PT86411B - PROCESS FOR THE PREPARATION OF ETHYLENE AND 1,3-BUTADIENE COPOLYMERS - Google Patents

Abstract

Novel copolymers comprise ethylene and at least 3 (pref. at least 5) mole % 1,3-butadiene and have a cluster index of 9 or less (pref. 5 or less). Pref. the copolymers have a mol.wt. distribution (Mw/Mn) of 3.0 or less and a mol.wt. (Mn) of 500-1,000,000 (partic. 500-200,000). Pref. most of the butadiene is incorporated in the polyethylene chain as cyclopentane rings connected in the 1 and 2 positions in the ring. Pref. at least 55 (partic. at least 70) wt.% of the copolymer molecules have a comonomer content within about 50% of the median comonomer content in mole % of the copolymer compsn. Opt. the copolymer may also comprise an alpha-olefin. Opt., besides the 1,2-cyclopentane units, the copolymer may also comprise at least one of 1,2 and cis and trans 1,4 noncyclic butadiene comonomer units. Prepn. of these copolymers in the presence of a metallocene/alumoxane catalyst system is also claimed.

Description

PROCESS FOR THE PREPARATION OF COPOLYMERS OF _ς ethylene and 1,3-butadiene

The present invention relates to ethylene copolymers which have cyclopentane rings attached at positions 1 and 2 in their structure. The ethylene copolymers according to the invention can be formed by polymerization of ethylene and butadiene and preferably have a predominance of copolymer units formed as 1,2-cyclopentane units, preferably trans-1,2-cyclopentane. Other butadiene units incorporate 1,2 and cis and 1,4 non-cyclic trans.

58,946

JL / PE-1542

18.0tZ.l987

Description of the object of the invention

What

EXXON CHEMICAL PATENTS, INC., North American, industrial, headquartered in Baytown Polymers Center, BAYTOWN, Texas 77522-5200, United States of America, intends to obtain in Portugal, for: PROCESS FOR THE PREPARATION OF ETHYLENE COPOLYMERS 1, 3-BUTADIENE.

the present invention relates to a process for the preparation of copolymers of ethylene and 1,3-butadiene.

This Patent Application is a partial continuation of US Patent Application Serial Number 747 615, filed on June 21, 1985.

Background of the Invention Invention refers to a new improved catalyst, useful for the polymerization of olefins and particularly useful for the polymerization of ethylene and the copolymerization of ethylene with 1-olefins, having three or more carbon atoms, such as, for example , propylene, i-butene, 1-butene, 1-hexene and 1-octene; dienes, such as butadiene,

1,7-octadiene and 1,4-hexadiene or cyclic olefins, such as nor-bornene ·

The invention relates in particular to a new supported catalyst, containing a heterogeneous, perfected transition metal, which can be used without use

58,946

JL / PE-1542

use of organo-metallic cocatalyst in the polymerization of olefins. The invention further relates generally to a process for the polymerization of ethylene alone or with other 1-olefins or diolefins, in the presence of the new supporting catalyst, the transition metal-containing catalyst, which comprises the reaction product of a metallocene and an alumoxane , in the presence of a support material, such as silica.

Traditionally, ethylene and 1-olefins have been polymerized or copolymerized in the presence of hydrocarbon insoluble catalyst systems, comprising a transition metal compound and an aluminum-alkyl. More recently, homogeneous catalyst systems have been discovered that comprise a bis- (cyclopentadienyl) -titanium-dialkyl or a bis- (cyclopentadienyl) -zirconium-dialkyl, an aluminum-trialkyl and water, which are useful for the polymerization of ethylene . These catalyst systems are generally referred to as Ziegler-type catalysts ”.

German Patent Application Number 2 6θ8 863 relates to the use of a catalyst system for the polymerization of ethylene consisting of bis- (cyclopentadienyl) -titanium-dialkyl, aluminum-trialkyl and water.

German Patent Application Number 2 6o8 933 relates to a catalyst system for the polymerization of ethylene consisting of zirconium-metallocenes of the general formula (cyclopentadienyl) _n ZrY ^, where n represents an integer from 1 to 4, Y stands for R, CHgAlR2, CH2 CHgAlRg ^and CHgCHÍAIRgJg, ^where R represents alkyl or metal-alkyl and an aluminum-trialkyl cocatalyst and water.

European Patent Application Number 0035242 relates to a process for the preparation of atactic propylene ethylene polymers in the presence of a halogen-free Ziegler catalyst system, consisting of

58,946

JL / PE-1542

.18 0EZ.1987

(1) a cyclopentadienyl derivative of the formula (cyclopentadienyl) MeYi, where n is an integer from 1 to η 4 — n

4, Me is a transition metal, especially zirconium and Y is either hydrogen, a C C-C ^ alkyl group or a metal-alkyl or radical which has the following general formula CH ₂ CH ₂ A1R ₂ and CH ₂ CH (A1R ₂ ) ₂ , where kilo in C_-C_ or metal-alkyl and

5; CH ₂ A] R ₂ ,

R represents a group al (2) an alumoxane.

Other indications about homogeneous catalyst systems comprising a metallocene and alumoxane are referred to in European Patent Application Number OO69951> issued to Kaminsky et al., U.S. Patent Number 4 4θ4 344, to Sinn et al. published on September 13, 1983, and in US Patent Applications Number 697 308, filed on February 1, 1985, Number 501 588, filed on May 27, 1983, Number 728 111, issued on 29 April 1985 and Number 501 740, filed June 6, 1983, all of them jointly assigned to Exxon Research and Engineering ^ ompany.

An advantage of the homogeneous metallocene-alumoxane catalyst system is the very high activity obtained for the polymerization of ethylene. Another significant advantage is that, contrary to what happens in olefin polymers produced in the presence of conventional heterogeneous Ziegler catalysts, terminal unsaturation is present in the polymers produced in the presence of these homogeneous catalysts. However, catalysts have the drawback that the ratio of alumoxane to metallocene is high, for example, on the order of 1,000 to 1 or greater. Such voluminous amounts of alumoxane require extensive treatment of the polymeric product obtained in order to eliminate undesirable alumina. A second drawback of homogeneous catalyst systems, which is also associated with heterogeneous Ziegler catalyst systems, is the multiplicity of systems.

- 3 58,946

JL / PE-1542

but supply required to introduce the individual components of the catalyst into the polymerization reactor.

It would be very desirable to provide a metallocene-based catalyst that is commercially useful for the polymerization of olefins, in which the ratio of aluminum to transition metal is within suitable ranges, and still provide a catalyst for polymerization that does not require the presence of a catalyst, thereby decreasing the number of delivery systems needed to introduce the catalyst into the polymerization reactor.

There is also a need to obtain new ethylene polymer structures from various co-monomers in which new or better properties are obtained.

Polymers of the prior art suffer from one or more difficulties that affect their physical properties. Difficulties include wide molecular weight distributions, wide comonomer composition distribution and inefficient comonomer distribution or dispersion along the copolymer polyethylene chain.

The extended molecular weight distribution of a polymer strongly influences its melt flow properties and these polymers tend to have a high concentration of high molecular weight molecules which makes them subject to orientation problems. θοπιο result, these resins give rise to strongly anisotropic physical properties in the direction of advancement in the machine in relation to the transversal direction, of the manufacturing process and these properties are harmful for a number of final applications.

Resins with a wide distribution of molecular weights also often contain a significant amount of polymers with a very low molecular weight

- 4 58,946

JL / PE-1542

DECZ2-87

xo. These molecules contain, almost invariably, high concentrations of comonomer and therefore tend to be amorphous or have a small degree of crystallinity. Consequently, these materials are exuded to the surface of the manufactured articles, causing stickiness when not desired and / or interfering with other additives of the polymer designed according to the particular application. An example of this is the superficially active property associated with the slip agents in the blown or cast film.

Most of the prior art copolymers tend to have a very wide distribution of the composition of the comonomer, that is, the distribution of the comonomer between the polymer molecules is not uniform, with some molecules having a relatively high comonomer concentration while others have a relatively small concentration of comonéme ro. This structural property of the prior art allows the part with the lowest comonomer content to have a high melting point and vice versa, which means a wide melting range for the complete polymeric composition.

Of course, the presence of a high melting component is inconvenient for many applications where a soft article is desired and may result in unwanted stiffness. On the other hand, the presence of materials with a high low melting point comonomer content often results in a large proportion of extractable components.

The prior art materials are generally characterized by a relatively inefficient use of the comonomer groupings along the polyethylene chains. The distribution of the comonomer along the chain is very important to determine the efficiency of using the as a number and the properties resulting from the polymer, especially with regard to the crystallinity of the polymer. These prior art polymers tend to have a high degree of

- 5 58,946

JL / PE-1542

18. TEN. 1987

agglomeration of the comonomer groupings along the polyethylene chain. That is, the comonomer units are adjacent or not isolated along the chain, which results in an inefficient use of the comonomer, since only a single introduction of the polyethylene chain results when several comonomer units are contiguous. This fact has extremely important applications in the total amount of the comonomer needed to obtain the crystalline. intended community. It is also often inconvenient to include unnecessary portions of the comonomer, especially when it is more difficult and more expensive to obtain diene comonomers. Often, the need to use a larger portion of the comonomer also tends to force the comonomer to the high molecular weight comonomer ends of the molecular weight distribution. As a consequence, it is necessary to obtain copolymers, terpolymers and interpolymers with better properties in the whole range of polymers from amorphous to highly crystalline.

Although it is recognized as desirable to incorporate a significant percentage of diene in an ethylene copolymer, the catalyst systems that produce these polymers with a tight molecular weight distribution and / or a tight distribution of comonomers are ineffective in incorporating dienes in any significant amount .

Summary of the Invention

The present invention relates to a process for the preparation of new ethylene copolymers, especially ethylene 1,3-butadiene copolymers, especially those having a concentration of cyclopentane structures as interruptions in the polyethylene chain. The present invention gives rise to new ethylene copolymers that have cyclic rings.

JL / PE-1542

clopentane in the ethylene chain, linked in compositions 1 and the ring.

According to the present invention, a new metallocene-alumoxane catalyst is provided for the polymerization of olefins, a catalyst that can be usefully used for the production of small, medium and high density polyethylene and ethylene copolymers with alpha-olefins , having three to eighteen or more carbon atoms and / or diolefins, having up to eighteen or more carbon atoms.

new catalyst provided according to an embodiment of the present invention comprises the product of the reaction of at least one metallocene with an alumoxane, carried out in the presence of a support material, thereby obtaining a metallocene-alumoxane reaction product supported, as the only catalyst component.

the supported reaction product polymerizes olefins at commercially acceptable rates without the presence of objectionable excess alumoxane, as is necessary in homogeneous systems.

According to another embodiment of the present invention, there is provided a process for the polymerization of ethylene and other olefins and, in particular, for obtaining ethylene homopolymers and copolymers of higher ethylene and alpha-olefins and / or diolefins and / or cyclic olefins, such as nor-bornene, carried out in the presence of the new catalysts.

The metallocenes employed in the production of

- 7 58,946 jl / pe-1542

18.0EZ.Wf

product of the reaction on the support are organometallic coordination compounds that are derived from cyclopentadienyl of a metal of Group 4B, 5B or ÓB of the Periodic Table (56 »Edition of the Handbook of Chemistry and Physics, CRC Prss (1975)) θ includes monocyclopentadienyls, dicyclopentadienyls and tricyclopentadienyls and their derivatives of transition metals. Metallocenes of a Group 4B and 5B metal, such as titanium, zirconium, hafnium and venadium, are particularly desirable. The alumoxanes used in the formation of the reaction product with the metallocenes are themselves the products of the reaction of an aluminum-trialkyl with water.

Alumoxanes are well known in the art and comprise linear and / or cyclic oligomeric alkyl alumoxanes represented by the formulas:

(i) R- (Al-O ^ -AlRg, in the case of linear oligomeric alumoxanes and

R (li) (-Al-0-) _m , in the case of oligomeric alumoxanes | cyclical,

R in which n is 1 - 40, preferably 10 - 20; m is 3 - 40, preferably 3-20; and R is a C 1 -C 6 alkyl group and, preferably, methyl. Generally, in the preparation of alumoxanes from, for example, aluminum-trimethyl and water, a mixture of linear and cyclic compounds is obtained.

Alumoxanes can be prepared according to a variety of processes. Preferably, they are prepared by contacting water with an aluminum-trialkyl solution

58,946 µl / pe-1542 such as, for example, aluminum trimethyl, in a suitable organic solvent, such as benzene or an aliphatic hydrocarbon. For example, aluminum-alkyl is treated with water in the form of a solvent containing moisture. According to the preferred method, aluminum-alkyl, for example, aluminum-trimethyl, may desirably be contacted with a hydrated salt, such as hydrated ferrous sulfate. The method comprises treating a diluted solution of aluminum trimethyl, for example, toluene, with ferrous sulfate heptahydrate.

Figure 1 is a graphic and verbal representation of the concept of the agglomeration index.

Figure 2 is a graphical representation of the agglomeration index as a function of the molar percentage of comonomer for various commercial resins and the resins according to the present invention.

Figure 3 is an overlapping graphical representation of the molecular weight distribution of resins according to the present invention on the distribution of commercial resin 3, represented as a percentage of the weight of the comonomer content.

Figure 4 is a graphical representation of the distribution of the comonomer composition in percentage by weight, as a function of the elution temperature for a resin according to the present invention and several commercial resins.

Figure 5 is a graphical representation that shows the correlation of the elution temperature as a function of the composition in molar percentage of comonomer (branches / thousand carbon atoms).

Figure 6 is a graphical representation of the melting point determined by DSC (differential scanning calorimetry) for the copolymer according to the present invention and several commercial polymers, showing the range

- 9 58,946

JL / PE-1542

W 0EZ.1S87

relatively tight melting point of the resin according to the present invention.

A preferred embodiment of the present invention is a copolymer obtained by polymerizing ethylene and at least one other polymerizable comonomer, comprising 1,3-butadiene, incorporating said copolymer in its structure at least about 3 mol% the wafting has at least one polymerizable comonomer and having an agglomeration index equal to about 9 or less.

A preferred embodiment of the present invention is a copolymer composition of ethylene and butadiene, said copolymer having a molecular weight distribution (Μ / m) equal to about 3.0 or less.

w n

A preferred embodiment of the present invention is a method for the preparation of ethylene and butadiene copolymers, comprising carrying out the polymerization in the presence of a metallocene / alumoxane catalyst system and forming a non-cross-linked ethylene / butadiene copolymer composition.

A preferred embodiment of the present invention is a copolymer obtained by polymerizing ethylene and at least one other polymerizable comonomer, comprising butadiene, said copolymer having a composition distribution in which at least about 55% by weight of the Copolymer molecules have a comonomer content within 50% of the average comonomer content in mole percent of said copolymer.

A preferred embodiment of the present invention is an ethylene copolymer which comprises, in its polyethylene chain, trans-1,2-cyclopentanes:

58,946

JL / PE-1542

A preferred embodiment of the present invention is an ethylene copolymer comprising in its polyethylene chain, as the sole cyclopentane unit, trans-1,2-cyclopentane.

term copolymer ”is intended to include copolymers, terpolymers and higher etpol interpolymers. lene, 1,3-butadiene and, optionally, other polymerizable comonomers. Copolymers have, in the ethylene chain, a plurality of cyclopentane rings attached to adjacent carbon atoms (1,2).

The copolymers according to the present invention preferably have at least about 10%, more preferably at least about 50% of the incorporated butadiene in the form of cyclopentane rings.

The copolymers according to the present invention can also include the incorporation of butadiene with the linear configuration 1,4 (cis and trans), as well as the well known configuration 1,2 (vinyl branching in the polymer chain).

In a preferred embodiment, copolymers are predominantly (50 - 100%) constituted by incorporation of cyclopentane and the remainder (0 - 50%) by incorporation 1,4- or 1,2. The incorporation 1,4 is generally greater than the incorporation 1,2 of butadiene in the polymers according to the present invention.

The use of butadiene in copolymerization (or terpolymerization or higher interpolymerization) of ethylene tends to give rise to higher molecular weight polymers compared to processes comparable with an alpha-olefin

According to the present invention, the butadie; no is incorporated into the copolymer (or higher polymer) with two adjacent carbon atoms of a cyclopentane metal in the chain (without unsaturation). Part of the butadiene is incorporated

58,946

JL / PE-1542

QEZ. Lo /

f - under the trans-1,4 configuration, forming a linear chain with unsaturation. Some butadiene can also be incorporated into the copolymer under the cis-1,4 configuration, also forming a linear chain with unsaturation (C = C double bond), but having both hydrogen atoms associated with the carbon atoms of the double bond on the same side as the double bond. Finally, some butadiene, usually a very small portion, or a null portion, can be incorporated in the 1,2 configuration, giving rise to a pendant vinyl group as an unsaturated branch on the saturated carbon chain. Consequently, the copolymer can form with a sufficient amount of rasidual unsaturation in the main chain or in the side chains, for possible use in special applications, such as crosslinking or chemical modification.

The ethylene copolymers according to the present invention have improved properties, as a result, in particular, of the more efficient use of the diene comonomer in controlling the crystallisability of the copolymer. That is, the efficient use of the diene comonomer comprises an improved isolation of the comonomer molecules along the polyethylene chain, as was not previously achieved in the case of these ethylene copolymers. Consequently, the polymers according to the present invention not only have an especially good application for the uses in which said polymers are previously used, but also have excellent global physical properties that constitute a significant improvement over the previously existing materials. The best properties of the products according to the present invention result from the isolated dispersion of the diene comonomer and other comonomers along the sequence of the polymer molecule according to the present invention.

Yet another preferred embodiment of the copolymers according to the present invention has a

58,946

JL / PE-1542 distribution in which more than 55% by weight of the copolymer molecules are within 5θ% of the median content of comonomers in mole percent, the said copolymer being formed by polymerization in the presence of a catalyst system that it comprises a metallocene of a metal of the group IVB, VB and VIB of the Periodic Table and an alumoxane or a product of the reaction.

The copolymeric products according to the present invention comprise bulk polymeric compositions produced in batch or continuous batches, having the properties and characteristics described in the present specification. None of these compositions had been discovered until today. That is, the complete unmodified polymerization product has advantageous properties.

The copolymeric compositions according to the present invention can be prepared by polymerizing ethylene and at least one comonomer. The at least comonomer comprises, that is, always includes some (or only) 1,3-butadiene.

The 1,3-butadiene comonomers incorporated in the polymers according to the present invention can be found in a small or large amount in relation to the amount of ethylene in the polymer. In an embodiment of the present invention, the polymers of the invention contain at least about 3 mole% of the total comonomer, based on the moles of ethylene and comonomers, in order to provide a wide dispersion of the comonomers in the composition of the polymeric product. This generally limits the density by less than 0.930 g / cm, preferably less than 0.92 g / cm, depending on the copolymers chosen and the method of incorporation. Thus, when a two-component polymeric composition is formed only from ethylene and diene, at least about 3 mole% of diene units and no more than about 97 mole% du

- 13 58,946

JL / PE-1542

ethylene units are present. For the higher terpolymers and interpolymers according to the present invention, only about 0.01% mole or more, preferably about 0.1% mole or more and more preferably 1% mole or more of the precise diene to be incorporated, so that the total incorporation of comonomers (diene and other or other comonomers) is at least equal to about 3 mol% for this embodiment.

Despite the incorporation of at least about 3 mol% of comonomer units in an embodiment of the polymeric compositions according to the present invention, the polymers, nevertheless, have a low aggregation index and, preferably, others characteristics described in this specification. The total comonomer content of the polymers according to the present invention may constitute the predominant portion of the polymer. Preferably, especially for solid polymers, ethylene units constitute the predominant component on a molar basis.

In a preferred embodiment of the present invention, the polymers according to the invention have better properties, attributable to the more uniform content of diene and other comonomers across the polymer molecules.

In contrast to the polymers of the prior art, the copolymers, terpolymers and other interpolymers according to the present invention have only a very small agglomeration of the comonomer molecules along the polyethylene chain, both in relation to the diene comonomer and any other polymerizable comonomer in the polyethylene chain. As a result, the use of comonomers in the formation of copolymers according to the present invention is very efficient in controlling crystallisability, protects against the formation of high comonomer content ends30

- 14 58,946

JL / PE-1542

... 18.uEZ.kEÍ

Mer / low molecular weight, reduces costs and improves properties.

In a preferred embodiment of the present invention, the copolymers according to the invention have a very tight composition distribution of the comonomer. That is, copolymers have a much more uniform distribution of comonomers between the molecules, avoiding the problem presented by resins with a wide distribution of the composition.

In a preferred embodiment of the present invention, the copolymers according to the present invention have better properties, resulting from the more consistent size of the polymer molecules that is not achieved in the prior art. This aspect of the most preferred embodiment is generally referred to as a greater molecular weight distribution or average molecular weight quotient by the average molecular weight in number of the polymeric material.

Also, in this preferred embodiment of the present invention, the copolymers of the invention have a relatively tight molecular weight distribution. That is, they have a relatively small ratio of average molecular weight by weight to average molecular weight in number. In other words, the concentration of very high molecular weight molecules and very small molecular weight molecules decreases in relation to the polymers of the prior art. The absence of high molecular weight molecules reduces the tendency for orientation in manufacturing processes and increases the isotropic physical properties in the machine / transverse direction. The absence of low molecular weight molecules (lower tail) in the copolymers according to the present invention reduces the tendency to form their sticky surfaces and, on the other hand, interferes with the superficially active agents in certain applications of the copolymers according to with the present invention.

- 15 58,946

JL / PE-1542

Polymers of the prior art do not have the corresponding structure or properties of the polymers according to the present invention. That is, they lack the low cluster index for ethylene copolymers (including terpolymers and interpolymers above) having at least about 3 $ by mole, preferably 5% ^to <no injury and, more preferably, $ 10 moles of co-monomer units according to the present invention. The absence of such a structure is generally reflected in easily measured characteristics of the products according to the present invention, such as the melting point temperature and the like. Polymers of the prior art are also generally lacking the tight molecular weight distribution and the tight comonomer distribution.

The polymers according to the present invention are capable of being able to be transformed into a wide variety of articles, as is known for ethylene homopolymers and ethylene copolymers of higher alpha-olefins.

The polymers according to the present invention can have a very variable density, over a wide range, from essentially amorphous materials to highly crystalline materials. They can be liquid (as with certain rubbers and lubricants and waxes) or solid.

The molecular weight of the copolymers according to the present invention can vary over a wide range. Preferably, the polymers have a number average molecular weight of about 500 or more, preferably. 1000 or more, more preferably, about 10,000 or more. Typically, the materials used for applications such as elastomers are either copolymers or terpolymers (often with the propylene monomer), with a density range between about 0.86-0.87

- 16 58,946

JL / PE-1542

To g / cm. Typically, these polymers contain 30% by weight or more of the comonomers and the remainder is made up of ethylene. Often, the elastomers of the unsaturated polymers according to the present invention have up to 48% by weight or more of the comonomer present.

The polymers according to the present invention can also include plastomers with a density between about 0.87 - 0.900 g / cm3 and containing about 20 to 30 by weight of comonomer. Also available in polymers according to the present invention are very low density polyethylene materials, with the inter

The density value is 0.900 - 0.915 g / cm and having about 10 to 20 by weight of comonomer present.

The polymers according to the present invention to can be formed as a polymer of linear low density polyethylene type weighing range by volume from about 0.915 g / cc to about 0.940 g / cc ^J and containing about 5 to 10% by weight of the comonomers. The polymers of steel according to the present invention can also be used in the form of high density polyethylene, having a volumic weight equal to about 0.940 g / cm3 and higher and containing up to about 5% by weight of comonomers. Unsaturated polymers according to the present invention can also form amorphous materials with a density less than 0.86 g / cm including sticky resins.

The polymers according to the present invention have particularly advantageous properties because of their tight molecular weight distribution, tight distribution of the composition and their configuration of the chain, which has isolated comonomer units.

Sequence distributions or the distribution of comonomer units along a polymer chain in, for example, low density linear polyethylenes, is a factor that affects the cost of the polymer because

- 17 58,946

JL / PE-1542

affects the amount of comonomers needed to achieve a desired polymer density. If the comonomer is efficiently incorporated, that is, with a small agglomeration of comonomer units, in a linear low density polyethylene, less comonomer is needed to decrease the density. Thus, the number of comonomer chains in a copolymer chain and the length of each set is significant in the structure of the polyethylene molecules and affects the physical properties of the polymer. Polymers according to the present invention are marked by a relatively high number of unique single comonomer units in the polymer chain in relation to the number of units containing more than a single comonomer molecule compared to the unsaturated polymers of the prior art .

The ethylene copolymers according to the present invention are, hereinafter, described in the present specification, described by their agglomeration index. This index reflects the degree to which the polymers according to the present invention have individual comonomer units dispersed along the polyethylene chain, preferably favoring the isolation of individual units over groups of two or more units. Given a minimal comonomer level, the unsaturated ethylene polymers according to the present invention are especially noted for their efficient use of comonomer molecules but which have more comonomer molecules isolated along the polyethylene chain and less agglomerations of molecules of comonomers in the polyethylene chain. That is, unsaturated polymers according to the present invention tend to deviate from the random distribution of comenomers towards less contiguous comonomer sequence. Thus, the agglomeration index allows for a quantitative assessment of the deviation from the random distribution of the comonomer in the polymer chain.

In the description of the agglomeration index ap30

58,946

JL / PE-1542

DEC.1287

I

sitting in the present Description there are two points of reference. Reference point 0 describes a polymer that has only isolated comonomer inserts, without any contiguous comonomer units forming an agglomeration; this, of course, also describes pure homopolymers. The second reference point is number 10, which is assigned to an ethylene polymer having a comonomer distribution that is exactly random (from Bernoulli) and thus contains a predictable number of contiguous comonomer units. Any polymer that has an aglo index value greater than 10 contains, proportionally, a greater number of contiguous comonomer sequences than those predicted by random distribution. Any polymer having an agglomeration index value between 0 and 10 is indicated to have fewer contiguous sequences than a polymer of random distribution (given a minimum comonomer). These values are typically associated with the polymer production process, including the catalyst used and the polymerization conditions employed.

Comparisons of the agglomeration index are best for polymers that have comparable comonomer contents or densities. The measurement of comonomer agglomeration along the polyethylene chain in a given polymer can be determined by a study using carbon 13 nuclear magnetic resonance spectroscopy (C 'rmMR). Using this assessment tool, the agglomeration index can be expressed as follows:

agglomeration index = 10 / ”(x) - (EXE27 // 2 (x) ² - (x) ³ J in which (x) is the molar percentage of total comonomer molecules in the copolymer and EXE is the molar fraction of the segment formed by a triad of three monomer units containing ethylene-comonomer-ethylene, these concentrations are easily measured using C NMR.

- 19 58,946

JL / PE-1542

The basis for the agglomeration index is further explained and exemplified below in the following discussion and with reference to the drawing in Figure 1.

Referring now to the drawing in Figure 1, the agglomeration index can be derived as follows, using reference point 10 as the expected random agglomeration in a polymerization and reference point 0 as the point where there is no agglomeration in a polymer ( absence of units with more than one contiguous comonomer in the molecule). Consequently:

agglomeration index ^ 10-10 xg ^In ) _o b _B e _r v _a do- ( ^EXE > _random 7 yJ- (X) - (BXB) _random .7 in which ”X is the molar percentage of comonomer in the copolymer of ethylene and EXE is the corresponding triad configuration in a single comonomer molecule contiguous to two ethylene molecules (units).

term (EXE) _n + '· serves as a point ά, ΧθεΐνΟΧ'ΧΗ of reference and its value can be calculated by any appropriate statistical model. In this case, Bernoulli's model was chosen. For the Bernoulli < ^EXE > random model “Z ¹ - ^X .7 ² / ' ^X -7 ·

Thus, replacing this value of (EXE) + ' ^{in the} formula of the agglomeration index, you get QJ-OSLbOriEL

up:

agglomeration index = 10 / (x) - (EXE) _observed 7 // ² ( ^x ) “( ^x ) ^ _ 7

58,946

JL / PE-1542

18. TEN. 1987

As a result, it can easily be seen in the drawing in Figure 1 that polymers that have more comonomer clusters than a random distribution appear to the left of the reference point 10 and those that have less comonomer clusters than a random distribution appear between 0 and 10.

In Figure 2, the polymers are plotted according to their agglomeration index, as described for Figure 1 and using the vertical axis to represent molar percentages of comonomer in the polymer samples. It is readily apparent from the drawing in Figure 2 that the polymers according to the present invention have a reduced glomeration index (for a given density of comonomer content) in relation to the polymers of the prior art, such as the commercial polymers plotted and appearing near or on the left side of reference point 10 (random clustering). The technique of using the C ^J NMR assay to obtain information necessary for the agglomeration index is known to those skilled in the art.

In Figure 2, the Dowlex octene copolymer agglomeration index of Dowlex 2088 (resin 9) »LLDPE octene copolymer Dowlex 2517 (Resin 10) and the hexane LLDPE copolymer Union Car bide 7θ99 (Resin 11) are also shown for comparison. ).

improvement of the agglomeration index of the polymers according to the present invention compared to the polymers of the prior art is detectable at a comonomer content equal to 3% by moles, easily perceptible at 5% by moles and noticeable at about 10% by soft or more.

agglomeration index described above can be considered to be first order or based on the total number of comonomer units minus the isolated comonomer units (EXE). A higher order agglomeration index can also be measured and calculated, mainly ba21

58,946

JL / PE-1542

based on the occurrence of dimeric segments (EXX) or (XXE), as observed. This measurement is slightly more discriminatory at low percentages of moles of comonomer (about three). Thus, an EXX index can also be calculated in a similar way, by the following expression

EXX index = 10-10 (EXX) observed - (EXX) by Bernoulli (EXX) Bernoulli

As (EXX) Bernoulli = 2 / ~ E_7 θ θ (EXX) observed is based on the two units (EXX) and (XXE), easily determined by the C ^ MNR test, the EXX index is easily determinable. For the definition of this index, a totally random polymer is measured as 10, a polymer totally without dimers is 0 (absence of contiguous XX) and an increasing deficient polymer in solitary units (EXE) will approach 20 .

EXX index constitutes a second measure of the polymer structure based directly on dimers and higher orders of (EXX and XXE) contiguous absorbed; it can be used independently or in conjunction with the agglomeration index (EXE) to distinguish polymers.

EXX index for commercial resins 3, 5 and 6, which are referred to in the attached Table, is 7.3, 12.4 and 15.0.

The ethylene polymers according to the present invention are preferably marked by a relatively tight molecular weight distribution compared to the polymers of the prior art. Molecular weights and molecular weight distributions were determined using Waters 150 C gel permeametry chromatography apparatus. These instruments are equipped with refractive index detectors that operate at 145 ° C and have a

58,946

JL / PE-1542

J.8.DEZ.W solvent flow rate equal to 1 ml per minute. The solvent used was 1,2,4-trichlorobenzene with an ultra-high degree of purity, obtained from Burdick and Jackson Co.. Before being used, the solvent was filtered through a 0.5 micron filter and stabilized up with 120 ppm BHT. Three Waters styrene gel columns with nominal porosities of 500, 10,000 and 1,000,000 angstroms were used. Each polymer sample was dissolved in trichlorobenzene solvent at 145 ° C until a concentration level of about 0.15% by weight was obtained and then filtered through a porous metal filter with 0, 5 micron. Then, a volume of about 300 microliters of this solution was injected into the gel permeametry chromatograph. The analysis time typically took forty-five minutes. The calibration of the apparatus for determining molecular weights was performed using polystyrene standards of tight molecular weight distribution, sold by the firm Toyo Soda Manufacturing Company. Sixteen patterns were used with molecular weights ranging from 526 to 5.2 x 10. The molecular weight distributions of these standards are comprised between 1.0 - 1.15, as determined by the quotient of average molecular weight by weight for the average molecular weight in number. These data on the molecular weights of polystyrene were then transformed into the polyethylene base, using the Mark-Houwink equation and using the following constants:

for polyethylene K = 5.17 x 1θ, a = 0.70 for polystyrene K = 2.78 x 10, a = 0.70

Each sample was tested in duplicate and the results thus obtained were averaged to obtain the reported molecular weight. The molecular weight distribution of the resin in Example 1, mentioned below, was

- 23 58,946

JL / PE-1542 plotted for comparison on the same graph with the percentage of the comonomer in moles of the linear low density polyethylene resin Exxon LL3OOO1, on a logarithmic molecular weight scale as a function of the weight percentage of the polymer in the molecular weight range considered . From the drawing of Figure 3 it can be concluded that the polymer according to the present invention has a strictly tighter molecular weight distribution than the commercially available linear low density polyethylene.

The polymers according to the present invention also preferably have a tight comonomer distribution between the polymer molecules compared to the polymers of the prior art. For comparison, the drawing in Figure 4 reflects the tight distribution of the unsaturated polymer of Example 1 compared to the relatively wide comonomer distribution of the polymers of the prior art. In Figure 4, the copolymer weight percentage (having a given comonomer content) is plotted, as a function of the elution temperature that directly reflects the comonomer content. This preferred embodiment of the polymers according to the present invention will be better understood by looking at Figure 4 and reading the following discussion.

Crystalline copolymers can be fractionated according to their comonomer content over a temperature range of 0 to 120 ° C, in tetrachlorethylene solvent. The compositions of the solution fractions are determined and, based on the data thus obtained, a solution temperature calibration curve as a function of the composition was constructed. Using this calibration curve, the temperature scale of the solubility distribution curve can be transformed into a scale of the composition and thus obtain a distribution curve of the composition, as shown in the drawing in Figure 4.

- 24 58,946 jl / pe-1542

18. TEN. 1987

An apparatus was set up to automatically determine the solubility distribution curve of a crystalline polymer. In the measuring instrument, a steel column is filled with small glass beads and immersed in an oil bath, the temperature of which can be programmed over a temperature range from about 0 to 150 ° C.

Tetrachlorethylene, used as a solvent, can be prevented from boiling by operating the instrument at a pressure of about 3 atmospheres using an automatic regulator. In a small sample preparation chamber, a heavy amount of sample, usually equal to about 1.6 grams, is placed, sealed and vacuum repeatedly and filled with water. A measured volume of solvent is then pumped into the sample preparation chamber, in which it is stirred and heated, so as to obtain a solution with a concentration equal to about 1%. A measured volume of this solution, usually about 100 cubic centimeters, is then pumped into the filled column, which has been thermostated at an elevated temperature, usually at least equal to about 120 ° C.

The sample of the polymer solution is subsequently crystallized by cooling the polymer in the column to 0 ° C., With a programmed speed of 5 ° C Ρθ ^Γ hour. The column was then maintained at 0 ° C for at least one hour. Then, the determination elution operation begins by pumping pure solvent through the column with a flow rate

Q of 6 cnr per minute. The column effluent passes through the reheater, where it is heated to 120 ° C before passing through an infrared detector, used to measure the absorbance of the effluent stream. The absorption of the infrared radiation from the carbon-hydrogen stretch bands of the polymer at about 2960 centimeters ¹ serves as the continuous measurement of the relative concentration of the polymer in the effluent. After passing through the infrared detector,

58,946

JL / PE-1542

the effluent temperature is lowered to about 110 ° C and the pressure is reduced to 1 atmosphere, before the current passes to the automatic fraction collector. In the elution operation, pure solvent is pumped through the column, guided at 0 ° C, for 1 hour. This operation serves to wash the polymer that did not crystallize during the crystallization phase out of the column, so that the relative percentage of non-crystallized polymer can be determined from the plotted curve of the infrared spectrum. The temperature is then programmed to cover up to 100 ° C with an ascent rate of 10 ° C per hour and 20 ° C per hour, from 100 ° C to 120 ° C.

The compositions of the fractions obtained from the various polymers were determined by infra red spectroscopy. The compositions determined by means of infrared are obtained from the intensity of the methyl band at 1378 cm ^-1 , the thickness of the sample and a calibration curve based on the samples whose compositions were determined independently by C NMR test. No compensation corrections were made to the polymer methyl end groups in the compositions obtained from the infrared spectrum data.

Figure 5 is a graphical representation of the elution temperature as a function of the comonomer content in percent in moles of comonomer (branches per 1000 carbon atoms) for the sample fractions. The ’Ά curve was obtained by connecting the various points. Thus, curve A can be used as a correlation curve between the elution temperature and the polymer composition for temperatures greater than 0 ° C. The calibration curve is extremely accurate for fractions with average molecular weights in number, 10 000, determined by size exclusion chromatography,

As seen in the drawing in Figure 4, polymer samples tend to peak at about 0 ° C

- 26 58,946 jl / pe-1542

18.TEN. 1987

elution temperature. This small peak represents the fraction of the total polymer that is not crystallizable at the minimum experiment temperature (about 0 ° C).

In summary, the device and the procedure described above provide a graphical representation of the relative weight percentage of the polymer as a function of the elution temperature, which in turn can be correlated with the composition and the mole percentage of the comonomer (branches per 1000 carbon atoms) in the polymer chain. Accordingly, the drawing in Figure 4 is an effective comparison of the comonomer distribution of the polymers according to the present invention with that of certain commercial polymers. As can be easily seen, the distribution of the polymer composition of the example according to the present invention is very tight compared.

When forming the polymers according to the present invention, it may be necessary to purify or isolate the diene and other optional comonomers according to the present invention in order to obtain their incorporation during polymerization. A recommended technical method is to pass the comonomer, especially the diene, through alumina, to remove foreign materials.

Figure 6 represents the melting point values determined by differential scanning calorimetry (DSC) for the resins according to the present invention compared to commercial resins. The melting point distributions were determined using a Perkin Elmer DSC-7 apparatus, operating as follows:

A sample of about 5 - 6mg was heated at 160 ° C and maintained at this temperature for 5 minutes. Then, the streak was cooled at 10 ° C per minute to a temperature of 0 ° C and reheated at 10 ° C per minute. The distributions of the indicated melting points were obtained during this reheating with the velocity

- 27 58,946

JL / PE-1542

Ο 10 C per minute.

The unsaturation concentrations in ethylene-based polymers were determined by comparing the infrared spectra of brominated polymer samples compared to original polymer samples, using the following bands

vinylene - 965 -1 cm -1 vinyl - 909 cm vinylidene - 888 -1 cm

Various analyzes of the copolymers according to the present invention and of polymers formed by the method according to the present invention show that these polymers have a significant predominance of butadiene ring addition as compared to addition 1.2 which can give rise to compressed chain branches and / or intermolecular coupling. A predominance of addition 1,2 may, in fact, lead to the crosslinking of the copolymer, as was seen in the prior art. All polymers according to the present invention are essentially completely non-cross-linked and non-gelled materials.

degree of coupling and / or branching of long chains of polymers according to the present invention can vary from a composition of a copolymer that is substantially free of such branches and coupling and that rheologically supports itself as linear molecules, to compositions that have a high degree of branching of long chains and intermolecular coupling without being cross-linked. Polymers are generally a non-cross-linked product and are soluble in reflux-heated xylene, according to recognized methods. That is, substantially all, generally more than 9% of the copolymers according to the present invention are soluble in xylene heated to 35 ° C.

58,946

JL / PE-1542

I flow.

A better understanding of the present invention will be achieved by reviewing the following examples, considered in conjunction with the drawings of the Figures. The best embodiment of the present invention is described below in the present specification.

Briefly, the transition metal containing catalyst according to the present invention is obtained by reacting an alumoxane with a metallocene in the presence of a solid support material. The reaction product in the carrier can be used as the sole catalyst component for the polymerization of olefins or, as a variant, an organo-metallic cocatalyst can be used.

Typically, the support can be any solid support, particularly pure support, such as ta, inorganic oxides and resinous support materials, such as polyolefins. Preferably, the support material is an inorganic oxide in finely divided form.

Suitable inorganic oxide matrices which are desirably employed in accordance with the present invention include metal oxides of Groups 2A, 3A, 4A or 4B, such as silica, alumina and silica-alumina and mixtures thereof. Other inorganic oxides that can be used either alone or in combination with silica, alumina or silica-alumina are magnesia, titania, zirconia and the like. However, other suitable support materials can be used, such as, for example, finely divided polyolefins, such as finely divided polyethylene.

Metal oxides generally contain acidic surface hydroxyl groups which react with alumoxane or the transition metal compound primarily added. to the solvent for carrying out the reaction. Before use, the inorganic oxide support is dehydrated, that is, subjected to a heat treatment, in order to eliminate

- 29 58,946

JL / PE-1542 uEZ. 7 /

water and reduce the concentration of surface hydroxyl groups. tials. The treatment is carried out in a vacuum or while purging with a dry inert gas, such as nitrogen, at a temperature of about 100 ° C to about 1000 ° C and, preferably, between about 300 to about 800 ° C . The consideration of pressure is not critical. The duration of the heat treatment can be from about one to twenty-four hours. However, shorter or longer time intervals can be preached, so that the balance with the perfect hydroxyl groups is established.

Advantageously, chemical dehydration can be used as an alternative method of dehydrating the support material consisting of metal oxide. Chemical dehydration transforms all water and all hydro groups. existing on the oxide surface in inert species. Useful chemical agents are, for example, SiCl4, chlorosilanes, such as trimethylchlorosilene, dimethylamino-trimethylsilane and the like. Chemical dehydration is carried out by suspending particulate inorganic material such as, for example, silica, in an inert low-boiling hydrocarbon, such as, for example, hexane,

During the chemical dehydration reaction, the silica must be kept in an atmosphere free of moisture and oxygen. To the silica suspension, a solution of the chemical dehydrating agent, such as, for example, dichlorodimethyl-dilan in an inert low-boiling hydrocarbon, is then added. The solution is added slowly to the suspension. The temperature ranges during the chemical dehydration reaction can vary from about 120 ° C; however, higher and lower temperatures can also be used. Preferably, the temperature will be about 50 to 70 ° C.

The chemical dehydration process should be allowed to continue until all moisture has been removed

58,946

JL / PE-1542

0EZ.1S87 of the particulate support material, as indicated by the interruption of gas evolution. Typically, the chemical dehydration reaction is allowed to proceed for about thirty minutes to about sixteen hours, preferably one to five hours. After chemical dehydration is complete, the particulate solid material is filtered under a nitrogen atmosphere and washed one or more times with an inert hydrocarbonate solvent, free of water and free of oxygen. The washing solvents, as well as the diluents used to form the suspension and the solutions of chemical dehydrating agents can be any suitable hydrocarbons. Examples of these hydrocarbons are hepté. no, hexane, toluene, isopentane and the like.

Meralocenes and alumoxanes normally soluble in hydrocarbons are transformed into a heterogeneous supported catalyst by depositing said metallocenes and alumoxanes on the dehydrated support material. The order in which metallocenes and alumoxanes are added to the support material may vary. For example, metallocene (pure or dissolved in an appropriate carbonated solvent) can be added first to the support material, followed by the addition of alumoxane; alumoxane and metallocene can be added simultaneously to the support material; alumoxane can be added first to the support material, followed by the addition of the metallocene. According to the preferred embodiment of the present invention, alumoxane, dissolved in the appropriate inert hydrocarbon solvent, is added to the support material suspended in the same or other suitable liquid hydrocarbon and then the metallocene is added to the suspension.

Treatment of the support material, as mentioned above, takes place in an inert solvent. The same solvent or a different inert solvent is also used to dissolve metallocenes and alumina. Preferred solvents include mineral oils and

58,946

JL / PE-1542

I8.DEZ.1S87

the various hydrocarbons that are liquid at the temperatures of carrying out the reaction and in which the individual ingredients are soluble.

Illustrative examples of useful solvents include alkanes, such as pentane, isopentane, hexane, heptane, octane and nonane; cycloalkanes, such as cyclopentane and cyclohexane; and aromatic hydrocarbons, such as benzene, toluene, ethylbenzene and diethylbenzene. Preferably, the support material is suspended in toluene and the metallocene and alumoxane are dissolved in toluene, prior to addition to the support material. The amount of solvent to be used is not critical. However, a sufficient amount should be used to provide adequate heat transfer by transferring from the catalyst components during the reaction and allowing a good mixing.

The supported catalyst according to the present invention is prepared by simply adding the reagents in the appropriate solvent and, preferably, toluene, the suspension of the support material, preferably silica suspended in toluene. The ingredients can be added to the reaction vessel quickly or slowly. The temperature maintained during the contact of the reagents can vary widely, for example, from 0 to 100 ° C. Higher or lower temperatures can also be used. Preferably, alumoxanes and metallocenes are added to silica at room temperature. The reaction between alumoxane and the support material is rapid; however, it is desirable for the alumoxane to be contacted with the support material for about an hour to eighteen hours or more. Preferably, the reaction is maintained for about an hour. The reaction of the food> xane, metallocene and support material is evidenced by its exothermic nature and color variation.

The individual ingredients as well as the recovered catalyst component are protected against the action of oxygen and moisture at all times. Therefore, the reactions must be carried out in an atmosphere free of oxygen and humi

10 $ 8.9 ^ 6

JL / PE-1542

and recovered in an atmosphere free of oxygen and moisture. Preferably, therefore, the reactions are carried out in the presence of a dry, inert gas, such as, for example, nitrogen. The recovered solid catalyst is also maintained in a nitrogen atmosphere.

After completing the reaction of metallocene and alumoxane with the support, the solid material can be recovered by any well-known technique. For example, the solid material can be recovered from the liquid by evaporation under vacuum or by decantation. The solid is then dried under a stream of dry nitrogen or vacuum dried.

The amount of alumoxane and metallocene usefully used in the preparation of the solid supported catalyst component can vary within a wide range. The concentration of the alumoxane added to the essentially dry support can be within the range of about 0.1 to about 10 millimoles / gram of support, but larger or smaller amounts may usefully be used. Preferably, the concentration of alumoxane is within the range of 0.5 to 10 millimoles / gram of support and, especially, 1 to 5 millimoles / gram of support. The amount of metallocene added is such that a ratio of aluminum to transition metal in moles ranging from about 1: 1 to about 100: 1 is provided. Preferably, the ratio is within the range of about 5 s 1 to about 50: 1 and, more preferably, within the range of about 10: 1 to about 20: 1. These ratios are significantly less than those required for the homogeneous system.

The unsaturated polymers according to the present invention are those with a tight agglomeration index and, preferably, have the additional structure described for molecular weight distribution and comonomer distribution, as well as the properties referred to in this specification. Such polymers can be prepared by

- 33 58,946

JL / PE-1542

18. TEN. 1387

any of the known polymerization techniques, including solution processes, high pressure polymerization and gas phase polymerization.

Polymers according to the present invention can be formed using catalyst and metallocene systems, that is, cyclopentadienyl catalyst systems, using a metallocene complex in association with an alumoxane cocatalyst or a reaction product, which are suitable for the preparation of polymers according to the present invention. The metallocene catalyst can be represented by the general formula (C) MR R ' ^v p'm np in which it is a substituted or unsubstituted cyclopentadienyl ring; M is a transition metal of Group IVB, VB or VIB; R and R 'are independently chosen from halogen, hydrocarcyl groups or hydrocarboxyl groups, having 1-20 carbon atoms; m = 1-3; n = O-3; p = 0-3 and the sum of m + n + p is equal to the oxidation number of M.

Various forms of the metallocene type catalyst system can be used for polymerization, in order to obtain polymers according to the present invention, including catalysts of the homogeneous or heterogeneous type supported, in which the catalyst and the cocatalyst of alumoxane are jointly supported or reacted together on an inert support, for polymerization in gas phase, under high pressure or in solution.

The cyclopentadienyls of the catalyst can be unsubstituted or replaced by hydrogen or hydrocarbyl radicals. Hydrocarbon radicals can include alkyl, alkenyl, aryl, alkylaryl, arylalkyl radicals, and the like, which contain from about 1 to twenty carbon atoms or two carbon atoms bonded together C ^-C ^.

- 34 10

I

58,946

JL / PE-1542

18.0EZ.i987

The present invention employs at least one metallocene compound in the formation of the supported catalyst. Metallocene, that is, a cyclopentadienylene, is a metallic derivative of a cyclopentadiene. The metallocenes employed usefully in accordance with the present invention contain at least one cyclopentadiene ring. The metal is chosen from the metals in Groups 4b, 5b and 6b, preferably in Groups 4b and 5b and is preferably titanium, zirconium, hafnium, chromium and vanadium, especially titanium and zirconium. The cyclopentadienyl ring can be unsubstituted or contain substituents such as, for example, a hydrocarbyl substituent. The metallocene may contain one, two or three cyclopentadienyl rings, however two rings are preferred.

Preferred metallocenes can be represented by the general formulas:

I. (c) mRX p m n q in which is a cyclopentadienyl ring; M is a transition metal of Groups 4b, 5b, or 6b; Re a hydrocarbi group. lo or hydrocarbon, which has from one to twenty carbon atoms; X is a halogen; and m = 1 - 3; n = O - 0 - 3;

q = 0 - 3 and the sum of m + n + q is equal to the oxidation level of the metal.

ÍI. (C ₅ Rp _g R _s (C ₅ Hi) MQ _{3. G} e

III. R _s (c ₅ R £) ₂ mq 'where (c ^ R ^.) Is a cyclopentadienyl or substituted cyclopentadienyl group; each R 'is the same or different and means hydrogen or a hydrocarbyl radical such as alkyl, alkenyl, aryl, arylalkyl or alkylaryl, containing one to twenty carbon atoms or two carbon atoms are joined together to form a C4 - ring C ^; R ”is an alkyl- 35 58,946 radical

JL / PE-1542 and not in C ^-C ^, a dialkyl-germanium or dialkyl-silicon radical or an alkyl-phosphine or amine radical that bridges the two rings (C C ^ R ^); Q is a hydrocarbyl radical, such as aryl, alkyl, alkenyl, alkylaryl, or arylalkyl, with one to twenty carbon atoms, a hydrocarbon radical with one to twenty carbon or halogen atoms and can be the same or different from each other; Q 'is an alkylidene radical having one to about twenty carbon atoms; s is O or 1; sort 0, 1 or 2; seO when g is 0; k is 4 when s is 1 and k is 5 when s is 0; and M is as defined above.

Examples of hydrocarbyl radicals are methyl, ethyl, propyl, butyl, amyl, iso-amyl, hexyl, isobutyl, heptyl, octyl, nonyl, decyl, cetyl, 2-ethylhexyl, phenyl and the like.

Examples of halogen atoms include chlorine, bromine, fluorine and iodine and, of these halogen atoms, chlorine is preferred.

Examples of hydrocarboxy radicals are methoxy, ethoxy, propoxy, butoxy, amyloxy and the like.

Examples of alkylidene radicals are methylidene, ethylidene and propylidene groups.

Non-limiting illustrative examples of the metallocenes represented by formula I are dialkyl-metallocenes, such as bis- (cyclopentadienyl) -titanium-dimethyl, bis- (cyclopentadienyl) -titanium-diphenyl, bis- (cyclopentadienyl) -zirconium-dimethyl, bis - (cyclopentadienyl) -zirconium-diphenyl, bis- (cyclopentadienyl) -hafnium-dimethyl and bis- (cyclopentadienyl) -diphenyl, bis- (cyclopentadienyl) -titanium-dineopentyl, bis- (cyclopentadienyl) -zirconium-di-neopop , bis- (cyclopentadienyl) -titanium-dibenzyl, bis- (cyclopentadienyl) -zirconium-dibenzyl, bis- (cyclopentadienyl) -vanadium-dimethyl: mono-alkylmetallocenes, such as bis- (cyclopentadienyl) -titanium- chloride methyl, bis- (cyclopentadienyl) -titanium-ethyl chloride, bis- (cyclopentadienyl) -titanium-phenyl chloride, bis- (cyclopentadienyl) -zirconium-chloride 36 58,946

JL / PE-1542

nio-methyl, bis- (cyclopentadienyl) -zirconium-ethyl chloride, bis- (cyclopentadienyl) -zirconium-phenyl chloride, bis- (cyclopentadienyl) -titanium-methyl bromide, bis- (cyclopentadienyl) -methyl iodide, bis- (cyclopentadienyl) -titanium-ethyl bromide, bis- (cyclopentadienyl) -titanium-ethyl iodide, bis- (cyclopentadienyl) -titanium-phenyl bromide, bis- (cyclopentadienyl) -titanium-iodide, phenyl bromide bis- (cyclopentadienyl) -zirconium ~ methyl, bis- (cyclopentadienyl) -zirconium-methyl iodide, bis- (cyclopentadienyl) -zirconium-ethyl bromide, bis- (cyclopentadienyl) -zirconium-ethyl iodide, bis- bromide (cyclopentadienyl) -zirconium-phenyl, bis- (cyclopentadienyl) -zirconium-phenyl iodide; and trialkyl-metallocenes, such as cyclopentadienyl-titanium-trimethyl, cyclopentadienyl-zirconium-triphenyl and cyclopentadienyl-zirconium-trineopentyl, cyclopentadienyl-zirconium-trimethyl, cyclopentadienyl-hafnio-triphenyl, cyclopentadien-cyclopentadienyl

Illustrative but not limiting examples of the metallocenes of formulas II and III that can be usefully employed in accordance with the present invention are the monocyclopentadienyl-titanocenes, such as, for example, pentamethylcyclopentadienyl-titanium trichloride, penta-ethyl-cyclopentadienyl-trichloride titanium;

bis- (pentamethylcyclopentadienyl) -titanium-diphenyl, the carbene represented by the formula bis- (cyclopentadienyl) -titanium = CH ₂ and derivatives of this reagent, such as bis- (cyclopentadienyl) -Ti = CH ₂ .AI (CH ^) ₂ , (Cp ₂ TiCH ₂ ) ₂ , Cp ₂ TiCH ₂ CH (CH ₃ ) CH ₂ , Cp ₂ Ti-CHCH ₂ àH ₂ ;

substituted bis- (cyclopentadienyl) -titanium (IV) derivatives, such as bis- (indenyl) -titanium-diphenyl or dichloride, bis- (methyl-cyclopentadienyl) -titanium-diphenyl or dihalides;

dialkyl-cyclopentadienyl-titanium compounds, trialkyl-cyclopentadienyl-titanium, tetralkyl-cyclopen

- 37 „Ί8 0EZJ987

58,946 - - „

JL / PE-1542 tadienyl-titanium and pentalquyl-cyclopentadienyl-titanium, such as bis- (1,2-dimethylcyclopentadienyl) -titanium-diphenyl or dichloride, bis- (1,2-diethylcyclopentadienyl) -titanium-diphenyl or dichloride and others dihalide complexes; and bridged cyclopentadiene complexes by silicon, phosphine, amine or carbon, such as dimethylsil-diclopentadienyl-titanium-diphenyl or dichloride, methyl-phosphine-dicyclopentadienyl-titanium-diphenyl or dichloride, methylene-dicyclopentadienyl-titanium- diphenyl or dichloride and other dihalide complexes and the like.

Other zirconocene catalysts useful in accordance with the present invention include bis- (cyclopentadienyl) -zirconium-dimethyl; bis- (cyclopentadienyl) -zirconium-dichloride, bis- (cyclopentadienyl) -zirconium-methyl-chloride. Illustrative but not limiting examples of zirconocenes of formula II and III that can be usefully employed according to the present invention are pentamethyl-cyclopentadienyl-zirconium trichloride, penta-ethyl-cyclopentadienyl-zirconium trichloride, bis- (pentamethyl-cyclopentadienyl) ) -zirconium-diphenyl;

Alkyl-substituted cyclopentadienes, such as bis- (ethyl-cyclopentadienyl) -zirconium-dimethyl, bis · - (p-phenylpropyl-cyclopentadienyl) -zirconium-dimethyl, bis- (methyl-cyclopentadienyl) -zirconium-dimethyl, bis- ( n-butyl-cyclopentadienyl) -zirconium-dimethyl, bis- (cyclohexylmethyl-cyclopentadienyl) -zirconium-dimethyl, bis- (n-octyl-cyclopentadienyl) -zirconium-dimethyl and halogen-alkyl and di-halide complexes above-mentioned compounds;

dialkyl-cyclopentadienes, trialkyl-cyclopentadienes, tetralkyl-cyclopentadienes and pentalquyl-cyclopentadienes, such as bis- (pentamethyl-cyclopentadienyl) -zirconium-dimethyl, bis- (1,2-dimethyl-cyclopentadienyl) -methyl and zirconium-complexes dihalide of these compounds; and cyclopentadiene complexes bridged by silicone, phosphorus and carbon, such as dimethyl-silyl-cyclic 18 TEN. 287

58,946

JL / PE-1542

clopentadienyl-zirconium-dimethyl or dihalide and methylene · -dicyclopentadienyl-zirconium-dimethyl or dihalide and methylene-dicyclopentadienyl-zirconium-dimethyl or dihalide, carbenes represented by the formula CpgZrsCHPfC ^ H ^ JgCH ^ compounds , such as Cp ^ ZrCH ^ CHfCH ^ JCH ^.

Illustrative examples of other metallocenes include bis- (cyclopentadienyl) -hafnium, bis- (cyclopentadienyl) -hafnium-dimethyl, bis- (pentadienyl) -vanadium dichloride and the like.

The inorganic oxide support used in the preparation of the catalyst can be any mixed oxide or particulate oxide, as described above, which has been thermally or chemically dehydrated, in such a way that it is substantially free of absorbed moisture.

The specific dimensions of the particles, the surface area, the volume of the pores and the number of surface hydroxyl groups characteristic of inorganic oxide are not critical for their use in the practice of the present in wind. However, as these characteristics determine the amount of inorganic oxide that is desirable to use in the catalyst compositions, and also affect the properties of the polymers formed with the aid of the catalyst compositions, these characteristics must often be taken into account when choosing an oxide for use in a particular aspect of the present invention. For example, when the catalyst composition is to be used in a gas phase polymerization process - a type of process in which it is known that the size of the polymer particles can vary by varying the size of the substrate particles - the oxide Inorganic material used in the preparation of the catalyst composition must be an oxide that has particle sizes that are appropriate for the production of the polymer that has the desired particle size. In general, optimal results are usually obtained using inorganic oxides 39 58,946

JL / PE-1542

I

tcos having an average particle size within the range of about 30 to 600 microns, preferably about 30 to 100 microns; a surface area of about 50 to 1000 square meters per gram, preferably about 100 to 400 square meters per gram and a pore volume equal to about 0.5 to 3.5 cubic centimeters per gram, preferably about 0.5 to 2 cubic centimeters per gram.

Polymerization can be carried out using the solution, suspension or gas phase polymerization technique, generally at a temperature within the range of about 0 to 16θ ° C or even higher and under conditions of atmospheric, subatmospheric or superatmospheric pressure; and, if desired, conventional auxiliary polymerization agents, such as hydrogen, can be used. It is generally preferred to use catalyst compositions with a concentration such that it provides about 0.000001 to 0.005%, more preferably about 0.00001 to 0.0003% by weight of transition metal relative to the weight of monomer or monomers, in the polymerization of ethylene, alone or with one or more higher olefins.

A suspension polymerization process can use subatmospheric or superatmospheric pressures and temperatures within the range of 40 to 110 ° C. In suspension polymerization, a suspension of solid polymer particles is formed, in a liquid polymerization medium, to which is added ethylene, alpha-olefin comonomer, hydrogen and catalyst. The liquid used as the polymerization medium can be an alkane or a cycloalkane, such as, for example, butane, pentane, hexane or cyclohexane, or an aromatic hydrocarbon, such as toluene, ethylbenzene or xylene. The medium used must be liquid under the conditions of carrying out the polymerization and relatively inert. Mayor. Reasonably, hexane or toluene is used.

A gas phase polymerization process

- 40 18 DEC. 1987

58,946

JL / PE-1542

uses superatmospheric pressure and temperatures within the range of about 50 to 120 ° C. The gas phase polymerization can be carried out in a stirred or fluidized bed of catalyst and product particles, in a pressure vessel, adapted to allow the separation of unreacted gaseous product parts. A thermostated gas mixture consisting of ethylene, comonomer, hydrogen and an inert diluent gas, such as nitrogen, can be introduced or recirculated, in order to keep the particles at a temperature between 5θ ^and 120 ° C. if triethyl aluminum as needed, to operate as an absorber of water, oxygen and other adventitious impurities. The olimeric product can be withdrawn continuously or semi-continuously, at a rate such that the constant amount of product inside the reactor is maintained. After polymerization and deactivation of the catalyst, the polymeric product can be recovered by any appropriate means. In commercial practice, the polymeric product can be recovered directly from the gas phase of the reactor, free of residual monomer with a nitrogen purge and used without any further deactivation or separation of the catalyst. The polymer thus obtained can be extruded into water and cut into tablets or other forms of appropriate small dimensions. Pigments, anti-oxidants and other additives can be added to the polymer, as is known in the art.

The molecular weight of the polymeric product obtained according to the present invention can vary over a wide range, such as from 5θθ to 2,000,000 or more, and preferably between 1,000 and about 500,000.

For the preparation of polymeric product having a tight molecular weight distribution, it is preferable to deposit only one metallocene on the inert porous support material and employ said metallocene support together with alumoxane as a polymerization catalyst.

TEN. 198 /

58,946

JL / PE-1542

It is highly desirable to have available for many applications, such as extrusion and molding processes, polyethylenes that have a wide distribution of molecular weights of the unimodal and / or multimodal type. These polj. ethylenes show excellent processability, that is, they can be processed at a much higher speed, with less energy requirements, and at the same time, these polymers show less disturbances of the flow in the melting state. These polyethylenes can be obtained by providing a catalyst component that comprises at least two different metallocenes, each having different propagation and finishing rate constants for ethylene polymers. These speed constants are easily determined by any person skilled in the art.

The molar ratio of the metallocene, such as, for example, from a zirconocene to a titanocene, in these catalysts, can vary over a wide range and, according to the present invention, the only limitation in molar proportions is the width of the distribution Mw or the desired degree of bimodality in the polymeric product. Desirably, the molar ratio of metallocene to metallocene is between about 1! 100 to about 100: 1, and preferably between 1: LO and about 10: 1.

the present invention also provides a process for the preparation of mixtures of reactor (co) polyolefins comprising polyethylene and alpha-olefin copolyethylene. Reactor mixtures are obtained directly during a single polymerization process, that is, the mixtures according to the present invention are obtained in a single reactor, simultaneously polymerizing ethylene and copolymerizing ethylene with an alpha-olefin, thereby eliminating mixing operations expensive. The process for preparing mixtures in the reactor according to the present invention can be used in association with other mixing processes of the prior art, for example, reactor mixtures>

- 42 18 DEC. £ 87

58,946

JL / PE-1542

produced in a first reactor can be subjected to further mixing in the second reactor, using the reactors in series.

In order to produce reactor mixtures, the supported metallocene catalyst component comprises at least two different metallocenes, each having different proportions of reactivity of the comonomer.

The proportions of the metallocene comonomer reactivity are generally obtained by well-known methods, for example, as described in the Linear Method for Determining Monomer Reactivity Ratios in Copolymerization ”, M. Fineman and SD Ross, J. Polymer Science J5 259 (195θ) or '' Copolymerization ”, FR Mayo and C. Walling, Chem. Rev _o , 46, 191 (1950), which are fully incorporated in this Descriptive Memorandum, as a reference. For example, to determine the proportions of reactivity, the most widely used copolymerization model is based on the following equations:

Μ _χ * + Μ _χ ^Κ 11 Μ, * (1) ^Μ 1 * ^{+ Μ} 2 ^Κ] - ² (

Μ ₂ * + Μ _χ ^Κ 21 Μ _ί * (3)

Μ ₂ * ^{+ Μ} 2 ^Κ22 (4) where Μ _χ refers to a monomer molecule that is arbitrarily designated as i (where i = 1,2) and Μ _χ * refers to a growing polymer chain , to which monomer i has most recently bonded.

The kij values are the rate constants for the indicated reactions. In this case, k _xx represents the speed at which an ethylene unit is inserted into the growing polymer chain at which the monomer unit pre-

JL / PE-1542

J8 0EZ.S87 vialy inserted was also ethylene. The reactivity speeds are as follows:

^r i ^'k l] / ^k 12 and ^r 2 ^x 22 ^ ^k 21 wherein ^ 12' ^k 22 ^k L ^S ^ ° ^{the rec} ^ ^an 'T ^s rate for ethylene (1) or addition of comonomer (2) to a catalyst site where the last polymerized monomer is ethylene (k _ix ) or comonomer (2) (k ^).

As, according to the present invention, a high viscosity polymeric product can be prepared at a relatively high temperature, temperature is not a limiting parameter, as is the case with the previously known metallocene / alumoxane catalyst. The catalyst systems described in the present specification, therefore, are suitable for the polymerization of olefins in solution, suspension or gas phase polymerizations and over a wide range of temperatures and pressures. For example, such temperatures may be within the range of about -60 to about 280 ° C, and especially within the range of about 0 to about 160 ° C. The pressures employed in the process according to the present invention are well known, for example, within the range of about 1 to 500 atmospheres; however, higher pressures can be used.

The polymers produced by the process according to the present invention can be transformed into a wide variety of articles, as is known for ethylene homopolymers and copolymers of ethylene and higher alpha-olefins.

In a suspension polymerization, the alkyl aluminum oxygen and moisture inhibitor is preferably dissolved in an appropriate solvent, typically in a dis. inert hydrocarbon solvent, such as toluene, xylene and

- 44 18 DEC. 1987

58,946

JL / PE-1542

„3 similar, in a molar concentration equal to about 5 x 10 M. However, larger or smaller amounts can be used.

Illustrative of other metallocenes is bis- (cyclopentadienyl) -haphnium, bis- (cyclopentadienyl) -haphnium-dimethyl, bis- (cyclopentadienyl) -vanadium dichloride and the like.

To prepare polymers according to the present invention, various inorganic oxide supports can be used for the supported catalyst systems. The polimeri. These operations are generally carried out within the temperature range of about 0 to 160 ° C or even higher, but this range should not be considered as exclusive for the preparation of the polymers of the present invention, which can be prepared by any technique. that allows obtaining the mentioned structures.

For polymerization using the metallocene catalyst described above, atmospheric, subatmospheric or superatmospheric pressure conditions can be used. Generally, it is preferred to use catalyst compositions with a concentration such that it provides about 1 ppm to about 5,000 ppm, more preferably 10 ppm to 300 ppm by weight of transition metal based on the weight of monomers, in carrying out the polymerization of ethylene polymers.

suspension polymerization processes can generally use subatmospheric or superatmospheric pressures and temperatures within the range of 4θ to 110 ° C. In suspension polymerization, a suspension of solid polymer particles is formed in a liquid polymerization medium, to which are added ethylene and comonomers, and often hydrogen, together with the catalyst. The liquid used as the polymerization medium can be an alkane or a cycloalkane or an aromatic hydrocarbon, such as toluene, ethylbenzene or xylene. The medium used must be liquid under the conditions of polymerization and relatively _ 45 58,946

JL / PE-1542

TEN. fc87

inert. Preferably, hexane or toluene is used.

According to a modification, the polymers of the present invention can be prepared by gas phase polymerization. A gas-phase process uses super-atmospheric pressure and temperatures within the range of about 50 to 120 ° C. The gas phase polymerization can be carried out in a stirred or fluidized bed of product particle catalyst, in a pressure vessel, adapted to allow the separation of the product particles from the unreacted gases.

Thermostated ethylene, comonomer (including diene), hydrogen and an inert diluent gas, such as nitrogen, can be introduced or cross-linked in order to keep the particles at a temperature between 50 and 120 ° C. When necessary, triethylalminium can be added as a water, oxygen and other adventitious impurities. The polymeric product can be withdrawn continuously or semi-continuously at a rate such that the amount of product inside the reactor remains constant. After polymerization and deactivation of the catalyst, the polymeric product can be recovered by any appropriate means. In commercial practice, the polymeric product can be recovered directly in the gas phase of the reactor, free of residual monomer with a nitrogen flush and used without further deactivation or separation of the catalyst. The polymer obtained can be extruded into water and cut into pellets or other suitable small forms. Pigments, anti-oxidants and other additives can be added to the polymer, as is known in the art.

The molecular weight of the polymeric product obtained according to the present invention can vary over a wide range, from 500 to 2,000,000 or more and, preferably, between 1,000 and 500,000.

58,946

JL / PE-1542

For the production of polymeric product which has a tight molecular weight distribution, it is preferable to deposit only one metallocene on a porous, inert support material, and to use said metallocene on the support together with alumoxane as a polymerization catalyst.

It is very desirable to have, for many applications such as polyethylene extrusion and molding processes that have a wide unimodal and / or multimodal molecular weight distribution. These polyethylenes have excellent processability, that is, they can be processed at a faster speed with less energy consumption and, at the same time, these polymers may show reduced flow disturbances in the molten state. These polyethylenes can be obtained by providing a catalyst component that comprises at least two different metallocenes, each having different propagation and finishing rate constants for ethylene polymerizations. These speed constants are easily determined by any person skilled in the art.

The molar ratio of metallocenes, such as, for example, zirconocene to titanocene in these catalysts, can vary within a wide range and, according to the present invention, the only limitation in molar proportions is the width of the Mw distribution or the degree of bimodality desired in the polymeric product. Conveniently, the ratio of one metallocene to another metallocene ranges from about 1: 100 to about 100: 1 and, preferably, between 1: 10 and about 10: 1.

the present invention is illustrated by means of the following Examples.

EXAMPLES

In the following examples, the alumoxane used was prepared by adding 76.5 grams of ferrous sulfate

- 47 58,946

JL / PE-1542

heptahydrate in four increments equally spaced in time, over a period of two hours, in a two-liter round-bottom flask, rapidly agitated, containing 1 liter of a 13.1% solution by weight of trimethyl aluminum (ΤΜΑ) in toluene. The flask was maintained at 50 ° θ θ under a nitrogen atmosphere. The methane produced simultaneously was continuously discharged into the atmosphere. After the addition of ferrous sulfate heptahydrate was completed, the flask was continuously maintained at a temperature of 50 ° C for six hours. The reaction mixture was cooled to room temperature and allowed to settle. The clear solution containing alumoxane was separated by decanting the insoluble solids.

The molecular weights were determined on a gel permeametry chromatography (GPC) apparatus, from Water's Associates, Model λ ⁹ 150C. The determinations were made by dissolving polymer samples in hot trichlorobenzene and filtering. The GPC assays were carried out at 145 ° C, in trichlorobenzene, at a flow rate of 1.0 ml / minute, using styrene gel columns from Perkin Elmer, Inc. 0.1 (300 microliter) solutions were injected. solution in trichlorobenzene) and the samples were tested in duplicate. The integration parameters were obtained with a Hewlett-Peckard Data Module.

Catalyst Preparation

Catalyst A

In 50 cubic centimeters of toluene, 10 grams of a high surface area silica (Davidson 952) were suspended, dehydrated in a stream of dry nitrogen at 800 ° C for five hours, at a temperature of 25 ° C. under nitrogen atmosphere, in a 250 cubic centimeter round bottom flask, using a magnetic stirrer. 25 cubic centimeters of methyl alumoxane (1.03 moles /

58,946 jl / pe-1542 / liter in aluminum), for five minutes, with constant agitation, to the silica suspension. Stirring was continued for thirty minutes, while maintaining the temperature at 25 ° C, then toluene was decanted and the solids were recovered. The silica treated with aluinoxane was added dropwise, over five minutes, with constant stirring, 25.0 cubic centimeters of a solution in toluene, containing 0.200 grams of dicyclopentadienyl-zirconium cycloride. The suspension was stirred for a further 1/2 hour while maintaining the temperature at 25 ° C and then toluene was decanted and the solids were recovered and dried in vacuo for four hours. The recovered solid was neither soluble nor extractable with hexane. Analysis of the catalyst showed that it contained 4.5 wt% aluminum, and 0.63 wt% zirconium.

Catalyst B

This catalyst serves to show that the use of the catalyst according to the present invention in the production of copolyethylene with 1-butene results in the most efficient incorporation of 1-butene, as demonstrated by the density of the polymeric product.

This was followed by the procedure used for the preparation of catalyst A, with the difference that the treatment of the support material with methyl alumoxane was eliminated. Analysis of the recovered solid indicated that it contained 0.63% by weight of zirconium and 0% by weight of aluminum.

Catalyst C

The procedure followed for the preparation of catalyst A was followed, with the difference that 0.300 grams of bis- (cyclopentadienyl) -zirconium-dimethyl was used instead of bis- (cyclopentadie- 49 58.946

JL / PE-1542

nil) -zirconium. Analysis of the recovered solid indicated that it contained 4.2 wt% aluminum and 1.1 wt% zirconium.

I

Catalyst D

The procedure used for the preparation of catalyst A was adopted, with the difference that 0.270 grams of bis- (n-butyl-cyclopentadienyl) -zirconium chloride was used, replacing bis- (cyclopentadienyl) dichloride - zirconium catalyst A and all operating modes have been performed at 80 ° C. Analysis of the recovered solids indicated that they contained 0.61% by weight of zirconium and 4.3% by weight of aluminum.

Catalyst E

This was followed by the procedure used in the preparation of catalyst D, with the exception of 0.250 grams of bis- (n-butyl-cyclopentadienyl) -zirconium-dimethyl being replaced by metallocene dichloride. Analysis of the recovered solid indicated that it contained 0.63% by weight of 4.2% aluminum zirconium.

Catalyst F

The procedure followed for the preparation of catalyst I) was followed, with the difference that 0.5θ0 grams of bis- (pentamethyl-cyclopentadienyl) -zirconium dichloride were used instead of metallocene. Analysis of the recovered solid indicated that it contained 0.65% by weight of zirconium and 4.7% by weight of aluminum.

Catalyst X

10 grams of silica with a high surface area were suspended (Davidson 95 ² ), dehydrated in a dry nitrogen stream at 800 ° C for five hours, in 50 centi

18. DEC.IS37

58,946

JL / PE-1542

cubic meters of toluene at 25 ° C, under a nitrogen atmosphere, in a 250 cubic centimeter round bottom flask, using a magnetic stirrer. 25 cubic centimeters of methyl alumoxane in toluene (1.03 moles / liter in aluminum) were added dropwise over five minutes to the silica suspension, with constant stirring. Stirring was continued for thirty minutes, while maintaining a temperature of 60 ° C, after which toluene was decanted and the solids were recovered. To the silica treated with alumoxane, 25 cubic centimeters of a solution in toluene containing 0.200 grams of bis- (n-butyl-cyclopentadienyl) -zirconium was added dropwise over five minutes and with constant stirring. The suspension was stirred for an additional 1/2 hour while maintaining a temperature of 60 ° C and then toluene was decanted and recovered in vacuo for four hours. The recovered solid was neither soluble in hexane nor extractable by hexane. Analysis of the catalyst indicated that it contained 4.5% by weight of aluminum and 0.63% by weight of zirconium.

The following examples refer to the preparation of copolymers according to the present invention from ethylene and butadiene.

Catalyst systems, especially of the metallocene-alumoxane type, are effective for the preparation of polymers. A better understanding of the invention will be achieved by revising the Examples together with the drawings of the attached Figures. The best embodiment of the present invention not known to Applicants is described below.

Example 1 (Suspension Polymerization in a Diluent

A pressure-resistant stainless steel vessel, with a capacity of two liters, was dried and deoxygenated with a nitrogen stream, equipped with a stirrer 51

58,946

JL / PE-1542 on slopes, outer water jacket for temperature control, an inlet with septum and discharge pipe to the atmosphere and with a regulated supply of dry ethylene and nitrogen.

800 cubic centimeters of dry degassed isopentane and 200 cubic centimeters of purified 1,3-butadiene were injected directly into the vessel. In the vessel, 15.0 cubic centimeters of 0.755 molar methylalumoxane (in total aluminum) were injected into toluene with a gas-sealed syringe through the septum inlet, and the mixture was stirred at 1,200 revolutions per minute and at 82 ° C for five minutes at a pressure of 0 kg / cm of nitrogen. Bis- (n-butyl-cyclopentadienyl) zirconium dichloride (300 mg), dissolved in 3 »θ ml of water-free and recently distilled toluene, was injected into the vessel. After 1 minute, ethylene was admitted to

8.4 kg / cm relative to (120 psig), while maintaining the reaction vessel at 82 ° C. The ethylene was passed through the vessel for twenty minutes, after which the reaction was stopped by rapidly discharging to the atmosphere and cooling. 33.1 grams of ethylene / butadiene polymer were recovered after the evaporation of the liquid components under a nitrogen atmosphere. Polymer 13 was analyzed by C NMR assay and it was found that for each cis-1, 4- (cis-vinylene) unit in the polymer chain, there were 0.6 parts of 1,2 units (vinyl group) pending from the chain);

4.7 units trans-1,4- (trans-vinylene in the chain) and 8.7 parts of cyclopentane rings (linked in the ethylene chain in 1.2 in the ring).

Example IA (Polymerization in Diluent

A pressure vessel, one liter stainless steel, was dried and deoxygenated with a nitrogen stream, equipped with an inclined blade stirrer, water jackets

- 52 58,946

JL / PE-1542

0EZ.1887

exterior for temperature control, inlet with septum and discharge pipe to the regulated atmosphere of ethylene and dry nitrogen.

500 cubic meters of toluene free of water and dissolved gases and 80 cubic centimeters of purified 1-hexane and 200 cubic centimeters of purified 1,3-butadiene were injected directly into the vessel. The vessel was injected with 10 cubic centimeters of 0.7 ^ molar methyl alumoxane solution (in total aluminum) in toluene into the vessel, using a gas-sealed syringe and through the septum inlet, and stirred. mix at 1,200 revolutions per minute and at 70 ° C for five minutes at 0 kg / / cm of nitrogen. The septum was injected into the bis- (n-butyl-cyclopentadienyl) zirconium cycloride (0.10 mg), dissolved in 0.10 ml of distilled, water-free toluene. After one minute, ethylene at 5.25 kg / cm relative to (75 psig) was admitted, while the reaction vessel was maintained at 70 ° C. The ethylene was passed through the vessel for twenty minutes, after which the reaction was stopped by rapidly venting to the atmosphere and cooling. After evaporation of the liquid components under a nitrogen atmosphere, 15.5 grams of ethylene / 1-hexane / 1,3-butadiene terpolymer were recovered.

Example 2 (Gas Phase Polymerization)

The polymerization was carried out in a gas phase in an autoclave reactor with a liter of capacity, equipped with a foot stirrer, external water jacket to control the temperature, inlet with septum and regulated supply of dry nitrogen, ethylene, hydrogen and 1 -butene.

The reactor containing 40.0 grams of granular polypropylene (particle size ^ ΆΟΟ micron) which was added to aid stirring in the gas phase was dried and carefully degreased at 85 ° C.

JL / PE-1542 uEZ. "387

moisture and oxygen, 0.3 cubic centimeters of triethyl aluminum solution to 20 wt. hexane was injected through the septum into the vessel, using a gas-sealed syringe, in order to eliminate traces of oxygen and Water. The reactor contents were stirred at 120 revolutions per minute at 85 ° C for one minute, under a pressure equal to 0 kg / cm relative nitrogen. 9.4 grams of liquid 1,3-butadiene were injected. In the reactor, 500.0 mg of catalyst X was injected and the reactor was subjected to a pressure of 14 kg / cm relative (200 psig) with ethylene. Polymerization was continued for 20 minutes, while the reaction vessel was maintained at 85 ° C and a relative pressure of 14 kg / cm 2 (200 psig), using a constant stream of ethylene. The reaction was stopped by rapidly cooling and venting to the atmosphere. 5.6 grams of copolymer / 1,3-butadiene were recovered. The polyethylene penei was recovered, leaving the fraction that had a particle size greater than 35θ micron in diameter. The polymer was analyzed by C ^J NMR and it was found that, for each cis-1,4 unit incorporated, there were no units of trans-1,4 and 14,9 cyclopentane rings (linked in the ethylene chain in 1, 2 on the ring.

Example 3 - Polymerization - Catalyst A

The polymerization was carried out in a gas phase, in a one liter autoclave reactor, equipped with a paddle stirrer, external water jacket for temperature control, septum inlet and regulated supply of dry nitrogen, ethylene, hydrogen and 1-butene.

The reactor containing 40.0 grams of ground polystyrene (10 mesh) was dried, which was added to aid stirring in the aqueous phase, and was carefully degassed at 85 ° C. As an agent for the absorption of moisture and oxygen, 2.0 cubic centimeters of a solution of methyl alumoxane (0.64 molar in total aluminum) were used.

- 54 58,946

JL / pe-1542

TEN. 1987

I injected through the septum entrance, into the vessel, using a gas-sealed syringe, in order to eliminate traces of oxygen and water. The reactor contents were stirred at 120 revolutions per minute, at 85 ° C, for one minute and at a pressure of nitrogen equal to 0 kg / cm 2 relative. 500.0 mg of catalyst A was injected into the reactor and the reactor was subjected to a relative pressure of 14 kg / cm (200 psig) with ethylene. Polymerization was continued for ten minutes, while the reaction vessel was maintained at 85 ° C and 14 kg / cm relative (200 psig), by adding a constant stream of ethylene. The reaction was stopped by rapid cooling and ventilation to the atmosphere. 12.3 grams of polyethylene were recovered. The polyethylene was recovered by shaking the product with 1 liter of dichloromethane at 40 ° C, filtering and washing the dichloromethane to recover the insoluble polyethylene product from the soluble polystyrene, used as stirring aid. The polyethylene had a molecular weight of 146,000.

Example 4 - Polymerization - Catalyst A

The polymerization was carried out as described in Example 3 in the presence of catalyst A, with the exception of having pressurized the reactor to 0.21 kg / cm (3.0 psig) of hydrogen, before the injection of ethylene. 13.2 grams of polyethylene was recovered, with a molecular weight of 29,000.

Example 5 - Polymerization - Catalyst A

Polymerization was carried out as in Example 3, in the presence of catalyst A, with the difference that 13.0 cubic centimeters (0.137 mole) of 1-butene were introduced into the reactor together with ethylene after the injection of the catalyst. 13.8 grams of polyethylene with a molecular weight of 39,000 and a weight of

- 55 58,946

JL / PE-1542

18.0LZ.fcH /

volume of Ο, 91θ g / cubic centimeters.

Comparative Example 5A - Polymerization - Catalyst B

Polymerization was carried out as described in Example 3, with the difference that catalyst B replaced catalyst A. 17.3 grams of polyethylene with a molecular weight of 67,000 and an equal volume at 0.935 g / cm. The higher density compared to that obtained in Example 3 demonstrates less efficient comonomer incorporation.

Example 6 - Polymerization - Catalyst C

The polymerization was performed as desc £ ⁵ veil in Example 3, except for using catalyst C instead of catalyst A. It is recovered 9.8 g of polyethylene with a molecular weight of 189 000 and a weight volume equal to 0.960 g / cm.

Example 7 - Polymerization - Catalyst C

The polymerization was carried out as described in Example 6, with the difference that 13.0 cubic centimeters of 1-butene (θ, 123 moles) and 0.042 kg / cm relative to (0.6 psig) of hydrogen were introduced (1.66 millimoles) together with ethylene. 6.5 grams of polyethylene having a molecular weight of 41,000 and a density of 0.926 g / cm ^{-2 were} recovered.

Example 8 - Polymerization - Catalyst C

Polymerization was carried out as described in Example 6, except that the methyl alumoxane used as an oxygen and moisture scavenging agent was eliminated and no other aluminum-alkyl was injected. 10.2 grams of polyethylene were recovered having

- 56 _

58,946

JL / PE-1542

I

a molecular weight of 120,000 and a density of 0.960 g / cm2.

Example 9 - Polymerization - Catalyst D

Polymerization was carried out as described in Example 3, with the difference of 0.6 cubic centimeters of solution at 25 wt.% Of triethyl aluminum in hexane having replaced the methyl alumoxane solution of Example 1 and using a catalyst D instead of catalyst A. 50.4 grams of polyethylene having a molecular weight 3 of 196,000 and a density of 0.95θ g / cm were recovered.

Example 10 - Polymerization - Catalyst D

Polymerization was carried out as described in Example 3, except that methyl alumoxane used to eliminate moisture and oxygen was eliminated, catalyst D was used instead of catalyst A and polymerization was stopped after five minutes. 28.8 grams of polyethylene having a molecular weight of 196 000 and a density of Ο, 95θ were recovered

The g / cm.

Example 11 - Polymerization - Catalyst E

The polymerization was carried out as in Example 10, using catalyst E without aluminum compound to eliminate moisture and oxygen. 24.0 grams of polyethylene having an average molecular weight in weight equal to Iço 000, an average molecular weight in number equal to 76 000 and a density equal to Ο, 95θ g / cm were recovered.

Example 12 - Polymerization - Catalyst F

Polymerization was carried out as described in Example 9, with the difference of, replacing ca30

- 57 58,946

JL / PE-1542

18.0EZ.1S87

talisador D, if 0.500 grams of catalyst F were used. 8.1 grams of polyethylene having a molecular weight of 137,000 and a density of 0.9 ^ 0 g / cm were recovered.

Modules of storage (G *) and loss (G) of the Polymers of Examples 1 at 150 ° C and 200 ° C were measured on a Rheometrics System-Four mechanical spectrometer, to determine the presence of long chain branches in the polymeric composition, as produced in the reactor. In a dissolution and precipitation process, a 1 gram sample (approximately) was washed and then stabilized with 1000 ppm BHT.

The following three criteria were used to decide whether or not a polyethylene resin contains long chain branches:

i) Melt elasticity, which is high in the case of polymers with long and small chain ramifications for polymers of linear molecules, which was evaluated from the storage modules in the region of small frequencies.

ii) Activation energy, which is equal to about 14 kcal / mole for polymers of long chain branches and about 6 kcal / mole for polymers of linear molecules, which was calculated from the displacement factor of the G 'spectra and G, and two different temperatures.

iii) Thermo-rheological characteristics, which are complex for polymers with long and simple chain branches for polymers of linear molecules, which were determined by comparing the displacement factors at different frequencies (rotation).

The results reported below indicate that the copolymer of Example 1 has a significant percentage of long chain branches.

- 58 58,946

JL / PE-1542

GEZ.S8Í

Rheological Data

Activity Energy ç Elasticity Viscous Description 0 Fusion (kcal / mole) Thermo-Rheological Example 1 elevated more than 10 complex

The structural characterization of the polymers according to the present invention and the comparative product are indicated in the following Table. An observation of the information and the Table shows that the polymers according to the present invention have improved structural properties based on their molecular weight distribution and / or comonomer distribution and / or aggregation index. In addition, the copolymers according to the present invention are not gelled but are polymers soluble in boiling heated xylene.

The polymer of Example 1 is indicated to have long chain branches, including intermolecular coupling, but it is not a crosslinked gel.

The polymers according to the present invention were tested for their degree of saturation by an infrared absorption procedure, in which the concentration of unsaturation in the ethylene-based polymers was determined by comparing the infrared spectra of brominated polymer samples. compared to original polymer samples, using the following bands

Vinylene 965 -1 cm -1 Vinyl 909 cm Vinylidene 888 -1 cm

58,946

JL / PE-1542

The way of proceeding to determine unsaturation is known to those skilled in the art.

Thus, the present invention relates to a process and a copolymer in which the copolymer has no long chain branches or intermolecular coupling or a controlled degree of intermolecular coupling, without forming a crosslinked product. The copolymers according to the present invention have significant utility in the various applications in which ethylene polymers and copolymers are normally used.

- 6th

58,946 jl / PE-1542

σΛ -d ^- Ο χο σι χο B- ΜΙ Ο · * • k · » • k and. ♦ k * .. -3 · J · m J · -3 · Η 00 -Cf Η Ο Η CM CM CM Η CM σ \ Η Η Η Η Η Η Η Η

(ΰ (you (β (you τ τ τι τ φ d cti φ -Ρ +> -Ρ (Ç Φ (you «J (you -P Ρ ρ Ρ 60 tó 6th hO 60 ρ φ φ Φ Ρ Ρ P P P φ Ρ < Λ Ρ · (β (you (you (you (you The < < U The The The The «N

O O O H mi t- O 1 XO • k • k • k * • k • k • k ui Ml Ml CM σχ H Ml σχ H H (you cti 73 75 (you cti (you P (you (you (you -P P | 1 60 (you 60 60 60 P Φ P 60 P P P Φ P. (you P (you (you (you Λ Ç The «| The > 4 U The m O O O B- σι σχ 00 O b ~ cl xO 01 t- XO t- CM • k • k • k • k «K • k • k «K CM 3 · ΓΊ ci Cl σΊ CM rd -Cf mi xo rd XO O r- σι rd • • k • k • k *> • k • k «K ί- H CM cn -3 * 00 m CM XO ο XO ui O H rd H 01 σχ r-i H H rd H H rd

O \ 1 H ^{1 1 1 1 1} 1 1 H I 1 § 1 ® I 1 1 I 1 Φ Sfi 1 1

• Η η φ Ctí

mi CM Cl B- oo -cf Cl Ul CM • k * • k * «K * * ·. H H H Cl CM • d ^- Cl Cl Ml O O 0 H P P 3 r-i H i — 1 H 1 1 H φ Φ Φ 1 i 1 1 H 0 1 • laughs • laughs • laughs 0 0 0 0 • laughs P 0 73 73 73 3 3 3 P -Ρ Φ P (you (you (you Φ Φ Φ Φ Φ -P Φ P P -P K -P P P E P P 3 3 3 φ 0 3 3 1 Φ 3 m m n s O m m • d- ft ffl H H Ctí O O H The O Ml O ç O Cl <r H The CM O O O 1-1 CM J ω CM 1-1 H CM r-1 J X H H rH 0 O 0 Z The Z Z O The <—1 rM rH O The O O ω Pl P. P, P. X X Pi Q The Q AND AND AND X Q X ίΟ H H J Φ Φ Φ The The The Q H s The K K X 1 1 1 1 1 1 The The The Cl -d · Ul XO B- oo

Φ

Ό

Ο Ρ φ ρ ο Η Ο • Η Η Ο

Φ τι

Η

Φ>

Η

Ο <0

Ρ ο 73 (ti <0 • Η Η

Φ -Ρ «J

Ο

Ε ο ο <0 Λ Ρ φ ρ.

cti φ

ιο »

I ο

Ν · Η φ Ρ <Η '• Η Ε η ΰ (ti Η Ή (t Ρ I Ο Η -Ρ · Η «J -Ρ Ρ Φ Ο £ φ ώ τι Η

Ο Ο -Ρ i (ti Φ Ο Ρ tti ο Ρ Η (ti Ο Ρι · Η Φ 3 ρ σ 'ρ. Η φ <ή <0

58,946

JL / PE-1542

The filing of the first application for the invention described above was made in the United States of America on December 19, 1986 under ο N2. 944,385.

Claims (16)

1 * - Process for the preparation of ethylene and butadiene copolymers, characterized by comprising polymerization, in the presence of a metallocene / alumoxane catalyst system and by forming a non-crosslinked ethylene / butadiene copolymer composition. Process according to claim 1, characterized in that it comprises the copolymerization of 50 to 99 mole parts of ethylene, 1 to 50 mole parts of butadiene and 0 to 50 mole parts of polymerizable thermometer. 3. A process according to claim 2, characterized in that said polymerizable thermomer is an alpha-olefin. 4. A process according to the preceding claims, characterized in that an ethylene copolymer is prepared comprising in its polyethylene chain trans-1,2-cyclopentanes. Process according to claim 4, characterized in that at least about 1 percent of all cyclopentane units in said copolymer are trans-1,2-cyclopentane. 62. The method of claim 5, wherein at least about 10 percent of all cyclopentane units are trans-1,2-cyclo-62. 58,946 JL / PE-1542 pentane. Process according to claim 6, characterized in that at least about 5% percent of all cyclopentane units are trans-1,2-cyclopentane. Process according to claim 4, characterized in that a copolymer is prepared which also has, in its polyethylene chain, at least one of the 1,2 and cis and trans-1,4-butadiene comonomer units non-cyclical. Process according to Claim 8, characterized in that in the butadiene comonomer incorporated in the polymer, at least 50 mole percent is incorporated 1,2cyclopentane, about 0 to 50 mole percent is incorporated, about 0 to 50 percent are cis-1.4 incorporated and about 0 to 50 mole percent are trans-incorporated 1.4. 10? Process according to the preceding claims, characterized in that the ethylene copolymer comprises in its polyethylene chain, as the only cyclopentane unit, trans-1,2-cyclopentane. 11 * - Process for the preparation of a polymer resulting from the polymerization of ethylene and at least one other polymerizable comonomer comprising 1,3-butadiene, characterized in that the copolymer incorporates in its structure at least about 3 mole percent of a polymerizable comonomer and having an aggregation index of about 9 or less. 12? Process according to claim 1, characterized in that at least 5 mole percent of polymerizable copolymer is incorporated into its structure 13 * Process according to Claim 1, characterized in that the polymerizable copolymer comprises 63 58,946 JL / PE-1542 also addresses an alpha-olefin. 143. The method of claim 3, wherein the butadiene is incorporated in an amount equal to at least about 0.1 mole percent. 15. The process of claim 1, wherein at least the polymerizable copolymer consists essentially of said butadiene. 16. The method of claim 1, wherein the copolymer has a molecular weight distribution (M _w / M _n ) of about 3.0 or less. 17 - Process according to claim 1, characterized in that most of the butadiene is incorporated in the polyethylene chain as cyclopentane with structure I 183 A process ing according to claim 1, characterized in that to obtain a composition with a molecular weight (^ _n) between about 500 and about than 1 000 000. Process according to claim 1, characterized in that at least about 5 mole percent of butadiene is incorporated. 203 - Process according to claim 1, characterized in that the aggregation index is about 5 or less. Process according to claim 18, characterized in that a composition is prepared with - 64 58,946 JL / PE-1542 is a molecular weight (M _n ) comprised between about 500 and 200,000 and being substantially free of long chain branches. 22. A composition according to claim 11, characterized in that the composition distribution is such that at least about 55 weight percent of the molecules of the polymeric composition have a comonomer content within about 50% of the average content of comonomer in molar percentage of the polymeric composition. Process according to claim 22, characterized in that at least about 70 percent by weight of the copolymer molecules have a comonomer content within about 50% of the average comonomer content in mole percent of that mentioned composition. Lisbon, * lt> moles of comonomer% moles of comonomer 10 _Ί 520 More aggregation of olefin 1 branches than a random distribution I I I I I I I I I I I I I I I I I I 1 I ---------------- --------------------- 1 ------ 15 10 random branch aggregation FIG. 1 Less aggregation of olefin 1 branches than a random distribution i I I I I i i I I I I I