RU2800648C2 - Composition of polypropylene random copolymer for cold and hot water supply pipes - Google Patents

Abstract

FIELD: polymer compositions.

SUBSTANCE: invention relates to polypropylene polymer compositions intended for the manufacture of extruded pipeline structures. The polypropylene polymer composition according to the invention contains a polypropylene random copolymer containing propylene as the primary monomer and a proportion of ethylene from 1 to 5% by weight, and a property-improving agent, and the property-improving agent is present in the composition in an amount sufficient to increase the impact strength or modulus of elasticity when the composition is bent, and the composition exhibits notched Izod impact strength from 400 to 900 J/m² at 23°C and a flexural modulus from 650 to 1200 MPa, said property-improving agent comprising: a phosphate ester salt, sodium benzoate, dibenzyl sorbitol, a dicarboxylic acid metal salt, or mixtures thereof; or 2,2'-methylene-bis-(4,6-di-tert-butylphenyl) sodium phosphate, dibenzylidene sorbitol, a metal salt of 4-cyclohexene-1,2-dicarboxylic acid, or mixtures thereof; or N,N'-dicyclohexylnaphthalene-2,6-dicarboxamide, 6-quinaziranesulfonic acid metal salt, o-phthalic acid disodium salt, isophthalic acid, terephthalic acid, or a combination of an organic dibasic acid and a Group II metal oxide, hydroxide or acid; or a combination of pimelic acid and calcium stearate; said composition is characterized by a xylene soluble fraction (XS) of 2 to 14%, and this polypropylene random copolymer is monomodal.

EFFECT: polypropylene polymer compositions of the present invention provide not only high impact strength, but also a relatively high flexural modulus.

10 cl, 3 tbl, 1 dwg, 23 ex

Description

Related Applications

this application is based on and claims priority to U.S. Provisional Application No. 62/752,008, filed October 29, 2018, and U.S. Provisional Application No. 62/751,290, filed October 26, 2018, the contents of which are incorporated herein in their entirety. document by reference.

Prerequisites for the creation of the invention

Polymeric materials are often used for pipes intended for various purposes such as the transport of fluids, i.e. the transport of a liquid or gas, such as water or natural gas, during which the fluid may be under pressure. In addition, the transported fluid may have various temperatures, typically in the temperature range from about 0°C to about 90°C.

Due to the application of high temperatures, hot water pipes made of polymer materials are a particularly problematic type of polymer pipes. Polymer hot water pipes must not only meet the requirements of other conventional polymer pipes such as cold water pipes, but they must additionally withstand the stresses associated with elevated temperatures. Hot water temperatures in hot water pipes commonly used for plumbing and heating purposes range from 30-70°C, which means that for safe long-term use, such a pipe must withstand higher temperatures than the indicated temperatures. Maximum temperatures can reach 100°C.

In the past, the pipes described above have been made from polyolefin polymers such as polypropylene polymers and polyethylene polymers. However, there have been difficulties in formulating a polyolefin resin composition that has an optimal blend of mechanical properties for various pipe applications. For example, in many applications, high impact strength combined with a relatively high flexural modulus is advantageous. However, in the past, the improvement of one of the above characteristics had a negative impact on other characteristics. Therefore, the present invention relates to polymer compositions having an improved balance of properties between impact strength and flexural modulus.

Brief summary of the invention

In general, the present invention relates to polypropylene polymer compositions containing a polypropylene random copolymer that is formulated and designed to have a good balance of mechanical properties. For example, polypropylene polymer compositions made in accordance with the present invention, in particular, are most suitable for the production of pipe structures for hot and cold water. In particular, the polypropylene resin compositions of the present invention are designed to provide not only high impact strength, but also a relatively high flexural modulus.

In one embodiment, the present invention relates to a polypropylene polymer composition containing a polypropylene random copolymer in combination with a property-improving agent. The random propylene copolymer may contain:

propylene as the primary monomer;

the proportion of ethylene (ET) from about 1% to about 5% by weight;

moreover, the melt flow rate is from more than about 0.01 g/10 min to about 2 g/10 min; And

molecular weight distribution from about 5 to about 10.

In accordance with the present invention, the above polypropylene random copolymer is combined with a property-improving agent in an amount sufficient to increase the value of at least one physical property of the composition, i.e., impact strength and/or flexural modulus. For example, the polymer composition may have a notched Izod impact strength at 23°C of greater than about 400 J/m, such as greater than about 500 J/m, such as greater than about 600 J/m, such as greater than about 700 J/m, whereby this value is substantially less than about 900 J/m. In addition to relatively high impact strength, the polymer composition of the present invention also has a relatively high flexural modulus. For example, the flexural modulus may be greater than about 650 MPa, such as greater than about 750 MPa, such as greater than about 850 MPa, such as greater than about 950 MPa, and substantially less than about 1200 MPa.

In one embodiment, the property enhancing agent may comprise a phosphate ester salt, sodium benzoate, dibenzyl sorbitol, or mixtures thereof. In this embodiment, the polymer composition may have a melt flow rate of less than about 0.5 g/10 min, may contain ethylene in an amount of from about 3.3% to about 5%, and have a molecular weight distribution of from about 5 to about 8. In one embodiment, the polypropylene random copolymer may be monomodal.

In one embodiment, the property enhancing agent may comprise N,N'-dicyclohexylnaphthalene-2,6-dicarboxamide, 6-quinaziranesulfonic acid metal salt, dicarboxylic acid metal salt, e.g. 4-cyclohexene-1,2-dicarboxylic acid metal salt, disodium salt o-phthalic acid, isophthalic acid, terephthalic acid, or a combination of an organic dibasic acid and a group II metal oxide, hydroxide or acid. In this embodiment, the polymer composition may have a melt flow rate of from about 0.15 g/10 min to 2 g/10 min, may contain ethylene in an amount of from about 1% to about 3% by weight, and may have a molecular weight distribution of about 6 to about 10.

The property enhancing agent may be added to the polymer composition after the formation of the random copolymer. For example, the polymer composition can be mixed with a property enhancing agent. In one embodiment, the property enhancing agent may be combined with the polypropylene random copolymer during extrusion of the polymer to form a molded article, such as a tubular structure. The amount of property enhancing agent incorporated into the polymer composition may depend on a variety of factors and the desired result. Typically, the property enhancing agent may be present in the polymer composition in an amount of from 100 ppm to about 5000 ppm. The polymer composition essentially contains a polypropylene random copolymer in an amount of more than about 70% by weight, for example in an amount of more than about 80% by weight, for example in an amount of more than about 90% by weight, for example in an amount of less than about 95% by weight.

The present invention also relates to piping structures and/or piping components made from the polymer composition described above. For example, in one embodiment, a pipeline component may include a tubular structure having a length. The tubular structure may form a hollow inner channel defined by a wall. The wall may be made from a polymeric composition as described above, containing a polypropylene random copolymer in combination with a property-improving agent.

Other features and aspects of the present invention are described in more detail below.

Brief description of graphic materials

On FIG. 1 shows one embodiment of a pipeline structure made in accordance with the present invention. This document provides a complete and sufficient description of the present invention, including the best way to carry it out, intended for those skilled in the art, with more specific details in the remainder of the description, which includes reference to the accompanying figure.

Definitions and Test Procedures

As used herein, the term "propylene-ethylene copolymer" means a copolymer containing propylene monomer in a predominant weight percent with respect to ethylene monomer as a secondary constituent. A "propylene-ethylene copolymer" (also sometimes referred to as polypropylene random copolymer, PPR, PP-R, RCP, or RACO) is a polymer having individual ethylene monomer repeat units present in the polymer chain in a random or random distribution.

The melt flow rate (MFR) in the context of the present description is measured in accordance with the test method set forth in ASTM D 1238 at 230° C. with a weight of 2.16 kg for propylene-based polymers.

Xylene solubles (XS) are defined as the weight percent of resin that remains in solution after a random propylene random copolymer resin sample is dissolved in hot xylene and the solution is cooled to 25°C. This method is also referred to as the gravimetric XS method according to ASTM D5492-98 using a 90 minute settling time and is also referred to herein as the "wet method".

The "wet method" for determining XS involves weighing a 2 g sample and dissolving the sample in 200 ml o-xylene in a 400 ml flask with a 24/40 cut. The flask is attached to a water-cooled condenser and the contents are stirred and heated under nitrogen (N ₂ ) until condensation appears and then refluxed for an additional 30 minutes. The solution is then cooled in a water bath maintained at 25° C. for 90 minutes to allow the xylene-insoluble fraction (XI) to crystallize. After cooling the solution and precipitation of the insoluble fraction from the solution, the separation of part XS from part XI is achieved by filtration through filter paper with a pore size of 25 μm. One hundred milliliters of the filtrate is collected in a pre-weighed aluminum pan and the o-xylene is evaporated from said 100 ml of the filtrate under a stream of nitrogen. After evaporation of the solvent, the tray and contents are placed in a vacuum oven at 100 °C for 30 minutes or until dry. The tray is then allowed to cool to room temperature and weighed. The content of the xylene-soluble part is calculated by the formula: where m ₁ is the original weight of the sample used, m ₂ is the weight of the empty aluminum pan, and m ₃ is the weight of the pan and the remainder (here and throughout this description, the asterisk (*) denotes the product of the terms or values given).

The order distribution of the monomers in the polymer can be determined by ¹³ C NMR, which also makes it possible to determine the arrangement of ethylene residues in relation to adjacent propylene residues. The ¹³ C NMR method can be used to determine ethylene content, Koenig's B value, triad distribution and triad regularity and is performed as described below.

Samples are prepared by adding about 2.7 g of a 50/50 mixture of tetrachloroethane-d2/orthodichlorobenzene containing 0.025 M Cr(AcAc)3 to 0.20 g of sample in a 10 mm Norell 1001-7 NMR tube. The samples are dissolved and homogenized by heating the tube and its contents to 150° C. using a heating block. Each sample is inspected to ensure uniformity.

Data collection was carried out using a Bruker 400 MHz spectrometer equipped with a Bruker Dual DUL CryoProbe high temperature sensor. Data collection is carried out using 512 transitions per data file, a pulse repetition delay of 6 s, a magnetization vector deflection angle of 90 degrees, an inverse suppression mode, and a sample temperature of 120°C. All measurements are carried out on non-rotating samples in blocking mode. Samples were allowed to reach thermal equilibrium for 10 minutes prior to data collection. The regularity of the molecular structure in percentage mm and the mass percentage of ethylene were calculated using methods commonly used in the art, which are briefly described below.

With regard to the measurement of chemical shifts of resonant frequencies, for the methyl group of the third unit in a sequence of 5 adjacent propylene units consisting of head-to-tail bonds and having the same relative chirality, a value of 21.83 ppm is taken. The chemical shift of other resonant frequencies of carbon is determined using the value mentioned above as a standard. The spectrum related to the region of carbon in the methyl group (17.0–23 ppm) can be divided into the first region (21.1–21.9 ppm), the second region (20.4–21.0 ppm), the third region (19.5–20.4 ppm) and the fourth region (17.0–17.5 ppm). Each peak in the spectrum is deciphered using a literary source such as articles in, for example, Polymer, T. Tsutsui et al., Vol. 30, Issue 7, (1989) 1350-1356 and/or Macromolecules, H. N. Cheng, 17 (1984) 1950-1955, the contents of which are incorporated herein by reference.

The first region contains the signal of the central methyl group in the PPP (mm) triad. In the second region, the signal of the central methyl group in the PPP (mr) triad and the methyl group of the propylene unit, adjacent to which the units are the propylene unit and the ethylene unit (PPE-methyl group), resonate. In the third region, the signal of the central methyl group in the PPP (rr) triad and the methyl group of the propylene unit, adjacent to which the units are ethylene units (EPE-methyl group), resonate.

The PPP(mm), PPP(mr), and PPP(rr) groups have the following chain structure of three propylene units with head-to-tail linkages, respectively. This is shown in the Fisher projection formulas below.

The regularity of the triad molecular structure (mm fraction) of the propylene random copolymer can be determined from the ¹³ C NMR spectrum of the propylene random copolymer using the following formula:

The peak areas used in the above calculation are not measured directly from the triad regions in the ¹³ C NMR spectrum. From these, the intensities of the mr and rr triad regions due to the order of the EPP and EPE groups, respectively, must be subtracted. The EPP area can be determined from the signal at 30.8 ppm after subtracting half the area from it for the sum of signals between 26 and 27.2 ppm and the signal at 30.1 ppm. The area due to EPE can be determined from the signal at 33.2 ppm.

For convenience, the ethylene content was also measured by Fourier transform infrared spectroscopy (FTIR), the results of these measurements correlate with the values of the ethylene content determined by the above-mentioned ¹³ C NMR as the main method. The relationship and agreement between measurements made using these two methods is described, for example, in JR Paxson, JC Randall, "Quantitative Measurement of Ethylene Incorporation into Propylene Copolymers by Carbon-13 Nuclear Magnetic Resonance and Infrared Spectroscopy", Analytical Chemistry, Vol. 50, no. 13 Nov. 1978, 1777–1780.

Flexural modulus is determined according to ASTM D790-10 method A using ASTM 3641 (latest version) type 1 specimen cast according to ASTM D4101 (latest version) at 1.3 mm/min.

The Mw/Mn ratio (also referred to as MWD) and Mz/Mw are measured by GPC according to the gel permeation chromatography (GPC) analytical method for polypropylene. The polymers were analyzed on a PL-220 series High Temperature Gel Permeation Chromatography (GPC) unit equipped with a refractive index detector and four PLgel Mixed-A (20 μm) columns (Polymer Laboratory Inc.). The oven temperature is set to 150 °C and the temperature of the hot and warm zones of the autosampler to 135 °C and 130 °C, respectively. The solvent is a nitrogen-purged 1,2,4-trichlorobenzene (TCB) containing ˜200 ppm of 2,6-di-t-butyl-4-methylphenol (BHT). The flow rate is 1.0 ml/min and the injection volume is 200 µl. A 2 mg/mL sample is prepared by dissolving the sample in N ₂ purged and preheated TCB (containing 200 ppm BHT) for 2.5 hours at 160°C with gentle agitation.

A set of GPC columns is calibrated by passing twenty polystyrene standards with a narrow molecular weight distribution. The molecular weight (MW) of the standards ranges from 580 to 8,400,000 g/mol, with the standards contained in 6 "cocktail" mixes. Each mixture based on a standard sample is characterized by at least a decimal place separating individual molecular weights. Polystyrene standards are prepared at 0.005 g in 20 ml solvent for molecular weights equal to or greater than 1,000,000 g/mol and 0.001 g in 20 ml solvent for molecular weights less than 1,000,000 g/mol. Standard samples of polystyrene are dissolved at 150 °C for 30 min with stirring. Narrowly distributed standard mixtures are passed first and in descending order of the component with the highest molecular weight to minimize the effect of deterioration in sensitivity. A logarithmic molecular weight calibration is performed using a fourth order polynomial approximation as a function of the elution volume. Polypropylene molecular weight equivalent values are calculated using the following equation using validated Mark-Houwink coefficients for polypropylene (Th. G. Scholte, N. L. J. Meijerink, H. M. Schoffeleers, and A. M. G. Brands, J. Appl. Polym. Sci., 29, 3763-3782 (1984)) and polystyrene (E. P. Otocka, R. J. Roe, N. Y. Hellman, P. M. Muglia, Macromolecules, 4, 507 (1971)):

where M _pp is the PP MW equivalent, M _PS is the PS MW equivalent, log K and the Mark-Houwink coefficients for PP and PS are shown in Table 1 below.

Table 1 Polymer A log K Polypropylene 0.725 -3.721 Polystyrene 0.702 -3,900

Izod impact strength is measured in accordance with ASTM D 256 (2018).

Detailed description

The person skilled in the art should understand that the present text is only a description of exemplary embodiments and is not intended to limit the broader aspects of the present invention.

In general, the present invention relates to a polypropylene polymer composition having a unique combination of physical properties. For example, the polypropylene resin composition of the present invention is formulated and designed to not only have high impact strength characteristics, but also to have relatively high flexural modulus characteristics. In accordance with the present invention, to achieve a balance between impact strength and flexural modulus, a polypropylene random copolymer is combined with a property-improving agent. For example, the property-improving agent may increase the stiffness of the polymer composition, may increase the toughness of the polymer composition, or may increase both the stiffness and toughness of the polymer composition. For example, a property enhancing agent is incorporated into the polymer composition in an amount sufficient to increase the value of at least one characteristic, ie, flexural modulus or toughness, without adversely affecting the other characteristic.

In addition, the polypropylene resin composition can have good flow characteristics, which makes it possible to manufacture various articles by extrusion. For example, in one embodiment, the polymeric composition can be used to manufacture tubular structures or pipe components for hot and cold water supply.

As described above, the polymer composition according to the present invention has a relatively high impact strength in combination with a relatively high flexural modulus. For example, the polymer composition of the present invention may have a notched Izod impact strength at 23°C of greater than about 400 J/m, such as greater than about 450 J/m, such as greater than about 500 J/m, such as greater than about 550 J/m, for example, greater than about 600 J/m, such as greater than about 650 J/m, such as greater than about 700 J/m. The Izod impact strength at 23° C. is substantially less than about 900 J/m. The polymer composition can also exhibit excellent toughness at lower temperatures. For example, the polymer composition may have an Izod impact strength at 0°C of greater than about 100 J/m, such as greater than about 150 J/m, such as greater than about 200 J/m, wherein the Izod impact strength at 0°C is substantially less than about 600 J/m.

Typically, the polymer composition as described herein may have a flexural modulus greater than about 650 MPa, such as greater than about 700 MPa, such as greater than about 750 MPa, such as greater than about 800 MPa. In one embodiment, the polymer composition may have a flexural modulus of less than about 1400 MPa, such as less than about 1200 MPa.

Polymer compositions formulated in accordance with the present invention may also have acceptable flow properties at higher temperatures, such as temperatures greater than about 180°C, such as greater than about 200°C, such as greater than about 220°C, such as greater than about 240°C , and essentially less than about 280°C, for example, less than about 260°C. In one embodiment, extruded products in accordance with the present invention are made at temperatures from about 240°C to about 260°C, for example from about 250°C to about 260°C. In general, the melt flow rate of the polymer composition may be less than about 2 g/10 min, such as less than about 1.5 g/10 min, such as less than about 1 g/10 min, such as less than about 0.75 g/10 min. The melt flow rate is substantially greater than about 0.01 g/10 min, such as greater than about 0.1 g/10 min, such as greater than about 0.15 g/10 min.

The polypropylene polymer composition contains a polypropylene random copolymer. The random propylene copolymer essentially contains propylene as the primary monomer in combination with an alkylene comonomer. For example, in one embodiment, the comonomer is ethylene. In one particular embodiment, the polypropylene random copolymer typically contains ethylene in an amount of less than about 6% by weight, such as less than about 5% by weight, such as less than about 4.5% by weight, such as substantially less than about 4 % by weight, such as less than about 3.5% by weight, such as less than about 3% by weight. The ethylene content is substantially greater than about 1%, such as greater than about 1.5%, such as greater than about 2%, such as greater than about 2.5%. Generally, increasing the ethylene content of the copolymer can lead to an increase in the toughness of the polymer composition. However, increasing the ethylene content can also lead to a decrease in the flexural modulus. In accordance with the present invention, the ethylene content of the random copolymer is carefully controlled in conjunction with the addition of a property enhancing agent. The property-improving agent acts synergistically in combination with the ethylene contained in the copolymer to produce a polymer composition having not only increased toughness, but also an increased flexural modulus.

In addition to controlled ethylene content, the polypropylene random copolymer can also have a relatively low xylene soluble content. For example, the total content or fraction of XS in the polymer composition may be less than about 14% by weight, such as less than about 12% by weight, such as less than about 11% by weight, such as less than about 10% by weight, such as less than about 9% by weight. , eg, less than about 8% by weight, eg, less than about 7% by weight, eg, less than about 6% by weight, eg, less than about 5% by weight. The XS content is substantially greater than about 2% by weight.

The polypropylene copolymer may comprise a Ziegler-Natta catalyzed polymer and may have a relatively controlled molecular weight distribution. For example, the molecular weight distribution (Mw/Mn) may be greater than about 5, such as greater than about 5.5, such as greater than about 6, such as greater than about 6.5, such as greater than about 7, such as greater than about 7.5, and substantially less than about 10, such as less than about 9, such as less than about 8.

In accordance with the present invention, the polypropylene random copolymer is combined with a property-improving agent to increase toughness, flexural modulus, or both toughness and flexural modulus. The property enhancing agent can be combined with the polypropylene random copolymer during polymerization, or preferably after polymerization. For example, the property enhancing agent may be blended with the polypropylene random copolymer, or it may be added to the polypropylene random copolymer during the molding of the polymer articles, such as during the extrusion process.

The property-improving agent may comprise any suitable compound capable of improving the mechanical properties of the polymer composition. For example, in one embodiment, the property-improving agent may contain a chemical component or mixture of chemical components that can influence the rate of crystallization of the polymer. For example, in one embodiment, the property enhancing agent can alter the crystallinity and structure of the polypropylene random copolymer. For example, the property enhancing agent may change the crystal structure of the polymer by changing the proportions of alpha crystals and beta crystals. For example, alpha crystals can be described as monoclinic, while beta crystals can be more hexagonal. The property enhancing agent can be used to modify and control the crystal structure of the polymer depending on the ethylene content of the polymer and various other factors. For example, in one embodiment, a property enhancing agent may be used to increase the proportion of alpha crystals. Alpha crystals may be present in the polymer, for example in an amount of more than about 50% by weight, for example in an amount of more than about 60% by weight, for example in an amount of more than about 70% by weight, and substantially less than about 95% by weight. In an alternative embodiment, a property enhancing agent may be used to increase the proportion of beta crystals in the polymer. For example, in one embodiment, a property enhancing agent can be used to control the amount of beta crystals; such that beta crystals may be present in the polymer in an amount of more than about 36% by weight, for example in an amount of more than about 40% by weight. by weight, for example in an amount of more than about 50% by weight, for example in an amount of more than about 60% by weight, for example in an amount of more than about 65% by weight, for example in an amount of more than about 70% by weight, for example in an amount of more than about 75 % by weight and substantially less than about 95% by weight

Various types of property enhancing agents can be incorporated into the polymer composition depending on the chosen application and the desired result. For example, in one embodiment, the property enhancing agent may comprise sodium benzoate. In an alternative embodiment, the property enhancing agent may comprise a phosphate ester salt. For example, the property enhancing agent may contain 2,2'-methylene-bis-(4,6-di-tert-butylphenyl)sodium phosphate.

In an alternative embodiment, the property enhancing agent may comprise a sorbitol compound, such as a sorbitol acetal derivative. For example, in one embodiment, the property enhancing agent may comprise dibenzyl sorbitol.

With regard to sorbitol acetal derivatives that can be used as an additive in some embodiments, a sorbitol acetal derivative is shown in formula (I):

where R1-R5 contain the same or different functional groups selected from hydrogen and C1-C3 alkyl.

In some embodiments, R1-R5 is hydrogen such that the sorbitan acetal derivative is 2,4-dibenzylidene sorbitol (DBS). In some embodiments, R1, R4 and R5 are hydrogen and R2 and R3 are methyl groups such that the sorbitol acetal derivative is 1,3:2,4-di-p-methyldibenzylidene-D-sorbitol (MDBS). In some embodiments, R1-R4 are methyl groups and R5 is hydrogen, such that the sorbitol acetal derivative is 1,3:2,4-bis(3,4-dimethylobenzylidene)sorbitol (DMDBS). In some embodiments, R2, R3 and R5 are propyl groups (-CH2-CH2-CH3) and R1 and R4 are hydrogen such that the sorbitol acetal derivative is 1,2,3-trideoxy-4.6:5 ,7-bis-O-(4-propylphenylmethylene)nonitol (TBPMN).

Other embodiments of property enhancing agents that may be used include:

1,3:2,4-dibenzylidene sorbitol;

1,3:2,4-bis(p-methylbenzylidene)sorbitol;

di(p-methylbenzylidene)sorbitol;

di(p-ethylbenzylidene)sorbitol;

bis(5', 6', 7', 8'-tetrahydro-2-naphthylidene)sorbitol.

In one embodiment, the property enhancing agent may also contain a bisamide, such as benzenetrisamide. In another embodiment, the property enhancing agent may comprise one or more aromatic diamides. For example, in one embodiment, the property enhancing agent may comprise N,N'-dicyclohexylnaphthalene-2,6-dicarboxamide. The property enhancing agent may also contain o-phthalic acid disodium, isophthalic acid, terephthalic acid, and salts thereof. In one embodiment, the property enhancing agent may comprise N,N'-dicyclohexyl terephthalamide.

In yet another embodiment, the property-improving agent may contain a metal salt, such as an aluminum salt of 6-quinaziranesulfonic acid. The property enhancing agent may contain a quinacridone dye. In one embodiment, the property enhancing agent may comprise 5,12-dihydroquino (2,3-b) acridine-7,14-dione, quino (2,3b) acridine-6,7,13,14, (5H,12H) -tetron or mixtures thereof.

In another embodiment, the property enhancing agent may comprise a metal salt of a carboxylic acid, such as a metal salt of a dicarboxylic acid. For example, the property enhancing agent may comprise a metal salt of cycloalkenedicarboxylic acid. The property enhancing agent may contain a metal salt of 4-cyclohexene-1,2-dicarboxylic acid.

In another embodiment of the present invention, the property enhancing agent may comprise an organic diacid in combination with an oxide, hydroxide, or acid of a Group II metal. The Group II metal may include, for example, magnesium or calcium. For example, the property enhancing agent may comprise a dicarboxylic acid salt having at least 7 carbon atoms, either alone or in combination with an acid. In one embodiment, the property enhancing agent may comprise calcium stearate alone or in combination with an acid, such as pimelic acid. Other examples of similar property-enhancing agents include hydrotalcite, talc, and the like. In one embodiment, metal stearate, hydrotalcite, talc, or similar property-enhancing agents may be combined with other agents described above. For example, in one embodiment, calcium stearate, hydrotalcite and/or talc can be combined with a metal salt of 4-cyclohexene-1,2-dicarboxylic acid.

The amount of property enhancing agent incorporated into the polymer composition may vary depending on the selected property enhancing agent, the amount of ethylene contained in the propylene random copolymer, depending on other characteristics of the polypropylene polymer, as well as depending on the desired result and other factors. Typically, one or more property enhancing agents may be present in the polymer composition in an amount greater than about 200 ppm, such as greater than about 400 ppm, such as greater than about 600 ppm, such as greater than about 800 ppm, such as greater than about 1000 ppm, such as greater than about 1200 ppm, such as greater than about 1400 ppm The one or more property enhancing agents are substantially present in an amount of less than about 4000 ppm, such as less than about 3500 ppm, such as less than about 3000 ppm, such as less than about 2500 ppm, such as less than about 2000 ppm, such as less than about 1800 ppm, such as less than about 1600 ppm In one embodiment, the property enhancing agent may be present in the polymer composition in an amount of from about 250 ppm to about 800 ppm. In an alternative embodiment, the property enhancing agent may be present in the polymer composition in an amount of from about 1000 ppm to about 1800 ppm.

There are many different polymeric compositions that can be formulated in accordance with the present invention that contain a polypropylene random copolymer in combination with one or more property-improving agents. For example, in one embodiment, the property enhancing agent may comprise sodium benzoate, a phosphate ester salt, or dibenzyl sorbitol. In this embodiment, the polypropylene random copolymer may have a melt flow rate of less than about 0.5 g/10 min, may contain ethylene in an amount of from about 3.3% by weight to about 5% by weight, and may have a molecular weight distribution of from about 5 up to about 8. The flexural modulus of the polymer composition may be greater than about 650 MPa, and the polymer composition may have a notched Izod impact strength of greater than about 4 J/m, such as greater than about 500 J/m.

In an alternative embodiment, the property enhancing agent may comprise N,N'-dicyclohexylnaphthalene-2,6-dicarboxamide and the polypropylene random copolymer may contain ethylene in an amount of about 1% to about 3% by weight, may have a melt flow rate of about 0 15 g/10 min to about 2 g/10 min and a molecular weight distribution of about 6 to about 10. In this embodiment, the polymer composition may have a flexural modulus greater than about 800 MPa and may have a notched Izod impact strength greater than about 600 J/m, for example more than about 700 J/m.

In addition to the polypropylene random copolymer and property enhancing agent, the polymer composition of the present invention may contain various other additives and ingredients. For example, the polypropylene composition may contain active site initiators, mold release agents, slip additives, antiblock additives, UV stabilizers, heat stabilizer (eg DSTDP), colorants/tints, and the like. In one embodiment, the polymer composition may contain an antioxidant, such as a hindered phenolic antioxidant. The polymer composition may also contain an acid scavenger. Each of the additives may be present in the polymer composition in substantially less than about 3% by weight, such as less than about 2% by weight, such as less than about 1% by weight, such as less than about 0.5% by weight. , and in most cases in an amount of more than about 0.001% by weight.

The polypropylene random copolymer incorporated into the polymer composition of the present invention can be produced using a variety of polymerization methods and processes. In one embodiment, a Ziegler-Natta catalyst is used to make the polymer. For example, polymerization of olefins can occur in the presence of a catalyst system that includes a catalyst, an internal electron donor, a co-catalyst, and optionally an external electron donor. Olefins of the formula CH ₂ =CHR, where R is hydrogen or a hydrocarbon radical containing from 1 to 12 atoms, can be contacted with the catalyst system under suitable conditions to form polymeric products. The copolymerization process can be carried out in stages. The polymerization process can be carried out using known techniques in gas phase using fluidized or stirred bed reactors or in slurry phase using an inert hydrocarbon solvent or diluent or liquid monomer.

The polypropylene random copolymer incorporated into the polymer composition may be a monomodal polymer or may comprise a heterophasic polymer composition. Typically, a monomodal random copolymer is produced in a single reactor. Monomodal random copolymers are single phase polymers with respect to molecular weight distribution, comonomer content and melt flow index.

On the other hand, heterophasic polymers are typically produced using multiple reactors. In one embodiment, the first phase polymer and the second phase polymer can be produced in a two step process which includes a first step producing a propylene random copolymer from a continuous polymer phase and a second step producing an elastomeric propylene copolymer. The first polymerization stage can be carried out in one or more block reactors or in one or more gas phase reactors. The second polymerization step may be carried out in one or more gas phase reactors. The second polymerization step is usually carried out immediately after the first polymerization step. For example, the polymerization product recovered in the first polymerization stage can be sent directly to the second polymerization stage. A heterophasic copolymer composition is obtained.

In one embodiment of the present invention, the polymerization is carried out in the presence of a stereoregular olefin polymerization catalyst. For example, the catalyst may be a Ziegler-Natta catalyst. For example, in one embodiment, a catalyst sold under the trade name CONSISTA, commercially available from W. R. Grace & Company, can be used. In one embodiment, phthalates-free electron donors are selected.

In one embodiment, the catalyst includes a procatalyst composition that contains a titanium functional group such as titanium chloride, a magnesium functional group such as magnesium chloride, and at least one internal electron donor.

The procatalyst precursor may include (i) magnesium, (ii) a transition metal compound of an element from Groups IV-VII of the Periodic Table of the Elements, (iii) halide, oxyhalide and/or alkoxide (i) or (i) and/or (ii) and (iv) a combination of (i), (ii) and (iii). Non-limiting examples of suitable procatalyst precursors include halides, oxyhalides, alkoxides of magnesium, manganese, titanium, vanadium, chromium, molybdenum, zirconium, hafnium, and combinations thereof.

In one embodiment, the procatalyst precursor contains magnesium as the only metal component. Non-limiting examples include anhydrous magnesium chloride and/or its alcohol adduct, magnesium alkoxide or aryloxide, mixed magnesium alkoxyhalide and/or carboxylated magnesium dialkoxide or aryloxide.

In one embodiment, the procatalyst precursor is an alcohol adduct of anhydrous magnesium chloride. The anhydrous magnesium chloride adduct is essentially defined as MgCl ₂ -nROH where n is in the range 1.5-6.0, preferably 2.5-4.0 and most preferably 2.8-3.5 moles of total alcohol. ROH is a C ₁ -C ₄ alcohol, a linear or branched alcohol, or an alcohol mixture. Preferably ROH is ethanol or a mixture of ethanol and a higher alcohol. If the ROH is a mixture, the molar ratio of ethanol to higher alcohol is at least 80:20, preferably 90:10, and most preferably at least 95:5.

In one embodiment, the substantially spherical MgCl ₂ -nEtOH adduct can be formed by a spray crystallization process. In one embodiment, the spherical MgCl ₂ precursor has a mean particle size (Malvern d ₅₀ ) of about 15-150 µm, preferably 20-100 µm, and most preferably 35-85 µm.

In one embodiment, the procatalyst precursor contains a transition metal compound and a magnesium metal compound. The transition metal compound has the general formula TrX _x where Tr is a transition metal, X is a halogen or C _1-10 hydrocarbyl group, and x is the number of such X groups in the compound in combination with the magnesium metal compound. Tr may be a metal from Group IV, V or VI. In one embodiment, Tr is a Group IV metal, such as titanium. X may be chloride, bromide, C _1-4 alkoxide or phenoxide, or a mixture thereof. In one embodiment, X is chloride.

The precursor composition can be obtained by chlorination of the above mixed magnesium compounds, titanium compounds or mixtures thereof.

In one embodiment, the precursor composition is a mixed magnesium/titanium compound of the formula Mg _d Ti(OR ^e ) _f X _g , where R ^e is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms, or COR' , where R represents an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms; all groups OR ^e may be the same or different; X is independently chlorine, bromine or iodine; D is from 0.5 to 56; or 2–4, or 3; F is 2 to 116 or 5 to 15; and g is 0.5 to 116 or 1 to 3.

In accordance with the present invention, the procatalyst precursor described above is combined with at least one internal electron donor. The internal electron donor may be a substituted phenylene aromatic diester.

In one embodiment, the first internal electron donor contains a substituted phenylene aromatic diester with the following structure (I):

where R ₁ -R ₁₄ may be the same or different. The R1-R14 groups are each selected from hydrogen, a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a heteroatom, and combinations thereof At least at least one of R ₁ -R ₁₄ is not hydrogen.

In one embodiment, the substituted phenylene aromatic diester may be any substituted phenylene aromatic diester as described in U.S. Patent Application No. 61/141,959, filed Dec. 31, 2008, the contents of which are incorporated herein by reference in their entirety.

In one embodiment, the substituted phenylene aromatic diester may be any substituted phenylene aromatic diester described in WO12088028, filed Dec. 20, 2011, the entire content of which is incorporated herein by reference.

In one embodiment, at least one (or two, or three, or four) R group(s) of R ₁ -R ₄ is(s) selected from a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon a group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a heteroatom, and combinations thereof.

In one embodiment, at least one (or some or all) of the R group(s) of R ₅ -R ₁₄ is(s) selected from a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, a heteroatom, and combinations thereof. In another embodiment, at least one of the R ₅ -R ₉ groups and at least one of the R ₁₀ -R ₁₄ groups are selected from a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, a heteroatom, and combinations thereof.

In one embodiment, at least one of the R ₁ -R ₄ groups and at least one of the R ₅ -R ₁₄ groups are selected from a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, a heteroatom, and combinations thereof. In another embodiment, at least one of the R ₁ -R ₄ groups, at least one of the R ₅ -R ₉ groups, and at least one of the R ₁₀ -R ₁₄ groups are selected from a substituted hydrocarbon group having from 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a heteroatom, and combinations thereof.

In one embodiment, any consecutive R groups in R ₁ -R ₄ , and/or any consecutive R groups in R ₅ -R ₉ , and/or any consecutive R groups in R ₁₀ -R ₁₄ may be linked together to form intermolecular cyclic or intramolecular cyclic structure. Such an inter- or intramolecular ring structure may or may not be aromatic. In one embodiment, the inter- or intramolecular ring structure is a C ₅ or C ₆ membered ring.

In one embodiment, at least one of the R ₁ -R ₄ groups is selected from a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and combinations thereof. At least one of R ₅ -R ₁₄ may optionally be a halogen atom or an alkoxy group having 1 to 20 carbon atoms. Groups R ₁ -R ₄ and/or R ₅ -R ₉ and/or R ₁₀ -R ₁₄ may optionally be linked to each other to form an intermolecular cyclic or intramolecular cyclic structure. Such intermolecular ring structure and/or intramolecular ring structure may or may not be aromatic.

In one embodiment, any consecutive R groups in R ₁ -R ₄ and/or R ₅ -R ₉ and/or R ₁₀ -R ₁₄ may be included in a C ₅ -C ₆ membered ring.

In one embodiment, the structure (I) includes groups R ₁ , R ₃ and R ₄ that represent hydrogen. R ₂ is selected from a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and combinations thereof. The R ₅ -R ₁₄ groups may be the same or different, and each of the R ₅ -R ₁₄ groups is selected from hydrogen, a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, halogen and combinations thereof.

In one embodiment, the R ₂ group is selected from a C ₁ -C ₈ alkyl group, a C ₃ -C ₆ cycloalkyl, or a substituted C ₃ -C ₆ cycloalkyl group. R ₂ may be a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a t-butyl group, an isobutyl group, a sec-butyl group, a 2,4,4-trimethylpentan-2-yl group, a cyclopentyl group, and a cyclohexyl group. .

In one embodiment, structure (I) includes an R ₂ group which is methyl and each of the R ₅ -R ₁₄ groups is hydrogen.

In one embodiment, structure (I) includes an R ₂ group which is ethyl and each of the R ₅ -R ₁₄ groups is hydrogen.

In one embodiment, structure (I) includes an R ₂ group which is t-butyl and each of the R ₅ -R ₁₄ groups is hydrogen.

In one embodiment, structure (I) includes an R ₂ group that is ethoxycarbonyl and each of the R ₅ -R ₁₄ groups is hydrogen.

In one embodiment, structure (I) includes R ₂ , R ₃ and R ₄ groups, each of which is hydrogen, and the R ₁ group is selected from a substituted hydrocarbon group having from 1 to 20 carbon atoms, an unsubstituted hydrocarbon group, having from 1 to 20 carbon atoms, and combinations thereof. The R ₅ -R ₁₄ groups may be the same or different and are each selected from hydrogen, a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, halogen and their combinations.

In one embodiment, structure (I) includes an R ₁ group which is methyl and each of the R ₅ -R ₁₄ groups is hydrogen.

In one embodiment, structure (I) includes R ₂ and R ₄ groups which are hydrogen, and R ₁ and R ₃ groups may be the same or different. Each of the R ₁ and R ₃ groups is selected from a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and combinations thereof. The R ₅ -R ₁₄ groups may be the same or different, and each of the R ₅ -R ₁₄ groups is selected from a substituted hydrocarbon group having 1 to 20 carbon atoms, an unsubstituted hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, halogen and combinations thereof.

In one embodiment, structure (I) includes R ₁ and R ₃ groups, which may be the same or different. Each of the R ₁ and R ₃ groups is selected from a C ₁ -C ₈ alkyl group, a C ₃ -C ₆ cycloalkyl group, or a substituted C ₃ -C ₆ cycloalkyl group. The R ₅ -R ₁₄ groups may be the same or different, and each of the R ₅ -R ₁₄ groups is selected from hydrogen, a C ₁ -C ₈ alkyl group, and halogen. Non-limiting examples of suitable C ₁ -C ₈ alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl and 2,4,4-trimethylpentan-2-yl group. Non-limiting examples of suitable C ₃ -C ₆ cycloalkyl groups include cyclopentyl and cyclohexyl groups. In a further embodiment, at least one of the R ₅ -R ₁₄ groups is a C ₁ -C ₈ alkyl group or halo.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₂ , R ₄ and R ₅ -R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes R ₁ and R ₃ groups, each of which is an isopropyl group. Each of the groups R ₂ , R ₄ and R ₅ -R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes R ₁ , R ₅ and R ₁₀ groups, each of which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₂ , R ₄ , R ₆ -R ₉ and R ₁₁ -R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes R ₁ , R ₇ and R ₁₂ groups, each of which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₇ and R ₁₂ represents an ethyl group. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes R ₁ , R ₅ , R ₇ , R ₉ , R ₁₀ , R ₁₂ and R ₁₄ groups each of which is a methyl group and an R ₃ group which is tert -butyl group. Each of the groups R ₂ , R ₄ , R ₆ , R ₈ , R ₁₁ and R ₁₃ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₅ , R ₇ , R ₉ , R ₁₀ , R ₁₂ and R ₁₄ represents an isopropyl group. Each of the groups R ₂ , R ₄ , R ₆ , R ₈ , R ₁₁ and R ₁₃ represents hydrogen.

In one embodiment, the substituted phenylene aromatic diester has the structure (II) which includes an R ₁ group which is a methyl group and an R ₃ group which is a tert-butyl group. Each of the groups R ₂ and R ₄ represents hydrogen. The R ₈ and R ₉ groups are included in the C ₆ -membered ring with the formation of a 1-naphthoyl fragment. Groups R ₁₃ and R ₁₄ are included in the C ₆ -membered ring with the formation of another 1-naphthoyl fragment. Structure (II) is shown below.

In one embodiment, the substituted phenylene aromatic diester has the structure (III) which includes an R ₁ group which is a methyl group and an R ₃ group which is a tert-butyl group. Each of the groups R ₂ and R ₄ represents hydrogen. The R ₆ and R ₇ groups are included in the C ₆ -membered ring with the formation of a 2-naphthoyl fragment. Groups R ₁₂ and R ₁₃ are included in the C ₆ -membered ring with the formation of a 2-naphthoyl fragment. Structure (III) is presented below.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the R ₇ and R ₁₂ groups represents an ethoxy group. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₇ and R ₁₂ represents a fluorine atom. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₇ and R ₁₂ represents a chlorine atom. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₇ and R ₁₂ represents a bromine atom. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₇ and R ₁₂ represents an iodine atom. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₆ , R ₇ , R ₁₁ and R ₁₂ represents a chlorine atom. Each of the groups R ₂ , R ₄ , R ₅ , R ₈ , R ₉ , R ₁₀ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₆ , R ₈ , R ₁₁ and R ₁₃ represents a chlorine atom. Each of the groups R ₂ , R ₄ , R ₅ , R ₇ , R ₉ , R ₁₀ , R ₁₂ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₂ , R ₄ and R ₅ -R ₁₄ represents a fluorine atom.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the R ₇ and R ₁₂ groups represents a trifluoromethyl group. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₇ and R ₁₂ represents an ethoxycarbonyl group. Each of the groups R ₂ , R ₄ , R ₅ , R _{6 ,} R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, the R ₁ group is a methyl group and the R ₃ group is a t-butyl group. Each of the R ₇ and R ₁₂ groups represents an ethoxy group. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group, which is a methyl group, and an R ₃ group, which is a tert-butyl group. Each of the groups R ₇ and R ₁₂ represents a diethylamine group. Each of the groups R ₂ , R ₄ , R ₅ , R ₆ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group which is a methyl group and an R ₃ group which is a 2,4,4-trimethylpentan-2-yl group. Each of the groups R ₂ , R ₄ and R ₅ -R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes R ₁ and R ₃ groups, each of which is a sec-butyl group. Each of the groups R ₂ , R ₄ and R ₅ -R ₁₄ represents hydrogen.

In one embodiment, the substituted phenylene aromatic diester has the structure (IV), wherein the R ₁ and R ₂ groups are included in a C ₆ membered ring to form a 1,2-naphthalene moiety. Each of the groups R ₅ -R ₁₄ represents hydrogen. Structure (IV) is shown below.

In one embodiment, the substituted phenylene aromatic diester has the structure (V), wherein the R ₂ and R ₃ groups are included in a C ₆ membered ring to form a 2,3-naphthalene functional group. Each of the groups R ₅ -R ₁₄ represents hydrogen. Structure (V) is shown below.

In one embodiment, structure (I) includes R ₁ and R ₄ groups, each of which is a methyl group. Each of the groups R ₂ , R ₃ , R ₅ -R ₉ and R ₁₀ -R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes an R ₁ group which is a methyl group. The R ₄ group is an isopropyl group. Each of the groups R ₂ , R ₃ , R ₅ -R ₉ and R ₁₀ -R ₁₄ represents hydrogen.

In one embodiment, structure (I) includes R ₁ , R ₃ and R ₄ groups, each of which represents an isopropyl group. Each of the groups R ₂ , R ₅ -R ₉ and R ₁₀ -R ₁₄ represents hydrogen.

In one embodiment, each of R ₁ and R ₄ is selected from a methyl group, an ethyl group, and a vinyl group. Each of the groups R ₂ and R ₃ is selected from hydrogen, a secondary alkyl group or a tertiary alkyl group, while R ₂ and R ₃ are not simultaneously hydrogen. In other words, if R2 is hydrogen, R3 is not hydrogen (and vice versa).

In one embodiment, a second internal electron donor can be used containing substantially a polyether that can be bidentately coordinated. In one embodiment, the second internal electron donor is a substituted 1,3-diester of structure VI:

where R ₁ and R ₂ are the same or different, methyl, C ₂ -C ₁₈ linear or branched alkyl, C ₃ -C ₁₈ cycloalkyl, C ₄ -C ₁₈ cycloalkyl-alkyl, C ₄ -C ₁₈ alkyl-cycloalkyl, phenyl, organosilicon, C ₇ -C ₁₈ arylalkyl or C ₇ -C ₁₈ alkylaryl radicals; and R ₁ or R ₂ may also be a hydrogen atom.

In one embodiment, the second internal electron donor may contain a 1,3-diester with a cyclic or polycyclic structure VII:

where R ₁ , R ₂ , R ₃ and R ₄ correspond to those described for R ₁ and R ₂ of structure VI or can be combined to form one or more C ₅ -C ₇ fused aromatic or non-aromatic ring structures, optionally containing a N, O or heteroatom S. Examples of the second internal electron donor include 4,4-bis(methoxymethyl)-2,6-dimethylheptane, 9,9-bis(methoxymethyl)fluorene, or mixtures thereof.

The precursor is converted to a solid procatalyst by subsequent reaction (halogenation) with an inorganic halide compound, preferably a titanium halide compound, and incorporation of internal electron donors.

One suitable method for halogenating the precursor is to react the precursor at elevated temperature with tetravalent titanium halide, optionally in the presence of a hydrocarbon or halocarbon diluent. The preferred tetravalent titanium halide is titanium tetrachloride.

The resulting procatalyst composition may substantially contain titanium in an amount of from about 0.5% to about 6% by weight, for example from about 1.5% to about 5% by weight, for example from about 2% to about 4% by weight. The solid catalyst may contain magnesium substantially greater than about 5% by weight, such as greater than about 8% by weight, such as greater than about 10% by weight, such as greater than about 12% by weight, such as greater than about 14% by weight, for example in an amount of more than about 16% by weight. Magnesium is present in the catalyst in an amount of less than about 25% by weight, such as less than about 23% by weight, such as less than about 20% by weight. The internal electron donor may be present in the catalyst composition in an amount of less than about 30% by weight, such as less than about 25% by weight, such as less than about 22% by weight, such as less than about 20% by weight, such as less than about 19% by weight. The internal electron donor is substantially greater than about 5% by weight, such as greater than about 9% by weight.

In one embodiment, the procatalyst composition is combined with a cocatalyst to form a catalyst system. The catalyst system is a system that forms an olefin-based polymer upon contact with an olefin under polymerization conditions. The catalyst system may optionally include an external electron donor, a catalyst activity limiting agent, and/or various other components.

As used herein, the term "co-catalyst" means a substance capable of converting a pro-catalyst into an active polymerization catalyst. The co-catalyst may include hydrides, alkyls or aryls of aluminum, lithium, zinc, tin, cadmium, beryllium, magnesium, and combinations thereof. In one embodiment, the cocatalyst is a hydrocarbylaluminum cocatalyst represented by the formula R ₃ Al, where each R group is an alkyl, cycloalkyl, aryl, or hydrogen radical; at least one R is a hydrocarbon radical; two or three R radicals can be combined into a cyclic radical to form a heterocyclic structure; each R may be the same or different, and each R which is a hydrocarbyl radical has 1 to 20 carbon atoms and preferably 1 to 10 carbon atoms. In a further embodiment, each alkyl radical may be straight or branched chain, and such hydrocarbyl radical may be a mixed radical, ie, the radical may contain alkyl, aryl and/or cycloalkyl groups. Non-limiting examples of suitable radicals are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, neopentyl, n-hexyl, 2-methylpentyl, n-heptyl, n-octyl , isooctyl, 2-ethylhexyl, 5,5-dimethylhexyl, n-nonyl, n-decyl, isodecyl, n-undecyl, n-dodecyl.

Non-limiting examples of suitable hydrocarbylaluminum compounds are triisobutylaluminum, tri-n-hexylaluminum, diisobutylaluminum hydride, di-n-hexylaluminum hydride, isobutylaluminum dihydride, n-hexylaluminum dihydride, diisobutylhexylaluminum, isobutyldihexylaluminum, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, tri-n-octylaluminum, tri-n-decylaluminum, tri-n-dodecylaluminum. In one embodiment, the preferred cocatalysts are selected from triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diisobutylaluminum hydride, and di-n-hexylaluminum hydride, with triethylaluminum being the most preferred cocatalyst.

In one embodiment, the co-catalyst is an organoaluminum compound represented by the formula R _n AlX _3-n where n = 1 or 2, R is alkyl, and X is a halide or alkoxide. Non-limiting examples of suitable compounds are methylalumoxane, isobutylaluminum, diethylaluminum ethoxide, diisobutylaluminum chloride, tetraethyldialumoxane, tetraisobutyldialumoxane, diethylaluminum chloride, ethylaluminum dichloride, methylaluminum dichloride and dimethylaluminum chloride.

In one embodiment, the catalyst composition includes an external electron donor. As used herein, the term "external electron donor" means a compound that is added regardless of the formation of the procatalyst and contains at least one functional group that is capable of donating an electron pair to a metal atom. Without wishing to be bound by any particular theory, it is believed that an external electron donor improves catalyst stereoselectivity (ie, reduces the amount of xylene-soluble material in the formant polymer).

In one embodiment, the external electron donor can be selected from one or more of the following: alkoxysilane, amine, ether, carboxylate, ketone, amide, carbamate, phosphine, phosphate, phosphite, sulfonate, sulfone, and/or sulfoxide.

In one embodiment, the external electron donor is an alkoxysilane. The alkoxysilane has the following general formula: SiR _m (OR') _4-m (I), where each of the R groups is independently hydrogen, or a hydrocarbon group, or an amino group, optionally substituted with one or more substituents containing one or more heteroatoms from the group 14, 15, 16 or 17, and the specified group R' contains up to 20 atoms, not counting hydrogen and halogen; R' is a C _1-4 alkyl group; and m is 0, 1, 2, or 3. In one embodiment, R is C _6-12 aryl, alkyl, or aralkyl, C _3-12 cycloalkyl, C _3-12 branched alkyl, or C _3-12 cyclic or acyclic amino, R' is C _1-4 alkyl and m is 1 or 2. Non-limiting examples of suitable silane compositions include dicyclopentyldimethoxysilane, di-tert-butyldimethoxysilane, methylcyclohexyldimethoxysilane, methylcyclohexyldiethoxysilane, ethylcyclohexyldimethoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, di-n- propyldimethoxysilane, diisobutyldimethoxysilane, diisobutyldiethoxysilane, isobutylisopropyldimethoxysilane, di-n-butyldimethoxysilane, cyclopentyltrimethoxysilane, isopropyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, ethyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, diethylaminotriethoxysilane, cyclopene tylpyrrolidinodimethoxysilane, bis(pyrrolidino)dimethoxysilane, bis(perhydroisoquinoline)dimethoxysilane and dimethyldimethoxysilane. In one embodiment, the silane-based composition is dicyclopentyldimethoxysilane (DCPDMS), methylcyclohexyldimethoxysilane (MChDMS), diisopropyldimethoxysilane (DIPDMS), n-propylmethoxysilane (NPTMS), diethylaminotriethoxysilane (DATES) or n-propyltriethoxysilane (PTES), and any combination thereof.

In one embodiment, the external donor may be a mixture of at least 2 alkoxysilanes. In a further embodiment, the mixture may contain dicyclopentyldimethoxysilane and methylcyclohexyldimethoxysilane, dicyclopentyldimethoxysilane and tetraethoxysilane, or dicyclopentyldimethoxysilane and n-propyltriethoxysilane.

In one embodiment, the external electron donor is selected from one or more of a benzoate and/or a diol ester. In another embodiment, the external electron donor is 2,2,6,6-tetramethylpiperidine. In yet another embodiment, the external electron donor is a diester.

In one embodiment, the catalyst composition includes an activity limiting agent (ALA). As used herein, the term "activity limiting agent" (ALA) refers to a material that reduces the activity of a catalyst at elevated temperature (ie, above about 85°C). ALA inhibits or otherwise prevents disruption of the polymerization reactor and ensures the continuity of the polymerization process. As a rule, with an increase in the reaction temperature, the activity of Ziegler-Natta catalysts increases. Ziegler-Natta catalysts also generally retain high activity near the softening point temperature of the resulting polymer. The heat generated during the exothermic polymerization reaction can cause the formation of agglomerates of polymer particles and, ultimately, disrupt the continuity of the polymer production process. ALA reduces catalyst activity at elevated temperatures, thereby preventing reactor disturbances, reduces (or prevents) particle agglomeration, and ensures continuity of the polymerization process.

The activity limiting agent may be a carboxylic acid ester, a diester, a poly(alkene glycol), a poly(alkene glycol ester), a diol ester, and combinations thereof. The carboxylic acid ether may be an aliphatic or aromatic mono- or polycarboxylic acid ether. Non-limiting examples of suitable monocarboxylic acid esters include ethyl and methyl benzoate, ethyl p-methoxybenzoate, methyl p-ethoxybenzoate, ethyl p-ethoxybenzoate, ethyl acrylate, methyl methacrylate, ethyl acetate, ethyl p-chlorobenzoate, hexyl p- aminobenzoate, isopropylnaphthenate, n-amyltoluate, ethylcyclohexanoate and propyl pivalate.

In one embodiment, an external electron donor and/or an activity limiting agent can be added to the reactor separately. In another embodiment, the external electron donor and the activity limiting agent may be premixed and then added to the reactor as a mixture. More than one external electron donor or more than one activity limiting agent can be used in the mixture. In one embodiment, the mixture is a mixture of dicyclopentyldimethoxysilane and isopropyl myristate, dicyclopentyldimethoxysilane and poly(ethylene glycol) laurate, dicyclopentyldimethoxysilane and isopropyl myristate with poly(ethylene glycol)dioleate, methylcyclohexyldimethoxysilane and isopropyl myristate, n-propyltrimethoxysilane and isopropyl myristate, dimethyldimethoxysilane and methylcyclohexyldimethoxysil ana with isopropyl myristate, dicyclopentyldimethoxysilane and n- propyltriethoxysilane with isopropyl myristate, dicyclopentyldimethoxysilane and tetraethoxysilane with isopropyl myristate; and combinations thereof.

In one embodiment, the catalyst composition includes any of the aforementioned external electron donors in combination with any of the aforementioned activity limiting agents.

In accordance with the present invention, once a polypropylene random copolymer has been prepared, the copolymer is combined with a property-improving agent in accordance with the present invention to improve toughness, flexural modulus, or both. For example, in one embodiment, the property-improving agent increases the toughness of the polymer composition by at least about 10%, such as at least 20%, such as at least 30%, such as at least 40%, and substantially less than about 200%. In an alternative embodiment, a property enhancing agent may be incorporated into the polymer composition such that the flexural modulus is increased by about 10%, such as at least about 20%, such as at least about 30%, such as at least about 40%, such as at least about 50%, and substantially less than about 200%.

The polymer composition according to the present invention can be used for the production of various products and articles. The polymer composition, for example, can be used for the extrusion of various products, such as pipeline structures.

For example, in FIG. 1 shows one embodiment of a conduit structure 10 that may be made in accordance with the present invention. As illustrated, the pipeline structure 10 includes a wall 12 made from a polymeric composition according to the present invention. Wall 12 forms a hollow inner channel 14. In the embodiment shown in FIG. 1, the conduit structure 10 includes a first opening 16 opposite the second opening 18. In addition, the conduit structure 10 includes an opening 20. The conduit structure 10 shown in FIG. 1 has a T-shape.

However, it should be understood that various types of piping structures can be manufactured in accordance with the present invention, including line pipes, curved pipes such as elbow pipes, pipe fittings, and the like.

The present invention can be better understood with reference to the following example.

Example

The following example demonstrates the improvement in the physical properties of polymer compositions made in accordance with the present invention, compared with the properties of polymer compositions that do not contain a property improving agent.

A random copolymer of polypropylene and ethylene was polymerized in a reactor using a non-phthalate catalyst as described above. The polymerization was carried out using a single reactor to produce a monomodal propylene random copolymer.

Received samples of polymer granules, which were introduced into the samples by injection molding. An additive package containing pentaerythritoltetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) was added to the polymer in an amount of 3000 ppm; tris(2,4-ditert-butylphenyl)phosphite 1500 ppm; calcium stearate in the amount of 300 hours/million; and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene at 3000 ppm. Samples were made in accordance with ASTM test D4101 to obtain specimens for bending and Izod impact tests.

Samples #1-8 below did not contain any enhancement agent. On the other hand, samples No. 9 and 10 contained 500 ppm N,N'-dicyclohexylnaphthalene-2,6-dicarboxamide. Sample #11 contained 900 ppm sodium benzoate. Sample #12 contained 500 ppm 4-cyclohexene-1,2-dicarboxylic acid metal salt, sample #13 contained 1000 ppm 4-cyclohexene-1,2-dicarboxylic acid metal salt, sample #14 contained 500 ppm ./million metal salt of 4-cyclohexene-1,2-dicarboxylic acid, sample No. 15 contained 1000 ppm metal salt of 4-cyclohexene-1,2-dicarboxylic acid, sample No. 16 contained 1200 ppm sodium benzoate, and Sample No. 17 contained 1500 ppm sodium benzoate. Sample #18 contained 250 ppm 2,2'-methylene-bis-(4,6-di-tert-butylphenyl) sodium phosphate and sample #19 contained 500 ppm 2,2'-methylene-bis -(4,6-di-tert-butylphenyl) sodium phosphate. Sample #20 contained 1800 ppm 1.3:2,4-bis(3,4-dimethylbenzylidene) sorbitol, sample #21 contained 800 ppm 1.3:2,4-bis(3,4- dimethylbenzylidene) sorbitol, sample #22 contained 1300 ppm 1.3:2,4-bis(3,4-dimethylbenzylidene) sorbitol, and sample #23 contained 1800 ppm 1.3:2,4-bis (3,4-dimethylbenzylidene) sorbitol.

Samples No. 11, 16 and 17 did not contain calcium stearate. Compound characteristics such as flexural modulus, impact strength, and tensile strength at yield strength were tested.

As shown in the table below, the ethylene content of the polypropylene random copolymer was varied. Essentially, the ethylene content of Samples No. 1 and 2 was equal to the ethylene content of Samples Nos. 10, 12, and 13. Essentially, the ethylene content of Sample No. 4 was equal to the ethylene content of Sample No. 9. Samples Nos. 14 and 15 contained ethylene in an amount of about 3%. Essentially, the remaining samples contained ethylene in an amount of 3.3% by weight to 4.5% by weight.

The following results were obtained.

Table 1

Sample No. MFR, g/min Et, % XS, % Modulus of elasticity in bending, MPa N. according to Izod at room temperature, J/m Tensile strength at yield strength, MPa 1 0.19 1.9 3.9 1162 114 34 2 0.16 1.99 4.4 1123 89 33 3 0.20 2.84 6.0 942 102 34 4 0.23 3.5 6.4 846 190 28 5 0.27 4.04 11.7 793 273 26 6 0.30 3.82 9.7 813 205 26 7 0.22 3.99 11.7 735 320 26 8 0.25 3.37 7.14 845 137 28 9 0.23 3.5 6.4 875 738 28 10 0.19 2.0 3.9 1182 686 33 eleven 0.20 4.44 11.0 686 730 25 12 0.16 2.07 4.4 1091 748 31 13 0.16 2.14 4.4 1089 751 thirty 14 0.19 3.00 6.0 900 730 28 15 0.22 3.02 6.0 908 732 28 16 0.20 4.53 11.0 685 726 25 17 0.20 4.54 11.0 695 715 25 18 0.20 4.36 11.8 683 717 24 19 0.20 4.43 12.8 686 738 25 20 0.26 3.53 7.14 899 544 29 21 0.19 4.35 10.5 694 721 25 22 0.19 4.41 10.5 691 740 25 23 0.20 4.47 10.5 707 755 25

The thermophysical properties of polymer samples nos. 1, 2, 3, 5, 9, 10, 12, 13, 14, and 15 were also tested. The following results were obtained.

Table 2. Results of the thermophysical properties test (DSC-HCH)

Sample No. Tc,°C Tm - form α, °C Tm - form β, °C HCH, ^2nd heating, β% 1 107 146 N/A N/A 2 106 147 N/A N/A 3 101 142 N/A N/A 5 105 140 N/A N/A 9 109 141 129 41 10 116 148 136 39 12 112 152 136 72 13 112 152 136 73 14 108 146 132 72 15 108 147 132 73

As shown above, the addition of a property-improving agent significantly increases the toughness of the polymer composition and does not adversely affect the flexural modulus.

These and other modifications and variations of the present invention may be made by those skilled in the art without departing from the spirit and scope of the present invention, which are more specifically set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be fully or partially interchangeable. Moreover, those skilled in the art will appreciate that the above description is by way of example only and is not intended to limit the invention, which is further described in the appended claims.

Claims (22)

1. Polypropylene polymer composition intended for the production of pipe structures for hot and cold water supply, containing: (a) a polypropylene random copolymer comprising: propylene as the primary monomer; the proportion of ethylene (ET) from 1 to 5% by weight, determined by ¹³ C NMR; and the melt flow rate, measured in accordance with ASTM D 1238 at 230°C and with a load of 2.16 kg, is from more than 0.01 g/10 min to 2 g/10 min; And (b) a property-improving agent, wherein the property-improving agent is present in the composition in an amount sufficient to increase the impact strength or flexural modulus of the composition, and wherein the composition exhibits notched Izod impact strength at 23°C from 400 to 900 J/ ^m2 measured in accordance with ASTM D 256 (2018) and a flexural modulus of 650 to 1200 MPa determined in accordance with Method A of ASTM D790-10 using a type 1 specimen in accordance with ASTM 3641 cast in accordance with ASTM D4101 at 1.3 mm/min; wherein said property-improving agent comprises: a phosphate ester salt, sodium benzoate, dibenzyl sorbitol, a dicarboxylic acid metal salt, or mixtures thereof; or 2,2'-methylene-bis-(4,6-di-tert-butylphenyl) sodium phosphate, dibenzylidene sorbitol, 4-cyclohexene-1,2-dicarboxylic acid metal salt or mixtures thereof; or N,N'-dicyclohexylnaphthalene-2,6-dicarboxamide, 6-quinaziranesulfonic acid metal salt, o-phthalic acid disodium salt, isophthalic acid, terephthalic acid, or a combination of an organic dibasic acid and a Group II metal oxide, hydroxide or acid; or a combination of pimelic acid and calcium stearate; wherein said composition contains a xylene soluble fraction (XS) in an amount of 2 to 14% as determined by the xylene soluble fraction gravimetric method according to ASTM D5492-98 using a 90 minute settling time; And wherein said polypropylene random copolymer is monomodal. 2. Polypropylene polymer composition according to claim 1, characterized in that the property-improving agent contains a phosphate ester salt, sodium benzoate, dibenzyl sorbitol, a carboxylic acid metal salt, or mixtures thereof, and the polymer composition has a melt flow rate of 0.01 g/10 min. to less than 0.5 g/10 min, an ethylene content of 3.3 to 4.5% by weight, and a notched Izod impact strength at 23°C of more than 500 to 900 J/m ² . 3. Polypropylene polymer composition according to claim 1, characterized in that the property-improving agent contains N,N'-dicyclohexylnaphthalene-2,6-dicarboxamide, metal salt of 6-quinaziranesulfonic acid, disodium salt of o-phthalic acid, isophthalic acid, terephthalic acid or a combination of an organic dibasic acid and an oxide, hydroxide or acid of a Group II metal; or the property enhancing agent comprises a combination of pimelic acid and calcium stearate; and the polymer composition has a melt flow rate of 0.15 g/10 min to 2 g/10 min, has an ethylene content of 1 to 3.5% by weight, has a flexural modulus in the range of more than 800 to 1200 MPa, and has impact strength according to Izod at 23°C from more than 600 to 900 J/m ² . 4. A polypropylene polymer composition according to any one of the preceding claims, characterized in that the property enhancing agent is present in the polymer composition in an amount of from 100 to 5000 ppm. 5. Polypropylene polymer composition according to any one of the preceding claims, characterized in that the polypropylene random copolymer is present in the polymer composition in an amount of more than 70% by weight, for example in an amount of more than 80% by weight, for example in an amount of more than 90% by weight, for example in more than 95% by weight. 6. A polypropylene polymer composition according to any one of the preceding claims, characterized in that the polypropylene random copolymer is catalyzed using a Ziegler-Natta catalyst. 7. Polypropylene polymer composition according to claim 6, characterized in that the polypropylene random copolymer is catalyzed in the presence of an internal electron donor containing a non-phthalate substituted phenylene aromatic diester. 8. Polypropylene polymer composition according to claim 1, characterized in that the property-improving agent contains a phosphate ester salt, sodium benzoate, dibenzyl sorbitol, a carboxylic acid metal salt, or mixtures thereof, and the composition contains a second property-improving agent, wherein the second property-improving agent contains stearate metal, hydrotalcite or talc. 9. A conduit structure having a length and defining a first opening at one end and a second opening at the opposite end, the conduit structure forming a hollow channel therebetween, the conduit structure being molded from the polypropylene resin composition of any one of the preceding claims. 10. The design of the pipeline according to claim 9, characterized in that the design of the pipeline was molded by extrusion.

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