RU2799447C2 - Antacids for polymers - Google Patents

Abstract

FIELD: polymers.

SUBSTANCE: invention relates to antacids and to a method of their use, as well as to improved polymer compositions containing antacids, and products formed from the polymer composition. A method of neutralizing acidic impurities in a polymer comprises bringing the polymer into contact with an amount of amorphous sodium magnesium aluminosilicate, the said polymer being a polyolefin, and the said amount of amorphous sodium magnesium aluminosilicate in the polymer ranging from about 0.005 wt. % to about 2.0 wt. % polymer. The invention also relates to a method of reducing the corrosivity of a polymer, as well as to a polymer composition having reduced corrosivity and to an article made from a polymer composition with reduced corrosivity.

EFFECT: improving properties, such as reduced corrosion activity and improved color stability, as well as improved transparency and excellent stability of the melt flow rate (MFR) in polymer compositions, such as polyolefin polymer compositions, in which amorphous aluminum silicate is used as an antacid.

27 cl, 4 tbl, 11 ex

Description

Scope of the invention

The present invention relates to antacids and their method of use. The invention also relates to improved polymer compositions containing antacids and products formed from the polymer composition.

Prerequisites for the creation of the invention

Polyolefins, such as polypropylene, have gained wide acceptance in numerous commercial applications due to their versatility, desirable properties such as excellent mechanical properties and clarity, and overall low manufacturing costs. In many industries, especially in the packaging industry, these polypropylene materials are used in a variety of processes such as extrusion, thermoforming, injection molding or blow molding to create a variety of finished products.

The process for producing polyolefins (eg, polyethylene and polypropylene) often includes a highly active polymerization catalyst, such as a Ziegler catalyst, to obtain a polymer with acceptable properties without the need for extraction to remove residual catalyst. Catalyst residues that remain in the polymer are generally acidic and can lead to problems in the processing of polyolefins. For example, the presence of an acidic material (eg, in the form of hydrogen chloride) can corrode metal surfaces of polymer processing equipment such as extruders or injection molding equipment.

In addition to the aforementioned problems associated with the polymer, the acid residue can also lead to problems with products made from polymers. For example, molded products made from polymers may also be subject to discoloration or damage. Films made from acid-containing polymers may have poor transparency.

To avoid or minimize such detrimental effects on the polymer and products made from it, it is common to add an antacid agent to the polymer during the manufacturing process to neutralize any acidic residues. One of the antacid agents used commercially in the manufacture and processing of polymers, in particular polyolefin polymers and products, is calcium stearate. Generally, calcium stearate or stearic acid (CA) as a neutralization product of acidic residues can migrate to the polymer surface and cause the polymer surface to become sticky or greasy. This material can also lead to the formation of smoke when spinning the fiber. Moreover, the migration of stearic acid can lead to water transfer in applications such as raffia and films.

Another type of antacid that is commercially used to process or manufacture polyolefins is hydrotalcite. (See, for example, US patent No. 4,347,353). However, these materials are generally more expensive than calcium stearate and often increase haze in applications that require a high degree of transparency, such as biaxially oriented polypropylene (BOPP) films, resulting in a less attractive film.

Other well-known antacids include crystalline zeolites and zinc oxides. US Pat. No. 5,510,413 discloses the inclusion of a minor proportion of a synthetic basic crystalline zeolite as an acid scavenger to neutralize or effectively remove the acidic components of unstabilized polymers. US Pat. No. 4,251,407 discloses the use of zinc oxide as an acid scavenger in polypropylene.

There is a need in the polymer industry for improved antacid compositions that are economical and prevent or reduce the problems described herein associated with antacids currently used in the processing and production of polymers.

Brief summary of the invention

The present invention satisfies the industry's need for new antacids to neutralize acidic impurities in the polymer. In particular, it has been found that the use of amorphous aluminum silicates as an antacid minimizes the adverse effects of acidic residues generated during polymer processing. It has surprisingly been found that polymer compositions such as polyolefin polymer compositions using amorphous aluminum silicate as the antacid have improved properties such as reduced corrosiveness and improved color stability as well as improved clarity and excellent melt flow rate (MFR) stability. ).

Accordingly, in one example of the present invention, there is provided an acid containing polymeric composition having improved corrosiveness, color stability, and transparency properties. The polymer composition may contain a polymer containing acidic impurities and an acid-neutralizing amount of amorphous aluminum silicate. In one embodiment, the polymer is a polyolefin.

In one embodiment, the invention provides a polymer containing acidic impurities having a corrosivity index below 6 and good color stability. In another embodiment, the refractive index of the amorphous aluminum silicate may be the same or substantially the same as the refractive index of the polymer.

In another embodiment, the present invention also provides a process for preparing the polymer compositions of the invention. As such, the process may include introducing into the polymer containing the acidic impurities an acid-neutralizing amount of amorphous aluminum silicate. In another embodiment, the process may include incorporating enough amorphous aluminum silicate to bring the polymer corrosion index below 6.

These and other features and advantages of the present invention will become apparent upon consideration of the following detailed description of the disclosed embodiments of the invention and the appended claims.

Detailed description

The present disclosure will be described in more detail with reference to embodiments so that those skilled in the art can better understand the technical solutions of the present disclosure.

The following terms used in the present description and the appended claims have the following definitions.

As used herein, the term "amorphous" means a material or materials in solid forms that are non-crystalline or lack the long-range order characteristic of a crystal. Typically, in x-ray diffraction, amorphous solids scatter x-rays in many directions, resulting in large bumps distributed over a wide range, rather than narrower peaks of high intensity, as is the case with crystalline solids.

A numerical value followed by the term "approximately" in this document means that the numerical value may vary by 10%.

As used herein, the term "corrosivity index" refers to a measure of the ability of a composition to cause corrosion or rust on a metal surface and is measured by the method described herein below in the examples.

As used herein, the term "neutralizing amount" is used to refer to the amount of amorphous antacid sufficient to neutralize all or substantially all of the acidic residues in the polymer. In this document, the term "essentially all" is used to indicate more than 85%, preferably more than 90% of all acidic residues in the polymer.

As used herein, the term "polyolefin" includes a propylene-based polymer, an ethylene-based polymer, a copolymer of at least one α-olefin with a diene, or a mixture thereof.

As used herein, the term "propylene-based polymer", also referred to as "polypropylene", includes a propylene homopolymer, a propylene copolymer, or a mixture thereof.

The process of the present invention is a method for neutralizing acid in a polymer. The process may include bringing the polymer into contact with a neutralizing amount of amorphous aluminum silicate. The process may also include obtaining an amount of amorphous aluminum silicate sufficient to provide the desired corrosivity index. The polymer may be a polyolefin.

In one embodiment, the polyolefin is a propylene-based polymer. Propylene-based polymers that can be used in the present invention include, for example, propylene homopolymer. Alternatively, the propylene-based polymer may be a propylene copolymer. Such a propylene copolymer may be a propylene random copolymer. The propylene copolymer may be a copolymer of propylene and at least one α-olefin. The α-olefin may have from 2 to 10 carbon atoms. In one embodiment, the α-olefin may be at least one selected from the group consisting of ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 4-methyl-1-pentene. Examples of comonomers used in the production of the propylene/α-olefin copolymer are C2-C10 α-olefins; for example α-olefins C2, C4, C6 and C8. Alternatively, such propylene copolymer may be a heterophasic propylene polymer. The heterophasic propylene polymer may, for example, contain a matrix phase and at least one discontinuous phase. The matrix phase of the heterophasic propylene polymer may, for example, contain a propylene-based polymer, such as a propylene homopolymer or a propylene copolymer. The propylene copolymer can be, for example, a polypropylene (PP) impact copolymer with an ethylene-propylene rubber phase or a PP impact copolymer with an α-olefin rubber phase.

In another embodiment, the polyolefin is an ethylene-based polymer. Ethylene-based polymers that can be used in the present invention include ethylene homopolymers such as, for example, high density polyethylene (HDPE). Alternatively, the ethylene-based polymer may be an ethylene copolymer such as, for example, high density polyethylene (HDPE), medium density polyethylene (MDPE) or linear low density polyethylene (LLDPE). The ethylene copolymer may be a copolymer of ethylene and at least one α-olefin. The α-olefin may have from 3 to 10 carbon atoms. In one embodiment, the α-olefin may be at least one selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 4-methyl-1-pentene.

In another embodiment, the polyolefin is a copolymer of at least one α-olefin with a diene. The α-olefin copolymer may have no more than 20 carbon atoms. For example, α-olefin comonomers may preferably have 3 to 10 carbon atoms, and more preferably 3 to 8 carbon atoms. Examples of α-olefin comonomers include, without limitation, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 4-methyl-1-pentene.

This document is not limited to a specific method for manufacturing a polyolefin. The polymer may suitably be made in a gas phase process. Alternatively, the polymer may be made in a liquid phase or slurry process. The polymerization may be carried out continuously, semi-continuously, or in batches, and the polymerization system may contain other materials, such as molecular hydrogen, known in the art.

This document is not limited to a specific method of bringing the polymer into contact with the desired amount of amorphous aluminum silicate. In one embodiment, the polymer can be mixed with amorphous aluminum silicate to form a homogeneous or heterogeneous mixture of polymer. In a preferred process, the amorphous aluminum silicate/polymer mixture can be mixed using an extruder or high shear mixer.

Amorphous aluminum silicates, also known as aluminosilicates used in the present invention, are chemical compounds that are obtained from alumina (Al ₂ O ₃ ) and silicon dioxide (SiO ₂ ). The amorphous aluminum silicate may be an amorphous alkali metal/alkaline earth metal aluminosilicate further containing an alkali metal and an alkaline earth metal. The alkali metal may be selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, francium, and mixtures thereof. In one embodiment, the alkali metal is sodium.

The amorphous alkali metal/alkaline earth metal aluminosilicate may also contain at least an alkaline earth metal selected from the group consisting of beryllium, magnesium, calcium, strontium, barium, radium, and mixtures thereof. In one embodiment, the alkaline earth metal is magnesium.

In a preferred embodiment, the amorphous alkali metal/alkaline earth metal aluminosilicate is an amorphous sodium magnesium aluminosilicate. The content of magnesium (in the form of magnesium oxide (MgO)) in the aluminosilicate may vary depending on the number of acid groups in the polymer to be neutralized. In one embodiment, the content of magnesium oxide is in the range from about 0.5% wt. up to about 10% wt. from the total content of amorphous sodium-magnesium aluminosilicate. In a preferred embodiment, the content of magnesium oxide is in the range from 1.0% wt. up to about 9.0% wt. from the total content of amorphous sodium-magnesium aluminosilicate. In the most preferred embodiment, the content of magnesium oxide is in the range from 1.5% wt. up to about 8.0% wt. from the total content of amorphous sodium-magnesium aluminosilicate.

As a rule, amorphous aluminum silicates have an average particle size in the range from about 0.2 microns to about 10.0 microns, preferably from about 0.5 microns to 5 microns. The amorphous aluminum silicate may have a pH in the range of 7.0 to 13.0, preferably in the range of 8.0 to 12.0, and more preferably in the range of 9.0 to 11.0.

In one embodiment, the refractive index of the amorphous aluminum silicate may be the same or substantially the same as the refractive index of the polymer. As used herein, the term "substantially the same" means that the absolute difference between the two refractive indices is equal to or less than 1.5% of the refractive index of the polymer. Preferably, the absolute difference between the two refractive indices is equal to or less than 1.0% of the refractive index of the polymer.

Amorphous aluminum silicate can be obtained using any standard tool. For example, an amorphous aluminum silicate such as sodium magnesium aluminum silicate can be obtained by a precipitation process using sodium silicate, aluminum chloride or sodium aluminate, magnesium chloride and a mineral acid such as sulfuric acid, in preparation processes similar to those described in GB 925001, US 3798046, US 3909286, US 4339421 or EP 07001534.

The amorphous aluminum silicate is added or mixed with the polymer containing the acid impurities in an acid-neutralizing amount. In one embodiment, the amount of amorphous alkali metal/alkaline earth metal aluminosilicate included in the polymer can range from about 0.005 wt. up to about 2.0% wt. polymer, preferably in the range from about 0.010% wt. up to about 1.0% wt. polymer and more preferably in the range from about 0.015% wt. up to about 0.8% wt. polymer.

In another embodiment, the amount of amorphous alkali metal/alkaline earth metal aluminosilicate included in the polymer may be sufficient to reduce the corrosion index of the polymer to below 6, preferably to below 3, and more preferably to below 1.

In addition to the amorphous aluminum silicate antacid, the polymeric compositions of the invention may include additional components, including other polymeric components, as well as ingredients or additives conventionally used in the art for various purposes in polymeric compositions, such as dyes, pigments, fillers. , antioxidants, secondary antioxidants, antistatic agents, slip agents (e.g. erucamide), foundry process lubricants, nucleating agents (both polymeric and non-polymeric), UV stabilizers, release agents, flame retardants, etc. Typically, these additional components will be used in conventional amounts depending on the intended use of the polymer composition.

This document is not limited to a specific method of introducing amorphous aluminum silicate and optional additional components into the polymer. In the present invention, any conventional methods of mixing the polymer with amorphous aluminum silicate can be used. In one embodiment, the polymer is mixed with a neutralizing amount of amorphous aluminum silicate to form a homogeneous or non-uniform mixture of polymer and amorphous aluminum silicate by means of a high shear extruder or mixer. In one embodiment, the polymer is mixed with amorphous aluminum silicate in the molten state. In another embodiment, a mixture of polymer and amorphous aluminum silicate is heated to melt the polymer. After that, the molten mixture is stirred, as described above in this document, with the formation of a homogeneous or heterogeneous mixture. In yet another embodiment, the polymer and amorphous aluminum silicate can be dissolved in a suitable solvent to form a solution or dispersion, which can then be molded and dried to form a polymer composition.

The polymer compositions of the invention have improved properties such as corrosiveness, color stability and transparency. Surprisingly, the polymer compositions have been found to have increased corrosiveness, as evidenced by a Corrosivity Index below 6, preferably below 3, and more preferably below 1. The polymer composition also exhibits increased transparency. Typically, the transparency of the resin composition is at least about 60%, preferably at least about 65%, as measured on an injection molded (IM) plate having a thickness of about 1 mm. Details on measuring the transparency of the polymer composition are further provided below in the examples.

The polymeric compositions of the invention can be processed to obtain a variety of products traditionally made from polymers. Such products may include, for example, articles such as films, fibers, molded articles, extruded profiles, sheets, boards, adhesives, foams, cable covers, or other finished parts. Articles made from the resin composition can be produced according to conventional means such as extrusion, blow molding, solution casting or injection molding. In one embodiment, the product is a film or fiber.

Products made using polymer/antacid compositions in accordance with the present invention contain less acidic residues that can be harmful to process equipment. Moreover, articles requiring transparent resin compositions exhibit improved transparency.

Descriptions of various embodiments of the present invention have been presented for purposes of illustration, but are not exhaustive and are not limited to the disclosed embodiments. Those of ordinary skill in the art will appreciate that many modifications and variations are possible without departing from the scope and spirit of the described embodiments. The terminology used in this document has been chosen to best explain the principles of embodiments, practical applications, or technical improvements over technologies present in the market, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein. .

Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to the following examples.

EXAMPLES

The following examples describe the present invention with the inclusion of amorphous aluminosilicate antacids and some other types of antacid materials in polypropylene, test methods and comparison results. These examples are provided for illustrative purposes only and do not limit the scope of the present invention.

materials

A 2.9 mg/10 min (ASTM D-1238) polypropylene homopolymer powder sample (as measured) was made on a Grace UNIPOL® PP pilot plant with a CONSISTA® catalyst.

Irganox® 1010 primary antioxidant and Irgafos® 168 secondary antioxidant were purchased from BASF. In all examples below, concentrations of 500 ppm for Irganox® 1010 and 750 ppm for Irgafos® 168 were used. CaSt (calcium stearate) from Faci (Jurong Island, Singapore) and magnesium aluminum hydroxide carbonate (hydrate) from Kyowa (Japan). Amorphous Calcium Ion Exchange Silica (Calcium Ion Exchange Silica Gel) from W.R. Grace. Crystalline sodium aluminosilicates 1 and 2 (zeolite) were commercial crystalline sodium aluminosilicate particles with different pore diameters (4 Å and 8 Å, respectively) supplied by W.R. Grace. Amorphous sodium magnesium aluminosilicates were prepared as described below.

Typically, the amount of antacid used in all samples was either 180 ppm or 300 ppm, as described in the examples below.

Table 1. Physical properties of antacid supplements Material type Refractive index (difference from main volume PP) median
particle size
(µm) Square
surfaces
(m ² /g) Pore volume
(cm ³ /g) pH calcium stearate n/a n/a n/a n/a n/a magnesium aluminum hydroxide carbonate 1.525 (0.020) 0.5 eleven n/a 9.5 Amorphous calcium ion exchange silica 1.440 (0.065) 3.0 < 100 < 0.4 9.5 Crystalline sodium aluminosilicate 1 1.450 (0.055) 4.0 N/A ~ 0.3 10.5 Crystalline sodium aluminosilicate 2 1.450 (0.055) 8.0 N/A ~ 0.3 10.5 Amorphous sodium-magnesium aluminosilicate, sample 1 1.495 (0.010) 5.5 80 ~ 0.3 11.0

Obtaining amorphous sodium-magnesium aluminosilicate

Samples 1-6 of amorphous sodium magnesium aluminosilicate with different Mg content were prepared as follows. The precipitation process was initiated by adding an aqueous solution of aluminum sulfate and magnesium chloride (preset ratios with the desired content of Mg) to a solution of sodium silicate (0.8% SiO ₂ ) with vigorous stirring to reduce the pH of the solution to 8.9 at 84°C for 5 minutes. After 5 minutes, the aluminum sulfate/magnesium chloride solution and the sodium silicate solution were added simultaneously in such a ratio to the solution that the pH of the solution remained at approximately 8.9 during the addition. The total reaction time was approximately 74 minutes. After the addition was completed, the precipitated particles were filtered and washed with deionized water 5 times, after which they were dried at 120°C overnight and ground to the desired particle size using a jet mill, or a vortex mill, or a small analytical mill.

Determination of Mg Content in Amorphous Sodium Magnesium Aluminosilicate Using Inductively Coupled Plasma (ICP)

Approximately 0.5 g of aluminosilicate particles were added to a Teflon digestion tube with an inner diameter of 47 mm and a height of 214 mm. As an internal standard, 1 ml of a 40 ppm cobalt salt solution was added to the aluminosilicate. 25 ml of 60% HClO ₄ , 5 ml of 69% HNO ₃ , 3 ml of 37% HCl and 12 ml of 48% HF were added to the container. The mixture was placed on a thermostat and digestion was performed at 550 F for 90 minutes. The remaining solution was then diluted to 250 ml with deionized water. The cooled sample was analyzed on a Spectro Arcos II instrument.

Titration of amorphous sodium-magnesium aluminosilicate in water

3 grams of amorphous sodium magnesium aluminosilicates were suspended in 40 ml of water and the suspension was titrated to pH 6.0 with 0.1 M HCl. The volumes of HCl consumed were recorded.

Table 2 shows the amount of MgO and titrated volumes of HCl for samples 1-6 of amorphous sodium magnesium aluminosilicate, as described above.

table 2 Sample number MgO content (%) Amount used 0.1 n. HCl (ml) 1 2.00 20.1 2 1.92 21.4 3 3.35 24.8 4 4.24 23.3 5 4.75 34.2 6 5.37 38.4

As shown in Table 2, the volume of HCl titration is proportional to the amount of MgO in the form of composition in the samples.

Nitrogen Pore Volume and Particle Size Measurement

The volume of nitrogen in the pores for aluminosilicate or other particles was measured using an Autosorb® iQ analyzer supplied by Quantachrome Instrument (Boyton Beach, FL, USA). Nitrogen adsorption and desorption isotherms were measured at 77 K with nitrogen pressure increasing from 0.01% atmosphere to 0.998% atmosphere and then decreasing from 0.998% atmosphere to 0.025% atmosphere, respectively. Pore volumes were calculated using AsiQwin™ version 5.0 software based on BJH theory. See, for example, Barrett et al., The Determination of Pore Volume and Area Distributions in Porous Substances. I. Computations from Nitrogen Isotherms, J. Am. Chem. Soc., 1951, 73 (1), pp 373-380, the subject matter of which is incorporated herein by reference in its entirety.

The particle sizes indicated in the examples were determined by light scattering using a Malvern Mastersizer 2000 or 3000, supplied by Malvern Instruments Ltd., in accordance with ASTM B822-10.

Process and test methods

Polymer extrusion and extrusion conditions

A 2.9 mg/10 min sample (ASTM D-1238) as measured was extruded with antacid additives in the amounts shown in the examples below.

The sample formulations were dry-tumbed and then pelletized on a W&P 28 mm twin screw extruder with a high energy screw configuration. The extruder was run at a speed of 300 rpm with a temperature profile of 210-220-235-235°C (from the feed funnel to the mold) with the filament fed from the mold into the water mass at a temperature of 50°C, and then into the granulating installation. The feed port was in N ₂ medium. The pellets produced at this stage were considered a zero extruder run and were used for MFR, corrosiveness, clarity and yellowness index (YI) tests.

Each of the formulations was then (re)extruded three more times on a W&P 28mm twin screw extruder under the same conditions as described above.

Measurement of melt flow rate (MFR) and yellowness index (YI)

MFR was measured in accordance with ASTM D1238 using a Tinius Olsen Melt Indexer MP993 (for PP, tests were performed with 2.16 kg at 230°C). The yellowness indices of all pellets were measured on a Hunter Lab Scan XE benchtop spectrophotometer in accordance with ASTM D6290. Reflection index (RI) measurement

Accurate RIs were measured according to ASTM C1648 using the Becke stripe method on a Nikon phase contrast microscope in dark field mode. RI matched fluids were purchased from Cargille Laboratories (Cedar Grove, 07009, NJ, USA). The refractive index of the polypropylene film was measured to be 1.505. This value was used as the refractive index of the bulk material.

Corrosion test

The ability of antacids to inhibit corrosion was measured on carbon steel plates (soft iron sheet: 5 cm x 5 cm 0.07 cm thick) using the following procedures.

Carbon steel plates were polished with pumice powder with a brass brush to reveal a fresh surface. The surface area of the plates was calculated based on the dimensions of the plates and thus SA = 5 x 5 x 2 + 0.07 x 5 x 4. The resulting pellets were placed in aluminum crucibles and kept in an oven at 230°C. Then these freshly polished steel plates were placed in a polymer melt (230°C) and left for four hours. After that, the plates were removed from the polymer melt and the polymer was wiped from the surface of the plate. Then the plates were weighed (m ₀ , initial weight), after which they were kept in a humidity chamber at a relative humidity of ~ 75% and room temperature for one week. After one week, the plates were removed from the chamber and carefully weighed (m ₁ , mass after corrosion). The corrosivity index was calculated according to Equation 1.

Уравнение 1Corrosivity index (CI) =

Equation 1

As can be seen from the equation, the closer the corrosivity index is to 0, the less corrosion.

Transparency measurement

Plates of various thicknesses were made on an Arburg Allrounder 221k 28 Ton injection molding machine with a 25 mm diameter cylinder. The injection molding machine was used with an injection speed of 13.8 mm/s. The cylinder temperature was set to 260°C (nozzle). A single-stage injection profile was used and the molding temperature was set to 40°C (±2°C). The back pressure was set to 0 bar. Table 3 lists the cycle times set for the molding process.

Table 3. Injection molding parameters setting injection delay 0.3 s injection 3.0-4.0 s Excerpt 6.0 s Cooling 12.0 s Form opening ~ 5.0 s

After molding, the plates were conditioned for 72 hours at 23°C ± 2°C and 50 ± 10% relative humidity and tested for clarity according to ASTM D1746 on a BYK Gardner Haze-Gard Plus 4725 instrument.

Example 1

The above polypropylene was mixed and extruded with sample 1 of amorphous sodium magnesium aluminosilicate 180 ppm.

Example 2

The above described polypropylene was mixed and extruded with Sample 1 of 300 ppm amorphous sodium magnesium aluminosilicate.

Comparative Example 1

The above described polypropylene was mixed and extruded without any antacid additive.

Comparative Example 2

The above polypropylene was blended and extruded with 300 ppm calcium stearate.

Comparative Example 3

The above described polypropylene was mixed and extruded with magnesium-aluminum hydroxide-carbonate 180 ppm.

Comparative Example 4

The above described polypropylene was mixed and extruded with 180 ppm amorphous calcium ion exchange silica.

Comparative Example 5

The above described polypropylene was mixed and extruded with 300 ppm amorphous calcium ion exchange silica.

Comparative Example 6

The above polypropylene was mixed and extruded with 1180 ppm crystalline sodium aluminosilicate.

Comparative Example 7

The above described polypropylene was mixed and extruded with 1300 ppm crystalline sodium aluminosilicate.

Comparative Example 8

The above described polypropylene was mixed and extruded with 2,180 ppm crystalline sodium aluminosilicate.

Comparative Example 9

The above described polypropylene was mixed and extruded with 2,300 ppm crystalline sodium aluminosilicate.

The test results for all examples (Ex. 1 and Ex. 2) and comparative examples (SP1-SP9) are shown in the following table 4.

Table 4. Test results

Etc. 1 Etc. 2 SP1 SP2 SP3 SP4 SP5 SP6 SP7 SP8 SP9 Corrosivity index, g/m ² 1.7 0.0 6.4 0.1 0.0 4.1 2.6 0.8 0.0 1.8 0.1 Transparency of a chip 1 mm thick, % 64 67 28 41 55 31 31 35 34 41 39 Transparency of a chip with a thickness of 1.6 mm, % 47 50 16 27 36 18 18 21 20 24 23 MFR (granule), zero run, g/10 min 3.4 3.7 3.6 3.3 3.2 3.6 3.4 3.3 3.5 4.0 3.6 MFR (granule), 1st run, g/10 min 4.3 4.4 4.3 3.8 4.0 4.2 4.1 3.9 4.0 4.7 4.2 MFR (granule), 3rd run, g/10 min 5.7 5.8 5.9 4.9 5.3 5.6 5.6 5.1 5.5 6.6 5.3 YI (granule), zero run 4.6 5.1 4.3 0.4 4.1 6.3 7.9 12.3 13.4 2.2 3.8 YI (granule), 1st run 7.7 7.8 9.9 3.5 9.7 10.9 11.1 19.5 21.1 5.6 7.2 YI (granule), 3rd run 12.1 11.6 15.4 7.5 11.2 15.9 15.0 26.3 29.7 9.2 11.2

As shown in Table 4, it was unexpectedly found that polyolefin compositions containing amorphous magnesium aluminosilicates have significantly improved clarity and excellent MFR and color stability, as well as reduced corrosiveness compared to the unstabilized system and systems stabilized with other types of antacids.

Claims (71)

1. The method of neutralizing acidic impurities in the polymer, including bringing the polymer into contact with the amount of amorphous sodium-magnesium aluminosilicate, and the specified polymer is a polyolefin; and the specified amount of amorphous sodium magnesium aluminosilicate in the polymer is in the range from about 0.005% wt. up to about 2.0% wt. polymer. 2. The method of claim 1, wherein the polyolefin is a propylene-based polymer, an ethylene-based polymer, a copolymer of at least one α-olefin with a diene, or a mixture thereof. 3. The method of claim 2, wherein the propylene-based polymer is a propylene homopolymer, a propylene copolymer, or a mixture thereof, wherein the propylene copolymer is preferably a propylene random copolymer, or moreover, the propylene copolymer is preferably a copolymer of propylene and at least one α-olefin, while the α-olefin has from 2 to 10 carbon atoms, and the α-olefin is preferably at least one selected from the group consisting of ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 4-methyl-1-pentene, or moreover, the propylene copolymer is a heterophasic propylene polymer, while the heterophasic propylene polymer contains a matrix phase and at least one dispersed phase, and the matrix phase of the heterophasic propylene polymer preferably contains a propylene homopolymer or a propylene copolymer. 4. The method of claim 2, wherein the ethylene-based polymer is an ethylene homopolymer, an ethylene copolymer, or a mixture thereof, wherein the ethylene copolymer is preferably a copolymer of ethylene and at least one α-olefin, wherein the α-olefin has from 3 to 10 carbon atoms, wherein the α-olefin is preferably at least one selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 4-methyl-1-pentene, or wherein the ethylene-based polymer is high density polyethylene (HDPE) or linear low density polyethylene (LLDPE). 5. The method of claim 2, wherein the polyolefin is a copolymer of at least one α-olefin with a diene, wherein the α-olefin has no more than 20 carbon atoms. 6. The method according to p. 1, in which the amorphous sodium magnesium aluminosilicate contains magnesium oxide in an amount of 0.5% wt. up to about 10% wt. from the total content of amorphous sodium-magnesium aluminosilicate. 7. The method of claim 1 or 6, wherein the amorphous sodium magnesium alumina silicate has an average particle size in the range of about 0.5 microns to about 10.0 microns, or wherein the amorphous sodium magnesium aluminum silicate has a pH in the range of 7, 0 to 13.0. 8. The method according to claim 1 or 6, wherein the amount of amorphous sodium magnesium aluminosilicate in the polymer is an amount sufficient to provide a corrosivity index of the polymer below 6, while the corrosivity index is obtained by: (a) placing freshly polished steel plates in the specified polymer at 230°C for four hours; (b) removing the polymer from said plates before weighing the plates to obtain a first mass m ₀ ; (c) maintaining said plates at approximately 75% relative humidity for one week before re-weighing the plates to obtain a second mass m ₁ ; And (d) calculating the corrosiveness index according to Equation 1:

where SA is the surface area of the plates. 9. The method according to p. 6, in which the amount of amorphous sodium-magnesium aluminosilicate in the polymer is in the range from about 0.010% wt. up to about 1.0% wt. polymer, preferably from about 0.015% wt. up to about 0.8% wt. polymer. 10. A method for reducing the corrosivity of a polymer containing acidic impurities, including: introducing into the polymer an amount of amorphous sodium-magnesium aluminosilicate sufficient to obtain a polymer composition having a corrosiveness index below 6, while the corrosivity index is obtained by: (a) placing freshly polished steel plates in the specified polymer at 230°C for four hours; (b) removing the polymer from said plates before weighing the plates to obtain a first mass m ₀ ; (c) maintaining said plates at approximately 75% relative humidity for one week before re-weighing the plates to obtain a second mass m ₁ ; And (d) calculating the corrosiveness index according to Equation 1:

where SA is the surface area of the plates; wherein said polymer is a polyolefin. 11. The method of claim 10, wherein the polyolefin is a propylene-based polymer, an ethylene-based polymer, a copolymer of at least one α-olefin with a diene, or a mixture thereof. 12. The method of claim 11, wherein the propylene-based polymer is a propylene homopolymer, a propylene copolymer, or a mixture thereof, wherein the propylene copolymer is preferably a propylene random copolymer, or moreover, the propylene copolymer is a copolymer of propylene and at least one α-olefin, while the α-olefin has from 2 to 10 carbon atoms, and the α-olefin is preferably at least one selected from the group consisting of ethylene, 1 -butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 4-methyl-1-pentene, or moreover, the propylene copolymer is a heterophasic propylene polymer, while the heterophasic propylene polymer contains a matrix phase and at least one dispersed phase, and the matrix phase of the heterophasic propylene polymer preferably contains a propylene homopolymer or a propylene copolymer. 13. The method of claim 11, wherein the ethylene-based polymer is an ethylene homopolymer, an ethylene copolymer, or a mixture thereof, wherein the ethylene copolymer is preferably a copolymer of ethylene and at least one α-olefin, wherein the α-olefin has from 3 to 10 carbon atoms, wherein the α-olefin is preferably at least one selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 4-methyl-1-pentene, or wherein the ethylene-based polymer is high density polyethylene (HDPE) or linear low density polyethylene (LLDPE). 14. The method of claim 11, wherein the polyolefin is a copolymer of at least one α-olefin with a diene, wherein the α-olefin has no more than 20 carbon atoms. 15. The method according to p. 10, in which the amorphous sodium-magnesium aluminosilicate contains magnesium oxide in an amount of 0.5% wt. up to about 10% wt. from the total content of amorphous sodium-magnesium aluminosilicate. 16. The method of claim 10 or 15, wherein the amorphous sodium magnesium alumina silicate has an average particle size in the range of about 0.5 microns to about 10.0 microns, or wherein the amorphous sodium magnesium aluminum silicate has a pH in the range of 7, 0 to 13.0. 17. The method of claim 15, wherein the amount of amorphous sodium magnesium aluminum silicate in the polymer is an amount sufficient to provide a corrosion index of the polymer below 1, or wherein the amount of amorphous sodium magnesium aluminum silicate in the polymer is in the range of about 0.005% wt. up to about 2.0% wt. polymer, or in which the amount of amorphous sodium-magnesium aluminosilicate in the polymer is in the range from about 0.010% wt. up to about 1.0% wt. polymer, or in which the amount of amorphous sodium magnesium aluminosilicate in the polymer is in the range from about 0.015% wt. up to about 0.5% wt. polymer. 18. The method of claim 10, wherein the transparency of the resin composition is at least about 60% as measured in accordance with ASTM D1746 on an injection molded (IM) plate having a thickness of about 1 mm. 19. A polymer composition having a reduced corrosiveness intended for the manufacture of a product made from a polyolefin containing a polyolefin containing acidic impurities and an amount of amorphous sodium magnesium aluminosilicate, and the specified amount of amorphous sodium magnesium aluminosilicate in the polymer composition is in the range from about 0.010 % wt. up to about 1.0% wt. polyolefin, and moreover, the specified polymer composition has a corrosivity index below 6, while the corrosivity index is obtained by: (a) placing freshly polished steel plates in the specified polymer at 230°C for four hours; (b) removing the polymer from said plates before weighing the plates to obtain a first mass m ₀ ; (c) maintaining said plates at about 75% relative humidity for one week before re-weighing the plates to obtain a second mass m ₁ ; And (d) calculating the corrosiveness index according to Equation 1:

where SA is the surface area of the plates. 20. The polymer composition of claim 19, wherein the polyolefin is a propylene-based polymer, an ethylene-based polymer, a copolymer of at least one α-olefin with a diene, or a mixture thereof. 21. The polymer composition according to claim 20, in which the propylene-based polymer is a propylene homopolymer, a propylene copolymer, or a mixture thereof, wherein the propylene copolymer is preferably a propylene random copolymer, or wherein the propylene copolymer is preferably a copolymer of propylene and at least one α-olefin, wherein the α-olefin has from 2 to 10 carbon atoms, and wherein the α-olefin is preferably at least one selected from the group consisting of ethylene , 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 4-methyl-1-pentene, or moreover, the propylene copolymer is a heterophasic propylene polymer, while the heterophasic propylene polymer contains a matrix phase and at least one dispersed phase, and the matrix phase of the heterophasic propylene polymer preferably contains a propylene homopolymer or a propylene copolymer. 22. The polymer composition according to claim 20, in which the ethylene-based polymer is an ethylene homopolymer, an ethylene copolymer, or a mixture thereof, wherein the ethylene copolymer is preferably a copolymer of ethylene and at least one α-olefin, wherein the α-olefin has from 3 to 10 carbon atoms, wherein the α-olefin is preferably at least one selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 4-methyl-1-pentene, or wherein the ethylene-based polymer is high density polyethylene (HDPE) or linear low density polyethylene (LLDPE). 23. The polymer composition of claim 20, wherein the polyolefin is a copolymer of at least one α-olefin with a diene, wherein the α-olefin has no more than 20 carbon atoms. 24. The polymer composition of claim 19, wherein the amorphous sodium magnesium aluminum silicate has an average particle size in the range of about 0.5 microns to about 10.0 microns, or wherein the amorphous sodium magnesium aluminum silicate has a pH in the range of 7.0 up to 13.0. 25. The polymer composition according to claim 19, in which the amount of amorphous sodium-magnesium aluminum silicate in the polyolefin is in the range from about 0.015% wt. up to about 0.5% wt. polyolefin. 26. The polymer composition of claim 19, wherein the transparency of the polymer composition is at least about 60% as measured in accordance with ASTM D1746 on an injection molded (IM) plate having a thickness of about 1 mm. 27. A product made from a polymer composition according to claim 19, which is a film.