KR101251696B1 - Method for solution polymerization of olefins with catalysts composed of transition metal complexes - Google Patents

Abstract

The present invention relates to an olefin polymerization method using a continuous solution polymerization method which improves the injection method or the order of injection of a transition metal catalyst, a promoter, a scavenger and a reactant, and prepares various copolymers at a wide range of temperatures and pressures. It is possible to produce not only high activity but also high molecular weight and ultra low density polyolefin when copolymerizing monomer having a large steric hindrance, and to improve the activity and yield of catalyst and polymerization reaction.

Polyolefins, Continuous Solution Polymerization, Transition Metal Catalysts, Cocatalysts

Description

Method for solution polymerization of olefins with catalysts composed of transition metal complexes

The present invention relates to an olefin polymerization method. Specifically, an olefin polymerization method using a continuous solution polymerization method of improving the injection method or the order of injection of a catalyst, a promoter, a scavenger and a reactant containing a transition metal compound It is about.

The production and application of polyolefins has advanced dramatically with the invention of a catalyst called Ziegler-Natta catalyst, and the production process and the use of the product have been variously developed. In particular, the development of polyolefin products using various single-site catalysts, together with the remarkable improvement of Ziegler-Natta catalysts, has also attracted much attention in the art. Such single site catalysts include metallocene catalysts, Dow's Constrained-Geometry-Catlyst (CGC), and catalysts using post-transition metals.

[Me ₂ Si (Me ₄ C ₅ ) N t Bu] TiCl ₂ (CGC) (US Pat. No. 5,064,802), published by Dow in the early 1990s, is a conventional metal for copolymerization of ethylene and alpha-olefins. Compared to Rosen catalysts, (1) high activity at high polymerization temperatures produces high molecular weight polymers, and (2) copolymerization of alpha-olefins with high steric hindrances such as 1-hexene and 1-octene is also very good. Showed excellent effect. In addition, during the polymerization reaction, various characteristics of CGC are gradually known, and efforts to synthesize derivatives thereof and use them as polymerization catalysts have been actively conducted in academia and industry.

One approach has been to synthesize and polymerize metal compounds in which various other bridges and nitrogen substituents have been introduced instead of silicon bridges. Opening exemplary metal compounds known to date to the same as the compounds (1) to (4) (Chem. Rev. 2003, 103, 283).

Compounds (1) to (4) have phosphorus (1), ethylene or propylene (2), methylidene (3), and methylene (4) bridges instead of CGC-structured silicon bridges, respectively, but ethylene polymerization Alternatively, when the copolymerization with the alpha-olefin is applied, there are no improved results in terms of activity or copolymerization performance compared to CGC.

In addition, as another approach, a large amount of compounds composed of oxydolides were synthesized instead of the amido ligands of CGC, and some polymerization using the compounds was attempted. The examples are summarized as follows.

Compound (5) was reported by TJ Marks et al. Characterized by crosslinking of Cp (cyclopentadiene) derivatives and oxido ligands with ortho-phenylene groups ( Organometallics 1997 , 16 , 5958). Compounds with the same crosslinks and polymerizations using them have also been reported by Mu et al. ( Organometallics 2004 , 23 , 540). In addition, it was reported by Rothwell et al . That an indenyl ligand and an oxido ligand were crosslinked by the same ortho-phenylene group ( Chem . Commun . 2003 , 1034). Compound (6), reported by Whitby et al., Is characterized by the piercing of cyclopentanienyl and oxido ligands by three carbons ( Organometallics 1999 , 18 , 348). These catalysts are syndiotactic. ) Have been reported to be active in polystyrene polymerization. Similar compounds have also been reported by Hessen et al. ( Organometallics 1998 , 17 , 1652). Compound (7), reported by Rau et al . , Is characterized by its activity in ethylene polymerization and ethylene / 1-hexene copolymerization at high temperatures and pressures (210 ^° C., 150 MPa) ( J. Organomet . Chem . 2000 , 608 , 71 ). In addition, a patent synthesis (8) and a high temperature, high pressure polymerization using the same structure has been patented by Sumitomo, Inc. (US Pat. No. 6,548,686).

However, among the trials, the catalysts actually applied to commercial plants are few, and there is a need for the development of catalysts showing improved polymerization performance.

Along with the catalyst development, a continuous polymerization method for mass production of olefin polymers has been developed.

Japanese Laid-Open Patent Publication No. 2000-063422 discloses a method of preparing a homopolymer primarily under a chromium-based catalyst in a first polymerization tank and then copolymerizing the homopolymer under a chromium-based catalyst and a cocatalyst in a second polymerization tank. . However, this method has a problem in the activity of the catalyst by introducing a chromium-based catalyst and a promoter simultaneously.

In addition, Korean Patent Publication No. 2001-15729 discloses a method of polymerizing a polyolefin by synthesizing a transition metal catalyst and a cocatalyst, but there is a problem in the activity of the catalyst as in the case of co-inflow.

Therefore, there is still a need for development of a suitable continuous polymerization process for mass production of polyolefins with good efficiency and low cost.

The present invention provides a method for preparing a polyolefin using a transition metal catalyst and a cocatalyst including a metallocene catalyst, and improves the injection method or the order of injection of the transition metal catalyst, the promoter, the scavenger and the reactant, thereby increasing the catalyst. It is to provide a method for polymerizing a polyolefin having activity and a polyolefin prepared according to the above method.

In addition, the present invention is to provide a method for producing polyolefin using a continuous solution polymerization method.

In order to achieve the above object, the present invention provides a method for producing a polyolefin comprising the step of introducing a transition metal catalyst and reactants into the reactor and the promoter is introduced into the reactor separately from the transition metal catalyst and reactants.

The present invention also provides a continuous solution polyolefin polymerization apparatus including a reactor and a separator.

The continuous solution polymerization process according to the present invention is capable of preparing a variety of copolymers at a wide range of temperatures and pressures, and exhibits high activity when copolymerizing high steric hindrance monomers as well as high molecular weight and ultra low density polyolefins of less than 0.910 g / cc. The preparation of the copolymer is possible.

In addition, according to the present invention, the order of introducing the reactant, the catalyst, the cocatalyst and the scavenger containing the diluent solvent, the comonomer and the monomer into the reactor can be improved to improve the activity and yield of the catalyst and the polymerization reaction. have.

The present invention provides a method for producing a polyolefin comprising (a) introducing a transition metal catalyst and a reactant into the reactor and (b) introducing a promoter into the reactor separately from the transition metal catalyst and the reactant.

In another aspect, the present invention provides a method for producing a polyolefin comprising the step of adding a scavenger in the step (a) with a transition metal catalyst or reactant.

The polyolefin production method of the present invention can improve the activity and yield of the catalyst and polymerization reaction by improving the method and order of introducing the reactants, transition metal catalyst, cocatalyst and scavenger into the reactor.

Hereinafter, the present invention will be described in more detail.

The method for preparing polyolefin of the present invention may first include mixing the reactant or transition metal catalyst with a scavenger in step (a) to remove impurities that adversely affect the catalyst and the reaction.

Then, when the reactant and the scavenger are mixed in step (a), the step of mixing the transition metal catalyst and the mixed solution may be performed before the mixed solution is introduced into the reactor.

The transition metal catalyst may be introduced into a solid powder or a liquid phase, and mixed with a diluent solvent. When the diluent solvent contains impurities, the scavenger may be mixed with the diluent solvent to remove impurities before mixing with the catalyst in the transition metal. In this case, the mixing of the transition metal catalyst and the diluent solvent may be performed in a tube introduced into the reactor, or may be sufficient mixing and contact in a separate space including a separate inlet tube.

In step (b), the promoter is transferred directly to the reactor, separately from the transfer path of the mixed solution of the reactant, the scavenger and the catalyst. At this time, the transfer path of the promoter may be directly connected to the outer wall of the reactor, or may be configured to extend to a specific portion inside the reactor. The transfer path of the cocatalyst to the specific part of the reactor may be around the stirrer inside the reactor or around the inlet of the reactant.

The promoter may be introduced as a solid powder or a liquid phase, and may be mixed with a diluent solvent to be introduced. When the scavenger is mixed in the promoter diluting solvent, an unwanted reaction may occur between the promoter and the scavenger, and the scavenger is not mixed in the promoter diluent solvent.

As described above, when the transition metal catalyst and the promoter are separately introduced into the reactor, the activity of the catalyst and the polymerization reaction may be increased.

Figure 1 schematically shows a method of introducing a reactant, a transition metal catalyst, a promoter and a scavenger according to the present invention into the reactor.

As shown in FIG. 1, a reactant, a diluent solvent, a transition metal catalyst, and a scavenger including a monomer or a comonomer may be mixed in advance and then transferred / injected into the reactor, and a promoter may be separately introduced. Preferably, the transition metal catalyst and cocatalyst meet in the reactor inlet or in the reactor, preferably in the closest possible position when meeting in the reactor.

When the reactant and the transition metal catalyst are introduced into the reactor first, and the promoter is not introduced later as in the present invention, the catalyst activity and the polymerization efficiency are lowered.

For example, when a monomer is directly introduced into a reactor and a mixture of a catalyst and a promoter is added, there is little activity of the catalyst or no polymerization occurs. In addition, when a monomer, a comonomer, a diluent solvent, a scavenger and a promoter are mixed in advance and introduced into the reactor, and a transition metal catalyst is separately introduced thereto, the activity of the catalyst is low and the polymerization efficiency is also reduced. In addition, monomers, comonomers, diluting solvents and scavengers are mixed in advance and introduced into the reactor, and the transition metal catalyst and the promoter are respectively introduced through separate and independent transfer tubes, or the catalyst and the promoter are introduced into the reactor. If the mixture is introduced just before, the activity of the catalyst and the polymerization efficiency are lowered. In addition, when a scavenger is mixed with the diluent solvent during the inflow of the promoter by mixing the cocatalyst into the diluent solvent, the activity of the catalyst and the polymerization efficiency decrease.

The transition metal catalyst is a transition metal compound in which a monocyclopentanidienyl ligand to which an amido group is introduced is coordinated. More specifically, the transition metal catalyst may be a transition metal compound represented by Chemical Formula 1 having a bridge including a quinoline group. However, the present invention is not particularly limited thereto.

Where

R1 and R2 Each independently represents a hydrogen atom; Alkyl radicals of 1 to 20 carbon atoms, aryl or silyl radicals of 6 to 40 carbon atoms; Alkenyl radicals having 2 to 20 carbon atoms, alkylaryl radicals having 7 to 40 carbon atoms, or arylalkyl radicals having 7 to 40 carbon atoms; Or a metalloid radical of a Group 14 metal substituted with hydrocarbyl; R ₁ And R ₂ Can be linked to each other by an alkylidine radical comprising an alkyl radical having 1 to 20 carbon atoms or an aryl radical having 6 to 40 carbon atoms to form a ring;

R4 Each independently represents a hydrogen atom; Halogen radicals; Or an alkyl radical having 1 to 20 carbon atoms or an aryl radical having 6 to 40 carbon atoms, wherein R4 Two R4 may be connected to each other to form a nested ring structure;

M is a Group 4 transition metal;

Q1 and Q2 Each independently represents a halogen radical; Alkyl amido having 1 to 20 carbon atoms or aryl amido radical having 6 to 40 carbon atoms; Alkyl of 1 to 20 carbon atoms, alkenyl of 2 to 20 carbon atoms, aryl of 6 to 40 carbon atoms, alkylaryl or arylalkyl radical of 7 to 40 carbon atoms; Or an alkylidene radical having 1 to 20 carbon atoms.

The transition metal compound represented by Chemical Formula 1 is preferably represented by the following Chemical Formula 2:

Where

R5 and R6 are hydrogen atoms; Or alkyl having 1 to 20 carbon atoms, aryl or silyl radical having 6 to 40 carbon atoms;

Q3 and Q4 are each independently a halogen radical; Alkyl amido having 1 to 20 carbon atoms or aryl amido radical having 6 to 40 carbon atoms; Or an alkyl radical having 1 to 20 carbon atoms;

M is the same as defined above.

The transition metal compound M is preferably selected from Group 4 transition metal compounds such as titanium (Ti), zirconium (Zi), hafnium (Hf) and Rutherfurdium.

The transition metal compound may be mixed or supported with an inorganic carrier such as silica, alumina and zeolite. It is also applicable to the polymerization and polymerization processes in slurry or gas phase.

The promoter may be one or more compounds selected from the group consisting of compounds represented by Formulas 3 and 4 below, but is not particularly limited thereto.

Wherein D is boron; Each R ₉ is independently a halogen radical; Hydrocarbyl radicals having 1 to 20 carbon atoms; Or a hydrocarbyl radical having 1 to 20 carbon atoms substituted with halogen;

Wherein L is a neutral or cationic Lewis acid; H is a hydrogen atom; Z is a Group 13 element; A is each independently an aryl or alkyl radical having 6 to 20 carbon atoms in which one or more hydrogen atoms are replaced by halogen, hydrocarbyl having 1 to 20 carbon atoms, alkoxy or phenoxy radicals.

Examples of the alkyl metal compound represented by Formula 3 may include trimethyl boron, triethyl boron, triisobutyl boron, tripropyl boron and tributyl boron.

Examples of the compound of Formula 4 include triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra (p-tolyl) boron, Trimethylammonium tetra (o, p-dimethylphenyl) boron, tributylammonium tetra (p-tripololomethylphenyl) boron, trimethylammonium tetra (p-trifluoromethylphenyl) boron, tributylammonium tetrapentafluoro Rophenylboron, N, N-diethylamyldium tetrapetylboron, N, N-diethylanilidedium tetraphenylboron, N, N-diethylanilinium tetrapentafluorophenylboron, diethylammonium Tetrapentafluorophenyl boron, triphenyl phosphonium tetraphenyl boron, trimethyl phosphonium tetraphenyl boron, triethyl ammonium tetraphenyl aluminum, tributyl ammonium tetraphenyl aluminum, tri Methylammonium tetraphenylaluminum, tripropylammonium tetraphenylaluminum, trimethylammonium tetra (p-tolyl) aluminum, tripropylammonium tetra (p-tolyl) aluminum, triethylammonium tetra (o, p-dimethylphenyl Aluminum, tributylammonium tetra (p-trifluoromethylphenyl) aluminum, trimethylammonium tetra (p-trifluoromethylphenyl) aluminum, tributylammonium tetrapentafluorophenylaluminum, N, N-diethylaniyl Linium tetraphenylaluminum, N, N-diethylanilinium tetrapentafluorophenylaluminum, diethylammonium tetrapentatentraphenylaluminum, triphenylphosphonium tetraphenylaluminum, trimethylphosphonium tetraphenylaluminum, tripropyl Ammonium tetra (p-tolyl) boron, triethylammonium tetra (o, p-dimethylphenyl) boron, trimethylammonium tetra (o, p-dimethylphenyl) bo , And the like N, N- diethyl shall not help tetraphenyl boron, triphenyl car I Titanium tetra as (p- methylphenyl tree pool to) boron, and triphenyl car I Titanium tetra pentafluorophenyl beam theory.

The mixing ratio of the transition metal catalyst: cocatalyst used in the present invention may be in the range of 2: 1 to 1: 100 on a molar ratio basis, preferably 1: 1 to 1:10, more preferably 1: 1 to 1 It can be used in the range of 1: 6.

The scavenger interacts with the promoter to interfere with the catalyst activation, and the compound formed by the action of the scavenger and the promoter occupies the active point of the catalyst to inactivate the catalyst.

In addition, the scavenger is used for the removal of impurities acting as a poison in the catalyst in the reactants, it may be represented by the formula (5) and (6). The impurity is represented by a polar compound having a non-covalent electron pair such as water or alcohol oil generated in a raw material or a process in the reactant. In general, the scavenger may be premixed with reactants, ie monomers, comonomers, and diluents, prior to the reactor inlet to remove impurities that act as catalyst poisons and then transferred to the reactor. It may also be included in the diluent solvent for the transition metal catalyst inlet may be transferred to the reactor with the catalyst. The amount of the scavenger added is not particularly limited as long as it is a well-known range known in the art depending on the amount of impurities contained therein. Specifically, the content of the scavenger may be about 0.1 to about 12 equivalents, preferably about 0.2 to about 5 equivalents, and more preferably about 0.5 to about 1.5 equivalents.

Wherein each R ₁₀ is independently a halogen radical; Hydrocarbyl radicals having 1 to 20 carbon atoms; Or a hydrocarbyl radical having 1 to 20 carbon atoms substituted with halogen; a is an integer of 2 or more;

Wherein D is aluminum; R ₁₀ are each independently as defined above.

Examples of the compound represented by Formula 5 include methyl aluminoxane, ethyl aluminoxane, isobutyl aluminoxane, butyl aluminoxane, and the like, and a preferable compound is methyl aluminoxane.

Examples of the alkyl metal compound represented by Formula 6 include trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, triisopropylaluminum, tri-s-butylaluminum, tricyclo Pentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyl dimethyl aluminum, methyl diethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide and dimethyl aluminum ethoxide And the like, and preferred compounds may be selected from trimethylaluminum, triethylaluminum and triisobutylaluminum.

Polyolefin production method according to the present invention can be applied in the polymerization process of the solution phase, slurry phase and gaseous phase, depending on the form of the reactant, preferably solution polymerization using a solution phase can be used.

In addition, the polyolefin production method according to the present invention can be carried out in a batch (batch) or a continuous (continuous) reaction, depending on whether the operation is continuous, the continuous reaction (CSTR) or continuous flow type ( PFR) polymerization can be used. Preferably continuous stirring polymerization can be used in the continuous reaction.

Therefore, it is more preferable to use the continuous solution polymerization method of the polyolefin manufacturing method according to the present invention.

The continuous solution polymerization method includes an activation catalyst composition process, a polymerization process, a solvent separation process and a recovery process.

Hereinafter, each said process is demonstrated concretely.

1) Activation Catalyst Composition Process

The transition metal catalysts and cocatalysts of the present invention are each aliphatic hydrocarbons having 5 to 12 carbon atoms such as pentane, hexane, heptane, nonane, decane, isomers thereof and the like suitable for the olefin polymerization process; Substituted or unsubstituted aromatic hydrocarbons having 6 to 12 carbon atoms such as toluene, benzene and xylene; It may be dissolved or diluted in one or more solvents selected from hydrocarbons substituted with chlorine atoms such as dichloromethane and chlorobenzene to be injected into the reactor to form an activated catalyst composition. The solvent used for the transition metal catalyst is preferably used by removing a small amount of water or air that acts as a catalyst poison by treating with a small amount of alkylaluminum or the like, and can also be carried out using an excessive amount of a promoter.

2) polymerization process

The polymerization process proceeds with the activated catalyst composition and monomer in the reactor. When preparing a copolymer, comonomers are introduced into the reactor. In the case of solution phase or slurry phase polymerization, a solvent as exemplified in the above catalytic process is injected onto the reactor. Preferably, in the case of solution polymerization, the reaction proceeds in a mixture of solvent, activated catalyst composition, monomer and comonomer, etc. on the reactor. The activated catalyst composition is formed to include a transition metal catalyst and a cocatalyst sequentially introduced as illustrated in the activated catalyst composition process.

The olefin monomers or comonomers include ethylene, alpha-olefins, cyclic olefins, and the like, and diene olefin monomers or triene olefin monomers having two or more double bonds can also be polymerized. Specific examples of the monomers include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dode Sen, 1-tetradecene, 1-hexadecene, 1-aitocene, norbornene, norbornadiene, ethylidenenorbornene, phenylnorbornene, vinylnorbornene, dicyclopentadiene, 1,4-butadiene, 1, 5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene, and 3-chloromethyl styrene, and the like, may be mixed and copolymerized.

Preferably, the monomer is ethylene, and the comonomer may be selected from the group consisting of propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene.

When the activated catalyst composition according to the present invention is used, an ultralow density copolymer having a high molecular weight of 0.910 g / cc or less while having a high molecular weight in the copolymerization reaction of a monomer having high steric hindrance such as ethylene and 1-octene even at a high reaction temperature of 70 ° C. or higher It can manufacture.

The solvent used in the catalytic process may be used as the polymerization reaction solvent, and it is preferable to remove a small amount of water or air acting as a catalyst poison by treating with a small amount of alkylaluminum.

Inflow of the raw material for the preparation of the ultra-low density copolymer having a high molecular weight of 0.910 g / cc or less in the copolymerization reaction of the present invention is as follows.

 The molar ratio of one monomer and the remaining monomers suitable for the above copolymerization reaction is from 100 to 1 to 1 to 100, preferably from 10 to 1 to 1 to 10, most preferably from 2 to 1 to 1 to 5.

The molar ratio of monomer to solvent suitable for the reaction is a ratio suitable for dissolving the raw material before the reaction and the polymer produced after the reaction, and is preferably from 10 to 1 to 10000, preferably 5 to 1 to 1 to 100, most preferably. One to one to one to twenty.

The solvent is introduced into the reactor at a temperature of -60 to 150 ° C using a heater or a freezer, and the polymerization is started with the monomer and the activating composition. A high capacity pump raises the pressure of the feed above 50 bar to feed the reactants and catalyst composition into the reactor through the movement of the pump, thereby allowing the mixture to pass through the reactor arrangement, pressure reducing means and separator without further pumping.

The polymerization reaction temperature in the reactor suitable for the present invention may be in the range of 40 ℃ to 300 ℃, preferably in the range of 70 ℃ to 200 ℃, more preferably 90 ℃ to 160 ℃.

Suitable reaction pressures for the present invention may range from atmospheric pressure to 300 bar, preferably from 30 to 200 bar, more preferably from 60 to 100 bar.

The polymer reacted in the reactor is maintained at a concentration of less than 20 wt% in the solvent and is passed to the first solvent separation process for solvent removal after a short residence time.

Residual times in the reactor suitable for the present invention may range from 1 minute to 10 hours, preferably from 3 minutes to 1 hour, more preferably from 5 minutes to 30 minutes.

c) solvent separation process

The solvent separation process is performed by changing the solution temperature and pressure to remove the solvent present with the polymer. The solvent separation process is performed by changing the solution temperature and pressure to remove the solvent present with the polymer exiting the reactor. The polymer solution transferred from the reactor is heated to about 200 ° C. to 240 ° C. using a heater, and then decompressed with a pressure drop device to vaporize unreacted raw materials and solvent in the first separator.

At this time the pressure in the separator may be in the range of 1 to 30 bar, preferably 1 to 10 bar, more preferably 3 to 8 bar. The temperature in the separator may range from 150 ° C to 250 ° C, preferably from 170 ° C to 230 ° C, more preferably from 180 ° C to 230 ° C.

The solvent gasified in the separator can be condensed in the overhead system and recycled to the reactor. When the first stage solvent separation process is performed, a concentrated polymer solution of up to 65% can be obtained, which is transferred to the second separator by the transfer pump through the heater, and the separation process for the residual solvent is performed in the second separator. In order to prevent the deformation of the polymer due to the high temperature while passing through the heater, a heat inhibitor is introduced into the heater together with a heat stabilizer to suppress the reaction of the polymer due to the residual activity of the activator present in the polymer solution. do. The residual solvent in the polymer solution injected into the second separator is finally completely removed by a vacuum pump, and the granulated polymer can be obtained by passing through the cooling water and the cutting machine. The solvent and other unreacted monomers vaporized in the second separation process can be sent to a recovery process for reuse after purification.

d) Recovery process

The organic solvent introduced with the raw material in the polymerization process may be recycled to the polymerization process together with the unreacted raw material in the primary solvent separation process. However, the solvent recovered in the secondary solvent separation process contains a large amount of water that acts as a catalyst poison in the solvent due to contamination due to incorporation of a reaction inhibitor to stop the catalytic activity and steam supply from a vacuum pump, and thus after purification in a recovery process. It is preferred to be reused.

In another embodiment of the present invention, there is provided a continuous solution polyolefin polymerization apparatus including a reactor and a separator, each of which is provided with an inlet of a transition metal catalyst and a promoter. A schematic diagram of the reactor is as shown in FIG. 1.

Specific conditions of the polymerization process and separation process occurring in the reactor are as described in the polymerization and separation process according to the continuous solution polymerization method.

The continuous solution polymerization apparatus can install a high capacity pump at the front end of the reactor to increase the pressure of the feed to 50bar or more to transfer the reaction product to the separator without additional equipment. In addition, by installing a heating means between the reactor and the separator can be prevented from being formed in two phases. In addition, the reaction product introduced into the separator is separated into a lean phase and a concentrated phase, and the lean phase is recycled after passing through the cooler and the purifier and recycled to the inlet side of the pump. The concentrated phase can also be sent to an additional separator to remove additional solvent to obtain a solid polymer. Here, the lean phase means a mixture having a low content of the polymer, and the concentrated phase means a mixture having a high content of the polymer.

Although the said reactor is not specifically limited, It is preferable that it is a continuous stirred tank reactor. In addition, the reactor can arrange one or more reactors in series or in parallel to produce copolymers of a wide range of compositions and molecular weights.

The present invention will be described in more detail with reference to the following Examples. However, the following examples are only for illustrating the present invention and the present invention is not limited only to the following examples.

≪ Example 1 >

In the present invention, 1L stainless steel reactor was used. Before the reaction, 351 g of hexane, a diluent solvent, was introduced into the reactor, and 78.54 g of 1-octene, a comonomer, was introduced, and the reaction temperature was gradually raised to 120 ° C. .

After the temperature was stabilized, 47.5 g of monomer ethylene was introduced to maintain the reactor pressure at 75 bar. Scavenger was added to the monomer, comonomer in an amount of 860 μmol. 3.6 μmol of the transition metal catalyst was introduced and 40 minutes later, the reaction was started by introducing a promoter. At this time, the flow rate of the promoter was 9 times that of the catalyst equivalent. The reaction time was continued for 1 hour to allow the polymerization to proceed sufficiently. The pressure decreases with the progress of the reaction to continuously inject nitrogen gas to maintain the pressure of 75bar.

The catalyst used in this reaction was Dow's [Me ₂ Si (Me ₄ C ₅ ) N t Bu] TiCl ₂ (Constrained-Geometry Catalyst, hereinafter abbreviated as CGC), and the promoter was triphenylcarbenium tetrakis (pentafluorophenyl) borate (TB) was used, and scavenger was used Triisobutylaluminum (Tibal).

≪ Comparative Example 1 &

The olefin was polymerized in the same manner as in Example 1 except that the cocatalyst was first introduced into the reactor and the reaction was started after 25 minutes by introducing a transition metal catalyst.

≪ Comparative Example 2 &

 The olefin was polymerized in the same manner as in Example 1 except that the transition metal catalyst was mixed with the cocatalyst immediately before entering the reactor and introduced into the reactor simultaneously with the contact of the transition metal catalyst and the promoter.

Comparative Example 3

The transition metal catalyst is mixed with the cocatalyst immediately before entering the reactor, the catalyst is introduced into the reactor simultaneously with the contact of the transition metal catalyst and the promoter, and after 60 minutes, the monomer ethylene is introduced to start the reaction, and the ethylene is continuously The olefin was polymerized in the same manner as in Example 1 except that the reaction pressure was maintained at 35 bar while injecting.

Table 1 summarizes the results of Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3.

As shown in Table 1, the catalyst activity, yield, and conversion of monomer ethylene at the time of catalyst introduction after catalyst introduction as in Example 1 were the best, and the catalyst and promoter were mixed or simultaneously introduced as in Comparative Example 2. In this case, it can be seen that the catalytic activity, yield, conversion of ethylene is reduced compared to Example 1. As in Comparative Example 1, when the catalyst is introduced after the introduction of the promoter, the catalytic activity, yield, and conversion rate of ethylene are drastically reduced to 50% or less. As in Comparative Example 3, when ethylene is introduced after the catalyst and the promoter are introduced, there is no catalytic activity and the reaction does not proceed. It is thought that the reaction does not proceed while the catalyst is deactivated under the above conditions regardless of the progress of the reaction after the catalyst activation by the promoter.

Example 2 Ethylene and 1- by a Continuous Solution Process Butene  Copolymerization

To a 1.5 L continuous stirred reactor (CSTR) is fed hexane (6.1 kg / h) solvent, 1-butene (0.5 kg / h) and ethylene monomer (0.87 kg / h) at a pressure of 89 bar. At this time, the reaction temperature is maintained at 146 ℃.

Dimethylaniline tetrakis (pentafluorophenyl) borate [(Dimethylanilium) as a cocatalyst and a transition metal catalyst represented by the formula (7) treated with a triisobutylaluminum compound from a catalyst storage tank The copolymerization reaction was carried out in the same manner as in Example 1 except that Tetrakis (pentafluorophenyl) borate (AB), 2.4 mmol / min) was used.

The polymer solution formed by the copolymerization reaction was depressurized to 7 bar at the rear of the reactor, and then transferred to a first solvent separator preheated to 230 ^° C. to remove most of the solvent. Then, the copolymer was transferred from the first solvent separator to the second solvent separator by a pump to completely remove residual solvent by a vacuum pump, and then passed through cooling water and a cutter to obtain granulated polymer.

As shown in Table 2, 0.864 g / cc of low density polyethylene was obtained with a yield of 90 wt% C2 conversion.

Physical property evaluation (melt index, melting point and density)

The melt index (Melt Index, MI) of the polymer was measured by ASTM D-1238 (Condition E, 190 ^° C., 2.16 Kg load). The melting point (T _m ) of the polymer was obtained using a differential scanning calorimeter (DSC: Differential Scanning Calorimeter 2920) manufactured by TA. That is, the temperature was increased to 200 ^° C., maintained at that temperature for 5 minutes, then lowered to 30 ^° C., and the temperature was increased again to make the top of the DSC curve a melting point. At this time, the rate of temperature rise and fall is 10 ^o C / min and the melting point is obtained during the second temperature rise.

In addition, the density of the polymer was measured by preparing a sheet treated with an antioxidant (1,000 ppm) with a thickness of 3 mm and a radius of 2 cm using a 180 ^o C press mold, and cooling it at 10 ^o C / min. Measurements were made on a Mettler balance.

Figure 1 schematically shows a method of introducing a reactant, a transition metal catalyst, a promoter and a scavenger according to the present invention into the reactor.

Claims (17)

(a) introducing a transition metal catalyst and reactant into the reactor, and (b) introducing a promoter into said reactor separately from said transition metal catalyst and reactant, In the step (a) comprises the step of mixing the scavenger with the transition metal catalyst or reactant, The transition metal catalyst is a Group 4 transition metal catalyst, The scavenger is a method for producing a polyolefin, characterized in that the compound represented by the formula (5); [Chemical Formula 5]

Wherein each R ₁₀ is independently a halogen radical; Hydrocarbyl radicals having 1 to 20 carbon atoms; Or a hydrocarbyl radical having 1 to 20 carbon atoms substituted with halogen; a is an integer of 2 or more. delete The method for producing a polyolefin according to claim 1, wherein the polymerization is continuously carried out in solution. The method according to claim 1, wherein the transition metal catalyst is a method for producing a polyolefin, characterized in that the compound represented by the formula (1): [Formula 1]

Where R1 and R2 Each independently represents a hydrogen atom; Alkyl radicals of 1 to 20 carbon atoms, aryl or silyl radicals of 6 to 40 carbon atoms; Alkenyl radicals having 2 to 20 carbon atoms, alkylaryl radicals having 7 to 40 carbon atoms, or arylalkyl radicals having 7 to 40 carbon atoms; Or a metalloid radical of a Group 14 metal substituted with hydrocarbyl; R ₁ And R ₂ Can be linked to each other by an alkylidine radical comprising an alkyl radical having 1 to 20 carbon atoms or an aryl radical having 6 to 40 carbon atoms to form a ring; R4 Each independently represents a hydrogen atom; Halogen radicals; Or an alkyl radical having 1 to 20 carbon atoms or an aryl radical having 6 to 40 carbon atoms, wherein R4 Two R4 may be connected to each other to form a nested ring structure; M is a Group 4 transition metal; Q1 and Q2 Each independently represents a halogen radical; Alkyl amido having 1 to 20 carbon atoms or aryl amido radical having 6 to 40 carbon atoms; Alkyl of 1 to 20 carbon atoms, alkenyl of 2 to 20 carbon atoms, aryl of 6 to 40 carbon atoms, alkylaryl or arylalkyl radical of 7 to 40 carbon atoms; Or an alkylidene radical having 1 to 20 carbon atoms. The method of claim 4, wherein the compound of Formula 1 is a compound represented by Formula 2 below: [Formula 2]

Where R5 and R6 are hydrogen atoms; Or alkyl having 1 to 20 carbon atoms, aryl or silyl radical having 6 to 40 carbon atoms; Q3 and Q4 are each independently a halogen radical; Alkyl amido having 1 to 20 carbon atoms or aryl amido radical having 6 to 40 carbon atoms; Or an alkyl radical having 1 to 20 carbon atoms; M is the same as defined above. The method according to claim 1, wherein the promoter is a method for producing a polyolefin, characterized in that selected from the compounds represented by the following formula (3) and formula (4); (3)

Wherein D is boron; Each R ₉ is independently a halogen radical; Hydrocarbyl radicals having 1 to 20 carbon atoms; Or a hydrocarbyl radical of 1 to 20 carbon atoms substituted with halogen; [Formula 4]

Wherein L is a neutral or cationic Lewis acid; H is a hydrogen atom; Z is a Group 13 element; A is each independently an aryl or alkyl radical having 6 to 20 carbon atoms in which one or more hydrogen atoms are replaced by halogen, hydrocarbyl having 1 to 20 carbon atoms, alkoxy or phenoxy radicals. delete The method of claim 1, wherein the mixing ratio of the transition metal catalyst: cocatalyst is 2: 1 to 1: 100 based on the molar ratio. The method of claim 8, wherein the mixing ratio of the transition metal catalyst: cocatalyst is 1: 1 to 1:10 based on the molar ratio. The method of claim 1, wherein the reactants are ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1 Dodecene, 1-tetradecene, 1-hexadecene, 1-aitocene, norbornene, norbonadiene, ethylidenenorbornene, phenylnorbornene, vinylnorbornene, dicyclopentadiene, 1,4-butadiene, Method for producing a polyolefin comprising at least one monomer selected from the group consisting of 1,5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene and 3-chloromethylstyrene . The solution of claim 3, wherein the solution comprises a solvent, and the solvent is one selected from the group consisting of pentane, hexane, heptane, nonane, decane, and isomers thereof, toluene, benzene, xylene, dichloromethane and chlorobenzene. It is the above solvent, The manufacturing method of polyolefin characterized by the above-mentioned. The method of claim 10, wherein the reactant comprises two or more monomers, and the molar ratio of any one monomer to the remaining monomers is 100: 1 to 1: 100. The method of claim 3, wherein the solution comprises a reactant and a solvent, and the reactant: solvent molar ratio is 10: 1 to 1: 10000. delete delete delete delete

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