CZ20003207A3 - Dynamic vulcanization of polymer blends in consecutive reactors - Google Patents

Abstract

A method for the dynamic vulcanization of a mixture of polymers produced by solution polymerization in reactors arranged in series. The polymer mixtures are mixed under conditions of heat and shear and a vulcanizing agent is added to at least partially crosslink the components of the mixture.

Description

Dynamic vulcanization of polymer blends in series reactors

Technical area

This invention relates to a method for preparing polymer blends using cascade reactors and a metallocene catalyst. The monomers used in this invention are ethylene, higher alpha-olefins (propylene is most preferred) and optionally a non-conjugated diene (preferably ethylidene norbornene ENB). More specifically, this invention relates to the preparation of EP (ethylene-propylene) copolymer blends in which the components of the blend differ in some of the following properties: 1. composition, 2. molecular weight and 3. crystallinity. The term EP copolymer is also used for terpolymers containing different amounts of non-conjugated diene. Such terpolymers are commonly known as EPDM.

There are various advantages to preparing the above blends. For example, EP (ethylene propylene copolymer) and EPDM (ethylene propylene diene terpolymer) polymers are often used as blends of two or more polymers to obtain the optimum properties of the polymer for a given application. Blending high and low molecular weight polymers broadens the molecular weight distribution and thus provides better processability than narrow molecular weight polymers with the same average molecular weight. A semi-crystalline polymer can be blended with an amorphous polymer to improve the toughness (green strength-strength after forming) of the amorphous component at temperatures below the melting point of the semi-crystalline polymer. Polymers with higher green strength have less tendency to cold flow and exhibit better properties in processing methods such as calendering and extrusion.

♦ ·

State of the art

One way to create the above-mentioned blends is to blend two different polymers after their polymerization in order to obtain the desired set of properties. However, this method is expensive and therefore it is much more desirable to prepare the blends by direct polymerization. Blends prepared by direct polymerization are well known from previously published patent documents such as the preparation of EPDM using Ziegler-Natta catalysts based on soluble vanadium in series reactors and the preparation of polymers with different properties in each reactor. Patent documents describing the use of vanadium processes in series reactors are U.S. Patent No. 3,629,212, U.S. Patent No. 4,016,342 and U.S. Patent No. 4,306,041, which are incorporated by reference for the purposes of U.S. patent law.

Although it is possible to perform polymer blending using Ziegler-Natta catalysts in series reactors, there are serious limitations on the amount and properties of the polymers that can be produced in both reactors, especially in the second reactor. For economic reasons, it is most advantageous to load the catalyst only in the first reactor in order to reduce the consumption of expensive catalyst components. Because the rate of deactivation of the active vanadium components is significant, the catalyst concentration in the second reactor in the series is very low and would be even lower in the others. As a result, it would be very difficult to prepare more than about 35)% of the total polymer in the second reactor. Low catalyst concentration can also limit the composition or molecular weight of the polymer. This problem can be overcome by adding catalyst activators or additional catalysts to the second and subsequent reactors, but this increases the production cost. In addition, vanadium catalysts have a limited ability to produce polymers with

with an ethylene content of less than 35 wt.%, because they polymerize ethylene much more readily than propylene or higher alpha-olefins. In addition, soluble vanadium catalysts are incapable of producing copolymers or terpolymers exhibiting crystallinity due to the presence of long sequences of isotactic polypropylene.

The essence of the invention

The present invention differs from the prior art in that it provides a method for producing polymer blends in series reactors that overcomes the quality problems of the prior art. It is noted that the terms multi-stage reactor and series reactors are used interchangeably herein. By using metallocene catalysts with high lifetime, polymer blends can be produced with a much wider range of components, composition and molecular weight than polymer blends that can be obtained using prior art vanadium catalysts. In particular, it is an object of the present invention to use series reactors to produce the following types of blends: a. blends in which the ethylene content of the polymer produced in the first and second reactors differs by 3 to 75 wt.%. ethylene, b. mixtures in which the molecular weight distribution (MWD) of the mixture is characterized by the ratio Mw/Mn = 2.5 to 20 and the MW/MN of the individual components of the mixture is 1.7 to 2.5 and c. mixtures in which both the polymer composition and the MWD meet the criteria in points a. and b. above and d. mixtures in which one component contains 0 to 20 wt. % ethylene, is semi-crystalline due to the presence of isotactic propylene sequences in the chain and has a melting point of 40 to 160 °C, and the other component is amorphous and e. mixtures in which one component contains 60 to 85 wt. % ethylene, is semi-crystalline due to the presence of long ethylene sequences in the chain and has a melting point of 40 - 120 °C and the other component is amorphous.

This polymer mixture prepared in series reactors is used in dynamic vulcanization to obtain improved thermoplastic elastomer products.

The polymerization is preferably carried out as a homogeneous solution polymerization. The catalyst is a cyclopentadienylmetallocene complex with two Cp (cyclopentadiene) ring systems for ligands or a monocyclopentadienylmetallocene catalyst.

The metallocene complexes are activated with an alumoxane, such as methylalumoxane (MAO) or a non-coordinating anion (NCA) described below. Optionally, a trialkylaluminum scavenger may be added to the reactor feed to protect the catalyst from deactivation by poisons. The reactors are preferably liquid-filled, stirred flow reactors. In a preferred embodiment, this process uses two or more stirred flow reactors in series with two reactors. The solvent and monomers are fed to all reactors, and it is preferred that only the first reactor is charged with catalyst. The reactors are cooled by a cooling jacket or coils, autorefrigeration, precooling of the feed, or a combination of all three. A self-cooled reactor requires the presence of a vapor phase in the reactor. Adiabatic reactors with a precooled feed are preferred. This allows for a temperature difference between the reactors, which helps control the molecular weight of the polymer. The monomers used in this process are ethylene and higher alpha-olefins C3C8. The most preferred higher alpha-olefin is propylene. If desired, the monomers may also include a non-conjugated diene, in which case the most preferred diene is ENB (55

• · • ·· • ♦ · · • ·

The temperatures in the second reactor vary between 40 and 160°C, with temperatures of 50-140°C being preferred and 60-120°C being most preferred.

When two reactors are used in series, the composition of the polymer produced in the first reactor is 0-85% by weight ethylene and the composition of the polymer in the second reactor is 0-85% by weight ethylene. The average composition of the polymer mixture is 6-85% by weight ethylene.

If the Mw/mn ratio of the mixture is less than 2.5, then the difference in the composition of the polymer produced in the first and second reactors is 3-75% ethylene, preferably 5-60% ethylene, and most preferably 7-50% ethylene. If the Mw/Mn ratio of the mixture is 2.5 or greater, then the composition of the components of the mixture may be either the same or different.

In another embodiment, the difference in ethylene content of the two components is such that one is semi-crystalline and the other is amorphous. Semi-crystalline is defined as having a melting point determined by DSC (differential scanning calorimetry) and a heat of fusion of at least 10 J/g, while amorphous is defined as having no melting point determined by DSC and a heat of fusion of less than 10 J/g. Semi-crystalline polymers of the present invention typically have a melting point of about 40-160 °C depending on the polymer composition. DSC measurements are performed as described in • ·

99 ·9 • 9 · 99

99 ·9 ·

9 9 9

9 9 9

9 9 9 in the Examples section. When using the catalysts of this invention, the ethylene-propylene copolymers are typically amorphous and have ethylene contents between 20 and 60% by weight. If a polymer component with ethylene crystallinity is to be present in the mixture, it must have more than 60% ethylene. On the other hand, if a component with propylene crystallinity is desired, it must have less than about 20% by weight ethylene. In addition, in this case, it is necessary to use a catalyst system capable of polymerizing propylene stereospecifically. Catalyst systems producing isotactic propylene sequences are most preferred.

Depending on the degree of crystallinity of the semi-crystalline component and the difference in composition between the components, the two components may be immiscible and form a mixture of phase-separated components upon exiting the reactor. The presence of multiple phases can be readily measured by standard polymer characterization techniques such as optical microscopy in visible light, electron microscopy, or atomic force microscopy (AFM). Biphasic polymer blends often have advantageous properties, and it is a particular object of the present invention to prepare such biphasic blends by direct polymerization.

When two reactors are used in series, the amount of polymer produced in the second reactor is 15-85% of the total polymer produced in both reactors, preferably 30-70% of the total polymer produced in both reactors.

The MWD of polymers produced using metallocene catalysts tends to be narrow (MW/Mn < 2.5) and as a result the polymers generally do not have good processing properties. It is a particular object of the present invention that the polymers prepared in the first and second reactors have sufficiently different molecular weights so that the MWD is broadened. The MW/Mn of the final product should preferably be 2.5-20.0 and most preferably 3.0-10.0.

·· ·*

The diene content of the polymer may vary from 0 to 15% by weight, preferably from 2 to 12% by weight and most preferably from 3 to 10% by weight. The diene contents of the polymers produced in the two reactors may be the same or different. The process of the invention can produce mixtures of copolymer and terpolymer. For example, if the diene is added only to the second reactor, a copolymer of ethylene and propylene can be produced in the first reactor, while a terpolymer of ethylene, propylene and diene can be produced in the second reactor.

A preferred embodiment of the invention is to operate the reactors arranged in series to produce mixtures in which the proportions of the components of the mixture differ by at least 3% by weight of ethylene, the Mw/Mn of the mixture is equal to or greater than 2.5, and one of the components of the mixture is semi-crystalline. Another preferred feature is that the semi-crystalline polymer comprises isotactic polypropylene exhibiting crystallinity.

In a mixture combining all the above-described features of the invention, for a given average ethylene content and molecular weight of the final product, the properties of the polymer will vary depending on the composition and molecular weight of all the components. The process according to the invention is capable of giving mixtures in which: a. polymer 1 either has a higher ethylene content and molecular weight than polymer 2, or b. polymer 1 has a higher ethylene content and a lower molecular weight than polymer 2. Polymer 1 and polymer 2 can be prepared in either the first or second reactor.

In the case of terpolymerization, the blends can further vary in the diene content of each component. Typically, it is preferred to have a higher diene content in the lower molecular weight component, which results in optimal product properties in vulcanized thermosetting compounds.

This invention can be characterized as a method > ·♦ • · ·· ·· ·· . * · <

• · · « • · · · forming a polymer mixture by solution polymerization, which includes: a. charging a first set of monomers and solvent in predetermined mutual ratios into a first reactor, b. adding a metallocene-based catalyst to the first reactor, c. polymerizing the first set of monomers in the first reactor so that the effluent from the reactor contains the first polymer, d. charging the effluent from c. to a second reactor, e. charging the second set of monomers in predetermined ratios into a second reactor with an optional additional solvent, f. polymerizing the second set of monomers in the second reactor onto the second polymer without adding a substantial amount of catalyst. Thus, more than 50% by weight of the total amount of catalyst charged to all reactors is preferably added to the first reactor, more preferably more than 75% by weight, and most preferably 100% of the total amount of catalyst added to all reactors is added to the first reactor. The first and second sets of monomers are selected from the group consisting of ethylene, higher alpha-olefins and non-conjugated dienes. The preferred higher alpha-olefin is polypropylene and the preferred non-conjugated diene is selected from the group consisting of 5-ethylidene-2-norbornene (ENB),

1,4-hexadiene, dicyclopentadiene (DCPD), norbornadiene and 5-vinyl-2-norbornene (VNB), with ENB being most preferred.

The non-conjugated diene may be added to the first set of monomers and/or to the second set of monomers in an amount such that the diene content in the polymer mixture is preferably from 0 to 15%, more preferably from 2 to 12%, and most preferably from 3 to 10%.

The relative proportions of monomers can be controlled to obtain different polymer mixtures with components containing different ethylene contents. For example, the proportions of monomers in the first reactor and in the second reactor can be controlled so that the ethylene contents in the first and second polymers differ by 39 ·* • · 4

4,444

44 · 4 «

4 4 4

4 4 «

4 4 4

44% by weight. In addition, the proportions of monomers in the first and second reactors can be controlled so that the first polymer contains 0 to 85% by weight of ethylene, the second polymer has 0 to 85% by weight of ethylene and the polymer mixture has 6 to 85% by weight of ethylene. Preferably, the mixture of semi-crystalline and amorphous polymers is obtained by adjusting the relative quantitative ratio of monomers in the first and second reactors so that the ethylene content in the first and second polymers differs such that either a. the first polymer is semi-crystalline and the second polymer is amorphous, or b. the first polymer is amorphous and the second polymer is semi-crystalline.

It is preferred that the molecular weight of the components of the mixture is determined to produce a polymer product with a broader MWD than the MWD of the individual components. Specifically, the molecular weight of the first and second polymers or both polymers can be controlled by at least one of the following: a. adding a chain transfer agent to the first or second or both reactors, b. operating the first and second reactors adiabatically with a temperature difference between the reactors. If a broader MWD is desired, it is preferred that the molecular weight of the first or second polymer or both polymers is controlled such that the first and second polymers have a Mw/Mn ratio of 1.7 to 2.5, while the polymer mixture has a Mw/Mn of 2.5-20. Most preferably, the molecular weight of the first and second polymers or both polymers is controlled such that the first and second polymers have a Mw/Mn of 1.7 to 2.5, and the polymer mixture has a Mw/Mn of 3.0 to 10.0. When a product with a narrow MWD is required for a particular application, the molecular weight of the first and second polymers is controlled so that the polymer blend has a Mw/Mn ratio below 2.5.

When the molecular weight distribution is broadened, it is necessary for one component of the mixture to have a higher molecular weight than the other component of the mixture. Therefore, the molecular weight of the first and second polymers or both polymers is controlled so that: a. either the first polymer has a higher molecular weight than the second polymer, b. or the first polymer has a lower molecular weight than the second polymer. The Mw of each component may be in the range of 10,000 to 2,000,000, preferably in the range of 25,000 to 1,000,000 and most preferably in the range of 50,000 to 500,000.

These mixed polymers from the reactors arranged in series can then be dynamically vulcanized by vulcanizing thermoplastics.

It is also possible to control the ethylene content and the molecular weight at the same time. When controlling the molecular weight in order to obtain a mixture in which one component has a higher molecular weight than the other, it is advantageous to control the ethylene content of each component. The relative proportions of the monomers in the first and second reactors can then be controlled so that: a. if the first polymer has a higher molecular weight, then the first polymer has a higher ethylene content compared to the second polymer, or b. if the first polymer has a lower molecular weight, then the first polymer has a lower ethylene content compared to the second polymer. In addition, the relative quantitative ratios of the monomers in the first reactor and in the second reactor can be controlled so that: a. if the first polymer has a higher molecular weight, then the first polymer has a lower ethylene content compared to the second polymer, or b. if the first polymer has a lower molecular weight, then the first polymer has a higher ethylene content compared to the second polymer.

As is apparent from the foregoing descriptions, when carrying out the process of the invention, polymer mixtures with various combinations of the distribution width of the components contained, the distribution width of the molecular weight or both can be obtained. When the molecular weight of the component of the polymer mixture is controlled so as to maintain the ratio Mw/Mn of the final product at 2.5 or less, it is preferable to control the quantitative ratio of the monomers in the first and second reactors so that the ethylene content in the first and second reactors differs by 3 to 7.5% by weight, more preferably 5-60% by weight and most preferably 7 to 50% by weight.

The relative ratio of the monomers can also be controlled to obtain a mixture in which one component is semi-crystalline, while the other is amorphous. In this way, the relative ratio of the monomers in the first reactor and in the second reactor can be controlled so that one of the two polymers contains 0 to 20% ethylene, is semi-crystalline due to the presence of isotactic propylene sequences and has a melting point of 40 to 160 ° C, while the other polymer is amorphous. In addition, the weight ratios in the first and second reactors can be controlled so that one of the two polymers contains 60 to 85% ethylene, is semi-crystalline due to the presence of isotactic propylene sequences and has a melting point of 40 to 120 ° C, while the other polymer is amorphous. Mixtures of two semi-crystalline polymers, one with 0-20% ethylene and the other with 60-85% ethylene, are also within the scope of the present invention. The degree of crystallinity and the difference in composition of the components can also be chosen so that the components of the mixture do not mix and the final product consists of a two-phase mixture. It is particularly desirable that one of the components of the two-phase mixture exhibits crystallinity as a result of the presence of isotactic propylene sequences. Such two-phase mixtures cannot be prepared using previously patented vanadium-based catalyst systems.

As regards the catalyst, it is advantageous for economic reasons that practically all of the catalyst is added to the first reactor. The catalyst components can be charged to this reactor either separately or premixed. The catalyst, which is described in more detail below, is based on a metallocene of groups 4, 5 and 6 and is activated with « « methylalumoxane MA.0 or a non-coordinating anion NCA and may optionally contain a scavenger. It is advantageous that this catalyst is chiral and stereorigid. It is advantageous that the catalyst is capable of producing stereoregular polypropylene.

With respect to temperatures, it is preferred that the first reactor operates at temperatures between about 0 and 110°C and the second reactor between about 40 and 160°C. Even more preferred is the first reactor operating at temperatures between about 10 and 90°C and the second reactor between about 50 and 140°C. Most preferred is the first reactor operating at temperatures between about 20 and 70°C and the second reactor between about 60 and 120°C. It is also preferred that the reactors are cooled at least in part by precooling the charge and that there is a temperature difference between the reactors.

To protect against catalyst deactivation, a scavenger may be added to at least one of the reactor charges prior to polymerization. Preferably, the scavenger is a trialkylaluminum.

As for the reactors, it is preferable that the first and second reactors are stirred flow reactors arranged in series. Furthermore, it is preferable that the polymerization in the first and second reactors is a homogeneous solution polymerization.

The process of the present invention can be carried out in any of the known multi-stage reactor systems. Two suitable systems are described in U.S. Patent Nos. 4,016,342 and 4,306,041, which are incorporated herein by reference. In addition, suitable multi-stage reactor systems are described in copending patent applications 98B009, filed March 4, 1998, and 98B011, filed March 4, 1998, and are incorporated herein by reference in accordance with U.S. patent law. If desired, more than two reactors can be used in the process of the present invention. The process of the present invention can be used in solution or suspension polymerization, but solution polymerization is preferred and is used herein in • · · ··

• · * ·

The choice of temperature used in the reactors depends on the effect of temperature on the rate of catalyst deactivation and on the properties of the polymer, particularly the molecular weight of the polymer. The temperatures should not exceed the point at which the concentration of catalyst in the second reactor is insufficient to form the desired polymer component in the required amount. This temperature is a function of the detailed characteristics of the catalyst system. In general, the temperature in the first reactor may be between 0 and 110 °C, with 10 to 90 °C being preferred and 20 to 70 °C being most preferred. The temperatures in the second reactor range from 40 to 160 °C, with 50 to 140 °C being more preferred and 60 to 120 °C being most preferred. The reactor may be cooled by a cooling jacket, cooling coils, self-cooling, pre-cooled charge and combinations of these. Adiabatic reactors with pre-cooled feed are preferred. This creates a temperature difference between the reactors, which helps control the molecular weight of the polymer.

In all reactor stages, the residence time is the same or different and is determined by the reactor volumes and flow rates.

The residence time is defined as the average length of time the reactants remain in the reactor space. The total residence time, i.e. the total time spent in all reactors, is preferably 2 to 80 minutes, and more preferably 5 to 40 minutes.

The polymer composition is controlled by the amount of monomers fed to each reactor of the system. In two-reactor series, unreacted monomers from the first reactor flow into the second reactor, and therefore the monomers added to the second reactor serve to adjust the composition of the reactants to the desired level, taking into account the monomer conversion from the first reactor. Depending on the reaction conditions in the first reactor (catalyst concentration, temperature, amount of monomer fed, and so on), it may happen that the amount of monomer at the outlet of the reactor is excessive in relation to the amount needed to achieve the desired composition in the second reactor. Since it is not economically feasible to remove monomer from the reaction mixture, this situation must be prevented by adjusting the reaction conditions. The amount of polymer produced in each reactor depends on a number of reactor operating conditions such as residence time, temperature, catalyst concentration, and monomer concentration, but is most dependent on the monomer concentration. Therefore, the amount and composition of the polymer formed in the second reactor are largely independent.

The molecular weight of the polymer is controlled by the reactor temperature, the monomer concentration and the addition of a chain transfer agent such as hydrogen. In the case of metallocene catalysts, the molecular weight of the polymers generally decreases with increasing reaction temperature and decreasing ethylene content in the polymer. When operating in a two-reactor setup with adiabatic reactors, the temperature in the second reactor is higher than in the first, which facilitates the formation of the lower molecular weight component in the second reactor. The molecular weight in the second reactor can be further reduced and the MWD extended by adding hydrogen to the second reactor. Hydrogen can also be added to the first reactor, but since unreacted hydrogen is transferred to the second reactor, the molecular weight of both polymer components will decrease in this case and the effect of hydrogen on the MWD will be much smaller. A high monomer concentration generally increases the molecular weight of the polymer.

Polymer composition can affect the molecular weight of the polymer, ceteris paribus, due to chain transfer processes involving alpha-olefin comonomers. It is often observed that molecular weight decreases as the alpha-olefin content of the polymer increases. In the context of molecular weight control

• · · ♦ · ** an alpha-olefin comonomer can be considered a chain transfer agent and can be used to influence the molecular weight of one of the components of a mixture.

In the case of two reactors in series, the diene can be added to one or the other reactor or to both. When preparing a copolymer/terpolymer mixture, the diene is added only to the second reactor.

The polymer product is recovered from the solution after completion of the polymerization by any of the techniques well known in the art, such as steam stripping, extrusion drying, and devolatilization extrusion.

Although the most preferred alpha-olefin for use in the present invention is propylene, other higher alpha-olefins may be used as shown below. Higher alpha-olefins suitable for this application may be branched or straight chain, cyclic, aromatically substituted or unsubstituted, and most preferably are C3-C18 alpha-olefins. Examples of suitable higher alpha-olefins include, but are not limited to, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 1-dodecene. Mixed alpha-olefins such as mixtures of alpha- and (non)alpha-olefins (e.g., mixtures of butenes) may also be used, provided that any non-polymerizable olefins in the mixture act inertly on the catalysts. Examples of such substituted higher alpha-olefins include compounds of the formula H ₂ C=CH-C _n H2n-X, in which n is an integer denoting the number of from 1 to 30 carbon atoms (preferably up to 10 atoms) and X preferably represents CH3, but can also mean aryl, alkaryl or cycloalkyl substituents. Also useful are higher alpha-olefins substituted with one or more such X-substituents, in which the substituent or substituents are bonded to a carbon that is not terminal and which is preferably 2 to 30 C away from the terminal carbon atom, provided that the thus substituted '4 »·

W · · ·· • · *»* · « · · · · · t · · · ·

B« «· ··* ·» »· • · · * • · · · » « · · * • ♦ · · »· ·· the carbon atom is preferably not in the olefin at position 1 or 2. If higher alpha-olefins are substituted, it is preferable that they are not substituted by aromatic rings or other bulky groups at position C2, since aromatic or bulky groups interfere with the subsequent desired polymerization.

Although the most preferred non-conjugated diene useful in the present invention is ENB, other non-conjugated dienes can be used as will be apparent from the following. Non-conjugated dienes useful as comonomers are preferably straight chain hydrocarbons, diolefins or alkene substituted cycloalkenyls having 6 to about 15 carbon atoms such as: a. straight chain acyclic dienes such as

1,4-hexadiene and 1,6-octadiene; b. branched-chain acyclic dienes such as 5-methyl-1,4-hexadiene; 3,7-dimethyl-1,6-octadiene and 3,7-dimethyl-1,7-octadiene; c. single-ring alicyclic dienes such as 1,4-cyclohexadiene; 1,5-cyclooctadiene and 1,7-cyclododecadiene; d. polycyclic fused and bridged-ring alicyclic dienes such as tetrahydroindene; norbornadiene; methyltetrahydroindene; dicyclopentadiene (DCPD); bicyclo(2,2,1)-hepta-2,5-diene; alkenyl-, alkylidene-, cycloalkenyl- and cycloalkylidenenorbornenes such as 5-methylene2-norbornene (MNB); 5-propenyl-2-norbornene; 5-isopropylidene-2-norbornene; 5-(4-cyclopentenyl)-2-norbornene; 5-cyclohexylidene-2-norbornene and 5-vinyl-2-norbornene (VNB); e. cycloalkenylalkenes such as vinylcyclohexene, allylcyclohexene, vinylcyclooctene, 4-vinylcyclohexene, allylcyclodecene and vinylcyclododecene. Of the non-conjugated dienes typically used, the preferred dienes are dicyclopentadiene, 1,4-hexadiene, 5methylene-2-norbornene, 5-ethylidene-2-norbornene and tetracyclo(Δ-11,12)5,8-dodecene. Particularly preferred diolefins are 5-ethylidene-2-norbornene (ENB), 1.417 ·« ·« « · 9 • · ··* • e · · · · · « Λ· ·· »· · · · · · • » « · · · · · · · · ···«< ·· »· hexadiene, dicyclopentadiene (DCPD), norbornadiene and 5-vinyl-2-norbornene (VNB). It is worth noting that in this application the terms nonconjugated diene and diene are used interchangeably.

Although hexane is the most suitable solvent for use in accordance with the invention, other useful solvents are hydrocarbons, such as aliphatic, cycloaliphatic and aromatic hydrocarbons, provided that the solvent is inert to the catalyst. Preferred solvents are C12 or lower saturated hydrocarbons with branched or unbranched chains and saturated alicyclic hydrocarbons or aromatic hydrocarbons of C5 to C9. Examples of such solvents or reaction media are hexane, butane, pentane, heptane, cyclopentane, cyclohexane, cycloheptane, methylcyclopentane, methylcyclohexane, isooctane, benzene, toluene and xylene. In addition, one or more olefins, either alone or mixed with other media, may serve as the reaction media at selected concentrations of such olefins.

The term metallocene or metallocene catalyst precursor as used in this application refers to compounds containing a transition metal M with cyclopentadienyl ligands (Cp), at least one ligand X not derived from cyclopentadienyl and a ligand Y containing no or one heteroatom, wherein the ligands are in a coordinate bond to M and their number corresponds to its valence. Metallocene catalyst precursors are generally neutral complexes, which, however, upon activation with suitable co-catalysts, provide an active metallocene catalyst, which is an organometallic complex with an unoccupied coordination site that can coordinate, bind or polymerize olefins. Metallocene catalyst precursors are preferably a metallocene compound or a mixture of metallocene compounds of one or both of the following types.

1. Cyclopentadienyl (Cp) complexes with two Cp ring systems as ligands. The Cp ligands form sandwich complexes with metals and may be free and rotatable, or may be locked in a rigid configuration by a bridging group. The Cp ring ligands may be the same or different, substituted or unsubstituted, or may be derived as a heterocyclic ring system which may be substituted and the substituents may condense to form other saturated or unsaturated ring systems such as tetrahydroindenyl, indenyl or fluorenyl ring systems. These cyclopentadienyl complexes have the general formula (Cp^JR^ÍCp^pJMXg) wherein Cp ¹ of the ligand (CP ¹ R ¹ «) and Cp ² of the ligand (Cp ² R ² p) are the same or different cyclopentadienyl rings, R ¹ and R ² are independently halogen, hydrocarbyl, halocarbyl, hydrocarbyl-substituted organometalloid or halocarbyl-substituted organometalloid group containing up to about 20 carbon atoms, m is 0 to 5, p is 0 to 5 and two R ¹ and/or R ² substituents on adjacent carbons of the cyclopentadienyl ring attached here can be joined together to form a ring containing from 4 to about 20 carbon atoms, R ³ is a bridging group, n is the number of atoms in the straight chain between the two ligands and is 0 to 8, preferably 0 to 3, M is a transition metal of valence 3 to 6, preferably from the groups 4, 5 or 6 of the Periodic Table of the Elements and is to be in its highest oxidation state, each X is a non-cyclopentadienyl ligand and is independently a halogen or a hydrocarbyl, oxyhydrocarbyl, halocarbyl, hydrocarbyl-substituted organometalloid, oxyhydrocarbyl-substituted organometalloid or halocarbyl-substituted organometalloid group containing up to about 20 carbon atoms, q corresponds to a valence of M /wws 2.

• · • · · · • ·

* ·

2. Monocyclopentadienyl complexes with only one Cp ring system as ligand. The Cp ligand forms a half-sandwich complex with the metal and may be free (unbridged) and capable of rotation, or it may be closed in a rigid configuration by bridging to the heteroatom ligand by a bridging group. The Cp cyclic ligand may be substituted or unsubstituted or derived therefrom as a heterocyclic ring system, which may be substituted and the substituents may condense to form other saturated or unsaturated cyclic systems such as tetrahydroindenyl, indenyl or fluorenyl ring systems. The ligand containing the heteroatom is bound to the metal and optionally to the Cp ligand by a bridging group. The heteroatom itself is an atom with coordination number three from group VA or VIA of the periodic table. These monocyclopentadienyl complexes have the general formula (Cp^) R ³ n(Y _r R ² )MX _s wherein R ¹ is independently halogen, hydrocarbyl, halocarbyl, hydrocarbyl-substituted organometalloid or halocarbyl-substituted organometalloid group containing up to about 20 carbon atoms, m is 0 to 5 and two R ¹ substituents on adjacent carbons of the cyclopentadienyl ring attached thereto may be joined together to form a ring containing from 4 to about 20 carbon atoms, R ³ is a bridging group, n is 0 to 3, preferably 0 to 3, M is a transition metal of valence 3 to 6, preferably from groups 4, 5 or 6 of the periodic table of elements and should be in its highest oxidation state, Y is a heteroatom-containing group, in which the heteroatom is an element with a coordination number of three from Group VA or with a coordination number of two from Group VIA, preferably nitrogen, phosphorus, oxygen or sulfur, R ² is a radical selected from the group consisting of C ¹ to C ²⁰ hydrocarbon radicals, substituted with C 1 to C 20 hydrocarbon radicals, wherein one or more of the hydrogen atoms is replaced by a halogen atom, and when Y has a coordination number of 3 and is unbridged, Y may be independently two radicals R ² selected from the group consisting of C 1 to C 20 hydrocarbon radicals, wherein one or more • · ► 4 4

4 4 4 4 4 4 4 4 4 4 • · · · • 4 4 · • ·· 4

4 4 4

4 4 4 hydrogen atoms are replaced by a halogen atom and each X is a non-cyclopentadienyl ligand and is independently halogen or a hydrocarbyl, oxyhydrocarbyl, halocarbyl, hydrocarbyl-substituted organometalloid, oxyhydrocarbyl-substituted organometalloid or halocarbyl-substituted organometalloid group containing up to about 20 carbon atoms, with corresponding to a valence of M hj/nus 2<

Examples of suitable biscyclopentadienyl metallocenes for this invention are described in U.S. Patents 5,324,800,

5,198,401, 5,278,119, 5,387,568, 5,120. 867, 5,017,714, 4,871,705, 4,542,199, 4,752,597, 5,132. 262, 5,391,629, 5,243.001, 5,278,264, 5,296.434 and 5,304 . 614, who are here

incorporated by reference.

Illustrative, but not exhaustive, examples of biscyclopentadienyl metallocenes suitable for the present invention, of the type described above in paragraph 1., are the racemic isomers of the compounds:

μ- (CH ₃ ) ₂ Si (indenyl) ₂ M(Cl) ₂ μ- (CH ₃ ) ₂ Si (indenyl) ₂ M (CH ₃ ) ₂ μ- (CH ₃ ) ₂ Si (tetrahydroindenyl) ₂ M (Cl) ₂ μ- (CH ₃ ) ₂ Si (tetrahydroindenyl) ₂ M (CH ₃ ) ₂ μ- (CH ₃ ) ₂ Si (indenyl) ₂ M(CH ₂ CH ₃ ) ₂ μ-(C ₆ H ₅ ) ₂ C (indenyl) ₂ M (CH ₃ ) ₂ , wherein M is selected from the group consisting of Zr and Hf.

Examples of suitable unsymmetrical cyclopentadienyl metallocenes of the type described above in paragraph 1. are described in U.S. Patents 4,892,851, 5,334,677, 5,416,228 and 5,449,651 and are also described in J.Am.Chem.Soc.

1988, vol. 110, p. 6255, which are incorporated herein by reference.

Illustrative, but not exhaustive, examples of unsymmetrical cyclopentadienyl metallocenes suitable for the present invention of the type described above in paragraph 1. are: μ-(C ₆ H ₅ ) ₂ C(cyclopentadienyl) (fluorenyl)M(R) ₂ μ-(C ₆ H ₅ ) ₂ C(3-methylcyclopentadienyl) (fluorenyl)M(R) ₂ μ-(CH ₃ ) ₂ C(cyclopentadienyl) (fluorenyl)M(R) ₂ • ·

μ-(C ₆ H ₅ ) ₂ C(cyclopentadienyl) (2-methylindenyl)M(CH ₃ ) 2 μ-(C ₆ H ₅ ) ₂ C(3-methylcyclopentadienyl) (2-methylindenyl)M(Cl) ₂ μ-(C ₆ H ₅ ) ₂ C(cyclopentadienyl) (2,7-dimethylfluorenyl)M(R) ₂ μ-(CH ₃ ) ₂ C(cyclopentadienyl) (2,7-dimethylfluorenyl)M (R) ₂ , wherein M is selected from the group consisting of Zr and Hf and R is selected from the group consisting of Cl and CH ₃ .

Examples of monocyclopentadienyl metallocenes of the type described above in paragraph 2. are described in U.S. Patents 5,026,798, 5,057,475, 5,350,723, 5,264,405 and 5,055,438 and are also described in WO 96/002244, which are incorporated herein by reference.

Illustrative examples of preferred monocyclopentadienyl metallocenes suitable for the present invention of the type described above in paragraph 2., but not exhaustive, are: μ- (CH ₃ ) ₂ Si(cyclopentadienyl) (1-adamantylamido)M(R)2 μ- (CH ₃ ) ₂ Si(3-tert.butylcyclopentadienyl) (1-adamantylamido)M(R) ₂ μ- (CH ₂ (tetramethylcyclopentadienyl) (1-adamantylamido)M(R) ₂ μ- (CH ₃ ) ₂ Si(tetramethylcyclopentadienyl) (1-adamantylamido)M(R)2 μ- (CH ₃ ) 2 C(tetramethylcyclopentadienyl) (1-adamantylamido)M(R) ₂ μ- (CH ₃ ) ₂ Si(tetramethylcyclopentadienyl) (1-tert.butylamido)M(R)2 μ- (CH ₃ ) ₂ Si(fluorenyl) (1-tert.butylamido)M(R) ₂ μ- (CH ₃ ) 2SÍ(tetramethylcyclopentadienyl) (1cyclododecylamido)M(R) ₂ μ-(C ₆ H ₅ ) ₂ C(tetramethylcyclopentadienyl) (1cyclododecylamido)M(R) ₂ , wherein M is selected from the group consisting of Ti, Zr and Hf and where R is selected from Cl and CH ₃ .

Another class of organometallic complexes useful as catalysts for the processes described herein are complexes with diimide ligands such as those of Du Pont described in WO 96/23010. These catalytic polymerization compounds are incorporated herein by reference.

The term non-coordinating anion (NCA) refers to an anion that either does not coordinate to the said transition metal cation • « or is only weakly coordinated to it and therefore remains sufficiently labile to be removed by a neutral Lewis base. Compatible non-coordinating anions are anions that do not degrade to a neutral compound upon decomposition of the primarily formed complex. In addition, the anion does not transfer an anionic substituent or fragment to the cation to form a neutral metallocene compound with four coordination bonds and a neutral by-product from the anion. Non-coordinating anions useful in the present invention are those that are compatible, stabilize the metallocene cation by stabilizing its charge to +1, while maintaining the necessary lability to allow their removal during polymerization by an ethylenically (double bond) or acetylenically (triple bond) unsaturated monomer. In addition, the anions useful in the present invention are large or bulky in the sense of having a sufficient molecular size to substantially inhibit or prevent neutralization of the cation by Lewis bases other than by the action of polymerizable monomers that may be present during the polymerization process. Typically, the anion has a molecular size greater than about 4 Angstroms or larger.

Descriptions of ionic catalysts for coordination polymerization containing metallocene cations activated by non-coordinating anions are found in earlier applications in EP-A-0,277,003, EP-A-0,277,004, US Patents 5,198,401, 5,278,119 and WO 92/00333. They describe a preferred method of preparation in which metallocenes (bisCp and monoCp) are protonated with anionic precursors in such a way that an alkyl or hydride group is cleaved from the transition metal, thereby both making it a cation and neutralizing it (balancing its charge) by the action of a non-coordinating anion. The use of an ionizing ionic compound which does not carry an active proton but is capable of forming both an active metallocene cation and a non-coordinating anion is also known, see EP-A-0,426,637, EP-A-0,573,403 and US Pat. No. 5,387,568. Reactive cations other than Bronsted acids capable of ionizing metallocene compounds include ferrocenium triphenylcarbonium and triethylsilyllinium. In the anion of the second activator compound,

may use or be contained in any metal or metalloid capable of forming a coordination complex resistant to the degradative effects of water (or other Bronsted or Lewis acids). Suitable metals include, but are not limited to, aluminum, gold, platinum, and the like. Suitable metalloids include, but are not limited to, boron, phosphorus, silicon, and the like. The disclosures of non-coordinating anions and their precursors in the cited patents are incorporated herein by reference under U.S. patent law.

Another method of preparing ionic catalysts uses ionizing anionic precursors which are originally neutral Lewis acids but upon ionization reaction with metallocene compounds form a cation and anion, for example tris(pentafluorophenyl)boron acts to cleave an alkyl, hydride or silyl ligand to form a metallocene cation and a stabilizing non-coordinating anion, see EP-A-0,427,697 and EP-A-0,520,732. Ionic catalysts for addition polymerization can also be prepared by oxidation of metal centers in transition metal compounds by anionic precursors which contain metal oxidizing groups together with anionic groups, see EP-A-0,495,375. The descriptions of coordinating anions and their precursors in these documents are hereby incorporated by reference in accordance with U.S. patent law.

Examples of suitable activators capable of ionic cationization of the metallocene compounds of the invention and subsequent stabilization with subsequent formation of a non-coordinating anion include: ammonium salts substituted with three alkyls such as;

triethylammonium tetraphenylborate tripropylammonium tetraphenylborate tri(n-butyl)ammonium tetraphenylborate trimethylammonium tetrakis(p-tolyl)borate trimethylammonium tetrakis(o-tolyl)borate tributylammonium tetrakis(pentafluorophenyl)borate tripropylammonium tetrakis(o,p-dimethylphenyl)borate tributylammonium tetrakis(m,m-dimethylphenyl)borate tributylammonium tetrakis(p-trifluoromethylphenyl)borate tributylammoniumtetrakis(pentafluorophenyl)borate tri(n-butyl)ammoniumtetrakis(p-tolyl)borate a *> Targets S oel j

N,N-dialkylanilinium salts such as;

N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate N,N-dimethylanilinium tetrakis(heptafluoronaphthyl)borate N,N-dimethylanilinium tetrakis(perfluoro-4-biphenyl)borate N,N-dimethylanilinium tetraphenylborate

N,N-diethylanilinium tetraphenylborate

N,N-2,4,6-pentamethylanilinium tetraphenylborate and the like;

dialkylammonium salts such as;

di(isopropyl)ammoniumtetrakis(pentafluorophenyl)borate dicyclohexylammoniumtetraphenylborate and the like;

and triarylphosphonium salts such as;

triphenylphosphonium tetraphenylborate tri(methylphenyl)phosphonium tetraphenylborate tri(dimethylphenyl)phosphonium tetraphenylborate and the like.

Other examples of suitable anionic precursors include precursors containing a carbonium ion and a compatible non-coordinating anion. These include;

tropylium tetrakis(pentafluorophenyl)borate triphenylmethyltetrakis(pentafluorophenyl)borate benzene(diazonium)tetrakis(pentafluorophenyl)borate tropylium phenyltris(pentafluorophenyl)borate triphenylmethyliumphenyl-(trispentafluorophenyl)borate benzene(diazonium)phenyltris(pentafluorophenyl)borate tropylium tetrakis(2,3,5,6-tetrafluorophenyl)borate triphenylmethyl tetrakis(2,3,5,β-tetrafluorophenyl)borate benzene(diazonium)tetrakis(3,4,5-trifluorophenyl)borate tropylium tetrakis(3,4,5-trifluorophenyl)borate • 9 ·

9 · ·* . * · · . · · ·

9 9 Benzene(diazonium)tetrakis(3,4,5-trifluorophenyl)borate tropylium tetrakis(3,4,5-trifluorophenyl)aluminate triphenylmethylium tetrakis(3,4,5-trifluorophenyl)aluminate benzene(diazonium)tetrakis(3,4,5-trifluorophenyl)aluminate tropylium tetrakis(1,2,2-trifluoroethenyl)borate triphenylmethyltetrakis(1,2,2-trifluoroethenyl)borate benzene(diazonium)tetrakis(1,2,2-trifluoroethenyl)borate tropylium tetrakis(2,3,4,5-tetrafluorophenyl)borate triphenylmethylium tetrakis(2,3,4,5-tetrafluorophenyl)borate benzene(diazonium)tetrakis(2,3,4,5-tetrafluorophenyl)borate and the like;

In cases where the metal ligands contain halide groups such as (methylphenyl)silylene(tetramethylcyclopentadienyl)(tert-butylamido)zirconium dichloride, which are not capable of ionization cleavage under standard conditions, they can be converted by known alkylation reactions using organometallic compounds such as lithium or aluminum hydrides or alkylAl or alkylLi, alkylalumoxanes, Grignard reagents and the like. See patent documents EP-A-0,500,944, EP-A1-0,570,982 and EP-A1-0,612,768 for methods describing the reaction of alkylaluminum compounds with dihalides of metallocene compounds before or simultaneously with the addition of the activating anionic compound. For example, the aluminumalkyl compound can be mixed with the metallocene before being added to the reaction vessel. However, since the aluminum alkyl is also useful as a scavenger, its use in excess, in a greater than stoichiometric amount required for the alkylation of the metallocene, allows it to be added to the reaction medium at the same time as the metallocene compound. Normally, the alumoxane would not be added together with the metallocene to avoid premature activation, but it can be added to the reaction vessel directly in the presence of polymerizable monomers if it serves both as a scavenger and as an alkylation activator.

Known alkylalumoxanes are also suitable as catalyst activators, especially for metallocenes containing halides.

44

4 4 4

4 4 ·

4 4 4

4 4 4

44 ligands. The alumoxane component useful as a catalyst activator is typically an oligomeric aluminum compound represented by the general formula (R-Al-O) _n , which is a cyclic compound, or R(R-A1-0) _n AlR ₂ , which is a linear compound. In the general formula, R is an alkyl radical of C1 to C5, for example methyl, ethyl, propyl, butyl or pentyl, and n is an integer from 1 to about 50. Most preferably, R is methyl and n is at least 4, representing methylalumoxane (MAO). Alumoxanes can be prepared by many methods known in the art. For example, an alkylaluminum can be reacted with water dissolved in an inert organic solvent, or it can be contacted with a hydrated salt such as hydrated copper sulfate suspended in an inert organic solvent to form an alumoxane. It is true that, regardless of the preparation method, the reaction of an aluminum alkyl with a limited amount of water yields a mixture of linear and cyclic alumoxane variants.

Although the most popular scavenger used in the present invention is trialkylaluminum, other scavengers may be used as set forth below. The term scavenger as used in this application and in the claims refers to compounds effective in removing polar impurities from the solvent used in the reaction. These impurities can be inadvertently introduced with any of the components of the polymerization reaction, particularly the solvent, monomer and comonomer, and adversely affect the activity and stability of the catalyst. The result can be a decrease in activity or even deactivation, especially when the catalyst system is a metallocene cation pair not coordinating an anion. Polar impurities or catalyst poisons include water, oxygen, oxygenated hydrocarbons, metal impurities, and so on. It is advantageous to take appropriate precautions before introducing them into the reaction vessel, for example by chemical treatment or careful separation procedures, but it is normally required to introduce at least a small amount of scavenger into the polymerization process. Typically, the scavenger is an organometallic compound such as a Group 13 organometallic compound according to Patent Nos. 5,153,157, 5,241,025, EP-A-638 and WO-A• · ·· ·· • · * • · ··· · • * · · * · · · · · · · · · · · · · · · · · » •

91/09882 and WO-A-94/03506, mentioned above, and WO-A-93/14132. Examples include compounds such as triethylaluminum, triethylborane, triisobutylaluminum, isobutylaluminumoxane, which have bulky substituents covalently bonded to a metal or metalloid center and have the advantage of minimizing unwanted interactions with the active catalyst. When alumoxane is used as the activator, no additional scavenger is required. The amount of scavenger usable with the metallocene-based cation-noncoordinating anion pair in the polymerization reaction is minimized to the amount needed to enhance the activity.

The metallocene-based catalyst and activator can be introduced into the reactor either separately or in a premix.

Catalyst systems particularly suitable for the polymerization of ethylene and propylene allow a combination of high activity, good incorporation of alpha-olefin and diene into the chain and sufficiently high molecular weight of the polymer for elastomer applications at economically interesting reaction temperatures. Catalyst systems particularly suitable for achieving these objectives include catalysts selected from the group consisting of μ(CH ₃ ) ₂ Si (indenyl) ₂ Hf (CH ₃ ) ₂ ;

μ-(CH ₃ ) ₂ Si[tetramethylcyclopentadienyl] [adamantylamido]Ti(CH ₃ ) ₂ , or μ-(C ₆ H ₅ ) ₂ Si[cyclopentadienyl] [fluorenyl]Hf(CH ₃ ) ₂ .

Although the most popular scavenger used in accordance with the present invention is trialkylaluminum, other scavengers may be used as set forth below. The term scavenger compounds as used in this application and in the claims refers to compounds effective in removing polar impurities from the mixture fed to the reactor. These impurities can be inadvertently introduced with any of the components of the polymerization reaction, particularly the solvent, monomer and comonomer, and adversely affect the activity and stability of the catalyst. The result can be a decrease in activity or even deactivation, especially when the catalyst system is a metallocene-based cation-noncoordinating anion pair. Polar impurities or catalyst poisons include water, oxygen, oxygenated hydrocarbons, metallic impurities, and so on. It is advantageous to take appropriate precautions before introducing them into the reaction vessel, for example by chemical treatment or careful separation procedures, but it is still normally required to introduce at least a small amount of a scavenger into the polymerization process. Typically, the scavenger is an organometallic compound such as a Group 13 organometallic compound according to Patents 5,153,157, 5,241,025, EP-A-638 and WO-A91/09882 and WO-A-94/03506, mentioned above, and WO-A-93/14132. Examples include compounds such as triethylaluminum, triethylborane, triisobutylaluminum, isobutylaluminumoxane, which have bulky substituents covalently bonded to the metal or metalloid center and have the advantage of minimizing unwanted interactions with the active catalyst. When alumoxane is used as the activator, no additional scavenger is required. The amount of scavenger usable with the metallocene-based cation-non-coordinating anion pair is minimized in the polymerization reaction to the amount needed to enhance activity.

The rubber components of the mixture from the reactors arranged in series are generally present as small, i.e. microscopic particles within a continuous matrix of thermoplastic resin, although depending on the rubber to plastic ratio, a co-continuous morphology or phase inversion is also possible. It is desirable that the rubber is at least partially crosslinked, and preferably completely crosslinked. It is preferred that the rubber is crosslinked by a dynamic vulcanization process. The term dynamic vulcanization as used in this application and claims means a vulcanization or curing process of rubber in a mixture with a thermoplastic resin in which the rubber is vulcanized under shear stress conditions and at a temperature at which the mixture is fluid. The rubber is thus simultaneously crosslinked and dispersed in fine particles within the matrix of the thermoplastic resin, although, as mentioned above, other morphological structures may also exist. Dynamic vulcanization takes place by mixing the components of the thermoplastic elastomer at elevated temperatures in common mixing equipment such as roller mills, Banbury and Brabender mixers, continuous mixers, mixing screw extruders, and the like. Unique • ·

• · · · • · ♦ · ·· ·· The advantage of dynamically cured compositions is that, regardless of whether the rubber component is partially or fully vulcanized, the composition can be processed or reprocessed using conventional plastic processing methods such as extrusion, injection molding and molding. Solid waste and evaporated volatile components can be captured and recycled.

The terms fully vulcanized, fully cured, and fully crosslinked as used in the application and claims mean that the vulcanizable rubber component has been cured or crosslinked to a state in which the elastomeric properties of the crosslinked rubber are similar to those of rubber in its normal vulcanized state, separate from the thermoplastic elastomer composition. The degree of cure may be described in terms of gel content or, conversely, extractable components. A rubber component may be described as fully vulcanized when less than about 5%, and preferably less than 3%, of the rubber capable of being vulcanized by hydrosilylation is extracted from the product thermoplastic elastomer by a solvent suitable for that rubber. Alternatively, the degree of vulcanization may be expressed in terms of crosslink density. All of these descriptions are known in the art, for example, in U.S. Patents 5,100,947 and 5,157,081, both of which are incorporated herein by reference.

The compositions can be processed and reprocessed by conventional plastic processing methods such as extrusion, injection molding, and molding. Those of ordinary skill in the art will be able to determine the appropriate proportions, types of curing systems, and curing conditions necessary to effect the curing of the rubber. The rubber can be cured using varying amounts of curing agent, varying temperatures, and varying curing times to achieve optimum crosslinking. Any known rubber curing system may be used as long as it is suitable under the curing conditions for the specific olefin rubber or combination of rubbers used with the polyolefin. Such curing agents include sulfur, sulfur donors, metal oxides, resin systems, peroxide-based systems, platinum or peroxide hydrosilation, and the like, in • · • 9 999

9 9 9 9

9 9 9

9 9 9

99 in both cases with or without accelerators and auxiliary agents.

Examples of embodiments of the invention

The polymerization was carried out in two stirred liter reactors arranged in series with continuous feedstock inflow into the system and continuous product withdrawal. The first reactor could also be operated separately. Solvents (hexane) and monomers (ethylene, propylene and ENB) were purified over a bed of alumina and molecular sieves. Toluene for catalyst preparation was also purified by the same technique. All input materials were pumped into the reactors by a metering pump with the exception of ethylene, which flowed in a gaseous state under its own pressure into a flow regulator.

The temperature in the reactor was controlled by circulating water in a cooling jacket. The pressure in the reactor was maintained above the saturated vapor pressure of the reactant mixture, thereby maintaining the reactants in the liquid phase. The reactors were operated completely filled with liquid reactants.

The ethylene and propylene feeds were combined into a single stream and then mixed with a precooled hexane stream that had been cooled to 0°C. If ENB was used, it was also added to the hexane stream before the monomers. A hexane solution of triisobutylaluminum scavenger was also added to the combined solvent and monomer stream before it entered the reactor to further reduce the concentration of any catalyst poison. Molar Ratio

TIBA/metallocene was typically 10-60. The catalyst component mixture in toluene was separately pumped into the reactor and entered it through a second inlet. The polymer solution leaving the first reactor entered the second reactor. The monomer solution in hexane was fed into the second reactor through a separate inlet. The product from the second reactor exited through a pressure reducing valve that reduced the pressure to atmospheric. As a result, the excess monomers in the solution were converted to a vapor phase that was vented from the top of the liquid-vapor separator. The liquid phase drained from the bottom of the separator and collected for polymer recovery. The polymer was recovered from the solution either by stripping with steam or by drying or evaporating the solvent by heat and vacuum.

The polymers from the first and second reactors were characterized by Mooney viscosity (Mooney viscometer, ASTM D1648), ethylene content (FTIR, ASTM D3900), ENB content (FTIR, ASTM D6047), melting point and/or glass transition temperature (DSC, described herein), and molecular weight (gel permeation chromatography GPC, described herein). The analysis of the polymers from the second reactor provides the properties of the entire polymer blend.

The methods of cell permeation chromatography (GPC) used to determine the properties of the products of the invention have been described in several publications, in particular in U.S. Patent 4,989,436, which is incorporated herein by reference in accordance with U.S. patent law. Molecular weight and composition measurements are described in the article G. Ver Strate, C. Cozewith, S. Ju, Macromolecules, vol. 21, p. 3360 (1988), which is incorporated herein by reference in accordance with U.S. patent law. Differential scanning calorimetry (DSC) was also used to characterize the products of the invention in the usual manner by placing a sample without forming deformations in a calorimeter at 20 ° C, heat treating at room temperature for 40 hours, cooling the sample to -75, scanning to 180 ° C at 10 ° C / min., cooling to

-75 °C and repeated scanning. T _g , T _m and heat of fusion were determined. In some cases, crystallinity is not detected in low melting polymer products during the second scan, because even at low temperatures it can develop for many hours.

Atomic force microscopy (AFM) was used to determine the number of polymer phases present in the final product after recovery from the reactor solution. AFM analysis is performed using a Digital Instruments Dimension 3000 instrument operating under ambient conditions. The instrument was operated in tapping mode and mapped height, amplitude, and phase shift. The height analysis provides the overall topography of the sample. The amplitude analysis provides a representation of the differential height and is sensitive to changes in height, but not to its absolute height. The phase shift analysis maps the surface from

4» • •4 • ·

4 • · 4 • 4

4·4 »·« • In ·4 · · 4

4 4 · • 4 4 4 • 4 4 4 • 4 4 44 in terms of elastic modulus and chemical nature. These analyses used silicon arms (225 μιη long and 30 μιη wide) with force constants between 0.4 and 5 N/m. When tapped in air, the arm oscillated at a frequency slightly lower than its resonant frequency and with an RMS amplitude between 3.5 and 4.0 Volts (measured with a position-sensitive detector). When analyzing the sample, the RMS amplitude was set to approximately 30% of the RMS amplitude of the arm oscillating in air. Before analysis, the elastomer samples were cryogenically processed at -150 °C using an ultramicrotome. The samples were allowed to warm to room temperature in a nitrogen-filled dissector and then analyzed at room temperature.

Samples of the polymer solution from the first and second reactors were analyzed for polymer concentration. From these measurements and the reactor flow rates, the polymerization rate in both reactors could be determined using material balances. The degree of monomer conversion was then calculated from the polymerization rate and polymer composition data for the first reactor alone and for both reactors combined. The following balance equations were used to calculate the polymerization rate and polymer composition in the second reactor alone:

PR2 = PRt-PRl

F1 = PRl/PRt

E2 = (Et-(FlxEl)}/(1-F1)

D2 = {Dt-(FlxDl)}/(1-F1)

MN2 = (1-F1)/(MNt-Fl/MNl)

MW2 = (Mwt - F1 * MW1)/(1-F1) where:

Equation 1 Equation 2 Equation 3 Equation 4 Equation 5 Equation 6

PR1 = polymerization rate in the 1st reactor

PR2 = polymerization rate in the 2nd reactor

PRt = total polymerization rate

El = Ethylene content in the polymer from the 1st reactor

E2 = Ethylene content in the polymer from the 2nd reactor

Et = Ethylene content in the polymer from the entire reactor Dl - Diene content in the polymer from the 1st reactor

D2 = Diene content in polymer from reactor 2 ·· *· • · · • · ··« • · · • · · · · *· • ·· ·· « · · · • » · · · • * « · · · • · · · · *«· ·· *·

Dt = Diene content in the polymer from the entire reactor

Fl = Fraction of all polymer produced in the 1st reactor

MNI = Numerically medium molecular weight polymer from 1. reactor MN2 = Numerically medium molecular weight polymer from 2 . reactor Mnt = Numerically medium molecular weight polymer from whole reactor

MW1 = Mass of the reactor medium molecular weight polymer from 1. MW2 = Mass of the reactor medium molecular weight polymer from 2. MWt = Mass medium molecular weight polymer from whole

reactor

A series of polymerizations were carried out to demonstrate the process and products of the invention. All reactor conditions, polymer prepared in reactor 1 (R-1) and total product are based on actual measurements made on the polymer from reactor 1 and the polymer mixture leaving reactor 2. The results for reactor 2 (R-2) alone were calculated from these data using the above formulas.

Example 1(121C)

Polymerization in series reactors was carried out with the catalyst dimethylsilylbisindenylhafnium dichloride (catalyst A) mixed with the activator N,N-dimethylaniliniumtetrakis(pentafluorophenyl)boron (DMPFB). The catalyst components were dissolved in toluene in a molar ratio of 1:1. Table 1 shows the reactor conditions and feed rates. The catalyst feed rates in this table refer to catalyst A only and the catalyst efficiency is calculated by dividing the polymerization rate by the feed rate of catalyst A. A mixture of ethylene and propylene was fed to the first reactor, but only ethylene was fed to the second reactor. The polymer produced in the first reactor had an ethylene content of 15.5% and the polymer in the second reactor had an ethylene content of 55%. Molecular weight of the polymers

prepared in both reactors was similar, so the product mixture did not have an extended MWD. The polymer from reactor 1 was semi-crystalline due to the crystallinity of propylene, but the polymer prepared in reactor 2 was amorphous.

Example 2 (125A)

The polymerization was carried out with catalyst A as in Example 1 except that diene (ENB) was fed to the second reactor to produce a terpolymer. The polymer from the first reactor was a semi-crystalline copolymer containing 17% by weight ethylene, melting over the range of 29.6-99°C. The polymer from the second reactor was an amorphous terpolymer containing 50.6% by weight ethylene and 3.29% by weight ENB.

The reactor conditions and polymerization results are shown in Table 1.

Example 3 (127A,B,C)

A series of polymerizations were carried out with catalyst A under similar conditions to those in Example 1, except that in runs A to C, increasing amounts of ethylene were fed to the second reactor. Table 1 shows the reaction conditions and polymerization results. As a result of the increasing feed of ethylene feed to the second reactor, the fraction of all polymer produced in the first reactor decreased from 36% to 20%, and the ethylene content in the polymer from the second reactor increased from 47.4% to 61% by weight. Thus, by adjusting the feed rate to the second reactor, the composition and amount of the second component in the mixture can be easily varied. The same amount would not have been possible using the vanadium catalyst of the earlier patents due to the lower catalyst concentration in the second reactor.

Example 4(131C)

The polymerization was carried out with the same catalyst and in the same manner as in Example 1 for the preparation of the terpolymer mixture. Table 1 shows the reactor conditions and the polymerization results. In this polymerization, ENB was fed to both reactors in addition to the other monomers. The polymer formed in the first reactor

had an ethylene content of 18.8 wt% and 3.53 wt% ENB, while the polymer produced in the second reactor had 47.8 wt% ethylene and 8.53 wt% ENB.

Example 5(173A)

The polymerization was carried out with the same catalyst and in the same manner as in Example 4 for the preparation of the terpolymer mixture. However, the reactor temperatures are higher than in the previous experiments and the second reactor is at 65°C compared to 40°C. Table 1 shows the reactor conditions and the polymerization results. In this example, the polymers produced in both reactors were amorphous and the polymer produced in the first reactor had 30.3% ethylene while the polymer produced in the second reactor had 53.1% ethylene by weight. The MWD of the final product was broadened due to the different molecular weights of the polymers produced in the two reactors. The Mw/Mn ratio was 2.84.

Example 6(272A)

The polymerization was carried out with the same catalyst and in the same manner as in Example 1, except that the catalyst was dimethylsilyltetracyclopentadienyl ada/mantylamidotitanium dichloride (catalyst B). As in Example 1, the reactor was charged in a 1:1 molar ratio with DMPFB dissolved in toluene. The copolymerization was carried out at reactor temperatures of 30°C and 75°C. The reactor conditions and polymerization results are shown in Table 1. Hydrogen was added to the first reactor to reduce the molecular weight of the polymer. An amorphous copolymer with 32.9% by weight of ethylene was formed in the first reactor, while a semi-crystalline copolymer with 79.5% by weight of ethylene was formed in the second reactor. 64% by weight of the product was produced in the first reactor. The MWD of the final product was narrow with a Mw/Mn ratio of 1.94.

Example 7(A,B,C,D).

A series of polymerizations were carried out with Catalyst B using the method of Example 6 to prepare copolymer and terpolymer blends with extended MWD. In this example, the reactor was brought to equilibrium under primary conditions (Run A). After taking a product sample, diene was added to both reactors, the terpolymer blend was prepared, and the reactor was brought to equilibrium again before taking a second sample (Run B). The same procedure was repeated in Runs C and D. The reactor conditions and polymerization results are shown in Table 1. In Runs A and B, the high ethylene component of the blend was prepared in the second reactor. In Runs C and D, the composition was reversed and the high ethylene component was produced in the first reactor.

Also, in runs C and D, hydrogen was added to the first reactor as a chain transfer agent to prepare a low molecular weight product. The polymers prepared in runs A, B and C had a broad MWD as indicated by Mw/Mn values of 4.5 to 9.8.

Example 8(319 B,C)

This run was carried out with catalyst B in the manner of Example 1 to demonstrate the advantages of feeding monomer to both reactors using reactors in series. In run B, reactors in series were used, but no monomer was fed to the second reactor as feed. The reactor conditions and polymerization results are shown in Table 1. In the second reactor, the polymerization rate was low due to the low monomer concentration, and the polymer composition was practically the same for the polymers from both reactors. In run C, the reactor conditions were the same except that monomer was now added to the second reactor. Compared to the initial run B, the polymerization rate and catalyst efficiency were improved, and a polymer mixture was obtained with one component containing -76.2% by weight of ethylene and the other containing 39.3% by weight of ethylene.

Example 9(268B, 272A, 307C, 318A, 320C, 293A)

A series of polymerizations were performed using the method of the Example to prepare polymer blends in which the two components are largely immiscible and the final product was a two-phase blend upon recovery from solution.

The reactor conditions and polymerization results are given in

Table 2. The products formed in runs 268A and 293A are mixtures of two essentially amorphous polymers prepared with catalysts A and B. The products prepared in runs 272A and 320C are mixtures of an amorphous component and a component that has a high ethylene content and is characterized by ethylene crystallinity. The polymers in runs 307C and 318C were prepared with catalyst A and contain a component exhibiting propylene crystallinity and a component with a higher ethylene content that does not exhibit propylene crystallinity.

All polymers were analyzed by atomic force microscopy (AFM) to determine the number of phases present. As can be seen from the result for polymer 318C in Figure 1, the polymer product was a two-phase mixture. All other products in this example gave similar results.

Example 10

A series of reactor mixtures were dynamically vulcanized in a Brabender mixer by mixing the mixture until the plastic phase had melted and the torsion had stabilized. The vulcanization system was now added and mixing continued for 4 minutes. The material was mixed at 180°C at 100 rpm and the temperature rose to approximately 200°C during vulcanization. The products were then removed from the Brabender mixer, extruded and evaluated for physical properties.

Table 4 shows the elastic properties and composition.

Table 1. Reactor operating conditions

DSC melting range °c 41.7- 71.0 29.6- 99 33-100 29.4- 97.6 CM CM melting heat J/g 8.3 22.6 12.9 10.97 15.5 GPC Mw/M n 1.93 1.85 i 1.92 2.28 2.54 2.38 X „ i ° 286 what σ> 225 237 227.3 209.2 £ x ? 148 107 117 104 89.4 87.9 monomer conversion % efficiency cat. g/g 17477 38805 56283 16335 19526 35861 17209 30353 47562 17609 41799 59408 13243 54612 67855 conv die- nu About About About About 28.4 28.4 About About About About About About About About About conv C3= 27.1 I 53.6 About) 24.9 23.4 41.9 26.4 35.8 55.6 26.6 62.5 CM b-“ Lf) 20.2 76.4 59.3 conv C2= IO o V“ i 78.5 I 80.5 127.6 35.9 42.3 120.3 72.5 75.9 134.6 8'NW 77.9 95.1 r- co 82.7 reactor injection g/h cat. 0.0044 Xt ^ř o o o 0.0044 0.0044 0.0044 days About about About about 9.98 9.98 About About About About About About About about About C3= 240 I about 240 240 About 240 I 242 about 242 242 about 242 242 about 242 C2= 120 what 9.6 120 130 10.2 90 100 10.2 150 160 10.2 180 190 or ¹ E θ ΐ ^c ε ⁷³ N temperature °C about CM About O CM O M· O CM O Tt O CM O Tf O CM WHAT m flj o < < < < < -j T &> £ i N 54.9 69.7 75.2 diene in polymer wt.% about about About about 3.29 67.4 About 39.2 About about C2=in polymer wt.% 15.5 54.9 42.7 l·- V” 50.6 35.3 what 47.4 36.1 what h- O WHAT 47.4 · m what in— WHAT 52.3 polymerization rate g/h 76.9 170.0 247.0 CM h- 86.1 158.0 76.2 134.0 210 00 b- 185 263 5837 T” CM 300 reactor R-1 R-2 total CM R-1 R-2 total 1 Qi R-2 total R-1 j R-2 I I i total V ^- 1 Qí R-2 total JZ »a> Ex. 121C Ex. 125A Ex. 127A 127B 127C

319C R-1 89 76.2 4.35 B 62 10.2 0 Πθ875 I 16.5 I 0.0064 60.1 Γ27 23.5 13865

Ø7 87^6 ~39/3 ~2J 90 T/Í7 15 240 Ó ŠŤJ ΪΪΛ Ϊ87 Ϊ3653 total 176.7 57.9 3.53 Ϊ5 Ϊ7Α 123 315 16/5 80/2 22/š 37.8 27518 ·· 99 ► ♦ * ♦ » · · ♦

Table 2. Reactor conditions for the example

Mw/Mw lall/dri 1,123 1.09 1.96 68* i- 1.04 1.07 1.02 Mw lali 223 CM 91.8 104 148 I 270 I 576 Mw/Mn lall/dri 2.26 2.34 1.96 1.89 2.42 6.40 2.45 Mw/Mn dri/dri 2.01 2.14 2.03 1.94 2.32 I 5.98 I 2.39 © T X cl ω o CL O Mw dří and 198 ! σ> o T“ In" 10 About) 0*901- 142.0 252 562 Mn dri 98.6 92.9 46.9 54.7 WHAT 42.2 235 monomer conversion % č ta ~ οι £ ° -2 °> 13962 19411 33373 20453 12287 32740 24662 30279 54941 31170 I ' 16150 I_ 47320 17478 25269 42746 25105 34470 59575 conv die- nu About CM O) CM 27.2 v~ r-T v 33.8 About 79.3 79.3 About about About 34.0 40.2 60.6 0 0 0 conv | C3= 24.8 25.5 44.7 WHAT it 60.97 54.63 j _1 51.3 ⁶⁵ ' 70.5 j _I 53.5 I 6*0 i 24.2 37.5 UÝ 40.6 52.8 V“ 0 X“ 75.3 j conv C2= T~ CN 10 58.5 76.6 10 66.6 143 | 62.1 66.3 92.4 49 j 96.1 66.8 89.3 96.1 65.2 92.6 94.4 I monomer injection g/h cat. 800*0 0.0066 | 0.0084 0.0057 0.006 0.005 .1 c 0 Φ About 25.1 25.1. O CM 7.02 27.0 About 12.9 12.9 About About About »0 0 10 °r° 0 0 0 11 what About 375 About 375 $3 32.4 WHAT 00 360 42 402 104 486 590 71.5 243 315 10 WHAT 32.4 l 197 I C2= 36.6 120 157 55.2 100 155 10 234 249 CM CO V“ About 132 108 10 123 60 0 0 T" 0 what spray H2 moi/h 0.013 About about 0.003 About 0 0 temperature °C 30 O 00 About what 10 r- About what 80 CM CO 10 62 With 0 what 75 “type cat. < what < < CQ CQ ML 125° 26.9 10.3 ’ί CD CM 10' 11.8 what what 3 Φ 0. - a. ^0.00 I 4.69 2.73 4.06 4.59 4.26 4.05 2.23 0.00 0.00 0.00 5.66 3.05 4.12 0.00 0 0 0“ 0.00 % C2 vEP -1 8*91- 48.6 35.3 32.9 79.5 50.4 10.4 58.3 36.8 68.7 5.32 1 47.1 72.9 30.9 48.1 T“ CO 64.5 50.4 speed polymerization g/h (0 T“ T~ 155.1 266.6 134 00 about what 214.4 205.9 252.8 458.8 177.7 t— CM O> 269.7 104.9 151.6 256.5 126.3 173.4 299.7 T“ oc CM and: total 5 R2 total Σ CM Q£ total in— and: R2 total ce CM and: total In Qí R2 total running 268B 272A 307C 318C 320C 293A

Table 3

Composition of the mixture from reactors arranged in series

Polymer Components Product composition Ethylene % wt. EDN % wt. DSC Tm (°C) DSC/Hf J/g Mixture A 45, 68 3.35 127 30 m-iPP Reactor 1 46.5 0 0 133 74 m-EPDM Reactor 2 53.5 85, 4 6.27 Mixture B 46.09 4.33 128 25 m-iPP Reactor 1 38.76 0 0 134 73 m-EPDM Reactor 2 61.24 75.3 7.07

and ·· ·· ·· ·· • ·» .

• « · · « · · · • · * · • · · * what <3*

Table 4. Properties of dynamic vulcanizates

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Claims (14)

PATENT CLAIMS A method of dynamically vulcanizing a polymer blend from solution polymerization, comprising the steps of: a. introducing the first group of monomers and solvent into predetermined amounts into the first reactor; b. adding the metallocene catalyst to the first reactor; c. operating the first reactor to polymerize the first monomer group to a polymer-containing stream; d. introducing the stream from (c) to a second reactor; e. introducing the second group of monomers in predetermined amounts into the second reactor and adding a solvent as necessary; f. operating a second reactor to polymerize the second monomer group and prepare a second polymer; g. mixing the resulting first and second polymers under heat and shear conditions such that the mixture flows; and h. adding a curative composition to one of the polymers to at least partially cross-link said polymer, wherein the first and second monomer groups are selected from the group consisting of ethylene, higher alpha-olefins and unconjugated diene, and wherein the monomer ratios in the first a second reactor such that the first polymer contains 0-85% by weight ethylene, the second polymer 0-85% by weight ethylene and the polymer blend 6-85% by weight ethylene, and wherein more than 50% by weight of the total amount of catalyst added to all reactors is added to of the first reactor. The process according to claim 1, wherein 100% by weight of the total amount of catalyst added to all the reactors is added to the first reactor. Method according to claim 1, characterized in that 9 9 9 99 9 9 99 99 9 9 9 9 9 9 9 9 9 9 9 9 The higher alpha-olefin is propylene. The process of claim 1, wherein the relative ratios of the monomers in the first and second reactors are controlled such that the ethylene content of the first and second polymers is different in that either (a) the first polymer is semi-crystalline and the second polymer is amorphous; or (b) the first polymer is amorphous and the second polymer is semi-crystalline. 5. The process of claim 1 wherein the polymer components are immiscible and the product is a biphasic mixture. with e degrees (f) 6. The process of claim 1 wherein the monomer relative ratios in the first and second reactors are controlled such that one of the polymers contains 0-20% by weight of ethylene, is semi-crystalline due to the presence of isotactic propylene sequences, and has a melting point of 40 to 160 ° C, while the second polymer is amorphous. 7. The process of claim 6 wherein the amorphous polymer is a diene-containing terpolymer. The method of claim 7, wherein the terpolymer comprises ethylene, propylene, and diene. The process of claim 1 wherein the unconjugated diene is selected from the group consisting of 5-ethylidene-2-norbornene, 1,4-hexadiene, dicyclopentadiene, norbornadiene, 5-vinyl-2-norbornene, and mixtures thereof. 10. The process of claim 1 wherein the catalyst is capable of producing stereoregular polypropylene. The method according to claim 10, characterized in that isotactic stereoregularity is achieved. 12. The method of claim 1, wherein the dynamically vulcanized composition has a permanent tensile strain of less than 50% as determined by ASTM D412. 13. The process of claim 1 wherein in step (h) a vulcanizing agent comprising a phenolic resin system is used to completely cross-link said polymer. A dynamic vulcanizate prepared by the method of claim