Process for producing an ethylene polymer composition

Process for producing and using ethylene polymers.

Full description

The subject of the present invention is a process for preparing a composition containing ethylene polymers, using a number of reactors arranged in a series, and it relates, in particular, to a process for preparing a composition containing ethylene polymers containing additionally alpha-olefin.

A process for preparing a composition containing ethylene polymers has been mentioned in the European patent Mitusi Petrochemical Industries (EP-22,376,Bl), according to which at least two reactors are used in series. A first part of the ethylene is polymerized in the presence of a catalyst in the first reactor of the series. The polymer and the catalyst are distilled from this reactor, and these are moved sequentially into the other reactors, in each of which another portion of ethylene is supplied, which is polymerized and thus recovered. A composition containing ethylene polymers is recovered. From the last reactor, this well-known process is used in every reactor, where the conditions for the polymerization event differ from those used in other reactors, so that we produce in each reactor a polymer, which has a different viscosity and, as a result, has a different melting point - from that produced in other reactors. In particular, the composition containing ethylene polymers produced by this well-known process includes a first polymer having an intrinsic viscosity of

0.3 to 3 and a second polymer has an intrinsic viscosity of 1 to 12, and the ratio between these two viscosities is at least 1.5.

This well-known process does not make it possible to achieve a significant difference in viscosities or melting points for polymers produced in different reactors, so it does not make it possible to obtain polymers that have good usability properties (characterizing polymers with high melting points) and good mechanical properties (characterizing polymers with high melting points). Low melting point).

Moreover, this well-known process is poorly adapted to adjusting the molecular weight distribution of the final formulation and, accordingly, it does not allow achieving a final formulation suitable for achieving injection objectives (formulation with distribution).

A distinct molecular weight with a Mw/Mn ratio of less than 10) nor to compositions that can be used to make thin films (slices) by straightening (formulations with a Mw/Mn ratio in which the aforementioned ratio is greater than 40).

This additionally known process has the disadvantage of causing rapid hydrogen saturation of the diluent, when a polymer with a low viscosity or a high melting point is prevented in one of the reactors in diluted hydrogen coal in the presence of hydrogen.

The present invention solves the aforementioned damages by providing a new method using a number of reactors that makes it possible to obtain a clear difference in the melting profiles of the polymers obtained in different reactors. This shows great flexibility in adjusting the molecular weight distribution of the final polymer composition, which makes - in addition This is possible in producing a polymer with a very high melting point in the presence of coal

Dilute hydrogen and in the presence of hydrogen, without the risk of premature saturation of hydrogen coal with hydrogen.

General description of the invention:

As a result, the invention relates to a process for preparing a composition containing ethylene polymers comprising a high melting point polymer and a low melting point polymer in at least two reactors, according to which a portion of the ethylene is introduced, and a catalyst derived from a transition metal selected from the group elements. VB, IVB, IIIB and VIB from the periodic table and a synergistic catalyst. All of this enters a first reactor, where the ethylene is converted into it, and a mixture containing one of these polymers, the catalyst and the synergistic catalyst is distilled from this reactor and the mixture and another part of ethylene are introduced into A subsequent reactor, where ethylene polymerizes to form the other polymer, and the weight ratio of the two polymers is equal

(30 to 70): (70 to 30); According to the invention, the catalyst has a weight distribution

The self-limiting Mw/Mn ratio is less than or equal to 10 and the activity inhibition constant is less than (0.5h-1) per hour or 0.5h-1. The polymer with a high melting point has a melting point of MI2, measured under a load of 2.16 kg at a temperature of 190°C. The low melting point polymer has a melting point of MI5, measured under a load of 5 kg at a temperature of 190°C, and the ratio is 0.01 to 2 g/10 min.

Between these two melting points is 500 to 50,000.

It is understood that the real molecular weight distribution of a catalyst indicates the molecular weight distribution of a polymer obtained at the stage of a single polymerization event and under constant polymerization conditions in the presence of this catalyst. As for the ratio Mw/Mn

The fact that characterizes this true molecular weight distribution indicates the ratio between the average molecular weight (Mw) of the polymer obtained in this way and the average molecular mass (Mn) of this polymer. This ratio was measured by stereochromatography through chromatographic analysis. In 1, 2, 4 - tertiary chlorobenzone was conducted at a temperature of 135°C on a 150C type of chromatograph from the Waters company.

It is understood that the constant of the inhibitor of the effectiveness of a catalyst indicates the angular factor that characterizes the linear relationship between the logarithm, the ratio of the rate of the speed of the polymerization event, the speed of the rate of the polymerization event starting (consumption), and the duration of the polymerization event. The polymerization event takes place in the presence of the catalyst. This angular factor is calculated using the linear regressor. .

The melting index MI2 (and hence MI5) for a polymer indicates the speed of the flow rate of the molten polymer at 190°C, as it flows through a mold with a diameter of 2 mm and a length of 8 mm, under the influence of a machined piston with a piston mass of 2.16 kg. Hence 5 kg), this flow rate velocity is expressed as d g/10 min d according to ASTM standard 1238 D.

Detailed description:

Ethylene is polyerized, in the process according to the invention, in the presence of a catalyst. An essential distinguishing characteristic of the process lies in the properties of the catalyst used. According to the invention, the catalyst has a real molecular weight distribution defined by an actual (real) ratio (Mw/Mn) equal at most to 10, and preferably less than 8, as values that are less than 7 or equal to 7 is the most useful,

For example, approximately 6.5 or 5, the actual ratio (Mw/Mn) is usually greater than 3, as values greater than 4 are most common.

The catalyst used in the process, according to the invention, additionally has an activity inhibition constant of less than 5.0h-1, or equal to it, and preferably equal to, mostly 0.3h-1, while values less than or equal to 0.5h-1, such as 015h-1. Approximately, they are recommended values, and in general, the effectiveness inhibition constant is greater than 0.05h-1, and values that are greater than or equal to 0.1h-1 are the recommended values.

The catalyst used in the process according to the invention can be chosen from Ziegler-type catalysts, especially those derived from titanium, and metallocene-type catalysts, as metallocene is a cyclopentyadienyl derivative of the transition metal, in particular Zirconium

Non-specific examples of Ziegler model catalysts that can be mentioned here include compounds containing a transition metal selected from groups VB, IVB, IIIB, or VIB of the periodic table. Magnesium and a halogen are obtained by mixing a magnesium compound with a transition metal compound and a halogen compound. The halogen may form an integral part of the magnesium compound or of the transition metal compound.

Undeniably, examples of metallocene-type catalysts are metallocenes activated with aluminoxane and ionic metallocenes activated with an ionizing agent as mentioned, for example, in the European patent application EP-500,944-AP (Mitsui Toatsu Chemicals). Chemicals).

Ziegler-type catalysts are preferred, among them, those containing at least one transition metal chosen from groups VB, IVB, IIIB and VIB, and at least one magnesium and a halogen, which are compatible very well, obtaining Good results include:

- From 10 to 30% by weight of the transition rate, thanks to 15 to 20% by weight, and is typical approximately 17% by weight.

- From 20 to 60% by weight is halogen, and values from 30 to 50% by weight are preferred (for example, approximately 40% by weight).

- From 0.5 to 20% by weight, magnesium is usually from 1 to 10% by weight, for example approximately 5% by weight.

- From 0.1 to 10% by weight of aluminum, and in general from

0.5 to 5% by weight, most common values are 1 to 3% by weight,

The balance consists, in general, of successful elements from the products used to manufacture it, such as coal, hydrogen, oxygen, and preferably the transition metal, titanium halogen, and chlorine.

halogen titanium and chlorine.

The polymerization event takes place, in the process, according to the invention, in the presence of a synergistic catalyst, and it is possible to use any synergistic catalyst known in industry, especially compounds involving at least one chemical bond between aluminum and coal, such as optionally halogenated organic aluminum compounds, which may include Oxygen or any element from Group I of the periodic table, and aluminoxanes. Among the mentioned examples of organic aluminum compounds are trialkylaluminium,

Such as triethylaluminium, trialkenyl aluminum, such as triisopropenylaluminium, and aluminum such as monofat alk oxide.

mono-and dialkoxides, such as: diethylahiminium ethoxide, mono-and dihalogenated alkylaluminium compounds, such as diethylaluminium chloride, and alkylaluminium mono- and dihydrides, such as: dihydride Dibutylaluminium hydride, and organic organoaluminium compounds containing lithium such as Li Al (C2 H5).

There are organoaluminium compounds, especially those that are not halogenated, which are well suited, and triethylaluminium and triisobutylaluminium are particularly useful.

In the process, according to the invention, a unit is used comprising at least two polymerization reactors arranged in series and connected one to the other, and each reactor is supplied with ethylene, the catalyst and the synergistic catalyst being introduced into the first reactor only, in which the ethylene is polymerized until it is obtained. A polymer that has the characteristics and characteristics of the conditions for the polymerization event in this reactor. A mixture originating from the first reactor is introduced and includes the polymer obtained in the last reactor, the catalyst and the synergistic catalyst. It is preferable that the mixture is continuously introduced into The second reactor. The ethylene is polymerized that was introduced into this second reactor. It is polymerized using the catalyst, the catalyst, and the synergistic catalyst resulting from the first reactor, and it takes advantage of the conditions of the polymerization event (temperature, carrier agent concentration).

The concentration of the optional monomers in this second reactor is different from that which was used in the first reactor. Thus, the polymer produced in the second reactor has a melting point that differs from that of the product produced in the first reactor, and the composition of the total polymer from the second reactor includes special features related to the conditions. Operation of the first reactor and special features related to the operating conditions of the second reactor.

In the process, according to the invention, a high-melting point polymer and a low-melting point polymer can be prepared according to any arrangement.

The industrial unit can clearly include more than two reactors connected in series. In this case, the first reactor in the series is provided with the catalyst and the synergistic catalyst. Each catalyst is supplied with ethylene and with the mixture resulting from the advanced (previous) reactor in the series. The mixture includes this catalyst and the synergistic catalyst. From polymers produced in advanced reactors in the series.

If the industrial unit includes more than two reactors in series,

The high-melting point polymer and the low-melting point polymer can be produced, as defined above, in two adjacent and non-adjacent reactors in series. In this particular case of use of the process or method according to the invention it is possible to produce, in other reactors of the series and under operating conditions, a polymer with either a melting index MI (d p. 5) of less than 5, from 5 to 1000 or greater than 1000 or It has a fusion index of MIs (MI5) of less than 0.01, 0.01 to 2 or more than 2.

(MI2) and (MI5) have been identified previously.

It is preferable that the reaction be limited to two reactors. In a first embodiment of the process according to the invention, the formation of the high-melting index polymer precedes the formation of the low-melting index polymer. It has been confirmed that this model is particularly useful if one seeks to obtain a composition containing ethylene polymers that can be used to prevent objects with blank surface shapes. Of the disadvantages such as harsh pointy heads.

In a second embodiment of the process, according to the invention, at least one of the reactors is supplied with hydrogen, which acts as a carrier agent that modifies the melting point of the polymer produced in such reactor.

The partial pressure of hydrogen in the reactor(s) ranges from 0.001 to 2 to 2 MPa 0.001, and especially from 0.002 to 1.5 m Pa to 1.5 MPa 0.005, and preferably from 0.005 to 1.3 m Pa 0.005 to 1.3 MPa. The ratio between the partial pressures For hydrogen, the partial pressures of ethylene generally do not exceed 5, and it is preferable that they do not exceed 3, which is, for example, between 0.01 and 2.0.

In another (other) form (image) of this second model, hydrogen enters continuously into all the reactors, as the ratio between the ethylene partial pressure and the hydrogen partial pressure in the first reactor differs from the partial pressures used in the other reactors. In this other form, it is It is important to keep these ratios constant in each reactor throughout the duration of the polymerization event. It is useful for the quotient of these two ratios to be greater than 20, or even better, more than 40. It is desirable that it does not exceed 30. For example, 200, and the quotient chosen from 45 To 175 a particularly good fit.

This embodiment of the process according to the invention has the advantageous feature of making it possible to obtain a polymer with a very high melting index in the presence of dilute hydrogen charcoal while avoiding rapid hydrogen saturation of the diluted hydrogen charcoal material.

In the process, according to the invention, the method of polymerization in reactors can be chosen from solution, from suspension, or from gas phase methods, regardless of the properties of the polymer to be prepared in it and regardless of the choice of the process used in the other reactor. For example, it is possible Conducting the polymerization event in two gas-phase reactors, or

In a first reactor in a suspended phase and in a second reactor in a gas or gas phase

In reverse order, the polymerization process is preferably carried out in a suspension phase in two reactors.

In the case of a suspension polymerization event, the latter generally takes place in an inert diluted hydrocarbon taking into account the catalyst, the synergistic catalyst, and the resulting polymer (e.g. liquid aliphatic, cycloaliphatic, cycloaliphatic and aromatic hydrocarbons), at a temperature such as At least 50% and preferably at least 70% of the polymer formed which is insoluble in it. The preferred diluents are linear alkanes such as n-butane, n-hexane, and n-heptane, or branched alkanes such as isobutane, isopentane, isooctane, and 2,2-dimethylpropane. 2,2-dimetylpropane or

Cycloalkanes and cyclohexane, or mixtures, choose the temperature at which the polymerization occurs, generally from 20°C to 200°C, preferably

From 50 to 100 m. As for the ethylene partial pressure, it is most often chosen from 0.1 to 5 MPa KPa, preferably from 0.2 to 2 MPa KPa, and especially from 0.4 to 1.5 0.4 to 1.5 MPa KPa.

In the process according to the invention, the second reactor and/or, if appropriate, at least one of the first reactors may optionally be equipped with a new catalyst and/or (new) synergistic catalyst. In any case, it is preferable to introduce the catalyst and synergistic catalyst exclusively into the first reactor.

In addition, in a specific embodiment of the process, according to the invention, alpha-olefin is introduced into at least one of the reactors, as if to manufacture, in this reactor, alpha-olefin, a synergistic polymer of ethylene, and from this alpha-olefin. -olefin. Alpha-olefin can be selected from unsaturated monoolefins containing from 3 to 8 coal atoms, such as propylene, 1-butene, propylene, l-pentene, and 3-methyl-1-butene. -metyl-1-butane

And 1-hexene, 3-and-4-methyl-1-pentene, 3-and 4-methyl-l_ pentene, and 1-l-octene. There are other examples of alpha-olefins, which are diolefins that include from 4 to 8 1 coal atom, preferably non-conjugated non-sequential aliphatic diolefins such as 4-vinylcyclohexane and 1,5-hexadiene, and alicyclic diolefins with an internal ring bridge such as 1.5-hexadiene. Dicyclopentadiene or methylene and ethylidene Ethylidenenorbornene, and successive aliphatic diolefins such as 1,3-butadiene and isoprene and 1,3-pentadiene, the preferred alpha-olefins are

.

Propylene, 1-butene, 1-hexane, 1-l-octene, and 1,5-hexadene. It gets good results with 1-butene and 1-hexene-E.

In general, alpha-olefin is introduced into this specific model of the process, according to the invention, in that reactor, in which the low-melting index polymer is produced. It is introduced in a controlled quantity such that this polymer includes 5, 0 to 20% by weight of alpha-olefin, preferably from 1 to 10% by weight, for example 2% by weight, and a portion of alpha-olefin may enter as a substitute in the other reactor, in a restricted quantity such that the content The alpha-olefin content of the high-melting index polymer does not exceed 1% by weight, preferably 3%, for example 1% by weight. The alpha-olefin content of the high-melting index polymer is usually equal to 0.01 over the least

The process is applied, according to the invention, in preparing compositions comprising ethylene polymers which can comprise a single homogeneous ethylene polymer or a plurality of homogeneous ethylene polymers and/or a single synergistic ethylene polymer or a plurality of synergistic ethylene polymers.

The process enables, according to the invention, to obtain compositions containing ethylene polymers, and optionally alpha-olefins, such that each individual polymer has a melting point sufficiently different from that of the other polymer or from each of the other polymers, in order to Benefit at the same time from the enhanced properties of the use of the polymer feature

High melting point and good mechanical properties characterize a low melting point polymer.

Moreover the process, according to the invention, has great flexibility of adjustment

The molecular weight distribution in the final composition, thus enabling the process, according

For the invention, a wide range of compositions containing ethylene polymers is made, ranging from those suitable for use in injection molded objects to those that can be used to make chips.

Thin by extrusion or calendering.

In addition, the process, according to the invention, enables compositions containing ethylene polymers and alpha-olefins to be obtained by testing, including alpha-olefin in a variable amount, which can reach 10% by weight, preferably from 5%. to 6% of weight,

For example, approximately 1% of the weight.

The process, according to the invention, proves to be particularly advantageous for making compositions containing ethylene polymers and, optionally, alpha-olefins which can be used to make articles having a high resistance to stress cracking, the surface of which is free of such defects as hard spikes.

Accordingly, the invention also relates to compositions containing ethylene polymers that have the aforementioned properties. These compositions include, on the one hand, a first polymer compound having a melting index (MI2) of 5 to 1000 m/10 min to 1000 g/10 min 5, d = min. Preferably from 10 to 500 g/10 min. On the other hand, it includes a second polymer with a melting index (MI5) of 0.01 to 2 g/m. 0.01 to 2 g/10 min.

Preferably from 0.03 to 1 g/10 min 0.03 to 1 g/10 min, especially from 0.05 to 0.7 g/01 min 0.05 to 0.7 g/10 min, and the ratio of the two melting points is from 500 to 50,000 and preferably from 1000 to 10,000 0 As for the weight ratio These two polymers are generally equivalent to (30 to 70):(70 to 30) and preferably (.4 to.6):(.6 to.4), for example (42 to 58):(58 to 42). The first aforementioned polymer may optionally include alpha-olefin in an amount approximately equal to 5% by weight, and the second polymer may include from 5% to 20% by weight of alpha-olefin. Feasible compositions include a homogeneous high-melting ethylene polymer and a synergistic low-melting ethylene polymer containing, for example, 0.5 to 6% by weight alpha-olefin. The compositions, according to the invention, have a specific molecular weight distribution (Mw/Mn) that can vary from 5 to 70, especially from 7 to 50, for example from 10 to 40. In addition, the compositions, according to the invention, have a Melting (MI5) from 0.1 to 10 g/10 min 0.1 to 10 g/10 min, especially from 0.5 to 8 g/10 min 10 g/0.5 to5 and has a dynamic viscosity expressed in dpa viscosity units measured at a speed of 100 s-1 100 S-1 at a temperature of 190°C, conforming to the relationship

<img file="SA465B1_D0001.tif" />

The compositions according to the invention typically contain 0.5 to 10% by weight of alpha-olefine and preferably 1 to 6% by weight.

The compositions, according to the invention, find useful use, especially in a wide range of immunological applications, as they have good usability properties as well as good mechanical properties; Such as impact resistance and cracking resistance under stress. The compositions, according to the invention, are usable by any conventional process of converting plastics, in particular by extrusion, blow extrusion, extrusion thermoforming, calendering and injection processes. These compositions are suitable for making formed articles such as thin strips, sheets, containers, bags and sachets of scented seeds, and are particularly suitable for the manufacture of pipes.

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The present invention also relates, consequently, to the use of the above-mentioned compositions for the manufacture of pipes.

The examples mentioned below are used to explain the invention.

The meaning of the symbols used in these examples, the units expressing the mentioned quantities, and the methods for measuring these quantities are explained below.

MI2 = Polymer melting point indicating the flow rate of the molten polymer at 190°C, which flows through a die with a diameter of 2 mm and a length of 8 mm, under the influence of a (piston) or a piston weighed with a mass of 2.16 kg. The rate of flow speed is This is expressed in g/10d, according to 1238 ASTM standard D

MI5 = melt index of a polymer (or polymer composition) indicative of the flow rate of the molten polymer (or molten composition)

At 190 degrees, it is 2 mm long and 8 mm long under the influence of a piston

Burdened with a mass of 5 kg, this flow rate is expressed as b

G/10D, according to ASTM standard D 1238 1238 ASTM standard D.

Mw/Mn = the ratio between the weight-average molecular mass (Mw) of a polymer (or polymer structure) and the number-average molecular mass (Mn) of this polymer (or structure) measured by stereochromatography analysis. In 1, 2,

4- Trichlorobenzene 1,2,4-trichlorobenzene at a temperature of 135°C on a T50 C chromatograph from Waters.

&amp; eta n '' = dynamic viscosity of a polymer (or polymer composition) expressed in units of dPa.

190 AD.

Kd = catalytic inhibitor constant expressed as sa-1 -h1, which is the angular factor that characterizes the linear relationship between the logarithm of the rate of the polymerization event, the rate of speed of consumption of the polymerization event, and the duration of the polymerization event. The polymerization event takes place in the presence of this catalyst. The angular factor is calculated using linear regression.

''Alpha α &amp; = catalytic activity in grams of an insoluble polymer obtained per hour and each gram of catalyst is divided by the molar fraction of ethylene in the diluent.

Example 1 (according to the invention)

A- Preparing the catalyst

Magnesium diethoxide reacts with titanium tetrabutoxide for 4 hours at a temperature of 0°C in quantities such that the molar ratio of titanium to magnesium is equal to 2. The resulting reaction product is only treated with chlorine and precipitated by bringing the latter into contact with ethylaluminium dichloride solution for a minute at a temperature of 45°C. The solid material obtained was collected from the suspension solution and included (% by weight): Ti: 17

Cl: 41

Al: 2

Mg: 5

B- Ethylene polymerization event in a single reactor

Introduce 1 liter of hexane and 1 mmol of triethylaluminium into a 1.5 liter shock, equipped with a stirrer. The temperature is then raised to 85°C, and kept constant throughout the duration of the polymerization event. Then insert a single charge of hydrogen under a pressure of 0.4 kilopascals (MPa), and then insert ethylene. Then 7 mg of the solid catalyst obtained in (A) was injected into it. The ethylene partial pressure was kept constant at a value of 1 kilopascal (1 MPa) for an hour. The sealed buffer was then removed from the gases and cooled.

The ratio of polymethylene collected from oxidized iron, Mw/Mn, is 6.7, and the catalyst Ka (th i) was 0.15.

C- The ethylene polymerization event in two reactors

The process of the polymerization event in two successive reactors simulated that of a single reactor with two separate stages by releasing an intermediate pressure and restarting the operating parameters again. First polymerization event (i)

Introduce two liters of hexane and 2 mmol of triethylauminium into a 5-litre autoclave, equipped with a stirrer, then raise the temperature to 85°C, keep it constant throughout the duration of the polymerization event, then introduce a single charge of hydrogen under pressure. The amount of 1.3 kilopascals (1.3 MPa), and then ethylene was introduced into it. The ethylene partial pressure was kept constant at 0.6 kiloPascals (0.6 MPa), then 2 mg of the solid catalyst obtained in (A) was injected into it. The sealed buffer was emptied, after 73 minutes. , from gas Thus, he obtained 200 g of polymer i and had a catalyst efficiency α of 10.3. Second polymerization event (ii)

Again, 200 ml of hexane was added to the sealed solution, the temperature was raised to 75°C and kept constant throughout the duration of the polymerization event, and then a hydrogen charge was introduced at a pressure of 0.08 kilopascals (0.08 MPa), and an ethylene and a butene charge was added to obtain an atomic mole ratio. Of butene/ethylene/butene in the liquid phase of 38.0, the partial pressure of ethylene was kept constant at 0.4 MPa until an additional amount of 169 g of polymer was obtained.

(ii), after extracting the gases, collected 369 g of oxidized acid for a composition containing polymers (i) and (ii), and the catalyst had an α efficiency of 7.3, and the following are the results of what he obtained: polymer (i) polymer:

MI2 = 168

polymer ii):

0.21 = MI5

15.9 = MI5 N = 6700

Mw/Mn = .21

Example 2 (reference)

In this example a catalyst was made with an actual distribution defined as a Mw/Mn ratio greater than 10, and this was then used in a process for ethylene polymerization in two reactors.

A- Preparing the catalyst

The molar ratio of Ti/Mg was equal to 0.6, and the molar ratio of Zr/Ti was equal to 1.2 ml. The result of this reaction was obtained with chloro and was precipitated when the latter came into contact with a solution of isobutylaluminium dichloride, initially at

The temperature was 45°C, and then at 60°C, the solid material thus obtained was collected from the suspension, and it included (% by weight): Ti: 6

Zr: 12

Cl: 50

Al: 2

Mg: 5

B- Ethylene polymerization event in a single reactor

Example 1(B) operations were repeated again under the following operating conditions:

- Hydrogen pressure at consumption: 1.2 kPa 1.2 MPa.

Partial pressure of ethylene: 0.6 kPa 0.6 MPa.

- Quantity of catalyst used: 12 mg.

- Duration of the polymerization event: 2 4 minutes.

- Quantity of polyethylene produced: 0.6 g.

The polymers obtained in this way had a Mw/Mn ratio of 19, and the catalyst had an inhibition constant Kd 1 of 1. C- The incident of ethylene polymerization in two reactors

Example 1(c) operations were repeated again under the following encryption conditions:

Polymerization event of the first polymer (i):

- Polymerization event temperature: 85°C.

- Partial pressure of hydrogen at consumption: 1.2 kPa 1.2 MPa.

Partial ethylene: 6 kilopascals, 0.6 MPa.

- Quantity of catalyst used: 12 mg.

- Quantity of polyethylene produced: 54 g. The catalyst had an α &amp; alpha '' effectiveness of 19.3. Second polymerization event (ii):

- Polymerization event temperature: 75°C.

- Partial pressure of hydrogen at consumption: 0.2 kPa 0.2 MPa.

Partial pressure of ethylene: 0.6 kPa 0.6 MPa.

- The ethylene/butene molar ratio is 0.28 ethylene/0.28 butene

- Quantity of polyethylene produced in the second stage: 80 g.

- The total amount of polyethylene produced: 134 grams

Below are the results he obtained:

Polymer i) : MI2 = 1.4

Polymer ii) : 15 = 0.03

Composition containing polymers (I) and (ii)

MI5 = 0.09

23500 =n

18. =Mw/Mn

When comparing the results of Example 2 with the results of Example 1, it becomes clear the progress achieved by the invention with regard to the difference between the melting points of the polymer (i) and (ii) occurring in the two reactors.