CZ2000710A3 - Modification process of polymer rheology that are prepared by employing metallocenes - Google Patents

Abstract

A method of modifying the rheology of polymers consists in preparation of the coupled polymer by heating the mixture, comprising: (1) (at least one ethylene-containing polyolefin and at least one) a comonomer selected from alpha-olefins having at least 3 carbon atoms, dienes and (2) at least one coupling amount Poly (sulfonylazide), wherein the polyolefin is a product polymerizing ethylene and at least one other alpha-olefin in the presence of a single site catalyst 'Containing a transition metal, such as V or Cr, metallocene.

Description

Method for modification of rheology of polymers prepared by metallocenes

Technical field

The invention relates to a process for the coupling of polyolefins, in particular to the coupling of polyolefins by insertion into carbon and hydrogen bonds (C-H).

BACKGROUND OF THE INVENTION

As used herein, the term rheology modification refers to a change in polymer melt viscosity as determined by dynamic mechanical spectroscopy. Preferably, the melt strength increases while maintaining a high shear viscosity (i.e., viscosity measured at a shear of 100 rad / sec by DMS) so that the polymer exhibits higher elongation resistance during drawing of the molten polymer under low shear conditions (i.e., shear viscosity 0.1). rad (sec using DMS) and does not lose properties under high shear conditions.

Polyolefins are often rheologically modified by non-selective free-radical chemistry generated, for example, by peroxides or high energy radiation. However, chemical processes using free radical formation at elevated temperatures also reduce the molecular weight, particularly for tertiary hydrogen containing polymers such as polystyrene, polypropylene, polyethylene copolymers, etc. The reaction of polypropylene with pentaerythritol peroxides and triacrylate is described in Wang et al. col. in Journal of Applied

Polymer Science, vol. 61, 1395-1404 (1996). It is reported that branching of isotactic polypropylene can be accomplished by grafting the free radicals of the divinyl and trivinyl compounds onto the polypropylene. In practice, however, this mechanism is not going well because the higher chain cleavage rate tends to outweigh the ongoing limited chain linking range. This occurs because chain cleavage is an intramolecular process with first order kinetics, while branching is an intermolecular process with at least second order kinetics. Chain cleavage results in a lower molecular weight and a higher melt flow rate than would be observed if the chain joining was not accompanied by cleavage. Since the cleavage is not uniform, the molecular weight distribution increases because lesser molecular weight polymer chains, referred to in the art as heels, are formed.

U.S. Pat.

US 3,058,944, 3,336,268 and 3,530,108 describe the reactions of some of the (sulfonylazide) compounds with isotactic polypropylene or other polyolefins by inserting nitrene into C-H bonds. The product disclosed in U.S. Patent 3,058,944 is cross-linked. The product disclosed in U.S. Pat. No. 3,530,108 is foamed and cured by a cycloalkane disulfonylazide of the above formula. In U.S. Pat. No. 3,336,268, the resulting reaction products are referred to as bridged polymers because the polymer chains are bridged by sulfonamide bridges. The described process includes a mixing step such as grinding or mixing the poles (sulfonylazide) with the polymer in solution or dispersion, then a heating step where a sufficient temperature is used to decompose the poles (sulfonylazide) u (100 ° C to 225 ° C depending on

azide decomposition temperature). The starting polypropylene polymer for the protected process has a molecular weight of at least

275 000. Mixtures disclosed in United States Patent

No. 3,336,268 have up to 25 percent ethylene propylene elastomer.

U.S. Patent 3,631,282 discloses the use of azide formate for crosslinking polyolefins.

U.S. Patent No. 3,341,418 discloses the use of sulfonylazide compounds and azide formate for crosslinking certain thermoplastics (PP (polypropylene), PS (polystyrene), PVC (polyvinyl chloride)) and mixtures thereof with certain rubbers (polyisobutene, EPDM (ethylene propylene diene rubber) )).

Similarly, Canadian Patent No. 797,917 (part of the family of inventions NL 6,503,188) describes a method of modifying rheology with 0.001-0.075% by weight of poly (sulfonylazide) to modify polyethylene homopolymers and mixtures thereof with polyisobutylene. It would be desirable to obtain polymers with modified rheology rather than crosslinked (i.e., containing less than 10 percent of the gel, as determined by xylene extraction according to ASTM 2765). Such polymers are preferably produced using single-site catalysts, preferably single-site single site metallocenes or single-site single site catalysts with constrained geometry and thus preferably with a narrow molecular weight distribution (MWD = Mw / Mn, where Mw is by weight average molecular weight and Mn is a number average molecular weight) (i.e., those having MWDs preferably less than or equal to 3.0, more preferably less than 2.5 Mw / Mn). Surprising results are particularly evident when the starting material is high polyethylene

Density (density greater than 0.945 g / ml) (hereinafter referred to as narrow MWD HDPE), where these polymers preferably exhibit a combination of good processability, as shown by higher strength melt at a constant low shear viscosity, for example 0.1 rad / sec as measured by DMS, and higher toughness and tensile elongation than high density polyethylene with a broader molecular weight distribution treated with sulfonylazides according to the prior art method using the same equivalents (stoichiometrically) and a higher toughness than the toughness of the same starting material coupled or rheologically modified using the same equivalents of the free radical coupling agent. The product should suitably have better organoleptic properties than coupled HDPE with a broader MWD. The compositions should preferably have less undesirable odor than the same starting materials coupled or rheologically modified using the same chemical equivalents of free radical generating agents. Advantageously, the process of the invention will result in more consistent coupling than the free radical coupling methods, i.e., the use of the same reagents, amounts and conditions will result in a consistent range of coupling or consistent (reproducible) changes in properties, in particular a consistent amount of gel formation. This process should preferably be less exposed to oxygen than the coupling or rheology modification process using free radical generating agents.

In the case of medium or low density polyethylene (i.e., polymers having a density of from 0.94 g / cm ³ to about 0.90 g / cm ³ ), which are preferably ethylene copolymers in which the percentage of comonomers is preferably 0.5 to 5 moles % comonomers based on total polymer, determined

· · ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **

By the method of ASTM 5017, polymers should preferably exhibit a combination of improved processability over the parent material while maintaining toughness, low initial melting point, low haze, high gloss and hot tack, i.e., the characteristics of the parent material.

In the case of elastomeric polymers containing repeating ethylene units, in which a comonomer content of 5 to 25 mol% and a density of preferably less than 0.89 g / ml is preferred, it would be desirable to achieve improved mechanical properties such as elongation and tensile strength. tensile strength than would be achieved with starting material or couplings using the same chemical equivalents of a free radical generating agent, such as peroxide.

SUMMARY OF THE INVENTION

It has been found that polymers with narrow molecular weight distribution or formed by single site catalysts, in particular polyolefins, produced using transition metal catalysts other than Ziegler Natta catalysts, especially those where the molecular weight distribution is 3 or less, surprisingly, they effectively coupled using poly (sulfonylazide) coupling agents. The resulting coupled polymers have at least one of said desirable properties.

Accordingly, the present invention provides a process for preparing coupled polymers comprising heating a mixture comprising (1) at least one polyolefin containing ethylene and optionally at least one comonomer selected from the group consisting of:

A group of alpha-olefins containing at least 3 carbon atoms, dienes, and combinations thereof, said polyolefin having a molecular weight distribution of less than or equal to 3 and (2) a coupling amount of at least one poly (sulfonylazide) to at least a decomposition temperature of the polysulfonylazide for a time sufficient to decompose at least 80% by weight of poly (sulfonylazide) and sufficient to yield the coupled polymer; especially in cases where the polyolefin is the product of the polymerization of ethylene and optionally at least one other alpha-olefin in the presence of a single catalyst network (for example, a transition metal such as V or Cr, metallocene, or constrained geometry catalyst). The amount of poly (sulfonylazide) is preferably 0.01 to 5% by weight, based on the polyolefin.

The polysulfonylazide and polyolefin preferably react at a temperature at least equal to decomposition temperature and above 150 ° C. The present invention also encompasses all compositions made by the process of the invention and all articles made from the composition, as well as methods of making such articles, particularly by melt processing (particularly when the article is formed from the melt composition of the invention), more preferably casting, blow molding. and melt extrusion blow molding. The present invention also encompasses the use of a composition of the invention in any of these processes.

The process of the invention is applicable to any thermoplastic polymer obtained by single network polymerization having at least one CH bond that can react with an azide, including homopolymers and copolymers with narrow and broad comonomer distributions (including bimodal), such as ethylene copolymers with one alpha-olefin (containing 3 to 20 carbon atoms), or with more such alpha-olefins, ethylenically unsaturated copolymers (EPDM or EODM, i.

ethylene-propylene-diene, or ethylene-octene-diene), or other polymers such as high density linear polyethylene, styrene-based block copolymers (SBS, SEBS,

SIS, i.e. styrene / butadiene / styrene, styrene / ethylene / butylene / styrene (hydrogenated SEBS), styrene / isoprene / styrene), essentially statistical interpolymers of at least one alpha-olefin with at least one vinylidene aromatic or sterically hindered vinylidene aliphatic comonomer, including ethylene-styrene interpolymers, syndiotactic polystyrene, atactic polystyrene, and combinations thereof. These polymers are preferably prepared using single site catalysts and thus preferably have a narrow molecular weight distribution MWD = Mw / Mn, preferably less than or equal to 3, i.e. lower MWD than a polymer of the same composition and average molecular weight produced by the catalyst. Ziegler-Natta

The term bimodal as used herein refers to polymers having two peaks in a graphical representation of data obtained by analysis suitable to measure the properties discussed. For example, in the case of molecular weight, curves constructed on the basis of gel permeation chromatography (GPC) results are used to determine the molecular weight distribution. These distributions are considered statistical values, that is, they are statistical distributions. That is, if one peak is detected, then the distribution has one mode and is therefore a unimodal characteristic. Polymers having two

«9« 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9

9 99 99 or more modes are multimodal. In the case of molecular weight distribution, bimodal polymers are very often a mixture of two polymers with different number average molecular weights. This mixture is optionally made as a mixture obtained in one reactor or a mixture produced by passing a first polymer produced in a first reactor to a second reactor in which a second polymer is obtained. Bimodal polymers are illustrative of multimodal polymers in the disclosure. That is, when discussing polymers having bimodal characteristics, this discussion also applies analogously to multimodal types. It will be apparent to those skilled in the art that these peaks typically have overlapping regions, so that mathematical analysis is sometimes required to distinguish multimodal curves from a wide range of irregular curves.

According to the present invention, where preferred molecular weight distributions (MWDs) are reported, these distributions refer to the MWD of the at least one component, which is represented by a single peak on the GPC curve. Preferably, the component is a component that is made using a single site catalyst.

Preferred polymers to be used in practice are polymers prepared from ethylene, preferably ethylene in combination with other monomers polymerizable with ethylene.

Such monomers include alpha-olefins and other monomers having at least one double bond. The polymer is a polyolefin, optionally a homopolymer, copolymer or interpolymer. Preferably these homo- or copolymers contain ethylene repeating units. In the case of polyethylene copolymers, the comonomer content of the present invention is preferably greater than 1% by weight as determined by ¹³ C NMR, and more preferably greater than 3% by weight of any ethylene copolymerizable monomer. preferably an alpha-olefin or a cyclic olefin, preferably the olefin contains less than 20 carbon atoms, most preferably contains 2 to 18 carbon atoms. This proportion of comonomers comprises at least one ethylene polymerizable comonomer, preferably less than 4 ethylene polymerizable comonomers, more preferably less than 2 comonomers.

These ethylene polymers are optionally any interpolymers of ethylene and at least one α-olefin. Preferred α-olefins can be represented by the following general formula:

CH ₂ = CHR in which:

R represents a hydrocarbyl group.

The R substituent typically contains one to twenty carbon atoms. Suitable α-olefins to be used as comonomers for solution, gas or slurry polymerization processes, or for the combination thereof include 1-propylene, 1-butene, 1-isobutylene, 1-pentene,

1-hexene, 4-methyl-1-pentene, 1-heptene and 1-octene, as well as other monomeric types such as tetrafluoroethylene, vinylbenzocyclobutane and cycloalkenes such as cyclopentene; and 5-ethylidene-2-norbornene (ENB). Preferably, the α-olefin is

1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 14-heptene,

1-octene or ENB or mixtures thereof. More preferably, the α-olefin is

1-hexene, 1-heptene, 1-octene or mixtures thereof. Most preferably, the α-olefin is

1-okten. The rheological modification of the ethylene polymer made according to the present invention is according to a preferred embodiment of the SLEP type modification (see the description below for an explanation). These interpolymers preferably contain at least 2 weight percent α-olefin, and more preferably at least 5 weight percent α-olefin.

The interpolymers suitable for practical use of the present invention optionally and in one preferred embodiment comprise monomers comprising at least two double bonds, which are preferably dienes or trienes. Suitable diene and triene comonomers include, for example

7-methyl-1,6-octadiene, 3,7-dimethyl-1,6-octadiene,

5,7-dimethyl-1,6-octadiene,

3,7,11-trimethyl-1,6,10-octatriene, 6-methyl-1,5-heptadiene,

1,3-butadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, bicyclo [2,2,1] hepta-2,5- diene (norbornadiene), tetracyclododecene, or mixtures thereof, preferably butadiene, hexadiene and octadiene, most preferably 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl 1,4-hexadiene, dicyclopentadiene, bicyclo [2.2.1] hepta-2,5-diene (norbornadien) and 5-ethylidene-2-norbornene (ENB).

• ·

The polyolefins are prepared by means and methods known to those skilled in the art.

Said alpha-olefin monomers and optionally other polymerizable addition monomers are polymerized under conditions well known to those skilled in the art. These conditions include processes employing metallocene catalysts and other single site catalysts, examples of which catalysts and process conditions are found in U.S. Patent No. 4,937,299 to Ewen et al. 218,071 Tsutsui et al., 5,278,272, 5,324,800, 5,084,534, 5,405,922, 4,588,794, 5,204,419 and the conditions discussed in more detail below.

According to one embodiment of the invention, substantially linear ethylene polymers (SLEP) are preferably used as starting polyolefins. These substantially linear ethylene polymers (SLEPs) are homogeneous polymers having long chain branches. These substances are described in detail in U.S. Pat.

272 236 and 5 278 272. These SLEP polymers are available as polymers produced by Insite ™ Process and Catalyst Technology, such as Engage ™ polymeric elastomers (POEs) commercially available from DuPont Dow Elastomers LLC and Affinity ™ polyolefin plastomers (POP), which are commercially available from The Dow Chemical Company. Specific examples of suitable Engage ™ POE elastomers include polymers designated SM 8400, EG 8100, and CL 8001, and specific examples of suitable Affinity POP plastomers include FM-1570, HM 1100 and SM 1300, all of which are commercially available. by The Dow Chemical • 0 · 0 · 0 · ···· · 0 · ····

0 0 ·

00 ·

Company Corporation. These SLEP polymers can be prepared by solution polymerization, suspension polymerization, or gas phase polymerization, preferably solution polymerization wherein α-olefin comonomers are polymerized in the presence of a limited geometry catalyst, such as those described in the European patent 416 815-A.

These substantially linear ethylene / .alpha.-olefin polymers are produced by a continuous process using suitable constrained geometry catalysts, preferably using the constrained geometry catalysts of U.S. Patent Nos. 5,132,380 and U.S. Patent Application Ser. No. 545,403, filed Jul. 3, 1990. Also suitable for the production of the polymers of the present invention are monocyclopentadienyl transition metal catalysts which are used as olefin polymerization catalysts and are described in U.S. Patent No. 5,026,798, provided that using the specific reaction conditions detailed below.

Suitable cocatalysts to be used herein include, but are not limited to, polymeric or oligomeric aluminoxanes, especially methylaluminoxane, as well as inert compatible non-coordinating ion-forming compounds. Preferred cocatalysts are inert, non-coordinating boron compounds.

By continuous process is meant a process in which the reactants are continuously added to the process and the product is continuously withdrawn from the process so that an approximately equilibrium state is reached (i.e., substantially constant concentrations of the reactants and product during the process). . The polymerization conditions for preparing the substantially linear ethylene / α-olefin polymers of the present invention generally include those suitable for carrying out the solution polymerization process, but the application of the present invention is not limited to these conditions. A slurry or gas phase polymerization process may also be used in an appropriate manner provided that suitable catalysts and polymerization conditions are used.

Multiple reactor polymerization processes, such as those described in U.S. Pat. No. 5,401,516, may also be used to prepare substantially linear olefin polymers and copolymers to modify the rheological properties of the present invention.

3,914,342. These multi-reactor systems may be operated in series or in parallel arrangement, with at least one limited geometry catalyst being used in one of these reactors.

By substantially linear, it is meant that, in addition to the short chain branches which are a hallmark of incorporating a homogeneous comonomer, the ethylene polymer is further characterized by the long chain black branch, i.e., the polymer backbone being substituted. an average of 0.01 to 3 long chain branches per 1000 carbon atoms. Ve. Preferably, the substantially linear polymers used in the present invention are substituted with 0.01 in.

I long chain branches per 1000 carbon atoms up to 1 long chain branches per 1000 carbon atoms and more preferably 0.05 long chain branches per 1000 carbon atoms

1000 carbon atoms up to 1 long chain branch per 1000 carbon atoms.

«..........................

In contrast to the term substantially linear, the term linear means that the polymer lacks a detectable fraction or a detectable fraction of long chain branches, that is, the polymer is substituted on average with less than 0.01 long chain branches per 1000 carbon atoms.

In the case of ethylene / α-olefin interpolymers, the term long chain branch (LCB) refers to a chain length longer than the short chain branch as a result of incorporating α-olefin (or olefins) into the polymer backbone. Each long chain branch has the same comonomer distribution as the polymer backbone (polymer backbone), and may be as long as the polymer backbone to which the branch is attached.

The empirical effect of the presence of long chain branches in the substantially linear ethylene / α-olefin interpolymers used in the present invention results in improved rheological properties that are quantified and expressed by gas extrusion rheometry (GER) results, wherein the ratio of melt index Ijo / 2 ^{and excit} mouth.

The presence of short chain branches up to 6 carbon atoms in length can be determined for ethylene polymers using ¹³ C nuclear magnetic *.

«F f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f f • ·· fe ·· ·>

Resonance Spectroscopy (NMR), quantification using the method of Randall Rev. Macromol. Chem. Phys., C.29, V.2 & 3, pp. 285-297.

In practice, however, current ¹³ C nuclear magnetic resonance spectroscopy is unable to determine the length of long-chain branches having more than six carbon atoms. However, there are other known methods that are suitable for determining the presence of long chain branches in ethylene polymers, including ethylene / 1-octene interpolymers. Two of these methods are gel permeation chromatography coupled with narrow band laser scattering detector (GPC-LALLS) and gel permeation chromatography coupled with differential viscometer / detector (GPC-DV).

The use of these methods for the determination of long chain branches and the related theoretical processing is well documented in the prior art literature. for example, Zimm, G.H, and Stockmayer, W.H., J. Chem.

Phys., 17, 1301 (1949) and Rudin A., Modern Methods of Polymer Characterization, John Wiley & Sons, New York (1991), pp. 103-112.

At the Federation of Analytical Chemistry and Spectroscopes Society (FACSS) Louis, Missouri,

On October 4, 1994, A. Willem deGrot and P. Steve Chum, both employees of The Dow Chemical Company, presented data demonstrating that the GPC-DV method is a suitable method for quantifying the presence of long chain branches in SLEP polymers. In particular, deGroot and Chum found that the level of long chain branches in homogeneous SLEP samples, as determined by the Zimm-Stockmayer equation, was well in agreement with the level of the t branches

Long-chain detection by ¹³ C NMR.

Furthermore, deGroot and Chem have found that the presence of octene does not cause a change in the hydrodynamic volume of the polyethylene samples in the solution, and thus the molecular weight increase caused by short chain octene branches can be calculated based on the mole percent of octene in that sample. By solving this relationship, the contribution to the increase in molecular weight can be attributed

Short chain 1-octene branches, deGroot and Chum have shown that the GPC-DV method can be used to quantify the level of long chain branches in substantially linear ethylene / octene copolymers.

It was also confirmed by deGroot and Chum that the plot of Log (I ₂ , melt flow index) as a function of Log (Mw) determined by GPC illustrates that aspects of the long chain branches (but not the long chain branch range) of SLEP polymers they are comparable to high pressure, high branched low density polyethylene (LDPE) and these aspects are quite different from those of ethylene polymers produced using Ziegler-type catalysts, such as titanium complexes and conventional catalysts for preparing homogeneous polymers such as hafnium-based complexes; vanadium.

SLEP polymers are further characterized by having the following characteristics:

(a) a melt flow index ratio of 5.63; (b) the molecular weight distribution, M _w / M _n , as determined by gel permeation chromatography, is defined by:

• j · · · »• · ·· · I ·, ···· (Mw / Mn) ^<(I I0 / ^I 2) 4.63, (c) a critical shear stress at onset of gross melt fracture, as determined by gas extrusion rheometry greater than 4 x 10 ⁶ dynes / cm ² , or gas extrusion rheology results such that the critical shear rate at the onset of surface melt fracture for SLEP polymers is at least 50 percent greater than the critical shear rate at the beginning surface melt fracture for linear ethylene polymers, wherein the linear ethylene polymer has an I ₂ , Mw / Mn value and preferably a density within the range of ten percent SLEP, and corresponding critical shear rates of the SLEP polymer and linear ethylene polymers are measured at the same melting point using a gas extrusion rheometer, and further preferably (d) a single melting peak determined by differential scanning calorimetry ( DSC) ranging from -30 to 150 ° C.

In the case of the substantially linear ethylene / α-olefin polymers used in the composition of the present invention, the ratio of I ₀ / I ₂ indicates the degree of range of the long chain branches, i.e. the higher this ratio ^Ι 1θ / ^Ι 2 ^{t ni v} ^ ^ce of long chain branching present in the polymer. Generally, this ratio Iio / _I2 ^{in the} case of these substantially linear ethylene / a-olefin polymers at least 5.63, preferably at least 7 according to the invention, particularly preferably at least 8 or higher, which value can be up to 25th

Melt flow index (measured according to ASTM D-1238 (190 ° C / 2.16 kilogram weight)) for substantially linear olefin polymers suitable for use in *

• ♦ /

The present invention is preferably at least 0.1 grams / 10 minutes (g / 10 minutes), more preferably at least 0.5 g / 10 minutes, and particularly preferably is at least 1 gram / 10 minutes, with values preferably up to 100 grams / 10 minutes, even more preferably values up to grams / 10 minutes, and particularly preferably values up to 20 grams / 10 minutes.

Determination of the critical shear rate and critical shear stress in relation to the melt fracture, as well as other rheological properties, such as rheological processing index (P1), is performed using a gas extrusion rheometer (GER). The method and apparatus of gas extrusion rheometry are described in: M. Shida,

R.N. Shroff and L.V. Cancio: Polymer Engineering Science

Vol. 17, No. 11, p. 770 (1977), and in:

Rheometers for Molten Plastics, John Dealy, publication by Van Nostrand Reinhold Co. (1982) on pages 97-99. The GER measurement procedure is carried out at 190 ° C and at a nitrogen pressure in the range of 1723.7 kPa to 37922.5 kPa (i.e. 250 psig to 5500 psig), using a nozzle with a diameter of 0.0754 millimeters, with an L ratio. / D 20: 1 and 180 ° inlet angle.

For the SLEP polymers of the present invention, P1 is the apparent viscosity (in kpoise) of the material measured by the GER method at an apparent shear stress of 2.15 χ 10 ⁶ dynes / cm ² . SLEP polymers used in the present invention include ethylene interpolymers having a PI in the range of 1 Pa.s to 5000 Pa.s (0.01 kpoise to 50 Kpoises), preferably 1500 Pa.s (15 Pa.s). kpoise) or smaller. Further, the SLEP polymers used in the present invention have a P1 value of less than or equal to 70 percent of the P1 value of a linear ethylene polymer (i.e. either e).

9 ·· · ·. !

a polymer obtained by Ziegler polymerization or linear uniformly branched polymers, as described, for example, in U.S. Patent 3,645,992, the author of which is incorporated herein by reference.

Elston) having I ₂ , M 2 / M 2 and density values all within the range of ten percent of the values for the SLEP polymer.

The rheological behavior of SLEP can also be characterized by the Dow Rheology Index (DRI), which expresses a normalized relaxation interval as a result of the presence of long chain branches in the polymer (see, for example, S. Lai and GW Knight Antec '93 Proceedings, INSITE ™ Technology Polyolefins (SLEP) - New Rules in the Structure / Rheology Relationship of Ethylene α-Olefin Copolymers, New Orleans, La., May 1993). DRI values range from 0 for polymers that do not have a measurable presence of long chain branches (such as Tafmer ™ products available from Mitsui Petrochemical Industries and Exact ™ products available from Exxon Chemical Company) to up to about 15, and these values are independent of the melt index. In general, for low to medium pressure ethylene polymers (especially low density products), DRI values provide better correlations with melt elasticity and high shear flow compared to the relationship with the same characteristics that the melt flow index attempts. . In the case of the SLEP polymer used in the present invention, the DRI value is preferably at least 0.1, and in particular is at least 0.5, most preferably at least 0.8. This DRI can be calculated according to:

t • ·

DRI = (3652879 * Τθ ¹ · ^θ0649 / ϊ} _θ - 1) / 10 in which:

τθ characteristic relaxation time of the material, and ^ 0 is zero shear viscosity of the material.

Both τθ and are the best fit values for

Cross equation, which is as follows:

T) / i) _Q = 1 / (1 + γ * τθ) ¹ “ ¹¹ in which:

n is the material force index, and

i) and γ are the measured viscosity and shear rate values.

The determination of viscosity and shear rate values based on baseline values can be performed using a Rheometric Mechanical Spectrometer RMS-800, with a dynamic modem of 0.1 to 100 radians / second at 190 ° C, and using a gas extrusion rheometer (GER, Gas Extrusion Rheometer), at an extrusion pressure in the range of 6.89 MPa to 34.5 MPa (or 1000 psi to 5000 psi), which correspond to a shear stress of 0.086 to 0.43 MPa using a nozzle with a diameter 0.0754 millimeter with a 1 / D value of 20: 1 at 190 ° C. Particular measurements can be made at a temperature in the range of 140 to 190 ° C, depending on the requirement to adapt to changes in melt index values. . .

The melt refraction phenomenon of ethylene polymers is used to identify the dependence of apparent shear and apparent shear rate and to quantify critical shear rate and critical shear. According to Ramamurthy, Journal of Rheology, 30 (2).

337-357, 1986, above a certain critical flow rate value, the observed extrudate irregularities can roughly be classified into two main types: surface melt fracture and coarse melt fracture.

The surface melt fracture occurs under seemingly stable flow conditions and is reflected in detail from the loss of the film's shine to a more intense sharkskin-like form. In the description of the present invention, the onset of surface melt fracture (OSMF) as determined by the GER method described above is characterized by an initial melt gloss loss at which the surface roughness of the extrudate can only be determined at 40 times magnification. The critical shear rate at the beginning of the surface melt fracture of a SLEP polymer is at least 50 percent greater than the critical shear rate at the beginning of the surface melt fracture of a linear ethylene polymer having substantially the same value

I ₂ a

Coarse melt fracture occurs under unstable extrusion flow conditions, and this phenomenon manifests in details from regular deformations (alternating rough and smooth surface, spiral deformations) to random deformations. In terms of commercial acceptability, and making it easier to utilize the functional properties of films, coatings and moldings to the maximum extent, surface defects should be minimized or even completely eliminated. The critical shear stress value at the beginning of the coarse melt fracture for SLEP polymers, especially for polymers having a density of > 0.910 g / cm ³ , used according to the present invention is greater than 4 χ 10 ⁶ dynes / cm ² . Critical shear rate at the beginning of the surface melt fracture (OSMF) and at «> · · · · * · · · ♦

The beginning of the coarse melt fracture (OGMF) as used herein is based on changes in surface roughness and configuration of extrudates extruded by the GER method.

The SLEP polymers used in the present invention are also characterized by one DSC melting peak. This single melting peak is determined using a differential scanning calorimetric method standardized with indium and deionized water. This method employs samples of 3 to 7 milligrams, first heated to about 180 ° C for 4 minutes, then cooling at 10 ° C / minute to -30 ° C. in which the sample is held for 3 minutes and then heated at a heating rate of 10 ° C / minute to a temperature of 140 ° C to effect a second heating. A single melting peak is obtained from the second heating from the heat-temperature curve. The total latent heat of fusion of this polymer is calculated from the area under this curve.

In the case of polymers having a density in the range of. O

0.875 g / cm to 0.910 g / cm ^J , this single melting peak exhibits a protrusion or bumps, depending on the sensitivity of the instrumentation used. on the underside of the melting, which represents less than 12 percent of the total latent heat of polymer melting, typically less than 9 percent of that latent heat of melting, and most commonly less than 6 percent of the total latent heat of melting of the polymer. This can be observed for other homogeneous branched polymers, such as Exact ™ polymers, and this phenomenon is discernible from the slope of this single peak. melting which occurs monotonically through the melting region. This phenomenon is 4 t · · <

it occurs at an interval of 34 ° C, usually at an interval of 27 ° C, and most commonly at an interval of 20 ° C, the melting point of this single melting peak. The latent heat of fusion corresponding to this phenomenon can be separately determined by the specific integration of its bonded area under the curve showing the dependence of heat flow on temperature.

The molecular weight distribution of ethylene / α-olefin polymers can be analyzed by gel permeation chromatography (GPC) on a Waters 150 ° C high-temperature chromatography unit equipped with a differential refractometer and three columns of mixed porosity. These columns are manufactured by Polymer Laboratories, typically using a pore size of ΙΟ ³ , ΙΟ ⁴ , 10 ^5, and 10 ⁶ ((10, 10 ^{4 4} , 10 ^-3 and 10 ² mm). The solvent used is 1,2,4-trichlorobenzene, and samples of 0.3 weight percent solutions are prepared for injection. The flow rate is 1.0 ml / min, the operating temperature of this unit is 140 C and the injection rate is 100 microliters.

The determination of the molecular weight with respect to the polymer backbone (polymer backbone) is derived from narrow (regular) polystyrene standards. molecular weight distributions (these standards are available from Polymer Laboratories) in combination with their elution volumes. The equivalent molecular weights of the polyethylenes are determined using appropriate

Mark-Houwink coefficients for polyethylene and polystyrene (the article by Williams and Ward in the Journal of Polymer Science, Polymer Letters,

Vol. 6, pp. 621 (1968), based on the equation:

^and polyethylene '(^ polystyrene in which:

a is 0.4316, and b is 1.0.

The mass average molecular weight M _w is calculated in the usual way by the equation:

Mj = (x (Wi x Μ _χ ^)) 3 in which:

is the mass fraction of molecules with molecular weight M ^ eluted from the GPC column in fraction i, aj = 1 in the calculation of aj = -1 in the calculation of M _n .

Density of linear or substantially linear ethylene polymers (measured by the standard method;

ASTM D-792) used in the present invention is typically less than 0.95 grams / cm. This density is preferably at least 0.85 grams / cm ³ and particularly preferably at least 0.86 grams / cm ³ , preferably up to 0.94 grams / cm ³ , even more preferably up to

0.92 grams / cm ³ . In the case of using these modified polymers for extrusion and injection, the density of the polymer used is preferably at least 0.855 grams / cm ³ , more preferably at least 0.965 grams / cm ^3, and even more preferably at least 0.840 grams / cm ³ , and this value The density in the case of the polymer thus used preferably ranges up to 0.900 grams / cm ³ , according to the invention. ·>

>> 5 * 3 ·) 3 «J? 7> 1 Ί -5 7>

Ί 3 -i j H 3> 5 l 1

·) ♦> · >> Ί 7 Ο ·> ·) «? 7 7 ti

J 7 7 7 3 3 5 ί

More preferably, up to 0.885 g / cm ³ and even more preferably up to 0.880 g / cm ³ .

The most preferred density is determined in particular by the modulus of elasticity or flexibility required for the molded article. This density remains substantially constant during the rheological modification of the present invention.

In another embodiment, preferred polymers used as starting materials in the practice of the present invention are high density slurry polymerized polyethylene homopolymers, preferably made using a single network (single position) catalyst, with a narrow MWD (molecular weight distribution), preferably less than 3, 0 Mw / Mn or equal to this value, even more preferably with a MWD of less than 2.5, most preferably with a density of greater than 0.945 grams / milliliter. The preferred melt index of the starting material depends on the desired application, but the preferred melt index for injection molding ranges from 0.5 to 50 grams / 10 minutes, for film making and thermoforming, the preferred melt index is in the range of 0.1 to 20 grams / 10 minutes, and in the case of blow molding, a preferred melt index is in the range of 0.01 to 20 grams / 10 minutes. These polymers have a good balance of mechanical properties and processability.

*. ». ·, 3» 'fr, VA,., *. · K · '- r

Most preferred polymers as starting materials for the present invention are narrow MWD ethylene copolymers (i.e., Mw / Mn less than 3, more preferably less than 3.0 and most preferably less than 2.5) . These polymers can be produced using at least one C 3 -C 20 olefin comonomer. Most preferably, the copolymer contains 3 to 10 carbon atoms. In the starting material, a comonomer content of 0.5 to 5 mole%, as determined by ASTM 5017, is preferred. Commercially available polymers of this category are known as Tafmer ™ polymers commercially available from Mitsui Petrochemical Industries, commercially available from Exxon Chemical Company, Affinity ™ polyolefin plastomers commercially available from The Dow Chemical Company, Engage ™ polyolefin elastomers commercially available from DuPont-Dow Elastomers . In the case of thermoplastic applications, such as foil and injection molding, most preferably the comonomer content is in the range of 3 to 25 weight percent. In the case of elastomeric applications, the preferred comonomer content is from 20 to 40 weight percent. The most preferred terpolymer is EPDM, such as the Nordel ™ ethylene / propylene / diene polymer, commercially available from DuPont-Dow Elastomers. Other highly suitable starting materials include polymers produced by the process described in International Patent Applications WO 97/43323 and WO 97/44371.

The melt flow index is measured according to the method of ASTM D-1238, condition 190 ° C / 2.16 kg (formerly known as condition E).

For modification of rheology or coupling, the polymer is reacted with a polyfunctional compound capable of insertion reaction into C-H bonds. Such polyfunctional compounds have at least two functional groups, preferably 2 functional groups. 9 9 9 9

9 9 9 9 9 9 9 9 9 9 99 99 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 Insertion reactions into C-H bonds and functional groups capable of such reactions are known to those skilled in the art. For example, carbenes formed from diazo compounds are exemplified by Mathur, N.C .; Snow, M.S .; Young, K.M. and Pincock, J.A; Tetrahedron, (1985), 41 (8), pp. 1509-1516, and nitrenes derived from azides, as described, for example, in Abramovitch, R.A .; Chellathurai, T .; Holcomb, W.D .; McMaster,

I.T and Vanderpool, D.P .; J.Org. Chem., (1977), (17), 2920-6, and Abramovitch, R.A., Knaus, G.N.,

J. Org.Chem. , (1975), 40 (17), 883-9.

Compounds having at least two sulfonylazide groups (-SO ₂ N ₃ ) capable of being inserted into a bond. CH, are referred to herein as coupling agents. For the purposes of the invention, a polysulfonylazide is any compound having at least two sulfonylazide groups capable of reacting with a polyolefin under reaction conditions. These polysulfonylazides preferably have the structure XRX, where each X is SO ₂ N ₃ and R represents an unsubstituted or inertly substituted hydrocarbyl, hydrocarbyl ether or silicon-containing group, preferably having sufficient carbon, oxygen or silicon, preferably carbon, atoms between functional groups. separating sulfonylazide groups that are sufficient to facilitate the reaction between the polyolefin and the sulfonylazide, preferably at least 1 carbon atom, more preferably at least 2, most preferably at least 3 carbon, oxygen or silicon atoms, preferably carbon. Although it is not critical for length R. boundary, each R between X preferably has at least one carbon or silicon atom and preferably has less than 50, more preferably less than 30, most preferably less than 20 carbon, oxygen or silicon atoms. Within these limits, a greater number is better due to: • 0. OQ - 0 0 0 0 0 · · 0 related to thermal and shock stability. When R is a straight chain alkyl hydrocarbon, less than 4 carbon atoms between the sulfonyl azide groups are preferred to reduce the tendency of the nitrene to bend and react.

Silicon containing groups include silane groups and siloxane groups, preferably siloxane groups. The term inertly substituted refers to substitution by atoms or groups that do not undesirably interfere with the desired reaction (s) or the desired properties of the resulting coupled polymers. If more than two polyolefin chains are to be joined, such groups include fluorine, aliphatic or aromatic ether groups, a siloxane group, and sulfonylazide groups. Suitable structures include R which represents an aryl group, an alkyl group, an arylalkaryl group, an arylalkylsilane group, a siloxane group or a heterocyclic group and other groups which are inert and separate the sulfonylazide groups as described. More preferably, R comprises at least one aryl group among sulfonyl groups, most preferably at least two aryl groups (for example when R is 4,4'-diphenyl ether or 4,4'-biphenyl). When R is one aryl group, it is preferred that the group has more than one ring, as in the case of naphthylenebis (sulfonylazides).

Poly (sulfonylazides) include such compounds as, for example, 1,5-pentane-bis (sulfonylazide), 1,8-octane-bis (sulfonylazide), 1, 10-decane-bis (sulfonylazide);

1,10-octadecane-bis (sulfonylazide), 1-octyl-2,4,6-benzenetris (sulfonylazide),

4,4'-diphenyl ether-bis (sulfonylazide),

1,6-bis (4'-sulfonazidophenyl) hexane

2.7- Naphthalene-bis (sulphonylazide) and mixed sulphonylazides of chlorinated aliphatic hydrocarbons, containing on average 0 · 0

0 «0

0 ·

From 0 to 8 chlorine atoms and from 2 to 5 sulfonylazide groups per molecule, and mixtures thereof. Preferred poly (sulfonylazides) include oxy-bis (4-sulfonylazidobenzene),

2,7-naphthalene-bis (sulfonylazide),

4,4´-bis (sulfonylazido) biphenyl,

4,4'-diphenyletherbis (sulfonylazide) and bis (4-sulfonylazidophenyl) methane and mixtures thereof.

The sulfonylazides are conveniently prepared by reacting sodium azide with the corresponding sulfonyl chloride, although oxidation of the sulfonylhydrazines with various reagents (nitrous acid, nitrogen dioxide, nitrosotetrafluoroborate) has been used.

Polyfunctional compounds capable of insertion into CH bonds also include carbene-forming compounds, such as alkylhydrazone and arylhydrazone salts and diazo compounds, and nitrile-forming compounds, such as alkylazides and arylazides (RN ₃ ), acylazides (RC (O) N ₃ ), azide formates (ROC (O) -N ₃ ), sulfonylazides (R-SO ₂ -N ₃ ), phosphorylazides ((RO) ₂ - (PO) -N ₃ ), phosphinazides (R ₂ -P (O) -N ₃ ) and silylazides (R ₃ -Si-N ₃ ). Some of the coupling agents of the invention are advantageous because of their tendency to produce a greater abundance of products by insertion into carbon-hydrogen bonds. Such compounds, such as hydrazone salts, diazo compounds, azide formates, sulfonylazides, phosphorylazides, and silylazides, are advantageous in that they form stable products with singlet electrons (carbenes and nitrenes) by means of which efficient carbon-hydrogen insertion reactions can be effected, rather rather than 1) switching mechanisms such as the Curtius rearrangement, as is the case with acylazides and phosphinazides, or 2) rapidly converting to a triplet electron configuration that preferentially undergoes reactions

4 4 4 4 4 4 4 4 4 ¹

444 4,444 4 · ·· ·

4 4 4 4 ·· 4444444 · · 4

4 4 4 · 4 ·· · ·

4 * 4 4 · 4 4 4 · · 4 hydrogen removal, as is the case with alkylazides and arylazides. It is also routinely possible to choose between preferred coupling agents because of the differences in temperatures at which different classes of coupling agents are converted to active carbene and nitrene products. For example, it is known to those skilled in the art that carbenes are formed from diazo compounds efficiently at temperatures below 100 ° C, while hydrazone, azide and sulfonylazide salts react at a suitable rate at temperatures above 100 ° C up to 200 ° C. (Appropriate rate is understood to mean that the compound reacts at a rate that is sufficiently fast to allow industrial processing, while reacting slowly enough to allow adequate mixing and mixing to achieve the end product with a sufficiently dispersed coupling agent, adequately dispersed and located substantially at the desired level. This localization and dispersion may vary between products depending on the desired properties of the end product). Phosphorylazides can react at temperatures above 180 ° C up to 300 ° C, while silylazides react preferentially at temperatures from 250 ° C to 400 ° C.

Polymers (sulfonylazide) are used to modify the rheology, also referred to herein as coupling, in a rheology-modifying amount, i.e. in an amount effective to increase the viscosity of the polymer at low shear (at 0.1 rad / sec), preferably at least 5% compared to starting material of the polymer, but less than the crosslinking amount, that is, an amount sufficient to produce at least 10% by weight of the gel measured by Method A of ASTM D2765. It is known to one of skill in the art that the amount of azide sufficient to increase the low shear viscosity and resulting in less than 10% gel will depend upon the effect of the gel. Based on the molecular weight of the azide used and the polymer used, the amount preferably being less than 5% by weight more preferably less than 2% by weight, most preferably less than 1% by weight, of poly (sulfonylazide), based on the total weight of the polymer, when the polysulfonylazide has a molecular weight of from 200 to 2000.

In order to achieve a measurable rheology modification, the amount of poly (sulfonylazide) is preferably at least 0.01% by weight, more preferably at least 0.05% by weight, most preferably at least 0.10% by weight, based on the total polymer.

To modify the rheology, the sulfonylazide is admixed to the polymer and heated to at least the decomposition temperature of the sulfonylazide. Azide decomposition temperature is understood to mean the temperature at which azide is converted to sulfonyl nitrene, whereby nitrogen is removed and heat is generated, as determined by differential scanning calorimetry (DSC). 130 ° C and is almost completely reacted at 160 ° C in DSC (sensed at 10 ° C / minute). Increased speed calorimetry (ARC) (sensed at 2 ° C / hour) shows an onset of decomposition at 100 ° C. The extent of reaction is a function of time and temperature. At the low azide levels used in the application of the present invention, optimum properties are not achieved until the azide has substantially reacted. The temperatures used in the process of the invention are also determined by the softening or melting points of the starting polymer material. For these reasons, the temperature is suitably above 90 ° C, preferably above 120 ° C, more preferably above 150 ° C, most preferably above 180 ° C.

Preferred times at the desired decomposition temperature are β 44 4 44 44

4 4 <4 4 4 4 4 4 4 • 4 · · 4 4 4 4 · · 4

4444 44 4 4444 4 4 44 4 4 4 4 4 4 4 4 4

Times which are sufficient to react the coupling agent with the polymer (s) without undesirable thermal degradation of the polymer matrix. Preferred reaction times, expressed as the half-life of the coupling reagent, i.e. the time required to react half of the reagent at a preselected temperature, which can be determined by DSC, are five times the half-life of the coupling reagent. For example, in the case of bis (sulfonylazide) u, the reaction time is preferably at least 4 minutes at 200 ° C.

The mixing of the polymer and the coupling reagent is conveniently carried out by any method conventional in the art.

The desired distribution is in many cases different depending on which rheological properties are to be modified.

In the homopolymer it is desirable to achieve co. most homogeneous distribution, preferably to dissolve the azide in the polymer melt. In the polymer blend it is desirable to achieve low solubility in the matrix of one polymer or in matrices of more polymers such that the azide is preferably in one or the other phase or predominantly in the interface region between the two phases.

Preferred methods include at least one of the following:

(a) dry-mixing the coupling agent with the polymer to advantageously form a substantially homogeneous mixture, and adding the mixture to a melt processing apparatus, such as a melt extruder, at a temperature at least equal to the decomposition temperature of the coupling agent to effect the coupling reaction;

(b) introducing, for example by spraying, a coupling agent in liquid form, for example dissolved in a solvent dissolving the substance or suspension of the coupling agent in a liquid, into a polymer-containing device, more preferably into a melt processing device, preferably 9 9 9 9 9 9 9 9 9 9 9 9 9999 9 9 9 9 9 9 9 9 9 9 9 9 polymer softened or melted, alternatively in particulate, solution or suspension form;

(c) forming a first mixture of the first portion of the first polymer and the coupling agent, suitably at a temperature below the decomposition temperature of the coupling agent, preferably by melt mixing, and then forming a second mixture of the first portion with the second portion of the second polymer (e.g. at least one polymer and optionally other additives are suitably mixed into the second polymer or a combination thereof with optional further additives to modify the second polymer (s);

(d) introducing at least one coupling agent, preferably. in solid form, more preferably finely divided, for example powder, directly into the softened or molten polymer, for example in a melt processing plant, for example in an extruder; or combinations thereof. Of methods (a) to (d), methods (b) and (c) are preferred, method (c) is most preferred. For example, method (c) is suitably used to produce a concentrate with a first polymer composition having a lower melting point, preferably below the decomposition temperature of the coupling agent, and the concentrate is melt blended into a second polymer composition having a higher melting point to complete the coupling. reaction. Concentrates are particularly preferred in cases where temperatures are high enough to be. achieves removal of the coupling agent by evaporation or decomposition, but does not result in treatment with the polymer, or under other conditions leading to this effect. Certain coupling occurs alternatively during mixing of the first polymer and the coupling agent, but a portion of the coupling agent remains unreacted until the concentrate is mixed into the second polymer composition. Each polymer or polymer composition comprises at least one homopolymer, copolymer, terpolymer or interpolymer, and optionally also other additives, 4 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9

9999 9. · 9 9999 4 4 4 9 9 '9 · · 9 4 4 9 9 9 ··· · 99 9 99 49 known in the art. In cases where the coupling agent is added in dry form, it is preferable to mix the agent and the polymer in a soft or molten state below the decomposition temperature of the coupling agent, then heat the resulting mixture to a temperature at least equal to the decomposition temperature of the coupling agent.

The term melt processing means any process by which the polymer is softened or melted, such as extrusion, pelletizing, molding, thermoforming, film blowing, polymer melt formation and fiber spinning.

The polyolefin (or polyolefins) and the coupling agent are suitably combined in any manner that results in their desired reaction, preferably by mixing the coupling agent with the polymer (s) under conditions which allow sufficient mixing prior to the reaction to avoid formation of unequal fractions and localized reactions and then subjecting the resulting mixture to a heat treatment sufficient to effect the reaction. Preferably, a substantially uniform mixture of the coupling agent and the polymer is formed prior to exposure to the conditions under which the chains are coupled. A substantially uniform mixture is one in which the distribution of the coupling agent in the polymer is sufficiently homogeneous; that the melt viscosity of the polymer after the reaction of the invention is at least such that it is (a) higher at a low angular frequency (e.g. 0.1 rad / sec) or (b) lower at a higher angular frequency (e.g. 100 rad / sec), than the viscosity of the same polymer that did not react with the coupling agent but was subjected to the same shear and thermal history. Thus, in a preferred embodiment of the present invention, the decomposition of the coupling agent preferably occurs after stirring sufficient to produce a substantially homogeneous mixture of the coupling agent.

4444 • 4 4

4 4

4 4 4

4 4 4 43 4

4 · 4

43 4 «4 * 4 ·« 4

4 4 4 4

4 4 4 | agent and polymer. This mixing is preferably achieved with the polymer in a molten or thawed state, i.e. above the melt crystallization temperature, or under dissolution or fine dispersion conditions, rather than in solid or particulate form. The molten or thawed form is preferable to ensure homogeneity rather than localized surface concentrations.

Preferably, any machine equipment is used for this treatment, preferably equipment which provides sufficient mixing and temperature control in the same equipment, but preferably the process of the invention is carried out in equipment such as an extruder or static polymer mixing equipment such as a Brabender mixer. . The term extruder is used in its broadest sense and includes such devices as the pellet extruder or pelletizer. In cases where a melt extrusion step is included between the production of the polymer and its use, then at least one step of the process of the invention preferably takes place in the melt extrusion step. It is also within the scope of the present invention to proceed in a solvent or other medium, but it is preferred that the reaction proceeds in a block to avoid further steps associated with removing the solvent or other medium.

For this purpose, a polymer with a temperature above the melt crystallization temperature is preferred for uniform mixing and for achieving the reaction temperature (sulfonylazide decomposition temperature).

Preferably, the process of the present invention is carried out in a single vessel, that is, the mixing of the coupling agent and the polymer takes place in the same vessel as heating to the decomposition temperature of the coupling agent. The container is preferably a twin-screw extruder, but a single-screw extruder, batch mixer or static mixer at the outlet end of the manufacturing process is also suitable. The reaction vessel preferably has at least two zones of different temperatures through which the reaction mixture passes, wherein the first zone is suitably maintained at a temperature at least equal to the melt crystallization temperature or the softening temperature of the polymer (s) and preferably lower than the decomposition temperature of the coupling agents; the band is at a temperature sufficient to decompose the coupling agent. The first zone preferably has a temperature high enough to soften the polymer and allows it to be coupled to the coupling agent by distribution mixing to a substantially homogeneous mixture.

In the case of polymers having a softening point above the decomposition temperature of the coupling agent (preferably greater than 200 ° C), and in particular where the incorporation of a lower melting polymer (e.g. in a concentrate) is undesirable, the preferred method of incorporating the coupling agent is adding a coupling agent in solution. admixing the coupling agent into the polymer to allow the polymer to soak (absorb or adsorb at least a portion of the coupling agent) and then evaporate the solvent. After evaporation, the resulting mixture is extruded. The solvent is preferably a solvent for the coupling agent and more preferably also for the polymer if the polymer is soluble, for example in the case of polycarbonates. Such solvents include polar solvents such as acetone, THF (tetrahydrofuran) and chlorinated hydrocarbons such as methylene chloride. Alternatively, other non-polar compounds, such as mineral oils, with which the coupling agent is sufficiently miscible, are used to disperse the coupling agent in the polymer.

In order to avoid the use of a separate step and the resulting costs of performing the re-extrusion and to ensure good mixing of the coupling agent with the polymer, it is preferred that the coupling agent is added downstream of the reactor of the polymer production plant. For example, in slurry polymerization to produce polyethylene, the coupling agent is added either in powder form or in liquid form to the powdered polyethylene after the solvent has been removed by decantation and before drying and the compaction extrusion process. Alternatively, in the case where the polymers are produced in the gas phase, the coupling agents are preferably added in powder or liquid form to the powdered polyethylene prior to compaction extrusion. In another alternative embodiment, the polymer is produced by polymerization. t.

by the solution process, the coupling agent is preferably added to the polymer melt stream after the volatiles have been removed and before pellet extrusion.

In carrying out the process of the invention for modifying the polymer rheology, polymers having rheologically modified or coupled chains, i.e. polymers having sulfonamide, amino, alkyl-substituted or aryl-substituted carboxamide, alkyl-substituted or aryl-substituted phosphoramide, alkyl-substituted, are obtained or aryl-substituted methylene linkages between different polymer chains. The resulting compounds preferably exhibit a higher low shear viscosity than the parent polymer due to the coupling of long polymer chains with polymer backbones (polymer backbones). Polymers with a broad monomodal molecular weight distribution (MWD 3.0 and above) and a gel level of less than 10% as determined by the xylene extraction method show less improvement compared to the strong effect observed •

--4 + - · --Τ - Π · »« - + - ”* - ... ^; ***. in the case of polymers with narrow MWD (e.g. MWD =

2.0) having a gel content of less than 10% as determined by xylene extraction. Alternatively, it will be apparent to those skilled in the art that it is possible to prepare polymers with a broader polydispersity (e.g., MWD greater than 2.0) by mixing low polydispersity polymers, either downstream of the reactor, or by preparing polymers in a multi-reactor configuration, Each reactor is controlled to obtain a polymer having the desired molecular weight and MWD for each specific polymer component in the final product.

Modification of rheology results in polymers having controlled rheological properties, in particular improved melt strength as evidenced by increased low shear viscosity, improved oil holding ability, improved scratch resistance, and destruction, improved tack, improved molding (melt) strength ,, higher orientation in high shear and high elongation processes such as injection molding, film extrusion (blow molding and casting), calendering, centrifugal forming, fiber production, profile extrusion, foaming, insulation for wires and cables, which is possible from the values tan delta, as described below, elasticity at viscosity at 0.1 rad / sec and optionally 100 rad / sec. It is also believed that this method can be used to produce dispersions having better low shear viscosity properties than the unmodified polymer as measured by DMS.

Rheological modified polymers are suitable due to the higher low shear viscosity for the production of large articles by blow molding, compared to unmodified polymers, and due to the high shear viscosity for processing as • 0

is indicated by high shear viscosity, foam materials with stable cell structure measured by low shear viscosity, for blown films due to better sleeve stability, measured by high shear viscosity, for fiber production due to better spinability, measured by high shear viscosity, for wire insulation production and cables due to the green strength, measured low shear viscosity, which prevents the polymer from falling or deforming on the wires, which are aspects of the invention.

The rheology-modified polymers of the present invention are superior to these unmodified polymeric materials for these uses by increasing the viscosity, preferably by at least 5% at low shear rates (0.1 rad / sec), due to sufficiently high melt strength to avoid deformation at heat treatment (e.g., to prevent collapsing during hot forming) or to achieve sleeve strength during blow molding, and due to sufficiently low viscosities at high shear rate to facilitate forming and extrusion. These rheological properties allow for faster filling of the injection molds at higher speeds than unmodified starting materials, foam formation (stable cell structure), as evidenced by the formation of closed cell foam of lower density, preferably higher tensile strength, insulating properties, by compression crushing or a combination thereof, due to the higher melt viscosity than is achieved by using coupling or rheology modification using coupling agents that produce free radicals. Preferably, the toughness and tensile strength of the starting material is maintained.

The resulting polymers obtained by the process of the invention differ from the prior art polymers disclosed in CA 797 917. The polymers of the present invention exhibit improved melt elasticity, i.e., higher tan delta as measured by DMS, better ductility, i.e., higher ductility. melt strength as measured by melt drawing, lower swelling as measured by melt blowing through the die and lower shrinkage as measured in the mold than the unmodified broad MWD polymer (greater than 3.0 Mw / Mn) when thermoformed and blown large parts.

There are many types of molding processes that can be used to produce useful products or components from the compositions described herein, including various injection molding techniques (e.g., described in Modern Plastics Encyclopaedia / 89, Mid October 1988 Issue, Volume 65, Number 11, Wed 264-268,

Introduction to Injection Molding and on pages 270-271 Injection Molding Thermoplastics) and blow molding procedures (for example, described in Modern Plastics Emcyklopaedia / 89, Mid October 1988 Issue, volume 65, number 11, pp. 217-218 Extrusion-Elow Molding) ), extrusion of profiles, calendering, pultrusion.

The rheologically modified ethylene polymers, processes for their preparation, and semifinished products for their production according to the invention are suitable in the automotive, industrial goods, construction and structural, electrical (for example, wire / cable coatings / insulation), and in tire production.

Some of the manufactured items include car hoses, single-layer coverings and stress insulations, and sheaths for wires and cables.

'· · ·

In particular, the films and film structures take advantage of the present invention, which products can be manufactured by conventional blow molding techniques or other biaxial oriented processes, such as a mechanical orientation process (in clamping jaws) or a twin blow process. Conventional blow molding processes are described, for example, in Encyclopadia of Chemical Technology, Kirk-Othmer, Third Edition, John Wiley & Sons, New York 1981, vol. 16, pages 416-417 and Vol. 18, pp. 191-192. The biaxially orientated film production process of the double blow molding process known from U.S. Pat. No. 3,456,044 (Pahlke) and the processes described in U.S. Pat. No. 3,456,044 may be used to produce film structures from the novel compositions described herein. U.S. Patent Nos. 4,352,849 (Mueller), 4,597,920 (Golike), 4,820,557 (Warren), 4,837,084 (Warren), 4,865,902 (Golike et al.), No. 4,927,708 (Herran et al.), 4,952,451 (Mueller), 4,963,419 (Lustig et al.) And 5,059,481 (Lustig et al.). As described, foil structures can also be made using clamping jaw technology, for example, used for oriented polypropylene.

^ 1!

Other techniques for producing multilayer films are described in Packaging Foods'With Plastics,

Wilmer A. Jenkins and James P. Harrington (1991), pp. 19-27- - and in Cextrusion Basics, Thomas I. Butler, Film Extrusion Manual: Process, Materials, Properties, pp. 31-80 (published by TAPPI Press (1992)).

The films may be single-layer or multi-layer. The film produced by the present invention can also be used in accordance with the present invention. 4 4 4 4 4 4444 4 4 4 4 4 4 Extruded together with another layer (s), or the film may be laminated to another layer (s) by a second operation, for example, by the methods described in the publication. Packaging Foods With Plastics by Wilmer A. Jenkins and James P.

Harrington (1991) or as described in Coextrusion for Barrier Packaging W.J. Schrenk and C.R. Finch, Society of Plastics Engineers, RETEC Proceedings, June 15-17 (1981), p. 211-229. In case the single-layer foil is produced using a foil sleeve (i.e. blow molding method) or a flat nozzle (flat foil) as described

K. R. Osborn and W.A. Jenkins in Plastic Films, Technology and Packaging Applications (Technomic Publishing Co., Inc., 1992), the film must undergo the next step of subsequent adhesive extrusion or extrusion lamination of additional layers of packaging material to form a multilayer structure. If the film is made by co-extruding two or more layers (also described by Osborneiir and Jenkins), it can still be laminated with additional layers of packaging material according to other physical requirements for the final film. Lamination v. Coextrusion, D. Dumbleton (Converting Magazine (September 1992)) also describes the issues of lamination and co-extrusion. The monolayer and co-extruded films can also be subjected to other technologies after extrusion, such as a biaxial orientation process.

Extrusion coating is another technology for producing multilayer film structures using the novel compositions described herein. The novel compositions of the present invention comprise at least one layer of film structure. Similar to flat film, extrusion coating is a method using flat nozzles. The weldable layer may be applied to the substrate by extrusion as a single layer or as a co-extruded material.

In general, in the case of the multilayer film structure of the present invention, the novel composition generally constitutes at least one layer of the overall multilayer film structure. Other layers of the multilayer structure include, but are not limited to, barrier layers or combinations thereof, tie layers, and structural layers. Various materials can be used for these layers, some of which are used multiple times in the same film structure. Some of these materials include: a thin layer of rubber compound, nylon, ethylene-vinyl alcohol (EVOH) copolymers, polyvinylidene chloride (PVDC), polyethylene terephthalate (PET), oriented polypropylene (OPP), ethylene-vinyl acetate (EVA) copolymers, ethylene-copolymers with acrylic acid (EAA), copolymers of ethylene with methacrylic acid (EMAA), LLDPE, HDPE, LDPE, nylon, graft adhesive polymers (for example, polyethylene grafted with maleic acid) and paper. Multilayer film structures typically comprise from 2 to 7 layers.

Such articles comprising a rheologically modified polymer of the invention can be produced by melt processing of a rheologically modified polymer of the invention. Such a process may include processing of pellets or granules of a polymer that has been rheologically modified in accordance with the present invention. In a preferred embodiment, the pellets or granules are substantially free of unreacted coupling agent when the coupling agent is a heat-activatable coupling agent. ‘

Such articles can also be made by treating the melt of an intermediate comprising a homogeneous polymer that is not substantially free of unreacted coupling agent. Such intermediates are preferably treated with a coupling agent, but are not subjected to subsequent melt processing until the polymer is melted to produce the article. The coupling agent may be either a radiation or a heat activated crosslinker.

The rheology modified polymers and intermediates used to produce rheology modified polymers can be used alone or in combination in a mixture of polymers with one or more other polymers.

If other polymers are present, they may be selected from any of the modified or unmodified homogeneous polymers described above for the present invention, from any modified or unmodified heterogeneous polymers, or combinations thereof.

The heterogeneous polyethylenes optionally combined with the rheologically modified polymers of the present invention fall into two broad categories, namely polyethylenes prepared using a free radical initiator at high temperature and high pressure, and polyethylenes prepared using coordination catalysts at high temperature and relatively low pressure. The first of these are commonly known as low density polyethylenes (LDPE) or low density polyethylenes and are characterized by branched chain units of polymerized monomer attached to the polymer backbone. LDPE polymers generally have a density between 0.910 and 0.935 g / cm ³ . Ethylene polymers and copolymers prepared using a coordination catalyst, such as a Ziegler or Phillips catalyst, are generally known as linear polymers due to the substantial absence of branched chain chains

• · · · to the main chain. High density polyethylene (HDPE), or high density polyethylene, typically having a density of from 0.941 to 0.965 g / cm ³ , is typically an ethylene homopolymer and contains relatively few branched chains compared to various linear copolymers of ethylene and an alpha-olefin. High density polyethylene HDPE is well known in the art and is available in several types on the market and can also be used in connection with the present invention. The density is measured according to ASTM D-792.

Linear copolymers of ethylene and at least one alpha-olefin containing 3 to 12 carbon atoms, preferably 4 to 8 carbon atoms, are also well known and commercially available. As is well known in the art, the density of an ethylene-alpha-olefin copolymer is a function of both the length of the alpha-olefin and the amount of the monomer in the copolymer relative to the amount of ethylene, the greater the alpha-olefin length and the greater the alpha- the lower the density of the copolymer. Linear low density polyethylene (LLDPE) is usually a copolymer of ethylene and an alpha-olefin of 3 to 12 carbon atoms, preferably of 4 to 8 carbon atoms (for example 1-butene, 1-octene, etc.) having a sufficient alpha- If the copolymer contains even more alpha-olefin, the density will fall below 0.91g / cm ³ and these copolymers are known as ultra-low density polyethylenes (ULDPE) or very high density polyethylenes. low density (VLDPE). The densities of these linear polymers are usually in the range of 0.87 to 0.91 g / cm ³ .

Both materials made with free radical catalysts and materials made using coordinating catalysts. Catalysts are well known in the art, as are methods for their preparation. Heterogeneous linear ethylene polymers are available from The Dow Chemical Company as Dowlex ™ LLDPE and Attane ™ ULDPE polymers. Heterogeneous linear ethylene polymers can be prepared by polymerizing ethylene and one or more optional alpha-olefin comonomers by solution, slurry, or gas phase polymerization in the presence of a Ziegler Natta catalyst, using procedures such as those described in U.S. Pat. No. 4,076,698 (Anderson et al.). Heterogeneous ethylene polymers are typically characterized by having a molecular weight distribution M _w / M _n ranging from 3.5 to 4.1. Discussions relating to this issue of both the above-mentioned groups of materials and methods of making them can be found in U.S. Patent No. 4,950,541 and the references cited therein.

The compositions according to the invention and the compositions produced by the process according to the invention are particularly suitable for their completely surprising properties. For example, the preferred polyethylenes and ethylene copolymers of medium density (density 0.90 g / cm ³ , comonomer content 0.5-5 mol%) according to the invention are particularly suitable for the production of blown films, such as garbage bags, trade bags, for sealing layers, »for binding layers, for various product bags, for clothing bags, for transport bags, for medical films, for shrink films, for stretch films, for agricultural films, for building films, for geomembranes or for stretch covers, preferably for garbage bags, agricultural films, building films and geomembranes. Similarly preferred embodiments of medium density polyethylene are suitable for the manufacture of: 00 00 00 00 00 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 · 0 0 0 0 0 0 0 cast films, eg for stretch film, diaper backing, for industrial packaging, for product packaging, for meat packaging, for consumer packaging, for shrink films or for flexible films, preferably for flexible films .

Preferred embodiments of high density polyethylene (density greater than 0.945 g / ml and preferably with MWD less than 3.0, or equal to 3.0) are particularly suitable for thermoforming, preferably for the production of the interior of refrigerators, thin-walled containers, medical bubble blister packs, modified atmosphere packagings; and for blow molding (including extrusion blow molding) for making articles such as oil bottles, pipes, fuel tanks including fillers, milk jugs and other containers. Preferred embodiments of low density ethylene copolymers (density less than 0.89 g / ml and comonomer content preferably 5 to 25 mol%) are particularly suitable for extrusion, such as extrusion of wire and cable coatings, pipes, profiles such as gaskets and gaskets, foils, for extrusion coating, such as, for example, carpet underside extrusion, for reinforcing agents and impact modifiers. Preferred embodiments of low density polyethylenes are also particularly suitable for calendering to produce materials such as sheets, wrapping films and non-wrapping films; for the production of foams, in particular for padding, for automotive purposes, for body parts, for aircraft seats, for florist and craft use, preferably for padding, for building and construction purposes, for automotive purposes and bodywork components; and for adhesives and sealants, in particular for hot-melt adhesives, for self-adhesive products (applied from solution or melt), for gaskets and as adhesives for other compositions.

Practical application of the present invention

• 9 · · · · · · · · · · ¹ · · · · · · · · · · · · · · · · · · · · · · · · · · · · ethylene polymers in the automotive field, especially high density polyethylene, and propylene polymers. With increased melt strength, it is now possible to produce automotive components such as belts, energy absorbers in bumpers, bumpers, door panels, door lock cases, seat backs, seat cushions, headrest cores, energy absorbing inserts, pillars, instrument panels, instrumentation equipment. panels, pads, glove boxes, doors, brackets, pipes, bale shelves, hat shelves, cargo floor, swing panels, covers and combinations thereof, these products being made by processes such as blow molding, injection molding, molding heat and gas injection. Further, automotive parts such as vehicle crossbars, exterior door panels, seat parts, and combinations thereof can be manufactured using processes such as blow molding, injection molding and thermoforming. Thermoforming can suitably produce components such as roof coverings, underbody covers, floor sensing layers, and wheel covers; further such objects are fuel tank fillers and the fuel tanks can then be manufactured by blow molding, centrifugal casting or injection molding. The door reinforcements are conveniently manufactured by injection molding, thermoforming and gas assisted injection molding. By extrusion or coextrusion, such articles as bumpers, door reinforcements, heating components, roof coverings, pipes, floor sensing layers, tank fillers, fuel pipes and fuel systems are suitably manufactured. Coextrusion is also suitable for the production of hinged panels and covers. Fuel systems are also optionally produced by centrifugal casting or blow molding. The centrifugal casting method is also suitable for the manufacture of such articles as energy-absorbing door supports, for «4 · 4 · ·

4 4 • 4444 · • · · · · · ·

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 panels, supports and pipes; in addition, blow molding is suitable for the production of energy absorbing door reinforcement products. Foaming is useful for the production of energy absorbers in bumpers, bumpers, door reinforcements, energy absorbing door inserts, door panels, seats, head restraints, washers, roof cladding, energy absorbing pads, columns, dashboard parts, supports and sensing layers. . For the manufacture of such items as bumpers, vehicle crossbars, door reinforcements, exterior door panels, door lock cases, seat backs, seat cushions, pads, roof covers, instrument panel parts, supports, piping, bale poles , hat shelves, cargo floor, hinged panels, covers, underbody covers, floor sensing layers, wheel covers and combinations thereof, it is advisable to use the hot pressing process, that is, hot forming at a pressure higher than 240 kPa. The practical application of the invention advantageously facilitates the process of blow molding, thermoforming and foaming of ethylene polymers and propylene polymers which, without reaction with the poles (sulfonylazide), could not be used for suitable molding of articles, these polymers having a fractional melt index (measured by ASTM method). D-1238 with a load of 5 kg and at a temperature of 109 ° C) at least one order of magnitude lower than the starting material prior to coupling.

• ♦ · · · · · ·

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be illustrated in more detail with reference to specific examples, which are provided to illustrate the invention. Ratios, parts and percentages are by weight unless otherwise indicated. Examples (Ex) are indicated by numbers, while comparative samples (C.S.) are indicated alphabetically and are not examples of the invention.

Test methods:

A dynamic mechanical spectrometer RMS-800 Rheometrics, Inc was used to determine dynamic rheological data. with parallel plates of 25 mm diameter. Sweep frequency sweeping by logarithmically spaced points per decade was performed in the range of 0.1 to 100 rad / s at 190 ° C. The voltage was determined to move in linear viscoelasticity by determining the voltage at 0.1 rad / s and 190 ° C, sweeping the frequency by 2 to 30 percent in 2 percent increments to determine the minimum voltage required to generate torque at sensor specification limits; an additional voltage sweep at 100 rad / s and 190 ° C was used to determine the maximum stress before nonlinearity occurred according to the procedure described in J.M. Dealy and K.F. Wissbrun Melt ϊ Rheology and Its Role in Plastics Processing, Van Nostrand,

New York (1990). All testing was conducted under nitrogen to.

The oxidation decomposition was minimized.

A Perkin Elmer model TMA 7 thermomechanical analyzer was used to measure the upper usable temperature. The probe strength was set at 102 grams and a heating rate of 5 ° C / minute. Each sample tested was a disc of thickness

9 ·

and a diameter of 2 millimeters, prepared by pressing at temperature

205 ° C and cooling in air at room temperature.

Xylene extraction was performed using 1 gram samples. The samples were transferred to a sieve basket, which was then placed in boiling xylene for 12 hours. After 12 hours, the sample baskets were removed and placed in a vacuum oven at 150 ° C with a vacuum of 28 inches of Hg for 12 hours. After 12 hours, the samples were removed, allowed to cool for 1 hour at room temperature and then weighed. Results were reported as percent of polymer extracted. Extracted Percentage = (Start Weight - End Weight / Start Weight according to ASTM D-2765 Procedure A.

Samples were prepared using either a stirrer commercially available from Haake, Inc. under the trademark HaakeBuchler Rheomix 600 with disc knives attached to a rheometer available from Haake, Inc. under the trademark HaakeBuchler Rheocord 9000 Torque rheometer, or using a Brabender mixer (type

R.E.E.No.A-19 / S.B.) With a 50 gram container.

All instruments were used according to the manufacturer's instructions.

Examples 1 and 2 / - and Comparative-A. .

Samples weighing 43 grams of substantially linear homogeneous ethylene-octene copolymers (6 mol% octene, estimated according to Kale et al. In Journal of Plastic Film and Sheeting, vol. 12, Jan. 1996, pp. 27-40) s Mw / Mn = 2.19 and Mw = 93,600, melt index 1, density 0.903 g / cm ³ ,

9, which is available from The Dow Chemical Company under the trade name AFFINITY PL 1880 (containing 500 ppm of a sterically hindered polyphenol antioxidant from Ciba Geigy Corporation under the trade name Irganox 1076 and 800 ppm of an antioxidant that is probably tetrakis- (2) 4-di-tertiary butyl-phenol) -4,4'-biphenylphosphonite from Sandoz Chemical Company under the trade name P-EPQ) was stirred in a Haake mixer. The polymer was melted for 2 minutes at 100 ° C until all the pellets had melted. Then, 0.05% w / w 4,4'-oxybis (benzenesulfonyl azide) (hereinafter BSA) CAS # [7456-68-0] was stirred into the molten polymer for 2 minutes. After perfect mixing, the temperature was set to 170 ° C and the rotation speed increased from 20 to 40 rpm for 7 minutes to reach a maximum of 180 ° C. The mixture was maintained at this higher temperature and higher rotation speed for 12 minutes and then cooled to 150 ° C. The sample was removed from the Haake mixer and allowed to cool to room temperature.

In the case of Example 2, the procedure of Sample 1 was repeated except that 0.1% by weight of 4,4'-oxybis (benzenesulfonylazide) was used.

The rheological properties (viscosity and tan delta) were measured according to the manufacturer's instructions for each sample and for the unmodified control (comparative sample A) at 190 ° C _w in the frequency range 0.1 to 100 rad / s. using a Rheometrics mechanical spectrometer equipped with 25 mm parallel discs. Low shear viscosity is the viscosity measured at the lowest frequency. High shear viscosity was determined by NSC at 100 rad / sec.

• · i

The results of these tests are shown in Table 1 below. '

Examples 3 and 4 and comparative sample B

The procedure of Example 1 was repeated using 6.6 mol% linear homogeneous copolymers of ethylene and butene comonomers with Mw / Mn = 1.9 and Mw = 118,600, MI = 1.2, density

0.9021, a melt index of 1.20 g / 10 minutes at 190 ° C, a melting point of 92 ° C, commercially available from Exxon Chemical Company under the trade name EXACT 3028, which has been reported to be produced using a metallocene catalyst using 0.05% by weight of BSA in the case of Example 3, 0.1% by weight in the case of Example 4 and without the poly (sulfonylazides) in Comparative Samples B.

Examples 5 and 6 and Comparative Example C:

The following is an example of using a multimodal polymer with a total MWD > 3.00 but at least one product component having a MWD < 3.0 and reported to have been produced using a metallocene catalyst.

The procedure of Example 1 was repeated using ethylene terpolymer (69% by weight), propylene (30.5% by weight) and diene (0.5% by weight) with a specific gravity of 0.88, a Mooney viscosity of 20 (according to ASTM D 1646). , Mw / Mn = 3.5, and Mw = 146,200, available from DuPont Dow Elastomers LLC under the trade name Nordel IP NDR 3720 (containing 1000 ppm f *. · Fe '* 9 fefe.) • · 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9

Irganox 1076) and using 0.05% by weight BSA in Example 5, 0.1% by weight in Example 6, and without poly (sulfonylazide). for reference C.

Comparative samples D, E and F:

The procedure of Example 1 was repeated using a terpolymer of ethylene (72% by weight), propylene (22% by weight) and diene (6% by weight) with a specific gravity of 0.87 at 22.4 ° C, Mw / Mn = 3.65 and Mw = 115,200, Mooney viscosity 20, available from DuPont Dow Elastomers LCC under the trade name Nordel 2722 Hydrocarbon Rubber (reported to be manufactured using a Ziegler Natta catalyst) with 0.5% BSA by weight in a comparative sample D, with 0.05% by weight of BSA for reference sample E and with 0.1% by weight of BSA for reference sample F.

Comparative samples G, H and I:

The procedure of Example 1 was repeated using terpolymer of ethylene (71% by weight), propylene (23% by weight) and diene (6% by weight) with Mw / Mn = 2.98 and Mw = 173,200, Mooney viscosity 45 ± 6 according to ASTM D 1646, commercially available from DuPont Dow Elastomers under the trade name Nordel 2744 Hydrocarbon Rubber (reported to be manufactured using a Ziegler Natta catalyst) with 0.0 or 0.05 with 0.10 % by weight of BSA in comparative samples G, Hal.

Examples 7 and 8 and comparative sample J

The procedure of Example 1 was repeated using essentially 0 9 9 0 9 0 9 0 9 9 0 9 0 9 ' »· ·· ···· ♦' · 0 • Fe Fe ·· · · · · ·· '· 9> ·. ·' 9 ^R ·· H ¹ linear copolymer of ethylene and octene with I ₂ = 1 gram / 10 minutes and a density of 0.870 g / cm ³ ,

Mw = 111 400 and Mw / Mn = 2.062, commercially available from DuPont Dow Elastomers LLC under the trade name ENGAGE EG8100 (reported to have been manufactured using constrained geometry catalyst s of 0 and optionally with 0.05 and 0.1% BSA, respectively, for Comparative Samples J, Example 7 and Example 8, respectively.

Examples 9 and 10 and comparative sample K

The procedure of Example 1 was repeated using a linear copolymer of ethylene and propylene with Mw / Mn = 2.02,

Mw = 122,000, I ₂ = 1/1 grams / 10 minutes and with a density of 0.87 g / cm ³ , Mw = 116,000 and Mw / Mn = 1.898, available from Mitsui Petrochemical Industries under the trade name Tafmer P0480 with 0 and 0.05, respectively, and 0.1% by weight of BSA in Comparative Sample K and Example 9 and Example 10 respectively.

Comparative samples L, M and N:

The procedure of Example 1 was repeated using a linear low density ethylene-octene copolymer (2.5 mol% octene, estimation according to Kale et al., J. Plastic Film-Sheeting, vol. 12, pp. 27-40, Jan) (1996)) with Mw / Mn = 3.96, in Mw = 114,800, I ₂ = 1.0 g / 10 minutes, and a density of 0.92 g / cm ³ available from Dow Chemical -Company under the trade name Dowlex 2045 (containing 1250 ppm calcium stearate and 200 ppm sterically hindered polyphenol antioxidants from Ciba Geigy under the trade name Irganox 1010) with 0.0, optionally 0.05 and 0.10%

·) · '·

0 «0 0.

Φ 0 0 0 0 • »· 0

0 * * «· · 0 0 0

0 ·?

by weight of BSA for reference samples L and M and N.

Examples 11 and 12 and comparative sample P

The following is an example of a modification of the rheology of a multimodal polymer product with a total MWD > 3 but in which at least one component has a MWD < 3 and is reported to have been produced using a metallocene catalyst. The procedure of Example 1 was repeated using ethylene-octene copolymers having a melt index

0.85 g / 10 minutes (according to ASTM D1238, 190 ° C / 2.16 kg), density 0.920 g / cm ³ (according to ASTM D 792), Mw / Mn = 3.45 and Mw-130 300 which is in the market available from. from The Dow Chemical Company under the trade name Elite 5100 (containing 1250 ppm calcium stearate, 500 ppm antioxidant Irganox 1076 and 800 ppm antioxidant P-EPQ) with 0% and 0.05%, respectively, and 0.1% BSA by reference sample P , optionally for Examples 11 and 12.

Example 13 and comparative sample Q:

The procedure of Example 1 was repeated using ethylene-octene copolymers with a melt index of 1.0 g / 10 minutes (according to ASTM D1238, 190 ° C / 2.16 kg), density 0.909 g / cm ³ (according to ASTM D 792) , Mw / Mn = 2.265 and Mw = 86.000, available from The Dow Chemical Company under the trade name Affinity PL 1840, containing 750 ppm by weight of octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate, CAS # 002082 and 1200 ppm tetrakis (2,4-di-tert-butylphenyl) -4,4 ', CAS # 038613-77-3

- 57 «> ·» ♦ ·· * 4 4 4 · 9 ·

4 4 4 -4? · 4 4 9 4 4 4 4 4 4 «4 4 · 4 ί 4 4 4 4 * 4 · k, ·· <9 · 9 and biphenylenediphosphonite, CAS # 119345-01-6 (available from Sandoz Chemical Company under the trade name P -EPG) with the addition of 0.0 wt% and 0.10 wt% BSA for Comparative Sample Q and optionally for Example 13.

Example 14 and comparative sample R

The procedure of Example 1 was repeated using an ethylene-octene copolymer with a melt index of 0.80 grams / 10 minutes (according to ASTM D1238, 190 ° C / 2.16 kg), a density of 0.905 g / cm ³ (according to ASTM D 792) , Mw / Mn = 4.04 and Mw = 120,500, available from The Dow Chemical Company under the trade name ATTANE 4203, containing 200 ppm by weight of tetrakis (methylene / 3,5-di-tert-butyl-4- hydroxyhydrocinamate) methane CAS # 06683-19-8; and 1250 ppm by weight of calcium stearate CAS # 001592/23/0, with the addition of 0.0% by weight and 0.10% by weight of BSA in the comparative sample R and Example 14, respectively.

Example 15 and Comparative Sample

The procedure of Example 1 was repeated using an ethylene-butene copolymer with a melt index of 1.20 g / 10. minutes (according to ASTM D1238, 190 ° C / 2.16 kg), density 0.910 g / cm ³ (according to ASTM D 792), Mw / Mn = 2.304 and Mw =, 118 700, available from Exxon Chemical Company under the trade name EXACT 3025, with the addition of 0.0% by weight and 0.10% by weight of BSA for comparative sample S and Example 15, respectively.

10 10> β β β β β β β

«. 0 ···· «0 · 0 · · 9 · · 0 · · ·. * * · 'T ¢.

TABLE 1 (Part I / L)

Viscosity measurement in English units

viscosity 0.1 poise viscosity 100 poise viscosity 0.1 / 100 Tan delta viscosity change 0.1 -% C, S, A 1, 29E + 05 1.64E + 03 7.85 4.6044 0 Ex.l 2.11E + O5 1.78E + 03 11.82 2.9446 63 Ex, 2 4.40E + 05 1.86E + 03 23.72 1,7186 241 ..........------ _---------- _ III ». . . ** C.S. (B) 7.15E + 04 2.63E + 03 2.72 33,027 0 Ex. 3 5.18E + 0.5 2,66E + 03 19,49 ' 1.5901 625 Ex. 4 1 / 65E + 06 2.81E + 03 58.85. 0.7916 2214 c.s.c 2.55E + 05 1.32E + 03 19.30 2,1627 0 Ex. 5 , 3.75E + 05 1.36E + 03 27.49 1,2659 47 EX.6 5,18E105 1.36E + 03 37.97 0.838 103 C.S. D 8.26E + 05 1.31E + 03 62.84 0.992 0 C.S.E 5.92E + 05 1.31E + 03 45.34 1,2753 -28 C.S.F 9.29E + 05 1.49E + 03 62.55 1,0214 13 C.S.G 2.07E + 06 2.24E + 03 92.54 0.6482 0 C.S.H 2.18E + 06 2.32E + 03 94.18 0.6185 5 C.S.I 3.37E + 06 2.33E + 03 144.78 0.4572 63

Table 1 (part 1/2) · ·% část% část část%%%%%%%%%%%

viscosity 0.1 poise viscosity 100 poise viscosity 0.1 / 100 Tan delta viscosity change 0.1 -% C. S. J 9.28E + 04 1.67E + 03 5.55 8,251 0 Ex.7 1.89E + 05 1.68E + 03 11.26 2.9234 104 Ex. 8 4.33E + 05 1.87E + 03 23.09 1,5487 366 -. . _ - - -------- J “ ¹ · - '--- ¹ C.S.K 1, 18E + 05 2.96E + 03 3.98 9.6377 0 Ex. 9 5.56E + 05 2.54E + 03 21.93 1,4587 ³⁷¹ Ex.10 7.21E + 05 3.00E + 03 24.04 1,2873 511 ____ ____ ^{1 1} —- - -------. --- ¹ ---- C. S. L 9.25E + 04 1.72E + 03 5.38 9.0761 0 C.S.M 2.35E + 05 1.68E + 03 13.95 2.1441 153 C.S.N 6.92E + 05 2.04E + 03. 33.97 1,2156 646 _________ • - - " - .. —-----. - ------'— f- · .— C.S.P 1.05E + 05 1.92E + 03 5.47 7,7074 0 Ex.ll 2.04E + 05 1.63E + 03 12.50 2,4803 94 Ex. 12 4.35E + 05 1.94E + 03 22.46 1.5344 313 ______ ....... ... ..... - -. “ ¹ · ·“ ““ —-- ' - .. _ »1, 2 C.S.Q , 1.47E + 05 1.64E + 04 8.96 0 Ex.13 6.20E + 05 1.69E + 04 36.96 422 __________ _____ _ ____ - . .. ”. ,. . _r - "" - - · ·· - ------ C.S.R 1.46E + 05 2.08E + 04 7.02 0 EX. 14 8,90E + 05 1.71E + 04 52.05 610 _________ ___________ _____________ _ _______ - ~ · ... .— ---- ~ - · - - c.s.s 8.74E + 04 3,29E + 04 2.66 0 Ex.15 1.63E + 06 3.58E + 04 45.53 1865

Table 1 (Part II / l

4 '4' 4 '· 4 4 4 1 ·'

4 4 4 4 4 4 4 '4 4 4 ··· «·> 4 4 4444 4 4' 4 '4 4' 4 4 · 4 4 4. 4 4 4 '• · 4 4. 4' · -4 4 4 '4 ·,

viscosity change 100 -% change Tan delta% viscosity 1000 poise change viscosity % Note C, S, A 0 0 4518,6 0 1 MI. narrow MWD Ex.l 8 -36 4714 4 density 0,908 Ex, 2 13 -63. 4701.8 4 high copulation C.S.B 0 0 4579.6 O 1.2MI, narrow MWD Ex.3 1 -95 4579.6 0 hust.0,900 butene · Ex. 4 7 -98 4695.7 3 without dome. c.s.c 0 0 3627.1 0 Mooney 20 narrow MWD Ex.5 3 -41 3816,4 5 Ex. 6 3 -41 4439,2 22nd C.S.D O 0 3932,4 0 Mooney 22 Wide MWD C.S.E -1 29 3517,2 -11 C.S.F 13 3 3724.8 -5 C.S.G 0 -0 5446.7 0 - - C.S.H 4 -5 5684,9 4 Mooney 44 Wide MWD C.S.I 4 -29 6442 18 ____ - ** · * - “------— -------- ¹ C.S. J 0 0 4164,4 0 1 MI, narrow MWD

Table 1 (Part II / 2)

viscosity change 100 -% change Tan delta% viscosity 1000 poise change viscosity % Note Ex.7 1 -65 4433.1 6 hust. 0.87 Ex. 8 12 -81 4994,9 20 May low .kopulace C.S.K 0 0 4433.1 0 1 MI, narrow MWD Ex. 9 -14 -85 4336,4 -2 hust.0,87 propylene? Ex.10  1 -87 4365,9 -2 without dome. C.S.L 0 0 3969 0 1MI, wide MWD, heter. C.S.M -2 -76 4066.7 2 hust.0,92 C.S.N 18 -87 3859, -1 -3 without dome. C.S.P 0 0 4311 0 0.85 MI wide MWD Ex.ll -15 -68 4280.4 -1 hust.0,92 Ex.12 1 -80 4072,8. -6 low kick. C. S. Q O Ex.13 3 > C.S. R 0 X ·, - Ex. 14 -18 . 1 c.s.s 1 o Ex.15 9

. = reference sample

Ex. = example

C.S

Table 1B (part 1/1) 9 9 • 0 0 0 0 0 0 0 0 0

0 0 000 0 '· 0' 0 0 ·· 0 0 'th

Summary of rheological results of the melt in metric units (all viscosities in Pa-S (Pascal-seconds)

viscosity 0.1 Pa-S viscosity 100 Pa-S viscosity 0.1 / 100 Tan delta 0.1 viscosity change 0.1 -% C, S, A 1, 29E + 04 1.64E + 03 7.85 4.6044 0 Ex.l 2.11E + O4 1.78E + 03 11.82 2.9446 63 Ex, 2 4.40E + 04 1.86E + 03 23.72 1,7186 241 C.S.B 7.15E + 03 2.63E + 03 2.72 33,027 0 EX. 3 5.18E + 04 2.66E + 03 19.49 1.5901 .625 Ex. 4 1.65E + 05 2.81E + 03 58.85 0.7916 2214 _____ __ τ · - - - - .. - c 2.55E + 04 1, 32E + 03 19.30 2,1627 0 Ex.5 - 3,75E + 04 1.36E + 03 27.49 1,2659 47 EX.6 5.18E + 04 1.36E + 03 37.97 0.838 103 ____: _____ _____ _________ ____ _ _ _· ___of._ - 2 · - - - · ·· - C.S.D 8.26E + 04 1.31E + 03 62.84 0.992 0 C.S.E 5.92E + 04 1.31E + 03 45.34 1,2753 -28 C.S.F 9.29E + 04 1.49E + 03 62.55 1,0214 13 ___________ - -, ^- - - ¹ ' ......---— _--, - C.S.G 2.07E + 05 2.24E + 03 92.54 0.6482 0 C.S.H 2.18E + 05 2.32E + 03 94.18 0.6185 5 C.S.I 3.37E + 05 2.33E + 03 144.78 0.4572 ⁶³

• · ····

Table IB (part 1/2) · ft · ft · ft · ft · ft · · ft ";

viscosity 0.1 Pa-S viscosity 100 Pa-s viscosity 0.1 / 100 Tan delta 0.1 viscosity change 0.1 -% C.S. J 9.28E + 03 1.67E + 03 5.55 8,2516 0 Ex.7 1.89E + 04 1.68E + 03 11.26 2.9234 104 Éx. 8 4.33E + 04 1.87E + 03 23.09 1,5487 366 C.S.K 1, 18E + 04 2.96E + 03 3.98 9.6377 0 EX.9 5.56E + 04 2.54E + 03 21.93 1,4587 371 EX.10 7.21E + 04 3.00E + 03 24.04 1,2873 511 C.S.L 9.25E + 03 1.72E + 03 5.38 9.0761 0 C.S.M 2.35E + 04 1.68E + 03 13.95 2.1441 153 C.S.N 6.92E + 04 2.04E + 03 33.97 1,2156 648 ________ - _ ____ • - - - - - -. - ¹ “---- ··· ---“ - _---, —---- C.S.P 1.05E + 04 1.92E + 03 5.47 7,7074 0 Ex. 11 2.04E + 04 1.63E + 03 12.50 2,4803 94 Ex.12 4.35E + 04 1.94E + 03 22.46 1.5344 313 ______ ____ _______ ___ _ .. ____ _ _ __ · ___ _ · "* -., ---. C. S. Q 1.47E + 04 1.64E + 04 8.96 0 EX. 13 6.20E + 04 1.69E + 04 36.96 422 C.S.R 1.46E + 04 - 2.08E + 04 7.02 0 Ex. 14 8,90E + 04 1.71E + 04 52.05 610 ___ ____________ ______________ "___ -. .-- '----- —-- - · ... —-- u-- c.s.s 8.74E + 03 3,29E + 04 2.66 0 Ex.15 1.63E + 05 3.58E + 04 45.53 1865

Table 1Β (part II / l) 99 99 φ 9 9 9 9 9 9 '9 • * · 4 4 4 4 · · 4 ·.

• 4 '4 · 4 · 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4'44 4 4.4 '4 <<4 9 9,

viscosity change 100 -% change Tan delta% viscosity 1000 Pa-S change viscosity % Note C, S, A 0 0 451.86 0 1 MI. narrow MWD Ex.l 8 -36 471.4 4 density 0,908 Ex, 2 13 -63 470.18 4 high copulation ---- - ___ “...... ”....... ¹ ...... ........ ^.. “· - ..... · · —- - ------— ² --- - C.S.B 0 0 457.96 0 1.2MI, narrow MWD • Ex. 3 1 -95 457.96 O hust.0,900 buten Ex. 4 7 -98 469.57 3 without dome. C.S.C 0 0 362.71 0 Mooney 20 narrow MWD EX.5 3 -41 381.64 5 EX.6 3 -41 443.92 22nd C. S. D 0 0 393.24 0 Mooney 22 Wide MWD C.S.E -1 29 351.72 -11 C.S.F 13 3 372.48 -5 C.S.G 0 0 544.67 II o 1 C.S.H 4 -5 568.49 · 4 Mooney 44 Wide MWD C.S.I 4 -29 644.2 18 _________ _ ___ ___. ·. ~ - .—. .. ------— ₁ _-- -. - LJ ---- C.S. J 0 0 416.44 0 0 1 MI, narrow MWD

- 65 Table 1B (Part II / 2). · «'·· ·. ·· .9 9 ·' · · · fe fe 9 fe 9 9 9» fe. fe · fe · fe · fefefefe · fefe · fe. · Fe ·> '' · · · '' fefe · · '' · ·. ·· * · • .r *

viscosity change 100 -% change Tan delta% viscosity 1000 poise change viscosity % Note Ex.7 1 -65 443.31 6 hust. 0.87 Ex. 8 12 -81 499.49 20 May low copulation C. S. TO 0 0 443.31 0 1 MI, narrow MWD EX. 9 -14 -85 433.64 -2 hust.0,87 propylene? Ex.10 1 -87 436.59 -2 - without dome. C.S.L 0 0 396.9 0 1MI, wide MWD, heter. C.S.M -2 -76 406.67 2 hust.0,92 C. S. N 18 -87 385.91 -3 without dome. C.S.P 0 0 431.1 0 . 0,85 MI wide MWD Ex. 11 -15 -68 428.04 -1 hust.0,92 Ex.12 1 -80 407.28 -6 low kick. C.S.Q 0 EX.13 3 C.S.R 0 - .... - - Ex.14 -18 C. S. WITH 0 EX.15 9

C.S Comparative sample

Ex. = example • · · W · _ »φ ΦΦ 'ΦΦ φ 9 9 Φ 9' · φ 9

Φφφ φ φ φ φ · · · Φ

Φ Φ ΦΦ Φ ι ι ι φ φ φ · • φ Φ ΦΦ ΦΦΦΦ

ΦΦ Φ ΦΦ ¹ Φ ΦΦ. 'ΦΦ

Surprisingly, the efficacy of rheology modification is influenced by molecular weight distribution, molecular weight, type of comonomers and comonomer content. In general, the direction is such that narrowly distributed or higher comonomer-containing polymers exhibit higher rheology modification efficiency. The degree of effectiveness depends on the type of polymer and will be discussed further below. These significant changes in the tapering MWD are largely unexpected.

............. ........................ «» »|» | ·· | · '<; '~ »'

The three EPDM samples (Example 6, Comparative Sample F and I) showed the greatest degree of rheology modification in Sample 6, which was prepared using a metallocene catalyst. (The results considered had an azide level of 0.1%.) Low shear viscosity (0.1 rad / s viscosity) increased by 103% over the base polymer, while higher shear viscosities increased less significantly by 3% at 100 rad / s. % at 1000 rad / s. Thus, metallocene-based EPDM has seen a significant increase in low shear viscosity (100% at 0.1 rad / s) correlated with an increase in melt strength with less significant changes in high shear viscosity (3% at 100 rad / s), which means good workability. Comparative Sample I of higher molecular weight exhibited considerable modification with a low shear viscosity increase of 63%, with a high shear viscosity increase of 4% at 100 rad / s. A comparative sample with a lower molecular weight F showed a significantly less 13% change in low viscosity

-shear and / 13% change in viscosity at higher shear. The tan 'delta change at 0.1 rad / s also decreased significantly from 3% to -29% to -61% from Comparative Samples Έ and F to Examples 5 and 6. (Note: Comparative Examples D and E with 0.05% azide was repeated again to verify that at 0.05% azide there was a slight decrease in low shear viscosity).

'* · .0 • · 0 ·. · ·. 00 0 0 0 0 '0 0 · ´ _ of - 7 · · · ··· <. 9

Ό f · 00 0 0 9 · 9 0 00 0 1 «· · 0 0 £ · - ···« 9 9 9 «'· 9 9 ··· 9 0 0' 0j 0 0 · 0, t '

In the substantially linear narrow-partition copolymers (Examples 1 and 2 and Examples 7 and 8), the higher comonomer content polymer (Examples 7 and 8) had better rheology modification efficiency, probably due to the higher comonomer content. For example, at a content of 0.1% by weight of the coupling agent, the viscosity change was 241% for Example 2 and 366% for Example 8.

In the case of narrowly distributed linear copolymers (Examples 3 and 4 and Examples 9 and 10), the rheology modification efficiency was high due to the combination of narrow MWD and high comonomer content. At a given density, the comonomer content used in these polymers (i.e. butene and possibly propylene) was higher than that of ethylene-octene copolymers of the same density. For example, with an amount of coupling agent of 0.1% by weight, the viscosity change at 0.1 rad / s was 241% for Example 2a and 2214% for Example 4.

The result of comparative sample M is quite surprising.

Although the MWD of this polymer was broader, the rheology modification efficiency was very high. For example, at 0.1% by weight of the coupling reagent, the viscosity changes at 0.1 rad / s were 241% for Sample 2 and 648% for Comparative Example M.

Comparative samples E and F showed less effect of coupling - in terms of changes in storage modulus and Tg. For the comparative Hal samples, no displacement in Tg was observed with a slight increase in modulus with increasing azide levels. Examples 5 and 6 showed a significant shift in the storage module, which increased by 38% at 26 ° C and by 167% at 153 ° C. At a level of 0.1% Tg also increased by 7'C.

i \ · ♦ • * * · · · · · · · · · · · · · · · · · · · · ·...... · ··· · ·· · ·. · ·· »· ·

For the polyethylene samples, Examples 1 and 2 showed an extension and increase in Tg and a significant increase in modulus (60%) in the melt mode (temperature above 100 ° C) when performing the coupling. Examples 7 and 8 showed no significant Tg shift but a significant increase in module at room temperature and a large increase in module at high temperature (471%). Examples 3 and 4 showed, with the coupling of extension and Tg increase, a significant increase in module at room temperature (43%) and module at high temperature

..... ... ...., - .—, ·· ....., J .................. X- _f ' _{| ί]} - ₁ .... _| - _{| [|} · ,. _|| . _{1 [} . ^ _{R |} . • 'ί, .- γ-ί _? · -, _{_,,%} (5914%). Examples 9 and 10 showed an increase in Tg of 3 ° C, an increase in modulus at room temperature of 30% and an increase in modulus at high temperature of 1017%. Comparative samples M and N showed no significant increase in Tg, but showed an increase in alpha transition intensity (melting), an increase in modulus at room temperature of 40% and an increase in modulus at high temperature of 605%. did not show a module change at room temperature, but showed a 510% increase in module at high temperature. In summary, the rheological behavior of the melt due to the coupling in the practice of the invention shows the greatest differences between the comparative samples (not subjected to the coupling reactions).

Claims (12)

PATENTOVÉ Claims A method for preparing a coupled polymer, comprising heating a mixture comprising (1) at least one polyolefin containing ethylene and optionally at least one comonomer selected from the group consisting of: Λ> · group consisting of alpha-olefins containing at least 3 carbon f <~ .'- -'I. "... Uf ¹ · lil 'm' T ii j '. wherein the polyolefin ' ¹ ' has a molecular weight distribution of less than or equal to 3, and (2) a coupling amount of at least one pole (sulfonylazide) to, at least a poly (sulfonylazide) u decomposition temperature for a time sufficient to decompose at least 80% by weight of the poly (sulfonylazide) u and sufficient to obtain the coupled polymer. 2. The process of claim 1 wherein the polyolefin is a polymerization product of ethylene and optionally at least one additional alpha-olefin in the presence of a single-position single site catalyst. The method of claim 2, wherein the polyolefin has a density of at least 0.945 g / ml. —Ř -. _ ....... · .................................. A method according to claim 1, characterized in that. the amount of poly (sulfonylazide) is 0.01 to 5% by weight, based on the polyolefin. Method according to one of Claims 1 to 4, characterized in that the coupling agent consists of at least one poly (sulfonylazide) having a structure> fe 9 9 XRX wherein each X is SO ₂ N ₃ and R represents an unsubstituted or inertly substituted hydrocarbyl group, a hydrocarbyl ether group, or a silicon-containing group. * '. »» »Ill III III III H || ||............. M M M M M M M M M M M M M | i | i | i1.l | iiwl'WIIIII ΙΙΙΙΙΙ I III II, r.1J »W» III »II« WI !! »r III.I II ι · II ΙΙΙ.ΙΙΙ IΙΙΜΙΙ1II. ι; Γ1Γ. I 1ΓΙΊΙ 11III Process according to any one of claims 1 to 5, characterized in that the at least one pole (sulfonylazide) has at least 3 atoms but less than 50 carbon, silicon or oxygen atoms between the sulfonylazide groups, and wherein R comprises at least Or wherein R is one aryl group having more than one ring. Method according to one of Claims 1 to 6, characterized in that the poles (sulfonylazide). is selected from the group consisting of 1,5-pentanebis (sulfonylazide), 1,8-octanbis (sulfonylazide), 1.10- decanbis (decanesulfonylazide), 1.10-octadecanbis (sulfonylazide), 1-octyl-2,4,6-benzentris (sulfonylazide), 4,4'-diphenyletherbis (sulfonylazide), 1,6-bis (4'-sulfonazidophenyl) hexane 2.7- Naphthalenebis (sulphonylazide), mixed sulphonylazides of chlorinated aliphatic hydrocarbons containing on average 1 to ‘8 chlorine atoms and from 2 to 5 sulphonylazide 3 groups, and mixtures thereof. Process according to any one of claims 1 to 6, characterized in that the poles (sulfonylazide) and the polyolefin react at a temperature at least equal to the decomposition temperature and higher than 150 ° C. • · 0 0 0 · · 0 0 0 · 00 * 000 · 0 · · 000 * · * • 00 • 0 0 0 0 0 0 · 0 t · 000000 · 0 · 0 0 0 0 A composition which is the product of any of the processes of claims 1 to 8. An article comprising the composition of claim 9. Use of any composition according to claim 9 in a molding, blow molding or extrusion blow molding process. The article of claim 1, which is a bottle, tube, fuel tank, fuel tank throat or milk jug.