infrared detector (PolymerChar). The column dimensions were 300×7.5 mm and the particle size was 13 μm. The mobile phase used was 1-2-4-trichlorobenzene (TCB) at a flow rate of 1.0 ml / min. All measurements were performed at 150°C. The TCB solution concentration was 0.1 g / dl, and 0.1 g / l of 2,6-diterbutyl-p-cresol (2,6-diterbuthyl-p-chresole) was added to prevent degradation. For GPC calculations, a universal calibration curve was obtained using 10 polystyrene (PS) standard samples (peak molecular weight range of 580 to 8500000) provided by Polymer Laboratories. A third-order polynomial fit was used to interpolate the experimental data and obtain a relevant calibration curve. Empower (Waters) was used for data acquisition and processing. The molecular weight distribution and the related average molecular weight were determined using the Mark-Houwink relationship: the K values ​​for PS and PB were K PS =1.21×10 -4 dL / g and K PB =1.78×10 -4 dL / g, using both the Mark-Houwink index α=0.706 for PS and the Mark-Houwink index α=0.725 for PB.

[0177] For butene-1 / ethylene copolymers, for data evaluation, the composition was assumed to be constant over the entire range of molecular weights and the K value of the Mark-Houwink relationship was calculated using a linear combination as follows:

[0178] K EB =x E K PE +x P K PB

[0179] Where K EB is the constant of the copolymer, K PE (4.06×10 -4 dL / g) and K PB (1.78×10 -4 dL / g) is a constant for polyethylene and polybutene, x E and x Bis the ethylene and butene-1 weight % content. The Mark-Houwink index α=0.725 is used for all butene-1 / ethylene copolymers, regardless of their composition.

[0180] density

[0181] Determined at 23°C according to standard ISO 1183-1:2019.

[0182] Examples 1 and 2 and Comparative Example 1

[0183] Materials used in the examples

[0184] PB-1: a butene-1 homopolymer having the characteristics described in Table 1.

[0185] Talc 1: Talc having the volume-based particle size distribution described in Table 2, without additives, sold by Imi Fabi under the trademark HM05.

[0186] Talc 2: A comparative zinc stearate coated talc having the volume based particle size distribution described in Table 2, sold by Imerys under the trademark Mistron ZSC.

[0187] HDPE: density is 0.954g / cm 3 An ethylene polymer having a MIF of 24 g / 10 min.

[0188] The materials were melt blended in a Leistritz Micro 27 extruder with co-rotating twin screws, 27 mm screw diameter segments, 40:1 L / D ratio, 500 rpm maximum screw speed.

[0189] The main extrusion parameters are:

[0190] - Temperature: 200°C;

[0191] -Screw speed: 200 rpm;

[0192] -Output: 15kg / h.

[0193] The amounts and characteristics of the components of the final composition thus obtained are reported in Table 3.

[0194] Table 1

[0195]

[0196] Table 2

[0197] talc Talc 1 Talc 2 Dv(0.10) μm 3.27 3.06 Dv(0.50) μm 6.25 7.41 Dv(0.90) μm 11.70 25.01 Dv(0.95) μm 13.70 59.75 Dv(0.99) μm 17.79 180.73

[0198] Table 3

[0199]

Claims

1. A butene-1 polymer composition comprising: A) 97.5% to 99.85% by weight of butene-1 polymers, relative to the total weight of A) and B); B) 0.5 to 2% by weight of talc in particulate form, relative to the total weight of A) and B), having a volume-based particle size distribution Dv(0.95) of 35 μm or less as determined by laser diffraction; and, optionally C) 0.01 to 2 wt% of an ethylene polymer; The amount of C) refers to the total weight of A)+B)+C), which adds up to 100%.

2. The butene-1 polymer composition of claim 1, wherein the butene-1 polymer comprises a polymer composition selected from crystalline butene-1 homopolymers and copolymers, or combinations thereof.

3. The butene-1 polymer composition of claim 1 , wherein the talc B) additionally has at least one of the following volume-based particle size distribution characteristics: -Dv(0.99) is 100μm or less; -Dv(0.90) is 20μm or less; -Dv(0.50) is 10μm or less; -Dv(0.10) is 5 μm or less.

4. The butene-1 polymer composition according to claim 1 or 3, wherein the crystallization temperature T c is 80°C or higher, the crystallization temperature T c It was measured after a melting cycle using the DSC method at a scanning rate of 10°C / min.

5. The butene-1 polymer composition according to claim 1 or 3, having a melting temperature of 90 to 125°C, measured by the DSC method at a scanning speed of 10°C / min during a second heating run after the first melting and cooling.

6. The butene-1 polymer composition according to claim 1 or 3, which has a MIE of 100 to 0.01 g / 10 min, wherein MIE is a melt flow index measured at 190°C / 2.16 kg according to ISO 1133-2:2011.

7. The butene-1 polymer composition of claim 1 or 3, having at least one of the following additional features: The crystallization half-time at -90°C is 90 to 160 seconds; - a flexural modulus of 450 to 650 MPa, measured according to standard ISO 178:2019, 10 days after molding; - a tensile modulus of elasticity of 500 to 800 MPa at 23°C, measured via DMTA analysis on 1 mm thick compression molded plaques according to ISO 6721-4:2019; - Izod impact resistance at 23°C measured according to ISO 180:2000 on compression panels in the range of 3 to 15 kJ / m according to ISO 8986-2:2009 2 ; - Izod impact resistance at 0°C measured according to ISO 180:2000 on compression panels in the range of 2 to 10 kJ / m according to ISO 8986-2:2009 2 .

8. The butene-1 polymer composition according to claim 1 or 3, wherein the butene-1 polymer component A) has a crystallization temperature T c is 75°C or higher, the crystallization temperature T c It was measured after a melting cycle using the DSC method at a scanning rate of 10°C / min.

9. The butene-1 polymer composition according to claim 1 or 3, wherein the butene-1 homopolymer and copolymer A) has an isotacticity of 90% to 99%, the isotacticity being measured according to mmmm pentads / total pentads using NMR analysis.

10. The butene-1 polymer composition according to claim 1 or 3, wherein the ethylene polymer component C) is selected from the group consisting of HDPE, LLDPE, LDPE and mixtures thereof.

11. An article comprising the butene-1 polymer composition of claim 1 or 3.

12. The article of claim 11, wherein the article is in the form of a pipe or a pipe fitting.

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